The crystal structure of Al20.6Ta22.4 and its relation to Frank–Kasper phases

The monoclinic phase in the Al–Ta system has been identified by means of X-ray single-crystal structure analysis as Al_{19+ x} Ta_{24? x} (x?=?1.6), Pearson symbol mP86. Al_20.58Ta_22.42 crystallizes in the space group P2₁/n, with a?=?987.86?pm, b?=?990.12?pm, c?=?1489.45?pm and β?=?99.958°. Twinned crystals of the title compound can be obtained by iodine-promoted reactions of the elements. In the experiments described here, the reactions took place in sealed tantalum ampoules at 1400°C. Single-phase samples were obtained by a metallurgical powder method, which minimizes aluminium loss by incongruent vapourization. The composition was found to span the range 0.51?≤?x _Ta?≤?0.53. Al_{19+ x} Ta_{24? x} decomposes in the solid state at 1450°C into Al₆₉Ta₃₉ and σ-AlTa₂. The crystal structure is analyzed in relation to tetrahedral close-packed structures. The kinship with Cr₃Si-type and H-type structures is accentuated.     

Microstructure and martensitic transformation behaviors of a Ti–Ni–Hf–Cu high-temperature shape memory alloy ribbon

The Ti₃₆Ni₄₁Hf₁₅Cu₈ melt-spun ribbon undergoes a B2 ? B19′ transformation upon cooling and heating. When the Ti₃₆Ni₄₁Hf₁₅Cu₈ melt-spun ribbon is annealed at 873 K for 1 h, the spherical (Ti, Hf)₂Ni particles with a diameter of 20–40 nm precipitate in the grain interior. The fine (Ti, Hf)₂Ni precipitates improve the stability of phase transformation temperatures and cause martensite domains, with (001) compound twins in three orientations dominant instead of (011) type I twins. {111}-, {113}- and (001)//{111}-type boundaries are observed among these martensite domains. When the (Ti,Hf)₂Ni precipitates coarsen, (011) type I twins become main martensite structures in the ribbon annealed at 973 K for 1 h.     

Strain rate response of a Ni–Ti shape memory alloy after hydrogen charging

In this work, we investigate the susceptibility of Ni–Ti superelastic wires to the strain rates during tensile testing after hydrogen charging. Cathodic hydrogen charging is performed at a current density of 10?A/m² during 2–12?h in 0.9% NaCl solution and aged for 24?h at room temperature. Specimens underwent one cycle of loading-unloading reaching a stress value of 700 MPa. During loading, strain rates from 10^?6 to 5?×?10^?2?^?s^?1 have been achieved. After 8?h of hydrogen charging, an embrittlement has been detected in the tensile strain rate range of 10^?6 to 10^?4?s^?1. In contrast, no embrittlement has been detected for strain rates of 10^?3?s^?1 and higher. However, after 12?h of hydrogen charging and 24?h of annealing at room temperature, the embrittlement occurs in the beginning of the austenite-martensite transformation for all the studied strain rate values. These results show that for a range of critical amounts of diffused hydrogen, the embrittlement of the Ni–Ti superelastic alloy strongly depends on the strain rate during the tensile test. Moreover, it has been shown that this embrittlement occurs for low values of strain rates rather than the higher ones. This behaviour is attributed to the interaction between the diffused hydrogen and growth of the martensitic domain.     

Peacebuilding in Indonesia: Christian–Muslim Alliances in Ambon Island

This article aims to examine two major issues: (1) religious roots of reconciliation and forgiveness, which are often unfortunately forgotten in the academic discussion of peacebuilding and peace policy-related issues, and (2) Christians' and Muslims' attempts to quell interreligious violence and prevent renewed outbreaks in the conflict zone of Ambon of the Moluccas (Maluku) in eastern Indonesia. More specifically, it discusses the role of Ambonese Christian and Muslim leaders in the process of interreligious peacemaking and reconciliation. A comparative study of conciliation within Islam and Christianity, the piece investigates factors underlying Christian–Muslim collaboration for establishing peaceful settlement in the region. Unlike most previous analyses and studies, which have tended to undermine the contribution of religion in the conflict settings of Ambon, the article shows that religious identities, discourses, and actors have contributed to and also enhanced the chances for peace and reconciliation. Why and how Ambonese Christian and Muslim leaders were willing to unite to fight against religious extremism and eagerly pursue pacification becomes the central question of this article.     

Theodor Bibliander's Machumetis saracenorum principis eiusque successorum vitae,doctrina ac ipse alcoran (1543) as the Sixteenth-century “Encyclopedia” of Islam

The Machumetis saracenorum principis (1543, second edition 1550), compiled by the Zurich theologian Theodor Bibliander, has long been recognized as one of the most significant texts on Islam published in the Latin West in the Early Modern era. The Qur'an translation it contained (the first ever to be printed) was not superseded for over 100 years. This article explores how the work functions as a whole text in the context of Bibliander's life and theology, with particular attention paid to its paratexts (that is, its framing devices) and organization. Bibliander's compilation is discovered to be a self-contradictory, problematic text. In the sixteenth century, new information on the Turks and their religion did not replace, but rather was placed simply alongside other materials, sometimes substantiating older materials, sometimes directly contradicting them. This ambiguity opened up space for new and different readings while supporting, simultaneously, the received tradition. All of this points to the important transitional nature of the sixteenth century in Christian–Islamic engagement.     

Étude des liens entre la fréquence de pratique sportive et la santé des étudiants : mesure des effets de genre sur les troubles alimentaires et les consommations de substances

A number of previous studies have focused on the effect of sport practice on eating disorders and substance use. Most of these studies suggest that among students sport practice is related to low levels of health issues like eating disorders and substance use. However, there is a relative dearth of evidence for these relationships and previous findings are based on comparisons between people involved in sport practice and physical activity and sedentary or largely inactive people. The present study aims to test the effects of frequency of sport practice on college students’ eating disorders and substance use when also controlling for gender effects.MethodsOne thousand and seventy-three first year college students (35.6% boys, 64.4% girls) volunteered to participate in the study. Participants were divided into three groups according to the frequency of their sport practice: students who rarely participated in sport practice (less than one hour a week and not every week; 406 students, 26.4% boys vs 73.6% girls), students who frequently participated in sport practice (every week but less than eight hours a week; 173 students, 33.5% boys vs 66.5% girls), and students who had intensive sport practice (eight hours a week or more; 494 students, 43.9% boys vs 56.1% girls). Alcohol, tobacco and cannabis use were assessed using the Alcohol Smoking and Substance Involvement Screening Test (ASSIST). Three different categories of eating disorders (Dieting, Bulimia, Oral control) were assessed using the EAT-26 inventory. ANOVAs were computed to test for gender differences across the three sport practice groups.ResultsResults of univariate ANOVAs revealed main effects for gender and sport practice on some of the substance use and eating disorder variables, ANOVA with multiple comparisons (Tamhan T Test) revealed a significant interaction effect of sport practice and gender on oral control and tobacco use. For girls, oral control and tobacco use do not vary within the three groups of sport practice whereas for boys the more frequent the sport practice, the lower their scores on oral control and tobacco use. For oral control, boys reported significantly higher scores than girls only when sport practice was rare. For tobacco use, boys reported significantly higher scores than girls when sport practice was rare and lower scores when sport practice was intensive.ConclusionThese results suggest that the positive effects of sport practice vary by gender and that the campaigns for promotion of physical activity might assist in the prevention of health issues amongst students but should be adapted according to the gender of the participants.