Wood-derived biomaterials for biomedical applications

Driven by the global trend in the sustainable economy development and environmental concerns, the exploring of plant-derived biomaterials or biocomposites for potential biomedical and/or pharmaceutical applications has received tremendous attention. Therefore, the work of this thesis is dedicated to high-value and high-efficiency utilization of plant-derived materials, with the focus on cellulose and hemicelluloses in the field of biomedical applications in a novel biorefinery concept. The residual cellulose of wood processing waste, sawdust, was converted into cellulose nanofibrils (CNFs) with tunable surface charge density and geometric size through 2,2,6,6-tetramethylpiperidinyloxy (TEMPO)-mediated oxidation and mechanical defibrillation. The sawdust-based CNFs and its resultant free-standing films showed comparable or even better mechanical properties than those from a commercial bleached kraft pulp at the same condition, demonstrating the feasibility of producing CNFs and films thereof with outstanding mechanical properties from birch sawdust by a process incorporated into a novel biorefinery platform recovering also polymeric hemicelluloses for other applications. Thus, it is providing an efficient route to upgrade sawdust waste to valuable products. The surface charge density and geometric size of the CNFs were found to play key roles in the stability of the CNF suspension, as well as the gelling properties, swelling behavior, mechanical stiffness, morphology and microscopic structural properties, and biocompatibility of CNF-based materials (i.e. films, hydrogels, and aerogels). The CNFs with tunable surface chemistry and geometric size was found promising applications as transparent and tough barrier materials or as reinforcing additive for production of biocomposites. The CNFs was also applied as structural matrices for the preparation of biocomposites possessing electrical conductivity and antimicrobial activity by in situ polymerization and coating of polypyrrole, and incorporation of silver nanoparticles, which make the material possible for potential wound healing application. The CNF-based matrices (films, hydrogels, and aerogels) with tunable structural and mechanical properties and biocompatibility were further prepared towards an application as 3D scaffolds in tissue engineering. The structural and mechanical strength of the CNF matrices could be tuned by controlling the charge density of the nanocellulose, as well as the pH and temperature values of the hydrogel formation conditions. Biological tests revealed that the CNF scaffolds could promote the survival and proliferation of tumor cells, and enhance the transfection of exogenous DNA into the cells, suggesting the usefulness of the CNF-based 3D matrices in supporting crucial cellular processes during cell growth and proliferation. The CNFs was applied as host materials to incorporate biomolecules for further biomedical application. For example, to investigate how the biocompatibility of a scaffold is influenced by its mechanical and structural properties, these properties of CNF-based composite matrices were controlled by incorporation of different hemicelluloses (O-acetyl galactoglucomanan (GGM), xyloglucan (XG), and xylan) into CNF hydrogel networks in different ratios and using two different approaches. The charge density of the CNFs, the incorporated hemicellulose type and amount, and the swelling time of the hydrogels were found to affect the pore structure, the mechanical strength, and thus the cells growth in the composite hydrogel scaffolds. The mechanical properties of the composite hydrogels were found to have an influence on the cell viability during the wound healing relevant 3T3 fibroblast cell culture. The thusprepared CNF composite hydrogels may work as promising scaffolds in wound healing application to provide supporting networks and to promote cells adhesion, growth, and proliferation.

The book of choice ferns for the garden, conservatory, and stove. Describing and giving explicit cultural directions for the best and most striking ferns and selaginellas in cultivation. Illustrated with coloured plates and numerous wood engravings, specially prepared for this work.

vol.I. Introduction to Athyrium.--vol.II. Blechnum to Nothochlaena.--vol.III. Ochropteris to Woodwardia, and Selaginella.

An expert model approach to assess the potential of non-wood forest products for forest owners

Mestrado em Engenharia Florestal e dos Recursos Naturais - Instituto Superior de Agronomia - UL

Development of the composition of oak wood during seasoning and its impact on wine

Mestrado Vinifera Euromaster - Instituto Superior de Agronomia - UL

Use of alternative wood chips from new botanical species. Their impact on phenolic composition and sensory properties of a white wine from Encruzado grape variety

Mestrado Vinifera Euromaster - Instituto Superior de Agronomia - UL

INTERACTIVE EFFECTS OF CLIMATE CHANGE AND FUNGAL COMMUNITIES ON THE DECOMPOSITION OF WOOD-DERIVED CARBON IN FOREST SOILS

Soils are the largest sinks of carbon in terrestrial ecosystems. Soil organic carbon is important for ecosystem balance as it supplies plants with nutrients, maintains soil structure, and helps control the exchange of CO2 with the atmosphere. The processes in which wood carbon is stabilized and destabilized in forest soils is still not understood completely. This study attempts to measure early wood decomposition by different fungal communities (inoculation with pure colonies of brown or white rot, or the original microbial community) under various interacting treatments: wood quality (wood from +CO2, +CO2+O3, or ambient atmosphere Aspen-FACE treatments from Rhinelander, WI), temperature (ambient or warmed), soil texture (loamy or sandy textured soil), and wood location (plot surface or buried 15cm below surface). Control plots with no wood chips added were also monitored throughout the study. By using isotopically-labelled wood chips from the Aspen-FACE experiment, we are able to track wood-derived carbon losses as soil CO2 efflux and as leached dissolved organic carbon (DOC). We analyzed soil water for chemical characteristics such as, total phenolics, SUVA254, humification, and molecular size. Wood chip samples were also analyzed for their proportion of lignin:carbohydrates using FTIR analysis at three time intervals throughout 12 months of decomposition. After two years of measurements, the average total soil CO2 efflux rates were significantly different depending on wood location, temperature, and wood quality. The wood-derived portion soil CO2 efflux also varied significantly by wood location, temperature, and wood quality. The average total DOC and the wood-derived portion of DOC differed between inoculation treatments, wood location, and temperature. Soil water chemical characteristics varied significantly by inoculation treatments, temperature, and wood quality. After 12 months of decomposition the proportion of lignin:carbohydrates varied significantly by inoculation treatment, with white rot having the only average proportional decrease in lignin:carbohydrates. Both soil CO2 efflux and DOC losses indicate that wood location is important. Carbon losses were greater from surface wood chips compared with buried wood chips, implying the importance of buried wood for total ecosystem carbon stabilization. Treatments associated with climate change also had an effect on the level of decomposition. DOC losses, soil water characteristics, and FTIR data demonstrate the importance of fungal community on the degree of decomposition and the resulting byproducts found throughout the soil.

Business Process Management and Process Mining within a Real Business Environment: An Empirical Analysis of Event Logs Data in a Consulting Project

Il presente elaborato esplora l’attitudine delle organizzazioni nei confronti dei processi di business che le sostengono: dalla semi-assenza di struttura, all’organizzazione funzionale, fino all’avvento del Business Process Reengineering e del Business Process Management, nato come superamento dei limiti e delle problematiche del modello precedente. All’interno del ciclo di vita del BPM, trova spazio la metodologia del process mining, che permette un livello di analisi dei processi a partire dagli event data log, ossia dai dati di registrazione degli eventi, che fanno riferimento a tutte quelle attività supportate da un sistema informativo aziendale. Il process mining può essere visto come naturale ponte che collega le discipline del management basate sui processi (ma non data-driven) e i nuovi sviluppi della business intelligence, capaci di gestire e manipolare l’enorme mole di dati a disposizione delle aziende (ma che non sono process-driven). Nella tesi, i requisiti e le tecnologie che abilitano l’utilizzo della disciplina sono descritti, cosi come le tre tecniche che questa abilita: process discovery, conformance checking e process enhancement. Il process mining è stato utilizzato come strumento principale in un progetto di consulenza da HSPI S.p.A. per conto di un importante cliente italiano, fornitore di piattaforme e di soluzioni IT. Il progetto a cui ho preso parte, descritto all’interno dell’elaborato, ha come scopo quello di sostenere l’organizzazione nel suo piano di improvement delle prestazioni interne e ha permesso di verificare l’applicabilità e i limiti delle tecniche di process mining. Infine, nell’appendice finale, è presente un paper da me realizzato, che raccoglie tutte le applicazioni della disciplina in un contesto di business reale, traendo dati e informazioni da working papers, casi aziendali e da canali diretti. Per la sua validità e completezza, questo documento è stata pubblicato nel sito dell'IEEE Task Force on Process Mining.

Improvement of termite resistance, dimensional stability and mechanical properties of pine wood by paraffin impregnation

Paraffin has been used as surface protection of wood throughout the ages but its use for impregnation to improve wood resistance to biodegradation is recent. This study determined the main improvements on wood properties with paraffin impregnation. Healthy Pinus pinaster Ait. wood was impregnated with paraffin at different levels using a hot–cold process. Weight gain, equilibrium moisture content and dimensional stability (ASE) at 35 and 65 % relative humidity, termite durability against Reticulitermes grassei (Clément), bending strength, bending stiffness (MOE) and Janka hardness were determined. Density increased from 0.57 to 0.99, ASE ranged between 38–96 % and 16–71 % for 35 and 65 % relative humidity, respectively. Equilibrium moisture content decreased from 9.9 and 12.0 % to 0.8 and 3.6 % for 35 and 65 % relative humidity. Termite durability improved from level 4 to level 3 of attack, and higher termite mortality was found in treated wood (52 % against 17 %). Bending strength (MOR) increased with paraffin weight gain, reaching a 39 % increase. MOE also increased by about 13 % for wood with a weight gain around 80 %. Janka hardness increased significantly reaching about 40 % for wood with 80 % weight gain. Paraffin impregnated wood has improved properties with regard to equilibrium moisture content, dimensional stability and density, bending strength and Janka hardness, and resistance against termites.

State of the art of industrial wood protection in Portugal

This work intended to give a perspective of industrial wood protection in Portugal. A survey was made of the companies treating wood mainly for use classes 3 and 4 such as autoclave treatments with biocides and wood modification procedures. Currently there are 23 companies with 33 production plants with an autoclave installed for wood preservation by impregnation. There are also two companies producing modified wood by thermal treatment. Most of the plants are located in the central and northern regions of Portugal. The leading preservation chemicals used in Portugal are Tanalith E and Celcure brands. The main wood species used in all companies is Pinus pinaster from local producers. The products commercialized by the treating companies are diverse: pre-fabricated houses, garden furniture and playgrounds, decks, poles, stakes, and sawn wood. Modified wood producers sell mostly decks and cladding. Considerable changes are expected in the next few years due to the requirements of European Directives and the typical constraints of the Portuguese market.

Comparative analysis of volatile and phenolic composition of alternative wood chips from cherry, acacia and oak for potential use in enology.

The aim of present work was to investigate the phenolic and volatile composition of cherry, acacia, and oak (from different species) wood chips. By the use of HPLC-DAD 18 different phenolic compounds were detected and quantified while for volatile composition, 33 different compounds were detected by GC-MS. In general, wood samples from oak species showed the higher number of phenolic compounds detected, while cherry wood samples showed the lowest levels. In addition, some individual phenolic compounds were detected, specifically in some wood samples, such as robinetin in acacia woods and naringenin in cherry wood. For volatile composition, cherry wood chips samples showed the lowest volatile composition followed by increasing order by acacia, French, Portuguese and American wood chip samples. Oak wood chip samples from American species showed the highest volatile content, as a result of high levels of several specific compounds (furfural, 5-methyfurfural, β-methyl-γ-octalactones, guaiacol, vanillin and siringaldehyde).

Examining Levels of Automation in the Wood Processing Industry - A case study

Companies operating in the wood processing industry need to increase their productivity by implementing automation technologies in their production systems. An increasing global competition and rising raw material prizes challenge their competitiveness. Yet, too extensive automation brings risks such as a deterioration in situation awareness and operator deskilling. The concept of Levels of Automation is generally seen as means to achieve a balanced task allocation between the operators’ skills and competences and the need for automation technology relieving the humans from repetitive or hazardous work activities. The aim of this thesis was to examine to what extent existing methods for assessing Levels of Automation in production processes are applicable in the wood processing industry when focusing on an improved competitiveness of production systems. This was done by answering the following research questions (RQ): RQ1: What method is most appropriate to be applied with measuring Levels of Automation in the wood processing industry? RQ2: How can the measurement of Levels of Automation contribute to an improved competitiveness of the wood processing industry’s production processes? Literature reviews were used to identify the main characteristics of the wood processing industry affecting its automation potential and appropriate assessment methods for Levels of Automation in order to answer RQ1. When selecting the most suitable method, factors like the relevance to the target industry, application complexity or operational level the method is penetrating were important. The DYNAMO++ method, which covers both a rather quantitative technical-physical and a more qualitative social-cognitive dimension, was seen as most appropriate when taking into account these factors. To answer RQ 2, a case study was undertaken at a major Swedish manufacturer of interior wood products to point out paths how the measurement of Levels of Automation contributes to an improved competitiveness of the wood processing industry. The focus was on the task level on shop floor and concrete improvement suggestions were elaborated after applying the measurement method for Levels of Automation. Main aspects considered for generalization were enhancements regarding ergonomics in process design and cognitive support tools for shop-floor personnel through task standardization. Furthermore, difficulties regarding the automation of grading and sorting processes due to the heterogeneous material properties of wood argue for a suitable arrangement of human intervention options in terms of work task allocation.  The application of a modified version of DYNAMO++ reveals its pros and cons during a case study which covers a high operator involvement in the improvement process and the distinct predisposition of DYNAMO++ to be applied in an assembly system.

Lighting ambiances and materialities of wood in architecture: a comparative evaluation of the quality of spaces in relation to interior finishes

Le bois est un matériau souvent utilisé par les architectes pour améliorer l’ambiance générale d’un espace, mais peu de recherches en présentent l’impact réel du matériau sur les impressions visuelles et les effets lumineux. Cette recherche étudie l’influence de la matérialité du bois par rapport à la création d’ambiances d’éclairage spécifiques dans l’architecture. Plus particulièrement, elle se concentre sur l’impact des panneaux décoratifs en bois à générer de la diversité lumineuse dans les espaces intérieurs et son potentiel à améliorer la satisfaction environnementale et l’efficacité énergétique. La recherche utilise des maquettes à l’échelle pour leur précision dans la représentation des ambiances lumineuses d’espaces éclairés naturellement ainsi que les technologies récentes d’imagerie digitale pour capturer et analyser les résultats. La méthodologie permet la comparaison entre les différents réglages des espaces intérieurs créés par une sélection des types de matérialités du bois: la réflectance (valeur), la couleur et la réflectivité. Les modalités spatiales sont comparées en présence d’ensoleillement direct et sous des conditions de ciel couvert puisque les modèles d’éclairage et les ambiances diffèrent considérablement. Les résultats permettent d’établir une discussion sur les ambiances en termes de brillance et de contraste, sur la couleur ainsi que la répartition des zones lumineuses dans l’espace. La recherche souligne le rôle des matérialités que peuvent prendre le bois pour optimiser la diversité lumineuse et la création d’ambiances visuellement confortables, ainsi que ses possibilités d’améliorer les ambiances architecturales par rapport à la lumière.

Conducta médica versus escala modificada Wood en bronquiolitis aguda

El diagnóstico y clasificación de la severidad de la bronquiolitis se basan en la historia clínica y el examen físico. Actualmente existe una variabilidad en el ámbito clínico en el uso de los predictores de hospitalización de estos pacientes. En Colombia debido al número limitado de camas hospitalarias, es importante diferenciar y clasificar adecuadamente el lugar de manejo para cada paciente, según sus características clínicas, antecedentes y rasgos sociodemográficos. De esta manera se evitará la morbilidad y mortalidad de los pacientes por esta causa, se dará un manejo oportuno y se optimizará un recurso limitado. La escala de severidad clínica de asma modificada de Wood (M-WCAS), combina síntomas y signos encontrados al examen físico para clasificar la severidad de la bronquiolitis aguda. Esta escala fue validada en Colombia en el año 2013 y podría ser un instrumento que apoye la toma de decisiones clínicas de estos pacientes en cuanto al lugar de manejo.

Adsorption of pesticides onto activated carbons from wood composites

A series of activated carbon was produced from particleboard and medium-density fibreboard monoliths, which are waste originated from the industry, and then characterized and evaluated for potential application for phenoxyacetic acids removals, such 2,4-dichlorophenoxyacetic acid (2,4-D), 2-methyl-4-chlorophenoxy acetic acid (MCPA) and 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron), from the liquid phase. All AC retain the shape of the precursor, and displays a microporous structure well-developed, reaching 0.58 cm 3 g -1. The adsorption isotherms for three pesticides were obtained in the optimal conditions and the AC with high superficial area and micropore volume exhibited better performance, allowing to state that, this AC could be a great substitute of those habitually used for this purpose. The pesticides adsorption data were linearized using the Langmuir and Freundlich equation, being the first a very good fit to the experimental data.