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This thesis investigates the existence and form of association between the technological structure of one of the most highly capital-intensive industries in the world, the paper and pulp (p&p) industry, and its dynamic behaviour in terms of market growth and development. Industrial structure issues are particularly relevant in highly capital-intensive sectors because they reflect the influence of economies of scale and changing patterns of entry and exit. The thesis draws upon two related bodies of literature: the dynamics of industrial structure, and heterogeneity within industry. It uses a quantitative hypothesis-deductive method and two panel databases. The first of these databases identifies key characteristics of the world's 150 largest p&p firms during the period 1978-2000, accounting for two-thirds of world output. The second dataset contains annual production capacity for the entire population of US p&p companies during the period 1970-2000. The US is the largest producer and consumer of p&p, accounting for one-third of world output. The main findings are as follows. Firstly, we demonstrate that p&p firms' growth is not a 'random walk' process, a generalization referred to in the literature as Gibrat's law. Nor is there a linear relation between growth and size distribution or between time and growth rates. We find that size, technology and time matter. Secondly, we demonstrate that this departure from Gibrat's law is due to the existence of three distinctive technological configurations or strategic groups of firms: 'Large & Diversified', 'Medium & Specialized', and 'Small & Very Specialized', which show persistently heterogeneous growth performance. In contrast with the findings in most of the recent empirical literature that shows smaller firms growing faster within the industry size distribution, the medium & specialized p&p companies show systematically the highest rates of growth. Thirdly, patterns of p&p firm survival and technological adoption behaviour over the last three decades are identified and related to the principal technological advances during the period, i.e. the very rapid increase in paper machine operating speed. The research contributes to the literature by providing robust new empirical evidence of the persistence over time of an intra-industry technological structure that systematically influences the heterogeneous performance of firms with different technological configurations and whose origins are linked to firms' growth processes (industrial dynamics) in the p&p industry.

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Cette thèse est à la première recherche doctorale menée au Kenya sur les causes de ladiminution des apprenants de français langue étrangère à l‘école secondaire. Elle analyse lecontexte d‘apprentissage des langues au Kenya : leurs origines, leurs usages, leurs usagers et lesrelations didactique, professionnelle, sociétale, économique et culturelle entretenues par leKenya avec les pays voisins. La coexistence des langues au Kenya présente des usages et desimportances variés. La langue française s‘inscrit dans cette société plurilingue et y est enseignéede l‘école primaire au niveau supérieur.Cette étude souligne les liens qui existent entre la situation sociolinguistique etl‘approche didactique du français langue étrangère. Elle présente l‘origine de la langue françaisedans ce pays anglophone, depuis la période de l‘esclavage, ainsi que la politique linguistiquedans le système éducatif du Kenya. Elle essaie de montrer l‘image du français dansl‘enseignement et l‘apprentissage. Les attitudes face au français et son image sont discutées.Sept acteurs responsables du français au Kenya et 64 enseignants de français ont étéinterviewés et 179 apprenants de FLE de l‘école secondaire ont répondu à un questionnaire. Lesquestions portaient sur l‘abandon, le choix et l‘enseignement de l‘étude du français à la fin de ladeuxième année de l‘école secondaire.Les résultats font apparaître que plusieurs facteurs poussent les apprenants à abandonnerou au contraire à poursuivre l'étude de la langue française. D‘une part, ceux qui abandonnent lefont à cause de plusieurs matières enseignées à l‘école secondaire et d‘autre part, ceux quipoursuivent le font grâce à l‘amour de la langue française. L‘étude a également permis d‘établirque la langue française, même si elle n‘est pas la seule langue étrangère présente et enseignée àl‘école secondaire au Kenya, est la langue la plus enseignée et préférée de l‘école primairejusqu'aux études supérieures.À l‘inverse, la diminution du nombre des apprenants de français a été constatée commela plus forte en troisième année dans des écoles secondaires. L‘étude a également montré ladémotivation des apprenants du français en cours dans les écoles secondaires kenyanes, situationqui fait que les effectifs, importants lors de l‘inscription initiale, se dégradent au niveauuniversitaire et dans les Alliances Françaises. / This thesis is the first doctoral research conducted in Kenya on causes of declinein French foreign language learners in high school. It analyzes the context of language learningin Kenya: their origins, their uses, their users and the didactic relations, professional, social,economic and cultural, maintained by Kenya and its neighboring countries. The coexistence oflanguages in Kenya has a variety of uses and importance. French language is part of thismultilingual society and is taught from primary school to higher level of learning.This study highlights the links between the sociolinguistic situation and didactic approachof French language. It shows the origin of French language in this English-speaking country,from the era of slavery and language policy on education in Kenya. It tries to show the image ofFrench in teaching and learning. Attitudes to French language and its image are also discussed.Seven French key officials in Kenya and 64 French teachers were interviewed. 179French learners from high school answered a questionnaire. The questions focused ondiscontinuation of the language and choice to continue the learning of French language at the endof the second year of high school.The results show that several factors are pushing students to drop or otherwise pursue thestudy of French language. First, those who drop out do so because of many subjects taught inhigh school and secondly, those who continue to learn, is because of the love of Frenchlanguage. The study also revealed that although French is not the only foreign language taught inhigh schools in Kenya, it is the most preferred by students from primary school through toinstitutions of higher learning.However, the decrease in the number of French learners was seen to occur a lot in thethird year of high school. The study also showed lack of motivation from French learners insecondary schools, a situation that makes the number decrease from the initial registration; fromform one to form four. The same scenario is noted in regard to French learners in Kenyanuniversities and at Alliances Française in Kenya.

The purpose of this study was to assess the decay resistance of wood modified with a variety of chemicals and to attempt to further understand the mechanism by which chemical modification protects wood from decay. Corsican pine (Pinus nigra) sapwood was modified with three cyclic anhydrides; succinic anhydride, alkenyl succinic anhydride (a derivative of succinic anhydride with a 16-18 carbon alkenyl chain) and phthalic anhydride, and with two more widely studied modifying chemicals; acetic anhydride and butyl isocyanate. All reactions were carried out using pyridine as solvent and catalyst. Modified wood was tested against decay fungi in a pure culture test against basidiomycete fungi (Coniophora puteana, Gloeophyllum trabeum, Trametes versicolor and Pycnoporus sanguineus) under different moisture content regimes, an unsterile soil soft rot test, a fungal cellar test and a field trial. Butyl isocyanate proved the most effective modifying chemical at protecting wood from decay, followed by acetic anhydride and then alkenyl succinic anhydride. Uneven distribution of the modifying chemical in wood was evident using each of these three chemicals, particularly in the case of acetic anhydride. Despite its apparent ability to control decay by basidiomycete fungi, alkenyl succinic anhydride was unable to completely protect wood from soft rot fungi. Phthalic and succinic anhydride modifications both proved susceptible to hydrolysis and leaching, and neither were effective as wood protection chemicals. Phthalic anhydride modified wood performed well in the pure culture test, apparently through biocidal action, but was susceptible to decay in unsterile conditions. The approach made in this study to understanding the mechanism of protection was to analyse physical properties of the modified wood cell wall. This involved the measurement of adsorption isotherms, volumetric swell due to water soak, and cell wall pore size (using the solute exclusion technique). Neither the moisture content of modified wood nor its cell wall moisture content (measured as the fibre saturation point from the adsorption analysis) provided a good explanation of decay resistance. In several cases, the relationship between volumetric swell (due to water soak) and weight loss (to a given fungus in pure culture) was found to be consistent between modification types. From this it is concluded that the extent by which water swells modified wood is important to decay resistance. A reduction in cell wall pore volume was measured using the solute exclusion technique, though no further conclusions could be drawn from this test. It is proposed that the mechanism of resistance to decay by basidiomycete fungi involves the blocking of cell wall pores, which restricts the access of degradative agents released by decay fungi. The amount by which wood swells is important in this theory since this will determine by how much transient pores in modified wood can open, and whether enough space is created to bypass this blocking effect. The possibility of the role of site substitution in decay resistance is not discounted, and may contribute to decay resistance, particularly against white rot fungi. Pore blocking is not thought to be the mechanism of protection against soft rot fungi. In this case the substitution and shielding of decay susceptible sites are thought to be more important.

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There is little doubt that moisture is a very important factor in relation to material durability. The need for tools to assist in the better understanding and systematic evaluation of moisture movement with the view of incorporating the results within the overall framework of the defect investigation, quality control, and long-term monitoring of moisture, have led to the development of various moisture monitoring and predicting techniques. With the purpose of helping to harmonise the interests in this field, this thesis addresses three major issues in the area of wood moisture. Various studies carried out have been shown that there are substantial discrepancies between specific timber species and published charts for equilibrium moisture content. One of the main objectives of this research was to focus on establishing the equilibrium moisture content for a range of relative humidity and temperature on an individual basis, for twenty commercially important species used in the United Kingdom. The rationale for carrying out the project, the results from the initial trial and the mainstream experiment, the hardware and methodology developed are provided. To meet the requirements of long term accurate and reliable moisture monitoring and to provide comprehensive moisture information, a new type of moisture sensor and related measurement system were developed. The methodology of system design and test procedures are described, emphasising the anti-polarisation method, noise rejection and contact resistance reduction techniques employed. Other aspects of the electrical performance of timber were also investigated. Results from a case study showed that the sensor developed can operate in the critical range of relative humidity with sensitive and accuracy. In the final part of the project, two moisture transport models were developed. Mathematical prediction models in both one dimension and three dimensions are presented for simulating the adsorption and desorption processes in wood. Comparisons are made against long-term experimental data for the one dimensional model. The finite differential method was employed to solve the mathematical expressions developed, resulting in accurate prediction of concentration-driven moisture flows. Investigations were also carried out into the moisture diffusion coefficient and moisture behaviour in the three principal wood directions by using the sensor developed which provided isothermal real-time continuous data.

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