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Wyszukujesz frazę "cone" wg kryterium: Temat


Tytuł:
Functions preserving a cone preorder and their duals
Autorzy:
Otachel, Zdzisław
Powiązania:
https://bibliotekanauki.pl/articles/962665.pdf
Data publikacji:
2005
Wydawca:
Polskie Towarzystwo Matematyczne
Tematy:
Isotone function
convex cone
dual cone
cone preorder
decreasing rearrangement of function
Steffensen Inequality
Opis:
In this paper isotone functions and their dual cones are studied. Special attention is devoted to functions preserving cone preorders. This isotonicity is characterized by integral inequalities. The result yields some generators of dual cones of isotone functions. As an application a generalization of Steffensen Inequality is given.
Źródło:
Commentationes Mathematicae; 2005, 45, 2; 171-189
0373-8299
Pojawia się w:
Commentationes Mathematicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zastosowanie wkładki typu cone in cone podczas wysypu kominowego
Using the cone in cone type insert during chimney pouring out
Autorzy:
Matuszek, D.
Tukiendorf, M.
Powiązania:
https://bibliotekanauki.pl/articles/287117.pdf
Data publikacji:
2009
Wydawca:
Polskie Towarzystwo Inżynierii Rolniczej
Tematy:
mieszanie
materiał ziarnisty
komputerowa analiza obrazu
wkładka cone in cone
mixing
granular material
computer image analysis
cone in cone type insert
Opis:
Praca przedstawia wyniki serii badań z zastosowaniem wkładki cone in cone oraz bez stosowania dodatkowych elementów. Konstrukcja zbiorników laboratoryjnych zapewniała przeprowadzenie testu dla wysypu kominowego. Dokonano analizy porównawczej mającej na celu określenie wpływu dodatkowego elementu konstrukcyjnego na stopień zmieszania składników ziarnistych. Równomierność rozmieszczenia składników oceniano w oparciu o komputerową analizę obrazu.
The paper presents results of test series carried out using the cone in cone insert, and without using any extra elements. The structure of laboratory containers allowed to carry out test for chimney pouring out. The researchers carried out comparative analysis aimed to determine the impact of an extra structural component on mixing degree of granular ingredients. Uniform distribution of ingredients was assessed on the basis of computer image analysis.
Źródło:
Inżynieria Rolnicza; 2009, R. 13, nr 8, 8; 121-126
1429-7264
Pojawia się w:
Inżynieria Rolnicza
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Relative tangent cone of analytic curves
Autorzy:
Ciesielska, Danuta
Powiązania:
https://bibliotekanauki.pl/articles/1293937.pdf
Data publikacji:
1999
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
intersection multiplicity
analytic curve
tangent cone
relative tangent cone
Opis:
The purpose of this paper is to give a characterization of the relative tangent cone of two analytic curves in $ℂ^m$ with an isolated intersection.
Źródło:
Annales Polonici Mathematici; 1999, 72, 2; 191-195
0066-2216
Pojawia się w:
Annales Polonici Mathematici
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The morphological traits of cones and seeds of Abies alba in the Middle Sudeten
Autorzy:
Tracz, M
Barzdajn, W.
Powiązania:
https://bibliotekanauki.pl/articles/41449.pdf
Data publikacji:
2007
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
fir
Abies alba
cone
seed
morphological trait
cone variability
Sudetes Mountains
cone size
seed feature
Opis:
Twenty Abies alba trees were selected for restoration purpose of species in the Sudeten. Eleven features of cone and seeds collected from those trees were examined and all of them significantly differed selected trees. Five features, i.e. cone length, cone biggest diameter, length and width of ovuliferous scales, and length of wings with were recommended as having the highest diagnostic value.
Źródło:
Dendrobiology; 2007, 58; 59-65
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Elementy daszkowe w mieszalniku przesypowym a jakość mieszanek ziarnistych
Roof type elements in pour mixer and quality of granular mixers
Autorzy:
Matuszek, D.
Tukiendorf, M.
Powiązania:
https://bibliotekanauki.pl/articles/287988.pdf
Data publikacji:
2009
Wydawca:
Polskie Towarzystwo Inżynierii Rolniczej
Tematy:
mieszanie
materiał ziarnisty
silos
cone in cone
double cone
roof shaped insert
mixing
granular material
Opis:
W pracy zaprezentowano wyniki badań wpływu elementów daszkowych na jakość dwuskładnikowej mieszaniny ziarnistej w procesie mieszania metodą przesypu. Podczas eksploatacji silosów najczęściej pojawiającymi się problemami są: nieodpowiednie wymieszanie składników o różnych właściwościach oraz zawieszanie się materiału w silosie co uniemożliwia jego opróżnienie bez interwencji czynnika zewnętrznego. W praktyce proponowane jest wspomaganie pracy silosów poprzez montowanie specjalnych wkładek: double cone, roof shaped insert czy cone in cone. Otrzymane wyniki porównano przy użyciu testu statystycznego Anova, udowadniając tym samym o statystycznie istotnych różnicach w przebiegu procesu mieszania dla analizowanych przypadków.
The paper presents results of the research on the impact of roof type elements on the quality of binary granular mixture in the process of mixing using the pouring method. Problems occurring most frequently during operation of silos include: improper intermixing of ingredients characterized by various properties, and material being suspended in the silo, which makes it impossible to empty the silo without intervention of an external factor. In practice, it is proposed to support operation of silos by mounting special inserts: double cone, roof shaped insert, or cone in cone. Obtained results have been compared using the Anova statistical test, thus proving statistically significant differences in mixing process progress for the analysed cases.
Źródło:
Inżynieria Rolnicza; 2009, R. 13, nr 9, 9; 163-169
1429-7264
Pojawia się w:
Inżynieria Rolnicza
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Deriving a reliable CPT cone resistance value for end-bearing capacity calculation of piles
Ustalenie miarodajnej wartości oporu stożka CPT na potrzeby wyznaczania nośności granicznej pali
Autorzy:
Bogusz, W.
Powiązania:
https://bibliotekanauki.pl/articles/40706.pdf
Data publikacji:
2016
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
pile
pile foundation
cone penetration test
cone resistance
bearing capacity
calculation
Opis:
The necessity of optimising the foundation design encourages the use of methods based on in situ test results in the design of pile foundations. For this purpose, a cone penetration test (CPT) is commonly used. Design methods developed over the last few decades may differ not only in factors used for correlating the cone resistance with bearing capacity of a given type of pile foundation, but also in adoption of the representative cone resistance value for the calculations. Contrary to the design of pile foundation in relatively homogeneous ground conditions, in the case of heterogeneous stratifi cation, the infl uence of the quality of test itself and the adoption of the average cone resistance for the calculation may have significant impact on the result. This is especially important issue when weaker strata, which may affect the end-bearing capacity, is present just below the pile, in its area of influence. The article presents some of the methods of averaging the measured cone resistance, how they may affect the obtained results and other factors affecting mainly end-bearing capacity of a single compressed pile.
Konieczność optymalizacji posadowienia konstrukcji wymusza w projektowaniu fundamentów palowych stosowanie metod opartych na bezpośrednich wynikach badań podłoża. W tym celu wykorzystuje się najczęściej sondowania statyczne CPT. Metody projektowania rozwijane przez ostatnie kilkadziesiąt lat różnią się nie tylko współczynnikami korelującymi opór stożka z wartościami jednostkowego oporu podstawy dla danego typu fundamentu palowego, ale także samym sposobem przyjęcia wartości oporu stożka, reprezentatywnej dla prowadzonych obliczeń. W odróżnieniu od realizacji pali we względnie jednorodnym ośrodku gruntowym, w przypadku podłoża uwarstwionego wpływ jakości przeprowadzonego badania i przyjęcia wartości średniej oporu stożka może mieć istotne znaczenie dla uzyskiwanych rezultatów. Ma to głównie znaczenie, gdy poniżej podstawy pojedynczego pala występują grunty słabsze, mogące istotnie wpływać na jego nośność. W artykule porównano sposoby uśredniania wartości oporu stożka oraz ich potencjalny wpływ na uzyskiwane rezultaty obliczonych nośności granicznych pojedynczych pali wciskanych.
Źródło:
Acta Scientiarum Polonorum. Architectura; 2016, 15, 2
1644-0633
Pojawia się w:
Acta Scientiarum Polonorum. Architectura
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling of the finite amplitude waves interaction problem inside truncated cone
Autorzy:
Baranowska, A.
Powiązania:
https://bibliotekanauki.pl/articles/332087.pdf
Data publikacji:
2003
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
amplitude waves
truncated cone
Opis:
The paper presents the results of theoretical investigations of the finite amplitude waves interaction in water. The mathematical model and some results of numerical investigations are presented. The acoustic pressure amplitude changes for different frequency waves (especially difference frequency wave) along the sound beam were investigated. The mathematical model was built on the basis of the KZK equation. It was assumed that a circular piston was the source of two different frequency finite amplitude waves. The problem was considered as an axial symmetric one. The solution of the problem was looked for inside a truncated cone. To solve the problem the finite-difference method was applied.
Źródło:
Hydroacoustics; 2003, 6; 131-136
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical behavior of the method of projection onto an acute cone with level control in convex minimization
Autorzy:
Dylewski, Robert
Powiązania:
https://bibliotekanauki.pl/articles/729267.pdf
Data publikacji:
2000
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
convex nondifferentiable minimization
projection method
subgradient method
acute cone
obtuse cone
Opis:
We present the numerical behavior of a projection method for convex minimization problems which was studied by Cegielski [1]. The method is a modification of the Polyak subgradient projection method [6] and of variable target value subgradient method of Kim, Ahn and Cho [2]. In each iteration of the method an obtuse cone is constructed. The obtuse cone is generated by a linearly independent system of subgradients. The next approximation of a solution is the projection onto a translated acute cone which is dual to the constructed obtuse cone. The target value which estimates the minimal objective value is updated in each iteration. The numerical tests for some tests problems are presented in which the method of Cegielski [1] is compared with the method of Kim, Ahn and Cho [2].
Źródło:
Discussiones Mathematicae, Differential Inclusions, Control and Optimization; 2000, 20, 2; 147-158
1509-9407
Pojawia się w:
Discussiones Mathematicae, Differential Inclusions, Control and Optimization
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cone 2-metric space nad Fixed point theorem of contractive mappings
Autorzy:
Singh, B.
Jain, Shishir
Bhagat, Prakash
Powiązania:
https://bibliotekanauki.pl/articles/746380.pdf
Data publikacji:
2012
Wydawca:
Polskie Towarzystwo Matematyczne
Tematy:
Cone 2-metric space
Fixed point
Cone metric space
2-metric space
Ordered Banach space
Opis:
In this paper we introduce cone 2-metric space and prove some fixed point theorems of a contractive mapping on a cone 2-metric space.
Źródło:
Commentationes Mathematicae; 2012, 52, 2
0373-8299
Pojawia się w:
Commentationes Mathematicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An intraoral cone system for a Neptun 10PC linear accelerator
Autorzy:
Shokrani, P.
Soltani, P.
Powiązania:
https://bibliotekanauki.pl/articles/147656.pdf
Data publikacji:
2011
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
intraoral cone
oral cavity
electron boost
Opis:
Intraoral irradiation, the treatment choice for well defined oral-cavity tumors, is done using intraoral cone (IOC) systems. In this study, an IOC system was developed for a Neptun 10PC linac. Beam parameters necessary to plan an intraoral electron treatment were evaluated for two applicators, a flat and a beveled end. Measurements were performed using a Scanditronix (p-Si) diode field detector in a Scanditronix (RFAplus) 3-D (three-dimensional) water phantom. Percent depth dose distributions, beam profiles, and leakage dose distributions for the developed cone system are presented.
Źródło:
Nukleonika; 2011, 56, 4; 381-384
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Extensions of convex functionals on convex cones
Autorzy:
Ignaczak, E.
Paszkiewicz, A.
Powiązania:
https://bibliotekanauki.pl/articles/1339018.pdf
Data publikacji:
1998
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
Hilbert space
convex functional
convex cone
Opis:
We prove that under some topological assumptions (e.g. if M has nonempty interior in X), a convex cone M in a linear topological space X is a linear subspace if and only if each convex functional on M has a convex extension on the whole space X.
Źródło:
Applicationes Mathematicae; 1998-1999, 25, 3; 381-386
1233-7234
Pojawia się w:
Applicationes Mathematicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Second-order necessary conditions for discrete inclusions with end point constraints
Autorzy:
Cernea, Aurelian
Powiązania:
https://bibliotekanauki.pl/articles/729636.pdf
Data publikacji:
2005
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
tangent cone
discrete inclusion
necessary optimality conditions
Opis:
We study an optimization problem given by a discrete inclusion with end point constraints. An approach concerning second-order optimality conditions is proposed.
Źródło:
Discussiones Mathematicae, Differential Inclusions, Control and Optimization; 2005, 25, 1; 47-58
1509-9407
Pojawia się w:
Discussiones Mathematicae, Differential Inclusions, Control and Optimization
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
HRTF Adjustments with Audio Quality Assessments
Autorzy:
Yao, S. N.
Chen, L. J.
Powiązania:
https://bibliotekanauki.pl/articles/950215.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
HRTF
PEAQ
cone of confusion
headphones
surround
Opis:
There are an increasing number of binaural systems embedded with head-related transfer functions (HRTFs), so listeners can experience virtual environments via conventional stereo loudspeakers or head- phones. As HRTFs vary from person to person, it is difficult to select appropriated HRTFs from already existing databases for users. Once the HRTFs in a binaural audio device hardly match the real ones of the users, poor localization happens especially on the cone of confusion. The most accurate way to obtain personalized HRTFs might be doing practical measurements. It is, however, expensive and time consuming. Modifying non-individualized HRTFs may be an effort-saving way, though the modifications are always accompanied by undesired audio distortion. This paper proposes a flexible HRTF adjustment system for users to define their own HRTFs. Also, the system can keep sounds from suffering intolerable distortion based on an objective measurement tool for evaluating the quality of processed audio.
Źródło:
Archives of Acoustics; 2013, 38, 1; 55-62
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of shear strength in silty soils
Autorzy:
Stefaniak, K.
Powiązania:
https://bibliotekanauki.pl/articles/178390.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
shear strength
cone factor Nkt
silty soil
Opis:
The article presents a comparison of shear strength values in silty soils from the area of Poznań, determined based on selected Nkt values recommended in literature, with values of shear strength established on the basis of Nkt values recommended by the author. Analysed silty soils are characterized by the carbonate cementation zone, which made it possible to compare selected empirical coefficients both in normally consolidated and overconsolidated soils.
Źródło:
Studia Geotechnica et Mechanica; 2015, 37, 2; 51-55
0137-6365
2083-831X
Pojawia się w:
Studia Geotechnica et Mechanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Study on the Pull-out Resistance of Dynamically Driven Nails and the Cavity Expansion Method
Autorzy:
Sawicki, A.
Powiązania:
https://bibliotekanauki.pl/articles/241374.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
soil nailing
cavity expansion
cone penetration tests
Opis:
The problem is how to assess normal stresses around dynamically driven nails. Pull-out tests show that these stresses are much higher than it would follow from classical analyses. Therefore, an analysis of the cavity expansion method was applied to study this problem. It was shown that the cavity expansion method, widely applied in soil mechanics, suffers from many shortcomings. It was also shown that this method is not closely related to cone penetration tests, nor to the technology of dynamic soil nailing.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2010, 57, 3-4; 243-260
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Statystyczne identyfikacje warstw gruntów na podstawie sondowań geotechnicznych
Soil classification based on CPT and DMT test
Autorzy:
Rabarijoely, S.
Sujka, P.
Powiązania:
https://bibliotekanauki.pl/articles/40937.pdf
Data publikacji:
2012
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
geotechnika
sondowanie gruntow
badania dylatometryczne
metoda CPT
warstwy gruntu
identyfikacja
analiza statystyczna
geotechnics
soil sounding
dilatometer test
cone penetration test
CPT method zob.cone penetration test
cone penetration technology zob.cone penetration test
soil layer
identification
statistical analysis
Źródło:
Acta Scientiarum Polonorum. Architectura; 2012, 11, 2
1644-0633
Pojawia się w:
Acta Scientiarum Polonorum. Architectura
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Morphological and anatomical differentiation in peripheral Pinus sylvestris L. populations from the Carpathian region
Autorzy:
Köbölkuti, Zoltán A.
Tóth, Endre G.
Ladányi, Márta
Höhn, Mária
Powiązania:
https://bibliotekanauki.pl/articles/957051.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
adaptation
cone morphology
geographic differentiation
needle anatomy
Opis:
Carpathian Scots pine populations having peripheral distribution within the species’ range are often sustained in specific types of habitats, such as peat bogs and rocky surfaces or lime consisting sandy substrates. Due to their long time adaptive processes, which involve genotypes that can be preadapted to a given selection pressure, historically isolated populations are subjects of particular interest in studies of in situ adaptation. In this study we focus on detecting the level of phenotypic differentiation based on cone morphology and needle anatomy in marginal populations of Pinus sylvestris L. in the Pannonian Basin and the Carpathian Mountains. Six cone morphological and eight needle anatomical characters were measured and four cone morphological and four needle anatomical ratios were calculated. Our results in concordance with paleobotanical data indicate a common origin of the populations from the Northern Carpathians and the Pannonian Basin. High levels of variation were observed in cone morphology. Discriminant function analysis based on the eight cone characteristics revealed clearly discernible groups of populations and indicated significant differentiation among populations growing in peat bogs and on rocky substrates. Significant differences among populations from different habitats were also revealed by comparing needle anatomical variables. The phenotypic differentiation by habitat type based on the measured characters might be evaluated as a sign of local adaptation with detectable phenotypic patterns.
Źródło:
Dendrobiology; 2017, 77; 105-117
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The use of resistivity and seismic cone penetration tests for site characterization
Autorzy:
Lech, M.
Bajda, M.
Markowska-Lech, K.
Powiązania:
https://bibliotekanauki.pl/articles/81857.pdf
Data publikacji:
2008
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
electrical resistivity
seismic cone
cone penetration test
site characteristics
porosity
shear wave velocity
geophysical test
seismic wave
measurement
Źródło:
Annals of Warsaw University of Life Sciences - SGGW. Land Reclamation; 2008, 40
0208-5771
Pojawia się w:
Annals of Warsaw University of Life Sciences - SGGW. Land Reclamation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cone solutions of multi-order fractional difference systems
Autorzy:
Girejko, E.
Mozyrska, D.
Powiązania:
https://bibliotekanauki.pl/articles/206510.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
fractional difference operator
fractional difference equation
cone solutions
Opis:
The fractional difference system of equations with different fractional orders is considered. We obtain the existence and uniqueness results for the initial value problem. Cone solutions are presented. An example is given to illustrate the results.
Źródło:
Control and Cybernetics; 2013, 42, 2; 419-429
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Morphology of strobili at different development positions and cone and seed characteristics of Pinus densiflora f. multicaulis
Autorzy:
Kwon, S.H.
Kim, Y.G.
Kang, H.I.
Shim, D.
Kang, K.S.
Powiązania:
https://bibliotekanauki.pl/articles/2078259.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
bisexual strobili
sex reversal
microsporangia
megasporangia
cone analysis
Opis:
Pinus densiflora f. multicaulis is a rare and unusual form of genus Pinus. It has excellent ornamen- tal values due to many trunks from its root collar, and produces female, male, and bisexual strobili on the same tree. However, there is limited study whether the bisexual strobili are functional, mature lateral cones produce filled seeds, and the seeds from the mature lateral cones germinate and grow as well as those from mature apical cones. The structure of apical female, and lateral male and bisexual strobili were analyzed in an open-pollination-progeny population. The strobili were photographed to obtain external, cross-section, and radial-section images using a 45× stereoscopic microscope. Radial sections of strobili were imaged using scanning electron microscopy. Characteristics of apical and lateral cones and seeds were surveyed by cone analysis and germination test. P. densiflora f. multicaulis developed typical female strobili apically, and ordinary male and bisexual strobili laterally. Additionally, female strobili developed laterally whereas the male strobili were normally located. The mature lateral female strobili had the same structure as the apical female. In the mature bisexual strobili, the proportion of male and female tissue was unequal. The cones developed from lateral female strobili showed highly significant differences in the length, width, and weight, being shorter (32.7%), narrower (26.9%), and lighter (59.8%) than those from apical female strobili. Both types produced filled seeds and seedlings, and well significant positive correlations were found among characteristics of seeds from apical and lateral female strobili. The initial seed germination rate of the seeds from apical female strobili was higher than that of seeds from lateral female strobili, but the difference decreased over time. The viability and spatial distribution of the female and male tissue of bisporangiate cones, and their frequent occurrence suggests a common mechanism for the production of bisporangiate structures in seed plants.
Źródło:
Dendrobiology; 2021, 85; 51-59
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Estimation of age by mental foramen using CBCT in central India
Autorzy:
Bose, Sourav
Sur, Jaideep
Khan, Fatima
Dewangan, Deeplaxmi
Paul, Sushmita
Sawriya, Ekta
Roul, Ayesha
Powiązania:
https://bibliotekanauki.pl/articles/27317669.pdf
Data publikacji:
2023-09-30
Wydawca:
Uniwersytet Rzeszowski. Wydawnictwo Uniwersytetu Rzeszowskiego
Tematy:
cone-beam computed tomography
forensic science
mental foramina
Opis:
Introduction and aim. This study aims to estimate the age of a population in Central India by analyzing the mental foramen using cone beam computed tomography (CBCT). The objectives of the study are to determine the parameters for age determination and study bilateral variations in mental foramen dimensions using CBCT. Material and methods. One hundred and twenty CBCT scans, HD LED monitor, GALAXIS GALLIEOS viewer. Results. Results from the study show significant values for various parameters such as the upper and lower borders of the mandible and mental foramen. Bilateral variations were also observed. The age regression model indicates a significant correlation between estimated and original ages for individuals aged between 31 to 50 years. While the study only analyzed five parameters of the mental foramen, it suggests that a more comprehensive assessment of mental foramen parameters with a larger sample size can yield more definitive results for age determination. Conclusion. As only five parameters of mental foramen had been assessed in this retrospective study, so a comprehensive assessment of various other parameters of mental foramen with an increased sample size may be done for more definitive results for gender and age determination.
Źródło:
European Journal of Clinical and Experimental Medicine; 2023, 3; 500-505
2544-2406
2544-1361
Pojawia się w:
European Journal of Clinical and Experimental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spatial construction of intersection points of two ellipses
Przestrzenna konstrukcja wspólnych punktów dwóch elips
Autorzy:
Bieliński, A.
Łapińska, C.
Powiązania:
https://bibliotekanauki.pl/articles/973250.pdf
Data publikacji:
2006
Wydawca:
Polskie Towarzystwo Geometrii i Grafiki Inżynierskiej
Tematy:
ellipse
elliptical cone
affinity
elipsa
stożek eliptyczny
pokrewieństwo
Opis:
A spatial construction of intersection points of two coplanar ellipses, whose major axes lie on the same line and minor axes are equal in length, is given.
Rozpad linii przenikania dwóch walców został tu wykorzystany do wyznaczenia punktów przecięcia się dwóch elips będących w określonym szczególnym położeniu – elipsy leżą w jednej płaszczyźnie, ich duże osie leżą na jednej prostej i częściowo pokrywają się, ich małe osie są równej długości.
Źródło:
Journal Biuletyn of Polish Society for Geometry and Engineering Graphics; 2006, 16; 17-19
1644-9363
Pojawia się w:
Journal Biuletyn of Polish Society for Geometry and Engineering Graphics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reconstructing an eroded scoria cone : the Miocene Soonica Hill volcano (Lower Silesia, SW Poland)
Autorzy:
Awdankiewicz, M.
Powiązania:
https://bibliotekanauki.pl/articles/2059700.pdf
Data publikacji:
2005
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Lower Silesia
Cenozoic
scoria cone
lava
intrusion
basalt
Opis:
The basaltic rocks of Sośnica Hill near Targowica (Fore-Sudetic Block) belong to the Cenozoic Central European Volcanic Province. The volcanic succession at Sośnica is over 40 m thick and comprises pyroclastic fall deposits (mainly tuff breccias), subvolcanic intrusions (plug, dykes and other intrusive sheets) and aa-type lavas. Field relationships and structural data enable a detailed reconstruction of the vent location, morphology and eruptive history of the original volcano. Initial Hawaiian to Strombolian-type explosive eruptions produced a pyroclastic cone. Subsequently subvolcanic intrusions and lavas were emplaced. The lavas were fed from the central vent of the volcano, breached the cone and flowed southwards. Later eruptions resumed at a new vent on the western slopes of themain cone. The final volcanic edifice-a breached Strombolian scoria cone with a lava flow and a parasitic cone-was 500-1000 m in diameter at the base and 90-180mhigh. The preserved SWsector of this volcano, where the pyroclastic deposits were protected from erosion by the surrounding plugs and lavas, corresponds to ca. 1/2 of the height and 1/8 of the volume of the original volcano. Compared with many other remnants of Cenozoic volcanic centres in Lower Silesia, this volcano is exceptionally well preserved and exposed.
Źródło:
Geological Quarterly; 2005, 49, 4; 439--448
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ocena zmian zwięzłości darni o odmiennym składzie gatunkowym roślin
Values of unit pressure at selected depths in ground covered with sod for varying sod use intensities
Autorzy:
Białczyk, W.
Czarnecki, J.
Jamroży, K.
Pieczarka, K.
Wolski, K.
Powiązania:
https://bibliotekanauki.pl/articles/288641.pdf
Data publikacji:
2010
Wydawca:
Polskie Towarzystwo Inżynierii Rolniczej
Tematy:
opór penetracji
stożek
zwięzłość
cone
penetration resistance
compactness
Opis:
W pracy przedstawiono wyniki badań oporu penetracji stożka oraz obliczonych na jego podstawie zwięzłości badanych podłoży zadarnionych. Badania przeprowadzono na trzech obiektach różniących się składem gatunkowym darni i odmienną wilgotnością podłoża. Stwierdzono odmienny charakter przebiegów oporów penetracji stożka dla darni o rożnej wilgotności, oraz wykazano wpływ głębokości penetracji na wartości obliczonych zwięzłości podłoża. Nie wykazano natomiast wpływu składu gatunkowego roślin na zwięzłość badanych obiektów.
The paper presents results of the research on cone penetration resistance, and the compactness values for examined grounds covered with sod computed on their basis. The tests were carried out for three objects differing in sod species composition and characterised by different ground humidity. The research has shown different character of cone penetration resistance curves for sod with different humidity, and the impact of penetration depth on computed ground compactness values. As for the impact of plant species composition on compactness of the examined objects, none has been shown.
Źródło:
Inżynieria Rolnicza; 2010, R. 14, nr 1, 1; 47-54
1429-7264
Pojawia się w:
Inżynieria Rolnicza
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Taurodontic teeth in cone beam computed tomography: pictorial review
Autorzy:
Fourneau, Eléonore
Olszewski, Raphael
Powiązania:
https://bibliotekanauki.pl/articles/48518226.pdf
Data publikacji:
2023
Wydawca:
Presses Universitaires de Louvain
Tematy:
taurodontism
CBCT
cone beam computed tomography
taurodontic teeth
Opis:
Objective: Taurodontism is a developmental disorder with enlargement of the body of the tooth and lack of cervical constriction, which results in a large pulp chamber and small roots with the apical displacement of furcation. Taurodontism exists in deciduous, and definitive unilateral, and bilateral teeth. We found that taurodontism was also described in 67 syndromes. We proposed a review of the open access literature on taurodontism, a new clinical classification of taurodontic teeth with illustrations from free open access literature, and from our case serie of 15 patients. Material and methods: We performed a systematic search for articles with free full text about taurodontism. The search was performed by one observer in PubMed database. We found 168 articles, and after application of inclusion/exclusion criteria we finally selected 136 articles for the review. Results: we provided 34 figures of taurodontic teeth related to: 1) Unilateral mandibular first premolar, 2) Unilateral mandibular second premolar, 3) Bilateral mandibular first and second premolar, 4) Bilateral upper maxillary first premolars, 5) Bilateral mandibular second molars, 6) Bilateral upper maxillary second premolar and left first molar, 7) Bilateral upper maxillary third molars, 8) Bilateral upper maxillary first and second molars, 9) Bilateral upper maxillary first, second, and third molars, 10) Bilateral upper maxillary molars (third molars, second, and first left upper molars), and mandibular molars (first right, and left mandibular molars, right third molar), 11) Bilateral upper maxillary molars (first, second, third right, and left upper molars), and mandibular molars, 12) Unilateral first mandibular premolar with cleft, 13) Bilateral molars of the mandible and the upper maxilla (adolescent patient who received chemotherapy at the age of 3-years-old to treat retinoblastoma), 14) Unilateral first maxillary molar (Treacher-Collins syndrome). Conclusions: We proposed a new clinical classification of taurodontic teeth based on hypo-, meso-, and hypertaurodontism, and on different types of deciduous, and definitive teeth (42 boxes). We were first to provide free reference images for: 1) upper maxillary second premolar hypertaurodontism, 2) mandibular second premolar mesotaurodontism, 3) upper maxillary third molar meso-and hypertaurodontism, 4) mandibular first molar hypotaurodontism, 5) mandibular third molar mesotaurodontism. We were also first to freely illustrate taurodontism related with chemotherapy, cleft palate patients, and Treacher-Collins syndrome.
Źródło:
Nemesis. Negative Effects in Medical Sciences Oral and Maxillofacial Surgery; 2023, 33, 1; 1-44
2593-3604
Pojawia się w:
Nemesis. Negative Effects in Medical Sciences Oral and Maxillofacial Surgery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Finite-time stability and stabilization of singular state-delay systems using improved estimation of a lower bound on a Lyapunov-like functional
Autorzy:
Stojanovic, S. B.
Debeljkovic, D. Lj.
Antic, D. S.
Powiązania:
https://bibliotekanauki.pl/articles/200145.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
singular systems
time-delay
LMIs
finite-time stability
stabilizing controllers
cone complementarity
linearization
cone complementarity linearization algorithm
systemy pojedyńcze
czas opóźnienia
stabilność w czasie skończonym
kontrolery stabilizujące
komplementarność
linearyzacja
algorytm cone complementarity linearization
Opis:
In this paper, the problems of finite-time stability and stabilization for a class of singular time-delay systems are studied. Using the Lyapunov-like functional (LLF) with (exponential or power) weighting function and a new estimation method for the lower bound on LLF, some sufficient stability conditions are introduced. It is shown that the weighting function significantly reduces the conservatism of the stability criteria in comparison to estimation of the lower bound on LLF without this function. To solve the finite-time stabilization problem, a stabilizing linear state controller is designed by exploiting the cone complementarity linearization algorithm. Two numerical examples are given to illustrate the effectiveness of the proposed method.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2015, 63, 2; 479-487
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Engineering Geological Properties of Coastal Plain Sands in Selected Areas in Ikoyi Area, a typical Coastal Sedimentary Terrain
Autorzy:
Alabere, Abdulquadri O.
Emmanuel, Olaoluwa E.
Powiązania:
https://bibliotekanauki.pl/articles/1162844.pdf
Data publikacji:
2018
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Bearing capacity
Displacement Piles
cone penetrometer
standard penetration test
Opis:
Coastal plain sands in some selected areas of Ikoyi, in Lagos, Dahomey basin southwestern Nigeria have been investigated with respect to their geotechnical properties to determine their suitability as construction materials and to recommend suitable foundation type for the proposed developments. Representative samples collected from each sites were subjected to standard engineering tests and CPT method was used for calculating the bearing capacity of the soil. The cone resistance values (Qc) ranges from 8-158 kg/cm3, 20-160 kg/cm3, 32-166 kg/cm3 for Sokoto street site, Parkview estate site, and Delta street site respectively. Correlating this result with standard penetration test values, it shows dense soil at 3m, 10m and 45m for Delta Street site, medium dense soil at 2m and 30m for Parkview estate site, and medium dense soil at 3m, 29m and 30m for Sokoto Street site. The undrained triaxial test revealed that undrained cohesion ranges from 47-70 KNm-2, 44-95 KNm-2, and 15-30 KNm-2 with no angle of internal friction for Sokoto Street, Delta Street and Parkview estate site respectively. These values show that the soils have low bearing capacity due to low undrained cohesion and angle of internal friction. The geotechnical analysis result show that for the proposed building (tower) on the three sites, shallow foundation cannot be supported because the foundation pressure exceeds the bearing capacities of the soil across the three sites at shallow depth and the loads needs to be transferred to more competent soil layer at deeper depth via a non- displacement (or replacement) pile.
Źródło:
World Scientific News; 2018, 110; 23-41
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Variational approach to some optimization control problems
Autorzy:
Bianchini, R.
Powiązania:
https://bibliotekanauki.pl/articles/1359657.pdf
Data publikacji:
1995
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
tangent vectors
variational cone
local controllability
Mayer's optimization problem
Opis:
This paper presents the variational approach to some optimization problems: Mayer's problem with or without constraints on the final point, local controllability of a trajectory, time-optimal problems.
Źródło:
Banach Center Publications; 1995, 32, 1; 83-94
0137-6934
Pojawia się w:
Banach Center Publications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the structure of characteristic surfaces related with partial differential equations of first and higher orders. Pt. 1
Autorzy:
Prykarpatska, N.K.
Pytel-Kudela, M.
Powiązania:
https://bibliotekanauki.pl/articles/255195.pdf
Data publikacji:
2005
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
characteristic surface
vector fields
tangency
Monge cone
tensor fields
Opis:
The geometric structure of characteristic surfaces related with partial differential equations of first and higer orders is studied making use the vector field technique on hypersurfaces. It is shown, that corresponding characteristics are defined uniquely up to some smooth tensor fields, thereby supplying additional information about the suitable set of their solutions. In particular, it may be very useful for studying asymptotic properties of solutions to our partial differential equations under some boundary conditions.
Źródło:
Opuscula Mathematica; 2005, 25, 2; 299-306
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Liquid limit of selected postglacial soils from west-central Poland
Autorzy:
Krawczyk, Dorota Anna
Flieger-Szymańska, Michalina
Wanatowski, Dariusz
Powiązania:
https://bibliotekanauki.pl/articles/2058633.pdf
Data publikacji:
2019
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
liquid limit
tills
varved clays
cone penetrometer
Casagrande apparatus
Opis:
The aim of this paper is to establish a correlation between the liquid limit value obtained in the Casagrande apparatus (wL/cup) and in the cone penetrometer (wL/cone) for typical glacial sediments from west-central Poland and compare them with the correlation equations published in the literature. The following correlation was formulated: wL/cone = 0.91wL/cup+ 1.98. The analysis presented in this paper proves that deriving a generalized and universal relationship wL/cup/wL/cone for all cohesive soils, regardless of their origin, is very challenging and may not be reliable for use in the engineering practice. It is verified that, in the range of low values of liquid limit, the cone penetrometer gives higher values of wL than those obtained from the Casagrande apparatus. However, for the Polish postglacial soils analysed in this paper, the cone penetrometer underestimates the results in relation to the Casagrande apparatus above wL = 22%. For the purpose of this study, wL = 22% was defined as “the point of equivalent results” (wL/cone = wL/cup).
Źródło:
Geological Quarterly; 2019, 63, 4; 711--720
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cinder movement experiments on scoria cones slopes : Rates and direction of transport
Autorzy:
Hooper, D. M.
Powiązania:
https://bibliotekanauki.pl/articles/294542.pdf
Data publikacji:
1999
Wydawca:
Stowarzyszenie Geomorfologów Polskich
Tematy:
erosion rates
San Francisco volcanic field
downslope transport
cinder cone
scoria cone
surficial processes
rainsplash
slope wash
overland flow
hillslope processes
Opis:
As part of a field experiment to examine slope processes, four experimental grids with painted and numbered cinders were placed on the outer crater rims of two scoria cones in the San Francisco volcanic field, Arizona. Each grid contained 50 cinders placed in five rows of ten each. Rows were placed parallel to local slope contours. The mean diameter for each cinder was 1.7±0.2 cm (n = 200) and the average grid slope was 20.2°. Grids were set in July 1992. They were revisited one month later in August 1992 and again two years later in August 1994. Although several cinders failed to show any movement in the August 1992 survey, the average length of movement was 11.2 cm (n = 118). If the total movement is averaged over the 197 cinders that were relocated, the average length of movement then becomes 6.7 cm (n = 197). All cinders showed movement in the August 1994 survey and the average distance of movement was 32.8 cm (n= 141 with 59 missing cinders). The mean annual rate of movement after 25 months was 15.8cm/yr(n= 141). Using the convention that the 180° azimuth direction is downslope and perpendicular to local slope contours, the direction of cinder movement more closely approaches 180° with an increase in time. The azimuth directions calculated after just one month of emplacement display greater scatter and variability than the more correlated results measured after 25 months. The mean azimuth value after the 1992 survey was 163.6±54.2° (n= 118), while the mean azimuth after the 1994 survey was 177.9±20.7° (n = 141). Several painted cinders displayed upslope movement when the grids were first visited after one month. However, after two years the cumulative movement for every cinder was downslope from its original position. Non-channel overland flow is interpreted to be the primary erosional agent responsible for moving the cinders in the downhill direction. Rainsplash is interpreted to be responsible for moving the cinders in the upslope direction and is believed to be the major contributor to the variability in the azimuth measurements.
Źródło:
Landform Analysis; 1999, 2; 5-18
1429-799X
Pojawia się w:
Landform Analysis
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Positive solutions to a third order nonlocal boundary value problem with a parameter
Autorzy:
Szajnowska, Gabriela
Zima, Mirosława
Powiązania:
https://bibliotekanauki.pl/articles/29519483.pdf
Data publikacji:
2024
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
boundary value problem
nonlocal boundary conditions
positive solution
cone
Opis:
We present some sufficient conditions for the existence of positive solutions to a third order differential equation subject to nonlocal boundary conditions. Our approach is based on the Krasnosel’skiĭ-Guo fixed point theorem in cones and the properties of the Green’s function corresponding to the BVP under study. The main results are illustrated by suitable examples.
Źródło:
Opuscula Mathematica; 2024, 44, 2; 267-283
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of acquisition and potential usage of conifer cones from Polish seed extraction houses between 2009-2012
Analiza pozyskania i możliwość wykorzystania na cele energetyczne szyszek gatunków drzew iglastych z polskich wyłuszczarni w latach 2009-2012
Autorzy:
Aniszewska, M.
Kuszpit, D.
Powiązania:
https://bibliotekanauki.pl/articles/56367.pdf
Data publikacji:
2015
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
acquisition
seed
extraction
conifer
cone
2009-2012 period
combustion
Opis:
The paper presents data on acquisition of conifer cones from 16 seed extraction plants operating on the territory of Poland during four consecutive years from 2009 to 2012. A high variability was observed in provision of seed units to the seed exaction plants related to specificity of a given seed year. During the four analyzed years the most commonly acquired cone was that of Scots pine – above 1.3 thousand Mg, and the most rare were pines of common fir – 31 Mg. The plants that process the largest number of cones are seed extraction plants in forest districts of Jarocin, Kluczbork and Rytel where over 600 Mg of cones were extracted. Conifer cones, which are usually treated as waste, may be utilized as an energy source. After seed extraction their mass decreases from 16 to 30% depending on the species. The analysis showed that the annual quantity of conifer cones that can be used as an energy source is on average 270 Mg of empty cones.
W artykule przedstawiono dane liczbowe dotyczące pozyskania szyszek czterech gatunków drzew: sosny zwyczajnej, świerka pospolitego, modrzewia europejskiego i jodły zwyczajnej, z 16 wyłuszczarni pracujących na terenie Polski w ciągu lat 2009-2012. Otwarte szyszki pozbawione nasion i traktowane jako odpad połuszczarski mogą być wykorzystane na cele energetyczne w lokalnych elektrowniach. Aby w tym celu można było je wykorzystać, należy na początek sprawdzić, ile rocznie pozyskuje się tego materiału. Zauważono dużą zmienność w dostarczaniu jednostek nasiennych do wyłuszczarni związaną z latami nasiennymi. Przez cztery analizowane lata najwięcej pozyskano szyszek sosny zwyczajnej ponad 1,3 tys. Mg, a najmniej jodły pospolitej - 31 Mg. Ze względu na stosunkowo małą masę pojedynczych szyszek i dużą objętość szyszki można transportować na niewielkie odległości. Do wyłuszczarni łuszczących najwięcej szyszek należą obiekty w Nadleśnictwach Jarocin, Kluczborki i Rytel, gdzie dostarczano łącznie 600 Mg szyszek rocznie. Po łuszczeniu szyszki zmniejszają swoją masę w zależności od gatunku od 16 do 30%. Analiza wykazała, że rocznie można wykorzystać na cele energetyczne średnio 270 Mg pustych szyszek. Szyszki traktowane jako odpad mogą być bezpośrednio spalane lub wykorzystane jako dodatek w produkcji brykietów i peletów.
Źródło:
Annals of Warsaw University of Life Sciences - SGGW. Agriculture; 2015, 65 Agric.Forest Eng.
0208-5712
Pojawia się w:
Annals of Warsaw University of Life Sciences - SGGW. Agriculture
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dental use of cone beam computed tomography in pediatric embolized arteriovenous maxillofacial malformation
Autorzy:
Olszewski, Raphael
Theys, Stéphanie
Powiązania:
https://bibliotekanauki.pl/articles/2129218.pdf
Data publikacji:
2021-10-02
Wydawca:
Presses Universitaires de Louvain
Tematy:
pediatric
arteriovenous malformation
CBCT
embolization
cone beam computed tomography
Opis:
Objective: Pediatric facial arteriovenous malformations (AVMs) are rare but can cause potentially fatal hemorrhages during dental procedures and oral surgery. In this article we present a systematic review of the medical open access literature on pediatric facial AVM. Case report: We illustrate our purpose with clinical dental use of cone beam computed tomography (CBCT) in pediatric embolized facial AVM to define the presence and the position of the right upper impacted canine. Conclusions: We advocate the use of CBCT as additional imaging tool in the follow-up of pediatric dentomaxillofacial AVM, and for depiction of dentoalveolar structures that are inaccessible by conventional dental radiography.
Źródło:
Nemesis. Negative Effects in Medical Sciences Oral and Maxillofacial Surgery; 2021, 20, 1; 1-20
2593-3604
Pojawia się w:
Nemesis. Negative Effects in Medical Sciences Oral and Maxillofacial Surgery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design and Experiments of A New Internal Cone Type Traveling Wave Ultrasonic Motor
Autorzy:
Chen, Ye
Yang, Junlin
Li, Liang
Xiao, Shihao
Powiązania:
https://bibliotekanauki.pl/articles/31339802.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
ultrasonic motors
traveling wave
internal cone type
bending vibration
Opis:
In order to simplify the motor structure, to reduce the difficulty of rotor pre-pressure application and to obtain better output performance, a new internal cone type rotating traveling wave ultrasonic motor is proposed. The parametric model of the internal cone type ultrasonic motor was established by the ANSYS finite element software. The ultrasonic motor consists of an internal cone type vibrator and a tapered rotor. The dynamic analysis of the motor vibrator is carried out, and two in-plane third-order bending modes with the same frequency and orthogonality are selected as the working modes. The other advantages of this motor are that pre-pressure can be imposed by the weight of the rotor. The prototype was trial-manufactured and experimentally tested for its vibration characteristics and output performance. When the excitation frequency is 22260.0 Hz, the pre-pressure is 0.1 N and the peak-to-peak excitation voltage is 300 V, the maximum output torque of the prototype is 1.06 N · mm, and the maximum no-load speed can reach 441.2 rpm. The optimal pre-pressure force under different loads is studied, and the influence of the pre-pressure force on the mechanical properties of the ultrasonic motor is analyzed. It is instructive in the practical application of this ultrasonic motor.
Źródło:
Archives of Acoustics; 2023, 48, 3; 373-380
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the relaxation of state-constrained linear control problems via Henig dilating cones
Autorzy:
Kogut, P. I.
Leugering, G.
Schiel, R.
Powiązania:
https://bibliotekanauki.pl/articles/206472.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
optimal control
state constrains
relaxation
Henig dilating cone
optimality conditions
Opis:
We discuss a regularization of state-constrained optimal control problems via a Henig relaxation of ordering cones. Considering a state-constrained optimal control problem, the pointwise state constraint is replaced by an inequality condition involving a so-called Henig dilating cone. It is shown that this class of cones provides a reasonable solid approximation of the typically nonsolid ordering cones which correspond to pointwise state constraints. Thereby, constraint qualifications, which are based on the existence of interior points, can be applied to given problems. Moreover, we characterize admissibility and solvability of the original problem by analyzing the associated relaxed problem. We also show that the optimality system for the original problem can be obtained through the limit passage in the corresponding optimality system for the relaxed problem. As an example of our approach, we derive the optimality conditions for a state constrained Neumann boundary optimal control problem and show that in this case the corresponding Lagrange multipliers are more regular than Borel measures.
Źródło:
Control and Cybernetics; 2016, 45, 2; 131-162
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On approach regions for the conjugate Poisson integral and singular integrals
Autorzy:
Ferrando, S.
Jones, R.
Reinhold, K.
Powiązania:
https://bibliotekanauki.pl/articles/1287340.pdf
Data publikacji:
1996
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
cone condition
conjugate Poisson integral
singular integrals
ergodic Hilbert transform
Opis:
Let ũ denote the conjugate Poisson integral of a function $f ∈ L^{p}(ℝ)$. We give conditions on a region Ω so that $lim_{(v,ε)→(0,0)}_{(v,ε)∈Ω} ũ(x+v,ε) = Hf(x)$, the Hilbert transform of f at x, for a.e. x. We also consider more general Calderón-Zygmund singular integrals and give conditions on a set Ω so that $sup_{(v,r)∈Ω} |ʃ_{|t|>r} k(x+v-t)f(t)dt|$ is a bounded operator on $L^p$, 1 < p < ∞, and is weak (1,1).
Źródło:
Studia Mathematica; 1996, 120, 2; 169-182
0039-3223
Pojawia się w:
Studia Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Challenges in diagnosing odontogenic lesions in maxillary sinuses
Autorzy:
Dobroś, Katarzyna
Zarzecka, Joanna
Powiązania:
https://bibliotekanauki.pl/articles/1397314.pdf
Data publikacji:
2020
Wydawca:
Index Copernicus International
Tematy:
Cone Bean Computed Tomography
maxillary sinusitis
periapical tissues
pulp disease
Opis:
Objectives: The study aimed to identify the patients with pathological lesions in the maxillary sinuses in which the reported symptoms might be indicative of odontogenic origin, as well as to establish specific causative risk factors promoting their development. Methods and Materials: The study covered 44 patients with suspected odontogenic maxillary sinusitis. Dental examination and Cone Beam Computed Tomography were completed. The age of patients ranged between 19 and 69 years, and the mean age was 43 (SD = 13.9) years. Results: Out of 44 patients, 22 (50%) had non-odontogenic lesions in maxillary sinuses, while in 15 (34.1%) dental origin was established. In the remaining 7 (15.9%) patients, no pathological changes were found in the sinuses. The median of reported symptoms was 10 months (Q1 = 4, Q3 = 24). The reported complaints were not associated with the actual cause of pathological lesions. Conclusions: Odontogenic cause of the lesions in the sinuses should primarily be hypothesized, especially in patients with long-term disease symptoms, also regarding any unilateral inflammations.
Źródło:
Polish Journal of Otolaryngology; 2020, 74, 3; 12-16
0030-6657
2300-8423
Pojawia się w:
Polish Journal of Otolaryngology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Set-valued minimax fractional programming problems under -cone arcwise connectedness
Autorzy:
Das, Koushik
Powiązania:
https://bibliotekanauki.pl/articles/2183488.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
convex cone
set-valued map
contingent epiderivative
arcwise connectedness
duality
Opis:
In this paper, we consider a set-valued minimax fractional programming problem (MFP), where the objective as well as constraint maps are set-valued. We introduce the notion of ρ- cone arcwise connectedness of set-valued maps as a generalization of cone arcwise connected set-valued maps. We establish the sufficient Karush-Kuhn-Tucker (KKT) conditions for the existence of minimizers of the problem (MFP) under ρ-cone arcwise connectedness assumption. Further, we study the Mond-Weir (MWD), Wolfe (WD), and mixed (MD) types of duality models and prove the corresponding weak, strong, and converse duality theorems between the primal (MFP) and the corresponding dual problems under ρ-cone arcwise connectedness assumption.
Źródło:
Control and Cybernetics; 2022, 51, 1; 43--69
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical study of MHD Williamson-nano fluid flow past a vertical cone in the presence of suction/injection and convective boundary conditions
Autorzy:
Sathyanarayana, Manthri
Goud, Tamtam Ramakrishna
Powiązania:
https://bibliotekanauki.pl/articles/27312230.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
Williamson fluid
nanofluid
vertical cone
suction/Injection
convective
boundary condition
Opis:
The primary objective is to perform a numerical synthesis of a Williamson fluid that has nanoparticles added to it and is directed toward a vertical cone in a uniform transverse magnetic field, under heat and mass transport, suction and injection, and convective boundary conditions. For this particular fluid flow, by utilising similarity transformations, the partial differential equations are transformed into ordinary differential equations. Calculating these kinds of equations with their suitable bounds requires the Runge–Kutta technique in combining a shooting strategy. The functions of a vast number of parameters are graphically represented and assessed on flow field profiles. The results show the local skin friction, local Nusselt number, and local Sherwood number and the changing values of the flow constraints. Finally, the results are compared to those from the previously published works and found to be in good agreement.
Źródło:
Archives of Thermodynamics; 2023, 44, 2; 115--138
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Φ- α(⋅)-K-monotone multifunctions with values in ordered Banach space with increasing norm
Autorzy:
Rolewicz, S.
Powiązania:
https://bibliotekanauki.pl/articles/206769.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
vector valued functions
normal cone
cone with bounded basis
Φ-α(⋅)-K-subgradi-ents
increasing norm
Φ-α(⋅)-k-subdifferential Fréchet Φ-differentiability
Opis:
Let (X, d) be a metric space. Let Y be an ordered Banach space with increasing norm. Let Φ be a separable linear family (a class) of Lipschitz functions defined on X and with values in Y . Let α(⋅) be a nondecreasing function mapping the interwal [0,+∞) into itself such that limt↓0 α(t) / t = 0. We say that a multifunction mapping X into Φ is Φ -α(⋅)-K-monotone if for all k in the interior of K, k ∈ Int K, there is a constant Ck > 0 such that for all φx ∈Γ (x),φy ∈Γ (y) we have φx(x) + φy(y) − φx(y) − φy(x) ≥K −Ckα(d(x, y))k.It is shown in the paper that under certain conditions on each Φ - Φα(⋅)-K-monotone multifunction is single-valued and continuous on a dense G δ-set..
Źródło:
Control and Cybernetics; 2013, 42, 4; 793-803
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Weak sharp minima revisited Part I : basic theory
Autorzy:
Burke, J.
Deng, S.
Powiązania:
https://bibliotekanauki.pl/articles/206183.pdf
Data publikacji:
2002
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
dwoistość
funkcja recesji
ograniczenie błędu
stożek recesji
boundedly weak sharp minima
duality
error bounds
normal cone inclusion
recession cone
recession function
weak sharp minima
Opis:
The notion of sharp minima, or strongly unique local minima, emerged in the late 1970's as an important tool in the analysis of the perturbation behavior of certain classes of optimization problems as well as in the convergence analysis of algorithms designed to solve these problems. The work of Cromme and Polyak is of particular importance in this development. In the late 1980's Ferris coined the term weak sharp minima to describe the extension of the notion of sharp minima to include the possibility of a non-unique solution set. This notion was later extensively studied by many authors. Of particular note in this regard is the paper by Burke and Ferrris which gives an extensive exposition of the notion and its impact on convex programming and convergence analysis in finite dimensions. In this paper we build on the work of Burke and Ferris. Specifically, we generalize their work to the normed linear space setting, further dissect the normal cone inclusion characterization for weak sharp minima, study the asymptotic properties of weak sharp minima in terms of associated recession functions, and give new characterizations for local weak sharp minima and boundely weak sharp minima. This paper is the first of a two part work on this subject. In Part II, we study the links between the notions of weak sharp minima, bounded linear regularity, linear regularity, metric regularity, and error bounds in convex programming. Along the way, we obtain both new results and reproduce many existing results from a fresh perspective.
Źródło:
Control and Cybernetics; 2002, 31, 3; 439-469
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiticheskaja model dvizhenija chasticy po poverkhnosti konusa diskovogo rotacionnogo dozatora-smesitelja dispersnykh materialov
Analytical models of particle motion on the surface of cone of disk rotary dispenser-mixer dispersed materials
Autorzy:
Dmitriv, V.
Gorodnjak, R.
Dmitriv, G.
Powiązania:
https://bibliotekanauki.pl/articles/76893.pdf
Data publikacji:
2015
Wydawca:
Komisja Motoryzacji i Energetyki Rolnictwa
Tematy:
technological parameter
cone disk
angular velocity
friction coefficient
coordinate system
Źródło:
Motrol. Motoryzacja i Energetyka Rolnictwa; 2015, 17, 9
1730-8658
Pojawia się w:
Motrol. Motoryzacja i Energetyka Rolnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of electrical resistivity tomography in assessing complex soil conditions
Autorzy:
Kowalczyk, S.
Zawrzykraj, P.
Mieszkowski, R.
Powiązania:
https://bibliotekanauki.pl/articles/2060284.pdf
Data publikacji:
2015
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
electrical resistivity tomography
ERT
resistivity cone penetration test
RCPT
peat
Opis:
Appropriate assessment of spatial variation of soil and hydrogeological conditions is a crucial issue in recognizing foundation soil. The best methods to achieve this goal are those that supply continuous rather than scattered data on soil medium variation. Electrical resistivity was measured with the resistivity cone penetration test (RCPT) and electrical resistance tomography (ERT) with electrodes spaced at 1 and 3 m in order to discriminate peat layers beneath low-resistivity clays. Soil conditions determined by drillings and ERT were not concordant, therefore resistivity modelling of the medium was conducted based on geological units determined by drillings and values of apparent resistivity obtained from RCPT. The strata thickness and electrode spacing is shown to have influence on resistivity imaging in complex soil conditions.
Źródło:
Geological Quarterly; 2015, 59, 2; 367--372
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ wybranych cech morfologicznych szyszek sosny zwyczajnej na przebieg procesu łuszczenia
The impact of selected morphological features of Scotch Pine cones on the progress of hulling process
Autorzy:
Aniszewska, M.
Powiązania:
https://bibliotekanauki.pl/articles/290180.pdf
Data publikacji:
2008
Wydawca:
Polskie Towarzystwo Inżynierii Rolniczej
Tematy:
sosna zwyczajna
szyszka
tarczka
wyłuszczanie
Scotch pine
cone
disk
hulling
Opis:
W artykule przedstawiono porównanie parametrów procesu łuszczenia i czasów pełnego otwarcia szyszek sosny zwyczajnej różniących się formami, określonymi na podstawie kształtu zewnętrznej części tarczki łuski. Dla szyszek jednego pochodzenia, różniących się cechami zewnętrznymi, nie stwierdzono istotnych różnic dla wyróżnianych parametrów równania opisujących przebieg procesu.
The paper presents comparison of hulling process parameters and full opening times for Scotch Pine cones, which differ in form, determined on the grounds of the shape of external part of hull disk. No significant differences for distinguished parameters of equation describing the process progress were found for cones of the same origin, which differ in their external features.
Źródło:
Inżynieria Rolnicza; 2008, R. 12, nr 1(99), 1(99); 9-15
1429-7264
Pojawia się w:
Inżynieria Rolnicza
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Roadmap for daily practice of CBCT in cleft lip palate paediatric patients: a pictorial review.
Autorzy:
Olszewski, Raphael
De Muylder, Antoine
Siciliano, Sergio
Powiązania:
https://bibliotekanauki.pl/articles/48519884.pdf
Data publikacji:
2023
Wydawca:
Presses Universitaires de Louvain
Tematy:
cone beam computed tomography
CBCT
cleft lip palate
paediatric
reporting
Opis:
Objective: to present and to illustrate a new methodology for daily practice in cone beam computed tomography (CBCT) interpretation and reporting in cleft lip palate (CLP) non syndromic paediatric patients. The proposed protocol is based on clinical experience and on systematic search of the literature. Material and methods: We performed two types of systematic search of articles: 1) articles related to the use of CBCT in CLP patients, and 2) articles related to the reporting and interpretation of the CBCT images by radiologists. We used two databases PubMed and Google scholar. Results: For indications of CBCT in CLP patients we found in PubMed 378 articles and 48 articles were selected for the review; in Google scholar we found 463 articles, and 9 articles were selected for the review. 2) For reporting in CBCT we found 956 articles in PubMed, and 9 articles were selected for the review. Conclusions: We presented the 6-steps system for interpretation and reporting information from CBCT of CLP paediatric patients: 1) Step 1 (axial view): presence or absence of bone bridge remnants of alveolar bone graft; Step 2 (3D dental tissue reconstruction): description of dental arch tooth by tooth, search for agenesis and supernumerary teeth, description of variation in the position of the tooth explaining the type of existing translation and rotation; Step 3 (coronal view): cleft palate pathway and its extension; anomaly in maxillary, ethmoid and sphenoid sinuses if existing; Step 4 (sagittal and coronal view): checking of the opening (calcification sites) of the sphenooccipital synchondrosis, and checking of anomalies of the occipital bone; Step 5 (3D bone tissue reconstruction): C1-C2 vertebra anomalies; Step 6 (3D soft tissue reconstruction): external ear anomalies. We illustrated our methodology with 46 figures from 5 CBCT of CLP patients.
Źródło:
Nemesis. Negative Effects in Medical Sciences Oral and Maxillofacial Surgery; 2023, 30, 1; 1-50
2593-3604
Pojawia się w:
Nemesis. Negative Effects in Medical Sciences Oral and Maxillofacial Surgery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Validation of the cone penetrometer suitability for determining the state of soil
Walidacja przydatności penetrometru stożkowego do określenia stanu gruntu na podstawie porównania z wynikami sondy statycznej CPT
Autorzy:
Maślakowski, M.
Brzeziński, K.
Zbiciak, A.
Józefiak, K.
Powiązania:
https://bibliotekanauki.pl/articles/230848.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
penetrometr stożkowy
sonda statyczna CPT
metoda in-situ
stan gruntu
korelacja
dynamic cone penetrometer
CPT static cone penetrometer
in-situ method
state of soil
correlation
Opis:
The article presents an assessment of the suitability of the cone penetrometer to determine the soil state. The work describes the principle of the device operation, which is similar to commonly used dynamic DPL probes. Then, the results of research conducted in Polish conditions using the new conical penetrometer were presented. A series of measurements were performed in real field conditions. On their basis, an attempt was made to correlate the results obtained with a conical penetrometer and a static probe CPT. Then, the obtained correlations were validated. On this basis preliminary evaluation of the conical penetrometer suitability for the soil state determining.
Artykuł przedstawia ocenę przydatności penetrometru stożkowego do określenia stanu gruntu. W pracy opisano zasadę działania urządzenia, podobną do powszechnie stosowanych sond dynamicznych typu DPL. Następnie przedstawiono wyniki badań przeprowadzonych w warunkach polskich z wykorzystaniem nowego penetrometru stożkowego. Szereg pomiarów wykonano w realnych warunkach terenowych. Na ich podstawie podjęto próbę korelacji wyników uzyskanych penetrometrem stożkowym oraz sondą statyczną CPT. Następnie uzyskane korelacje poddano walidacji i na tej podstawie wstępnie oceniono przydatność zastosowania penetrometru stożkowego do określenia stanu gruntu.
Źródło:
Archives of Civil Engineering; 2018, 64, 4/I; 265-280
1230-2945
Pojawia się w:
Archives of Civil Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Etapy formowania się stożka osadu w zbiorniku testowym kadzi wirowej whirlpool
Formation phases of a sediment cone inside a test tank of a whirlpool vat
Autorzy:
Jakubowski, M.
Sterczyńska, M.
Poreda, A.
Powiązania:
https://bibliotekanauki.pl/articles/292115.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Inżynierii Rolniczej
Tematy:
whirlpool
stożek osadu
ruch wirowy
torus
sediment cone
rotational motion
thorus
Opis:
Artykuł stanowi prezentację wyników badań eksperymentalnych przepływu mieszaniny separowanej w zbiorniku laboratoryjnej kadzi wirowej. Przedmiotem badań były charakterystyczne etapy formowania się stożka osadu w zależności od umiejscowienia (wysokości) otworu wlotowego i prędkości napełniania. Badania eksperymentalne zostały wykonane z wykorzystaniem zbiornika modelowego kadzi wirowej (tzw. whirlpoola) o pojemności V=2 hl i średnicy D=640 mm. W wyniku przeprowadzonych doświadczeń ustalono, iż w zjawisku formowania się stożka można wydzielić pewne charakterystyczne stany. W ramach przeprowadzonych badań porównano czasy ich występowania, a poprzez ich porównanie określono najkorzystniejsze prędkości napełniania, a także najkorzystniejsze wysokości umiejscowienia otworu wlotowego.
The article presents results of the experimental research on the flow of mixture separated inside a laboratory cycling vat. The specific stages of forming the sediment cone depending on the position of the inlet (the placement height) and the speed of filling were the subject of the research. The research was carried out using a cycling vat (also called a whirlpool) scale model with capacity of V = 2hl and diameter of D = 640 mm. As a result of the experiments it was determined that as a part of the phenomenon of forming the cone, a few specific stages can be distinguished. The research involved a comparison of their timing, which allowed determination of the optimal speed of filling as well as the best height of placing the inlet.
Źródło:
Inżynieria Rolnicza; 2013, R. 17, nr 1, t. 1, 1, t. 1; 83-92
1429-7264
Pojawia się w:
Inżynieria Rolnicza
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reachability of cone fractional continuous-time linear systems
Autorzy:
Kaczorek, T.
Powiązania:
https://bibliotekanauki.pl/articles/907852.pdf
Data publikacji:
2009
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
system ułamkowy
system liniowy
osiągalność
cone fractional system
linear system
reachability
Opis:
A new class of cone fractional continuous-time linear systems is introduced. Necessary and sufficient conditions for a fractional linear system to be a cone fractional one are established. Sufficient conditions for the reachability of cone fractional systems are given. The discussion is illustrated with an example of linear cone fractional systems.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2009, 19, 1; 89-93
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Projektowanie geotechniczne posadowienia turbiny wiatrowej
Geotechnical designing of the wind turbines
Autorzy:
Batog, A.
Hawrysz, M.
Powiązania:
https://bibliotekanauki.pl/articles/350466.pdf
Data publikacji:
2011
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
sondowanie statyczne
fundamentowanie
elektrownie wiatrowe
cone penetration test
foundation
wind turbines
Opis:
W pracy przedstawiono proces projektowania geotechnicznego związany z realizacją jednej z elektrowni wiatrowych należących do Pyrzyckiej Farmy Wiatrowej zlokalizowanej w województwie zachodniopomorskim. Podano sposób wykorzystania wyników sondowania statycznego CPTU w celu zaprojektowania posadowienia elektrowni wiatrowej. Wykorzystano je zarówno do ustalenia wyprowadzonych wartości parametrów geotechnicznych jak i do oceny nośności podłoża oraz osiadań fundamentu. Na podstawie przeprowadzonych obliczeń porównawczych z powszechnie stosowaną metodą projektowania posadowień fundamentów stwierdzono, iż zastosowanie metodyki badań oraz projektowania na podstawie badań CPTU pozwala w szybki i ekonomiczny sposób wyznaczyć model podłoża gruntowego oraz z dużym zapasem bezpieczeństwa ocenić nośność i osiadania podłoża fundamentu turbiny wiatrowej.
This paper presents the geotechnical designing method of the wind turbine located in the Pyrzyce Wind Farm. The guidelines for the application of the investigation results obtained from the cone penetration testing for designing of those constructions were presented. The CPT results were used both to determine of geotechnical parameters of soils as well as to the estimation of the subsoil bearing capacity and the value of the foundation settlements. The comparative calculations based on the Polish Standard were performed and the usability, economical advantage and the high safety margin in case of the wind turbine foundation designing were demonstrated.
Źródło:
Górnictwo i Geoinżynieria; 2011, 35, 2; 69-77
1732-6702
Pojawia się w:
Górnictwo i Geoinżynieria
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Aberrant phyllotactic patterns in cones of some conifers: a quantitative study
Autorzy:
Fierz, V.
Powiązania:
https://bibliotekanauki.pl/articles/56470.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
phyllotactic diversity
phyllotaxis
Pinus nigra
Larix decidua
cone
conifer
quantitative study
Opis:
The scale patterns of 6000 cones from one single tree of Pinus nigra Arn. have been examined. Apart from the main Fibonacci pattern with 8 and 13 parastichies, nine aberrant spiral patterns with Fibonacci-type sequences have been found. They are quite rare and occur with different frequencies. The parastichy quotient 8/13 of the prevalent pattern is very close to the golden ratio 0.618. In case of the black pine it appeared that the greater the deviation of the parastichy quotient m/n from 0.618, the rarer the pattern. Similar results obtained for the sample of 1506 cones collected from three individual trees of larch (Larix decidua Mill.) suggest a true correlation between the frequency of a pattern and the deviation of its parastichy quotient from the golden ratio.
Źródło:
Acta Societatis Botanicorum Poloniae; 2015, 84, 2
0001-6977
2083-9480
Pojawia się w:
Acta Societatis Botanicorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
First natural transverse frequency of truncated cone and wedge beams
Pierwsza częstość drgań własnych belek w kształcie ściętego stożka i klina
Autorzy:
Bagdasaryan, V.
Chalecki, M.
Gierasimiuk, M.
Jaworski, J.
Szlachetka, O.
Powiązania:
https://bibliotekanauki.pl/articles/40497.pdf
Data publikacji:
2018
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
vibration
transverse frequency
truncated cone beam
truncated wedge beam
Rayleigh's method
Źródło:
Acta Scientiarum Polonorum. Architectura; 2018, 17, 1
1644-0633
Pojawia się w:
Acta Scientiarum Polonorum. Architectura
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Flowering and cone bearing of Picea abies grafts in second-generation seed orchards
Autorzy:
Misiorny, A
Chalupka, W.
Powiązania:
https://bibliotekanauki.pl/articles/41542.pdf
Data publikacji:
2006
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
Norway spruce
Picea abies
cone yield
seed production
flowering
seed orchard
Opis:
In 2004, abundant flowering of Norway spruce (Picea abies (L.) Karst.) was observed in two second- generation seed orchards: (1) ‘Outbreeding’, promoting crossing between clones of five geographically distant populations; and (2) ‘Kolonowskie’, restoring a population whose offspring exists only in an international experiment (IUFRO 1964/1968). In bothseed orchards, female strobili were produced by 91.3% and 91.7% of clones, represented by 64.1% and 55.5% of grafts, respectively, and statistically significant differences between clones were found in the number of mature cones. In the case of the seed orchard ‘Outbreeding’, the number of mature cones in individual clones was significantly correlated with latitude of the origin of maternal populations (r = 0.8826, p = 0.0470). The majority (95%) of cones in seed orchards ‘Outbreeding’ and ‘Kolonowskie’ were produced by only 28.2% and 38.5% of all clones, and 21.4% and 25.7% of all grafts, respectively. These data attest to a disparity between the level of genetic diversity in seed orchard progeny resulting from the observed numbers of cone-bearing clones and grafts and the genetic diversity expected from the actual participation of clones and grafts in seed orchard composition. The estimated seed production per 1 ha of seed orchard area in 2004 reached 21.05 kg for ‘Outbreeding’ and 21.72 kg for ‘Kolonowskie’.
Źródło:
Dendrobiology; 2006, 56; 51-59
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical checking method for positive invariance of polyhedral sets for linear dynamical systems
Autorzy:
Yang, H.
Hu, Y.
Powiązania:
https://bibliotekanauki.pl/articles/200512.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
positively invariant sets
linear system
polyhedral set
polyhedral cone
linear programming
Opis:
Positively invariant sets play an important role in the theory and applications of dynamical systems. The stability in Lyapunov sense of equilibrium x = 0 is equivalent to the existence of the ellipsoidal positively invariant sets. The constraints on the state and control vectors of dynamical systems can be formulated as polyhedral positively invariant sets in practical engineering problems. Numerical checking method of positive invariance of polyhedral sets is addressed in this paper. The validation of the positively invariant sets can be done by solving LPs which can be easily implemented numerically. The effectiveness of the proposed checking method is illustrated by examples. Compared with the now existing algebraic methods, numerical checking method is attractive and, importantly, easy to be implemented.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2020, 68, 3; 593-599
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Contribution of dental private practitioners to publications on anatomical variations using cone beam computed tomography
Autorzy:
Hebda, Aleksandra
Theys, Stéphanie
de Roissart, Jean
Perez, Eytan
Olszewski, Raphael
Powiązania:
https://bibliotekanauki.pl/articles/2129253.pdf
Data publikacji:
2020-12-16
Wydawca:
Presses Universitaires de Louvain
Tematy:
citizen science
open access
cone beam computed tomography
CBCT
anatomical variation
Opis:
Objective: To investigate the participation of citizens-dental private practitioner in scientific articles about anatomical variations on dentomaxillofacial CBCT. Our null hypothesis was that private practice practitioners are not involved in publications on anatomical variations using cone beam computed tomography. Material and methods: This study was performed from home without access to our university library. Only PubMed database was used to perform our study. We found 384 articles published among 1830 articles corresponding to our inclusion/exclusion criteria. For each selected article we searched for affiliation of all of the authors (university, private dental practice, students, other). We applied a co-creation approach to involve colleagues from private practice in analyzing results of this study. Results: A large majority of authors have university affiliation (96.5%). Only 3% of authors come from private practice. Most of articles belong to the group of 7 emergent economies (E7), and from Asia. 47.9% of 96 journals published only one article on anatomical variations discovered on CBCT. The higher number of articles (18.75%) were published by journals related to endodontics. The 84% of articles were dispersed among a vast span of general and specific dental, and maxillofacial journals. The 68.4% of articles on variations in CBCT were available in closed access and 31.6% of articles were available in open access. Only 6.7% of articles were published in open access without author publication charges (APC). The 31.6% of authors with university affiliation choose open access for their article. 7.8% of authors from private practice were involved in publishing in closed access journals and 2.34% in open access journals. Only 3 articles (0.78%) were published by authors affiliated to private practice without involvement of university authors. 2.6% of articles involved students as co-authors. Authors with other affiliation were involved only in one closed access publication. For the step of co-creation none of 183 private practitioners, and 3/33 (9%) university-affiliated members of Nemesis Facebook group actively participated in analyzing the results of this study. Conclusions: the null hypothesis was accepted: dentists from private practice are exceptionally involved in publications on anatomical variations using CBCT in dentomaxillofacial area.
Źródło:
Nemesis. Negative Effects in Medical Sciences Oral and Maxillofacial Surgery; 2020, 14, 1; 1-54
2593-3604
Pojawia się w:
Nemesis. Negative Effects in Medical Sciences Oral and Maxillofacial Surgery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simplified computation methodology for contact forces on tapered rolling bearing with flexible parts
Autorzy:
Sapietová, A.
Novák, P.
Šulka, P.
Sapieta, M.
Jakubovičová, L.
Powiązania:
https://bibliotekanauki.pl/articles/196269.pdf
Data publikacji:
2018
Wydawca:
Politechnika Śląska. Wydawnictwo Politechniki Śląskiej
Tematy:
contact force
cone bearing
ANSYS
FE analysis
siła styczna
łożysko stożkowe
Opis:
Durability calculations of bearings take in account the distribution of forces on rollers. Calculation of these forces in flexibly supported rings is the aim of the paper. We use simplified finite element (FE) models of bearings, which are integrated into the external geometry. This approach can consider the stiffness of the surrounding structure as well as the clearance of the bearing rings, the misalignment of bearings, shaft deflections, and the forces of crowning rollers. The presented results show an influence of the initial radial interference of the outer ring with housing on the distribution of forces in bearing rollers. As the radial stiffness of the housing is close to the stiffness of the outer ring interference, this causes considerable deformation of the housing. The presented approach is also able to calculate the distribution of contact pressures over any rolling element.
Źródło:
Zeszyty Naukowe. Transport / Politechnika Śląska; 2018, 99; 177-182
0209-3324
2450-1549
Pojawia się w:
Zeszyty Naukowe. Transport / Politechnika Śląska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Smoke parameters obtained from the cone calorimeter method and the single-Chamber test
Autorzy:
Dowbysz, Adriana Małgorzata
Samsonowicz, Mariola
Powiązania:
https://bibliotekanauki.pl/chapters/31233750.pdf
Data publikacji:
2021
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
cone calorimeter
smoke chamber
smoke parameters
smoke extinction area
smoke density
Opis:
Smoke generated in the combustion process of plastics reduces the visibility and contains toxic products causing severe health problems for society. It may be hazardous to both people and the environment. Therefore, the awareness of smoke specification is important. This paper presents two most common small-scale methods for measuring smoke parameters. The cone calorimeter method and single-chamber test respectively standardized by ISO 5660 and PN-EN ISO 5659-2 were reviewed. Fundamentals of these methods and measurement techniques were described. Diverse smoke parameters obtained from these methods were collected and specified. Attention was also drawn to the relevance of these parameters to standard requirements for various industry fields such as rail transport or shipbuilding.
Źródło:
Innovations – Sustainability – Modernity – Openness. Modernity in engineering; 101-114
9788366391901
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The extent and volcanic structures of the Quaternary Andahua Group, Andes, southern Peru
Autorzy:
Gałaś, A.
Powiązania:
https://bibliotekanauki.pl/articles/191656.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Geologiczne
Tematy:
lava dome
pyroclastic cone
minor volcanic centres
Andahua group
Peruvian Andes
Opis:
The Quaternary Andahua volcanic group in southern Peru has been studied by present author since 2003. The Andahua Group stretches out at intervals within an area, which is 110 km long and 110 km wide. Seven regions bearing centres of volcanic eruptions have been distinguished: the Valley of the Volcanoes, Antapuna, Rio Molloco, Laguna Parihuana, Rio Colca Valley, Jaran, and Huambo. The Valley of the Volcanoes, where the Andahua Group was identified for the first time, contains the biggest variety of volcanic landforms. The valley is covered by a nearly 60 km long, continuous cover of lava flows. 165 individual eruption centres of the Andahua Group were distinguished including apparent pyroclastic cones, 50–300 m high, and usually smaller lava domes and fissure vents. Domes, eruptive vents and lava craters greatly outnumber pyroclastic cones. Most commonly, lava flows start from lava domes or craters. Small domes are often aligned along their feeding fissures. Lava domes and pyroclastic cones of the Andahua Group are aligned mainly along N–S and WNW–ESE trending fault systems. Projection points of the analysed Andahua lavas on the TAS diagram concentrate in the lower part of the trachyandesite field, entering also the basaltic trachyandesite or trachyte/trachydacite fields.
Źródło:
Annales Societatis Geologorum Poloniae; 2011, 81, No 1; 1-19
0208-9068
Pojawia się w:
Annales Societatis Geologorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Necessary optimality conditions for a set valued fractional programming problem in terms of contingent epiderivatives
Autorzy:
Gadhi, A. N.
Idrissi, M. El.
Powiązania:
https://bibliotekanauki.pl/articles/205692.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
fractional optimization
multi-objective optimization
cone-convex mapping
optimality conditions
subdifferential
Opis:
In this paper, we are concerned with a multi-objective fractional extremal programming problem. Using the concept of subdifferential of cone-convex set valued mappings, introduced by Baier and Jahn (1999), together with the convex separation principle, we give necessary optimality conditions. An example illustrating the usefulness of our results is also provided.
Źródło:
Control and Cybernetics; 2018, 47, 2; 147-156
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Failure of gas turbine cone burner by carburization
Autorzy:
Ardy, H.
Putra, S.
Hardianto, T.
Powiązania:
https://bibliotekanauki.pl/articles/247322.pdf
Data publikacji:
2012
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
gas turbine
cone burner
Hastelloy-X
carburization
microstructure
carbide
thermodynamic simulation
Opis:
Gas turbine for a power plant has 72 pieces of cone burner in its combustion chamber. High-speed diesel oil (HSD) is use as fuel to produce 130 MW of power at 3,000 rpm. The maximum temperature at the turbine inlet is estimated about 1087 centigrade and at the outlet is between 400-540oC. Sixty percent of the cone burner failed repetitively at one side of the tip-end after 6,000 hours of service. The refurbished cone burner has to be replaced by a new one after 18,000 of service-hours. The cone burner material is cast Hastelloy-X (nickel based alloys). Metallurgical analyses by microstructural observation using optical and scanning electron microscopes, and energy dispersive spectroscope have been performed to observe the change in burner microstructure. Thermodynamics analysis has been performed to obtain temperature distribution around the failed section. Two failed cone burners have been examined; cone burner that has not been repaired, and that has been repaired twice. Thermodynamics analysis result shown that the temperature around the failed section is between 897 to 1087 centigrade. Microstructure of the good part, far from the failed section, consists of cast structure of austenite matrix and fine carbide particles. Severe carbide precipitation and growth was observed on the failed section even the nominal carbon content in material is only 0.10 percent (max.). Severe carbide precipitation occurred because of carbon ingress from the environment (carburization) which combines with carbide forming elements in material (chromium, molybdenum, and tungsten). As a result, the corrosion and oxidation resistance of material decreased significantly after long time exposure at high temperature that led to oxidation, thinning, and failure of the cone burner tip. Failure only localized on one side of the tip-edge, therefore refurbishment by welding and coating can be performed to extend the life cycle of cone burner. The current examination results shows that the replacement cycle is not only limited to 18,000 hours but can also be extended to 48,000 hours.
Źródło:
Journal of KONES; 2012, 19, 2; 9-16
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Selection strategies in projection methods for convex minimization problems
Autorzy:
Cegielski, Andrzej
Dylewski, Robert
Powiązania:
https://bibliotekanauki.pl/articles/729560.pdf
Data publikacji:
2002
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
convex minimization
projection method
long steps
residual selection
obtuse cone selection
Opis:
We propose new projection method for nonsmooth convex minimization problems. We present some method of subgradient selection, which is based on the so called residual selection model and is a generalization of the so called obtuse cone model. We also present numerical results for some test problems and compare these results with some other convex nonsmooth minimization methods. The numerical results show that the presented selection strategies ensure long steps and lead to an essential acceleration of the convergence of projection methods.
Źródło:
Discussiones Mathematicae, Differential Inclusions, Control and Optimization; 2002, 22, 1; 97-123
1509-9407
Pojawia się w:
Discussiones Mathematicae, Differential Inclusions, Control and Optimization
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Diagnostic value of cone beam computed tomography in complex and compound odontomas: a systematic review and open classification matrix
Autorzy:
Dubron, Kathia
Gurniak, Anna
Gurniak, Eliza
Politis, Constantinus
Olszewski, Raphael
Powiązania:
https://bibliotekanauki.pl/articles/2129084.pdf
Data publikacji:
2022-05-08
Wydawca:
Presses Universitaires de Louvain
Tematy:
cone beam computed tomography
CBCT
complex odontoma
compound odontoma
odontogenic tumours
Opis:
Objective: Firstly, this review aims to analyse the recent literature about three-dimensional (3D) diagnostic imaging in complex and compound odontomas and compare it to two-dimensional (2D) imaging. Panoramic radiographs help to evaluate the vertical position of odontomas, and occlusal radiographs are used to evaluate the proximity to adjacent teeth. However, cone beam computed tomography (CBCT) can offer volumetric images, and therefore, a more accurate three-dimensional analysis. Secondly, this research aims to construct an open classification matrix for complex and compound odontomas for dentomaxillofacial CBCT radiology protocols based on a systematic literature review. Material and methods: Two systematic literature searches were conducted in PubMed (Medline), on 2 February 2022 concerning classification systems, and on 5 February 2022 concerning CBCT images. Results: In total, these searches revealed 391 papers by reviewing the databases mentioned above. Six articles were selected for inclusion on classification of odontomas and 13 articles were found on CBCT imaging. Consequently, the construction of an open classification matrix for compound and complex odontomas for dentomaxillofacial CBCT radiology protocols was performed using these 19 articles. Conclusions: CBCT offers a more precise position and accurate diagnosis of complex and compound odontomas compared to 2D imaging. Consequently, it enhances the detailed view of the site (multiple or unique), location (intraosseous, partially or completely extragnathic), size, extension (bony expansion, thinning or perforation cortical bone), density and type (denticulo type, particle type, denticulo-particle type, denticulo-amorphous type, amorphous tissue), relationship (with the crown or root of the definitive tooth), adjacent teeth resorption (deciduous or definitive), adjacent teeth (retention or impaction), and distance with adjacent structures (inferior alveolar nerve, sinus maxillaris), as well as adequate surgical planning. Moreover, this research presents an open classification matrix for the most complete description of compound and complex odontomas when analysing CBCT imaging.  
Źródło:
Nemesis. Negative Effects in Medical Sciences Oral and Maxillofacial Surgery; 2022, 23, 1; 1-50
2593-3604
Pojawia się w:
Nemesis. Negative Effects in Medical Sciences Oral and Maxillofacial Surgery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Conic sections in axonometric projection
Przekroje stożka w rzucie aksonemetrycznym
Autorzy:
Banaszak, K.
Powiązania:
https://bibliotekanauki.pl/articles/119256.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Geometrii i Grafiki Inżynierskiej
Tematy:
cone
conic section
axonometric projection
collineation
stożek
sekcja stożkowa
rzut aksonometryczny
kolineacja
Opis:
This paper demonstrates the classification and examples of the conic sections done in axonometry without the help of collineation. Presently there are no collineation transformations in most descriptive geometry programs. Therefore these sections were made without collineation with the use of only common elements.
W niniejszym artykule przedstawiono klasyfikację oraz przykłady przekrojów stożka wykonane w aksonometrii bez użycia kolineacji. Obecnie w większości programów geometrii wykreślnej nie ma przekształceń kolineacyjnych. Dlatego przekroje te zostały zrealizowane bez kolineacji z wykorzystaniem tylko elementów wspólnych.
Źródło:
Journal Biuletyn of Polish Society for Geometry and Engineering Graphics; 2018, 31; 11-13
1644-9363
Pojawia się w:
Journal Biuletyn of Polish Society for Geometry and Engineering Graphics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ocena zmian parametrów wytrzymałościowych darni użytkowanej z różną intensywnością
Evaluation of changes of strength parameters for sod used with varying intensity
Autorzy:
Białczyk, W.
Czarnecki, J.
Cudzik, A.
Jamroży, K.
Powiązania:
https://bibliotekanauki.pl/articles/286890.pdf
Data publikacji:
2010
Wydawca:
Polskie Towarzystwo Inżynierii Rolniczej
Tematy:
darń
opór penetracji
stożek
stempel
zwięzłość
sod
cone
punch
resistance penetrations
compactness
Opis:
W pracy przedstawiono wyniki badań wybranych parametrów wytrzymałościowych darni użytkowanej z różną intensywnością. Badania przeprowadzono na darni naturalnie porastającej tereny zalewowe rzeki Odry we Wrocławiu. Parametrami analizowanymi w pracy były opór penetracji stożka i stempla, na podstawie których obliczono zwięzłość podłoża i naciski jednostkowe Zwiększenie intensywności użytkowania badanej darni powoduje jej zagęszczenie, co przejawia się wzrostem oporów penetracji stożka i zwięzłości podłoża. Największe przyrosty tych parametrów zaobserwowano w warstwie 0-0,02 m, natomiast największą wartość (4,71 MPa) zanotowano na głębokości 0,15 m dla darni użytkowanej z największą z analizowanych intensywności (tzw. 100% poziom użytkowania). Obliczone na podstawie oporów penetracji stempla wartości nacisków jednostkowych mieściły się w przedziale od 0,12 MPa do 2,65 MPa.
The work presents the results of tests of selected strength parameters for sod used with varying intensity. The tests were carried out for the sod which naturally overgrows the flooded areas of the Oder River in Wrocław. The parameters analysed in this work were cone penetration resistance and punch penetration resistance, on the basis of which the compactness of soil and unit pressures were calculated. The increase of intensity of use of the sod under analysis results in its compaction, which is reflected by an increase in cone penetration resistance and soil compaction. The biggest increases of those parameters were observed in the layer of 0-0.02 m, whereas the biggest value (4.71 MPa) was recorded at the depth of 0.15 m for the sod used with the highest analysed intensity (100% level of use). Unit pressure values calculated on the basis of punch penetration resistances ranged from 0.12 MPa to 2.65 MPa.
Źródło:
Inżynieria Rolnicza; 2010, R. 14, nr 4, 4; 15-22
1429-7264
Pojawia się w:
Inżynieria Rolnicza
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Soil mechanical resistance measurement by an unique multi-cone tips horizontal sensor
Autorzy:
Sharifi, A.
Mohsenimanesh, A.
Powiązania:
https://bibliotekanauki.pl/articles/25550.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
soil resistance
mechanical resistance
measurement
multi-cone tips horizontal sensor
horizontal penetrometer
Opis:
Amulti-tips horizontal sensor was developed and mounted horizontally on a tine face by shafts. The length of shafts was reduced from top to down the tine. The developed system was evaluated in the controlled soil bin laboratory conditions with clay loam soil and uniform soil moisture content. The experiment was designed with soil compaction at three levels of uniform and nonuniform soil compaction in completely randomized block design with four replications. Vertical standard penetrometer was also used to compare with horizontal sensor data at whole working depth of 0 to 400 mm. The results indicated that there is a correlation with R2 = 0.86 between soil cone penetrometer values and the horizontal soil mechanical resistance measurement system data. It can be concluded that the idea of reducing the length of the tips from top to down the tine face would give promising results.
Źródło:
International Agrophysics; 2012, 26, 1
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical three-dimensional model of airport terminal drainage system
Autorzy:
Strzelecki, M.
Powiązania:
https://bibliotekanauki.pl/articles/178280.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
numerical modeling
drainage system
depression cone
modelowanie numeryczne
system odwodnienia
lej depresyjny
Opis:
During the construction of an airport terminal it was found that as a result of the hydrostatic pressure of underground water the foundation plate of the building had dangerously shifted in the direction opposite to that of the gravitational forces. The only effective measure was to introduce a drainage system on the site. The complex geology of the area indicated that two independent drainage systems, i.e., a horizontal system in the Quaternary beds and a vertical system in the Tertiary water-bearing levels, were necessary. This paper presents numerical FEM calculations of the two drainage systems being part of the airport terminal drainaged esign. The computer simulation which was carried out took into consideration the actual effect of the drainage systems and their impact on the depression cone being formed in the two aquifers.
Źródło:
Studia Geotechnica et Mechanica; 2014, 36, 1; 111-119
0137-6365
2083-831X
Pojawia się w:
Studia Geotechnica et Mechanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Three-dimensional analysis of airway space and mandibular morphology in Pierre Robin sequence using cone beam computed tomography.
Autorzy:
Olszewski, Raphael
Dontaine, Timothée
Odri, Guillaume A
Zech, Francis
Bayet, Benedicte
Reychler, Hervé
Powiązania:
https://bibliotekanauki.pl/articles/2129267.pdf
Data publikacji:
2018-06-19
Wydawca:
Presses Universitaires de Louvain
Tematy:
Pierre Robin syndrome
cone beam computed tomography
airways
segmentation
cephalometry
three-dimensional
Opis:
Objectives: The Pierre Robin sequence (PRS) is defined by retromicrognathia, glossoptosis, and sleep apnea and can also be associated with cleft palate. Diagnosis, management and mandibular catch-up growth are still controversial issues in PRS patients. The aim of our retrospective study was to evaluate in three dimensions (3D) the airway space and mandibular morphology in PRS compared to a normal control group patients in the pre-orthodontic period of life. The null hypothesis was that we would not find a significant difference between the PRS and control group patients in oropharyngeal airway volume measurements. Material and methods: We analyzed 9 PRS patients (mean age: 8 years-old) who underwent cleft palate surgery in the first four months of life, performed by the same surgeon using the same technique. Cone-beam computed tomography (CBCT) was performed in these patients after local ethical committee approval. The control group consisted of 15 patients (mean age: 9 years-old) with CBCT already performed for other reasons. 3D Slicer was used in both groups for semi-automatic segmentation of the airway space. Two independent observers performed semi-automatic segmentations twice in each patient with a one- week interval between the two series of measurements. Airway volume was automatically measured using 3D Slicer. We also developed a 3D cephalometric analysis with Maxilim software in order to define a 3D mandibular morphology which consisted of 25 landmarks, 4 planes, and 23 distances. Two independent observers performed the 3D cephalometric analysis twice for each patient, with a one- week interval between the two series of measurements. Results: There was no significant difference in the intra- and inter-observer measurements between the PRS and control groups for airway space volume (p<0.05). However, there was a significant difference in the shape of the mandible between the PRS group and the control group (p<0.05). Conclusions: Vertical ramus width and mandibular global anteroposterior length were significantly lower in the PRS group. Mandibular hypoplasia could be found in PRS patients not only in the horizontal dimension. Nemesis relevance: the null hypothesis was confirmed. Moreover we failed to find exactly the same control group under 9 years-old due to radioprotection restrictions of application of cone beam CT in children.
Źródło:
Nemesis. Negative Effects in Medical Sciences Oral and Maxillofacial Surgery; 2018, 2, 1; 1-27
2593-3604
Pojawia się w:
Nemesis. Negative Effects in Medical Sciences Oral and Maxillofacial Surgery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Verification of strength resistance of sandy soil using small scale penetrometer tests
Autorzy:
Saleem, Hiba D.
Aldefae, Asad H.
Humaish, Wissam H.
Powiązania:
https://bibliotekanauki.pl/articles/35538646.pdf
Data publikacji:
2021
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
cone penetration
tip resistance
sleeve resistance
relative density
angle of internal friction
Opis:
This study focuses on utilizing cone penetrometer models to determine strength (resistance) of sandy soil and also assessment how the relative density and the angle of friction effects on the measured cone penetration resistance in sandy soil. Simple empirical equations are used also to determine the cone penetration resistance components such as the sleeve resistance and the tip resistance. Simple comparison is performed between the measured and calculated soil strength and well agreement is noticed between them.
Źródło:
Scientific Review Engineering and Environmental Sciences; 2021, 30, 2; 304-314
1732-9353
Pojawia się w:
Scientific Review Engineering and Environmental Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the interpretation of seismic cone penetration test (SCPT) results
Autorzy:
Bagińska, I.
Janecki, W.
Sobótka, M.
Powiązania:
https://bibliotekanauki.pl/articles/178824.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
badania sejsmiczne
fala sejsmiczna
test sejsmiczny
SCPTU
sondowanie CPTU
penetracja stożka
testy CPTU
seismic sounding SCPTU
cone penetration
cone penetration tests CPTu
seismic research
seismic wave
seismic tests
Opis:
The paper deals with the methodology of performing and interpretation of seismic cone penetration test (SCPT). This type of test is used to determine velocity of the seismic wave in the soil medium. This study is focused on shear wave. The wave is triggered on the ground surface by hitting an anvil with a sledgehammer. Then, vibrations induced at different depths are measured. Based on recorded measurements wave velocity (Vs) and thus also small strain shear modulus Gmax may be calculated. An interpretation of exemplary seismic test results is presented. Crossover and cross-correlation methods are discussed and another, more adequate one is featured and then applied in the interpretation example. Conditions for correct test performance and interpretation are discussed.
Źródło:
Studia Geotechnica et Mechanica; 2013, 35, 4; 3-11
0137-6365
2083-831X
Pojawia się w:
Studia Geotechnica et Mechanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A correction method of the wall-slip effect in a cone-plate rheometer
Autorzy:
Kiljański, Tomasz
Powiązania:
https://bibliotekanauki.pl/articles/185048.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
rheometry
wall-slip
cone-plate rheometer
reometria
poślizg na ścianie
reometr stożkowy
Opis:
The flow of the investigated fluid in a measuring system of a rheometer – a capillary or a slit between rotating parts – may be disturbed by anisotropic behavior of the fluid near the wall. This phenomenon, so-called wall slip, often takes place in concentrated suspensions and solutions of linear polymers and introduces experimental errors to measurement results. There are methods of correction of these errors in the case of capillary and coaxial cylinders measuring systems. In the cone and plate system the correction seems to be more difficult because the width of the gap between cone and plate changes along the radius and thus the influence of the wall slip on the shear stress varies along the radius in an unpredictable and complicated manner. This dependency of the shear stress on the distance from the axis underlies the presented method of correction of experimental results obtained in the cone and plate system. The method requires several series of measurements of shear stress vs. shear rate performed using one measuring set, at various degrees of filling the gap.
Źródło:
Chemical and Process Engineering; 2019, 40, 2; 201--206
0208-6425
2300-1925
Pojawia się w:
Chemical and Process Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of the Atterberg Limits of Eemian Gyttja on Samples With Different Composition
Autorzy:
Goławska, Katarzyna
Lechowicz, Zbigniew
Matusiewicz, Władysław
Sulewska, Maria Jolanta
Powiązania:
https://bibliotekanauki.pl/articles/949854.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
plastic limit
liquid limit
Eemian gyttja
Casagrande cup
cone penetrometer
statistical analysis
Opis:
The paper presents the results of laboratory tests of plastic limit wP and liquid limit wL of Eemian gyttja characterized by different organic matter content Iom and calcium carbonate content CaCO3. Comparison of the liquid limit wL determined with the use of the Casagrande apparatus wLC and a cone penetrometer with cones having apex angles of 60° wL60 and 30° wL30 is shown. Based on statistical analysis of the test results, single- and twofactor empirical relationships for evaluating the plastic limit wP and liquid limit wL of Eemian gyttja depending on the organic matter content Iom and/or calcium carbonate content CaCO3 are presented in this study.
Źródło:
Studia Geotechnica et Mechanica; 2020, 42, 2; 168-178
0137-6365
2083-831X
Pojawia się w:
Studia Geotechnica et Mechanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ zwięzłości gleby na wartości sił pionowych działających na narzędzia kultywacyjne
Influence of soil cone index on vertical forces acting on the cultivator tools
Autorzy:
Lejman, K.
Powiązania:
https://bibliotekanauki.pl/articles/292190.pdf
Data publikacji:
2008
Wydawca:
Polskie Towarzystwo Inżynierii Rolniczej
Tematy:
gleba
zwięzłość
skrawanie
siły pionowe
cutting
soil
vertical forces
soil cone index
Opis:
Przedstawiono wyniki badań sił pionowych działających na narzędzia o kształtach klina prostego i symetrycznego klina ukośnego skrawające glebę. Badania przeprowadzono w warunkach polowych w glinie piaszczystej o wilgotności 10,8-12,2%. Stwierdzono niemonotoniczny przebieg zmian sił pionowych przy wzroście zwięzłości gleby, który można opisać równaniem paraboli, niezależnie od kształtu narzędzia oraz prędkości i głębokości skrawania. Większe wartości sił zagłębiających oraz ich gradienty przy wzroście zwięzłości zaobserwowano przy większych głębokościach i prędkościach skrawania. Większe wartości i intensywności zmian tych sił stwierdzono również przy skrawaniu narzędziami o kształcie symetrycznego klina ukośnego w porównaniu z klinem prostym.
Results of investigations on vertical soil forces acting on wedge shape and skew wedge shape soil cutting tools are presented. Research was conducted in field conditions in sandy loam soil of 10,8 to 12,2% moisture. It has been found that course of vertical forces as a soil cone index function is non-monotonic. That course can be described by parabola (quadratic) equation independent of tool shape, cutting depth and cutting speed. Higher values of sink forces and higher their gradients as a result of cone index increase were observed in higher cutting depth and speed. It was found that higher values and higher change intensity of sink forces occur for skew wedge shape tools in comparison with wedge-shape tools.
Źródło:
Inżynieria Rolnicza; 2008, R. 12, nr 5(103), 5(103); 51-57
1429-7264
Pojawia się w:
Inżynieria Rolnicza
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
CFD analysis of the impact of a cone opening angle parameter on the hydrodynamic lubrication of the conical slide bearing
Autorzy:
Czaban, A.
Powiązania:
https://bibliotekanauki.pl/articles/242697.pdf
Data publikacji:
2016
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
hydrodynamic lubrication
slide bearing
conical bearing
cone opening angle
CFD
pressure distribution
Opis:
The height of the oil lubrication gap is the primary quantity that determines in simulations the operating parameters of a hydrodynamic slide bearing. It is influenced by multiple effects, such as vibrations during operation, varying load, misalignment between the shaft axis and the axis of the bearing sleeve, the roughness of the journal and sleeve surfaces, change in the viscosity value of lubricating oil caused by changes in temperature, pressure, shear rate or by oil ageing, wear of journal and sleeve surfaces etc. It is important to take into account such effects considering hydrodynamic lubrication simulations and design of the slide bearings. The one of the factors influencing the height of the oil lubrication gap of the conical slide bearing is the difference between the opening angle of the cone of bearing shaft and opening angle of the cone of bearing sleeve. The aim of this work is to investigate the impact of the difference between the values of these angles on the hydrodynamic lubrication of the conical slide bearing. The commercial CFD software Ansys Fluent, from the Ansys Workbench 2 platform, was used to determine the hydrodynamic pressure distributions, load carrying capacities and friction torques of the simulated bearings. It was assumed, that the bearings operate in a steady state conditions, the flow in the bearing lubrication gap is laminar and non-isothermal, there is no misalignment between the axis of bearing journal and axis of bearing sleeve, the surfaces of the journal and sleeve are smooth and lubricating oil acts as a liquid described by the Ostwald-de Waele power law model.
Źródło:
Journal of KONES; 2016, 23, 3; 71-77
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multiple positive solutions of a nonlinear fourth order periodic boundary value problem
Autorzy:
Kong, Lingbin
Jiang, Daqing
Powiązania:
https://bibliotekanauki.pl/articles/1294291.pdf
Data publikacji:
1998
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
nonlinear periodic boundary value problem
multiple positive solutions
cone
fixed point index
Opis:
The fourth order periodic boundary value problem $u^{(4)} - m⁴u + F(t,u) = 0$, 0 < t < 2π, with $u^{(i)}(0) = u^{(i)}(2π)$, i = 0,1,2,3, is studied by using the fixed point index of mappings in cones, where F is a nonnegative continuous function and 0 < m < 1. Under suitable conditions on F, it is proved that the problem has at least two positive solutions if m ∈ (0,M), where M is the smallest positive root of the equation tan mπ = -tanh mπ, which takes the value 0.7528094 with an error of $±10^{-7}$.
Źródło:
Annales Polonici Mathematici; 1998, 69, 3; 265-270
0066-2216
Pojawia się w:
Annales Polonici Mathematici
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Novel Design of a Counter-flow Vortex Tube by Suitable Automation at Hot and Cold Ends
Autorzy:
Macha, D.
Renganathan, M.
Arockiadoss, A. S.
Powiązania:
https://bibliotekanauki.pl/articles/950970.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
counter-flow vortex tube
temperature separation
automation
orifice area controller
blockage cone
Opis:
Separating the cold and hot air by using the principles of the vortex tube can be applied to industrial applications such as cooling equipment in CNC machines, heating processes, cooling suits, refrigerators etc. The vortex tube is well-suited for these applications because it is simple with no moving parts, quiet, compact, and does not use refrigerants. This study is devoted to the development and testing of an automated vortex tube that can meet the demands of time variant applications such as spot cooling during welding. This is achieved with the help of a moving blockage cone at hot end and orifice area controller at cold end. The performance of a counter-flow vortex tube is validated by comparing the results obtained from the present work with the literature.
Źródło:
Journal of Automation Mobile Robotics and Intelligent Systems; 2016, 10, 3; 34-37
1897-8649
2080-2145
Pojawia się w:
Journal of Automation Mobile Robotics and Intelligent Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identyfikacja lokalnych gruntów organicznych na podstawie wyników badań sondą statyczną CPT
Identification of local organic soils based on cone penetration test results
Autorzy:
Straż, G.
Powiązania:
https://bibliotekanauki.pl/articles/390164.pdf
Data publikacji:
2014
Wydawca:
Politechnika Lubelska. Wydawnictwo Politechniki Lubelskiej
Tematy:
grunty organiczne
torf
sonda statyczna CPT
organic soils
peat
cone penetration CPT
Opis:
W pracy zaprezentowano wyniki prób identyfikacji gruntów organicznych na podstawie rezultatów badań przeprowadzonych w warunkach in situ za pomocą sondy statycznej CPT. Przeanalizowano wyniki wybranych 439 sondowań, które odzwierciedlały zachowanie lokalnych gruntów organicznych zawierających od 6,3 do 17,4% części organicznych. Postawę rozpoznania gruntów stanowiły wartości pomierzone oporu pod stożkiem (qc) i na pobocznicy walcowej końcówki sondy (fs) oraz obliczony na ich podstawie współczynnik tarcia (Rf). Do identyfikacji gruntów organicznych wykorzystano wybrane kryteria zaprezentowane między innymi przez: Mayne’a [1], Marra [2,3,4], Bergmanna [2], Schmertmanna [2], Capanellę oraz Robertsona [3,4,5,6] i Młynarka [3,7]. Przeprowadzona analiza wykazała, że identyfikacja rodzajów gruntów organicznych w aspekcie współczesnej klasyfikacji normowej [8,9] z uwzględnieniem przyjętych kryteriów jest niejednoznaczna i nie pozwala na ich dokładne rozpoznanie na podstawie sondowań CPT.
This paper presents the results of attempts to identify organic soils on the basis of test results performed under in situ conditions by cone penetration testing (CPT). The results of 439 selected tests were analysed which reflected the behaviour of local organic soils of organic matter ranging from 6,3 to 17,4%. Crucial to soil investigation were values measured of cone resistance (qc) and sleeve friction (fs) and the friction ratio (Rf) estimated according to those values. To identify organic soils, selected criteria were used, proposed among others by: Mayne, Marr, Bergmann, Schmertmann, Capanella and Robertson [2,5]. An analysis showed that an identification of organic soil types in terms of the present classification of standards, in view of the criteria used, is ambiguous and does not allow to identify them precisely by CPT.
Źródło:
Budownictwo i Architektura; 2014, 13, 2; 49-56
1899-0665
Pojawia się w:
Budownictwo i Architektura
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Second-order optimality conditions in nonsmooth vector optimization
Autorzy:
Yadav, Priyanka
Powiązania:
https://bibliotekanauki.pl/articles/31342762.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
vector optimization
cones
nonsmooth second-order cone-convexity
second-order optimality
duality
Opis:
In this paper, we introduce new classes of nonsmooth second-order cone-convex functions and respective generalizations in terms of first and second-order directional derivative. These classes encapsulate several already existing classes of cone-convex functions and their weaker variants. Second-order KKT type sufficient optimality conditions and duality results for a nonsmooth vector optimization problem are proved using these functions. The results have been supported by examples.
Źródło:
Control and Cybernetics; 2023, 52, 1; 35-51
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zastosowanie metody georadarowej do określania położenia swobodnego zwierciadła wód podziemnych w trakcie próbnego pompowania
On application of ground penetriation radar method in defining position of the free aquifer during of the test pumping
Autorzy:
Gańko, M.
Mieszkowski, R.
Gańko, A.
Powiązania:
https://bibliotekanauki.pl/articles/2075387.pdf
Data publikacji:
2015
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
wody podziemne
piezometr
lej depresji
pompowanie
sondowanie statyczne
CPT
metoda georadarowa
GPR
free aquifer
piezometer
depression cone
pumping well with observation weels
cone penetration test
ground penetrating radar
Opis:
In this paper were verify the possibilities of use the ground penetrating radar method to defining the range of depression cone during pumping test the first free aquifer. On the experimental area there were: pumping well with observation weels, geotechnical weels and cone penetration tests. This made possible the credible interpretation of the results with GPR investigations. GPR measurements were executed before pumping and after stabilizing the depression. On the echograms there were clearly appeared the free aquifer before and during of the pumping. On the basis of geophisical investigations it was successful to interpret the position of free aquifer and the range of depression cone.
Źródło:
Przegląd Geologiczny; 2015, 63, 10/1; 721--726
0033-2151
Pojawia się w:
Przegląd Geologiczny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electrospinning of polymeric fibres: an unconventional view on the influence of surface tension on fibre diameter
Elektroprzędzenie włókien polimerowych – niekonwencjonalny pogląd na wpływ naprężenia powierzchniowego na średnice włókien
Autorzy:
Araújo, E. S.
Nascimento, M. L. F.
de Oliveira, H. P.
Powiązania:
https://bibliotekanauki.pl/articles/232610.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
electrospinning
polymeric fibres
Taylor-cone
surfactant
surface tension
elektroprzędzenie
włókna polimerowe
napięcie powierzchniowe
Opis:
The production of regular and bead-free electrospun polymeric fibres requires an adequate combination of different parameters applied in the experimental setup viz. voltage for electrodeposition, viscosity of the solution, density of the polymeric support, the distance between electrodes and the geometry of the spinneret. Determination of the physical balance of forces on the droplet during fibre production was explored and provides relevant theoretical information about the surface tension and radius of polymeric fibres. Based on these predictions, we prepared polymeric electropun fibres of poly (vinyl alcohol), poly (vinyl pyrrolidone) and Eudragit® L100 in order to analyse non-conventional physical properties of experimental systems such as droplet stiffness and their influence on the diameter of resulting fibres.
Produkcja za pomocą elektroprzędzenia regularnych włókien polimerowych, wolnych od zgrubień wymaga dobrania odpowiedniej kombinacji różnych parametrów stanowiska przędącego takich jak np. napięcie między elektrodami, lepkość roztworu przędzalniczego, gęstość, odległość pomiędzy elektrodami i geometria układu przędącego. Badano fizycznie określony balans sił działający na wypychaną kroplę roztworu podczas tworzenia włókna. Badania eksperymentalne dostarczyły odpowiednich teoretycznych informacji o naprężeniu powierzchniowym i średnicy tworzonych włókien polimerowych. W oparciu o uzyskane informacje przygotowano elektroprzędzenie włókien z alkoholu poliwinylowego, alkoholu poliwinylopirolidowego i preparatu Eudragit® L100. Następnie na podstawie wcześniejszych rozważań i uzyskanych wyników eksperymentalnych przeprowadzono analizę wpływu poszczególnych czynników na średnicę otrzymywanych włókien.
Źródło:
Fibres & Textiles in Eastern Europe; 2016, 1 (115); 22-29
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zmiany warunków wodnych wskutek działalności górniczej w rejonie Gałęzice–Bolechowice–Borków w Górach Świętokrzyskich
Changes of hydrologic conditions due to mining operations in the Gałęzice-Bolechowice-Borków region, Holy Cross Mountains
Autorzy:
Prażak, Jan
Bruczyńska, Joanna
Kaczor-Kurzawa, Dorota
Młyńczak, Tomnasz
Powiązania:
https://bibliotekanauki.pl/articles/2076059.pdf
Data publikacji:
2020
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
odwadnianie kopalni
lej depresyjny
Góry Świętokrzyskie
mine dewatering
depression cone
Holy Cross Mountains
Opis:
In the Gałęzice-Bolechowice-Borków region, located in the Holy Cross Mountains, several limestone and dolomite quarries are currently in operation. Deep drainage of these quarries caused the formation of a large regional depression cone that affected numerous groundwater intakes, including those supplying potable water for communes, and a large intake in the Dyminy quarter of Kielce. The range of the depression cone will increase in the future, both vertically and laterally, due to expanding extraction of industrial stones from continuously deepened mining levels. Prognoses of further changes of hydrologic conditions in the region and their impact on admissible volumes of groundwater resources available in particular intakes are calculated using the stationary mathematical model.
Źródło:
Przegląd Geologiczny; 2020, 68, 4; 233--236
0033-2151
Pojawia się w:
Przegląd Geologiczny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pore pressure profiling in Siercza landslide colluvium in the Carpathian flysch using a Cone Penetration Test (CPTU)
Autorzy:
Stanisz, Jacek
Pilecki, Zenon
Powiązania:
https://bibliotekanauki.pl/articles/2058632.pdf
Data publikacji:
2019
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
cone penetration test
pore pressure
inclinometer displacement
landslide
colluvium
slip surface
Carpathian flysch
Opis:
This study identifies zones with significant changes in pore water pressure influenced by landslide processes. Measurements were taken in the near-surface strata of the Carpathian flysch, in colluvium of the Siercza landslide, near Kraków. Measurement of pore water pressure in flysch deposits is complicated due to the strongly heterogeneous properties of the medium and by variable water conditions, which are strongly influenced by rainfall intensity. Pore pressure profiling was performed in six series using a cone penetration test with a NOVA Acoustic cone. The tests were carried out in the colluvium to a depth of ~6.0 m under varying water conditions. The cone pore pressure results were compared to results of inclinometer measurements in the research area. Five zones with significant differences in pore pressure have been identified. Changes in both cone pore pressure and inclinometer displacement are evident at a depth range from 1.5 to 2.5 m. Two slip surfaces are likely present in this section. Such information can be used in engineering practice for more reliable assessment of slope stability in the Carpathian flysch.
Źródło:
Geological Quarterly; 2019, 63, 4; 839--848
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of the initiating ability of conically shaped charges
Badanie zdolności inicjującej detonatorów o kształcie stożkowym
Autorzy:
Zakusylo, R.
Powiązania:
https://bibliotekanauki.pl/articles/92775.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
charge
cone
initiating ability
detonation wave
detonator pośredni
stożek
zdolność inicjowania
fala detonacyjna
Opis:
The influence of the shape of donor charges on their initiating ability is investigated. The composition of these charges, based on chopped ammonium nitrate(V) and nitromethane in the ratio of 95-80% to 5-20%, was investigated experimentally. The composition has a detonation velocity of 3000-3300 m/s and a critical diameter of 5-9 mm. It is established that the use of the truncated conical form of donor charges with a truncated taper angle of 15°, 30°and 45°, contributes to the concentration of the detonation wave along its axis. The use in these charges of a composition based on ammonium nitrate(V) and nitromethane with low energy characteristics will increase the quality of blasting operations. For reasons of safety, it is proposed that mixing is carried out on-site.
Zbadano wpływ postaci detonatora pośredniego na jego zdolności inicjujące. Mieszanina użyta w badanych stożkowych detonatorach pośrednich zawierała kawałki azotanu(V) amonu oraz nitrometan w proporcji 95-80% do 5-20%. Prędkość detonacji tej mieszaniny wynosiła 3000-3300 m/s, a średnica krytyczna wynosiła 5-9 mm. Stwierdzono, że w przypadku detonatorów pośrednich o kącie stożka 15°, 30° i 45°, ze stożkiem ściętym, obserwuje się skupienie fali detonacyjnej wzdłuż ich osi. Zastosowanie detonatorów pośrednich z mieszaniną azotanu(V) amonu oraz nitrometanu pozwala na otrzymanie wyrobów o niskiej energii wybuchu, co powinno zwiększyć wydajność prac strzałowych. Ze względów bezpieczeństwa, proponuje się wytwarzanie, omawianych w pracy, wyrobów w miejscu prowadzenia prac strzałowych.
Źródło:
Materiały Wysokoenergetyczne; 2018, T. 10; 69-76
2083-0165
Pojawia się w:
Materiały Wysokoenergetyczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Virtual surgical planning and cone beam computed tomography in reconstruction of head and neck tumors – pilot study
Autorzy:
Krakowczyk, Łukasz
Piotrowska-Seweryn, Agnieszka
Szymczyk, Cezary
Wierzgoń, Janusz
Oleś, Krzysztof
Ulczok, Rafał
Donocik, Karolina
Dowgierd, Krzysztof
Maciejewski, Adam
Powiązania:
https://bibliotekanauki.pl/articles/1397270.pdf
Data publikacji:
2021
Wydawca:
Index Copernicus International
Tematy:
cone beam computed tomography
free flap
head and neck
reconstruction
virtual surgical planning
Opis:
Introduction: The aim of the study was to prove that a combination of visual surgical planning (VSP) and cone beam computed tomography (CBCT) is an optimal technique in fibular free flap reconstructions after complex tumor resections in the head and neck region and that it leads to better functional and aesthetic outcomes. Material and method: Six patients (3 females, 3 males) with head and neck tumors were included in the study. The region concerned midface in 2 cases and mandible in 4 patients. On the basis of computed tomography of the head, fibular free flap (FFF) reconstruction was planned with the VSP technique. The 3D-printed models were prepared. At the beginning of the operation and a few minutes after the reconstruction, an xCAT CBCT by XORAN was performed. Minor corrections of the angles of the reconstructed bony parts were made where needed. The time of the operation was assessed for each case. Functional and cosmetic results were evaluated in a 1-year follow-up. Results: The mean time of operation was 6 hours and 48 minutes, which was approximately 1hour and 40 minutes less than standard reconstructive surgery. Functional recovery was achieved in all patients. Aesthetic result was unsatisfactory for 2 patients due to insufficient soft tissue masses of FFF. Conclusions: The authors claim that intraoperative CBCT imaging, regardless of the cost, improves the accuracy of aesthetic outcome of reconstructive surgeries based on VSP, especially in the region of the midface and the mandible. Further studies on a higher number of subjects are required.
Źródło:
Polish Journal of Otolaryngology; 2021, 75, 2; 28-33
0030-6657
2300-8423
Pojawia się w:
Polish Journal of Otolaryngology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
SEM studies on sporangia and pollen morphology of Gingko biloba cultivars
Autorzy:
Klimko, M.
Bykowska, J.
Korszun, S.
Powiązania:
https://bibliotekanauki.pl/articles/790563.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Przyrodniczy w Poznaniu
Tematy:
SEM analysis
sporangia
pollen morphology
pollen grain
Ginkgo biloba
male
cone
plant cultivar
Opis:
The present study was conducted to illustrate the micromorphology of mature sporangia and pollen grains of four Ginkgo biloba cultivars: ‘Horizontalis’, ‘Lasiocarpa’, ‘Pragensis’ and ‘Tubifolia’ and is a continuation of earlier investigations on this subject. The sporophylls bear typically two pendulous sporangia, whereas three were found in one cultivar. The sporangia varied in shape from oval, elliptical elongate to boat-shaped and dehisced along a longitudinal slit. The sporangial walls are multilayered. The sculpture of the sporangium is rugose covered with wax crystals (tubules) and the endothecium shows clearly visible fibrous thickening on the wall. The pollen grains are monosulcate, the non-apertural surface is irregularly ridged (striate) or rugulate, with perforations and the germinal aperture (furrow) is covered with verrucae. The current study did not differentiate significantly four cultivars based on sporangia and pollen morphology. The micromorphological traits may be useful for identification and classification of fragments of fossil sporangia and pollen grains.
Źródło:
Steciana; 2016, 20, 3
1689-653X
Pojawia się w:
Steciana
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical study of a cone mill for emulsion preparation: Hydrodynamics and population balance modelling
Autorzy:
Lupieri, Guido
Bagkeris, Ioannis
Janssen, Jo J.M.
Kowalski, Adam J.
Powiązania:
https://bibliotekanauki.pl/articles/2086806.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
cone mill
CFD
hydrodynamics
population balance model
młyn stożkowy
hydrodynamika
model bilansu populacji
Opis:
The work concerns numerical simulations of a cone mill used for emulsion preparation. Hydrodynamics, power consumption and population balance are investigated for various operating conditions at high phase volume emulsions and for different rheologies. Cone mills are usually simplified as a simple gap between rotor and stator but by increasing the complexity of the geometry till it represents the commercial device identifies a wealth of additional features such as recirculation zones above (which enhance breakage) and below (which allow for coalescence) the rotor-stator gap. Two separate sets of population balance modelling constants are required to capture all the experiment results – even with the most complex geometries. Some suggestions are made for improvements and further studies will consider other rotor-stator devices.
Źródło:
Chemical and Process Engineering; 2021, 42, 4; 295--320
0208-6425
2300-1925
Pojawia się w:
Chemical and Process Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sensitivity analysis for state constrained optimal control problems
Autorzy:
Malanowski, K.
Powiązania:
https://bibliotekanauki.pl/articles/206110.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
sensitivity analysis
cone-constrained optimization problems
nonlinear optimal control
first order state constraints
Opis:
A sensitivity result for cone-constrained optimization problem in abstract Hilbert spaces is obtained, using a slight modification of Haraux's theorem on differentiability of the metric projection onto polyhedric sets. This result is applied to sensitivity analysis for nonlinear optimal control problems subject to first order state constraints.
Źródło:
Control and Cybernetics; 2011, 40, 4; 1043-1058
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simple solution of time travel problems
Autorzy:
Majka, M.
Hasan, Md. K.
Majka, T. M.
Powiązania:
https://bibliotekanauki.pl/articles/134901.pdf
Data publikacji:
2015
Wydawca:
Tomasz Mariusz Majka
Tematy:
time travel
wormhole hypothesis
Minkowski light cone
event causality
grandfather paradox
philosophical perspective
Opis:
The most desired journey by human being is definitely travel through time. For centuries, people dream about time travel, to be able to go back and fix mistakes of the past. But there are many complications associated with time travel - starting from technological aspects ending with the philosophical paradoxes. Yet, is time travel possible from the technological and philosophical perspectives? How to solve the paradoxes of time travel? It should be noted that realisation of time travel leads not only to the discovery of the nature of time, but also to the understanding how much is unknown about it. In this paper, probability of time travel and solutions to paradoxes will be critically analysed from philosophical perspectives.
Źródło:
Journal of Education and Technical Sciences; 2015, 2, 1; 34-37
2300-7419
2392-036X
Pojawia się w:
Journal of Education and Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Przyrosty zwięzłości gleb gliniastych zagęszczanych kołami ciągnika
Cone index increments of the clay soils compacted by tractor wheels
Autorzy:
Owsiak, Z.
Lejman, K.
Powiązania:
https://bibliotekanauki.pl/articles/286414.pdf
Data publikacji:
2006
Wydawca:
Polskie Towarzystwo Inżynierii Rolniczej
Tematy:
gleba
koło ciągnika
ugniatanie
zwięzłość
soil
tractor wheel
soil packing
cone index increments
Opis:
Przedstawiono wyniki badań przyrostów zwięzłości gleby zagęszczanej kołami ciągnika. Badania prowadzono w warunkach polowych w glebach gliniastej lekkiej i gliniastej ciężkiej w tym samym terminie agrotechnicznym. Stwierdzono, że przyrosty zwięzłości maleją liniowo wraz ze wzrostem odległości od osi koleiny i rosną wraz z głębokością pomiaru. Nie stwierdzono istotnego wpływu gatunku gleby na wartości średnich przyrostów zwięzłości w warstwie ornej gleby.
Results of investigations on distribution of cone index increments in the soil compacted by tractor wheels are presented. Research was conducted in field conditions in sandy loam and clay soils. It has been found that cone index increments decrease linearly with the distance between the measuring point and the symmetry axis of wheel track and increase with measuring depth. Type of soil doesn't influence on the observed cone index increments.
Źródło:
Inżynieria Rolnicza; 2006, R. 10, nr 4(79), 4(79); 37-44
1429-7264
Pojawia się w:
Inżynieria Rolnicza
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Calculation of calibration force of gear teeth by expanding with cone-shaped punch
Raschet usilija kalibrovki zubev shesterni razdachejj konicheskim puansonom
Autorzy:
Morneva, M.
Gavrysh, V.
Kuzmenko, N.
Powiązania:
https://bibliotekanauki.pl/articles/792204.pdf
Data publikacji:
2012
Wydawca:
Komisja Motoryzacji i Energetyki Rolnictwa
Tematy:
gear wheel
calibration
calculation
tension
cone-shaped punch
gear tooth
radial flow
metal
Opis:
The technology of producing gear-wheels by stamping with division of operations of rough and finishing forming is examined. A solution for stress and deforming force of calibration of gear teeth in a stamp with cone-shaped punch is found.
Рассматривается технология изготовления зубчатых колес штамповкой с разделением операций предварительного и окончательного формообразования. Получено решение для напряжений и деформирующего усилия операции калибровки зубьев шестерни в штампе коническим пуансоном.
Źródło:
Teka Komisji Motoryzacji i Energetyki Rolnictwa; 2012, 12, 3
1641-7739
Pojawia się w:
Teka Komisji Motoryzacji i Energetyki Rolnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On weak sharp minima for a special class of nonsmooth functions
Autorzy:
Studniarski, Marcin
Powiązania:
https://bibliotekanauki.pl/articles/729367.pdf
Data publikacji:
2000
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
weak sharp minimizer of order one
maximum function
strictly differentiable function
normal cone
Opis:
We present a characterization of weak sharp local minimizers of order one for a function f: ℝⁿ → ℝ defined by $f(x): = max{f_i(x)| i = 1,...,p}$, where the functions $f_i$ are strictly differentiable. It is given in terms of the gradients of $f_i$ and the Mordukhovich normal cone to a given set on which f is constant. Then we apply this result to a smooth nonlinear programming problem with constraints.
Źródło:
Discussiones Mathematicae, Differential Inclusions, Control and Optimization; 2000, 20, 2; 195-207
1509-9407
Pojawia się w:
Discussiones Mathematicae, Differential Inclusions, Control and Optimization
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Cone Size on the Bonding Strength of Bimetallic Composite Pipes Produced by Drawing Approach
Autorzy:
Zheng, M.
Zhao, T.
Gao, H.
Teng, H.
Hu, J.
Powiązania:
https://bibliotekanauki.pl/articles/352274.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
bi-metallic composite pipe
drawing approach
cone size
interfacial bonding strength
ideal elastoplastic
Opis:
The effect of cone size on interfacial bonding strength of bimetallic composite pipe manufactured by drawing approach is studied on base of the plane strain assumption and ideal elastic-plastic model, a simple expression for the effect of cone size on the bonding strength of bimetallic composite pipes is proposed. The agreement of the predicted results with the experimental results shows the reliability.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 1; 451-456
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hereditarily weakly confluent induced mappings are homeomorphisms
Autorzy:
Charatonik, Janusz
Charatonik, Włodzimierz
Powiązania:
https://bibliotekanauki.pl/articles/966016.pdf
Data publikacji:
1998
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
atriodic
semi-confluent
hereditary
confluent
atomic
homeomorphism
cone
weakly confluent
monotone
hyperspace
joining
continuum
Opis:
For a given mapping f between continua we consider the induced mappings between the corresponding hyperspaces of closed subsets or of subcontinua. It is shown that if either of the two induced mappings is hereditarily weakly confluent (or hereditarily confluent, or hereditarily monotone, or atomic), then f is a homeomorphism, and consequently so are both the induced mappings. Similar results are obtained for mappings between cones over the domain and over the range continua.
Źródło:
Colloquium Mathematicum; 1998, 75, 2; 195-203
0010-1354
Pojawia się w:
Colloquium Mathematicum
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analytic-numerical model of a convective boundary layer and heat transfer on a horizontal cone
Autorzy:
Leble, S.
Pelc, W.
Powiązania:
https://bibliotekanauki.pl/articles/1943220.pdf
Data publikacji:
2009
Wydawca:
Politechnika Gdańska
Tematy:
natural convection
Fourier-Kirchhoff equations
boundary layer equation
isothermal cone
matching of Frobenius expansions
Opis:
An approximate analytical solution of a two dimensional problem for stationary Navier-Stokes, continuity and Fourier-Kirchhoff equations describing a free convective heat transfer from an isothermal cone is presented. The problem formulation is based on assumptions typical for natural convection: non-compressibility and the Boussinesq approximation. The solution is based on Frobenius expansions at the vicinities of two points: the initial point and the singular point of the boundary layer equation. Numerical matching of the expansions and Nusselt number evaluations are traced.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2009, 13, 1-2; 133-144
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ocena możliwości stosowania metody jednopunktowej z wykorzystaniem penetrometru stożkowego w celu oznaczenia granicy płynności
Determination of liquid limits by the fall cone one point method
Autorzy:
Jaśkiewicz, K.
Wszędyrówny-Nast, M.
Powiązania:
https://bibliotekanauki.pl/articles/2075721.pdf
Data publikacji:
2017
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
granica płynności
paramety stożków stosowanych
testy laboratoryjne
liquid limit
fall cone test
laboratory tests
Opis:
Atterberg Limits are main parameters characterizing the properties of cohesive soils. The cone penetrometer is a standard apparatus for testing of liquid limits according to PN-B-04481:1988 and PKN-CENISO/TS17892-12. The test allows to obtain the relationship between moisture of soil paste and cone depth penetration. The result is determined by interpolation between at least four points. The paper presents feasibility study of determination of liquid limits by the fall cone one point method. The publication contains a comparison of values obtained with the one point method by Sherwood and Ryley in 1970., Nagraj and Jayadeva in 1981 and by Leroueil and Lebihan in 1996 with the fall cone method presented in PKN-CEN.
Źródło:
Przegląd Geologiczny; 2017, 65, 10/2; 737--742
0033-2151
Pojawia się w:
Przegląd Geologiczny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improving seed germination and seedling emergence in the Juniperus communis
Autorzy:
Tylkowski, T
Powiązania:
https://bibliotekanauki.pl/articles/41555.pdf
Data publikacji:
2009
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
juniper
Juniperus communis
seedling emergence
seed germination
seed cone
propagation
individual variability
natural regeneration
Opis:
The observed juniper decline, lack of natural regeneration, and disappearance of numerous populations of the common juniper in Poland, were the major reasons for initiation of research on its sexual propagation and seedling production. This study shows that seed dormancy in this species is broken by warm-cold stratification at 15°C/3°C, for 14+12 weeks, respectively. Seed drying for 72 h at room temperature in the middle of the warm phase (i.e. after 4–8 weeks of stratification at 15°C) and the following cold stratification at 3°C, cause a significant increase in seed germination capacity at cyclically alternating temperatures of 3~15°C, and in seedling emergence in growing trays (67 cells each) in a greenhouse. However, seedling emergence was over 2-fold to 4-fold lower in an open nursery than in the greenhouse. After sowing in the nursery, secondary dormancy was probably induced, because some seeds germinated in the following year. Some very young, 2-year-old seedlings started to produce male or rarely female cones. This study also showed that soil conditions of mother plants can influence the pattern of seed germination and seed ling emergence.
Źródło:
Dendrobiology; 2009, 61; 47-53
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Radial solutions for nonlinear elliptic equation with nonlinear nonlocal boundary conditions
Autorzy:
Kossowski, Igor
Powiązania:
https://bibliotekanauki.pl/articles/29519502.pdf
Data publikacji:
2023
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
nonlocal boundary value problem
radial solution
elliptic equation
Krasnoselskii's fixed point theorem in cone
Opis:
In this article, we prove existence of radial solutions for a nonlinear elliptic equation with nonlinear nonlocal boundary conditions. Our method is based on some fixed point theorem in a cone.
Źródło:
Opuscula Mathematica; 2023, 43, 5; 675-687
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of polluted environment on the female and male strobili bearing of European Scots pine provenances
Autorzy:
Chalupka, W.
Rozkowski, R.
Powiązania:
https://bibliotekanauki.pl/articles/41518.pdf
Data publikacji:
2000
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
Scotch pine
pollen
male flower
polluted environment
provenance
Pinus sylvestris
male
female cone
female
Opis:
Studies on female and male strobili production as well as on pollen production and viability were performed at a polluted (Luboń) and a control (Kórnik) sites. Female strobili bearing per tree and total length of male strobili produced per tree were significantly higher in Luboń than in Kórnik and the stand density and tree crown exposition to sunlight were likely responsible for that result. Percentage of pollen germination was not affected by any variables studied. Neither provenance nor provenance x site interactions were found.
Źródło:
Dendrobiology; 2000, 45
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative analysis of some soil compaction measurement techniques
Autorzy:
Ronai, D.
Shmulevich, I.
Powiązania:
https://bibliotekanauki.pl/articles/26270.pdf
Data publikacji:
1995
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
cone index
soil mechanics
measurement technique
needle penetration
energy consumption
plant growth
soil compaction
Źródło:
International Agrophysics; 1995, 09, 3
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Points mapping in the central-reflexive projection on conical surface
Odwzorowanie punktu w rzucie środkowo-refleksyjnym na powierzchni bocznej stożka
Autorzy:
Ułamek, K
Powiązania:
https://bibliotekanauki.pl/articles/119099.pdf
Data publikacji:
2009
Wydawca:
Polskie Towarzystwo Geometrii i Grafiki Inżynierskiej
Tematy:
cone
mirror reflection
curved mirror
spatial curve
stożek
odbicie zwierciadlane
zwierciadło zakrzywione
krzywa przestrzenna
Opis:
The paper suggests the Solution to the problem of seeking the mirror reflection of any point from the flank surface of a cone in relation to the eye point, which is the centre of projection, on the grounds of descriptive geometry. To accomplish this goal a couple of spatial curves is used, whose point of interception is the sought point.
Celem tej pracy było zbudowanie modelu geometrycznego, który pozwoliłby zrealizować odwzorowanie odbicia dowolnego punktu Ρ znajdującego się w przestrzeni rzutowej S³ w zwierciadle utworzonym na powierzchni bocznej stożka γ2. Należy znaleźć taki punkt R na powierzchni γ2, aby promień wychodzący z punktu Ρ po odbiciu w R przebiegł przez środek rzutowania Ε (przez oko). Odnalezienie punktu odbicia w sposób przybliżony (z dowolną dokładnością) okazuje się być możliwe na gruncie geometrii wykreślnej po przeanalizowaniu współzależności jakie występują pomiędzy elementami tej sytuacji geometrycznej. Są to: 1. R należy do powierzchni γ2, 2. prosta prostopadła do γ2 w punkcie R (prosta normalna n) jest prostopadła do prostej 1, prostej tworzącej stożek przez obrót wokół prostej s, 3. prosta η ma punkt wspólny z prostą s, 4. prosta η ma punkt wspólny z prostą k, prostą utworzoną z punktów Ε i Ρ (niech przecięciem tych prostych będzie punkt X), punkt ten leży pomiędzy punktami Ρ i E, 5. kąt XRP i kąt XRE są równe co do wartości i współpłaszczyznowe. Droga do odnalezienia poszukiwanego punktu składa się z trzech etapów. W pierwszym etapie poszukiwany jest zbiór punktów, który spełnia spośród wymienionych uprzednio warunki 1,2,3 i 4. Powstaje w ten sposób zbiór punktów, który możemy zapisać jako krzywą przestrzenną na rysunku. W drugim etapie konstrukcji poszukujmy zbioru punktów, które spełniałyby warunki 2,3,4 i 5. Dzięki temu otrzymujemy drugą krzywą przestrzenną. W trzecim etapie odnajdujemy punkt R jako część wspólną obu tych krzywych.
Źródło:
Journal Biuletyn of Polish Society for Geometry and Engineering Graphics; 2009, 19; 79-85
1644-9363
Pojawia się w:
Journal Biuletyn of Polish Society for Geometry and Engineering Graphics
Dostawca treści:
Biblioteka Nauki
Artykuł

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