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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.
Traditional firewood is still the most popular type of solid fuel. This is mainly because of the availability of raw materials and simple production process, which involves mostly just sawing and cleaving. Cleaving increases the surface of the wood through which water evaporates, which in turn speeds up the drying. Dry wood has a higher calorific value and its combustion releases less harmful carbon monoxide and hydrocarbons. Wood cleaving process can be divided into three phases that lasts from the introduction of the wedge till the appearance of a crack (phase I), from the appearance of the crack till the stop of the slots (phase II) and then until the piece of the wood is completely cleaved (phase III). Although it is a conditional phase and it does not always occur in the case of the firewood species popular in Poland, the last phase takes the longest and has the greatest impact on the cleaving performance. The aim of the study was to determine the effect of wood and its moisture content on the duration of the phase III during the trial cleaving. The tested samples comprised of five popular in Poland species: hornbeam, beech, birch, alder and ash. The cleaving were carried out immediately after cutting and sawing the timber and after 3−month−long period of natural drying. For hornbeam, beech and alder humidity does not affect the hollow wedge in wood at the time of rupture. The duration of phase III was significantly longer than duration of phases I and II for each species independently of humidity. Significant dependence was observed for depression wedge as a function of humidity obtained in phase I and II for silver birch, and in phase III for ash.
Przetestowano 29 gatunków grzybów zgniliznowych zasiedlających głównie pniaki świerkowe. Doświadczenie przeprowadzono w warunkach laboratoryjnych, na klockach świerkowych o wilgotności bezwzględnej 50%, 90% i 120%. Klocki podzielono na dwie partie: inokulowane tylko 1 grzybem i inokulowane 3 grzybami równocześnie, przy wykorzystaniu różnych kombinacji grzybów. Poza tym zbadano interakcje pomiędzy poszczególnymi gatunkami grzybów w tzw. teście na antagonizm (kultury dwuorganizmowe). Tylko 4 gatunki – Antrodia serialis, Diplomitoporus flavescens, Fomitopsis pinicola, Sparassis crispa, powodowały ubytek suchej masy powyżej 20%. Stwierdzono istotną zależność pomiędzy wilgotnością drewna a intensywnością jego rozkładu, przy czym optymalna wilgotność wynosiła 90%, a najsłabiej grzyby rozkładały drewno przy wilgotności 50%. Najczęściej grzyby wszczepiane pojedynczo efektywniej rozkładały drewno niż w kombinacji 2-3 różnych gatunków. Uzyskane wyniki mogą być przydatne przy zwalczaniu biologicznym opieńki w zamierających drzewostanach świerkowych.
Investigations covered 28 basidiomycete fungi species settled on the spruce stumps. The experiment was conducted under laboratory conditions, on spruce blocks of absolute (dry basis) moisture contents 50%, 90% and 120%. The blocks were divided into two parts: inoculated with 1 fungus only and inoculated with 3 fungi simultaneously, by using fungi in different combinations. Moreover the interactions were examined among the fungi of particular species by e.g. test for antagonism (double system culture). Only 4 species – Antrodia serialis, Diplomitoporus flavescens, Fomitopsis pinicola, Sparassis crispa, caused the dry matter decrease above 20%. Significant dependence was stated between wood moisture content and the intensity of its decay, but the optimum moisture content was 90% and fungi decomposed the wood poorly at the moisture content 50%. Grafted individually fungi decomposed wood more effectively than in combination of 2-3 different species. Obtained results may be useful in biological control of the honey fungus in decaying spruce stands.
Methodical questions of monitoring of water status in soil, cereals grain and wood are discused ( where monitoring is understood as registration of time and spatial variability of selected properties). Amount of viariables which is necessary in order to determine water status depends on the complexion of the considered phenomena and is, so far, the matter of arbitrary choice. In most practical cases the water status is expressed only by moisture of the considered material ( like the building timber). In practical terms, two variables suffice to express water status in cereal grain: moisture and temperature. To describe water status in the soil not less then five variables are needed: amount of water (the soil moisture) soil water potential, salinity, oxygenation and temperature. The only sensors that can be integrated in modern data acquisition system must be read electrically. Therefore electroresistance and electrocapacitance methods were considered. Dielectric sensors were recognized as the proper choice.Soil is a complex material having instable characteristics. For this reason it is the most difficult task to monitor soil water status, particularly to determine the soil moisture. Therefore it has been assumed that measuring methods verified for the soil will be also suitable for other, less complex materials. Thus, monitoring of soil water status was mainly discussed. Special attention was focused to the time domain reflectometry, TDR, as the semi selective method for the soil moisture and salinity determination.
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