Effect of Seed Transfer on Selected Wood Quality Attributes of Jack Pine (Pinus banksiana Lamb.)

So far, few studies have considered the impacts of seed sources transfer on jack pine (Pinus banksiana Lamb.) wood quality, although wood quality attributes (WQA) in general and the differences between juvenile and mature wood in particular will determine suitability of the produced wood for end-uses. The main objective of this study was to examine the possibility of selecting superior jack pine provenances based on selected WQA. Twenty-two provenances of jack pine were planted in 1964 in Petawawa Research Forest, ON, Canada, as part of a provenance test. The plantation location offers conditions close to optimum for jack pine growth. Transition ages at breast height, determined with tracheids length, were computed with a piecewise model. Measurements at age 42 from seed were subjected to analyses of variance. Radial variations from pith to bark, as well as trends with seed sources origin of the selected WQA were also considered. A ranking was made based on a selection index built with four WQA. The provenances matured between 8 and 14 years, corresponding to 17%-48% of juvenile wood proportion. Significant differences among provenances were observed for ring width, ring density, tracheid length, and diameter at breast height but not for tracheid diameter, tree height, transition age, and juvenile wood proportion. None of the provenances ranked the best with all the selected WQA, but it was possible to find provenances exhibiting both high growth rate and good wood quality. A surprising result of this study was that tracheid diameter initially enlarged for 8 years, before declining toward the bark. It is possible to select provenances for a higher growth rate and for good physical (i.e., related to wood density) and anatomical (i.e., related to tracheid dimensions) wood quality attributes

Effect of Forest Biomass Pretreatment on Essential Oil Yield and Properties

Essential oils (EOs) are natural and economically valuable aromatic compounds obtained from a variety of crops and trees, including forest trees, which have different therapeutic and biological activities. This project aims to assess the impact of different residual forest biomass pretreatments on the yield and the properties of EOs, including their antibacterial and antioxidant characteristics. Forest biomass from black spruce (BS, Picea mariana Mill.), balsam fir (BF, Abies balsamea), and jack pine (JP, Pinus banksiana Lamb.) was processed mechanically by (i) shredding, (ii) grinding, (iii) pelletizing, and (iv) bundling. EOs were then extracted by hydro- and steam distillation. The densification into bundles was found to improve EOs yield compared to the other residual forest biomass pretreatments. For example, the yield of bundled BF was improved by 68%, 83%, and 93% compared to shredded, ground, and granulated biomass, respectively. The highest yield was obtained when densification into bundles was combined with extraction through hydrodistillation. As for EOs' chemical composition, JP had the highest polyphenol content and consequently the greatest antioxidant activity. EOs derived from BS inhibited the growth of Grampositive Staphylococcus aureus bacteria and Gram-negative Salmonella typhimurium and Escherichia coli bacteria. The densification of forest biomass into bundles did not affect the antioxidant capacity or the antibacterial activity of EOs, thereby preserving both properties. Thus, the pretreatment of forest biomass residue could have an impact on the volume and the transport costs and therefore improve the bioproducts market and the bioeconomy in Canada

Phenotypic Correlations Between Juvenile-Mature Wood Density and Growth in Black Spruce

Phenotypic correlations between juvenile-mature wood density and growth were examined based on increment core samples from two plantations, a provenance test and a commercial plantation, of black spruce [Picea mariana (Mill.) B.S.P.]. The ring density components are significantly correlated to their respective ring width components: earlywood and ring densities are negatively correlated to ring and earlywood widths, respectively, while ring and latewood densities are positively correlated to latewood width. These hold true in both juvenile and mature wood. However, the correlation between ring width and ring density decreases with increasing age. This suggests that the correlation between wood density and growth rate tends to lessen as the tree ages. For each character, the correlation between juvenile and mature wood is significant but moderate. Thus, juvenile wood characters are only indicative of mature wood ones. On the other hand, trees with 12 growth rings from the pith were good predictors of wood density and radial growth of the whole tree. Individual growth rings from the juvenile-mature wood transition zone can be used to predict to some extent the wood density of either mature wood or the whole tree

Binderless Fiberboard Made from Primary and Secondary Pulp and Paper Sludge

Pulp and paper sludge is valuable in fiberboard manufacturing because primary sludge (PS) contains fibers and secondary sludge (SS) has adhesive properties. We evaluated properties of binderless fiberboard made from conventional pulp and paper mill sludge sources using a factorial design in which the factors were SS:PS ratio (1:9, 2:8, and 3:7) and pulping process (thermomechanical [TMP], chemical-thermomechanical [CTMP], and kraft). Sludge was collected, refined, dried, and characterized for chemical composition and fiber length. Internal bond strength of CTMP panels increased 90% and thickness swell of TMP panels improved 92% with increasing SS content from 10-30%. IR Fourier transform and X-ray photoelectron spectroscopy analyses were conducted to better understand these results. Increased bonding was attributed to presence of proteins and lignin on the sludge fiber surface, which enhanced adhesion during hot pressing, whereas surface contamination decreased bonding efficiency. The TMP formulation at SS:PS ratio 3:7 met the ANSI requirement for basic hardboard. All other formulations were not dimensionally stable enough to meet the standard. The CTMP source resulted in the highest mechanical properties, and thickness swell was similar for the TMP and CTMP pulping processes. The kraft source produced low-integrity and dimensionally unstable panels

Medium-Density Fiberboard Produced Using Pulp and Paper Sludge from Different Pulping Processes

Pulp and paper sludge can be recycled in the manufacture of medium-density fiberboard (MDF) because it contains wood fibers. A comparative study was conducted to evaluate the properties of MDF made from virgin fibers mixed with different pulp and paper sludge sources. A factorial design was used in which factors were mill pulping processes, thermal-mechanical pulping (TMP), chemical-thermal-mechanical pulping (CTMP), and kraft pulping, and percentage of sludge mixed with virgin fibers (0, 25, 50, and 75%). Virgin fibers were obtained from paper birch wood, an underutilized species. Chemical composition, physical characteristics, pH, and buffer capacity of sludge were measured. MDF properties decreased mostly linearly with sludge content. Panel properties negatively correlated with the proportion of nonfibrous material such as ash and extractives. TMP and CTMP sludge sources produced panels of similar quality, and kraft sludge produced the lowest quality. It was concluded that the amount of sludge that can be incorporated into MDF without excessive decrease in panel quality depends on the pulping process. At 25% sludge content, all panels met ANSI quality requirements for MDF used for interior applications

Decomposition-based mission planning for fixed-wing UAVs surveying in wind

This paper presents a new method for planning fixed-wing aerial survey paths that ensures efficient image coverage of a large complex agricultural field in the presence of wind. By decomposing any complex polygonal field into multiple convex polygons, the traditional back-and-forth boustrophedon paths can be used to ensure coverage of these decomposed regions. To decompose a complex field in an efficient and fast manner, a top-down recursive greedy approach is used to traverse the search space in order to minimise flight time of the survey. This optimisation can be computed fast enough for use in the field. As wind can severely affect flight time, it is included in the flight time calculation in a systematic way using a verified cost function that offer greatly reduced survey times in wind. Other improved cost functions have been developed to take into account real world problems, e.g. No Fly Zones, in addition to flight time. A number of real surveys are performed in order to show the flight time in wind model is accurate, to make further comparisons to previous techniques and to show that the proposed method works in real-world conditions providing total image coverage. A number of missions are generated and flown for real complex agricultural fields. In addition to this, the wind field around a survey area is measured from a multi-rotor carrying an ultrasonic wind speed sensor. This shows that the assumption of steady uniform wind holds true for the small areas and time scales of a Unmanned Aerial Vehicle (UAV) aerial survey.</div

La maladie de cowden a propos d’un cas

La maladie de Cowden est une maladie héréditaire à transmission autosomique dominante caractérisée par des lésions associant des atteintes cutanées constantes et caractéristiques (lésions papuleuses au niveau de la face et des extrémités) et des lésions viscérales inconstantes notamment thyroïdiennes, mammaires, intestinales et rénales à haut risque de dégénérescence. Nous rapportons un cas chez une femme de 30 ans porteuse d’une craniomégalie, de polypes intestinaux, d’un fibroadénome des seins, de lésions papuleuses des gencives et d’un goitre multi-nodulaire. Elle a eu dans notre service une thyroïdectomie totale dont l’analyse anatomopathologique définitive de la pièce a révélé un micro-carcinome vésiculaire du lobe gauche de la thyroïde. Les lésions thyroïdiennes sont habituellement bien limitées, mais devant la multifocalité, le risque accru de récidive et de dégénérescence maligne, une thyroïdectomie totale doit être préconisée.Mots clès : Maladie de Cowden, Cancer de la thyro

Cholesteatome Congenital De L’oreille Moyenne A Propos De Deux Cas

But :Le cholesteatome congenital de l’oreille moyenne est une entite rare. L’objectif de ce travail est de discuter les particularites cliniques et therapeutiques de cette pathologie a travers deux observations de malades presentant un cholesteatome congenital operes et suivis au service d’ORL et de chirurgie cervico-faciale Fattouma Bourguiba Monastir, entre 2002 et 2008. Résultats : Il s’agissait de deux garcons, ages de 5 et 7 ans. La symptomatologie etait dominee par l’apparition d’une hypoacousie et l’examen otologique a revele un tympan complet dans les deux cas. La TDM des rochers a permis d’evoquer le diagnostic du cholesteatome congenital et d’apprecier les extensions locales des lesions. Les deux malades ont eu une tympanoplastie en technique fermee. Conclusion : L’evolution du cholesteatome congenital est insidieuse et le diagnostic est souvent tardif. Le traitement est chirurgical, domine par la tympanoplastie en technique fermee. Mots clès : Chlolesteatome congenital, hypoacousie, tympan complet, tympanoplastie en technique fermee, technique ouverte

Myxome Du Maxillaire A Propos D\'un Cas

Les myxomes des maxillaires sont des tumeurs bénignes rares dont la pathogénie reste encore controversée. Leur indolence et la pauvreté des manifestations qui les accompagnent rendent leur diagnostic souvent tardif et leur prise en charge difficile. Nous présentons un cas de myxome du maxillaire chez un nourrisson âgé de 12 mois suivi d\'une revue de la littérature permettant de synthétiser les données cliniques ainsi que la stratégie thérapeutique à adopter.Maxillary myxoma are rare benign tumours whose pathogenesis remains extremely discussed. The poor clinical picture and the absence of pain makes the diagnosis difficult. We report a pediatric case of maxillary myxoma of a 12- monthold infant and review the clinical features, radiographic evaluation and the appropriate treatment Keywords:Myxoma - maxillary - benign tumor. Journal Tunisien d\'ORL et de chirurgie cervico-faciale Vol. 18 2007: pp. 43-4

Fistule carotido-caverneuse post-traumatique

Introduction : La fistule carotido-caverneuse (FCC) est une complication rare, mais grave des traumatismes craniofaciaux pouvant engager le pronostic fonctionnel oculaire et le pronostic vital. elle réalise une communication anormale entre le système artériel carotidien et le sinus caverneux.Buts : Rapporter un cas de FCC directe post-traumatique et étudier les aspects cliniques, diagnostiques et thérapeutiques de cette pathologie.Observation : Nous rapportons un cas de FCC apparue dans les suites d’un traumatisme craniofacial et survenue chez un homme de 25 ans ayant été victime d’un accident de la voie publique. Le diagnostic a été suspecté devant l’apparition, au 19ème jour d’hospitalisation, d’une exophtalmie unilatérale gauche pulsatile associée à un important chémosis et à une pupille aréflectique. Une artériographie cérébrale pratiquée 9 jours après la constatation de l’exophtalmie a objectivé une large FCC gauche. Une embolisation au moyen de deux ballonnets intravasculaires largables et de l’injection de colle biologique a été réalisée au même temps sans incidents permettant d’obtenir l’occlusion complète de la fistule. L’évolution a été marquée par la régression de l’exophtalmie et du chémosis et par l’amélioration partielle de l’acuité visuelle.Conclusion : Le traitement des FCC est urgent et est principalement basé sur la neuroradiologie interventionnelle. en effet, l’angiographie cérébrale constitue l’examen clé et possède un double intérêt diagnostique et thérapeutique.Mots clés : fistule carotido-caverneuse, traumatisme craniofacial, artériographie cérébrale, embolisation