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The distribution of bacteria in Sitka spruce stumps between one and ten years old was investigated by dilution plating wood chips taken from seven sampling positions up to 55 mm from the stump surface. The same wood chips were used to determine the presence Basidiomycotina within the stump wood. The number of bacterial colony forming units in the wood samples decreased in stumps between one and five years old, reaching a minimum after six years, before increasing in stumps up to ten years old. There was also a decline in numbers of bacteria isolated with increasing distance from the stump surface and the stump edge. A similar trend was detected in the diversity of the bacterial community. The size of the bacterial population was also correlated with stump moisture content. The presence of Basidiomycotina was associated with the presence of bacteria within the sample. However, the number of bacteria isolated from samples containing Basidiomycotina did not differ from that where no Basidiomycotina were isolated. Interactions between wood-decay fungi, including Heterobasidion annosum, and bacterial isolates were studied in vitro. The growth medium, timing of inoculations, and bacterial and fungal species tested were fund to significantly affect the outcome of the interaction. Bacterial isolates degraded cellulose, pectin and starch, cellulolytic ability increased with increasing stump age. Siderophores and chitinase, potential antifungal compounds, were produced by 29% and 2% of isolates respectively, however, these isolates had no effect on the distribution of Basidiomycotina in the stumps. Four groups of bacteria were identified from cluster analysis of 13 phenotypic characteristics. Different groups of bacteria were found to dominate bacteria isolated from stumps of different ages indicating that bacterial successions occur in decaying Sitka spruce stumps.

Submitted in partial fulfillment of the requirements for the degree of Master of Technology: Chemistry, Durban Institute of Technology, Durban, 2003. / Boron, in spite of its exceptional properties as a timber preservative, is not widely used for this purpose. The three key agents that contribute to the destruction of timber are insects, fungi and ultraviolet radiation. Boron is a good fungicide and insecticide and the acrylic/styrene polymer blend resists ultraviolet attack. Treating timber with boron compounds is very easy and, in most instances, does not require sophisticated equipment. The movement of boron into timber is diffusion driven and requires moisture of between 30-50% in the timber. Unfortunately, this superb mobility of boron results in one major disadvantage, namely, the leaching of boron when moisture enters timber. Various methods have been used to impede the movement of boron out of timber (wax coating, paints, varnishes and water-based polymer coatings. None of them have been completely successful. For instance, varnishes, used to prevent boron from leaching out of timber are unsuitable because they also prevent moisture leaving the timber. This results in blistering of the coatings used to contain the boron. In this project, an all-in-one system was developed by systematically varying the nature of the boron compound and the polymer. The successful formulation, which contained disodium octaborate tetrahydrate, as the source of boron and a styrene acrylic polymer blend, has been found to: Allow the uninhibited diffusion of boron into timber. Form a clear continuous polymer film on curing on the surface of the timber. o Display good resistance to ultraviolet attack on the polymer and the timber substrate The product developed has been formulated with the following concentrations: 60 grams per litre of boric acid equivalent 150 grams per litre of boric acid equivalent 200 grams per litre of boric acid equivalent The efficiency of the acrylic/styrene polymer barrier was shown by performing qualitative tests for the presence of boron on the surface of the timber treated with the all-in-one formulation. Furthermore, leaching tests were performed by submerging the treated timber in water and thereafter, analyzing the water for leached boron at regular intervals. The results of these tests showed that the new formulation (60 gIL, 150 gIL and 200 gIL) is suitable for treatment of timber that is destined for above - ground applications. The preservative containing a concentration equivalent to 60 gIL of boric acid was sufficient for remedial treatment. The preservative containing an equivalent of 150 gIL and 200 g/L of boric acid was ideal for treating freshly felled timber. The patent application for this preservative has been accepted. / M

The removal of phenols from the waste waters of wood preserving plants has always presented problems. The purpose of this paper is to investigate the possibility of employing a biological system to reduce the phenol content of effluent from these plants.

The set of 68 misericords in Beverley Minster, Yorkshire, carved in 1520, are considered here both as a corpus of 'folkloric' imagery in their own right, and in a eider cultural context. A detailed iconographic examination of the individual misericords under such headings as 'The Fool and Follies', 'Satires', 'The bestiary' 'Exempla', etc., leads to the isolation of a small number of motifs which are seen not to belong to the native tradition. These non-English motifs are traced to two main sources, the border woodcuts in early Parisian printed Horae and Flemish & German prints. The identification of these sources for the Beverley designs leads to further identifications else here, and especially in the stalls of St. George's Chapel, llindsor, c. 1430. In the case of Beverley it is suggested that the means of transmission of such Continental imagery is via the port of Hull (the Customs Accounts for the port being examined in this light), and the printers and book-sellers of York. The local cultural milieu in which the Beverley stalls were created is examined and Henry Percy, the 'Magnificent' Fifth Earl of Northumberland, shown to be an influential patron of the arts; but other local influences considered include the late medieval dramatic cycles played in Beverley, the town 's patron saint John (portrayed as a 'hairy anchorite') and a York & London printer known to have printed in Beverley, Hugo Goes (whose unique woodblock-printed wallpaper is also discussed). Goes's Flemish origin leads to a consideration of the presence of other alien artists and craftsmen (e. q. ! Maynard Weywick who provided the patterns for Torrigiano's Westminster tombs) at work in late medieval and early Tudor England -- much of it assembled here for the first time.

<p> The effects of cultural intensity (operational and intensive) and planting densities (741, 1483, 2224, and 2965 ha^-1) on modulus of elasticity (MOE), modulus of rupture (MOR) and specific gravity (SG) of small clear samples obtained from 15 and 16 year-old loblolly pine (<i> Pinus taeda</i>) from the Lower Coastal Plain and Piedmont region of the southeastern United State were examined. Planting density and distance from pith showed a significant (<i>p</i> &lt; 0.0001) and strong main effect on stiffness (MOE) and strength (MOR) for the samples. Regardless of planting density, MOE, MOR and SG of samples increased significantly from pith toward bark. A significant culture &times; density interaction (<i> p</i> &lt; 0.0001) was observed for the samples obtained from the Lower Coastal Plain. </p><p> The project also determined the feasibility of measuring microfibril angle (MFA) on solid wood loblolly pine samples using scanning electron microscopy and transmission electron microscopy with the angle analyzed using image analysis. Measurements of MFA revealed minor differences (5⁰) between juvenile wood and mature wood.</p>

Introduction: Throughout many parts of the world, forests exist in one form or another. And for the timber from these forests to be used, it must be processed by, for example, sawing into planks and dried. Studies have shown that profits for the forest owners increase from beneficial processing of these raw materials. An efficient use of this raw material is to process it into lightweight panels. Some general incentives for using lightweight constructions are: economical, technical and environmental. Some general weaknesses with sandwich constructions are more sensitive to impact and bumps, risk for delamination, harder to make fastenings, and more sensitive to the concentration of point loads. This work aims to increase the knowledge of properties and design of wood based lightweight panels used for interiors and furniture. The intention with this knowledge is that it can contribute to the development of lightweight panels. Material and method: A lightweight panel of cross glued sandwich type and a cross-glued multi-layered panel with densified face sheets have been used as an example to investigate and understand which parameters are crucial for a lightweight panel, made of wood. The lightweight panel of sandwich construction has been studied to consider the changes of shape brought about by moisture, as well as which mechanical properties this panel has, with a focus on creep deformation. Two methods for reducing the moisture-generated shape changes so as to increase the shape stability of the panel have also been studied. The methods are crossgluing and thermal treatment of the wood material. In the investigations of the panels, primarily quantitative methods in the form of empirical tests have been used. Some numerical simulations describing the moisture-generated shape changes and stresses that arise in the investigated lightweight panels were also made. Results and discussion: Cross-gluing of a multi-layered panel and also for the lightweight panel used in this study is a way to reduce the movement in the panel, generated by moisture. The drawbacks with this method are that stresses occur in the panels when the moisture change, and this can lead to a decrease in the shape stability of the panel. Thermal treatment can also be used to decrease the moisture-generated movement in wood, and in this way increase the shape stability of the product. In those cases where the empirical experiments were combined with numerical simulations, there was good agreement between the experimental and the numerical results. With the lightweight panels a weight reduction was achieved from 307 to 540 kg/m3 compared with a solid beech wood panel. The creep deformation of the lightweight panel was better or comparable for 6 of the 8 studied groups, compared to solid beech wood panel. The study also show that is possible to adapt the mechanical properties through its design of this lightweight panel.

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