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    Wyświetlanie 1-8 z 8
    Tytuł:
    Dostawy drewna po wprowadzeniu normatywnych przeliczników gęstości drewna do określenia masy ładunku
    Timber deliveries after introduction of the normative calculators of wood density to determine the load weight
    Autorzy:
    Trzciński, G.
    Tymendorf, L.
    Powiązania:
    https://bibliotekanauki.pl/articles/989076.pdf
    Data publikacji:
    2017
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    lesnictwo
    surowce drzewne
    lancuch dostaw
    drewno
    gestosc drewna
    przeliczniki gestosci drewna
    masa ladunku
    transport
    dostawy drewna
    wood supply chain
    timber logistic
    structure of wood supply
    wood deliveries
    Opis:
    The State Forests National Forest Holding that manages 77.1% of the forests in Poland intend to harvest over 40 million m³ of timber, which is supposed to supply the demand from some thousand timber processing companies. Introduction of a new normative for determination of the timber load weight as a result of multiplication its volume and wood density significantly changed timber transport regulations in 2012. The study analyzes the timber supply to a large (over 300 thousand m³ of wood per year) sawmill in the first half of 2012 and 2016. On the first date standard mass conversion indices were not implemented yet. We analysed whether there are significant differences in the timber deliveries between 2012 and 2016 with regard to monthly and weekly scale as well as in relation to the days of the week. In the first half of 2012 there was 4946 deliveries, which provided more than 126 thousand m³ of timber. In the same period of 2016 there was 6109 deliveries with total volume of 178 thousand m³. Increase in timber demand by 41% resulted in an increase in the number of transports only by 23.5%. Considering the distribution of the deliveries in each of 27 weeks, the average number of courses equal to 183 per week in 2012 and 226 in 2016. In first half of 2012, no courses were recorded in week 18, 26 and 27, while the highest number – in the week 16 (305 shipments). In 2016 only in first week there was no courses, and the maximum (312 deliveries) was reached in the sixth week. Average volume of weekly deliveries in 2012 amounted to 5234 m³, while in 2016 it reached 6595 m³. Maximum values equaled 7706 and 9026 m³ respectively. We noticed significant difference in the number of shipments and the volume of the delivered timber between the study periods, which results mainly from the increased production and demand.
    Źródło:
    Sylwan; 2017, 161, 06; 451-459
    0039-7660
    Pojawia się w:
    Sylwan
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Obciazenie drog lesnych wynikajace z transportu surowca drzewnego
    Loading of forest roads resulting from timber transportation
    Autorzy:
    Trzcinski, G
    Powiązania:
    https://bibliotekanauki.pl/articles/883041.pdf
    Data publikacji:
    2010
    Wydawca:
    Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Maszyn Rolniczych
    Tematy:
    lesnictwo
    drogi lesne
    obciazenia
    drewno
    transport
    wywoz drewna
    zestawy transportowe
    masa ladunku
    nacisk na os
    Opis:
    Określenie charakterystyki obciążenia drogi wiąże się z analizą ilościową i jakościową poruszających się po niej pojazdów. Celem pracy było określenie rzeczywistych obciążeń powstałych na osiach zestawu przy transporcie drewna. W pracy przedstawiono wyniki analizy parametrów zestawów do wywozu drewna: masy całkowitej zestawu (GVW), obciążenia poszczególnych osi, jednostkowych ładunków mas drewna. Badania przeprowadzono na 230 samochodach transportujących drewno wielkowymiarowe WC0 i średniowymiarowe S2 w zestawach wywozowych pięcioosiowych i sześcioosiowych. Samochody jednorazowo przewoziły ładunki drewna o wielkości od 20,1 do 43,4 m . Samochody transportujące drewno sosnowe miały masę całkowitą zestawu GVW na poziomie 42,3-60,2 Mg (WC0) oraz 39,7-58,5 Mg (S2). Średnie naciski na poszczególnych osiach zestawu pięcioosiowego z S2 wynosiły 72-106 kN oraz 83-119 kN dla WC0, a w zestawach sześcioosiowych 73-93 kN dla samochodów z S2 i 83-106 kN dla samochodów z WC0.
    Determination of load acting on a road relates to quantitative and qualitative analysis of travelling vehicles. The objective of this research was to recognize the real loads felt by vehicle's axles during timber transportation. The paper presents the analysis of parameters of vehicles used in timber transport: gross vehicle weight (GVW), load on each axle and unit mass of timber cargo. The research was carried out on 230 vehicles transporting large-size (WC0) and medium-size (S2) timber in five- and six-axle vehicle sets. Single load capacity varied from 20.1 to 43.4 m of timber. Vehicles transporting pine timber had their GVW varying from 42.3 up to 60.2 Mg (WC0) and from 39.7 to 58.5 Mg (S2). With these received high GVW values, average single load on particular axle varied from 72 to 106 kN for the S2 and from 83 to 119 kN for WC0. Smaller loads were observed in six-axle vehicle sets. Anyway values were still higher than official limits that amount 73-93 kN for S2 and 83-106 kN for Wc0.
    Źródło:
    Technika Rolnicza Ogrodnicza Leśna; 2010, 06; 15-18
    1732-1719
    2719-4221
    Pojawia się w:
    Technika Rolnicza Ogrodnicza Leśna
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Wywóz drewna wielkowymiarowego a obciążenie dróg leśnych
    Impact of the timber haulage on loading of the forest roads
    Autorzy:
    Trzciński, G.
    Powiązania:
    https://bibliotekanauki.pl/articles/238729.pdf
    Data publikacji:
    2011
    Wydawca:
    Instytut Technologiczno-Przyrodniczy
    Tematy:
    obciążenie
    droga leśna
    masa całkowita
    samochód
    oś pojazdu
    transport drewna
    loading
    forest road
    gross vehicle weight
    load per axle
    timber transport
    Opis:
    Wywóz drewna jest realizowany 5- i 6-osiowymi samochodami wysokotonażowymi, których masa całkowita nie powinna przekraczać 40 t. W pracy przedstawiono wyniki analiz zestawów wywozowych, stosowanych w transporcie drewna wielkowymiarowego: parametrów zewnętrznych, masy całkowitej zestawu, obciążenia poszczególnych osi, jednostkowych ładunków drewna. Badaniom poddano 80 samochodów różnych marek w zestawach 3+2 osie lub 3+3 osie. Masa całkowita zestawów wynosiła od 42 do 60 t, a średnie obciążenie pojedynczej osi - od 80 do 120 kN.
    Wood transport is carried out with the use of five-axle and six-axle high tonnage vehicles whose total weight should not exceed 40 tons. The objective of this study was to recognize the real loads on vehicle's axles during transportation of timber. Paper presented an analysis of the parameters for vehicles used to wood transportation, such as technical characteristics, gross vehicle weight, load on particular axles, single timber loads. 80 vehicles of different types and marks, in sets of 3+2 or 3+3 axles, were investigated. The total weight of vehicles ranged from 42 to 60 t, and the average load per single axle from 80 to 120 kN.
    Źródło:
    Problemy Inżynierii Rolniczej; 2011, R. 19, nr 1, 1; 185-193
    1231-0093
    Pojawia się w:
    Problemy Inżynierii Rolniczej
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Możliwości ręcznego przemieszczania surowca krótkiego podczas pozyskania sosny, świerka, brzozy i buka w cięciach pielęgnacyjnych
    Capabilities of manhandling small logs in commercial thinning in pine, spruce, beech, and birch stands
    Autorzy:
    Tomczak, A.
    Grzywiński, W.
    Jelonek, T.
    Powiązania:
    https://bibliotekanauki.pl/articles/986671.pdf
    Data publikacji:
    2018
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    lesnictwo
    drzewostany
    ciecia pielegnacyjne
    sosna
    swierk
    brzoza
    buk
    pozyskiwanie drewna
    drewno krotkie
    drewno sredniowymiarowe
    masa drewna
    reczne przemieszczanie surowca drzewnego
    przemieszczanie ciezarow
    health
    musculoskeletal symptoms
    loggers
    weight of logs
    green density
    Opis:
    The aim of this study was to measure the weight of timber obtained from freshly cut trees and compare it with the applicable legal provisions pertaining the capability of transporting heavy loads by hand and also to indicate a problem significant for the occupational safety and health protection of employees working at wood harvesting. In Poland, about 40 million m3 of timber is harvested annually. The logs, with small diameter and length, are prepared for forwarding by arranging them by employees in the so called ‘packages’, which are placed by the route of the machine that collects and transports them to the logging road. Manhandling of the logs is an activity requiring the greatest energy expenditure (over 30 kJ/min) in the process of tree harvesting. Furthermore, it is also one of the key factors, which may lead to the development of musculoskeletal disorders. Regulations existing in the Polish labour law regulate the permitted weight of transported loads depending on the activity duration. For loads transported single−handedly this is 30 kg for a permanent employer, whereas 50 kg for workers doing the job occasionally or temporarily (no more than 4 times per hour and no longer than 4 hours during workday). Logs heavier than 50 kg may be carried only collectively providing the requirements of the minimal length (0,75 m) of the log per one person are met. We produced 2,5 m long logs and weighted them with an accuracy of 0,1 kg. The analysis revealed that approximately 30% of logs weighed between 30 and 50 kg, which introduces limitations in the number of carried logs per one person within a single shift. However, about 10% of the pine, 15% of spruce, 12% of beech and 38% of birch logs were heavier than 50 kg which should prevent carrying them single−handedly. Unfortunately, collective preparation of timber for forwarding is not popular among workers due to reduction in output, and at the same time the lower salary. Even if log for forwarding is prepared by two labourers, they most often work separately. As a result, the limits of the weight carried single− handedly by labourer are notoriously violated and exceeded.
    Źródło:
    Sylwan; 2018, 162, 07; 531-538
    0039-7660
    Pojawia się w:
    Sylwan
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Naturalne suszenie surowca drzewnego w miejscu pozyskania
    Natural drying of wood in the cutting area
    Autorzy:
    Tomczak, A.
    Jelonek, T.
    Leszczyński, N.
    Korzeniewicz, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/988961.pdf
    Data publikacji:
    2017
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    lesnictwo
    uzytkowanie lasu
    surowce drzewne
    drewno swiezo sciete
    masa drewna
    wilgotnosc drewna
    suszenie naturalne
    magazynowanie
    biomass
    energy wood
    industrial wood
    storage
    moisture content
    Opis:
    Wood obtained from freshly cut trees has a high moisture content and therefore its mass per volume unit is higher than the mass of dry wood. The natural drying is a simple and effective method of weight (moisture content) reduction, making a better use of the vehicle's payload, and thus reducing costs, including environmental costs. The conclusion is based on simulations and analyzes attempting to evaluate different solutions. As evidenced, the drying process of logs depends on numerous factors, which entails attempts at development of an optimal logging method, especially concerning energy wood, allowing for maximum value growth in as little time as possible. The suggestions cover various forms of logging (of whole trees, long timber), arranging (in piles, bundles), storing (in stands, by the roadside near cutting areas), and protection. Combined methods such as storing under canvas for winter only or storing in cutting areas and later in piles at the exit road also work in practice, but require more funds because their cost is determined by the number of stages composing the whole process. In case of wood, development of an optimal and simultaneously universal method used to prepare the lumber for transport and its delivery with consideration of as little environmental impact as possible is complicated. The numerous variables, some of which cannot be controlled or affected, create a considerable scientific problem as well. The authors covered in the presented literature review often stress the role of specific weather conditions accompanying an experiment or its location, the storage method, or lumber dimensions in the drying process. Storage time is perceived as equally important, but it is a derivative more or less determined by the previous variables. Previous studies of drying at the cutting area have been focused mainly on energy wood and less on industrial wood. They analysed the results of long−term storage and did not stress the potential advantages of short−term drying. Furthermore, we do not have sufficient information on species, including forest trees, which have a lower share in the volume of the logged wood. Advanced research can help establish the minimum mass (moisture content) with considerable impact on supply chain effectiveness improvement or evaluated various storing and drying methods. We reviewed reports explaining the impact of various factors on natural drying of wood, models and storage effects, and analyzing potential economic and environmental benefits.
    Źródło:
    Sylwan; 2017, 161, 11; 898-908
    0039-7660
    Pojawia się w:
    Sylwan
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Problemy i możliwości konserwacji dębów rogalińskich
    PROBLEMS OF CONSERVATION OF OLD OAK — TREES IN ROGALIN
    Autorzy:
    Spława-Neyman, Stanisław
    Ratajczak, Zdzisław
    Powiązania:
    https://bibliotekanauki.pl/articles/537238.pdf
    Data publikacji:
    1972
    Wydawca:
    Narodowy Instytut Dziedzictwa
    Tematy:
    dęby rogalińskie
    Pałac w Rogalinie
    dezynfekcja drewna
    zabezpieczanie drewna
    masa bitumiczna
    Opis:
    One of the most interesting Nature Reserves is the complex of nearly a thousand oak-trees over 500 years old in Rogalin, Wielkopolska. A few years ago alarming condition of the trees necessitated an expertise and working out of a special preserving treatment. The methods used throughout those years have brought satisfactory results and may be recommended for further use. Besides routine statics improving - interventions and desinfections, several agro-technical measures have been taken. One of the most important was intensifying the impairment overgroving process through introducing some stimulating means into the tissue forming places.
    Źródło:
    Ochrona Zabytków; 1972, 2; 117-119
    0029-8247
    Pojawia się w:
    Ochrona Zabytków
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Częściowe usunięcie zniszczonego drewna rzeźby polichromowanej i zastąpienie go skorupą z tworzyw sztucznych
    PARTIAL REPLACEMENT OF REMOVED WOOD MATERIAL FROM POLYCHROME SCULPTURES WITH PLASTIC SHELL
    Autorzy:
    Płuska, Ireneusz
    Powiązania:
    https://bibliotekanauki.pl/articles/537936.pdf
    Data publikacji:
    1970
    Wydawca:
    Narodowy Instytut Dziedzictwa
    Tematy:
    figura św. Anny ze Szczytnej Śląskiej
    usunięcie elementów drewna z rzeźby
    nieskuteczna impregnacja
    masa stearynowo-parafinowa
    tworzywo sztuczne w konserwacji drewna
    Opis:
    The subject of preservating operations discussed by the author consisted in the polychrome St. Ann statue from Szczytna Śląska the wood material of which has been almost entirely destroyed by lignicole insects. The polychrome surface was secured by glueing on й the threefold layer of gauze placed on a bed prepared from the stearin-paraffin m ix ture. Then the decayed wood material was removed from the statue’s interior so that only quite thin layer of it has been left immediately underneath the polychrome paint coat and in turn saturated with 5 per cent solution of acetal polyvinyl acetate. The interior of statue has been lined with the layer of preparation and lime wood dust mixed together in 50 to 50 per cent proportion. For the third time the same medium has been applied in 5 per cent solution for glueing of the glass fibre fabric strips with which the statue’s interior was lined. It deserves to be pointed out that all the above three operations are fully reversible. To reinforce the whole the interior was lined with plates formed of the putty consisting of „Epidian 5” mixed with lime wood dust which in case of need may be easily removed owing to the presence of spacings especially left between them. The protective gauze layer has been removed mechanically from polychrome surfaces and, finally, the whole cleansed thoroughly with light petrol.
    Źródło:
    Ochrona Zabytków; 1970, 2; 101-105
    0029-8247
    Pojawia się w:
    Ochrona Zabytków
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Dokładność określania świeżej masy strzał jodły na podstawie przeliczników wagowo-objętościowych
    Accuracy of estimation silver fir stem mass on the basis of volume to weight conversion factors
    Autorzy:
    Ochal, W.
    Wertz, B.
    Grabczyński, S.
    Orzeł, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/985798.pdf
    Data publikacji:
    2018
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    lesnictwo
    drzewa lesne
    jodla pospolita
    Abies alba
    biomasa drzewna
    masa strzaly drzew
    biomasa swieza
    szacowanie biomasy
    wspolczynniki wagowo-objetosciowe
    gestosc drewna
    abies alba
    wood density
    stem biomass
    biomass estimation
    Opis:
    The paper describes the accuracy of estimation of silver fir stem fresh mass on the basis of volume to weight conversion factor, derived from samples, collected from few different places along the stem. The research material contained 13 sample trees selected from homogenous 70−years old stand, situated in mountainous area of the Beskid Sądecki in Polish part of the Carpathians (S Poland). Volume over the bark of sample trees was calculated with section−wise method and the whole stem fresh biomass was directly weighted. For each sample tree three stem discs were collected at 1/6, 1/2 and 5/6 of tree height, their weight and volume were precisely determined and the biomass conversion factors (equivalent of stem density) were calculated. The assessment of the accuracy of whole fresh stem biomass was conducted according to five variants: for the biomass conversion factors derived from each individual stem disc (lower, middle or upper), from weighted mean density and on the basis of the constructed mixed model, where relative height and diameter were treated as fixed effects and influence of individual trees was included as a random term. The volume of sample fir stems ranged from 0.15 to 2.22 m3, while their fresh biomass varied between 138.1 and 1896.7 kg. Obtained results show that variation of the density was higher within stems than between them (coefficient of variation amounted to 8.4% i 3.3% respectively). The average density increased along stem, from 835.6 kg/m3 for lower part (1/6H) to 986.8 kg/m3 for the upper part (5/6H). Estimating the biomass on the basis of just lower stem disc resulted in the average relative error equal to –5.8%, while for middle stem disc the error was +1.2%, and for upper disc +11.3%. The use of conversion factors derived from weighted average density of all three stem discs resulted in average bias equal to –1,7% with standard error 1,0%. Despite the presence of mean bias of –2.3%, the constructed density model gave the most precise estimation of the stem biomass (standard error 0.7%), which indicates the reasons for its further improvements and usage.
    Źródło:
    Sylwan; 2018, 162, 04; 277-287
    0039-7660
    Pojawia się w:
    Sylwan
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-8 z 8

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