Effect of 12C+^{12}C+ 12C^{12}C Reaction & Convective Mixing on the Progenitor Mass of ONe White Dwarfs

Stars in the mass range ~8 - 12 $M_{\odot }$ are the most numerous massive stars. This mass range is critical because it may lead to supernova (SN) explosion, so it is important for the production of heavy elements and the chemical evolution of the galaxy. We investigate the critical transition mass ($M_{up}$), which is the minimum initial stellar mass that attains the conditions for hydrostatic carbon burning. Stars of masses < $M_{up}$ evolve to the Asymptotic Giant Branch and then develop CO White Dwarfs, while stars of masses $\geqslant$ $M_{up}$ ignite carbon in a partially degenerate CO core and form electron degenerate ONe cores. These stars evolve to the Super AGB (SAGB) phase and either become progenitors of ONe White Dwarfs or eventually explode as electron-capture SN (EC-SN). We study the sensitivity of $M_{up}$ to the C-burning reaction rate and to the treatment of convective mixing. In particular, we show the effect of a recent determination of the $^{12}C+$ $^{12}C$ fusion rate, as well as the extension of the convective core during hydrogen and helium burning on $M_{up}$ in solar metallicity stars. We choose the 9$M_{\odot }$ model to show the detailed characteristics of the evolution with the new C-burning rate.Comment: Submitted to AIP Conference proceedings of Carpathian Summer School of Physics-201

Competitive intelligence and its effect on UK banking strategy

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Synthesis of C-rich dust in CO nova ourbursts

Context. Classical novae are thermonuclear explosions that take place in the envelopes of accreting white dwarfs in stellar binary systems. The material transferred onto the white dwarf piles up under degenerate conditions, driving a thermonuclear runaway. In those outbursts, about 10-7 - 10-3 Msun, enriched in CNO and, sometimes, other intermediate-mass elements (e.g., Ne, Na, Mg, or Al, for ONe novae) are ejected into the interstellar medium. The large concentrations of metals spectroscopically inferred in the nova ejecta reveal that the (solar-like) material transferred from the secondary mixes with the outermost layers of the underlying white dwarf. Aims. Most theoretical models of nova outbursts reported to date yield, on average, outflows characterized by O > C, from which only oxidized condensates (e.g, O-rich grains) would be expected, in principle. Methods. To specifically address whether CO novae can actually produce C-rich dust, six different hydrodynamic nova models have been evolved, from accretion to the expansion and ejection stages, with different choices for the composition of the substrate with which the solar-like accreted material mixes. Updated chemical profiles inside the H-exhausted core have been used, based on stellar evolution calculations for a progenitor of 8 Msun through H and He-burning phases. Results. We show that these profiles lead to C-rich ejecta after the nova outburst. This extends the possible contribution of novae to the inventory of presolar grains identified in meteorites, particularly in a number of carbonaceous phases (i.e., nanodiamonds, silicon carbides and graphites).Comment: 5 pages, accepted for publication in Astronomy & Astrophysic

The Paved Treasures in the Events of al-Shuf

Este artículo presenta a un sacerdote griego católico, historiador de Líbano, Hanania al-Munayyir (1756-1823) y su obra al-Durr al-Marsuf fi Hawadith al-Shuf. Al-Munayyir será analizado como cronógrafo seguidor de la secuencia anual de eventos, como un neocronógrafo que interpreta y ofrece su opinión, así como un historiador metódico cuyo enfoque analítico, versatilidad y comprensión de la historia de Líbano en su contexto local, regional e internacional refleja la historia del cristianismo de Bilad al-Sham escrita en el s. XVIII. Al-Munayyir fue capaz de liberarse de los límites de su comunidad religiosa y observar a Líbano como una entidad única, pero frágil, continuamente vulnerable por causa de las luchas internas y las interferencias externas en sus asuntos.This article introduces a Greek Catholic priest, a historian from Lebanon, Hanania al-Munayyir (1756-1823) and his book al-Durr al-Marsuf fi Hawadith al-Shuf (The paved Treasures in the Events of al-Shuf). Al-Munayyir will be discussed as a chronicler who followed the yearly sequence in relating the events, as a neo chronicler who interpreted and gave his opinion, and as an analytical historian whose thematic approach, versatility, and understanding of the history of Lebanon in its local, regional and international context reflect Christian historical writing in 18th century Bilad al-Sham. Al-Munayyir was able to rid himself of the confines of his religious community and to view Lebanon as a unique, but fragile entity continuously vulnerable to internal strife and external interference in its affairs

carried away : Love, bly, and secrecy in Henry James\u27 The Turn of the Screw

The function of the prologue in Henry James’ The Turn of the Screw is decidedly ambiguous, as the characters in the prologue, much like the uncle of the main text, are seemingly never seen again. For this reason, the purpose of this prologue is much debated.1 As Rolf Lundén states in his article “‘Not in any literal, vulgar way’: The Encoded Love Story of Henry James’ The Turn of the Screw,” “The openness of Henry James\u27 The Turn of the Screw has invited more analytical attempts, and more critical controversy, than most literary texts” (30). Lundén summarizes four schools of thought regarding the interpretation of James’ novella (30). The first is a metaphysical reading of the text, in which critics see the text as an actual ghost story. The second is a psychoanalytical interpretation of the novella, in which the Quint and Jessel function as a result of the governess’ sexually hysteric mind. A third, less popular, analysis of the text claims that Mrs. Grose is sabotaging the governess in order to take the governess’ position at Bly. The fourth reading of the text, according to Lundén, contends that Miles lives, and Douglas and Miles are in fact the same person. I will argue that the prologue of The Turn of the Screw also seems to serve as an epilogue, an explanation of what happens after the conclusion of the main text. Douglas, the holder of the governess’ written story, is the only character who knows or comes into contact with the governess after Miles’ ambiguous death scene. However, Douglas, though he has read a text that implicates the governess as a potential murderer, describes her as “the most agreeable woman I’ve ever known in her position; she’d have been worthy of any whatever” (24). This seeming confession to murder, in which “his [Miles’] little heart, dispossessed, had stopped” (120), thus does not appear to have any negative impact on Douglas’ opinion of the governess, engendering speculation as to what places the governess in his high regard. Douglas claims his association with the governess occurred over approximately one year, and “it was a beautiful one” (24). In this year, the two had, as Douglas casually puts it, “some strolls and talks in the garden—talks in which she struck me as awfully clever and nice” (24). These “some” talks and walks, as described, do not seem intimate enough to provide the governess with enough comfort to tell Douglas a story “she had never told anyone” (24), placing Douglas’ reliability as a narrator into suspicion.2 Therefore, it seems there must be more to the intimacy of the pair that is not shared with Douglas’ audience. This unrevealed closeness is further suggested in Douglas’ declaration of assurance that the governess had indeed never told this story to someone else; “I knew she hadn’t, I was sure; I could see” (24). Douglas’ ability to know the truth just by glancing upon the governess’ face thus provides even more evidence of the great amount of intimacy implicit between the two. It is also important to note neither the first nor last name of the governess is ever given in the narrative or by Douglas. Secrecy regarding her identity is thus seemingly of the utmost importance; her name must remain concealed even after her death. Furthermore, as Douglas reveals, he even carries the key to the locked drawer which contains the narrative with him at all times; “‘I shall have to send to town…I could write to my man and enclose the key; he could send down the packet as he finds it’” (23). His strong desire to protect the governess’ name and story is highly indicative of their suggested intimacy. Also, though Douglas himself did not write the narrative, he reveals that he does takes the impression of it; ““I took that here”—he tapped his heart. “I’ve never lost it”” (26). The seemingly permanent effect of this story on his heart highly suggests a personal involvement in it. The other characters of the prologue also speculate upon the relationship between Douglas and the governess. After insinuations of romance are made, one character claims, “She was ten years older,” to which another responds “Raison de plus” (25). Mrs. Griffin builds upon this idea, stating, “Well if I don’t know who she was in love with I know who he was” (25), for the reason the prologue’s narrator deduces why the governess had not told anyone this story is not because it implicates her as a murderer, but, rather, because “she was in love” (24). The major question by the end of the text thus remains: who was the governess in love with? Since she shares this story with Douglas, leaving him its written narrative, it seems as the governess is in love with Douglas. However, though the conclusion of The Turn of the Screw is as ambiguous as its prologue, what seems apparent is a romantic love that exists between the governess and her charge, Miles. In paralleling the seemingly reciprocated love that Douglas has for the governess with the governess’ love for Miles, I will argue that Douglas and Miles are the same person

Rethinking relationships in the construction industry : integrating sustainable development into project management processes

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