bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lignin-Carbohydrate Condensation Product Formation in a Biomimetic Model Pulp Bleaching System
Authors: Walker C. C. , McDonough T. J. , Dinus R. J. , Eriksson K.-E. L. 
Published: September 2004

Abstract
Three biomimetic compounds were evaluated for their ability to preferentially degrade lignin in
the presence of carbohydrate using two water-soluble polymeric model compounds: lignosulfonate
and hydroxyethyl cellulose (HEC). The three biomimetic systems studied were FeSO4, Fe-EDTA and hemoglobin, each in the presence of hydrogen peroxide. When both polymeric substrates
were present, a high molecular weight product was observed to form upon addition of
H2O2. This high molecular weight product is believed to be the result of a condensation reaction
between lignosulfonate and HEC. The condensation product was also observed to form in the absence
of biomimetic catalyst.
For all reactions, the molecular weight of the condensation product was observed to decrease
with increasing reaction time. By altering the ratio of lignosulfonate to HEC, a limit was observed
in the relative amount of condensation product formed. The formation of this condensation product
is believed to limit the effectiveness of acidic bleaching systems.
Viscoelastic Behaviour of Wood Fibres during the Hot Pressing of Medium Density Fibreboard
Authors: Houts J. van , Bhattacharyya D. , Jayaraman K. 
Published: September 2004

Summary
Sufficient stress relaxation within a medium density fibreboard (MDF) mat during hot pressing is
critical for producing a panel with acceptable mechanical properties and dimensional stability.
This paper describes a series of load relaxation tests of wood fibres conducted at temperatures and
moisture contents similar to those within an MDF mat during the hot pressing process (temperatures
ranging from 80°C to 100°C with relative humidity levels ranging from 9% to 68%). The results
clearly show an increase in relaxation when either the temperature or relative humidity is increased.
The relaxation behaviour of MDF is also measured and the trends observed are
comparable to those of the wood fibres. Taguchi experimental design is employed to analyse the
effects of temperature, moisture content and initial stress on the viscoelastic behaviour of MDF.
Modeling Ovendry Softwood Resistivity Based on the Resistor Network Theory
Authors: Jiang Z.-H. , Chen Z. , Fen B.-H. , Hou Z.-Q. , Chen G.-H. 
Published: September 2004

Summary
This study develops a method to theoretically calculate ovendry softwood resistance and resistivity
based on block transformation theory. The resistance of a single cell was calculated as the sum of a
combination of serial and parallel connections of the two end cell walls, four side cell walls and cell
cavity. One cell was considered as a resistor, and the wood as a network of single cell resistors. Resistance
was calculated for a group of four resistors. After several iterations, the total resistance of wood
was obtained. To test the model, experiments were conducted on Masson pine specimens. The resistances
of fifty specimens were measured and their resistivities calculated. A comparison of the theoretical
calculations and the measured results revealed a difference between the measured average resistivity
of specimens and the model calculations of less than 8%. The resistivity of softwood was
found to relate to the size of wood cells, amount of ray cells and the percentage of latewood.
Comparison of the TL-Shear Strength of Normal and Compression Wood of European Larch
Authors: Gindl W. , A.Teischinger A. 
Published: September 2004

Summary
The strength of larch compression wood specimens in longitudinal shear in the radial plane was
determined and compared to normal wood. Fracture surfaces were examined with a scanning electron
microscope. Compression wood showed higher shear strength than normal wood. The difference
persisted after correction of the strength values for density. Scanning electron microscopy revealed
clear differences in the pattern of failure in normal wood compared to compression wood.
While transwall and intrawall fracture predominate in normal wood, intercell fracture at the middle
lamella occurs in compression wood. An explanation of this change in fracture behaviour is
proposed in terms of microfibril angle and lignification of the cell wall.
Comparing the Effect of Chemical and Physical Properties on Complex Electrical Impedance of Scots Pine Wood
Authors: Tiitta M. , Kainulainen P. , Harju A. M. , Venäläinen M. , Manninen A.-M. , Vuorinen M. , H.Viitanen H. 
Published: September 2004

Summary
This study examined the effects of physical (moisture content, water content and wood density)
and chemical properties (concentration of phenolics and resin acids) on the electrical properties of
Scots pine (Pinus sylvesteris L.) wood specimens. Complex impedance was measured from heartwood
and sapwood specimens using frequencies between 5 kHz and 1 MHz. Significant correlation
between density and electrical properties was found at high frequencies with sapwood specimens
in which the extractive content was low. Moisture content had an effect on electrical
properties over the whole frequency range. Electrical properties of heartwood samples with high
extractive content were differently affected by the chemical and physical properties. Electrical
properties were sufficient to distinguish between the samples from the brown-rot resistant and
susceptible Scots pine trees.
The Oriented Structure of Lignin and its Viscoelastic Properties Studied by Static and Dynamic FT-IR Spectroscopy
Authors: Åkerholm M. , Salmén L. 
Published: September 2004

Summary
In order to define the role of lignin for stress transfer in the fiber wall, its orientation and mechanical
interaction with other cell-wall components were investigated. Polarized infrared spectra of
oriented thermomechanical pulp fiber sheets were used to determine the molecular orientation,
and dynamic infrared spectroscopy was used to study the rheology of lignin in the cell wall. The results
indicate that there is a preferred orientation of the phenyl-propane units of lignin along the
fiber axis in spruce tracheids. This implies there is an ordered structure of lignin in the secondary
wall of tracheids analogous to that of the cell-wall polysaccharides. The dynamic IR-spectra also
indicated that lignin exhibits a much more viscoelastic behavior than do the carbohydrates, a
knowledge of importance in the interpretation of transverse fiber properties.
Effect of Ozonation on Assembly of Xylans
Authors: Linder Å. , Roubroeks J. P. , Gatenholm P. 
Published: September 2004

Summary
In this study the molecular structure of birch xylan was altered by ozonation. Longer ozonation
times increased the cleavage of aromatic rings in the lignin residues attached to the xylan molecules,
resulting in the formation of muconic acid derivatives and other carboxylic acid structures.
Size exclusion chromatography showed a decreasing molar mass of xylan after ozonation. The
ozonation improved xylan solubility as evidenced by the reduced amounts of aggregates in aqueous
solution. Atomic force microscopy showed increases in the sizes of the aggregates. Furthermore,
the ozonation resulted in a decreased ability of xylan to assemble into particle-like structures
on cellulose surfaces. We therefore believe that there is a relationship between xylan
aggregation in aqueous solution and the formation of xylan surface structures on cellulose.
Optimization of a Laccase-Mediator Stage for TCF Bleaching of Flax Pulp
Authors: García O. , Camarero S. , Colom J. F. , Martínez Á. T. , Martínez M. J. , Monje R. , Vidal T. 
Published: September 2004

SummaryFlax pulp obtained by anthraquinone-soda pulping, resulting in a kappa number of 11.1, a viscosity of 950 ml/g and 36.7% ISO brightness, was bleached in a totally chlorine-free sequence using the enzyme laccase from the fungusPycnoporus cinnabarinusand 1-hydroxybenzotriazole (HBT) as redox mediator (stage L), followed by a hydrogen peroxide stage (P). The laccase treatment was optimized using a three-variable sequential statistical plan over the following ranges: 1–20 U/g o.d.p. (oven-dried pulp) laccase dose, 0.5–7.5% o.d.p. HBT dose and 1–24 h reaction time. The influence of these variables on several pulp properties after the P stage of the LP sequence was examined. The models defined from the results obtained predicted variations in ISO brightness, viscosity and kappa number of 57.6–74.8%,590–955 ml/g and 0–6.2, respectively. The variables most strongly influencing these pulp properties were found to be the reaction time and the enzyme dose. A compromise was adopted as regards the operating conditions in order to ensure optimum results. The study was completed by conducting a biobleaching assay in a pressurized reactor (590 kPa) to assess the effect of oxygen pressure. The high pressure level resulted in improved pulp properties by the laccase-mediator system.
Analysis of Black Wattle (Acacia mearnsii De Wild) Bark by Near Infrared Spectroscopy
Authors: Schimleck L. R. , Yazaki Y. 
Published: September 2004

Summary
The analysis of two sets of Acacia mearnsii De Wild (Black Wattle) samples by near infrared
(NIR) spectroscopy is reported. Set 1 samples were characterised in terms of hot water extractives,
Stiasny value and polyflavanoid content. Set 2 samples were characterised by nine different parameters,
including tannin content. NIR spectra were obtained from the milled bark of all samples
and calibrations developed for each parameter. Calibrations developed for hot water extractives
and polyflavanoid content (set 1) gave very good coefficients of determination (R2) and performed
well in prediction. Set 2 calibrations were generally good with total and soluble solids, tannin
content, Stiasny value-2 and UV-2, all having R2 greater than 0.8. Owing to the small number of
set 2 samples, no predictions were made using the calibrations. The strong relationships obtained
for many parameters in this study indicates that NIR spectroscopy has considerable potential for
the rapid assessment of the quality of extractives in A. mearnsii bark.
Computer Aided Identification of the Moisture Transport Parameters in Spruce Wood
Authors: Koc P. , Houka M. , Štok B. 
Published: September 2004

Summary
An inverse identification method for characterization of wood sorptive properties is presented.
The method relies on a computer simulation of a real experiment, in our case a desorption experiment,
where spruce heartwood samples were dried from 27% to 8% moisture content. Three samples,
distinguished by the respective moisture flow pattern through the specimen, were investigated.
A computer aided material characterization using the so-called inverse problem identification
method was performed on the measurements. The solution of the specified inverse problem enabled
us to estimate the moisture diffusion coefficients of wood and to determine the moisture
content field in the sample simultaneously. The method is first verified on two simple cases of uniaxial
moisture flow, and then is used to characterize the diffusion coefficients on a biaxial moisture
flow sample. In the latter case some salient features of the proposed method are exhibited.
The Adjusted Dynamic Modulus of Elasticity Above the Fiber Saturation Point in Taiwania Plantation Wood by Ultrasonic-Wave Measurement
Authors: S.-Y.Wang S.-Y. , Lin C.-J. , Chiu C.-M. 
Published: September 2004

Summary
In this study, the effects of moisture content and bulk density on the ultrasonic velocity of Taiwania
(Taiwania cryptomerioides Hay.) plantation wood in the longitudinal and radial directions are investigated.
The dynamic modulus of elasticity is adjusted above the fiber saturation point by a simple
method. It was observed that ultrasonic velocity tended to increase with a decrease in moisture
content, and the effect of moisture content on the ultrasonic speed below the fiber saturation point
was stronger than that above. Moreover, for this species ultrasonic speed in the longitudinal direction
decreased with increasing bulk density, while that in the radial direction increased. The correlations
between ultrasonic velocity, moisture and bulk density could be represented by a polynomial
regression model. The K value for ultrasonic wave was affected by density. The adjusted
dynamic modulus of elasticity remained fairly constant above the fiber saturation point using this
simple method. Therefore, the results obtained by the ultrasonic-wave technique should be adjusted
before estimating some physical properties of standing trees.
Variations in the Tensor Veli Palatini Muscle with Special Reference to Its Origin and Insertion
Authors: Abe Masato , Murakami Gen , Noguchi Makoto , Kitamura Seiichiro , Shimada Kazuyuki , Kohama Gen-iku 
Published: September 2004

Objective Previous research on the tensor veli palatini muscle (TVP) has produced conflicting descriptions of its functions and topographical relationships with other orofacial structures. The goal of this study was to describe the morphology of the TVP in a systematic and comprehensive manner. Methods One hundred nineteen sides of 77 human heads from donated cadavers were partially dissected under a binocular microscope. Histological examination of the hard tissue–muscle interfaces was also undertaken. Results There were two adjacent origins of the TVP: the cranial base origin (CB origin) and the auditory tube cartilage origin (AT origin). The CB origin always lay anterior to the AT origin and there was no septum or loose tissue between the two muscular laminae leading from these origins. The muscle fibers converged on a central tendinous plate in the muscle belly, which gradually became a common tendon that rounded the pterygoid hamulus before inserting into the palatine aponeurosis. Notably, secondary insertions were found on the maxillary tuber (33.6%) and/or in the submucosal tissue near the palatoglossal arch (37.8%). Maxillary insertions were almost exclusively associated with an AT origin that was wide as or wider than the CB origin. Histological observations confirmed that the hamulus acted purely as a pulley and suggested that a connecting band to the tensor tympani had no or few functions of an intermediate tendon. Conclusions The TVP appears to act as the dilator tubae and that this function can be maintained by preserving or reconstructing the maxillary insertion during push-back surgery, even if hamulotomy is necessary.
An Acoustic Study of the Temporal Characteristics of Nasalization in Children with and without Cleft Palate
Authors: Ha Seunghee , Sim Hyunsub , Zhi Minje , Kuehn David P. 
Published: September 2004

Objective The purpose of this study was to measure the oral and nasal cavity acoustic energies to determine whether temporal patterns of nasalization differentiate children with and without cleft palate and the extent to which vowel context contributes to these temporal differences. Design Nasal onset interval, nasal offset interval, and total nasalization duration measures were obtained from acoustic waveforms, spectrograms, and energy contours acquired using the Computerized Speech Lab (Kay Elemetrics, Lincoln Park, NJ). In addition to absolute temporal values, proportional durations of nasalization were measured to obtain information regarding the relative duration of nasalization. Participants Fifteen children with cleft palate exhibiting mild hypernasality and 15 children without cleft palate participated in the study. Children in both groups were between 4 and 7 years of age. Results Each of the three absolute measures was significantly different between the two groups of subjects and within the three vowel contexts. Children with cleft palate showed longer temporal characteristics than children without cleft palate in all three absolute measures. The three temporal variables of the high vowel contexts were generally longer than those of low vowel contexts. Regarding proportional measures, nasal offset interval ratio, and total nasalization ratio showed significant differences between the two groups. Conclusions Nasalization, as reflected by acoustic signals, showed different timing characteristics between children with cleft palate and without cleft palate and across vowel contexts. This suggests that the duration of nasalization reflecting temporal patterns of the oral-nasal acoustic impedance may have an influence on the perception of hypernasality.
Speech Outcome following Treatment in Cross-Linguistic Cleft Palate Studies: Methodological Implications
Authors: Hutters Birgit , Henningsson Gunilla 
Published: September 2004

Objective In cross-linguistic studies of cleft palate speech outcome following treatment, treatment is the independent variable, speech outcome is the dependent variable, and the speakers’ language background is a background variable, like sex, age, and cleft type, which must be eliminated. This article focuses on language as a background variable and how it should be treated. The methodological problems are illustrated through a presentation of two cross-linguistic speech outcome studies. Conclusion When speakers of different language background are included in cleft palate studies of speech outcome following treatment, speech outcome data should be based on speech units that are phonetically identical across languages. This affects the make-up of the speech material used in the study. In practice, the requirement of phonetically identical speech units may not be totally met, and detailed information regarding the interaction between the cleft condition and speech sound production is still required to fully understand how the validity of data is affected if this requirement is not met.
Abnormal Vomer Development in Human Fetuses with Isolated Cleft Palate
Authors: Hansen Lene , Nolting Dorrit , Holm Gitte , Hansen Birgit Fischer , Kjaer Inger 
Published: September 2004

Objective The aim of this study was to elucidate the prenatal human development of the vomer with emphasis on the vomeral footplate and to assess vomeral morphology in fetuses with isolated cleft palate. Material and Methods Nine human fetuses of which four were normal (menstrual age [MA] 13 to 21 weeks) and five with isolated cleft palate (14 to 19 weeks MA) were studied. Midaxial cranial tissue blocks from the fetuses were cut frontally in 4μm serial sections. Sections were stained with toluidine blue in 30% ethanol. Results From 16 weeks MA, the vomeral footplate of normal fetuses was formed from bilateral ossifications located below a U-shaped vomeral body. Later in development, an osseous connection was found between the footplate and the vomeral body. Neither bilateral areas of ossification below the vomer nor a vomeral footplate was observed in isolated cleft palate fetuses. Conclusions In normal fetuses, the base or footplate of the vomeral bone appears from 16 weeks MA in frontal sections. In fetuses with isolated cleft palates, with no connection between the nasal septum and the maxillary processes, this vomeral footplate does not develop in the period observed (14 to 19 weeks MA).
Cleft Palate in a Newborn with Duplication 2(q13q23)
Authors: Wenger Sharon L. , Bleigh Ona C. , Hummel Marybeth 
Published: September 2004

Objectives A preterm boy was born with multiple anomalies including cleft palate and ventricular septal defect. Chromosome analysis on a blood sample identified additional material within the long arm of chromosome 2. Setting The newborn was in the neonatal intensive care unit requiring tertiary care during his 22 days of life. Results A supplementary fluorescent in situ hybridization test was performed to confirm the extra chromosomal material was chromosome 2. Parents’ chromosomes were normal, indicating a de novo duplication of 2q13q23. Conclusion Comparison of this case with those in the literature suggests involvement of cleft palate of cases with duplication of 2q13.
Digital Three-Dimensional Photogrammetry: Evaluation of Anthropometric Precision and Accuracy Using a Genex 3D Camera System
Authors: Weinberg Seth M. , Scott Nicole M. , Neiswanger Katherine , Brandon Carla A. , Marazita Mary L. 
Published: September 2004

Objective To determine the precision and accuracy of facial anthropometric measurements obtained through digital three-dimensional (3D) photogrammetry. Design Nineteen standard craniofacial measurements were repeatedly obtained on 20 subjects by two independent observers, using calipers and 3D photos (obtained with a Genex 3D camera system), both with and without facial landmarks labeled. Four different precision estimates were then calculated and compared statistically across techniques. In addition, mean measurements from 3D photos were compared statistically with those from direct anthropometry. Results In terms of measurement precision, the 3D photos were clearly better than direct anthropometry. In almost all cases, the 3D photo with landmarks labeled had the highest overall precision. In addition, labeling landmarks prior to taking measurements improved precision, regardless of method. Good congruence was observed between means derived from the 3D photos and direct anthropometry. Statistically significant differences were noted for seven measurements; however, the magnitude of these differences was often clinically insignificant (< 2 mm). Conclusions Digital 3D photogrammetry with the Genex camera system is sufficiently precise and accurate for the anthropometric needs of most medical and craniofacial research designs.
A Comparison of Oral-Nasal Balance Patterns in Speakers who are Categorized as “Almost but Not Quite” and “Sometimes but Not Always”
Authors: Jones David L. , Morris Hughlett L. , Van Demark Duane R. 
Published: September 2004

Objective The purpose of this study was to determine whether amplitude or temporal patterns of oral-nasal balance differentiate speakers with cleft palate who are classified as belonging to the “almost but not quite” (ABNQ) and “sometimes but not always” (SBNA) subgroups of marginal velopharyngeal inadequacy. Design The nasal accelerometric vibrational index (NAVI) was used to measure amplitude and temporal aspects of oral-nasal balance during the productions of oral and nasal syllables, words, and sentences. NAVI measures obtained include mean amplitude, time integral (area under the curve), duration, rise time, and fall time. Setting Tertiary care center for patients with cleft palate–craniofacial anomalies. Participants Seventeen patients with repaired cleft palate who were assigned by perceptual assessment to the ABNQ subgroup and 17 patients who were assigned to the SBNA subgroup. Results No differences were found between the ABNQ and SBNA subgroups with regard to patterns of nasalization. Further analysis as a function of level of production and phonetic context revealed no differences between the subgroups. Conclusions Although clinicians may report perceived differences in the resonance patterns of speakers who fall within the category of marginal velopharyngeal inadequacy, further division into the ABNQ and SBNA subgroups has yet to be validated.