bluuebunny/crossref_metadata_2025 huggingface dataset:
Burkholderia cenocepacia strains isolated from cystic fibrosis patients are apparently more invasive and more virulent than rhizosphere strains
Authors: Pirone Luisa , Bragonzi Alessandra , Farcomeni Alessio , Paroni Moira , Auriche Cristina , Conese Massimo , Chiarini Luigi , Dalmastri Claudia , Bevivino Annamaria , Ascenzioni Fiorentina
Published: July 2008

Given the widespread presence of Burkholderia cenocepacia in the rhizosphere it is important to determine whether rhizosphere strains are pathogenic for cystic fibrosis patients or not. Eighteen B. cenocepacia strains of rhizosphere and clinical origin were typed by multi‐locus sequence typing (MLST) analysis and compared for their ability to invade pulmonary epithelial cells and their virulence in a mouse model of airway infection. Although there was great variability, clinical strains were the most invasive in vitro. Almost all the rhizosphere and two clinical strains were defined as non‐invasive, six clinical strains as invasive, and two strains of both clinical and environmental origin as indeterminate. Exposure of murine airways to clinical strains caused higher acute mortality than that seen after challenge with rhizosphere strains. Furthermore, both clinical and environmental strains were able to persist in the lungs of infected mice, with no significant differences in bacterial loads and localization 14 days after challenge. DNA dot blot analyses of AHL synthase, porin and amidase genes, which play a role in B. cenocepacia virulence, showed that they were present in B. cenocepacia strains irrespective of their origin. Overall, our results suggest that rhizosphere strains do not differ from clinical strains in some pathogenic traits.
The Mth60 fimbriae of Methanothermobacter thermoautotrophicus are functional adhesins
Authors: Thoma Christine , Frank Monika , Rachel Reinhard , Schmid Silvia , Näther Daniela , Wanner Gerhard , Wirth Reinhard
Published: July 2008

The ability to adhere onto surfaces is of very high importance for microorganisms, enabling them to stay in a favourable habitat for life. In the case of Bacteria cell surface organelles called fimbriae/pili have been shown to be used for adhesion; corresponding cell surface appendages of Archaea have not yet been defined. The first detailed characterization of archaeal fimbriae, namely those of Methanothermobacter thermoautotrophicus, allowed us to identify mth60 as the main structural fimbrin gene. Recombinant expression of mth60 in Escherichia coli was used to generate sufficient amounts of Mth60 to induce antibodies in rabbits. The antiserum reacted specifically with the 16 kDa fimbrial glycoprotein and could specifically detach adhering M. thermoautotrophicus cells from various surfaces. In addition we proved that cells adhering to solid surfaces – organic and inorganic ones – express many more fimbriae than cells growing in liquid cultures. The Mth60 fimbriae therefore are used by M. thermoautotrophicus as adhesins.
The Interplay between Conscious and Automatic Self‐Regulation and Adolescents’ Physical Activity: The Role of Planning, Intentions, and Lack of Awareness
Authors: Dombrowski Stephan , Luszczynska Aleksandra
Published: July 2008

This study investigated the interplay between conscious and automatic self‐regulatory variables and adolescents’ physical activity. It was hypothesised that intention, planning, and lack of awareness would predict adolescents’ behaviour. One hundred and fifty‐five individuals (aged 13 to 17 years) completed questionnaires in two waves (with a time gap of 10 days). The results of cross‐lagged panel analysis suggested that both past behaviour and planning predicted physical activity at follow‐up, whereas physical activity predicted intention. Although lack of awareness, a facet of automatic processes, was negatively related to physical activity, the nested model comparison analysis indicated that the relation between lack of awareness and physical activity might be negligible. Among the self‐regulatory processes, planning was found to be the most important predictor of adolescents’ physical activity, although past behaviour remained the strongest predictor of future behaviour.

Cette recherche porte sur l’interaction entre les variables autorégulatrices conscientes et automatiques et l’activité physique des adolescents. On a fait l’hypothèse que l’intention, la planification et l’absence de prise de conscience allaient prédire le comportement des adolescents. 155 individus âgés de 13 à 17 ans ont rempli des questionnaires en deux temps avec un intervalle de dix jours. Les résultats d’une analyse en panel retardé croisé montrent que la conduite antérieure et la planification prédisent l’activité physique qui s’ensuit alors que l’activité physique prédit l’intention. Bien que le manque de prise de conscience, une facette des processus automatiques, soit négativement corréléà l’activité physique, l’analyse de variance indique que la relation entre l’absence de prise de conscience et l’activité physique pourrait être négligeable. Des différents processus d’autorégulation, c’est la planification qui est apparue comme étant le prédicteur majeur de l’activité physique des adolescents, bien que la conduite passée reste le prédicteur le plus fiable du comportement à venir.
The changing focus of microarray analysis
Authors: Armstrong Nicola J.
Published: July 2008

In the biological sciences, the advent of microarray technology changed the way experiments were performed. Microarrays were the first mainstream high‐throughput technology, generating enormous amounts of data for both the biologist and the statistician to understand. Here, I follow my own experience in microarray analysis, starting during my time at EURANDOM with experimental design and continuing today in my present position at the Netherlands Cancer Institute where the exploitation of data from many different sources is hoped will give greater insight into different aspects of cancer.
VP Raising in a VOS Language
Authors: Cole Peter , Hermon Gabriella
Published: July 2008

Abstract. Toba Batak displays a variety of properties that are typologically rare: (1) The predominant word order is V‐O‐S‐IO and V‐O‐S‐Adv. (2) Extraction of direct objects/passive agents (by relativization, etc.) is ungrammatical, but subjects, IOs, and adverbials can be extracted. (3) In Toba Batak anaphoric binding, the active subject binds the DO and active DOs can bind the IO, but, additionally, the “passive agent” can bind a passive subject. We argue that these facts are explained by an analysis in which V‐O‐S‐IO order is derived by VP‐raising and in which the passive agent is an argument, generated as the specifier of vP rather than as an adjunct. Furthermore, the passive subject undergoes optional reconstruction to its base‐generated position in VP. We also argue that, although c‐command relations among elements of vP are critical, linear order plays no role whatsoever in the base structure. That is, the output of Merge can be unordered linearly, and it can be shown that all surface word orders in Toba Batak can be derived from various movement rules out of an unordered base. Linear order comes into play only when constituents move out of the vP to higher functional projections, linear order being simply a by‐product of Move.
Morphosyntax of Movement Dependencies in Haitian Creole
Authors: Takahashi Shoichi , Gračanin‐Yuksek Martina
Published: July 2008

Abstract. In Haitian Creole the lexical itemkishows up when a subject (but not an object) undergoes operator movement inwh‐questions, clefts, and relative clauses. We argue thatkiis a phonological reflex of agreement between the complementizer and awh‐phrase. More specifically, the complementizer is spelled out askiif all its features are checked off by a single goal. We demonstrate that this is accomplished only when the operator is a subject.
The ‘Act When Mild’ (AwM) Study: A Step Forward in Our Understanding of Early Treatment in Acute Migraine
Authors: Goadsby PJ
Published: July 2008

An important issue in the management of migraine is the advice given to patients as to when to take their treatment in the course of the attack. While it seems common sense almost to take treatment early in the attack, the evidence base for that advice is not as robust as could be expected. The ‘Act when Mild’ (AwM) Study was a randomized, four-arm, multicentre, multinational, double-blind, placebo-controlled trial of almotriptan (12.5 mg) to compare outcomes after administration of treatment when pain intensity was mild and within 1 h of headache onset (mild/early) with outcomes when pain had become moderate or severe. Of 491 migraineurs enrolled, 403 were evaluable with an intention-to-treat population (ITT) of 404. At the primary end-point, 2 h pain free, on the ITT analysis 49% of patients in the almotriptan 12.5 mg treat early/mild group and 40% in the treat moderate/severe group had responded ( P = 0.21). Of these patients, 43 did not take medication according to their randomly allocated baseline pain intensity (mild or moderate/severe) and were subsequently reassigned, prior to study unblinding, to the appropriate group (AwM population) for re-analysis of the primary outcome measure: 2-h pain-free rates. In the almotriptan arms, 53% of the mild/early group and 37.5% of the moderate/severe group were pain free at 2 h ( P = 0.02; AwM population). The corresponding proportions in the placebo groups were 24.7% and 17.5% (significantly lower than the respective almotriptan arms; P ≤ 0.01). Considering the ITT population, secondary end-points were also significantly in favour of treatment with almotriptan in the mild/early vs. the moderate/severe stage, including: sustained pain-free, 45.6% vs. 30.5% ( P = 0.02); headache recurrence at 24 h, 6% vs. 24% ( P = 0.0124). Adverse events were reported in < 5% of patients, with no significant differences between almotriptan and placebo and no serious events in any group. Treatment with almotriptan while migraine pain is still mild and within 1 h of onset provides statistically significant and clinically relevant enhancements in efficacy compared with waiting until pain has reached higher severity levels.
Size Control of α‐Al2O3 Platelets Synthesized in Molten Na2SO4 Flux
Authors: Jin Xihai , Gao Lian
Published: July 2008

α‐Al2O3 platelet powders were synthesized in molten Na2SO4 flux. The size of α‐Al2O3 platelets was significantly reduced when partially decomposed rather than pure Al2(SO4)3 was used as the source of Al2O3; a further reduction in the platelet size was realized through additional seeding with nanosized α‐Al2O3 seeds. The addition of microsized α‐Al2O3 platelet seeds significantly influenced the platelet morphology of the final powder, as well. The platelet size of the final powder was in direct proportion to the size of the platelet seeds, and was in reverse proportion to the cube root of the platelet seed content.
Sintering of Lead Titanate Using a Spark‐Plasma‐Sintering Technique
Authors: Kakegawa Kazuyuki , Kawai Yukiko , Wu YongJun , Uekawa Naofumi , Sasaki Yoshinori
Published: July 2008

Lead titanate (PbTiO3) is difficult to sinter without additives, even when a spark‐plasma‐sintering technique is applied. The high tetragonality, c/a, of PbTiO3 causes destructive strain after sintering. We found that a sintered body of PbTiO3 could be obtained, when the PbO/TiO2 value was <0.9. However, decreasing the ratio did not increase the bulk density; rather, it caused a decrease in the grain size. The mechanical strain that resulted from the phase change from cubic, at the sintering temperature, to tetragonal, at room temperature after the sintering, was released by the decrease in the grain size.
Localized Densification during the Stage II–III Transition ‐ Compaction Efficiency at High Pressures
Authors: Nam Jin , Lannutti John J.
Published: July 2008

Localized densification and compaction efficiency at high pressures was studied using X‐ray computed tomography. Stage III begins with the initiation of a region of uniform average density within the overall high‐density zone. No further densification occurs in this region; additional pressure is transmitted into adjacent, less‐dense zones and the die wall. This localized increase in wall friction continuously decreases compaction efficiency. Discrete element modeling was used to visualize force transfer. The transition was governed by events that ranged from the microscale to the macroscale. Terapascal levels of pressure were required to produce a uniform compact.
Fabrication of Machinable Silicon Carbide‐Boron Nitride Ceramic Nanocomposites
Authors: Wang Xiangdong , Qiao Guanjun , Jin Zhihao
Published: July 2008

SiC/BN nanocomposite powders with the microstructure of micrometer‐sized SiC particles coated with nanometer‐sized BN particles were prepared via a chemical reaction, which used a mixture of boric acid (H3BO3) and urea (CO(NH2)2) as reactants coated on the surface of the SiC particles to react under a nitrogen‐gas atmosphere. The results of XRD, TEM, and SAED studies showed that the coating layer (BN) was composed mostly of amorphous and nanometer‐sized BN particles at the reaction temperature of 850°C. When the nanocomposite powders were hot‐pressed at 1850°C, machinable SiC/BN ceramic nanocomposites with fine grain size and homogeneous microstructure were fabricated. The composite that contained 20 wt% BN exhibited high strength (the three‐point bending strength was 588.4 ± 26.8 MPa) and excellent machinability.
Structure–Property Relations in xBaTiO3–(1−x)La(Mg1/2Ti1/2)O3 Solid Solutions
Authors: Seabra Maria P. , Avdeev Maxim , Ferreira Victor M. , Pullar Rob C. , Alford* Neil McN. , Reaney* Ian M.
Published: July 2008

The microwave dielectric properties and microstructures of compounds in the solid solution series xBaTiO3–(1−x)La(Mg1/2Ti1/2)O3 (BTLMT) have been investigated. The structural phase transitions that occur as a function of x have been studied and are related to changes in the dielectric properties. For compounds where x≤ 0.1, X‐ray diffraction (XRD) showed evidence of 1:1 ordering between Mg and Ti cations. For x≤ 0.3, XRD and electron diffraction revealed that compounds were tilted in both antiphase and in‐phase. However, for 0.3 < x < 0.7, only antiphase tilting was present. The temperature coefficient of resonant frequency (τf) vs the relative permittivity (ɛr) was linear until x= 0.5 at which point in the solid solution the transition to a nontilted structure resulted in nonlinear behavior. τf values close to zero (−2 ppm/°C) were achieved at x= 0.5 (ɛr∼ 60), which had a quality factor (Q·fo) of 9600 GHz.
Effect of Double Reinforcements on Elevated‐Temperature Strength and Toughness of Molybdenum Disilicide
Authors: Tantry Srikari P. , Ramasesha Sheela K. , Lee Jae‐Seol , Yano Toyohiko , Ramamurty Upadrasta
Published: July 2008

Flexural strength and fracture toughness of molybdenum disilicide and its composites with 10 wt% TiB2 and 10 wt% TiB2+ 10 wt% SiC, synthesized by the hot‐pressing technique, were evaluated as a function of temperature, ranging from ambient temperature to 1600°C. Results show that the composites have higher strength and slightly lower toughness as compared with monolithic MoSi2 at room temperature. At high temperatures, the composites exhibit higher strength as well as higher toughness vis‐à‐vis monolithic MoSi2. Among the composites, the double reinforcement of SiC and TiB2 was found to be more effective in improving the mechanical properties. A transition from brittle to ductile behavior was observed at temperatures greater than 1300°C for all materials tested. The high‐temperature mechanical behavior was found to be significantly influenced by the flow of an intergranular glassy phase and the attendant cavity nucleation and growth along the grain boundaries. Micromechanisms responsible for the ambient as well as the elevated‐temperature property improvement in composites are discussed with the aid of fractography.
Phase Transformation and Densification of an Attrition‐Milled Amorphous Yttria‐Partially‐Stabilized Zirconia–20 mol% Alumina Powder
Authors: Kumagai Tatsuo , Hongo Kazuhiro , Kimura Hiroshi
Published: July 2008

Phase transformations during consolidation treatments of an attrition‐milled amorphous yttria‐partially‐stabilized zirconia (Y‐PSZ: ZrO2–3 mol% Y2O3)–20 mol% Al2O3 powder and the resulting microstructures have been investigated. A metastable cubic phase (c‐ZrO2 solid solution) together with an α‐Al2O3 phase is formed in the amorphous matrix by consolidation at temperatures below 1204 K. The metastable cubic phase transforms to a stable tetragonal phase (t‐ZrO2 solid solution) with an increase in the consolidation temperature. Fully dense bulk samples consisting of extremely fine tetragonal grains together with a small amount of α‐Al2O3 particles could be obtained by consolidation at temperatures above 1432 K. Important features concerned with the densification behavior are as follows: (1) Marked increase in the relative density occurs after cubic crystallization and subsequent cubic‐to‐tetragonal transformation. (2) All of the consolidated bulk samples show extremely fine grain structure with grain sizes of several tens of nanometers, irrespective of the consolidation temperature. (3) The regularity of the lattice fringe contrast in each tetragonal grain seems to be kept in the vicinity of grain boundaries. These results suggest that densification of the attrition‐milled amorphous powder proceeds via superplastic flow and/or diffusional creep, rather than viscous flow of the initial amorphous phase before crystallization.
Microstructural Characterization of SiC–SiC Joint by Raman Spectroscopy
Authors: Magnani Giuseppe , Brillante Aldo , Farina Luca , Beaulardi Leandro
Published: July 2008

Analysis of the SiC–SiC joint and its brazing mixture has been performed using a Raman spectroscopy microprobe technique. A careful mapping of the sample clearly shows the spatial distribution of the chemical species close to and within the joint. A different distribution of the 4H and 6H α‐SiC polytypes, grown during the brazing process, was observed inside the joint. Furthermore, identification of the bands related to the Nowotny phase was also possible.
Distribution of Grain Boundaries in SrTiO3 as a Function of Five Macroscopic Parameters
Authors: Saylor David M. , El Dasher Bassem , Sano Tomoko , Rohrer Gregory S.
Published: July 2008

Measurements of the grain boundary population as a function of misorientation and boundary plane orientation show that the distribution is inversely correlated to the sum of the energies of the surfaces comprising each boundary. The observed correlation suggests that the difference between the energy of a high‐angle grain boundary and the two component surfaces is relatively constant as a function of misorientation. Two exceptions to this correlation were identified: low‐misorientation‐angle boundaries and the coherent twin boundary, where the (111) planes in the adjoining crystals are parallel to each other, but rotated by 60° around the [111] axis. In these cases, the high degree of coincidence across this interface probably lowers the boundary energy with respect to that of the component surfaces. For all other boundaries, the anisotropy of the population is accurately predicted by the surface energy anisotropy, and in general, boundaries display a preference for {100} orientations, the planes of minimum surface energy.
Isomorphic A‐Site Substitution on Sillenite‐Type Compounds
Authors: Valant Matjaz , Meden Anton , Suvorov Danilo
Published: July 2008

Investigations of A‐site substitution in sillenite‐type compounds showed that only a substituent ion with a lone‐electron pair can be successfully incorporated onto the A‐site in place of Bi3+. This is because the stability of sillenite structural polyhedra is conditioned by the presence of a stereochemically active lone‐electron pair. Accordingly, the substitutional experiments combined with an X‐ray diffraction analysis, energy‐ and wavelength‐dispersive microanalysis, and Rietveld refinement showed that Nd3+ and La3+ ions, which do not possess a lone‐electron pair, cannot be incorporated into the sillenite‐type structure above the detection limits of the applied analytical techniques. In contrast, the A‐site substitution of Pb2+, Tl+, and Sb3+ ions, which do possess a lone‐electron pair, was experimentally confirmed. Te4+ also possesses a lone‐electron pair, but the substitutional experiments showed that this ion did not incorporate into the sillenite structure.
Thermodynamic Assessment of the Gallium‐Oxygen System
Authors: Zinkevich Matvei , Aldinger Fritz
Published: July 2008

The experimental information relevant to the Ga‐O binary system has been critically assessed. A self‐consistent set of Gibbs energy functions describing the phases in this system and a phase diagram are presented for the first time. The adjustable parameters of the models are obtained by a least‐squares fit to the experimental data. The liquid phase is described by Hillert's partially ionic liquid model. The gallium oxides (α‐, β‐, γ‐, and δ‐Ga2O3) are modeled as stoichiometric phases. The gas phase is treated as an ideal solution of the species Ga, Ga2, Ga2O, GaO, O, O2, and O3. The calculated phase diagram and thermodynamic properties agree very well with most of the experimental measurements.
Synthesis of Nanocrystalline Zirconium Nitride Powders by Reduction–Nitridation of Zirconium Oxide
Authors: Fu Bo , Gao Lian
Published: July 2008

Nanocrystalline ZrN powder was synthesized by reduction–nitridation of nanosized ZrO2 powder in ammonia gas with magnesium as the reducing agent. The effects of nitridation temperature, holding time, and Mg:ZrO2 mole ratio on the powder properties were investigated. Cubic phase ZrN powder with a 30–100‐nm particle size was synthesized at 1000°C for 6 h, under a Mg:ZrO2 mole ratio of 10:1.
Tribological Behavior of a Si3N4/Carbon Short Fiber Composite under Water Lubrication
Authors: Hyuga Hideki , Jones Mark I. , Hirao Kiyoshi , Yamauchi Yukihiko
Published: July 2008

The tribological behavior of monolithic Si3N4 and a Si3N4/carbon fiber composite has been assessed under high load and low speeds in an aqueous environment. The results showed that the friction coefficient of the Si3N4 was not significantly reduced when compared with dry sliding, and this was attributed to the failure to maintain a lubricating layer between the solid–solid surfaces. In the case of the composite, the initial high friction coefficient was reduced shortly after the beginning of the wear test and maintained a low value (about 0.03) throughout. This was attributed to the solid lubricating effect of the composite resulting in lower stress at the contact asperities, preventing the removal of the lubricating layer.
Self‐Propagating High‐Temperature Synthesis of α‐SiAlON Doped by RE (RE=Eu,Pr,Ce) and Codoped by RE and Yttrium
Authors: Jiang Jiuxin , Wang Peiling , He Wanbao , Chen Weiwu , Zhuang Hanrui , Cheng Yibing , Yan Dongsheng
Published: July 2008

Self‐propagating high‐temperature synthesis (SHS) was applied to synthesize α‐SiAlON powders doped by RE (RE = Eu,Pr,Ce) and codoped by RE and yttrium. The results showed that the weight ratio of α‐SiAlON to (α‐SiAlON +β‐SiAlON) decreased from 70%, 55%, and 25% for europium‐, praseodymium‐, and cerium‐doped α‐SiAlON compositions, respectively, and the weight percentage of α‐SiAlON phase increased to 100% for both (Eu,Y) and (Pr,Y) systems and 94% for the (Ce,Y) system, indicating SHS is a promising approach for synthesizing α‐SiAlONs stabilized by the cations that could not be incorporated into the α‐SiAlON structure by conventional sintering methods.
Kinked Grain Boundaries in Alumina Doped with Y2O3
Authors: Kim Mi Jin , Cho Young Kyu , Yoon Duk Yong
Published: July 2008

Polycrystalline alumina specimens with and without MgO doping show smoothly curved grain boundaries after heat treatment at 1400°C indicating their rough structure. When heat‐treated at 1400° and 1500°C for 24 h after packing in an alumina–YAG powder mixture, many grain boundaries (without any liquid phase) develop kinks of large and small scales as observed by scanning electron microscopy and transmission electron microscopy. The addition of Y2O3 at concentrations close to the solubility limit is thus shown to induce the grain boundary transition to singular structures.
Habits of Grains in Dense Polycrystalline Solids
Authors: Saylor David M. , El Dasher Bassem , Pang Ying , Miller Herbert M. , Wynblatt Paul , Rollett Anthony D. , Rohrer Gregory S.
Published: July 2008

We show here that the boundaries of individual grains in dense polycrystals prefer certain crystallographic habit planes, almost as if they were independent of the neighboring crystals. In MgO, SrTiO3, MgAl2O4, TiO2, and aluminum, the specific habit planes within the polycrystal correspond to the same planes that dominate the external growth forms and equilibrium shapes of isolated crystals of the same phase. The observations decrease the apparent complexity of interfacial networks and suggest that the mechanisms of solid‐state grain growth may be analogous to conventional crystal growth. The results also indicate that a model for grain‐boundary energy and structure based on grain surface relationships is more appropriate than the widely accepted models based on lattice orientation relationships.
Effect of Ba6Ti17O40/BaTiO3 Interface Structure on {111} Twin Formation and Abnormal Grain Growth in BaTiO3
Authors: Jung Yang‐Il , Lee Byoung‐Ki , Kang Suk‐Joong L.
Published: July 2008

A structural transition of Ba6Ti17O40/BaTiO3 interfaces from faceted to rough was induced by reducing oxygen partial pressure in the atmosphere. As the oxygen partial pressure decreased, the number densities of {111} twins and abnormal grain decreased. TEM observation showed that the twin formation was governed only by the faceting of the interface. Experimental evidence of {111} twin‐assisted abnormal growth of faceted BaTiO3 grains was also obtained.
Water Incorporation in Tetragonal Zirconia
Authors: Guo Xin , Schober Tilman
Published: July 2008

Samples of 3 mol% Y2O3‐stabilized tetragonal ZrO2 ceramics were annealed at 250°C in atmospheres of water vapor pressures of 1 bar and 26 mbar. As demonstrated by the water uptake and the lattice expansion, water molecules were incorporated into the ZrO2 lattice during annealing, and the amount of the incorporated water is determined by the water vapor pressure. Owing to the filling of oxygen vacancies by the incorporated water molecules, part of the tetragonal ZrO2 transformed to the monoclinic structure, and protonic defects were induced. The expected proton conduction was confirmed by the polarity of the water vapor concentration cells.
Chemisorption of Yttrium Nitrate on AlN Particles
Authors: Mukhopadhyay Ranta , Maiti Himadri S. , Biswas Sampad K.
Published: July 2008

Homogenization of Y2O3 as a sintering additive in AlN green compact has been achieved by chemisorption of Y(NO3)3 on AlN particles in isopropanol suspension. Substantial adsorption of Y(NO3)3 equivalent to a Y2O3 content up to a maximum of 1.4 wt% of AlN has been observed. Electrokinetic mobility measurements of the coated particles and the adsorption studies show that the adsorption takes place in isopropanol suspension. SEM shows a good homogeneous distribution of Y2O3 in the green ceramic compacts, and no trace of secondary crystallization has been observed.
Diagnostic compatibility of structural and haemodynamic parameters in open‐angle glaucoma patients
Authors: Janulevičienė Ingrida , Sliesoraitytė Ieva , Siesky Brent , Harris Alon
Published: July 2008

Purpose:  Current evidence indicates that alteration in ocular blood flow may be relevant in open‐angle glaucoma (OAG) patients independent of intraocular pressure (IOP). Presently, the lack of an adequate methodology capable of assessing all vascular beds limits the clinical role of blood flow parameters in glaucoma management. We aimed to compare differences in retinal nerve fibre layer (RNFL) thickness and retrobulbar haemodynamics between OAG patients and healthy age‐matched control subjects.

Methods:  Sixty eyes of 30 OAG patients and 30 healthy age‐matched controls were enrolled into the prospective, randomized study. Retinal nerve fibre layer thickness was analysed by scanning laser polarimetry (SLP). Standard SLP parameters were determined, including: average temporal, superior, nasal, inferior thickness (TSNIT); superior and inferior averages; TSNIT standard deviation (TSNIT‐SD), and nerve fibre indicator (NFI). Retrobulbar haemodynamics were assessed using colour Doppler imaging (CDI). Peak systolic velocity (PSV), end‐diastolic velocity (EDV), pulsatility index (PI) and resistivity index (RI) in the ophthalmic artery (OA), central retinal artery (CRA) and short posterior ciliary artery (SPCA) were evaluated.

Results:  The RNFL in OAG patients was statistically significantly thinner compared with that in age‐matched controls: the NFI was 24.9 ± 10.24 in OAG patients and 16.13 ± 7.95  in healthy controls (p < 0.05). Statistically significant differences were observed: CRA PSV was 20.54 ± 7.84 cm/second in OAG subjects and 16.5 ± 6.19 cm/second in healthy controls (p = 0.0038); OA EDV was 8.99 ± 4.71 cm/second in OAG subjects and 5.93 ± 3.23 cm/second in healthy controls (p = 0.0048). Correlation analysis of NFI was in positive association with CRA EDV (r = 0.395; p < 0.05) and CRA PI (r = 0.403; p < 0.05) in OAG subjects, but no statistically significant association was seen in healthy controls.

Conclusions:  Statistically significant thinning of the RNFL in association with reduced retrobulbar blood flow velocities was observed in OAG patients. Combining ocular structural alterations with ocular circulation assessment may increase our ability to elucidate potential IOP‐independent glaucomatous risk factors.
Single vs. Multiple Discount Rates: How to Limit “Influence Costs” in the Capital Allocation Process*
Authors: Martin John , Titman Sheridan
Published: July 2008

Most finance textbooks suggest that companies evaluate investment projects using discount rates that reflect both the debt capacity and the unique risks of the project. In practice, however, companies often use their company‐wide WACC to evaluate such investments because of the difficulty of (and subjectivity involved in) estimating the risk of individual projects, and the potential for managerial bias and influence to distort the estimates.

This article proposes a practicable method for calculating the cost of capital that produces different discount rates for investment projects with different risks while minimizing the “influence costs” that arise when managers have discretion in the choice of discount rates. The proposed approach makes use of market information (in the form of the firm‐wide costs of debt and equity), thereby limiting managerial discretion, while typically still providing a good approximation of theoretically correct, project‐specific discount rates. The key to the method's effectiveness is its use of a project's debt capacity to define the capital structure weights, where debt capacity is defined by the amount of debt financing the project will support without lowering the firm's credit rating.
Transfer Pricing for Corporate Treasury in the Multinational Enterprise
Authors: Curtis Stephen L.
Published: July 2008

Intercompany financing transactions are becoming increasingly important to multinational enterprises (MNEs) as they expand internationally. Corporate treasurers of MNEs have many responsibilities, including the management of international capital structure and cost of capital, the financing of cross‐border acquisitions, foreign direct investment, international capital budgeting and cash management, management of foreign exchange and transactional risk, and port‐folio and investment management.

This article focuses on a corporate function, transfer pricing, that is potentially relevant to each of these activities. Whenever a payment crosses borders in a treasury context—whether to provide a loan, purchase a receivable, provide a guarantee, sweep cash, factor a receivable, provide a hedge or insurance product—a transfer pricing issue is present. Transfer pricing is often viewed as a taxation issue and thus the responsibility of the corporate tax department. This article challenges that view, and makes the case that an integrated, multi‐functional approach to MNE treasury planning in the context of transfer pricing can be an important component in improving the efficiency of cross‐border financial management. The paper uses conceptual and empirical information as well as numerical examples to illustrate relevant tax and transfer pricing concepts for policy planners and others responsible for MNE treasury and tax planning.
Analytic and Experimental Investigation of Dihedral Configurations of Three-Winglet Planforms
Authors: Miklosovic David S.
Published: July 2008

An analytic and experimental effort was undertaken to assess the effectiveness and efficiency of three winglets mounted chordwise to the tip of a rectangular wing. The winglets, with an aspect ratio of 4.6, were mounted on a half-span wing having an effective aspect ratio of 6.29. 13 configurations of varying dihedral arrangements were analyzed with a vortex lattice method and tested in a low-speed wind tunnel at a Reynolds number of 600,000. While the analytic method provided fair agreement with the experimental results, the predicted trends in lift, drag, and (to a lesser degree) pitching moment were in good agreement. The analytic distributions of wake velocity, circulation, and downwash angle verified that highly nonplanar configurations tended to reduce and diffuse the regions of highest circulation and to create more moderate downwash angles in the wake. This was manifest as an overall drag reduction. More specifically, the results showed that the winglets could be placed in various optimum orientations to increase the lift coefficient as much as 65% at the same angle of attack, decrease the drag coefficient as much as 54% at the same lift coefficient, or improve the maximum L∕D by up to 57%. The most dramatic findings from this study show that positioning the winglet dihedral angles had the result of adjusting the magnitude and slope of the pitching moment coefficient. These observations suggest that multiple winglet dihedral variations may be feasible for use as actively controlled surfaces to improve the performance of aircraft at various flight conditions and to “tune” the longitudinal stability characteristics of the configuration.
The Analysis on Causes of Rupture of a HP-Nb High Temperature Alloy Radiant Furnace Tube
Authors: Lu Shuanlu , Zhang Pinsheng , Qin Changyi , Wang Xinhu , Luo Faqian , Zhou Jie
Published: July 2008

An explosion accident occurred in a HP-Nb high temperature alloy radiant furnace tube. Twenty one lengths of furnace tubes were broken and cracked during this explosion. This paper investigates the explosion accident. The broken furnace tubes were investigated by fractographic observation and metallographic inspection and with mechanical performance test and analysis to determine the cause of the explosion. The results of the analysis indicated that the failure of the furnace tube was caused by high temperature creep. In order to determine the temperature of the furnace tube failure, some heat simulation tests from 900°C to 1200°C were carried out, the results of which confirmed that the failure of the furnace tube was primarily due to creep fracture because of the high temperature.
Fluid Forces on a Moving Body at Low Amplitude in Fluid at Rest: Part 2 — Analytical and Numerical Study for an Accelerated Circular Cylinder
Authors: Melot Vincent , Sigrist Jean Franc¸ois , Laine Christian , Auvity Bruno , Peerhossaini Hassan
Published: July 2008

The present paper deals with the study of fluid forces in an incompressible viscous fluid at rest around an accelerated rigid circular cylinder. The movement subjected to the cylinder is an impulsive motion represented by a only one period of a sinusoidal acceleration. After this period, the cylinder is stopped. This study is performed for small displacement of the cylinder, i.e. for low KEULEGAN-CARPENTER numbers, and for various STOKES numbers. An analytical formulation of fluid forces exerted on a cylinder subjected to any motion is first proposed. The starting point of the analytical approach is the solution of fluid forces in steady state harmonic motion. A Fourier transform is applied on the harmonic solution to capture the wide frequency spectrum composing the transient motion. Then an inverse Fourier transform is applied on the expression to achieve the solution in the temporal space. A numerical simulation is then carried out with a CFD code using finite volume method with moving mesh technique in ALE formulation. The analytical and numerical solutions are exposed and discussed in the case of a cylinder subjected to a sine wave acceleration. The competition between the viscous diffusion time and the wave duration time is studied and highlights the history effect on pressure forces and shear forces.
Ageing of UNS6625 Grade 2 Alloy and Its Welds for Steam Generator Applications
Authors: Cortial Franc¸ois
Published: July 2008

No data were existing concerning the fracture toughness and crack propagation properties of UNS6625 grade 2 alloy or 625 weld metal after long thermal exposures at 520°C. To have a realistic idea of the worst, ageing was performed on base metal and Gas Tungsten Arc (GTA) weld metal up to 10 000 h at 520°C and 700°C. Structures and fracture features examinations, Charpy tests, fracture toughness (20, 520, 700°C) and fatigue crack growth tests (520°C) were performed. The drastic drop of ECVN after ageing at 520°C corresponds to a K1J fall in the same order for the base metal and the joint (≤ 100 MPa m) in relationship with the development level of the γ″ Ni3Nb phase with a ductile rupture feature. In comparison, the fracture toughness curves at room temperature of the 700°C ageings show an asymptotic trend beyond 6000 h, with K1J ≥ 130 MPa m after 10 000 h and a brittle/ductile rupture feature (δ Ni3Nb phase +carbides). The J/Δ a curves at 520°C of the 520°C aged states reveal a saturation effect. Finally, in spite of the metallurgical changes that take place, the behaviour after prolonged use of UNS6625 base metal and its welds at 520°C of pressure shell materials is satisfactory regarding an in service risk of brittle rupture.
Study on Type-IV Damage Prevention in High-Temperature Welded Structures of Next-Generation Reactor Plants: Part I — Fatigue and Creep-Fatigue Behavior of Welded Joints of Modified 9Cr-1Mo Steel
Authors: Takahashi Yukio
Published: July 2008

High-chromium ferritic steels, such as modified 9Cr-1Mo steel, are regarded as candidate structural materials for new generation nuclear power plants and reliable design methods need to be developed. Of particular importance is prevention of premature failure, commonly referred to as type-IV failure, in softened regions of the heat-affected zones as several incidents of type IV failures of high-chromium steels in the fossil power plants have been reported. As part of the work aimed at developing design method for high-chromium steels applicable to new generation reactor plants, strain-controlled fatigue and creep-fatigue tests were conducted for welded joints of modified 9Cr-1Mo steel plate mainly at 550°C and 600°C. Failure typically occurred in the base metal in the pure fatigue tests but type-IV failure in the heat-affected zone occurred in most of the creep-fatigue tests where a large life reduction due to strain hold was observed. Life prediction method of the welded joint under creep-fatigue loading condition was studied based on these results.
SMILE Project — The Effect of Warm Pre-Stress in RPV Assessment: Synthesis of Experimental Results and Analyses
Authors: Moinereau Dominique , Dahl Anna , Chapuliot Ste´phane , Lidbury David
Published: July 2008

Within framework of 5th EC European SMILE project, some R&D actions have been conducted to demonstrate, to model and to validate the beneficial warm pre-stress (WPS) effect regarding the risk of brittle failure in a RPV assessment. An important experimental work has been conducted including classical WPS type experiments on CT specimens on usual RPV steels, and one PTS type transient on a large cracked cylinder. All experimental results confirm the beneficial effect of warm pre-stress, with a significant increase of the materials resistance regarding the risk of brittle failure. The experiments have been analyzed using fracture mechanics, including both engineering methods (Chell, Haigh, Wallin) and more refined analyses based on local approach to fracture (‘modified Beremin’ model). Following a short description of WPS concept, the paper summarizes the main experimental results and presents a synthesis of mechanical analyses involving engineering approaches and numerical analyses.
Effects of V and Carbides on the Temper Embrittlement of the 2.25Cr-1Mo Steel
Authors: Kim Jeong Tae , Kim Byung Hoon , Kong Byeong Ook , Kim Dong Jin
Published: July 2008

The characteristics of temper embrittlement and carbides precipitated in 2.25Cr-1Mo and 2.25Cr-1Mo-V steels which were aged up to 50,000h at 454∼515°C were investigated. The temper embrittlement susceptibility was evaluated as the shift of 54 Joule transition temperature (vTr54) and 50% fracture appearance transition temperature (FATT50) by the Charpy v-notch impact tests. The shift of vTr54 and FATT50 in the 2.25Cr-1Mo steel rapidly increased with the aging time up to 10,000h and then slowly saturated. Peak ΔvTr54 and ΔFATT50 in the 2.25Cr-1Mo-V steel were obtained up to 30,000h aging at 454°C. The distribution of phosphorus in the 2.25Cr-1Mo-V steel and 2.25Cr-1Mo steel after aging treatment was different. Phosphorus in the conventional 2.25Cr-1Mo steel was mainly observed at the prior austenite grain boundary, however, phosphorus in the 2.25Cr-1Mo-V steel was observed at the prior austenite grain boundary and the interfaces between carbide and matrix. The type and composition of carbides were changed to the stable Mo-rich ones, the carbide of M6C type was manifestly precipitated in both steels, and the new type of M4C3 carbides in the 2.25Cr-1Mo-V steel were finely distributed within grain and the atomic ratio of M4C3 was changed from (Fe0.08Cr0.21Mo2.61V1.10)C3 in the PWHT state to (Fe0.22Cr0.20Mo2.78V0.80)C3 with aging.
Development of a Computer Simulation Model for Blowing Glass Containers
Authors: Giannopapa C. G.
Published: July 2008

In glass container manufacturing (e.g. production of glass bottles and jars) an important process step is the blowing of the final product. This process is fast and is characterized by large deformations and the interaction of a hot glass fluid that gets into contact with a colder metal, the mould. The objective of this paper is to create a robust finite element model to be used for industrial purposes that accurately captures the blowing step of glass containers. The model should be able to correctly represent the flow of glass and the energy exchange during the process. For tracking the geometry of the deforming inner and outer interface of glass, level set technique is applied on structured and unstructured fixed mesh. At each time step the coupled problem of flow and energy exchange is solved by the model. Here the flow problem is only solved for the domain enclosed by the mould, whereas in the energy calculations, the mould domain is also taken into account in the computations. For all the calculations the material parameters (like viscosity) are based on the glass position, i.e. the position of the level sets. The velocity distribution, as found from this solution procedure, is then used to update the two level sets by means of solving a convection equation. A re-initialization algorithm is applied after each time step in order to let the level sets re-attain the property of being a signed distance function. The model is validated by several examples focusing on both the overall behavior (such as conservation of mass and energy) and the local behavior of the flow (such as glass-mould contact) and temperature distributions for different mesh size, time step, level set settings and material parameters.
Numerical Modelling of a Hand in Water
Authors: Wakes Sarah J. , Brown Chris
Published: July 2008

The pressures of modern competition swimming has increased the desire for the use of technology and science in the pursuit of a speed advantage. This has lead to revolutionary new suits and other equipment such as goggles and for training. Attention to technique and minimising drag have had a less prominent profile but are beginning to become more important. Part of the lack of advancement has been that a swimming stroke is very complex action and determining precise angles and orientations is necessary before drag and lift calculations can be undertaken. Work has been done that has established that the hand could be treated as an aerofoil. Work was undertaken to numerically model a mechanical hand that was being used to undertake both static and dynamic experimental testing within a flume. This paper is concerned with the initial modelling phase and static testing. It will look at comparisons of data at different incident angles and different flow velocities to establish the validity of progressing this work. Issues with the generic nature of the model will also be addressed.
Determination of Thermal-Hydraulic Loads on Reactor Internals in a DBA-Situation
Authors: Lestinen Ville , Toppila Timo , Timperi Antti , Pa¨ttikangas Timo , Ha¨nninen Markku
Published: July 2008

According to Finnish regulatory requirements, reactor internals have to stay intact in design basis accident (DBA) situations, so that control rods can always penetrate into the core. This is the basic motivation to study and develop more detailed methods for analyses of thermal-hydraulic loads on reactor internals during the DBA situation in the Loviisa Nuclear Power Plant (NPP) in Finland. In this work, the studied accident situation is Large Break Loss of Coolant Accident (LBLOCA). The objective of this work is to connect thermal-hydraulic and mechanical analysis methods with the goal to produce a reliable method for determination of thermal-hydraulic and mechanical loads on reactor internals in the accident situation. In the present model, the downcomer of a PWR is only included and the reactor internals will be added later. The tools studied are thermal-hydraulic system codes, computational fluid dynamics (CFD) codes and finite element analysis (FEA) codes. Both thermal-hydraulic and mechanical aspects are discussed in this paper. Firstly, the pressure boundary condition in the pipe break point was calculated with the system code. In the second step, CFD analyses were made. Finally, the full fluid-structure interaction coupling between the CFD and FEA codes was used. The codes used for development and simulations are APROS system code for boundary condition calculations, STAR-CD and FLUENT for CFD calculations and ABAQUS for FEA calculations.
Hot Explosive Compaction of Hard Powders Using Cylindrical Configuration
Authors: Taira Kazuya , Hokamoto Kazuyuki , Itoh Shigeru , Mori Akihisa , Pruemmer Rolf A.
Published: July 2008

We tried hot explosive compaction to make bulk materials of hard-to-consolidate powders using cylindrical configuration. By heating above 1000°C, it is possible to give the ability of plastic deformation for hard ceramic powders and also possible to enhance the surface melting to bond each particle. Using the cylindrical configuration, hot explosive compaction experiment was carried out for consolidation of TiB2 powders at elevated temperature. A central hole and a melting spot at the end of the tube were observed for a sample recovered. High compaction density and high hardness (above 3000 VHN highest) were measured for the samples recovered. The central hole and the melting spot are considered to be generated by the formation of mach stem at the center and the high-velocity collision towards the end plug. Numerical simulation was carried out using AUTODYN-2D code and compared with the experimental results for the TiB2 compacts.