bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Influence of Material Variables on Corrosion and Deuterium Uptake of Zr-2.5Nb Alloy During Irradiation
Authors: McDougall GM , Urbanic VF 
Published: September 2009

Current CANDU2 reactors use Zr-2.5Nb pressure tubes that are extruded at 1088 K, cold-drawn 27%, and autoclaved at 673 K for 24 h. This results in a metastable, two-phase microstructure consisting of elongated α-Zr grains surrounded by a network of β-Zr filaments. To develop a mathematical model of corrosion and deuterium ingress in pressure tubes, we have considered the impact of variables including: fast neutron flux, temperature, and the asfabricated microstructure and its evolution during irradiation.
Small specimens of Zr-2.5Nb are being exposed under CANDU water chemistry conditions in the Halden Boiling Water Reactor.3 The experiments involve fast neutron fluxes (E ≥ 1.05 MeV) of 0, 1.7, and 4.5 × 1017 n ∙ m-2 ∙ s-1, and temperatures of 523 and 598 K. Specimens have been prepared from pressure tube materials representative of all current CANDU reactors, materials subject to thermal decomposition of the β-Zr phase, and tubes extruded over a range of conditions.
Results from the first three years of the Halden test program are summarized. At both 523 and 598 K, tubes made of β-quenched material exhibit lower oxidation rates than those made from non-β-quenched materials. In short-term out-of-flux exposures at 523 K, three non-β quenched tubes appear to show linear oxidation kinetics. Similar behavior is not observed in tests conducted out-of-flux at 598 K, or in-flux at either temperature. At 598 K, β-quenched tubes exhibit significantly lower deuterium pickup rates than non-β-quenched tubes. When tested at 598 K, thermally aged specimens show declining oxidation and deuterium pickup rates with increasing β-Zr phase decomposition. At 523 K, the impact of thermal aging was less significant. Preliminary results from an “extrusion variable test” suggest that tubes fabricated according to the current CANDU specification show the best corrosion resistance.
Experimental Study and Preliminary Thermodynamic Calculations of the Pseudo-Ternary Zr-Nb-Fe-(O,Sn) System
Authors: Toffolon C , Brachet J-C , Servant C , Legras L , Charquet D , Barberis P , Mardon JP 
Published: September 2009

Zirconium-niobium alloys, and especially the Framatome Zr-1%Nb-0 (M5™) alloy [1], are now considered to be the reference materials for application to the cladding tubes and structural components of PWR fuel assembly. Low contents of iron are present as impurity or intentionally introduced in such alloys, and, consequently, the precipitation of Zr-Nb-Fe intermetallic phases occur due to the very low solubility of iron in the α-Zr matrix (less than ∼100 ppm). Taking into account that these intermetallic precipitates may influence some of the alloy properties (corrosion resistance, irradiation growth …) and that the crystallographic structure, the chemical stoichiometry, and the temperature of precipitation/dissolution of these phases are not well established, it appeared necessary to get a better insight of the Zr-Nb-Fe-(O) phase diagram. For that reason, both thermodynamic calculations and associated experimental works were performed.
Different alloys with a niobium content ranging from 0.5 to 2 wt% and a Fe content from 0.03 to 0.75 wt% are considered. Two ternary intermetallic phases are present in these alloys: one has a hexagonal crystallographic structure (hc: a ∼ 0.54 nm, c ∼ 0.86 nm) and the other one has a face-centered cubic structure (fcc: a ∼ 1.21 nm). The chemical stoichiometry of both phases is determined by energy and wave dispersive spectrometries (EDS and WDS). The phase existence temperature range is determined by transmission electron microscopy (TEM) performed after heat treatments at different temperatures, by calorimetry, and by specific neutron diffraction experiments under heating/cooling. The results obtained using these experimental techniques show a good agreement. Moreover, the crystallographic space groups of the two intermetallic phases are determined using electron, X-ray, and neutron diffraction facilities in order to obtain a thermodynamic description of the Zr-Nb-Fe system. To assess the results obtained on dilute alloys (Zr &gt; 97%), two Nb and Fe-enriched alloys were fabricated by CEZUS, with an intermetallic volume fraction higher than 80%.
Finally, a first thermodynamic calculation of the Zr-Nb-Fe(O) system is proposed, using all the experimental data obtained. Calculated and experimental data are then compared at different temperatures.
Predicting the In-Reactor Mechanical Behavior of Zr-2.5Nb Pressure Tubes from Postirradiation Microstructural Examination Data
Authors: Griffiths M , Davies PH , Davies WG , Sagat S 
Published: September 2009

Postirradiation microstructure examinations of Zr-2.5Nb pressure tubes removed from service in CANDU™ reactors have shown clear trends in the dislocation structure and the state of the β-phase, as a function of operating temperature, neutron flux, and time. These microstructural parameters correlate well with changes in the mechanical properties. For example, the rapid increase in dislocation loop density in the early stages of irradiation corresponds with a rapid increase in tensile strength and DHC velocity, and a corresponding decrease in fracture toughness. There is also a strong negative correlation between the degree of β-phase decomposition and DHC velocity. In addition to the effects of microstructure evolution on the mechanical properties, changes in the a-type and c-component dislocation loop densities also affect irradiation deformation (creep and growth).Statistical analyses of the irradiation microstructure data have been used to derive empirical relationships between dislocation densities and β-phase structure with temperature, flux, and time. The relationships thus derived are useful in predicting where the mechanical properties are most affected by the in-reactor operating conditions. The predictions are compared with mechanical test data for samples from various axial and circumferential locations of 42 pressure tubes removed from operating CANDU reactors. The results are discussed in terms of the mechanisms controlling tensile strength, fracture, delayed-hydride-cracking, and in-reactor deformation.
Impact of Irradiation Defects Annealing on Long-Term Thermal Creep of Irradiated ircaloy-4 Cladding Tube
Authors: Cappelaere C , Limon R , Gilbon D , Bredel T , Rabouille O , Bouffioux P , Mardon JP 
Published: September 2009

Functions that can be allocated to cladding during interim storage depend on the evolution of cladding properties with time. The fuel rod cladding is strained by the end of-life internal fuel rod pressure (40–60 bars NTP) and the potential release of fission gases and helium during dry storage. Within the temperature range that is expected during dry interim storage, long-term creep under over-pressure of the cladding might probably be a relevant strain mechanism, which could lead to breaching.Creep experiments were carried out on 4 cycles irradiated Cold Worked Stress Relieved (CWSR) Zircaloy-4 cladding under internal pressure within the temperature range of 470–520°C for up to 10 days, in order to estimate the eventual effect of a transient period at higher temperature on creep behavior during storage. Therefore, some of the tests consist of two periods: the first period at high temperature (470°C), followed by a second period at a lower temperature (320–400°C). A metallurgical characterization (TEM, optical microscopy) was carried out after the tests.A significant impact of the stress level is observed at the temperature of 470°C on creep strain. Tertiary creep is reached after a few days for 100 or 120 MPa. The effect of a first period at 470°C on the next creep behavior at 400°C for 150 MPa is confirmed. The probable induced annealing of irradiation defects contributes to increase the secondary creep rate at 400°C. Moreover, the creep kinetics of the tests conducted to rupture show in all the cases a ductile rupture with ballooning instability, which might be partially the result of an annealing of irradiation defects.The microscopic characterization confirms the hypothesis of a partial annealing of the irradiation defects after a period of 10 days at 470°C, which leads to a microstructure intermediate between irradiated and as-received CWSR condition, while a temperature of 520°C leads to a microstructure that looks like recrystallized Zircaloy-4 condition.After the creep test, hydrides morphology, distribution, and orientation appear rather different from usual post-irradiation hydrides characteristics. The hydrides are distributed uniformly throughout the thickness of the tube. A cooling under mechanical loading influences the hydrides precipitation, particularly by leading to a radial “reorientation.” A stress level of 80 MPa during cooling is sufficient to lead to radial hydrides formation as hydrogen precipites in the cladding.
Influence of Water Composition on Corrosion in High-Temperature, High-Purity Water
Authors: Wroughton Donald M. , Seamon James M. , Brown Paul E. 
Published: September 2009

Corrosion tests have indicated that, except for pH, water composition within the range of variables studied has a minor influence on corrosion rates of carbon steel under conditions which may exist in the primary coolant of water-cooled and moderated reactors. Water conditions, however, cannot be considered unimportant, because (a) the range of variables studied has been limited by considerations of induced radioactivity and radiation stability of possible corrosion inhibitors, (b) special considerations associated with the primary coolant technology of reactor systems make water conditions important, and (c) the influence of water condition on the characteristics of the corrosion products formed may be of considerable concern.
Some inhibitors were effective in reducing corrosion rates in autoclave tests but unsuitable for reactor operation. The possibility is discussed of using inhibitors during precritical operation of a new system to minimize the high corrosion rates normally experienced with new surfaces.
The relationship existing between water condition and corrosion product behavior in the primary system of a water-cooled reactor is noted. Possible undesirable results of the adverse behavior of system corrosion products are: (1) fouling of the reactor core or other heat transfer surfaces by deposition, (2) fouling or wear of valves or mechanisms which operate in the primary system water, and (3) rapid pressure drop build-up on some types of filters used to remove the corrosion products.
Current water technology studies have as their objective the operation of the primary systems of water-cooled and moderated reactors with the minimum control of water composition compatible with trouble-free operation. The establishment of minimum water-quality control requires knowledge concerning variations in water composition that may occur in reactor operation and how these variations affect plant integrity.
Therapeutic analysis in Chinese patients with thyrotoxic periodic paralysis over 6 years
Authors: Shiang Jeng-Chuan , Cheng Chih-Jen , Tsai Ming-Kai , Hung Yi-Jen , Hsu Yu-Juei , Yang Sung-Sen , Chu Shi-Jye , Lin Shih-Hua 
Published: September 2009

ObjectiveTo characterize the course of therapy in a large cohort of Chinese patients with thyrotoxic periodic paralysis (TPP), a reversible electrolyte emergency fraught with therapeutic challenges.Design and methodsIn this prospective interventional study, 78 patients with TPP (75 males and three females with an age range of 16–48 years) were consecutively enrolled over a 6-year period. Intravenous KCl at a rate of 10 mmol/h was administered until muscle strength recovered. Serum potassium (K+) and phosphorus concentrations were measured hourly during the paralytic attack and for 6 h after recovery.ResultsThe serum potassium (K+) on attack was 2.1±0.2 mmol/l. The dose of KCl administered to restore muscle strength was 63±32 mmol, and peak serum K+ concentration after recovery was 5.3±0.5 mmol/l. A paradoxical fall in serum K+ concentration >0.1 mmol/l difference between presentation and treatment nadir was observed in approximately one-fourth of TPP patients (n=20). These patients had significantly higher serum-free thyroxine concentration, systolic blood pressure, and heart rate on presentation, as well as serum phosphate concentration on recovery. They not only needed much more KCl supplementation (104±34 vs 48±19 mmol, P<0.001), but also had significantly more severe rebound hyperkalemia (5.8±0.5 vs 5.1±0.4 mmol/l, P<0.001) on recovery than those who did not have paradoxical hypokalemia. There was a positive correlation between the dose of KCl administered and the difference between peak and nadir serum K+ (Δ K+) (r=0.68, P<0.001).ConclusionsTPP patients who do not develop paradoxical hypokalemia need a smaller KCl dose to achieve recovery, whereas those who develop paradoxical hypokalemia have more severe hyperthyroidism and hyperadrenergic activity and may require blockage of intracellular K+ shift to prevent rebound hyperkalemia.
Paramadina and its Approach to Culture and Communication : an Engagement in Civil Society
Authors: Faisal Bakti Andi 
Published: September 2009

Andi Faisal Bakti
Les questions relatives à la «société civile» ont été largement débattues en Indonésie durant ces dix dernières années. Les experts musulmans utilisent deux termes différents pour exprimer ce concept : masyarakat sipil et masyarakat madani, le premier étant surtout populaire dans les cercles proches du Nahdlatul Ulama, réputé « traditionnaliste » ; le deuxième parmi les musulmans qui se veulent «modernistes» et «néo-modernistes», ces divers qualificatifs ne manquant pas d'ambiguïté. L'auteur examine le rôle de la fondation Paramadina, créée par Nurcholis Madjid, au sein des efforts consentis de part et d'autre pour l'établissement d'une «société civile», ainsi que les atouts personnels, idéologiques et stratégiques de la fondation pour atteindre ses objectifs.
La pierre et le foyer [Note sur les vers 453 à 506 de la Théogonie hésiodique]
Authors: Mezzadri Bernard 
Published: September 2009

La pierre et le foyer (pp. 215-220)
Une même conception du centre et une même structure logique informent l'épisode hésiodique de la naissance des enfants de Cronos et la célèbre légende étiologique de l'omphalos. Mais l'un articule temporellemént ce que l'autre exprime spatialement: Zeus dernier et premier, Hestia première et dernière, conjoignent des opposés comme les deux aigles relient des extrêmes. La double position d'Hestia -au début et à la fin- correspond en outre à des faits indo-européens.
La prophétie de Tirésias
Authors: Ballabriga Alain 
Published: September 2009

La prophétie de Tirésias (pp. 291-304)
Une analyse philologique de la prophétie de Tirésias ( Od. 1 1 , 126-37) peut établir assez facilement la faiblesse des principes aristarchéens qui en ont guidé la lecture jusqu'à nos jours: loin d'être "post-homériques" , les légendes de la Télégonie font l'objet d'une incontestable allusion dans l'Odyssée. Mais, à en juger par le résumé de Proclus, l'état final de la légende d'Ulysse dans la Télégonie se situe à son tour par rapport à l'Odyssée. D'une façon générale les relations entre poèmes épiques doivent se formuler en termes d'interactions opérant tout au long des 7e/6e siècles.
La menace du silence pour le héros de l'Iliade
Authors: Montiglio Silvia 
Published: September 2009

La menace du silence pour le héros de l'Iliade (pp. 161-186)
Cette étude cherche à cerner les connotations principales du silence dans la première épopée, à partir du texte lui-même aussi bien que des gloses anciennes. Dans le cadre du "combat de paroles" auquel se livrent les héros de l'lliade, le silence s'avère être surtout une marque de défaite, d'inertie, d'impuissance. Le code homérique de la parole, en effet, présuppose la circulation rapide d'un epos constamment échangé, si bien que toute suspension silencieuse apparaît comme la rupture non souhaitable d'un tissu sonore qui se veut compact et continu. Arrêt troublant, le silence est souvent entouré de voix puissantes et toujours surmonté par une voix nouvelle, qui semble conjurer la menace qu'il représente pour le héros aussi bien que pour l'aède.
L'hybride et le mixte
Authors: Fourgous Denise 
Published: September 2009

L'hybride et le mixte (pp. 231-246)
Quelles interprétations les auteurs anciens donnèrent-ils du qualificatif de διφυής appliqué à Cécrops, premier roi mythique d'Athènes ? Certains l'expliquèrent par son autochtonie, d'autres par son origine étrangère, d'autres encore par sa qualité d'inventeur, responsable de nombreuses et importantes découvertes pour la cité. Une thèse fort originale (Diodore de Sicile, I, 28) voit en cette double nature l'expression de la double "citoyenneté" de Cécrops, grecque et barbare. Ainsi l'hybride correspond-il exceptionnellement au mixte. On repose enfin la question du rapport entre nature hybride ou mixte et inventivité à travers l'examen rapide de quelques cas.
Cimetières et tombeaux des villages de la Syrie du Nord
Authors: Griesheimer Marc 
Published: September 2009

lages of North Syria (Massif calcaire: 2nd-6th centuries AD). It provides an archaeological survey from 1991 to 1993. The analysis of the funerary areas is conducted by a spacial approach. First, the context of the tombs, second
their organisation within the built or excavated monu-
ments, finally the localisation of the funerary monuments
around the villages.
Etude de la permanence des tracés urbains et ruraux antiques à Antioche-sur-l'Oronte
Authors: Leblanc J. , Poccardi Grégoire 
Published: September 2009

The systematic study of a set of ancient aerial vertical photographs of the Mandate Period belonging to the CNRS (UPR 7541) led us to establish the existence of four parcel divisions in the town of Antioch on the Orontes, its neighbourhood and the famous suburb of Daphne.
Two of them are organized according to the major directions of the reliefs. They have the same module (116 x 58 m). The third one occupies the ancient Orontes island (about 105 x 35 m). The last one is specific to Daphne.
At Antioch and Daphne, some ancient monuments have been integrated in these networks: particularly, a hippodrome and a temple in the island, maybe a theatre in Antioch, finally the Olympic stadium of Daphne, the location of which seems confirmed by its representation on a border of a late Roman mosaic called Megalopsychia found at Yakto (Daphne).
Pattern of Arterial Calcification in Patients with Systemic Lupus Erythematosus
Authors: YIU KAI-HANG , WANG SILUN , MOK MO-YIN , OOI GAIK CHENG , KHONG PEK-LAN , MAK KA-FUNG HENRY , LAM KWOK-FAI , LAU CHAK-SING , TSE HUNG-FAT 
Published: September 2009

Objective.To evaluate the prevalence and pattern of arterial calcification in patients with asymptomatic systemic lupus erythematosus (SLE) compared with control subjects. SLE patients are prone to adverse cardiovascular events; however, the underlying atherosclerotic process is unknown. Multidetector computed tomography (MDCT) measured arterial calcium score (CS) reflecting underlying atherosclerosis and is closely associated with cardiovascular events.Methods.Fifty age and sex matched SLE patients and controls were enrolled. All subjects underwent 64 slice MDCT scan to evaluate CS in coronary, carotid arteries and the aorta.Results.As compared with controls, SLE patients had higher mean CS and prevalence of CS > 0 across all vascular beds. After adjustment for age and sex, SLE patient odds of having CS > 0 in any vascular bed was 33.6 (95% CI: 9.5–165.2) were higher versus patients in the control group, mainly due to more prevalent coronary calcification (OR 30.0, 95% CI: 6.7–203.8). In SLE patients, the most frequent vessel with CS > 0 was coronary (42%) followed by carotid artery (24%). Further, arterial calcification occurred early involving 40% of SLE patients at age < 40 years, with increasing prevalence as age advanced.Conclusion.Our study confirms that patients with SLE have significantly higher prevalence and extent of systemic arterial calcification compared with age and sex matched controls.
InitiatortRNAsin Bacteria and Eukaryotes
Authors: Rasmussen Louise CV , Laursen Brian S , Mortensen Kim K , Sperling‐Petersen Hans U 
Published: September 2009

AbstractA special type of transferribonucleic acid(tRNA) is employed in the initiation step of protein synthesis. The differences between the tRNAs involved in initiation and elongation establish the specificity and recognition of the tRNAs by the factors and enzymes involved in the initiation and elongation steps of protein synthesis. The important determinants of the initiator tRNA in bacteria are the absence of a Watson–Crick base pair between positions 1 and 72 in the acceptor stem and the presence of three conserved consecutive G:C base pairs in the anticodon stem. Formylation of the methionine attached to this initiator tRNA is an important feature. Conversely, the eukaryotic initiator tRNA is mainly determined by the presence of a particular A1:U72 Watson–Crick base pair in the acceptor stem as well as the nature of the base pairs 50:64 and 51:63 in the TΨC (T) stem.Key conceptsInitiator tRNA brings methionine to the initiation complex for initiation of protein synthesis.Structural features of initiator tRNAs ensure that they are recognized by translation initiation factors and discriminated against by translation elongation factors.The important determinants of initiator tRNA in bacteria are the absence of a Watson–Crick base pair between positions 1 and 72 in the acceptor stem and the presence of three conserved consecutive G:C base pairs in the anticodon stem.The important determinants of initiator tRNA in eukaryotes are the presence of a particular A1:U72 Watson–Crick base pair in the acceptor stem as well as the nature of the base pairs 50:64 and 51:63 in the T stem.Bacterial initiator tRNA is aminoacylated by methionyl tRNA synthetase, which mainly interacts with the anticodon.The methionine of bacterial initiator tRNA is formylated by methionyl tRNA transformylase, which mainly recognizes the absence of the 1:72 base pair.Initiation factor IF2 ensures recognition and correct binding of bacterial initiator tRNA to the ribosomal P‐site by interacting primarily with the formyl group and the 3′ end of the acceptor arm.Initiation factor IF3 performs proofreading of the 30S initiation complex by verifying base pairing between 5′C of bacterial initiator tRNA anticodon and 3′G of mRNA initiation codon.Bacterial initiator tRNA undergoes several conformational changes during translation initiation to ensure correct positioning in the P‐site of the ribosome.Bacterial initiator tRNA is not a substrate for peptidyl tRNA hydrolase.