bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Reaction of Phenolic Model Compounds in the Laccase-Mediator System (LMS) Investigations by Matrix Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF-MS)
Authors: Potthast A. , Rosenau T. , Koch H. , Fischer K. 
Published: October 2004

SummaryMatrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) was used to investigate the reaction products obtained by treatment of phenolic substances with the laccase-mediator system, consisting of the enzyme laccase and a low-molecular-weight substance, the so-called mediator.Two mediators, 2,2′-azino-bis(3-ethylbenzothiazoline)-6-sulfonic acid diammonium salt (ABTS) and 1-hydroxybenzotriazole (HOBT), were employed. Polymerizing and depolymerizing properties of the LMS were investigated and assigned to specific components of the system,i. e., laccase and mediator. The polymerizing action of laccase and the ABTS cation radical on phenols was demonstrated in addition to the depolymerizing effect of the LMS. The LMS causes polymerization of phenolic substrates in the initial phase of the reaction, but then degrades the initially formed polymers. The extensive breakdown of this oligomeric and polymeric material occurs exclusively in the presence of both components, mediator and laccase. Furthermore, it is also dependent on the type of polymer formed.
Surface Composition and Morphology of CTMP Fibers
Authors: Börås Linda , Gatenholm Paul 
Published: October 2004

Summary
The aim of this study was to investigate the surface composition and morphology of Chemithermomechanical
pulp (CTMP) fibers from spruce. The fibers were exposed to a sequence of mild
treatments such as washing, peroxide bleaching and extraction. The effects of treatments on fiber
bulk composition and surface properties were investigated. All treatments did not significantly result
in changes in total lignin and carbohydrate content. However, the extractives were stepwise
removed. With the Electron Spectroscopy for Chemical Analysis (ESCA) technique, a gradual
reduction of unoxidized carbon in the C1s resolved peak was shown, which was correlated to the
removal of non-carbohydrates. Variations in surface topography among the analyzed samples were
displayed with Atomic Force Microscopy (AFM) imaging of fibers in tapping mode. The wetting
properties of all pulps were measured by Dynamic Contact Angle (DCA) on the single fibers. The
advancing contact angle decreased and the hysteresis is also reduced, as a result of treatments.
ESCA, AFM and contact angle analyses suggest that the extractives are distributed as globular
particles at the fiber surface. Phase imaging AFM indicated the presence of lignin as irregular
patches at the surface. A model of the CTMP fiber surface based on experimental findings in this
work is proposed.
Influence of Growth Rate and Cambial Age on Density of Rauli (Nothofagus nervosa) in Relation to Vessel Lumen Areas and Numbers
Authors: Denne M. P. , Cahalan C. M. , Aebischer D. P. 
Published: October 2004

Summary
To assess the likely effects of silvicultural treatment on the wood quality of Nothofagus nervosa grown
in the UK, and the possibilities of independent selection within seed origins for density and growth
rate, ring width and wood density were analysed from pith to bark of 19 trees. Variations in vessel
lumen size, vessel number mm−2, and total lumen area mm−2 were analysed in ten trees. Since density
increased by only 0.005g cm−3 per mm increase in ring width, silvicultural practices such as initial
spacing and thinning are not likely to have a substantial effect on the wood density of rauli. Similarly,
variation in density with cambial age was significant but relatively minor in the 40- and 60-year old
trees of the present sample, suggesting that the rotation length is unlikely to have any practical influence
on the density of rauli. Considerable between-tree differences in density were found which did not
correspond to differences in ring width, suggesting it should be feasible to select independently for
density and growth rate. These differences in density were associated with differences in both vessel
lumen size and vessel number mm−2
Convective Mass Transfer Coefficient at Wooden Surface in Jet Drying of Veneer
Authors: Hukka Antti , Oksanen Olli 
Published: October 2004

Summary
The relationship between heat and mass transfer at wooden surface is investigated experimentally by
drying 1.6 mm thick birch veneers in constant conditions in a laboratory-scale roller dryer. By
intermediate weighing of the samples a drying curve is established for each specimen. The drying curves
are formulated in a functional form to produce the drying rate as a function of wood moisture content.
Based on that and the measured heat-transfer coefficient a correction factor is calculated for the mass
transfer coefficient predicted by the boundary layer theory.
The results show that the convective mass transfer coefficient for wooden surfaces substantially deviates
from that given by the analogy between heat and mass transfer. The correction factor describing the
internal resistance for evaporation is strongly dependent on wood temperature within the range
50–90°C, but for practical purposes not dependent on the average moisture content of the veneer (range
40–70%). The numerical value of the correction coefficient established is somewhat lower than
published earlier by other researchers.
Tangential Youngs Modulus of Coniferous Early Wood Investigated Using Cell Models
Authors: Watanabe Ugai , Norimoto Misato , Ohgama Toshimasa , Fujita Minoru 
Published: October 2004

Summary
The relationship between the tangential Young's modulus and the transverse cell shape in coniferous
early wood was investigated by using cell models constructed by power spectrum analysis. The
calculated Young's moduli of the cell models explained qualitatively the change of the experimental
Young's moduli with density as well as the difference in the experimental values among species. The
calculated Young's moduli differed significantly among species depending on the cell model shapes
when compared at the same density. With increasing element angle in the model, the Young's modulus
greatly increased without a significant change in the density, especially at the larger ratios of the axial
length of the tangential cell wall to that of the radial cell wall.
Effects of Heat Treatments of Wood on the Feeding Behaviour of Two Subterranean Termites
Authors: Doi S. , Kurimoto Y. , Ohmura W. , Ohara S. , Aoyama M. , Yoshimura T. 
Published: October 2004

Summary
This paper deals with the results of choice feeding tests of two termite species, Coptotermes formosanus Shiraki and Reticulitermes speratus (Kolbe), with steam-treated and dry-heated samples of Japanese commercial woods. Some steam-treated species were heavily attacked by C. formosanus and R. speratus while all dry-heated samples were attacked not more than unheated controls except for the combination Japanese larch-R. speratus. The steam treatment in some wood species produced feeding attractants which were removed by hot water extraction. Termite species showed some differences in the susceptibility to these substances. Attraction of the termites to steam-treated Japanese beech was different from that to the steam-treated softwoods. These phenomena were discussed with references to heat treatment of wood as well as to termite attractive factors.
The Resistance of Wood Chemically Modified with Isocyanates. Part 1. Brown Rot, White Rot and Acid Chlorite Delignification
Authors: Williams F. Cardias , Hale M.D. 
Published: October 2004

Summary
This study was to assess the bioprotectant performance of chemical modification with three different isocyanates (n-butyl, hexyl and 1,6-diisocyanatohexane, BuNCO, HeNCO and HDI respectively) in Corsican pine (Pinus nigra Schneid) sapwood. Wood-isocyanate bond formation was verified by the increase in sample weight, volume and by infra-red spectroscopy.
Basidiomycete (Coniophora puteana, Gloeophyllum trabeum, Coriolus versicolor, Pycnoporus sanguineus) decay tests demonstrated protection by chemical modification. The relationships of fungal species, weight percent gain (WPG), and decay induced weight loss were examined. One of the brown rot fungi, C. puteana, showed higher threshold protection values than the other fungi tested and the diisocyanate showed better performance.
Chemical characteristics of the sound and brown rotted wood (C. puteana) have been examined using sulphuric acid and sodium chlorite procedures to clarify the principles which govern isocyanate modifications and restrict fungal decay. These demonstrated that appreciable wood protection against C. puteana only occurred when the holocellulose fraction showed substantial changes due to chemical modification.
Effect of IPBC/DDAC on Spore Germination and Hyphal Growth of the Sapstaining Fungus Ophiostoma piceae
Authors: Xiao Y. , Kreber B. 
Published: October 2004

Summary
Fungicide interactions were investigated using Ophiostoma piceae (Münch) H. and P. Syd, unseasoned radiata pine (Pinus radiata D. Don) and an antisapstain formulation based on 3-iodo-2-propynyl butyl carbamate (IPBC) and didecyl dimethyl ammonium chloride (DDAC). Treated and untreated wood samples were inoculated with O. piceae and then periodically examined over an incubation period of one month using light microscopy and scanning electron microscopy. Additional treated and infected wafers were removed after 8 and 15 days, rinsed with distilled, sterile water and then further incubated on malt agar nutrient media before examining microscopically.
The results of the study showed that prolific spore germination and mycelial growth of O. piceae occurred on untreated radiata pine within 24 hours whereas the majority of spores did not germinate on treated wood. However, in some spores the process of germination was only delayed, occurring after 20 days of incubation. Furthermore, it was noticed that once spore germination occurred hyphae rapidly colonised treated wafers possibly indicating that mycelium of O. piceae is more tolerant to IPBC/DDAC treatment, than spores. The possible mode of action of IPBC/DDAC on spores and mycelium of O. piceae is discussed.
Biodegradability of Extractives in Sapwood and Heartwood from Scots Pine by Sapstain and White-Rot Fungi
Authors: Martínez-Inigo M.J. , Immerzeel P. , Gutierrez A. , Río J.C. del , Sierra-Alvarez R. 
Published: October 2004

SummaryThe fungal degradation of lipophilic extractives in sapwood and heartwood from Scots pine (Pinus sylvestris) was studied. In sapwood, the white rot fungi,Bjerkanderasp. andFunalia trogii, removed higher amounts of extractives than the sapstain strains,Ophiostoma ainoaeandCeratocystis allantospora. Triglycerides, long chain fatty acids, steryl esters and waxes in pine sapwood were almost completely degraded by all the fungi. Sterols and resin acids were also extensively degraded by the white rot strains; however, these components were not or only poorly removed by the sapstain fungi. The removal of total extractives by all the fungal strains was higher in sapwood as compared to heartwood. The highly concentrated extractive fraction in pine heartwood mainly consists of resin acids. As observed in sapwood, sapstain were also poorly effective in the degradation of the resin acids present in heartwood. The fungal degradation of heartwood extractives was not only limited by the degradative ability of the various test microorganisms, but also by the inhibitory effect exerted by the extractive fraction. The white rot fungusF. trogiiwas particularly inhibited on heartwood.Bjerkanderasp. showed a higher tolerance to toxic extractives and was the most efficient fungus in degrading extractive constituents in both Scots pine heartwood and sapwood. Therefore,Bjerkanderasp. strain BOS55 should be considered as a potential agent for pitch control in pulp and paper manufacture.
Fractional Isolation and Characterization of Polysaccharides from Oil Palm Trunk and Empty Fruit Bunch Fibres
Authors: Sun R. , Fang J.M. , Mott L. , Bolton J. 
Published: October 2004

Summary
The polysaccharides in oil palm trunk fibre and empty fruit bunch (EFB) fibre were fractionated into cold water solubles, hot water solubles, 1% NaOH solubles, and 17.5% NaOH soluble fractions. Cellulose (approximately 42%) and hemicelluloses (approximately 33%) were the major polysaccharides in the palm trunk fibre and EFB fibre. Extractions of the lignified fibres with cold water, hot water, and 1% NaOH produced the hemicellulosic fractions, which were enriched in xylose and glucose and to a lesser extent, arabinose-, galactose-, mannose-, rhamnose-, and ribose-containing polysaccharides, together with noticeable amounts of associated lignin (4.5–31.2%). Further extraction of the delignified fibre residues with aqueous 17.5% NaOH removed the hemicellulosic fractions, which were strongly enriched in xylose-containing polysaccharides and relatively free of associated lignin (0.3–0.7%). Eight phenolic acids and aldehydes, including p-hydroxybenzoic acid, p-hydroxybenzaldehyde, vanillic acid, syringic acid, vanillin, syringaldehyde, p-coumaric acid, and ferulic acid, were detected in the mixtures of alkaline nitrobenzene oxidation of associated lignin in all the sixteen polysaccharide fractions. The results obtained showed that hemicelluloses in the cell walls of oil palm trunk and EFB fibres, are mainly bonded with lignin by syringyl units.
Chemical Modification of Wood with Perfluoralkyl Ethanol and 4,4'-Diphenylmethane Diisocyanate
Authors: Engonga P. Edou , Schneider R. , Gérardin P. , Loubinoux B. 
Published: October 2004

Summary
Grafting of perfluoroalkyl ethanol derivatives on spruce meal (Picea abies) and beech blocks (Fagus sylvatica) was performed using 4,4′-diphenylmethane diisocyanate (MDI). The formation of urethane bonds between MDI, perfluoroalkyl ethanol and wood allowed to increase wood's dimensional stability. Contact angle measurements were also performed. θ values obtained for wood grafted with perfluoroalkyl ethanol derivatives were greater and did not decrease with time compared to those obtained with unmodified wood.
Radical Formation in Ozone Reactions with Lignin and Carbohydrate Model Compounds
Authors: Ragnar M. , Eriksson T. , Reitberger T. 
Published: October 2004

Summary
Using different independent methods, the kinetics of ozone consumption and the initial radical yield in reactions of ozone with lignin and carbohydrate model compounds were investigated. It was demonstrated that ozone reacts with phenolates several orders of magnitude more rapidly than with corresponding undissociated phenols. The pH dependence of the radical yield does not completely follow the pK
a-value of the phenols. In fact, the radical yield starts to increase at pH 3 for all the phenolic model compounds investigated. Several indications suggest that superoxide rather than the hydroxyl radical is initially formed when ozone reacts with lignin model compounds. In contrast to lignin model compounds no radicals were detected in ozone reactions with carbohydrate model compounds or olefins. On the basis of this study, it may be concluded that ozone bleaching should preferably be performed at pH 3 and at a higher consistency. No significant effect of metal ions was observed.
Cement Hydration Tests Using Wood Flour may not Predict the Suitability of Acacia mangium and Eucalyptus pellita for the Manufacture of Wood-Wool Cement Boards
Authors: Semple K.E. , Cunningham R.B. , Evans P.D. 
Published: October 2004

Summary
Wood-wool cement boards (WWCBs) are manufactured in many tropical countries which have extensive eucalypt and acacia plantations. Wood from such plantations could act as a potential raw material for WWCBs, but the suitability of most tropical eucalypts and acacias for the manufacture of such products is unknown. This study was undertaken to assess whether the standard laboratory test for wood-cement compatibility, which measures heat of hydration in wood flour-cement mixtures, is an appropriate method for screening tropical eucalypts and acacias for their compatibility with cement and suitability for the manufacture of WWCBs. Wood samples from a tropical eucalypt (E. pellita) and a tropical acacia (A. mangium) were tested in two forms, i. e. flour and wool, for their compatibility (expressed by maximum hydration temperature and CA-factor) with Portland cement. Form significantly influenced the effect of the wood on cement hydration, resulting in a different species compatibility ranking for flour and wool. As the heartwood content of wood-wool-cement hydration test samples increased, Tmax. and CA factor increased whereas the opposite occured for those containing wood flour. Tests using wood flour ranked E. pellita as being more compatible with cement than A. mangium whereas the ranking was reversed when wood-wool was used. Furthermore at low wood levels the compatibility of samples containing wood-wool or wood flour with cement was similar whereas at high wood levels, samples containing wood-wool were much more compatible with cement than those containing wood flour. Laboratory tests designed to screen eucalypts and acacias for their compatibility with cement should use wood in a coarser form with a lower surface-to-volume ratio than flour. Caution should be exercised if using results from wood flour-cement hydration tests to estimate the suitability of wood species for the manufacture of WWCBs and possibly other wood-cement composites.
Modifications of Hybrid Walnut (Juglans nigra 23 x Juglans regia) Wood Colour and Phenolic Composition Under Various Steaming Conditions
Authors: Burtin Patricia , Jay-Allemand Christian , Charpentier Jean-Paul , Janin Gérard 
Published: October 2004

Summary
The effects of steaming were studied on Walnut wood from a hybrid (Juglans nigra 23 × J. regia) tree
in terms of wood colour and phenolic composition. Wood samples were subjected to treatments at 75,
100 and 125°C for 4, 8, 16 and 24 hours. Colour changes were measured in the CIELCh colour system
and phenolics were characterized and quantified by means of HPLC. Steaming mainly resulted in a darkening
of wood tissues. Colour changes increased as temperature increased from 75 to 125°C. Lightness
L* gradually decreased from 0 to 24 h at 75°C, whereas with higher temperatures, most of the darkening
occurred within the first 4 hours of exposure. Contrast in colour, between sapwood and heartwood
in particular, could be reduced by steaming at 125°C. The best steaming treatment, leading to a colour
of steamed sapwood close to that of natural heartwood, was at 100°C/16 h. Hydrojuglone glucoside
(HJG), ellagic and gallic acid derivatives (E1, E2 and G respectively) were gradually degraded by steaming,
whereas a new flavonol (F) and oxidation products (OP) increased. Relationships between wood
colour and phenolic content are discussed.
Modelling the Moisture Induced Risk of Decay for Treated and Untreated Wood Above Ground
Authors: Rapp A. O. , Peek R.-D. , Sailer M. 
Published: October 2004

Summary
During two years of natural weathering the course of the moisture content of test samples of pine sapwood
(Pinus sylvestris L.), Norway spruce (Picea abies L.), oak heartwood (Quercus robur L.) and Douglas
fir heartwood (Pseudotsuga menziesii Franco.) was recorded by means of 12,000 individual gravimetric
readings. The samples were untreated, treated with a weather protection varnish, or impregnated
with melamine resin. The data were evaluated with regard to the number of days per year on which the
moisture content of wood exceeded the limit of 25%. From the results of subsequent laboratory investigations
into the adsorption of liquid water and moisture vapour desorption using the same test material,
it was possible to work out a mathematical relationship (MRI = moisture induced risk index) which
correlates closely with the number of days of more than 25% moisture content during the second year
of natural weathering. The MRI is proposed as a parameter for the assessment of the protective effect of
wood treatments which are intended to reduce moisture content and also for durability prediction of
untreated wood in out of ground contact situations.
A Comparative Study on Reactions of Hydrogen Peroxide and Peracetic Acid with Lignin Chromophores. Part 1. The Reaction of Coniferaldehyde Model Compounds
Authors: Pan George X. , Spencer Liam , Leary Gordon J. 
Published: October 2004

Summary
The reactions of chromophoric model compounds of the coniferaldehyde type with hydrogen peroxide and
peracetic acid have been investigated in relation to lignin-retaining bleaching. Analysis of the main reaction
products indicated that the side chain of coniferaldehyde could cleave either between the α, β double
bond or between the β, γ bond. Comparison of possible reaction pathways to the formation of oxidation
products from hydrogen peroxide and peracetic acid suggested that peracetic acid is more effective than
hydrogen peroxide. Advantages of peracetic acid over hydrogen peroxide include a faster rate of reaction,
more efficient utilization of the bleaching agent and less likelihood of producing new chromophores.
A Comparative Study on Reactions of Hydrogen Peroxide and Peracetic Acid with Lignin Chromophores. Part 2. The Reaction of Stilbene-Type Model Compounds
Authors: Pan George X. , Spencer Liam , Leary Gordon J. 
Published: October 2004

Summary
The reactions of three hydroxy- and/or methoxy-substituted stilbenes with hydrogen peroxide and peracetic
acid have been investigated. Overall, the reactivity of stilbenes was greater towards peracetic acid
than towards hydrogen peroxide. Among the stilbene model compounds studied, 4-hydroxystilbene (I)
was virtually unreactive to hydrogen peroxide, but was oxidized by peracetic acid to a varying extent
that was highly pH-dependent. 4,4′-Dihydroxy-3,3′-dimethoxystilbene (II) and 3,5-dimethoxy-4-hydroxystilbene (III) showed a greater reactivity to either hydrogen peroxide or peracetic acid than
4-hydroxystilbene (I).
Dynamics of Hardwood Impregnation
Authors: Costanza Vicente , Miyara Alberto José 
Published: October 2004

Summary
The phenomenon of axial liquid penetration in hardwoods is modeled through two different mechanisms:
in one of them the driving force is taken to be the empty space that remains unfilled inside the material;
in the other one, it is the pressure differential between the interior of the material and its liquid environment.
The equations obtained show an increase of liquid retention exponentially approaching an asymptote,
which agrees with experimental results. By combining them with existing models for liquid permeability,
an equation is obtained for predicting retention as a function of wood ultrastructure for a given
liquid under fixed conditions.
Heating ventilation air‐conditioner system for multi‐regional commercial buildings based on deep reinforcement learning
Authors: Yang Juan , Yu Jing , Wang Shijing 
Published: February 2024

AbstractIn an era of significant energy consumption by commercial building HVAC systems, this study introduces a Deep Reinforcement Learning (DRL) approach to optimize these systems in multi‐zone commercial buildings, targeting reduced energy usage and enhanced user comfort. The research begins with the development of an energy consumption model for multi‐zone HVAC systems, considering the complexity and uncertainty of system parameters. This model informs the creation of a novel DRL‐based optimization algorithm, which incorporates multi‐stage training and a multi‐agent attention mechanism, enhancing stability and scalability. Comparative analysis against traditional control methods shows the proposed algorithm's effectiveness in reducing energy consumption while maintaining indoor comfort. The study presents an innovative DRL strategy for energy management in commercial HVAC systems, offering substantial potential for sustainable practices in building management.