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EU Council Directive (2008/120/EC) prohibits the routine practice of tail docking to control tail biting in pigs, yet most pigs in Europe are still tail-docked. This is primarily due to a lack of effective solutions with the least economic impact for the producers, especially in fully-slatted systems. This PhD project aimed to find strategies to manage tail biting in pigs housed on fully-slatted floors, using enrichment and dietary strategies. The first two experiments started with identifying suitable materials as enrichment for docked pigs housed in fully-slatted system. Pigs' enrichment use was compared between four different wood types; beech (Fagus sylvatica), larch (Larix decidua), spruce (Picea sitchensis) and Scots pine (Pinus sylvestris L.), and also between wood types (beech, larch, spruce) and a rubber floor toy. Pigs were consistently observed interacting with the spruce more frequently than the other wood types in the two experiments, and the rubber floor toy also generated a similar amount of interaction from pigs as the spruce post. No carcass damage was found which could be directly related to using dried wood sourced from a commercial sawmill. The next experiment used a single enrichment item and different fibre levels in the diet to rear undocked pigs. In a 2×2×2 design, the pigs had either: A) a standard (weaner 3.7% finisher 5.9%) or high fibre (weaner 5.3% finisher 11.6%) diet; B) a spruce post or a rubber floor toy as enrichment in the weaner stage; C) the same/alternated enrichment given in the finisher stage. During this experiment a high level of tail biting was recorded (n=26 tail biting outbreaks), and a substantial number of pigs were removed temporarily or permanently from their home pens due to tail biting. Pigs fed with a high fibre diet had worse tail damage score and performed more tail biting. Pigs which had the floor toy in the weaner stage and wood in the finisher stage had slightly lower tail lesion scores. Pigs receiving the floor toy interacted with the enrichment more frequently overall. This study showed that higher dietary fibre in a relatively barren environment did not help reduce tail biting or tail lesions Moreover, a single enrichment item, which was preferred by pigs in the previous studies, was not enough in a group of 14 pigs to control tail biting, and thus the quantity of enrichment may be important factor to consider. In the final experiment, a 2 × 3 design was used to further investigate the effect of A) an enriched/barren environment during farrowing and B) three enrichment management strategies post-weaning, based on the frequency of replenishment ("Low": on Monday/Wednesday/Friday; "Medium": once daily; "High": ad libitum). All pens received the same enrichment (8 items/12 pigs, including an elevated rack supplied with fresh-cut grass). The average daily gain in the finishing stage was slightly higher in "High" than "Low" pigs. "Low" pigs also performed more damaging behaviours (tail/ear biting, belly-nosing, mounting, other biting and aggressive behaviours) than "High" and "Medium" pigs. No difference in lesion scores was found between treatments. Although sporadic tail biting outbreaks occurred (n=14, halved compared to the previous trial), they usually resolved within 2 weeks, and all but one tail-injured pig were successfully reintroduced back to their home pens after removals. Thus, this study concluded that by employing appropriate enrichment management strategies, tail biting can be kept at a level without a negative impact on the production cost in undocked pigs housed in a fully-slatted system.

Wood from coniferous trees is an important source of renewable biomass. It can contribute to provision of carbon neutral energy, biomaterials and housing for a growing population. Softwood is mainly composed of cellulose, galactoglucomannan, xylan and lignin. This thesis focuses on the biosynthesis and function of Glucuronic acid (GlcA) decorations on softwood xylan. Results demonstrate that this GUX (GlucUronic acid substitution of Xylan)-dependent xylan branching is critical for the maintenance of biomass recalcitrance in a model vascular plant Arabidopsis thaliana. Experiments employing in vitro and in planta activity assays show that conifer transcriptomes encode at least two distinct GUX enzymes which are active glucuronosyltransferases. Interestingly, these enzymes have different specific activities, with one adding evenly spaced GlcA branches and the other one being able to add consecutive decorations. It is possible that these different patterns of xylan branching may have an impact on ability of xylan to interact with cellulose fibrils. To investigate the role for xylan binding to cellulose, Arabidopsis mutant plants in which this interaction is lost were evaluated alongside transgenic mutant lines in which the interaction may be restored. Results of this analysis indicate that the presence of cellulose-bound xylan might have an influence on plant vasculature integrity and thus it may have an effect on plant growth and biomass properties. Moreover, further results indicate that some xylan cellulose interaction is likely to occur in cell wall macrofibrils which can be detected in softwood. Taken together, this thesis provides insights into the process of conifer xylan glucuronidation and the possible role these branches may be playing in the maintenance of softwood recalcitrance and mechanical properties. In addition to identifying potential mutagenesis targets for improving softwood processing, this work is a proof of concept for the use of GUX enzymes for in vivo and in vitro biosynthesis of novel xylan structures with potential industrial application.

Pallets represent a large part of the North American solid wood market, with an estimated demand of 1.9 billion pallets in 2024, and 3.1 billion pallets in stock in 2019(Freedonia, 2020). In 2021, 1.18 billion pallets were produced, 919 million were new pallets, and 280 million were repaired or remanufactured (Hobbs, 2024). When pallets reach their end of life, they are landfilled, or recovered by grinding them for mulch or fuel. The objectives of this study are to quantify the number of pallets that are landfilled or recovered, investigate historical trends regarding wood waste at Municipal Solid Waste and Construction and Demolition landfills and investigate alternate uses for pallets. This study was conducted by sending out paper and electronic questionnaires to active landfills in the continental U.S. The study found that 76.8 million pallets, 8.4% of new pallets in 2021, end up in a landfill but 4% of these pallets will be recovered to some useful product such as mulch and only 4.4% will be buried in the landfill. Landfills encourage the population to separate wood before they send material for landfilling, and they are doing this with lower tipping fees. Landfills indicated alternate uses for recovered pallets include alternate daily cover, to ship e-waste, used for road base, given to residents and chipped for mulch or fuel. The study found that 95-97% of wooden pallets produced in the U.S. are repaired for reused, used for repairing other pallets, or converted into value adding by-products.

This thesis explores the development of material approaches in archaeology to discuss the relationship between material engagements in the world and cosmological schemes. In particular, the role of key materials in cosmologies is considered in light of ideas about elements and their fundamental role in the composition of the world. Three materials (wood, fire and water) are then considered in detail using anthropological illustrations to highlight the range of ways wood, fire and water are understood in traditional societies. Archaeological examples from the late Mesolithic and earliest Neolithic are examined in light of these ideas to suggest new possibilities for interpretations of the material remains discussed. These discussions of materials and cosmologies are set against a background of the debates surrounding the transition to the Neolithic. In particular, recent challenges to perceptions of the Mesolithic are considered to highlight the problematic discourses that have traditionally dominated studies of the period. It is amongst these critical reappraisals that this thesis contributes to emerging narratives of lives in the Mesolithic. The use of wood, fire and water is examined in contexts of the late Mesolithic and earliest Neolithic and is suggested to show much continuity in the practices that used wood, fire and water. Similar properties were actively called upon in these continued practices however, their deployment in new contexts and practices is suggested to indicate a shift in the importance of certain properties or characteristics. The implications of this in relation to cosmological schemes suggests aspects of continuity such as connections between materials and the landscape but accompanied by a stronger emphasis on certain relationships and processes within the world such as the transformation of bodies and articulation of community.

Wooden pallets are essential part of the supply chain carrying approximately 80% of all products shipped domestically. The production of pallets is also strongly correlated with the U.S. G.D.P and manufacturing G.D.P. This research was conducted to obtain important information on the market and raw material usage trends in the wooden pallet and container industry from 2019 through 2021. These trends have been compared to historical data that has been collected by Virginia tech and U.S. Forest Service pallet surveys from 1991-2016. This study was conducted by sending out physical and online surveys to 2319 companies who produce and broker wooden pallets and crates. The wooden pallet and container industry produced and estimated 919 million new pallets in 2021 which is an estimated 75% increase since 2016. The 48"x40" pallet size continues to be the dominant new pallet size with a 29% market share. The share of softwood lumber used in the industry steadily increased since 2016 and accounted for 81% of the lumber used in pallet production. The industry used 38.6% percent of the total sawn softwood lumber produced and 37.6% of the total sawn hardwood lumber produced in the U.S. The industry also produced 280 million repaired and remanufactured pallets. This is an estimated 16.4% decrease from previous research conducted in 2016. In 2021 approximately 89% of all recovered wooden pallets are converted to repaired or remanufactured pallets. Approximately 22% of respondents stated that they were not affected by the pandemic. A majority of 51% of respondents stated that they exceeded their 2019 sales, with 12% seeing no change in sales in 2020 compared to 2019.

Biocomposites exhibit properties like many petrochemical-based polymers composites. They have the potentials be used in the automotive and decking industries and as biodegradable packaging. However, the high cost as well as, poor mechanical and thermal properties have restricted their widespread use. There are a number of technical issues that need to be addressed before bio-composites can be widely used. In this research Polylactic acid (PLA) composites, reinforced with natural fibres (wood, flax) and mineral fillers (talc) were investigated. The thermal and mechanical properties of the composites were studied by means of Differential Scanning Calorimetry (DSC), Tensile Testing and Dynamic Mechanical Analysis (DMA), while morphology and crystallization processes of the composites were studied by hot stage optical microscopy. The experimental results are also compared with different theoretical models of the response of the composites. PLA / wood composites were developed by mixing PLA with wood in different ratios using a melt compounding process. PLA/wood (90/10. 80/20, 60/40), PLA/wood/copolymers (85/10/05, 80/10/10, 75/20/05, 70/20/10, 55/40/05, 50/40/10) and PLA/wood/coupling agent (80/20/silane coating) were the three different composite systems that were developed. Adding increasing amount of wood into the PLA, the thermal properties remain unchanged but the mechanical properties increased significantly, bringing a stiffening effect to the composites. Tensile modulus increased from 4.1± 0.6 to 9.8 ± 1.2 (GPa) as the wood content increased from 0 to 40 (wt %), but the tensile strength at break reduced from 43.8 ± 3.1 to 31.8 ± 2.8 MPa. The experimental results of the PLA-wood composites were modelled according to the Halpin-Tsai equation. The addition of copolymer affected the thermal properties considerably by decreasing the glass transition temperature of the composite. The glass transition temperature dropped from 54 ± 0.7 (0C) to 48 ± 0.36 (0C) when the content of copolymer was increased from 0 to 10 (wt %). The cold crystallization temperature also decreased from 127 ± 1.41 (0C) to 103 ± 2.58 (0C) when the copolymer was incorporated into the PLA/wood composites. The significant aspect was the occurrence of a double peak in the melting endotherm. The degree of crystallinity also increased from 2 ± 0.83 (%) to 11 ± 1.23 (%) when the amount of copolymer was increased to 10 (wt %). PLA, flax and expoidizied natural rubber (ENR) composites were also developed using a melt compounding process. The mechanical properties were affected significantly when the flax fibres were mixed with PLA in the ratios of 10, 20 and 30 (wt %). Addition of flax fibres increased the elastic modulus significantly but reduced the tensile strength and strain at break. To improve the toughness of the PLA- Flax composites, ENR was incorporated into the PLA- Flax composites. In order to balance the modulus of the reinforcement and the matrix, the PLA- Flax and ENR composites were annealed above the glass transition temperature and the degree of crystallinity increased from 2 to 35 (%). The integral blending of PLA, Flax and ENR did not affect the brittle fracture but introducing a masterbatch of flax fibres and ENR into the PLA matrix during melt processing had a considerable effect on the fracture behaviour of the composites. The elastic modulus of the composites decreased due to the elastomeric content in the composites and there was an increase in elongation-to-break. The effect of talc on the crystallinity and mechanical properties of a series of polylactic acid (PLA) / talc composites was investigated. PLA talc composites were developed by incorporating different types of the talc into the PLA in the ratios of 10, 20 and 30 (wt %). The composites were prepared by melt blending followed by compression moulding. It was found that talc acted as a nucleating agent and increased the crystallinity of the PLA from 2% to 25%. There was significant improvement in Young s modulus of the composites with increasing talc addition and these results were found to fit the Halpin Tsai model. Thermo-mechanical tests confirmed that the combination of increased crystallinity and storage modulus leads to improvement in the heat distortion properties.

This project investigates the use of wood in Iceland during the Viking and Early Medieval Periods, and discusses the control and management of wood resources and their variation over space and time. Previous palaeoenvironmental studies and historical sources had suggested that after the colonisation of Iceland around AD 870, the Norse settlers cleared the native Icelandic birch woodland to make way for hay fields, and used the timber for fuel and construction, rapidly reducing the woodland cover from its original 18-40% to the 1% present today. This investigation, which compares archaeological evidence to information about wood resources given in historical sources, reassesses these traditional models and interprets the decline of Icelandic woodland in relation to the utilisation and control of wood resources on the island, to understand the relationships between sites in terms of wood procurement, control and sharing. Wood anatomical analysis is used to assign taxonomic identifications to wooden artefacts and charred and mineralised wood remains from ten study sites across Iceland, allowing the origin of these assemblages to be identified as native wood, driftwood or imported wood. Understanding the distribution of non-native woods is essential to the understanding of how wood resources were shared and controlled on the island. The results show that despite the decline of the native woodlands, wood continued to be used as fuel and in artefact production and the construction of buildings and boats throughout the Medieval Period, and that the control of access to these resources was key to their continued availability. This project integrates for the first time archaeological, environmental and historical evidence, resulting in a holistic view of wood use during Viking Age and Medieval Iceland, and provides an important contribution to the understanding of natural resource use and human-environment interactions in the North Atlantic region.

Orangutans are the only great ape to live an almost completely arboreal lifestyle, spending the majority of their time in the canopy of the tropical forest. The orangutans’ large size and habitual arboreal lifestyle means they are uniquely constrained by the mechanical properties of their canopy habitat. It is therefore necessary to have knowledge of the mechanics of trees and the wood material of which they are made in order to gain a greater understanding of orangutan ecology. This thesis begins with an investigation into the bending failure of three temperate tree species. Observations and electron microscopy of the fractures of hand bent branches were coupled with mechanical tests of the branch structures and the wood material. It was shown that the fracture mechanisms observed were related to the anatomy and consequent mechanical properties of the wood material. Light woods buckled due to their low transverse compressive strength, whilst denser woods tend to break in greenstick fracture, in which the fracture is diverted longitudinally at the midline, due to the low tangential tensile strength of the wood material. Three neotropical tree species were investigated in the same way and it was shown that all species tested failed in greenstick fracture with the modes of failure explained, at least in part by the differences in their wood anatomy and mechanical properties. These results were used to inform an investigation of orangutan nest architecture. The compliance of the nest structures was measured and the morphology, mechanical properties and modes of fracture of the nest elements were recorded. It was shown that nests were slightly more compliant where the orangutans’ weight was situated. Orangutans built the structural part of the nest by selecting, half breaking and weaving together thicker more rigid branches. However, the nest lining was generally made from completely detached narrower and less rigid branches. This suggests orangutans have a degree of technical knowledge, selecting the correct material for a certain construction role. In order to achieve a greater understanding of the mechanically complex canopy substrate that the orangutan inhabits, a study in to the mechanics of the canopy substrate was performed. Direct measurements of compliance and frequency of oscillation were taken from a range of tropical branches used by orangutans. It was shown that compliance increases dramatically towards the tip of branch and that branch diameter is the most effective branch morphological trait for predicting compliance levels. This study allowed a greater understanding of how these properties may affect orangutan ecology. To address whether conditions are present for energy storage and return during bouts of orangutan bipedalism, measurements of compliance and branch oscillation times were used in conjunction with analysis of video footage of orangutans. It was found that long step times of orangutans fall between the minimum and optimum step times for energy return, calculated from mechanical properties of bipedal supports. These results were supported by videos demonstrating in-phase branch movement and step kinematics. These results suggest that local diameter is the single most useful trait to predict the strength and rigidity of tropical branches, and their compliance and oscillatory frequency. This suggests that this is the cue used by the apes, and helps validate the assumptions made by previous researchers investigating arboreal primate locomotion. They also suggest that the conditions do exist in the natural environment that may facilitate energy storage and return on compliant branches during bipedal locomotion.

Scots pine (Pinus sylvestris L.) represents around 16% of the area of commercial conifer plantations in Great Britain, but around 30% in north and north-eastern Scotland. Most of the timber produced from these forests goes into lower-value markets such as fencing and panel products, and only a small proportion is converted into high-value structural timber. In order to maximise financial returns from this resource in the medium and long term, it will be necessary to increase the outturn of structural timber. However, this requires knowledge of the variation in those wood properties that influence structural timber performance and of the effects of silviculture on wood quality. Changes in silvicultural practices in recent decades—wider initial spacings, a preference for artificial regeneration, and an increased use of mechanised thinnings, have led to concerns about the suitability of Scots pine timber for use in structural applications due to potentially poorer stem form, a greater proportion of juvenile wood and larger, more numerous knots. As part of the research presented here, novel predictive equations were developed for the key physical, mechanical and branching properties that determine structural timber quality in Scots pine, namely: microfibril angle, wood density, clearwood bending strength and stiffness, and branch number, size, insertion angle and status (alive or dead). Simulations were carried out using these equations to examine the effects of different silvicultural regimes on each wood and branch property of interest. Based on these simulations it is recommended that in order to produce high quality Scots pine timber, trees are planted at narrower initial spacings and grown on longer rotations than currently prescribed, and, where appropriate, thinnings should be delayed. Together, these measures will restrict final branch size and the amount of mechanically inferior juvenile wood in the final crop.

Tree breeders worldwide have highlighted the importance of wood quality within the juvenile core in determining final timber strength. The potential for improving timber strength by estimating genetic parameters of certain wood properties of Sitka spruce (Picea sitchensis) within the outer zone of the juvenile core was investigated. Fifteen trees were sampled from each of 33 families selected from a 20 year old open pollinated progeny trial. A number of wood properties critical to wood strength were measured; namely, density, grain angle, microfibril angle and branching characteristics. Clearwood stiffness and strength along with indirect measures of stiffness using acoustics and density using Pilodyn measurements were assessed. All wood properties were moderately heritable, wood density and acoustic velocity were the most heritable traits (h2 i 0.71 and 0.67 respectively). Genetic correlations showed that wood strength and stiffness were strongly correlated with wood density (0.86 and 1.04 respectively) and microfibril angle (-0.79 and -0.62 respectively). Acoustic velocity was strongly correlated with wood stiffness (0.81) and microfibril angle (- 0.83). The ability to select trees for wood stiffness with the use of acoustics along with the moderate inheritance of this trait should enable improvements in the wood quality of Sitka spruce. Despite the unfavourable correlation between growth rate and some key wood quality traits associated with timber strength, selection of certain families would enable modest gains to be made in both growth rate and wood quality.

Timber joints fastened with prototype double-sided nail plates were fabricated from European whitewood of densities generally in the range 350 to 600 kg/m3 . Joint behaviour was characterised from experimental results of 150 joint tests conducted to current European standard methods. Three characteristics, namely tooth load-carrying capacity, slip modulus and ultimate modulus, were required to fully describe the joint behaviour envelope up to maximum load. Joint performance was found to be well correlated to timber density and empirical models relating each characteristic to density were derived. For analytical modelling purposes, each nail plate tooth was assumed to act as a dowel. Theoretical capacity based Johansen's pin joint theory and the Eurocode 5 embedding strength prediction for driven nails over-predicted the empirical model by 15% at 350 kg/m3 density, improving with increasing density to 8% at 600 kg/m3 . Also, effective embedding strengths derived from Johansen's theory were perfectly correlated to those predicted from an empirical model based on tests conducted using a rigid embedment tool on fine-sanded wood surfaces. On the assumption of no joint separation at failure, the effective embedding strength was half the rigid embedment value. The proportion decreased for assumed larger gaps. Modelling of nail plate fastened timber joints is complex and often relies on empirical calibration. In contrast to the conventional approach of using non-linear springs to lump tooth-wood interaction at the tooth root, modelling in this thesis treated the double-sided nail plate as separate from the timber. Tooth-wood interaction was modelled using contact mechanics and effective material properties determined from inverse modelling. FE modelling was done using ABAQUS 6.3 software. Analysis using a two-tooth joint model showed that tooth capacity per unit length increased with decreasing tooth length but other factors outside the scope of the study precluded the determination of optimal tooth length. Parametric studies based on the nail plate tooth width were undertaken using a 1⁄2 joint model. At optimum, the tooth width increment was 25% and the capacity gain was 12%. Base plate buckling, which was absent in the original configuration, was well pronounced at optimum.

The water content of the wood cell wall has been investigated, for modern and waterlogged archaeological wood samples, by differential scanning calorimetry (DSC) and inverse chromatography (IC). DSC was used to measure the amount of water in the wood that did not freeze on cooling to -40° C, in samples dried to different water contents. The unfrozen water was found by plotting the heat of melting of ice in the sample against the fractional water content. For modem woods, the unfrozen water contents (UFW) were in the range 0.28 to 0.34 g water / g wood. For the archaeological woods, the UFW ranged from 0.534 up to 1.2 g water / g wood. IC was performed with chromatographic columns made of powdered wood, using ethylene glycol, diethylene glycol, sugars and narrow molecular weight distribution dextran standards as probe molecules to determine the water content of the wood cell wall. For the modem woods examined, these gave results similar to those of DSC in that no variation with wood density was found, but the results are higher. Packing columns with waterlogged archaeological wood proved to be very difficult, and no definitive results for the water content of the cell wall were obtained. The wood columns were also used to study the penetration, size exclusion and adsorption of polyethylene glycols (PEGs) and salts with the cell wall. PEGs showed a variety of elution behaviours, from size exclusion to adsorption. In balsa wood, and in all the archaeological woods studied, PEGs were adsorbed. It is suggested that this was adsorption onto the lignin. Salts were excluded from the wood pores to a degree dependent on their concentration and position in the lyotropic series. The implications for the conservation of waterlogged archaeological wood are discussed.

This research programme was instigated in response to concerns regarding the potential impact of sewage contamination from a long sea-outfall commissioned in 1991 in Portsmouth, Hampshire, on the long-term quality of local, historic wreck timbers. Information pertaining to the quality of seawater and the degradation of sacrificial wood samples, with particular emphasis on the action of the wood-boring crustacean, Limnoria spp, was collected and is presented in this thesis. The data was collected from three wreck sites in the Solent and surrounding waters: the Mary Rose (1509 - 1545), HMS Invincible (1744 - 1758) and HMS Hazardous (1698 - 1706). Both the Mary Rose and HMS Invincible sites are situated in an area of the Solent that was contaminated by sewage discharge. The site of HMS Hazardous is in cleaner water at Bracklesham Bay and was therefore designated as the control. Limnoriid activity was found to be higher at the HMS Invincible site than at the Mary Rose site - the HMS Invincible site also recorded the highest levels of sewage contamination. However, limnoriid activity was greater still at the "clean" control site of HMS Hazardous, thereby ruling out a conclusive link with sewage contamination. Water quality analyses showed the existence of vertical layering in the water column for many of the parameters determined. L. quadripunctata dominated the limnoriid population at the three sites but there was a significant presence of L. lignorum at the deeper Mary Rose site. On one occasion (winter 93/94), L. lignorum dominated the limnoriid population at the Mary Rose site. At the same time, the affinity for Scots pine wood observed during the rest of the study was not apparent. Faecal indicator bacteria were isolated from the biofouling layer of the wood blocks at both the Mary Rose and HMS Invincible sites and microbiological activity appeared to be greatest at the Mary Rose site. Fouling barnacles on the wood samples appeared to offer some protection from limnoriid activity in the short-term but had no long-term protective effect.

Wood is a versatile and strong engineering material which displays a high level of anisotropy. Modelled as an homogeneous orthotropic solid, its natural variability and unique micro structure presents a serious challenge to the application of standard nondestructive evaluation techniques for quality assessment. In this work the characterisation of wood using ultrasonic techniques is considered. Addressing the problem is seen as requiring knowledge of three distinct areas - the structure of wood, the theoretical basis of elastic wave propagation in an orthotropic solid and ultrasonic measurement science. This forms the basis of a critical review of the literature pertaining to ultrasonic characterisation of wood. A systematic study of ultrasound velocity and attenuation over a range of frequencies is reported in chapter 6 of this work. From this study which examines three species of wood with different microstructures a number of significant results emerge. The species are seen to display different levels of anisotropy. Velocity is seen to increase significantly with frequency, particularly for some species. Attenuation is seen to be frequency dependent. The results point to the significance of the inhomogeneity of wood. The variation of ultrasound properties from pith to bark and at different levels within the tree is also measured. The orthotropic model is extended to include the effect of the inhomogeneity due to the annual ring structure in wood. This is modelled as a quasi-periodic structure. A novel set of measurements of acoustic inhomogeneity in the longitudinal and tangential directions, which can resolve within ring variations in wavespeeds, is presented. These measurements are used, along with data from the literature to show that the potential stop and pass bands may exist for waves travelling in the radial direction. A phase cancellation artefact and other interference effects are seen to exist for propagation in the longitudinal and tangential directions. Finally artificial neural network analysis is used to show that ultrasonic signals may be classified by the species through which they have propagated. This method is seen as having potential for engineering applications.

Buried wooden artefacts can be readily imaged by Chirp-sourced reflection seismology. Compressional wave velocity parallel to the wood grain (VL) is consistently faster than that across-grain (VR and VT). Theoretical and experimental predictions of reflection coefficients (KR) calculated for wood buried in unconsolidated marine sediments are typically large and negative (KR = +0.27 to -0.79; KRoak = 0.03 to -0.64). Variations in KR are dependent upon the burial-sediment, wood species and structural coherency of the artefact. Synthetic modelling demonstrates that small changes in the seafloor impedance profile causes random switches in the polarity of the Chirp pulse. Reflection coefficients are calculated from Chirp sub-bottom data using amplitude-time relationships and polarity information derived from trace-mixing. Calculations from Chirp data acquired over a partially buried 17th Century oak-wreck provide an average KR of -0.26, in agreement with the predicted range. A pseudo 3-dimensional Chirp survey of the excavated Mary Rose wreck site (East Solent, UK) identified two brightspot anomalies, buried to a depth of 4-5 m, trending east-west adjacent to the western margin of the excavation hole. These anomalous reflectors are interpreted as infilled palaeo-scour features associated with the wrecking and subsequent degradation of the Mary Rose. Fill material comprises wreck fragments and coarse sediment sourced from the ship's ballast. Longitudinal scour features were previously unrecognised on the site, and represent the first time such palaeo-scour marks have been recognised in the sedimentary record. Integrated Chirp and side-scan sonar surveys of the Invincible site (East Solent, UK) demonstrate the capability of high-resolution acoustic techniques to: identify the extent and coherency of semi-exposed wrecks, determine the wrecking history of a site and act as an effective management tool. The distribution of wreck material is primarily controlled by storm-associated wave action, depositing the bulk of fragmented wreck-structure to the north and north-east of the in situ port side. Evidence suggests that current site stability is controlled by a combination of tidally induced currents and anthropogenic activity.

A beautiful floor, a forgotten element, draws the eye down, a rare direction to view architecture. The presence of a floor, realized through travel, led to a curiosity about the patterns adorning the surface and an architecture generated by the floor. A pattern becomes a floor when lines turn into joints. The subtle interruptions of a pattern's repetition, revealed through geometric construction, establishes the boundary of a floor and the order of a room. In a series of rooms determined by the floor, the transition from one pattern to another, with respect to tectonics, creates the thresholds and fenestrations within the procession. The acts of making and ichnographic drawing, under the watchful hand of craft, directed this study of a floor as the principal architectural consideration.

Corsican pine (Pinus nigra) and beech (Fagus sylvatica) wood specimens were modified with n-butyl isocyanate (n-Bu-NCO), phenyl isocyanate (Ph-NCO), 1,6-diisocyanatohexane (HDI) and tolylene 2,4-diisocyanate (TDI), using pyndine as the swelling agent and catalyst. Several levels of weight gain were achieved by varying the reaction time. For each species the approximate general reaction rate order based on hydroxyl substitution was Ph-NCO > n-BuNCO > HDI > TDI for Corsican pine, and HDI > Ph-NCO > n-Bu-NCO > TDI for beech. The effect of chemical modification in the sorption properties and in the associated dimensional stability of wood was investigated by determining sorption isotherms and measuring the respective volumetric swelling at each relative humidity (RH) level. The treatment depressed the isotherms evenly over the entire range of RH for all levels of reaction, however, the difunctionally modified wood tended to show lower reduction in sorption at low RH's. The reduction in sorption was closely accompanied by a reduction in swelling indicating that within the accuracy of the experiment no voids were formed within the cell walls due to the treatment. The TDI treated specimens showed higher reduction in swelling under RH conditions than at saturation in liquid water. This was interpreted as to be caused by the formation of rigid TDI crosslinkages. The mechanisms of reduction in wood hydroscopicity were investigated by fitting data to the Hailwood-Horrobin sorption model. It was shown that the chemical modification treatment affects both monomolecular and polymolecular sorption. The accessibility of bonding sites was also reduced. Regression analysis revealed that the reduction in monomolecular sorption is chiefly governed by the decrease in site accessibility and that the reduction in polymolecular sorption is governed by the increase in the adduct volume in the cell wall. Investigation of the causes of the reduction in site accessibility by analyzing the sorption isotherms for wood modified with n-Bu-NCO and with a bulkier monofunctional isocyanate (octadecyl isocyanate) suggest that the accessibility of the internal wood surfaces is related to the weight gain and not to the fraction of hydroxyl groups (OH) reacted. This suggests that the reduction in accessibility is caused by a 'shielding effect' where the adducts physically cover some of the adjacent unreacted sorption sites. With difunctionally modified wood no evidence of crosslinking effectiveness was indicated at saturation in liquid water. However, when the samples were soaked in pyridine, the crosslinkages seemed to influence superswelling in comparison to that shown by mono functionally reacted wood. Finally, tensile strength tests carried out on modified and unmodified wood strips revealed that with the exception of n-Bu-NCO treated samples, the wood strength is slightly but significantly reduced by the treatments.

In a balancing act between fear and curiosity, I have created a series of wood-based artifacts to serve as vessels in which I may pose questions to myself. At the core of each artifact is a sphere primarily produced from a log allowed to dry and fracture naturally, capturing a snapshot of change in motion. Through the creation of these vessels, I attempted to better understand how I define what it means for me to be queer and non-binary. Although these artifacts are contemporary works, I have removed them from a particular known visual time in hopes of providing a level of escapism into a world of mystery and intrigue of the unknown.