Upgrading of suberin from cork and birch outer bark

O trabalho aqui apresentado teve como principal prop��sito o estudo do potencial da suberina como fonte de produtos de qu��mica fina e como precursor de novos materiais macromoleculares de origem renov��vel. O interesse na suberina reside, n��o s�� na sua ubiquidade e nas suas propriedades ��nicas em termos de composi����o qu��mica e hidrofobicidade, mas tamb��m no facto de ser um dos principais componentes macromoleculares dos subprodutos da ind��stria corticeira de Quercus suber L. no Sul da Europa, e da ind��stria de pasta de papel do Norte da Europa, que utiliza a Betula pendula Roth como mat��ria-prima. A primeira parte do presente trabalho consistiu no estudo detalhado da composi����o qu��mica da corti��a de Quercus suber L. e respectivos res��duos industriais bem como da casca de Betula pendula Roth recorrendo a diferentes t��cnicas de caracteriza����o, nomeadamente GC-MS, IV, RMN de 1H e de 13C, DSC, termomicroscopia, TGA e difrac����o de raios-X. Os resultados mostraram que os produtos de despolimeriza����o da suberina representam tipicamente uma frac����o substancial de todas as amostras. Para al��m da suberina, foram tamb��m identificados nas diversas amostras quantidades vari��veis de compostos triterp��nicos, lenhina, polissacar��deos e mat��ria inorg��nica. Os principais resultados da an��lise por GC-MS mostraram que todas as amostras de suberina despolimerizada s��o fontes abundantes de ��-hidroxi��cidos e de ��cidos dicarbox��licos, bem como dos correspondentes derivados ep��xidados. No entanto, as quantidades relativas de cada componente identificado foram significativamente diferentes entre amostras. Por exemplo, em amostras de suberina da casca de Quercus suber L. isoladas por metan��lise alcalina o composto maiorit��rio encontrado foi o ��cido 22-hidroxidocosan��ico, enquanto que a suberina tamb��m proveniente da corti��a, mas isolada por hidr��lise alcalina era composta maioritariamente pelo ��cido 9,10-dihidroxioctadecan��ico. J�� no caso da amostra de suberina despolimerizada proveniente da casca externa da b��tula o composto identificado como mais abundante foi o ��cido 9,10-epoxi-18-hidroxioctadecan��ico. A caracteriza����o das diversas amostras de suberina despolimerizada por FTIR e RMN de 1H e de 13C foram concordantes com os resultados de GC-MS, evidenciando a sua natureza predominantemente lipof��lica. Foi ainda determinada a raz��o entre os grupos CO2H/OH e CO2CH3/OH por RMN de 1H das amostras convenientemente derivatizadas com isocianato de tricloroacetilo, verificando-se que a suberina despolimerizada possu��a quantidades n��o-estequiom��tricas destes grupos funcionais. A investiga����o do comportamento t��rmico das amostras de suberina despolimerizada, por DSC e termomicroscopia, bem como a an��lise por difrac����o de raios-X, permitiu concluir que algumas amostras de suberina despolimerizada possu��am importantes dom��nios cristalinos e pontos de fus��o bem definidos, tipicamente pr��ximos de 70 oC, enquanto outras amostras eram essencialmente amorfa. Factores como a fonte de suberina ou as condi����es de despolimeriza����o estiveram na origem destas diferen��as. iv Neste trabalho estudaram-se tamb��m os extract��veis lipof��licos da corti��a e dos seus res��duos industriais, em particular os do p�� industrial de corti��a e dos condensados negros, mostrando que os extract��veis lipof��licos s��o uma fonte abundante de compostos triterp��nicos, em particular de ��cido betul��nico e de friedelina. Foram ainda identificadas frac����es abundantes de ��-hidroxi��cidos e de ��cidos dicarbox��licos no condensado negro. A segunda parte deste trabalho abordou a s��ntese e a caracteriza����o de novos poli��steres alif��ticos derivados de suberina. Estes materiais foram sintetizados utilizando, quer misturas de suberina despolimerizada, quer mon��meros modelo estruturalmente an��logos aos existentes na suberina. Recorreu-se para o efeito a duas aproxima����es distintas de polimeriza����o por passos, a policondensa����o e a politransesterifica����o. Procurou-se em simult��neo maximizar a efici��ncia da polimeriza����o em termos de peso molecular e de extens��o da reac����o e utilizar condi����es de reac����o de qu��mica ���verdes���. Neste sentido, utilizou-se a policondensa����o em emuls��o utilizando um tensioactivo como catalisador e a policondensa����o em massa utilizando a lipase B de Candida antarctica. Adicionalmente foram tamb��m testado os catalisadores trifluorometanosulfonato de bismuto(III) no caso da policondensa����o, e ainda os catalisadores cl��ssicos ��xido de antim��nio(III) e o carbonato de pot��ssio no caso da politransesterifica����o. Os poli��steres resultantes foram caracterizados atrav��s de v��rias t��cnicas, tais como IV, RMN (de 1H e de 13C), DSC, DMA, TGA, difrac����o de raios-X e medidas dos ��ngulos de contacto. Verificou-se que os catalisadores trifluorometanosulfonato de bismuto (III), ��xido de antim��nio(III) e carbonato de pot��ssio conduziram aos rendimentos de isolamento dos pol��meros resultantes mais elevados. No caso dos poli��steres derivados da suberina os resultados em termos de rendimentos e pesos moleculares sofreram um incremento substancial quando a estequiometria da reac����o de polimeriza����o foi adequadamente balanceada (r=1) com a adi����o de uma quantidade extra de um comon��mero. Verificou-se a predomin��ncia de diferentes estruturas consoante a amostra de suberina utilizada e as condi����es de s��ntese adoptada, predominando as cadeias lineares ou ent��o quantidades substanciais de estruturas reticuladas. Globalmente, este primeiro estudo sistem��tico da utiliza����o de suberina como um precursor de novos poli��steres alif��ticos confirmou o elevado potencial deste recurso abundante e renov��vel como precursor para preparar materiais macromoleculares.

Valorization of solid wastes from cellulose and paper industry

This thesis reports in detail studies of industrial solid wastes valorization as alternative raw materials. All tested wastes are classified as non-hazardous and are generated in the pulp and paper process, including primary sludge, dregs, grits, lime mud and bottom ash (this generated in a process that occurs in parallel to the production of cellulose, whose aim is the production of energy to supply the plant through the combustion of forest biomass in fluidized bed). A detailed general characterization was performed at each waste and according to their characteristics, they were selected some applications in materials with potential use, specifically in Fibercement, Bituminous Mixture for regularization layer and industrial mortars (rendering mortars and cementitious-adhesive). After decided to application each waste was specifically tested to proceed the setting up of formulations containing different content of waste in replacement of the raw conventional material. As an isolated case, the bottom ash was tested not only as an alternative raw material for construction materials, but also it was tested for its use in fluidized bed in which the waste is generated as raw material. Both dregs and bottom ash had undergone special treatment to make possible to obtain a better quality of waste in order do not compromise the final product characteristics and process. The dregs were tested in bituminous mixtures as received and also washed (on the laboratory scale to remove soluble salts) and bottom ash were washed and screened in industrial scale (for removal of soluble salts, especially chlorides and coarse fraction particles elimination - particles larger than 1 mm size). The remaining residues form used in such as received avoiding additional costs. The results indicated potential and some limitations for each application to the use of these wastes as alternative raw material, but in some cases, the benefits in relation to valorization overlap with its limitations in both aspects, environmental and economic.

The Long Range Transport of Birch (Betula) Pollen from Poland and Germany Causes Significant Pre-season Concentrations in Denmark

Background Birch pollen is highly allergic and has the potential for episodically long range transport. Such episodes will in general occur out of the main pollen season. During that time allergy patients are unprotected and high pollen concentrations will therefore have a full allergenic impact. Objective To show that Denmark obtains significant quantities of birch pollen from Poland or Germany before the local trees start to flower. Methods Simultaneous observations of pollen concentrations and phenology in the potential source area in Poland as well as in Denmark were performed in 2006. The Danish pollen records from 2000-2006 were analysed for possible long range transport episodes and analysed with trajectories in combination with a birch tree source map. Results In 2006 high pollen concentrations were observed in Denmark with bi-hourly concentrations above 500 grains/ m3 before the local trees began to flower. Poland was identified as a source region. The analysis of the historical pollen record from Copenhagen shows significant pre-seasonal pollen episodes almost every year from 2000-2006. In all episodes trajectory analysis identified Germany or Poland as source regions. Conclusion Denmark obtains significant pre-seasonal quantities of birch pollen from either Poland or Germany almost every year. Forecasting of birch pollen quantities relevant to allergy patients must therefore take into account long-range transport. This cannot be based on measured concentrations in Denmark. The most effective way to improve the current Danish pollen forecasts is to extend the current forecasts with atmospheric transport models that take into account pollen emission and transport from countries such as Germany and Poland. Unless long range transport is taken into account pre-seasonal pollen episodes will have a full allergic impact, as the allergy patients in general will be unprotected during that time.

Lessons Learnt From Ragweed and Birch Studies

Here we review some of the most important aspects of recent work on Ragweed (Ambrosia) and birch (Betula) concerning: 1) sources, 2) trends & phenology and 3) dispersion and transformation. Sources: At Northern latitudes the birch fraction in forests usually exceeds 50% of all broadleaved trees and the abundance of birch decreases with latitude from 5%-20% in many mid-latitude regions and down to 0%-2% in more southern areas. Birches are also commonly found in small woodlands or planted as ornamental trees in urban areas. Ragweeds are herbaceous weed species that are associated with areas of disturbance. Ragweed is native to North America, but considered an invasive species in Europe, Australia and China. In Europe, the four main centres are: The Pannonian Plain, Ukraine, The Po Valley (Italy) and the Rhone Valley (France). Trends & Phenology: Birch pollen seasons have started earlier during the last decades. This trend appears have decreased during recent years despite increasing spring temperatures. Ragweed tends to experience less change in flowering date as ragweed flowering depends on photoperiod. Ragweed is increasing its distribution in Europe, but airborne concentrations of ragweed pollen are not universally increasing, e.g. due to control measures or pest attacks. Dispersion & transformation: The beginning of the birch pollen season is often heralded by episodes of Long Distance Transport (LDT) from the south. Similar LDT episodes are intermittently seen for ragweed, which can reach as far north as Scandinavia. Humidity and air pollution can modify pollen grains during atmospheric transport. This can cause a change in allergenic potential of the pollen grain and is a direction for future research including the effect of co-exposure of air pollution and the transformation of aeroallergens.

Risk of Exposure to Airborne Ambrosia Pollen from Local and Distant Sources in Europe ��� an Example from Denmark

Background. Ambrosia artemisiifolia L. is a noxious invasive alien species in Europe. It is an important aeroallergen and millions of people are exposed to its pollen. Objective. The main aim of this study is to show that atmospheric concentrations of Ambrosia pollen recorded in Denmark can be derived from local or more distant sources. Methods. This was achieved by using a combination of pollen measurements, air mass trajectory calculations using the HYPLIT model and mapping all known Ambrosia locations in Denmark and relating them to land cover types. Results. The annual pollen index recorded in Copenhagen during a 15-year period varied from a few pollen grains to more than 100. Since 2005, small quantities of Ambrosia pollen has been observed in the air every year. We have demonstrated, through a combination of Lagrangian back-trajectory calculations and atmospheric pollen measurements, that pollen arrived in Denmark via long-distance transport from centres of Ambrosia infection, such as the Pannonian Plain and Ukraine. Combining observations with results from a local scale dispersion model show that it is possible that Ambrosia pollen could be derived from local sources identified within Denmark. Conclusions. The high allergenic capacity of Ambrosia pollen means that only small amounts of pollen are relevant for allergy sufferers, and just a few plants will be sufficient to produce enough pollen to affect pollen allergy sufferers within a short distance from the source. It is necessary to adopt control measures to restrict Ambrosia numbers. Recommendations for the removal of all Ambrosia plants can effectively reduce the amount of local pollen, as long as the population of Ambrosia plants is small.

The Long Distance Transport of Airborne Ambrosia Pollen to the UK and the Netherlands from Central and South Europe

Background: The invasive alien species Ambrosia artemisiifolia (common or short ragweed) is increasing its range in Europe. In the UK and the Netherlands airborne concentrations of Ambrosia pollen are usually low. However, more than 30 Ambrosia pollen grains per cubic metre of air (above the level capable to trigger allergic symptoms) were recorded in Leicester (UK) and Leiden (NL) on 4 and 5 September 2014. Objective: The aims of this study were to determine whether the highly allergenic Ambrosia pollen recorded during the episode could be the result of long distance transport, to identify the potential sources of these pollen grains and describe the conditions that facilitated this possible long distance transport. Methods: Airborne Ambrosia pollen data were collected at 10 sites in Europe. Back trajectory and atmospheric dispersion calculations were performed using HYSPLIT_4. Results: Back trajectories calculated at Leicester and Leiden show that higher altitude air masses (1500m) originated from source areas on the Pannonian Plain and Ukraine. During the episode, air masses veered to the west and passed over the Rh��ne Valley. Dispersion calculations showed that the atmospheric conditions were suitable for Ambrosia pollen released from the Pannonian Plain and the Rh��ne Valley to reach the higher levels and enter the air stream moving to Northwest Europe where they were deposited at ground level and recorded by monitoring sites. Conclusions: The study indicates that the Ambrosia pollen grains recorded during the episode in Leicester and Leiden were probably not produced by local sources, but transported long distances from potential source regions in East Europe, i.e. the Pannonian Plain and Ukraine, as well as the Rh��ne Valley in France.

Polarimetry In Radar Backscattering from Soil and Vegetated Surfaces

Thesis (Ph.D.)--University of Washington, 2015

Introduction to the Special Section Value Development from Middle Childhood to Early Adulthood: New Insights from Longitudinal and Genetically Informed Research

Research into values at an early age has only started recently, although it has expanded quickly and dynamically in the past years. The purpose of this article is twofold: First, it provides an introduction to a special section that aims to help fill the gap in value development research. The special section brings together four new longitudinal and genetically informed studies of value development from the beginning of middle childhood through early adulthood. Second, this article reviews recent research from this special section and beyond, aiming to provide new directions to the field. With new methods for assessing children's values and an increased awareness of the role of values in children's and adolescents' development, the field now seems ripe for an in-depth investigation. Our review of empirical evidence shows that, as is the case with adults, children's values are organized based on compatibilities and conflicts in their underlying motivations. Values show some consistency across situations, as well as stability across time. This longitudinal stability tends to increase with age, although mean changes are also observed. These patterns of change seem to be compatible with Schwartz's (1992) theory of values (e.g., if the importance of openness to change values increases, the importance of conservation values decreases). The contributions of culture, family, peers, significant life events, and individual characteristics to values are discussed, as well as the development of values as guides for behavior.