9,433 research outputs found
Main propulsion system test requirements for the two-engine Shuttle-C
The Shuttle-C is an unmanned cargo carrying derivative of the space shuttle with optional two or three space shuttle main engines (SSME's), whereas the shuttle has three SSME's. Design and operational differences between the Shuttle-C and shuttle were assessed to determine requirements for additional main propulsion system (MPS) verification testing. Also, reviews were made of the shuttle main propulsion test program objectives and test results and shuttle flight experience. It was concluded that, if significant MPS modifications are not made beyond those currently planned, then main propulsion system verification can be concluded with an on-pad flight readiness firing
Corporate governance, Islamic governance and earnings management in Oman: A new empirical insights from a behavioural theoretical framework
Purpose: This paper examines the impact of corporate (CG) and Islamic (IG) governance mechanisms on corporate earnings management (EM) behaviour in Oman.
Design/Methodology/Approach: We employ one of the largest and extensive datasets to-date on CG, IG and EM in any developing country, consisting of a sample of 116 unique Omani listed corporations from 2001 to 2011 (i.e.,1,152 firm-year observations) and a broad CG index containing 72 CG provisions. We also employ a number of robust econometric models that sufficiently account for alternative CG/EM proxies and potential endogeneities.
Findings: First, we find that, on average, better-governed corporations tend to engage significantly less in EM than their poorly-governed counterparts. Second, our evidence suggests that corporations that depict greater commitment towards incorporating Islamic religious beliefs and values into their operations through the establishment of an IG committee tend to engage significantly less in EM than their counterparts without such a committee. Finally and by contrast, we do not find any evidence that board size, audit firm size, the presence of a CG committee and board gender diversity have any significant relationship with the extent of EM.
Originality: To the best of our knowledge, this is a first empirical attempt at examining the extent to which CG and IG structures may drive EM practices that explicitly seeks to draw new insights from a behavioural theoretical framework (i.e., behavioural theory of corporate boards and governance).
Keywords: Corporate governance, Islamic governance, earnings management, behavioural theory, endogeneity, Oman.
Paper type: Research pape
Longitudinal Polarization at future Colliders and Virtual New Physics Effects
The theoretical merits of longitudinal polarization asymmetries of
electron-positron annihilation into two final fermions at future colliders are
examined, using a recently proposed theoretical description. A number of
interesting features, valid for searches of virtual effects of new physics, is
underlined, that is reminiscent of analogous properties valid on top of
resonance. As an application to a concrete example, we consider the case of a
model with triple anomalous gauge couplings and show that the additional
information provided by these asymmetries would lead to a drastic reduction of
the allowed domain of the relevant parameters.Comment: 18 pages and 1 figure. e-mail: [email protected]
Students\u27 use of personal technology in the classroom: analyzing the perceptions of the digital generation
Faculty frequently express concerns about studentsâ personal use of information
and communication technologies in todayâs university classrooms. As a requirement
of a graduate research methodology course in a university in Ontario,
Canada, the authors conducted qualitative research to gain an in-depth understanding
of studentsâ perceptions of this issue. Their findings reveal studentsâ
complex considerations about the acceptability of technology use. Their analysis
of the broader contexts of studentsâ use reveals that despite a technological revolution,
university teaching practices have remained largely the same, resulting in
âcultural lagâ within the classroom. While faculty are technically âin chargeâ, students
wield power through course evaluations, surveillance technologies and
Internet postings. Neoliberalism and the corporatisation of the university have
engendered an âentrepreneurial studentâ customer who sees education as a means
to a career. Understanding studentsâ perceptions and their technological, social
and political contexts offers insights into the tensions within todayâs classrooms
Antiferromagnetic Order of the Ru and Gd in Superconducting RuSr2GdCu2O8
Neutron diffraction has been used to study the magnetic order in
RuSr{2}GdCu2O8. The Ru moments order antiferromagnetically at T{N}=136(2)K,
coincident with the previously reported onset of ferromagnetism. Neighboring
spins are antiparallel in all three directions, with a low T moment of 1.18(6)
mu {B} along the c-axis. Our measurements put an upper limit of ~0.1 mu{B} to
any net zero-field moment, with fields exceeding ~0.4T needed to induce a
measurable magnetization. The Gd ions order independently at T{N}=2.50(2)K with
the same spin configuration. PACS numbers: 74.72.Jt, 75.25.+z, 74.25.Ha,
75.30.KzComment: Four pages, Latex, 5 eps figure
Search for Magnetic Order in Superconducting RuSr2Eu1.2Ce0.8Cu2O10
Neutron diffraction, polarized neutron transmission, and small angle neutron
scattering have been used to investigate the crystal structure and nature of
the magnetic order in a polycrystalline sample of RuSr2Eu1.2Ce0.8Cu2O10. The
sample was made with the Eu-153 (98.8%) isotope to reduce the high neutron
absorption for the naturally occurring element. Full refinements of the crystal
structure, space group I4/mmm, are reported. At low temperatures only a single
magnetic peak is clearly observed in a relatively wide angular range. A sharp
spin reorientation transition (SRT) is observed around 35 K, close to the
superconducting transition temperature (Tc~40 K). Between the spin
reorientation temperature and the Neel temperature of 59 K, additional magnetic
reflections are observed. However, none of these can be simply indexed on the
chemical unit cell, either as commensurate peaks or simple incommensurate
magnetism, and the paucity of reflections at low T compels the conclusion that
these magnetic Bragg peaks arise from an impurity phase. X-ray and neutron
diffraction on the pressed pellet both show that the sample does not appear to
contain substantial impurity phases, but it turns out that the magnetic
impurity peaks exhibit strong preferred orientation with respect to the pellet
orientation, while the primary phase does not. We have been unable to observe
any magnetic order that can be identified with the ruthenate-cuprate system.Comment: 7 figures. Submitted to Phys. Rev.
Positronium reflection and positronium beams
Specular reflection of positronium, Ps was observed and that there is adequate intensity at higher energies to make further study worthwhile was established. The scattering appears to be restricted to the outermost surface with a mean free path of (0.75 + or - 0.15)A for Ps in LiF(100). With a greater intensity Ps beam one should see higher order diffraction beams as the result of the periodicity of the surface. Ps diffraction thus offers the possibility of being a novel and valuable probe to study the outermost surface and to study adsorbants on it. Two methods for producing Ps beams are described
Cutaneous Blood Flow and Percutaneous Absorption: A Quantitative Analysis Using a Laser Doppler Velocimeter and a Blood Flow Meter
Cutaneous blood flow has been directly quantitated in vivo for the first time without animal death utilizing the rat skin sandwich flap. This was accomplished by conducting experiments that made a direct correlation between two instruments: a laser Doppler velocimeter and an electromagnetic blood flow meter. Data demonstrate that the correlation between these two instruments is high and reproducible (r = 0.96) with a small (1.3%) coefficient of variation. Blood flow to skin in the unmanipulated state varies from 0.7 to 1.2 mls/min in an anesthetized rat. Application of the blood flow correlation to the determination of percutaneous absorption of caffeine across human skin and benzoic acid across rat skin demonstrates that assuming cutaneous blood flow is a particular value day to day in any skin type results in an apparent wide range of total compound absorbed across that skin on independent occasions. Utilizing actual blood flow measurements to calculate the amount of chemical absorbed reduces the range of variability in the total amount of chemical absorbed and provides a more accurate knowledge of events occurring during a particular time of the absorption process. Quantitation of cutaneous blood flow will be useful in physiologic and pharmacologic studies where actual cutaneous blood flow is likely to be important to the processes studied, e.g., delivery of drug to skin, metabolism within the skin, and disposition of drug to blood and skin following topical drug application
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