27 research outputs found
Fabrication Of A Spun Elliptically Birefringent Photonic Crystal Fiber And Its Characterization As An Electrical Current Sensor
In this paper a spun elliptically birefringent photonic crystal fiber is fabricated and characterized. Its performance as a current sensor, using a polarimetric configuration, was tested and compared against single mode fiber at 633 nm. In particular the sensor sensitivity and linearity was investigated using fiber loops with different radius or number of turns around the conductor. The results obtained show that the spun fiber (40 rotation per meter) is able to suppress quite effectively the effects of the bend induced birefringence as compared to the standard fiber. © 2013 SPIE.8794 Innovative Economy National Cohesion Strategy,InPhoTech Ltd.,AMS Technologies,PHOENIXSilva, R., Optical current sensors for high power systems: A review (2012) Appl. Sci., 2, pp. 602-628GForman, P., Jahoda, F., Linear birefringence effects on fiber-optic current sensors (1988) Applied Optics, 27 (15), pp. 3088-3096Rose, A.H., Ren, Z., Day, G., Twisting and annealing optical fiber for current sensors (1996) Journal of Lightwave Technology, 14 (11), pp. 2492-2498Laming, R.I., Payne, S., Electric-current sensors employing spun highly birefringent optical fibers (1989) Journal of Lightwave Technology, 7 (12), pp. 2084-2094Michie, A., Spun elliptically birefringent photonic crystal fibre for current sensing (2007) Meas. Sci. Technol, 18, pp. 3070-307
Quantum jumps induced by the center-of-mass motion of a trapped atom
We theoretically study the occurrence of quantum jumps in the resonance
fluorescence of a trapped atom. Here, the atom is laser cooled in a
configuration of level such that the occurrence of a quantum jump is associated
to a change of the vibrational center-of-mass motion by one phonon. The
statistics of the occurrence of the dark fluorescence period is studied as a
function of the physical parameters and the corresponding features in the
spectrum of resonance fluorescence are identified. We discuss the information
which can be extracted on the atomic motion from the observation of a quantum
jump in the considered setup
Morphology and magnetism of multifunctional nanostructured -FeO films: Simulation and experiments
This paper introduces a new approach for simulating magnetic properties of
nanocomposites comprising magnetic particles embedded in a non-magnetic matrix,
taking into account the 3D structure of the system in which particles'
positions correctly mimic real samples. The proposed approach develops a
multistage simulation procedure in which the size and distribution of particles
within the hosting matrix is firstly attained by means of the Cell Dynamic
System (CDS) model. The 3D structure provided by the CDS step is further
employed in a Monte Carlo (MC) simulation of zero-field-cooled/field-cooled
(ZFC/FC) and magnetic hysteresis loops ( curves) for the system.
Simulations are aimed to draw a realistic picture of the as-produced ultra-thin
films comprising maghemite nanoparticles dispersed in polyaniline. Comparison
(ZFC/FC and curves) between experiments and simulations regarding
the maximum of the ZFC curve (), remanence () and
coercivity () revealed the great accuracy of the multistage approach
proposed here while providing information about the system's morphology and
magnetic properties. For a typical sample the value we found experimentally for
(54 K) was very close to the value provided by the
simulation (53 K). For the parameters depending on the nanoparticle clustering
the experimental values were consistently lower ( = 0.32 and =
210 Oe) than the values we found in the simulation ( = 0.53 and
= 274 Oe). Indeed, the approach introduced here is very promising for the
design of real magnetic nanocomposite samples with optimized features.Comment: 19 pages (one column), 5 figure
Heavy quarkonium: progress, puzzles, and opportunities
A golden age for heavy quarkonium physics dawned a decade ago, initiated by
the confluence of exciting advances in quantum chromodynamics (QCD) and an
explosion of related experimental activity. The early years of this period were
chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in
2004, which presented a comprehensive review of the status of the field at that
time and provided specific recommendations for further progress. However, the
broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles
could only be partially anticipated. Since the release of the YR, the BESII
program concluded only to give birth to BESIII; the -factories and CLEO-c
flourished; quarkonium production and polarization measurements at HERA and the
Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the
deconfinement regime. All these experiments leave legacies of quality,
precision, and unsolved mysteries for quarkonium physics, and therefore beg for
continuing investigations. The plethora of newly-found quarkonium-like states
unleashed a flood of theoretical investigations into new forms of matter such
as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the
spectroscopy, decays, production, and in-medium behavior of c\bar{c}, b\bar{b},
and b\bar{c} bound states have been shown to validate some theoretical
approaches to QCD and highlight lack of quantitative success for others. The
intriguing details of quarkonium suppression in heavy-ion collisions that have
emerged from RHIC have elevated the importance of separating hot- and
cold-nuclear-matter effects in quark-gluon plasma studies. This review
systematically addresses all these matters and concludes by prioritizing
directions for ongoing and future efforts.Comment: 182 pages, 112 figures. Editors: N. Brambilla, S. Eidelman, B. K.
Heltsley, R. Vogt. Section Coordinators: G. T. Bodwin, E. Eichten, A. D.
Frawley, A. B. Meyer, R. E. Mitchell, V. Papadimitriou, P. Petreczky, A. A.
Petrov, P. Robbe, A. Vair
IgM antibodies against malondialdehyde and phosphorylcholine in different systemic rheumatic diseases
IgM antibodies against phosphorylcholine (anti-PC) and malondialdehyde (anti-MDA) may have protective properties in cardiovascular and rheumatic diseases. We here compare these antibodies in systemic rheumatic conditions and study their properties. Anti-PC and anti-MDA was measured using ELISA in patients with SLE (374), RA (354), Mixed connective tissue disease (MCTD, 77), Systemic sclerosis (SSc, 331), Sj\uf6gren\u2019s syndrome (SjS, 324), primary antiphospholipid syndrome (PAPs, 65), undifferentiated connective tissue disease (UCTD, 118) and 515 matched healthy controls (HC). Cardiovascular score (CV) was broadly defined based on clinical disease symptoms. Anti-PC and anti-MDA peptide/protein characterization were compared using a proteomics de novo sequencing approach. anti-MDA and anti-PC were extracted from total IgM. The proportion of Treg cells was determined by flow cytometry. The maximal difference between cases and controls was shown for MCTD: significantly lower IgM Anti-PC but not anti-MDA among patients (median 49.3RU/ml vs 70.4 in healthy controls, p(t-test) = 0.0037). IgM low levels were more prevalent in MCTD, SLE, SjS, SSc and UCTD. IgM anti-PC variable region profiles were different from and more homologous than anti-MDA. Anti-PC but not anti-MDA were significantly negatively correlated with CV in the whole patient group. In contrast to IgM anti-PC, anti-MDA did not promote polarization of Tregs. Taken together, Anti-PC is decreased in MCTD and also in SLE, SjS and SSc but not in other studied diseases. Anti-PC may thus differentiate between these. In contrast, anti-MDA did not show these differences between diseases studied. Anti-PC level is negatively correlated with CV in the patient group cohort. In contrast to anti-PC, anti-MDA did not promote Treg polarization. These findings could have both diagnostic and therapeutic implications, one possibility being active or passive immunization with PC in some rheumatic conditions
Body appreciation around the world: Measurement invariance of the Body Appreciation Scale-2 (BAS-2) across 65 nations, 40 languages, gender identities, and age.
The Body Appreciation Scale-2 (BAS-2) is a widely used measure of a core facet of the positive body image construct. However, extant research concerning measurement invariance of the BAS-2 across a large number of nations remains limited. Here, we utilised the Body Image in Nature (BINS) dataset - with data collected between 2020 and 2022 - to assess measurement invariance of the BAS-2 across 65 nations, 40 languages, gender identities, and age groups. Multi-group confirmatory factor analysis indicated that full scalar invariance was upheld across all nations, languages, gender identities, and age groups, suggesting that the unidimensional BAS-2 model has widespread applicability. There were large differences across nations and languages in latent body appreciation, while differences across gender identities and age groups were negligible-to-small. Additionally, greater body appreciation was significantly associated with higher life satisfaction, being single (versus being married or in a committed relationship), and greater rurality (versus urbanicity). Across a subset of nations where nation-level data were available, greater body appreciation was also significantly associated with greater cultural distance from the United States and greater relative income inequality. These findings suggest that the BAS-2 likely captures a near-universal conceptualisation of the body appreciation construct, which should facilitate further cross-cultural research. [Abstract copyright: Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.
Advances in Fourier transform infrared (FTIR) spectroscopy of biological tissues
This article reviews some of the recent advances on FTIR spectroscopy in areas related to natural tissues and cell biology. It is an update on our previously published review on the applications of spectroscopic methods employed for the analysis of biological molecules, and summarizes some of the most widely used peak frequencies and their assignments. The aim of this review is to update and consolidate our previously published spectral database, which will help researchers in defining the chemical structure of the biological tissues introducing most of the important peaks present in the natural tissues more precisely and accurately. In spite of applying different methods, there seems to be a considerable similarity in defining the peaks of identical areas of the FTIR spectra. As a result, it is believed that preparing a unique collection of the frequencies encountered in FTIR spectroscopic studies can provide substantial help for future studies. In this article, we have included recent studies that have been reported since previous publication that will be of considerable assistance and added value to those who are focusing their research on defining chemical pathway to the progression of different diseases. © 2017 Taylor & Francis Group, LLC
Fabrication And Characterization Of Spun Hibi Pcf Fibers For Current Sensing Applications
In this paper three highly birefringent (HiBi) spun photonic crystal fibers (PCF) are fabricated and their performance are characterized for electrical current measurement. These fibers are tested by coiling them around an electric conductor using three distinct winding diameters with different turns. The results present a very good linear relation with the current and its sensitivity depends on the winding diameter and on the number of turns. For the larger winding diameter, the fiber with lower circular pitch had higher sensitivity and for the smaller winding diameter the best sensitivity result was for the fiber with higher circular pitch. © 2014 SPIE.9157BaySpec,COPSESA,et al.,FiberCore,FiberSensing,OZ OpticsEl-Khozondar, R.J., Koch, A.W., Magnetic field inhomogeneity induced on the Magneto-optical current sensors (2011) Information PhotonicsRahmatian, F., High-voltage current and voltage sensors for a smarter transmission grid and their use in live-line testing and calibration (2010) Power and Energy Society General Meeting, pp. 10-12Donaldson, E.F., Gibson, G.R., Pilling, N.A., Taylor, B.T., Hybrid optical current transformer with optical and power-line energisation (2000) Generation, Transmission and Distribution, 147 (5), pp. 304-309Laming, R.I., Payne, D.N., Electric current sensors employing spun highly birefringent optical fibers (1989) Journal of Lightwave Technology, 7 (12), pp. 2084-2094Gubin, V.P., Isaev, V.A., Morshnev, S.K., Sazonov, A.I., Starostin, N.I., Chamorovsky, Y.K., Oussov, A.I., Use of Spun optical fibres in current sensors (2006) Quantum Electronics, 36 (3), pp. 287-291Michie, A., Canning, J., Lyytikäinen, K., Aslund, M., Digweed, J., Temperature independent highly birefringent photonic crystal fibre (2004) Optics Express, 12 (21), pp. 5160-5165Michie, A., Canning, J., Bassett, I., Haywood, J., Digweed, K., Ashton, B., Stevenson, M., Lau, A., Spun elliptically birefringent photonic crystal fibre for current sensing (2007) Measurement Science and Technology, 18 (10), pp. 3070-3074Russell, P., Photonic crystal fibers (2003) Science, 299 (5605), pp. 358-362. , New York, N. YWest, R.H., Dispersion of verdet constant in stress-birefringent silica fibre (1984) Electronics Letters, 20 (22), pp. 20-2