Dissertations / Theses: 'Spröde'

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Kohl, Marcel [Verfasser], Ellen [Akademischer Betreuer] Freiberger, Cornel [Gutachter] Sieber, and Ellen [Gutachter] Freiberger. "Epidemiologie und Therapie der Osteoporose bei stationären geriatrischen Patienten. Spröde Diagnostik bei spröden Knochen / Marcel Kohl ; Gutachter: Cornel Sieber, Ellen Freiberger ; Betreuer: Ellen Freiberger." Erlangen : Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 2021. http://d-nb.info/122468432X/34.

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Pröchtel, Patrick. "Anisotrope Schädigungsmodellierung von Beton mit Adaptiver Bruchenergetischer Regularisierung." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2008. http://nbn-resolving.de/urn:nbn:de:bsz:14-ds-1224751435667-29771.

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Der Gegenstand der vorliegenden Arbeit ist die Simulation von Betonstrukturen beliebiger Geometrie unter überwiegender Zugbelastung. Die Modellierung erfolgt auf Makroebene als Kontinuum und zur Lösung des mechanischen Feldproblems wird die Finite-Elemente-Methode verwendet. Ein neues Materialmodell für Beton und eine Erweiterung der Bruchenergetischen Regularisierung werden vorgestellt. Die Arbeit ist in zwei Teile gegliedert. Im ersten Teil wird ein lokales, anisotropes Schädigungsmodell abgeleitet, wobei als Schädigungsvariable ein symmetrischer Tensor zweiter Stufe gewählt wird. Die Verwendung einer Normalenregel im Raum der dissipativen Kräfte zur Bestimmung der Schädigungsevolution und die Definition der Schädigungsgrenzflächen im Raum der dissipativen Kräfte gewährleisten die Gültigkeit der Hauptsätze der Thermodynamik und des Prinzips der maximalen Dissipationsrate. Vorteilhaft ist die Symmetrie der Materialtangente, die sich aus diesem Vorgehen ergibt. Eine Formulierung mit drei entkoppelten Schädigungsgrenzflächen wird vorgeschlagen. Eine wichtige Forderung bei der Ableitung des Materialmodells war die Verwendung einer möglichst geringen Anzahl von Materialparametern, welche darüber hinaus aus wenigen Standardversuchen bestimmbar sein sollten. Das Schädigungsmodell enthält als Materialparameter den Elastizitätsmodul, die Querdehnzahl, die Zugfestigkeit und die auf eine Einheitsfläche bezogene Bruchenergie. Im zweiten Teil der Arbeit stehen Lokalisierung und Regularisierung im Fokus der Betrachtungen. Aufgrund der lokalen Formulierung des Materialmodells tritt bei Finite-Elemente Simulationen eine Netzabhängigkeit der Simulationsergebnisse auf. Um dieser Problematik zu begegnen und netzunabhängige Simulationen zu erreichen, werden Regularisierungstechniken angewendet. In dieser Arbeit wird die Bruchenergetische Regularisierung eingesetzt, die durch die Einführung einer äquivalenten Breite in ein lokal formuliertes Stoffgesetz gekennzeichnet ist. Die spezielle Wahl eines Wertes für die äquivalente Breite beruht auf der Forderung, dass in der Simulation die korrekte Bruchenergie je Einheitsfläche für den Bruchprozess verbraucht wird, d.h. die Energiedissipation der Realität entspricht. In vorliegender Arbeit wird die neue These aufgestellt, dass die Energiedissipation nur für den Fall korrekt abgebildet wird, wenn die im Stoffgesetz enthaltene äquivalente Breite in jedem Belastungsinkrement der Breite des Bereiches entspricht, in dem in der Simulation Energie dissipiert wird. In einer Simulation wird in den Bereichen Energie dissipiert, in denen die Schädigung im aktuellen Belastungsinkrement zunimmt. In vorliegender Arbeit werden die energiedissipierenden Bereiche daher als Pfad der Schädigungsrate bezeichnet. Um Erkenntnisse über die Entwicklung des Pfades der Schädigungsrate über den Belastungsverlauf zu erhalten, wurden umfangreiche Untersuchungen anhand von Simulationen eines beidseitig gekerbten Betonprobekörpers unter kombinierter Zug-Schubbeanspruchung durchgeführt, wobei die gewählten Werte für die äquivalente Breite variiert wurden. Es wurde stets eine Diskretisierung mit linearen Verschiebungselementen verwendet, wobei die Bereiche mit zu erwartender Schädigung feiner und regelmäßig mit Elementen quadratischer Geometrie diskretisiert wurden. Die Ergebnisse der Untersuchungen zeigen, dass die Breite des Pfades der Schädigungsrate abhängig ist von der Schädigung am betrachteten Materialpunkt, dem von Schädigungsrichtung und Elementkante eingeschlossenen Winkel, der Elementgröße und den Materialparametern. Um die geforderte Übereinstimmung von äquivalenter Breite und der Breite des Pfades der Schädigungsrate zu erreichen, werden neue Ansätze für die äquivalente Breite vorgeschlagen, die die erwähnten Einflüsse berücksichtigen. Simulationen unter Verwendung der neuen Ansätze für die äquivalente Breite führen zu einer guten Übereinstimmung von äquivalenter Breite und der Breite des Pfades der Schädigungsrate in der Simulation. Die Ergebnisse der Simulationen, wie z.B. Last-Verformungsbeziehung und Rissverläufe, sind netzunabhängig und stimmen gut mit den experimentellen Beobachtungen überein. Basierend auf den gewonnenen Erkenntnissen wird eine Erweiterung der Bruchenergetischen Regularisierung vorgeschlagen: die Adaptive Bruchenergetische Regularisierung. Im abschließenden Kapitel der Arbeit werden mit der vorgeschlagenen Theorie, dem neuen Schädigungsmodell und der Adaptiven Bruchenergetischen Regularisierung, noch zwei in der Literatur gut dokumentierte Versuche simuliert. Die Simulationsergebnisse entsprechen den experimentellen Beobachtungen
This doctoral thesis deals with the simulation of predominantly tensile loaded plain concrete structures. Concrete is modeled on the macro level and the Finite Element Method is applied to solve the resulting mechanical field problem. A new material model for concrete based on continuum damage mechanics and an extended regularization technique based on the fracture energy approach are presented. The thesis is subdivided into two parts. In the first part, a local, anisotropic damage model for concrete is derived. This model uses a symmetric second-order tensor as the damage variable, which enables the simulation of orthotropic degradation. The validity of the first and the second law of thermodynamics as well as the validity of the principle of maximum dissipation rate are required. Using a normal rule in the space of the dissipative forces, which are the thermodynamically conjugated variables to the damage variables, and the definition of the loading functions in the space of the dissipative forces guarantee their validity. The suggested formulation contains three decoupled loading functions. A further requirement in the derivation of the model was the minimization of the number of material parameters, which should be determined by a small number of standard experiments. The material parameters of the new damage model are the Young’s modulus, the Poisson’s ratio, the tensile strength and the fracture energy per unit area. The second part of the work focuses on localization and regularization. If a Finite Element simulation is performed using a local material model for concrete, the results of the Finite Element simulation are mesh-dependent. To attain mesh-independent simulations, a regularization technique must be applied. The fracture energy approach, which is characterized by introducing a characteristic length in a locally formulated material model, is used as regularization technique in this work. The choice of a value for the characteristic length is founded by the requirement, that the fracture energy per unit area, which is consumed for the fracture process in the simulation, must be the same as in experiment, i.e. the energy dissipation must be correct. In this dissertation, the new idea is suggested that the correct energy dissipation can be only attained if the characteristic length in the material model coincides in every loading increment with the width of the energy-dissipating zone in the simulation. The energy-dissipating zone in a simulation is formed by the integration points with increasing damage and obtains the name: damage rate path. Detailed investigations based on simulations of a double-edge notched specimen under mixed-mode loading are performed with varying characteristic lengths in order to obtain information concerning the evolution of the damage rate path during a simulation. All simulations were performed using displacement-based elements with four nodes. The range with expected damage was always finer and regularly discretized. The results of the simulations show that the width of the damage rate path depends on the damage at the specific material point, on the angle between damage direction and element edges, on the element size and on the material parameters. Based on these observations, new approaches for the characteristic length are suggested in order to attain the coincidence of the characteristic length with the width of the damage rate path. Simulations by using the new approaches yield a sufficient coincidence of the characteristic length with the width of the damage rate path. The simulations are mesh-independent and the results of the simulation, like load-displacement curves or crack paths, correspond to the experimental results. Based on all new information concerning the regularization technique, an extension of the fracture energy approach is suggested: the adaptive fracture energy approach. The validity and applicability of the suggested theory, the new anisotropic damage model and the adaptive fracture energy approach, are verified in the final chapter of the work with simulations of two additional experiments, which are well documented in the literature. The results of the simulations correspond to the observations in the experiments

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Woldt, Dirk. "Zerkleinerung nicht-spröder Stoffe in Rotorscheren und -reißern." Doctoral thesis, Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola&quot, 2009. http://nbn-resolving.de/urn:nbn:de:swb:105-5257457.

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Für die Grob- und Mittelzerkleinerung der sich überwiegend zäh verhaltenden Abfälle und Schrotte werden verbreitet Rotorscheren und -reißer eingesetzt. Um die für die Optimierung dieser Maschinen erforderlichen Kenntnisse über die Einzugs- und Zerkleinerungsvorgänge zu erlangen, wurden Untersuchungen zur Schneid-, Scher- und Reißbeanspruchung mit verschiedenen Modellapparaturen sowie Versuche mit kleintechnischen ein- und zweirotorigen Rotorscheren und -reißern durchgeführt. Die Untersuchungen haben gezeigt, dass in Rotorscheren und -reißern komplexe Beanspruchungen auftreten, die in Abhängigkeit von der Anordnung und Gestalt der Zerkleinerungselemente auf eine Überlagerung von Schneid-, Scher- und/oder Reißbeanspruchungen zurückzuführen sind. Gleichzeitig treten Reibungs- und Verformungsvorgänge auf, die den Gesamtenergiebedarf erheblich erhöhen können. Das Zerkleinerungsergebnis der ein- und zweirotorigen Rotorscheren und -reißer wird zusätzlich von einer Vielzahl konstruktiver, stoffbedingter und betriebsbedingter Parameter beeinflusst.

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Dumstorff, Peter [Verfasser]. "Modellierung und numerische Simulation von Rissfortschritt in spröden und quasi-spröden Materialien auf Basis der Extended Finite Element Method / Peter Dumstorff." Aachen : Shaker, 2009. http://d-nb.info/1156518784/34.

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Kurnatowski, Benjamin [Verfasser]. "Zweiskalensimulation von mikroheterogenen Strukturen aus spröden Faserverbundwerkstoffen / Benjamin Kurnatowski." Kassel : Universitätsbibliothek Kassel, 2010. http://d-nb.info/1005817669/34.

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Jackson, Deborah Louise. "The mechanism of resistance in Sitka spruce to the green spruce aphid." Thesis, University of East Anglia, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.359316.

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Wallentin, Cristofer. "Thinning of Norway spruce /." Alnarp : Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, 2007. http://epsilon.slu.se/200729.pdf.

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Spångberg, Kalle. "Sorting Norway spruce pulpwood /." Uppsala : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 1998. http://epsilon.slu.se/avh/1998/91-576-5616-9.gif.

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Caron-Decloquement, Annabelle. "Extractives from Sitka spruce." Thesis, University of Glasgow, 2010. http://theses.gla.ac.uk/1546/.

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The term extractives defines chemical compounds of different classes that can be extracted from wood or bark by means of polar or non-polar solvents. Extractives are derived mostly from the metabolic processes of the tree, particularly the sapwood to heartwood transformation. The first objective of the research was to study the distribution of extractives within Sitka spruce trees at different heights in the trunk, as well as the distribution between bark, rootwood, knotwood, heartwood and sapwood. The second aim of the work was to learn about the influence of yield class, site elevation, North/East location and thinning on the extractives content and composition of Sitka spruce across Scotland. The samples were sawdust obtained in different ways from either discs, knots or roots sawn from Sitka spruce trees freshly cut in the forest, or collected during the coring of trees from 64 sites all around Scotland and northern England. The extraction was carried out on Soxhlet extractors using acetone as solvent. Two analytical techniques were used: gas chromatography and Fourier transform infrared spectroscopy. The results of the research showed that the extractive content and composition of Sitka spruce differed according to the type of wood studied with the largest amount detected in bark and the lowest in heartwood and sapwood. The last two types of wood were studied in more detail, showing that the difference in extractive content between heartwood and sapwood was consistent at all heights in the trunk. The chromatographic analysis of heartwood, sapwood, knotwood, rootwood and bark showed that their compositions differed slightly from published data on Norway spruce.

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Harper, George James. "The effect of cold storage duration and soil temperature on the photosynthetic ability of Picea glauca seedlings." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/28774.

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In response to concern over the failure and poor growth of many interior and white spruce plantations in British Columbia the effect of storage duration and soil temperature on the photosynthetic ability of white spruce seedlings was explored. Seedlings of Picea glauca were dark freezer stored (-5°C) from 9.6 to 30.6 weeks, thawed and grown for 28 days in a growth chamber at three different soil temperatures (3,7,11°C). During this period gas exchange variables and chlorophyll fluorescence kinetics were followed. Seedlings stored for periods of 22 weeks or longer had significantly lower rates of photosynthesis dependent on the outplanting soil temperature. Stomatal conductance was initially low upon outplanting and showed a recovery period of 4-7 days duration. The level of stomatal conductance increased in seedlings after they were stored for 26.1 weeks or longer. Chlorophyll fluorescence measurements of seedlings stored from 22 to 30.6 weeks showed a recovery period in photosynthetic efficiency (Fy/Fp) related to changes in photosynthesis. A decrease in seedling Fy/Fp with increasing periods of storage was noted at day 5 after outplanting. A disproportionate increase in new root growth with the increasing soil temperatures, measured after the 28 day growth period, suggested a soil temperature threshold for root growth exists between the 7°C and ll°C. In contrast, the stomatal conductance and photosynthesis results suggest the seedling shoots were not directly affected by the cold soil temperatures. In general, the results suggest Picea glauca seedlings stored longer than 22 weeks in freezer conditions have reduced photosynthetic ability, root growth and overall vigor. Fluorescence and bud break data suggest the reduction was possibly due to freezing damage sustained in storage affecting photosynthetic electron transport through photoinhibition upon returning seedlings to the light.
Forestry, Faculty of
Graduate

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Méndez, Espinoza Claudia. "White spruce resistance against the spruce budworm : genetic control and insect-host interaction." Doctoral thesis, Université Laval, 2018. http://hdl.handle.net/20.500.11794/33970.

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Picea glauca (Moench) Voss (l’épinette blanche) est l’un des principaux hôtes de la tordeuse des bourgeons de l’épinette (TBE), le défoliateur épidémique le plus dommageable de l’est du Canada qui est à l’origine de la mortalité d’arbres et de pertes économiques d’envergure considérables. Un mécanisme constitutif de résistance contre la TBE a récemment été découvert. Dans la présente thèse, nous avons étudié ce mécanisme basé sur l’accumulation foliaire du picéol et du pungénol, deux acétophénones découlant de la surexpression du gène Pgglu-1. Ces trois facteurs sont désignés comme étant des «biomarqueurs de résistance». Nous avons aussi étudié la picéine, un acétophénone glycosilé qui est le précurseur du picéol, et l’ensemble des quatre facteurssont désignés «biomarqueurs de défense». La première partie de la thèse présente une approche de génétique quantitative s’appuyant sur l’analyse de 874 arbres représentant 33 familles et 71 lignées clonales répartis dans sept emplacements de l’est du Canada. Nos objectifs étaient : i) de déterminer le contrôle génétique des biomarqueurs de défense, ii) d’estimer les corrélations génétiques et phénotypiques entre les quatre traits de défense, iii) d’évaluer la présence de compromis entre les biomarqueurs de défense et la croissance primaire. Nous avons conclu que l’héritabilité au sens strict du picéol, du pungénol et de l’expression du gène Pgglu-1 était modérée (0,55, 0,50 et 0,58 respectivement), et obtenu des estimés un peu plus élevées pour l’héritabilité au sens large du picéol et du pungénol (0,66 et 0,60 respectivement), ce qui indique que ces traits de résistance sont soumis à un contrôle génétique additif. Les traits de résistance et la croissance montrent des corrélations génétiques positives (de 0,14 à 0,30), ce qui suggère que le mécanisme de résistance n’entraine pas un effet négatif sur la croissance de l’épinette blanche. Dans la deuxième partie de la thèse, nous avons étudié l’interaction insecte-hôte en menant des essais d’élevage d’insectes sur différents clones d’épinettes blanches. Nos objectifs étaient iv) de caractériser la variation développementale des acétophénones de défense, v) d’évaluer l’influence du stade phénologique de l’hôte sur le niveau de résistance indiqué par la performance biologique de la TBE et vi) de déterminer si les traits de résistance sont inductibles. Nous concluons que la variation des acétophénones dépend du phénotype de résistance de l’arbre, et que l’efficacité des traits de résistance dépend du synchronisme entre le Piceaglauca et l’alimentation des insectes. Finalement, nous avons démontré que ce mécanisme de résistance peut être inductible.
Picea glauca (Moench) Voss (white spruce) is one of the main hosts of the spruce budworm (SBW), anepidemic defoliator that is the most damaging in forests of eastern North America causing tree mortality and large economic losses. A constitutive resistance mechanism against the SBW was recently discovered. In this thesis, we studied this mechanism based on the foliar accumulation of aglycon acetophenones ̶piceol and pungenol ̶resulting from the expression of the Pgglu-1gene; and we refer to them as resistance biomarkers. Picein, the glycoside precursor of piceol was also investigated and we refer to all four traits togetheras defense biomarkers. The first part of this thesis presents a quantitative genetic study, which analysed 874 trees representing 33 full-sib families and 71 clonal lines from seven field locations in Eastern Canada. The goals were to i) determine the genetic control of the defense biomarkers, ii) estimate the genetic and phenotypic correlations among the four defensive traits and growth, and iii) evaluate the occurrence of trade-offs between the defense biomarkers and primary growth. Narrowsense heritability of piceol, pungenol and Pgglu-1 gene expression was moderate (0.55, 0.50 and 0.58, respectively). Slightly higher broad sense heritability estimates were obtained for acetophenones (0.66 and 0.60 respectively), indicating that additive genetic effects playa major role in these resistance biomarkers. Positive genetic correlations were found between the resistance traits and growth (from 0.14 to 0.30), suggesting that the resistance mechanism does not compromise growth in white spruce. In the second partof the thesis, we studied the insect-host interaction by use of insect rearing trials in severalwhite spruce clones. Our objectives were to iv) characterize the developmental and phenological variation of the defense acetophenones, v) evaluate the impact of the matched and delayed host phenology windows on the biological performance of the SBW, and vi) assess the inducibility potential of the resistance traits. Weshow that there are considerable variations in the acetophenone accumulation profiles between individual trees supporting their classification as Resistant (R) and Non-Resistant (NR); that the efficiency of the resistance traits is influenced by the synchronization between the P. glauca phenology and the insect feeding. Finally, we show that the resistance mechanism can be inducible.

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Bernauer, Günter [Verfasser]. "Einsatz mikromechanischer Schädigungsmodelle im spröd-duktilen Übergangsbereich / Günter Bernauer." Karlsruhe : KIT-Bibliothek, 1997. http://d-nb.info/1013896580/34.

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Day, Michael. "Factors Influencing Net Primary Production in Red Spruce." Fogler Library, University of Maine, 2000. http://www.library.umaine.edu/theses/pdf/DayME2000.pdf.

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Ward, Margaret H. "Age-Related Trends in Red Spruce Needle Anatomy and Their Relationship to Declining Productivity." Fogler Library, University of Maine, 2004. http://www.library.umaine.edu/theses/pdf/WardMH2004.pdf.

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Schneider, Ines. "Fließverhalten und Morphologieeinfluß granulierter spröder Materialien bei hohen Drücken und Belastungsgeschwindigkeiten." Doctoral thesis, Universitätsbibliothek Chemnitz, 2001. http://nbn-resolving.de/urn:nbn:de:swb:ch1-200100916.

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Die Arbeit beschäftigt sich mit der Weiterentwicklung des verdämmten Druckversuches zur Bestimmung experimenteller Daten an verschiedenen Keramik- und Glassorten. Die untersuchten Materialien (Al2O3, TiB2, B4C, Floatglas, schweres Flintglas) lagen in Form von Fragmenten (Bruchstücken) vor und wurden aus realen Impaktexperimenten wiedergewonnen. Zusätzlich wurden thermisch vorgeschädigte Aluminiumoxidzylinder in die Betrachtungen einbezogen. Daten granulierter bzw. vorgeschädigter spröder Materialien sind von besonderem Interesse für Finite Element Rechnungen, um beispielsweise experimentell sehr aufwendige Beschußversuche rechnerisch zu simulieren.Als Untersuchungsmethode wurde der verdämmte Druckversuch verwendet und sowohl an quasistatische als auch an schlagdynamische Belastungsbedingungen angepaßt. Außerdem wurden die entwickelten Testaufbauten für sehr hohe hydrostatische Drücke optimiert. In den quasistatischen Experimenten konnten damit Drücke von 380 MPa bis 1960 MPa und in den dynamischen Versuchen von 495 MPa bis 2060 MPa erreicht werden. Im Ergebnis wurden mechanische Kennwerte der granulierten bzw. vorgeschädigten Materialien ermittelt (Restfestigkeit, Verdichtungsverhalten) und deren Schädigungsgrad vor und nach den Versuchen bestimmt (Rasterelektronenmikroskopie und Messung der spezifischen Oberfläche). Die vielversprechenden Resultate der verschiedenen Keramiken und Gläser wurden verglichen und die Materialien im Hinblick auf ihr Energieaufnahmevermögen unter schlagartiger Belastung bewertet.

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Danielsson, Marie. "Chemical defence in Norway spruce." Doctoral thesis, KTH, Organisk kemi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-31133.

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Norway spruce (Picea abies) responds to stress by biosynthesis of chemical substances, which can deter invading insects or pathogens. Some of these substances are volatile and can be emitted to the surroundings while others are accumulated within the tree. Information about the susceptibility of individual plants to infestation, their volatile emissions and chemical defence is of interest, for example, in selecting plants for tree breeding programs. The first part of this research focused on volatiles emitted by Norway spruce plants. Collection of headspace volatiles by SPME and subsequent separation and identification with GC-MS was used to investigate Norway spruce plants of different ages and stress conditions as well as trapping semiochemicals like nepetalactone emitted by the spruce shoot aphids. It was even possible to analyse the emission of single needles in vivo and obtain spatial localisation of the stress reaction to methyl jasmonate or spruce spinning mites. Seedlings of different ages showed differences in chemical composition of emitted volatiles, with the pine weevil repellent, (4S)-(-)-limonene, one of the main compounds. Wounded phloem of conventional plants emitted high amounts of monoterpenes while the phloem of mini plants emitted (3Z)-hexenal and (3Z)-hexen-1-ol. In addition, a method to separate and identify the four diastereomers of nepetalactone by GC-MS and characteristic m/z-fragments was accomplished. The second part of the research deals with the chemical response of Norway spruce roots to inoculation with Heterobasidion annosum. Terpene concentrations increased after inoculation or wounding but the composition was mainly associated with clone identity and not to susceptibility or treatment. In contrast, inoculation with H. annosum induced a treatment-specific alteration of phenol composition. The constitutive phenol composition differed between more and less susceptible clones. The phenols astringin and astringin dimers (piceasides) as well as the terpene α-longipinene may be suitable markers of low susceptibility for P. abies to Heterobasidion.
QC 20110314

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Säll, Harald. "Spiral Grain in Norway Spruce." Doctoral thesis, Växjö universitet, Institutionen för teknik och design, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:vxu:diva-538.

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Wood is a major construction material that is used in many contexts, and for different purposes. Serious problems may arise, however, when moisture related deformations as twist occur in wood used in different types of building structures, joinery and furniture. Twist can be explained to a great degree by the helical deviation of the grain angle in relation to the longitudinal direction of the log or the sawn board. Wood fibres form a spiral within the tree, and this is a natural occurrence that is named spiral grain. The wood fibres close to the pith in Norway spruce form a left-handed spiral. In most trees the grain angle turns over to be right-handed with time. Sawn timber that exhibits large grain angles lead to problems of shape stability and stiffness in finished constructions. In this thesis the spiral grain in Norway spruce (Picea abies (L.) Karst.) was stated as well as the effect on sawn timber. The material was based on sample trees from Sweden and Finland. Samples were taken in twenty-two stands at different heights in tree. From six stands studs were sawn and dried for measuring twist and other deformations. The spiral grain was measured with the method scribe test on 390 log discs taken at the top-end of the logs. Account was given concerning changes in grain angle from pith to bark, regarding both increasing annual ring numbers and distance from pith. The development of grain angle over tree age was utilized to study whether annual growth, size of tree, height in tree as well as silvicultural treatments affected spiral grain. Moreover, the relation between grain angle and distance to pith (in mm) was used to forecast twist in sawn timber. The left-handed grain angle was at its greatest between the fourth and eighth annual rings. Thereafter for most trees the grain angle turned from left-handed to right-handed in a linear fashion, in a manner that was unique for each individual tree. The pattern of spiral grain differed significantly between different stands, regarding change of inclination with increasing age or distance from pith. The culmination of the grain angle close to the pith occurred at somewhat higher age higher up in the trunk. The grain angle decreased faster in top logs than it did in the butt logs. The largest trees within a stand had a grain angle that turned to right in a slower way than smaller ones. The thinning strength and type of thinning regime also affected the character of spiral grain in the remaining trees in a stand. There was an indication that strong thinnings, where fast growing trees are retained, may lead to more individuals in a stand that exhibit high grain angles under bark. With knowledge of the size and direction of the grain angle under bark, and the diameter of the log, calculations can be made that show how twisted the sawn timber will be after drying. This can be used for deciding whether an individual log can profitably be sawn and processed further or not. The grain angle under bark can be used to remove trees showing the greatest degree of spiral grain already in the first thinning. Silvicultural methods aiming at even and dense Norway spruce stands, which normally is practised in Scandinavia, will probably result in timber with relatively low risk concerning large grain angle and subsequent risk for twist in sawn wood.

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Neumann, Miroslav. "Interní audit ve veřejné správe." Master's thesis, Vysoká škola ekonomická v Praze, 2010. http://www.nusl.cz/ntk/nusl-74133.

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The thesis focuses on the area of the internal audit in public administratition in the Czech Republic. The theoretical part deals with the audit, the definitions and its development. Furthemore, the code of Ethics, Standards and the system for Public Internal Financial Control (PIFC) are introduced. The main objective of the thesis is to provide a comprehensive picture of the internal audit of the Regional Office of South Bohemian region. The practical part includes the position of the internal audit, its activities in the above mentioned Office of public administration. On one specific example are shown the particular stages of auditing.

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Ibrahim, Omnia Gamal El-Dien. "Genomic selection in White Spruce." Thesis, University of British Columbia, 2017. http://hdl.handle.net/2429/61006.

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Tree improvement programs are long-term and resource-demanding endeavors consisting of repeated cycles of breeding, testing, and selection and suffer from protracted testing phases. Phenotypic selection is commonly practiced and often requires trees reaching certain age and/or size resulting in slow accumulation of genetic gain. Open-pollinated (OP) family testing is the simplest and most economical means for screening, evaluating, and ranking large number of candidate parent trees but suffers from inflated additive genetic variance and heritability estimates. This dissertation investigates genomic selection (GS) and its applicability to forestry in selection and progeny testing evaluation. To address these two applications, I studied yield and wood traits from two white spruce populations, genotyped using Genotyping-by-Sequencing and SNPs array. I investigated the applicability of GS using the Ridge Regression Best Linear Unbiased Predictor (RR-BLUP) and the Generalized Ridge Regression (GRR)) algorithms and validated the derived predictive models in space across three progeny testing sites in interior British Columbia. Moreover, using principal component analysis (PCA), I fitted a multi-traits GS predictive model to address the inter-correlation among the studied attributes. Additionally, the Genomic Best Linear Unbiased Predictor (GBLUP) was used in genetic variance decomposition framework to unravel additive from non-additive genetic variances and I compared the results to that from the traditional pedigree-based (ABLUP) analysis. Differences between the RR-BLUP and GRR predictive models’ accuracies were observed indicating that the studied attributes’ genetic architecture is complex. Validating the GS’s predictive models in space clearly confirmed multi- to single-site superiority as they account for the genotype x environment interaction, commonly observed in forestry evaluation trials. When PCA scores used as multi-trait representatives, GS prediction models produced surprising results where the concurrent selection of negatively correlated traits such as wood density and growth is possible. The genetic variance decomposition indicated that the genomic-based approach outperformed that of the pedigree-based with the successfully separation of additive from non-additive genetic effects. This approach was demonstrated in a single- and extended to multi-site scenario, propelling OP testing to the forefront of forest trees genetic evaluation. In general, the effectiveness of GS was clearly demonstrated as an alternative selection and evaluation method.
Forestry, Faculty of
Graduate

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Klinka, Karel, Qingli Wang, G. G. Wang, K. Dave Coates, and Christine Chourmouzis. "Predicting site index of Lodgepole pine and interior spruce in the sub-boreal spruce zone." Forest Sciences Department, University of British Columbia, 2001. http://hdl.handle.net/2429/684.

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Knowledge of ecological site characteristics and tree growth on different sites is fundamental for silvicultural decisionmaking and planning. With biogeoclimatic ecosystem classification in place in British Columbia, silvicultural management has been given an ecological foundation; however, relationships between growth and site quality have not yet been fully investigated. The purpose of this study was to determine how site conditions within the SBS zone affect the height growth of lodgepole pine (Pl) and interior spruce (Sx).

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21

Daggett, R. Howard. "Long-Term Effects of Herbicide and Precommercial Thinning Treatments on Species Composition, Stand Structure, and Net Present Value in Spruce-Fir Stands in Maine: The Austin Pond Study." Fogler Library, University of Maine, 2003. http://www.library.umaine.edu/theses/pdf/DaggettRH2003.pdf.

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Denti, Daniela. "The influence of male and female strobilus production on rates of self-fertilization in a clonal white spruce seed orchard /." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=66076.

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23

Brewster, Sarah A. "Evaluating white spruce decline and mortality in the upper Great Lakes region /." Link to full text, 2009. http://epapers.uwsp.edu/thesis/2009/Brewster.pdf.

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Thesis (M.S.)--University of Wisconsin--Stevens Point, 2009.
Submitted in partial fulfillment of the requirements of the degree Master of Science in Natural Resources (Forestry), College of Natural Resources. Includes bibliographical references (p. 43-50).

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24

Petruncio, Markian Demetrius. "Effects of pruning on growth of Western hemlock (Tsuga heterophylla (Raf.) Sarg.) and Sitka spruce (Picea sitchensis (Bong) Carr.) in Southeast Alaska /." Thesis, Connect to this title online; UW restricted, 1994. http://hdl.handle.net/1773/5521.

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25

Wadenbäck, Johan. "Lignin studies of transgenic Norway spruce /." Uppsala : Dept. of Plant Biology and Forest Genetics, Swedish University of Agricultural Sciences, 2006. http://epsilon.slu.se/200664.pdf.

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Beinstein, Zbyněk. "Nestability spreje u trysek typu effervescent." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2009. http://www.nusl.cz/ntk/nusl-228558.

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Master thesis focused on the research of the effervescent atomizers. Effervescent atomizers belong to a group of two-phase atomizers, which are often used in combustion applications. Right there in combustion applications, the degree of the stability sprays has a significant impact on combustion efficiency and exhaust gas emissions. The main aim of this work was to asses the level of spray unsteadiness depending on the atomizer design and its operating mode. The effect of construction was studied on the diameter and length of mixing chamber, and then on the size, number and location of aeration holes. Seventeen specific variants of the atomizer were constructed by different combinations of these design parameters. Each of these variants was measured in three operating modes, which were represented by a liquid pressure at the inlet to the atomizer and gas-to-liquid mass flow ratio (GLR). To evaluate the level of spray unsteadiness was used a methodology, which compares the ideal element´s distribution into the interparticle time bin, defined for the ideal (stable) spray, with the experimentally observed distribution. The laser measurement system P/DPA (Phase Doppler Particle Analyzer) was used to determine the experimental interparticle distribution. The result of the comparison of the ideal and the experimental distribution was the parameter , which expresses the level of spray unsteadiness for a specific atomizer and operating mode. With that parameter it was possible to compare the individual atomizers and determinate to the benefit of various construction´s correction of the atomizer. The results showed the recommendation for the modifications of the atomizer, creating a spray with a minimum level of spray´s unsteadiness. For the surveyed atomizer and his individual costruction´s variations the drawing was made.

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Adams, Stephanie L. "A Physiological Examination of the Age-related Decline in Photosynthesis in Picea rubens." Fogler Library, University of Maine, 2006. http://www.library.umaine.edu/theses/pdf/AdamsSL2006.pdf.

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Swift, Kathie. "Response of interior spruce to fertilization in the interior of British Columbia." Thesis, University of British Columbia, 1991. http://hdl.handle.net/2429/29754.

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In 1987, a research project, conducted in the interior of British Columbia, was undertaken in order to obtain preliminary fertilization response data for three interior species. In 1988, as part of this contract, 12 screening trials were established in young interior spruce stands in the north-central interior of B. C. using factorial combinations of nitrogen and "complete" mix fertilizer. Initial assessment of the unfertilized foliage obtained from the 12 installations indicated that all stands exibited low nitrogen and potentially low sulphur levels. After fertilization, the effects of the treatments were measured by needle weight response, nutrient concentration, and subsequent nutrient content response. In all 12 installations the largest needle weight response occured when the nitrogen and the "complete" mix fertilizers were combined.. In the treatments where nitrogen was applied alone, no significant change in needle size was recorded. Nutritionally, nitrogen fertilization resulted in large increases in nitrogen concentration, indicating this element was limiting. As well, nitrogen fertilization also produced large decreases in K, S, and S04-S concentrations. Nitrogen-only fertilization also caused large elevations in the N/S ratios to occur. This elevation in N/S ratios and the subsequent decreases in S and S04-S concentrations seem to indicate that nitrogen-only fertilization has a negative impact on the sulphur nutrition of interior spruce. The addition of the "complete" mix fertilizer was, in most cases, successful in returning the decreased nutrient concentration levels of K, S, and S04 and the elevated N/S ratios back to their original unfertilized status. From these results it appears that nitrogen fertilization of interior spruce should only be considered if it is accompanied by a mixture of other nutrients; the most important component being sulphur.
Forestry, Faculty of
Graduate

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29

Cook, Paul Andrew. "Effect of the spruce root aphid, Pachypappa vesicalis on the growth and physiology of Sitka spruce seedlings." Thesis, Lancaster University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337573.

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Jorgensen, Carl Arik. "The Effects of Spruce Beetle (Coleoptera: Curculionidae: Scolytinae) on Fuels and Fire in Intermountain Spruce-Fir Forests." DigitalCommons@USU, 2010. https://digitalcommons.usu.edu/etd/646.

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In spruce-fir forests, there are many biotic and abiotic disturbances that can alter stand structure and composition. Many of these disturbances can produce high percentages of tree mortality at different scales. Spruce beetle has been considered a devastating disturbance agent, capable of creating high levels of mortality that will alter fuel complexes that may affect fire behavior. For comparison, stand data were gathered in endemic (near Loa and Moab, UT), epidemic (near Loa and Fairview, UT), and post-epidemic (near Salina and Loa, UT) condition classes of spruce beetle activity. Generally, fine fuels were higher during the epidemic and returned to background levels during post-epidemic conditions. Also, herbaceous and shrub components increase following outbreak situations with an initial pulse of herbaceous material during epidemics followed by the expansion of shrub material in post-epidemic areas. Fuel bed bulk depth, large diameter woody material, sound and rotten, and duff did not significantly differ between spruce beetle condition classes. Available live canopy fuel, canopy bulk density, and canopy base height were significantly reduced from endemic when compared to epidemic and post-epidemic condition classes. The fuel complex alterations resulted in changes to calculated surface and crown fire behavior. Crown base height decreased in post-epidemic classes, which allowed for easier crown fire initiation. Due to large gaps in canopy continuity, no active crown fire was initiated. In endemic situations, canopy bulk density was adequate to maintain active crown fire runs, but crown base height was too high to initiate crown fire. Surface fire, estimated from the custom fuel models following fuel complex alterations, showed that fireline intensity and rates of spread were greater in post-epidemic areas, but mostly due to reduced overstory sheltering. When custom fuel models were compared with similar mid-flame wind speeds, epidemic and post-epidemic fire behavior predictions were similar, indicating that reduced sheltering was more dominant than the influence of the fuels complex or solar radiation. When custom fuel models were compared with established fuel models, none predicted the same fire behavior outputs.

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Guldstrand, Frank. "Kartering och beskrivning av spröda deformationsstrukturer i södra Stockholm ur ett ingenjörsgeologiskt perspektiv." Thesis, Uppsala universitet, Berggrundsgeologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-206540.

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Stockholm är en mycket expansiv region med flera större infrastrukturella projekt plane- rade vilket kommer att medföra arbeten i och vid berg. Utan nödvändiga förundersökningar ökar risken för ras i samband med byggnationen och en fara för framtida stabilitet förelig- ger. En ingenjörsgeologisk förundersökning där man kartlägger strukturer i det påtänkta området bör genomföras och som beskriver de bergtekniska parametrar enligt Q- och RMR-systemen för bergkvalitetsklassificering. Detta arbete fokuserar på ett område norr om Månskärsvägen och söder om Skär- holmsvägen i södra Stockholm där Huddinge kommun planerat anlägga en gång- och cy- kelväg samt en bro. Området, benämnt kvadraten 3 av Huddinge kommun, karterades mellan den 25 – 27 mars och 2 april 2013 då området fortfarande var snötäckt. Kartering- en, efter projicering av sprickdata i Stereo32, visar att det råder fyra dominerande sprick- riktningar i området; en nordväst-sydostlig, en nordost-sydvästligt, en nord-sydlig sprick- riktning och en foliationsparallell sprickgrupp i öst-västlig riktning. Den sistnämnda böjer av ca 15° mot öst vid förflyttning mot den nordöstra delen av området, möjligtvis förklaras detta av en observerad veckomböj. Övriga sprickgruppers strykningar varierar inom ett spann av 40° och stupar ca 50°. Dessa spricksystem i kombination med hållfasthetssän- kande sprickfyllnadsmineral och metertjocka sprickzoner med i stort sett helt krossat berg kommer att utgöra stora risker vid bygget i form av ras och potentiella kilutglidningar. Arbe- ten i detta berg bör göras under stor försiktighet och i kombination med fortsatta geolo- giska undersökningar under det att projektet fortlöper.

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Lundgren, Christina Persson Bengt. "Wood and fibre properties of fertilized Norway spruce /." Uppsala : Swedish University of Agricultural Sciences, 2003. http://diss-epsilon.slu.se/archive/00000360/.

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Thesis (doctoral)--Swedish University of Agricultural Sciences, 2003.
Thesis documentation sheet inserted. Appendix reprints four papers and manuscripts, one co-authored with Bengt Persson. Includes bibliographical references. Also issued electronically via World Wide Web in PDF format; online version lacks appendix.

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33

Majeed, Zainal A. "An evaluation of AVHRR NDVI data for monitoring western spruce budworm defoliation." Morgantown, W. Va. : [West Virginia University Libraries], 1999. http://etd.wvu.edu/templates/showETD.cfm?recnum=1189.

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Thesis (M.A.)--West Virginia University, 1999.
Title from document title page. Document formatted into pages; contains xi, 80 p. : ill. (some col.), maps (some col.). Vita. Includes abstract. Includes bibliographical references (p. 72-77).

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34

Pettit, Jessika M. "Engelmann Spruce Survival and Regeneration After an Epidemic Spruce Beetle Outbreak on the Markagunt Plateau in Southern Utah." DigitalCommons@USU, 2018. https://digitalcommons.usu.edu/etd/7199.

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Bark beetle outbreaks are becoming more intense and severe when coupled with the effects of climate change. Engelmann spruce (Picea engelmannii) is one such species facing large-scale, epidemic spruce beetle outbreaks. Large-scale disturbances, such as beetle outbreaks, have major consequences for the future success of the ecosystem, thus highlighting the importance of understanding what promotes amplified outbreaks as well as their effects on future seedling establishment. Our research focused on two parts of a large-scale beetle outbreak: the mortality of spruce trees and the subsequent regeneration of seedlings. Our first study examined the timing of spruce mortality during an outbreak in order to identify the extent to which drought promotes host species mortality. Trees that are drought stressed have less resources to defend themselves against beetle attacks, however, the warmer temperatures associated with droughts also promote a more rapid population expansion of spruce beetles. We were specifically interested in determining the contribution that host drought stress plays during an epidemic outbreak. Our second study analyzed the patterns of regenerating seedlings with an aim to identify changes associated with the outbreak. Specifically, we were interested in how an epidemic outbreak changes the drivers of seedling establishment.

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Johnson, Karen J. "Effectiveness of Carbaryl and Pyrethroid Insecticides for Protection of Engelmann Spruce from Attack by Spruce Beetle (Coleoptera: Scolytidae)." DigitalCommons@USU, 1996. https://digitalcommons.usu.edu/etd/7311.

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A field experiment tested the effectiveness of carbaryl and two pyrethroid insecticides, cyfluthrin and esfenvalerate, in protecting high-value Engelmann spruce trees from attack by Dendroctonus rufipennis Kirby. Carbaryl suspension at the 2% registered rate and a reduced rate of 1 % were both effective in protecting Engelmann spruce from attack by D. rufipennis through two pheromone baiting periods and 24 months following insecticide application . Cyfluthrin at 0.025% rate and esfenvalerate at 0.025 and 0.05% rates provided effective protection through one pheromone baiting and 12 months following insecticide application. Only cyfluthrin at 0.008% rate was judged ineffective protection 12 months following insecticide application. A laboratory evaluation utilizing a 32-h bioassay on D. rufipennis adults determined all three insecticides were toxic by contact. Carbaryl and piperonyl butoxide bioassays testing synergism were inconclusive. The methodology presented provides a means for forest land managers to quantify insecticide toxicity and monitor for resistance development.

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Ahmed, Suborna Shekhor. "Impacts of tree improvement programs on yields of white spruce and hybrid spruce in the Canadian boreal forest." Thesis, University of British Columbia, 2016. http://hdl.handle.net/2429/59494.

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Local and regional timber shortages may be ameliorated via planting improved stocks with higher yields. In this dissertation, I addressed an important knowledge gap on the impacts of tree improvement programs on yields of white spruce (Picea glauca (Moench) Voss) and hybrid spruce (Picea engelmannii Parry ex Engelmann x Picea glauca (Moench) Voss) plantations across the boreal and hemiboreal forests of Canada using meta-modelling approaches. In particular, I used meta-data for white and hybrid spruce provenance trials extracted from the literature to: (i) forecast provenance yields over time for broad spatial and temporal extents; (ii) model yields of provenances relative to standard stocks (termed “gain”) over time; and (iii) test alternatives for forecasting each provenance at a location using available repeated-measures data. In the first study, provenance height over time trajectories were modelled by incorporating the effects of climatic variables, provenances and site characteristics into mixed-effects nonlinear models via a random coefficients modelling approach. Height trajectories were strongly affected by planting site and provenance climates, along with planting site characteristics. The height trajectory meta-model was incorporated into an existing growth and yield model, which can be used to predict provenance yields for long temporal and large spatial extents. In the second study, the impacts of the particular gain definition (i.e., selection age, proportion of top performers) were examined using the model from the first study, and one definition was selected. A meta-model of gain as a function of plantation age, planting density, and planting site climate was developed. Planting site climate strongly affected these gain trajectories. The gain definition and trajectory model can be used to evaluate potential gains of using improved white and hybrid spruce stocks. Forecasts are needed to evaluate provenance (or progeny) performance at harvest, often 80 or more years from planting. In the third study, three alternative procedures (population-averaged, subject-specific, and autocorrelation) to forecast repeated measures for a particular progeny at a location were compared and evaluated by virtually removing some repeated measures. The subject-specific forecasts were best with accuracies similar to the measurement precision using standard height measurement devices given five or more prior measurements.
Forestry, Faculty of
Graduate

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Bonnekoh, Carsten [Verfasser], and A. [Akademischer Betreuer] Möslang. "Der Spröd-duktil-Übergang in ultrafeinkörnigem Wolfram / Carsten Bonnekoh ; Betreuer: A. Möslang." Karlsruhe : KIT-Bibliothek, 2021. http://nbn-resolving.de/urn:nbn:de:101:1-2021092905000095918962.

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Kaul, Sonu. "Uptake, transport and bioactivity of exogenously applied ABA and ABA analogues in white spruce and wheat seedlings." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ36644.pdf.

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39

Pond, Sharon Elizabeth. "Improving germination in white spruce somatic embryos with desiccation and/or cold treatments." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ37359.pdf.

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Nicholas, Niki Stephanie. "Stand structure, growth, and mortality in southern Appalachian spruce-fir /." This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-06062008-165928/.

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41

Giesecke, Thomas. "The Holocene Spread of Spruce in Scandinavia." Doctoral thesis, Uppsala University, Department of Earth Sciences, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4623.

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The Holocene spread of Picea abies in Scandinavia provides an excellent opportunity for detailed study of the dynamics of tree spread and population expansion. Early- and mid-Holocene macrofossil evidence for the presence of Picea abies in Scandinavia has questioned traditional interpretations of the timing and direction of its spread. This study aims to determine the pattern of the spread of Picea abies in Scandinavia from pollen and other data, to evaluate the significance of possible early outpost populations and to deduce possible factors that influenced the spread and population expansion of Picea abies in Scandinavia.

Palaeoecological investigations were carried out on the sediments of four small lakes in central Sweden to gain detailed insight into the dynamics of the spread. Holocene pollen diagrams with independent dating control were collected from Fennoscandia and adjacent areas to compare the timing of selected features of the Picea abies pollen curve. Computer models were used to test possible scenarios for the spread and Picea abies population expansion.

Picea abies entered the Scandinavian peninsula from the east at different times and by different pathways. Early-Holocene outposts can be discerned in pollen records from northwest Russia, eastern and northeastern Finland for the time before 9000 cal. BP. Pollen records from Sweden and Norway indicate small Picea abies populations after 8000 cal. BP. The mid to late-Holocene spread, which superficially resembles a front-like pattern, may in fact represent a wave of expanding populations. Disturbance through fire and human activity did not significantly influence the pattern of the spread. Changing climate parameters, slow adaptation and gene flow through seeds and pollen have to be considered as possible explanations for the late spread of the tree. Population dynamics and propagule pressure are likely to be important factors that shaped the spread of Picea abies.

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Axelsson, Josefin. "Separate Hydrolysis and Fermentation of Pretreated Spruce." Thesis, Linköpings universitet, Institutionen för fysik, kemi och biologi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-69487.

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Bioethanol from lignocellulose is expected to be the most likely fuel alternative in the near future. SEKAB E-Technology in Örnsköldsvik, Sweden develops the technology of the 2nd generation ethanol production; to produce ethanol from lignocellulosic raw material. The objective of this master’s thesis was to achieve a better knowledge of the potential and limitations of separate hydrolysis and fermentation (SHF) as a process concept for the 2nd generation ethanol production. The effects of enzyme concentration, temperature and pH on the glucose concentration in the enzymatic hydrolysis were investigated for pretreated spruce at 10% DM using a multiple factor design. Enzyme concentration and temperature showed significant effects on the glucose concentration, while pH had no significant effect on the concentration in the tested interval of pH 4.5-5.5. To obtain the maximum glucose concentration (46.4 g/l) for a residence time of 48 h, the optimal settings within the studied parameter window are a temperature of 45.7⁰C and enzyme concentration of 15 FPU/g substrate. However, a higher enzyme concentration would probably further increase the glucose concentration. If enzymatic hydrolysis should be performed for very short residence times, e.g. 6 h, the temperature should be 48.1⁰C to obtain maximum glucose concentration. The efficiency of the enzymes was inhibited when additional glucose was supplied to the slurry prior to enzymatic hydrolysis. It could be concluded that end product inhibition by glucose occurs and results in a distinct decrease in glucose conversion. No clear conclusions could be drawn according to different techniques for slurry and enzymes, i.e. batch and fed-batch, in the enzymatic hydrolysis process. Investigations of the fermentability of the hydrolysate revealed that the fermentation step in SHF is problematic. Inhibition of the yeast decrease the fermentation efficiency and it is therefore difficult to achieve the 4% ethanol limit. Residence time for enzymatic hydrolysis (48 h) and fermentation (24 h) need to be prolonged to achieve a sufficient SHF process. However, short processing times are a key parameter to an economically viable industrial process and to prolong the residence times should therefore not be seen as a desirable alternative. SHF as a process alternative in an industrial bioethanol plant has both potential and limitations. The main advantage is the possibility to separately optimize the process steps, especially to be able to run the enzymatic hydrolysis at an optimal temperature. Although, it is important to include all the process steps in the optimization work. The fermentation difficulties together with the end product inhibition are two limitations of the SHF process that have to be improved before SHF is a preferable alternative in a large scale bioethanol plant.

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Miyazawa, Kae. "Comparative ecophysiology of North American spruce species." Thesis, McGill University, 1999. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=30705.

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An ecophysiological comparison among species was conducted to investigate the possible factors controlling the distribution of North American spruce (Picea) species, especially with regard to the possible influence of global change. The seedlings of 8 North American spruce species were grown in a growth chamber, with half of them being given an episodic 'increased temperature and drought' stress treatment. Trait values among species, particularly growth analysis components, were compared and related to climatic variables associated with the geographical range of the species. Relative growth rate (RGR) and specific leaf area (SLA) were positively correlated with latitude, and the leaf weight ratio (LWR) variation negatively with the dryness of species' natural ranges. All these relationships hold with both messed and unstressed seedlings, even thou seedling response to the stress was significant. The SLA-latitude and LWR-dryness relationships are likely to have ecological significance, and this indicates that foliage stricture (SLA) and allocation (LWR) play important roles determining a species range along temperature and dryness gradients.

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44

Pettersson, Marie. "Stress Related Emissions of Norway Spruce Plants." Licentiate thesis, Stockholm : [Kemi, Kungliga Tekniska högskolan], 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4353.

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45

Wiweger, Malgorzata. "Signal molecules in embryogenesis of Norway spruce /." Uppsala : Dept. of Plant Biology and Forest Genetics, Swedish Univ. of Agricultural Sciences, 2003. http://epsilon.slu.se/s293.pdf.

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46

Azhar, Shoaib. "Extraction of Polymeric Hemicelluloses from Spruce Wood." Doctoral thesis, KTH, Träkemi och massateknologi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-158966.

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Hemicelluloses are one of the three main components of spruce wood and constitute about 20% of the wood material. During mechanical pulping, 5–10% of the hemicelluloses are accumulated in waste waters, whereas during chemical pulping 70–80% of the hemicelluloses are lost in process liquors. The concept of integrated forest biorefinery involves the development of methods to extract these hemicelluloses prior to pulping in order to produce value-added products besides pulp. This thesis describes some of the feasible possibilities of extracting hemicelluloses from wood at a high molecular weight prior to pulping in addition to presenting a deeper understanding of their degradation under mild treatment conditions. A major obstacle for the efficient extraction of hemicelluloses is the recalcitrance due to the network of lignin and polysaccharides. This network can be loosely opened by the use of enzymes and this improves the extraction of hemicelluloses. A chemical impregnation of the wood chips was performed to enhance the accessibility of the cell wall to enzymes. The ability of different additives to stabilize the hemicelluloses against peeling during the alkaline impregnation stage was also investigated in order to obtain a better yield in subsequent extraction. Increasing the surface area and decreasing the mass transport length could also improve the yield of hemicelluloses extracted from wood. This was achieved with a mild mechanical pre-treatment of wood chips using an impressafiner and a fiberizer. Polymers mainly consisting of galactoglucomannan with an average molecular weight of 30 kDa were extracted from fiberized wood with water. Different pre-treatment and extraction methods were combined to demonstrate the concept of material biorefinery based on wood. The kinetics of degradation of spruce galactoglucomannan were studied under alkaline conditions. It was degraded in two phases at two different rates. A kinetic model was developed to fit the experimental data and to estimate the activation energies.

QC 20150119

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Crute, Stephen John. "Computer simulations of green spruce aphid populations." Thesis, University of Ulster, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.281228.

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48

Williams, David Thomas. "Impact of defoliating insects on Sitka spruce." Thesis, University of Ulster, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.268604.

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Shen, Elizabeth M. "Sprite tracking in two-dimensional video games." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/113111.

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Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2017.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (page 32).
I explore various computer vision techniques and their application towards processing and extracting information from two-dimensional video games. The bulk of existing research is designed to work on real-world images, and thus makes assumptions about the world that do not translate to synthetic, stylized environments. Processing video game footage has promising applications in competitive gaming, such as analyzing strategy in multiplayer online games, or optimizing routes in speed-running. I present the exploratory results, details of a successful algorithm, and some sample applications.
by Elizabeth M. Shen.
M. Eng.

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Ďurdina, Lukáš. "Stanovení charakteristik spreje pomocí optických měřících metod." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2012. http://www.nusl.cz/ntk/nusl-230349.

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Abstract:

Diplomová práce se zabývá měřením charakteristik sprejů dvou tlakových vířivých trysek pro spalovací komoru malého turbínového motoru na zkušebním stavu za studena pomocí metod Particle Image Velocimetry (PIV) a fázové Dopplerovské anemometrie (PDA). Cílem měření bylo stanovit a porovnat charakteristiky sprejů obou trysek. Výsledky měření mají objasnit rozdílnost chování trysek za provozu a možný dopad na proces spalování. Úvodní teoretická část pojednává o základních fyzikálních principech atomizace kapalin, konstrukci a oblasti uplatnění tlakových vířivých trysek a o principech laserových diagnostických metod použitých při experimentálním měření. Nasledující část popisuje návrh a montáž zkušební trati a dalších zařízení navržených pro experimentální měření v této práci. Experimentální část se zabývá nastavením parametrů měřícího systému a zpracováním dat. Výsledky měření zahrnují vektorová rychlostní pole, axiální rychlostní profily a distribuce velikosti kapek pro různé provozní podmínky obou trysek.

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