1,437 research outputs found
Sensitivity of the blue loops of intermediate-mass stars to nuclear reactions
No full textWe investigate the effects of a modification of the 14N(p, γ)15O reaction rate, as suggested by recent evaluations, on the formation and extension of the blue loops encountered during the evolution of the stars in the mass range 5M⊙ to 12M⊙. We show that the blue loops of stars in the mass range 5M⊙ to 8M ⊙, that is the range of super ABG stars, are severely affected by a modification of the important 14N(p,γ)15O reaction rate. We also show that the blue loops can be restored if envelope overshooting is included, which is necessary to explain the observations of the Cepheid stars. © 2012 American Institute of Physics.Adelberger EG, 2011, REV MOD PHYS, V83, P195, DOI 10.1103-RevModPhys.83.195; Angulo C., 1999, NUPHA, VA656, p3A; Cyburt, 2010, APJS, V189, P240; El Eid M.F., 2009, SSRV, V147, p1E; El Eid MF, 2004, ASTROPHYS J, V611, P452, DOI 10.1086-422162; EVANS NR, 1993, ASTRON J, V105, P1956, DOI 10.1086-116570; Fernie J. D., 1995, IBVS, V4148, p1F; Halabi G. M., 2012, APJ UNPUB; Imbriani, 2005, EUR PHYS J A, V25, P455; Mermilliod J.-C., 1981, Astronomy and Astrophysics Supplement Series, V44; SCHMIDT EG, 1984, ASTROPHYS J, V287, P261, DOI 10.1086-1626850
convective mixing on the evolution of a 6Mȯ star
No full textWe present the evolution of a 6M⊙ star, of solar-like initial metallicity, and investigate the effects of key nuclear reaction rates, as well as the treatment of the convective mixing on its evolution along the Cepheid instability strip. In particular, we study the effect of recent estimates of the 14N(p,γ)15O reaction on the formation and extension of the blue loop during core helium burning. We also investigate the effects induced on this blue loop by the adoption of non-standard convective mixing prescriptions, as well as the implications of modifying the Mixing Length Theory. © 2014 AIP Publishing LLC
The effect of the 14N(p, γ)15O reaction on the blue loops in intermediate-mass stars
No full textWe present stellar evolutionary sequences of stars in the mass range 5-12 M , having solar-like initial composition. The stellar models are obtained using updated input physics, including recent rates of thermonuclear reactions. We investigate the effects of a modification of the 14N(p, γ) 15O reaction rate, as suggested by recent evaluations, on the formation and extension of the blue loops encountered during the evolution of the stars in the above mass range. We find that a reduced 14N(p, γ)15O rate, as described in the text, has a striking impact on the physical conditions of burning and mixing during shell hydrogen burning when the blue loops are formed. In particular, we find that the efficiency of shell hydrogen burning is crucial for the formation of an extended blue loop. We show that a significantly reduced 14N(p, γ)15O rate affects severely the extension of the blue loops and the time spent by the star in the blue part of the Hertzsprung-Russell diagram in the mass range 5-7 M if the treatment of convection is based on the Schwarzschild criterion only. In this case, envelope overshooting helps to restore well-extended blue loops as supported by the observations of the Cepheid stars. If core overshooting is included during the core hydrogen and core helium burning phases, the loop formation and its properties depend on how this overshooting is treated for a given stellar mass range, as well as on its efficiency. © 2012. The American Astronomical Society. All rights reserved..Adelberger EG, 2011, REV MOD PHYS, V83, P195, DOI 10.1103-RevModPhys.83.195; ALONGI M, 1991, ASTRON ASTROPHYS, V244, P95; Angulo C, 2005, NUCL PHYS A, V758, p391C, DOI 10.1016-j.nuclphysa.2005.05.070; Angulo C, 1999, NUCL PHYS A, V656, P3, DOI 10.1016-S0375-9474(99)00030-5; Artemov SV, 2012, PHYS ATOM NUCL+, V75, P291, DOI 10.1134-S1063778812020032; Bemmerer D, 2006, NUCL PHYS A, V779, P297, DOI 10.1016-j.nuciphysa.2006.09.001; Bertone P. F., 2010, THESIS U N CAROLINA; Borowski M, 2009, AIP CONF PROC, V1090, P450; CARSON TR, 1976, ASTROPHYS J, V204, P461, DOI 10.1086-154190; Cassisi S, 2002, ASTROPHYS J, V565, P1231, DOI 10.1086-324695; Cyburt RH, 2010, ASTROPHYS J SUPPL S, V189, P240, DOI 10.1088-0067-0049-189-1-240; El Eid MF, 2009, SPACE SCI REV, V147, P1, DOI 10.1007-s11214-009-9517-6; El Eid MF, 2004, ASTROPHYS J, V611, P452, DOI 10.1086-422162; ELEID MF, 1995, MON NOT R ASTRON SOC, V275, P983; EVANS NR, 1993, ASTRON J, V105, P1956, DOI 10.1086-116570; Fernie J.D., 1995, IBVS, V4148, P1; Formicola A, 2004, PHYS LETT B, V591, P61, DOI 10.1016-j.physletb.2004.03.092; Freytag R., 1996, ASTRON ASTROPHYS, V313, P497; GIEREN WP, 1989, ASTROPHYS J, V342, P467, DOI 10.1086-167606; HARRIS GLH, 1976, ASTROPHYS J SUPPL S, V30, P451, DOI 10.1086-190368; Iliadis C., 2007, NUCL PHYS STARS; Imbriani G, 2005, EUR PHYS J A, V25, P455, DOI 10.1140-epja-i2005-10138-7; Lai XJ, 2011, RES ASTRON ASTROPHYS, V11, P1351; LANGER N, 1995, ASTRON ASTROPHYS, V295, P685; Lemut A, 2006, PHYS LETT B, V634, P483, DOI 10.1016-j.physletb.2006.02.021; Marta M, 2011, PHYS REV C, V83, DOI 10.1103-PhysRevC.83.045804; MATRAKA B, 1982, ASTRON ASTROPHYS, V107, P283; Mermilliod J.-C., 1981, Astronomy and Astrophysics Supplement Series, V44; Neilson HR, 2011, ASTR SOC P, V448, P155; Reimers D., 1975, Memoires de la Societe Royal des Sciences de Liege. Collection in-8, V8; Runkle RC, 2005, PHYS REV LETT, V94, DOI 10.1103-PhysRevLett.94.082503; SCHMIDT EG, 1984, ASTROPHYS J, V287, P261, DOI 10.1086-162685; SCHRODER U, 1987, NUCL PHYS A, V467, P240, DOI 10.1016-0375-9474(87)90528-8; STOTHERS RB, 1991, ASTROPHYS J, V374, P288, DOI 10.1086-170117; STOTHERS RB, 1991, ASTROPHYS J, V383, P820, DOI 10.1086-170840; Valle G, 2009, ASTRON ASTROPHYS, V507, P1541, DOI 10.1051-0004-6361-200912004; Weiss A, 2005, ASTRON ASTROPHYS, V441, P1129, DOI 10.1051-0004-6361:20053084; Xu HY, 2004, ASTRON ASTROPHYS, V418, P213, DOI 10.1051-0004-6361:2004002423
The synthesis of monodisperse alkanes with long chains
No full textThis thesis discusses reasons for the interest in monodisperse long chain alkanes and describes attempts, past and present, to synthesise such molecules. Chapter 1 discusses why the synthesis of such molecules are important and the objectives of this project. Chapter 2 reviews the methods previous groups have devised to prepare pure samples of long chain alkanes. In particular, work carried out by Whiting et al. at Bristol, whose scheme formed the basis of the early work in Durham. Chapter 3 describes the work in Durham and improvements which were made to Whiting's method, allowing the synthesis of longer chain lengths and greater quantities of materials to be achieved. Chapter 4 provides a summary of the practical work carried out by the author. Chapter 5 gives experimental details of the work described in Chapter 4
Towards the Theatre: Opasnyi Povorot (Dangerous Corner). The 1939 Production by G.M. Kozintsev at the Leningrad Comedy Theater
No full textThe subject of this research is the first production in a series of theatrical works by G.M. Kozintsev (1905–1973) of the late 1930s — early 1950s, which are fundamentally important both in his creative biography and in the history of Soviet theatre of that era. The author suggests that the entry of the famous film director into theatre was caused by the desire to find a way out of a creative impasse.
The director’s appeal to the play of the modern English novelist and playwright J.B. Priestley and its controversial interpretation were driven by the dramatic atmosphere of the late 1930s. The eccentric grotesque of the play and its pamphlet character, which was insisted on by the director, are considered as a parody of tragedy by the author of the research. This reveals a fundamental connection between the production under consideration and the subsequent successful experiments of G.M. Kozintsev in the field of theatrical Shakespeareana. The article draws attention to the fundamental connection between the style of the production and the general style of the Leningrad State Comedy Theatre developed by its director — the outstanding theatre director and set designer, G.M. Kozintsev and E.L. Schwartz’s friend and associate, N.P. Akimov. The research is based on the performance reviews, testimonies of the participants of the performance, contemporaries close to the director (especially the playwright and screenwriter E.L. Schwartz and the long-term G.M. Kozintsev’s co-author L.Z. Trauberg), as well as the surviving radio version of the play
Stevin Outlet Sluices: Wave impact under a beam
No full textThe Dutch department of Public Works had a problem regarding wave impacts on a beam in the Stevin outlet sluices, located in the Afsluitdijk. Wave impacts on this beam could also cause a peak pressure on the barrier gate, just behind the beam. The numerical program ComFLOW and physical scale experiments were used to predict the wave impacts for different hydraulic conditions (i.e. wave height, wave period and water level). The research questions were: 1. How is the wave load on the northern gates depending on the presence of the military beam? 2. How large is a wave impact load on the bottom of the military beam in the Stevin outlet sluices? 3. How well can the numerical model ComFLOW and physical modelling be used to determine the wave impact on the bottom of the military beam in the Stevin outlet sluices? 2D scaled experiments were performed making use of a model with the (simplified) geometry of the Stevin outlet sluices and regular waves. It was found that the largest wave impacts occurred for water levels equal to the bottom plane of the beam or slightly under it. This happened for the shortest waves in the test domain. The largest pressure measured on the beam was approximately 50 kPa or 35H, with H representing the incident wave height in front of the model. It was also found that the spread in the peak pressures for one single experiment was large. The results of the measured impulse per peak showed far less spread. The effect of wave impacts under the beam was also found on the vertical wall under the beam. The actual pressures however were less and they were decreasing with increasing depth. Besides physical wave impact testing, a few experiments were performed with the beam removed from the model. This resulted in wave simply running up the vertical wall of the model. They did not cause a wave impact. The measurements of both type of experiments, with and without a beam, were compared. This revealed that the total wave impulse on the gate was not affected by the presence of the beam. However the distribution of the pressure within a single wave period was significantly different. In case of a beam, a large impact peak was observed, whereas the other wave only showed a small hump caused by the deflected flow against the vertical wall. When the calculated and measured wave impact results were compared it became clear that ComFLOW underestimated the peak pressures by a factor 2 to 20 for the pressures on the impact plane. The same was done for the peak impulse. This showed that the impulse of the peak on the impact plane were underestimated by a factor 2 at most. These results confirmed that the used grid was too coarse for the program to model the physics correctly. The main conclusions to the research questions were: 1. The presence of the military beam causes a different distribution of the force on the gate within a wave period. The total amount of impulse is more or less the same as for the situation without a beam. With the military beam, a wave impact results in a peak force on the gate. Without the beam, there will be no peak force. 2. The largest measured wave impact pressure is 35H. 3. Both ComFLOW and physical modelling can be used to predict wave impacts for the geometry of Stevin outlet sluices. Much care should be taken when modelling and much attention should go to the input parameters of the program.Hydraulic StructuresHydraulic EngineeringCivil Engineering and Geoscience
A Professional Author-How G.M. Glaskin Earned a Living
No full textWestern Australian author Gerald Marcus Glaskin (GMG; 16 December 1923-11 March 2000) wrote from life, using his experiences to continually expand his creative repertoire. In one sense, this was to be his downfall, as his life was unconventional for his time. Because he mined own experiences so much in his creative writing, his works eventually moved out of mainstream markets. However, this paper focuses on his financial success as a writer, details of which can be documented through study of the meticulous records kept by both GMG and his publisher, Barrie & Rockliff of London. Other scholarly analysis of the income received by authors is limited. Katherine Bode (2012) does not deal with the subject in her otherwise comprehensive quantitative analysis of Australian publishing. What little is known about the income of professional authors from this or other periods, and whether they were able to survive on the proceeds of their writing, is incidental to other research
A more comprehensive and commanding delineation: Mary Shelley's narrative strategy in Frankenstein
No full textThis thesis argues that the first edition of Frankenstein challenges conventional reading by employing what Simpson in Irony and Authority in Romantic Poetry calls Romantic irony, where the absence of a stable 'metacomment' precludes an authoritative reading. The novel hints at such readings but prevents them. The insights offered by Tropp's Mary Shelley's Monster, Baldick's In Frankenstein's Shadow, Poovey's The Proper Lady and the woman writer and Swingle's, 'Frankenstein's Monster and its Relatives: Problems of Knowledge in English Romanticism' are considered, but none recognises the full implications of the instability deriving from multiple first- person narratives. Clemit's The Godwinian Navel acknowledges the novel's indeterminacy, but reads a specific ideological purpose in it. Paradise Last provides a language to describe the relationship between the monster and Frankenstein, but proves too unstable to fix identity or establish moral value. Similarly, Necessity ultimately fails to provide a stable explanation in terms of cause and effect. The status of nature shifts between foreground and background, never allowing final definition. These uncertainties destabilise knowledge which is compromised by its provisional nature: no authoritative reading is possible, yet the novel has narrative coherence. The reader is encouraged to try to develop a reading the structure prevents. The radical nature of the first edition is highlighted by comparison with the 1831 edition, which removes much of the ambivalence and gives the novel a clearer morality. The novel challenges conventional methods of deriving authority by disturbing the reader's orthodox orientation in the world around him' (Simpson) in order to afford 'a point of view to the imagination for the delineation of human passions more comprehensive and commanding than any which the ordinary relations of existing events can yield' (Mary Shelley)
Efficacy and Safety of the Extreme Lateral Interbody Fusion (XLIF) Technique in Spine Surgery: Meta-Analysis of 1409 Patients
No full textG.M. is the corresponding author for this article. Contributor roles: concep-
tualization: P.P., I.P., A.P., J.C.G., G.M. and A.L.; methodology: P.P., I.P., A.P., J.C.G., G.M. and A.L.;
software: P.P., I.P. and G.M.; validation: P.P., I.P., A.P., J.C.G., G.M. and A.L.; formal analysis: P.P.,
I.P., A.P., J.C.G., G.M. and A.L.; investigation: P.P., I.P., A.P., J.C.G., G.M. and A.L.; data curation P.P.,
I.P., A.P., J.C.G., G.M. and A.L. supervision: P.P.; visualization: P.P., I.P., A.P., J.C.G., G.M. and A.L.;
writing original draft: P.P., I.P., A.P., J.C.G., G.M. and A.L.; writing—review and editing: P.P., I.P., A.P.,
J.C.G., G.M. and A.L.; project administration: P.P. and G.M. All authors have read and agreed to the
published version of the manuscript.The objective of this study was to quantify the exact clinical-radiological
efficacy and safety of the extreme lateral interbody fusion (XLIF) technique in spinal surgery.Medicin
Extra- cellular Pectinase Activity of Post-harvest Fungi from Papaya Fruits in Presence of Different Influencing Factors
No full textThe present paper deals with the study of pectinase enzyme activity of post-harvest fungi of papaya fruits under the influence of nutritional factors, antibiotics, vitamins and fungicides. It was found that carboxy methyl cellulose (CMC), sodium sulphate; ferrous sulphate, barium chloride, sodium chloride, magnesium chloride, zinc, ferrous, manganese, copper, barium, fungicides and ampicillin inhibits the pectinase action of all tested post-harvest fungi while other factors induces the same. --------------------------------------------------------------------------------------------------------1Dept. of Botany, Shrikrishna Mahavidyalaya, Gunjoti, Dist Osmanabad, Aurangabad; 2Seed pathology and Fungal Biotechnology Laboratory, Dept. of Botany, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad- 431 004. (M.S.) India.* Corresponding Author, Email: [email protected] Please Cite This Article As: G.M. Rathod and Ashok M. Chavan. 2010. Extra- cellular Pectinase Activity of Post-harvest Fungi from Papaya Fruits in Presence of Different Influencing Factors. J. Exp. Sci. 1(2): 07-11
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