2761. Internal and external moisture transport resistance during non-stationary adsorption of moisture into woodBojan Bučar, 2007, izvirni znanstveni članek Povzetek: The assumption that non-stationary sorption processes associated with wood canbe evaluated by analysis of their transient system response to the disturbance developed is undoubtedly correct. In general it is, in fact, possible to obtain by time analysis of the transient phenomenon - involving the transition into an arbitrary new state of equilibrium - all data required for a credible evaluation of the observed system. Evaluation of moisture movement during drying or moistening requires determination of external moisture transfer resistance from or to wood surfaces, as well as internal resistance. Time-dependent changes in the moisture content of the spruce (Picea abies Karst.) samples of different thickness were monitored gravimetrically, during which the frequency of weighing was in accord with thespeed of moistening. It was assumed that quasi-isothermal sorption processes associated with wood could be evaluated as first order systems. The characteristic time constant ? determines, wholly and uniformly, the time dependence of the sorption process for the relevant sorption range of wood tissue. The connection between the time constant and the thickness of the sample measured in the direction of the material flux is potential, with the power depending solely on the relationship between the external mass transfer convection and internal diffusion resistance. To determine the said resistances or coefficients of mass transfer convection and diffusivity, the experiment must be carried out on samples of varying thickness. It is only in this way that the external mass transfer convection and internal diffusion resistance can be correctly distinguished.
Ključne besede: wood sorption, first order system, time constant, mass transfer, diffusivity
Objavljeno v DiRROS: 12.07.2017; Ogledov: 4404; Prenosov: 1886
 Celotno besedilo (428,03 KB) |
2762. Structure, development and growth of selection forests at the Granata research siteMatej Reščič, Andrej Bončina, 2007, izvirni znanstveni članek Povzetek: The Granata research site was established for the study of structure, growth and regeneration of silver fir-European beech single stem selection forest. Three phytocoenological relevés were carried out, all trees ?5 cm diameter at breast height (d.b.h.) were measured by full callipering, tree growth was analysed for sample trees, regeneration of tree species was registered on 63 sampling plots. In addition, historical data from past forest inventories werestudied. In the period from 1952 to 2003, the share of silver fir has decreased from 86% to 26%, the share of Norway spruce increased significantly,whereas the share of beech and sycamore has slightly increased. The current growing stock amounts to 350 m3 ha-1, with large-size diameter trees (d.b.h. ?50 cm) representing 51% of total growing stock. The site is divided into 16 stand patches with significant differences in tree species composition and diameter distribution. Regeneration is sufficient with silver fir prevailing in total number of seedlings (42%). 23% of all seedlings are damaged as a result of game browsing.
Ključne besede: selection forest, plenterwald, selection system management, stand structure, tree species composition, regeneration, diameter distribution
Objavljeno v DiRROS: 12.07.2017; Ogledov: 4759; Prenosov: 2035
Celotno besedilo (558,46 KB) |
2763. Measuring the limits of uphill timber skidding with a WOODY 110 forestry tractorBoštjan Košir, Jurij Marenče, 2007, kratki znanstveni prispevek Povzetek: The paper deals with the test results of uphill skidding of wood with a WOODY 110 cable skidder. The aim of the study was to find the limits of uphill skidding in relation to load size, log orientation and the slope. The trial was prepared on a test track of concave shape in the forest and with pre-designed loads of different sizes. The loads were skidded uphill once withbutt-end and then with top-end forward, until the tractor stopped because of the slope. The results show that butt-end forward skidding is more efficient. The difference between maximum loads at specific maximum slopes is almost constant (0.53 t). Proper load formation (butt-end forward if possible)is more important when skidding on steeper slopes.
Ključne besede: forestry, tractor, skiiding, maximum slope, maximum load
Objavljeno v DiRROS: 12.07.2017; Ogledov: 4240; Prenosov: 1926
Celotno besedilo (436,49 KB) |
2764. Inclusion of consumers in the forming of wood fuel trade market on the pattern of questionnaired householdsBenjamin Leskovec, Iztok Winkler, 2007, izvirni znanstveni članek Povzetek: The research of wood fuel trade is market management oriented at household level. We devoted our attention to determine the key questions, market segmentation and market potentials. 909 households, which took part in the questionnaire and received financial support to purchase a wood biomass boilerfrom 2003 until 2006, represented our data source. The analysed pattern of questionnaired households indicates a vast unrealized developmental potential at placing additional quantities of chunkwood and forest chips on the market. Own forests still represent the most important heating source in households. Switching to wood biomass heating is practiced particularly by fuel oil consumers. Since the consumer has been placed into the centre of our research, we present some fundamental findings on product making and product development, its price, sale, promotion and management control. Our findings indicate that right business decisions and the ability to adjust to the marketfluctuation enable us good developmental possibilities.
Ključne besede: wood biomass, wood fuel trade, households, market management, chunkwood, forest chips, pellets, Slovenia
Objavljeno v DiRROS: 12.07.2017; Ogledov: 4311; Prenosov: 1932
Celotno besedilo (515,49 KB) |
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2766. Organisational model of a globally oriented wood industry companyJože Kropivšek, Rudi Rozman, 2007, pregledni znanstveni članek Povzetek: The paper provides an answer to the question as to in what way and with which organizational steps a wood industry company can be (more) adaptable and successful in a rapidly changing (global) business environment. The purpose ofthe article is to form an organizational model of a globally oriented wood industry company, considering the three required model properties: repeatability, efficiency and productiveness, as well as practical applicability. Research is limited to actual state in Slovenian wood industry practice with some specifics that should be considered by other implications of the research. Practical applicability of the model is based on these findings and is ensured by making guidelines on the basis of which companies can organise their businesses. These guidelines include suggested measures forindividual areas of business organization with the intention of increasing adaptability and innovativeness of business operation, improving competitive ability, and the ability of constant improvement. The paper provides a new organizational approach, specialized for making wood industry companies successful in the changing business environment.
Ključne besede: adaptability, globalisation, model, organization, wood industry company
Objavljeno v DiRROS: 12.07.2017; Ogledov: 4222; Prenosov: 1917
Celotno besedilo (474,46 KB) |
2767. Anatomija lesa za loke godalKatarina Čufar, Blaž Demšar, Martin Zupančič, Gerald Koch, Primož Oven, 2007, izvirni znanstveni članek Povzetek: V goslarski delavnici "Atelje Demšar" smo dobili štiri vzorce lesa za godalne loke tujih dobaviteljev, ki so jih označili z imeni (1) pernambuk, (2) konjskomeso, (3) brazil in (4) kačji les. Les smo anatomsko preiskali ter določili vrste: (1) Guilandina echinata (pernambuk, pau brazil, brazil), (2) Manilkara bidentata (massaranduba, konjsko meso), (3) Shorea laevis (balau, bangkirai), (4) Brosimum guianense syn. Piratinera guianensis (Schlangenholz, snakewood, kačji les). Identifikacija je v treh (1, 2 in 4) od štirih primerovpotrdila lesno vrsto, kot jo je navedel dobavitelj lesa. Preiskane lesne vrste pernambuk, konjsko meso in kačji les (1, 2 in 4) iz južne Amerike imajo skupne naslednje lastnosti: fino teksturo, temno obarvano jedrovino, dekorativen videz, visoko gostoto, visoko trdnost, dobro dimenzijsko stabilnost in dobre obdelavnostne lastnosti, posebno struženje in površinsko obdelavo. Vse so zelo cenjene za godalne loke, za najboljšega pa velja les pernambuka. Les balau iz Azije ima slabše lastnosti in ni tipična lesna vrsta za loke. Razlike v zgradbi lesa preiskanih vrst so najverjetneje vzrok za razlike v kvaliteti končnega izdelka. Podajamo opis izdelave lesenega loka, opis lesnih lastnosti in pomen pravilne identifikacije in poimenovanja lesa.
Ključne besede: godalni lok, pernambuk, Guilandina echinata syn. Caesalpina echinata, massaranduba syn., konjsko meso, Manilkara bidentata, kačji les, Brosimum guianense syn. Piratinera guianensis, balau, Shorea laevis, anatomija lesa
Objavljeno v DiRROS: 12.07.2017; Ogledov: 4962; Prenosov: 2021
Celotno besedilo (1,49 MB) |
2768. Morfološka analiza puhastega hrasta (Quercus pubescens Willd.) v SlovenijiMateja Jerše, Franc Batič, 2007, izvirni znanstveni članek Povzetek: Z raziskavo smo poskusili ovrednotiti morfološke raznolikosti puhastega hrasta(Quercus pubescens Willd.) v Sloveniji. Raznolikost je posledica pestrosti rastišč in možnosti križanja z drugimi vrstami hrastov. Rezultati analize so bili dobljeni na osnovi meritev in opazovanja listov, plodov in kratkih poganjkov puhastegarasta, vzorčenih v osmih populacijah po Sloveniji. Na posamezni lokaciji je bilo izbranih do pet dreves in na posameznem drevesu nabranih do sto listov s kratkih poganjkov v osvetljenem delu krošnje. Na osebkih s plodovi so bili nabrani tudi plodovi. V laboratoriju je bilo na listih izmerjenih, ocenjenih in izračunanih 13 parametrov, na plodovih in kratkih poganjkih pa po en parameter. Uporabljene so bile deskriptivne, univariatne in multivariatne statistične metode za izvrednotenje rezultatov. Analize morfoloških parametrov so pokazale značilne razlike tako med posameznimi osebki v populacijah kot med populacijami. Ugotovljeno je bilo tudi, da vrsto Q. virgiliana (Ten.) Ten. lahko obravnavamo znotraj vrste Q. pubescens.
Ključne besede: puhasti hrast, Quercus pubescens Willd., Quercus virgiliana (Ten.), morfologija, listi, plodovi, Slovenija, oak, morphology, leaf, fruit, Slovenia
Objavljeno v DiRROS: 12.07.2017; Ogledov: 4943; Prenosov: 2019
Celotno besedilo (857,31 KB) |
2769. Pregled in analiza izbranih podatkovnih zbirk ter predmetnih oznak za področje lesarskih znanosti in tehnologijeTomaž Bartol, 2007, pregledni znanstveni članek Povzetek: Uporabniki morajo znati identificirati najrelevantnejše vire kakovostnih znanstvenih in tehničnih informacij. Razumeti morajo strukturo zbirk, iskalne tehnike, kontroliran besednjak, terminologijo in klasifikacijske sheme. V članku podajamo glavne značilnosti bibliografskih podatkovnih zbirk (Agricola,Agris, Cab Abstracts (CABI), Compendex, Inspec, Iconda), statističnih zbirk (Eurostat, Faostat) in zbirk tehničnih dokumentov - standardov in patentov (ISO, WIPO) glede na značilnosti lesarstva oz. predelave gozdnih proizvodov. Opisane so razlike v posameznih iskalnih poljih in iskalna načela (platforme, Boolovi logični operatorji, predpone, pripone, znaki za krajšanje ali maskiranje). Posebno pozornost namenjamo predmetnim oznakam: ožje ključne besede (Descriptors, Heading Words, Controlled Terms, Keywords) in širše predmetne kategorije (Subject Categories, Concept Codes, CABI Codes, Classification Codes). Podani so seštevki besed oz. indeksnih gesel ali pojmov z najvišjo pojavnostjo. S tem pregledom želimo spodbuditi rabo dodatnih podatkovnih zbirk ter rabo strukturiranih besednjakov, kar naj se izrazi v boljših iskalnih rezultatih.
Ključne besede: lesarstvo, predelava gozdnih proizvodov, podatkovne zbirke, kontrolirani besednjaki, predmetne oznake, indeksiranje, standardi, patenti, statistika
Objavljeno v DiRROS: 12.07.2017; Ogledov: 4634; Prenosov: 2006
Celotno besedilo (488,48 KB) |
2770. Talne in vegetacijske razmere na oglednih točkah v GGE Vzhodno PohorjeMihej Urbančič, Lado Kutnar, Milan Kobal, Mateja Cojzer, Ljubo Cenčič, 2007, izvedensko mnenje, arbitražna odločba Ključne besede: tla, vegetacija, Vzhodno Pohorje
Objavljeno v DiRROS: 12.07.2017; Ogledov: 2796; Prenosov: 775
Celotno besedilo (2,67 MB) |
