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Wyszukujesz frazę "Tomczak, M." wg kryterium: Autor


Wyświetlanie 1-3 z 3
Tytuł:
Wytrzymałość na ściskanie wzdłuż włókien drewna sosny zwyczajnej uszkodzonej i nieuszkodzonej przez wiatr
Compressive strength parallel to grain of Scots pine wood of wind-damaged and undamaged trees
Autorzy:
Jakubowski, M.
Jelonek, T.
Tomczak, A.
Powiązania:
https://bibliotekanauki.pl/articles/990848.pdf
Data publikacji:
2014
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
uzytkowanie lasu
drzewostany pokleskowe
wiatry
uszkodzenia drzew
drzewostany sosnowe
drzewa uszkodzone
sosna zwyczajna
Pinus sylvestris
drewno sosnowe
wytrzymalosc na sciskanie wzdluz wlokien
wood properties
strong wind
scots pine
wood defects
Opis:
Research was carried out in Scots pine (Pinus sylvestris L.) stands damaged by strong wind in six locations in Poland. The aim of this study was to analyse the radial variation of compressive strength parallel to grain in the wind−broken trees and neighbouring survivors. Strength tests were conducted in moisture above saturation fibre point. There were no significant differences in the radial distribution of the compressive strength between the compression side (breakage side) and the tension side (the opposite one). Either there were no significant differences between compression strength of damaged trees and neighbouring standing trees.
Źródło:
Sylwan; 2014, 158, 10; 787-794
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Utrata masy i zmiany gęstości średniowymiarowego surowca sosnowego pozyskanego i magazynowanego w okresie letnim
Weight loss and green density changes of Scots pine pulpwood harvested and stored during the summer
Autorzy:
Tomczak, A.
Wesołowski, P.
Jelonek, T.
Jakubowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/989611.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
pozyskiwanie drewna
lato
sosna zwyczajna
Pinus sylvestris
drewno sosnowe
drewno sredniowymiarowe
drewno swiezo sciete
magazynowanie
utrata masy drewna
gestosc drewna
scots pine
mass of logs
timber
freshly−cut trees
bark
wood moisture
Opis:
The study objectives included: i) determination of the mass and green density of pulpwood (wood+bark) and ii) comparison of the changes in these parameters during 14−day−long storage period. The experiment was conducted between 15 and 28 July 2014 and the material was taken from the 67 year−old Scots pine stand (Tuchola Forest District, northern Poland). Using the Urich method, 30 model trees were selected. After felling and delimbing, logs of 2.5 m length were cut, with diameter at the small end not less than 7 cm outside the bark. In total, 133 logs were harvested (mean diameter inside the bark at the thicker end – 13.1 cm, in the thinner end – 11.4 cm). After diameter measurements were taken, each log was weighed (total over bark volume equaled 4.69 m³, while total weight – 3955 kg). Mass measurement took place daily between 8 and 10 a.m. In Poland, the raw material is not recommended to be stored too long in summer, due to the possibility of its depreciation. Storage time should be as short as possible and not exceed 2 weeks. The mass of the 1 m³ of wood harvested from freshly−cut trees amounted to 844 kg. After 14 days it decreased to 814 kg (–3.5%). Differences were not statistically significant. Because the moisture content has the highest influence on mass, the rain and thereby an increase in the air humidity significantly reduce drying. Mass of 1 m³ of raw material was reduced to the day of rain by 2.9 kg (–0.35%) per day on average. After the occurrence of rainfall, between 10th and 14th day of storage the mean weight loss was 1.3 kg/m³ (–0.16%). The mean weight loss reached 30 kg/m³ in analyzed period. Generally two weeks storage is too short time to obtain a large weight loss. However, in this case of total mass of haulage vehicles together with their cargo may be a few hundred kilos smaller.
Źródło:
Sylwan; 2016, 160, 08; 619-626
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Właściwości drewna sosny zwyczajnej (Pinus sylvestris L.) pochodzącej z gruntów porolnych
Properties of wood of Scots pine [Pinus sylvestris L.] growing on former farmlands
Autorzy:
Jelonek, T.
Pazdrowski, W.
Arasimowicz-Jelonek, M.
Tomczak, A.
Powiązania:
https://bibliotekanauki.pl/articles/1009458.pdf
Data publikacji:
2010
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
grunty porolne
drzewa lesne
sosna zwyczajna
Pinus sylvestris
drewno sosnowe
jakosc
gestosc drewna
wlasciwosci mechaniczne
wytrzymalosc na sciskanie wzdluz wlokien
zginanie statyczne
wzmocnienie desorpcyjne
scots pine
wood quality
basic density
former farmland
juvenile wood
mature wood
desorption strengthening
Opis:
Analyses were conducted on wood from twelve Scots pines from northern Poland, aged 102 to 110 years, growing on former farmland and on forest grounds. The study was an attempt to determine basic density of wood, compressive strength along the grain, bending strength of absolutely dry wood and wood with moisture content above saturation point. Desorption strengthening was determined for analyzed strength properties of wood. Wood properties were determined in terms of juvenile and mature wood zones. Generally pines growing on former farmlands were characterized by wood with higher density and slightly lower strength than pines growing on typical forest soils. Conducted investigations indicate varied structure and properties of wood tissue formed in pines growing on former farmlands, which is different from that of typical forest soils.
Źródło:
Sylwan; 2010, 154, 05; 299-311
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-3 z 3

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