Chemical changes in biomass during torrefaction

Torrefaction is moderate thermal treatment (~200-300 °C) of biomass in an inert atmosphere. The torrefied fuel offers advantages to traditional biomass, such as higher heating value, reduced hydrophilic nature, increased its resistance to biological decay, and improved grindability. These factors could, for instance, lead to better handling and storage of biomass and increased use of biomass in pulverized combustors. In this work, we look at several aspects of changes in the biomass during torrefaction. We investigate the fate of carboxylic groups during torrefaction and its dependency to equilibrium moisture content. The changes in the wood components including carbohydrates, lignin, extractable materials and ashforming matters are also studied. And at last, the effect of K on torrefaction is investigated and then modeled. In biomass, carboxylic sites are partially responsible for its hydrophilic characteristic. These sites are degraded to varying extents during torrefaction. In this work, methylene blue sorption and potentiometric titration were applied to measure the concentration of carboxylic groups in torrefied spruce wood. The results from both methods were applicable and the values agreed well. A decrease in the equilibrium moisture content at different humidity was also measured for the torrefied wood samples, which is in good agreement with the decrease in carboxylic group contents. Thus, both methods offer a means of directly measuring the decomposition of carboxylic groups in biomass during torrefaction as a valuable parameter in evaluating the extent of torrefaction. This provides new information to the chemical changes occurring during torrefaction. The effect of torrefaction temperature on the chemistry of birch wood was investigated. The samples were from a pilot plant at Energy research Center of the Netherlands (ECN). And in that way they were representative of industrially produced samples. Sugar analysis was applied to analyze the hemicellulose and cellulose content during torrefaction. The results show a significant degradation of hemicellulose already at 240 °C, while cellulose degradation becomes significant above 270 °C torrefaction. Several methods including Klason lignin method, solid state NMR and Py-GC-MS analyses were applied to measure the changes in lignin during torrefaction. The changes in the ratio of phenyl, guaiacyl and syringyl units show that lignin degrades already at 240 °C to a small extent. To investigate the changes in the extractives from acetone extraction during torrefaction, gravimetric method, HP-SEC and GC-FID followed by GC-MS analysis were performed. The content of acetone-extractable material increases already at 240 °C torrefaction through the degradation of carbohydrate and lignin. The molecular weight of the acetone-extractable material decreases with increasing the torrefaction temperature. The formation of some valuable materials like syringaresinol or vanillin is also observed which is important from biorefinery perspective. To investigate the change in the chemical association of ash-forming elements in birch wood during torrefaction, chemical fractionation was performed on the original and torrefied birch samples. These results give a first understanding of the changes in the association of ashforming elements during torrefaction. The most significant changes can be seen in the distribution of calcium, magnesium and manganese, with some change in water solubility seen in potassium. These changes may in part be due to the destruction of carboxylic groups. In addition to some changes in water and acid solubility of phosphorous, a clear decrease in the concentration of both chlorine and sulfur was observed. This would be a significant additional benefit for the combustion of torrefied biomass. Another objective of this work is studying the impact of organically bound K, Na, Ca and Mn on mass loss of biomass during torrefaction. These elements were of interest because they have been shown to be catalytically active in solid fuels during pyrolysis and/or gasification. The biomasses were first acid washed to remove the ash-forming matters and then organic sites were doped with K, Na, Ca or Mn. The results show that K and Na bound to organic sites can significantly increase the mass loss during torrefaction. It is also seen that Mn bound to organic sites increases the mass loss and Ca addition does not influence the mass loss rate on torrefaction. This increase in mass loss during torrefaction with alkali addition is unlike what has been found in the case of pyrolysis where alkali addition resulted in a reduced mass loss. These results are important for the future operation of torrefaction plants, which will likely be designed to handle various biomasses with significantly different contents of K. The results imply that shorter retention times are possible for high K-containing biomasses. The mass loss of spruce wood with different content of K was modeled using a two-step reaction model based on four kinetic rate constants. The results show that it is possible to model the mass loss of spruce wood doped with different levels of K using the same activation energies but different pre-exponential factors for the rate constants. Three of the pre-exponential factors increased linearly with increasing K content, while one of the preexponential factors decreased with increasing K content. Therefore, a new torrefaction model was formulated using the hemicellulose and cellulose content and K content. The new torrefaction model was validated against the mass loss during the torrefaction of aspen, miscanthus, straw and bark. There is good agreement between the model and the experimental data for the other biomasses, except bark. For bark, the mass loss of acetone extractable material is also needed to be taken into account. The new model can describe the kinetics of mass loss during torrefaction of different types of biomass. This is important for considering fuel flexibility in torrefaction plants.

Trophic cascades in boreal landscapes: top predator protection on tree seedlings and forest grouse

Changes in the abundance of top predators have brought about notable, cascading effects in ecosystems around the world. In this thesis, I examined several potential trophic cascades in boreal ecosystems, and their separate interspecific interactions. The main aim of the thesis was to investigate whether predators in the boreal forests have direct or indirect cascading effects on the lower trophic levels. First, I compared the browsing effects of different mammalian herbivores by excluding varying combinations of voles, hares and cervids from accessing the seedlings of silver birch (Betula pendula), Scots pine (Pinus sylvestris) and Norway spruce (Picea abies). Additionally, I studied the effect of simulated predation risk on vole browsing by using auditory cues of owls. Moving upwards on the trophic levels, I examined the intraguild interactions between the golden eagle (Aquila chrysaetos), and its mesopredator prey, the red fox (Vulpes vulpes) and the pine marten (Martes martes). To look at an entire potential trophic cascade, I further studied the combined impacts of eagles and mesopredators on the black grouse (Tetrao tetrix) and the hazel grouse (Tetrastes bonasia), predicting that the shared forest grouse prey would benefit from eagle presence. From the tree species studied, birch appears to be the most palatable one for the mammalian herbivores. I observed growth reductions in the presences of cervids and low survival associated with hares and voles, which suggests that they all weaken regeneration in birch stands. Furthermore, the simulated owl predation risk appeared to reduce vole browsing on birches in late summer, although the preferred grass forage is then old and less palatable. Browsing by voles and hares had a negative effect on the condition and survival of Scots pine, but in contrast, the impact of mammalian herbivores on spruce was found to be small, at least when more preferred food is available. I observed that the presence of golden eagles had a negative effect on the abundance of adult black grouse but a positive, protective effect on the proportion of juveniles in both black grouse and hazel grouse. Yet, this positive effect was not dependent on the abundance foxes or martens, nor did eagles seem to effectively decrease the abundance of these mesopredators. Conversely, the protection effect on grouse could arise from fear effects and also be mediated by other mesopredators. The results of this thesis provide important new information about trophic interactions in the boreal food webs. They highlight how different groups of mammalian herbivores vary in their effects on the growth and condition of different tree seedlings. Lowered cervid abundances could improve birch regeneration, which indirectly supports the idea that the key predators of cervids could cause cascading effects also in Fennoscandian forests. Owls seem to reduce vole browsing through an intimidation effect, which is a novel result of the cascading effects of owl vocalisation and could even have applications for protecting birch seedlings. In the third cascade examined in this thesis, I found the golden eagle to have a protective effect on the reproducing forest grouse, but it remains unclear through which smaller predators this effect is mediated. Overall, the results of this thesis further support the idea that there are cascading effects in the forests of Northern Europe, and that they are triggered by both direct and non‐lethal effects of predation.

Tuotannon- ja materiaalinsuunnittelu ja sen ennustaminen Metsä Wood:n Suolahden koivuvaneritehtaalla

Tässä diplomityössä tutkitaan Metsä Woodin Suolahden koivuvaneritehtaan toimitustarkkuuteen negatiivisesti vaikuttavia tekijöitä. Tarkoituksena on löytää ne ongelmakohdat, mitkä heijastuvat toimitusten myöhästymisenä sekä muutostekijät, mitkä vaikuttavat toimitusviikon myöntämiseen. Lisäksi työssä kartoitetaan kuinka hyvin tietoa ja informaatiota on tarjolla sitä tarvitseville henkilöstötahoille. Teoriaosuudessa tarkastellaan tuotannonsuunnitteluun liittyviä teorioita sekä tiedon liikkumista organisaation sisällä. Työssä kuvataan Suolahden koivuvaneritehtaan nykyinen vanerin valmistusprosessi ja tuotannonsuunnittelu. Varsinainen tutkimustyö suoritetaan laadullisia tutkimusmenetelmiä hyväksikäyttäen. Tulosten tarkastelussa käsitellään työn aikana tapahtuneita muutoksia ja ongelmakohtia sekä analysoidaan kyselytutkimuksen tuloksia ja tulosten luotettavuutta. Yhteenvedossa esitetään pääongelmakohdat ja niiden ratkaisut ja esitetään uusia mielenkiintoisia jatkotutkimusaiheita.

Wood species identification by visual characterization of fibers

Kandidaatintyö tehtiin osana PulpVision-tutkimusprojektia, jonka tarkoituksena on kehittää kuvapohjaisia laskenta- ja luokittelumetodeja sellun laaduntarkkailuun paperin valmistuksessa. Tämän tutkimusprojektin osana on aiemmin kehitetty metodi, jolla etsittiin kaarevia rakenteita kuvista, ja tätä metodia hyödynnettiin kuitujen etsintään kuvista. Tätä metodia käytettiin lähtökohtana kandidaatintyölle. Työn tarkoituksena oli tutkia, voidaanko erilaisista kuitukuvista laskettujen piirteiden avulla tunnistaa kuvassa olevien kuitujen laji. Näissä kuitukuvissa oli kuituja neljästä eri puulajista ja yhdestä kasvista. Nämä lajit olivat akasia, koivu, mänty, eukalyptus ja vehnä. Jokaisesta lajista valittiin 100 kuitukuvaa ja nämä kuvat jaettiin kahteen ryhmään, joista ensimmäistä käytettiin opetusryhmänä ja toista testausryhmänä. Opetusryhmän avulla jokaiselle kuitulajille laskettiin näitä kuvaavia piirteitä, joiden avulla pyrittiin tunnistamaan testausryhmän kuvissa olevat kuitulajit. Nämä kuvat oli tuottanut CEMIS-Oulu (Center for Measurement and Information Systems), joka on mittaustekniikkaan keskittynyt yksikkö Oulun yliopistossa. Yksittäiselle opetusryhmän kuitukuvalle laskettiin keskiarvot ja keskihajonnat kolmesta eri piirteestä, jotka olivat pituus, leveys ja kaarevuus. Lisäksi laskettiin, kuinka monta kuitua kuvasta löydettiin. Näiden piirteiden eri yhdistelmien avulla testattiin tunnistamisen tarkkuutta käyttämällä k:n lähimmän naapurin menetelmää ja Naiivi Bayes -luokitinta testausryhmän kuville. Testeistä saatiin lupaavia tuloksia muun muassa pituuden ja leveyden keskiarvoja käytettäessä saavutettiin jopa noin 98 %:n tarkkuus molemmilla algoritmeilla. Tunnistuksessa kuitujen keskimäärinen pituus vaikutti olevan kuitukuvia parhaiten kuvaava piirre. Käytettyjen algoritmien välillä ei ollut suurta vaihtelua tarkkuudessa. Testeissä saatujen tulosten perusteella voidaan todeta, että kuitukuvien tunnistaminen on mahdollista. Testien perusteella kuitukuvista tarvitsee laskea vain kaksi piirrettä, joilla kuidut voidaan tunnistaa tarkasti. Käytetyt lajittelualgoritmit olivat hyvin yksinkertaisia, mutta ne toimivat testeissä hyvin.

Canadian Niagara Power Company fonds

Power at the Falls: The first recorded harnessing of Niagara Falls power was in 1759 by Daniel Joncairs. On the American side of the Falls he dug a small ditch and drew water to turn a wheel which powered a sawmill. In 1805 brothers Augustus and Peter Porter expanded on Joncairs idea. They bought the American Falls from New York State at public auction. Using Joncairs old site they built a gristmill and tannery which stayed in business for twenty years. The next attempt at using the Falls came in 1860 when construction of the hydraulic canal began by the Niagara Falls Hydraulic Power and Manufacturing Co. The canal was complete in 1861 and brought water from the Niagara river, above the falls, to the mills below. By 1881 the Niagara Falls Hydraulic Power and Manufacturing Co. had a small generating station which provided some electricity to the village of Niagara Falls and the Mills. This lasted only four years and then the company sold its assets at public auction due to bankruptcy. Jacob Schoellkopf arrived at the Falls in 1877 with the purchase of the hydraulic canal land and water and power rights. In 1879 Schoellkopf teamed up with Charles Brush (of Euclid Ohio) and powered Brush’s generator and carbon arc lights with the power from his water turbines, to illuminate the Falls electrically for the first time. The year 1895 marked the opening of the Adam No. 1 generating station on the American side. The station was the beginnings of modern electrical utility operations. The design and operations of the generating station came from worldwide competitions held by panels of experts. Some who were involved in the project include; George Westinghouse, J. Pierpont Morgan, Lord Kelvin and Nikoli Tesla. The plants were operated by the Niagara Falls Power Company until 1961, when the Robert Moses Plant began operation in Lewiston, NY. The Adams plants were demolished that same year and the site used as a sewage treatment plant. The Canadian side of the Falls began generating their own power on January 1, 1905. This power came from the William Birch Rankine Power Station located 500 yards above the Horseshoe Falls. This power station provided the village of Fort Erie with its first electricity in 1907, using its two 10,000 electrical horsepower generators. Today 11 generators produce 100,000 horsepower (75 megawatts) and operate as part of the Niagara Mohawk and Fortis Incorporated Power Group.

Canadian Niagara Power League Meeting (1897)

Remarks of Mr. William B. Rankine, secretary of the Canadian Niagara Power Company.

Canadian Niagara Power Company fonds, 1901, 1925, no date.

The Canadian Niagara Power Company was created in 1892, in large part due to the efforts of William Birch Rankine, a businessman who pioneered the development of hydropower on both the Canadian and American shores of the Niagara River. Numerous delays and problems postponed the construction and operation of the company's powerhouse, which was formally opened on January 2, 1905. Upon opening, the powerhouse boasted the largest generators of their kind in the world, with a capacity of 10,000 electrical horsepower each. The company was acquired by FortisOntario in 2002. In 2009, the company’s water rights expired and the Canadian Niagara Powerhouse building, also known as the Rankine Generating Station, was turned over to the Niagara Parks Commission.

Ontario Forest Industries Association records, 1900-1989, n.d.

The Ontario Forest Industries Association (OFIA) was founded in 1944. It is a provincial trade association that represents member companies who produce a wide range of products, including pulp, paper, paperboard, lumber, panelboard, plywood and veneer. The OFIA works with its member companies to address issues of common interest and concern, and communicates these issues to the appropriate government, industrial or business sector. The Ontario Forest Information Service represented the OFIA from 1951 to 1988 as the publishers of their industry periodicals. Bush News was the first periodical published by the Service for the OFIA and ran until 1964, when it was replaced by Ontario Logger. In 1968, the name was changed to The Logger. In 1970, this was replaced by The Forest Scene. This new periodical was a departure from the earlier versions, which had served primarily as an internal communication system for the industry. The Forest Scene adopted a new format and editorial approach, emphasizing outdoor activities, recreation, hunting and fishing, conservation, and forestry operations and methods, thus appealing to a much wider readership. The Forest Scene ceased publication in 1988.

Impact des coupes partielles sur l’activité de coléoptères phloeophages et xylophages en forêt boréale

Ce projet de recherche évalue la réponse à court terme de coléoptères phloeophages et xylophages (Cerambycidae et Scolytinae) à différentes intensités de coupes partielles (0, 25 et 40% de la surface terrière prélevée) afin de déterminer la viabilité de cette méthode sylvicole en forêt boréale. Disposant de 12 parcelles expérimentales (4 répétitions pour chaque intensité de coupe) dans une sapinière à bouleau blanc située au sud de la forêt boréale (Québec, Canada), nous avons évalué l’abondance, la diversité ainsi que l’établissement (taux d’attaque) de ces deux groupes d’insectes, et ce dès la première année suivant la coupe. L’échantillonnage a été réalisé à l’aide de pièges à interception multidirectionnelle et de l’écorçage de sections de 3 espèces d’arbres exposées dans l’ensemble des parcelles. Nos résultats montrent une plus grande activité/abondance des deux taxons (abondance 5 à 6 fois plus élevée) ainsi qu’une composition en espèces différente et plus diversifiée dans les peuplements partiellement coupés (25 et 40%). De plus, la présence et la distribution d’espèces colonisant habituellement des hôtes affaiblis (e.g., Trypodendron lineatum, Rhagium inquisitor) – et pouvant donc réduire la valeur économique d’arbres résiduels – a été recensée et semble être favorisée entres autres par l’ouverture de la canopée et des blessures physiques faites aux arbres pendant les opérations sylvicoles. Par ailleurs, l’approche combinant différentes techniques d’échantillonnage a permis une meilleure compréhension des mécanismes de localisation/sélection d’hôte (variant en fonction de l’espèce), un aspect important de la dynamique des insectes pour l’évaluation des risques suite aux coupes forestières. Sur la base de cette étude à court terme, il ne semblerait pas y avoir de différence significative sur les risques pour le milieu quant à l’augmentation d’activité des Cerambycidae et Scolytinae entre les deux traitements de coupe appliqués. Il reste cependant indispensable de vérifier la validité de ces résultats sur une plus longue période afin d’établir des plans d’aménagement forestier durables pour la forêt boréale.

L’histoire postglaciaire de la végétation et des feux dans la région du Lac Mégantic

La région du lac Mégantic est probablement la première zone à s'être déglacée au Québec, ce qui lui confère un intérêt particulier. L'analyse pollinique et anthracologique des sédiments des trois lacs situés à ses abords, soit les lacs Clinton, Dubuc et des Joncs ont permis de reconstituer l'histoire locale et régionale de la végétation et des feux. La présence d'un gradient altitudinal a entrainé des décalages surtout dans l'instauration des premières phases forestières. La région s'est déglacée vers 13 500 ans AA, et une toundra s'y est installée. Le début de l'afforestation est marqué par l'arrivée du sapin baumier et de l'épinette noire. Par la multiplication de leurs populations, la forêt s'est fermée vers 10 000 ans AA pour constituer une forêt boréale qui fût alors perturbée par plusieurs épisodes de feux. Vers 8000 ans AA, les nouvelles conditions climatiques favorisent les espèces feuillues et instaurent une érablière à bouleau jaune et une diminution de la fréquence des feux. Les résultats obtenus permettent d'enrichir les connaissances paléophytogéographiques et anthracologiques du Québec.

Critique du modèle neurophysiologique de la desphinothérapie. Sonophorèse et écholocation.

Un certain nombre de chercheurs (Birch, 1996; Cole, 1995, 1996; De Bergerac, 1998) fondent sur un modèle neurophysiologique leurs arguments en faveur de la delphinothérapie pour traiter divers désordres (DSM-IV) cognitifs et émotifs chez les enfants et les jeunes. Ce modèle recourt à des analogies avec les mécanismes de sonophorèse, d'écholocation et de transmission neurohormonale dans son application thérapeutique. Dans le but de démystifier les éléments pseudo-scientifiques auprès d'un lectorat non spécialisé, cet article critique les postulats et les implications relatifs à ces mécanismes et il conclut à l'absence d'un soutien pertinent et valide concernant ce modèle.

Motivación de logro y sus relaciones con características de personalidad en adolescentes.

Presentar las principales corrientes teóricas surgidas en torno a la motivación de logro así como de las diversas interpretaciones que se han dado a los resultados obtenidos en las investigaciones realizadas en el área, durante los últimos 35 años, y analizar las características de personalidad de los grupos de sujetos con diferente motivación de logro. Estudiantes voluntarios de tercer curso de BUP del Instituto Padre Manjón de Granada, con una edad media de 17 años. Aplicación de diferentes cuestionarios y pruebas a los alumnos, para hallar el grado de motivación de logro resultante; basándose en el rendimiento de los sujetos y las calificaciones medias finales de curso. Medida 'N ACH' de la motivación de logro, escala de Ray-Lynn de la motivación de logro, PTM de Hermans, cuestionario de motivación de logro de Mehrbian, cuestionarios de ansiedad (DAS, TAQ, MAS) para la medida del motivo de miedo al fracaso, prueba de rendimiento, test de inteligencia general, test de aptitudes diferenciales (DAT), cuestionario de personalidad 16 PF. BMDP 2d Frecuency Count Routine, se analiza mediante un Chi cuadrado la frecuencia de historias relacionadas con el logro y no relacionadas, correlación de Pearson, aplicación de la fórmula de Kuder-Richardson, BMDP 6r Partial Correlation and Multivariate Regression, cálculo del coeficiente de semejanza de perfiles. Los resultados de la investigación apoyan la posición de Atkinson y Birch. Ante la imposibilidad de utilizar los cuestionarios como medida alternativa al sistema proyectivo, es la puntuación combinada 'N ACH-DAS' la única que ofrece las suficientes garantías de estar realmente midiendo la motivación de logro resultante de los sujetos. Son las imagenes con un mayor nivel de sugerncia las que provocan una mayor activación de la necesidad de logro, la puntuación 'N ACH TAT' permite pronosticar el rendimiento de los sujetos, los sujetos con un mismo nivel de motivación de logro resultante difieren significativamente entre si en personalidad, en función del sexo, el cuestionario PMT de Hermans y la subescala OT de Ray son los que presentaron una mayor validez predictiva referente al rendimiento de mujeres y hombres.

Creative Commons Quiz/Lecture notes/Lecture slides(group 22)

The resource set of info2009 coursework 2 is produced by group22. it contains: 1. poster 2. internet link of a set of multiple questions 3. a pdf file of a set of multiple questions 4. reference list 5. lecture slides 6. lecture notes ps: Edward Payne (ejp1x07@ecs.soton.ac.uk) has not contributed to any part of the activities.

Identity is the new Money

Three things to think about and Three possible futures to discuss

English L2 reading : getting to the bottom.

Este libro proporciona un examen lingüístico y psicolingüístico de los niveles más bajos del proceso de lectura, tanto a nivel teórico como práctico. Presenta las estrategias que los lectores de otras lenguas desarrollan en respuesta a sus propios sistemas de escritura y los compara con una explicación de las estrategias que los lectores de inglés desarrollan en respuesta a la compleja ortografía inglesa, explicando cómo los métodos del nivel L1 en morfología y formación de palabras pueden ayudar o dificultar la adquisición del nivel L2 de lectura en inglés.