Peroxyacetic Acid Delignification of Wood and Bark from Ponderosa Pine (Pinus ponderosa)

Ruminant species, which include cattle, sheep and goats, have the unique capability of digesting. cellulose and hemicellulose, the cell-wall carbohydrates that constitute 70 to 80 percent of wood fiber. By their conversion of these higher polysaccharides, which are indigestible by humans and other monogastrics, to animal products the ruminant species offer a potential means for solving the residue disposal problems of the wood industry while concomitantly extending the food supply for human nutrition. The ability of ruminants to digest the cell-wall carbohydrates depends on the microbial digestion that occurs in the reticule-rumen. This organ lies between the esophagus and the abomasum or true stomach and contains large numbers of bacterial and protozoal organisms in an anaerobic atmosphere. Many of these microorganisms possess enzyme systems which are capable of hydrolyzing the beta configuration of the glycosidic linkages which join the monomeric subunits of cellulose and hemicellulose. Through this process of enzymatic hydrolysis cellulose and hemicellulose are gradually degraded to their basic sugar units which are further metabolized to volatile fatty acids, primarily acetic and propionic. These fatty acids are absorbed through the reticule-rumen wall and serve as the main source of energy to the animal. As a potential food source wood has several advantages. It is one of the few renewable resources that is available in abundant supply and can be obtained year-round. Because its growth occurs slowly over a period of many years short term fluctuations in supply are not likely to be a problem. Its ability to grow on land area that is not well suited for human habitation or domestic crop cultivation makes it very noncompetitive for land use. Many researchers have investigated the inclusion of raw wood fiber into ruminant rations and numerous physical and chemical treatments have been conducted in attempts to improve its nutritional quality. In spite of these efforts a desirable processing technique has yet to be achieved. One of the major limitations is the nature of the raw material itself. Wood is a heterogeneous substance that varies in physical and chemical composition among genera and species. Within a single tree, composition varies cross-sectionally and longitudinally and is influenced by seasonal changes. This investigation will review previous work concerning the use of wood fiber as a ruminant feed and will evaluate the effectiveness of peroxyacetic acid treatment of wood fibers to improve their digestibility

Characterisation of Rosa Mosqueta seeds : cell wall polysaccharide composition and light microscopy observations

The utilisation of enzymes for the extraction of vegetable oils from seeds has been a topic of growing interest in recent years. Knowledge of the cell wall polysaccharide composition is important to select the enzyme(s) necessary for the most effective degradation of the cell walls. The purpose of the present work is to characterise the seeds of Rosa Mosqueta (Rosa aff rubiginosa) by light microscopy (where several differential staining methods were applied to analyse the seed structure) and by the isolation of cell wall polysaccharide extracts. The mature seed of Rosa Mosqueta has a very thick and structurally complex seed coat comprising heavily lignified tissue. The embryo has two cell layers of remaining endosperm tissue (indicating that this is an exalbuminous seed), two voluminous cotyledons that contain the oil, and bundles of provascular tissues distributed perpendicularly to the transverse axis of the embryo. The major non-cellulosic polysaccharides from the non-lignified tissues are glucuronoxylans and pectic polysaccharides; glucans are also present in small amounts. The major non-cellulosic polysaccharides from the lignified tissues are glucuronoxylans. Concerning the use of enzymes for oil extraction, microscopy and cell wall polysaccharide analysis showed that the use of pectic enzymes followed by a xylanase or a cellulase should be explored.União Europeia (UE) - Contract INCO-DC: 96-2205

Fiber Surface Structure and Fiber Liberation in Soda-anthraquinone Kraft and Soda Pulps as Determined by Conventional Electron Microscopy

Comparative studies on the surface structure of defibrated fibers and fiber liberation in nondefibrated chips from three different pulping processes, soda-anthraquinone (soda/AQ), kraft and soda pulping, were performed via conventional electron microscopy. By comparing the exposed fiber surface structure with the degree of fiber liberation, delignification processes in middle lamella regions were elucidated for these pulping systems. Soda/AQ pulping resulted in fiber liberation with less lignin removal than for either kraft or soda pulping process

Characterising postural sway fluctuations in humans using linear and nonlinear methods

Introduction: Postural control is a prerequisite to many everyday and sporting activities which requires the interaction of multiple sensorimotor processes. As long as we have no balance disorders, the maintenance of an erect standing position is taken for granted with automatic running control processes. It is well known that with increasing age or disease balance problems occur which often cause fall-related injuries. To assess balance performance, posturography is widely applied in which body sway is traditionally viewed as a manifestation of random fluctuations. Thus, the amount of sway is solely used as an index of postural stability, that is, less sway is an indication of better control. But, traditional measures of variability fail to account for the temporal organisation of postural sway. The concept of nonlinear dynamics suggests that variability in the motor output is not random but structured. It provides the stimulus to reveal the functionality of postural sway. This thesis evaluates nonlinear analysis tools in addition to classic linear methods in terms of age-related modifications of postural control and under different standing conditions in order to broaden the existing knowledge of postural control processes. Methods: Static posturographic analyses were conducted which included the recording of centre of pressure (COP) time series by means of a force plate. Linear and nonlinear methods were used to quantify postural sway variability in order to evaluate both the amount and structure of sway. Classic time and frequency domain COP parameters were computed. In addition, wavelet transform (WT), multiscale entropy, detrended fluctuation analysis, and scaled windowed variance method were applied to COP signals in order to derive structural COP parameters. Two experiments were performed. 1) 16 young (26.1 ± 6.7 years), healthy subjects were asked to adopt a bipedal stance under single- and dual-task conditions. Three trials were conduced each with a different sampling duration: 30, 60, and 300 seconds [s]. 2) 26 young (28.15 ± 5.86 years) and 13 elderly (72 ± 7 years) subjects stood quietly for 60 s on five different surfaces which imposed different biomechanical constraints: level ground (LG), one foot on a step (ST), uphill (UH), downhill (DH), and slope (SL). Additional to COP recordings, limb load symmetry was assessed via foot pressure insoles. Results: We found a higher sensitivity of structural COP parameters to modulations of postural control and partly an improved evaluation of sway dynamics in longer COP recordings. WT revealed a reweighing of frequency bands in response to altered standing conditions. Scaling exponents and entropy values of COP signals were task-dependent. Higher entropy values were found under the dual-task and condition ST. The time scales affected under the altered standing positions differed between groups and sway directions. Mainly larger posturograms were found in the elderly. Age effects were especially revealed in position ST and concerning medial-lateral COP signals. Load asymmetry was stronger in elderly subjects for LG, UH, and DH positions. Discussion: Modifications of multiple time scales corresponds to an interplay of control subsystems to cope with the altered task demands. The affected time scales are age-dependent suggesting a change of control processes. Higher irregularity under the dual-task indicates a more complex motor output which is interpreted as less attentional investment into postural control. Larger complexity is evident for ST in contrast to LG position. ST obviously challenges lateral sway which is counteracted differently between groups. Load asymmetry suggests that especially elderly subjects adopt a step-initiation strategy. Conclusion: A continued application of nonlinear methods is necessary to broaden the understanding of postural control mechanisms and to identify classifiers for balance dysfunctions. Structural COP parameters provide a more comprehensive indication of postural control system properties between groups and task demands. COP recordings of at least 60 s are recommended to adequately quantify COP signal structure. The analysis of postural strategies in everyday activities increases the ecological validity of postural control studies and can provide valuable information regarding the development of effective rehabilitation programs.Die posturale Kontrolle ist eine Voraussetzung für viele Alltagsaktivitäten und sportliche Bewegungen. Man weiß heute, dass den Kontrollmechanismen eine komplexe Interaktion sensomotorischer Prozesse unterliegt (Horak and Mcpherson, 1996; Oie et al., 2002). Solange keine Gleichgewichtsdefizite vorliegen, nehmen wir es als selbstverständlich wahr aufrecht Stehen zu können, ohne uns der Komplexität posturaler Kontrollmechanismen bewusst zu sein. Studien haben gezeigt, dass es mit zunehmendem Alter zu Defiziten in der posturalen Kontrolle kommt (Pasquier et al., 2003; Woollacott, 1993). Oftmals ist ein erhöhtes Sturzrisiko die Folge, welches unter anderem mit Verletzungen, einer eingeschränkten Mobilitätsowie einer verminderten Lebensqualität einhergehen kann (Era et al., 1997; Frank and Patla, 2003). Seit vielen Jahren schon werden posturographische Untersuchungen durchgeführt mit dem Ziel, posturale Kontrollmechanismen abzuleiten undDysfunktionen im posturalen System zu diagnostizieren (Piirtola and Era, 2006). Jedoch sind die Mechanismen, die der posturalen Kontrolle unterliegen, bis heute nicht eindeutig verstanden. Neue Erkenntnisse konnten in den letzten Jahrenvor allem durch ein erweitertes Verständnis von Bewegungsvariabilität gewonnen werden (Stergiou and Decker, 2011; Lippens and Nagel, 2009). Traditionell werden posturale Analysen unter der Annahme durchgeführt und interpretiert, dass Variabilität eine Art “Rauschen” (white noise) ist und somit Ausdruck eines Fehlers. Posturale Schwankungen werden als zufällige, nicht intendierte Abweichungen gesehen (Loosch, 1997). Der Parameter “Schwankungsausmaß” wird zur Diagnostik des statischen Gleichgewichts herangezogen und bei einer größeren Schwankung wird eine schlechtere posturale Kontrolle diagnostiziert. Im Gegensatz dazu weist der systemdynamische Modellansatz auf die funktionale Rolle der Variabilität hin (van Emmerik and van Wegen, 2002). Variabilität ist Ausdruck der Anpassung und Flexibilität und somit notwendig, um auf ständige Umweltveränderungen reagieren zu können. Ein erhöhtes Schwankungsausmaß ist demnach nicht ausschließlich ein Zeichen für Instabilität (Newell et al., 1993). Eine größere Variabilität posturaler Schwankungen kann auch positiv im Sinne von mehr Umweltexploration interpretiert werden (Lacour et al., 2008). So konnte gezeigt werden, dass posturale Schwankungen nicht zufällig sind, sondern eine Struktur enthalten (Duarte and Zatsiorsky, 2000), dessen Charakterisierung zusätzliche Informationen über die Organisation des posturalen Kontrollsystems liefert (Stergiou and Decker, 2011). Die vorliegende Arbeit evaluiert nichtlineare Methoden unter dem systemdynamischen Ansatz zusätzlich zu den traditionell eingesetzten linearen Methoden. Ziel ist es, neben der Quantifizierung des Ausmaßes posturaler Schwankungen ihre Struktur zu charakterisieren, um das Verständnis für posturale Kontrollmechanismen zu erweitern. Die Evaluierung erfolgt zunächst über den Vergleich von Stehen mit und ohne kognitiver Zusatzaufgabe, wo Studien erste Hinweise auf eine veränderte COP1 Signalstruktur geben (Cavanaugh et al., 2007; Donker et al., 2007; Stins et al., 2009). Durch das Betrachten unterschiedlicher Signallängen und eines umfangreichen Methodenspektrums sollen Anhaltspunkte für die Applikation vonnichtlinearen in Kombination mit linearen Analyseverfahren abgeleitet werden. In einer zweiten Untersuchung werden diese dann in einem angewandten Studiendesign umgesetzt. Dabei wird die Veränderung posturaler Kontrollstrategien bei unterschiedlichen Standpositionen untersucht, welche alltägliche Situationen simulieren, unter Berücksichtigung altersbedingter Effekte. Dies ist ein erster Ansatz zur Erreichung einer hohen ökologischen Validität posturaler Studien (Frank and Patla, 2003; Visser et al., 2008). Erst kürzlich wurde gezeigt, dass bei älteren Menschen meist interne Auslöser (z.B. Gewichtsverlagerungen) ursächlich für Stürze sind (Robinovitch et al., 2013). Zudem haben ältere Personen größere Schwierigkeiten auf Umgebungsveränderungen zu reagieren (Nardone and Schieppati, 2010). Es ist jedoch bisher unbekannt, wie sich Defizite in der Gleichgewichtskontrolle älterer Menschen auf die Struktur posturaler Schwankungen auswirken. ..

Easily deconstructed, high aspect ratio cellulose nanofibres from Triodia pungens; an abundant grass of Australia's arid zone

The production of high aspect ratio cellulose nanofibres without resorting to very harsh mechanical and/or chemical processing steps remains a challenge that hinders progress in the fast-moving nanocellulose field. In response to this challenge, herein we report the preparation of high aspect ratio (>500) and small diameter

Study on Soda−Ethanol Delignification of Pine Sawdust for a Biorefinery

The soda–ethanol process was conceived as a sulfur-free pulping process, which may also be an alternative to conventional alkaline pulping, such as kraft or soda–AQ in the biorefinery context. An in-depth study using two experimental designs was conducted to establish the viability of soda–ethanol delignification of pine sawdust. At first, a simple factorial design involving the ethanol–water ratio (ethanol:water) and the alkaline load (AL, % over dry wood, odw) was applied to define the levels of these variables and their eventual interaction. Then, a 32 experimental design was performed to evaluate the ability of the process concerning the pulping of pine sawdust. The tested conditions were carefully selected to screen a broad range of cooking times (60, 100, and 140 min) and alkaline loads (19.0, 23.3, and 27.6 %odw) to obtain pulps with different extents of delignification (residual lignin contents). Finally, the kraft, soda–AQ, and soda–ethanol treatments were compared. Soda–ethanol pulping was shown to be a suitable delignification stage for a biorefinery scheme of Pinus elliottii and Pinus taeda sawdust. It has many advantages over traditional processes regarding its environmental impact, harmless chemicals, and selectivity. The tested conditions were similar to those frequently used in conventional pulping at an industrial scale, suggesting the technical feasibility of the soda–ethanol process for pine sawdust processing.Fil: Imlauer Vedoya, Camila María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; ArgentinaFil: Area, Maria Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; ArgentinaFil: Raffaeli, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; ArgentinaFil: Felissia, Fernando Esteban. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales. Laboratorio de Investigaciones en Maderas; Argentin

Organosolv delignification of steam exploded wheat straw

Atualmente tem-se aumentado o interesse no estudo de processos alternativos depolpação que conciliam um alto desempenho e causando pouco impacto ambiental. Da mesmamaneira, o uso de resíduos agrícolas é cada vez mais citado como matéria-prima promissorapara produção de produtos químicos. A palha de trigo é um resíduo agrícola muito abundantee foi usado em muitos países para a produção de polpas de celulose. Este trabalho descreveo efeito do pré-tratamento através de uma explosão a vapor seguido de uma polpação comacetona/água na palha de trigo. As amostras de palha de trigo foram tratadas através de explosão a vapor com temperaturas variando entre 190 e 210 oC durante 4 min e em seguidasubmetidas ao tratamento com acetona/água (1:1/v:v) a diferentes temperaturas (140, 160e 200oC) durante um tempo de 60 min de polpação. O pré-tratamento por explosão a vaporlevou a um aumento da quantidade de lignina extraída pela polpação organossolve. Esteefeito foi mais pronunciado para as polpações realizadas a menores temperaturas. O uso detemperaturas mais elevadas no tratamento por explosão a vapor foi mais signi…cativo, poisresultou em menores valores de rendimento de polpa e maiores taxas de deslignificação

Bioethanol production from coconut husk using DES-NADES pretreatment and enzymatic hydrolysis method

Bioethanol is an alternative fuel produced during biomass fermentation. Among the available biomass resources for bioethanol production, coconut husk is an interesting raw material due to its high cellulose content. This study aims to evaluate the coconut husk conversion into bioethanol using DES (ChCl:MEA) and NADES (Be:La) solvents for the delignication process. The molar ratios of HBA and HBD of the two solvents were varied (1:4, 1:6, 1:8) at 2, 4, 6, and 8 h for each ratio. The deligni- ed samples were hydrolyzed using the 5% (w/w) of cellulase enzymes and fermented for seven days using Saccharomyces cerevisiae. The results showed that DES (ChCl:MEA) and NADES (Be:La) could remove lignin at about 60.53% and 65.81%. The glucose content was obtained at 0.5% (brix) by both solvents and bioethanol content was obtained at 13.9% and 14% (v/v) for DES and NADES, respectively

Does breathing disturb arm to leg coordination in butterfly

International audienc