GAIA: AGB stars as tracers of star formation histories in the Galaxy and beyond

We discuss the tracing of star formation histories with ESA's space astrometry mission GAIA, emphasizing the advantages of AGB stars for this purpose. GAIA's microarcsecond-level astrometry, multi-band photometry and spectroscopy will provide individual distances, motions, effective temperatures, gravities and metallicities for vast numbers of AGB stars in the Galaxy and beyond. Reliable ages of AGB stars can be determined to distances of \~200 kpc in a wide range of ages and metallicities, allowing star formation histories to be studied in a diversity of astrophysical environments.Comment: 4 pages, 1 figure, to be appear in 'Mass-Losing Pulsating Stars and their Circumstellar Matter', eds. Y. Nakada, M. Honma & M. Seki, Kluwer ASSL series, vol. 28

Substituting the main group element in cobalt - iron based Heusler alloys: Co2_2FeAl1−x_{1-x}Six_x

This work reports about electronic structure calculations for the Heusler compound Co$_2$FeAl$_{1-x}$Si$_x$. Particular emphasis was put on the role of the main group element in this compound. The substitution of Al by Si leads to an increase of the number of valence electrons with increasing Si content and may be seen as electron-doping. Self-consistent electronic structure calculations were performed to investigate the consequences of the electron doping for the magnetic properties. The series Co$_2$FeAl$_{1-x}$Si$_x$ is found to exhibit half-metallic ferromagnetism and the magnetic moment follows the Slater-Pauling rule. It is shown that the electron-doping stabilises the gap in the minority states for $x=0.5$.Comment: J. Phys. D (accepted

Factors affecting community pharmacist work: A scoping review and thematic synthesis using role theory

© 2019 Elsevier Inc. Many community pharmacists ideologically support recent changes to their roles in primary healthcare. However, their antithetical resistance towards practice change could have systemic causes (i.e. role stresses), which may account for increased job dissatisfaction, burnout, and job turnover in the profession. Deeper comprehension was sought using a role theory framework. Objective: To identify factors leading to role stresses and strain responses for community pharmacists, and to create a framework for community pharmacist role management. Method: PubMed, Scopus and Web of Science databases were searched for qualitative studies identifying community pharmacist role stress and strain using scoping review methodology from 1990 to 2019. Content and thematic analysis using the framework method was performed, and themes were reported using thematic synthesis. Results: Screening of 10,880 records resulted in 33 studies identified, with 41 factors categorised into four domains: Interpersonal Interactions, Social Setting, Individual Attributes, and Extra-Role. All role stresses were present. Reported role strains suggest role system imbalance. Conclusion: Community pharmacists are in a multifactorial transitional environment. Reported role stresses may be a function of past pharmacist roles and increased role expectations, amplified by many requisite interactions and individual pharmacist characteristics. Social science theories were found to be applicable to the community pharmacy setting

COMPARATIVE ANALYSIS OF THE USE OF INTERNAL MEASURES FOR QUALITY ASSURANCE IN PUBLIC AND PRIVATE UNIVERSITIES IN SOUTH EAST NIGERIA

The seeming decline in the quality of university education in Nigeria necessitated this study on the comparative analysis of the internal measures that are used in public and private universities in south east geo-political zone of Nigeria for quality assurance. The study adopted the descriptive survey research design. Three research questions and three hypotheses guided the study. The population of the study comprised 29,083 made up of 7,444 lecturers and 21,639 students admitted in the 2011/2012 academic session in the 74 faculties and 413 departments of the 13 universities (five public and eight private) in the south-east geo political zone, Nigeria. The sample of the study comprised 2,106 respondents which were made up of 936 lecturers and 1, 170 students from four universities sampled. The sample was composed through multi-stage sampling technique. Questionnaire developed by the researchers titled “Students’ Questionnaire on Internal Measures for Quality Assurance” (SQIMFQA) and “Lecturers’ Questionnaire on Internal Measures for Quality Assurance” (LQIMFQA).was the instrument used for data collection. The instrument was validated by three experts, one in Educational measurement and evaluation and the others in Educational planning from the departments of Educational foundations and Educational Management and Policy all in the faculty of Education Nnamdi Azikiwe University, Awka. The Cronbach’s alpha method was used to determine the internal consistency of the items and this yielded a result of 0.74. The researcher with the help of eight research assistants distributed and successfully collected all the 2,106 copies of the questionnaire administered. The research questions were analyzed using the mean, while the hypotheses were tested using z-test at 0.05 level of significance. It was found among others that internal measures for quality assurance of student intake measures, evaluation of students’ learning experience and teacher quality measures were not adequately used in both public and private universities in the south-east geo-political zone of Nigeria for quality assurance. Based on the findings, recommendations were made

COMPARATIVE ANALYSIS OF THE USE OF INTERNAL MEASURES FOR QUALITY ASSURANCE IN PUBLIC AND PRIVATE UNIVERSITIES IN SOUTH EAST NIGERIA

The seeming decline in the quality of university education in Nigeria necessitated this study on the comparative analysis of the internal measures that are used in public and private universities in south east geo-political zone of Nigeria for quality assurance. The study adopted the descriptive survey research design. Three research questions and three hypotheses guided the study. The population of the study comprised 29,083 made up of 7,444 lecturers and 21,639 students admitted in the 2011/2012 academic session in the 74 faculties and 413 departments of the 13 universities (five public and eight private) in the south-east geo political zone, Nigeria. The sample of the study comprised 2,106 respondents which were made up of 936 lecturers and 1, 170 students from four universities sampled. The sample was composed through multi-stage sampling technique. Questionnaire developed by the researchers titled “Students’ Questionnaire on Internal Measures for Quality Assurance” (SQIMFQA) and “Lecturers’ Questionnaire on Internal Measures for Quality Assurance” (LQIMFQA).was the instrument used for data collection. The instrument was validated by three experts, one in Educational measurement and evaluation and the others in Educational planning from the departments of Educational foundations and Educational Management and Policy all in the faculty of Education Nnamdi Azikiwe University, Awka. The Cronbach’s alpha method was used to determine the internal consistency of the items and this yielded a result of 0.74. The researcher with the help of eight research assistants distributed and successfully collected all the 2,106 copies of the questionnaire administered. The research questions were analyzed using the mean, while the hypotheses were tested using z-test at 0.05 level of significance. It was found among others that internal measures for quality assurance of student intake measures, evaluation of students’ learning experience and teacher quality measures were not adequately used in both public and private universities in the south-east geo-political zone of Nigeria for quality assurance. Based on the findings, recommendations were made

Trapping of a random walk by diffusing traps

We present a systematic analytical approach to the trapping of a random walk by a finite density rho of diffusing traps in arbitrary dimension d. We confirm the phenomenologically predicted e^{-c_d rho t^{d/2}} time decay of the survival probability, and compute the dimension dependent constant c_d to leading order within an eps=2-d expansion.Comment: 16 pages, to appear in J. Phys.

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Specific heat of MgB_2 after irradiation

We studied the effect of disorder on the superconducting properties of polycrystalline MgB_2 by specific-heat measurements. In the pristine state, these measurements give a bulk confirmation of the presence of two superconducting gaps with 2 Delta 0 / k_B T_c = 1.3 and 3.9 with nearly equal weights. The scattering introduced by irradiation suppresses T_c and tends to average the two gaps although less than predicted by theory. We also found that by a suitable irradiation process by fast neutrons, a substantial bulk increase of dH_{c2}/dT at T_c can be obtained without sacrificing more than a few degrees in T_c. The upper critical field of the sample after irradiation exceeds 28 T at T goes to 0 K.Comment: 11 pages text, 6 figures, accepted by Journal of Physics: Condensed Matte

Hund's rule and metallic ferromagnetism

We study tight-binding models of itinerant electrons in two different bands, with effective on-site interactions expressing Coulomb repulsion and Hund's rule. We prove that, for sufficiently large on-site exchange anisotropy, all ground states show metallic ferromagnetism: They exhibit a macroscopic magnetization, a macroscopic fraction of the electrons is spatially delocalized, and there is no energy gap for kinetic excitations.Comment: 17 page

Physical realization of coupled Hilbert-space mirrors for quantum-state engineering

Manipulation of superpositions of discrete quantum states has a mathematical counterpart in the motion of a unit-length statevector in an N-dimensional Hilbert space. Any such statevector motion can be regarded as a succession of two-dimensional rotations. But the desired statevector change can also be treated as a succession of reflections, the generalization of Householder transformations. In multidimensional Hilbert space such reflection sequences offer more efficient procedures for statevector manipulation than do sequences of rotations. We here show how such reflections can be designed for a system with two degenerate levels - a generalization of the traditional two-state atom - that allows the construction of propagators for angular momentum states. We use the Morris-Shore transformation to express the propagator in terms of Morris-Shore basis states and Cayley-Klein parameters, which allows us to connect properties of laser pulses to Hilbert-space motion. Under suitable conditions on the couplings and the common detuning, the propagators within each set of degenerate states represent products of generalized Householder reflections, with orthogonal vectors. We propose physical realizations of this novel geometrical object with resonant, near-resonant and far-off-resonant laser pulses. We give several examples of implementations in real atoms or molecules.Comment: 15 pages, 6 figure