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Analysis of free vibrations of cantilever bars with parabolically variable cross-sections using the Rayleigh's method

100%

Szlachetka O., Jaworski J., Chalecki M.

Acta Scientiarum Polonorum. Architectura

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2017

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tom 16

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nr 4

The Rayleigh’s method can be used to determine the first natural frequency of bars (beams or posts) with non-uniform cross-section. The authors have analysed slender bars made of an elastic material and having the shape of a solid of revolution: a curvilinear truncated cone and curvilinear conical pipe. It has been assumed that the bar axis deflected during vibrations has a shape of a beam deflected by a static constant continuous load. The Rayleigh’s method has been applied in the paper in aim to determine the first frequency of free (transverse) vibrations of posts formed as a cantilever bars having the shape of solid and hollow curvilinear truncated cone with the generatrix being a parabola which is convex in relation to the cone axis. The results of calculations are very close to those obtained with finite element method (FEM).

2

Analysis of cross-section area of the cut energetic plant shoots

100%

Nowakowski T.

Annals of Warsaw University of Life Sciences - SGGW. Agriculture

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2012

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nr 59 Agric.Forest Eng.

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Post-irradiation atrophy of spleen is not followed by depletion of local tissue mast cell

86%

Wlodarski K. H.

Bulletin of the Polish Academy of Sciences. Biological Sciences

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1987

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tom 35

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nr 1-3

4

Turbulent kinetic energy of water in a compound channel

86%

Koziol A. P.

Annals of Warsaw University of Life Sciences - SGGW. Land Reclamation

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2011

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tom 43

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nr 2

5

The Kolmogorov's microscale eddies in a compound channel

86%

Koziol A. P.

Annals of Warsaw University of Life Sciences - SGGW. Land Reclamation

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2012

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tom 44

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nr 2

Investigations of the longitudinal sizes of the smallest eddies (Kolmogorov’s microscale) presented in the paper are based on measurements of instantaneous velocities in a hydraulic laboratory in a compound trapezoidal channel with different roughness conditions (smooth bed, rough bed) and with trees system on the floodplains. Sizes of the smallest eddies varied in the ranges of 0.08 to 0.48 mm. The changes of longitudinal sizes of the floodplain microeddies are not caused by: the increase of floodplain roughness, the presence of trees, but only when the main channel bed is smooth, and they are also not caused by the increase of roughness of the main channel sloping banks. However, the increase of the size of the floodplain microeddies is influenced by trees, when the roughness of the floodplains and the main channel sloping banks are identical. The increase of microeddies size in the main channel is infl uenced by: the increase of the main channel sloping banks roughness, by the presence of trees on the floodplains, but only when the roughness of the floodplains and the main channel sloping banks are identical. Microeddies are larger in the main channel centerline than on the floodplains, and the smallest ones were present in the main channel/floodplain interface. The calculated values of microeddies reached decimal parts of a millimeter, and that is why it is difficult to prove vital changes of their values, caused by bed roughness and floodplain trees influence.

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Emission of volatile organic compounds from cross section of spruce wood (Picea abies (L.) H.Karst)

72%

Czajka M., Fabisiak E.

Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology

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2013

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tom 82

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Dominant discharge in the Indus river from downstream of the Kotri barrage dam

72%

Radecki-Pawlik A., Laszek W., Plesinski K., Khan Lashari B.

Acta Scientiarum Polonorum. Formatio Circumiectus

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2014

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tom 13

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nr 4

Hydraulic data of the Indus River, downstream of Kotri Barrage dam are analyzed. An attempt has been made to determine the dominant discharge, which is defined as that discharge which over a long time period transports the most sediments and could be used to predict the shape of river cross-section. For dominant discharge calculation Wolman and Miller’s approach has been applied. Since the transport of sediment concentration could be a more effective variable for forming the shape of the river cross-section, suspended sediment concentration has been introduced, because more than 85% of total load is in suspension. We show in the paper that water discharge Q = 1000 m³ · sˉ¹ of water is a frequent discharge and carries maximum sediment load. This discharge we call here the dominant discharge (Qdd) for the Kotri dam cross section.

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On the influence of boundary layer phenomena onto averaged temperature field

72%

Wierzbicki E.

Electronic Journal of Polish Agricultural Universities. Series Civil Engineering

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2010

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tom 13

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nr 4

9

Mathematical model of deformation of railway sleeper track structure with the step change of stiffness on the elastic winkler foundation of the constant stiffness

72%

Slobodyanyuk M., Nikitina A., Nechayev G., Rakovskaya N.

Teka Komisji Motoryzacji i Energetyki Rolnictwa

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2014

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tom 14

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nr 2

10

Probing measurements of the Meyer hardness index of radial, tangential and cross section of various types of wood

72%

Koczan G.

Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology

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2023

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tom 121

11

Dynamics of cutting power during sawing with circular saw blades as an effect of wood properties changes in the cross section

58%

Orlowski K. A., Ochrymiuk T.

Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology

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2013

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tom 83

12

Variability of the share of heartwood on the stem cross-section of Douglas fir (Pseudotsuga menziesii var. viridis Franco) in Poland

58%

Wasik R.

Acta Scientiarum Polonorum. Silvarum Colendarum Ratio et Industria Lignaria

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2007

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tom 06

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nr 4

This paper presents the results of investigation into the variability of the share of heartwood on the stem cross-section of Douglas fir in Poland. The research was conducted in Douglas fir stands in the IV and V age classes. The feature was analysed on increment cores taken from the trees at 1.3 m level from the base of the stem, in the N and S direction. The differences of the share of heartwood between Douglas firs of the V and VI age classes as well as between the trees growing in moderate and broken crown closure were not significant. No significant differences occurred between specimens of different vitality, either; however, the trend towards increasing the share of heartwood in weak trees with relation to normal and lush ones was noticeable. No significant correlations between the share of heartwood and crown parameters were noted. Three regions were distinguished in the territory of Poland: the southern and north-western ones, where Douglas firs have a higher share of heartwood on the stem cross-section, and the central-western one, where the share is lower.

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Emission of volatile organic compounds from cross section of pine wood (Pinus sylvestris L.)

58%

Czajka M., Fabisiak E.

Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology

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2012

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tom 77

Emission of volatile organic compounds from cross section of pine wood (Pinus sylvestris L.). The level of emission of volatile organic compounds from heartwood and sapwood part of pine wood was determined. The tests were performed according to the chamber method based on the requirements of ISO 16000 standards. Air from the chamber was sampled after 3, 7 and 14 days. Within the whole test period the heartwood sample emitted several times higher amounts of volatile organic compounds than the sapwood sample. In both cases the composition of the analysed air was dominated by terpenes.

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Zastosowanie metody interferometrii plamkowej do pomiaru przemieszczen przekroju poprzecznego korzenia marchwi

58%

Stopa R., Romanski L.

Acta Scientiarum Polonorum. Technica Agraria

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2003

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tom 02

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nr 1

43-54

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Impact of the environmental pollution originated from sulfur mining on the chemical composition of wood and bark of birch (Betula pendula Roth.)

51%

Krutul D., Zielenkiewicz T., Radomski A., Zawadzki J., Antczak A., Drozdzek M.

Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology

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2014

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tom 88

Impact of environmental pollution caused by sulphur mining on the chemical composition of wood and bark of birch (Betula pendula Roth.) Content of extractives, cellulose, !% NaOH soluble substances and lignin were examined. Samples were gained from cca. 70-year old birch (Betula pendula Roth.) grown in the environment polluted by sulfur mining industry. 200mm height disks were cut in the butt-end, middle and top section of the trunk. Disk from the main branch was also collected. Bark was collected from butt-end section. On the cross-section from butt-end and middle part of the trunk following zones were marked: outer, center and pith adjacent wood. On the cross-section from the top part wood was divided into outer and pith adjacent. Only one zone was marked in branch. Results show that environmental pollution caused by sulfur mining industry influences the content and distribution of extractives on the cross- and longitudinal sections. It also causes the increase of extractives content in bark. Content and distribution of 1% NaOH soluble substances are also changed on both cross-sections. Environmental pollution decreased lignin content in wood and increased this content in bark from butt-end section.

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Rozkłady prędkości w korycie rzecznym o złożonym przekroju poprzecznym z roślinnością wysoką w terenach zalewowych

51%

Koziol A., Kubrak J., Kubrak E., Krukowski M., Kiczko A.

Acta Scientiarum Polonorum. Formatio Circumiectus

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2016

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tom 15

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nr 4

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Influence of the environmental pollution on the distribution of some elements on the cross-section of stem and branches wood of Norway maple (Acer plantanoides L.)

51%

Krutul D., Zielenkiewicz T., Radomski A., Zawadzki J., Antczak A., Kupczyk M., Drozdzek M.

Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology

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2012

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tom 78

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Ocena stanu oraz identyfikacja zaburzeń procesów fluwialnych w korytach rzek karpackich

44%

Struzynski A.

Acta Scientiarum Polonorum. Formatio Circumiectus

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2013

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tom 12

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nr 2

Obowiązujące w Polsce prawo wodne wprowadza wymóg waloryzacji stanu i poprawy jakości wód. Ocenę stanu wód wykonuje się głównie na podstawie parametrów biotycznych i fizykochemicznych. Pytanie o jakość parametrów hydromorfologicznych nie pojawia się, gdy stan wód płynących jest bardzo dobry, a kiedy jest dobry i średni, ich wynik powinien być zgodny z pozostałymi waloryzacjami. Tego typu podejście nastawione jest na ocenę skutków i nie odpowiada na pytanie o przyczyny postawienia dobrej oceny danemu odcinkowi rzeki. Nie można w takiej sytuacji określić trwałości istniejącego ekosystemu ani tendencji, jakim może on podlegać w przyszłości. Ważnym elementem waloryzacji hydromorfologicznej jest określenie intensywności procesów fluwialnych w korycie rzeki oraz możliwej dynamiki ich zmian. Presje hydromorfologiczne powodują zaburzenia równowagi hydrodynamicznej objawiające się zmianami typu koryta, jego wcięciem oraz zmianą składu granulometrycznego uziarnienia dna. W artykule podjęto próbę waloryzacji procesów fluwialnych. Jej wynik może być zastosowany do dokładnej oceny aktualnej jakości i możliwych zmian w korytach rzek górskich.

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Mozliwosci produkcyjne drzewostanu lipowego w rezerwacie 'Las Lipowy Obrozyska'

44%

Gralek K., Jaworski A., Kolodziej Z., Majerczyk K.

Acta Agraria et Silvestria. Series Silvestris

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2009

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tom 47

3-26

The aim of this study was to determine the productive potentiality (stand volume, basal area, and their increments) of the natural little leaf linden stand 26.68 ha in area. This stand is a part of the Obrożyska nature reserve of the total forest area of 98.25 ha. Measurements were carried out in 1995 and 2005 on 26 4-are sample plots established according to the statistical-mathematical system of forest inventory and control, and in 1999 and 2000 on three permanent sample plots which represented different developmental stages and phases of the virgin forest. Between 1990 and 2005, the mean volume of the entire stand increased from 538 to 567 m3/ha. In the growing up stage it increased from 554 to 584 m3/ha, while in the optimum stage from 510 to 541 m3/ha. The volume increment in these two stages was 66 and 51 m3/ha/10 years respectively. Volume of the stand representing the growing up stage in transition to the optimum stage (Obrożyska I classical permanent sample plot) increased during the 10-year period from 700 to 768 m3/ha, while in the stand representing the initial phase of the optimum stage (Obrożyska II) it increased from 797 to 861 m3/ha, and in the stand representing the growing up stage (Obrożyska III) from 696 to 761 m3/ha. The volume increment in these three plots was almost 80, 96, and 82 m3/ha/10 years respectively. The stand volume per hectare of the little leaf linden forest in the Obrożyska reserve is one of the highest among stands of natural character in the Polish part of the Carpathians. A very high productive potentiality of the investigated little leaf linden stand permits to accept this tree species as the main species in stands of the submontane zone as well as in the lower part of the lower montane zone in the Poprad river valley and in the climate close to that of the surroundings of the town of Muszyna.

20

Optymalizacja wymiarów konstrukcji uszczelniających wały przeciwpowodziowe

44%

Mirecki J., Pitera P.

Acta Scientiarum Polonorum. Architectura

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2013

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tom 12

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nr 4

Artykuł dotyczy oceny wpływu rozmiarów (w przekroju poprzecznym) uszczelnienia pionowego i poziomego na stateczność skarpy obwałowania. Obliczenia symulacyjne wykonano dla jednego z przekrojów poprzecznych prawego obwałowania rzeki Warty w pobliżu Poznania. Optymalizacja wymiarów uszczelnienia obwałowania i jego podłoża jest również wynikiem oceny wpływu długości przesłony (pionowej i poziomej) na wartości współczynnika stateczności. Rozważano trzy warianty, które dotyczyły: przesłony pionowej w podłożu obwałowania, zlokalizowanej u podstawy skarpy odwodnej połączonej z ekranem na tej skarpie, przesłony poziomej (fartucha) połączonego z ekranem na skarpie odwodnej i przesłony pionowej wykonanej z korony wału.

Ograniczanie wyników

Analysis of free vibrations of cantilever bars with parabolically variable cross-sections using the Rayleigh's method

Analysis of cross-section area of the cut energetic plant shoots

Post-irradiation atrophy of spleen is not followed by depletion of local tissue mast cell

Turbulent kinetic energy of water in a compound channel

The Kolmogorov's microscale eddies in a compound channel

Emission of volatile organic compounds from cross section of spruce wood (Picea abies (L.) H.Karst)

Dominant discharge in the Indus river from downstream of the Kotri barrage dam

On the influence of boundary layer phenomena onto averaged temperature field

Mathematical model of deformation of railway sleeper track structure with the step change of stiffness on the elastic winkler foundation of the constant stiffness

Probing measurements of the Meyer hardness index of radial, tangential and cross section of various types of wood

Dynamics of cutting power during sawing with circular saw blades as an effect of wood properties changes in the cross section

Variability of the share of heartwood on the stem cross-section of Douglas fir (Pseudotsuga menziesii var. viridis Franco) in Poland

Emission of volatile organic compounds from cross section of pine wood (Pinus sylvestris L.)

Zastosowanie metody interferometrii plamkowej do pomiaru przemieszczen przekroju poprzecznego korzenia marchwi

Impact of the environmental pollution originated from sulfur mining on the chemical composition of wood and bark of birch (Betula pendula Roth.)

Rozkłady prędkości w korycie rzecznym o złożonym przekroju poprzecznym z roślinnością wysoką w terenach zalewowych

Influence of the environmental pollution on the distribution of some elements on the cross-section of stem and branches wood of Norway maple (Acer plantanoides L.)

Ocena stanu oraz identyfikacja zaburzeń procesów fluwialnych w korytach rzek karpackich

Mozliwosci produkcyjne drzewostanu lipowego w rezerwacie 'Las Lipowy Obrozyska'

Optymalizacja wymiarów konstrukcji uszczelniających wały przeciwpowodziowe