bluuebunny/crossref_metadata_2025_split huggingface dataset:
Changes in the Properties of Light-Irradiated Wood with Heat Treatment. Part 1. Effect of Treatment Conditions on the Change in Color
Authors: Mitsui K. , Takada H. , Sugiyama M. , Hasegawa R. 
Published: October 2004

Summary
The effect of heat treatment on changing the color of light-irradiated wood was investigated. The change
in the lightness, ∆L*, of light-irradiated wood with heat treatment was much greater than that of unirradiated
wood. The chroma coordinates, ∆a*, of irradiated wood increased with treatment temperature and
time. ∆b* decreased after showing a sharp increase with a short period of heat treatment. It is thought
that the changes are related to a change in the chemical composition which was accelerated by heat. With
low temperature treatment, the color of irradiated wood changed remarkably with high relative humidity.
Little change in color was observed with low relative humidity. Therefore, heat and the presence of
water accelerated the change in the color of irradiated wood. This treatment is available as a new coloring
method.
Evaluating Strength Properties of Pinus radiata from Ultrasonic Measurements on Increment Cores
Authors: Yang J.-L. , Fortin Y. 
Published: October 2004

Summary
Static bending tests were conducted on seasoned plantation-grown Pinus radiata D. Don specimens.
After the tests, core specimens of two different sizes (ø 10 × 30 mm and ø 10 × 20 mm) and small clear
specimens of 20 × 20 × 60 mm were taken from intact zones of the post-test specimens. Ultrasonic
measurements were made on the core specimens and the apparent longitudinal dynamic modulus of elasticity
(ELD) calculated. The small clear specimens were subjected to parallel-to-grain compression tests.
The coefficient of determination was 0.85 between the static bending modulus of elasticity and ELD, 0.62
between the modulus of rupture and ELD, and 0.56 between the maximum crushing strength and ELD.
Delignification Mechanism during High-Boiling Solvent Pulping. Part 1. Reaction of Guaiacylglycerol-β-Guaiacyl Ether
Authors: Kishimoto T. , Sano Y. 
Published: October 2004

Summary
A phenolic β-O-4 type lignin model compound, guaiacylglycerol-β-guaiacyl ether (1) was treated with
70 wt% aq 1,3-butanediol solution at 160–200°C to investigate the delignification mechanism under
HBS (high-boiling solvent) pulping conditions. The following compounds were identified from the reaction
products by use of GC-MS: guaiacol (2), coniferyl alcohol (3), γ-etherified coniferyl alcohols (4)
and α-etherified guaiacylglycerol-β-guaiacyl ethers (5), but acidolysis products, such as Hibbert's
ketones were not detected. These results strongly suggest that the phenolic β-O-4 linkage was cleaved
homolytically under HBS pulping conditions. The cleavage of β-ether exhibited a pseudo first-order rate
behavior. The pseudo first-order rate constants were as follows: k = 0.94 × 10−2 min−1 at 160 °C;
k = 1.97 × 10−2 min−1 at 170°C; k = 3.22 × 10−2 min−1 at 180 °C; k = 9.76 x 10−2 min−1 at 200 °C.
The activation energy was 98.3 kJmol−1. The formation of higher molecular weight compounds was confirmed
by GPC. It is highly probable that the oligomeric products were derived from the recombination
of phenoxy radicals formed by homolysis of the β-aryl ether.
Liquefaction Mechanism of β-O-4 Lignin Model Compound in the Presence of Phenol under Acid Catalysis. Part 1. Identification of the Reaction Products
Authors: Lin L. , Yao Y. , Shiraishi N. 
Published: October 2004

Summary
Guaiacylglycerol-β-guaiacyl ether (GG) was used as a lignin model compound to study the liquefaction
reaction mechanism of lignin in the presence of phenol under the catalysis of several typical acids such
as sulfuric, phosphoric and oxalic acids. The reaction products were isolated by silicagel column chromatography
and high performance liquid chromatography (HPLC). The structures of the obtained compounds
were identified by means of GC-MS, 1H-NMR, 13C-NMR, 1H-1H COSY, HMBC and HMQC.
As a result, about 30 compounds were obtained as the main reaction products. It was found that their
structural characteristics were significantly different from those yielded at the non-catalyzed liquefaction
(Lin et al. 1997a), and independent on the acid species. The dominant products were guaiacylglycerol-α-phenyl-β-guaiacyl ethers, followed by guaiacol, triphenylethanes, diphenylmethanes, benzocyclobutanes
and phenylcoumarans. The structural characteristics and yields of these main reaction products
indicated that condensation between phenol and GG in its C-α and further cleavages in both the
β-O-4 linkage and Cβ–Cγ bonding could be the dominant reaction pathways.
Liquefaction Mechanism of β-O-4 Lignin Model Compound in the Presence of Phenol under Acid Catalysis. Part 2. Reaction Behaviour and Pathways
Authors: Lin L. , Nakagame S. , Yao Y. , Shiraishi M. Yoshioka and N. , Shiraishi N. 
Published: October 2004

Summary
By means of high performance liquid chromatography (HPLC) and gel permeation chromatography
(GPC), the yields of the main reaction products and the polymeric portion formed in the reaction of guaiacylglycerol-β-guaiacyl ether (GG) under various acid-catalyzed conditions were quantified as a function
of reaction time. Based on their forming sequence and reaction behavior, as well as their structural
characteristics, an acid-catalyzed reaction mechanism of GG with phenol was proposed.
Study of Residual Lignin in Pulp by UV Resonance Raman Spectroscopy
Authors: Halttunen M. , Vyörykkä J. , Hortling B. , Tamminen T. , Batchelder D. , Zimmermann A. , Vuorinen T. 
Published: October 2004

Summary
A major problem in the development of new bleaching technologies for pulp is the difficulty of analysing
the changes induced by bleaching chemicals in the structures of residual lignin. Separation and isolation
of the residual lignin before the analysis may modify the constituents of interest, whereas if the pulp is
analysed directly, the responses from cellulose and hemicelluloses will overlap the signal from the residual
lignin. In this study, UV resonance Raman spectroscopy, a powerful technique for detecting trace
components in complex mixtures, was applied to detect the changes in the residual lignin content after
bleaching stages. The resonance Raman technique was found to be highly sensitive and selective for
lignin structures allowing the detection of trace amounts of lignin after the final bleaching stages. Furthermore,
it enabled rapid and easy determination of hexenuronic acid content. UV resonance Raman
spectroscopy would appear to be a technique of great potential for pulping and bleaching research.
The Importance of Xylan for the Strength Properties of Spruce Kraft Pulp Fibres
Authors: Schönberg C. , Oksanen T. , Suurnäkki A. , Kettunen H. , Buchert J. 
Published: October 2004

Summary
In this work the role of xylan in spruce kraft pulp fibres was investigated by selectively removing the
pulp fibre xylan and also by sorbing xylan onto the pulp fibres. The effects of xylan removal and sorption
on fibre properties were measured and the chemical composition of the fibres and also that of the
selectively removed xylans was analyzed. According to the results the xylanase could act on both sorbed
and native xylan located on accessible fibre surfaces.
Xylan was found to affect the strength properties of handsheets. The location and the charge of xylan
had a considerable impact on the formation of interfibre bonds. Scott Bond-values correlated with the
amount of surface xylan on fibre surfaces, whereas tensile strength was affected by the total amount of
xylan and particularly by the total charge of the fibres. The fracture energy was determined by the combined
effect of interfibre bonding ability and effective fibre length.
Eucalyptus globulus Kraft Pulp Residual Lignin. Part 2. Modification of Residual Lignin Structure in Oxygen Bleaching
Authors: Duarte A.P. , Robert D. , Lachenal D. 
Published: October 2004

Summary
Residual lignins were isolated from unbleached and oxygen-bleached Eucalyptus kraft pulps by acid
hydrolysis. The structural changes and degradation of residual lignin occurring during kraft pulping and
oxygen bleaching were followed and identified by elemental analysis, residual carbohydrate analysis,
molecular mass distribution, as well as qualitative and quantitative solution 13C NMR. The dissolved
lignins in the kraft cooked and oxygen bleached liquors were also studied and compared with the corresponding
residual lignins. Milled wood lignin treated under acid hydrolysis conditions served as a reference
for the structural comparison. The results show that etherified syringyl structures were quite
resistant towards degradation in the oxygen bleaching, causing little depolymerisation in residual lignin
and a small increase in carboxylic acid content, but producing appreciable amounts of saturated aliphatic
methylene groups.
Monitoring Acoustic Emissions from Finger-Joints from Tropical African Hardwoods for Predicting Ultimate Tensile Strength
Authors: Ayarkwa J. , Hirashima Y. , Ando K. , Sasaki Y. 
Published: October 2004

Summary
The patterns of acoustic emissions generated during tension test of finger-joints from three tropical
African hardwoods, Obeche (Triplochiton scleroxylon), Makore (Tieghemella heckelii) and Moabi (Baillonella
toxisperma) were evaluated to assess their potential usefulness for non-destructively predicting
ultimate tensile strength. The acoustic emission patterns generated were observed to differ depending on
the type of finger profile and the wood species. Regression coefficients from cumulative acoustic emission
count versus applied stress squared functions also varied with the profile and species type. When
ultimate tensile strength was correlated with these regression coefficients, for stresses applied up to 50%
of mean ultimate strength, the logarithmic regression model developed could predict finger-joint strength
accurate to ±12%, ±13% and ±18% for Obeche, Makore and Moabi, respectively. The model was also
sensitive to the type of finger profile used for all three tropical African hardwoods.
The results indicate that this acoustic emission monitoring procedure could be useful for non-destructively
predicting ultimate tensile strength of finger-joints from the three tropical African hardwoods.
Hydrolytic Processes and Condensation Reactions in the Cellulose Solvent System N,N-Dimethylacetamide/Lithium Chloride. Part 1.
Authors: Rosenau T. , Potthast A. , Hofinger A. , Sixta H. , Kosma P. 
Published: October 2004

Summary
Refluxing of cellulose samples in N,N-dimethylacetamide (DMAc, 1), or in DMAc containing low concentrations
of LiCl, is a common protocol to facilitate dissolution of the cellulose for GPC measurements.
The formation of chromophoric condensation products, whose structures have been elucidated
for the first time, and of secondary chromophores by reaction with carbohydrate structures has been
demonstrated.
DMAc containing traces of water is slowly hydrolyzed to dimethylammonium acetate (2) under
reflux conditions. The reaction is accelerated in the presence of lithium chloride. In contrast, absolute
DMAc produces five different condensation products upon thermal treatment, which were isolated by
non-traditional column chromatography approach. The primary condensation product N,N-dimethylacetoacetamide
(3) is formed as the major component and acts as the precursor to the other chromophore
products, namely dehydroacetic acid and isodehydroacetic acid derivatives. Compound 3 is able to form
furan derivatives by reaction with reducing end groups or carbonyls in carbohydrate structures as demonstrated
by reactions with model compounds. As a consequence, it must be concluded that heating/refluxing
in DMAc or DMAc/LiCl generates a number of potent chromophores from the solvent and, furthermore,
can chemically alter pulp samples by introducing reactive structures.
Viscoelastic Properties of Liquefied Wood/Epoxy Resin and its Bond Strength
Authors: Kobayashi M. , Hatano Y. , Tomita B. 
Published: October 2004

Summary
A new resin system, in which liquefied wood was reacted with various epoxy compounds, was previously
developed. This paper reports the syntheses of two types of liquefied wood/epoxy resins with the
ratio of liquefied wood to epoxy compounds (L/E ratio) of either 1/0.5 or 1/1. Furthermore, the viscoelastic
properties obtained from the dynamic mechanical measurements of the cured resins and their
adhesive bond properties measured as tensile shear strength are reported. The results from dynamic
mechanical measurements indicated that the resins with a L/E ratio of 1/0.5 could be cured at 90°C,
while the resins with L/E ratio of 1/1 were cured at 150°C. The resins cured with triethylene tetramine
(TETA) at 150°C or 90°C had almost the same level of the normal adhesive shear strength as that of the
commercial epoxy resin. The high level of adhesive shear strength of the resin cured at 150°C was maintained
after the glued specimens were soaked in water at 60°C, while the share strength of the resins
cured at 90°C was reduced by either the water soaking at 60°C or the cyclic boiling test.
Structural changes upon the temperature dependent C2/c → P21/c phase transition in LiMe3+Si2O6 clinopyroxenes, Me = Cr, Ga, Fe, V, Sc and In
Authors: Redhammer Günther J. , Roth Georg 
Published: October 2004

Abstract
Within the Li-clinopyroxene series LiMe3+Si2O6, a temperature induced C2/c → P21/c phase transition has been observed for Me = Cr, Ga, V, and Sc at temperatures of 330(1), 286(1), 205(3) and 234(1) K, respectively. There is no phase transition for the Al3+ and the pure In3+ compound down to 80 K. Within the LiSc1–

x
In
x
Si2O6 solid solution se ries, the transition temperature rapidly decreases with increasing In3+ content and drops below 90 K between x = 0.26 and 0.30. The C → P phase transition is found only in samples with nearly fully extended tetrahedral chains. The phase transition in LiScSi2O6, with its “O-rotated” and distinctly more kinked tetrahedral chains in C2/c (O3—O3—O3 angle = 175.7(1)° at 298 K), exhibits a different character: the decay of the b-type Bragg reflections hkl: h + k ≠ 2n and the structural changes in the vicinity of the phase transition are less rapid. The temperature dependent evolution of the order parameter Q2 (as expressed by the decay of the b-type Bragg reflections) suggests a second order thermodynamic character of the C → P phase transition in the Sc3+ compound, whereas it is close to a tri-critical behaviour in the other ones. The structural changes, taking place at the phase transition and below are similar to those in LiFeSi2O6, i.e. dislinkage and appearance of two differently kinked tetrahedral chains in P21/c, decrease of the coordination number of Li+ from 6 to 5, slight alterations of octahedral bond lengths. The structural changes at the phase transition are of similar magnitude in the Ga, Cr, V and Fe compound. LiScSi2O6 is again exceptional. Different thermal expansion of octahedral and tetrahedral sites and increasing site distortion of the M1 site as a consequence of tetrahedral chain kinking in C2/c are assumed to be factors inducing the C2/c → P21/c phase transition.
X-ray diffraction study of decagonal Al—Co—Ni as a function of composition
Authors: Katrych Sergiy , Steurer Walter 
Published: October 2004

AbstractThe evolution was studied of structural order/disorder phenomena across the wide stability field of the decagonal phase in the system Al—Co—Ni. Full single-crystal X-ray diffraction data sets were collected of 31 samples annealed at 900 °C. Based on reciprocal space reconstructions of the imaging-plate-scanner data, the variation in Bragg as well as in diffuse scattering is discussed in detail. The samples were also characterized metallographically, by powder X-ray diffraction, differential thermal analysis and energy-dispersive X-ray spectroscopy. The (quasi)lattice parameters vary smoothly over the stability range of decagonal Al71.5Co28.5—xNix(8 ≤x≤ 20). A smooth variation is also observed for the diffuse scattering related to the ≈8 Å superstructure. These observations indicate a continuous ordering process at 900 °C from the basic Co-rich phase via the type II and type I superstructures to the basic Ni-rich phase.
The correlation between metal oxidation state and bond valence parameters for M—O bonds (M = V, Fe and Cu). A simple method to search for the metal oxidation-state independent parameter pairs
Authors: Hu Sheng-Zhi , Zhou Zhao-Hui 
Published: October 2004

Abstract
Based on the latest available crystal data and the reported bond valence parameters, the linear correlation between the bond valence parameter R
0 with B = 0.37 Å for M—O bonds (M = V, Fe and Cu) and the metal oxidation state n is shown for the first time. For V—O bonds, a linear equation of R
0 ∼ n is perfectly established as R
0 = 0.0250n + 1.674 (n = 2–5). Similarly, a linear equation for Fe—O bonds is fitted as R
0 = 0.0335n + 1.648 (n = 2–4), as well as R
0 = 0.0855n + 1.482 (n = 1–3) for Cu—O bonds fitted properly. In addition, the linear correlation between R
0 and n within certain range of B values for V—O and Fe—O bonds is also established. Consequently, the oxidation-state independent parameters (R
0, B) of (1.788, 0.32 Å) for V—O bonds and (1.795, 0.30 Å) for Fe—O bonds can be derived from the zero slope of the R
0 ∼ n straight lines. However, a similar parameter pair for Cu—O bonds cannot be found using this unique approach.
Calculated growth form of melilites
Authors: Nicolov Mirela F. 
Published: October 2004

Abstract
The Hartman-Perdok theory was used to explain the relation between crystal structure and crystal morphology for Ca2AlSi2O7. Theoretical growth forms were constructed from the calculated attachment energies E
hkl
a, which are assumed to be directly proportional to the growth rate for F faces. F forms calculated, are {110} {101}, {111}, {021}, {120}, {001}, {100} and {130}. The theoretical growth forms are simulated for different values of the charges (normal and Matsui charges).
Similarities between the clathrasils DOH, DDR, MEP and MTN
Authors: van Koningsveld Henk , Gies Hermann 
Published: October 2004

AbstractClathrasils are porous framework silicates with cage-like voids. Structural similarities between the clathrasilsDOH,MTN,MEP, DD3H andDDRhave been analyzed in the context of host/guest interaction and crystallization mechanism. A building unit consisting of 30 T atoms is used as common structural feature to give an alternative description of the well-known layers of [512]-cages. The [512]-layers, or Periodic Building Units (PerBU’s), are constructed from two 12-rings connected through a common 6-ring to form two half cages or a 12-ring double cup. These ‘half-cages’ are essentially the bottom of the large ‘inter-layer’ cages in the clathrasils. The rigorous derivation of all possible framework types and their cages based on these principles shows the richness of the concept and makes possible new strategies for the synthesis. The ‘half-cages’ are also possible candidates for precursors which might exist in solution in close contact with templating guest species initiating the nucleation of the crystals.
Thermal expansion, elastic and thermoelastic properties including crystal structure analyses of K-, Rb- and Cs-nitrilotriacetates
Authors: Haussühl Eiken , Haussühl Siegfried , Tillmanns Ekkehart 
Published: October 2004

Abstract
Single crystals of the title compounds having optical quality and dimensions up to 60 mm have been grown from aqueous solutions. X-ray crystal structure analyses of K2H[N(CH2COO)3] · H2O (I), K2H[N(CH2COO)3] · 2 H2O (II), and Cs2H[N(CH2COO)3] · H2O (III) has been done. Thermal expansion, elastic and thermoelastic properties of the title compounds have been measured employing mechanical and optical dilatometers and ultrasonic resonance techniques, respectively. They possess quite different structural motifs contrary to most other salts having a common anion. An anomalous large molecular volume and a small mean elastic stiffness of K2H[N(CH2COO)3] · 2 H2O is qualitatively interpreted by the small number of Coulomb interactions between the single charged cations and oxygen atoms of the anions. Differences in thermal and elastic properties of corresponding alkali nitrilotriacetates and alkali salts of other large anions are discussed.
Dichloro(cyclohexilidene-1-methylene)(phenyl)Te(IV). Looking for the theoretical treatment
Authors: Vega-Teijido Maurício , Zukerman-Schpector Julio , Ventura Oscar N. , Camillo Robinson L. , Caracelli Ignez , Guadagnin Rafael C. , Braga Antonio L. , Silveira Claudio C. 
Published: October 2004

Abstract
C13H16Cl2Te, M
r = 370.76, P21/a, a = 8.1833(8), b = 8.4163(8), c = 20.787(2) Å, β = 99.52(1)°, Z = 4, R
1 = 0,0275. The primary coordination around the TeIV atom is consistent with a pseudo-trigonal bipyramidal bond configuration with two Cl atoms occupying axial positions while the C atoms and the lone pair of electrons occupy the equatorial positions. The TeIV atom is involved in an intermolecular secondary interaction resulting in the self assembly of zigzag-chains supramolecular array.
In order to determine the theoretical basis set for the Te atom which leads to the best agreement with the experimental data, a large series of geometry optimizations were performed on dichloro dimethyl Te(IV), as a model compound, and the results compared with the mean distances and angles obtained from 45 X-ray structures. The Ahlrichs basis set plus the Hay & Wadt ECP was selected and used for a series of calculations performed on the title compound.
Synthesis, crystal structure and molecular conformation of (±)-1-oxoferruginol and (±)-shonanol
Authors: Mondal Swastik , Mukherjee Monika , Roy Arnab , Mukherjee Debabrata 
Published: October 2004

Abstract
(±)-1-oxoferruginol and (±)-shonanol, two potential intermediates in the synthesis of tricyclic diterpenoid ferruginol, have been prepared and crystal structures of the compounds have been investigated using single-crystal X-ray diffraction data. The methyl groups of the isopropyl moiety in (±)-shonanol are disordered over two positions with occupation factors 0.65(1) and 0.35(1), respectively. Although the chemical structures of two compounds are very similar, a C—C single bond in the terminal six-membered ring of (±)-1-oxoferruginol is replaced by a C=C bond in (±)-shonanol, the quantitative isostructurality index calculations indicate that the structures are not isostructural. Intermolecular O—H…O hydrogen bonds between pairs of molecules in the compounds related by center of inversion lead to characteristic dimers forming R2
2(16) rings. The molecular conformation of (±)-1-oxoferruginol obtained from the semi-empirical quantum mechanical AM1 calculation shows good agreement with the X-ray structures.
Triphenylphosphine adducts of silver di-iso-propyl dithiophosphate
Authors: Huang Yihui , Tiekink Edward R. T. 
Published: October 2004

AbstractThe molecular structure of dimeric {[S2P(OiPr)2](PPh3)}2· 2 CHCl3is built up about a centrosymmetric eight-membered ring that adopts a chair conformation as a result of bidentate bridging dithiophos phate ligands. The silver atom is in a trigonal planar geometry. Relatively close transannular Ag…S interactions are noted which, if considered significant, leads to a tridentate dithiophosphate ligand and a distorted tetrahedral geometry for silver. The presence of two PPh3molecules in the coordination sphere of silver in monomeric Ag[S2P(OiPr)2](PPh3)2· 3 CHCl3as well as a bidentate di thiophosphate ligand gives rise to a tetrahedral geometry. Adducts with lower or greater numbers of PPh3ligands could not be obtained pointing to the inherent stability of the characterised structures.