4,499 research outputs found
Reference correlation of the viscosity of ortho-xylene from 273 K to 673 K and up to 110 MPa
A new correlation for the viscosity of ortho-xylene (o-xylene) is presented. The correlation is based upon a body of experimental data that has been critically assessed for internal consistency and for agreement with theory. It is applicable in the temperature range from 273 to 673 K at pressures up to 110 MPa. The overall uncertainty of the proposed correlation, estimated as the combined expanded uncertainty with a coverage factor of 2, varies from 1% for the viscosity at atmospheric pressure to 5% for the highest temperatures and pressures of interest. Tables of the viscosity generated by the relevant equations, at selected temperatures and pressures and along the saturation line, are provided
Sample entropy analysis of EEG signals via artificial neural networks to model patients' consciousness level based on anesthesiologists experience.
Electroencephalogram (EEG) signals, as it can express the human brain's activities and reflect awareness, have been widely used in many research and medical equipment to build a noninvasive monitoring index to the depth of anesthesia (DOA). Bispectral (BIS) index monitor is one of the famous and important indicators for anesthesiologists primarily using EEG signals when assessing the DOA. In this study, an attempt is made to build a new indicator using EEG signals to provide a more valuable reference to the DOA for clinical researchers. The EEG signals are collected from patients under anesthetic surgery which are filtered using multivariate empirical mode decomposition (MEMD) method and analyzed using sample entropy (SampEn) analysis. The calculated signals from SampEn are utilized to train an artificial neural network (ANN) model through using expert assessment of consciousness level (EACL) which is assessed by experienced anesthesiologists as the target to train, validate, and test the ANN. The results that are achieved using the proposed system are compared to BIS index. The proposed system results show that it is not only having similar characteristic to BIS index but also more close to experienced anesthesiologists which illustrates the consciousness level and reflects the DOA successfully.This research is supported by the Center forDynamical Biomarkers and Translational Medicine, National Central University, Taiwan, which is sponsored by Ministry of Science and Technology (Grant no. MOST103-2911-I-008-001). Also, it is supported by National Chung-Shan Institute of Science & Technology in Taiwan (Grant nos. CSIST-095-V301 and CSIST-095-V302)
Resonant Subband Landau Level Coupling in Symmetric Quantum Well
Subband structure and depolarization shifts in an ultra-high mobility
GaAs/Al_{0.24}Ga_{0.76}As quantum well are studied using magneto-infrared
spectroscopy via resonant subband Landau level coupling. Resonant couplings
between the 1st and up to the 4th subbands are identified by well-separated
anti-level-crossing split resonance, while the hy-lying subbands were
identified by the cyclotron resonance linewidth broadening in the literature.
In addition, a forbidden intersubband transition (1st to 3rd) has been
observed. With the precise determination of the subband structure, we find that
the depolarization shift can be well described by the semiclassical slab plasma
model, and the possible origins for the forbidden transition are discussed.Comment: 4 pages, 2 figure
The d* dibaryon in the extended quark-delocalization, color-screening model
The quark-delocalization, color-screening model, extended by inclusion of a
one-pion-exchange (OPE) tail, is applied to the study of the deuteron and the
d* dibaryon. The results show that the properties of the deuteron (an extended
object) are well reproduced, greatly improving the agreement with experimental
data as compared to our previous study (without OPE). At the same time, the
mass and decay width of the d* (a compact object) are, as expected, not altered
significantly.Comment: 9 pages, no figures, LaTeX, subm. to Phys. Rev.
Transmission Investment and Expansion Planning in Electricity Market Environment
One of the most serious challenges for power industry restructuring is to maintain power system reliability at an acceptable level and to promote the overall economic efficiency of the whole power industry. To this end, transmission investment and expansion is inevitable. In the past decade, much effort has been made to address institutional structures, business models, incentives and regulation to assure appropriate transmission investments be made, and to develop workable assessment and planning methods for the deregulated environment. In this paper, a comprehensive survey is made on the state-of-the-art of several important issues associated with transmission investment and expansion planning in the electricity market environment, including: challenges of transmission investment and planning in the competitive market environment; transmission investment; merchant transmission; transmission rights; business models; transmission regulation; management of transmission investment and expansion; transmission planning methods; international experience.8 輸電監管在電力市場環境下,仍然需要對輸電系統進行監管,因為其仍具有自然壟斷特征,且要為實現公平競爭提供必要的場所。輸電監管的一個主要目標就是要促使輸電系統在滿足給定的可靠性要求的同時使經濟成本最低或經濟效益最高,例如使系統以最小的總成本向用戶供電。具體來講,對基于管制的輸電投資與擴展規劃進行監管的主要目的是降低未來不能有效利用輸電設備的風險,而對基于市場驅動的輸電投資與擴展規劃進行監管的主要目的是遏制有損整體社會福利的輸電投資
The d' dibaryon in the quark-delocalization, color-screening model
We study the questions of the existence and mass of the proposed dibaryon in the quark-delocalization, color-screening model
(QDCSM). The transformation between physical and symmetry bases has been
extended to the cases beyond the SU(2) orbital symmetry. Using parameters fixed
by baryon properties and scattering, we find a mild attraction in the
channel, but it is not strong enough to form a deeply bound state
as proposed for the state. Nor does the (isospin) I=2 N
configuration have a deeply bound state. These results show that if a narrow
dibaryon state does exist, it must have a more complicated structure.Comment: 12 pp. latex, no figs., 2 tables, additional refs., Report-no was
adde
Interdependent network reciprocity in evolutionary games
Besides the structure of interactions within networks, also the interactions between networks are of the outmost
importance. We therefore study the outcome of the public goods game on two interdependent networks that are
connected by means of a utility function, which determines how payoffs on both networks jointly influence the
success of players in each individual network. We show that an unbiased coupling allows the spontaneous
emergence of interdependent network reciprocity, which is capable to maintain healthy levels of public
cooperation even in extremely adverse conditions. The mechanism, however, requires simultaneous formation of
correlated cooperator clusters on both networks. If this does not emerge or if the coordination process is
disturbed, network reciprocity fails, resulting in the total collapse of cooperation. Network interdependence can
thus be exploited effectively to promote cooperation past the limits imposed by isolated networks, but only if the
coordination between the interdependent networks is not disturbe
Zika virus impairs the development of blood vessels in a mouse model of congenital infection
Zika virus (ZIKV) is associated with brain development abnormalities such as primary microcephaly, a severe reduction in brain growth. Here we demonstrated in vivo the impact of congenital ZIKV infection in blood vessel development, a crucial step in organogenesis. ZIKV was injected intravenously in the pregnant type 2 interferon (IFN)-deficient mouse at embryonic day (E) 12.5. The embryos were collected at E15.5 and postnatal day (P)2. Immunohistochemistry for cortical progenitors and neuronal markers at E15.5 showed the reduction of both populations as a result of ZIKV infection. Using confocal 3D imaging, we found that ZIKV infected brain sections displayed a reduction in the vasculature density and vessel branching compared to mocks at E15.5; altogether, cortical vessels presented a comparatively immature pattern in the infected tissue. These impaired vascular patterns were also apparent in the placenta and retina. Moreover, proteomic analysis has shown that angiogenesis proteins are deregulated in the infected brains compared to controls. At P2, the cortical size and brain weight were reduced in comparison to mock-infected animals. In sum, our results indicate that ZIKV impairs angiogenesis in addition to neurogenesis during development. The vasculature defects represent a limitation for general brain growth but also could regulate neurogenesis directly
Recommended from our members
High contrast dual-mode optical and 13C magnetic resonance imaging in diamond particles
Multichannel imaging -- the ability to acquire images of an object through
more than one imaging mode simultaneously -- has opened interesting new
perspectives in areas ranging from astronomy to medicine. Visible optics and
magnetic resonance imaging (MRI) offer complementary advantages of resolution,
speed and depth of penetration, and as such would be attractive in combination.
In this paper, we take first steps towards marrying together optical and MR
imaging in a class of biocompatible particulate materials constructed out of
diamond. The particles are endowed with a high density of quantum defects
(Nitrogen Vacancy centers) that under optical excitation fluoresce brightly in
the visible, but also concurrently electron spin polarize. This allows the
hyperpolarization of lattice 13C nuclei to make the particles over three-orders
of magnitude brighter than in conventional MRI. Dual-mode optical and MR
imaging permits immediate access to improvements in resolution and
signal-to-noise especially in scattering environments. We highlight additional
benefits in background-free imaging, demonstrating lock-in suppression by
factors of 2 and 5 in optical and MR domains respectively. Ultimate limits
could approach as much as two orders of magnitude in each domain. Finally,
leveraging the ability of optical and MR imaging to simultaneously probe
Fourier-reciprocal domains (real and k-space), we elucidate the ability to
employ hybrid sub-sampling in both conjugate spaces to vastly accelerate
dual-image acquisition, by as much as two orders of magnitude in practically
relevant sparse-imaging scenarios. This is accompanied by a reduction in
optical power by the same factor. Our work suggests interesting possibilities
for the simultaneous optical and low-field MR imaging of targeted diamond
nanoparticles
Evanescent light-matter Interactions in Atomic Cladding Wave Guides
Alkali vapors, and in particular rubidium, are being used extensively in
several important fields of research such as slow and stored light non-linear
optics3 and quantum computation. Additionally, the technology of alkali vapors
plays a major role in realizing myriad industrial applications including for
example atomic clocks magentometers8 and optical frequency stabilization.
Lately, there is a growing effort towards miniaturizing traditional
centimeter-size alkali vapor cells. Owing to the significant reduction in
device dimensions, light matter interactions are greatly enhanced, enabling new
functionalities due to the low power threshold needed for non-linear
interactions. Here, taking advantage of the mature Complimentary
Metal-Oxide-Semiconductor (CMOS) compatible platform of silicon photonics, we
construct an efficient and flexible platform for tailored light vapor
interactions on a chip. Specifically, we demonstrate light matter interactions
in an atomic cladding wave guide (ACWG), consisting of CMOS compatible silicon
nitride nano wave-guide core with a Rubidium (Rb) vapor cladding. We observe
the highly efficient interaction of the electromagnetic guided mode with the
thermal Rb cladding. The nature of such interactions is explained by a model
which predicts the transmission spectrum of the system taking into account
Doppler and transit time broadening. We show, that due to the high confinement
of the optical mode (with a mode area of 0.3{\lambda}2), the Rb absorption
saturates at powers in the nW regime.Comment: 10 Pages 4 Figures. 1 Supplementar
- …