472 research outputs found
The role of corporate culture and ethical environment in directing individuals’ behavior
This study is aimed at verifying the conception that a strong corporate culture supported with a positive ethical environment is central for directing and guiding the behavior of individuals toward achieving organizational objectives. The rationale for this study stems from the circumstance that formal controls systems suffer from consecutive failures, as the performance of organizations is still suffering from financial collapses. Reasons behind such failures might be related to the insufficient appreciation of the culture-based controls given that formal controls are influenced by the human nature of employees and the affixed moral side.Data subject to analysis are obtained from a judgmental sampling method using a self-completion questionnaire covering the listed companies at Jordan Securities Commission. A factor analysis and a standard multiple regression analysis have been conducted with the aim of proving the hypotheses of the research. The research results show that strong corporate culture supported with a positive ethical environment can direct the behavior of employees for the good of organizations. Results also support the importance of involvement of top management considering its role in filling the gap between the embraced and the workable values and beliefs of an entity
Robotic right ventricle is a biohybrid platform that simulates right ventricular function in (patho)physiological conditions and intervention
The increasing recognition of the right ventricle (RV) necessitates the development of RV-focused interventions, devices and testbeds. In this study, we developed a soft robotic model of the right heart that accurately mimics RV biomechanics and hemodynamics, including free wall, septal and valve motion. This model uses a biohybrid approach, combining a chemically treated endocardial scaffold with a soft robotic synthetic myocardium. When connected to a circulatory flow loop, the robotic right ventricle (RRV) replicates real-time hemodynamic changes in healthy and pathological conditions, including volume overload, RV systolic failure and pressure overload. The RRV also mimics clinical markers of RV dysfunction and is validated using an in vivo porcine model. Additionally, the RRV recreates chordae tension, simulating papillary muscle motion, and shows the potential for tricuspid valve repair and replacement in vitro. This work aims to provide a platform for developing tools for research and treatment for RV pathophysiology.</p
Drude Conductivity of Dirac Fermions in Graphene
Electrons moving in graphene behave as massless Dirac fermions, and they
exhibit fascinating low-frequency electrical transport phenomena. Their dynamic
response, however, is little known at frequencies above one terahertz (THz).
Such knowledge is important not only for a deeper understanding of the Dirac
electron quantum transport, but also for graphene applications in ultrahigh
speed THz electronics and IR optoelectronics. In this paper, we report the
first measurement of high-frequency conductivity of graphene from THz to mid-IR
at different carrier concentrations. The conductivity exhibits Drude-like
frequency dependence and increases dramatically at THz frequencies, but its
absolute strength is substantially lower than theoretical predictions. This
anomalous reduction of free electron oscillator strength is corroborated by
corresponding changes in graphene interband transitions, as required by the sum
rule. Our surprising observation indicates that many-body effects and Dirac
fermion-impurity interactions beyond current transport theories are important
for Dirac fermion electrical response in graphene
BAT AGN Spectroscopic Survey XXVII: Scattered X-Ray Radiation in Obscured Active Galactic Nuclei
Accreting supermassive black holes (SMBHs), also known as active galactic
nuclei (AGN), are generally surrounded by large amounts of gas and dust. This
surrounding material reprocesses the primary X-ray emission produced close to
the SMBH and gives rise to several components in the broadband X-ray spectra of
AGN, including a power-law possibly associated with Thomson-scattered
radiation. In this work, we study the properties of this scattered component
for a sample of 386 hard-X-ray-selected, nearby () obscured AGN
from the 70-month Swift/BAT catalog. We investigate how the fraction of
Thomson-scattered radiation correlates with different physical properties of
AGN, such as line-of-sight column density, X-ray luminosity, black hole mass,
and Eddington ratio. We find a significant negative correlation between the
scattering fraction and the column density. Based on a large number of spectral
simulations, we exclude the possibility that this anti-correlation is due to
degeneracies between the parameters. The negative correlation also persists
when considering different ranges of luminosity, black hole mass, and Eddington
ratio. We discuss how this correlation might be either due to the angle
dependence of the Thomson cross-section or to more obscured sources having a
higher covering factor of the torus. We also find a positive correlation
between the scattering fraction and the ratio of [OIII] 5007 to X-ray
luminosity. This result is consistent with previous studies and suggests that
the Thomson-scattered component is associated with the narrow-line region.Comment: Accepted for publication in MNRAS, 18 pages, 9 figures, 2 tables, 1
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Performance of self-compacting concrete incorporating waste glass as coarse aggregate
The purpose of this paper is to develop gather data on the rheological and mechanical properties of self-compacting
concrete (SCC) containing varying percentages of waste glass aggregate (WGA). In this current experiment, the coarse
aggregate was substituted by adding WGA, with replacement percentages of 0%, 10%, 20%, and 30% by weight being
investigated. The rheological properties of SCC were performed to explore the consequence of WGA using various
methods, including the J-ring, slump flow, L-box, and V-funnel. In contrast, the compressive, flexural, modulus of
elasticity, and stress-strain responses of hardened concrete were assessed in this study. The results of the fresh
concrete tests revealed that the substitution of an optimal level of waste glass in SCC provides adequate implementation in flowability, passing ability, and viscosity behaviors. Besides, hardened characteristics were shown to have a steady decrease in strength with increasing WGA content in the concrete mixtures
Intraband Optical Transitions in Graphene
Abstract: We measured tunable interband and intraband transitions in graphene using infrared spectroscopy. Graphene electrons have strong intraband absorption at terahertz frequency range. The absorption spectra are described by a Drude-like frequency dependence
Giant Phonon-induced Conductance in Scanning Tunneling Spectroscopy of Gate-tunable Graphene
The honeycomb lattice of graphene is a unique two-dimensional (2D) system
where the quantum mechanics of electrons is equivalent to that of relativistic
Dirac fermions. Novel nanometer-scale behavior in this material, including
electronic scattering, spin-based phenomena, and collective excitations, is
predicted to be sensitive to charge carrier density. In order to probe local,
carrier-density dependent properties in graphene we have performed
atomically-resolved scanning tunneling spectroscopy measurements on
mechanically cleaved graphene flake devices equipped with tunable back-gate
electrodes. We observe an unexpected gap-like feature in the graphene tunneling
spectrum which remains pinned to the Fermi level (E_F) regardless of graphene
electron density. This gap is found to arise from a suppression of electronic
tunneling to graphene states near E_F and a simultaneous giant enhancement of
electronic tunneling at higher energies due to a phonon-mediated inelastic
channel. Phonons thus act as a "floodgate" that controls the flow of tunneling
electrons in graphene. This work reveals important new tunneling processes in
gate-tunable graphitic layers
A Tunable Phonon-Exciton Fano System in Bilayer Graphene
Interference between different possible paths lies at the heart of quantum
physics. Such interference between coupled discrete and continuum states of a
system can profoundly change its interaction with light as seen in Fano
resonance. Here we present a unique many-body Fano system composed of a
discrete phonon vibration and continuous electron-hole pair transitions in
bilayer graphene. Mediated by the electron-phonon interactions, the excited
state is described by new quanta of elementary excitations of hybrid
phonon-exciton nature. Infrared absorption of the hybrid states exhibit
characteristic Fano lineshapes with parameters renormalized by many-body
interactions. Remarkably, the Fano resonance in bilayer graphene is
continuously tunable through electrical gating. Further control of the
phonon-exciton coupling may be achieved with an optical field exploiting the
excited state infrared activity. This tunable phonon-exciton system also offers
the intriguing possibility of a 'phonon laser' with stimulated phonon
amplification generated by population inversion of band-edge electrons.Comment: 21 pages, 3 figure
Prospects for the development of probiotics and prebiotics for oral applications
There has been a paradigm shift towards an ecological and microbial community-based approach to understanding oral diseases. This has significant implications for approaches to therapy and has raised the possibility of developing novel strategies through manipulation of the resident oral microbiota and modulation of host immune responses. The increased popularity of using probiotic bacteria and/or prebiotic supplements to improve gastrointestinal health has prompted interest in the utility of this approach for oral applications. Evidence now suggests that probiotics may function not only by direct inhibition of, or enhanced competition with, pathogenic micro-organisms, but also by more subtle mechanisms including modulation of the mucosal immune system. Similarly, prebiotics could promote the growth of beneficial micro-organisms that comprise part of the resident microbiota. The evidence for the use of pro or prebiotics for the prevention of caries or periodontal diseases is reviewed, and issues that could arise from their use, as well as questions that still need to be answered, are raised. A complete understanding of the broad ecological changes induced in the mouth by probiotics or prebiotics will be essential to assess their long-term consequences for oral health and disease
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