2,831 research outputs found
Cavity optomechanics with stoichiometric SiN films
We study high-stress SiN films for reaching the quantum regime with
mesoscopic oscillators connected to a room-temperature thermal bath, for which
there are stringent requirements on the oscillators' quality factors and
frequencies. Our SiN films support mechanical modes with unprecedented products
of mechanical quality factor and frequency reaching Hz. The SiN membranes exhibit a low optical absorption
characterized by Im at 935 nm, representing a 15 times
reduction for SiN membranes. We have developed an apparatus to simultaneously
cool the motion of multiple mechanical modes based on a short, high-finesse
Fabry-Perot cavity and present initial cooling results along with future
possibilities.Comment: 4 pages, 5 figure
Interval Tree-Based Task Scheduling Method for Mobile Crowd Sensing Systems
Nowadays there is an increasing demand to provide a real-time environmental information. So, the growing number of mobile devices carried by users establish a new and fastgrowing sensing paradigm to satisfy this need, which is called Mobile Crowd Sensing (MCS). The MCS uses different sensing abilities to acquire local knowledge through enhanced mobile devices. In MCS, it is very important to collect high-quality sensory data that satisfies the needs of all assigned tasks and the task organizers with a minimum cost for the participants. One of the most important factors which affect the MCS cost is how to schedule different sensing tasks which must be assigned to a smartphone with the objective of minimizing sensing energy consumption while ensuring high-quality sensory data. In this paper, the problem of task scheduling the which have mutual sensor is formulated and a scheduling method to minimize the energy consumption by reducing the sensor utilization is proposed. The proposed method will incentive the users to participate in multiple tasks at the same time, which minimizes the total cost of the performed tasks and increases his rewards. The experimental results by using synthetic and real data show that the proposed scheduling method can minimize the energy consumption and preserve the task requirements compared to existing algorithms
Self-consistent treatment of the self-energy in nuclear matter
The influence of hole-hole propagation in addition to the conventional
particle-particle propagation, on the energy per nucleon and the momentum
distribution is investigated. The results are compared to the
Brueckner-Hartree-Fock (BHF) calculations with a continuous choice and
conventional choice for the single-particle spectrum. The Bethe-Goldstone
equation has been solved using realistic interactions. Also, the structure
of nucleon self-energy in nuclear matter is evaluated. All the self-energies
are calculated self-consistently. Starting from the BHF approximation without
the usual angle-average approximation, the effects of hole-hole contributions
and a self-consistent treatment within the framework of the Green function
approach are investigated. Using the self-consistent self-energy, the hole and
particle self-consistent spectral functions including the particle-particle and
hole-hole ladder contributions in nuclear matter are calculated using realistic
interactions. We found that, the difference in binding energy between both
results, i.e. BHF and self-consistent Green function, is not large. This
explains why is the BHF ignored the 2h1p contribution.Comment: Preprint 20 pages including 15 figures and one tabl
Capacity for health economics research and practice in Jordan, Lebanon, the occupied Palestinian territories and Turkey: needs assessment and options for development
Background: Capacity for health economics analysis and research is indispensable for evidence-informed allocations of scarce health resources, however little is known about the experience and capacity strengthening preferences of academics and practitioners in the Eastern Mediterranean region. This study aimed to assess the needs for strengthening health economics capacity in Jordan, Lebanon, the occupied Palestinian territories and Turkey as part of the Research for Health in Conflict in Middle East and North Africa (R4HC-MENA) project. Methods: Bibliometric analysis of health economics outputs combined with an online survey of academic researchers and non-academic practitioners. The bibliometric analysis was based on a literature search conducted across seven databases. Included records were original studies and reviews with an explicit economic outcome related to health, disease or disability; had at least one author in Jordan, Lebanon, Palestine or Turkey; and were published between January 2014 and December 2018. Two types of analyses were conducted using VOSviewer software: keyword co-occurrence; and co-publication networks across countries and organizations. The online survey asked academic researchers, analysts and decision-makers – identified through the bibliometric analysis and regional professional networks – about previous exposure to and preference for capacity development in health economics. Results: Of 15,185 records returned by the literature search, 566 were included in the bibliometric analysis. Organizations in Turkey contributed more than 80% of records and had the broadest and most diverse network of collaborators, nationally and internationally. Only 1% (n=7) studies were collaborations between researchers in two or more different jurisdictions. Cost analysis, cost-effectiveness analysis and health system economics were the main health economics topics across the included studies. Economic evaluation, measuring the economic burden of disease and health equity were reported by survey respondents (n=80) as the most important areas to develop in. Short courses, learn-by-doing and mentoring from an experienced professional were, in aggregate, the most preferred capacity development modalities. Conclusions: Existing pockets of health economic expertise in the region can constitute the base of future capacity development efforts. Building confidence toward applying specific methods and trust toward stimulating cross-jurisdiction collaborations appear essential components for sustainably developing health economics capacity
CP violation and the 4th generation
Within the Standard model with the 4th generation quarks b' and t' we have
analyzed CP-violating flavor changing neutral current processes t -> cX; b'->
sX, b'-> bX,t'-> cX, and t'-> tX, with X=Z,H,gamma,g, by constructing and
employing global, unique fit for the 4th generation mass mixing matrix CKM4 at
300 < m_t' < 700 GeV. All quantities appearing in the CKM4 were subject to our
fitting procedure. We have found that our fit produces the following CP partial
rate asymmetry dominance: a_CP(b'-> s(Z,H,gamma,g))= (90,73,52,30)%, at m_t' ~
300,300,380,400 GeV, respectively. From the experimental point of view the best
decay mode, out of the above four, is certainly b'-> s gamma, because of the
presence of a clean high energy single final state photon. We have also
obtained relatively large a_CP(t -> c g) ~ 15 (10)% for t' running in the loops
with the mass m_t'= 650(500) GeV. There are fair chances that the 4th
generation quarks will be discovered at Tevatron or LHC and that some of their
decay rates shall be measured. If b' and t' exist at energies we assumed, with
well executed tagging, large a_CP could be found too.Comment: 19 pages, 12 figures, some of them new, references added, minor
corrections in the text, version to appear in PR
Energy and Momentum densities of cosmological models, with equation of state , in general relativity and teleparallel gravity
We calculated the energy and momentum densities of stiff fluid solutions,
using Einstein, Bergmann-Thomson and Landau-Lifshitz energy-momentum complexes,
in both general relativity and teleparallel gravity. In our analysis we get
different results comparing the aforementioned complexes with each other when
calculated in the same gravitational theory, either this is in general
relativity and teleparallel gravity. However, interestingly enough, each
complex's value is the same either in general relativity or teleparallel
gravity. Our results sustain that (i) general relativity or teleparallel
gravity are equivalent theories (ii) different energy-momentum complexes do not
provide the same energy and momentum densities neither in general relativity
nor in teleparallel gravity. In the context of the theory of teleparallel
gravity, the vector and axial-vector parts of the torsion are obtained. We show
that the axial-vector torsion vanishes for the space-time under study.Comment: 15 pages, no figures, Minor typos corrected; version to appear in
International Journal of Theoretical Physic
ZOLMITRIPTAN BRAIN TARGETING VIA INTRANASAL ROUTE USING SOLID LIPID NANOPARTICLES FOR MIGRAINE THERAPY: FORMULATION, CHARACTERIZATION, IN-VITRO AND IN-VIVO ASSESSMENT
Objective: Zolmitriptan, a class of antidepressant drugs with poor bioavailability due to its first-pass metabolism. The aim of this study was to improve systemic bioavailability and explore the brain targeting impact of nasal Zolmitriptan (Zol) solid lipid nanoparticles (SLNs) gel for migraine treatment.
Methods: Stearic acid and cholesterol used as solid lipid and lecithin as a surfactant, emulsion solvent evaporation technique was used to produce Zolmitriptan SLNs. (Zol) SLNs were characterized for particle size, percent entrapment efficiency and in vitro drug release. Formula S6 showed greater percent entrapment efficiency (PEE), adequate particle size and sustained drug release behavior. Formula S6 was integrated into HPMC gel (3%) to prepare nasal gel. Zol SLN nasal gel was subjected to histopathological study to ensure brain targeting.
Results: It was observed that all prepared Zol SLNs were in the nano-sized range with a polydispersity index of<0.5. In the cholesterol/lecithin combination, higher PEE%, better stability, and less agglomeration inclination were discovered. Results of the release profiles showed that developed Zol-SLNs were able to release Zolmitriptan in a sustained manner. Histopathological study of the brain tissues showed that Zolmitriptan SLN nasal gel can reach brain cells and localized for 24 h although the hydrophobicity of the target drug.
Conclusion: Intranasal administration of Solid lipid nanostructure of Zolmitriptan through the olfactory pathway in which it travels from the nasal cavity to brain tissue achieved drug targeting potential of about 90% compared with conventional Zolmitriptan tablets. The small particle size helped them to squeeze themselves through the small opening in the olfactory neurons to the brain via different endo-cystic pathways of neuronal cells in nasal tissue membranes
Energy Distribution of a Stringy Charged Black Hole
The energy distribution associated with a stringy charged black hole is
studied using M{\o}ller's energy-momentum complex. Our result is reasonable and
it differs from that known in literature using Einstein's energy-momentum
complex.Comment: Latex, no figure
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