bluuebunny/crossref_metadata_2025_split huggingface dataset:
Softwood Bark Pyrolysis Oil-PF Resols. Part 2. Thermal Analysis by DSC and TG
Authors: Amen-Chen C. , Riedl B. , Roy C. 
Published: September 2004

Summary
Cure behavior of resins formulated with petroleum phenol replaced by 25 and 50 wt% of softwood
bark-derived pyrolysis oils, using various formaldehyde to phenolics molar ratios and alkalinity
content, was characterized by Differential Scanning Calorimetry (DSC). Kinetic parameters were
obtained by the Borchart-Daniels method and the model-free (Vyazovkin) method. Resins containing
up to 50% by wt of pyrolysis oils had slower cure kinetics and lower extent of condensation reaction
compared to a neat laboratory made phenol-formaldehyde resin. However, very similar kinetic curing
behavior to the standard resins was found for resols having 25% by wt of the petroleum phenol
replaced by the pyrolysis oils. Thermogravimetric analysis (TG) of cured pyrolysis oil-PF resins has
been done under nitrogen and air environments at a constant heating rate. Thermal behavior of resins
containing pyrolysis oils differed depending on the nature of the purge gas used in TG. Increasing the
amount of pyrolysis oils decreased the thermal resistance of the experimental resins.
Softwood Bark Pyrolysis Oil-PF Resols. Part 3. Use of Propylene Carbonate as Resin Cure Accelerator
Authors: Amen-Chen C. , Riedl B. , Wang X.-M. , Roy C. 
Published: September 2004

Summary
Phenol-formaldehyde (PF) resols were prepared with different proportions of phenol replaced with
softwood bark pyrolysis oils under varying formaldehyde to phenolics molar ratios and sodium
hydroxide contents. Propylene carbonate (PC) was added to these adhesives to improve the cure of
resins. The cure behavior was characterized by differential scanning calorimetry (DSC). Cure kinetics
and amount of cure of the experimental resin were improved by adding PC to the resins. Low amounts
of PC were used (less than 1.5% of PC on a resin solid basis) to avoid premature gelling of the
adhesives. Results obtained by DSC suggested that PC catalyzed the resin cure reaction and also
participated in resin cross-linking reactions. Low percentages of PC, 0.5 and 1% on a resin solid basis,
were added to the experimental resins for bonding strandboards. These addition levels did not
significantly improve mechanical properties of strandboards. It is concluded that a PC addition level
of more than 1% by wt (on a resin solid basis) should be used to modify the mechanical properties of
panels bonded with pyrolysis oil-PF resins.
Characterization of Black Liquors from Soda-AQ Pulping of Reed Canary Grass (Phalaris arundinacea L.)
Authors: Feng Z. , Alén R. , Pakkanen H. 
Published: September 2004

Summary
Reed canary grass (Phalaris arundinacea L.) was delignified in a laboratory-scale digester by conventional
soda-AQ pulping under varying conditions. The chemical composition of the corresponding
black liquors was analyzed with respect to their main organic constituents. The results showed that the
dry solids of the black liquors contained 33–34% lignin, 14–19% aliphatic carboxylic acids and 12–16% polysaccharides. No significant differences were found in the average molecular masses (M̄w

4700–5600 Da and M̄n
650–750 Da) of the dissolved lignins in these black liquors, although the
polydispersity (M̄w
/M̄n
) values (6.6–7.9) indicated that the molecular masses had a wide distribution.
Lignin clearly degraded in the black liquors as delignification proceeded. Of the monosaccharide
moieties detected in the polysaccharides, xylose was predominant, suggesting that xylan was a major
hemicellulose constituent in the black liquors.
Modification of the Nitrogen Content and C:N Ratio of Sitka Spruce Timber by Kiln and Air Drying
Authors: Payne C. 
Published: September 2004

Summary
Loss of N from Sitka spruce timber was investigated by sampling battens before drying, after 5 and 41
days air drying, after exposure to a full kiln drying schedule and at 24 h intervals during kiln drying.
Undried sapwood and heartwood had similar total N content. Kiln drying significantly reduced total N
content of the sapwood and heartwood within the first 24 h of the drying schedule when wood
temperature was below 50°C. Tests using timber from trees felled at different times of the year and
grown in different locations with considerably different undried N content indicated a constant N loss
of approx 30% of the total as a result of kiln drying. No evidence of absolute N enrichment of
evaporation surfaces of battens was found, although a slight enrichment relative to wood within battens
did develop as a result of kiln drying. Air drying also reduced N content but to a lesser extent than kiln
drying, even after 41 days exposure. Nitrogen was lost more quickly from heartwood than sapwood
during air drying. Loss of N from the wood appears to be in a gaseous or vapour form which is suggested
to be through loss of naturally present ammonia and deamination of amino acids to produce further
ammonia. GC-MS analysis of gasses/vapours released by wood samples indicated that molecules of 17
amu, which may include ammonia, were liberated in relatively large quantities from undried heartwood
but not from partly kiln dried heartwood when heated. Sapwood released these molecules more
slowly and continued to do so following partial kiln drying possibly indicating a less volatile source.
Temperature gradients within battens during kiln drying were relatively small, with temperature
similar to that of the kiln air.
High Resolution Measurement of the Surface Layer Moisture Content during Drying of Wood Using a Novel Magnetic Resonance Imaging Technique
Authors: Rosenkilde A. , Glover P. 
Published: September 2004

Summary
The moisture content profile in the surface layer of Scots pine (Pinus sylvestris) sapwood has been
measured using the MRI (Magnetic Resonance Imaging) technique.Anovel high-gradient permanent
magnet was used for the measurement of the moisture profile in the wood during the drying process,
giving a depth resolution of better than 20 μm. This paper demonstrates for the first time the possibility
of measuring the moisture content depth profile in the surface layer from raw state down to 4%
moisture content without removing the wood sample from the apparatus. The main advantage of this
technique and apparatus is a high resolution over a large field of view. It is possible to measure the
moisture content in the wood surface layer during drying up to a depth of 300 μm. A single moisture
content profile may be obtained in less than 5 min. Hence, more accurate dynamic drying information,
on a single sample, maybe achieved than with current techniques. In this preliminary studywe observed
that the wood cells at the surface had a moisture content higher than the equilibrium moisture content
for wood in the surrounding bulk air. We conclude that for a wood moisture content of above
approximately 50% the resulting profiles were almost flat from a depth of 90 μm and further into
the wood and in between the surface and 90 μm deep there was a steep gradient. Below 50% there was a
gradient in moisture content to at least 300 μm depth.
Longitudinal Permeability and Diffusivity of Steam in Beech Determined with a Wicke-Kallenbach-Cell
Authors: Mouchot N. , Zoulalian A. 
Published: September 2004

Summary
To create a model of beech wood drying in the hygroscopic range, knowledge of longitudinal permeability
and diffusivity parameters of wet air in wood is needed. These data were obtained using a Wicke-Kallenbach-cell running in an open system and crossed either by an inert gas (nitrogen) or by two
streams of two inert gases (helium and nitrogen), that prevent the adsorption phenomena in wood.
Taking into account the relations between apparent and molecular diffusivities, the diffusivities of
steam could be calculated from those of helium. Longitudinal diffusivity and permeability increase
slightly with the moisture content of wood; the average values obtained at the ambient temperature
(20°C) for the axial diffusivity (8. 1. 10−6 m2/s) and for the axial permeability (2. 2. 10−11 m2) are
compatible with those reported in the literature for this species.
Characteristics of Attack of Coastal Timbers by Pselactus spadix (Herbst) (Col.: Curc.: Cossoninae) and an Investigation of its Life History
Authors: Oevering P. , Pitman A.J. 
Published: September 2004

Summary

Pselactus spadix attack of marine timbers was characterised by circular emergence holes 1.48±0.05 mm in diameter and adult tunnels (1.49±0.34 mm) breaking through the wood surface. Larval tunnels measured 0.407–1.892 mm in diameter, initiated from adult tunnels and increased in diameter away from the adult tunnel terminating in frass free pupal chambers (1.6±0.3 mm × 3.5±0.7 mm). Observations of larval tunnel locations indicated oviposition occurred inside the adult tunnels. P. spadix life history was investigated in Scots pine (Pinus sylvestris) heartwood at 22±2 °C and 99±1% r.h. Mean adult longevity was 11.5±6.5 months, with mean post-mating longevity for males (11.7±2.9 months) significantly longer than for females (6.3±1.1 months). Adults of at least 2–3 months old were found mating in galleries, which, with observations of the larval tunnel pattern, indicated P. spadix can complete its life cycle without emerging from wood. Five larval instars were identified by measurement of 1722 head capsule widths and application of Dyar's law. Mean development time from 2nd instar to adult emergence was 70.5±6.9 weeks and pupation took 14.6±5.8 days. Development from 2nd instar to reproductive adult took between 17–20 months, with life cycle approximating 24 months at 22±2 °C and 99±1%
Bacterial Cellulose Production Using Monosaccharides Derived from Hemicelluloses in Water-Soluble Fraction of Waste Liquor from Atmospheric Acetic Acid Pulping
Authors: Uraki Y. , Morito M. , Kishimoto T. , Sano Y. 
Published: September 2004

Summary
The water-soluble fraction (WS) from waste liquor of atmospheric acetic acid pulping was analyzed in order to explore its potential utilization as a carbon source for bacterial cellulose (BC) production. The unpurified WS that contained colored compounds had appreciable antibacterial activity and was therefore not used as a carbon source for BC production with the bacteria Acetobacter xylinum ATCC 10245 and 53582. However, the bacteria produced BC from purified WS of both fir and birch after activated carbon treatment. The yields of BC were much lower compared to those using glucose as a typical carbon source in the Hestrin-Schramm (HS) medium. In order to improve the cellulose production, monosaccharides derived from hemicellulose sugars in WS were modified. The WS from softwood was reduced by catalytic reduction, i.e. mannose, the major component of softwood monosaccharides derived from hemicelluloses, was converted to mannitol. In the case of hardwood WS, xylose was isomerized with glucose isomerase to xylulose. The yield of BC was considerably enhanced by both modifications of the WS. The yield of BC using the modified WS from the pulping of fir was superior to that using glucose as carbon source.
Birch (Betula pendula) Wood Discolouration during Drying. Effect of Environmental Factors and Wood Location in the Trunk
Authors: Luostarinen K. , Möttönen V. , Asikainen A. , Luostarinen J. 
Published: September 2004

SummaryBirch wood discolours during artificial drying, which is a considerable problem for the use of birch as raw material in the mechanical wood industry. In this investigation sample boards ofBetula pendulawere sawn to the dimensions used as raw material for parquet billets. The variables studied were those that may affect wood discolouration: growing site, felling date, length of the storage period for logs and location of the wood in the trunk. Discoloration of birch wood was studied in conventional and vacuum drying processes. The wood layer of about 2–5 mm under the yellow surface of conventionally dried boards remained light-coloured, while the inner wood of the boards became discoloured. During vacuum drying, however, the inner wood of sample boards clearly became discoloured. The radial location of the wood in the trunk affected the colour of dried wood more than the longitudinal location did. To keep the colour of dry wood as light as possible, it may be best to fell birch in winter and store the wood for several weeks before conventional drying. On the other hand, the lightest coloured wood obtained during vacuum drying was from autumnfelled five weeks stored birches, which may indicate differences in the process of discoloration in these two drying methods.
Immuno Electron Microscopic Localization of Peroxidases in the Differentiating Xylem of Populus spp.
Authors: Kim Y.S. , Wi S.-G. , Grünwald C. , Schmitt U. 
Published: September 2004

Summary
Peroxidases were localized in differentiating xylem cells of Populus spp. by means of immunogold labelling in combination with transmission electron microscopy (TEM). Polyclonal antibodies raised in rabbits against horseradish peroxidase were used for these experiments. Within the cytoplasm, TEM revealed a distinct labelling of the dictyosomes, indicating that these organelles are involved in the transport of peroxidases to the plasma membrane. During the formation of primary and secondary walls, cell corner regions became distinctly labelled, the developing secondary wall layers to a much lesser degree. Significant differences in the immunogold labelling between the intercorner middle lamella and the secondary cell wall layers were not observed. According to the immunogold labelling, peroxidases are incorporated into the secondary wall more or less simultaneously with deposition of polysaccharides. Correlations between peroxidase incorporation and lignification are discussed.
Study of Lewis Acid-Base Properties of Wood by Contact Angle Analysis
Authors: Wålinder M. E. P. 
Published: September 2004

Summary
In the present work, an attempt is made to study the Lewis acid-base properties of wood by contact angle analysis. Using contact angle data for extracted, non-extracted, fresh and aged pine wood veneer samples, the Lewis acid-base contribution to the work of adhesion (W

a
AB
) and the Lewis acid-base components of the surface free energy of the wood samples were determined by basic wetting theory, and by the so-called van Oss-Chaudhury-Good (vOCG) model. Results show, on the one hand, that W

a
AB
between water and the non-extracted wood decreases with increasing aging time. This indicates that extractives migrate from the interior of wood to its exterior surface during the aging, creating a hydrophobic wood surface. On the other hand, W

a
AB
between the non-extracted wood and ethylene glycol tends to increase with longer aging times. No such trends are observed for extracted samples. If water is considered to be predominantly Lewis acidic, and ethylene glycol predominantly Lewis basic, the changes in W

a
AB
with longer aging times, indicate that the acidity and the basicity of non-extracted wood in these cases increases and decreases, respectively. This is presumably due to the presence of the extractives, and to reorientation of functional groups and oxidation at the wood/extractives-air interface. The acid-base characterization by the vOCG model also indicates that the acidity and the basicity of the non-extracted wood increases and decreases, respectively, with increasing aging time. However, there seems to be a similar trend even for extracted wood, presumably due to reorientation of functional groups at the wood-air interface. In the vOCG model, considerably higher base/acid ratios are obtained when using probe liquid parameters according to van Oss compared to those obtained by using liquid parameters according to Della Volpe and Siboni.
Lipophilic Extractives of the Inner and Outer Barks of Eucalyptus globulus
Authors: Freire C. S. R. , Silvestre A. J. D. , Neto C. Pascoal , Cavaleiro J.A.S. 
Published: September 2004

Summary
The chemical compositions of the dichloromethane extracts of inner and outer barks of E. globulus were studied by gas chromatography-mass spectrometry. The two fractions show very different chemical compositions: triterpenic acids, such as betulinic, ursolic and oleanolic acids, were the major components of the outer bark extract, whereas β-sitosterol and β-amirin along with palmitic, linoleic and oleic acids predominate in the inner bark extract. Several α-and β-hydroxy fatty acids, recently reported for the first time as E. globulus wood components, were also identified in the outer and inner barks. In the outer bark extract, minor amounts of ferulic acid esters, also previously reported to occur in E. globulus wood were identified. In general, the inner bark lipophilic extractives resemble more closely that of E. globulus wood.
Thick-Target PIXE Analysis of Trace Elements in Wood Incoming to a Pulp Mill
Authors: Saarela K.-E. , Harju L. , Lill J.-O. , Rajander J. , Lindroos A. , Heselius S.-J. , Saari K. 
Published: September 2004

Summary
Trunk-wood samples of wood raw material incoming to a pulp mill were analysed by thick-target particle induced X-ray emission (PIXE). The tree species studied were pine and spruce from Finland, birch from Finland and Poland and eucalyptus from Uruguay. The wood samples were dry ashed to 550 °C prior to the analysis in order to increase the sensitivity of the method. The method was calibrated and validated using some wood based certified reference materials. The elements determined with the method were P, S, K, Ca, Ti, Mn, Fe, Ni, Cu, Zn, Pb, Sr, Rb, Ba and F. The concentrations of the main elements P, S, K, Ca and Mn exceeded 50 ppm in most wood samples. The concentrations of heavy metal ions like Cu, Ni and Pb in the samples studied were below or close to 1 ppm. The ash content of birch, pine and spruce wood were in the range 0.2–0.4% and that of eucalyptus ca 0.5%.
Formation of Aliphatic Carboxylic Acids during Soda-AQ Pulping of Kenaf Bark
Authors: Feng Z. , Alén R. , Niemelä K. 
Published: September 2004

Summary
The formation of aliphatic carboxylic acids during soda-AQ pulping of kenaf bark was studied. In addition to formic and acetic acids, a variety of hydroxy monocarboxylic and dicarboxylic acids were monitored. The results showed that the formation of hydroxy acids and formic acid significantly depend, in contrast to acetic acid, on the cooking conditions employed. Detailed gas chromatographic studies revealed that the most abundant hydroxy carboxylic acids were glucoisosaccharinic, lactic, glycolic, 3-deoxypentonic, 2-hydroxybutanoic, xyloisosaccharinic, 3,4-dideoxypentonic, 2-hydroxyglutaric, and glucoisosaccharinaric acids. The total amount of aliphatic carboxylic acids corresponded to 12–16% of o.d. kenaf bark.
Comparing Mechanical Properties of Normal and Compression Wood in Norway Spruce: The Role of Lignin in Compression Parallel to the Grain
Authors: Gindl W. 
Published: September 2004

Summary
Cell-wall lignin content and composition, as well as microfibril angle of normal and compression wood samples were determined prior to mechanical testing in compression parallel to the grain. No effect of increased lignin content on the Young's modulus in compression wood was discernible because of the dominating influence of microfibril angle. In contrast, compressive strength of compression wood was not negatively affected by the high microfibril angle. It is proposed that the observed high lignification in compression wood increases the resistance of the cell walls to compression failure. An increased percentage of p-hydroxyphenylpropane units observed in compression wood lignin may also contribute to the comparably high compressive strength of compression wood.
Oxidative Ammonolysis of Technical Lignins. Part 3. Effect of Temperature on the Reaction Rate
Authors: Capanema E. A. , Balakshin M. Y. , Chen C.-L. , Gratzl J. S. , Kirkman A. G. 
Published: September 2004

Summary
The effect of the reaction temperature on the kinetics and the reaction mechanism of oxidative ammonolysis of Repap organosolv lignin have been studied. The reaction was conducted in 0.8 M Nh4oh solution under oxygen pressure of 12 bar and at three different temperatures, 70 °C, 100 °C and 130 °C. The resulting N-modified lignins were analyzed by elemental and methoxyl group. About 20–25% of maximum nitrogen content is incorporated into the lignin very fast, in 1–2 min of the reaction. The reaction kinetics then follows a pseudo-first order reaction law and consists of two phases. The activation energies for nitrogen incorporation and lignin solubilization are rather low, in the range of 33–34 kJ/mol. Linear correlation between nitrogen incorporated into the lignin and molecular oxygen uptake, oxygen incorporation, CO2 formation, O-demethylation and total carbon loss was analyzed at the different reaction temperatures. On the basis of kinetic data obtained so far, we have postulated that the reaction temperature affects the reaction rate, but not the reaction pathways. The reaction temperature also affects the ratios between different reaction pathways, though the effect is not very strong. The results obtained are discussed in the terms of competitive reactions of lignin oxidation followed by nitrogen incorporation and lignin deactivation involving nitrogen
The Erythro/Threo Ratio of β-O-4 Structures as an Important Structural Characteristic of Lignin. Part 2. Changes in Erythro/Threo (E/T) Ratio of β-O-4 Structures during Delignification Reactions
Authors: Sugimoto T. , Akiyama T. , Matsumoto Y. , Meshitsuka G. 
Published: September 2004

Summary
The ozonation method was applied to an analysis of the changes in erythro and threo (E/T) ratio of arylglycerol-β-aryl ether (β-O-4) structures in the residual lignins of delignified wood samples. When delignified by alkali cook, not only the total yield of erythronic and threonic acids per lignin decreased, but also the E/T ratio decreased with the progress of delignification. These results indicate that residual lignin of alkali-delignified wood contain only a small amount of arylglycerol-β-aryl ether structures and/or glycerol side chains, which are relatively rich in the threo form. A suggested reason for this, in addition to the stereo-preferential degradation of the erythroβ-O-4 structure, is the increasing contribution of topologically-inert lignin and/or chemically-inert lignin structures with a low original E/T ratio. In contrast, when the wood samples are delignified by NaClO2 treatment, no significant change is observed in the E/T ratio. This confirms that the NaClO2 delignification proceeds without the residual lignin retaining special configurational characteristics in its side chains.