Spontaneous emission by moving atoms

International Nuclear Information System (INIS)

Meystre, P.; Wilkens, M.

1994-01-01

It is well known that spontaneous emission is not an intrinsic atomic property, but rather results from the coupling of the atom to the vacuum modes of the electromagnetic field. As such, it can be modified by tailoring the electromagnetic environment into which the atom can radiate. This was already realized by Purcell, who noted that the spontaneous emission rate can be enhanced if the atom placed inside a cavity is resonant with one of the cavity is resonant with one of the cavity modes, and by Kleppner, who discussed the opposite case of inhibited spontaneous emission. It has also been recognized that spontaneous emission need not be an irreversible process. Indeed, a system consisting of a single atom coupled to a single mode of the electromagnetic field undergoes a periodic exchange of excitation between the atom and the field. This periodic exchange remains dominant as long as the strength of the coupling between the atom and a cavity mode is itself dominant. 23 refs., 6 figs

Spectrally narrowed emissions in 2,5-bis(4-biphenylyl)thiophene crystals pumped by fs laser pulse

International Nuclear Information System (INIS)

Kobayashi, S.; Sasaki, F.; Yanagi, H.; Hotta, S.; Ichikawa, M.; Taniguchi, Y.

2005-01-01

Spectrally narrowed emission (SNE) in 2,5-bis(4-biphenylyl)thiophene (BP1T) crystals is investigated using fs laser pulse. Two different types of narrowing are observed at different vibronic emission bands with increasing pump intensities. Based on their pump intensity dependence and illumination area dependence, we assign the SNE at 20,200 cm -1 (β-band) to amplified spontaneous emission (ASE) and the SNE at 21,600 cm -1 (α-band) to superfluorescence rather than ASE

Quantifying emissions from spontaneous combustion

Energy Technology Data Exchange (ETDEWEB)

NONE

2013-09-01

Spontaneous combustion can be a significant problem in the coal industry, not only due to the obvious safety hazard and the potential loss of valuable assets, but also with respect to the release of gaseous pollutants, especially CO2, from uncontrolled coal fires. This report reviews methodologies for measuring emissions from spontaneous combustion and discusses methods for quantifying, estimating and accounting for the purpose of preparing emission inventories.

Self-Seeded RSOA-Fiber Cavity Lasers vs. ASE Spectrum-Sliced or Externally Seeded Transmitters—A Comparative Study

Directory of Open Access Journals (Sweden)

Simon A. Gebrewold

2015-12-01

Full Text Available Reflective semiconductor optical amplifier fiber cavity lasers (RSOA-FCLs are appealing, colorless, self-seeded, self-tuning and cost-efficient upstream transmitters. They are of interest for wavelength division multiplexed passive optical networks (WDM-PONs based links. In this paper, we compare RSOA-FCLs with alternative colorless sources, namely the amplified spontaneous emission (ASE spectrum-sliced and the externally seeded RSOAs. We compare the differences in output power, signal-to-noise ratio (SNR, relative intensity noise (RIN, frequency response and transmission characteristics of these three sources. It is shown that an RSOA-FCL offers a higher output power over an ASE spectrum-sliced source with SNR, RIN and frequency response characteristics halfway between an ASE spectrum-sliced and a more expensive externally seeded RSOA. The results show that the RSOA-FCL is a cost-efficient WDM-PON upstream source, borrowing simplicity and cost-efficiency from ASE spectrum slicing with characteristics that are, in many instances, good enough to perform short-haul transmission. To substantiate our statement and to quantitatively compare the potential of the three schemes, we perform data transmission experiments at 5 and 10 Gbit/s.

Measurement of amplified spontaneous emission at 200 A

International Nuclear Information System (INIS)

Ceglio, N.M.

1985-01-01

Recent interest in the production of laser radiation at soft x-ray wavelengths makes appropriate the discussion of diagnostic considerations and techniques for the measurement of same. A source of soft x-ray ASE has a number of characteristics which drive the design of diagnostic instruments: (1) the anisotropy of the ASE makes target alignment a critical part of the diagnosis, and couples collection solid angle to S/N considerations in the measurement; (2) the narrow linewidth of the amplified emission and its long wavelength put a high S/N premium on spectroscopic instrumentation of high spectral resolution and good higher-order discrimination; (3) the specialized plasma conditions required to produce gain are typically short lived, requiring time-resolved or at least time-discriminating spectroscopy; (4) the nonlinear nature of the threshold processes involved in ASE requires instrumentation of large dynamic range, broad angular acceptance, and large field of view and depth of focus. Of the many possible methods for gain verification of the x-ray source, five are discussed: (1) probe amplification; (2) spatial coherence measurement (as a function of gain length); (3) output intensity measurement (absolute measurement and nonlinear variation with gain length); (4) divergence measurement; and (5) cavity formation. In addition, recent soft x-ray laser experiments at LLNL are discussed along with descriptions of the instruments used to measure the ASE. Diagnostic design suggestions for future soft x-ray laser experiments are also presented

Ion cyclotron emission by spontaneous emission

Energy Technology Data Exchange (ETDEWEB)

Da Costa, O [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Gresillon, D [Ecole Polytechnique, 91 - Palaiseau (France). Lab. de Physique des Milieux Ionises

1994-07-01

The goal of the study is to examine whether the spontaneous emission can account for ICE (ion cyclotron emission) experimental results, or part of them. A straightforward approach to plasma emission is chosen, investigating the near equilibrium wave radiation by gyrating ions, and thus building from the majority and fast fusion ions the plasma fluctuations and emission on the fast magnetoacoustic or compressional Alfven wave mode in the IC frequency range. Similarities with the ICE experiments are shown: the emission temperature in the presence of fast ions (even in a very small amount), the strong fast ion emission increase with the harmonic, the fine double-line splitting of each peak, the linear but not proportional increase of the peak width with the harmonic. 3 refs., 2 figs.

Ion cyclotron emission by spontaneous emission

International Nuclear Information System (INIS)

Da Costa, O.; Gresillon, D.

1994-01-01

The goal of the study is to examine whether the spontaneous emission can account for ICE (ion cyclotron emission) experimental results, or part of them. A straightforward approach to plasma emission is chosen, investigating the near equilibrium wave radiation by gyrating ions, and thus building from the majority and fast fusion ions the plasma fluctuations and emission on the fast magnetoacoustic or compressional Alfven wave mode in the IC frequency range. Similarities with the ICE experiments are shown: the emission temperature in the presence of fast ions (even in a very small amount), the strong fast ion emission increase with the harmonic, the fine double-line splitting of each peak, the linear but not proportional increase of the peak width with the harmonic. 3 refs., 2 figs

Gain optimization method of a DQW superluminescent diode with broad multi-state emission

KAUST Repository

Dimas, Clara E.

2010-01-01

Optimizing gain through systematic methods of varying current injection schemes analytically is significant to maximize experimentally device yield and evaluation. Various techniques are used to calculate the amplified spontaneous emission (ASE) gain for light emitting devices consisting of single-section and multiple-sections of even length. Recently double quantum well (DQW) superluminescent diodes (SLD) have shown a broad multi-state emission due to mutlielectrodes of non-equal lengths and at high non-equal current densities. In this study, we adopt an improved method utilizing an ASE intensity ratio to calibrate a gain curve based on the sum of the measured ASE spectra to efficiently estimate the gain. Although the laser gain for GaAs/AlGaAs material is well studied, the ASE gain of SLD devices has not been systematically studied particular to further explain the multiple-state emission observed in fabricated devices. In addition a unique gain estimate was achieved where the excited state gain clamps prior to the ground state due to approaching saturation levels. In our results, high current densities in long sectioned active regions achieved sufficient un-truncated gain that show evidence of excited state emission has been observed.

General theory of spontaneous emission near exceptional points.

Science.gov (United States)

Pick, Adi; Zhen, Bo; Miller, Owen D; Hsu, Chia W; Hernandez, Felipe; Rodriguez, Alejandro W; Soljačić, Marin; Johnson, Steven G

2017-05-29

We present a general theory of spontaneous emission at exceptional points (EPs)-exotic degeneracies in non-Hermitian systems. Our theory extends beyond spontaneous emission to any light-matter interaction described by the local density of states (e.g., absorption, thermal emission, and nonlinear frequency conversion). Whereas traditional spontaneous-emission theories imply infinite enhancement factors at EPs, we derive finite bounds on the enhancement, proving maximum enhancement of 4 in passive systems with second-order EPs and significantly larger enhancements (exceeding 400×) in gain-aided and higher-order EP systems. In contrast to non-degenerate resonances, which are typically associated with Lorentzian emission curves in systems with low losses, EPs are associated with non-Lorentzian lineshapes, leading to enhancements that scale nonlinearly with the resonance quality factor. Our theory can be applied to dispersive media, with proper normalization of the resonant modes.

Cavity enhanced rephased amplified spontaneous emission

International Nuclear Information System (INIS)

A Williamson, Lewis; J Longdell, Jevon

2014-01-01

Amplified spontaneous emission is usually treated as an incoherent noise process. Recent theoretical and experimental work using rephasing optical pulses has shown that rephased amplified spontaneous emission (RASE) is a potential source of wide bandwidth time-delayed entanglement. Due to poor echo efficiency the plain RASE protocol does not in theory achieve perfect entanglement. Experiments done to date show a very small amount of entanglement at best. Here we show that RASE can, in principle, produce perfect multimode time-delayed two mode squeezing when the active medium is placed inside a Q-switched cavity. (paper)

Spontaneous emission from active dielectric microstructures

DEFF Research Database (Denmark)

Søndergaard, Thomas; Tromborg, Bjarne

2001-01-01

and engineered due to the dependence of the emission rate on the location and polarisation of the emitters in the structure. This paper addresses the methods of quantum electrodynamics of dielectric media which enable calculation of the local rate of spontaneous emission in active microstructures....

Spontaneous emission control in a tunable hybrid photonic system

NARCIS (Netherlands)

Frimmer, M.; Koenderink, A.F.

2013-01-01

We experimentally demonstrate control of the rate of spontaneous emission in a tunable hybrid photonic system that consists of two canonical building blocks for spontaneous emission control, an optical antenna and a mirror, each providing a modification of the local density of optical states (LDOS).

Synchronization of cubic distortion spontaneous otoacoustic emissions

NARCIS (Netherlands)

van Dijk, P; Wit, HP

A spontaneous otoacoustic emission spectrum may contain equally spaced emission peaks. Then, two peaks, at frequencies, f(1) and f(2), respectively, apparently generate a distortion product at f(d)=2f(1)-f(2) [or 2f(2)-f(1)]. For the three emission peaks of nine of such triplets tin six emission

Spontaneous emission of the non-Wiener type

International Nuclear Information System (INIS)

Basharov, A. M.

2011-01-01

The spontaneous emission of a quantum particle and superradiation of an ensemble of identical quantum particles in a vacuum electromagnetic field with zero photon density are examined under the conditions of significant Stark particle and field interaction. New fundamental effects are established: suppression of spontaneous emission by the Stark interaction, an additional “decay” shift in energy of the decaying level as a consequence of Stark interaction unrelated to the Lamb and Stark level shifts, excitation conservation phenomena in a sufficiently dense ensemble of identical particles and suppression of superradiaton in the decay of an ensemble of excited quantum particles of a certain density. The main equations describing the emission processes under conditions of significant Stark interaction are obtained in the effective Hamiltonian representation of quantum stochastic differential equations. It is proved that the Stark interaction between a single quantum particle and a broadband electromagnetic field is represented as a quantum Poisson process and the stochastic differential equations are of the non-Wiener (generalized Langevin) type. From the examined case of spontaneous emission of a quantum particle, the main rules are formulated for studying open systems in the effective Hamiltonian representation.

Intra-cavity upconversion to 631 nm of images illuminated by an eye-safe ASE source at 1550 nm.

Science.gov (United States)

Torregrosa, A J; Maestre, H; Capmany, J

2015-11-15

We report an image wavelength upconversion system. The system mixes an incoming image at around 1550 nm (eye-safe region) illuminated by an amplified spontaneous emission (ASE) fiber source with a Gaussian beam at 1064 nm generated in a continuous-wave diode-pumped Nd(3+):GdVO(4) laser. Mixing takes place in a periodically poled lithium niobate (PPLN) crystal placed intra-cavity. The upconverted image obtained by sum-frequency mixing falls around the 631 nm red spectral region, well within the spectral response of standard silicon focal plane array bi-dimensional sensors, commonly used in charge-coupled device (CCD) or complementary metal-oxide-semiconductor (CMOS) video cameras, and of most image intensifiers. The use of ASE illumination benefits from a noticeable increase in the field of view (FOV) that can be upconverted with regard to using coherent laser illumination. The upconverted power allows us to capture real-time video in a standard nonintensified CCD camera.

1.7  μm band narrow-linewidth tunable Raman fiber lasers pumped by spectrum-sliced amplified spontaneous emission.

Science.gov (United States)

Zhang, Peng; Wu, Di; Du, Quanli; Li, Xiaoyan; Han, Kexuan; Zhang, Lizhong; Wang, Tianshu; Jiang, Huilin

2017-12-10

A 1.7 μm band tunable narrow-linewidth Raman fiber laser based on spectrally sliced amplified spontaneous emission (SS-ASE) and multiple filter structures is proposed and experimentally demonstrated. In this scheme, an SS-ASE source is employed as a pump source in order to avoid stimulated Brillouin scattering. The ring configuration includes a 500 m long high nonlinear optical fiber and a 10 km long dispersion shifted fiber as the gain medium. A segment of un-pumped polarization-maintaining erbium-doped fiber is used to modify the shape of the spectrum. Furthermore, a nonlinear polarization rotation scheme is applied as the wavelength selector to generate lasers. A high-finesse ring filter and a ring filter are used to narrow the linewidth of the laser, respectively. We demonstrate tuning capabilities of a single laser over 28 nm between 1652 nm and 1680 nm by adjusting the polarization controller (PC) and tunable filter. The tunable laser has a 0.023 nm effective linewidth with the high-finesse ring filter. The stable multi-wavelength laser operation of up to four wavelengths can be obtained by adjusting the PC carefully when the pump power increases.

Shell theorem for spontaneous emission

DEFF Research Database (Denmark)

Kristensen, Philip Trøst; Mortensen, Jakob Egeberg; Lodahl, Peter

2013-01-01

and therefore is given exactly by the dipole approximation theory. This surprising result is a spontaneous emission counterpart to the shell theorems of classical mechanics and electrostatics and provides insights into the physics of mesoscopic emitters as well as great simplifications in practical calculations....

Role of spontaneous and stimulated emission in photon correlations

International Nuclear Information System (INIS)

Chopra, S.; Bohidar, H.; Harwalkar, V.

1984-01-01

Photon correlations have been alternately attributed to either spontaneous or stimulated emission by various authors. In this paper, the authors interpret, on the basis of available experimental data, the contribution of each emission form to the evolution of photon statistics. The laser is used as an example of a source which exhibits different statistical characteristics depending on the level of excitation, which is governed by the pump parameter a. From the data, it is evident that the transition from below to above threshold is accompanied by a significant drop in the magnitude of correlation and an increase in decay time. It may be noted that this transition causes a substantial increase in the coherent output which emphasizes the predominance of stimulated emission. In the case of a laser below threshold, however, photon correlations arise due to superposition of the more dominant spontaneously emitted wavetrains. Exact solutions of quantized systems do not exist in the presence of saturation effects. This implies that factorization and identification of terms with spontaneous or stimulated emission has not yet been done. This does not preculde a physical and intuitive interpretation of photon statistics within the framework of a standard model, and it is therefore argued that spontaneous emission is responsible for photon correlations while stimulated emission shows up in the dynamics as the coherence time

Pulse distortion, energy extraction, and ASE in an HF amplifier with angular multiplexing

International Nuclear Information System (INIS)

McGuire, E.J.

1976-09-01

It has been proposed that 1 ns pulses can be efficiently extracted from the e-beam initiated HF laser by angular multiplexing, i.e., filling the amplifier with the 1 ns pulses, 1 ns apart in time, each pulse at a slightly different angle; each pulse has an input intensity of 1 W/cm 2 per line and almost fills the amplifier. We have treated this in a one dimensional model, neglecting transverse amplified spontaneous emission. We conclude that the scheme is efficient, and that most of the pulses are amplified but not distorted. The first few pulses are distorted by transient effects and the last pulse has an enhanced tail. The ratio of peak pulse intensity to forward ASE at the output is 10 4 . We then include transverse ASE and find a drastically different situation. ASE saturates the inversion after a short time depending on pulse intensity (4 ns at I/sub o/ = 1 W/cm 2 , 7 ns at I/sub o/ = 100 W/cm 2 ). The saturation time is only weakly dependent on the transverse reflection coefficient. Calculations were done on an amplifier system designed for 10 KJ output. At an incident peak pulse intensity of 10 4 W/cm 2 -line (.77 MW/cm 2 for 77 lines) 2.5 KJ was obtained in amplified pulse energy, i.e., only 6 pulses of the 24 pulse train were fully amplified. The calculations indicate that double passing the pulse train through the amplifier would enhance the energy extracted

Broadband enhancement of spontaneous emission in a photonic-plasmonic structure

DEFF Research Database (Denmark)

Zhu, Xiaolong; Xie, Fengxian; Shi, Lei

2012-01-01

We demonstrate that a broadband enhancement of spontaneous emission can be achieved within a photonic-plasmonic structure. The structure can strongly modify the spontaneous emission by exciting plasmonic modes. Because of the excited plasmonic modes, an enhancement up to 30 times is observed, lea......, leading to a 4 times broader emission spectrum. The reflectance measurement and the finite-difference time-domain simulation are carried out to support these results....

Nonclassical photon streams using rephased amplified spontaneous emission

International Nuclear Information System (INIS)

Ledingham, Patrick M.; Naylor, William R.; Longdell, Jevon J.; Beavan, Sarah E.; Sellars, Matthew J.

2010-01-01

We present a fully quantum mechanical treatment of optically rephased photon echoes. These echoes exhibit noise due to amplified spontaneous emission; however, this noise can be seen as a consequence of the entanglement between the atoms and the output light. With a rephasing pulse one can get an 'echo' of the amplified spontaneous emission, leading to light with nonclassical correlations at points separated in time, which is of interest in the context of building wide bandwith quantum repeaters. We also suggest a wideband version of DLCZ protocol based on the same ideas.

Highly Efficient Spontaneous Emission from Self-Assembled Quantum Dots

DEFF Research Database (Denmark)

Johansen, Jeppe; Lund-Hansen, Toke; Hvam, Jørn Märcher

2006-01-01

We present time resolved measurements of spontaneous emission (SE) from InAs/GaAs quantum dots (QDs). The measurements are interpreted using Fermi's Golden Rule and from this analysis we establish the parameters for high quantum efficiency.......We present time resolved measurements of spontaneous emission (SE) from InAs/GaAs quantum dots (QDs). The measurements are interpreted using Fermi's Golden Rule and from this analysis we establish the parameters for high quantum efficiency....

Simulation investigation of storage ring optical klystron spontaneous emission

International Nuclear Information System (INIS)

Xu Hongliang; Liu Jinying; He Duohui; Diao Caozheng; Jia Qika; Sun Baogen

1998-01-01

The spontaneous emission of TOK in Hefei storage ring was simulated with Monte Carlo method. Section one described the structure of the permanent magnet TOK and the magnet field of TOK. Section two simulated results, and simulated results illustrated how the energy spread and emittance of electron beam impose on the spectrum of spontaneous emission. And with help of simulated results, the causes of small modulation factor which was measured by experiment was discussed

A hybrid nanoantenna for highly enhanced directional spontaneous emission

Energy Technology Data Exchange (ETDEWEB)

Chou, R. Yuanying; Lu, Guowei, E-mail: guowei.lu@pku.edu.cn; Shen, Hongming; He, Yingbo; Cheng, Yuqing [State Key Laboratory for Mesoscopic Physics, Department of Physics, Peking University, Beijing 100871 (China); Perriat, Pascal [MATEIS, UMR 5510 CNRS, INSA-Lyon, Université de Lyon, Villeurbanne Cedex 69621 (France); Martini, Matteo; Tillement, Olivier [ILM, UMR 5306 CNRS, Université de Lyon, Villeurbanne Cedex 69622 (France); Gong, Qihuang [State Key Laboratory for Mesoscopic Physics, Department of Physics, Peking University, Beijing 100871 (China); Collaborative Innovation Center of Quantum Matter, Beijing 100871 (China)

2014-06-28

Spontaneous emission modulated by a hybrid plasmonic nanoantenna has been investigated by employing finite-difference time-domain method. The hybrid nanoantenna configurations constituted by a gap hot-spot and of a plasmonic corrugated grating and a metal reflector sandwiching a SiO{sub 2} thin layer which appears promising for high spontaneous emission enhancement devices. Simulation assays show that the coupling between the gap-antenna and plasmonic corrugations reaches an ultra-high near-field enhancement factor in the excitation process. Moreover, concerning the emission process, the corrugations concentrate the far-field radiated power within a tiny angular volume, offering unprecedented collection efficiency. In the past decades, many kinds of optical antennas have been proposed and optimized to enhance single molecule detection. However, the excitation enhancement effect for single individual or dimmer plasmonic nanostructure is limited due to intrinsic nonradiative decay of the nanoparticle plasmon and quantum tunneling effect. The proposed hybrid configuration overwhelms the enhancement limit of single individual plasmonic structure. The findings provide an insight into spontaneous emission high enhancement through integrating the functions of different metallic nanostructures.

A hybrid nanoantenna for highly enhanced directional spontaneous emission

International Nuclear Information System (INIS)

Chou, R. Yuanying; Lu, Guowei; Shen, Hongming; He, Yingbo; Cheng, Yuqing; Perriat, Pascal; Martini, Matteo; Tillement, Olivier; Gong, Qihuang

2014-01-01

Spontaneous emission modulated by a hybrid plasmonic nanoantenna has been investigated by employing finite-difference time-domain method. The hybrid nanoantenna configurations constituted by a gap hot-spot and of a plasmonic corrugated grating and a metal reflector sandwiching a SiO 2 thin layer which appears promising for high spontaneous emission enhancement devices. Simulation assays show that the coupling between the gap-antenna and plasmonic corrugations reaches an ultra-high near-field enhancement factor in the excitation process. Moreover, concerning the emission process, the corrugations concentrate the far-field radiated power within a tiny angular volume, offering unprecedented collection efficiency. In the past decades, many kinds of optical antennas have been proposed and optimized to enhance single molecule detection. However, the excitation enhancement effect for single individual or dimmer plasmonic nanostructure is limited due to intrinsic nonradiative decay of the nanoparticle plasmon and quantum tunneling effect. The proposed hybrid configuration overwhelms the enhancement limit of single individual plasmonic structure. The findings provide an insight into spontaneous emission high enhancement through integrating the functions of different metallic nanostructures.

Polarization control of spontaneous emission for rapid quantum-state initialization

Science.gov (United States)

DiLoreto, C. S.; Rangan, C.

2017-04-01

We propose an efficient method to selectively enhance the spontaneous emission rate of a quantum system by changing the polarization of an incident control field, and exploiting the polarization dependence of the system's spontaneous emission rate. This differs from the usual Purcell enhancement of spontaneous emission rates as it can be selectively turned on and off. Using a three-level Λ system in a quantum dot placed in between two silver nanoparticles and a linearly polarized, monochromatic driving field, we present a protocol for rapid quantum state initialization, while maintaining long coherence times for control operations. This process increases the overall amount of time that a quantum system can be effectively utilized for quantum operations, and presents a key advance in quantum computing.

An Easy Approach to Control β-Phase Formation in PFO Films for Optimized Emission Properties

Directory of Open Access Journals (Sweden)

Qi Zhang

2017-02-01

Full Text Available We demonstrate a novel approach to control β-phase content generated in poly(9,9-dioctylfluorene (PFO films. A very small amount of paraffin oil was used as the additive to the PFO solution in toluene. The β-phase fraction in the spin-coated PFO films can be modified from 0% to 20% simply by changing the volume percentage of paraffin oil in the mixed solution. Organic light emitting diodes (OLEDs and amplified spontaneous emission (ASE study confirmed low β-phase fraction promise better OLEDs device, while high β-phase fraction benefits ASE performance.

Transformation quantum optics: designing spontaneous emission using coordinate transformations

DEFF Research Database (Denmark)

Zhang, Jingjing; Wubs, Martijn; Ginzburg, Pavel

2016-01-01

Spontaneous decay is a fundamental quantum property of emitters that can be controlled in a material environment via modification of the local density of optical states (LDOS). Here we use transformation optics methods in order to design required density of states and thus spontaneous emission (S......, affect the LDOS in complex materials. Tailoring SE properties using transformation optics approach provides an innovative way for designing emission properties in a complex material environment needed for the development of active nanophotonic devices....

Spontaneous light emission in complex nanostructures

Science.gov (United States)

Blanco, L. A.; García de Abajo, F. J.

2004-05-01

The spontaneous emission of an excited atom surrounded by different materials is studied in the framework of a semiclassical approach, where the transition dipole moment acts as the source of the emission field. The emission in the presence of semiinfinite media, metallic nanorings, spheres, gratings, and other complex geometries is investigated. Strong emission enhancement effects are obtained in some of these geometries associated to the excitation of plasmons (e.g., in nanorings or spheres). Furthermore, the emission is shown to take place only along narrow angular distributions when the atom is located inside a low-index dielectric and near its planar surface, or when metallic nanogratings are employed at certain resonant wave lengths. In particular, axially symmetric gratings made of real silver metal are considered, and both emission rate enhancement and focused far-field emission are achieved simultaneously when the grating is decorated with further nanostructures.

Spontaneous Emission and Energy Transfer Rates Near a Coated Metallic Cylinder

OpenAIRE

BRADLEY, LOUISE

2014-01-01

PUBLISHED The spontaneous emission and energy transfer rates of quantum systems in proximity to a dielectrically coated metallic cylinder are investigated using a Green's tensor formalism. The excitation of surface plasmon modes can significantly modify these rates. The spontaneous emission and energy transfer rates are investigated as a function of the material and dimensions of the core and coating, as well as the emission wavelength of the donor. For the material of the core we consider...

Coherent manipulation of spontaneous emission spectra in coupled semiconductor quantum well structures.

Science.gov (United States)

Chen, Aixi

2014-11-03

In triple coupled semiconductor quantum well structures (SQWs) interacting with a coherent driving filed, a coherent coupling field and a weak probe field, spontaneous emission spectra are investigated. Our studies show emission spectra can easily be manipulated through changing the intensity of the driving and coupling field, detuning of the driving field. Some interesting physical phenomena such as spectral-line enhancement/suppression, spectral-line narrowing and spontaneous emission quenching may be obtained in our system. The theoretical studies of spontaneous emission spectra in SQWS have potential application in high-precision spectroscopy. Our studies are based on the real physical system [Appl. Phys. Lett.86(20), 201112 (2005)], and this scheme might be realizable with presently available techniques.

Temporal and transverse coherence of self-amplified spontaneous emission

International Nuclear Information System (INIS)

Kim, K.J.

1997-06-01

The authors review the coherence properties of the self-amplified spontaneous emission (SASE). Temporally, SASE is similar to the spontaneous undulator radiation except that the spectral bandwidth is about ten times narrower compared with typical undulator radiation. The situation is quite different in the transverse dimension, where SASE is fully coherent

Cooperative spontaneous emission of nano-emitters with inter-emitter coupling in a leaky microcavity

International Nuclear Information System (INIS)

Hong, Suc-Kyoung; Nam, Seog Woo; Yang, Hyung Jin

2015-01-01

We study the spontaneous emission from a few two-level nano-emitters placed in a leaky microcavity with Lorentzian spectral density near a critically damped regime. Collective features of the spontaneous emission are investigated by numerical analysis of the excitation dynamics when initially one nano-emitter is totally excited but we do not know which one. The results show that there are three decay rates in the excitation dynamics, two for simple exponential decays and one for damped oscillatory decay. The excitation dynamics is found to critically depend on the regime of the system. It is shown that the spontaneous emission is enhanced or suppressed depending on whether the system is in the underdamped or overdamped regime, respectively. On the other hand, the cooperative spontaneous emission is suppressed in the underdamped while it is enhanced in the overdamped regime. Furthermore, the effect of the direct inter-emitter coupling on the breaking of the cooperativeness of the spontaneous emission is shown as well. (paper)

Amplified spontaneous emission from ZnO in n-ZnO/ZnO nanodots-SiO(2) composite/p-AlGaN heterojunction light-emitting diodes.

Science.gov (United States)

Shih, Ying Tsang; Wu, Mong Kai; Li, Wei Chih; Kuan, Hon; Yang, Jer Ren; Shiojiri, Makoto; Chen, Miin Jang

2009-04-22

This study demonstrates amplified spontaneous emission (ASE) of the ultraviolet (UV) electroluminescence (EL) from ZnO at lambda~380 nm in the n-ZnO/ZnO nanodots-SiO(2) composite/p- Al(0.12)Ga(0.88)N heterojunction light-emitting diode. A SiO(2) layer embedded with ZnO nanodots was prepared on the p-type Al(0.12)Ga(0.88)N using spin-on coating of SiO(2) nanoparticles followed by atomic layer deposition (ALD) of ZnO. An n-type Al-doped ZnO layer was deposited upon the ZnO nanodots-SiO(2) composite layer also by the ALD technique. High-resolution transmission electron microscopy (HRTEM) reveals that the ZnO nanodots embedded in the SiO(2) matrix have diameters of 3-8 nm and the wurtzite crystal structure, which allows the transport of carriers through the thick ZnO nanodots-SiO(2) composite layer. The high quality of the n-ZnO layer was manifested by the well crystallized lattice image in the HRTEM picture and the low-threshold optically pumped stimulated emission. The low refractive index of the ZnO nanodots-SiO(2) composite layer results in the increase in the light extraction efficiency from n-ZnO and the internal optical feedback of UV EL into n-ZnO layer. Consequently, significant enhancement of the UV EL intensity and super-linear increase in the EL intensity, as well as the spectral narrowing, with injection current were observed owing to ASE in the n-ZnO layer.

Emissions in potassium vapour under 4S1/2-7S1/2 two-photon nsec excitation

International Nuclear Information System (INIS)

Pentaris, D.; Chatzikyriakos, G.; Armyras, A.; Efthimiopoulos, T.

2010-01-01

The two-photon excitation of 4S 1/2 -7S 1/2 transition of potassium atoms is studied. Several coherent emissions and processes are possible, such as parametric four-wave (PFWM), parametric six-wave (PSWM) mixing and competition with the stimulated hyper Raman (SHRS) and the amplified spontaneous emission (ASE). The radiations at the transitions 6P 3/2,1/2 -4S 1/2 , 6S 1/2 -4P 3/2,1/2 and 5P 3/2,1/2 -4S 1/2 are emitted only in the forward direction (indicating a parametric process), while the radiation at the transition 4P 3/2,1/2 -4S 1/2 is emitted in the forward and in the backward direction, indicating an ASE process.

Spontaneous emission spectra and simulating multiple spontaneous generation coherence in a five-level atomic medium

International Nuclear Information System (INIS)

Li Jiahua; Liu Jibing; Qi Chunchao; Chen Aixi

2006-01-01

We investigate the features of the spontaneous emission spectra in a coherently driven cold five-level atomic system by means of a radio frequency (rf) or microwave field driving a hyperfine transition within the ground state. It is shown that a few interesting phenomena such as spectral-line narrowing, spectral-line enhancement, spectral-line suppression, and spontaneous emission quenching can be realized by modulating the frequency and intensity of the rf-driving field in our system. In the dressed-state picture of the coupling and rf-driving fields, we find that this coherently driven atomic system has three close-lying levels so that multiple spontaneously generated coherence (SGC) arises. Our considered atomic model can be found in real atoms, such as rubidium or sodium, so a corresponding experiment can be done to observe the expected phenomena related to SGC reported by Fountoulakis et al. [Phys. Rev. A 73, 033811 (2006)], since no rigorous conditions are required

Spontaneous emission of quantum dots in disordered photonic crystal waveguides

DEFF Research Database (Denmark)

Sapienza, Luca; Nielsen, Henri Thyrrestrup; Stobbe, Søren

2010-01-01

We report on the enhancement of the spontaneous emission rate of single semiconductor quantum dots embedded in a photonic crystal waveguide with engineered disorder. Random high-Q cavities, that are signature of Anderson localization, are measured in photoluminescence experiments and appear...... in the slow light regime of the waveguide mode. Time resolved experiments show a 15-fold enhancement of the spontaneous emission rate, with coupling efficiencies of single photons into Anderson localized cavity modes of 94%. These results show that the performances of Anderson-localized cavities...

Spontaneous Emission Enhancement at Finite-length Metal

DEFF Research Database (Denmark)

Filonenko, K.; Willatzen, Morten; Bordo, V.

2013-01-01

We study spontaneous emission enhancement of a two-level atomic emitter placed in a dielectric medium near a finite-length cylindrical metal nanowire. We calculate the dependence of the Purcell factor and the normalized decay rate to a continuous spectrum on the nanowire radius for several emitter...

Electrically induced spontaneous emission in open electronic system

Science.gov (United States)

Wang, Rulin; Zhang, Yu; Yam, Chiyung; Computation Algorithms Division (CSRC) Team; Theoretical; Computational Chemistry (HKU) Collaboration

A quantum mechanical approach is formulated for simulation of electroluminescence process in open electronic system. Based on nonequilibrium Green's function quantum transport equations and combining with photon-electron interaction, this method is used to describe electrically induced spontaneous emission caused by electron-hole recombination. The accuracy and reliability of simulation depends critically on correct description of the electronic band structure and the electron occupancy in the system. In this work, instead of considering electron-hole recombination in discrete states in the previous work, we take continuous states into account to simulate the spontaneous emission in open electronic system, and discover that the polarization of emitted photon is closely related to its propagation direction. Numerical studies have been performed to silicon nanowire-based P-N junction with different bias voltage.

Two-dimensional sub-half-wavelength atom localization via controlled spontaneous emission.

Science.gov (United States)

Wan, Ren-Gang; Zhang, Tong-Yi

2011-12-05

We propose a scheme for two-dimensional (2D) atom localization based on the controlled spontaneous emission, in which the atom interacts with two orthogonal standing-wave fields. Due to the spatially dependent atom-field interaction, the position probability distribution of the atom can be directly determined by measuring the resulting spontaneously emission spectrum. The phase sensitive property of the atomic system leads to quenching of the spontaneous emission in some regions of the standing-waves, which significantly reduces the uncertainty in the position measurement of the atom. We find that the frequency measurement of the emitted light localizes the atom in half-wavelength domain. Especially the probability of finding the atom at a particular position can reach 100% when a photon with certain frequency is detected. By increasing the Rabi frequencies of the driving fields, such 2D sub-half-wavelength atom localization can acquire high spatial resolution.

Performance of the 2-D asynchronous OCDMA system with ASE light sources

Science.gov (United States)

Ni, Bin; Lehnert, James S.

2005-09-01

The wavelength-hopping/time-spreading scheme for optical code-division multiple-access (OCDMA), also known as the 2-D scheme, has been studied by many researchers for more than a decade. In all of previous analyses, the light sources were modeled as perfectly incoherent, which requires infinite bandwidth, and chip-synchrony was assumed for mathematical simplicity. Therefore, it is important to study how the system actually performs with true asynchrony and practical light sources. The amplified spontaneous emission (ASE) source is a desirable source for the incoherent OCDMA system because of its broad bandwidth, large power, and low cost. In this paper, each chip generated by the transmitter is a rectangular ASE pulse with a Gaussian-distributed electrical field. The coherence time is much smaller than the chip duration, but non-zero. Because of this partial coherence of the light source, beat noise will occur when multiple pulses are combined. In addition, interfering pulses may only partially overlap with the pulses from the desired user due to the asynchrony, which introduces more randomness into the decision statistic. Both factors are taken into account when the distribution of the decision statistic is derived mathematically. Simulations of the bit-error rate (BER) are performed, and the results show that the coherence time may be the major limiting factor on the system performance. For example, when the coherence time is only 1/100 of the chip duration, the BER is 1-4 orders of magnitude worse than that of the ideal case.

Rocket experiment on spontaneously and artificially stimulated VLF plasma waves in the ionosphere

International Nuclear Information System (INIS)

Matsumoto, H.; Miyatake, S.; Kimura, I.

1975-01-01

In situ active experiments on the nonlinear wave-wave and wave-particle interactions in the ionospheric plasma were performed by a Japanese sounding rocket K-9M-41. Both spontaneously and artificially stimulated plasma waves in the VLF range were observed. When a large amplitude electron plasma wave was transmitted from the rocket, parametrically excited ion acoustic waves were observed in addition to natural emissions such as whistlers, LHR emissions, and hisslike emissions. It was also found that 'risers' were triggered by the LHR emissions, which seem to be very similar to a phenomenon of the so-called ASE (artificially stimulated emissions). When a slow electron beam with energy lower than 3 eV was ejected from the rocket, a new type of periodic U-shaped discrete emission was observed which was excited through a wave-particle interaction. The frequency of these emissions is lower than the LHR frequency and decreases as the beam energy is increased. Spectrograms of the observed plasma are presented, and some are analyzed theoretically. (auth)

Modulation response of quantum dot nanolight-emitting-diodes exploiting purcell-enhanced spontaneous emission

DEFF Research Database (Denmark)

Skovgård, Troels Suhr; Gregersen, Niels; Lorke, Michael

2011-01-01

The modulation bandwidth for a quantum dot light-emitting device is calculated using a detailed model for the spontaneous emission including the optical and electronic density-of-states. We show that the Purcell enhancement of the spontaneous emission rate depends critically on the degree...... of inhomogeneous broadening relative to the cavity linewidth and can improve the modulation speed only within certain parameter regimes....

Spontaneous emission in the presence of a realistically sized cylindrical waveguide

International Nuclear Information System (INIS)

Dung, Ho Trung

2016-01-01

Various quantities characterizing the spontaneous emission process of a dipole emitter including the emission rate and the emission pattern can be expressed in terms of the Green tensor of the surrounding environment. By expanding the Green tensor around some analytically known background one as a Born series, and truncating it under appropriate conditions, complicated boundaries can be tackled with ease. However, when the emitter is embedded in the medium, even the calculation of the first-order term in the Born series is problematic because of the presence of a singularity. We show how to eliminate this singularity for a medium of arbitrary size and shape by expanding around the bulk medium rather than vacuum. In the highly symmetric configuration of an emitter located on the axis of a realistically sized cylinder, it is shown that the singularity can be removed by changing the integral variables and then the order of integration. Using both methods, we investigate the spontaneous emission rate of an initially excited two-level dipole emitter, embedded in a realistically sized cylinder, which can be a common optical fiber in the long-length limit and a disk in the short-length limit. The spatial distribution of the emitted light is calculated using the Born-expansion approach, and local-field corrections to the spontaneous emission rate are briefly discussed. (paper)

Quantitative analysis of directional spontaneous emission spectra from light sources in photonic crystals

International Nuclear Information System (INIS)

Nikolaev, Ivan S.; Lodahl, Peter; Vos, Willem L.

2005-01-01

We have performed angle-resolved measurements of spontaneous-emission spectra from laser dyes and quantum dots in opal and inverse opal photonic crystals. Pronounced directional dependencies of the emission spectra are observed: angular ranges of strongly reduced emission adjoin with angular ranges of enhanced emission. It appears that emission from embedded light sources is affected both by the periodicity and by the structural imperfections of the crystals: the photons are Bragg diffracted by lattice planes and scattered by unavoidable structural disorder. Using a model comprising diffuse light transport and photonic band structure, we quantitatively explain the directional emission spectra. This work provides detailed understanding of the transport of spontaneously emitted light in real photonic crystals, which is essential in the interpretation of quantum optics in photonic-band-gap crystals and for applications wherein directional emission and total emission power are controlled

Violet-to-Blue Gain and Lasing from Colloidal CdS Nanoplatelets: Low-Threshold Stimulated Emission Despite Low Photoluminescence Quantum Yield

Energy Technology Data Exchange (ETDEWEB)

Diroll, Benjamin T.; Talapin, Dmitri V.; Schaller, Richard D.

2017-02-13

Amplified spontaneous emission (ASE) and lasing from solution-processed materials are demonstrated in the challenging violet-to-blue (430–490 nm) spectral region for colloidal nanoplatelets of CdS and newly synthesized core/shell CdS/ZnS nanoplatelets. Despite modest band-edge photoluminescence quantum yields of 2% or less for single excitons, which we show results from hole trapping, the samples exhibit low ASE thresholds. Furthermore, four-monolayer CdS samples show ASE at shorter wavelengths than any reported film of colloidal quantum-confined material. This work underlines that low quantum yields for single excitons do not necessarily lead to a poor gain medium. The low ASE thresholds originate from negligible dispersion in thickness, large absorption cross sections of 2.8 × 10–14 cm–2, and rather slow (150 to 300 ps) biexciton recombination. We show that under higher-fluence excitation, ASE can kinetically outcompete hole trapping. Using nanoplatelets as the gain medium, lasing is observed in a linear optical cavity. This work confirms the fundamental advantages of colloidal quantum well structures as gain media, even in the absence of high photoluminescence efficiency.

Ultrafast spontaneous emission of copper-doped silicon enhanced by an optical nanocavity.

Science.gov (United States)

Sumikura, Hisashi; Kuramochi, Eiichi; Taniyama, Hideaki; Notomi, Masaya

2014-05-23

Dopants in silicon (Si) have attracted attention in the fields of photonics and quantum optics. However, the optical characteristics are limited by the small spontaneous emission rate of dopants in Si. This study demonstrates a large increase in the spontaneous emission rate of copper isoelectronic centres (Cu-IECs) doped into Si photonic crystal nanocavities. In a cavity with a quality factor (Q) of ~16,000, the photoluminescence (PL) lifetime of the Cu-IECs is 1.1 ns, which is 30 times shorter than the lifetime of a sample without a cavity. The PL decay rate is increased in proportion to Q/Vc (Vc is the cavity mode volume), which indicates the Purcell effect. This is the first demonstration of a cavity-enhanced ultrafast spontaneous emission from dopants in Si, and it may lead to the development of fast and efficient Si light emitters and Si quantum optical devices based on dopants with efficient optical access.

Dynamics of Spontaneous Emission Controlled by Local Density of States in Photonic Crystals

DEFF Research Database (Denmark)

Lodahl, Peter; Nikolaev, Ivan S.; van Driel, A. Floris

2006-01-01

We have measured time-resolved spontaneous emission from quantum dots in 3D photonic crystals. Due to the spatially dependent local density of states, the distribution of decay rates varies strongly with the photonic crystal lattice parameter.......We have measured time-resolved spontaneous emission from quantum dots in 3D photonic crystals. Due to the spatially dependent local density of states, the distribution of decay rates varies strongly with the photonic crystal lattice parameter....

The effect of calcium salts on Dna-ase and Rna-ase activity of irradiated plants

International Nuclear Information System (INIS)

Arslanova, S.V.

1978-01-01

The influence of the post-radiation factor helping the restoration of radiation damages in the early sorts of cotton plant 1306'DV Goss. hirsutum was studied. In particular the action of treating the irradiated seed in the solution of calcium salts on the functional state of alcaline and acid forms of nucleases in cellular components was investigated. The dry seed of cotton was irradiated with gamma-rays at dose of 30 krad. It was found that irradiation of the dry seed at the radiosensitive organ (roots) increased the acid DNA-ase in the cellular nuclei, in the radioresistant (leaves) - the alcaline DNA-ase and RNA-ase. With irradiation both forms of DNA-ase in the mitochondriae diminished. After treatment of the irradiated seed in the solution of calcium salts the activity of acid nucleases and alcaline enzymes remained normal

Spontaneous emission spectra from a staggered-array undulator

International Nuclear Information System (INIS)

Shimada, Shigeki; Okada, Kouji; Masuda, Kai; Sobajima, Masaaki; Yoshikawa, Kiyoshi; Ohnishi, Masami; Yamamoto, Yasushi; Toku, Hisayuki

1997-01-01

A staggered-array undulator set inside the superconducting solenoid coils is shown to be able to provide high undulator fields larger than the longitudinal magnetic fields, a small undulator period, easy tunability through the solenoid coil current, and compact and easy fabrication. The overall performance characteristics of this undulator were studied mainly with respect to iron and aluminum disk widths, and spontaneous emission spectra through the numerical calculations. The maximum undulator field is found to be obtained for the ratio of the aluminum disk width to the undulator period of 0.45. The line widths (FWHM) of the spontaneous emission spectra, however, do not show N w -1 dependence on the number of the undulator period N w for practical beams with a Gaussian distribution, compared with for a single electron. The energy spread among various parameters is seen to play an important role in reducing the FWHM with increase of N w . The large tunability of the wavelength is proved to cover 6-10 mm by changing the solenoid magnetic field from 0.4 T to 1.6 T. (author)

Modal analysis of spontaneous emission in a planar microcavity

International Nuclear Information System (INIS)

Rigneault, H.; Monneret, S.

1996-01-01

A complete set of cavity modes in planar dielectric microcavities is presented which naturally includes guided modes. We show that most of these orthonormal fields can be derived from a coherent superposition of plane waves incoming on the stack from the air and from the substrate. Spontaneous emission of a dipole located inside the microcavity is analyzed, in terms of cavity modes. Derivation of the radiation pattern in the air and in the substrate is presented. The power emitted into the guided modes is also determined. Finally, a numerical analysis of the radiative properties of an erbium atom located in a Fabry-Pacute erot multilayer dielectric microcavity is investigated. We show that a large amount of light is emitted into the guided modes of the structure, in spite of the Fabry-Pacute erot resonance, which increases the spontaneous emission rate in a normal direction. copyright 1996 The American Physical Society

Amplified spontaneous emission and thermal management on a high average-power diode-pumped solid-state laser - the Lucia laser system

International Nuclear Information System (INIS)

Albach, D.

2010-01-01

The development of the laser triggered the birth of numerous fields in both scientific and industrial domains. High intensity laser pulses are a unique tool for light/matter interaction studies and applications. However, current flash-pumped glass-based systems are inherently limited in repetition-rate and efficiency. Development within recent years in the field of semiconductor lasers and gain media drew special attention to a new class of lasers, the so-called Diode Pumped Solid State Laser (DPSSL). DPSSLs are highly efficient lasers and are candidates of choice for compact, high average-power systems required for industrial applications but also as high-power pump sources for ultra-high intense lasers. The work described in this thesis takes place in the context of the 1 kilowatt average-power DPSSL program Lucia, currently under construction at the 'Laboratoire d'Utilisation des Laser Intenses' (LULI) at the Ecole Polytechnique, France. Generation of sub-10 nanosecond long pulses with energies of up to 100 joules at repetition rates of 10 hertz are mainly limited by Amplified Spontaneous Emission (ASE) and thermal effects. These limitations are the central themes of this work. Their impact is discussed within the context of a first Lucia milestone, set around 10 joules. The developed laser system is shown in detail from the oscillator level to the end of the amplification line. A comprehensive discussion of the impact of ASE and thermal effects is completed by related experimental benchmarks. The validated models are used to predict the performances of the laser system, finally resulting in a first activation of the laser system at an energy level of 7 joules in a single-shot regime and 6.6 joules at repetition rates up to 2 hertz. Limitations and further scaling approaches are discussed, followed by an outlook for the further development. (author) [fr

Electron bunchlength measurement from analysis of fluctuations in spontaneous emission

International Nuclear Information System (INIS)

Catravas, P.; Leemans, W.P.; Wurtele, J.S.; Zolotorev, M.S.; Babzien, M.; Ben-Zvi, I.; Segalov, Z.; Wang, X.; Yakimenko, V.

1999-01-01

A statistical analysis of fluctuations in the spontaneous emission of a single bunch of electrons is shown to provide a new bunchlength diagnostic. This concept, originally proposed by Zolotorev and Stupakov [1], is based on the fact that shot noise from a finite bunch has a correlation length defined by the bunchlength, and therefore has a spiky spectrum. Single shot spectra of wiggler spontaneous emission have been measured at 632 nm from 44 MeV single electron bunches of 1 - 5 ps. The scaling of the spectral fluctuations with frequency resolution and the scaling of the spectral intensity distribution with bunchlength are studied. Bunchlength was extracted in a single shot measurement. Agreement was obtained between the experiment and a theoretical model, and with independent time integrated measurements. copyright 1999 American Institute of Physics

Psoríase pustulosa

Directory of Open Access Journals (Sweden)

Vanessa Barsotti

2008-01-01

Full Text Available A psoríase é uma doença da pele relativamente freqüente, que afeta de 1% a 3% da população geral e atinge homens e mulheres, e é mais freqüente na raça branca. Caracteriza-se pelo aparecimento na pele de lesões róseas ou avermelhadas, recobertas de escamas secas e esbranquiçadas. Muitas vezes, essas lesões estão localizadas apenas nos cotovelos, joelhos ou couro cabeludo. Em outros casos, as lesões podem se espalhar por toda a pele, atingir unhas e, raramente, as articulações, causando a artrite psoriásica. A psoríase pode ser dividida em classes: vulgar, pustulosa, artrite psiriásica e psoríase eritrodérmica.

Control of spontaneous emission from a microwave-field-driven four-level atom in an anisotropic photonic crystal

Energy Technology Data Exchange (ETDEWEB)

Zhang, Duo, E-mail: zhangduo10@gmail.com [Wuhan National Laboratory for Optoelectronics and School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China); School of Electrical and Electronic Engineering, Wuhan Polytechnic University, Wuhan 430023 (China); Li, Jiahua, E-mail: huajia_li@163.com [Wuhan National Laboratory for Optoelectronics and School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China); Ding, Chunling; Yang, Xiaoxue [Wuhan National Laboratory for Optoelectronics and School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China)

2012-05-21

The spontaneous emission properties of a microwave-field-driven four-level atom embedded in anisotropic double-band photonic crystals (PCs) are investigated. We discuss the influences of the band-edge positions, Rabi frequency and detuning of the microwave field on the emission spectrum. It is found that several interesting features such as spectral-line enhancement, spectral-line suppression, spectral-line overlap, and multi-peak structures can be observed in the spectra. The proposed scheme can be achieved by use of a microwave-coupled field into hyperfine levels in rubidium atom confined in a photonic crystal. These theoretical investigations may provide more degrees of freedom to manipulate the atomic spontaneous emission. -- Highlights: ► Spontaneous emission properties of an atom embedded in PCs are investigated. ► Spectral-line enhancement, suppression and overlapping are observed. ► The results provide more degrees of freedom to control atomic spontaneous emission.

Control of spontaneous emission from a microwave-field-driven four-level atom in an anisotropic photonic crystal

International Nuclear Information System (INIS)

Zhang, Duo; Li, Jiahua; Ding, Chunling; Yang, Xiaoxue

2012-01-01

The spontaneous emission properties of a microwave-field-driven four-level atom embedded in anisotropic double-band photonic crystals (PCs) are investigated. We discuss the influences of the band-edge positions, Rabi frequency and detuning of the microwave field on the emission spectrum. It is found that several interesting features such as spectral-line enhancement, spectral-line suppression, spectral-line overlap, and multi-peak structures can be observed in the spectra. The proposed scheme can be achieved by use of a microwave-coupled field into hyperfine levels in rubidium atom confined in a photonic crystal. These theoretical investigations may provide more degrees of freedom to manipulate the atomic spontaneous emission. -- Highlights: ► Spontaneous emission properties of an atom embedded in PCs are investigated. ► Spectral-line enhancement, suppression and overlapping are observed. ► The results provide more degrees of freedom to control atomic spontaneous emission.

Controlling spontaneous emission dynamics in semiconductor micro cavities

Science.gov (United States)

Gayral, B.

Spontaneous emission of light can be controlled, cavity quantum electrodynamics tells us, and many experiments in atomic physics demonstrated this fact. In particular, coupling an emitter to a resonant photon mode of a cavity can enhance its spontaneous emission rate: this is the so-called Purcell effect. Though appealing it might seem to implement these concepts for the benefit of light-emitting semiconductor devices, great care has to be taken as to which emitter/cavity system should be used. Semiconductor quantum boxes prove to be good candidates for witnessing the Purcell effect. Also, low volume cavities having a high optical quality in other words a long photon storage time are required. State-of-the-art fabrication techniques of such cavities are presented and discussed.We demonstrate spontaneous emission rate enhancement for InAs/GaAs quantum boxes in time-resolved and continuous-wave photoluminescence experiments. This is done for two kinds of cavities, namely GaAs/AlAs micropillars (global enhancement by a factor of 5), and GaAs microdisks (global enhancement by a factor of 20). Prospects for lasers, light-emitting diodes and single photon sources based on the Purcell effect are discussed. L'émission spontanée de lumière peut être contrôlée, ainsi que nous l'enseigne l'électrodynamique quantique en cavité, ce fait a été démontré expérimentalement en physique atomique. En particulier, coupler un émetteur à un mode photonique résonnant d'une cavité peut exalter son taux d'émission spontanée : c'est l'effet Purcell. Bien qu'il semble très prometteur de mettre en pratique ces concepts pour améliorer les dispositifs semi-conducteurs émetteurs de lumière, le choix du système émetteur/cavité est crucial. Nous montrons que les boîtes quantiques semi-conductrices sont des bons candidats pour observer l'effet Purcell. Il faut par ailleurs des cavités de faible volume ayant une grande qualité optique en d'autres mots un long temps de

Genética e hanseníase

OpenAIRE

Beiguelman Bernardo

2002-01-01

As diferentes linhas de pesquisa utilizadas para investigar a importância dos fatores hereditários humanos na determinação da resistência/suscetibilidade à infecção pelo Mycobacterium leprae foram discutidas no presente trabalho. Uma síntese dessas abordagens permitiu analisar os resultados das investigações sobre associação da hanseníase com polimorfismos genéticos, distribuição familial da hanseníase, prevalência da hanseníase e distância genética, concordância da hanseníase em gêmeos e est...

Controlling spontaneous emission of light by photonic crystals

DEFF Research Database (Denmark)

Lodahl, Peter

2005-01-01

Photonic bandgap crystals were proposed almost two decades ago as a unique tool for controlling propagation and emission of light. Since then the research field of photonic crystals has exploded and many beautiful demonstrations of the use of photonic crystals and fibers for molding light...... propagation have appeared that hold great promises for integrated optics. These major achievements solidly demonstrate the ability to control propagation of light. In contrast, an experimental demonstration of the use of photonic crystals for timing the emission of light has so far lacked. In a recent...... publication in Nature, we have demonstrated experimentally that both the direction and time of spontaneous emission can be controlled, thereby confirming the original proposal by Eli Yablonovich that founded the field of photonic crystals. We believe that this work opens new opportunities for solid...

Spontaneous emission between an unusual pair of plates

International Nuclear Information System (INIS)

Alves, D.T.; Farina, C.; Tort, A.C.

1999-08-01

We compute the modification in the spontaneous emission rate for a two-level atom when it is located between two parallel plates of different nature: a perfectly conducting plate (ε->∞) and infinitely permeable one (μ->∞). We also discuss the case of two infinity permeable plates. We compare our results with those found in the literature for the case of two perfectly conducting plates. (author)

Spatial variation in carrier dynamics along a single CdSSe nanowire

International Nuclear Information System (INIS)

Blake, Jolie C.; Eldridge, Peter S.; Gundlach, Lars

2014-01-01

Highlights: • Femtosecond Kerr-gate microscopy allows ultrafast fluorescence measurements along different positions of a single nanowire. • Amplified spontaneous emission observed at high fluences can be used to calculate recombination rates. • Observation of ASE at different locations along a single CdSSe nanowire provides the ability to extract defect densities. - Abstract: Ultrafast charge carrier dynamics along individual CdS x Se 1−x nanowires has been measured. The use of an improved ultrafast Kerr-gated microscope allows for spatially resolved luminescence measurements along a single nanowire. Amplified spontaneous emission (ASE) was observed at high excitation fluences. Position dependent variations of ultrafast ASE dynamics were observed. SEM and colorimetric measurements showed that the difference in dynamics can be attributed to variations in non-radiative recombination rates along the wire. The dominant Shockley-Read recombination rate can be extracted from ASE dynamics and can be directly related to charge carrier mobility and defect density. Employing ASE as a probe for defect densities provides a new sub-micron spatially resolved, contactless method for measurements of charge carrier mobility

Interactions between hair cells shape spontaneous otoacoustic emissions in a model of the tokay gecko's cochlea.

Directory of Open Access Journals (Sweden)

Michael Gelfand

2010-06-01

Full Text Available The hearing of tetrapods including humans is enhanced by an active process that amplifies the mechanical inputs associated with sound, sharpens frequency selectivity, and compresses the range of responsiveness. The most striking manifestation of the active process is spontaneous otoacoustic emission, the unprovoked emergence of sound from an ear. Hair cells, the sensory receptors of the inner ear, are known to provide the energy for such emissions; it is unclear, though, how ensembles of such cells collude to power observable emissions.We have measured and modeled spontaneous otoacoustic emissions from the ear of the tokay gecko, a convenient experimental subject that produces robust emissions. Using a van der Pol formulation to represent each cluster of hair cells within a tonotopic array, we have examined the factors that influence the cooperative interaction between oscillators.A model that includes viscous interactions between adjacent hair cells fails to produce emissions similar to those observed experimentally. In contrast, elastic coupling yields realistic results, especially if the oscillators near the ends of the array are weakened so as to minimize boundary effects. Introducing stochastic irregularity in the strength of oscillators stabilizes peaks in the spectrum of modeled emissions, further increasing the similarity to the responses of actual ears. Finally, and again in agreement with experimental findings, the inclusion of a pure-tone external stimulus repels the spectral peaks of spontaneous emissions. Our results suggest that elastic coupling between oscillators of slightly differing strength explains several properties of the spontaneous otoacoustic emissions in the gecko.

Interactions between hair cells shape spontaneous otoacoustic emissions in a model of the tokay gecko's cochlea.

Science.gov (United States)

Gelfand, Michael; Piro, Oreste; Magnasco, Marcelo O; Hudspeth, A J

2010-06-15

The hearing of tetrapods including humans is enhanced by an active process that amplifies the mechanical inputs associated with sound, sharpens frequency selectivity, and compresses the range of responsiveness. The most striking manifestation of the active process is spontaneous otoacoustic emission, the unprovoked emergence of sound from an ear. Hair cells, the sensory receptors of the inner ear, are known to provide the energy for such emissions; it is unclear, though, how ensembles of such cells collude to power observable emissions. We have measured and modeled spontaneous otoacoustic emissions from the ear of the tokay gecko, a convenient experimental subject that produces robust emissions. Using a van der Pol formulation to represent each cluster of hair cells within a tonotopic array, we have examined the factors that influence the cooperative interaction between oscillators. A model that includes viscous interactions between adjacent hair cells fails to produce emissions similar to those observed experimentally. In contrast, elastic coupling yields realistic results, especially if the oscillators near the ends of the array are weakened so as to minimize boundary effects. Introducing stochastic irregularity in the strength of oscillators stabilizes peaks in the spectrum of modeled emissions, further increasing the similarity to the responses of actual ears. Finally, and again in agreement with experimental findings, the inclusion of a pure-tone external stimulus repels the spectral peaks of spontaneous emissions. Our results suggest that elastic coupling between oscillators of slightly differing strength explains several properties of the spontaneous otoacoustic emissions in the gecko.

Genética e hanseníase

Directory of Open Access Journals (Sweden)

Bernardo Beiguelman

Full Text Available As diferentes linhas de pesquisa utilizadas para investigar a importância dos fatores hereditários humanos na determinação da resistência/suscetibilidade à infecção pelo Mycobacterium leprae foram discutidas no presente trabalho. Uma síntese dessas abordagens permitiu analisar os resultados das investigações sobre associação da hanseníase com polimorfismos genéticos, distribuição familial da hanseníase, prevalência da hanseníase e distância genética, concordância da hanseníase em gêmeos e estudos genéticos sobre a reação de Mitsuda.

Covariation of binaural, concurrently-measured spontaneous otoacoustic emissions.

Science.gov (United States)

Penner, M J; Brauth, S E; Jastreboff, P J

1994-03-01

Simultaneous recordings of binaural spontaneous otoacoustic emissions (SOAEs) were made for 2 female subjects. For SOAEs below about 3.6 kHz measured within a testing session, the frequencies of nearby monaural and binaural SOAEs tended to move in tandem, whereas widely separated SOAEs did not. Across many testing sessions spanning a menstrual cycle, all monaural and binaural SOAE frequencies shifted in tandem. Possible mechanisms consistent with these results are discussed.

Spontaneous emission and gain in a waveguide free-electron laser

International Nuclear Information System (INIS)

Golightly, W.J.; Ride, S.K.

1991-01-01

A free-electron laser enclosed in a waveguide of narrowly spaced parallel plates has been proposed as a compact, coherent source of far-infrared radiation. In this paper, the spontaneous emission and small-signal gain of such a device are analyzed. Maxwell's equations are solved for the fields of a relativistic electron beam passing through a linearly polarized undulator in the presence of a parallel-plane waveguide. The radiation intensity is resolved into its component waveguide modes for the fundamental frequency and for all harmonics. The intensity profile in a given harmonic mode is altered significantly when a parameter involving the undulator period, beam energy, and transverse dimension of the guide is such that the radiation group velocity is close to the electrons' axial velocity. The small-signal gain in the waveguide free-electron laser is calculated and related to the spontaneous emission. Near zero slip, the gain curve is significantly different from that of a free-space free-electron laser with the same parameters

Are Einstein's transition probabilities for spontaneous emission constant in plasmas?

Science.gov (United States)

Griem, H. R.; Huang, Y. W.; Wang, J.-S.; Moreno, J. C.

1991-01-01

An investigation is conducted with a ruby laser to experimentally confirm the quenching of spontaneous emission coefficients and propose a mechanism for the phenomenon. Results of previous experiments are examined to determine the consistency and validity of interpretations of the spontaneous emissions. For the C IV 3s-3p and 2s-3p transitions, the line-intensity ratios are found to be dependent on the separation of the laser from the target. Density gradients and Stark broadening are proposed to interpret the results in a way that does not invalidate the Einstein A values. The interpretation is extended to C III and N V, both of which demonstrate similar changes in A values in previous experiments. The apparent quenching of Ar II by photon collisions is explained by Rabi oscillations and power broadening in the argon-ion laser cavity. It is concluded that the changes in A values cannot result from dense plasma effects.

To decay or not to decay - or both ! quantum mechanics of spontaneous emission

DEFF Research Database (Denmark)

Kristensen, Philip Trøst; Lodahl, Peter; Mørk, Jesper

2008-01-01

We discuss calculations of spontaneous emission from quantum dots in photonic crystals and show how the decay depends on the intrinsic properties of the emitter as well as the position. A number of fundamentally different types of spontaneous decay dynamics are shown to be possible, including...... counter intuitive situations in which the quantum dot decays only partially....

Spontaneous and stimulated emission induced by an electron, electron bunch, and electron beam in a plasma

International Nuclear Information System (INIS)

Kuzelev, M V; Rukhadze, A A

2008-01-01

Two fundamental mechanisms - the Cherenkov effect and anomalous Doppler effect - underlying the emission by an electron during its superluminal motion in medium are considered. Cherenkov emission induced by a single electron and a small electron bunch is spontaneous. In the course of spontaneous Cherenkov emission, the translational motion of an electron is slowed down and the radiation energy grows linearly with time. As the number of radiating electrons increases, Cherenkov emission becomes stimulated. Stimulated Cherenkov emission represents a resonance beam instability. This emission process is accompanied by longitudinal electron bunching in the beam or by the breaking of an electron bunch into smaller bunches, in which case the radiation energy grows exponentially with time. In terms of the longitudinal size L e of the electron bunch there is a transition region λ e 0 -1 between the spontaneous and stimulated Cherenkov effects, where λ is the average radiation wavelength, and δ 0 is the dimensionless (in units of the radiation frequency) growth rate of the Cherenkov beam instability. The range to the left of this region is dominated by spontaneous emission, whereas the range to the right of this region is dominated by stimulated emission. In contrast to the Vavilov-Cherenkov effect, the anomalous Doppler effect should always (even for a single electron) be considered as stimulated, because it can only be explained by accounting for the reverse action of the radiation field on the moving electron. During stimulated emission in conditions where anomalous Doppler effect shows itself, an electron is slowed down and spins up; in this case, the radiation energy grows exponentially with time. (reviews of topical problems)

Spontaneous light emission from fibers in MINOS

International Nuclear Information System (INIS)

Avvakumov, S.; Barrett, W.L.; Belias, T.; Bower, C.; Erwin, A.; Kordosky, M.; Lang, K.; Lee, R.; Liu, J.; Miller, W.; Mualem, L.; Nichol, R.; Nelson, J.; Pearce, G.; Proga, M.; Rebel, B.; Ruddick, K.; Smith, C.; Thomas, J.; Vahle, P.; Webb, R.

2005-01-01

We report on the observation and measurements of unexpected background rates in the MINOS Far Detector. The noise level at the Far Detector is significantly greater than that expected from natural radioactivity and intrinsic photomultiplier dark current. We have conducted a series of additional tests which demonstrate that the excess rate is caused by spontaneous light emission in the wavelength-shifting fibers, which are used to read out signals from scintillator strips. This noise due to fibers exhibits an exponential fall off with time with a decay time constant of the order of 100 days

Solid state solvation effect and reduced amplified spontaneous emission threshold value of glass forming DCM derivative in PMMA films

Energy Technology Data Exchange (ETDEWEB)

Vembris, Aivars, E-mail: aivars.vembris@cfi.lu.lv [Institute of Solid State Physics, University of Latvia, 8 Kengaraga Street, Riga LV 1063 (Latvia); Zarins, Elmars; Kokars, Valdis [Institute of Applied Chemistry, Riga Technical University, 14/24 Azenes Street, Riga LV 1048 (Latvia)

2015-02-15

Molecule crystallization is one of the limitations for obtaining high-gain organic laser systems. One of the examples is well known red laser dye 4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran (DCM). The lowest threshold value of amplified spontaneous emission was achieved by doping 2 wt% of DCM molecule in tris-(8-hydroxy quinoline) aluminum (Alq{sub 3}) matrix. Further increase of the DCM dye concentration makes the system less efficient as its threshold value increases. It is due to large intermolecular interaction, which induces photoluminescence quenching. Compounds with reduced intermolecular interaction could be prospective in organic laser systems due to higher possible doping. In this work photoluminescence and amplified spontaneous emission properties of modified DCM molecule in poly(methyl methacrylate) (PMMA) matrix were investigated. Bulky trityloxyethyl groups were attached to the donor part of DCM. These groups increase intermolecular distance wherewith reduce photoluminescence quenching. More than one order of magnitude lower excitation threshold energy of the amplified spontaneous emission was achieved in doped polymer films with investigated compound in comparison to doped polymer with DCM. It means that the investigated compound is more perspective as a laser material compared to the previously studied. In addition, amplified spontaneous emission maximum could be tuned within 15 nm by changing concentration from 0.1 wt% to 10 wt% DWK-1 in PMMA matrix due to solid state solvation effect. - Highlights: • Bulky groups attached to DCM dye reduce photoluminescence quenching. • Amplified spontaneous emission is in red spectral region. • Amplified spontaneous emission spectra were tuned by 15 nm. • Amplified spontaneous emission threshold value was reduced by one order of magnitude.

Quantum dot lattice as nano-antenna for collective spontaneous emission

NARCIS (Netherlands)

Mokhlespour, S.; Haverkort, J.E.M.; Slepyan, G.Y.; Maksimenko, S.A.; Hoffmann, A.; Maffucci, A.; Maksimenko, S.A.

2016-01-01

We present a theory for the collective spontaneous emission of timed Dicke states in a periodic 2D-array of quantum dots (QDs) coupled by dipoledipole (d-d) interactions. The master equation is first reformulated with respect to the timed Dicke basis. As a result, we obtain simple analytical

Spontaneous radiation emission during penetration of ions in solids

International Nuclear Information System (INIS)

Miraglia, J.E.; Pacher, M.C.

1988-01-01

In this work, the principal continuum radiative emission processes, which occur during the penetration of ions in solids or gases, are resumed. The characteristics of the following processes are discussed: secondary electron bremsstrahlung (SEB), atomic bremsstrahlung (AB), and internuclear bremsstrahlung (INB). Recent advances of the ion channeling effects in crystal solids on the spontaneous radiative spectra are exposed. (A.C.A.S.) [pt

A model for the relation between stimulus frequency and spontaneous otoacoustic emissions in lizard papillae

NARCIS (Netherlands)

Wit, Hero P.; van Dijk, Pim; Manley, Geoffrey A.

2012-01-01

Spontaneous otoacoustic emissions (SOAEs) and stimulus frequency otoacoustic emissions (SFOAEs) have been described from lizard ears. Although there are several models for these systems, none has modeled the characteristics of both of these types of otoacoustic emissions based upon their being

Spontaneous emission spectrum of a four-level atom coupled by three kinds of reservoirs

International Nuclear Information System (INIS)

Yang Dong; Wang Jian; Zhang, Hanzhuang; Yao Jinbo

2007-01-01

A model of a four-level atom embedded in a double-band photonic crystal (PC) is presented. The atomic transitions from the upper two levels to the lower two levels are coupled by the same reservoir which is assumed in turn to be isotropic PC modes, anisotropic PC modes and free vacuum modes. The effects of the fine structure of the atomic ground state levels and the quantum interference on the spontaneous emission spectrum of an atom are investigated in detail. Most interestingly, it is shown for the first time that new spontaneous emission lines are produced from the fine splitting of atomic ground state levels in the isotropic PC case. Quantum interference induces additional narrow spontaneous lines near the transition from the empty upper level to the lower levels

Non-exponential spontaneous emission dynamics for emitters in a time-dependent optical cavity

NARCIS (Netherlands)

Thyrrestrup Nielsen, Henri; Hartsuiker, A.; Gerard, J.M.; Vos, Willem L.

2013-01-01

We have theoretically studied the effect of deterministic temporal control of spontaneous emission in a dynamic optical microcavity. We propose a new paradigm in light emission: we envision an ensemble of two-level emitters in an environment where the local density of optical states is modified on a

Transparency and spontaneous emission in a densely doped photonic band gap material

Energy Technology Data Exchange (ETDEWEB)

Singh, Mahi R [Department of Physics and Astronomy, University of Western Ontario, London N6A 3K7 (Canada)

2006-12-28

The susceptibility has been calculated for a photonic crystal in the presence of spontaneous cancellation and dipole-dipole interaction. The crystal is densely doped with an ensemble of four-level nano-particles in Y-type configuration. Probe and a pump laser fields are applied to manipulate the absorption coefficient of the system. The expression of the susceptibility has been calculated in the linear response regime of the probe field but nonlinear terms are included for the pump field. It is found that in the presence of spontaneous emission cancellation there is an increase in the height of the two absorption peaks however the phenomenon of electromagnetically induced transparency (EIT) is not affected. On the other hand, there is a change in the height and location of the two peaks in the presence of dipole-dipole interactions. For certain values the particle density of the system can be switched from the EIT state to the non-EIT state. It is also found that when the resonance energies for two spontaneous emission channels lie close to the band edge, the EIT phenomenon disappears.

A model for the relation between stimulus frequency and spontaneous otoacoustic emissions in lizard papillae.

Science.gov (United States)

Wit, Hero P; van Dijk, Pim; Manley, Geoffrey A

2012-11-01

Spontaneous otoacoustic emissions (SOAEs) and stimulus frequency otoacoustic emissions (SFOAEs) have been described from lizard ears. Although there are several models for these systems, none has modeled the characteristics of both of these types of otoacoustic emissions based upon their being derived from hair cells as active oscillators. Data from the ears of two lizard species, one lacking a tectorial membrane and one with a chain of tectorial sallets, as described by Bergevin et al. ["Coupled, active oscillators and lizard otoacoustic emissions," AIP Conf. Proc. 1403, 453 (2008)], are modeled as an array of coupled self-sustained oscillators. The model, originally developed by Vilfan and Duke ["Frequency clustering in spontaneous otoacoustic emissions from a lizard's ear," Biophys. J. 95, 4622-4630 (2008)], well describes both the amplitude and phase characteristics of SFOAEs and the relation between SFOAEs and SOAEs.

Cavity-enhanced spontaneous emission rates for rhodamine 6-G in levitated microdroplets

International Nuclear Information System (INIS)

Barnes, M.D.; Whitten, W.B.; Ramsey, J.M.; Arnold, S.

1992-01-01

Fluorescence decay kinetics of Rhodamine 6-G molecules in levitated glycerol microdroplets (4--20 microns in diameter) have been investigated to determine the effects of spherical cavity resonances on spontaneous emission rates. For droplet diameters greater than 10 microns, the fluorescence lifetime is essentially the same as in bulk glycerol. As the droplet diameter is decreased below 10 microns, bi-exponential decay behavior is observed with a slow component whose rate is similar to bulk glycerol, and a fast component whose rate is as much as a factor of 10 larger than the bulk decay rate. This fast component is attributed to cavity enhancement of the spontaneous emission rate and, within the weak coupling approximation, a value for the homogeneous linewidth at room temperature can be estimated from the fluorescence lifetime data

Studies of new modes of radioactive decay by spontaneous emission of complex nuclei

International Nuclear Information System (INIS)

Barwick, S.W.; Hulet, E.K.; Moody, K.; Price, P.B.; Ravn, H.L.

1990-01-01

Impressive progress has been made in the two years since Rose and Jones first reported the novel spontaneous decay mode 223 Ra → 14 C + 209 Pb. Since then, the isotopes 222 Ra, 224 Ra, and 226 Ra have been observed to emit 14 C, and stringent upper limits have been set on branching ratios B( 14 C/α) for 221 Ra and 225 Ac. The discoveries of emission of 24 Ne from 232 U, and 231 Pa, and 233 U show that the phenomenon of heavy ion emission is a general one. A goal of recent experiments by the authors collaboration is to test models that differ by as much as 10 5 in predicted half-lives for the emission of complex nuclei with Z ≥ 12. Due to small branching ratios B approx-lt 10 -14 , and large fission background, they are developing new techniques to insure reliable identification of such rare decay modes. Experimental support for the unified models of alpha decay, complex nuclei emission, and spontaneous fission are addressed

The Effects of Air Pressure on Spontaneous Otoacoustic Emissions of Lizards

NARCIS (Netherlands)

van Dijk, Pim; Manley, Geoffrey A.

Small changes of air pressure outside the eardrum of five lizard species led to changes in frequency, level, and peak width of spontaneous otoacoustic emissions (SOAE). In contrast to humans, these changes generally occurred at very small pressures (<20 mbar). As in humans, SOAE amplitudes were

Self-amplified spontaneous emission for short wavelength coherent radiation

International Nuclear Information System (INIS)

Kim, K.J.; Xie, M.

1992-09-01

We review the recent progress in our understanding of the self-amplified spontaneous emission (SASE), emphasizing the application to short wavelength generation. Simple formulae are given for the start-up, exponential gain and the saturation of SASE. Accelerator technologies producing high brightness electron beams required for short wavelength SASE are discussed. An example utilizing electron beams from a photocathode-linac system to produce 4nm SASE in the multigigawatt range is presented

On spontaneous photon emission in collapse models

International Nuclear Information System (INIS)

Adler, Stephen L; Bassi, Angelo; Donadi, Sandro

2013-01-01

We reanalyze the problem of spontaneous photon emission in collapse models. We show that the extra term found by Bassi and Dürr is present for non-white (colored) noise, but its coefficient is proportional to the zero frequency Fourier component of the noise. This leads one to suspect that the extra term is an artifact. When the calculation is repeated with the final electron in a wave packet and with the noise confined to a bounded region, the extra term vanishes in the limit of continuum state normalization. The result obtained by Fu and by Adler and Ramazanoğlu from application of the Golden Rule is then recovered. (paper)

Spontaneous emission and quantum discord: Comparison of Hilbert–Schmidt and trace distance discord

Energy Technology Data Exchange (ETDEWEB)

Jakóbczyk, Lech, E-mail: ljak@ift.uni.wroc.pl

2014-09-12

Hilbert–Schmidt and trace norm geometric quantum discord are compared with regard to their behavior during local time evolution. We consider the system of independent two-level atoms with time evolution given by the dissipative process of spontaneous emission. It is explicitly shown that the Hilbert–Schmidt norm discord has nonphysical properties with respect to such local evolution and cannot serve as a reasonable measure of quantum correlations and the better choice is to use trace norm discord as such a measure. - Highlights: • We compare Hilbert–Schmidt and trace norm geometric quantum discord. • We consider the system of independent two-level atoms with time evolution given by spontaneous emission. • We show explicitly that Hilbert–Schmidt norm discord has nonphysical properties.

Spontaneous emission of an atom in the presence of nanobodies

International Nuclear Information System (INIS)

Klimov, Vasilii V; Ducloy, M; Letokhov, V S

2001-01-01

The effect of nanobodies, i.e., the bodies whose size is small compared to the emission wavelength, on spontaneous emission of an atom located near them is considered. The results of calculations performed within the framework of quantum and classical electrodynamics are presented both in analytic and graphical forms and can be readily used for planning experiments and analysis of experimental data. It is shown that nanobodies can be used to control efficiently the rate of spontaneous transitions. Thus, an excited atom located near a nanocylinder or a nanospheroid pole, whose transition dipole moment is directed normally to the nanobody surface, can decay with the rate that is tens and hundreds times higher than the decay rate in a free space. In the case of some (negative) dielectric constants, the decay rate can increase by a factor of 10 5 -10 6 and more. On the other hand, the decay of an excited atom whose transition dipole moment is directed tangentially to the nanobody surface substantially slows down. The probability of nonradiative decay of the excited state is shown to increase substantially in the presence of na-nobodies possessing losses. (review)

Simulations of the spontaneous emission of a quantum dot near a gap plasmon waveguide

Energy Technology Data Exchange (ETDEWEB)

Perera, Chamanei S., E-mail: cp.hettiarachchige@qut.edu.au; Vernon, Kristy C.; Mcleod, Angus [Plasmonic Device Group, Queensland University of Technology, GPO box 2434, Brisbane, Queensland (Australia)

2014-02-07

In this paper, we modeled a quantum dot at near proximity to a gap plasmon waveguide to study the quantum dot-plasmon interactions. Assuming that the waveguide is single mode, this paper is concerned about the dependence of spontaneous emission rate of the quantum dot on waveguide dimensions such as width and height. We compare coupling efficiency of a gap waveguide with symmetric configuration and asymmetric configuration illustrating that symmetric waveguide has a better coupling efficiency to the quantum dot. We also demonstrate that optimally placed quantum dot near a symmetric waveguide with 50 nm × 50 nm cross section can capture 80% of the spontaneous emission into a guided plasmon mode.

Simulations of the spontaneous emission of a quantum dot near a gap plasmon waveguide

International Nuclear Information System (INIS)

Perera, Chamanei S.; Vernon, Kristy C.; Mcleod, Angus

2014-01-01

In this paper, we modeled a quantum dot at near proximity to a gap plasmon waveguide to study the quantum dot-plasmon interactions. Assuming that the waveguide is single mode, this paper is concerned about the dependence of spontaneous emission rate of the quantum dot on waveguide dimensions such as width and height. We compare coupling efficiency of a gap waveguide with symmetric configuration and asymmetric configuration illustrating that symmetric waveguide has a better coupling efficiency to the quantum dot. We also demonstrate that optimally placed quantum dot near a symmetric waveguide with 50 nm × 50 nm cross section can capture 80% of the spontaneous emission into a guided plasmon mode

Amplified spontaneous emission and laser emission from a high optical-gain medium of dye-doped dendrimer

International Nuclear Information System (INIS)

Yokoyama, Shiyoshi; Nakahama, Tatsuo; Mashiko, Shinro

2005-01-01

We measured the amplified spontaneous emission and laser emission from high-gain media of laser-dye encapsulated dendrimers. A highly branched poly(amidoamine) (PAMAM-OH) dendrimer formed a guest-host complex with a conventional laser-dye (DCM), resulting in a high optical-gain. Of particular note was the appearance of a laser threshold, above which a super-narrowed laser spectrum was observed, although laser feedback was caused without any mirror cavity devices. The optical feedback was attributed to spatial confinement of the light due to gain guiding under optical excitation. The laser spectrum clearly indicated a resonant laser-mode with a spectrum linewidth of less than 0.1 nm. This order of spectrum narrowing is comparable to that seen in the laser emission from ordinary laser devices

Atom localization via controlled spontaneous emission in a five-level atomic system

International Nuclear Information System (INIS)

Wang Zhiping; Yu Benli; Zhu Jun; Cao Zhigang; Zhen Shenglai; Wu Xuqiang; Xu Feng

2012-01-01

We investigate the one- and two-dimensional atom localization behaviors via spontaneous emission in a coherently driven five-level atomic system by means of a radio-frequency field driving a hyperfine transition. It is found that the detecting probability and precision of atom localization behaviors can be significantly improved via adjusting the system parameters. More importantly, the two-dimensional atom localization patterns reveal that the maximal probability of finding an atom within the sub-wavelength domain of the standing waves can reach unity when the corresponding conditions are satisfied. As a result, our scheme may be helpful in laser cooling or the atom nano-lithography via atom localization. - Highlights: ► One- and two-dimensional atom localization behaviors via spontaneous emission in five-level atoms are investigated. ► An assisting radio-frequency field is used to control the atom localization behaviors. ► High-precision and high-resolution two-dimensional atom localization can be realized in this scheme.

Control of spontaneous emission from a microwave-field-driven four-level atom in an anisotropic photonic crystal

Science.gov (United States)

Zhang, Duo; Li, Jiahua; Ding, Chunling; Yang, Xiaoxue

2012-05-01

The spontaneous emission properties of a microwave-field-driven four-level atom embedded in anisotropic double-band photonic crystals (PCs) are investigated. We discuss the influences of the band-edge positions, Rabi frequency and detuning of the microwave field on the emission spectrum. It is found that several interesting features such as spectral-line enhancement, spectral-line suppression, spectral-line overlap, and multi-peak structures can be observed in the spectra. The proposed scheme can be achieved by use of a microwave-coupled field into hyperfine levels in rubidium atom confined in a photonic crystal. These theoretical investigations may provide more degrees of freedom to manipulate the atomic spontaneous emission.

Analysis and simulation of nonlinearity and effects of spontaneous emission in Schottky-junction-based plasmonic amplifiers.

Science.gov (United States)

Livani, Abdolber Mallah; Kaatuzian, Hassan

2015-07-01

An amplifier that operates on surface plasmon polaritons has been analyzed and simulated. Nonlinearity behavior and the spontaneous emission effects of the plasmonic amplifier are investigated in this paper. A rate equations approach has been used in which parameters are derived from simulation results of the plasmonic amplifier (Silvaco/ATLAS). Details on the method of this derivation are included, which were not previously reported. Rate equations are solved numerically by MATLAB codes. These codes verify the Silvaco results. The plasmonic amplifier operates on surface plasmons with a free-space wavelength of 1550 nm. Results show that, even without the effect of spontaneous emission, gain of the plasmonic amplifier saturates in high input levels. Saturation power, which can be used for comparing nonlinearity of different amplifiers, is 2.1 dBm for this amplifier. Amplified spontaneous emission reduces the gain of the amplifiers, which is long. There is an optimum value for the length of the amplifier. For the amplifier of this work, the optimum length for the small signal condition is 265 μm.

Experimental characterization of true spontaneous emission rate of optically-pumped InGaAs/GaAs quantum-well laser structure

Directory of Open Access Journals (Sweden)

Q.-N. Yu

2017-08-01

Full Text Available In this paper, an experimental approach to acquiring true spontaneous emission rate of optically-pumped InGaAs/GaAs quantum-well laser structure is described. This method is based on a single edge-emitting laser chip with simple sample processing. The photoluminescence spectra are measured at both facets of the edge-emitting device and transformed to the spontaneous emission rate following the theory described here. The unusual double peaks appearing in the spontaneous emission rate spectra are observed for the InGaAs/GaAs quantum-well structure. The result is analyzed in terms of Indium-rich island and Model-Solid theories. The proposed method is suitable for electrically-pumped quantum-well laser structures, as well.

Psoríase com eosinofilia: relato de caso

Directory of Open Access Journals (Sweden)

Thays Brunelli Pugliesi

2015-10-01

Full Text Available A psoríase, doença inflamatória crônica é caracterizada por lesões dérmicas sobrepostas a áreas de lesões eritematosas ou pustulares. Ocorre pela alteração no ciclo de crescimento das células epidérmicas, levando ao espessamento epidérmico decorrente da hiperproliferação celular e vascular com presença de infiltrado linfocitário. Pode desencadear manifestações como febre, mal-estar, fraqueza e outros. Seu diagnóstico é predominantemente clínico, podendo ser complementado pela biópsia das lesões. Entretanto, alguns casos encontrados na literatura e no caso que será relatado existe a presença de eosinofilia, mesmo na ausência de fatores que justificariam o surgimento desse sinal em pacientes portadores da psoríase. Objetivo: Relatar o caso de paciente encaminhado à hematologia com quadro de psoríase concomitante à eosinofilia. Relato de Caso: Paciente de 67 anos, masculino, vem encaminhado com hipótese diagnóstica de Síndrome Hipereosinofílica. Queixa de eosinofilia persistente (>1500 por mais de seis meses tendo realizado tratamento com Albendazol e Metronidazol, sem êxito. Concomitantemente, apresenta psoríase em acompanhamento da dermatologia sem sintomas sistêmicos. Exames laboratoriais: NR para Hepatite B ou C, HIV ou Toxocara canis. Ausência de população celular com imunofenótipo anômalo. Aumento do percentual de granulócitos eosinófilos. Coleta de JAK2 e BLC/ABR negativos. Tratamento da psoríase é realizado com shampoo indicado. Após dois meses, ainda apresenta eosinófilos = 1820. Conclusão: Recentemente, estabeleceu-se uma relação entre a eosinofilia e o aparecimento da psoríase. Não encontramos mais nenhuma causa possível que explique a eosinofilia deste paciente. Pretendemos acompanhá-lo e avaliar se o tratamento da psoríase relaciona-se com a diminuição da eosinofilia

Quantitative criterion for quantum interference within spontaneous emission modification of a driven ladder atom

International Nuclear Information System (INIS)

Liu Jiaren; Zhang Zhiyi; Xiao George; Grover, C P

2003-01-01

The spontaneous emission spectrum of a ladder three-level atom with an upper transition driven by a coherent field is calculated under a universal model where various decays, any incoherent pumping and coherent driving are taken into account. The analytical expression for the spectrum profile is given on the basis of the quantum regression theorem. To our knowledge, it is the first time that the quantitative criterion condition Ω ab - γ ac vertical bar, under which quantum destructive interference induced by the coherent driving field occurs, is deduced for the modification of spontaneous emission from the middle level to the ground level. The roles and limits of incoherent pumping, coherent driving and experimental configuration are discussed for realizing the quantum interference and reducing the Doppler effects

Fluorescence and amplified spontaneous emission of glass forming compounds containing styryl-4H-pyran-4-ylidene fragment

Energy Technology Data Exchange (ETDEWEB)

Vembris, Aivars, E-mail: aivars.vembris@cfi.lu.lv [Institute of Solid State Physics, University of Latvia, 8 Kengaraga Street, Riga LV-1063 (Latvia); Muzikante, Inta [Institute of Solid State Physics, University of Latvia, 8 Kengaraga Street, Riga LV-1063 (Latvia); Karpicz, Renata; Sliauzys, Gytis [Institute of Physics, Center for Physical Sciences and Technology, A. Gostauto 11, LT-01108 Vilnius (Lithuania); Miasojedovas, Arunas; Jursenas, Saulius [Institute of Applied Research, Vilnius University, Sauletekio 9-III, LT-10222 Vilnius (Lithuania); Gulbinas, Vidmantas [Institute of Physics, Center for Physical Sciences and Technology, A. Gostauto 11, LT-01108 Vilnius (Lithuania)

2012-09-15

Potential of glassy films of newly synthesised low molecular weight organic molecules for light amplification and lasing applications has been investigated by analysing fluorescence, transient differential absorption and amplified spontaneous emission properties. These non-symmetric and symmetric molecules contain styryl-4H-pyran-4-ylidene fragment with three different electron acceptor groups: dicyanomethylene, barbituric acid, indene-1,3-dione. Fluorescence quantum yields of the investigated compounds in solutions are between 0.32 and 0.54, while they drop down by an order of magnitude in thin solid films. Incorporation of bulky side groups reduced excitonic interactions enabling manifestation of amplified spontaneous emission in the neat films of the investigated derivatives. - Highlights: Black-Right-Pointing-Pointer Bulky substituents attached to DCM dye enable formation of neat glassy films. Black-Right-Pointing-Pointer Investigated dyes show amplified spontaneous emission in neat films. Black-Right-Pointing-Pointer Two electron donor groups negatively influence light amplification.

Are human spontaneous otoacoustic emissions generated by a chain of coupled nonlinear oscillators?

NARCIS (Netherlands)

Wit, Hero P.; van Dijk, Pim

Spontaneous otoacoustic emissions (SOAEs) are generated by self-sustained cochlear oscillators. Properties of a computational model for a linear array of active oscillators with nearest neighbor coupling are investigated. The model can produce many experimentally well-established properties of

High-precision atom localization via controllable spontaneous emission in a cycle-configuration atomic system.

Science.gov (United States)

Ding, Chunling; Li, Jiahua; Yu, Rong; Hao, Xiangying; Wu, Ying

2012-03-26

A scheme for realizing two-dimensional (2D) atom localization is proposed based on controllable spontaneous emission in a coherently driven cycle-configuration atomic system. As the spatial-position-dependent atom-field interaction, the frequency of the spontaneously emitted photon carries the information about the position of the atom. Therefore, by detecting the emitted photon one could obtain the position information available, and then we demonstrate high-precision and high-resolution 2D atom localization induced by the quantum interference between the multiple spontaneous decay channels. Moreover, we can achieve 100% probability of finding the atom at an expected position by choosing appropriate system parameters under certain conditions.

Are human spontaneous otoacoustic emissions generated by a chain of coupled nonlinear oscillators?

Science.gov (United States)

Wit, Hero P; van Dijk, Pim

2012-08-01

Spontaneous otoacoustic emissions (SOAEs) are generated by self-sustained cochlear oscillators. Properties of a computational model for a linear array of active oscillators with nearest neighbor coupling are investigated. The model can produce many experimentally well-established properties of SOAEs.

Slow-light enhancement of spontaneous emission in active photonic crystal waveguides

DEFF Research Database (Denmark)

Ek, Sara; Chen, Yaohui; Semenova, Elizaveta

2012-01-01

Photonic crystal defect waveguides with embedded active layers containing single or multiple quantum wells or quantum dots have been fabricated. Spontaneous emission spectra are enhanced close to the bandedge, consistently with the enhancement of gain by slow light effects. These are promising...... results for future compact devices for terabit/s communication, such as miniaturised semiconductor optical amplifiers and mode-locked lasers....

Miíase na topografia de saco lacrimal

Directory of Open Access Journals (Sweden)

Simone Haber Duellberg von Faber Bison

2016-02-01

Full Text Available RESUMO A miíase é a infestação dos tecidos humanos por larvas Diptera. O comprometimento ocular é raro. Os autores apresentam um caso de miíase na topografia do saco lacrimal e discutem as modalidades terapêuticas para o tratamento desta doença.

Trace element emissions from spontaneous combustion of gob piles in coal mines, Shanxi, China

Science.gov (United States)

Zhao, Y.; Zhang, Jiahua; Chou, C.-L.; Li, Y.; Wang, Z.; Ge, Y.; Zheng, C.

2008-01-01

The emissions of potentially hazardous trace elements from spontaneous combustion of gob piles from coal mining in Shanxi Province, China, have been studied. More than ninety samples of solid waste from gob piles in Shanxi were collected and the contents of twenty potentially hazardous trace elements (Be, F, V, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Sn, Sb, Hg, Tl, Pb, Th, and U) in these samples were determined. Trace element contents in solid waste samples showed wide ranges. As compared with the upper continental crust, the solid waste samples are significantly enriched in Se (20x) and Tl (12x) and are moderately enriched in F, As, Mo, Sn, Sb, Hg, Th, and U (2-5x). The solid waste samples are depleted in V, Cr, Mn, Co, Ni, Cu, and Zn. The solid waste samples are enriched in F, V, Mn, Cr, Co, Ni, Cu, Zn, Sb, Th, and U as compared with the Shanxi coals. Most trace elements are higher in the clinker than in the unburnt solid waste except F, Sn, and Hg. Trace element abundances are related to the ash content and composition of the samples. The content of F is negatively correlated with the ash content, while Pb is positively correlated with the ash. The concentrations of As, Mn, Zn, and Cd are highly positively correlated with Fe2O3 in the solid waste. The As content increases with increasing sulfur content in the solid waste. The trace element emissions are calculated for mass balance. The emission factors of trace elements during the spontaneous combustion of the gobs are determined and the trace element concentrations in the flue gas from the spontaneous combustion of solid waste are calculated. More than a half of F, Se, Hg and Pb are released to the atmosphere during spontaneous combustion. Some trace element concentrations in flue gas are higher than the national emission standards. Thus, gob piles from coal mining pose a serious environmental problem. ?? 2007 Elsevier B.V. All rights reserved.

Surface-plasmon-induced modification on the spontaneous emission spectrum via subwavelength-confined anisotropic Purcell factor.

Science.gov (United States)

Gu, Ying; Wang, Luojia; Ren, Pan; Zhang, Junxiang; Zhang, Tiancai; Martin, Olivier J F; Gong, Qihuang

2012-05-09

The mechanism of using the anisotropic Purcell factor to control the spontaneous emission linewidths in a four-level atom is theoretically demonstrated; if the polarization angle bisector of the two dipole moments lies along the axis of large/small Purcell factor, destructive/constructive interference narrows/widens the fluorescence center spectral lines. Large anisotropy of the Purcell factor, confined in the subwavelength optical mode volume, leads to rapid spectral line narrowing of atom approaching a metallic nanowire, nanoscale line width pulsing following periodically varying decay rates near a periodic metallic nanostructure, and dramatic modification on the spontaneous emission spectrum near a custom-designed resonant plasmon nanostructure. The combined system opens a good perspective for applications in ultracompact active quantum devices.

REVIEW: Spontaneous emission of an atom in the presence of nanobodies

Science.gov (United States)

Klimov, Vasilii V.; Ducloy, M.; Letokhov, V. S.

2001-07-01

The effect of nanobodies, i.e., the bodies whose size is small compared to the emission wavelength, on spontaneous emission of an atom located near them is considered. The results of calculations performed within the framework of quantum and classical electrodynamics are presented both in analytic and graphical forms and can be readily used for planning experiments and analysis of experimental data. It is shown that nanobodies can be used to control efficiently the rate of spontaneous transitions. Thus, an excited atom located near a nanocylinder or a nanospheroid pole, whose transition dipole moment is directed normally to the nanobody surface, can decay with the rate that is tens and hundreds times higher than the decay rate in a free space. In the case of some (negative) dielectric constants, the decay rate can increase by a factor of 105—106 and more. On the other hand, the decay of an excited atom whose transition dipole moment is directed tangentially to the nanobody surface substantially slows down. The probability of nonradiative decay of the excited state is shown to increase substantially in the presence of na-nobodies possessing losses.

Synchronization of spontaneous otoacoustic emissions in the tokay gecko

Science.gov (United States)

Roongthumskul, Yuttana; Hudspeth, A. J.

2018-05-01

Spontaneous otoacoustic emissions (SOAEs) are a universal feature of all classes of tetrapods. Although the generation mechanism of SOAEs are incompletely understood, these emissions are undoubtedly associated with the active process of the inner ear. In most lizards, unlike mammals and amphibians, robust SOAEs can ordinarily be detected from both ears. In this work, we investigated the interactions between emissions recorded simultaneously from the two ears of tokay geckos. We found that the frequency spectra of SOAEs from both ears of an individual animal are partially correlated: the peaks of several emissions occur at identical frequencies. To investigate the underlying mechanisms of these identical-frequency SOAEs, we perturbed the emissions from one or both ears by manipulating the pressure in the ear canals or by decreasing the local temperature in the vicinity of one inner ear. Suppression of SOAEs due to large positive pressures revealed that some identical-frequency emissions were generated unilaterally, whereas others were contributed by both ears at identical or slightly different frequencies. These bilaterally generated SOAEs became desynchronized as their frequency detuning grew sufficiently large, a phenomenon consistent with the synchronization of two active oscillators. Finally, we found that manipulations of the volume of the oral cavity or altering the impedance of the tympanum strongly affected the synchronization of SOAEs. These findings agreed with previous studies suggesting that the tokay gecko, like other lizards, exhibits strong acoustic coupling between its tympani through the oral cavity.

Urolitíase no alotransplante renal

Directory of Open Access Journals (Sweden)

Cologna Adauto José

2003-01-01

Full Text Available OBJETIVO: A litíase urinária é uma complicação incomum no alotransplante renal, a incidência varia de 0,02 a 3,4%. A maioria dos cálculos forma-se após o transplante, porém alguns podem ser transferidos junto com o enxerto para o hospedeiro. O tratamento desta complicação está baseado em alguns casos descritos na literatura. O objetivo deste trabalho é o de relatar a incidência da litíase renal no paciente com transplante renal, assim como a conduta adotada no HCFMRPUSP. MÉTODOS: Foram analisados 953 pacientes submetidos a transplante renal no HCFMRPUSP, de fevereiro 1968 a maio de 2003. A idade média foi de 47,2 anos (35 a 63 anos. Em 09 pacientes, o rim foi proveniente de doador cadáver e apenas 01 doador vivo. RESULTADOS:Foram diagnosticados 10 casos de litíase (1,05%. Em 02 pacientes (20% o cálculo foi diagnosticado no intraoperatório, em 01 (10% no peri-operatório (5º. dia, os 07 restantes (70% no pós-operatório tardio. Em 04 pacientes (57% não havia sintomatologia específica, 02 (29% apresentaram ITU, em 03 (43% ocorreu elevação da creatinina sérica. De 8 pacientes com litíase no pós-operatorio, em 06 os cálculos estavam localizados no rim e 02 no ureter. Dos pacientes com cálculos renais, 02 foram observados, 02 submetidos a LECO, 01 a nefrolitripsia percutânea, 01 à pielolitotomia. Em 01 paciente com cálculo ureteral foi realizada pielovesicostomia (cálculo + estenose, no outro paciente foi feita a ureterorrenoscopia retrógrada. CONCLUSÃO: A urolitíase é complicação rara no transplante renal, a conduta terapêutica no pós-operatório tardio é semelhante à da população geral.

On the spontaneous emission of electromagnetic radiation in the CSL model

International Nuclear Information System (INIS)

Donadi, Sandro; Deckert, Dirk-André; Bassi, Angelo

2014-01-01

Spontaneous photon emission in the Continuous Spontaneous Localization (CSL) model is studied one more time. In the CSL model each particle interacts with a noise field that induces the collapse of its wave function. As a consequence of this interaction, when the particle is electrically charged, it radiates. As discussed in Adler (2013) the formula for the emission rate, to first perturbative order, contains two terms: one is proportional to the Fourier component of the noise field at the same frequency as that of the emitted photon and one is proportional to the zero Fourier component of the noise field. As discussed in previous works, this second term seems unphysical. In Adler (2013) it was shown that the unphysical term disappears when the noise is confined to a bounded region and the final particle’s state is a wave packet. Here we investigate the origin of this unphysical term and why it vanishes according to the previous prescription. We will see that perturbation theory is formally not valid in the large time limit since the effect of the noise accumulates continuously in time. Therefore either one performs an exact calculation (or at least in some way includes higher order terms) as we do here, or one finds a way to make a perturbative calculation meaningful, e.g., by confining the system as in Adler (2013). -- Highlights: •We compute the electromagnetic radiation emission in collapse models. •Under only the dipole approximation, the equations of motion are solved exactly. •The electromagnetic interaction must be treated exactly. •In order to obtain the correct emission rate the particle must be bounded

Steady State Entanglement and Saturation Effects in Correlated Spontaneous Emission Lasers

International Nuclear Information System (INIS)

Fei, Wang; Xiang-Ming, Hu; Wen-Xing, Shi

2009-01-01

It has recently been shown that correlated spontaneous emission lasers (CEL) exhibit transient entanglement in the linear regime. Here we re-examine the quantum correlations in two-photon CEL and explore the saturation effects on continuous variable entanglement. It is shown that the steady state entanglement is obtainable in the weak or moderate saturation regime, while is washed out in the deep saturation regime. (general)

Effect of composition on the spontaneous emission probabilities, stimulated emission cross-sections and local environment of Tm{sup 3+} in TeO{sub 2}-WO{sub 3} glass

Energy Technology Data Exchange (ETDEWEB)

Oezen, G. E-mail: gozenl@itu.edu.tr; Aydinli, A.; Cenk, S.; Sennaroglu, A

2003-04-01

Effect of composition on the structure, spontaneous and stimulated emission probabilities of various 1.0 mol% Tm{sub 2}O{sub 3} doped (1-x)TeO{sub 2}+(x)WO{sub 3} glasses were investigated using Raman spectroscopy, ultraviolet-visible-near-infrared (UV/VIS/NIR) absorption and luminescence measurements. Absorption measurements in the UV/VIS/NIR region were used to determine spontaneous emission probabilities for the 4f-4f transitions of Tm{sup 3+} ions. Six absorption bands corresponding to the absorption of the {sup 1}G{sub 4}, {sup 3}F{sub 2}, {sup 3}F{sub 3} and {sup 3}F{sub 4}, {sup 3}H{sub 5} and {sup 3}H{sub 4} levels from the {sup 3}H{sub 6} ground level were observed. Integrated absorption cross-section of each band except that of {sup 3}H{sub 5} level was found to vary with the glass composition. Luminescence spectra of the samples were measured upon 457.9 nm excitation. Three emission bands centered at 476 nm ({sup 1}G{sub 4}{yields}{sup 3}H{sub 6} transition), 651 nm ({sup 1}G{sub 4}{yields}{sup 3}H{sub 4} transition) and 800 nm ({sup 1}G{sub 4}{yields}{sup 3}H{sub 5} transition) were observed. Spontaneous emission cross-sections together with the luminescence spectra measured upon 457.9 nm excitation were used to determine the stimulated emission cross-sections of these emissions. The effect of glass composition on the Judd-Ofelt parameters and therefore on the spontaneous and the stimulated emission cross-sections for the metastable levels of Tm{sup 3+} ions were discussed in detail. The effect of temperature on the stimulated emission cross-sections for the emissions observed upon 457.9 nm excitation was also discussed.

Resonant stimulation of Raman scattering from single-crystal thiophene/phenylene co-oligomers

International Nuclear Information System (INIS)

Yanagi, Hisao; Marutani, Yusuke; Matsuoka, Naoki; Hiramatsu, Toru; Ishizumi, Atsushi; Sasaki, Fumio; Hotta, Shu

2013-01-01

Amplified Raman scattering was observed from single crystals of thiophene/phenylene co-oligomers (TPCOs). Under ns-pulsed excitation, the TPCO crystals exhibited amplified spontaneous emission (ASE) at resonant absorption wavelengths. With increasing excitation wavelength to the 0-0 absorption edge, the stimulated resonant Raman peaks appeared both in the 0-1 and 0-2 ASE band regions. When the excitation wavelength coincided with the 0-1 ASE band energy, the Raman peaks selectively appeared in the 0-2 ASE band. Such unusual enhancement of the 0-2 Raman scattering was ascribed to resonant stimulation via vibronic coupling with electronic transitions in the uniaxially oriented TPCO molecules

Gain media edge treatment to suppress amplified spontaneous emission in a high power laser

Science.gov (United States)

Hackel, Lloyd A.; Soules, Thomas F.; Fochs, Scott N.; Rotter, Mark D.; Letts, Stephan A.

2008-12-09

A novel method and apparatus for suppressing ASE and parasitic oscillation modes in a high average power laser is introduced. By roughening one or more peripheral edges of a solid-state crystal or ceramic laser gain media and by bonding such edges using a substantially high index bonding elastomer or epoxy to a predetermined electromagnetic absorbing arranged adjacent to the entire outer surface of the peripheral edges of the roughened laser gain media, ASE and parasitic oscillation modes can be effectively suppressed.

Coherent control of spontaneous emission near a photonic band edge

International Nuclear Information System (INIS)

Woldeyohannes, Mesfin; John, Sajeev

2003-01-01

We demonstrate the coherent control of spontaneous emission for a three-level atom located within a photonic band gap (PBG) material, with one resonant frequency near the edge of the PBG. Spontaneous emission from the three-level atom can be totally suppressed or strongly enhanced depending on the relative phase between the steady-state control laser coupling the two upper levels and the pump laser pulse used to create an excited state of the atom in the form of a coherent superposition of the two upper levels. Unlike the free-space case, the steady-state inversion of the atomic system is strongly dependent on the externally prescribed initial conditions. This non-zero steady-state population is achieved by virtue of the localization of light in the vicinity of the emitting atom. It is robust to decoherence effects provided that the Rabi frequency of the control laser field exceeds the rate of dephasing interactions. As a result, such a system may be relevant for a single-atom, phase-sensitive optical memory device on the atomic scale. The protected electric dipole within the PBG provides a basis for a qubit to encode information for quantum computations. A detailed literature survey on the nature, fabrication and applications of PBG materials is presented to provide context for this research. (phd tutorial)

Enhancement of the spontaneous emission in subwavelength quasi-two-dimensional waveguides and resonators

Science.gov (United States)

Tokman, Mikhail; Long, Zhongqu; AlMutairi, Sultan; Wang, Yongrui; Belkin, Mikhail; Belyanin, Alexey

2018-04-01

We consider a quantum-electrodynamic problem of the spontaneous emission from a two-dimensional (2D) emitter, such as a quantum well or a 2D semiconductor, placed in a quasi-2D waveguide or cavity with subwavelength confinement in one direction. We apply the Heisenberg-Langevin approach, which includes dissipation and fluctuations in the electron ensemble and in the electromagnetic field of a cavity on equal footing. The Langevin noise operators that we introduce do not depend on any particular model of dissipative reservoir and can be applied to any dissipation mechanism. Moreover, our approach is applicable to nonequilibrium electron systems, e.g., in the presence of pumping, beyond the applicability of the standard fluctuation-dissipation theorem. We derive analytic results for simple but practically important geometries: strip lines and rectangular cavities. Our results show that a significant enhancement of the spontaneous emission, by a factor of order 100 or higher, is possible for quantum wells and other 2D emitters in a subwavelength cavity.

Gamma-radiation effect of the ATP-ASE-activity in various parts of cotton sprouts

International Nuclear Information System (INIS)

Kazimov, A.K.

1975-01-01

ATP-ase is a thiol enzyme whose sulfhydryl group plays an important role. The transport of substances through biological membranes is the result of the action of the sodium-potassium pump of the cell, which functions with ATP energy. The action of this transport mechanism depends on the activity of ATP-ase. It may be postulated, therefore, that the suppression of the active transport of Na + and K + ions in cells under irradiation is partially the result of a disturbance of the activity of the ATP enzyme system. The author studied the effect of gamma radiation on ATP-ase activity in various parts of seven-day-old seedlings of type 108-F cotton, which were irradiated using Co 60 gamma radiation. The results of the experiment showed that the ATP-ase activity of the cotton seedling rootlets depends on the dose and the time elapsed after irradiation (a table is given). Small radiation doses (0.2 and 0.5 krad) significantly increased ATP-ase activity in the rootlets, while heavy doses inhibited it significantly. Similar results were obtained for the stems and leaves (tables are given). It was estblished that the ATP-ase of cotton seedlings has varying sensitivity to irradiation. The most sensitive ATP-ases were those of the rootlets. The activity of background ATP-ase is less subject to change than Na + and K + activated ATP-ases. For example, while the activity of ATP-ase (without ions) was inhibited by 25% when a 25 krad irradiation dose was administered, the retardation of Na + and K + activated ATP-ases reached 41%. The author suggests that the inhibition of ATP-ase activity under irradiation is mainly the result of a disturbance of the structure of the membrane functions. It is also possible that ATP-ase activity decreases because of a lack of the enzyme substrate - ATP, which is formed during the process of oxydative phosphorylization. A table is also provided showing the effect of irradiation on the activity of ATP-ase activated by various ions in the roots of

Mechanism of f-decay - spontaneous emission of fragments by heavy nuclei

International Nuclear Information System (INIS)

Rubchenya, V.A.; Ehjsmont, V.P.; Yavshits, S.G.

1987-01-01

A new type of model of radioactive decay - spontaneous emission of fragments by heavy nuclei, for which f-decay has been suggested, is formulated. The consideration is based on representation about a disintegrating configuration, for which the probability of f-cluster formation is close to 1. The moments method is used to determine the parameters of the disintegrating configuration. The probability of disintegrating configuration formation is determined by collective properties of a disintegrating nucleus. Effect of nucleon shells of the daughter nucleus and fragment leads to more compact disintegrating configuration and to decay energy increase, that's why at f-decay magic nuclei are formed. Probable spontaneous f-decay values calculated agree satisfactorily with experimental data. The calculational results testify to considerable decrease of f-decay probability at Z≥94

Ultra-thin Glass Film Coated with Graphene: A New Material for Spontaneous Emission Enhancement of Quantum Emitter

Institute of Scientific and Technical Information of China (English)

Lu Sun; Chun Jiang

2015-01-01

We propose an ultra-thin glass film coated with graphene as a new kind of surrounding material which can greatly enhance spontaneous emission rate(SER) of dipole emitter embedded in it. With properly designed parameters,numerical results show that SER-enhanced factors as high as 1.286 9 106 can be achieved. The influences of glass film thickness and chemical potential/doping level of graphene on spontaneous emission enhancement are also studied in this paper. A comparison is made between graphene and other coating materials such as gold and silver to see their performances in SER enhancement.

Multiparameter-dependent spontaneous emission in PbSe quantum dot-doped liquid-core multi-mode fiber

International Nuclear Information System (INIS)

Zhang, Lei; Zhang, Yu; Wu, Hua; Zhang, Tieqiang; Gu, Pengfei; Chu, Hairong; Cui, Tian; Wang, Yiding; Zhang, Hanzhuang; Zhao, Jun; Yu, William W.

2013-01-01

A theoretical model was established in this paper to analyze the properties of 3.50 and 4.39 nm PbSe quantum dot-doped liquid-core multi-mode fiber. This model was applicable to both single- and multi-mode fiber. The three-level system-based light-propagation equations and rate equations were used to calculate the guided spontaneous emission spectra. Considering the multi-mode in the fiber, the normalized intensity distribution of transversal model was improved and simplified. The detailed calculating results were thus obtained and explained using the above-mentioned model. The redshift of the peak position and the evolution of the emission power were observed and analyzed considering the influence of the fiber length, fiber diameter, doping concentration, and the pump power. The redshift increased with the increases of fiber length, fiber diameter, and doping concentration. The optimal fiber length, fiber diameter, and doping concentration were analyzed and confirmed, and the related spontaneous emission power was obtained. Besides, the normalized emission intensity increased with the increase of pump power in a nearly linear way. The calculating results fitted well to the experimental data

Trace Elements Concentrations in Water and Aquatic Biota from Ase ...

African Journals Online (AJOL)

MICHAEL HORSFALL

pollution of the Ase-creek. Metal concentrations in the fish species and aquatic plants in this study .... analysis of water, fishes and aquatic plants samples from Ase-Creek in the Niger .... Speciation in the Environment. Blackie A and P, New.

Modification of spontaneous emission from nanodiamond colour centres on a structured surface

International Nuclear Information System (INIS)

Inam, F A; Gaebel, T; Bradac, C; Withford, M J; Rabeau, J R; Steel, M J; Stewart, L; Dawes, J M

2011-01-01

Colour centres in diamond are promising candidates as a platform for quantum technologies and biomedical imaging based on spins and/or photons. Controlling the emission properties of colour centres in diamond is a key requirement for the development of efficient single-photon sources having high collection efficiency. A number of groups have achieved an enhancement in the emission rate over narrow wavelength ranges by coupling single emitters in nanodiamond crystals to resonant electromagnetic structures. In this paper, we characterize in detail the spontaneous emission rates of nitrogen-vacancy centres at various locations on a structured substrate. We found a factor of 1.5 average enhancement of the total emission rate when nanodiamonds are on an opal photonic crystal surface, and observed changes in the lifetime distribution. We present a model for explaining these observations and associate the lifetime properties with dipole orientation and polarization effects.

Modification of spontaneous emission from nanodiamond colour centres on a structured surface

Energy Technology Data Exchange (ETDEWEB)

Inam, F A; Gaebel, T; Bradac, C; Withford, M J; Rabeau, J R; Steel, M J [Centre for Quantum Science and Technology, Department of Physics and Astronomy, Macquarie University, Sydney, NSW 2109 (Australia); Stewart, L; Dawes, J M, E-mail: james.rabeau@mq.edu.au, E-mail: michael.steel@mq.edu.au [MQ Photonics Research Centre, Department of Physics and Astronomy, Macquarie University, Sydney, NSW 2109 (Australia)

2011-07-15

Colour centres in diamond are promising candidates as a platform for quantum technologies and biomedical imaging based on spins and/or photons. Controlling the emission properties of colour centres in diamond is a key requirement for the development of efficient single-photon sources having high collection efficiency. A number of groups have achieved an enhancement in the emission rate over narrow wavelength ranges by coupling single emitters in nanodiamond crystals to resonant electromagnetic structures. In this paper, we characterize in detail the spontaneous emission rates of nitrogen-vacancy centres at various locations on a structured substrate. We found a factor of 1.5 average enhancement of the total emission rate when nanodiamonds are on an opal photonic crystal surface, and observed changes in the lifetime distribution. We present a model for explaining these observations and associate the lifetime properties with dipole orientation and polarization effects.

General theory for spontaneous emission in active dielectric microstructures: Example of a fiber amplifier

DEFF Research Database (Denmark)

Søndergaard, Thomas; Tromborg, Bjarne

2001-01-01

A model for spontaneous emission in active dielectric microstructures is given in terms of the classical electric field Green's tensor and the quantum-mechanical operators for the generating currents. A formalism is given for calculating the Green's tensor, which does not rely on the existence...

Neurotoxocarosis Neurotoxocaríase

Directory of Open Access Journals (Sweden)

Josef Finsterer

2007-10-01

Full Text Available Infection of humans with embryonated eggs of Toxocara canis (larva migrans remains asymptomatic, or results in covert or common toxocarosis, visceral larva migrans syndrome, or ophthalmologic and neurologic impairment. Though neurological manifestations of Toxocara canis larvae are rare, toxocarosis remains an important differential diagnosis of various neurological disorders. Manifestations of the central nervous system are dementia, meningo-encephalitis, myelitis, cerebral vasculitis, epilepsy, or optic neuritis. Manifestations of the peripheral nervous system comprise radiculitis, affection of cranial nerves, or musculo-skeletal involvement. If toxocarosis is neglected, ignored, or refused as a differential of these abnormalities, it may be easily overlooked for years. Early recognition and treatment of the infection is, however, of paramount importance since it reduces morbidity and mortality and the risk of secondary superinfection. Like the visceral manifestations, neurological manifestations of toxocarosis are treated by benzimidazole components, most frequently albendazole, corticosteroids, or diethylcarbamazine. If detected and treated early, the prognosis of neurological manifestations of toxocarosis is favourable.Infecção humana com ovos embrionados de Toxocara canis (larva migrans pode permanecer assintomática ou resultar em toxocaríase acentuada ou comum, síndrome da larva migrans visceral ou manifestações neurológicas ou oftalmológicas. Embora manifestações neurológicas das larvas de Toxocara canis sejam raras, a toxocaríase permanece como importante diagnóstico diferencial de várias manifestações neurológicas. Manifestações do sistema nervoso central são demência, meningoencefalite, mielite, vasculite cerebral, epilepsia, ou neurite ótica. Manifestações do sistema nervoso periférico compreendem radiculite, agressão de nervos cranianos ou envolvimento músculo-esquelético. Se a toxocaríase �

Spontaneous emission spectra and quantum light-matter interactions from a strongly coupled quantum dot metal-nanoparticle system

DEFF Research Database (Denmark)

Van Vlack, C.; Kristensen, Philip Trøst; Hughes, S.

2012-01-01

the dot to the detector, we demonstrate that the strong-coupling regime should be observable in the far-field spontaneous emission spectrum, even at room temperature. The vacuum-induced emission spectra show that the usual vacuum Rabi doublet becomes a rich spectral triplet or quartet with two of the four...

AMPLITUDE FLUCTUATIONS OF SPONTANEOUS OTOACOUSTIC EMISSIONS CAUSED BY INTERNAL AND EXTERNALLY APPLIED NOISE SOURCES

NARCIS (Netherlands)

WIT, HP

1993-01-01

The simplest description for the generator of a spontaneous otoacoustic emission (SOAE) is that of a single (isolated) limit-cycle oscillator. Evidence is given that this description is too simple. And it is concluded that study of systems of coupled oscillators is needed to obtain more insight in

REDUCED THROMBOGENICITY OF VASCULAR PROSTHESES BY COATING WITH ADP-ASE

NARCIS (Netherlands)

VANDERLEI, B; ROBINSON, PH; BAKKER, WW; Bartels, H.

1992-01-01

In this pilot study ADP-ase coated polyurethane (PL) vascular prostheses and noncoated (control) PU vascular prostheses (all vascular prostheses: ID 1.5 mm, length 1,5 cm) were implanted into the carotid artery of the rabbit to test wheter ADP-ase might function as an adequate anti-thrombogenic

Broadband filters for abatement of spontaneous emission in circuit quantum electrodynamics

Energy Technology Data Exchange (ETDEWEB)

Bronn, Nicholas T., E-mail: ntbronn@us.ibm.com; Hertzberg, Jared B.; Córcoles, Antonio D.; Gambetta, Jay M.; Chow, Jerry M. [IBM T.J. Watson Research Center, 1101 Kitchawan Road, Yorktown Heights, New York 10598 (United States); Liu, Yanbing; Houck, Andrew A. [Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544 (United States)

2015-10-26

The ability to perform fast, high-fidelity readout of quantum bits (qubits) is essential to the goal of building a quantum computer. However, coupling a fast measurement channel to a superconducting qubit typically also speeds up its relaxation via spontaneous emission. Here, we use impedance engineering to design a filter by which photons may easily leave the resonator at the cavity frequency but not at the qubit frequency. We implement this broadband filter in both an on-chip and off-chip configuration.

Child and adolescent service experience (ChASE): measuring service quality and therapeutic process.

Science.gov (United States)

Day, Crispin; Michelson, Daniel; Hassan, Imren

2011-11-01

OBJECTIVES. Dissatisfaction with services has been associated with poorer child mental health outcomes, early treatment termination as well as disagreements over the nature of mental health difficulties, reasons for referral and therapy goals. The development of straightforward, reliable, and accurate methods of eliciting service users' views is essential within child and adolescent mental health care. This paper describes the development of the child and adolescent service experience (ChASE), a tool to measure children and young people's service experience DESIGN. The study comprises a non-experimental, cross-sectional design. METHODS. Participants were 132 mental health service users aged 8-18 years. Participants and their main carer completed the ChASE, Parent Satisfaction Questionnaire (PSQ) (Stallard, 1996) and Strengths and Difficulties (SDQ) Impact Supplement. Clinicians completed the SDQ Impact Supplement and provided clinical activity data. A sub-sample of participants completed the ChASE on a second occasion, 6 weeks after the completion of the first questionnaire. RESULTS. Scrutiny of ChASE data indicated high levels of completion. Principal axis factoring identified three factors within the ChASE: Relationship, Privacy, and Session Activity. The ChASE has good internal consistency and test-retest reliability. Significant correlations were found between the ChASE and carer satisfaction, service use, and youth clinical outcomes. CONCLUSIONS. The ChASE is a short, psychometrically robust tool for routine measurement of children, and young people's experience of mental health services, which users can complete easily. The results underline the importance of alliance factors to children and young people and their association with clinical improvement as well as the potential for the ChASE to be used a measure of children's therapeutic progress and alliance. ©2011 The British Psychological Society.

On quantum effects in spontaneous emission by a relativistic electron beam in an undulator

Energy Technology Data Exchange (ETDEWEB)

Geloni, Gianluca [European XFEL GmbH, Hamburg (Germany); Kocharyan, Vitali; Saldin, Evgeni [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

2012-02-15

Robb and Bonifacio (2011) claimed that a previously neglected quantum effect results in noticeable changes in the evolution of the energy distribution associated with spontaneous emission in long undulators. They revisited theoretical models used to describe the emission of radiation by relativistic electrons as a continuous diffusive process, and claimed that in the asymptotic limit for a large number of undulator periods the evolution of the electron energy distribution occurs as discrete energy groups according to Poisson distribution. We show that these novel results have no physical sense, because they are based on a one-dimensional model of spontaneous emission and assume that electrons are sheets of charge. However, electrons are point-like particles and, as is well-known, the bandwidth of the angular-integrated spectrum of undulator radiation is independent of the number of undulator periods. If we determine the evolution of the energy distribution using a three-dimensional theory we find the well-known results consistent with a continuous diffusive process. The additional pedagogical purpose of this paper is to review how quantum diffusion of electron energy in an undulator with small undulator parameter can be simply analyzed using the Thomson cross-section expression, unlike the conventional treatment based on the expression for the Lienard-Wiechert fields. (orig.)

3-D ASE calculation for high power output XeCl excimer lasers

International Nuclear Information System (INIS)

Tu Qinfen; Zhang Jianquan; Wu Baosheng

1996-01-01

The 3-dimensional ASE calculation for electron beam pumping XeCl excimer laser is presented by M-C method. In the model wall-reflected ASE is included. This calculation also includes non-saturable absorption and mirror that reflect ASE flux back into the active gain medium. Results show optimum scaling of injected flux. It can provide theoretical basis and experimental references for experiments on excimer lasers, and be extrapolated to any other type of laser

Spontaneous emission spectrum from a V-type three-level atom in a double-band photonic crystal

International Nuclear Information System (INIS)

Zhang Han Zhuang; Tang Sing Hai; Dong Po; He Jun

2002-01-01

The spontaneous emission spectrum from a V-type three-level atom embedded in a double-band photonic band gap (PBG) material has been investigated for the first time. Most interestingly it is shown that there is not only a black dark line, but also a narrow spontaneous line near the edges of the double photonic band. The positions of the dark line and narrow spontaneous line are near the transition from an empty upper level to a lower level. The lines stem from destructive and constructive quantum interferences, which induce population transfer between the two upper levels, in the PBG reservoirs. The effects of system parameters on the interference have been discussed in detail

Ultrafast spontaneous emission modulation of graphene quantum dots interacting with Ag nanoparticles in solution

Energy Technology Data Exchange (ETDEWEB)

Zhao, Jianwei [Department of Physics, Shanghai University, Shanghai 200444 (China); Research Center of Quantum Macro-Phenomenon and Application, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210 (China); Lu, Jian, E-mail: luj@sari.ac.cn; Wang, Zhongyang, E-mail: wangzy@sari.ac.cn [Research Center of Quantum Macro-Phenomenon and Application, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210 (China); Wang, Liang [School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444 (China); Institute of Nanochemistry and Nanobiology, Shanghai University, Shanghai 200444 (China); Tian, Linfan [Research Center of Quantum Macro-Phenomenon and Application, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210 (China); School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210 (China); Deng, Xingxia [Research Center of Quantum Macro-Phenomenon and Application, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210 (China); School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Tian, Lijun [Department of Physics, Shanghai University, Shanghai 200444 (China); Pan, Dengyu [School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444 (China)

2016-07-11

We investigated the strong interaction between graphene quantum dots and silver nanoparticles in solution using time-resolved photoluminescence techniques. In solution, the silver nanoparticles are surrounded by graphene quantum dots and interacted with graphene quantum dots through exciton-plasmon coupling. An ultrafast spontaneous emission process (lifetime 27 ps) was observed in such a mixed solution. This ultrafast lifetime corresponds to the emission rate exceeding 35 GHz, with the purcell enhancement by a factor of ∼12. These experiment results pave the way for the realization of future high speed light sources applications.

The research and implementation of coalfield spontaneous combustion of carbon emission WebGIS based on Silverlight and ArcGIS server

International Nuclear Information System (INIS)

Zhu, Z; Bi, J; Wang, X; Zhu, W

2014-01-01

As an important sub-topic of the natural process of carbon emission data public information platform construction, coalfield spontaneous combustion of carbon emission WebGIS system has become an important study object. In connection with data features of coalfield spontaneous combustion carbon emissions (i.e. a wide range of data, which is rich and complex) and the geospatial characteristics, data is divided into attribute data and spatial data. Based on full analysis of the data, completed the detailed design of the Oracle database and stored on the Oracle database. Through Silverlight rich client technology and the expansion of WCF services, achieved the attribute data of web dynamic query, retrieval, statistical, analysis and other functions. For spatial data, we take advantage of ArcGIS Server and Silverlight-based API to invoke GIS server background published map services, GP services, Image services and other services, implemented coalfield spontaneous combustion of remote sensing image data and web map data display, data analysis, thematic map production. The study found that the Silverlight technology, based on rich client and object-oriented framework for WCF service, can efficiently constructed a WebGIS system. And then, combined with ArcGIS Silverlight API to achieve interactive query attribute data and spatial data of coalfield spontaneous emmission, can greatly improve the performance of WebGIS system. At the same time, it provided a strong guarantee for the construction of public information on China's carbon emission data

Effects of salicylates and aminoglycosides on spontaneous otoacoustic emissions in the Tokay gecko.

Science.gov (United States)

Stewart, C E; Hudspeth, A J

2000-01-04

The high sensitivity and sharp frequency discrimination of hearing depend on mechanical amplification in the cochlea. To explore the basis of this active process, we examined the pharmacological sensitivity of spontaneous otoacoustic emissions (SOAEs) in a lizard, the Tokay gecko. In a quiet environment, each ear produced a complex but stable pattern of emissions. These SOAEs were reversibly modulated by drugs that affect mammalian otoacoustic emissions, the salicylates and the aminoglycoside antibiotics. The effect of a single i.p. injection of sodium salicylate depended on the initial power of the emissions: ears with strong control SOAEs displayed suppression at all frequencies, whereas those with weak control emissions showed enhancement. Repeated oral administration of acetylsalicylic acid reduced all emissions. Single i.p. doses of gentamicin or kanamycin suppressed SOAEs below 2.6 kHz, while modulating those above 2.6 kHz in either of two ways. For ears whose emission power at 2.6-5.2 kHz encompassed more than half of the total, individual emissions displayed facilitation as great as 35-fold. For the remaining ears, emissions dropped to as little as one-sixth of their initial values. The similarity of the responses of reptilian and mammalian cochleas to pharmacological intervention provides further evidence for a common mechanism of cochlear amplification.

A microfabricated, low dark current a-Se detector for measurement of microplasma optical emission in the UV for possible use on-site

Science.gov (United States)

Abbaszadeh, Shiva; Karim, Karim S.; Karanassios, Vassili

2013-05-01

Traditionally, samples are collected on-site (i.e., in the field) and are shipped to a lab for chemical analysis. An alternative is offered by using portable chemical analysis instruments that can be used on-site (i.e., in the field). Many analytical measurements by optical emission spectrometry require use of light-sources and of spectral lines that are in the Ultra-Violet (UV, ~200 nm - 400 nm wavelength) region of the spectrum. For such measurements, a portable, battery-operated, fiber-optic spectrometer equipped with an un-cooled, linear, solid-state detector may be used. To take full advantage of the advanced measurement capabilities offered by state-of-the-art solid-state detectors, cooling of the detector is required. But cooling and other thermal management hamper portability and use on-site because they add size and weight and they increase electrical power requirements. To address these considerations, an alternative was implemented, as described here. Specifically, a microfabricated solid-state detector for measurement of UV photons will be described. Unlike solid-state detectors developed on crystalline Silicon, this miniaturized and low-cost detector utilizes amorphous Selenium (a-Se) as its photosensitive material. Due to its low dark current, this detector does not require cooling, thus it is better suited for portable use and for chemical measurements on-site. In this paper, a microplasma will be used as a light-source of UV photons for the a-Se detector. For example, spectra acquired using a microplasma as a light-source will be compared with those obtained with a portable, fiber-optic spectrometer equipped with a Si-based 2080-element detector. And, analytical performance obtained by introducing ng-amounts of analytes into the microplasma will be described.

High-sensitive portable ASE-2 X-ray analyzer of sulfur in mineral oil

International Nuclear Information System (INIS)

Anchugov, I.S.; Goganov, A.D.; Plotnikov, R.I.

2007-01-01

The high-sensitivity ASE-2 analyzer of sulfur on the basis of existing ASE-I device is designed. ASE-2 analyzer realizes a standard method of energy dispersion X-ray fluorescent determinations of a sulfur mass fraction in mineral oil and allows to carry out the quantitative determination of sulfur in hydrocarbonic raw material and fuel in a 0.002-5 mass.% range [ru

Fano-induced spontaneous emission enhancement of molecule placed in a cluster of asymmetrically-arranged metallic nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Le, Khai Q., E-mail: khai.lequang@hoasen.edu.vn [Faculty of Science and Technology, Hoa Sen University, Ho Chi Minh (Viet Nam); Department of Electrical Engineering, University of Minnesota, Duluth, MN 55812 (United States); Bai, Jing [Department of Electrical Engineering, University of Minnesota, Duluth, MN 55812 (United States); Nguyen, H.P.T. [Department of Electrical and Computer Engineering, New Jersey Institute of Technology, NJ 07102 (United States)

2016-05-15

We demonstrate that plasmonic Fano resonance significantly boosts spontaneous emission rate of a single emitter, e.g. atom, molecule and quantum dot, over a moderately broad emission spectrum. An emission enhancement of up to 140 times compared to the system with no external inclusion at tunable frequencies is achieved, providing a new complementary enhancement mechanism. Fano resonance is induced in clusters of four asymmetric-arranged nanoparticles with ultra-small inter-particle gaps. It is shown to play a dominant role in light-emitting enhancement, mediated by combined localized surface plasmon resonances.

The 'spontaneous' acoustic emission of the shock front in a perfect fluid: solving a riddle

International Nuclear Information System (INIS)

Brun, Louis

2013-06-01

In the fifties, S. D'yakov discovered that theory allows for suitable EOS shock fronts to emit acoustic waves 'spontaneously'. Section 90 of Fluid Mechanics of Landau and Lifshitz, 2. Ed., deals with the phenomenon, leaving it unexplained. This open question was chosen to introduce a monograph in progress about 'the shock front in the perfect fluid'. The novelty of our approach consists in having the phenomenon generated - which means it is non-spontaneous -- from an appropriate solicitation of the front and studying its development analytically. The non classical source and mechanism of the emission are thus brought to light. (author)

Modification and control of the spontaneous emission from an M-type atom embedded in an anisotropic photonic crystal

International Nuclear Information System (INIS)

Ding Chunling; Li Jiahua; Yang Xiaoxue; Lue Xinyou

2011-01-01

We describe the spontaneous emission properties of an M-type five-level atom embedded in a photonic crystal (PC), which is coherently driven by two external laser fields. It leads to two types of quantum interference: reservoir-induced interference and laser-induced interference. Considering different detunings of atomic transition frequencies from band edges, we reveal some interesting phenomena such as spectral-line enhancement, spectral-line suppression, spectral-line narrowing, reservoir-induced cancellation of spontaneous emission and the appearance of dark lines, which originate from the quantum interference effects and the control of external laser fields. These investigations suggest possible applications in quantum optics, optical communications and in the fabrication of novel optoelectronic devices.

Frequency-time behavior of artificially stimulated vlf emissions

International Nuclear Information System (INIS)

Stiles, G.S.; Helliwell, R.A.

1975-01-01

Artificially stimulated VLF emissions (ASE's) are emissions triggered in the magnetosphere by the whistler mode signals from VLF transmitters. These emissions may be separated into two classes, rising and falling, depending on whether the final value of df/dt is positive or negative. Several hundred ASE's triggered by three transmitters have been analyzed using the fast Fourier transform with a filter spacing of 25 Hz and an effective filter width of about 45 Hz. The study was limited to the initial frequency-time behavior of ASE's. Averages taken over many events reveal that both rising and falling tones show the same initial behavior. The emissions begin at the frequency of the triggering signal. Both tones initially rise in frequency, falling tones reversing slope at a point 25--300 Hz above the triggering signal. The slope of rising tones, particularly those triggered by NAA, often abruptly levels off in this same frequency range; as a result, a short (approximately 40 ms) plateau is formed that precedes the final rising phase. The initial frequency offset commonly observed in individual events appears to result from the frequent coincidence with this plateau of a peak in amplitude. Emissions stimulated by all three transmitters show essentially the same features; this finding indicates that their frequency behavior does not depend strongly on transmitter power. The process appears to be asymmetric in frequency; no evidence of initial growth below the triggering frequency has been found. (U.S.)

Localization of the relative position of two atoms induced by spontaneous emission

International Nuclear Information System (INIS)

Zheng, L.; Li, C.; Li, Y.; Sun, C.P.

2005-01-01

We reexamine the back-action of emitted photons on the wave packet evolution about the relative position of two cold atoms. We show that photon recoil resulting from the spontaneous emission can induce the localization of the relative position of the two atoms through the entanglement between the spatial motion of individual atoms and their emitted photons. The obtained result provides a more realistic model for the analysis of the environment-induced localization of a macroscopic object

Final amplifier design and mercury

International Nuclear Information System (INIS)

Rose, E.A.; Hanson, D.E.

1991-01-01

The final amplifier for the Mercury KrF excimer facility is being designed. The design exercise involves extensive modeling to predict amplifier performance. Models of the pulsed-power system, including a Child-Langmuir diode with closure, electron-beam energy deposition, KrF laser kinetics, amplified spontaneous emission (ASE), a time-dependent laser extraction in the presence of ASE are presented as a design package. The design exercise indicates that the energy objective of Phase I -- 100 joules -- will be met

Interactions between Hair Cells Shape Spontaneous Otoacoustic Emissions in a Model of the Tokay Gecko's Cochlea

OpenAIRE

Gelfand, Michael; Piro, Oreste; Magnasco, Marcelo O.; Hudspeth, A. J.

2010-01-01

Background The hearing of tetrapods including humans is enhanced by an active process that amplifies the mechanical inputs associated with sound, sharpens frequency selectivity, and compresses the range of responsiveness. The most striking manifestation of the active process is spontaneous otoacoustic emission, the unprovoked emergence of sound from an ear. Hair cells, the sensory receptors of the inner ear, are known to provide the energy for such emissions; it is unclear, though, how ens...

Effect of atomic initial phase difference on spontaneous emission of an atom embedded in photonic crystal

International Nuclear Information System (INIS)

Bing, Zhang; Xiu-Dong, Sun; Xiang-Qian, Jiang

2010-01-01

We investigate the effect of initial phase difference between the two excited states of a V-type three-level atom on its steady state behaviour of spontaneous emission. A modified density of modes is introduced to calculate the spontaneous emission spectra in photonic crystal. Spectra in free space are also shown to compare with that in photonic crystal with different relative positions of the excited levels from upper band-edge frequency. It is found that the initial phase difference plays an important role in the quantum interference property between the two decay channels. For a zero initial phase, destructive property is presented in the spectra. With the increase of initial phase difference, quantum interference between the two decay channels from upper levels to ground level turns to be constructive. Furthermore, we give an interpretation for the property of these spectra. (atomic and molecular physics)

FEL gain optimisation and spontaneous radiation

Energy Technology Data Exchange (ETDEWEB)

Bali, L.M.; Srivastava, A.; Pandya, T.P. [Lucknow Univ. (India)] [and others

1995-12-31

Colson have evaluated FEL gains for small deviations from perfect electron beam injection, with radiation of the same polarisation as that of the wiggler fields. We find that for optimum gain the polarisation of the optical field should be the same as that of the spontaneous emission under these conditions. With a helical wiggler the axial oscillations resulting from small departures from perfect electron beam injection lead to injection dependent unequal amplitudes and phases of the spontaneous radiation in the two transverse directions. Viewed along the axis therefore the spontaneous emission is elliptically polarised. The azimuth of the ellipse varies with the difference of phase of the two transverse components of spontaneous emission but the eccentricity remains the same. With planar wigglers the spontaneous emission viewed in the axial direction is linearly polarised, again with an injection dependent azimuth. For optimum coherent gain of a radiation field its polarisation characteristics must be the same as those of the spontaneous radiation with both types of wiggler. Thus, with a helical wiggler and the data reported earlier, an increase of 10% in the FEL gain at the fundamental frequency and of 11% at the fifth harmonic has been calculated in the small gain per pass limit. Larger enhancements in gain may result from more favourable values of input parameters.

Detection of experimental pancreas necrosis by DNA-ase labelled with radioiodine

International Nuclear Information System (INIS)

Tihanyi, Tibor; Duffek, Laszlo; Balint, Istvan; Flautner, Lajos

1986-01-01

Detection of pancreas necrosis was attempted in dog experiments. Strong association between pancreatic DNA-ase and actin molecules in vitro provided the theoretical basis for the procedure. Pancreatic DNA-ase labelled with 125 I was administered intravenously to dogs in which experimental pancreas necrosis was elicited. Accumulation ratio of radioactivity was above 20 in the necrotic pancreas whereas it varied between 1.6 and 5.6 in other tissues. After administration of 37 MBq 131 I labelled DNA-ase, accumulation of radioactivity could be clearly visualized in the necrotic portions of the removed pancreas by a gamma camera. The investigations will be extended in order to develop a clinically utilizable test. (L.E.)

Model of pulse extraction from a copper laser amplifier

International Nuclear Information System (INIS)

Boley, C.D.; Warner, B.E.

1997-03-01

A computational model of pulse propagation through a copper laser amplifier has been developed. The model contains a system of 1-D (in the axial direction), time-dependent equations for the laser intensity and amplified spontaneous emission (ASE), coupled to rate equations for the atomic levels. Detailed calculations are presented for a high-power amplifier at Lawrence Livermore National Laboratory. The extracted power agrees with experiment near saturation. At lower input power the calculation overestimates experiment, probably because of increased ASE effects. 6 refs., 6 figs

Calculation of spontaneous emission from a V-type three-level atom in photonic crystals using fractional calculus

International Nuclear Information System (INIS)

Huang, Chih-Hsien; Hsieh, Wen-Feng; Wu, Jing-Nuo; Cheng, Szu-Cheng; Li, Yen-Yin

2011-01-01

Fractional time derivative, an abstract mathematical operator of fractional calculus, is used to describe the real optical system of a V-type three-level atom embedded in a photonic crystal. A fractional kinetic equation governing the dynamics of the spontaneous emission from this optical system is obtained as a fractional Langevin equation. Solving this fractional kinetic equation by fractional calculus leads to the analytical solutions expressed in terms of fractional exponential functions. The accuracy of the obtained solutions is verified through reducing the system into the special cases whose results are consistent with the experimental observation. With accurate physical results and avoiding the complex integration for solving this optical system, we propose fractional calculus with fractional time derivative as a better mathematical method to study spontaneous emission dynamics from the optical system with non-Markovian dynamics.

Modified spontaneous emission of silicon nanocrystals embedded in artificial opals

Science.gov (United States)

Janda, Petr; Valenta, Jan; Rehspringer, Jean-Luc; Mafouana, Rodrigue R.; Linnros, Jan; Elliman, Robert G.

2007-10-01

Si nanocrystals (NCs) were embedded in synthetic silica opals by means of Si-ion implantation or opal impregnation with porous-Si suspensions. In both types of sample photoluminescence (PL) is strongly Bragg-reflection attenuated (up to 75%) at the frequency of the opal stop-band in a direction perpendicular to the (1 1 1) face of the perfect hcp opal structure. Time-resolved PL shows a rich distribution of decay rates, which contains both shorter and longer decay components compared with the ordinary stretched exponential decay of Si NCs. This effect reflects changes in the spontaneous emission rate of Si NCs due to variations in the local density of states of real opal containing defects.

Modified spontaneous emission of silicon nanocrystals embedded in artificial opals

International Nuclear Information System (INIS)

Janda, Petr; Valenta, Jan; Rehspringer, Jean-Luc; Mafouana, Rodrigue R; Linnros, Jan; Elliman, Robert G

2007-01-01

Si nanocrystals (NCs) were embedded in synthetic silica opals by means of Si-ion implantation or opal impregnation with porous-Si suspensions. In both types of sample photoluminescence (PL) is strongly Bragg-reflection attenuated (up to 75%) at the frequency of the opal stop-band in a direction perpendicular to the (1 1 1) face of the perfect hcp opal structure. Time-resolved PL shows a rich distribution of decay rates, which contains both shorter and longer decay components compared with the ordinary stretched exponential decay of Si NCs. This effect reflects changes in the spontaneous emission rate of Si NCs due to variations in the local density of states of real opal containing defects

Modified spontaneous emission of silicon nanocrystals embedded in artificial opals

Energy Technology Data Exchange (ETDEWEB)

Janda, Petr [Department of Chemical Physics and Optics, Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16 Prague 2 (Czech Republic); Valenta, Jan [Department of Chemical Physics and Optics, Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16 Prague 2 (Czech Republic); Rehspringer, Jean-Luc [Institut de Physique et Chimie des Materiaux de Strasbourg, GMI et GONLO, UMR46 CNRS-ULP-ECPM, 23, rue du Loess, F-67037 Strasbourg (France); Mafouana, Rodrigue R [Institut de Physique et Chimie des Materiaux de Strasbourg, GMI et GONLO, UMR46 CNRS-ULP-ECPM, 23, rue du Loess, F-67037 Strasbourg (France); Linnros, Jan [Laboratory of Material and Semiconductor Physics, Royal Institute of Technology, Electrum 229, 164 21 Kista-Stockholm (Sweden); Elliman, Robert G [Electronic Materials Engineering Department, Research School of Physical Sciences and Engineering, Australian National University, Canberra, ACT 0200 (Australia)

2007-10-07

Si nanocrystals (NCs) were embedded in synthetic silica opals by means of Si-ion implantation or opal impregnation with porous-Si suspensions. In both types of sample photoluminescence (PL) is strongly Bragg-reflection attenuated (up to 75%) at the frequency of the opal stop-band in a direction perpendicular to the (1 1 1) face of the perfect hcp opal structure. Time-resolved PL shows a rich distribution of decay rates, which contains both shorter and longer decay components compared with the ordinary stretched exponential decay of Si NCs. This effect reflects changes in the spontaneous emission rate of Si NCs due to variations in the local density of states of real opal containing defects.

Spontaneous emission near the band edge of a three-dimensional photonic crystal: a fractional calculus approach

International Nuclear Information System (INIS)

Cheng, S-C; Wu, J-N; Tsai, M-R; Hsieh, W-F

2009-01-01

We suggest a better mathematical method, fractional calculus, for studying the behavior of the atom-field interaction in photonic crystals. By studying the spontaneous emission of an atom in a photonic crystal with a one-band isotropic model, we found that the long-time inducing memory of the spontaneous emission is a fractional phenomenon. This behavior could be well described by fractional calculus. The results show no steady photon-atom bound state for the atomic resonant transition frequency lying in the proximity of the allowed band edge which was encountered in a previous study (Woldeyohannes and John 2003 J. Opt. B: Quantum Semiclass. Opt. 5 R43). The correctness of this result is validated by the 'cut-off smoothing' density of photon states (DOS) with fractional calculus. By obtaining a rigorous solution without the multiple-valued problem for the system, we show that the method of fractional calculus has a logically concise property.

Calculations of the self-amplified spontaneous emission performance of a free-electron laser

International Nuclear Information System (INIS)

Dejus, R. J.

1999-01-01

The linear integral equation based computer code (RON: Roger Oleg Nikolai), which was recently developed at Argonne National Laboratory, was used to calculate the self-amplified spontaneous emission (SASE) performance of the free-electron laser (FEL) being built at Argonne. Signal growth calculations under different conditions are used for estimating tolerances of actual design parameters. The radiation characteristics are discussed, and calculations using an ideal undulator magnetic field and a real measured magnetic field will be compared and discussed

Teleporting the one-qubit state via two-level atoms with spontaneous emission

Energy Technology Data Exchange (ETDEWEB)

Hu Mingliang, E-mail: mingliang0301@xupt.edu.cn, E-mail: mingliang0301@163.com [School of Science, Xi' an University of Posts and Telecommunications, Xi' an 710061 (China)

2011-05-14

We study quantum teleportation via two two-level atoms coupled collectively to a multimode vacuum field and prepared initially in different atomic states. We concentrated on the influence of the spontaneous emission, collective damping and dipole-dipole interaction of the atoms on fidelity dynamics of quantum teleportation and obtained the region of spatial distance between the two atoms over which the state can be teleported nonclassically. Moreover, we showed through concrete examples that entanglement of the channel state is the prerequisite but not the only essential quantity for predicting the teleportation fidelity.

Candidíase vulvovaginal: fatores predisponentes do hospedeiro e virulência das leveduras

OpenAIRE

Álvares,Cassiana Aparecida; Svidzinski,Terezinha Inez Estivalet; Consolaro,Márcia Edilaine Lopes

2007-01-01

INTRODUÇÃO: Leveduras do gênero Candida são patógenos oportunistas freqüentemente isolados das superfícies mucosas de indivíduos normais, mas podem levar ao desenvolvimento de infecções denominadas candidíases, que variam desde lesões superficiais até infecções disseminadas. OBJETIVOS: Ampliar os conhecimentos sobre candidíase vulvovaginal (CVV: infecção de vulva e vagina, causada por leveduras comensais que habitam a mucosa vaginal) e candidíase vulvovaginal recorrente (CVVR: ocorrência de q...

Polymorph-Dependent Green, Yellow, and Red Emissions of Organic Crystals for Laser Applications.

Science.gov (United States)

Xu, Zhenzhen; Zhang, Zhiwei; Jin, Xue; Liao, Qing; Fu, Hongbing

2017-12-05

Color tuning of organic solid-state luminescent materials remains difficult and time-consuming through conventional chemical synthesis. Herein, we reported highly efficient polymorph-dependent green (P1), yellow (P2), and red (P3) emissions of organic crystals made by the same molecular building blocks of 4-(2-{4-[2-(4-diphenylamino-phenyl)-vinyl]-phenyl}-vinyl)-benzonitrile (DOPVB). Single-crystal X-ray diffraction (XRD) and spectroscopic data reveal that all three polymorphs follow the herringbone packing motif in H-type aggregations. On the one hand, from P1, P2 to P3, the reduced pitch translation along π stacks increases the intermolecular interactions between adjacent molecules, therefore leading to gradually red-shifted emissions from 540, 570 to 614 nm. On the other hand, the edge-to-face arrangement and large roll translations avoid strong π-π overlap, making P1, P2 and P3 highly emissive with record-high solid-state fluorescence quantum yields of 0.60, 0.98, and 0.68, respectively. Furthermore, the optically allowed 0-1 transitions of herringbone H-aggregates of P1, P2 and P3 naturally provide a four-level scheme, enabling green and yellow amplified spontaneous emissions (ASE) with very low thresholds. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cooperative spontaneous emission from volume sources in layered media

International Nuclear Information System (INIS)

Nichelatti, E.

2009-01-01

The classical theory of radiation from a dipole located inside a microcavity is extended to the case of a volume source placed inside a layered medium. Cooperation phenomena that can take place in the spontaneous emission process are taken into account with an approach based on the theory of spatial coherence. Three cases are considered: noncooperation, long-range cooperation, and short-range cooperation. In all these cases, the expressions found for the out coupled power are analytical. As an application of the theory, an Alq 3 -based organic light emitting diode is analyzed. The optical properties of the device are evaluated and compared for two different types of cathode, one consisting of an Al layer, the other one consisting of an Al/LiF bi-layer. The results found show that the ultra-thin LiF layer significantly improves extraction efficiency [it

Periungual capillaroscopy in psoriasis Capilaroscopia periungueal em psoríase

Directory of Open Access Journals (Sweden)

Camila Ferrari Ribeiro

2012-08-01

Full Text Available BACKGROUND: Nailfold capillaroscopy is a useful technique for evaluating changes in microcirculation. OBJECTIVE: To investigate changes at nailfold capillaroscopy in psoriatic patients compared with controls. METHODS: Nailfold capillaroscopy was performed in 46 psoriatic patients and 50 controls to assess microscopic morphological changes, capillary density and the presence of areas with devascularization. RESULTS: Patients with psoriasis had lower capillary density (p=0.0005, increased avascular areas (p=0.0035 and an increased number of morphologically abnormal capillaries (coiled, pFUNDAMENTOS: A capilaroscopia periungueal é um método utilizado no estudo de alterações da microcirculação. OBJETIVO: Verificar alterações na capilaroscopia periungueal de pacientes com psoríase, comparando-os com controles saudáveis. MÉTODOS: A capilaroscopia periungueal foi realizada em 46 pacientes com psoríase e 50 controles, utilizando-se um estereomicroscópio e observando-se alterações morfológicas, densidade capilar e presença de áreas com desvascularização. RESULTADOS: Pacientes com psoríase tinham menor densidade capilar (p=0,0005, maior presença de áreas avasculares (p=0,0035 e de capilares morfologicamente alterados (enrodilhados; p<0.0001 do que os controles. Não se encontrou associação entre densidade capilar e tempo de doença (p=0.92 ou grau de envolvimento cutâneo medido pelo PASI (p=0.59. A presença de áreas avasculares foi mais comum em indivíduos com psoríase que tinham envolvimento ungueal (p=0,047. CONCLUSÃO: Pacientes com psoríase têm menor densidade capilar e presença de capilares morfologicamente alterados em relação aos controles.

Simulations of longitudinally pumped dye laser amplifier

International Nuclear Information System (INIS)

Takehisa, Kiwamu; Takemori, Satoshi

1995-01-01

Simulations of a copper laser pumped dye laser amplifier and new designs of the longitudinally pumped dye laser amplifier are presented. The simulations take the consideration of the amplified spontaneous emission (ASE). The new designs utilize a center-hole reflector instead of a dichroic mirror. The simulation results indicate that the poor spatial overlap between the pump beam and the dye beam in the transverse pumping not only reduces the laser output power, but also generates ASE strongly. The results also indicate that the longitudinal pumping is as efficient as the transverse pumping. (author)

Avaliação da resposta imune celular em pacientes com candidíase recorrente

OpenAIRE

Carvalho,Lucas P.; Bacellar,Olívia; Neves,Nilma A.; Carvalho,Edgar M.; Jesus,Amélia R. de

2003-01-01

A candidíase recorrente cutânea ou mucosa é caracterizada pela ocorrência de, no mínimo, 4 episódios de candidíase no período de um ano. Não são conhecidos os fatores que levam à recorrência desta infecção. O presente estudo avaliou a resposta linfoproliferativa e a produção de IFN-g de pacientes com candidíase recorrente. Os índices de estimulação da resposta linfoproliferativa em culturas de células de pacientes com candidíase recorrente estimuladas com antígeno de Candida albicans, PPD e T...

Avaliação da resposta imune celular em pacientes com candidíase recorrente

OpenAIRE

Carvalho, Lucas Pedreira de; Bacellar, Maria Olívia Amado Ramos; Neves, Nilma Antas; Carvalho Filho, Edgar Marcelino de; Jesus, Amélia R. de

2003-01-01

p. 571-576 A candidíase recorrente cutânea ou mucosa é caracterizada pela ocorrência de, no mínimo, 4 episódios de candidíase no período de um ano. Não são conhecidos os fatores que levam à recorrência desta infecção. O presente estudo avaliou a resposta linfoproliferativa e a produção de IFN-g de pacientes com candidíase recorrente. Os índices de estimulação da resposta linfoproliferativa em culturas de células de pacientes com candidíase recorrente estimuladas com antígeno de Candida alb...

Low-frequency-field-induced spontaneous-emission interference in a two-level atom placed in an anisotropic photonic crystal

International Nuclear Information System (INIS)

Li Gaoxiang; Evers, Joerg; Keitel, Christoph H

2005-01-01

We investigate the spontaneous-emission properties of a two-level atom embedded in a three-dimensional anisotropic photonic crystal. In addition to the modified density of states, the atom is driven by a coherent intense low-frequency field (LFF), which creates additional multiphoton decay channels with the exchange of two low-frequency photons and one spontaneous photon during an atomic transition. Due to the low frequency of the applied field, the various transition pathways may interfere with each other and thus give rise to a modified system dynamics. We find that even if all the atomic (bare and induced) transition frequencies are in the conducting band of the photonic crystal, there still may exist a photon-atom bound state in coexistence with propagating modes. The system also allows us to generate narrow lines in the spontaneous-emission spectrum. This spectrum is a function of the distance of the observer from the atom due to the band gap in the photonic crystal. The system properties depend on three characteristic frequencies, which are influenced by quantum interference effects. Thus these results can be attributed to a combination of interference and band-gap effects

The Recombination Mechanism and True Green Amplified Spontaneous Emission in CH3NH3PbBr3 Perovskite

KAUST Repository

Priante, Davide

2015-01-01

. M. Bakr, and B. S. Ooi, "The recombination mechanisms leading to amplified spontaneous emission at the true-green wavelength in CH3NH3PbBr3 perovskites", Applied Physics Letters, 106, 081902, 2015. DOI: 10.1063/1.4913463

KEBIJAKAN INVESTASI ASING BIDANG PERTAMBANGAN DI KABUPATEN POHUWATO PROVINSI GORONTALO KEBIJAKAN INVESTASI ASING BIDANG PERTAMBANGAN DI KABUPATEN POHUWATO PROVINSI GORONTALO KEBIJAKAN INVESTASI ASING BIDANG PERTAMBANGAN DI KABUPATEN POHUWATO PROVINSI GORONTALO KASUS PT. PANI DHARMA MAS KASUS PT. PANI DHARMA MAS KASUS PT. PANI DHARMA MAS

OpenAIRE

PUYO, AJENG MAWADDAH PUYO AJENG MAWADDAH PUYO AJENG MAWADDAH

2016-01-01

2016 AJENG MAWADDAH PUYO, E 131 12 003, "Kebijakan Investasi Asing Dalam Bidang Pertambangan di Kabupaten Pohuwato Provinsi Gorontalo Kasus PT. Pani Dharma MAS", dibawah bimbingan Dr. H. Adi Suryadi B., MA selaku pembimbing I dan Pusparida Syahdan. S.sos., MSI, Departemen Ilmu Hubungan internasional, Fakultas Ilmu Sosial dan Ilmu Politik, Universitas Hasanuddin. Penelitian ini bertujuan untuk mengetahui peran stakeholders dalam perumusan kebijakan investasi asing da...

Observation and analysis of self-amplified spontaneous emission at the APS low-energy undulator test line

Science.gov (United States)

Arnold, N. D.; Attig, J.; Banks, G.; Bechtold, R.; Beczek, K.; Benson, C.; Berg, S.; Berg, W.; Biedron, S. G.; Biggs, J. A.; Borland, M.; Boerste, K.; Bosek, M.; Brzowski, W. R.; Budz, J.; Carwardine, J. A.; Castro, P.; Chae, Y.-C.; Christensen, S.; Clark, C.; Conde, M.; Crosbie, E. A.; Decker, G. A.; Dejus, R. J.; DeLeon, H.; Den Hartog, P. K.; Deriy, B. N.; Dohan, D.; Dombrowski, P.; Donkers, D.; Doose, C. L.; Dortwegt, R. J.; Edwards, G. A.; Eidelman, Y.; Erdmann, M. J.; Error, J.; Ferry, R.; Flood, R.; Forrestal, J.; Freund, H.; Friedsam, H.; Gagliano, J.; Gai, W.; Galayda, J. N.; Gerig, R.; Gilmore, R. L.; Gluskin, E.; Goeppner, G. A.; Goetzen, J.; Gold, C.; Gorski, A. J.; Grelick, A. E.; Hahne, M. W.; Hanuska, S.; Harkay, K. C.; Harris, G.; Hillman, A. L.; Hogrefe, R.; Hoyt, J.; Huang, Z.; Jagger, J. M.; Jansma, W. G.; Jaski, M.; Jones, S. J.; Keane, R. T.; Kelly, A. L.; Keyser, C.; Kim, K.-J.; Kim, S. H.; Kirshenbaum, M.; Klick, J. H.; Knoerzer, K.; Koldenhoven, R. J.; Knott, M.; Labuda, S.; Laird, R.; Lang, J.; Lenkszus, F.; Lessner, E. S.; Lewellen, J. W.; Li, Y.; Lill, R. M.; Lumpkin, A. H.; Makarov, O. A.; Markovich, G. M.; McDowell, M.; McDowell, W. P.; McNamara, P. E.; Meier, T.; Meyer, D.; Michalek, W.; Milton, S. V.; Moe, H.; Moog, E. R.; Morrison, L.; Nassiri, A.; Noonan, J. R.; Otto, R.; Pace, J.; Pasky, S. J.; Penicka, J. M.; Pietryla, A. F.; Pile, G.; Pitts, C.; Power, J.; Powers, T.; Putnam, C. C.; Puttkammer, A. J.; Reigle, D.; Reigle, L.; Ronzhin, D.; Rotela, E. R.; Russell, E. F.; Sajaev, V.; Sarkar, S.; Scapino, J. C.; Schroeder, K.; Seglem, R. A.; Sereno, N. S.; Sharma, S. K.; Sidarous, J. F.; Singh, O.; Smith, T. L.; Soliday, R.; Sprau, G. A.; Stein, S. J.; Stejskal, B.; Svirtun, V.; Teng, L. C.; Theres, E.; Thompson, K.; Tieman, B. J.; Torres, J. A.; Trakhtenberg, E. M.; Travish, G.; Trento, G. F.; Vacca, J.; Vasserman, I. B.; Vinokurov, N. A.; Walters, D. R.; Wang, J.; Wang, X. J.; Warren, J.; Wesling, S.; Weyer, D. L.; Wiemerslage, G.; Wilhelmi, K.; Wright, R.; Wyncott, D.; Xu, S.; Yang, B.-X.; Yoder, W.; Zabel, R. B.

2001-12-01

Exponential growth of self-amplified spontaneous emission at 530 nm was first experimentally observed at the Advanced Photon Source low-energy undulator test line in December 1999. Since then, further detailed measurements and analysis of the results have been made. Here, we present the measurements and compare these with calculations based on measured electron beam properties and theoretical expectations.

Observation and analysis of self-amplified spontaneous emission at the APS low-energy undulator test line

CERN Document Server

Arnold, N D; Banks, G; Bechtold, R; Beczek, K; Benson, C; Berg, S; Berg, W; Biedron, S G; Biggs, J A; Boerste, K; Borland, M; Bosek, M; Brzowski, W R; Budz, J; Carwardine, J A; Castro, P; Chae, Y C; Christensen, S; Clark, C; Conde, M; Crosbie, E A; Decker, G A; Dejus, Roger J; Deleon, H; Den Hartog, P K; Deriy, B N; Dohan, D; Dombrowski, P; Donkers, D; Doose, C L; Dortwegt, R J; Edwards, G A; Eidelman, Y; Erdmann, M J; Error, J J; Ferry, R; Flood, R; Forrestal, J; Freund, H; Friedsam, H; Gagliano, J; Gai, W; Galayda, J N; Gerig, R; Gilmore, R L; Gluskin, E; Goeppner, G A; Goetzen, J; Gold, C; Grelick, A E; Hahne, M W; Hanuska, S; Harkay, K C; Harris, G; Hillman, A L; Hogrefe, R; Hoyt, J; Huang, Z; Jagger, J M; Jansma, W G; Jaski, M; Jones, S J; Keane, R T; Kelly, A L; Keyser, C; Kim, K J; Kim, S H; Kirshenbaum, M; Klick, J H; Knoerzer, K; Knott, M; Koldenhoven, R J; Labuda, S; Laird, R; Lang, J; Lenkszus, F R; Lessner, E S; Lewellen, J W; Li, Y; Lill, R M; Lumpkin, Alex H; Makarov, O A; Markovich, G M; McDowell, M; McDowell, W P; McNamara, P E; Meier, T; Meyer, D; Michalek, W; Milton, S V; Moe, H; Moog, E; Morrison, L; Nassiri, A; Noonan, J R; Otto, R; Pace, J; Pasky, S J; Penicka, J M; Pietryla, A F; Pile, G; Pitts, C; Power, J; Powers, T; Putnam, C C; Puttkammer, A J; Reigle, D; Reigle, L; Ronzhin, D; Rotela, E R; Russell, E F; Sajaev, Vadim; Sarkar, S; Scapino, J C; Schröder, K; Seglem, R A; Sereno, N S; Sharma, S K; Sidarous, J F; Singh, O; Smith, T L; Soliday, R; Sprau, G A; Stein, S J; Stejskal, B; Svirtun, V; Teng, L C; Theres, E; Thompson, K; Tieman, B J; Torres, J A; Trakhtenberg, E; Travish, G; Trento, G F; Vacca, J; Vasserman, I B; Vinokurov, N A; Walters, D R; Wang, J; Wang, X J; Warren, J; Wesling, S; Weyer, D L; Wiemerslage, G; Wilhelmi, K; Wright, R; Wyncott, D; Xu, S; Yang, B X; Yoder, W; Zabel, R B

2001-01-01

Exponential growth of self-amplified spontaneous emission at 530 nm was first experimentally observed at the Advanced Photon Source low-energy undulator test line in December 1999. Since then, further detailed measurements and analysis of the results have been made. Here, we present the measurements and compare these with calculations based on measured electron beam properties and theoretical expectations.

Quasi-static method and finite element method for obtaining the modifications of the spontaneous emission rate and energy level shift near a plasmonic nanostructure.

Science.gov (United States)

Zhao, Yun-Jin; Tian, Meng; Wang, Xiao-Yun; Yang, Hong; Zhao, Heping; Huang, Yong-Gang

2018-01-22

We provide numerical demonstrations of the applicability and accuracy of the quasi-static method and the finite-element method in the investigation of the modifications of the spontaneous emission rate and the energy level shift of an emitter placed near a silver-air interface or a silver nano-sphere. The analytical results are presented as a reference. Our calculations show that the finite element method is an accurate and general method. For frequency away from the radiative mode, the quasi-static method can be applied more effectively for calculating the energy level shift than the spontaneous emission rate. But for frequency around, there is a blue shift for both and this shift increases with the increasing of emitter-silver distance. Applying the theory to the nanosphere dimmer, we see similar phenomenon and find extremely large modifications of the spontaneous emission rate and energy level shift. These findings are instructive in the fields of quantum light-matter interactions.

HEX kiirustab ASe end registreerima / Virkko Lepassalu

Index Scriptorium Estoniae

Lepassalu, Virkko, 1971-

2003-01-01

Ilmunud ka: Delovõje Vedomosti 28. mai lk. 2. Eesti väärtpaberite keskregistri seaduse ja äriseadustiku muudatustest, mille kohaselt peavad 1. juuliks kõik aktsiaseltsid olema end väärtpaberite keskregistris arvele võtnud. Lisatud tabel: kolmandik ASe registreerimata

Investigation of X-ray lasing in a capillary discharge

NARCIS (Netherlands)

Ellwi, S. S.; Juschkin, L.; Ferri, S.; Kunze, H. J.; E. Louis,

2001-01-01

Using a new technique of an induced MHD instability in a capillary made of polyacetal we observed an intense spike (signal) of the Balmer-a line of C VI at 18.22 nm during the second half cycle of the discharge. The spike is identified as Amplified Spontaneous Emission (ASE), and enhancements are

On-chip plasmonic cavity-enhanced spontaneous emission rate at the zero-phonon line

DEFF Research Database (Denmark)

Siampour, Hamidreza; Kumar, Shailesh; Bozhevolnyi, Sergey I.

Highly confined surface plasmon polariton (SPP) modes can be utilized to enhance light-matter interaction at the single emitter level of quantum optical systems [1-4]. Dielectric-loaded SPP waveguides (DLSPPWs) confine SPPs laterally with relatively low propagation loss, enabling to benefit both ...... and an up to 42-fold spontaneous emission rate enhancement at the zero-phonon line (a ∼7-fold resonance enhancement in addition to a ∼6-fold broadband enhancement) is achieved, revealing the potential of our approach for on-chip realization of quantum-optical networks....... from a large Purcell factor and from a large radiative efficiency (low quenching rates) [1, 2]. In this work, we present a DLSPPW-based Bragg cavity resonator to direct emission from a single diamond nitrogen vacancy (NV) center into the zero-phonon line (Fig. 1). A quality factor of ∼70 for the cavity...

Enhancement of Spontaneous Erbium Emission near the Photonic Band Edge of Distributed Bragg Reflectors Based on a-Si:H/a-SiOx:H

International Nuclear Information System (INIS)

Medvedev, A.V.; Feoktistov, N.A.; Pevtsov, A.B.; Golubev, V.G.

2005-01-01

Results obtained in an experimental study of spontaneous emission from erbium ions in a spectral range corresponding to the lower photonic band edge of distributed Bragg reflectors (1D photonic crystals) are presented. The photonic crystals were constituted of alternating quarter-wave a-Si:H and a-SiO x :H layers grown by PECVD. Erbium was introduced into the a-Si:H layers by magnetron sputtering of an erbium target in the course of structure growth. The change observed in the intensity of spontaneous emission is due to the nonmonotonic behavior of the density of optical modes near the photonic band edge

Estudo piloto sobre alimentos que devem ser evitados nos portadores de psoríase

OpenAIRE

Festugato,Moira

2011-01-01

FUNDAMENTOS: Psoríase é uma doença inflamatória crônica, sistêmica, mediada por fatores imunológicos. Serão abordados os alimentos que atuam sobre estes fatores, contribuindo para a psoríase. Como doença sistêmica, que compartilha o mesmo substrato fisiopatológico com outras comorbidades, a dieta alimentar também leva à piora das comorbidades. OBJETIVO: Destacar um grupo de alimentos que pode atuar como um fator de manifestação e/ou agravo da psoríase e ao mesmo tempo viabilizar estratégias i...

Studies on a one-dimensional model for the spontaneous emission in the semiclassical approximation

International Nuclear Information System (INIS)

Crestana, S.

1983-01-01

Some generalization are made on the spontaneous emission by a plane of excited atoms, described by two level atom-model, in the Δ1=1, Δm=1, transition and using the semiclassical radiation approximation -both discussed in the text. Initially, the radiation rate of an infinite plane of excited atoms is investigated, using Δ1=0, Δm=0, transition. It is shown that we can observe a limit solution depending on the coupling between field and matter. (author)

Continuously tunable sub-half-wavelength localization via coherent control of spontaneous emission

International Nuclear Information System (INIS)

Wang Fei; Tan Xin-Yu; Gong Cheng; Shi Wen-Xing

2012-01-01

We propose a continuously tunable method of sub-half-wavelength localization via the coherent control of the spontaneous emission of a four-level Y-type atomic system, which is coupled to three strong coupling fields including a standing-wave field together with a weak probe field. It is shown that the sub-half-wavelength atomic localization is realized for both resonance and off-resonance cases. Furthermore, by varying the probe detuning in succession, the positions of the two localization peaks are tuned continuously within a wide range of probe field frequencies, which provides convenience for the realization of sub-half-wavelength atomic localization experimentally

Summary of the working group on FEL theory

International Nuclear Information System (INIS)

Pellegrini, C.

1984-01-01

The working group on FEL theory dedicated most of its discussions to topics relevant to the high gain regime in a free electron laser. In addition the area of interest was mainly restricted to FELs for the production of XUV radiation (<1000 A). A list of the topics that were felt to be relevant is: (1) characterization of the FEL high gain regime; (2) the amplified spontaneous emission mode of operation (ASE); (3) superradiance in FELs; (4) diffraction effects for high gain FELs; (5) noise and start-up; (6) coherence properties of the radiation for the ASE and superradiant FELS. 9 references

Tolerance of laser-driven microshell targets to fluorescence and prepulse energy

International Nuclear Information System (INIS)

Leonard, T.; Moncur, N.K.; Sullivan, D.

1976-01-01

Glass-shell targets currently being used for laser-fusion experiments are susceptible to damage by preenergy from the laser. This energy can result from amplified spontaneous emission (ASE) throughout the laser chain during the period of high-population inversion or it can take the form of a short prepulse nanoseconds before the main laser pulse. We point out the energy levels which a typical target can tolerate in the form of ASE and prepulses. These energies are low enough that special precautions must be taken to prevent significant perturbations of the target or its environment before the main laser pulse

Summary of the working group on FEL theory

Energy Technology Data Exchange (ETDEWEB)

Pellegrini, C.

1984-01-01

The working group on FEL theory dedicated most of its discussions to topics relevant to the high gain regime in a free electron laser. In addition the area of interest was mainly restricted to FELs for the production of XUV radiation (<1000 A). A list of the topics that were felt to be relevant is: (1) characterization of the FEL high gain regime; (2) the amplified spontaneous emission mode of operation (ASE); (3) superradiance in FELs; (4) diffraction effects for high gain FELs; (5) noise and start-up; (6) coherence properties of the radiation for the ASE and superradiant FELS. 9 references.

Triphenylamine based benzimidazole and benzothiazole: Synthesis and applications in fluorescent chemosensors and laser dyes

Energy Technology Data Exchange (ETDEWEB)

Yang, Yang [State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); University of Chinese Academy of Sciences, Beijing 100039 (China); Li, Bin, E-mail: libinteacher@163.com [State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); Zhang, Liming; Guan, Yunlong [State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China)

2014-01-15

Triphenylamine based fluorescent dyes TPA-benzimidazole and TPA-benzothiazole have been designed and synthesized. The TPA-benzimidazole chemosensor was tested for a number of metal ions and found to exhibit binding affinity for Fe{sup 3+} and Hg{sup 2+} in acetonitrile, and the fluorescence quenching was achieved through a PET process. The appearance of an isosbestic point in absorption titrations and Job's plot analysis supported 1:1 stoichiometries for Fe{sup 3+} and Hg{sup 2+} ions. Laser experiments showed that under transversal pumping with a Q-switched Nd:YAG (355 nm) laser in toluene, TPA-benzothiazole exhibits efficient and stable amplified spontaneous emissions (ASE) at 436 nm. -- Highlights: • Triphenylamine based fluorescent dyes TPA-benzimidazole and TPA-benzothiazole have been designed and synthesized. • The TPA-benzimidazole exhibits binding affinity for Fe{sup 3+} and Hg{sup 2+} in acetonitrile and the fluorescence quenching was achieved through a PET process. • Under transversal pumping at 355 nm in toluene, TPA-benzothiazole exhibits efficient and stable amplified spontaneous emissions (ASE) in 436 nm.

Triphenylamine based benzimidazole and benzothiazole: Synthesis and applications in fluorescent chemosensors and laser dyes

International Nuclear Information System (INIS)

Yang, Yang; Li, Bin; Zhang, Liming; Guan, Yunlong

2014-01-01

Triphenylamine based fluorescent dyes TPA-benzimidazole and TPA-benzothiazole have been designed and synthesized. The TPA-benzimidazole chemosensor was tested for a number of metal ions and found to exhibit binding affinity for Fe 3+ and Hg 2+ in acetonitrile, and the fluorescence quenching was achieved through a PET process. The appearance of an isosbestic point in absorption titrations and Job's plot analysis supported 1:1 stoichiometries for Fe 3+ and Hg 2+ ions. Laser experiments showed that under transversal pumping with a Q-switched Nd:YAG (355 nm) laser in toluene, TPA-benzothiazole exhibits efficient and stable amplified spontaneous emissions (ASE) at 436 nm. -- Highlights: • Triphenylamine based fluorescent dyes TPA-benzimidazole and TPA-benzothiazole have been designed and synthesized. • The TPA-benzimidazole exhibits binding affinity for Fe 3+ and Hg 2+ in acetonitrile and the fluorescence quenching was achieved through a PET process. • Under transversal pumping at 355 nm in toluene, TPA-benzothiazole exhibits efficient and stable amplified spontaneous emissions (ASE) in 436 nm

Obtaining attosecond x-ray pulses using a self-amplified spontaneous emission free electron laser

Directory of Open Access Journals (Sweden)

A. A. Zholents

2005-05-01

Full Text Available We describe a technique for the generation of a solitary attosecond x-ray pulse in a free-electron laser (FEL, via a process of self-amplified spontaneous emission. In this method, electrons experience an energy modulation upon interacting with laser pulses having a duration of a few cycles within single-period wiggler magnets. Two consecutive modulation sections, followed by compression in a dispersive section, are used to obtain a single, subfemtosecond spike in the electron peak current. This region of the electron beam experiences an enhanced growth rate for FEL amplification. After propagation through a long undulator, this current spike emits a ∼250   attosecond x-ray pulse whose intensity dominates the x-ray emission from the rest of the electron bunch.

Quantum yield measurements of light-induced H₂ generation in a photosystem I-[FeFe]-H₂ase nanoconstruct.

Science.gov (United States)

Applegate, Amanda M; Lubner, Carolyn E; Knörzer, Philipp; Happe, Thomas; Golbeck, John H

2016-01-01

The quantum yield for light-induced H2 generation was measured for a previously optimized bio-hybrid cytochrome c 6-crosslinked PSI(C13G)-1,8-octanedithiol-[FeFe]-H2ase(C97G) (PSI-H2ase) nanoconstruct. The theoretical quantum yield for the PSI-H2ase nanoconstruct is 0.50 molecules of H2 per photon absorbed, which equates to a requirement of two photons per H2 generated. Illumination of the PSI-H2ase nanoconstruct with visible light between 400 and 700 nm resulted in an average quantum yield of 0.10-0.15 molecules of H2 per photon absorbed, which equates to a requirement of 6.7-10 photons per H2 generated. A possible reason for the difference between the theoretical and experimental quantum yield is the occurrence of non-productive PSI(C13G)-1,8-octanedithiol-PSIC13G (PSI-PSI) conjugates, which would absorb light without generating H2. Assuming the thiol-Fe coupling is equally efficient at producing PSI-PSI conjugates as well as in producing PSI-H2ase nanoconstructs, the theoretical quantum yield would decrease to 0.167 molecules of H2 per photon absorbed, which equates to 6 photons per H2 generated. This value is close to the range of measured values in the current study. A strategy that purifies the PSI-H2ase nanoconstructs from the unproductive PSI-PSI conjugates or that incorporates different chemistries on the PSI and [FeFe]-H2ase enzyme sites could potentially allow the PSI-H2ase nanoconstruct to approach the expected theoretical quantum yield for light-induced H2 generation.

Imunologia da hanseníase Immunology of leprosy

Directory of Open Access Journals (Sweden)

Vanessa Amaral Mendonça

2008-08-01

Full Text Available A hanseníase é doença crônica infecciosa que se caracteriza por apresentar formas clínicas contrastantes, que são dependentes da interação do bacilo com a resposta imune do hospedeiro. O estudo dos processos imunológicos torna-se fundamental para o entendimento dos mecanismos envolvidos na apresentação e no desenvolvimento da doença. Neste artigo, é revisada a imunopatogênese da hanseníase.Leprosy is a chronic infectious disease characterized by contrasting clinical forms that are dependent on the interactions between the bacillus and the host immune response. Thus, the study of the immunological process is extremely relevant for the comprehension of the mechanisms involved in leprosy presentation and development. In this paper, the immunopathogenesis of leprosy is reviewed.

The Roles of Fission Yeast Ase1 in Mitotic Cell Division, Meiotic Nuclear Oscillation, and Cytokinesis Checkpoint SignalingD⃞V⃞

OpenAIRE

Yamashita, Akira; Sato, Masamitsu; Fujita, Akiko; Yamamoto, Masayuki; Toda, Takashi

2005-01-01

The Ase1/Prc1 proteins constitute a conserved microtubule-associated protein family that is implicated in central spindle formation and cytokinesis. Here we characterize a role for fission yeast Ase1. Ase1 localizes to microtubule overlapping zones and displays dynamic alterations of localization during the cell cycle. In particular, its spindle localization during metaphase is reduced substantially, followed by robust appearance at the spindle midzone in anaphase. ase1 deletions are viable b...

Optical bistability via quantum interference from incoherent pumping and spontaneous emission

International Nuclear Information System (INIS)

Sahrai, M.; Asadpour, S.H.; Sadighi-Bonabi, R.

2011-01-01

We theoretically investigate the optical bistability (OB) in a V-type three-level atomic system confined in a unidirectional ring cavity via incoherent pumping field. It is shown that the threshold of optical bistability can be controlled by the rate of an incoherent pumping field and by interference mechanism arising from the spontaneous emission and incoherent pumping field. We demonstrate that the optical bistability converts to optical multi-stability (OM) by the quantum interference mechanism. - Highlights: → We modulate the optical bistability (OB) in a four-level N-type atomic system. → The threshold of optical bistability can be controlled by the quantum interferences. → OB converts to optical multi-stability (OM) by the quantum interferences. → We discuss the effect of an incoherent pumping field on reduction of OB threshold.

Spatial Dependent Spontaneous Emission of an Atom in a Semi-Infinite Waveguide of Rectangular Cross Section

Science.gov (United States)

Song, Hai-Xi; Sun, Xiao-Qi; Lu, Jing; Zhou, Lan

2018-01-01

We study a quantum electrodynamics (QED) system made of a two-level atom and a semi-infinite rectangular waveguide, which behaves as a perfect mirror in one end. The spatial dependence of the atomic spontaneous emission has been included in the coupling strength relevant to the eigenmodes of the waveguide. The role of retardation is studied for the atomic transition frequency far away from the cutoff frequencies. The atom-mirror distance introduces different phases and retardation times into the dynamics of the atom interacting resonantly with the corresponding transverse modes. It is found that the upper state population decreases from its initial as long as the atom-mirror distance does not vanish, and is lowered and lowered when more and more transverse modes are resonant with the atom. The atomic spontaneous emission can be either suppressed or enhanced by adjusting the atomic location for short retardation time. There are partial revivals and collapses due to the photon reabsorbed and re-emitted by the atom for long retardation time. Supported by National Natural Science Foundation of China under Grant Nos. 11374095, 11422540, 11434011, and 11575058, National Fundamental Research Program of China (the 973 Program) under Grant No. 2012CB922103, and Hunan Provincial Natural Science Foundation of China under Grant No. 11JJ7001

Energy-Transfer Kinetics for Xe (6p[1/2]0) Atoms in Kr, Ar, Ne, and He.

Science.gov (United States)

He, Shan; Liu, Dong; Li, Xueyang; Chu, Junzhi; Guo, Jingwei; Liu, Jinbo; Hu, Shu; Sang, Fengting; Jin, Yuqi

2018-06-11

The kinetic processes for the Xe (6p[1/2] 0 ) atoms in Kr, Ar, Ne, and He buffer gases were studied. We found that Kr, Ar, and Ne atoms can be used to switch the amplified spontaneous emission (ASE) channel from 3408 nm (6p[1/2] 0 -6s'[1/2] 1 ) to 3680 nm (5d[1/2] 1 -6p[1/2] 1 ), while Xe and He atoms do not show such a phenomenon. This ASE channel switch is mainly ascribed to the fast transfer of 6p[1/2] 0 → 5d[1/2] 1 . On the basis of the rate equations for two-state coupling (energy-transfer processes between the two states are very rapid), the reason why the ASE channel switch effect normally coincides with a double exponential decay of the spontaneous emission at 828 nm (6p[1/2] 0 -6s[3/2] 1 ) is explained. The actual situations in Xe, Ar, Ne, and He follow this rule. However, the strictly single exponential decay of the spontaneous emission at 828 nm and strong ASE channel switch effect simultaneously emerge in Kr. This indicates that the transfer of 6p[1/2] 0 → 5d[1/2] 1 in Kr does not occur via two-state coupling, but via two steps of near-resonance collision through the 5s[3/2] 2 (Kr) state as the intermediate state (6p[1/2] 0 → 5s[3/2] 2 (Kr) → 5d[1/2] 1 ). In addition, we found Xe (6p[1/2] 0 ) atoms strongly tend to reach the 6p[3/2] 2 , 6p[3/2] 1 , and 6p[5/2] 2 states through the 5s[3/2] 2 (Kr) state as the intermediate state in Kr. The 5s[3/2] 2 (Kr) state plays a very important role in the energy-transfer kinetics for the Xe (6p[1/2] 0 ) atoms. Kr is probably an excellent buffer gas for laser systems based on Xe.

Giardíase e helmintíases em crianças de creches e escolas de 1° e 2° graus (públicas e privadas da cidade de Mirassol (SP, Brasil

Directory of Open Access Journals (Sweden)

Machado Renato Carlos

1999-01-01

Full Text Available O presente trabalho mostrou freqüências diferentes de parasitoses intestinais (giardíase e helmintíases entre crianças de pré-escolas e de escolas de 1 e 2 Graus, públicas e privadas. Pesquisou-se 199 indivíduos, sendo 96 pertencentes às instituições públicas e 103 pertencentes às instituições particulares. Nas instituições públicas as freqüências de giardíase foram maiores que nas instituições privadas. Para as helmintíases, as freqüências foram semelhantes entre as creches, porém maiores na escola pública em relação à particular. Indicadores do nível sócio-econômico, de escolaridade, de saneamento básico, como determinantes de parasitose intestinal, evidenciaram que as maiores freqüências de parasitoses ocorreram tanto entre as crianças de baixa renda quanto entre as que tinham pais com nível de escolaridade mais baixo. Também a origem das hortaliças foi um fator significativo para determinação destas parasitoses.

Self-amplified spontaneous emission free electron laser devices and nonideal electron beam transport

Directory of Open Access Journals (Sweden)

L. L. Lazzarino

2014-11-01

Full Text Available We have developed, at the SPARC test facility, a procedure for a real time self-amplified spontaneous emission free electron laser (FEL device performance control. We describe an actual FEL, including electron and optical beam transport, through a set of analytical formulas, allowing a fast and reliable on-line “simulation” of the experiment. The system is designed in such a way that the characteristics of the transport elements and the laser intensity are measured and adjusted, via a real time computation, during the experimental run, to obtain an on-line feedback of the laser performances. The detail of the procedure and the relevant experimental results are discussed.

Enhanced spontaneous emission from the inside of a multilayer hyperbolic metamaterial (presentation video)

Science.gov (United States)

Ferrari, Lorenzo; Lu, Dylan; Lepage, Dominic; Liu, Zhaowei

2014-09-01

We study the spontaneous emission enhancement inside a hyperbolic metamaterial, composed of a periodic stack of silver and silicon layers. After showing that the decay rate outside the multilayer can be spectrally altered via the metallic filling ratio, we embed the source within the individual silicon layers, and predict a 3-fold increase of the Purcell factor with respect to its outer value. Then we include the emitter in a polymethyl-methacrylate (PMMA) layer, and extract the plasmonic modes by means of a triangular and a rectangular grating, obtaining respectively a 10-fold and 6-fold enhancement in the power emitted into the far-field.

Vacuum field energy and spontaneous emission in anomalously dispersive cavities

International Nuclear Information System (INIS)

Bradshaw, Douglas H.; Di Rosa, Michael D.

2011-01-01

Anomalously dispersive cavities, particularly white-light cavities, may have larger bandwidth to finesse ratios than their normally dispersive counterparts. Partly for this reason, they have been proposed for use in laser interferometer gravitational-wave observatory (LIGO)-like gravity-wave detectors and in ring-laser gyroscopes. In this paper we analyze the quantum noise associated with anomalously dispersive cavity modes. The vacuum field energy associated with a particular cavity mode is proportional to the cavity-averaged group velocity of that mode. For anomalously dispersive cavities with group index values between 1 and 0, this means that the total vacuum field energy associated with a particular cavity mode must exceed (ℎ/2π)ω/2. For white-light cavities in particular, the group index approaches zero and the vacuum field energy of a particular spatial mode may be significantly enhanced. We predict enhanced spontaneous emission rates into anomalously dispersive cavity modes and broadened laser linewidths when the linewidth of intracavity emitters is broader than the cavity linewidth.

Trace Elements Concentrations in Water and Aquatic Biota from Ase ...

African Journals Online (AJOL)

Trace Elements Concentrations in Water and Aquatic Biota from Ase Creek in Niger ... arsenic, chromium, lead, molybdenum, bismuth and cadmium using atomic ... metal pollution, metal variation, environmental monitoring, bioaccumulation.

ATP-ase positive cells in human oral mucosa transplanted to nude mice

DEFF Research Database (Denmark)

Dabelsteen, E; Kirkeby, S

1981-01-01

A model to study the differentiation of human oral epithelium in vivo utilizing transplantation of human tissue to nude mice has been described. Previous studies have described the epithelial cells in this model. In this study we demonstrate that 8 d after transplantation, Langerhans cells, ident......, identified as ATP-ase positive dendritic cells, have almost disappeared from the transplanted epithelium whereas at day 21 after transplantation such cells were abundant. It is suggested that the ATP-ase positive cells which reappear in the transplanted epithelium are of mouse origin....

Longitudinal versus transversal excitation in doped graded-index polymer optical fibers

Science.gov (United States)

Illarramendi, M. A.; Arrue, J.; Ayesta, I.; Jiménez, F.; Zubia, J.; Bikandi, I.; Tagaya, A.; Koike, Y.

2014-03-01

In this work we perform a detailed experimental and theoretical analysis of the properties of amplified spontaneous emission (ASE) in a rhodamine-6G-doped graded-index polymer optical fiber when the fiber is pumped either longitudinally or transversally with respect to the fiber axis. The dependence of the ASE threshold and efficiency on fiber length has been compared for both schemes of excitation. A theoretical model for longitudinal excitation has been carried out by means of the laser rate equations as functions of time, distance traveled by light and wavelength. The analysis takes into account that the fiber is a typical graded-index POF in which the radial distributions of light power density and dye concentration are not uniform. The theoretical calculations agree satisfactorily with the experimental results. The photodegradation of the ASE intensity has also been measured for both pumping schemes.

Pitiríase versicolor e síndrome da imunodeficiência adquirida (SIDA

Directory of Open Access Journals (Sweden)

Roza Marlon Soares

2003-01-01

Full Text Available FUNDAMENTOS: A pitiríase versicolor é uma infecção crônica recorrente da camada córnea causada pela Malassezia furfur, geralmente assintomática, podendo ser causa de fungemia. A síndrome da imunodeficiência adquirida caracteriza-se por uma importante depressão celular, o que propicia a ocorrência de infecções oportunistas. OBJETIVOS: Dados a imunodepressão causada pelo HIV e o risco da presença de M. furfur em sua forma patogênica no imunocomprometido, realizou-se este trabalho comparativo buscando as reais diferenças da pitiríase versicolor no imunocompetente e no imunodeprimido pelo HIV. PACIENTES E MÉTODOS: Foram avaliados, no período de julho de 1998 a junho de 1999, 50 pacientes HIV positivos do Hospital Universitário da UFJF. Como grupo controle, foram examinados de forma aleatória 50 pacientes soronegativos para HIV. Para cada paciente foi preenchido um protocolo constando de identificação e exames clínicos e laboratoriais. RESULTADOS: A pitiríase versicolor foi diagnosticada clinicamente no grupo HIV positivo em sete (14% pacientes, resultado coincidente no grupo controle. Quanto ao passado para a pitiríase versicolor, 12 (24% pacientes já haviam apresentado tal doença no grupo HIV positivo, e igual incidência ocorreu no grupo controle. CONCLUSÕES: A pitiríase versicolor não se mostrou mais freqüente e nem mais agressiva na população imunodeprimida pelo HIV em relação ao grupo controle, enquanto a dermatite seborréica apresentou-se mais freqüente no grupo infectado pelo HIV.

Estrongiloidíase em pacientes com pênfigo foliáceo

OpenAIRE

Tavares-Neto,José; Alves,Denise Barcelos; Franciscon,José Umberto; Serrano,Carlos Roberto S.

1991-01-01

Em 30 pacientes com pênfigo foliáceo, a freqüência da estrongiloidíase foi de 40,0%, através de três exames de Baermann-Moraes. No "Hospital do Pênfigo", em Uberaba, as freqüências da estrongiloidíase nos funcionários (n = 14) e escolares (n = 47) da Escola-creche, anexa, também foram altas, respectivamente 35,7% e 23,4%. Em 7 (58,3 %) das 12 amostras do solo, do jardim/pátio do "Hospital", foram observadas formas de vida livre do Strongyloides stercoralis. O fator ambiental e a predisposição...

Simulating spontaneously generated coherence in a four-level atomic system

International Nuclear Information System (INIS)

Li Aijun; Gao Jinyue; Wu Jinhui; Wang Lei

2005-01-01

We study the spontaneous emission property of a four-level atomic system driven by two coherent fields. By numerical calculations in the bare state picture, we show that such interesting phenomena as extremely narrow peaks and spontaneous emission quenching can be realized, which are well understood by qualitative explanations in the partially and fully dressed state pictures. Especially, this coherently driven atomic system has two close-lying levels in the partially dressed state picture so that spontaneously generated coherence arises. Using our considered scheme it is feasible to carry out experiments based on spontaneously generated coherence because all rigorous requirements have been avoided in the bare state picture

Effect of atomic-state coherence and spontaneous emission on three-level dynamics

International Nuclear Information System (INIS)

Cardimona, D.A.

1990-01-01

For a three-level atom in the ssV configuration (i.e., having two excited states each dipole-coupled to a common ground state), we have found a particular linear combination of bare-atom states in which Rabi oscillations and their associated collapses and revivals do not occur. Moving to a dressed-state picture, we discover that this particular linear combination state is just that dressed state which is decoupled from all the field modes. It is a dressed state for which the transition dipole moments with the other dressed states are zero. The existence of this decoupled dressed state depends on the tuning of the dressing laser field, which in turn depends on the bare-atom excited-state dipole moments and energy-level separation. When we include spontaneous emission, the population decays from the other dressed states into this decoupled state and remains coherently trapped there, producing a system that experiences no dynamical behavior. This is exact for δ-function photon statistics (i.e., if there is no intensity uncertainty). The trapping becomes less perfect as the photon statistics are allowed to have a greater bandwidth. Also, if the applied field is tuned incorrectly, the spontaneous realignment of the atomic state amplitudes does not result in a totally decoupled dressed state, and the dynamics proceed normally

Considerations in going public on the ASE

International Nuclear Information System (INIS)

Romanzin, G.A.

1997-01-01

The possible reasons why an oil or gas company would seek public equity and financing and a listing on a stock exchange were discussed. This crucial decision for junior companies is often prompted by the need for expansion capital. In the last three years, 456 companies decided to list on the Alberta Stock Exchange (ASE) using the two most commonly used methods of going public: the Exchange Offering Prospectus (EOP) program, and the Junior Capital Pool (JCP) program. The EOP program is a simplified form of prospectus in which the distribution of securities is made through the facilities of the ASE. Companies that do not have significant operating assets, other than cash, nor agreements in place to acquire operating assets, are eligible under the JCP program which involves a two-stage process. Stage one requires the filing and clearing of a prospectus through the Alberta Securities Commission and the listing of the company's shares on the Exchange. Stage two requires completing a major transaction within 18 months of being listed on the Exchange. Details of the minimum listing requirements for either the EOP or the JCP programs were described

Tunable organic distributed feedback dye laser device excited through Förster mechanism

Science.gov (United States)

Tsutsumi, Naoto; Hinode, Taiki

2017-03-01

Tunable organic distributed feedback (DFB) dye laser performances are re-investigated and characterized. The slab-type waveguide DFB device consists of air/active layer/glass substrate. Active layer consisted of tris(8-quinolinolato)aluminum (Alq3), 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran (DCM) dye, and polystyrene (PS) matrix. Effective energy transfer from Alq3 to DCM through Förster mechanism enhances the laser emission. Slope efficiency in the range of 4.9 and 10% is observed at pump energy region higher than 0.10-0.15 mJ cm-2 (lower threshold), which is due to the amplified spontaneous emission (ASE) and lasing. Typical slope efficiency for lasing in the range of 2.0 and 3.0% is observed at pump energy region higher than 0.25-0.30 mJ cm-2 (higher threshold). The tuning wavelength for the laser emission is ranged from 620 to 645 nm depending on the ASE region.

Severe exercise and exercise training exert opposite effects on human neutrophil apoptosis via altering the redox status.

Directory of Open Access Journals (Sweden)

Guan-Da Syu

Full Text Available Neutrophil spontaneous apoptosis, a process crucial for immune regulation, is mainly controlled by alterations in reactive oxygen species (ROS and mitochondria integrity. Exercise has been proposed to be a physiological way to modulate immunity; while acute severe exercise (ASE usually impedes immunity, chronic moderate exercise (CME improves it. This study aimed to investigate whether and how ASE and CME oppositely regulate human neutrophil apoptosis. Thirteen sedentary young males underwent an initial ASE and were subsequently divided into exercise and control groups. The exercise group (n = 8 underwent 2 months of CME followed by 2 months of detraining. Additional ASE paradigms were performed at the end of each month. Neutrophils were isolated from blood specimens drawn at rest and immediately after each ASE for assaying neutrophil spontaneous apoptosis (annexin-V binding on the outer surface along with redox-related parameters and mitochondria-related parameters. Our results showed that i the initial ASE immediately increased the oxidative stress (cytosolic ROS and glutathione oxidation, and sequentially accelerated the reduction of mitochondrial membrane potential, the surface binding of annexin-V, and the generation of mitochondrial ROS; ii CME upregulated glutathione level, retarded spontaneous apoptosis and delayed mitochondria deterioration; iii most effects of CME were unchanged after detraining; and iv CME blocked ASE effects and this capability remained intact even after detraining. Furthermore, the ASE effects on neutrophil spontaneous apoptosis were mimicked by adding exogenous H(2O(2, but not by suppressing mitochondrial membrane potential. In conclusion, while ASE induced an oxidative state and resulted in acceleration of human neutrophil apoptosis, CME delayed neutrophil apoptosis by maintaining a reduced state for long periods of time even after detraining.

Wideband thulium–holmium-doped fiber source with combined forward and backward amplified spontaneous emission at 1600–2300 nm spectral band

Czech Academy of Sciences Publication Activity Database

Honzátko, Pavel; Baravets, Yauhen; Kašík, Ivan; Podrazký, Ondřej

2014-01-01

Roč. 39, č. 12 (2014), s. 3650-3653 ISSN 0146-9592 R&D Projects: GA ČR(CZ) GAP205/11/1840 Institutional support: RVO:67985882 Keywords : Bandwidth * Spontaneous emission * Holmium Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 3.292, year: 2014

Spontaneous emission in Cherenkov FEL devices

International Nuclear Information System (INIS)

Ciocci, F.; Dattoli, G.; Doria, A.; Schettini, G.; Torre, A.; Walsh, J.E.

1987-01-01

The main features of the spectral characteristics of the spontaneously emitted Cherenkov light in circular and rectangular wave-guides filled with dielectric are discussed. The characteristics of the radiation emitted by an electron beam moving near and parallel to the surface of a dielectric slab are also analysed. Finally, the relevance of these results to a possible FEL-Cherenkov operation is briefly discussed

The Einstein A-coefficient of spontaneous emission: A relativistic calculation in the Heisenberg representation

International Nuclear Information System (INIS)

Barut, A.O.; Salamin, Y.I.

1989-07-01

We present a simple approach to the relativistic calculation of the rates of spontaneous emission starting from the Heisenberg picture formula for the power radiated by a charged particle undergoing acceleration, and evaluate atomic decay rates using relativistic Dirac-Coulomb wavefunctions. The spin of the electron, embedded in its relativistic wavefunction, is shown to correctly provide the two polarization states of the emitted radiation. We discuss selection rules and calculate the Hydrogen 2 P → 1 S transition rate, among others, to be Γ = (6.2650 ± 0.0007)x10 8 s -1 in good agreement with the full field theory calculation as well as with experiment. (author). 14 refs

Effect of amplified spontaneous emission and parasitic oscillations on the performance of cryogenically-cooled slab amplifiers

Czech Academy of Sciences Publication Activity Database

Sawicka, Magdalena; Divoký, Martin; Lucianetti, Antonio; Mocek, Tomáš

2013-01-01

Roč. 31, č. 4 (2013), s. 553-560 ISSN 0263-0346 R&D Projects: GA MŠk ED2.1.00/01.0027; GA MŠk EE2.3.20.0143 Grant - others:HILASE(XE) CZ.1.05/2.1.00/01.0027; OP VK 6(XE) CZ.1.07/2.3.00/20.0143 Institutional support: RVO:68378271 Keywords : amplified spontaneous emission * cryogenic cooling * parasitic oscillations * slab lasers * Yb:YAG, Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.701, year: 2013

Accelerated solvent extraction (ASE) - a fast and automated technique with low solvent consumption for the extraction of solid samples (T12)

International Nuclear Information System (INIS)

Hoefler, F.

2002-01-01

Full text: Accelerated solvent extraction (ASE) is a modern extraction technique that significantly streamlines sample preparation. A common organic solvent as well as water is used as extraction solvent at elevated temperature and pressure to increase extraction speed and efficiency. The entire extraction process is fully automated and performed within 15 minutes with a solvent consumption of 18 ml for a 10 g sample. For many matrices and for a variety of solutes, ASE has proven to be equivalent or superior to sonication, Soxhlet, and reflux extraction techniques while requiring less time, solvent and labor. First ASE has been applied for the extraction of environmental hazards from solid matrices. Within a very short time ASE was approved by the U.S. EPA for the extraction of BNAs, PAHs, PCBs, pesticides, herbicides, TPH, and dioxins from solid samples in method 3545. Especially for the extraction of dioxins the extraction time with ASE is reduced to 20 minutes in comparison to 18 h using Soxhlet. In food analysis ASE is used for the extraction of pesticide and mycotoxin residues from fruits and vegetables, the fat determination and extraction of vitamins. Time consuming and solvent intensive methods for the extraction of additives from polymers as well as for the extraction of marker compounds from herbal supplements can be performed with higher efficiencies using ASE. For the analysis of chemical weapons the extraction process and sample clean-up including derivatization can be automated and combined with GC-MS using an online ASE-APEC-GC system. (author)

Comparison of ASE and SFE with Soxhlet, Sonication, and Methanolic Saponification Extractions for the Determination of Organic Micropollutants in Marine Particulate Matter.

Science.gov (United States)

Heemken, O P; Theobald, N; Wenclawiak, B W

1997-06-01

The methods of accelerated solvent extraction (ASE) and supercritical fluid extraction (SFE) of polycyclic aromatic hydrocarbons (PAHs), aliphatic hydrocarbons, and chlorinated hydrocarbons from marine samples were investigated. The results of extractions of a certified sediment and four samples of suspended particulate matter (SPM) were compared to classical Soxhlet (SOX), ultrasonication (USE), and methanolic saponification extraction (MSE) methods. The recovery data, including precision and systematic deviations of each method, were evaluated statistically. It was found that recoveries and precision of ASE and SFE compared well with the other methods investigated. Using SFE, the average recoveries of PAHs in three different samples ranged from 96 to 105%, for ASE the recoveries were in the range of 97-108% compared to the reference methods. Compared to the certified values of sediment HS-6, the average recoveries of SFE and ASE were 87 and 88%, most compounds being within the limits of confidence. Also, for alkanes the average recoveries by SFE and ASE were equal to the results obtained by SOX, USE, and MSE. In the case of SFE, the recoveries were in the range 93-115%, and ASE achieved recoveries of 94-107% as compared to the other methods. For ASE and SFE, the influence of water on the extraction efficiency was examined. While the natural water content of the SPM sample (56 wt %) led to insufficient recoveries in ASE and SFE, quantitative extractions were achieved in SFE after addition of anhydrous sodium sulfate to the sample. Finally, ASE was applied to SPM-loaded filter candles whereby a mixture of n-hexane/acetone as extraction solvent allowed the simultaneous determination of PAHs, alkanes, and chlorinated hydrocarbons.

Self-cavity lasing in optically pumped single crystals of p-sexiphenyl

International Nuclear Information System (INIS)

Yanagi, Hisao; Tamura, Kenji; Sasaki, Fumio

2016-01-01

Organic single-crystal self-cavities are prepared by solution growth of p-sexiphenyl (p-6P). Based on Fabry-Pérot feedback inside a quasi-lozenge-shaped platelet crystal, edge-emitting laser is obtained under optical pumping. The multimode lasing band appears at the 0-1 or 0-2 vibronic progressions depending on the excitation conditions which affect the self-absorption effect. Cavity-size dependence of amplified spontaneous emission (ASE) is investigated with laser-etched single crystals of p-6P. As the cavity length of square-shaped crystal is reduced from 100 to 10 μm, ASE threshold fluence is decreased probably due to size-dependent light confinement in the crystal cavity.

A 98 W 1178 nm Yb-doped solid-core photonic bandgap fiber oscillator

International Nuclear Information System (INIS)

Fan, Xinyan; Chen, Mingchen; Shirakawa, Akira; Ueda, Ken-ichi; Olausson, Christina B; Broeng, Jes

2013-01-01

A high-power ytterbium-doped solid-core photonic bandgap fiber laser directly oscillating at 1178 nm is reported. The sharp-cut bandpass distributed filtering effect of photonic bandgap fiber can suppress amplified spontaneous emission (ASE) in the conventional high-gain spectral region. The oscillator is composed of a high reflection fiber Bragg grating spliced with a 39 m gain fiber and a Fresnel fiber end surface. A model based on rate equations is investigated numerically. A record output power of 98 W is achieved with a slope efficiency of 54%. The laser linewidth is 0.5 nm. The spectrum at 98 W indicates that ASE and parasitic lasing are suppressed effectively. (letter)

Mechanisms of reversible photodegradation in disperse orange 11 dye doped in PMMA polymer

International Nuclear Information System (INIS)

Embaye, Natnael B.; Ramini, Shiva K.; Kuzyk, Mark G.

2008-01-01

We use amplified spontaneous emission (ASE) and linear absorption spectroscopy to study the mechanisms of reversible photodegradation of 1-amino-2-methylanthraquinone (disperse orange 11-DO11) in solid poly(methyl methacrylate). Measurements as a function of intensity, concentration, and time suggest that ASE originates in a state (be it a tautomer or a vibronic level) that can form a dimer or some other aggregate upon relaxation, which through fluorescence quenching leads to degradation of the ASE signal. Whatever the degradation route, a high concentration of DO11 is required and the polymer plays a key role in the process of opening a new reversible degradation pathway that is not available at lower concentrations or in liquid solutions. We construct an energy level diagram that describes all measured quantities in the decay and recovery processes and propose a hypothesis of the nature of the associated states

Mixed quantum-classical electrodynamics: Understanding spontaneous decay and zero-point energy

Science.gov (United States)

Li, Tao E.; Nitzan, Abraham; Sukharev, Maxim; Martinez, Todd; Chen, Hsing-Ta; Subotnik, Joseph E.

2018-03-01

The dynamics of an electronic two-level system coupled to an electromagnetic field are simulated explicitly for one- and three-dimensional systems through semiclassical propagation of the Maxwell-Liouville equations. We consider three flavors of mixed quantum-classical dynamics: (i) the classical path approximation (CPA), (ii) Ehrenfest dynamics, and (iii) symmetrical quasiclassical (SQC) dynamics. Our findings are as follows: (i) The CPA fails to recover a consistent description of spontaneous emission, (ii) a consistent "spontaneous" emission can be obtained from Ehrenfest dynamics, provided that one starts in an electronic superposition state, and (iii) spontaneous emission is always obtained using SQC dynamics. Using the SQC and Ehrenfest frameworks, we further calculate the dynamics following an incoming pulse, but here we find very different responses: SQC and Ehrenfest dynamics deviate sometimes strongly in the calculated rate of decay of the transient excited state. Nevertheless, our work confirms the earlier observations by Miller [J. Chem. Phys. 69, 2188 (1978), 10.1063/1.436793] that Ehrenfest dynamics can effectively describe some aspects of spontaneous emission and highlights interesting possibilities for studying light-matter interactions with semiclassical mechanics.

Coherent spontaneous radiation from highly bunched electron beams

International Nuclear Information System (INIS)

Berryman, K.W.; Crosson, E.R.; Ricci, K.N.

1995-01-01

Coherent spontaneous radiation has now been observed in several FELs, and is a subject of great importance to the design of self-amplified spontaneous emission (SASE) devices. We report observations of coherent spontaneous radiation in both FIREFLY and the mid-infrared FEL at the Stanford Picosecond FEL Center. Coherent emission has been observed at wavelengths as short as 5 microns, and enhancement over incoherent levels by as much as a factor of 4x10 4 has been observed at longer wavelengths. The latter behavior was observed at 45 microns in FIREFLY with short bunches produced by off-peak acceleration and dispersive compression. We present temporal measurements of the highly bunched electron distributions responsible for the large enhancements, using both transition radiation and energy-phase techniques

Control of gain in conjugated polymers and perylene dyes

International Nuclear Information System (INIS)

Sheridan, A.

2001-03-01

This thesis presents an investigation into the factors which control the gain and amplification properties in conjugated materials. Conjugated polymers and perylene dyes are highly fluorescent, are easy to process into thin films, and exhibit strong amplification over a broad gain bandwidth making them ideal for use in lasers and amplifiers. The stimulated emission created when thin films of the red emitting polymer poly(2-methoxy-5-(2'-ethylhexyloxy)-p-phenylenvinylene) (MEH-PPV) were photoexcited with high energy laser pulses was investigated. This was characterised by a dramatic narrowing of the emission spectrum which has been assigned to amplified spontaneous emission (ASE). The emission was found to have a gaussian profile and the gain coefficient was found to be 4 cm -1 . The temperature dependence of the absorption, photoluminescence and ASE of films of MEH-PPV was measured. The effect of film morphology on the photophysical properties was investigated by using films cast from two spinning solvents, chlorobenzene (CB) and tetrahydrofuran (THF). Film morphology was found to greatly affect the temperature dependence. A particularly important property is the spectral position of the ASE and the factors which affect it. By controlling the film thickness close to the cut-off thickness for waveguiding in the polymer film it was shown that the peak position of the ASE could be tuned by 31 nm. Modelling of the waveguide modes in the polymer films was used to explain this effect. The cut-off wavelength for each film was measured and good agreement with the theory was found. In order to investigate ways in which energy transfer could be used to control the emission, two perylene dyes were used as a donor-acceptor pair in a host matrix of poly methymethacralate (PMMA). The position of the ASE was found to depend on the acceptor concentration. Measurements of the photoluminescence quantum yield and time-resolved luminescence measurements showed that the energy transfer

Finite-element modeling of spontaneous emission of a quantum emitter at nanoscale proximity to plasmonic waveguides

DEFF Research Database (Denmark)

Chen, Yuntian; Nielsen, Torben Roland; Gregersen, Niels

2010-01-01

of the plasmonic waveguide can be arbitrary. The fraction of the energy coupled to the plasmonic mode can be calculated exactly, which can be used to determine the efficiency with which single optical plasmons are generated. We apply our numerical method to calculate the coupling of a quantum emitter......We develop a self-consistent finite-element method to quantitatively study spontaneous emission from emitters in nanoscale proximity of plasmonic waveguides. In the model, it is assumed that only one guided mode is dominatingly excited by the quantum emitter, while the cross section...

Tratamento cirúrgico da litíase vesical: revisão de literatura

Directory of Open Access Journals (Sweden)

Fabio Cesar Miranda Torricelli

Full Text Available Cálculos vesicais são raros e a maioria dos casos ocorre em homens adultos com obstrução infravesical. Atualmente, existem poucos dados sobre o melhor tratamento desta doença. O objetivo desta revisão foi discutir alguns aspectos da patogênese e abordar o tratamento da litíase vesical. Uma ampla pesquisa na base de dados da "National Library of Medicine"/Pubmed foi realizada com os seguintes unitermos e descritores: vesical ou bexiga associados a cálculo, pedra ou litíase, e cistolitotripsia. Cento e setenta e um artigos foram identificados. Os artigos foram avaliados independentemente por dois revisores com experiência em urolitíase. Foram incluídos quando os resultados, complicações e seguimento foram claramente reportados. No final, 32 estudos preencheram os critérios de inclusão. Nota-se que diversas opções para o tratamento da litíase vesical estão disponíveis, porém não há estudos randomizados comparando-as. Diferentes taxas de pacientes livres de cálculo são descritas, sendo: litotripsia extracorpórea com ondas de choque (75-100%, cistolitotripsia transureteroscópica (63-100%, cistolitotripsia percutânea (89-100% e cirurgia aberta (100%. O acesso percutâneo apresenta menor morbidade com resultados semelhantes ao tratamento transuretral, enquanto a litotrispsia extracorpórea apresenta as menores de taxas de eliminação de cálculos e fica reservada aos pacientes de alto risco cirúrgico.

Ase1p Organizes Antiparallel Microtubule Arrays during Interphase and Mitosis in Fission YeastV⃞

OpenAIRE

Loïodice, Isabelle; Staub, Jayme; Setty, Thanuja Gangi; Nguyen, Nam-Phuong T.; Paoletti, Anne; Tran, P. T.

2005-01-01

Proper microtubule organization is essential for cellular processes such as organelle positioning during interphase and spindle formation during mitosis. The fission yeast Schizosaccharomyces pombe presents a good model for understanding microtubule organization. We identify fission yeast ase1p, a member of the conserved ASE1/PRC1/MAP65 family of microtubule bundling proteins, which functions in organizing the spindle midzone during mitosis. Using fluorescence live cell imaging, we show that ...

The feeding ecology of schilbeid catfishes in river Ase, Niger delta ...

African Journals Online (AJOL)

The feeding ecology of schilbeid catfishes in river Ase, Niger delta, Southern Nigeria. ... Open Access DOWNLOAD FULL TEXT ... in feeding intensity were described for Eutropius niloticus and Schilbe mystus which had adequate data.

Candidíase em pacientes aidéticos

Directory of Open Access Journals (Sweden)

C.E.O.P. Campos

1992-09-01

Full Text Available Trinta e cinco aidéticos entre 19 e 55 anos admitidos e tratados de candidíase no Hospital Emílio Ribas, SP, com ELISA positivo para HIV e confirmado pelo Western Blot. Tuberculose em 9 sendo 2 com pericardite; neurotoxoplasmose em 6; neurocriptococose em 5; herpes labial em 4; pneumocistose em 3 e sarcoma de Kaposi em 2, achavam-se associadas. A concentração inibitória mínima 50% (MIC 50% para os azoles foi: ketoconazol= 2,2 µg/ml; itraconazol- 21,0 µg/ml; fluconazol = 19,0 µg/ml. O MIC 50% para ospolienos: nistatina- 50,0 µg/ml; anfotericina B= 0,12 µg/ml e para 5 fluorcitosina= 1,6 µg/ml nas 35 amostras de Candida isoladas. Testes não paramétricos de Siegel revelaram significante identificação (80% das Candida albicans na candidíase, e que a dose de AMB não modificou o número de óbitos, precoce e tardio, ocorridos nesses aidéticos. O uso prévio dos azoles e da nistatina explicaria, talvez, o elevado MIC 50% observado nas amostras de Candida isoladas.

Epidemiologia da hanseníase em coorte de contatos intradomiciliares no Rio de Janeiro (1987-1991

Directory of Open Access Journals (Sweden)

Matos Haroldo José de

1999-01-01

Full Text Available Este trabalho foi desenvolvido para estudar os fatores que influem no adoecimento dos contatos intradomiciliares de hanseníase. Foi estabelecida uma coorte de contatos intradomiciliares de hanseníase no setor de Hanseníase da Fiocruz, no Rio de Janeiro. Entre 1987 e 1991, em que foram acompanhados 670 contatos saudáveis, a taxa de incidência por pessoa-ano de follow-up foi de 0,01694. Porém, houve variação com o tempo de acompanhamento de cada indivíduo, sendo de 0,06385 ao final do primeiro ano, de 0,03299 ao final do segundo, 0,02370 ao final do terceiro, 0,018622 ao final do quarto e 0,01694 ao final do período. Foi especificado um modelo de regressão logística para os indivíduos acompanhados nos primeiros cinco anos, envolvendo 758 contatos, incluindo nessa situação os casos co-prevalentes. O risco de incidência de hanseníase está relacionado com a negatividade do teste de Mitsuda, com OR de 3,093 (IC95% = 1,735-5,514, com a vacinação pelo BCG, OR de 0,3802 (IC95% = 0,2151-0,66719, e com a forma multibacilar do caso-índice, OR de 2,547 (IC95% = 1,249-5,192. Os resultados indicam que a incidência da hanseníase em contatos está associada à forma multibacilar da doença e aos fatores imunes dos contatos.

A new ASE filter: the 20-fold prism monochromator

NARCIS (Netherlands)

Bakker, L.P.; Freriks, J.M.; Kroesen, G.M.W.

1999-01-01

A new ASE filter is presented, consisting of 20 dispersion prisms and two spatial filters. The transmission of the filter is measured with a ring-dye laser. The 1 width of the filter is 0.23 nm. The transmission is approximately 80% for the transmitted wavelengths. The rejection is in the order of .

Self energy QED: Multipole spontaneous emission

International Nuclear Information System (INIS)

Salamin, Y.I.

1990-08-01

Within the context of Barut's self-field approach, we write the exact expression of the spontaneous atomic decay rate (Phys. Rev. A37, 2284 (1988)), in the long wavelength approximation, in terms of electric- and magnetic-like multipole contributions which are related to the matrix elements of the transition charge and current distributions of the relativistic electron. A number of features of these expressions are discussed and their generalization to interacting composite systems is also pointed out. (author). 8 refs

Continuous-wave infrared optical gain and amplified spontaneous emission at ultralow threshold by colloidal HgTe quantum dots.

Science.gov (United States)

Geiregat, Pieter; Houtepen, Arjan J; Sagar, Laxmi Kishore; Infante, Ivan; Zapata, Felipe; Grigel, Valeriia; Allan, Guy; Delerue, Christophe; Van Thourhout, Dries; Hens, Zeger

2018-01-01

Colloidal quantum dots (QDs) raise more and more interest as solution-processable and tunable optical gain materials. However, especially for infrared active QDs, optical gain remains inefficient. Since stimulated emission involves multifold degenerate band-edge states, population inversion can be attained only at high pump power and must compete with efficient multi-exciton recombination. Here, we show that mercury telluride (HgTe) QDs exhibit size-tunable stimulated emission throughout the near-infrared telecom window at thresholds unmatched by any QD studied before. We attribute this unique behaviour to surface-localized states in the bandgap that turn HgTe QDs into 4-level systems. The resulting long-lived population inversion induces amplified spontaneous emission under continuous-wave optical pumping at power levels compatible with solar irradiation and direct current electrical pumping. These results introduce an alternative approach for low-threshold QD-based gain media based on intentional trap states that paves the way for solution-processed infrared QD lasers and amplifiers.

Continuous-wave infrared optical gain and amplified spontaneous emission at ultralow threshold by colloidal HgTe quantum dots

Science.gov (United States)

Geiregat, Pieter; Houtepen, Arjan J.; Sagar, Laxmi Kishore; Infante, Ivan; Zapata, Felipe; Grigel, Valeriia; Allan, Guy; Delerue, Christophe; van Thourhout, Dries; Hens, Zeger

2018-01-01

Colloidal quantum dots (QDs) raise more and more interest as solution-processable and tunable optical gain materials. However, especially for infrared active QDs, optical gain remains inefficient. Since stimulated emission involves multifold degenerate band-edge states, population inversion can be attained only at high pump power and must compete with efficient multi-exciton recombination. Here, we show that mercury telluride (HgTe) QDs exhibit size-tunable stimulated emission throughout the near-infrared telecom window at thresholds unmatched by any QD studied before. We attribute this unique behaviour to surface-localized states in the bandgap that turn HgTe QDs into 4-level systems. The resulting long-lived population inversion induces amplified spontaneous emission under continuous-wave optical pumping at power levels compatible with solar irradiation and direct current electrical pumping. These results introduce an alternative approach for low-threshold QD-based gain media based on intentional trap states that paves the way for solution-processed infrared QD lasers and amplifiers.

Significant effect of NSP-ase enzyme supplementation in sunflower meal-based diet on the growth and nutrient digestibility in broilers.

Science.gov (United States)

Bilal, M; Mirza, M A; Kaleem, M; Saeed, M; Reyad-Ul-Ferdous, Md; Abd El-Hack, M E

2017-04-01

The response of broiler chickens to 3 levels of sunflower meal and 2 levels of NSP-ase enzyme combination (with and without) was investigated in 3 × 2 factorial arrangement under complete randomized design (CRD). A total of 240 Hubbard broiler chicks were fed on practical mash diets having 2950 kcal of ME and 21% CP from 1 to 42 days of age. The BW gain was not significantly reduced when 25% SFM was added in the diets during 1 to 42 days of age. Supplementation of NSP-ase in broiler diets (day 1-42 overall) demonstrated non-significant differences (p Replacement of SBM with SFM or inclusion of SFM at higher level (25%) increased/deteriorated FCR. The addition of exogenous NSP-ase showed a significant improvement (p < 0.01) in feed:gain. The improvement was clearly demonstrated when SFM was added to the experimental diet at 15% or even 20%. Supplementation of NSP-ase at the 25% inclusion level could not, however, sustain the beneficial effect, which was possibly due to excessively high dietary CF. No difference was noted across the treatments regarding carcass response. Relative gizzard weight and intestinal weight were observed to be improved in birds consuming higher levels of SFM (p = 0.00). The digestibility of CF was observed to improve when SFM was used at 20% and 25% in the diets. No improvement in the digestibility of CF was observed with NSP-ase supplementation, which meant other factors were clearly involved. Supplementation of NSP-ase improved FCR up to 20% SFM. At 25% SFM, no improvement in the digestibility of CF was observed with NSP-ase supplementation. Journal of Animal Physiology and Animal Nutrition © 2016 Blackwell Verlag GmbH.

A novel, simple and efficient dye laser with low amplified spontaneous emission background for analytical fluorescence and ionization spectroscopy

International Nuclear Information System (INIS)

Matveev, Oleg I.; Omenetto, Nicolo'

1995-01-01

A new, simple, compact and efficient, grazing- incidence type of dye laser is suggested which has a low level of Amplified Spontaneous Emission. By using a Coumarin dye (LD 5000) pumped with a 20 mJ XeCl excimer laser, and a diffraction grating with 3000 grooves/mm, an efficiency of 11%, a spectral bandwidth of 0.6 cm -1 and a tuning range from 458 to 517 nm have been obtained

High-efficiency electroluminescence and amplified spontaneous emission from a thermally activated delayed fluorescent near-infrared emitter

Science.gov (United States)

Kim, Dae-Hyeon; D'Aléo, Anthony; Chen, Xian-Kai; Sandanayaka, Atula D. S.; Yao, Dandan; Zhao, Li; Komino, Takeshi; Zaborova, Elena; Canard, Gabriel; Tsuchiya, Youichi; Choi, Eunyoung; Wu, Jeong Weon; Fages, Frédéric; Brédas, Jean-Luc; Ribierre, Jean-Charles; Adachi, Chihaya

2018-02-01

Near-infrared organic light-emitting diodes and semiconductor lasers could benefit a variety of applications including night-vision displays, sensors and information-secured displays. Organic dyes can generate electroluminescence efficiently at visible wavelengths, but organic light-emitting diodes are still underperforming in the near-infrared region. Here, we report thermally activated delayed fluorescent organic light-emitting diodes that operate at near-infrared wavelengths with a maximum external quantum efficiency of nearly 10% using a boron difluoride curcuminoid derivative. As well as an effective upconversion from triplet to singlet excited states due to the non-adiabatic coupling effect, this donor-acceptor-donor compound also exhibits efficient amplified spontaneous emission. By controlling the polarity of the active medium, the maximum emission wavelength of the electroluminescence spectrum can be tuned from 700 to 780 nm. This study represents an important advance in near-infrared organic light-emitting diodes and the design of alternative molecular architectures for photonic applications based on thermally activated delayed fluorescence.

Analysis of the outlook for using narrow-band spontaneous emission sources for atmospheric air purification

International Nuclear Information System (INIS)

Boyarchuk, K A; Karelin, A V; Shirokov, R V

2003-01-01

The outlook for using narrow-band spontaneous emission sources for purification of smoke gases from sulphur and nitrogen oxides is demonstrated by calculations based on a nonstationary kinetic model of the N 2 - O 2 - H 2 O - CO 2 - SO 2 mixture. The dependences of the mixture purification efficiency on the UV source power at different wavelengths, the exposure time, and the mixture temperature are calculated. It is shown that the radiation sources proposed in the paper will provide better purification of waste gases in the atmosphere. The most promising is a KrCl* lamp emitting an average power of no less than 100 W at 222 nm. (laser applications and other topics in quantum electronics)

Position Dependent Spontaneous Emission Spectra of a Λ-Type Atomic System Embedded in a Defective Photonic Crystal

International Nuclear Information System (INIS)

Entezar, S. Roshan

2012-01-01

We investigate the position dependent spontaneous emission spectra of a Λ-type three-level atom with one transition coupled to the free vacuum reservoir and the other one coupled to a double-band photonic band gap reservoir with a defect mode in the band gap. It is shown that, for the atom at the defect location, we have a two-peak spectrum with a wide dark line due to the strong coupling between the atom and the defect mode. While, when the atom is far from the defect location (or in the absence of the defect mode), the spectrum has three peaks with two dark lines due to the coupling between the atom and the photonic band gap reservoir with the largest density of states near the band edges. On the other hand, we have a four-peak spectrum for the atom at the space in between. Moreover, the average spontaneous emission spectra of the atoms uniformly embedded in high dielectric or low dielectric regions are described. It is shown that the atoms embedded in high (low) dielectric regions far from the defect location, effectively couple to the modes of the lower (upper) photonic band. However, the atoms embedded in high dielectric or low dielectric regions at the defect location, are coupled mainly to the defect modes. While, the atoms uniformly embedded in high (low) dielectric regions with a normal distance from the defect location, are coupled to both of defect and lower (upper) photonic band modes. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

Atuação do enfermeiro no controle epidemiológico da hanseníase

Directory of Open Access Journals (Sweden)

Sara Augusta dos Santos

1992-09-01

Full Text Available Analisou-se seníase, na Seção de Dermatologia Sanitária do Hospital Universitário Pedro Ernesto, UERJ. Pretendeu-se alcançar três objetivos entre eles comparar a qualidade do controle epidemiológico dos casos novos de hanseníase em registro ativo de 1986, com os mesmos casos relativos ao período de 1987. Aplicou-se o método descritivo e análise de documentos dos prontuários desses clientes. Utilizou-se um formulário com questões de múltipla escolha e preenchimento de claros, totalizando 27 itens. Constatou-se que o enfermeiro interfere nas variáveis: exames para firmar diagnóstico, exames de contatos e educação para saúde, contribuindo para a melhoria da qualidade assistencial do hanseniano. Conclui-se que há diferença significativa na qualidade do controle epidemiológico da hanseníase entre os grupos constituídos.

Implicações clínicas e imunológicas da associação entre o HTLV-1 e a estrongiloidíase

OpenAIRE

Porto, Maria Aurélia da Fonseca; Muniz, André Luís Nunes; Oliveira Júnior, Jamary; Carvalho Filho, Edgar Marcelino de

2002-01-01

P. 641-649,Nov-Dez. A estrongiloidíase é uma das mais importantes helmintíases em países tropicais e estudos epidemiológicos têm demonstrado associação desta parasitose com o vírus HTLV-1. Em regiões onde estes dois agentes são endêmicos a coinfecção pode resultar no desenvolvimento de formas disseminadas da estrongiloidíase assim como em estrongiloidíase recorrente. Enquanto que o vírus HTLV-1 está relacionado com uma alta produção de IFN-g e desvio da resposta imune para o tipo Th1, a pr...

Implicações clínicas e imunológicas da associação entre o HTLV-1 e a estrongiloidíase

OpenAIRE

Porto,Maria Aurélia F.; Muniz,André; Oliveira Júnior,Jamary; Carvalho,Edgar Marcelino

2002-01-01

A estrongiloidíase é uma das mais importantes helmintíases em países tropicais e estudos epidemiológicos têm demonstrado associação desta parasitose com o vírus HTLV-1. Em regiões onde estes dois agentes são endêmicos a coinfecção pode resultar no desenvolvimento de formas disseminadas da estrongiloidíase assim como em estrongiloidíase recorrente. Enquanto que o vírus HTLV-1 está relacionado com uma alta produção de IFN-γ e desvio da resposta imune para o tipo Th1, a proteção contra helm...

Switching mechanism due to the spontaneous emission cancellation in photonic band gap materials doped with nano-particles

Energy Technology Data Exchange (ETDEWEB)

Singh, Mahi R. [Department of Physics and Astronomy, University of Western Ontario, London, Canada N6A 3K7 (Canada)]. E-mail: msingh@uwo.ca

2007-03-26

We have investigated the switching mechanism due to the spontaneous emission cancellation in a photonic band gap (PBG) material doped with an ensemble of four-level nano-particles. The effect of the dipole-dipole interaction has also been studied. The linear susceptibility has been calculated in the mean field theory. Numerical simulations for the imaginary susceptibility are performed for a PBG material which is made from periodic dielectric spheres. It is predicted that the system can be switched between the absorbing state and the non-absorbing state by changing the resonance energy within the energy bands of the photonic band gap material.0.

Fístula vesicovaginal por litíase: relato de caso

Directory of Open Access Journals (Sweden)

Chambô Filho Antônio

2003-01-01

Full Text Available As fístulas de etiologia traumática são raras, sobretudo as intrínsecas por litíase vesical. O manejo dessas fístulas tem controvérsias no que diz respeito à técnica cirúrgica ideal. Uma variedade de tratamentos tem sido descrita, incluindo reparação cirúrgica por vias transvaginal e transabdominal. Os autores relatam o caso de uma paciente com queixa de perda urinária contínua com evolução de seis meses, sendo identificado ao exame especular orifício fistuloso no terço médio da parede anterior da vagina, por onde se exteriorizava urina. Nesta topografia, identificava-se, durante o toque bimanual, estrutura de consistência pétrea. A suspeita de litíase vesical foi confirmada pela radiografia de pelve. O tratamento cirúrgico se deu em dois tempos, com exérese do cálculo vesical e posterior correção da fístula por via vaginal.

Associação timoma e estrongiloidíase intestinal grave

OpenAIRE

Godoy,Pérsio; Campos,Christian Marcellus Camargos; Costa,Guilherme; Castro,Lúcia Porto Fonseca de

1998-01-01

Os autores relatam o caso de um homem de 59 anos de idade com timoma e estrongiloidíase intestinal grave. São revistos aspectos da resposta imunitária relacionados ao tumor e, possivelmente, implicados no desenvolvimento da hiperinfecção pelo Strongyloides stercoralis.

Urolitíase: estudo comparativo em bovinos Guzerá oriundos de propriedades com e sem o problema

Directory of Open Access Journals (Sweden)

S.R. Sacco

2011-03-01

Full Text Available Diversos fatores podem contribuir para a formação de cálculos urinários, dentre estes, o desequilíbrio nutricional e a dureza da água consumida pelos ruminantes. O objetivo deste estudo foi identificar as características de propriedades que predispõem à urolitíase, através da avaliação da água, da dieta e determinações séricas e urinárias de cálcio, fósforo, magnésio, cloretos, sódio, potássio, cálculo da excreção fracionada (EF dos eletrólitos, e da creatinina, proteína total, albumina e globulinas séricas. Foram colhidas amostras de sangue e urina de bovinos, Guzerá, criados semi intensivamente, distribuídos por dois grupos. O primeiro denominado grupo urolitíase (Gu, composto de animais com histórico, sinais clínicos e confirmação ultrassonográfica que apresentavam urolitíase; o segundo: grupo controle (Gc, sem histórico, nem sintomas da doença. Os bovinos do grupo urolitíase consumiam água com dureza total na concentração de 166,0mg CaCO3/L. A dieta dos animais do Gu apresentava maior concentração de fósforo e relação Ca:P inadequada. Os teores de fósforo sérico e urinário dos animais do Gu foram maiores do que os do Gc, assim como a concentração sérica de magnésio (p0,05, mas houve diminuição significativa nas EFs de magnésio, cloretos e de potássio do grupo urolitíase (p<0,05. A união destes fatores contribuiu para a ocorrência da urolitíase, sendo dureza total da água e a alta concentração de fósforo na dieta os principais fatores na gênese dos cálculos em bovinos.

Candidíase oral como marcador de prognóstico em pacientes portadores do HIV

OpenAIRE

Cavassani Valdinês Gonçalves dos Santos; Andrade Sobrinho Jozias de; Homem Maria da Graça Naclério; Rapoport Abrão

2002-01-01

Introdução: A candidíase oral é uma das doenças oportunistas mais fortemente associadas à infecção pelo Vírus da Imunodeficiência Humana (HIV). Vários relatos epidemiológicos enfatizam a prevalência da candidíase em pacientes HIV positivos e ressaltam a sua importância como marcador da progressão da doença e preditivo para o aumento da imunodepressão. Objetivo: Verificar as alterações estomatológicas em pacientes portadores do HIV tratados no Hospital Heliópolis - São Paulo, Brasil e comparar...

Spontaneous emission of electromagnetic radiation in turbulent plasmas

Energy Technology Data Exchange (ETDEWEB)

Ziebell, L. F., E-mail: luiz.ziebell@ufrgs.br [Instituto de Física, UFRGS, Porto Alegre, Rio Grande do Sul (Brazil); Yoon, P. H., E-mail: yoonp@umd.edu [School of Space Research, Kyung Hee University, Yongin, Gyeonggi 446-701, South Korea and University of Maryland, College Park, Maryland 20742 (United States); Simões, F. J. R.; Pavan, J. [Instituto de Física e Matemática, UFPel, Pelotas, Rio Grande do Sul (Brazil); Gaelzer, R. [Instituto de Física, UFRGS, Porto Alegre, Rio Grande do Sul (Brazil); Instituto de Física e Matemática, UFPel, Pelotas, Rio Grande do Sul (Brazil)

2014-01-15

Known radiation emission mechanisms in plasmas include bremmstrahlung (or free-free emission), gyro- and synchrotron radiation, cyclotron maser, and plasma emission. For unmagnetized plasmas, only bremmstrahlung and plasma emissions are viable. Of these, bremmstrahlung becomes inoperative in the absence of collisions, and the plasma emission requires the presence of electron beam, followed by various scattering and conversion processes. The present Letter proposes a new type of radiation emission process for plasmas in a state of thermodynamic quasi-equilibrium between particles and enhanced Langmuir turbulence. The radiation emission mechanism proposed in the present Letter is not predicted by the linear theory of thermal plasmas, but it relies on nonlinear wave-particle resonance processes. The electromagnetic particle-in-cell numerical simulation supports the new mechanism.

Time Evolution of the Excimer State of a Conjugated Polymer Laser

Directory of Open Access Journals (Sweden)

Wafa Musa Mujamammi

2017-11-01

Full Text Available An excited dimer is an important complex formed in nano- or pico-second time scales in many photophysics and photochemistry applications. The spectral and temporal profile of the excimer state of a laser from a new conjugated polymer, namely, poly (9,9-dioctylfluorenyl-2,7-diyl (PFO, under several concentrations in benzene were investigated. These solutions were optically pumped by intense pulsed third-harmonic Nd:YAG laser (355-nm to obtain the amplified spontaneous emission (ASE spectra of a monomer and an excimer with bandwidths of 6 and 7 nm, respectively. The monomer and excimer ASEs were dependent on the PFO concentration, pump power, and temperature. Employing a sophisticated picosecond spectrometer, the time evolution of the excimer state of this polymer, which is over 400 ps, can be monitored.

Magnetic and spontaneous Barkhausen noise techniques used in investigation of a martensitic transformation

Science.gov (United States)

Capò Sànchez, J.; Huallpa, E.; Farina, P.; Padovese, L. R.; Goldenstein, H.

2011-10-01

Magnetic Barkhausen noise (MBN) was used to characterize the progress of austenite to martensite phase transformation while cooling steel specimens, using a conventional Barkhausen noise emission setup stimulated by an alternating magnetic field. The phase transformation was also followed by electrical resistivity measurements and by optical and scanning electron microscopy. MBN measurements on a AISI D2 tool steel austenitized at 1473 K and cooled to liquid nitrogen temperature presented a clear change near 225 K during cooling, corresponding to the MS (martensite start) temperature, as confirmed by resistivity measurements. Analysis of the resulting signals suggested a novel experimental technique that measures spontaneous magnetic emission during transformation, in the absence of any external field. Spontaneous magnetic noise emission measurements were registered in situ while cooling an initially austenitic sample in liquid nitrogen, showing that local microstructural changes, corresponding to an avalanche or "burst" phenomena, could be detected. This spontaneous magnetic emission (SME) can thus be considered a new experimental tool for the study of martensite transformations in ferrous alloys, at the same level as acoustic emission.

Spontaneous otoacoustic emissions, threshold microstructure, and psychophysical tuning over a wide frequency range in humansa

Science.gov (United States)

Baiduc, Rachael R.; Lee, Jungmee; Dhar, Sumitrajit

2014-01-01

Hearing thresholds have been shown to exhibit periodic minima and maxima, a pattern known as threshold microstructure. Microstructure has previously been linked to spontaneous otoacoustic emissions (SOAEs) and normal cochlear function. However, SOAEs at high frequencies (>4 kHz) have been associated with hearing loss or cochlear pathology in some reports. Microstructure would not be expected near these high-frequency SOAEs. Psychophysical tuning curves (PTCs), the expression of frequency selectivity, may also be altered by SOAEs. Prior comparisons of tuning between ears with and without SOAEs demonstrated sharper tuning in ears with emissions. Here, threshold microstructure and PTCs were compared at SOAE frequencies ranging between 1.2 and 13.9 kHz using subjects without SOAEs as controls. Results indicate: (1) Threshold microstructure is observable in the vicinity of SOAEs of all frequencies; (2) PTCs are influenced by SOAEs, resulting in shifted tuning curve tips, multiple tips, or inversion. High frequency SOAEs show a greater effect on PTC morphology. The influence of most SOAEs at high frequencies on threshold microstructure and PTCs is consistent with those at lower frequencies, suggesting that high-frequency SOAEs reflect the same cochlear processes that lead to SOAEs at lower frequencies. PMID:24437770

Coherent optical transition radiation and self-amplified spontaneous emission generated by chicane-compressed electron beams

Directory of Open Access Journals (Sweden)

A. H. Lumpkin

2009-04-01

Full Text Available Observations of strongly enhanced optical transition radiation (OTR following significant bunch compression of photoinjector beams by a chicane have been reported during the commissioning of the Linac Coherent Light Source accelerator and recently at the Advanced Photon Source (APS linac. These localized transverse spatial features involve signal enhancements of nearly a factor of 10 and 100 in the APS case at the 150-MeV and 375-MeV OTR stations, respectively. They are consistent with a coherent process seeded by noise and may be evidence of a longitudinal space charge microbunching instability which leads to coherent OTR emissions. Additionally, we suggest that localized transverse structure in the previous self-amplified spontaneous emission (SASE free-electron laser (FEL data at APS in the visible regime as reported at FEL02 may be attributed to such beam structure entering the FEL undulators and inducing the SASE startup at those “prebunched” structures. Separate beam structures 120 microns apart in x and 2.9 nm apart in wavelength were reported. The details of these observations and operational parameters will be presented.

NASA/American Society for Engineering Education (ASEE) Summer Faculty Fellowship Program, 1985. [Space Stations and Their Environments

Science.gov (United States)

Chilton, R. G. (Editor); Williams, C. E. (Editor)

1986-01-01

The 1985 NASA/ASEE Summer Faculty Fellowship Research Program was conducted by Texas A&M University and the Johnson Space Center. The ten week program was operated under the auspices of the American Society for Engineering Education (ASEE). The faculty fellows spent the time at JSC engaged in research projects commensurate with their interests and background and worked in collaboration with NASA/JSC colleagues. This document is a compilation of the final reports of their research during the summer of 1985.

Spontaneous emission of heavy-ions from uranium

International Nuclear Information System (INIS)

Carvalho, H.G. de; Martins, J.B.; Souza, I.O. de; Tavares, O.A.P.

1974-09-01

The experimental evidences that 238 U, and perhaps other heavy nuclei, besides undergoing spontaneous fission, are also emitters of ions in the mass-range from 20 to 70. Estimates obtained by means of the WKB method indicate half-lifes of 10 15 to 10 18 years for some of these processes, which agree with our findings. Our results are supported by a systematic observation of neon and argon with abnormal isotopic abundance in both radioactive minerals and helium-bearing natural gases

ATP-ase activity in the human oral mucous membrane, the guinea pig and the rabbit epidermis. A light- and electronmicroscopical investigation

DEFF Research Database (Denmark)

Zelander, T; Kirkeby, S

1984-01-01

The activity for ATP-ase was investigated in cells of rabbit and guinea pig epidermis and human oral mucosa. Observations both in the light- and electron microscope indicate that the ATP-ase positive cells of guinea pig and human epithelia are Langerhans cells while in the rabbit epidermis...

Change in ATP-ase activity and transport of rna of liver cell nuclei of pregnant rats and embryos following irradiation

International Nuclear Information System (INIS)

Shamsutdinova, G.T.; Mirkhamidova, P.; Ibragimkhodzhaeva, M.P.; Mirakhmedov, A.K.

1990-01-01

The effect of radiation on ATP-ase activity in rat liver nuclei and RNA transport of isolated liver nuclei in vitro is studied. It is shown that irradiation changes RNA transport from isolated liver cell nuclei of maternal organism and embryos. Irradiation during prefetus and fetus periods changes ATP-ase activity of embryon and maternal organism nuclei

Optical band gap study of a-Se and Se-Sb thin films

International Nuclear Information System (INIS)

Kaur, Ramandeep; Singh, Palwinder; Thakur, Anup

2016-01-01

Amorphous selenium (a-Se) and a-Se_9_5Sb_5 alloy were prepared using melt quenching technique. X-ray diffraction (XRD) pattern confirmed the amorphous nature of the prepared samples. Composition of the prepared samples has been determined using Energy dispersive X-ray fluorescence (EDXRF) technique. Differential thermal analysis (DTA) confirmed the glassy nature of the prepared samples. Thin films of the prepared samples were deposited on glass substrate using thermal evaporation method. Amorphous nature of the deposited films was confirmed using XRD. Optical properties of these films were obtained from the UV-VIS transmission spectra, at normal incidence, over 200-1100 nm spectral range. The optical absorption edge was described by using the model given by the Tauc. Optical band gap of the deposited films was calculated using Tauc plot. Optical characterization showed that average transmission and optical band gap decreased with the addition of antinomy.

Photoluminescence and lasing properties of ZnO nanorods

International Nuclear Information System (INIS)

Lee, Geon Joon; Lee, Young Pak; Min, Sun Ki; Han, Sung Hwan; Lim, Hwan Hong; Cha, Myoung Sik; Kim, Sung Soo; Cheong, Hyeon Sik

2010-01-01

In this study, we investigated the structures, photoluminescence (PL), and lasing characteristics of the ZnO nanorods prepared by using chemical bath deposition. The continuous-wave HeCd laser excited PL spectra of the ZnO nanorods exhibited two emission bands, one in the UV region and the other in the visible region. The UV emission band has its peak at 3.25 eV with a bandwidth of 160 meV. However, the PL spectra under 355-nm, 35-ps pulse excitation exhibited a spectrally-narrowed UV emission band with a peak at 3.20 eV and a spectral width of 35 meV. The lasing phenomena were ascribed to the amplified spontaneous emission (ASE) caused by coupling of the microcavity effect of ZnO nanorods and the high-intensity excitation. Above the lasing threshold, the ASE peak intensity exhibited a superlinear dependence on the excitation intensity. For an excitation pulse energy of 3 mJ, the ASE peak intensity was increased by enlarging the length of the ZnO nanorods from 1 μm to 4 μm. In addition, the PL spectrum under 800-nm femtosecond pulse excitation exhibited second harmonic generation, as well as the multiphoton absorption-induced UV emission band. In this research, ZnO nanorods were grown on seed layers by using chemical bath deposition in an aqueous solution of Zn(NO 3 ) 2 and hexamethyltetramine. The seed layers were prepared on conducting glass substrates by dip coating in an aqueous colloidal dispersion containing 50% 70-nm ZnO nanoparticles. Scanning electron microscopy clearly revealed that ZnO nanorods were successfully grown on the seed layers.

High energy {gamma} emission in the spontaneous fission of {sup 252}Cf; Emission {gamma} de grande energie dans la fission spontanee de {sup 252}Cf

Energy Technology Data Exchange (ETDEWEB)

Badimon, C.; Barreau, G.; Doan, T.P.; Pedemay, G. [Centre d`Etudes Nucleaires, Bordeaux-1 Univ., 33 Gradignan (France); Gautherin, C.; Houry, M.; Korten, W.; Le Coz, Y.; Lucas, R.; Thiesen, Ch. [Dept. d`Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l`Instrumentation Associee, CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France); Belier, G.; Meot, M.V. [CEA Centre d`Etudes de Bruyeres-le-Chatel, 91 (France); Astier, A.; Ducroux, L.; Meyer, M.; Redon, N. [Inst.de Physique Nucleaire, Lyon-1 Univ., 69 - Villeurbanne (France)

1997-06-01

The prompt {gamma} emission in the spontaneous fission of {sup 252}Cf is characterized by an energy spectrum which extends up to 20 MeV. It was established that the spectrum presents in the neighbourhood of symmetric fission an intensity bump in the 3-8 MeV {gamma} energy interval. The origin of this phenomenon is still not well understood, so that it was found interesting to carry out new measurements. The spectrum of the {gamma} rays emitted in spontaneous fission of {sup 252}Cf has been measurement in the EUROGAM II multidetector using photovoltaic cells to detect fragments. The aim of the experiment was to investigate the {gamma} yield enhancement which appears for mass fragment ratio near 132/120. This enhancement was found to be composed of two peaks located at 4 MeV and 5.5 MeV respectively. The results obtained confirm the intensity bound in the 3-8 MeV region but this augmentation reaches the maximum when the heavy fragment is near the mass 132. Beyond mass 140 the phenomenon diminish and the {gamma} spectrum regains the behaviour expected for a statistic emission. The additional structure at 5.5 MeV does not vary with excitation energy while the excitation function of the 4 MeV structure is more structured and presents a maximum when the excitation energy is near 8 MeV. It is likely that all or part of this observed phenomenon is due to a particular excitation mode of this isotope associated for instance with a low energy dipole resonance. A theoretical study of this collective effect is under way 3 refs.

Amplification of spontaneous emission of neon-like argon in a fast gas-filled capillary discharge

International Nuclear Information System (INIS)

Kolacek, K.; Schmidt, J.; Bohacek, V.; Ripa, M.; Frolov, O.; Vrba, P.; Straus, J.; Prukner, V.; Rupasov, A. A.; Shikanov, A. S.

2008-01-01

The evolution of the CAPEX facility and its basic diagnostics are described. The experiments carried out in the last modification of this facility accomplished with the demonstration of amplified spontaneous emission of neon-like argon (Ar 8+ ) at the wavelength 46.88 nm. The first version of the facility, CAPEX1, operated with a plastic capillary and had a short high-power passive prepulse and an imperfect gas-filling system. In the second version, CAPEX2, a ceramic capillary was used, the prepulse amplitude was lowered, and the gas-filling system was improved. In the third, most successful version, CAPEX3, the capillary bending was reduced, a longer external prepulse was used, and the gas-filling system was further optimized. For each version, results of X-ray measurements are presented and interpreted

Peran Sistem Informasi Dalam Meningkatkan Investasi Asing Pada Sektor Properti Di Indonesia di Era Pasar Bebas

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Yosi Agustiawan

2016-02-01

Full Text Available Abstrak Pasar bebas adalah hasil dari proses globalisasi yang telah menciptakan integrasi ekonomi antar negara. Artikel ini mengkaji dampak globalisasi di pasar properti global dan peran sistem informasi untuk meningkatkan investasi asing di Indonesia. Meningkatnya investasi asing langsung (Foreign Direct Investmen/FDI yang mengalir ke negara berkembang termasuk Indonesia di berbagai sektor termasuk properti telah memberikan banyak manfaat untuk meningkatkan ekonomi. Buruknya peraturan kepemilikan tanah dan infrastruktur adalah masalah utama yang harus diatasi untuk menjaga agar investor asing masih berniat untuk menanamkan modalnya dalam pasar properti global. Sistem informasi dapat digunakan sebagai alat yang efektif untuk mengatasi masalah-masalah tersebut melalui penggunaan e-government dan perencanaan strategis implementasi sistem informasi dalam proyek infrastruktur. Kata kunci: globalisasi, investasi asing, pasar properti global, e-government, sistem informasi. Abstract Cross-border relationships do not only affect many aspects but it also creates economic integration among countries. This essay examines the impact of globalization on the property market and the role of information system to promote foreign direct investment (FDI in Indonesia. Allowing foreign direct investment (FDI flows to those developing in various industries including property has clearly provided positive opportunities to improve their economic. Poor land regulations and infrastructure are the main issues that must be overcome to maintain foreign investor still intend to capitalize on the global property market. Information system can be used as effective tool to resolve those issues through e-government and trategic implementation in projects infrastructure. Key word: globalization, foreign direct investment, global property market, e-government, system information

Analysis of emissions from prebunched electron beams

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Jia Qika

2017-07-01

Full Text Available The emissions of the prebunched electron beam, including the coherent spontaneous emission and the self-amplified stimulated emission, are analyzed by using one-dimensional FEL theory. Neglecting the interaction of the electrons and the radiation field, the formula of the coherent spontaneous emission is given, the power of which is proportional to the square of the initial bunching factor and of the undulator length. For the general emission case of the prebunched electron beam, the evolution equation of the optical field is deducted. Then the analytical expression of the emission power is obtained for the resonant case; it is applicable to the regions from the low gain to the high gain. It is found that when the undulator length is shorter than four gain lengths, the emission is just the coherent spontaneous emission, and conversely, it is the self-amplified stimulated emission growing exponentially. For the nonresonant prebunched electron beam, the variations of the emission intensity with the detuning parameter for different interaction length are presented. The radiation field characters of the prebunched electron beam are discussed and compared with that of the seeded FEL amplifier.

Terapia fotodinâmica para tratamento de candidíase vulvovaginal em modelo experimental com camundongas

OpenAIRE

Santi, Maria Eugenia Simões Onofre de

2014-01-01

Candidíase vulvovaginal é a segunda mais comum infecção ginecológica e afeta 75% das mulheres pelo menos uma vez durante seu período reprodutivo. A candidíase vulvovaginal recorrente representa um desafio à prática ginecológica, uma vez que muitas pacientes experimentam recorrências imediatamente após finalizarem um tratamento. A terapia fotodinâmica (PDT) é considerada uma abordagem terapêutica no tratamento de infecções fúngicas. O objetivo deste estudo foi investigar a eficácia da PDT em v...

Tendências da hanseníase no Tocantins, um estado hiperendêmico do Norte do Brasil, 2001-2012

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Lorena Dias Monteiro

2015-05-01

Full Text Available A hanseníase é hiperendêmica no Estado do Tocantins, Brasil. O objetivo do estudo foi analisar as tendências dos indicadores da hanseníase no Tocantins em 2001-2012. Análise de dados advindos do Sistema de Informação de Agravos de Notificação (SINAN. Incluíram-se casos novos de residentes no Tocantins. Calcularam-se os indicadores da hanseníase e analisaram-se as tendências temporais por meio de regressão polinomial. Houve tendência significativa e decrescente para a detecção geral (R2 = 0,40; p 0,05, detecção de casos com grau 2 de incapacidade física (R2 = 0,37; p > 0,05 e proporção de casos com grau 2 (R2 = 0,49; p > 0,05. Houve aumento significativo para a proporção de casos com grau 1 de incapacidade (R2 = 0,82; p < 0,05 e proporção de casos multibacilares (R2 = 0,81; p < 0,05. O Tocantins apresenta regiões com alta transmissão e diagnóstico tardio da hanseníase, apontando a expansão da doença de forma heterogênea na análise temporal.

Perjanjian Berbahasa Asing yang Dibuat Oleh Notaris Berdasarkan Undang-Undang Nomor 30 Tahun 2004 Tentang Jabatan Notaris

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Aliya Sandra Dewi

2016-04-01

Full Text Available Perjanjian Berbahasa Asing yang Dibuat Notaris Berdasarkan Undang-Undang Nomor 30 Tahun 2004. Posisi notaris sebagai fungsionaris dalam masyarakat dianggap sebagai tempat resmi yang dapat memperoleh saran. Segala sesuatu yang ditulis dan ditetapkan sudah benar dan pejabat produsen resmi dalam dokumen kekuatan hukum, khususnya dokumen yang berkaitan dengan kontrak yang terjadi di masyarakat. Dengan perkembangan hubungan antara subjek hukum warga negara yang berbeda untuk membuat perjanjian dalam bahasa asing selalu digunakan antara pihak-pihak yang memilikin perbedaan karena perbedaan bahasa kewarganegaraan.DOI:10.15408/jch.v1i1.2922

Two-photon resonant, stimulated processes in krypton and xenon

International Nuclear Information System (INIS)

Miller, J.C.

1988-11-01

Both on-axis and conical emissions have been observed following two-photon pumping of the 5p states of krypton and the 6p', 7p, 8p, and 4f states of xenon. In the former case, coherent emissions from the 5p states to the 5s are observed, and in the latter case, many p→s, d→p, and f→d cascade emissions are observed. By analogy to the well-studied alkali and alkaline earth examples, the emissions are discussed in terms of amplified spontaneous emission (ASE), stimulated hyper-Raman scattering, and parametric four-wave mixing. The physical processes responsible for the conical emission and for intensity anomalies in the xenon p→s emissions are not understood at present. Interference effects due to coherent cancellation between competing excitation pathways may be occurring. 4 refs., 3 figs

Scanning Emitter Lifetime Imaging Microscopy for Spontaneous Emission Control

DEFF Research Database (Denmark)

Frimmer, Martin; Chen, Yuntian; Koenderink, A. Femius

2011-01-01

We report an experimental technique to map and exploit the local density of optical states of arbitrary planar nanophotonic structures. The method relies on positioning a spontaneous emitter attached to a scanning probe deterministically and reversibly with respect to its photonic environment while...

X-ray effects on the activity of a Mg2+-dependent, Na+- and K+-activable microsomal membrane ATP-ase system

International Nuclear Information System (INIS)

Froehlich, D.

1978-01-01

The bahviour of a Mg 2+ -dependent, Na + - and K + -activable ATP-ase sytem on irradiation was investigated using a microsome fraction of guinea pig myocardial cells prepared by fractionated centrifugation. The Na + - and K + -activable component, transport-ATPase, was particularly radiation-sensitive. Three stages of development were observed for a 1,500 R radiation damage until 24 h p.r.. In the first stage, until 30 minutes p.r., the activity of transport-ATP-ase was inhibited. This was followed by repair processes which had reached a peak value clearly higher than the control values at 4 hours p.r.. In the third stage, the activity was reduced again; 15 and 24 hours after termination of exposure, values again were nearly the same as after 30 minutes where a maximum was observed for this radiation dose. Radiation-induced electrolyte displacements, active transport, and radiation-induced inhibition of transport-ATP-ase were correlated and discussed; the assumption was that changes in, the electrolyte conditions in the membranes on irradiation are at least partly due to the described inhibition of transport-ATP-ase. (orig./AJ) [de

The сalix[4]arene C-107 is highly effective supramolecular inhibitor of the Na(+,K(+-АТРase of plasmatic membrane

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O. V. Bevza

2013-04-01

Full Text Available The inhibition of the Na+,K+-АТРase activity of the myometrium cell plasma membranes with calixarene С-107 (5,17-diamino(2-pyridylmethylphosphono-11,23-di-tret-butyl-26,28-dihydroxy-25,27-dipropoxycalix[4]arene was investigated. It has been shown that calixarene С-107 reduced the Na+,K+-АТРase activity more efficiently than ouabain did, while it did not practically influence the “basal” Mg2+-АТРase activity of the same membrane. The magnitude of the cofficient of inhibition I0.5 was 33 ± 4 nМ, Hill coefficient was 0.38 ± 0.06. The model calixa­rene C-150 – the calixarene “scaffold” (26,28-dihydroxy-25,27-dipropoxycalix[4]arene, and the model compound М-3 (4-hydroxyaniline(2-pyridinemethylphosphonic acid – a fragment of the calixarene С-107, had practically no influence on the enzymatic activity of Na+,K+-АТРase and Mg2+-АТРаse. We carried out the computer simulation of interaction of calixarenes C-107 and the mentioned model compound with ligand binding sites of the Na+,K+-АТРase of plasma membrane and structure foundation of their intermolecular interaction was found out. The participation of hydrogen, hydrophobic, electrostatic and π-π (stacking interaction between calixarene and enzyme aminoacid residues, some of which are located near the active center of Na+,K+-АТРase, was discussed.

Novos aspectos na evolução clínica da pitiríase versicolor New aspects in the clinical course of pityriasis versicolor

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Valéria Maria de Souza Framil

2011-12-01

Full Text Available FUNDAMENTO: A pitiríase versicolor é uma doença infecciosa causada por várias espécies de Malassezia com uma tendência a se tornar recidivante ou crônica. OBJETIVOS: Este trabalho foi conduzido na tentativa de conhecer a evolução clínica da pitiríase versicolor em relação ao número de recidivas após um tratamento adequado no período de 12 meses e correlacionar o número de recidivas com as espécies de Malassezia isoladas. MATERIAL E MÉTODOS: Cento e dois pacientes com diagnóstico clínico e laboratorial de pitiríase versicolor foram acompanhados por um período de 12 meses para observarmos o número de recidivas da doença. RESULTADOS: A pitiríase versicolor, após um tratamento adequado, apresentou três tipos de evolução clínica num período de 12 meses: pitiríase versicolor sem nenhum episódio de recidiva (32,35%; pitiríase versicolor recidivante, com um a quatro episódios de recidiva (52,94% devidos a fatores de predisposição relacionados; e pitiríase versicolor crônica, com mais de quatro episódios de recidiva (14,70% sem nenhuma relação com fatores de predisposição. CONCLUSÕES: A pitiríase versicolor apresentou uma evolução clínica de acordo com o número de episódios de recidiva da doença analisados durante um período de 12 meses que pode ser considerada da seguinte maneira: pitiríase versicolor com cura clínica e micológica, pitiríase versicolor recidivante e pitiríase versicolor crônica.BACKGROUND: Pytiriasis versicolor is an infectious disease caused by several Malassezia species which has a tendency to become relapsing or chronic. OBJECTIVES: This study was conducted in an attempt to investigate the clinical course of pityriasis versicolor with regard to the number of relapses after a 12-month therapy and correlate this number with isolates of Malassezia species. MATERIAL AND METHODS: 102 patients with clinical and laboratory diagnosis of pityriasis versicolor were monitored for 12

Platelet activating factor-acylhydrolase (PAF-ase) activity is higher in serum of men than women and is related to levels of low density lipoprotein (LDL)

International Nuclear Information System (INIS)

Farr, R.S.; Howell, S.E.; Wardlow, M.L.

1986-01-01

PAF-ase is a specific serum enzyme that inactivates PAF by hydrolyzing acetate from the sn-2 position of the glycerol backbone. A reproducible PAF-ase activity assay was developed. A unit is based on the amount of serum required to release 3.61 +/- 0.042 pm 3 H-acetate from 10 pm 3 H-labeled PAF after incubation for 1 hr at 37 0 C. Assays on two single reference serums repeated 7 days were 0.63 +/- 0.013 U and 1.33 +/- 0.031 U. Serum from 20 normal men and 20 normal premenopausal women had significantly different (p = <0.001) levels of 1.32 +/- 0.072 U and 0.97 +/- 0.051 U respectively. They previously reported that PAF-ase is associated with B-lipoprotein. Therefore, total cholesterol (TC), LDL and high density lipoproteins (HDL) were determined on these 40 serums. Regression analysis revealed PAF-ase units were correlated with LDL (r = 0.740; p = < 0.001) and, parenthetically, with the TC (r = 0.620; p = < 0.001) but not with HDL. These correlations were similar for men and women. Thus, serum PAF-ase was partially controlled by serum LDL levels and the higher PAF-ase levels in serum from men were due in part to higher (p = < 0.01) LDL levels in men (147.6 +/- 6.9 mg/dl) as contrasted to women (119.0 +/- 7.6 mg/dl). PAF is a potent inflammatory, bronchoconstrictive and hypotensive agent. These data indicate that sex and serum LDL levels of subjects must be considered during future studies of the role of PAF vs PAF-ase in different disease states

The effects of low-intensity electromagnetic irradiation at the frequencies of 51.8 and 53 GHz and antibiotic ceftazidime on Lactobacillus acidophilus F0F1 ATP-ase activity

International Nuclear Information System (INIS)

Soghomonyan, D.R.

2013-01-01

The effects of low intensity electromagnetic irradiation (EMI) at the frequencies 51.8 and 53 GHz and antibiotic ceftazidime on N,N'-dicyclohexylcarbodiimide (DCCD), inhibited ATP-ase activity of Lactobacillus acidophilus membrane vesicles were investigated. It was shown that both frequencies decreased the ATP-ase activity, moreover, ceftazidime increase the sensitivity of cells to DCCD, inhibitor of the F 0 F 1 -ATP-ase. EMI combined with ceftazidime and DCCD markedly decreased the ATPase activity. The F 0 F 1 -ATP-ase is suggested can be a target for the effects observed

Novel O-band tunable fiber laser using an array waveguide grating

International Nuclear Information System (INIS)

Ahmad, H; Zulkifli, M Z; Latif, A A; Harun, S W

2010-01-01

A novel tunable fibre laser (TFL) operating in the ordinary band (O-band) of 1310 nm is proposed and demonstrated. The proposed TFL is developed using a 1×16 arrayed waveguide grating (AWG) as a slicing mechanism for the broadband amplified spontaneous emission (ASE) source and an optical channel selector (OCS) to provide the tunability. A semiconductor optical amplifier (SOA) with a centre wavelength of 1310 nm serves as the compact gain medium for the TFL and also as a broadband ASE source. The TFL has a tuning range of 1301.26 nm to 1311.18 nm with 9.92 nm span and a channel spacing of 0.7 nm. The measured output power is about –4 and –8 dBm and with a side node suppression ratio (SMSR) of 29 to 33 dB

Aspectos epidemiológicos dateníase-cisticercose na área endêmica de Lagamar, MG

OpenAIRE

Silva-Vergara, Mario León; Prata, Aluízio; Vieira, Cláudio de Oliveira; Castro, João Henrique; Micheletti, Luciane Giroto; Otaño, Arturo Santana; Franquini Júnior, João

1995-01-01

Um inquérito epidemiológico sobre teníase-cisticercose foi realizado em Lagamar- MG em 1992. Cadastradas 1109 casas com 3344 habitantes. O inquérito abrangeu 875 (86%) famílias e foi respondido por um informante que, em 80% dos casos, foi o pai. Na cidade havia 100 chiqueiros em 100 (11,4%) casas que albergavam 406 suínos, em condições extremamente precárias. Em 300 (34,2%) casas havia o antecedente de teníase em algum membro da família. O antecedente de convulsão foi relatado por 125 (14,2%)...

Effect of hydrogen peroxide on the main kinetic parameters of ATP hydrolysis by ouabain sensitive Na+, K+-ATP-ase in spermatozoa of infertile men

Directory of Open Access Journals (Sweden)

Р. В. Фафула

2017-12-01

Full Text Available Background: It is known that Na+,K+-ATP-ase plays important role in physiology of spermatozoa including their motility. Na+,K+-ATP-ase is one of the targets for reactive oxygen species. Hyperproduction of reactive oxygen species can damage sperm cells and it is considered to be as one of the mechanisms of male infertility. Objectives: To evaluate the H2O2 effect on the main kinetic parameters of ATP hydrolysis by ouabain-sensitive Na+,K+-ATPase of spermatozoa of fertile (normozoospermia and infertility men (asthenozoospermia. Materials and methods: Na+, K+-ATP-ase activity was determined spectrophotometrically by production of Pi. Concentration dependencies ware linearized in Lineweaver-Burk plot. Results: Effective inhibitory effect of H2O2 on ouabain-sensitive Na+,K+-ATP-ase activity of sperm cells of fertile and infertile men was demonstrated. The effects of H2O2 on the main kinetic parameters of the ATP hydrolysis with the involvement of Na+, K+-ATP-ase was studied. In the whole range of studied concentrations of ATP the Na+, K+-ATP-ase activity of spermatozoa of fertile and infertile men was reduced in the presence of H2O2 in the incubation medium. However, the optimal activity of the Na+, K+-ATP-ase activity of sperm cells in both normozoospermic and asthenozoospermic men was observed in the presence of 5 mM ATP in the incubation medium. By linearization of concentration curves in Lineweaver-Burk plot the main kinetic parameters of Na+, K+-activated, Mg2+-dependent ATP hydrolysis in the sperm cells of fertile and infertile men were determined. Under the effect of H2O2, the affinity constant of enzyme to ATP in normozoospermic and asthenozoospermic men increases several times. The initial maximum rate of ATP hydrolysis was significantly reduced only in the spermatozoa of fertile men with normozoospermia. Conclusions: Under conditions of H2O2-induced oxidative stress the inhibition of ouabain-sensitive Na+,K+-ATP-ase activity in sperm cells

Caso fatal de balantidíase intestinal

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Maria da Conceição Pinheiro

1991-09-01

Full Text Available Caso fatal de balantidíase em mulher desnutrida de 63 anos, criadora de porcos, da zona rural de Uberaba. A doença evoluiu em oito dias com disenteria, náusea e vômitos, culminando em óbito por enterorragia. A necropsia constatou-se colite ulcerada causada por B. coli, facilmente identificado ao exame histológico do intestino grosso.A fatal case of a 63-year old pig-raising country woman with an eight-day course of nausea, vomiting. dysentery with intestinal bleeding the latter being the direct cause of death. The autopsy showed ulcerative colitis due to B. coli, which was easily observed on histological examination of the large bowel.

Noise filtering in a multi-channel system using a tunable liquid crystal photonic bandgap fiber

DEFF Research Database (Denmark)

Petersen, Martin Nordal; Scolari, Lara; Tokle, Torger

2008-01-01

This paper reports on the first application of a liquid crystal infiltrated photonic bandgap fiber used as a tunable filter in an optical transmission system. The device allows low-cost amplified spontaneous emission (ASE) noise filtering and gain equalization with low insertion loss and broad...... tunability. System experiments show that the use of this filter increases for times the distance over which the optical signal-to-noise ratio (OSNR) is sufficient for error-free transmission with respect to the case in which no filtering is used....

PELAKSANAAN ITIKAD BAIK MEMORY OF UNDERSTANDINGDALAM PERJANJIAN JOINT VENTUREPERUSAHAAN MODAL ASING

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Heru Guntoro

2014-11-01

Full Text Available This paper examines the perspective of law in implementation good conviction memory of understanding in joint venture agreement and the result from law implementation memory of understanding in join venture agreement in the supreme court decision. This research is a literary research, the legal matters are analyzed qualitatively using normatif and juridical approach. From research can concludes, implementation from good conviction Memory of Understanding in the joint venture agreement are command of regulation with there are measure and explisit sanction to they who break a promise. Tulisan ini bertujuan untuk mengkaji perspektif hukum perdata terhadap pelaksanaan itikad baik dan akibat hukum pelaksanaan Memory of Understandingdalam perjanjian joint venturePerusahaan Modal Asing dalam Putusan Mahkamah Agung. Penelitian yang dilakukan adalah penelitian kepustakaan, bahanbahan hukum yang dianalisis secara kualitatif dengan pendekatan yuridis normatif dan komparatif. Dari penelitian yang dilakukan dapat disimpulkan bahwa: pelaksanaan itikad baik Memory of Understandingdalam perjanjian joint venturePerusahaan Modal Asing merupakan perintah Undang-Undang serta ada tindakan dan sanksi tegas bagi mereka yang telah melakukan wanprestasi (beritikad tidak baik.

Influências nutricionais na psoríase Nutritional influences in psoriasis

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Maria Lúcia Diniz Araujo

2009-02-01

Full Text Available A psoríase é uma doença inflamatória de pele, mediada por células T, hereditária, que sofre influência ambiental. Ingestão elevada de ômega-3, jejum, dietas hipocalóricas e vegetarianas mostram efeitos benéficos. Alguns pacientes que apresentam anticorpos antigliadina IgA/IgG, com sensibilidade ao glúten, melhoram após a retirada deste. O calcitriol é usado no tratamento tópico. Ingestão de álcool pode exacerbar a doença. Neste trabalho, analisam-se fatores dietéticos e descrevem-se seus benefícios na psoríase.Psoriasis is an inherited inflammatory skin disease mediated by T-cells and influenced by environmental factors. High intake of omega-3, fasting, low-calorie and vegetarian diets show beneficial effects. Some patients presenting IgA/IgG antigliadin antibodies and who are gluten-sensitive improve after a gluten-free diet. Calcitriol is used in topical treatment. The use of alcohol may exacerbate the disease. In this report, diet factorsare analyzed and their benefits in psoriasis are described.

Detecção de casos novos de hanseníase no município de Prudentópolis, PR: uma análise de 1998 a 2005

OpenAIRE

Sanches,Lucas Augusto Thomé; Pittner,Elaine; Sanches,Hermes Francisco; Monteiro,Marta Chagas

2007-01-01

Este trabalho teve como objetivo detectar os casos novos de hanseníase do período de 1998 a 2005 no município de Prudentópolis, PR. Assim como, verificar a faixa etária e a forma clínica predominante entre os casos de hanseníase. Os dados foram obtidos através das fichas clínico-epidemiológicas de casos com diagnóstico definitivo de hanseníase notificado no Sistema de Informação sobre Agravos de Notificação, de 1998 a 2005. Neste período, foram relatados 222 casos de hanseníase, dos quais 63%...

Research reports: 1990 NASA/ASEE Summer faculty fellowship program

International Nuclear Information System (INIS)

Freeman, L.M.; Chappell, C.R.; Six, F.; Karr, G.R.

1990-10-01

Reports on the research projects performed under the NASA/ASEE Summer faculty fellowship program are presented. The program was conducted by The University of Alabama and MSFC during the period from June 4, 1990 through August 10, 1990. Some of the topics covered include: (1) Space Shuttles; (2) Space Station Freedom; (3) information systems; (4) materials and processes; (4) Space Shuttle main engine; (5) aerospace sciences; (6) mathematical models; (7) mission operations; (8) systems analysis and integration; (9) systems control; (10) structures and dynamics; (11) aerospace safety; and (12) remote sensing

Aspectos dermatoscópicos na psoríase ungueal Dermoscopy in nail psoriasis

Directory of Open Access Journals (Sweden)

Débora Cadore de Farias

2010-02-01

Full Text Available Os autores relatam sua experiência no uso da dermatoscopia na psoríase ungueal e descrevem os achados dessa ferramenta diagnóstica.The authors report on their experience with the use of dermoscopy in nail psoriasis and describe their findings with this diagnostic tool.

PERBANDINGAN KOMUNIKASI NONVERBAL PENUTUR ASLI DAN PENUTUR ASING BAHASA INGGRIS DALAM PUBLIC SPEAKING

Directory of Open Access Journals (Sweden)

I Made Suta Paramarta

2016-08-01

Full Text Available Abstrak Tujuan penelitian ini adalah untuk membandingkan fitur-fitur nonverbal penutur asli dan penutur asing dalam public speaking. Perbedaan budaya antara kedua kelompok penutur tersebut menimbulkan perbedaan penggunaan fitur nonverbal dalam public speaking. Desain penelitian ini adalah desain deskriptif kualitatif dengan 10 subjek. 5 subjek adalah video penutur asli Bahasa Inggris dan 5 video subjek yang lain adalah video mahasiswa Jurusan D III Bahasa Inggris Universitas Pendidikan Ganesha. Penutur asli menunjukkan gerakan nonverbal yang jauh lebih variatif dari penutur asing Bahasa Inggris. Penutur asli memiliki gerakan-gerakan spesifik yang mengacu pada makna yang spesifik juga. Di lain pihak, penutur asing menunjukkan gerakan nonverbal yang bersifat umum tanpa rujukan pasti pada maksud yang spesifik. Fitur nonverbal yang dicermati dikelompokkan pada gerakan kepala, gerakan badan, dan kontak mata. Kata kunci: perbandingan, nonverbal, public speaking Abstract The purpose of this research is to compare the nonverbal features of the native speakers and the non-native speakers of English in public speaking. Cultural differences between the two groups make significant differences on using the nonverbal features in public speaking. The design of this research was a descriptive-qualitative design with 10 subjects. 5 subjects were videos of 5 English native speakers and the other 5 subjects were the videos of 5 students of Diploma III English Department Universitas Pendidikan Ganesha. The native speakers showed more variative nonverbal movements compared to the non-native speakers. The native speakers made specific gestures which refered to certain specific meanings. On the other hand, the non-native speakers applied general nonverbal movements without specific referents. The investigated nonverbal features were grouped into head movements, body movements, and eye contacts. Keywords: comparison, nonverbal, public speaking

Criterion of transverse coherence of self-amplified spontaneous emission in high gain free electron laser amplifiers

International Nuclear Information System (INIS)

Xie, M.; Kim, K.J.

1995-01-01

In a high gain free electron laser amplifier based on Self-Amplified Spontaneous Emission (SASE) the spontaneous radiation generated by an electron beam near the undulator entrance is amplified many orders of magnitude along the undulator. The transverse coherence properties of the amplified radiation depends on both the amplification process and the coherence of the seed radiation (the undulator radiation generated in the first gain length or so). The evolution of the transverse coherence in the amplification process is studied based on the solution of the coupled Maxwell-Vlasov equations including higher order transverse modes. The coherence of the seed radiation is determined by the number of coherent modes in the phase space area of the undulator radiation. We discuss the criterion of transverse coherence and identify governing parameters over a broad range of parameters. In particular we re-examine the well known emittance criterion for the undulator radiation, which states that full transverse coherence is guaranteed if the rms emittance is smaller than the wavelength divided by 4π. It is found that this criterion is modified for SASE because of the different optimization conditions required for the electron beam. Our analysis is a generalization of the previous study by Yu and Krinsky for the case of vanishing emittance with parallel electron beam. Understanding the transverse coherence of SASE is important for the X-ray free electron laser projects now under consideration at SLAC and DESY

Development of Demonstrably Predictive Models for Emissions from Alternative Fuels Based Aircraft Engines

Science.gov (United States)

2017-05-01

Engineering Chemistry Fundamentals, Vol. 5, No. 3, 1966, pp. 356–363. [14] Burns, R. A., Development of scalar and velocity imaging diagnostics...in an Aero- Engine Model Combustor at Elevated Pressure Using URANS and Finite- Rate Chemistry ,” 50th AIAA/ASME/SAE/ASEE Joint Propulsion Conference...FINAL REPORT Development of Demonstrably Predictive Models for Emissions from Alternative Fuels Based Aircraft Engines SERDP Project WP-2151

Driving pockels cells in multi-arm lasers

International Nuclear Information System (INIS)

Carder, B.M.

1978-01-01

This paper describes the method used to drive Pockels cells on the 20-arm Shiva laser for inertial confinement fusion research at the Lawrence Livermore Laboratory. Shiva became operational last fall, and has just completed a series of 20-arm target shots. It uses two pockels cell gates in each laser arm for suppression of amplified spontaneous emission (ASE) that can damage or destroy the target before the main pulse arrives. Two additional Pockels cells are used in the preamplification stages, so that a total of 42 cells must be driven by the pulser system

Experimental investigation of the cascadability of a cross-gain modulation wavelength converter

DEFF Research Database (Denmark)

Zheng, Xueyan; Liu, Fenghai; Kloch, Allan

2000-01-01

by adding a fiber grating-based optical add-drop multiplexer after the semiconductor optical amplifier (SOA) to enhance the high-frequency response of the wavelength converter. However, the low-frequency degradation of the signal together with amplified spontaneous emission (ASE) noise and jitter......The cascading characteristics of a wavelength converter based on cross-gain modulation (XGM) are studied experimentally using a recirculating loop at 10 Gb/s. The maximum cascaded number of the wavelength converter converting the signal to the same wavelength is improved from five to eight...

Rinolitíase como causa de fístula oronasal Rhinolithiasis as cause of oronasal fistula

Directory of Open Access Journals (Sweden)

Gabriel Cesar Dib

2005-02-01

Full Text Available A Rinolitíase é uma doença na qual ocorre a deposição de compostos orgânicos e inorgânicos em torno de um núcleo na cavidade nasal, causando rinorréia, obstrução nasal unilateral, odor fétido, epistaxe, podendo haver complicações. Os autores apresentam um caso de rinolitíase com fístula oronasal e revisão de literatura.Rhinolithiasis is a disease caused by deposition of organic and inorganic compounds in the nasal cavity, leading to unilateral nasal obstruction, fetid rhinorrhea, epistaxis, and it may cause complications. The authors present a case of rhinolithiasis with oronasal fistula and literature review.

Multi-format all-optical processing based on a large-scale, hybridly integrated photonic circuit.

Science.gov (United States)

Bougioukos, M; Kouloumentas, Ch; Spyropoulou, M; Giannoulis, G; Kalavrouziotis, D; Maziotis, A; Bakopoulos, P; Harmon, R; Rogers, D; Harrison, J; Poustie, A; Maxwell, G; Avramopoulos, H

2011-06-06

We investigate through numerical studies and experiments the performance of a large scale, silica-on-silicon photonic integrated circuit for multi-format regeneration and wavelength-conversion. The circuit encompasses a monolithically integrated array of four SOAs inside two parallel Mach-Zehnder structures, four delay interferometers and a large number of silica waveguides and couplers. Exploiting phase-incoherent techniques, the circuit is capable of processing OOK signals at variable bit rates, DPSK signals at 22 or 44 Gb/s and DQPSK signals at 44 Gbaud. Simulation studies reveal the wavelength-conversion potential of the circuit with enhanced regenerative capabilities for OOK and DPSK modulation formats and acceptable quality degradation for DQPSK format. Regeneration of 22 Gb/s OOK signals with amplified spontaneous emission (ASE) noise and DPSK data signals degraded with amplitude, phase and ASE noise is experimentally validated demonstrating a power penalty improvement up to 1.5 dB.

Parametric amplification and cascaded-nonlinearity processes in common atomic system.

Science.gov (United States)

Zheng, Huaibin; Zhang, Xun; Zhang, Zhaoyang; Tian, Yaling; Chen, Haixia; Li, Changbiao; Zhang, Yanpeng

2013-01-01

For the first time, we study the parametric amplification process of multi-wave mixing (PA-MWM) signal and cascaded-nonlinearity process (CNP) in sodium vapors both theoretically and experimentally, based on a conventional phase-conjugate MWM and a self-diffraction four-wave mixing (SD-FWM) processes, which are pumped by laser or amplified spontaneous emission (ASE), respectively. For laser pumping case, SD-FWM process serves as a quantum linear amplifier (a CNP) out (inside) of the resonant absorption region. While for ASE case, only the CNP occurs and the output linewidth is much narrower than that of the MWM signal due to the second selected effect of its electromagnetically induced transparency window. In addition, the phase-sensitive amplifying process seeded by two MWM processes is discussed for the first time. Theoretical fittings agree well with the experiment. The investigations have important potential applications in quantum communication.

Amplification of picosecond pulse by electron-beam pumped KrF laser amplifiers. Denshi beam reiki KrF laser zofukuki ni yoru piko byo pulse no zofuku

Energy Technology Data Exchange (ETDEWEB)

Okuda, I.; Tomie, T.; Owadano, Y.; Yano, M. (Electrotechnical Laboratory, Tsukuba (Japan))

1991-08-20

Experiments on the amplification of a picosecond pulse by electron-beam pumped KrF laser amplifiers were carried out for the purpose of its application to the field such as excitation light source for soft X-ray laser which requires large energy besides peak power. The picosecond pulse was amplified by a discharge pumped KrF amplifier and two electron-beam pumped KrF amplifiers(at the middle stage and the final stage). The energy of 4J, which was the largest energy for short pulse excimer laser so far, was obtained by these devices. About 90% of the window area of the final amplifier with 29cm diameter was filled by the input beam, and energy density of the picosecond beam reached 3.9 times saturation energy density. Measured energy of amplified spontaneous emission(ASE) showed good agreement with the theoretically estimated value. Most of ASE was derived from the discharge pumped laser as the first amplifier. As for the focused power density, the power density ratio of the picosecond pulse to ASE was estimated to be as large as 10{sup 5}. 11 refs., 4 figs.

Spectrum of spontaneous photon emission as a promising biophysical indicator for breast cancer research.

Science.gov (United States)

Zhao, Xiaolei; Yang, Meina; Wang, Yong; Pang, Jingxiang; Wijk, Eduard Van; Liu, Yanli; Fan, Hua; Zhang, Liewei; Han, Jinxiang

2017-10-12

In this study, we investigated the spectral characteristics of Spontaneous Photon Emission (SPE) from the body surface of a human breast cancer-bearing nude mice model during the overall growth process of breast cancers. By comparing and analyzing the data, we found that there was a striking difference between tumor mice and healthy controls in the spectral distribution of SPE from the body surface of lesion site, even when the morphological changes at the lesion site were not obvious. The spectral distribution of SPE from the healthy site of the tumor mice also differed from that of the healthy controls as the breast cancer developed to a certain stage. In addition, the difference in spectrum was related with different growth states of tumors. Interestingly, there was a positive correlation between the spectral ratio (610-630/395-455 nm) and the logarithm of the tumor volume for both the lesion site (R 2  = 0.947; p spectrum of SPE was sensitive to changes in the tumor status.

Generation, amplification and propagation of partially coherent light in a Nd:glass laser driver for inertial confinement fusion

International Nuclear Information System (INIS)

Nakano, Hitoshi; Tsubakimoto, Kouji; Miyanaga, Noriaki; Nakatsuka, Masahiro; Kanabe, Tadashi.

1992-01-01

A partially coherent light source has been introduced into the high power twelve beam Nd:glass laser system, Gekko XII for obtaining the smooth intensity distribution of a focused beam pattern. An amplified spontaneous emission (ASE) from Nd:glass was used as a partially coherent source. We adopted the angularly dispersed spectrum not only for beam smoothing but for efficient harmonic conversion. The temporal evolution of the speckle smoothing was experimentally evaluated and compared with a statistical model of speckle pattern. In the amplification of a partially coherent light in Gekko XII, no reduction of the energy gain was found at high power operation 1kJ level. The ASE light can be propagated using image relaying spatial filters, with maintaining the beam divergence up to 32 times diffraction limited. Irradiation nonuniformities on a spherical target were estimated from the focused beam patterns measured at an equivalent target plane. A partially coherent light is quite effective for reducing the nonuniformity from 19.7% (the coherent laser with random phase plate) to 3.8%. Doubling efficiency was found to be reduced at high intensity region due to the phase mismatching with the beam divergence of the ASE light. We discuss possible approaches to obtain the sufficient harmonic conversion with keeping the incoherency of the ASE light. (author)

Two-photon cooperative emission in the presence of athermal electromagnetic field

International Nuclear Information System (INIS)

Enaki, N.A.; Mihalache, D.

1997-01-01

The possibility of cooperative spontaneous two-photon emission of an extended radiators system and the influence of the external thermal electromagnetic field on the spontaneous emission rate, in such a system, are investigated. It is concluded that, in an external electromagnetic field, the two-photon cooperative emission rate increases significantly. The importance of this effect on the emission of gamma rays from inverted long-lived isomers triggered by X-ray thermal fields, is emphasized

Imunopatogênese da psoríase: revisando conceitos Reviewing concepts in the immunopathogenesis of psoriasis

Directory of Open Access Journals (Sweden)

Emerson de Andrade Lima

2011-12-01

Full Text Available O conhecimento sobre a fisiopatogenia da psoríase possibilitou o desenvolvimento de ferramentas terapêuticas que visam ao bloqueio do seu gatilho imunológico. Paralelamente, citocinas como o TNF têm sido reconhecidas como integrantes da etiopatogenia da psoríase e comorbidades a ela relacionadas. Estudos genéticos e epidemiológicos contribuíram efetivamente para as conclusões a que se tem chegado atualmente sobre esta complexa patologia.Insights into the pathogenesis of psoriasis led to the development of therapeutic tools aimed at blocking its immunological trigger. In parallel, cytokines such as the tumor necrosis factor (TNF have been recognized as playing a crucial role in the pathogenesis of psoriasis and its associated comorbidities. Genetic and immunological studies have contributed effectively towards establishing the currently held concepts regarding this complex disease.

Peran Sistem Informasi Dalam Meningkatkan Investasi Asing Pada Sektor Properti Di Indonesia Di Era Pasar Bebas

Directory of Open Access Journals (Sweden)

Yosi Agustiawan

2015-01-01

Full Text Available Abstrak Pasar bebas adalah hasil dari proses globalisasi yang telah menciptakan integrasi ekonomi antar negara. Artikel ini mengkaji dampak globalisasi di pasar properti global dan peran sistem informasi untuk meningkatkan investasi asing di Indonesia. Meningkatnya investasi asing langsung (Foreign Direct Investmen/FDI yang mengalir ke negara berkembang termasuk Indonesia di berbagai sektor termasuk properti telah memberikan banyak manfaat untuk meningkatkan ekonomi. Buruknya peraturan kepemilikan tanah dan infrastruktur adalah masalah utama yang harus diatasi untuk menjaga agar investor asing masih berniat untuk menanamkan modalnya dalam pasar properti global. Sistem informasi dapat digunakan sebagai alat yang efektif untuk mengatasi masalah-masalah tersebut melalui penggunaan e-government dan perencanaan strategis implementasi sistem informasi dalam proyek infrastruktur. Abstract Cross-border relationships do not only affect many aspects but it also creates economic integration among countries. This essay examines the impact of globalization on the property market and the role of information system to promote foreign direct investment (FDI in Indonesia. Allowing foreign direct investment (FDI flows to those developing in various industries including property has clearly provided positive opportunities to improve their economic. Poor land regulations and infrastructure are the main issues that must be overcome to maintain foreign investor still intend to capitalize on the global property market. Information system can be used as effective tool to resolve those issues through e-government and strategic implementation in projects infrastructure.

PERLINDUNGAN HUKUM TERHADAP INVESTOR ASING PERUSAHAAN JOINT VENTURE SEKTOR AIR BERSIH DI KABUPATEN DELI SERDANG (Studi Pada PT. Tirta Lyonnaise Medan

Directory of Open Access Journals (Sweden)

Sjahril Effendy

2017-08-01

Full Text Available Penanaman modal asing memegang peranan penting dalam perekonomian. Keberhasilan suatu pembangunan nasional tidak dapat dipisahkan dari penanaman modal asing sebagai faktor penunjang dan turut menentukan pembangunan ekonomi, antara lain dapat menciptakan pekerjaan, terjadinya alih teknologi, memberikan masukan dari segi perpajakan dan pendapatan negara dan daerah. Menciptakan kepastian hukum terhadap investor asing perusahaan joint venture sebagai bentuk perlindungan hukum. Pemerintah  Kabupaten Deli Serdang dalam pembangunan sektor air bersih juga memberlakukan Undang-Undang No.25 Tahun 2007 tentang Penanaman Modal walaupun belum sepenuhnya diterapkan. Hambatan-hambatan yang dihadapi antara lain berupa perjanjian kerjasama dengan PDAM Tirtanadi tidak sepenuhnya dilaksanakan, penyerahan air bersih merupakan objek PPN padahal menurut ketentuan merupakan objek yang bebas dari PPN, dan UU No.13 Tahun 2003 tentang Ketenagakerjaan telah disalahgunakan oleh oknum serikat pekerja perusahaan. Penyelesaian sengketa berpedoman kepada  perjanjian kerjasama  antara PT. Tirta Lyonnaise Medan dengan PDAM Tirtanadi Provinsi Sumatera Utara.

Estudo da ocorrência de litíase renal e ureteral em gatos com doença renal crônica

Directory of Open Access Journals (Sweden)

Marcela Malvini Pimenta

2014-06-01

Full Text Available Investigou-se a ocorrência de nefrolitíase e/ou ureterolitíase em 72 gatos portadores de doença renal crônica (DRC, classificados predominantemente no estágio II, segundo os critérios designados pela IRIS - International Renal Interest Society. Destes pacientes, 47 (65,27% apresentaram litíase renal e ou ureteral. Não houve diferença estatística entre o grupo de estudo (DRC com cálculo e o grupo controle (DRC sem cálculo em relação à idade (p=0,274. Apesar disso, os pacientes portadores de nefrolitíase e/ou ureterolitíase apresentaram maiores indícios de lesão renal, caracterizados por diferenças estatisticamente relevantes da densidade urinária (p=0,013 e pelo menor tamanho dos rins direito (p=0,009 e esquerdo (p=0,048. Encontrou-se similaridade entre os grupos em relação a outros parâmetros, tais como as concentrações plasmáticas de cálcio total, cálcio ionizado, fósforo, sódio, potássio e paratormônio intacto (PTHi. Os valores das concentrações séricas de ureia e bicarbonato diferiram entre os grupos, com valores de p=0,039 e p=0,037, respectivamente. Além disso, foi mensurada a pressão arterial, que se manteve inalterada na comparação entre o grupo de estudo e o grupo controle. Os resultados obtidos reforçam a necessidade de acompanhamento ultrassonográfico de todos os pacientes portadores de DRC, mesmo daqueles assintomáticos ou em estágios iniciais da doença.

Ivermectina no tratamento de miíase orbitária: relato de caso Ivermectine in the treatment of orbital myiasis: case report

Directory of Open Access Journals (Sweden)

Mario Enrique Lovatón Rodriguez

2003-08-01

Full Text Available OBJETIVO: Relatar um caso de miíase associada a carcinoma basocelular de órbita, tratada com ivermectina previamente ao ato cirúrgico. MÉTODOS: Apresentamos um caso e enfatizamos a eficácia da ivermectina no tratamento da miíase como terapêutica alternativa. RESULTADO: Após o tratamento com ivermectina via oral em dose única, observou-se a resolução completa do quadro de miíase num período de 48 horas. CONCLUSÃO: A ivermectina pode ser utilizada com eficácia no tratamento da miíase orbitária, tornado desnecessária a remoção mecânica das larvas.OBJECTIVE: We report a case of myiasis in a patient with basocellular carcinoma of the orbit, treated with ivermectine prior to surgery. METHODS: We report a case and emphasize the efficacy of ivermectine in the treatment of myiasis, as alternative therapy. RESULTS: After oral administration of a single dose of ivermectine we saw a complete resolution of the myiasis in a 48-hour period. CONCLUSION: Ivermectine can be used successfully in the treatment of orbital myiasis, turning the mechanical removal of larvae an unnecessary procedure.

Corporate Governance for A.S.E. Listed Firms

Directory of Open Access Journals (Sweden)

Tellidou Theognosia

2016-03-01

Full Text Available The present paper focuses on the level of compliance and application of corporate governance from the corporations listed in the Athens Stock Exchange (A.S.E. and attempts to highlight improvements from the adoption of best practices suggested by corporate governance recent trends worldwide. In order for the research to be conducted, a series of qualitative and quantitative variables were used, as derived from the financial statements of 162 public companies. A more extensive analysis regarding the level of compliance with corporate governance was conducted in 25 companies with the highest and 25 corporations with the lowest score, whose classification in these positions was the result of a rating system that was created for this purpose.

Miíase vulvar: relato de caso Vulvar myiasis: a case report

Directory of Open Access Journals (Sweden)

Carlos Augusto Real Martinez

2003-05-01

Full Text Available A miíase de localização vulvar é doença rara. O objetivo do presente relato é descrever um caso de miíase vulvar por larvas de Cochliomyia hominivorax em mulher de 77 anos, com precários hábitos higiênicos, apresentando dor, prurido e secreção de odor fétido na região genital há 10 dias. O exame ginecológico demonstrou lesão ulcerada no grande lábio vulvar, com seis centímetros, que se estendia ao monte do pube, preenchida por larvas. A doente evoluiu favoravelmente após remoção das larvas, desbridamento cirúrgico e curativos diários, sendo realizada, quatorze dias após o desbridamento, rotação de retalho cutâneo. Apresentou evolução satisfatória, estando assintomática dois meses após a intervenção. A miíase vulvar deve ser considerada no diagnóstico diferencial das doenças infecciosas vulvares de doentes com hábitos de higiene precários.Myiasis located in the vulva is a rarely described disease. The objective of the present report is to describe a case of vulvar myiasis due to larvae of Cochliomyia hominivorax. A 77-year-old woman with precarious hygienic habits presented pain, pruritus and secretions with a fetid smell in the genital region for 10 days. Gynecological examination demonstrated an ulcerated lesion in the labium majus of the vulva measuring six centimeters that extended to the mons pubis and was found to be filled with larvae. The patient progressed favorably after removal of the larvae, surgical debridement and daily dressings. Fourteen days after the debridement, she was submitted to skin flap rotation, with good local scar formation. Two months after the intervention, she remained asymptomatic. Vulvar myiasis must be considered in the differential diagnosis of infectious diseases of the vulva in patients with precarious hygienic habits.

Predicting adherence to prophylactic medication in adolescents with asthma: an application of the ASE-model

NARCIS (Netherlands)

van Es, S.M.; Kaptein, A.A.; Bezemer, P.D.; Nagelkerke, A.F.; Colland, V.T.; Bouter, L.M.

2002-01-01

An explanatory framework, referred to as the attitude/social influence/self-efficacy-model (ASE-model), was utilised to explain future self-reported adherence of adolescents to daily inhaled prophylactic asthma medication. The objective was to investigate the long-term influence of these earlier

Predicting adherence to prophylactic medication in adolescents with asthma : an application of the ASE-model

NARCIS (Netherlands)

van Es, Saskia M; Kaptein, Adrian A; Bezemer, P Dick; Nagelkerke, Ad F; Colland, Vivian T; Bouter, Lex M

An explanatory framework, referred to as the attitude/social influence/self-efficacy-model (ASE-model), was utilised to explain future self-reported adherence of adolescents to daily inhaled prophylactic asthma medication. The objective was to investigate the long-term influence of these earlier

Stimulated-emission effects in particle creation near black holes

International Nuclear Information System (INIS)

Wald, R.M.

1976-01-01

It has recently been shown that if a black hole is formed by gravitational collapse, spontaneous particle creation will occur and a thermal spectrum of all species of particles will be emitted to infinity if the quantum matter was initially in the vacuum state. In this paper we investigate the stimulated-emission effects which occur if particles are present initially. We show in general that for a Hermitian scalar field in an external potential or in curved, asymptotically flat spacetime, stimulated-emission effects can occur precisely in those modes for which there is spontaneous particle creation from the vacuum. For the case of a Schwarzschild black hole, this result appears paradoxical, since spontaneous emission occurs at late times but there is no classical analog of stimulated emission at late times. The resolution of this paradox is that in order to induce emission of particles which emerge at late times one must send in particles at early times, so that they reach the black hole very near the instant of its formation. However, enormous energy is required of these incoming particles in order to stimulate emission of particles which emerge at late times. Thus, for a Schwarzschild black hole, even if particles are initially present (with limited energy) they will induce emission only at early times; at late times one will see only the spontaneously emitted blackbody thermal radiation. For the case of a Kerr black hole stimulated emission can be induced by particles sent in at late times with the appropriate frequencies and angular dependence. If the number of incoming particles is large, this quantum stimulated emission just gives the classical superradiant scattering

Particle-in-cell simulations on spontaneous thermal magnetic field fluctuations

Energy Technology Data Exchange (ETDEWEB)

Simões, F. J. R. Jr.; Pavan, J. [Instituto de Física e Matemática, UFPel, Pelotas, RS (Brazil); Gaelzer, R.; Ziebell, L. F. [Instituto de Física, UFRGS, Porto Alegre, RS (Brazil); Yoon, P. H. [Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742 (United States)

2013-10-15

In this paper an electromagnetic particle code is used to investigate the spontaneous thermal emission. Specifically we perform particle-in-cell simulations employing a non-relativistic isotropic Maxwellian particle distribution to show that thermal fluctuations are related to the origin of spontaneous magnetic field fluctuation. These thermal fluctuations can become seed for further amplification mechanisms and thus be considered at the origin of the cosmological magnetic field, at microgauss levels. Our numerical results are in accordance with theoretical results presented in the literature.

Comparative Study on Electronic, Emission, Spontaneous Property of Porous Silicon in Different Solvents

Directory of Open Access Journals (Sweden)

M. Naziruddin Khan

2014-01-01

Full Text Available Luminescent porous silicon (Psi fabricated by simple chemical etching technique in different organic solvents was studied. By quantifying the silicon wafer piece, optical properties of the Psi in solutions were investigated. Observation shows that no photoluminescence light of Psi in all solvents is emitted. Morphology of Psi in different solvents indicates that the structure and distribution of Psi are differently observed. Particles are uniformly dispersive with the sizes around more or less 5–8 nm. The crystallographic plane and high crystalline nature of Psi is observed by selected area diffraction (SED and XRD. Electronic properties of Psi in solutions are influenced due to the variation of quantity of wafer and nature of solvent. Influence in band gaps of Psi calculated by Tauc’s method is obtained due to change of absorption edge of Psi in solvents. PL intensities are observed to be depending on quantity of silicon wafer, etched cross-section area on wafer surface. Effects on emission peaks and bands of Psi under temperature annealing are observed. The spontaneous signals of Psi measured under high power Pico second laser 355 nm source are significant, influenced by the nature of solvent, pumped energy, and quantity of Si wafer piece used in etching process.

The 1989 NASA-ASEE Summer Faculty Fellowship Program in Aeronautics and Research

Science.gov (United States)

Boroson, Harold R.; Soffen, Gerald A.; Fan, Dah-Nien

1989-01-01

The 1989 NASA-ASEE Summer Faculty Fellowship Program at the Goddard Space Flight Center was conducted during 5 Jun. 1989 to 11 Aug. 1989. The research projects were previously assigned. Work summaries are presented for the following topics: optical properties data base; particle acceleration; satellite imagery; telemetry workstation; spectroscopy; image processing; stellar spectra; optical radar; robotics; atmospheric composition; semiconductors computer networks; remote sensing; software engineering; solar flares; and glaciers.

The Rate of Success of the Accelerated Solvent Extraction (Ase of Fat and Organochlorine Pesticides from Dried Fish Meat Samples

Directory of Open Access Journals (Sweden)

Ana Andreea CIOCA

2017-05-01

Full Text Available The replacement of conventional sample preparation techniques with newer techniques which are automated, faster and more eco-friendly, is nowadays desired in every analytical laboratory. One of the techniques with the attributes mentioned above is the Accelerated Solvent Extraction. In order to evaluate how successful this method is for the extraction of fat and organochlorine pesticides (OCPs from dried fish meat samples, we have tested two series of diverse fish using Dionex™ 350 ASE provided by Thermo Scientific™ (Germany. For a more interesting approach, we added to our investigation 7 polychlorinated biphenyl (PCBs, 3 thricholorobenzenes, 2 tetrachlorobenzenes, 1 pentachlorobenzenes and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD. The study focused on comparing the recoveries of these analytes from different fish samples, after replacing the conventional reference method of the laboratory with ASE. The ASE parameters tested were previously used for the extraction of fat and polybrominated diphenyl ethers (PBDE from fish samples: temperature: 120 ° C; static time: 5 min; number of cycles: 3; flushing volume: 25%; rinse with nitrogen: 90 s; solvent: cyclohexane/ethyl acetate (ratio 1:1. The ASE method provided similar and in some cases better results when compared to the standard reference method, more rapidly, eco-friendly and safer. Any high or low recoveries of the analytes taken into study are attributed to random or systematic errors during the Clean-up step of the extracts and the quantification with Gas Chromatography coupled with Tandem Mass-Spectrometry (GC MS/MS.

Research reports: 1989 NASA/ASEE Summer faculty fellowship program

International Nuclear Information System (INIS)

Karr, G.R.; Six, R.; Freeman, L.M.

1989-12-01

For the twenty-fifth consecutive year, a NASA/ASEE Summer Faculty Fellowship Program was conducted at the Marshall Space Flight Center (MSFC). The basic objectives of the programs are: (1) to further the professional knowledge of qualified engineering and science faculty members; (2) to stimulate an exchange of ideas between participants and NASA; (3) to enrich and refresh the research and teaching activities of the participants' institutions; and (4) to contribute to the research objectives of the NASA Centers. The Faculty Fellows spent ten weeks at MSFC engaged in a research project compatible with their interests and background and worked in collaboration with a NASA/MSFC colleague

Prevenção de incapacidade na hanseníase com apoio em um manual de autocuidado para pacientes

OpenAIRE

Rodini,Fernanda Carvalho Batista; Gonçalves,Mayara; Barros,Ana Regina de Souza Bavaresco; Mazzer,Nilton; Elui,Valéria Meirelles Carril; Fonseca,Marisa de Cássia Registro

2010-01-01

A hanseníase é uma doença infectocontagiosa, de evolução lenta, que se manifesta por sinais e sintomas dermatoneurológicos, com lesões na pele e nos nervos periféricos. O objetivo deste estudo foi avaliar o status físico e funcional de olhos, mãos e pés de pacientes com hanseníase, em relação ao aparecimento e evolução de deficiências sensitivo-motoras, grau de incapacidade e qualidade de vida, tendo os pacientes recebido e utilizado durante um ano um manual especialmente elaborado, com orien...

Avaliação da dor em portadores de hanseníase submetidos à mobilização neural

OpenAIRE

Véras,Larissa Sales Téles; Vale,Rodrigo Gomes de Souza; Mello,Danielli Braga de; Castro,José Adail Fonseca de; Dantas,Estélio Henrique Martin

2011-01-01

Este estudo tem como objetivo avaliar o efeito da técnica de mobilização neural sobre a percepção da dor em portadores de hanseníase. A amostra de 56 indivíduos portadores de hanseníase foi randomizada em: grupo experimental (GMN) composto por 29 indivíduos submetidos ao tratamento com mobilização neural e grupo controle (GC) composto por 27 indivíduos que foram submetidos ao tratamento convencional. A percepção da dor foi avaliada através da Escala Visual Analógica, indicando-se em uma extre...

Vivências compartilhadas de filhos separados pela hanseníase no RN a luz da história oral de vida

OpenAIRE

Cabral, Ana Michele de Farias

2013-01-01

Várias epidemias marcaram a vida das pessoas e coletividades, em todos os períodos históricos, sendo um dos principais exemplos a hanseníase, doença infecto-contagiosa, marcada pelo estigma, preconceito e exclusão social. No passado, o isolamento compulsório dos pacientes portadores de hanseníase causou sérios problemas sociais e psicológicos, resultando no afastamento e na ruptura total ou parcial do vínculo familiar. Os filhos privados desse convívio, retirados muitas vezes de forma desuman...

Applications of anomalous diffraction systems, generation of attosecond electron and photon pulses and Raman amplification by stimulated emission of radiation

Science.gov (United States)

Vartak, Sameer Dinkar

1998-10-01

efficient delivery of this power to the screen. We describe a method based on optical rectification to create an electron acceleration process which can act simultaneously on a femtosecond photo-electron pulse as well as cancel space-charge effects. This method can be used to produce attosecond electron and photon pulses. Narrow linewidth high intensity tunable light pulses are very useful for applications such as spectroscopic studies and remote sensing. Tunable lasers and stimulated Raman scattering (SRS) process are commonly used for this purpose. SRS process has high threshold because of small spontaneous Raman scattering cross-sections. We combined amplified spontaneous emission (ASE) from dye molecules with SRS process in solvent molecules in which dye molecules are dissolved. ASE seeds SRS process and SRS peak is further amplified by stimulated emission gain. We got amplifications ~100 over SRS from pure solvent. This peak can be tuned over gain bandwidth of dye molecules.

Inclusive bit error rate analysis for coherent optical code-division multiple-access system

Science.gov (United States)

Katz, Gilad; Sadot, Dan

2002-06-01

Inclusive noise and bit error rate (BER) analysis for optical code-division multiplexing (OCDM) using coherence techniques is presented. The analysis contains crosstalk calculation of the mutual field variance for different number of users. It is shown that the crosstalk noise depends deeply on the receiver integration time, the laser coherence time, and the number of users. In addition, analytical results of the power fluctuation at the received channel due to the data modulation at the rejected channels are presented. The analysis also includes amplified spontaneous emission (ASE)-related noise effects of in-line amplifiers in a long-distance communication link.

Neutron-antineutron oscillation and baryonic majoron: low scale spontaneous baryon violation

Energy Technology Data Exchange (ETDEWEB)

Berezhiani, Zurab [Universita dell' Aquila, Dipartimento delle Scienze Fisiche e Chimiche, L' Aquila (Italy); INFN, Laboratori Nazionali Gran Sasso, L' Aquila (Italy)

2016-12-15

We discuss the possibility that baryon number B is spontaneously broken at low scales, of the order of MeV or even smaller, inducing the neutron-antineutron oscillation at the experimentally accessible level. An associated Goldstone particle-baryonic majoron can have observable effects in neutron to antineutron transitions in nuclei or dense nuclear matter. By extending baryon number to an anomaly-free B - L symmetry, the baryo-majoron can be identified with the ordinary majoron associated with the spontaneous breaking of lepton number, and it can have interesting implications for neutrinoless 2β decay with the majoron emission. We also discuss the hypothesis that baryon number can be spontaneously broken by QCD itself via the six-quark condensates. (orig.)

1998 NASA-ASEE-Stanford Summer Faculty Fellowship Program

Science.gov (United States)

1998-01-01

This report presents the essential features and highlights of the 1998 Summer Faculty Fellowship Program at Ames Research Center and Dryden Flight Research Center in a comprehensive and concise form. Summary reports describing the fellows' technical accomplishments are enclosed in the attached technical report. The proposal for the 1999 NASA-ASEE-Stanford Summer Faculty Fellowship Program is being submitted under separate cover. Of the 31 participating fellows, 27 were at Ames and 4 were at Dryden. The Program's central feature is the active participation by each fellow in one of the key technical activities currently under way at either the NASA Ames Research Center or the NASA Dryden Flight Research Center. The research topic is carefully chosen in advance to satisfy the criteria of: (1) importance to NASA, (2) high technical level, and (3) a good match to the interests, ability, and experience of the fellow, with the implied possibility of NASA-supported follow-on work at the fellow's home institution. Other features of the Summer Faculty Fellowship Program include participation by the fellows in workshops and seminars at Stanford, the Ames Research Center, and other off-site locations. These enrichment programs take place either directly or remotely, via the Stanford Center for Professional Development, and also involve specific interactions between fellows and Stanford faculty on technical and other academic subjects. A few, brief remarks are in order to summarize the fellows' opinions of the summer program. It is noteworthy that 90% of the fellows gave the NASA-Ames/Dryden- Stanford program an "excellent" rating and the remaining 10%, "good." Also, 100% would recommend the program to their colleagues as an effective means of furthering their professional development as teachers and researchers. Last, but not least, 87% of the fellows stated that a continuing research relationship with their NASA colleagues' organization probably would be maintained. Therefore

National Aeronautics and Space Administration (NASA)/American Society for Engineering Education (ASEE) Summer Faculty Fellowship Program, 1987, volume 2

Science.gov (United States)

Jones, William B., Jr. (Editor); Goldstein, Stanley H. (Editor)

1987-01-01

The 1987 Johnson Space Center (JCS) National Aeronautics and Space Administration (NASA)/American Society for Engineering Education (ASEE) Summer Faculty Fellowship program was conducted by Texas A and M University and JSC. The 10-week program was operated under the auspices of ASEE. The basic objectives of the program are: to further the professional knowledge of qualified engineering and science faculty members; to stimulate an exchange of ideas between participants and NASA; to enrich and refresh the research and teaching activities of participants' institutions; and to contribute to the research objective of the NASA Centers. This document is a compilation of the final reports on the research projects done by the faculty fellows during the summer of 1987.

Patient self-report section of the ASES questionnaire: a Spanish validation study using classical test theory and the Rasch model.

Science.gov (United States)

Vrotsou, Kalliopi; Cuéllar, Ricardo; Silió, Félix; Rodriguez, Miguel Ángel; Garay, Daniel; Busto, Gorka; Trancho, Ziortza; Escobar, Antonio

2016-10-18

The aim of the current study was to validate the self-report section of the American Shoulder and Elbow Surgeons questionnaire (ASES-p) into Spanish. Shoulder pathology patients were recruited and followed up to 6 months post treatment. The ASES-p, Constant, SF-36 and Barthel scales were filled-in pre and post treatment. Reliability was tested with Cronbach's alpha, convergent validity with Spearman's correlations coefficients. Confirmatory factor analysis (CFA) and the Rasch model were implemented for assessing structural validity and unidimensionality of the scale. Models with and without the pain item were considered. Responsiveness to change was explored via standardised effect sizes. Results were acceptable for both tested models. Cronbach's alpha was 0.91, total scale correlations with Constant and physical SF-36 dimensions were >0.50. Factor loadings for CFA were >0.40. The Rasch model confirmed unidimensionality of the scale, even though item 10 "do usual sport" was suggested as non-informative. Finally, patients with improved post treatment shoulder function and those receiving surgery had higher standardised effect sizes. The adapted Spanish ASES-p version is a valid and reliable tool for shoulder evaluation and its unidimensionality is supported by the data.

Fatores de risco clínicos e ultra-sonográficos relacionados à litíase vesicular assintomática em mulheres

Directory of Open Access Journals (Sweden)

Ferreira Adilson Cunha

2004-01-01

Full Text Available OBJETIVO: Analisar variáveis clínicas e ultra-sonográficas, como presença ou ausência de barro biliar, espessura da parede e medida transversal da vesícula biliar, idade, paridade, presença ou ausência de diabetes mellitus associadas a litíase vesicular assintomática, bem como determinar a sua prevalência em pacientes submetidas ao exame ultra-sonográfico. MATERAIS E MÉTODOS: Foram analisadas, em estudo prospectivo, 265 pacientes do sexo feminino, atendidas na Escola de Ultra-sonografia e Reciclagem Médica de Ribeirão Preto, durante o período de janeiro a setembro de 2001. RESULTADOS: Evidenciou-se diferença estatisticamente significativa relacionada à litíase da vesícula biliar e espessura da parede da vesícula biliar, barro biliar, diâmetro transverso da vesícula biliar, faixa etária, paridade, passando de 4,1% nas nulíparas para 39,1% nas multíparas e diabéticas. A prevalência de litíase na vesícula biliar em pacientes assintomáticas foi de 14,7%. CONCLUSÃO: A litíase vesicular assintomática em mulheres ocorre principalmente com o decorrer da idade e da paridade. Os achados ultra-sonográficos mais freqüentemente encontrados foram presença de barro biliar e de espessamento da parede da vesícula biliar.

Fatores associados à candidíase vulvovaginal: estudo exploratório

Directory of Open Access Journals (Sweden)

Rosa Maria Inês da

2004-01-01

Full Text Available OBJETIVO: avaliar fatores de risco para candidíase vulvovaginal identificados ao exame e anamnese ginecológica, em amostra de conveniência. MÉTODO: estudo transversal, com amostra de conveniência, envolvendo todas as trabalhadoras (135 de uma indústria de confecção em Criciúma (SC, sintomáticas e assintomáticas, no período de julho a setembro de 2002. Foi utilizada, como técnica de coleta dos dados, entrevista roteirizada investigando-se possíveis fatores de risco. O exame ginecológico detectou a presença ou não de sinais clínicos de vulvovaginites. Realizou-se cultura de secreção vaginal em meio de ágar Sabouraud para isolamento de Candida sp. Os dados foram processados e analisados no programa Epi-Info, versão 6.0. A medida de intensidade de associação usada foi a razão de prevalência. O intervalo de confiança adotado para inferência estatística foi de 95%. A análise multivariada dos dados foi realizada pelo programa SPSS versão 10.0, empregando-se modelo de regressão logística. RESULTADOS: os resultados mostraram que a prevalência da candidíase vulvovaginal foi de 19,3%. A freqüência de vulvovaginite diagnosticada pelo exame clínico foi de 17%, com sensibilidade de 38% e especificidade de 88%. O fator de risco significante para vulvovaginite por Candida nessa população foi a presença de ciclos menstruais regulares e para vulvovaginite clínica foi o uso de hormônios e idade entre 25 e 34 anos. CONCLUSÃO: a prevalência de candidíase vulvovaginal é alta entre mulheres consideradas hígidas e o fator de risco encontrado com significância estatística foi a presença de ciclos menstruais regulares, reforçando a importância de possível relação entre ciclo hormonal e esta infecção. Devido à limitação do presente estudo, esta possível associação, juntamente com outras, devem ser estudadas num futuro desenho de coorte com amostra de tamanho apropriado e medidas de níveis hormonais ao longo

Frequency shifts in spontaneous emission from two interacting atoms

International Nuclear Information System (INIS)

James, D.F.V.

1993-01-01

A model radiating system consisting of two atoms in close proximity is analyzed. This system demonstrates the influence of spatial coherence on the spectrum of the radiation field. Explicit expressions for the degree of coherence, the source spectrum, and the spectrum of the radiation field are derived. The results are discussed in terms of Wolf's work [Phys. Rev. Lett. 56, 1370 (1986)] on this effect, which can be considered in terms of a multiple-atom analog of the effects of radiation reaction on a single atom, i.e., spontaneous decay and the Lamb shift

Galvanic manifestation of spontaneous coherence in the negative glow

International Nuclear Information System (INIS)

Zhechev, D; Parvanova, N

2002-01-01

Both the magnetic depolarization of the spontaneous emission from self-aligned states and the discharge galvanic reaction are measured simultaneously in a magnetic field. The observed galvanic peak is ascribed to magnetic destruction of self-aligned ensembles of atoms. This presents galvanic manifestation of coherent conductivity. (letter to the editor)

Gain measurement in a CW medium-power diode pumped Nd:YAG laser amplifier by ASE analysis

International Nuclear Information System (INIS)

Razzaghi, D; Hajiesmaeilbaigi, F; Ruzbehani, M

2014-01-01

Using the relation between amplified spontaneous emission intensity and gain, a set of formulas is derived for gain evaluation by comparing fluorescence yield in two different lengths of the active medium. Experimental measurements are carried out and gain is calculated by solving the derived formula. For comparison, measurements are also carried out using the probe beam method, which shows good agreement between the two methods in a typical CW medium-power diode pumped Nd:YAG amplifier. (paper)

Aspectos epidemiológicos dateníase-cisticercose na área endêmica de Lagamar, MG

Directory of Open Access Journals (Sweden)

Mario León Silva-Vergara

1995-12-01

Full Text Available Um inquérito epidemiológico sobre teníase-cisticercose foi realizado em Lagamar- MG em 1992. Cadastradas 1109 casas com 3344 habitantes. O inquérito abrangeu 875 (86% famílias e foi respondido por um informante que, em 80% dos casos, foi o pai. Na cidade havia 100 chiqueiros em 100 (11,4% casas que albergavam 406 suínos, em condições extremamente precárias. Em 300 (34,2% casas havia o antecedente de teníase em algum membro da família. O antecedente de convulsão foi relatado por 125 (14,2% famílias. O início das convulsões na idade adulta foi caracterizado em 39 (3 7,8% famílias e o antecedente de doenças mentais foi relatado em 53 (6% casas. Os exames parasitológicos de fezes mostraram ovos de Taenia spp em 24 (1,3% das 1850 amostras examinadas.

Amiloidose e insuficiência renal crônica terminal associada à hanseníase Amyloidosis and end-stage renal disease associated with leprosy

Directory of Open Access Journals (Sweden)

Geraldo Bezerra da Silva Júnior

2010-08-01

Full Text Available O envolvimento renal na hanseníase é diverso, incluindo glomerulonefrites, amiloidose e nefrite túbulo-intersticial. Um homem de 58 anos foi admitido com edema de membros inferiores e dispnéia. Na admissão, havia retenção de escórias nitrogenadas, anemia, hipercalemia e acidose metabólica, com necessidade de hemodiálise. Referia história de hanseníase virchoviana. Foi realizada biopsia renal, compatível com amiloidose. O paciente evoluiu estável, sem recuperação da função renal, permanecendo em tratamento hemodialítico. A hanseníase deve ser investigada em todo paciente com perda de função renal, sobretudo naqueles que apresentam lesões cutâneas ou outras manifestações sugestivas de hanseníase.Renal involvement in leprosy includes glomerulonephritis, amyloidosis and tubulointerstitial nephritis. A 58-year-old man was admitted with complaints of lower limb edema and dyspnea. At admission, nitrogen retention, anemia, hyperkalemia and metabolic acidosis were observed, requiring hemodialysis. The patient had a history of lepromatous leprosy. A renal biopsy was performed that was compatible with amyloidosis. The patient had a stable outcome, but without renal function recovery and remained on regular hemodialysis. Leprosy should be investigated in every patient with renal function loss, particularly in those with cutaneous lesions or other manifestations suggestive of leprosy.

Emission and Dynamics of Charge Carriers in Uncoated and Organic/Metal Coated Semiconductor Nanowires

Science.gov (United States)

Kaveh Baghbadorani, Masoud

coating reveal a significant reduction of the PL intensity compared with the uncoated NWs. Organic-plasmonic NWs with an additional Alq3 interlayer show a noticeably stronger PL intensity which increases with rising Alq3 spacer thickness. Metal induced band bending is mainly attributed to be responsible for the PL quenching. TR PL measurements support our interpretation by showing an increase in the exciton decay times as we increase the spacer thickness. Au coated NWs also reveal a strong polarization dependent absorption which is mainly due to the significant dielectric mismatch between the nanowires and the adjacent vacuum environment. Finally, the amplified spontaneous emission (ASE) and possible plasmonic NW lasing from hybrid plasmonic core-shell GaAs NW heterostructures was investigated. The plasmonic heterostructures are composed of either bare NWs on an Au coated glass substrate or Au coated NWs on a bare glass substrate. Intensity-dependent PL on plasmonic NW samples reveals a super linear increase of the PL intensities which is attributed to an ASE at a threshold energy fluence of 1 GW/cm 2. Measurements above the threshold power reveal few weakly resolved broad bands around the maximum emission of the PL band which suggest plasmonic film induced lasing. This interpretation is supported by the fact that lasing from such 100 nm narrow uncoated GaAs NWs is not possible.

Gain flattened L-band EDFA based on upgraded C-band EDFA using forward ASE pumping in an EDF section

DEFF Research Database (Denmark)

Buxens Azcoaga, Alvaro Juan; Poulsen, Henrik Nørskov; Clausen, Anders

2000-01-01

A novel method is presented for implementing an L-band erbium doped fibre amplifier (EDFA) making use of forward amplified spontaneous emission pumping, from a commercially available c-band EDFA, in an erbium doped fibre. Tuning of the length of erbium doped fibre enables a flat gain characteristic...... to be obtained with a low noise figure over the entire L-band window....

Start-to-end simulation of self-amplified spontaneous emission free electron lasers from the gun through the undulator

CERN Document Server

Borland, M M; Emma, P; Lewellen, J W; Bharadwaj, V K; Fawley, W M; Krejcik, P; Limborg, C; Milton, S V; Nuhn, H D; Soliday, R; Woodley, M

2002-01-01

It is widely appreciated that the performance of self-amplified spontaneous emission free-electron lasers (FELs) depends critically on the properties of the drive beam. In view of this, a multi-laboratory collaboration has explored methods and software tools for integrated simulation of the photoinjector, linear accelerator, bunch compressor, and FEL. Rather than create a single code to handle such a system, our goal has been a robust, generic solution wherein pre-existing simulation codes are used sequentially. We have standardized on the use of Argonne National Laboratory's Self-Describing Data Sets file protocol for transfer of data among codes. The simulation codes used are PARMELA, elegant, and GENESIS. We describe the software methodology and its advantages, then provide examples involving Argonne's Low-Energy Undulator Test Line and Stanford Linear Accelerator Center's Linac Coherent Light Source. We also indicate possible future direction of this work.

Lead-free solder technology transfer from ASE Americas

Energy Technology Data Exchange (ETDEWEB)

FTHENAKIS,V.

1999-10-19

To safeguard the environmental friendliness of photovoltaics, the PV industry follows a proactive, long-term environmental strategy involving a life-of-cycle approach to prevent environmental damage by its processes and products from cradle to grave. Part of this strategy is to examine substituting lead-based solder on PV modules with other solder alloys. Lead is a toxic metal that, if ingested, can damage the brain, nervous system, liver and kidneys. Lead from solder in electronic products has been found to leach out from municipal waste landfills and municipal incinerator ash was found to be high in lead also because of disposed consumer electronics and batteries. Consequently, there is a movement in Europe and Japan to ban lead altogether from use in electronic products and to restrict the movement across geographical boundaries of waste containing lead. Photovoltaic modules may contain small amounts of regulated materials, which vary from one technology to another. Environmental regulations impact the cost and complexity of dealing with end-of-life PV modules. If they were classified as hazardous according to Federal or State criteria, then special requirements for material handling, disposal, record-keeping and reporting would escalate the cost of decommissioning the modules. Fthenakis showed that several of today's x-Si modules failed the US-EPA Toxicity Characteristic Leaching Procedure (TCLP) for potential leaching of Pb in landfills and also California's standard on Total Threshold Limit Concentration (TTLC) for Pb. Consequently, such modules may be classified as hazardous waste. He highlighted potential legislation in Europe and Japan which could ban or restrict the use of lead and the efforts of the printed-circuit industries in developing Pb-free solder technologies in response to such expected legislation. Japanese firms already have introduced electronic products with Pb-free solder, and one PV manufacturer in the US, ASE Americas has used a

Edema na hanseníase: aspectos clínicos e terapêuticos

OpenAIRE

Valentini,Attilio; Nery,José A.C.; Salles,Ana Maria; Vieira,Leila M.M.; Sarno,Euzenir N.

1999-01-01

Durante o curso da hanseníase, o edema comumente descrito como um sintoma de estados reacionais, pode ocorrer. Tanto o diagnóstico como a terapêutica adequada são, freqüentemente, difíceis de conseguir e assim podem acarretar permanente dano aos membros inferiores. Em um ano de acompanhamento, pacientes hansenianos - 10 multibacilares e 1 paucibacilar -, que foram submetidos a um protocolo clínico para o diagnóstico e classificação histopatológica, apresentaram clinicamente edema, localizado ...

Do static atoms outside a Schwarzschild black hole spontaneously excite?

International Nuclear Information System (INIS)

Yu Hongwei; Zhou Wenting

2007-01-01

The spontaneous excitation of a two-level atom held static outside a four dimensional Schwarzschild black hole and in interaction with a massless scalar field in the Boulware, Unruh, and Hartle-Hawking vacuums is investigated, and the contributions of the vacuum fluctuations and radiation reaction to the rate of change of the mean atomic energy are calculated separately. We find that, for the Boulware vacuum, the spontaneous excitation does not occur and the ground-state atoms are stable, while the spontaneous emission rate for excited atoms in the Boulware vacuum, which is well behaved at the event horizon, is not the same as that in the usual Minkowski vacuum. However, for both the Unruh vacuum and the Hartle-Hawking vacuum, our results show that the atom would spontaneously excite, as if there were an outgoing thermal flux of radiation or as if it were in a thermal bath of radiation at a proper temperature which reduces to the Hawking temperature in the spatial asymptotic region, depending on whether the scalar field is in the Unruh or Hartle-Hawking vacuum

Top-Down Cognitive and Linguistic Influences on the Suppression of Spontaneous Otoacoustic Emissions

Directory of Open Access Journals (Sweden)

Viorica Marian

2018-06-01

Full Text Available Auditory sensation is often thought of as a bottom-up process, yet the brain exerts top-down control to affect how and what we hear. We report the discovery that the magnitude of top-down influence varies across individuals as a result of differences in linguistic background and executive function. Participants were 32 normal-hearing individuals (23 female varying in language background (11 English monolinguals, 10 Korean-English late bilinguals, and 11 Korean-English early bilinguals, as well as cognitive abilities (working memory, cognitive control. To assess efferent control over inner ear function, participants were presented with speech-sounds (e.g., /ba/, /pa/ in one ear while spontaneous otoacoustic emissions (SOAEs were measured in the contralateral ear. SOAEs are associated with the amplification of sound in the cochlea, and can be used as an index of top-down efferent activity. Individuals with bilingual experience and those with better cognitive control experienced larger reductions in the amplitude of SOAEs in response to speech stimuli, likely as a result of greater efferent suppression of amplification in the cochlea. This suppression may aid in the critical task of speech perception by minimizing the disruptive effects of noise. In contrast, individuals with better working memory exert less control over the cochlea, possibly due to a greater capacity to process complex stimuli at later stages. These findings demonstrate that even peripheral mechanics of auditory perception are shaped by top-down cognitive and linguistic influences.

Towards shorter wavelength x-ray lasers using a high power, short pulse pump laser

International Nuclear Information System (INIS)

Tighe, W.; Krushelnick, K.; Valeo, E.; Suckewer, S.

1991-05-01

A near-terawatt, KrF* laser system, focussable to power densities >10 18 W/cm 2 has been constructed for use as a pump laser in various schemes aimed at the development of x-ray lasing below 5nm. The laser system along with output characteristics such as the pulse duration, the focal spot size, and the percentage of amplified spontaneous emission (ASE) emitted along with the laser pulse will be presented. Schemes intended to lead to shorter wavelength x-ray emission will be described. The resultant requirements on the pump laser characteristics and the target design will be outlined. Results from recent solid target experiments and two-laser experiments, showing the interaction of a high-power, short pulse laser with a preformed plasma, will be presented. 13 refs., 5 figs

National Aeronautics and Space Administration (NASA)/American Society for Engineering Education (ASEE) Summer Faculty Fellowship Program, 1989, volume 2

Science.gov (United States)

Jones, William B., Jr. (Editor); Goldstein, Stanley H. (Editor)

1989-01-01

The 1989 Johnson Space Center (JSC) National Aeronautics and Space Administration (NASA)/American Society for Engineering Education (ASEE) Summer Faculty Fellowship Program was conducted by Texas A and M University and JSC. The 10-week program was operated under the auspices of the ASEE. The program at JSC, as well as the programs at other NASA Centers, was funded by the Office of University Affairs, NASA Headquarters, Washington, D.C. The objectives of the program, which began nationally in 1964 and at JSC in 1965, are: (1) to further the professional knowledge of qualified engineering and science faculty members; (2) to stimulate an exchange of ideas between participants and NASA; (3) to enrich and refresh the research and teaching activities of participants' institutions; and (4) to contribute to the research objective of the NASA Centers.

National Aeronautics and Space Administration (NASA)/American Society for Engineering Education (ASEE) Summer Faculty Fellowship Program 1988, volume 2

Science.gov (United States)

Bannerot, Richard B.; Goldstein, Stanley H.

1989-01-01

The 1988 Johnson Space Center (JSC) National Aeronautics and Space Administration (NASA)/American Society for Engineering Education (ASEE) Summer Faculty Fellowship Program was conducted by the University of Houston and JCS. The 10-week program was operated under the auspices of the ASEE. The program at JSC, as well as the programs at other NASA Centers, was funded by the Office of University Affairs, NASA Headquarters, Washington, D.C. The objectives of the program, which began in 1965 at JSC and in 1964 nationally, are: (1) to further the professional knowledge of qualified engineering and science faculty members; (2) to stimulate an exchange of ideas between participants and NASA; (3) to enrich and refresh the research and teaching activities of participants' institutions; and (4) to contribute to the research objectives of the NASA Centers.

National Aeronautics and Space Administration (NASA)/American Society for Engineering Education (ASEE) Summer Faculty Fellowship Program, 1998. Volume 1

Science.gov (United States)

Bannerot, Richard B. (Editor); Sickorez, Donn G. (Editor)

1999-01-01

JSC NASA/ASEE Summer Faculty Fellowship Program was conducted by the University of Houston and JSC, under ASEE. The objectives of the program are to further the professional knowledge of qualified engineering and science members; stimulate an exchange of ideas between participants and NASA; enrich and refresh the research and teaching activities of participants; and contribute to the research objectives of the NASA Centers. Each faculty fellow spent at least 10 weeks at JSC engaged in a research project commensurate with his/her interests and background and worked in collaboration with a NASA/JSC colleague. This document is a compilation of the final reports on the fellows' research projects performed during the summer of 1998. Volume 1, current volume, contains the first reports, and volume 2 contains the remaining reports.

National Aeronautics and Space Administration (NASA)/American Society for Engineering Education (ASEE) Summer Faculty Fellowship Program, 1989, volume 1

Science.gov (United States)

Jones, William B., Jr. (Editor); Goldstein, Stanley H. (Editor)

1989-01-01

The 1989 Johnson Space Center (JSC) National Aeronautics and Space Administration (NASA)/American Society for Engineering Education (ASEE) Summer Faculty Fellowship Program was conducted by Texas A and M University and JSC. The 10-week program was operated under the auspices of the ASEE. The program at JSC, as well as the programs at other NASA Centers, was funded by the Office of University Affairs, NASA Headquarters, Washington, D.C. The objectives of the program, which began nationally in 1964 and at JSC in 1965, are: (1) to further the professional knowledge of qualified engineering and science faculty members; (2) to stimulate an exchange of ideas between participants and NASA; (3) to enrich and refresh the research and teaching activities of participants' institutions; and (4) to contribute to the research objective of the NASA Centers.

National Aeronautics and Space Administration (NASA)/American Society for Engineering Education (ASEE) Summer Faculty Fellowship Program 1988, volume 1

Science.gov (United States)

Bannerot, Richard B. (Editor); Goldstein, Stanley H. (Editor)

1989-01-01

The 1988 Johnson Space Center (JSC) National Aeronautics and Space Administration (NASA)/American Society for Engineering Education (ASEE) Summer Faculty Fellowship Program was conducted by the University of Houston and JSC. The 10-week program was operated under the auspices of the ASEE. The program at JSC, as well as the programs at other NASA Centers, was funded by the Office of University Affairs, NASA Headquarters, Washington, D.C. The objectives of the program, which began in 1965 at JSC and in 1964 nationally, are (1) to further the professional knowledge of qualified engineering and science faculty members; (2) to stimulate an exchange of ideas between participants and NASA; (3) to enrich and refresh the research and teaching activities of participants' institutions; and (4) to contribute to the research objectives of the NASA Centers.

Edema na hanseníase: aspectos clínicos e terapêuticos

Directory of Open Access Journals (Sweden)

Valentini Attilio

1999-01-01

Full Text Available Durante o curso da hanseníase, o edema comumente descrito como um sintoma de estados reacionais, pode ocorrer. Tanto o diagnóstico como a terapêutica adequada são, freqüentemente, difíceis de conseguir e assim podem acarretar permanente dano aos membros inferiores. Em um ano de acompanhamento, pacientes hansenianos - 10 multibacilares e 1 paucibacilar -, que foram submetidos a um protocolo clínico para o diagnóstico e classificação histopatológica, apresentaram clinicamente edema, localizado ou sistêmico. Entre estes pacientes, cinco apresentaram simultaneamente outros sintomas de reação, 4 foram classificados como reação Tipo I e um como reação tipo II. Por outro lado, três pacientes não apresentaram reação no momento do diagnóstico, mas desenvolveram alguns aspectos de reação posteriormente (2 tiveram neurite e um teve reação tipo I. Os edemas observados precedendo ou associados a quadros reacionais apresentaram ótima resposta clínica às drogas de ação anti-inflamatória (corticóide, talidomida e pentoxifilina utilizadas para o tratamento dos estados reacionais, na ausência de qualquer outro tratamento normalmente usado para edema. Embora necessitem ser confirmados por estudos controlados, estes dados sugerem fortemente que mecanismos imunológicos estejam envolvidos na fisiopatologia dos edemas na hanseníase.

Spontaneous radiation of a chiral molecule located near a half-space of a bi-isotropic material

Science.gov (United States)

Guzatov, D. V.; Klimov, V. V.; Poprukailo, N. S.

2013-04-01

Analytical expressions for the rate of spontaneous emission from a chiral (optically active) molecule located near a half-space occupied by a chiral (bi-isotropic) material have been obtained and analyzed in detail. It is established that the rates of spontaneous emission from the "right" and "left" enantiomers of molecules occurring near the chiral medium may significantly differ in cases of chiral materials with (i) both negative dielectric permittivity and magnetic permeability (DNG metamaterial) and (ii) negative permeability and positive permittivity (MNG metamaterial). Based on this phenomenon, DMG and MNG metamaterials can be used to create devices capable of separating right and left enantiomers in racemic mixtures.

Spontaneous radiation of a chiral molecule located near a half-space of a bi-isotropic material

Energy Technology Data Exchange (ETDEWEB)

Guzatov, D. V., E-mail: vklimov@sci.lebedev.ru [Yanka Kupala Grodno State University (Belarus); Klimov, V. V., E-mail: klimov256@gmail.com [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation); Poprukailo, N. S. [Yanka Kupala Grodno State University (Belarus)

2013-04-15

Analytical expressions for the rate of spontaneous emission from a chiral (optically active) molecule located near a half-space occupied by a chiral (bi-isotropic) material have been obtained and analyzed in detail. It is established that the rates of spontaneous emission from the 'right' and 'left' enantiomers of molecules occurring near the chiral medium may significantly differ in cases of chiral materials with (i) both negative dielectric permittivity and magnetic permeability (DNG metamaterial) and (ii) negative permeability and positive permittivity (MNG metamaterial). Based on this phenomenon, DMG and MNG metamaterials can be used to create devices capable of separating right and left enantiomers in racemic mixtures.

Spontaneous radiation of a chiral molecule located near a half-space of a bi-isotropic material

International Nuclear Information System (INIS)

Guzatov, D. V.; Klimov, V. V.; Poprukailo, N. S.

2013-01-01

Analytical expressions for the rate of spontaneous emission from a chiral (optically active) molecule located near a half-space occupied by a chiral (bi-isotropic) material have been obtained and analyzed in detail. It is established that the rates of spontaneous emission from the “right” and “left” enantiomers of molecules occurring near the chiral medium may significantly differ in cases of chiral materials with (i) both negative dielectric permittivity and magnetic permeability (DNG metamaterial) and (ii) negative permeability and positive permittivity (MNG metamaterial). Based on this phenomenon, DMG and MNG metamaterials can be used to create devices capable of separating right and left enantiomers in racemic mixtures.

WE-G-204-05: Relative Object Detectability Evaluation of a New High Resolution A-Se Direct Detection System Compared to Indirect Micro-Angiographic Fluoroscopic (MAF) Detectors

International Nuclear Information System (INIS)

Russ, M; Nagesh, S Setlur; Ionita, C; Bednarek, D; Rudin, S; Scott, C; Karim, K

2015-01-01

Purpose: To evaluate the task specific imaging performance of a new 25µm pixel pitch, 1000µm thick amorphous selenium direct detection system with CMOS readout for typical angiographic exposure parameters using the relative object detectability (ROD) metric. Methods: The ROD metric uses a simulated object function weighted at each spatial frequency by the detectors’ detective quantum efficiency (DQE), which is an intrinsic performance metric. For this study, the simulated objects were aluminum spheres of varying diameter (0.05–0.6mm). The weighted object function is then integrated over the full range of detectable frequencies inherent to each detector, and a ratio is taken of the resulting value for two detectors. The DQE for the 25µm detector was obtained from a simulation of a proposed a-Se detector using an exposure of 200µR for a 50keV x-ray beam. This a-Se detector was compared to two microangiographic fluoroscope (MAF) detectors [the MAF-CCD with pixel size of 35µm and Nyquist frequency of 14.2 cycles/mm and the MAF-CMOS with pixel size of 75µm and Nyquist frequency of 6.6 cycles/mm] and a standard flat-panel detector (FPD with pixel size of 194µm and Nyquist frequency of 2.5cycles/mm). Results: ROD calculations indicated vastly superior performance by the a-Se detector in imaging small aluminum spheres. For the 50µm diameter sphere, the ROD values for the a-Se detector compared to the MAF-CCD, the MAF-CMOS, and the FPD were 7.3, 9.3 and 58, respectively. Detector performance in the low frequency regime was dictated by each detector’s DQE(0) value. Conclusion: The a-Se with CMOS readout is unique and appears to have distinctive advantages of incomparable high resolution, low noise, no readout lag, and expandable design. The a-Se direct detection system will be a powerful imaging tool in angiography, with potential break-through applications in diagnosis and treatment of neuro-vascular disease. Supported by NIH Grant: 2R01EB002873 and an

WE-G-204-05: Relative Object Detectability Evaluation of a New High Resolution A-Se Direct Detection System Compared to Indirect Micro-Angiographic Fluoroscopic (MAF) Detectors

Energy Technology Data Exchange (ETDEWEB)

Russ, M; Nagesh, S Setlur; Ionita, C; Bednarek, D; Rudin, S [Toshiba Stroke and Vascular Research Center, University at Buffalo (SUNY), Buffalo, NY (United States); Scott, C; Karim, K [University of Waterloo, Waterloo, ON (Canada)

2015-06-15

Purpose: To evaluate the task specific imaging performance of a new 25µm pixel pitch, 1000µm thick amorphous selenium direct detection system with CMOS readout for typical angiographic exposure parameters using the relative object detectability (ROD) metric. Methods: The ROD metric uses a simulated object function weighted at each spatial frequency by the detectors’ detective quantum efficiency (DQE), which is an intrinsic performance metric. For this study, the simulated objects were aluminum spheres of varying diameter (0.05–0.6mm). The weighted object function is then integrated over the full range of detectable frequencies inherent to each detector, and a ratio is taken of the resulting value for two detectors. The DQE for the 25µm detector was obtained from a simulation of a proposed a-Se detector using an exposure of 200µR for a 50keV x-ray beam. This a-Se detector was compared to two microangiographic fluoroscope (MAF) detectors [the MAF-CCD with pixel size of 35µm and Nyquist frequency of 14.2 cycles/mm and the MAF-CMOS with pixel size of 75µm and Nyquist frequency of 6.6 cycles/mm] and a standard flat-panel detector (FPD with pixel size of 194µm and Nyquist frequency of 2.5cycles/mm). Results: ROD calculations indicated vastly superior performance by the a-Se detector in imaging small aluminum spheres. For the 50µm diameter sphere, the ROD values for the a-Se detector compared to the MAF-CCD, the MAF-CMOS, and the FPD were 7.3, 9.3 and 58, respectively. Detector performance in the low frequency regime was dictated by each detector’s DQE(0) value. Conclusion: The a-Se with CMOS readout is unique and appears to have distinctive advantages of incomparable high resolution, low noise, no readout lag, and expandable design. The a-Se direct detection system will be a powerful imaging tool in angiography, with potential break-through applications in diagnosis and treatment of neuro-vascular disease. Supported by NIH Grant: 2R01EB002873 and an

Prepulse and amplified spontaneous emission effects on the interaction of a petawatt class laser with thin solid targets

Energy Technology Data Exchange (ETDEWEB)

Esirkepov, Timur Zh. [QuBS, Japan Atomic Energy Agency, Kizugawa, Kyoto 619-0215 (Japan); Koga, James K., E-mail: koga.james@jaea.go.jp [QuBS, Japan Atomic Energy Agency, Kizugawa, Kyoto 619-0215 (Japan); Sunahara, Atsushi [Institute for Laser Technology, 2-6 Yamadaoka Suita, Osaka 565-0871 (Japan); Morita, Toshimasa; Nishikino, Masaharu [QuBS, Japan Atomic Energy Agency, Kizugawa, Kyoto 619-0215 (Japan); Kageyama, Kei [Graduate School of Engineering, Osaka University, Osaka 565-0871 (Japan); Nagatomo, Hideo; Nishihara, Katsunobu [Institute of Laser Engineering, 2-6 Yamadaoka Suita, Osaka 565-0871 (Japan); Sagisaka, Akito; Kotaki, Hideyuki; Nakamura, Tatsufumi; Fukuda, Yuji; Okada, Hajime; Pirozhkov, Alexander S.; Yogo, Akifumi; Nishiuchi, Mamiko; Kiriyama, Hiromitsu; Kondo, Kiminori; Kando, Masaki [QuBS, Japan Atomic Energy Agency, Kizugawa, Kyoto 619-0215 (Japan); Bulanov, Sergei V. [QuBS, Japan Atomic Energy Agency, Kizugawa, Kyoto 619-0215 (Japan); A.M. Prokhorov Institute of General Physics of RAS, Vavilova st. 38, Moscow 117942 (Russian Federation); Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region 141700 (Russian Federation)

2014-05-01

When a finite contrast petawatt laser pulse irradiates a micron-thick foil, a prepulse (including amplified spontaneous emission) creates a preplasma, where an ultrashort relativistically strong portion of the laser pulse (the main pulse) acquires higher intensity due to relativistic self-focusing and undergoes fast depletion transferring energy to fast electrons. If the preplasma thickness is optimal, the main pulse can reach the target accelerating fast ions more efficiently than an ideal, infinite contrast, laser pulse. A simple analytical model of a target with preplasma formation is developed and the radiation pressure dominant acceleration of ions in this target is predicted. The preplasma formation by a nanosecond prepulse is analyzed with dissipative hydrodynamic simulations. The main pulse interaction with the preplasma is studied with multi-parametric particle-in-cell simulations. The optimal conditions for hundreds of MeV ion acceleration are found with accompanying effects important for diagnostics, including high-order harmonics generation.

A Study of Coherent Radiation Generated in an Ablative Capillary Discharge

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Jakub Hübner

2013-01-01

Full Text Available Feasible soft-X-ray amplification in the CVI and NVII Balmer transition is investigated in a capillary discharge. The best conditions and parameters for the experimental set-up are found for an ablative capillary. The most optimistic results have shown that the gain would be greater than one, which is the condition for successful ASE (Amplified spontaneous emission in capillary discharges. The capillary discharge evolution is modeled using the NPINCH program, employing a one-dimensional physical model based on MHD equations. The information about the capillary discharge evolution is processed in the FLY, FLYPAPER, FLYSPEC programs, enabling the population to be modeled on specific levels during capillary discharge.

Wavelength interrogation of fiber Bragg grating sensors using tapered hollow Bragg waveguides.

Science.gov (United States)

Potts, C; Allen, T W; Azar, A; Melnyk, A; Dennison, C R; DeCorby, R G

2014-10-15

We describe an integrated system for wavelength interrogation, which uses tapered hollow Bragg waveguides coupled to an image sensor. Spectral shifts are extracted from the wavelength dependence of the light radiated at mode cutoff. Wavelength shifts as small as ~10  pm were resolved by employing a simple peak detection algorithm. Si/SiO₂-based cladding mirrors enable a potential operational range of several hundred nanometers in the 1550 nm wavelength region for a taper length of ~1  mm. Interrogation of a strain-tuned grating was accomplished using a broadband amplified spontaneous emission (ASE) source, and potential for single-chip interrogation of multiplexed sensor arrays is demonstrated.

Design of application specific long period waveguide grating filters using adaptive particle swarm optimization algorithms

International Nuclear Information System (INIS)

Semwal, Girish; Rastogi, Vipul

2014-01-01

We present design optimization of wavelength filters based on long period waveguide gratings (LPWGs) using the adaptive particle swarm optimization (APSO) technique. We demonstrate optimization of the LPWG parameters for single-band, wide-band and dual-band rejection filters for testing the convergence of APSO algorithms. After convergence tests on the algorithms, the optimization technique has been implemented to design more complicated application specific filters such as erbium doped fiber amplifier (EDFA) amplified spontaneous emission (ASE) flattening, erbium doped waveguide amplifier (EDWA) gain flattening and pre-defined broadband rejection filters. The technique is useful for designing and optimizing the parameters of LPWGs to achieve complicated application specific spectra. (paper)

Hiperparatiroidismo primário em idade pediátrica: uma causa rara de litíase renal

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Ana Teresa Soares

2017-07-01

Conclusão: O hiperparatiroidismo primário deve ser considerado no diagnóstico diferencial de litíase renal, de forma a permitir uma intervenção precoce determinante na prevenção de lesão de órgão-alvo.

Attempt to enrich of a new spontaneous fissioning nuclide by evaporation of natural brine

International Nuclear Information System (INIS)

Adamek, A.; Zhuravleva, E.L.; Constantinescu, M.; Constantinescu, o.; Chuburkov, Yu.T.

1983-01-01

The enrichment of the new spontaneous fissioning nuclide discovered in the Cheleken brine, was made by evaporation. The purpose of this work was the comparison of behaviour of the new spontaneous fissioning nuclide with that of the known elements in the formation processes of the high concentration brines. Spontaneous fission of the nuclide was measured by means of the counters for multiple emission of neutrons. It is shown that the new spontaneous fissioning nuclide was enriched as well as other trace elements (Hg, Tl, Bi and Pb) in a solution remained after the evaporation of the initial solution. The conclusion is drawn that from the sea water brines could be obtained by evaporation which are enriched in trace elements with an enrichment degree higher than the natural brines

Eletrólise com radiofrequência no tratamento da triquíase Treatment of trichiasis with high-frequency radio wave electrosurgery

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Rodrigo Beraldi Kormann

2007-03-01

Full Text Available OBJETIVOS: Triquíase é uma condição adquirida dos cílios, que perdem o direcionamento normal e tocam a superfície ocular. O tratamento da triquíase tem sido um problema terapêutico. Apesar das várias modalidades de tratamento: epilação mecânica, eletrólise com bipolar, crioterapia, fotocoagulação com laser de argônio e procedimentos cirúrgicos, a recidiva da triquíase é comum. Com o objetivo de encontrar técnica próxima ao ideal, realizamos estudo utilizando eletrólise com aparelho de radiofreqüência, avaliando-se a efetividade da técnica. MÉTODOS: Foram estudados, prospectivamente, 34 pacientes (54 segmentos palpebrais com triquíase, submetidos à eletrólise com aparelho de radiofreqüência. Reavaliaram-se os pacientes em oito semanas, quanto à cura, recidiva e possíveis complicações. RESULTADOS: Observou-se a cura da triquíase com apenas uma única sessão de eletrólise com radiofreqüência em 22 pacientes e com duas ou mais sessões em 12 pacientes. CONCLUSÃO: A eletrólise com aparelho de radiofreqüência é método simples, de baixo custo, que não demanda experiência do cirurgião, com ausência de complicações relevantes e com alto índice de sucesso.PURPOSE: Trichiasis is an acquired condition in which the eyelashes are directed posteriorly, touching the surface of the cornea. It poses a complex therapeutic problem. Despite several therapeutic options (epilation, electroepilation, cryotherapy, laser ablation and standard surgical techniques, relapse is frequent. METHODS: A prospective, nonmasked study was conducted to determine the efficacy of high-frequency radioelectrosurgery for treatment of trichiasis. Thirty-four patients (fifty-four eyelid segments were treated with this technique. After eight weeks, all patients were reviewed regarding the success rate, relapse and complications. RESULTS: Cure was achieved after only one session of treatment in twenty-two patients, and two or more sessions

Spontaneous mutation by mutagenic repair of spontaneous lesions in DNA

International Nuclear Information System (INIS)

Hastings, P.J.; Quah, S.-K.; Borstel, R.C. von

1976-01-01

It is stated that strains of yeast carrying mutations in many of the steps in pathways repairing radiation-induced damage to DNA have enhanced spontaneous mutation rates. Most strains isolated because they have enhanced spontaneous mutation carry mutations in DNA repair systems. This suggests that much spontaneous mutation arises by mutagenic repair of spontaneous lesions. (author)

Growth and characterization of ZnCdMgSe-based green light emitters and distributed Bragg reflectors towards II-VI based semiconductor disk lasers

International Nuclear Information System (INIS)

De Jesus, Joel; Gayen, Swapan K.; Garcia, Thor A.; Tamargo, Maria C.; Kartazaev, Vladimir; Jones, Brynmor E.; Schlosser, Peter J.; Hastie, Jennifer E.

2015-01-01

We report the structural and optical properties of molecular beam epitaxy grown II-VI semiconductor multiple quantum well (MQW) structures and distributed Bragg reflector (DBR) on InP substrates for application in developing optically-pumped semiconductor disk lasers (SDLs) operating in the green spectral range. One sample was grown directly on an InP substrate with an InGaAs buffer layer, while another had a 5-period ZnCdMgSe-based DBR grown on the InGaAs/InP substrate. X-ray diffraction and scanning electron microscopy measurements revealed sharp superlattice peaks and abrupt layer interfaces, while steady-state photoluminescence measurements demonstrated surface emission between 540-570 nm. Under pulsed excitation both samples exhibited features of amplified spontaneous emission (ASE) or stimulated emission, accompanied by luminescence lifetime shortening. The sample with the DBR showed higher surface luminescence and the onset of ASE at lower pump power. To further explore the design and performance of a ZnCdMgSe-based DBR, a 20-period DBR was grown and a reflectivity of 83% was obtained at ∝560 nm. We estimate that a DBR with ∝40 periods would be needed for optimal performance in a SDL using these materials. These results show the potential of II-VI MQW structures on InP substrates for the development of SDLs operational in the green-yellow wavelength range. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Effect of metallic and hyperbolic metamaterial surface on electric and magnetic dipole emission

DEFF Research Database (Denmark)

Ni, Xingjie; Naik, Gururaj V.; Kildishev, Alexander V.

2010-01-01

Spontaneous emission patterns of electric and magnetic dipoles on different material surfaces were studied numerically and experimentally. The results show the modified behavior of electric and magnetic dipoles on metallic and HMM surfaces.......Spontaneous emission patterns of electric and magnetic dipoles on different material surfaces were studied numerically and experimentally. The results show the modified behavior of electric and magnetic dipoles on metallic and HMM surfaces....

Transmission performance of a 400 Gbit s−1 all-optical orthogonal frequency division multiplexing system

International Nuclear Information System (INIS)

Tang, Jing; Xia, Min; Li, Wei; Yang, Kecheng; Liu, Deming; Huang, Benxiong

2013-01-01

The performance of a 400 Gbit s −1 all-optical orthogonal frequency division multiplexing (AO-OFDM) transmission system is researched with the effects of chromatic dispersion, fiber nonlinearities and amplified spontaneous emission (ASE) noise. The numerical simulation results show that the AO-OFDM system can provide a higher spectral efficiency (SE) and a better sensitivity than a dense wavelength division multiplexing (DWDM) system. The accumulated dispersion tolerance of the system reaches 330 ps nm −1 . When transmitted over single-span 80 km single-mode fiber (SMF), AO-OFDM signals have a 1.5 dB power penalty at BER=10 −3 due to the fiber Kerr nonlinearities, and the receiver sensitivity of the AO-OFDM system is obviously degraded with increasing incident optical power. In multispan transmission, the interaction of the fiber Kerr nonlinearity with the ASE noise is analyzed. A 1320 km maximum transmission distance is realized at 0 dBm incident optical power. The transmission discount due to the ASE noise and fiber nonlinearities in the AO-OFDM system is calculated. Fiber Kerr nonlinearities impose a greater limitation on the performance of the AO-OFDM system for long-distance transmission. All results clearly indicate the feasibility of AO-OFDM technology for next generation 400 Gbit s −1 fiber communication and multiservice networks. (paper)

The Recombination Mechanism and True Green Amplified Spontaneous Emission in CH3NH3PbBr3 Perovskite

KAUST Repository

Priante, Davide

2015-08-01

True-green wavelength emitters at 555 nm are currently dominated by III-V semiconductor-based inorganic materials. Nevertheless, due to high lattice- and thermal-mismatch, the overall power efficiency in this range tends to decline for high current density showing the so-called efficiency droop in the green region (“green gap”). In order to fill the research green gap, this thesis examines the low cost solution-processability of organometal halide perovskites, which presents a unique opportunity for light-emitting devices in the green-yellow region owing to their superior photophysic properties such as high photoluminescence quantum efficiency, small capture cross section of defect states as well as optical bandgap tunability across the visible light regime. Specifically, the mechanisms of radiative recombination in a CH3NH3PbBr3 hybrid perovskite material were investigated using low-temperature, power-dependent (77 K), temperature-dependent photoluminescence (PL) measurements. We noted three recombination peaks at 77K, one of which originated from bulk defect states, and other two from surface defect states. The latter were identified as bound-excitonic (BE) radiative transitions related to particle size inhomogeneity or grain size induced surface state in the sample. Both transitions led to PL spectra broadening as a result of concurrent blue- and red-shifts of these excitonic peaks. The blue-shift is most likely due to the Burstein-Moss (band filling) effect. Interestingly, the red-shift of the second excitonic peak becomes pronounced with increasing temperature leading to a true-green wavelength of 553 nm for CH3NH3PbBr3. On the other hand, red-shifted peak originates from the strong absorption in the second excitonic peak owed to the high density of surface states and carrier filling of these states due to the excitation from the first excitonic recombination. We also achieved amplified spontaneous emission around excitation threshold energy of 350 μJ/cm2

National Aeronautics and Space Administration (NASA)/American Society of Engineering Education (ASEE) Summer Faculty Fellowship Program - 2000

Science.gov (United States)

Bannerot, Richard B. (Editor); Sickorez, Donn G. (Editor)

2003-01-01

The 2000 Johnson Space Center (JSC) National Aeronautics and Space Administration (NASA)/American Society for Engineering Education (ASEE) Summer Faculty Fellowship Program was conducted by the University of Houston and JSC. The 10-week program was operated under the auspices of the ASEE. The program at JSC, as well as the programs at other NASA Centers, was funded by the Office of University Affairs, NASA Headquarters, Washington, D.C. The objectives of the program, which began in 1965 at JSC and 1964 nationally, are to (1) further the professional knowledge of qualified engineering and science faculty, (2) stimulate an exchange of ideas between participants and NASA, (3) enrich and refresh the research and teaching activities of participants' institutions, and (4) contribute to the research objectives of the NASA Centers. Each faculty fellow spent at least 10 weeks at JSC engaged in a research project commensurate with her/his interests and background, and worked in collabroation with a NASA/JSC colleague. This document is a compilation of the final reports on the research projects done by the faculty fellows during the summer of 2000.

Candidíase em pacientes aidéticos

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C.E.O.P. Campos

1992-09-01

Full Text Available Trinta e cinco aidéticos entre 19 e 55 anos admitidos e tratados de candidíase no Hospital Emílio Ribas, SP, com ELISA positivo para HIV e confirmado pelo Western Blot. Tuberculose em 9 sendo 2 com pericardite; neurotoxoplasmose em 6; neurocriptococose em 5; herpes labial em 4; pneumocistose em 3 e sarcoma de Kaposi em 2, achavam-se associadas. A concentração inibitória mínima 50% (MIC 50% para os azoles foi: ketoconazol= 2,2 µg/ml; itraconazol- 21,0 µg/ml; fluconazol = 19,0 µg/ml. O MIC 50% para ospolienos: nistatina- 50,0 µg/ml; anfotericina B= 0,12 µg/ml e para 5 fluorcitosina= 1,6 µg/ml nas 35 amostras de Candida isoladas. Testes não paramétricos de Siegel revelaram significante identificação (80% das Candida albicans na candidíase, e que a dose de AMB não modificou o número de óbitos, precoce e tardio, ocorridos nesses aidéticos. O uso prévio dos azoles e da nistatina explicaria, talvez, o elevado MIC 50% observado nas amostras de Candida isoladas.A total of 35 in patients admitted at Emilio Ribas Hospital - São Paulo, Brazil, with digestive candidiasis and AIDS clinical diagnostic were evaluated 10 month later, being 29 male and 6 female; white outnumbering black with age ranged from 30 to 50 years old. Agar Sabouraud culture and tube germinative tests identified 28 (80% Candida albicans out 35 strains. Minimum inhibitory concentration (MIC 50% was against azoles (ketoconazole= 2.2 µg/ml; itraconazole = 21.0 µg/ml and fluconazole- 19.0 µg/ml; polyenes (ny statine - 50.0 µg/ml and amphotericin B= 0.12 µg/ml and 5 fluorcytosine= 1.6µg/ml. Siegeltests showed significant Candida albicans proportions in strains isolated from 35 AIDS patients. There was no significant relation between AMB dosis and early or late death. Conclusions: candidiasis in AIDS patients showed high MIC 50% to azoles and nystatine and significant Candida albicans proportion in all strains isolated from AIDS patients. Previous amphotericin B

Spontaneous and light-induced photon emission from intact brains of chick embryos

Institute of Scientific and Technical Information of China (English)

张锦珠; 于文斗; 孙彤

1997-01-01

Photon emission (PE) and light-induced photon emission(LPE) of intact brains isolated from chick embryos have been measured by using the single photon counting device. Experimental results showed that the intensi-ty level of photon emission was detected to be higher from intact brain than from the medium in which the brain was immerged during measuring, and the emission intensity was related to the developmental stages, the healthy situation of the measured embryos, and the freshness of isolated brains as well. After white light illumination, a short-life de-layed emission from intact brains was observed, and its relaxation behavior followed a hyperbolic rather than an expo-nential law. According to the hypothesis of biophoton emission originating from a delocalized coherent electromagnetic field and Frohlich’s idea of coherent long-range interactions in biological systems, discussions were made on the signifi-cance of photon emission in studying cell communication, biological regulation, living system’

KETIDAKSEIMBANGAN HAK DAN KEWAJIBAN ANTARA INVESTOR ASING DENGAN PEKERJA INDONESIA DALAM PENGATURAN PENANAMAN MODAL DAN KETENAGAKERJAAN

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Mrs. Sulistyowati

2015-10-01

Full Text Available This research purports to identify and find the form of imparity on the rights and obligations of the foreign investors and Indonesian workers in Indonesian regulations of investment law. The imparity is shown in: (idiscrepancies in minimum wage among employee working in foreign investment and domestic investment;(ii rights and obligations; as well as (iii legal culture which perceives Indonesian employee as one ofthe production factors. Such imparity, however, are not without purpose. It is aimed to complete verticalharmonization to avoid overlapping regulations. Nonetheless, the author finds this imparity still bringmore favour to the foreign investors. Penelitian ini ditujukan untuk mengidentifikasi dan menemukan bentuk-bentuk ketidakseimbangan hak dan kewajiban antara penanam modal asing dan pekerja Indonesia dalam peraturan perundang-undanganmengenai penanaman modal. Ketidakseimbangan tampak pada: (i upah minimum yang sama terhadappekerja Indonesia baik yang bekerja di PMA maupun PMDN; (ii hak dan kewajiban; serta (iii budayahukum yang menganggap pekerja Indonesia sebagai salah satu faktor produksi yang sama halnya denganfaktor produksi lainnya. Ketidakseimbangan ini bukanlah tanpa tujuan. Ketidakseimbangan yang adaditujukan untuk menciptakan harmonisasi vertikal dalam rangka menghindari kebijakan yang tumpangtindih. Hanya saja, penulis berpendapat bahwa ketidakseimbangan ini masih lebih menguntungkanpenanam modal asing.

Perfil clínico-epidemiológico da hanseníase em menores de 15 anos no município de Juazeiro-BA

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Igara Cavalcanti Feitosa Luna

2013-06-01

Full Text Available Objetivo: Descrever o perfil epidemiológico e clínico dos casos novos de hanseníase em menores de 15 anos notificados à Secretaria Municipal de Saúde (SMS de Juazeiro-BA, no período de 2001 a 2010. Métodos: Trata-se de um estudo quantitativo, de natureza exploratória e descritiva, realizado a partir da análise dos dados contidos no Sistema de Informação de Agravos de Notificação (SINAN municipal. Resultados: Os resultados mostraram que145 (7,94% casos novos de hanseníase ocorreram em menores de 15 anos. Verificaram-se taxas de detecção altas para essa faixa etária, com predominância no sexo feminino (n=81; 55,86% e maior acometimento na faixa etária entre 10 e 14 anos (n=85; 58,62%. As formas paucibacilares (n=107; 74,48% da doença predominaram sobre as formas multibacilares (n=37; 25,52%, sendo a forma clínica tuberculoide (n=80; 55,17% a mais prevalente. As incapacidades atingiram 18 (12,41% dos pacientes avaliados no diagnóstico e 15 (10,34% na alta. Uma grande parte de casos (n=58; 40,07% deixou de ser avaliada ou foi ignorada. Conclusão: O perfil epidemiológico e clínico da ocorrência de casos novos de hanseníase no município de Juazeiro-BA evidenciou que os coeficientes de detecção geral de hanseníase e em menores de 15 anos se mantiveram em nível hiperendêmico no período avaliado.

Hanseníase e vulnerabilidade social: uma análise do perfil socioeconômico de usuários em tratamento irregular

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Viviane Aparecida Siqueira Lopes

Full Text Available Este artigo analisa a determinação social da hanseníase, a partir do reconhecimento da vulnerabilidade social dos usuários em tratamento irregular, no Programa de Controle da Hanseníase do município de Campos dos Goytacazes (RJ. Para isso, apresenta uma pesquisa documental, com base nas Fichas de Cadastro Social dos usuários mencionados, destacando aspectos como trabalho, renda, formação familiar e acesso a políticas públicas. Seus resultados registram significativa presença de trabalho precarizado associado a baixos níveis de renda e de escolaridade, sendo a maioria considerada pobre ou indigente (51,5% e não usuária de benefícios assistenciais (66,7%.

Hanseníase: a realidade do ser adolescente Lepra: la realidad para el adolescente Leprosy: the reality for the adolescent

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Keila Maria de Azevedo Ponte

2005-06-01

Full Text Available A hanseníase é uma doença contagiosa, estigmatizante, de grande potencial incapacitante, e os adolescentes por estarem numa fase de mudanças e de adaptação, esta doença pode interferir na construção de sua vida. O estudo objetiva caracterizar os adolescentes portadores de hanseníase segundo aspectos sócio-demograficos; realizar análise epidemiológico-operacional da hanseníase; verificar o conhecimento dos adolescentes sobre a hanseníase e as reações manifestadas pelos mesmos após sua descoberta; Identificar as mudanças ocorridas após a doença na vida do adolescente e as dificuldades vivenciadas pelo mesmo após a da doença. Trata-se de uma pesquisa exploratória e descritiva, constituída de 31 adolescentes portadores de hanseníase, assistido pela Estratégia Saúde da Família no Município de Sobral- Ceará. Os resultados sinalizam a necessidade de uma assistência integral e continuada ao adolescente portador de hanseníase, evitando que essa doença provoque mudanças significativas em sua vida, dificultando na construção de sua nova identidade.La lepra es una enfermedad contagiosa, de un gran potencial incapacitante y los adolescentes por estaren viviendo en una fase de cambios e adaptación esta enfermedad puede interferir en la construcción de sus vidas. Esta investigación apunta caracterizar los adolescentes portadores de lepra según aspectos sociales-demográficos; hacer un análisis epidémico-operacional de la enfermedad lepra; verificar el conocimiento de los adolescentes sobre la lepra y las relaciones manifestadas por los mismos después de su descubierta; identificar los cambios ocurridos en la vida del adolescente después de la descubierta de la enfermedad. Tratase de una investigación exploratoria y descriptiva donde participarón 31 adolescentes portadores de lepra ayudados por la Estrategia Salud de la Familia en el municipio de Sobral - Ceará. Los resultados señalan la necesidad de una

Optical, photo-physical properties and photostability of pyrromethene (PM-597) in ionic liquids as benign green-solvents

International Nuclear Information System (INIS)

AL-Aqmar, Dalal M.; Abdelkader, H.I.; Abou Kana, Maram T.H.

2015-01-01

Laser dye pyrromethene-597 was dissolved with different concentrations in three types of ionic liquids (ILs): 1-Butyl-3-methylimidazolium chloride (BMIM Cl), 1-butyl-3-methylimidazolium tetrachloroaluminate (BMIM AlCl 4 ) and 1-butyl-3-methylimidazolium tetrafluoro-borate (BMIM BF 4 ) in addition to ethanol as reference solvent. This paper investigates optical spectra and some photo-physical parameters of PM-597 in BMIM Cl, BMIM AlCl 4 , BMIM BF 4 and ethanol. These parameters are absorption and emission cross sections, fluorescence lifetime and quantum yield. The amplified spontaneous emission (ASE) was studied using the second harmonic Nd-YAG laser of 532 nm. Also, the gain and energy conversion efficiencies were investigated. Relatively high efficiency was obtained with good photostability in case of PM-597 in BMIM BF 4 that was a decrease to ~90% of the initial amplified spontaneous emission. This output energy was observed after pumping by 75,000 shots at a relatively high repetition rate of 10 Hz and pumping energy of 37 mJ. The composition and properties of the matrix of ILs were found to lead to optimize the laser performance and photostability of the investigated laser dye. In this study, we considered ionic liquids as the environmentally benign green solvents in place of volatile toxic organic solvents. - Highlights: • Pyrromethen-597 as laser dye was dissolved in three types of ionic liquids (ILs): BMIM Cl, BMIM AlCl 4 and BMIM BF 4 as benign green-solvent in addition to ethanol as reference solvent. • Important spectroscopic properties of PM-597 dye such as quantum yield, fluorescence lifetime, radiative and nonradiative rate, transition dipole moment, attenuation length and oscillator strength were affected by changing the host material. • The dye laser gain, quantum yield, peak intensity of ASE and photostability were found to be better in BMIM BF 4 than in BMIM Cl and in ethanol. • ILs may be used as ideal hosts for dye laser systems to

Ensaio terapêutico com «mebendazole suspensão» nas helmintíases intestinais em crianças

Directory of Open Access Journals (Sweden)

Donald Huggins

1975-06-01

Full Text Available O Autor medicou 24 crianças portadoras de poliverminoses, com idades entre 8 a 14 anos, todas do sexo feminino, com Mebendazole (suspensão, na dose de 5 ml (100 mg duas vezes por dia e durante três dias consecutives. O diagnóstico e o controle de cura parasitológica foram realizados pelas técnicas de Lutz, Willis, Baerman-Moraes e Graham, antes e no 7.°, 14.° e 21.° dias após o tratamento para as três primeiras, enquanto a última foi executada durante sete dias consecutivos a partir do sétimo dia de encerrada a terapêutica. Verificou cura parasitológica em 100% dos casos para ascariase e enterobiase, 69,2% para tricocefalíase, 36,36% para ancilostomíase e 0% para estrongiloidiase. Nenhuma manifestação colateral foi relatada pelos doentes.

DR (a-Se) versus CR (DLR) - is an improvement of the accuracy possible? A retrospective histologic analysis (n=100)

International Nuclear Information System (INIS)

Schulz-Wendtland, R.; Lell, M.; Wenkel, E.; Boehner, C.; Dassel, M.S.; Bautz, W.

2007-01-01

Purpose: A retrospective clinical-histological study to determine the diagnostic accuracy using high-resolution digital phosphor storage plates (CR) (hardcopy) and full-field digital mammography (DR) (hardcopy) for microcalcifications and focal lesions (BI-RADS category 4 or 5) (n=100). Materials and Methods: From 01/2004 to 06/2004, 100 patients underwent digital storage plate mammography (CR) and, after diagnosis and preoperative wire localization, full-field digital mammography (a-Se) (DR) with the same exposure parameters. Five investigators retrospectively determined the diagnosis after the operation from randomly distributed mediolateral views (hardcopy reading). These results were correlated with the final histology. Results: The accuracy of digital storage plate mammography (CR) and full-field digital mammography (DR) was 73% and 76% for all findings (n=100), 74%, 78% for microcalcifications (n=50) and 72%, 74% for focal lesions (n=50). The overall results showed no difference. Conclusion: Our findings indicate equivalence of high-resolution digital phosphor storage plate mammography (CR) and full-field digital mammography (a-Se) (DR). (orig.)

Fast iterative technique for the calculation of frequency dependent gain in excimer laser amplifiers

International Nuclear Information System (INIS)

Sze, R.C.

1991-01-01

The motivation in initiating these calculations is to allow us to observe the frequency evolution of a laser pulse as it propagates through an amplifier and then through a sequence of amplifiers. The question we seek to answer is what pulse shape do we need to produce out of a front-end oscillator so that after it propagates through the whole Aurora KrF fusion amplifier chain will result in high energy, broad-band laser fields of a given bandwidth that can be focussed onto a fusion target. The propagation of a single frequency source through an amplifier with distributed loss was considered by Rigrod and was significantly expanded by Hunter and Hunter. The latter included amplified spontaneous emission [ASE] considerations both in the direction of and transverse to the coherent field. Analytic solutions that include forward and backward prapagating fields and ASE were derived which were transcendental in nature but allowed for fairly easy computer calculations. Transverse ASE were calculated using the unsaturated gain resulting from longitudinal fields and were used to compare this with the longitudinal field equations. Large computer programs are now available at LANL which include the influence of transverse ASE on the longitudinal fields. However, none of these considerations have worried about the changes in the frequency characteristics of the propagating field or of how each of the frequency field components contributes to the saturation of the gain. The inclusion of full frequency characteristics to the analytic solutions of Hunter and Hunter proved impossible at least for this author and a new calculational technique was developed and is the subject of this talk

Towards spontaneous parametric down-conversion at low temperatures

Directory of Open Access Journals (Sweden)

Akatiev Dmitrii

2017-01-01

Full Text Available The possibility of observing spontaneous parametric down-conversion in doped nonlinear crystals at low temperatures, which would be useful for combining heralded single-photon sources and quantum memories, is studied theoretically. The ordinary refractive index of a lithium niobate crystal doped with magnesium oxide LiNbO3:MgO is measured at liquid nitrogen and helium temperatures. On the basis of the experimental data, the coefficients of the Sellmeier equation are determined for the temperatures from 5 to 300 K. In addition, a poling period of the nonlinear crystal has been calculated for observing type-0 spontaneous parametric down-conversion (ooo-synchronism at the liquid helium temperature under pumping at the wavelength of λp = 532 nm and emission of the signal field at the wavelength of λs = 794 nm, which corresponds to the resonant absorption line of Tm3+ doped ions.

Detecção de emissão espontânea de luz em ensaios de colimetria aplicados ao monitoramento de efluentes sanitários Spontaneous light emission in coliforms test applied to wastewater monitoring

Directory of Open Access Journals (Sweden)

Samuel Ricardo dos Santos

2011-03-01

Full Text Available No presente trabalho avaliou-se o potencial do emprego da técnica biofotônica ao monitoramento da qualidade microbiológica de efluentes sanitários, por meio da detecção de emissão ultrafraca de luz em testes envolvendo bactéria do grupo coliforme. Foram acompanhados os padrões de emissão de luz em câmara escura com o uso de efluente doméstico, antes e após tratamento, incubados em meio nutritivo à base de lactose e lauril triptose. O controle foi efetuado com o uso de cepa de Escherichia coli (ATCC 25.922, tendo seu crescimento sido monitorado por emissão de luz em câmara escura com fotomultiplicador acoplado. Os dados demonstraram que o monitoramento microbiológico pode ser efetuado por meio técnica biofotônica, podendo ser aplicado, com respostas rápidas, ao monitoramento microbiológico de efluentes, por meio de testes envolvendo coliformes.The spontaneous light emission of living systems emerge as a promising methodology that applied to microbiological in monitoring water can lead to short-term analysis. The present study evaluated the potential of biophoton measurements applied to wastewater monitoring by using ultraweak light emission in coliform tests. The procedure is based on photon-counting measurements inside a dark-chamber, of wastewater samples, before and after treatment, inoculated in nutrient presence/absence medium (lactose and lauryl triptose broth. Strain of Escherichia coli (ATCC 25,922 was used in control tests by monitoring the light emission inside a dark-chamber with an acoplade photomultiplier. The data showed that microbiological monitoring can be done by photon-counting in real-time applied to microbiological wastewater monitoring using coliform test.

Study of a high and low pressure plasma produced in a He-N2 mixture: application to spontaneous emissions by radiative collisions

International Nuclear Information System (INIS)

Marcum, S.D.

1983-01-01

This thesis is centered on the study of the energy transfer from helium metastable atoms to ground state nitrogen molecules by the process of radiative collisions. Experimental techniques employed include the analysis of spontaneous emission from the reaction: He(2 3 S)+N 2 (X,v=0) → He(1 1 S)+(N 2 sup(R)(B,v'=4,5) → N 2 sup(R)(X,v'')+hω), where R indicates highly excited nitrogen Rydberg states. As the lower level Rydberg states are autoionizing, the net effect of the radiative collision is identical that of Penning ionization where the Rydberg to states are intermediates. The results of this study lend support to the validity of a radiative collision based laser amplifier model proposed in the thesis [fr

Gaseous emissions from coal stockpiles

Energy Technology Data Exchange (ETDEWEB)

NONE

2013-01-15

Stockpiled coal undergoes atmospheric oxidation and desorption processes during open air storage. These processes release gases to the environment which may effect health and safety by their toxicity and flammability. In extreme cases, this could lead to a fire. This report discusses gaseous emissions from coal stockpiles. It covers gas emission mechanisms, and gas sampling and testing methods, before examining in more detail the principal gases that have been emitted. It concludes that there is limited research in this area and more data are needed to evaluate the risks of gaseous emissions. Some methods used to prevent coal self-heating and spontaneous combustion can be applied to reduce emissions from coal stockpiles.

Estudo da microcirculação na hanseníase virchowiana com o uso da microscopia de luz ortogonal polarizada e com laser-doppler fluxometria

OpenAIRE

Curt Mafra Treu

2010-01-01

A hanseníase é uma doença infecciosa com características únicas, dentre elas o fato de atingir intensamente a inervação da pele e seus anexos. Entremeando estes anexos, está a microcirculação cutânea, que a principio também tem sua inervação comprometida. Vários artigos apontam para alterações de disautonomia microcirculatória, citando como exemplo as alterações no reflexo vasomotor. O presente estudo se propõe a avaliar a microcirculação cutânea na hanseníase virchowiana, tanto em sua morfol...

Mensuração do ângulo articular do cotovelo no teste de tensão neural em indivíduos com hanseníase

OpenAIRE

Scheibe,Débora; Oliveira,Jaqueline Francieli Pacheco de; Gonçalves,Sibelly Blum; Gomes,Anna Raquel Silveira; Macedo,Ana Carolina Brandt de

2012-01-01

A hanseníase é uma patologia crônica e granulomatosa, que atinge a pele e o sistema nervoso periférico pela invasão no sistema imune do Mycobacterium leprae. O objetivo deste estudo foi mensurar o ângulo articular do cotovelo com a aplicação do teste de tensão neural do nervo ulnar em pacientes com hanseníase. Na aplicação do teste de tensão neural, foram utilizadas a goniometria e a fotometria para a mensuração do ângulo articular do cotovelo, sendo que para a realização da fotometria foi ut...

O papel da ictioterapia no tratamento da psoríase: relato de caso

OpenAIRE

Cabral, Helena; Carneiro, Joana

2014-01-01

Introdução: A psoríase é uma das dermatoses mais frequentes, afetando entre 1 a 3% da população portuguesa. Apresenta uma evolução crónica, com lesões que podem atingir grande parte da superfície corporal. Devido à frequente exuberância das lesões, a doença é muitas vezes percebida como estigmatizante pelo indivíduo que se sente envergonhado e rejeitado pelo outro. Pode apresentar impacto significativo nas relações sociais, na autoimagem e na autoestima. Atualmente, o tratamento consiste em r...

Does Spontaneous Favorability to Power (vs. Universalism) Values Predict Spontaneous Prejudice and Discrimination?

Science.gov (United States)

Souchon, Nicolas; Maio, Gregory R; Hanel, Paul H P; Bardin, Brigitte

2017-10-01

We conducted five studies testing whether an implicit measure of favorability toward power over universalism values predicts spontaneous prejudice and discrimination. Studies 1 (N = 192) and 2 (N = 86) examined correlations between spontaneous favorability toward power (vs. universalism) values, achievement (vs. benevolence) values, and a spontaneous measure of prejudice toward ethnic minorities. Study 3 (N = 159) tested whether conditioning participants to associate power values with positive adjectives and universalism values with negative adjectives (or inversely) affects spontaneous prejudice. Study 4 (N = 95) tested whether decision bias toward female handball players could be predicted by spontaneous attitude toward power (vs. universalism) values. Study 5 (N = 123) examined correlations between spontaneous attitude toward power (vs. universalism) values, spontaneous importance toward power (vs. universalism) values, and spontaneous prejudice toward Black African people. Spontaneous positivity toward power (vs. universalism) values was associated with spontaneous negativity toward minorities and predicted gender bias in a decision task, whereas the explicit measures did not. These results indicate that the implicit assessment of evaluative responses attached to human values helps to model value-attitude-behavior relations. © 2016 The Authors. Journal of Personality Published by Wiley Periodicals, Inc.

Crystallization kinetics of a-Se, part 4: thin films

Science.gov (United States)

Svoboda, Roman; Gutwirth, Jan; Málek, Jiří

2014-09-01

Differential scanning calorimetry was used to study the crystallization behaviour of selenium thin films in dependence on film thickness and deposition rate. In the current work, which is the fourth in a sequence of articles dealing with crystallization kinetics of a-Se, the non-isothermal crystallization kinetics was described in terms of the Johnson-Mehl-Avrami nucleation-growth model. Two-dimensional crystallite growth, consistent with the idea of sterically restricted crystallization in a thin layer, was confirmed for all data. It was found that neither the film thickness (tested within the 100-2350 nm range) nor the deposition rate appears to have any significant influence on the crystallization kinetics. However, the higher amount of intrinsic defects possibly produced by a higher deposition rate seems to accelerate the crystallization, shifting it towards lower temperatures. Very good correlation between the results obtained for thin films and those for fine powders was found. Based on the obtained results, interpretations of relevant literature data were made.

Study of organic light emitting devices (OLEDs) with optimal emission efficiency

Energy Technology Data Exchange (ETDEWEB)

Singh, Jai [School of Engineering and IT, B-purple 12, Faculty of EHS, Charles Darwin University, Darwin, NT 0909 (Australia)

2010-04-15

The external emission efficiency of organic light emitting devices (OLEDs) is analysed by studying the rate of spontaneous emission of both singlet and triplet excitons and their corresponding radiative lifetimes. Rates of spontaneous emissions are calculated from the first order perturbation theory using the newly discovered time-dependent spin-orbit-exciton-photon interaction operator as the perturbation operator. It is clearly shown how the new interaction operator is responsible for attracting triplet excitons to a phosphor (heavy metal atom) and then it flips the spins to a singlet configuration. Thus, the spin forbidden transition becomes spin allowed. Calculated rates agree with the experimental results qualitatively. Results are of general interests for OLED studies. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Ulceração das placas psoriáticas - efeito cutâneo adverso do metotrexato em altas doses no tratamento da psoríase: relato de três casos

Directory of Open Access Journals (Sweden)

Ataíde Deborah Skusa de Torre

2003-01-01

Full Text Available Os autores relatam três casos de pacientes portadores de psoríase que utilizaram inadvertidamente doses elevadas de metotrexato e apresentaram ulceração das lesões cutâneas de psoríase. Os efeitos adversos cutâneos do metotrexato são raros, algumas vezes dose-dependentes, outras idiossincrásicos ou relacionados com alteração de metabolização da droga, ou, ainda, interações medicamentosas

Sources of spontaneous emission based on indium arsenide

International Nuclear Information System (INIS)

Zotova, N. V.; Il'inskaya, N. D.; Karandashev, S. A.; Matveev, B. A.; Remennyi, M. A.; Stus', N. M.

2008-01-01

The results obtained for light-emitting diodes based on heterostructures that contain InAs in the active region and are grown by the methods of liquid-phase, molecular-beam, and vapor-phase epitaxy from organometallic compounds are reviewed. The emission intensity, the near-field patterns, and the light-current and current-voltage characteristics of light-emitting diodes that have flip-chip structure or feature a point contact are analyzed.

Sources of spontaneous emission based on indium arsenide

Energy Technology Data Exchange (ETDEWEB)

Zotova, N V; Il' inskaya, N D; Karandashev, S A; Matveev, B. A., E-mail: bmat@iropt3.ioffe.rssi.ru; Remennyi, M A; Stus' , N M [Russian Academy of Sciences, Ioffe Physicotechnical Institute (Russian Federation)

2008-06-15

The results obtained for light-emitting diodes based on heterostructures that contain InAs in the active region and are grown by the methods of liquid-phase, molecular-beam, and vapor-phase epitaxy from organometallic compounds are reviewed. The emission intensity, the near-field patterns, and the light-current and current-voltage characteristics of light-emitting diodes that have flip-chip structure or feature a point contact are analyzed.

Psoríase em paciente HIV positivo

Directory of Open Access Journals (Sweden)

Mario León Silva-Vergara

1996-12-01

Full Text Available Dois pacientes com síndrome de imunodeficiência adquirida (SIDA desenvolveram psoríase, um com quadro mais grave e outro com apresentação mais benigna, sendo tratados com zidovudine na dose oral de 200mg a cada oito horas. No primeiro caso, a resposta terapêutica foi completa e, após nove meses em esquema de manutenção, o paciente se apresenta sem nenhuma lesão. No segundo, a despeito de resposta evidente, após seis meses de tratamento, o paciente ainda apresenta descamação furfurãcea a nível dos membros inferiores, mesmo em uso de medicação.Two patients with the acquired immunodeficiency syndrome (AIDS developed psoriasis, one of them presenting the more severe form and the other one the milder form of the disease, were treated with zidovudine per oral via, 200mg 3 times a day. In the first case the therapeutical response was complete. No lesion was verified in the patient after 9 months under maintenance schedule. In the second case, despite the response being clear, after 6 months of treatment, the patient still presented furfuraceous scalings at limbs even under the medication schedule.

The recombination mechanisms leading to amplified spontaneous emission at the true-green wavelength in CH3NH3PbBr3 perovskites

Science.gov (United States)

Priante, D.; Dursun, I.; Alias, M. S.; Shi, D.; Melnikov, V. A.; Ng, T. K.; Mohammed, O. F.; Bakr, O. M.; Ooi, B. S.

2015-02-01

We investigated the mechanisms of radiative recombination in a CH3NH3PbBr3 hybrid perovskite material using low-temperature, power-dependent (77 K), and temperature-dependent photoluminescence (PL) measurements. Two bound-excitonic radiative transitions related to grain size inhomogeneity were identified. Both transitions led to PL spectra broadening as a result of concurrent blue and red shifts of these excitonic peaks. The red-shifted bound-excitonic peak dominated at high PL excitation led to a true-green wavelength of 553 nm for CH3NH3PbBr3 powders that are encapsulated in polydimethylsiloxane. Amplified spontaneous emission was eventually achieved for an excitation threshold energy of approximately 350 μJ/cm2. Our results provide a platform for potential extension towards a true-green light-emitting device for solid-state lighting and display applications.

The recombination mechanisms leading to amplified spontaneous emission at the true-green wavelength in CH3NH3PbBr3 perovskites

KAUST Repository

Priante, Davide

2015-02-23

We investigated the mechanisms of radiative recombination in a CH3NH3PbBr3 hybrid perovskite material using low-temperature, power-dependent (77K), and temperature-dependent photoluminescence (PL) measurements. Two bound-excitonic radiative transitions related to grain size inhomogeneity were identified. Both transitions led to PL spectra broadening as a result of concurrent blue and red shifts of these excitonic peaks. The red-shifted bound-excitonic peak dominated at high PL excitation led to a true-green wavelength of 553nm for CH3NH3PbBr3 powders that are encapsulated in polydimethylsiloxane. Amplified spontaneous emission was eventually achieved for an excitation threshold energy of approximately 350μJ/cm2. Our results provide a platform for potential extension towards a true-green light-emitting device for solid-state lighting and display applications.

Absorption and emission properties of photonic crystals and metamaterials

International Nuclear Information System (INIS)

Peng, Lili

2007-01-01

We study the emission and absorption properties of photonic crystals and metamaterials using Comsol Multiphysics and Ansoft HFSS as simulation tools. We calculate the emission properties of metallic designs using drude model and the results illustrate that an appropriate termination of the surface of the metallic structure can significantly increase the absorption and therefore the thermal emissivity. We investigate the spontaneous emission rate modifications that occur for emitters inside two-dimensional photonic crystals and find the isotropic and directional emissions with respect to different frequencies as we have expected.

A ação educativa do enfermeiro educador na estratégia Saúde da Família ao portador de hanseníase

OpenAIRE

Alberici, Priscila de Souza; UNIABEU; Jóia, Thalita; UNIABEU; Moreira, Leandro Arantes; UNIABEU

2011-01-01

Introdução: O enfermeiro na Estratégia Saúde da Família como educador, objetivando a promoção da saúde e a prevenção da doença. Problemática: Seria a falta de conhecimento/comprometimento do profissional de saúde em relação à gravidade da doença o motivo pelo qual o Brasil não erradicar a hanseníase? Objetivo: Refletir sobre a ação educativa do enfermeiro na ESF ao portador de hanseníase. Metodologia: Estudo descritivo e exploratório, método de abordagem qualitativa. A revisão bibliográfica s...

Avaliação da frequência do polimorfismo nos genes que codificam a lecitina ligadora da manose (MBL) e o antagonista do receptor da interleucina-1 (IL1-Ra) em mulheres portadoras de candidíase vulvovaginal recorrente

OpenAIRE

Maria Dulce Caoro Horie Wojitani

2011-01-01

A candidíase vulvovaginal corresponde a uma das mais frequentes infecções do trato reprodutivo. Estima-se que 75% das mulheres na idade reprodutiva experimentarão pelo menos um episódio de candidíase vulvovaginal durante suas vidas, a maioria evoluirá com episódios infrequentes, entretanto, 5% sofrerão recorrência, ou seja, quatro ou mais episódios de candidíase vulvovaginal comprovadas clínica e laboratorialmente no período de 1ano. Os mecanismos pelos quais as recorrências ocorrem ainda são...

Quantum-dot nano-cavity lasers with Purcell-enhanced stimulated emission

DEFF Research Database (Denmark)

Gregersen, Niels; Skovgård, Troels Suhr; Lorke, Michael

2012-01-01

We present a rate equation model for quantum-dot light-emitting devices that take into account Purcell enhancement of both spontaneous emission and stimulated emission as well as the spectral profile of the optical and electronic density-of-states. We find that below threshold the b-factor in a q...

Correlated spins of complementary fragment pairs in the spontaneous fission of 252Cf

International Nuclear Information System (INIS)

Smith, A. G.; Simpson, G. S.; Billowes, J.; Dagnall, P. J.; Durell, J. L.; Freeman, S. J.; Leddy, M.; Phillips, W. R.; Roach, A. A.; Smith, J. F.

1999-01-01

A study of the γ-ray decay of low-lying excited states in fragments produced in the spontaneous fission of 252 Cf has revealed a significant correlation between the angles of emission of the 2 1 + →0 1 + transitions of complementary fragment pairs. Calculations of the amount of dealignment that is needed to reproduce the measured a 2 values, and a comparison with the results of previous fragment-γ angular distribution measurements, suggests that at scission there may be significant population of m≠0 substates associated with the projection of the fragment spin vector on the fission axis. Fragments from the spontaneous fission of 248 Cm emit 2 1 + →0 1 + γ rays that show markedly reduced interfragment correlations, suggesting that either a larger role is played by the relative angular momentum of the fragments, or that the dealignment introduced by the neutron emission and statistical γ decay to the 2 1 + state is larger in 248 Cm than 252 Cf fission. (c) 1999 The American Physical Society

ASE extraction method for simultaneous carbon and nitrogen stable isotope analysis in soft tissues of aquatic organisms

International Nuclear Information System (INIS)

Bodin, Nathalie; Budzinski, Helene; Le Menach, Karyn; Tapie, Nathalie

2009-01-01

Since lipids are depleted in 13 C relative to proteins and carbohydrates, variations in lipid composition among species and within individuals significantly influence δ 13 C and may result in misleading ecological interpretations. Whereas lipid extraction before IRMS analysis constitutes a way of stable isotope result lipid-normalisation, such a procedure was given up because of the un-controlled effects of the methods used (i.e., 'Bligh and Dyer', Soxhlet, etc.) on δ 15 N. The aim of this work was to develop a simple, rapid and efficient lipid extraction method allowing for simultaneous C and N stable isotope analysis in the biological soft tissues of aquatic organisms. The goal was to be free from the lipid influence on δ 13 C values without interfering with δ 15 N values. For that purpose, the modern automated pressurized liquid extraction technique ASE (accelerated solvent extraction) was selected. Eel muscles representative of a broad range of fat contents were extracted via ASE by using different semi-polar solvents (100% dichloromethane and 80% n-hexane/20% acetone) and by operating at different temperature (ambient temperature and 100 deg. C) and pressure (750 and 1900 psi) conditions. The results were discussed in terms of lipid extraction efficiency as well as δ 13 C and δ 15 N variability.

Sorologia da hanseníase utilizando PGL-I: revisão sistemática

OpenAIRE

Moura,Rodrigo Scaliante de; Calado,Karla Lucena; Oliveira,Maria Leide W.; Bührer-Sékula,Samira

2008-01-01

A sorologia utilizando o antígeno espécie-específico do Mycobacterium leprae, PGL-I, pode ser um marcador de carga bacteriana em pacientes com hanseníase. Estudos identificaram potencial de uso da sorologia na classificação de pacientes para fins de tratamento, monitoramento de terapia, risco de recidiva e na seleção dos contatos com maior risco de adoecer. Foi realizada uma revisão sistemática e 26 artigos foram incluídos na análise comparativa. Avaliamos os resultados do uso da sorologia PG...

Spontaneous excitation of a static multilevel atom coupled with electromagnetic vacuum fluctuations in Schwarzschild spacetime

International Nuclear Information System (INIS)

Zhou Wenting; Yu Hongwei

2012-01-01

We study the spontaneous excitation of a radially polarized static multilevel atom outside a spherically symmetric black hole in multipolar interaction with quantum electromagnetic fluctuations in the Boulware, Unruh and Hartle-Hawking vacuum states. We find that spontaneous excitation does not occur in the Boulware vacuum, and, in contrast to the scalar field case, the spontaneous emission rate is not well behaved at the event horizon as a result of the blow-up of the proper acceleration of the static atom. However, spontaneous excitation can take place both in the Unruh and the Hartle-Hawking vacua as if there were thermal radiation from the black hole. Distinctive features in contrast to the scalar field case are the existence of a term proportional to the proper acceleration squared in the rate of change of the mean atomic energy in the Unruh and the Hartle-Hawking vacua and the structural similarity in the spontaneous excitation rate between the static atoms outside a black hole and uniformly accelerated ones in a flat space with a reflecting boundary, which is particularly dramatic at the event horizon where a complete equivalence exists. (paper)

A haplotype of polymorphisms in ASE-1, RAI and ERCC1 and the effects of tobacco smoking and alcohol consumption on risk of colorectal cancer: a Danish prospective case-cohort study

DEFF Research Database (Denmark)

Hansen, Rikke D; Sørensen, Mette; Tjønneland, Anne

2008-01-01

BACKGROUND: Single nucleotide polymorphisms (SNPs) are the most frequent type of genetic variation in the human genome, and are of interest for the study of susceptibility to and protection from diseases. The haplotype at chromosome 19q13.2-3 encompassing the three SNPs ASE-1 G-21A, RAI IVS1 A4364G...... and ERCC1 Asn118Asn have been associated with risk of breast cancer and lung cancer. Haplotype carriers are defined as the homozygous carriers of RAI IVS1 A4364GA, ERCC1 Asn118AsnT and ASE-1 G-21AG. We aimed to evaluate whether the three polymorphisms and the haplotype are associated to risk of colorectal...... of colorectal cancer were found. No statistically significant interactions between the genotypes and the lifestyle exposures smoking or alcohol consumption were observed. CONCLUSION: Our results suggest that the ASE-1 G-21A, RAI IVS1 A4364G and ERCC1 Asn118Asn polymorphisms and the previously identified...

'J-KAREN' - high intensity, high contrast laser

International Nuclear Information System (INIS)

Kiriyama, Hiromitsu; Mori, Michiaki; Nakai, Yoshiki; Okada, Hajime; Sasao, Hajime; Sagisaka, Akito; Ochi, Yoshihiro; Tanaka, Momoko; Kondo, Kiminori; Tateno, Ryo; Sugiyama, Akira; Daido, Hiroyuki; Koike, Masato; Kawanishi, Syunichi; Shimomura, Takuya; Tanoue, Manabu; Wakai, Daisuke; Kondo, Shuji; Kanazawa, Shuhei

2010-01-01

We report on the high intensity, high contrast double chirped-pulse amplification (CPA) Ti:sapphire laser system (named J-KAREN). By use of an optical parametric chirped-pulse amplification (OPCPA) preamplifier that is seeded by a cleaned high-energy pulse, a background amplified spontaneous emission (ASE) level of 10 -10 relative to the peak main femtosecond pulse on the picosecond timescales demonstrated with an output energy of 1.7 J and a pulse duration of 30 fs, corresponding to a peak power of 60TW at a 10 Hz repetition rate. This system which uses a cryogenically-cooled Ti:sapphire final amplifier generates focused peak intensity in excess of 10 20 W/cm 2 at a 10 Hz repetition rate. (author)

Output Beam Polarisation of X-ray Lasers with Transient Inversion

Science.gov (United States)

Janulewicz, K. A.; Kim, C. M.; Matouš, B.; Stiel, H.; Nishikino, M.; Hasegawa, N.; Kawachi, T.

It is commonly accepted that X-ray lasers, as the devices based on amplified spontaneous emission (ASE), did not show any specific polarization in the output beam. The theoretical analysis within the uniform (single-mode) approximation suggested that the output radiation should show some defined polarization feature, but randomly changing from shot-to-shot. This hypothesis has been verified by experiment using traditional double-pulse scheme of transient inversion. Membrane beam-splitter was used as a polarization selector. It was found that the output radiation has a significant component of p-polarisation in each shot. To explain the effect and place it in the line with available, but scarce data, propagation and kinetic effects in the non-uniform plasma have been analysed.

Estratégias de coping e níveis de estresse em pacientes portadores de psoríase Coping strategies and stress levels in patients with psoriasis

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Juliana Dors Tigre da Silva

2006-03-01

Full Text Available FUNDAMENTOS: Pesquisas atuais estão direcionando seu foco aos aspectos psicossociais envolvidos nas dermatoses crônicas. Esses fatores podem contribuir para a exacerbação da psoríase entre 40 e 80% dos casos, causando grande impacto na qualidade de vida desses pacientes. OBJETIVOS: Verificar estratégias de coping e identificar níveis de estresse do portador de psoríase. MÉTODOS: Estudo transversal, com amostra de 115 pacientes, divididos em 61 com psoríase e 54 do grupo controle com dermatoses crônicas. Instrumentos: Inventário de Estratégias de coping e Inventário de Sintomas de Estresse para Adultos de Lipp. RESULTADOS: Destacam-se as estratégias de coping autocontrole (p=0,027 e fuga e esquiva (p=0,014 utilizadas mais pelo grupo com psoríase e níveis de estresse altos para os dois grupos (p=0,838. CONCLUSÃO: Pacientes com psoríase utilizam estratégias de coping específicas para o enfrentamento da doença de pele, quando comparados a outros pacientes com doenças crônicas de pele demonstrando relevante nível de estresse. A integração dos resultados possibilita o entendimento do estado específico que portadores de psoríase vivenciam e que denuncia a premência de intervenções mais abrangentes que envolvam também as dimensões psíquica e social.ABSTRACT BACKGROUND: Psychosocial aspects are the current focus of research on chronic dermatoses. These aspects may contribute to exacerbation of psoriasis in 40 to 80% of cases, thus having great impact on patients’ quality of life. OBJECTIVES: This study aims to assess coping strategies and to identify stress levels of patients with psoriasis. METHODS: This is a cross-sectional study of a sample of 115 patients, which included 61 patients with psoriasis and 54 patients with other chronic dermatoses as controls. Instruments: The Ways of Coping Questionnaire and the Lipp Stress Symptoms Inventory for Adults. RESULTS: The coping strategies of self-control (p=0.027 and

On the influence of ultraviolet radiation on spontaneous tumors in NMRI mice

International Nuclear Information System (INIS)

Koenigsmann, G.; Kinkel, H.J.; Bocionek, P.; Wolff, F.

1981-01-01

During a period of 12 and 15 months respectively, female NMRI mice were irradiated twelve hours per day with specific parts of the ultraviolet spectrum (three groups, each comprising 100 animals: non-irradiated control group, animals irradiated with B units, animals irradiated with A/B units). No considerable influence of the chronic exposure to ultraviolet radiation could be demonstrated with regard to the development of the body weight and the hematologic condition. Group B had the same rate of spontaneous tumors of the respiratory tract as the control group; this rate was higher in group A/B. As to the development of spontaneous tumors in the lymphatic tissues, there seems to be a dependence on radiation: the animals of group B presented a slightly higher, those of group A/B a higher development than the animals of the nonirradiated control group. It cannot be definitely clarified yet to what extent this increased tumor rate was additionally induced by the higher environmental temperature or other influences involved by experiment. Harding-Passey melanomas were inoculated in NMRI mice and, 48 hours later, they were exposed to defined emission spectra within the natural ultraviolet spectrum. The exposed animals showed a slower growth of the transplanted tumors than the non-exposed animals, and especially the animals exposed to UVB radiation had a longer survival time. This chronic irradiation test was carried out in order to examine the influence of defined emission spectra on autochthonous tumors in NMRI mice and on their spontaneous tumor rate and blood count. (orig.) [de

Acervo de materiais educativos sobre hanseníase: um dispositivo da memória e das práticas comunicativas

Directory of Open Access Journals (Sweden)

Adriana Kelly-Santos

Full Text Available Neste trabalho objetiva-se: descrever o processo de elaboração de um banco de 276 materiais sobre hanseníase produzidos por instituições públicas e não-governamentais, entre 1972-2008; analisar o tipo, o público e os objetivos. O banco foi elaborado numa base eletrônica de dados, contendo a análise descritiva e temática e um link para o documento completo dos materiais. Os materiais destinam-se ao público em geral (75%, profissionais de saúde (12%, público infanto-juvenil (6%, portadores de hanseníase (3% e outros (4%. Predominam panfletos (26%, folhetos (24%, cartazes (23%, seguidos de cartilhas (15%, álbuns seriados (3% e outros (9%. Objetivam aumentar a autossuspeição, detecção de casos e divulgar os serviços de saúde. Predomina o discurso biomédico, a linguagem técnica-prescritiva e as relações hierarquizadas entre enunciador-destinatário.

Acervo de materiais educativos sobre hanseníase: um dispositivo da memória e das práticas comunicativas

Directory of Open Access Journals (Sweden)

Adriana Kelly-Santos

2010-03-01

Full Text Available Neste trabalho objetiva-se: descrever o processo de elaboração de um banco de 276 materiais sobre hanseníase produzidos por instituições públicas e não-governamentais, entre 1972-2008; analisar o tipo, o público e os objetivos. O banco foi elaborado numa base eletrônica de dados, contendo a análise descritiva e temática e um link para o documento completo dos materiais. Os materiais destinam-se ao público em geral (75%, profissionais de saúde (12%, público infanto-juvenil (6%, portadores de hanseníase (3% e outros (4%. Predominam panfletos (26%, folhetos (24%, cartazes (23%, seguidos de cartilhas (15%, álbuns seriados (3% e outros (9%. Objetivam aumentar a autossuspeição, detecção de casos e divulgar os serviços de saúde. Predomina o discurso biomédico, a linguagem técnica-prescritiva e as relações hierarquizadas entre enunciador-destinatário.

Spontaneous acute spinal subdural hematoma: spontaneous recovery from severe paraparesis--case report and review.

Science.gov (United States)

Payer, Michael; Agosti, Reto

2010-11-01

Spontaneous idiopathic acute spinal subdural hematomas are highly exceptional. Neurological symptoms are usually severe, and rapid diagnosis with MRI is mandatory. Surgical evacuation has frequently been used therapeutically; however, spontaneous recovery in mild cases has also been reported. We present a case of spontaneous recovery from severe paraparesis after spontaneous acute SSDH, and review the English-speaking literature.

Internal wave emission from baroclinic jets: experimental results

Science.gov (United States)

Borcia, Ion D.; Rodda, Costanza; Harlander, Uwe

2016-04-01

Large-scale balanced flows can spontaneously radiate meso-scale inertia-gravity waves (IGWs) and are thus in fact unbalanced. While flow-dependent parameterizations for the radiation of IGWs from orographic and convective sources do exist, the situation is less developed for spontaneously emitted IGWs. Observations identify increased IGW activity in the vicinity of jet exit regions. A direct interpretation of those based on geostrophic adjustment might be tempting. However, directly applying this concept to the parameterization of spontaneous imbalance is difficult since the dynamics itself is continuously re-establishing an unbalanced flow which then sheds imbalances by GW radiation. Examining spontaneous IGW emission in the atmosphere and validating parameterization schemes confronts the scientist with particular challenges. Due to its extreme complexity, GW emission will always be embedded in the interaction of a multitude of interdependent processes, many of which are hardly detectable from analysis or campaign data. The benefits of repeated and more detailed measurements, while representing the only source of information about the real atmosphere, are limited by the non-repeatability of an atmospheric situation. The same event never occurs twice. This argues for complementary laboratory experiments, which can provide a more focused dialogue between experiment and theory. Indeed, life cycles are also examined in rotating-annulus laboratory experiments. Thus, these experiments might form a useful empirical benchmark for theoretical and modeling work that is also independent of any sort of subgrid model. In addition, the more direct correspondence between experimental and model data and the data reproducibility makes lab experiments a powerful testbed for parameterizations. Here we show first results from a small rotating annulus experiments and we will further present our new experimental facility to study wave emission from jets and fronts.

Necrose de canto medial associado a hanseníase virchowiana: relato de caso

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Leiser Franco

2010-12-01

Full Text Available O caso em relato aborda uma etiologia rara para necrose de canto medial da pálpebra com comprometimento do sistema canalicular em uma paciente em tratamento para hanseníase virchowiana. O exame histopatológico da lesão necrótica evidenciou reação inflamatória granulomatosa com acúmulo de histiócitos e presença de bacilos álcool-ácido resistentes. Após tratamento medicamentoso a paciente apresentou uma evolução favorável com recuperação espontânea da arquitetura do canto medial, porém com destruição total do sistema canalicular.

Study on Spectrum Estimation in Biophoton Emission Signal Analysis of Wheat Varieties

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Yitao Liang

2014-01-01

Full Text Available The photon emission signal in visible range (380 nm–630 nm was measured from various wheat kernels by means of a low noise photomultiplier system. To study the features of the photon emission signal, the spectrum estimation method of the photon emission signal is described for the first time. The biophoton emission signal, belonging to four varieties of wheat, is analyzed in time domain and frequency domain. It shows that the intensity of the biophoton emission signal for four varieties of wheat kernels is relatively weak and has dramatic changes over time. Mean and mean square value are obviously different in four varieties; the range was, respectively, 3.7837 and 74.8819. The difference of variance is not significant. The range is 1.1764. The results of power spectrum estimation deduced that the biophoton emission signal is a low frequency signal, and its power spectrum is mostly distributed in the frequency less than 0.1 Hz. Then three parameters, which are spectral edge frequency, spectral gravity frequency, and power spectral entropy, are adopted to explain the features of the kernels’ spontaneous biophoton emission signal. It shows that the parameters of the spontaneous biophoton emission signal for different varieties of wheat are similar.

Schemes of Superradiant Emission from Electron Beams and "Spin-Flip Emission of Radiation"

CERN Document Server

Gover, A

2005-01-01

A unified analysis for Superradiant emission from bunched electron beams in various kinds of radiation scheme is presented. Radiation schemes that can be described by the formulation include Pre-bunched FEL (PB-FEL), Coherent Synchrotron Radiation (CSR), Smith-Purcell Radiation, Cerenkov-Radiation, Transition-Radiation and more. The theory is based on mode excitation formulation - either discrete or continuous (the latter - in open structures). The discrete mode formulation permits simple evaluation of the spatially coherent power and spectral power of the source. These figures of merit of the radiation source are useful for characterizing and comparing the performance of different radiation schemes. When the bunched electron beam emits superradiantly, these parameters scale like the square of the number of electrons, orders of magnitude more than spontaneous emission. The formulation applies to emission from single electron bunches, periodically bunched beams, or emission from a finite number of bunches in a...

Colelitíase no paciente pediátrico portador de doença falciforme Cholelithiasis in children with sickle cell disease

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Ana Paula S. Gumiero

2007-12-01

Full Text Available OBJETIVO: Considerando a alta freqüência da colelitíase no paciente pediátrico com doença falciforme e a controvérsia na literatura sobre a abordagem da condição, o presente texto objetiva revisar a literatura disponível. FONTE DE DADOS: Revisão dos estudos sobre colelitíase no paciente falciforme, publicados no período entre 1980 e 2007, em língua inglesa e portuguesa, envolvendo pacientes na faixa etária de zero a 18 anos e utilizando os bancos de dados Medline e Lilacs. SÍNTESE DOS DADOS: A colelitíase é a complicação digestiva mais comum no paciente falciforme e sua incidência aumenta com a faixa etária. Os mecanismos fisiopatológicos são conhecidos, assim como os métodos diagnósticos. A conduta terapêutica consensual na colelitíase sintomática é a colecistectomia, preferencialmente por via laparoscópica. Nos casos assintomáticos, a maioria dos autores recomenda a conduta cirúrgica, para evitar complicações, confusão no diagnóstico diferencial de dor abdominal futura e menor risco cirúrgico. Contudo, não existe consenso na literatura, havendo base para a adoção de conduta expectante. CONCLUSÕES: A doença falciforme tem grandes variações em sua apresentação clinica, história natural e gravidade da hemólise. Algumas populações podem apresentar menor freqüência de colelitíase e menor número de pacientes sintomáticos, possivelmente em razão de variações de haplótipos, fatores ambientais e diferentes manejos clínicos. Ainda não existem dados suficientes na literatura ou estudos randomizados e controlados que possibilitem definir o momento ideal para a colecistectomia no paciente falciforme com litíase assintomática. Dessa maneira, dependendo de características individuais e da população, podem ser aceitos o seguimento clínico ou a indicação precoce de colecistectomia.OBJECTIVE: Given the high frequency of cholelithiasis in children with sickle cell disease and the controversies

Associação timoma e estrongiloidíase intestinal grave Thymoma and severe intestinal strongyloidiasis association

OpenAIRE

Pérsio Godoy; Christian Marcellus Camargos Campos; Guilherme Costa; Lúcia Porto Fonseca de Castro

1998-01-01

Os autores relatam o caso de um homem de 59 anos de idade com timoma e estrongiloidíase intestinal grave. São revistos aspectos da resposta imunitária relacionados ao tumor e, possivelmente, implicados no desenvolvimento da hiperinfecção pelo Strongyloides stercoralis.A 59-years-old man with thymoma and severe intestinal strongyloidiasis is reported. The authors pointed out a possible influence of immunological response related with thymoma in the development of hyperinfection by Strongyloide...

INVESTASI ASING LANGSUNG DI INDONESIA DAN FAKTOR YANG MEMPENGARUHINYA

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Sarwedi Sarwedi

2002-01-01

Full Text Available There have been many studies on the determinants of foreign direct investment or FDI. Howerer, they are different both in the methodologies and the results. Although the influence of many factors that are assumed to be fixed (ceteris paribus are very strong-such as macroeconomic variables GDP, economic growth and inflation, they left various conclusions and debates. FDI can be one of the important sources of capital in developing countries, and contribute, the national development by transfer of asset, management, and technology to stimulate the economy of the country. The research model uses some domestic characteristics, that will be combined in a short and long run period by using OLS. The Error Correction Model (ECM and Granger Causality Test, are applied to the determine the factors that influence the foreign direct investment (FDI in Indonesia within 1978 -2001. The result shows that economic variables such as GDP, growth, wage and export have positive effect to FDI. While non-economic variables such as Political Stability (SP shows a negative effect. This conclusion is in a harmony with the empirical study done by Schneider and Frey (1986 that politicaal stability has a negative relations ship with FDI. Abstract in Bahasa Indonesia : Saat ini sudah terdapat banyak studi tentang faktor-faktor yang mempengaruhi investasi asing langsung (foreign direct investment atau FDI. Namun demikian metodologi yang digunakan dan hasil studi masih sangat bervariasi. Meskipun faktor-faktor yang dianggap tetap (ceteris paribus pengaruhnya sangat kuat, seperti variabel makro ekonomi yaitu pendapatan nasional, pertumbuhan ekonomi dan inflasi, tetapi masih juga terdapat kesimpulan yang berbeda dan menimbulkan berbagai perdebatan. FDI menjadi salah satu sumber pembiayaan (modal yang penting bagi negara berkembang, dan mampu memberikan kontribusi yang cukup besar bagi pembangunan melalui transfer asset dan manajemen, serta transfer teknologi guna mendorong

Espaços vigiados: um estudo do isolamento compulsório dos portadores de hanseníase no asilo-colônia Santo Ângelo (1890/1960)

OpenAIRE

Vânia Regina Miranda Postigo

2008-01-01

Esta pesquisa procura analisar o isolamento compulsório dos portadores de hanseníase no Asilo-colônia Santo Ângelo localizado em Mogi das Cruzes, São Paulo, tendo como ponto de partida os anos 1890, época em que as primeiras medidas de controle da hanseníase e de outras doenças foram adotadas pelo poder público paulista. A criação de várias instituições e do primeiro código sanitário marcaram o início da construção de uma forte estrutura para o desenvolvimento de políticas públicas de saúde n...

Perfil fenotípico, diferenciação molecular, produção de enzimas e sensibilidade aos antifúngicos de amostras de leveduras isoladas em três grupos amostrais: mulheres assintomáticas, com candidíase vulvovaginal primária e recorrente.

OpenAIRE

Debora Moreira

2012-01-01

O presente estudo foi realizado com 258 mulheres, com e sem sintomas de candidíase vulvovaginal, atendidas no Centro de Saúde Geraldo Paula Souza, da Faculdade de Saúde Pública da USP. Leveduras foram isoladas em 162 mulheres, sendo que 34% foram de mulheres assintomáticas, 34% com sintomas de candidíase vulvovaginal primária (CVV) e 32% com candidíase vulvovaginal recorrente (CVVR). As espécies mais isoladas foram C . albicans, C. parapsilosis, C. glabrata e C. tropicalis. Espécies como C. m...

Smith-Purcell Distributed Feedback Laser

CERN Document Server

Kipnis, D; Gover, A

2005-01-01

Smith-Purcell radiation is the emission of electromagnetic radiation by an electron beam passing next to an optical grating. Recently measurement of relatively intense power of such radiation was observed in the THz-regime [1]. To explain the high intensity and the super-linear dependence on current beyond a threshold it was suggested that the radiating device operated in the high gain regime, amplifying spontaneous emission (ASE) [1,2]. We contest this interpretation and suggest an alternative mechanism. According to our interpretation the device operates as a distributed feedback (DFB) laser oscillator, in which a forward going surface wave, excited by the beam on the grating surface, is coupled to a backward going surface wave by a second order Bragg reflection process. This feedback process produces a saturated oscillator. We present theoretical analysis of the proposed process, which fits the reported experimental results, and enables better design of the radiation device, operating as a Smith-Purcell DF...

Measurement of excited oxygen (O2:[sup 1][Delta]g) concentration by spontaneous emission. Hakko kyodo ni yoru reiki sanso ([sup 1][Delta]g) nodo no sokutei

Energy Technology Data Exchange (ETDEWEB)

Takahashi, S.; Hasegawa, Y.; Yamashita, I. (Mechanical Engineering Laboratory, Tsukuba (Japan))

1993-11-25

The concentration of excited oxygen ([sup 1][Delta]g), which was generated by microwave discharge in a pure oxygen flow, was measured from the intensity of spontaneous emission. The conversion factor to density was determined by spectroscopic analysis of the rotational structure and calibration of the emission intensity using a black-body furnace as light source. Consequently, a good agreement was found between the observed profiles and those calculated from spectroscopic data, and it was illustrated that the absolute concentration can be obtained by coupling band analysis and the calibration method. In addition, even when the concentration was low, it was shown that the excited oxygen concentration can be measured by considering the reflection at the cell wall. The excited oxygen concentration at the microwave discharge cavity was estimated to be around 1% under the pressure ranging from 0.5 torr to 2 torr. Furthermore, the comparison of the profiles calculated at different temperature provided that the band profile can be a good indicator of gas temperature when the signal-to-noise ratio is high. 9 refs., 10 figs., 2 tabs.

Influence of local field on spontaneous light emission by nanoparticles

DEFF Research Database (Denmark)

Keller, Ole; Lozovski, V.; Iezhokin, I.

2009-01-01

moment of transition that takes local-field effects into account. The effective dipole moment depends on the particle shape and size. Therefore, dipole radiation depends on those parameters too. The direction patterns of light emission by cubic particles have been calculated. The particles have been......A self-consistent approach based on the local-field concept has been proposed to calculate the direction patterns of light emission by nanoparticles with various shapes. The main idea of the method consists in constructing self-consistent equations for the electromagnetic field at any point...... of the system. The solution of the equations brings about relationships between the local field at an arbitrary point in the system and the external long-wave field via the local-field factor. The latter connects the initial moment of optical dipole transition per system volume unit and the effective dipole...

Estudo da microcirculação na hanseníase usando videomicroscopia (Microscan) e laser-Doppler associado à iontoforese: um modelo de disautonomia vascular por denervação

OpenAIRE

Livia Cristina de Melo Pino Machado

2013-01-01

A hanseníase é uma doença infecciosa com características únicas, dentre elas o fato de atingir intensamente a inervação da pele e seus anexos. Entremeando estes anexos, está a microcirculação cutânea, que a principio também tem sua inervação comprometida. Vários artigos apontam para alterações de disautonomiamicrocirculatória. O presente estudo se propõe a avaliar a microcirculação cutânea na hanseníase tuberculóide. Utilizamos a videomicroscopia de campo escuro (Microscan), a análise de Four...

Candidíase oral como marcador de prognóstico em pacientes portadores do HIV Oral candidiasis as prognostic marker of HIV-infected patients

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Valdinês Gonçalves dos Santos Cavassani

2002-10-01

Full Text Available Introdução: A candidíase oral é uma das doenças oportunistas mais fortemente associadas à infecção pelo Vírus da Imunodeficiência Humana (HIV. Vários relatos epidemiológicos enfatizam a prevalência da candidíase em pacientes HIV positivos e ressaltam a sua importância como marcador da progressão da doença e preditivo para o aumento da imunodepressão. Objetivo: Verificar as alterações estomatológicas em pacientes portadores do HIV tratados no Hospital Heliópolis - São Paulo, Brasil e comparar com a literatura. Forma de Estudo: Retrospectivo clínico não-randomizado. Casuística e Método: Foram analisados 431 pacientes HIV+/AIDS (298 homens e 133 mulheres no Hospital Heliópolis - São Paulo, Brasil, no período de 1995 a 2001. Resultados: A idade média mais comum foi dos 31 aos 40 anos (47,10%; a via de contágio mais comum foi a sexual (71,26%. Dentre as patologias, a candidíase apresentou maior prevalência (29,69%, seguida pela gengivite (16,70% e queilite angular (14,15%. Conclusões: Concluímos que o exame oral e o diagnóstico precoce da candidíase em pacientes infectados pelo HIV são fundamentais para o tratamento imediato, melhorando a sua qualidade de vida, uma vez que a candidíase é uma lesão bucal muito freqüente nesta população.Introduction: Strongly associated with Human Immunodeficiency Virus(HIV, oral candidiasis is one of the most common opportunistic infections. Various epedemiological data now emphasize the prevalence of candidiasis in HIV-infected patients and its importance as useful marker for disease progression and prediction for increasing immunossupression. Aim: The purposes of this study were to assess a group of HIV positive patients treated in Heliopólis Hospital, Hosphel - São Paulo, Brazil and refer the oral changing related to the syndrom and compared the results to the literature. Study design: Retrospective clinical no randomized. Casuistic and method: Four hundred thirty one

Taeniasis and cysticercosis prevalence in a small village from Northeastern Brazil Prevalência de teníase e sorologia positiva para cisticercose em Mulungu do Morro, Bahia

Directory of Open Access Journals (Sweden)

Irenio Gomes

2002-06-01

Full Text Available Although not considered as an endemic region, the Northeast of Brazil has the necessary conditions for the development of taeniasis-cysticercosis complex. In a previous paper, we demonstrated that Mulungu do Morro municipality, in the State of Bahia, has a high seroprevalence to cysticercosis in epileptic patients. OBJECTIVE: to determine the prevalence of taeniasis and positive cysticercosis serology in the population of Mulungu do Morro. METHOD: blood and stool samples were collected from a random sampling of the population, by family. The identification of antibodies against T. solium cysticerci was made by EITB and T. solium antigens were identified using a polyclonal antibody-capture ELISA. RESULTS: the cysticercosis seroprevalence was 1.6% (C.I. = 0.8 to 2.8% and the taeniasis prevalence 4.5% (C.I. = 3.0 to 6.5%. Seropositivity to cysticercosis was higher among those who lived in a house of a person testing positive for coproantigen, p=0.017. CONCLUSION: our results demonstrate that the taeniasis-cysticercosis complex is endemic in Mulungu do Morro. We believe that all areas in the world with the same socio-economic and sanitary characteristics are likely to have high prevalence of this parasite.Embora alguns autores não a considerem uma região endêmica, existem no Nordeste do Brasil as condições necessárias para o desenvolvimento do complexo teníase/ cisticercose. Em uma publicação prévia demosntramos no município de Mulungu do Morro, Bahia, alta soroprevalência para cisticercose em pacientes epilépticos. OBJETIVO: determinar a prevalência de teníase e sorologia positiva para cisticercose na população de Mulungu do Morro. MÉTODO: foram coletadas amostras de sangue e fezes em 175 famílias definidas aleatoriamente. A identificação de anticorpos séricos anti-cisticerco foi feita através do método de EITB e a presença de teníase foi verificada através de ELISA de captura para identificação de antígenos do

Aqueous clay suspensions stabilized by alginate fluid gels for coal spontaneous combustion prevention and control.

Science.gov (United States)

Qin, Botao; Ma, Dong; Li, Fanglei; Li, Yong

2017-11-01

We have developed aqueous clay suspensions stabilized by alginate fluid gels (AFG) for coal spontaneous combustion prevention and control. Specially, this study aimed to characterize the effect of AFG on the microstructure, static and dynamic stability, and coal fire inhibition performances of the prepared AFG-stabilized clay suspensions. Compared with aqueous clay suspensions, the AFG-stabilized clay suspensions manifest high static and dynamic stability, which can be ascribed to the formation of a robust three-dimensional gel network by AFG. The coal acceleration oxidation experimental results show that the prepared AFG-stabilized clay suspensions can improve the coal thermal stability and effectively inhibit the coal spontaneous oxidation process by increasing crossing point temperature (CPT) and reducing CO emission. The prepared low-cost and nontoxic AFG-stabilized clay suspensions, exhibiting excellent coal fire extinguishing performances, indicate great application potentials in coal spontaneous combustion prevention and control.

Optical, photo-physical properties and photostability of pyrromethene (PM-597) in ionic liquids as benign green-solvents

Energy Technology Data Exchange (ETDEWEB)

AL-Aqmar, Dalal M. [Physics Department, Ibb University, Ibb (Yemen); Physics Department, Faculty of Science, Mansoura University, Mansoura (Egypt); Abdelkader, H.I. [Physics Department, Faculty of Science, Mansoura University, Mansoura (Egypt); Abou Kana, Maram T.H., E-mail: mabou202@niles.edu.eg [National Institute of Laser Enhanced Sciences, Cairo University, Giza (Egypt)

2015-05-15

Laser dye pyrromethene-597 was dissolved with different concentrations in three types of ionic liquids (ILs): 1-Butyl-3-methylimidazolium chloride (BMIM Cl), 1-butyl-3-methylimidazolium tetrachloroaluminate (BMIM AlCl{sub 4}) and 1-butyl-3-methylimidazolium tetrafluoro-borate (BMIM BF{sub 4}) in addition to ethanol as reference solvent. This paper investigates optical spectra and some photo-physical parameters of PM-597 in BMIM Cl, BMIM AlCl{sub 4}, BMIM BF{sub 4} and ethanol. These parameters are absorption and emission cross sections, fluorescence lifetime and quantum yield. The amplified spontaneous emission (ASE) was studied using the second harmonic Nd-YAG laser of 532 nm. Also, the gain and energy conversion efficiencies were investigated. Relatively high efficiency was obtained with good photostability in case of PM-597 in BMIM BF{sub 4} that was a decrease to ~90% of the initial amplified spontaneous emission. This output energy was observed after pumping by 75,000 shots at a relatively high repetition rate of 10 Hz and pumping energy of 37 mJ. The composition and properties of the matrix of ILs were found to lead to optimize the laser performance and photostability of the investigated laser dye. In this study, we considered ionic liquids as the environmentally benign green solvents in place of volatile toxic organic solvents. - Highlights: • Pyrromethen-597 as laser dye was dissolved in three types of ionic liquids (ILs): BMIM Cl, BMIM AlCl{sub 4} and BMIM BF{sub 4} as benign green-solvent in addition to ethanol as reference solvent. • Important spectroscopic properties of PM-597 dye such as quantum yield, fluorescence lifetime, radiative and nonradiative rate, transition dipole moment, attenuation length and oscillator strength were affected by changing the host material. • The dye laser gain, quantum yield, peak intensity of ASE and photostability were found to be better in BMIM BF{sub 4} than in BMIM Cl and in ethanol. • ILs may be used as ideal

Effect of ionizing radiation on catalytic properties of Ca2+-ATP-ase from sarcoplasmic reticulum of skeletal muscle

International Nuclear Information System (INIS)

Bagel', I.M.; Shafranovskaya, E.V.; Gorokh, G.A.; Markova, A.G.

1999-01-01

It was studied kinetic and thermodynamic characteristics of Ca 2+ -ATP-ase of rat skeletal muscle (membranes of sarcoplasmic reticulum) after irradiation in doses 0,5, 4,0 and 8,0 Gy. It was shown that external gamma-irradiation at different doses changed kinetic and thermodynamic characteristics of the enzyme of sarcoplasmic reticulum membranes of skeletal muscle. These alterations probably correlate with disbalance of hormonal regulation of intracellular calcium metabolism and changes in membrane structure and functions

Spontaneous external gallbladder perforation

International Nuclear Information System (INIS)

Noeldge, G.; Wimmer, B.; Kirchner, R.

1981-01-01

Spontaneous perforation of the gallbladder is one complication of cholelithiasis. There is a greater occurence of free perforation in the peritoneal cavity with bilary pertonitis, followed by the perforation into the stomach, small intestine and colon. A single case of the nowadays rare spontaneous perforation in and through the abdominal wall will be reported. Spontaneous gallbladder perforation appears nearly asymptomatic in its clinical course because of absent biliary peritonitis. (orig.) [de

Performance improvement of 64-QAM coherent optical communication system by optimizing symbol decision boundary based on support vector machine

Science.gov (United States)

Chen, Wei; Zhang, Junfeng; Gao, Mingyi; Shen, Gangxiang

2018-03-01

High-order modulation signals are suited for high-capacity communication systems because of their high spectral efficiency, but they are more vulnerable to various impairments. For the signals that experience degradation, when symbol points overlap on the constellation diagram, the original linear decision boundary cannot be used to distinguish the classification of symbol. Therefore, it is advantageous to create an optimum symbol decision boundary for the degraded signals. In this work, we experimentally demonstrated the 64-quadrature-amplitude modulation (64-QAM) coherent optical communication system using support-vector machine (SVM) decision boundary algorithm to create the optimum symbol decision boundary for improving the system performance. We investigated the influence of various impairments on the 64-QAM coherent optical communication systems, such as the impairments caused by modulator nonlinearity, phase skew between in-phase (I) arm and quadrature-phase (Q) arm of the modulator, fiber Kerr nonlinearity and amplified spontaneous emission (ASE) noise. We measured the bit-error-ratio (BER) performance of 75-Gb/s 64-QAM signals in the back-to-back and 50-km transmission. By using SVM to optimize symbol decision boundary, the impairments caused by I/Q phase skew of the modulator, fiber Kerr nonlinearity and ASE noise are greatly mitigated.

Temperature-Insensitive Bend Sensor Using Entirely Centered Erbium Doping in the Fiber Core

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Sulaiman Wadi Harun

2013-07-01

Full Text Available A fiber based bend sensor using a uniquely designed Bend-Sensitive Erbium Doped Fiber (BSEDF is proposed and demonstrated. The BSEDF has two core regions, namely an undoped outer region with a diameter of about 9.38 μm encompassing a doped, inner core region with a diameter of 4.00 μm. The doped core region has about 400 ppm of an Er2O3 dopant. Pumping the BSEDF with a conventional 980 nm laser diode gives an Amplified Spontaneous Emission (ASE spectrum spanning from 1,510 nm to over 1,560 nm at the output power level of about −58 dBm. The ASE spectrum has a peak power of −52 dBm at a central wavelength of 1,533 nm when not spooled. Spooling the BSEDF with diameters of 10 cm to 2 cm yields decreasing peak powers from −57.0 dBm to −61.8 dBm, while the central wavelength remains unchanged. The output is highly stable over time, with a low temperature sensitivity of around ~0.005 dBm/°C, thus allowing for the development of a highly stable sensor system based in the change of the peak power alone.

Yields of correlated fragment pairs and neutron multiplicity in spontaneous fission of {sup 242}Pu

Energy Technology Data Exchange (ETDEWEB)

Veselsky, M.; Kliman, J.; Morhaccaron, M. [Institute of Physics of Slovak Academy of Sciences, Dubravska 9, 84228 Bratislava (Slovakia); Ramayya, A.V.; Kormicki, J.; Daniel, A.V. [Physics Department, Vanderbilt University, Nashville (United States)] Rasmussen, J.O. [Lawrence Berkeley National Laboratory, Berkeley (United States)] Stoyer, M.A. [Lawrence Livermore National Laboratory, Livermore (United States); Daniel, A.V.; Popeko, G.S.; Oganessian, Yu. Ts. [Joint Institute for Nuclear Research, Dubna (Russia)] Greiner, W. [Institut fur Theoretische Physik, J. W. Goethe Universitaet, Frankfurt a. M. (Germany); Aryaeinejad, R. [Idaho National Engineering Laboratory, Idaho Falls (United States)

1998-10-01

Yields of correlated fragment pairs were obtained in spontaneous fission of {sup 242}Pu. Charge, mass and neutron multiplicity distributions of fragment pairs were determined and compared to available data. The yield of cold fission without neutron emission was determined to about 10{percent} for the set of observed correlated fragment pairs. {copyright} {ital 1998 American Institute of Physics.}

Performance evaluation and optimization of multiband phase-modulated radio over IsOWC link with balanced coherent homodyne detection

Science.gov (United States)

Zong, Kang; Zhu, Jiang

2018-04-01

In this paper, we present a multiband phase-modulated (PM) radio over intersatellite optical wireless communication (IsOWC) link with balanced coherent homodyne detection. The proposed system can provide the transparent transport of multiband radio frequency (RF) signals with higher linearity and better receiver sensitivity than intensity modulated with direct detection (IM/DD) system. The expressions of RF gain, noise figure (NF) and third-order spurious-free dynamic range (SFDR) are derived considering the third-order intermodulation product and amplifier spontaneous emission (ASE) noise. The optimal power of local oscillator (LO) optical signal is also derived theoretically. Numerical results for RF gain, NF and third-order SFDR are given for demonstration. Results indicate that the gain of the optical preamplifier and the power of LO optical signal should be optimized to obtain the satisfactory performance.

Fast optical shutters for Nova, a high power fusion laser

International Nuclear Information System (INIS)

Bradley, L.P.; Gagnon, W.L.; Carder, B.M.

1977-01-01

Preliminary design and performance test results for fast optical shutters intended for use in the Nova high power fusion laser system are briefly described. Both an opening shutter to protect the pellet target from amplified spontaneous emission (ASE), and a closing shutter to protect the laser from light reflected back from the target are discussed. Faraday rotators, synchronized by a 400 Hz oscillator, provide an opening shutter mechanism with an opening time of approximately 10 μs. A plasma closing shutter, employing electrical sublimation of a foil, provide a shutter closing time of 70 ns +- 20 ns. Energy for foil sublimation is provided by discharge of a 42 J capacitor bank. Implementation of these shutter techniques in the Nova system is anticipated to improve laser output power and efficiency

Effect of multipulse waveform on gains of soft X-ray lines of lithium-like aluminum ions in recombining plasmas

International Nuclear Information System (INIS)

Okasaka, Kazunobu; Hara, Tamio; Yamaguchi, Naohiro; Ando, Kozo; Kawachi, Tetsuya; Oyama, Hitoshi

2000-01-01

Using the recombination plasma scheme, we investigated the amplified spontaneous emissions (ASE) from lithium-like aluminum plasmas produced by multipulse laser irradiation. Three types of multipulse waveforms of Nd-glass laser beam were treated. We measured the time-integrated intensities of the 3d-4f (15.5 nm) and the 3d-5f (10.6 nm) lines of lithium-like aluminum ions for 2.5-cm-long and 1.25-cm-long plasmas. The effective time-averaged gains estimated from these time-integrated intensities varied with the multipulse waveforms. using a hydrodynamic simulation, we discussed the time history of plasma parameters in the recombining plasma. We concluded that the modifying multipulse waveform contributed to the effective time-averaged gain by maintaining the helium-like ion density until the gain was generated. (author)

Pure neural leprosy: steroids prevent neuropathy progression Corticosteróides previnem a neuropatia na hanseníase

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Márcia R. Jardim

2007-12-01

Full Text Available Multidrug therapy (MDT, with rifampicin, dapsone, and clofazimine, treats leprosy infection but is insufficient in arresting or preventing the nerve damage that causes impairments and disabilities. This case-series study evaluates the benefits of the combined use of steroids and MDT in preventing nerve damage in patients with pure neural leprosy (PNL. In addition to MDT, 24 patients (88% male aged 20-79 years, median=41 received a daily morning dose of 60 mg prednisone (PDN that was gradually reduced by 10 mg during each of the following 5 months. PNL was clinically diagnosed and confirmed by nerve histopathology or PCR. A low prevalence (8.3% of reaction was observed after release from treatment. However, most of the clinical parameters showed significant improvement; and a reduction of nerve conduction block was observed in 42% of the patients. The administration of full-dose PDN improved the clinical and electrophysiological condition of the PNL patients, contributing to the prevention of further neurological damage.A poliquimioterapia (PQT, com rifampicina, dapsona, e clofazimina, trata a infecção na hanseníase, mas é insuficiente para interromper ou prevenir o comprometimento neurológico que causa as incapacidades e desabilidades, nesta enfermidade. Este estudo de série de casos avalia o benefício do uso combinado de prednisona e PQT na prevenção do dano neurológico em pacientes com a forma neural pura da hanseníase (FNP. Além do PQT, 24 pacientes (88% homens, com idade variando entre 20-79, mediana=41 receberam uma dose diária de 60 mg prednisona que foi reduzida gradualmente na dose de 10 mg durante cada um dos 5 meses subseqüentes. FNP foi diagnosticada clinicamente e confirmada através do estudo histopatológico ou PCR. Baixa prevalência de reação (8,3% foi observada apenas após o final do tratamento. A maioria dos parâmetros clínicos mostrou melhora significativa e redução do bloqueio de condução foi observada

Jejunal perforation caused by abdominal angiostrongyliasis Perfuração jejunal causada por angiostrongilíase abdominal

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Jaques WAISBERG

1999-09-01

Full Text Available The authors describe a case of abdominal angiostrongyliasis in an adult patient presenting acute abdominal pain caused by jejunal perforation. The case was unusual, as this affliction habitually involves the terminal ileum, appendix, cecum or ascending colon. The disease is caused by the nematode Angiostrongylus costaricensis, whose definitive hosts are forest rodents while snails and slugs are its intermediate hosts. Infection in humans is accidental and occurs via the ingestion of snail or slug mucoid secretions found on vegetables, or by direct contact with the mucus. Abdominal angiostrongyliasis is clinically characterized by prolonged fever, anorexia, abdominal pain in the right-lower quadrant, and peripheral blood eosinophilia. Although usually of a benign nature, its course may evolve to more complicated forms such as intestinal obstruction or perforation likely to require a surgical approach. Currently, no efficient medication for the treatment of abdominal angiostrongyliasis is known to be available. In this study, the authors provide a review on the subject, considering its etiopathogeny, clinical picture, diagnosis and treatment.Os autores descrevem caso de angiostrongilíase abdominal em doente adulto que se manifestou como abdômen agudo devido à perfuração de alça jejunal, evento raro, uma vez que esta afecção geralmente envolve o íleo terminal, apêndice, ceco ou cólon ascendente. A doença é causada pelo nematódeo Angiostrongylus costaricensis cujos hospedeiros definitivos são roedores silvestres e os hospedeiros intermediários são caracóis e caramujos. A infecção em humanos é acidental e ocorre pela ingestão de secreção mucóide destes invertebrados presentes em vegetais ou por contato direto com o muco. A angiostrongilíase abdominal é clinicamente caracterizada pela presença de febre prolongada, anorexia, dor no quadrante inferior direito do abdômen e eosinofilia periférica. Embora a doença seja de

Atomic nuclei decay modes by spontaneous emission of heavy ions

International Nuclear Information System (INIS)

Poenaru, D.N.; Ivascu, M.; Sandulescu, A.

1984-01-01

The great majority of the known nuclei, including the so-called stable nuclides, are in fact metastable with respect to several modes of spontaneous superasymmetric splitting. If the lifetime against these processes is larger than 10 30 s, the phenomenon is not detectable with available experimental techniques, hence one can admit stability from the practical point of view. A model extended from the fission theory of alpha decay allows one to estimate the lifetimes and the branching ratios relatively to the alpha decay for these natural radioactivities. From a huge amount of systematical calculations it is concluded that the process should proceed with maximum intensity in the trans-lead nuclei, where the minimum lifetime is obtained for parent nuclei - heavy clusters leading to a magic ( 208 Pb) or almost daughter nucleus. More than 140 nuclides with atomic number smaller than 25 are possible candidates to be emitted from heavy nuclei, with half-life n the 10 10 -10 30 s range. The shell structure and pairing effects are clearly manifested in these new decay modes

Definition of spontaneous reconnection

International Nuclear Information System (INIS)

Schindler, K.

1984-01-01

The author discusses his view of driven versus spontaneous. There is a close link between ''spontaneous'' and ''instability.'' One of the prominent examples for instability is the thermal convection instability. Just to remind you, if you heat a fluid layer from below, it takes a certain Rayleigh number to make it unstable. Beyond the onset point you find qualitatively new features. That is called ''spontaneous,'' and this is a bit more than semantics. It's a new qualitative property that appears and it is spontaneous although we have an energy flux through the system. It's a misconception, to call this ''driven'' pointing at the energy flux through it. Of course, the convection would not exist without this energy flux. But what makes it ''spontaneous'' is that without any particular external signal, a new qualitative feature appears. And this is what is called an ''instability'' and ''spontaneous.'' From these considerations the author got a little reassured of what distinction should be made in the field of the magnetosphere. If we have a smooth energy transport into the magnetosphere and suddenly we have this qualitatively new feature (change of B-topology) coming up; then, using this terminology we don't have a choice other than calling this spontaneous or unstable, if you like. If we ''tell'' the system where it should make its neutral line and where it should make its plasmoids, then, it is driven. And this provides a very clear-cut observational distinction. The author emphasizes the difference he sees is a qualitative difference, not only a quantitative one

Abscesso cervical gigante provocado por sialolitíase de glândula submandibular

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Fernanda Fruet

2016-10-01

Full Text Available Introdução: As infecções cervicais profundas apresentam alta mortalidade, apesar da eficácia da antibioticoterapia atual. Uma das principais complicações é a obstrução das vias aéreas superiores. A principal causa dessas infecções é de origem odontogênica e, raramente, a infecção das glândulas salivares. Objetivo: Apresentar um caso de abscesso cervical profundo, cuja etiologia rara está associada à sialolitíase com origem em glândula submandibular. Metodologia: O caso foi acompanhado no serviço de Cabeça e Pescoço do Conjunto Hospitalar de Sorocaba (CHS e sua descrição embasada na literatura. Relato de Caso: Paciente iniciou quadro de dor localizada em região submandibular posterior direita, acompanhada de disfagia e dispneia contínua. Procurou atendimento médico na cidade de origem, onde recebeu antibioticoterapia. Evoluiu com insuficiência respiratória, necessitando de transferência para o serviço de emergência do CHS aos cuidados da equipe de Cabeça e Pescoço. Ao exame físico, apresentava edema, abaulamento e hiperemia da lateral direita do pescoço. A Tomografia Computadorizada evidenciou abscesso em espaço retro-faríngeo com compressão da parede posterior da orofaringe e hipofaringe, além de glândula submandibular direita aumentada e imagem de cálculo. Foi realizada a traqueostomia e a resolução cirúrgica por meio da drenagem do abscesso através da incisão transversa em colar. Conclusão: O caso apresentado mostra um abscesso cervical profundo causado por etiologia incomum, a sialolitíase, cujo diagnóstico precoce, seguido do tratamento adequado, poderiam ter evitado a evolução grave do paciente. Neste caso, a drenagem cirúrgica precoce mostra sua importância na prevenção de insuficiência respiratória.

A ENFERMAGEM DE SAÚDE PÚBLICA NO CONTROLE DA HANSENÍASE. Análise das atividades realizadas

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Elisete Silva Pedrazzani

Full Text Available A presentase um estudo com o objetivo de cotejar as atividades realizadas peto pessoal de enfermagem, com as preconizadas pelo Subprograma de Controle da Hanseníase, nos Centros de Saúde I do Departamento Regional de Saúde de Ribeirão Preto, da Secretaria da Saúde, do Estado de São Paulo. Destacam-se as atividades desenvolvidas pelos enfermeiros, sendo que os mesmos estão vinculados preponderantemente às funções administrativas e de assessoria.

Neutron emission during acceleration of 252Cf fission fragments

International Nuclear Information System (INIS)

Batenkov, O.I.; Blinov, M.V.; Blinov, A.B.; Smirnov, S.N.

1991-01-01

We investigate neutron emission during acceleration of fission fragments in the process of spontaneous fission of 252 Cf. Experimental angular and energy distributions of neutrons are compared with the results of calculations of neutron evaporation during fragment acceleration. (author). 8 refs, 3 figs

A search for back-to-back e+e- pairs in the spontaneous-fission disintegration of 252Cf

International Nuclear Information System (INIS)

Tsunoda, T.; Nakamura, S.; Orito, S.; Minowa, M.

1995-01-01

A back-to-back electron-positron pair is searched for in spontaneous-fission disintegration of 252 Cf. The emission of such a pair, if observed, might be a manifestation of production and prompt decay of a heretofore unknown neutral particle. The emission rate of such a pair is found to be less than (2.5-5.5) . 10 -10 per fission at the 95% confidence level depending on the mass of the hypothetical particle which is between 40 and 200 MeV/c 2 . (orig.)

In Situ Measurement of Alkali Metals in an MSW Incinerator Using a Spontaneous Emission Spectrum

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Weijie Yan

2017-03-01

Full Text Available This paper presents experimental investigations of the in situ diagnosis of the alkali metals in the municipal solid waste (MSW flame of an industrial grade incinerator using flame emission spectroscopy. The spectral radiation intensities of the MSW flame were obtained using a spectrometer. A linear polynomial fitting method is proposed to uncouple the continuous spectrum and the characteristic line. Based on spectra processing and a non-gray emissivity model, the flame temperature, emissivity, and intensities of the emission of alkali metals were calculated by means of measuring the spectral radiation intensities of the MSW flame. Experimental results indicate that the MSW flame contains alkali metals, including Na, K, and even Rb, and it demonstrates non-gray characteristics in a wavelength range from 500 nm to 900 nm. Peak intensities of the emission of the alkali metals were found to increase when the primary air was high, and the measured temperature varied in the same way as the primary air. The temperature and peak intensities of the lines of emission of the alkali metals may be used to adjust the primary airflow and to manage the feeding of the MSW to control the alkali metals in the MSW flame. It was found that the peak intensity of the K emission line had a linear relationship with the peak intensity of the Na emission line; this correlation may be attributed to their similar physicochemical characteristics in the MSW. The variation trend of the emissivity of the MSW flame and the oxygen content in the flue gas were almost opposite because the increased oxygen content suppressed soot formation and decreased soot emissivity. These results prove that the flame emission spectroscopy technique is feasible for monitoring combustion in the MSW incinerator in situ.

Optimized emission in nanorod arrays through quasi-aperiodic inverse design.

Science.gov (United States)

Anderson, P Duke; Povinelli, Michelle L

2015-06-01

We investigate a new class of quasi-aperiodic nanorod structures for the enhancement of incoherent light emission. We identify one optimized structure using an inverse design algorithm and the finite-difference time-domain method. We carry out emission calculations on both the optimized structure as well as a simple periodic array. The optimized structure achieves nearly perfect light extraction while maintaining a high spontaneous emission rate. Overall, the optimized structure can achieve a 20%-42% increase in external quantum efficiency relative to a simple periodic design, depending on material quality.

The (μ-, e+) conversion with Majoron emission

International Nuclear Information System (INIS)

Zahir, M.S.; Picciotto, C.E.

1982-07-01

We study the process of μ - → e + in nuclei with the emission of a Majoron with B-L symmetry spontaneously broken by the vacuum expectation value of a Higgs triplet. We find that this mechanism may contribute to the μ - → e + conversion rate at the same level as predicted by earlier models

Estudo piloto sobre alimentos que devem ser evitados nos portadores de psoríase Pilot study on which foods should be avoided by patients with psoriasis

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Moira Festugato

2011-12-01

Full Text Available FUNDAMENTOS: Psoríase é uma doença inflamatória crônica, sistêmica, mediada por fatores imunológicos. Serão abordados os alimentos que atuam sobre estes fatores, contribuindo para a psoríase. Como doença sistêmica, que compartilha o mesmo substrato fisiopatológico com outras comorbidades, a dieta alimentar também leva à piora das comorbidades. OBJETIVO: Destacar um grupo de alimentos que pode atuar como um fator de manifestação e/ou agravo da psoríase e ao mesmo tempo viabilizar estratégias individuais para alimentos que devam ser introduzidos. MÉTODOS: 43 pacientes foram selecionados, com diversas formas de psoríase (exceto psoríase pustulosa e eritrodérmica, e responderam a um questionário sobre seus hábitos alimentares na primeira consulta, focando a atenção no consumo de café preto, chá preto, chocolate, mate, pimenta, defumados, carne de gado e realçador de sabor (glutamato monossódico. Na sequência, o paciente foi orientado a suspender bebidas com qualquer percentagem alcoólica e o tabagismo. RESULTADO: A carne de gado é o alimento mais consumido pelos pacientes seguida por: realçador de sabor (glutamato monossódico, que existe nos alimentos industrializados, mate e café preto, chocolate, defumados, pimenta e chá preto. 88,37% notaram diminuição das escamas e eritema, surtos mais brandos durante o ano e melhora da qualidade de vida; 11,63% (5 pacientes não notaram repercussões na pele. CONCLUSÃO: Foi observada ingestão dietética precária nos pacientes com psoríase. Além de uma orientação científica adequada, o paciente necessita de uma ação educativa frente aos seus hábitos alimentares para uma melhoria da qualidade de vida e como coadjuvante na terapia medicamentosa empregada.FUNDAMENT: Psoriasis is a chronic inflammatory systemic disease mediated by immune factors. We will explore the foods that act on these factors contributing to psoriasis. As a systemic disease, which shares the

Spontaneous intracranial hypotension.

LENUS (Irish Health Repository)

Fullam, L

2012-01-31

INTRODUCTION: Spontaneous\\/primary intracranial hypotension is characterised by orthostatic headache and is associated with characteristic magnetic resonance imaging findings. CASE REPORT: We present a case report of a patient with typical symptoms and classical radiological images. DISCUSSION: Spontaneous intracranial hypotension is an under-recognised cause of headache and can be diagnosed by history of typical orthostatic headache and findings on MRI brain.

Radioactive decay of 223Ra by 14C emission

International Nuclear Information System (INIS)

Yashita, S.; Gregorich, K.; Ghiorso, A.

1985-01-01

Recently H.J. Rose and G.A. Jones at the University of Oxford reported the very difficult observation of an exotic radioactive decay mode in 233 Ra, its spontaneous disintegration by the emission of 14 C particles. The authors have confirmed their somewhat surprising discovery by an independent method. Within the present experimental accuracy the magnetic rigidity, energy and branching ratio support the assignment of 14 C emission from 223 Ra as proposed by the Oxford experiment

[Spontaneous bacterial peritonitis].

Science.gov (United States)

Velkey, Bálint; Vitális, Eszter; Vitális, Zsuzsanna

2017-01-01

Spontaneous bacterial peritonitis occurs most commonly in cirrhotic patients with ascites. Pathogens get into the circulation by intestinal translocation and colonize in peritoneal fluid. Diagnosis of spontaneous bacterial peritonitis is based on elevated polymorphonuclear leukocyte count in the ascites (>0,25 G/L). Ascites culture is often negative but aids to get information about antibiotic sensitivity in positive cases. Treatment in stable patient can be intravenous then orally administrated ciprofloxacin or amoxicillin/clavulanic acid, while in severe cases intravenous III. generation cephalosporin. Nosocomial spontaneous bacterial peritonitis often caused by Gram-positive bacteria and multi-resistant pathogens can also be expected thus carbapenem should be the choice of the empiric treatment. Antibiotic prophylaxis should be considered. Norfloxacin is used most commonly, but changes are expected due to increase in quinolone resistance. As a primary prophylaxis, a short-term antibiotic treatment is recommended after gastrointestinal bleeding for 5 days, while long-term prophylaxis is for patients with low ascites protein, and advanced disease (400 mg/day). Secondary prophylaxis is recommended for all patients recovered from spontaneous bacterial peritonitis. Due to increasing antibiotic use of antibiotics prophylaxis is debated to some degree. Orv. Hetil., 2017, 158(2), 50-57.

Estudo da incidência de coledocolitíase em pacientes com colecistite calculosa aguda e crônica submetidos à colecistectomia vídeolaparoscópica

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Sidney Moreno Gil

Full Text Available OBJETIVO: Avaliar a incidência da coledocolitiase em pacientes submetidos à colecistectomia laparoscópica, portadores de colecistopatia calculosa aguda e crônica. O presente estudo, também, analisa se a era laparoscópica modificou a incidência e a história natural da litíase da via biliar quando compara os dados da literatura com os índices do Grupo estudado. MÉTODO: O estudo foi realizado em um Grupo de 946 pacientes, distribuídos em Grupo A de 214 pacientes de 1991-1995 e Grupo B de 732 pacientes de 1999-2007 colecistectomizados pelo método laparoscópico. O critério diagnóstico de coledocolitíase foi estabelecido por colangiofluoroscopia de rotina em todas as operações. RESULTADOS: A incidência total de coledocolitiase no Grupo A de 9,8% e no B de 5,8% não mostram diferença estatística significativa entre si e com a literatura mundial (p=0,08.Nos pacientes operados por colecistite aguda também não se observou diferença estatística entre o grupo A e B na incidência de litíase da via biliar( p=0,8. A análise dos dados nos pacientes operados por colecistite crônica revela uma taxa de coledocolitíase menor no Grupo B de 3,7% com significância estatística do que no A de 8,4% p=0,03. CONCLUSÃO: O presente estudo revela uma diminuição expressiva na incidência de coledocolitiase no Grupo B em relação ao A e a literatura mundial quando a indicação cirúrgica ocorre na fase não complicada da doença litiásica biliar. O estudo também demonstra um aumento significativo na indicação da colecistectomia laparoscópica eletiva mais precoce no Grupo B como já observado em diversas publicações da literatura médica.

Spontaneous emission enhancement of colloidal perovskite nanocrystals

Science.gov (United States)

Yang, Zhili; Waks, Edo

Halide perovskite semiconductors have emerged as prominent photovoltaic materials since their high conversion efficiency and promising light emitting materials in optoelectronics. In particular, easy-to-fabricated colloidal perovskite nanocrystals based on CsPbX3 quantum dots has been intensively investigated recently. Their luminescent wavelength could be tuned precisely by their chemical composition and size of growth. This opens new applications including light-emitting diodes, optical amplifiers and lasing since their promising performance as emitters. However, this potentially high-efficient emitter and gain material has not been fully investigated and realized in integrated photonic structures. Here we demonstrate Purcell enhancement effect of CsPbBr3 perovskite nanocrystals by coupling to an optimized photonic crystal nanobeam cavity as a first crucial step towards realization of integrated on-chip coherent light source with low energy consumption. We show clearly highly-enhanced photoluminescent spectrum and an averaged Purcell enhancement factor of 2.9 is achieved when they are coupled to nanobeam photonic crystal cavities compared to the ones on unpatterned surface in our lifetime measurement. Our success in enhancement of emission from CsPbX3 perovskite nanocrystals paves the way towards the realization of efficient light sources for integrated optoelectronic devices with low energy consumption.

Fatores preditivos de coledocolitíase em doentes com pancreatite aguda biliar Predictors of choledocholithiasis in patients sustaining acute biliary pancreatitis

Directory of Open Access Journals (Sweden)

José Gustavo Parreira

2004-12-01

Full Text Available OBJETIVO: Avaliar o papel da fosfatase alcalina (FA, gama glutamiltransferase (gamaGT e ultra-sonografia (US como fatores preditivos de coledocolitíase em doentes com pancreatite aguda biliar (PAB. MÉTODOS: Os dados foram coletados prospectivamente durante um período de 31 meses. Quarenta doentes foram incluídos, sendo 30 mulheres, com média etária de 49 + 16 anos. Foram registrados os dados de todos os doentes com pancreatite aguda biliar. Aqueles doentes ictéricos e com a forma grave da doença foram excluídos. As dosagens de FA e GGT, assim como a US, eram realizadas na admissão e 48 horas antes da cirurgia. Todos os pacientes foram submetidos à colangiografia intra-operatória (CIO ou à colangiografia retrógrada endoscópica (CPRE pré-operatória, que era definida baseada na probabilidade de coledocolitíase. Com o intuito de identificar os indicadores de coledocolitíase, as variáveis foram comparadas entre os pacientes com ou sem coledocolitíase. Os testes t de Student, Qui-quadrado e Fisher foram empregados para a análise estatística, considerando-se pBACKGROUND: To assess the role of alkaline phosphatase (AP, gamil-glutamyltransferase (gammaGT and abdominal ultrasound (US as predictors of choledocholithiasis in patients sustaining acute biliary pancreatitis. METHODS: Data was prospectively collected during a period of 31 months. Forty patients were included, 30 were female and the mean age was 49 + 16. All patients sustaining acute biliary pancreatitis were enrolled. Patients with clinical jaundice and severe pancreatitis were excluded. Serum content of AP and gGT as well as US were assessed at admission and 48 hours before cholecistectomy. All patients underwent intra-operative cholangiography (IOC or pre-operative endoscopic retrograde cholangiography (ERCP, which was indicated based on the odds of choledocholithiasis. In order to identify the predictors of choledocholithiasis, variables were compared between patients

Genetics Home Reference: primary spontaneous pneumothorax

Science.gov (United States)

... Home Health Conditions Primary spontaneous pneumothorax Primary spontaneous pneumothorax Printable PDF Open All Close All Enable Javascript ... view the expand/collapse boxes. Description Primary spontaneous pneumothorax is an abnormal accumulation of air in the ...

Atmospheric-like rotating annulus experiment: gravity wave emission from baroclinic jets

Science.gov (United States)

Rodda, Costanza; Borcia, Ion; Harlander, Uwe

2017-04-01

Large-scale balanced flows can spontaneously radiate meso-scale inertia-gravity waves (IGWs) and are thus in fact unbalanced. While flow-dependent parameterizations for the radiation of IGWs from orographic and convective sources do exist, the situation is less developed for spontaneously emitted IGWs. Observations identify increased IGW activity in the vicinity of jet exit regions. A direct interpretation of those based on geostrophic adjustment might be tempting. However, directly applying this concept to the parameterization of spontaneous imbalance is difficult since the dynamics itself is continuously re-establishing an unbalanced flow which then sheds imbalances by GW radiation. Examining spontaneous IGW emission in the atmosphere and validating parameterization schemes confronts the scientist with particular challenges. Due to its extreme complexity, GW emission will always be embedded in the interaction of a multitude of interdependent processes, many of which are hardly detectable from analysis or campaign data. The benefits of repeated and more detailed measurements, while representing the only source of information about the real atmosphere, are limited by the non-repeatability of an atmospheric situation. The same event never occurs twice. This argues for complementary laboratory experiments, which can provide a more focused dialogue between experiment and theory. Indeed, life cycles are also examined in rotating- annulus laboratory experiments. Thus, these experiments might form a useful empirical benchmark for theoretical and modelling work that is also independent of any sort of subgrid model. In addition, the more direct correspondence between experimental and model data and the data reproducibility makes lab experiments a powerful testbed for parameterizations. Joint laboratory experiment and numerical simulation have been conducted. The comparison between the data obtained from the experiment and the numerical simulations shows a very good

Dinamika Penanaman Modal Asing (PMA Bidang Pertambangan Umum di Indonesia

Directory of Open Access Journals (Sweden)

Ukar Wijaya Soelistijo

2011-06-01

Full Text Available During 1967 – 1988, seven generations of Contract of Work (COW were in lieu with foreign  capital  investment in the area of non-coal general mining,  followed by three generations of Coal Contract (CCOW in Indonesia.  An analysis toward details of COW showed that the contract requirements were transformed from time to time. At the first phase, tax holiday was offered. Meanwhile, the later generations reduced such facilities as complained by mining companies.  This research suggests the importance of regulation to manage  Indonesia’s income resulted from windfall profit of oil prices increase. Sepanjang periode 1967 – 1988, Indonesia telah menghasilkan  tujuh generasi Kontrak Kerja dalam investasi modal asing untuk bidang pertambangan umum non batubara, diikuti oleh tiga generasi Kontrak Batubara. Analisis terhadap rincian Kontrak Kerja tersebut memperlihatkan perubahan  persyaratan kontrak  dari waktu ke waktu. Pada fase pertama, Kontrak Kerja menawarkan fasilitas bebas pajak (tax holiday. Hal ini tidak berlaku lagi pada Kontrak Kerja selanjutnya, sebagaimana dikeluhkan perusahaan-perusahaan tambang. Riset ini merekomendasikan pentingnya regulasi untuk mengelola pendapatan Indonesia yang bisa diperoleh dari keuntungan tambahan (windfall profit akibat kenaikan harga minyak.

Spatiotemporal Monte Carlo transport methods in x-ray semiconductor detectors: application to pulse-height spectroscopy in a-Se.

Science.gov (United States)

Fang, Yuan; Badal, Andreu; Allec, Nicholas; Karim, Karim S; Badano, Aldo

2012-01-01

The authors describe a detailed Monte Carlo (MC) method for the coupled transport of ionizing particles and charge carriers in amorphous selenium (a-Se) semiconductor x-ray detectors, and model the effect of statistical variations on the detected signal. A detailed transport code was developed for modeling the signal formation process in semiconductor x-ray detectors. The charge transport routines include three-dimensional spatial and temporal models of electron-hole pair transport taking into account recombination and trapping. Many electron-hole pairs are created simultaneously in bursts from energy deposition events. Carrier transport processes include drift due to external field and Coulombic interactions, and diffusion due to Brownian motion. Pulse-height spectra (PHS) have been simulated with different transport conditions for a range of monoenergetic incident x-ray energies and mammography radiation beam qualities. Two methods for calculating Swank factors from simulated PHS are shown, one using the entire PHS distribution, and the other using the photopeak. The latter ignores contributions from Compton scattering and K-fluorescence. Comparisons differ by approximately 2% between experimental measurements and simulations. The a-Se x-ray detector PHS responses simulated in this work include three-dimensional spatial and temporal transport of electron-hole pairs. These PHS were used to calculate the Swank factor and compare it with experimental measurements. The Swank factor was shown to be a function of x-ray energy and applied electric field. Trapping and recombination models are all shown to affect the Swank factor.

Stimulated growth of coherent VLF waves in the magnetosphere

International Nuclear Information System (INIS)

Stiles, G.S.; Helliwell, R.A.

1977-01-01

The amplitude behavior of several hundred VLF whistler mode pulse signals and of their associated artificially stimulated emissions (ASE's) was analyzed with digital signal processing techniques. A survey of the results indicates that the pulse signals characteristically show exponential growth with time that is highly repeatable over short periods. However, the growth rate varies widely from time to time, covering a range of 25 to 250 dB/s. During the exponential growth phase of the pulse there is no observable change in frequency. Emissions may begin when growth stops or when the input pulse terminates, whichever occurs first. Low growth rates and falling emissions characterize the beginning and ending of extended periods of emission activity. Rising emissions are prominent at the height of activity. ASE's triggered by station NAA (14.7 kHz, 1 MW radiated) begin when the transmitted Morse dash terminates (dash length, 150 ms). Some ASE's triggered by pulses from Siple Station, Antarctica (1.6 to 7 kHz, < or = to 1 kW), and Omega, New York (10.2 kHz, 100 W), show similar behavior; others, however, begin prior to the termination of the triggering pulse when the pulse length exceeds 200 ms. Growth and frequency change of the ASE tend to be independent of one another. For transmitted pulses of sufficient duration the amplitude saturates prior to termination. Signal amplitudes may reach 30 dB or more above the initial level. During growth the measured bandwidth of the signal remains near the minimum possible (approximately 27 Hz) with the given analysis resolution (approximately 30 ms, approximately 50 Hz). By comparison with mathematical models it is shown that the observed signals have the maximum possible coherence for the measured values of growth rate and duration. These observations are in qualitative agreement with a model that attributes signal growth and ASE's to an interaction between coherent waves and counterstreaming gyroresonant electrons

A qubit strongly coupled to a resonant cavity: asymmetry of the spontaneous emission spectrum beyond the rotating wave approximation

Energy Technology Data Exchange (ETDEWEB)

Cao, X [Department of Physics and Institute of Theoretical Physics and Astrophysics, Xiamen University, Xiamen, 361005 (China); You, J Q; Nori, F [Advanced Science Institute, RIKEN, Wako-shi 351-0198 (Japan); Zheng, H, E-mail: xfcao@xmu.edu.cn [Department of Physics, Shanghai Jiao Tong University, Shanghai 200240 (China)

2011-07-15

We investigate the spontaneous emission (SE) spectrum of a qubit in a lossy resonant cavity. We use neither the rotating-wave approximation nor the Markov approximation. For the weak-coupling case, the SE spectrum of the qubit is a single peak, with its location depending on the spectral density of the qubit environment. Then, the asymmetry (of the location and heights of the two peaks) of the two SE peaks (which are related to the vacuum Rabi splitting) changes as the qubit-cavity coupling increases. Explicitly, for a qubit in a low-frequency intrinsic bath, the height asymmetry of the splitting peaks is enhanced as the qubit-cavity coupling strength increases. However, for a qubit in an Ohmic bath, the height asymmetry of the spectral peaks is inverted compared to the low-frequency bath case. With further increasing the qubit-cavity coupling to the ultra-strong regime, the height asymmetry of the left and right peaks is slightly inverted, which is consistent with the corresponding case of a low-frequency bath. This inversion of the asymmetry arises from the competition between the Ohmic bath and the cavity bath. Therefore, after considering the anti-rotating terms, our results explicitly show how the height asymmetry in the SE spectrum peaks depends on the qubit-cavity coupling and the type of intrinsic noise experienced by the qubit.

Ziprasidone-induced spontaneous orgasm.

Science.gov (United States)

Boora, K; Chiappone, K; Dubovsky, S; Xu, J

2010-06-01

Neuroleptic treatment in schizophrenic patients has been associated with sexual dysfunction, including impotence and decreased libido. Spontaneous ejaculation without sexual arousal during typical antipsychotic treatment is a rare condition that has been described with zuclopentixol, trifluoperazine, and thiothixene. Here, we are reporting a case of spontaneous orgasm with ziprasidone in a bipolar patient. This patient began to repeatedly experience spontaneous sexual arousal and orgasm, which she had never experienced in the past. Ziprasidone might be causing an increase in sexual orgasm by 5-HT2 receptor antagonism, which preclinical evidence suggests that it facilitates dopamine release in the cortex.

Avaliação do programa de controle da hanseníase em um município hiperendêmico do Estado do Maranhão, Brasil, 1991-1995

Directory of Open Access Journals (Sweden)

Aquino Dorlene Maria Cardoso de

2003-01-01

Full Text Available Estudo descritivo, objetivando avaliar o programa de controle da hanseníase do Município de Buriticupu, Maranhão. Foram analisados 214 prontuários de pacientes portadores das diversas formas clínicas de hanseníase, atendidos na unidade de saúde da Universidade Federal do Maranhão, localizada no referido município. A população de estudo foi constituída de 110 casos de hanseníase das formas paucibacilares (PB e 104 das formas multibacilares (MB registrados no período de janeiro de 1991 a dezembro de 1995. As informações referentes à forma clínica, número de contatos registrados, examinados e avaliados, grau de incapacidade no início e final do tratamento e situação de registro, foram coletadas num formulário específico. A análise dos resultados foi baseada nos parâmetros dos indicadores operacionais definidos pelo Ministério da Saúde. Houve um discreto predomínio da forma PB da doença. Observou-se baixos percentuais em relação aos pacientes com grau de incapacidade física avaliada no início e final do tratamento, a alta por cura e contatos examinados. O percentual de abandono foi elevado. O programa foi considerado "precário" em todos os indicadores utilizados para o estudo.

Avaliação da limitação das atividades diárias e qualidade de vida de pacientes com hanseníase submetidos à cirurgia de neurólise para tratamento das neurites

OpenAIRE

Reis,Felipe José Jandre dos; Gomes,Maria Kátia; Cunha,Antonio José Ledo Alves da

2013-01-01

A neurólise é indicada para reduzir o ­sofrimento neural e impedir a instalação de sequelas e incapacidades em pacientes com hanseníase. O objetivo deste estudo foi verificar o grau de limitação das atividades e a qualidade de vida de pacientes com hanseníase submetidos a neurólise para tratamento das neurites. Participaram do estudo os pacientes submetidos à neurólise no período de 1998 a 2011. Foram coletadas informações sociodemográficas e clínicas, limitações das atividades (SALSA) e a qu...

Research on the ϕ-OTDR fiber sensor sensitive for all of the distance

Science.gov (United States)

Kong, Yong; Liu, Yang; Shi, Yi; Ansari, Farhad; Taylor, Todd

2018-01-01

In this paper, a modified construction for the traditional ϕ-OTDR fiber sensor sensitive for all of distance is presented, the related numerical simulation and experiment analysis results show that this construction can reduce the gain imbalance for all of the distance along the fiber caused by the Rayleigh scattering loss of the fiber and the gain imbalance of Raman fiber amplifier in this fiber sensor system. In order to improve further the vibration sensitivity of this system, the possible methods to restrain the influences of modulation instability effect, Stimulated Brillouin effect, reduce the amplified spontaneous emission (ASE) noises of Raman laser (RL) and Erbium3+-doped fiber amplifiers (EDFA), double Rayleigh backscattering noise in this system are discussed, which will offer a great reference value for the science research and engineering application in the field of fiber sensor as we believe.

Ytterbium‐doped distributed spectral filtering photonic crystal fibers for use at wavelengths above 1100 nm

DEFF Research Database (Denmark)

Petersen, Sidsel Rübner; Alkeskjold, Thomas Tanggaard; Lægsgaard, Jesper

to avoid parasitic lasing due to Amplified Spontaneous Emission (ASE) build‐up. Nonlinear effects, such as stimulated Raman scattering, stimulated Brillouin scattering and four‐wave mixing, set the upper limit for achievable powers in fiber amplifiers. To increase the nonlinear threshold, Large......Rare‐earth doped high‐power fiber lasers and amplifiers have attracted a lot of attention, due to the advantages of the fiber amplification scheme. Compared to conventional optically pumped bulk lasers, heat is dissipated much more effectively in fiber lasers, having a large surface......‐to‐active volume ratio. Thereby, a stable beam with nearly diffraction‐limited quality can be achieved. The fibers are often cladding‐pumped with a number of low‐brightness semiconductor laser diodes, in which way a low‐cost pump of several kilowatts can be achieved [1]. However, the frequencies, which can...

Optical Sensor of Thermal Gas Flow Based on Fiber Bragg Grating

Directory of Open Access Journals (Sweden)

Xu Jiang

2017-02-01

Full Text Available This paper aims at solving the problem of explosion proof in measurement of thermal gas flow using electronic sensor by presenting a new type of flow sensor by optical fiber heating. A measuring unit based on fiber Bragg grating (FBG for fluid temperature and a unit for heat dissipation are designed to replace the traditional electronic sensors. The light in C band from the amplified spontaneous emission (ASE light source is split, with one part used to heat the absorbing coating and the other part used in the signal processing unit. In the heating unit, an absorbing coating is introduced to replace the traditional resistance heating module to minimize the risk of explosion. The measurement results demonstrate a fine consistency between the flow and temperature difference in simulation. The method to enhance the measurement resolution of flow is also discussed.

Receptores de estrógenos (ER E ER) e proteínas envolvidas no transporte transepitelial de cálcio na litíase epididimária de galos domésticos

OpenAIRE

Andre Gustavo de Oliveira

2012-01-01

A litíase epididimária é uma anomalia caracterizada pela presença de cálculos ricos em cálcio na região epididimária de galos. Esta disfunção causa redução na fertilidade, tendo impacto negativo na avicultura. A causa da litíase não é conhecida, mas sabe-se que a formação de cálculos acomete principalmente os dúctulos eferentes, responsáveis pela reabsorção do fluido testicular e de cálcio. O transporte transepitelial de cálcio ocorre em etapas distintas que envolvem a entrada de cálcio na cé...

Capturing triplet emission in white organic light emitting devices

Energy Technology Data Exchange (ETDEWEB)

Singh, Jai [Faculty of EHSE, School of Engineering and IT, B-purple-12, Charles Darwin University, Darwin, NT 0909 (Australia)

2011-08-15

The state-of-the art in the white organic light emitting devices (WOLEDs) is reviewed for further developments with a view to enhance the capture of triplet emission. In particular, applying the new exciton-spin-orbit-photon interaction operator as a perturbation, rates of spontaneous emission are calculated in a few phosphorescent materials and compared with experimental results. For iridium based phosphorescent materials the rates agree quite well with the experimental results. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Aspectos epidemiológicos dateníase-cisticercose na área endêmica de Lagamar, MG

Directory of Open Access Journals (Sweden)

Mario León Silva-Vergara

1995-12-01

Full Text Available Um inquérito epidemiológico sobre teníase-cisticercose foi realizado em Lagamar- MG em 1992. Cadastradas 1109 casas com 3344 habitantes. O inquérito abrangeu 875 (86% famílias e foi respondido por um informante que, em 80% dos casos, foi o pai. Na cidade havia 100 chiqueiros em 100 (11,4% casas que albergavam 406 suínos, em condições extremamente precárias. Em 300 (34,2% casas havia o antecedente de teníase em algum membro da família. O antecedente de convulsão foi relatado por 125 (14,2% famílias. O início das convulsões na idade adulta foi caracterizado em 39 (3 7,8% famílias e o antecedente de doenças mentais foi relatado em 53 (6% casas. Os exames parasitológicos de fezes mostraram ovos de Taenia spp em 24 (1,3% das 1850 amostras examinadas.An epidemiological inquiry of human- cysticercosis due to Taenia solium was carried out in Lagamar, Minas Gerais State, Brazil, in 1992. A survey of 1109 houses with 3344. inhabitants was made. The inquiry included 875 (86% families and the questionaire was answered by an informer, who was the father in 80% of the cases. One hmidred pigsties, sheltering 406 swines in extremely precarious conditions, were found in 100 (11.4% houses. A history on taeniasis in some member of the family was verified in 300 (34.2% houses. A histoiy of seizures was referred to by 125 (14.2% of families. The outset of convulsion in adult age was characterized in 39 (37.8% families. A history of mental disorder was reported in 53 (6.0% of houses. Stool examinations were positive for Taenia spp in 24 (1.3% of samples examined.

Spontaneous rib fractures.

Science.gov (United States)

Katrancioglu, Ozgur; Akkas, Yucel; Arslan, Sulhattin; Sahin, Ekber

2015-07-01

Other than trauma, rib fracture can occur spontaneously due to a severe cough or sneeze. In this study, patients with spontaneous rib fractures were analyzed according to age, sex, underlying pathology, treatment, and complications. Twelve patients who presented between February 2009 and February 2011 with spontaneous rib fracture were reviewed retrospectively. The patients' data were evaluated according to anamnesis, physical examination, and chest radiographs. The ages of the patients ranged from 34 to 77 years (mean 55.91 ± 12.20 years), and 7 (58.4%) were male. All patients had severe cough and chest pain. The fractures were most frequently between 4th and 9th ribs; multiple rib fractures were detected in 5 (41.7%) patients. Eight (66.7%) patients had chronic obstructive pulmonary disease, 2 (16.7%) had bronchial asthma, and 2 (16.7%) had osteoporosis. Bone densitometry revealed a high risk of bone fracture in all patients. Patients with chronic obstructive pulmonary disease or bronchial asthma had been treated with high-dose steroids for over a year. Spontaneous rib fracture due to severe cough may occur in patients with osteoporosis, chronic obstructive pulmonary disease, or bronchial asthma, receiving long-term steroid therapy. If these patients have severe chest pain, chest radiography should be performed to check for bone lesions. © The Author(s) 2015.

High mass asymmetry in spontaneous and induced desintegration of heavy nuclei

International Nuclear Information System (INIS)

Tavares, O.A.P.

1978-01-01

The experimental and theoretical results related to a new rupture mode of heavy ions (A>230) in mass fragments more different than ordinary ission products, are presented and disussed. Experiences of long exposure time by nuclear emulsion technique, show that, the U 238 is also a spontaneous emitter of ions with mass number between 20 and 70. The results are interpreted as a high mass asymmetry in fission process or as a nucleon cluster emission mechanism by potential barrier penetration. Preliminary estimation show good agreement with experimental results for U 238 . Glass laminas with uranium thin films prepared 16 years ago, are also analysed aiming to confirm these results. Several experiences with nuclear emulsions and mica sandwich, and radiochemical data show to be possible heavy ion emission from U 238 induced by photons of low energy as well as neutrons of reactor (M.C.K.) [pt

Unexpected role of excess noise in spontaneous emission

International Nuclear Information System (INIS)

Lamprecht, C.; Ritsch, H.

2002-01-01

A single inverted two-level atom is used as a theoretical model for a quantum noise detector to investigate fundamental properties of excess noise in an unstable optical resonator. For a symmetric unstable spherical mirror cavity, we develop an analytic quantum description of the field in terms of a complete set of normalizable biorthogonal quasimodes and adjoint modes. Including the interaction with a single two-level atom leads to a description analogous to the Jaynes-Cummings model with modified coupling constants. One finds a strong position and geometry-dependent atomic decay probability proportional to the square root √(K) of the excess noise factor K at the cavity center. Introducing an additional homogeneous gain one recovers the K-fold emission enhancement that has been predicted before for the linewidth of an unstable cavity laser. We find that excess noise may be viewed as a spatial redistribution of the field quantum noise inside the resonator. Taking a position average of the atomic decay rate over the cavity volume leads to a cancellation of the excess noise enhancement

Lippmann-Schwinger integral equation approach to the emission of radiation by sources located inside finite-sized dielectric structures

DEFF Research Database (Denmark)

Søndergaard, T.; Tromborg, Bjarne

2002-01-01

uses for analyzing the emission of light by sources in some antennas and optical components such as vertical cavity surface emitting lasers, microdisk lasers, and light emitting diodes. The methods also have prospective uses in quantum electrodynamics for studies of spontaneous emission from, e...

Prevalência e fisiopatologia da litíase biliar em pacientes submetidos a transplante de órgãos

OpenAIRE

Coelho,Júlio Cesar Uili; Contieri,Fabiana Loss de; Matias,Jorge Eduardo Fouto; Parolin,Mônica Beatriz; Godoy,Jose Luiz de

2009-01-01

INTRODUÇÃO: O objetivo do presente estudo é apresentar revisão da prevalência e dos principais mecanismos fisiopatológicos que levam a formação da litíase biliar em pacientes submetidos a transplante de órgãos. MÉTODOS: Revisão da literatura abrangendo 29 publicações obtidas das bases Medline/Pubmed, Scielo e Lilacs com cruzamento dos unitermos "transplante, transplante renal, transplante hepático, cálculo biliar, colecistite.". Vários estudos que utilizaram a ultrassonografia demonstraram au...

Tratamento da amebíase intestinal por meio de pequenas quantidades diárias de etofamida, usadas em esquemas de curta duração

Directory of Open Access Journals (Sweden)

Guido Carlos Levi

1973-12-01

Full Text Available Por meio da etofamida, trataram os autores 40 indivíduos acometidos de amebíase intestinal e representados por crianças e adultos de ambos os sexos. Os esquemas posológicos recomendados para os componentes de dois grupos de 20 elementos foram os seguintes: A 100 mg três vezes em 24 horas, durante cinco dias; B 100 mg, cinco vezes em 24 horas, durante três dias. Foi expressiva a percentagem global de 90% de curas obtidas, mas a administração de maior quantidade diária da droga, durante período mais curto, mostrou-se dotada de melhor efetividade e possibilitou a eliminação da parasitose de todas as pessoas medicadas. O estudo que efetuaram, correspondente à amebíase intestinal assintomática, oligossintomática ou aparente como colite crônica, deixou patente a eficácia do remédio usado, que praticamente não causou distúrbios colaterais e pode ser prescrito segundo planejamentos singelos e executáveis com facilidade.

Gain-clamping techniques in two-stage double-pass L-band EDFA

Indian Academy of Sciences (India)

Two designs of long-wavelength band erbium-doped fiber amplifier (L-band. EDFA) for gain clamping in double-pass systems are demonstrated and compared. The first design is based on ring laser technique where a backward amplified spontaneous emis- sion (ASE) from the second stage is routed into the feedback loop ...

Spontaneous tension haemopneumothorax.

Science.gov (United States)

Patterson, Benjamin Oliver; Itam, Sarah; Probst, Fey

2008-10-31

We present a patient with sudden onset progressive shortness of breath and no history of trauma, who rapidly became haemodynamically compromised with a pneumothorax and pleural effusion seen on chest radiograph. He was treated for spontaneous tension pneumothorax but this was soon revealed to be a tension haemopneumothorax. He underwent urgent thoracotomy after persistent bleeding to explore an apical vascular abnormality seen on CT scanning. To our knowledge this is the first such case reported.Aetiology and current approach to spontaneous haemothorax are discussed briefly.

Density functional theory for field emission from carbon nano-structures

Energy Technology Data Exchange (ETDEWEB)

Li, Zhibing, E-mail: stslzb@mail.sysu.edu.cn

2015-12-15

Electron field emission is understood as a quantum mechanical many-body problem in which an electronic quasi-particle of the emitter is converted into an electron in vacuum. Fundamental concepts of field emission, such as the field enhancement factor, work-function, edge barrier and emission current density, will be investigated, using carbon nanotubes and graphene as examples. A multi-scale algorithm basing on density functional theory is introduced. We will argue that such a first principle approach is necessary and appropriate for field emission of nano-structures, not only for a more accurate quantitative description, but, more importantly, for deeper insight into field emission. - Highlights: • Applications of DFT to electron field emission of nano-structures are reviewed. • Fundamental concepts of field emission are re-visited with emphasis on the many-body effects. • New insights to field emission of nano-structures are obtained by multi-scale DFT calculations. • It is shown that the exchange–correlation effect on the emission barrier is significant. • Spontaneous symmetry breaking in field emission of CNT has been predicted.

Ultra-weak photon emission as a non-invasive tool for monitoring of oxidative processes in the epidermal cells of human skin: comparative study on the dorsal and the palm side of the hand.

Science.gov (United States)

Rastogi, Anshu; Pospísil, Pavel

2010-08-01

All living organisms emit spontaneous ultra-weak photon emission as a result of cellular metabolic processes. Exposure of living organisms to exogenous factors results in oxidative processes and enhancement in ultra-weak photon emission. Here, hydrogen peroxide (H(2)O(2)), as a strongly oxidizing molecule, was used to induce oxidative processes and enhance ultra-weak photon emission in human hand skin. The presented work intends to compare both spontaneous and peroxide-induced ultra-weak photon emission from the epidermal cells on the dorsal and the palm side of the hand. A highly sensitive photomultiplier tube and a charge-coupled device camera were used to detect ultra-weak photon emission from human hand skin. Spontaneous ultra-weak photon emission from the epidermal cells on the dorsal side of the hand was 4 counts/s. Topical application of 500 mM H(2)O(2) to the dorsal side of the hand caused enhancement in ultra-weak photon emission to 40 counts/s. Interestingly, both spontaneous and peroxide-induced ultra-weak photon emission from the epidermal cells on the palm side of the hand were observed to increase twice their values, i.e. 8 and 80 counts/s, respectively. Similarly, the two-dimensional image of ultra-weak photon emission observed after topical application of H(2)O(2) to human skin reveals that photon emission from the palm side exceeds the photon emission from the dorsal side of the hand. The results presented indicate that the ultra-weak photon emission originating from the epidermal cells on the dorsal and the palm side of the hand is related to the histological structure of the human hand skin. Ultra-weak photon emission is shown as a non-destructive technique for monitoring of oxidative processes in the epidermal cells of the human hand skin and as a diagnostic tool for skin diseases.

Solution processable 2-(trityloxy)ethyl and tert-butyl group containing amorphous molecular glasses of pyranylidene derivatives with light-emitting and amplified spontaneous emission properties

Science.gov (United States)

Zarins, Elmars; Vembris, Aivars; Misina, Elina; Narels, Martins; Grzibovskis, Raitis; Kokars, Valdis

2015-11-01

Small organic molecules with incorporated 4H-pyran-4-ylidene (pyranylidene) fragment as the π-conjugation system which bonds the electron acceptor fragment (A) with electron donor part (D) in the molecule - also well known as derivatives of 4-(dicyano-methylene)-2-methyl-6-[p-(dimethylamino)styryl]-4H-pyran (DCM) laser dye-have attracted considerable attention of scientists as potential new generation materials for organic photonics and molecular electronics due to their low-cost fabrication possibility, flexibility and low-weight. Six glassy derivatives of 4H-pyran-4-ylidene (pyranylidene) with attached bulky 2-(trityloxy)ethyl and tert-butyl groups are described in this report. Almost all of the synthesized compounds form good optical quality transparent amorphous films from volatile organic solvents and could be obtained in good yields up to 75%. Their light emission in solution and thin solid films is in the range of 600-700 nm, they are thermally stable and show glass transition in the range of 108-158 °C. The amplified spontaneous emission threshold values of the neat films of the glassy pyranylidene derivatives vary from 155 to 450 μJ/cm2 and their HOMO and LUMO energy levels are between of those of tris(8-hydroxy quinolinato) aluminum (Alq3). The photoluminescence quantum yields of the glassy compounds are in the range from 1% to about 7.7% and their electroluminescence properties have been investigated. Therefore, glassy pyranylidene derivatives could be a very potential low-cost solution processable materials for Alq3 hosted light-amplification and light-emitting application studies.

Hepatobiliary alterations in massive biliary ascariasis: histopathological aspects of an autopsy case Lesões hepatobiliares em ascaridíase biliar maciça: aspectos histopatológicos em um caso de autópsia

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Luiz Carlos da Costa Gayotto

1990-04-01

Full Text Available Hepatobiliary alterations found in an autopsy case of massive Biliary Ascariasis, are reported on histological grounds. Severe cholangitis was the main finding, but other changes were also detected, such as pyloric and intestinal metaplasia, hyperplasia of the epithelial lining, with intraductal papillomas and adenomatous proliferation. Remnants of the worm were observed tightly adhered to the epithelium, forming microscopic intrahepatic calculi. Mucopolysaccharides, especially acid, showed to be strongly positive on the luminal border, and in proliferated glands around the ducts. The authors discuss the similarity between such findings and Oriental Cholangiohepatitis, and suggest that inflammation and the presence of the parasitic remnants are responsible for the hyperplastic and metaplastic changes, similarly with what occurs in chlonorchiasis, fascioliasis and schistosomiasis.Os autores apresentam os aspectos histopatológicos encontrados no fígado de um caso de autópsia de Ascaridíase Biliar maciça. A intensa colangite foi o aspecto predominante, mas outras lesões também foram encontradas, tais como metaplasia pilórica e intestinal, hiperplasia epitelial com papilomas intraductais, e por vezes padrão adenomatoso. Restos do helminto foram encontrados fortemente aderidos ao epitélio, sendo intensa a positividade de mucopolissacárides, principalmente ácidos, na borda luminal do epitélio ductal e em glândulas proliferadas ao redor dos ductos. Os autores discutem a semelhança da Ascaridíase Biliar com a Colangio Hepatite Oriental, e sugerem que o processo inflamatório e a presença de restos do verme são responsáveis pelas alterações hiperplásicas e metaplásicas, analogamente ao que ocorre na clonorquíase, fasciolíase e esquistossomose.

EUV stimulated emission from MgO pumped by FEL pulses

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Philippe Jonnard

2017-09-01

Full Text Available Stimulated emission is a fundamental process in nature that deserves to be investigated and understood in the extreme ultra-violet (EUV and x-ray regimes. Today, this is definitely possible through high energy density free electron laser (FEL beams. In this context, we give evidence for soft-x-ray stimulated emission from a magnesium oxide solid target pumped by EUV FEL pulses formed in the regime of travelling-wave amplified spontaneous emission in backward geometry. Our results combine two effects separately reported in previous works: emission in a privileged direction and existence of a material-dependent threshold for the stimulated emission. We develop a novel theoretical framework, based on coupled rate and transport equations taking into account the solid-density plasma state of the target. Our model accounts for both observed mechanisms that are the privileged direction for the stimulated emission of the Mg L2,3 characteristic emission and the pumping threshold.

Spontaneous tension haemopneumothorax

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Itam Sarah

2008-10-01

Full Text Available Abstract We present a patient with sudden onset progressive shortness of breath and no history of trauma, who rapidly became haemodynamically compromised with a pneumothorax and pleural effusion seen on chest radiograph. He was treated for spontaneous tension pneumothorax but this was soon revealed to be a tension haemopneumothorax. He underwent urgent thoracotomy after persistent bleeding to explore an apical vascular abnormality seen on CT scanning. To our knowledge this is the first such case reported. Aetiology and current approach to spontaneous haemothorax are discussed briefly.

Spontaneous compactification to homogeneous spaces

International Nuclear Information System (INIS)

Mourao, J.M.

1988-01-01

The spontaneous compactification of extra dimensions to compact homogeneous spaces is studied. The methods developed within the framework of coset space dimensional reduction scheme and the most general form of invariant metrics are used to find solutions of spontaneous compactification equations

Case of spontaneous ventriculocisternostomy

Energy Technology Data Exchange (ETDEWEB)

Yamane, Kanji; Yoshimoto, Hisanori; Harada, Kiyoshi; Uozumi, Tohru [Hiroshima Univ. (Japan). School of Medicine; Kuwabara, Satoshi

1983-05-01

The authors experienced a case of spontaneous ventriculocisternostomy diagnosed by CT scan with metrizamide and Conray. Patient was 23-year-old male who had been in good health until one month before admission, when he began to have headache and tinnitus. He noticed bilateral visual acuity was decreased about one week before admission and vomiting appeared two days before admission. He was admitted to our hospital because of bilateral papilledema and remarkable hydrocephalus diagnosed by CT scan. On admission, no abnormal neurological signs except for bilateral papilledema were noted. Immediately, right ventricular drainage was performed. Pressure of the ventricle was over 300mmH/sub 2/O and CSF was clear. PVG and PEG disclosed an another cavity behind the third ventricle, which was communicated with the third ventricle, and occlusion of aqueduct of Sylvius. Metrizamide CT scan and Conray CT scan showed a communication between this cavity and quadrigeminal and supracerebellar cisterns. On these neuroradiological findings, the diagnosis of obstructive hydrocephalus due to benign aqueduct stenosis accompanied with spontaneous ventriculocisternostomy was obtained. Spontaneous ventriculocisternostomy was noticed to produce arrest of hydrocephalus, but with our case, spontaneous regression of such symptoms did not appeared. By surgical ventriculocisternostomy (method by Torkildsen, Dandy, or Scarff), arrest of hydrocephalus was seen in about 50 to 70 per cent, which was the same results as those of spontaneous ventriculocisternostomy. It is concluded that VP shunt or VA shunt is thought to be better treatment of obstructive hydrocephalus than the various kinds of surgical ventriculocisternostomy.

Spontaneous Intracranial Hypotension without Orthostatic Headache

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Tülay Kansu

2009-03-01

Full Text Available We report 2 cases of spontaneous intracranial hypotension that presented with unilateral abducens nerve palsy, without orthostatic headache. While sixth nerve palsies improved without any intervention, subdural hematoma was detected with magnetic resonance imaging. We conclude that headache may be absent in spontaneous intracranial hypotension and spontaneous improvement of sixth nerve palsy can occur, even after the development of a subdural hematoma

Orestes Kinetics Model for the Electra KrF Laser

Science.gov (United States)

Giuliani, J. L.; Kepple, P.; Lehmberg, R. H.; Myers, M. C.; Sethian, J. D.; Petrov, G.; Wolford, M.; Hegeler, F.

2003-10-01

Orestes is a first principles simulation code for the electron deposition, plasma chemistry, laser transport, and amplified spontaneous emission (ASE) in an e-beam pumped KrF laser. Orestes has been benchmarked against results from Nike at NRL and the Keio laser facility. The modeling tasks are to support ongoing oscillator experiments on the Electra laser ( 500 J), to predict performance of Electra as an amplifier, and to develop scaling relations for larger systems such as envisioned for an inertial fusion energy power plant. In Orestes the energy deposition of the primary beam electrons is assumed to be spatially uniform, but the excitation and ionization of the Ar/Kr/F2 target gas by the secondary electrons is determined from the energy distribution function as calculated by a Boltzmann code. The subsequent plasma kinetics of 23 species subject to over 100 reactions is followed with 1-D spatial resolution along the lasing axis. In addition, the vibrational relaxation among excited electronic states of the KrF molecule are included in the kinetics since lasing at 248 nm can occur from several vibrational lines of the B state. Transport of the lasing photons is solved by the method of characteristics. The time dependent ASE is calculated in 3-D using a ``local look-back'' scheme with discrete ordinates and includes specular reflection off the side walls and rear mirror. Gain narrowing is treated by multi-frequency transport of the ASE. Calculations for the gain, saturation intensity, extraction efficiency, and laser output from the Orestes model will be presented and compared with available data from Electra operated as an oscillator. Potential implications for the difference in optimal F2 concentration will be discussed along with the effects of window transmissivity at 248 nm.

Spontaneous intraorbital hematoma: case report

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Vinodan Paramanathan

2010-12-01

Full Text Available Vinodan Paramanathan, Ardalan ZolnourianQueen's Hospital NHS Foundation Trust, Burton on Trent, Staffordshire DE13 0RB, UKAbstract: Spontaneous intraorbital hematoma is an uncommon clinical entity seen in ophthalmology practice. It is poorly represented in the literature. Current evidence attributes it to orbital trauma, neoplasm, vascular malformations, acute sinusitis, and systemic abnormalities. A 65-year-old female presented with spontaneous intraorbital hematoma manifesting as severe ocular pains, eyelid edema, proptosis, and diplopia, without a history of trauma. Computer tomography demonstrated a fairly well defined extraconal lesion with opacification of the paranasal sinuses. The principal differential based on all findings was that of a spreading sinus infection and an extraconal tumor. An unprecedented finding of a spontaneous orbital hematoma was discovered when the patient was taken to theater. We discuss the rarity of this condition and its management.Keywords: hemorrhage, ophthalmology, spontaneous, intra-orbital, hematoma

A device for quantitative plutonium testing in mixed fuel by its neutron emission

International Nuclear Information System (INIS)

Gadzhiev, G.I.; Gorobets, A.K.; Golushko, V.V.; Dunaev, E.S.; Leshchenko, Yu.I.

1987-01-01

A device for quantitative plutonium testing in mixed fuel by its neutron emission is described. The method of ''assigned dead time'' for isolation of neutrons of spontaneous fission is used in the device. The main characteristics of the registrating equipment specifying the regime of measuring and affecting testing errors are presented. The results of spontaneous fission neutrons detection in the range up to 100 g of plutonium linearly depend on 240 Pu. Sensitivity of testing makes up about 28 pul./s per 1 g of 240 Pu

Regressão de psoríase em paciente HIV-positivo após terapia anti-retroviral Regression of psoriasis in HIV patient after antiretroviral therapy

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Maria de Fátima Amorin Ruiz

2003-12-01

Full Text Available A síndrome da imunodeficiência adquirida foi reconhecida pela primeira vez como nova doença em 1981 devido à associação atípica de sarcoma de Kaposi e pneumonia por Pneumocystis carinii em homens. A pele é sede freqüente de doenças conseqüentes a essa infecção. A psoríase é dermatose crônica que afeta proporção que varia de 1,3 a 5% dos pacientes infectados com HIV. Portadores de psoríase que apresentem formas clínicas exacerbadas e dificuldade de resposta terapêutica devem ser investigados para possível infecção pelo HIV. É relatado caso de paciente do sexo masculino, de 44 anos, que iniciou com lesões eritêmato-escamosas no couro cabeludo, nos cotovelos, joelhos, palma das mãos, planta dos pés, além de comprometimento ungueal, após infecção pelo HIV. Confirmado o diagnóstico de psoríase e introduzida a terapia anti-retroviral, houve melhora significativa das lesões.Immunodeficiency syndrome was first described as a new disease in 1981 because an unusual association of Kaposi's Sarcoma and Pneumocystis carinii pneumonia in men. The skin is a frequent site of diseases due to this infection. Psoriasis is a chronic dermatitis that affects 1.3-5% of HIV-positive patients. The case is described of a 44-year-old man with onset of erythematous scaly lesions in scalp, elbows, knees, hands, feet and nails following HIV infection. After diagnosis of psoriasis was confirmed and antiretroviral therapy instigated, he presented improvement of the psoriasis lesions.

Screening for spontaneous preterm birth

NARCIS (Netherlands)

van Os, M.A.; van Dam, A.J.E.M.

2015-01-01

Preterm birth is the most important cause of perinatal morbidity and mortality worldwide. In this thesis studies on spontaneous preterm birth are presented. The main objective was to investigate the predictive capacity of mid-trimester cervical length measurement for spontaneous preterm birth in a

Early pregnancy angiogenic markers and spontaneous abortion

DEFF Research Database (Denmark)

Andersen, Louise B; Dechend, Ralf; Karumanchi, S Ananth

2016-01-01

BACKGROUND: Spontaneous abortion is the most commonly observed adverse pregnancy outcome. The angiogenic factors soluble Fms-like kinase 1 and placental growth factor are critical for normal pregnancy and may be associated to spontaneous abortion. OBJECTIVE: We investigated the association between...... maternal serum concentrations of soluble Fms-like kinase 1 and placental growth factor, and subsequent spontaneous abortion. STUDY DESIGN: In the prospective observational Odense Child Cohort, 1676 pregnant women donated serum in early pregnancy, gestational week ..., interquartile range 71-103). Concentrations of soluble Fms-like kinase 1 and placental growth factor were determined with novel automated assays. Spontaneous abortion was defined as complete or incomplete spontaneous abortion, missed abortion, or blighted ovum

Nonlinear time-domain cochlear model for transient stimulation and human otoacoustic emission

DEFF Research Database (Denmark)

Verhulst, Sarah; Dau, Torsten; Shera, Christopher A.

2012-01-01

This paper describes the implementation and performance of a nonlinear time-domain model of the cochlea for transient stimulation and human otoacoustic emission generation. The nonlinearity simulates compressive growth of measured basilar-membrane impulse responses. The model accounts...... for reflection and distortion-source otoacoustic emissions (OAEs) and simulates spontaneous OAEs through manipulation of the middle-ear reflectance. The model was calibrated using human psychoacoustical and otoacoustic tuning parameters. It can be used to investigate time-dependent properties of cochlear...

Atingidos pela hanseníase, reparados pelo Estado : as múltiplas histórias performadas da Lei 11.520/2007

OpenAIRE

Glaucia Cristina Maricato Moreto

2015-01-01

Esta dissertação gira em torno da lei nº 11.520, que em setembro de 2007 estabeleceu o direito a uma pensão especial a todas as pessoas atingidas pela hanseníase e compulsoriamente internadas em colônias hospitalares até 31 de dezembro de 1986. Por um lado, alinhado ao trabalho de diversas pesquisadoras, tais como Vianna (2013), Bevilaqua (2013), Schuch (2008), Das e Polle (2008), Vecchioli (2001) e Ferreira (2009), o enfoque não é direcionado à letra da lei 11.520/2007 (enquanto conjunto de ...

A Case of Multiple Spontaneous Keloid Scars

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Abdulhadi Jfri

2015-07-01

Full Text Available Keloid scars result from an abnormal healing response to cutaneous injury or inflammation that extends beyond the borders of the original wound. Spontaneous keloid scars forming in the absence of any previous trauma or surgical procedure are rare. Certain syndromes have been associated with this phenomenon, and few reports have discussed the evidence of single spontaneous keloid scar, which raises the question whether they are really spontaneous. Here, we present a 27-year-old mentally retarded single female with orbital hypertelorism, broad nasal bridge, repaired cleft lip and high-arched palate who presented with progressive multiple spontaneous keloid scars in different parts of her body which were confirmed histologically by the presence of typical keloidal collagen. This report supports the fact that keloid scars can appear spontaneously and are possibly linked to a genetic factor. Furthermore, it describes a new presentation of spontaneous keloid scars in the form of multiple large lesions in different sites of the body.

Modification of electric and magnetic dipole emission in anisotropic plasmonic systems.

Science.gov (United States)

Noginova, N; Hussain, R; Noginov, M A; Vella, J; Urbas, A

2013-10-07

In order to investigate the effects of plasmonic environments on spontaneous emission of magnetic and electric dipoles, we have studied luminescence of Eu³⁺ ions in close vicinity to gold nanostrip arrays. Significant changes in the emission kinetics, emission polarization, and radiation patterns have been observed in the wavelength range corresponding to the plasmonic resonance. The effect of the plasmonic resonance on the magnetic dipole transition ⁵D₀-->⁷F₁ is found to be very different from its effect on the electric dipole transitions. This makes Eu³⁺₋ containing complexes promising for mapping local distributions of magnetic and electric fields in metamaterials and plasmonic systems.

Asma e ascaridíase em crianças de 2 a 10 anos de um bairro de periferia Asthma and ascariasis in children aged two to ten living in a low income suburb

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Maria Teresa Nascimento Silva

2003-06-01

Full Text Available OBJETIVO: avaliar a associação entre asma e ascaridíase em crianças do bairro Pedregal, da cidade de Campina Grande (Paraíba, onde são baixos os indicadores de desenvolvimento humano. MATERIAL E MÉTODO: foi aplicado o questionário padrão do International Study of Asthma and Allergies in Childhood (ISAAC, em 1.095 crianças, mas apenas 742 o responderam e entregaram a amostra fecal para realização do exame parasitológico. A faixa etária das 742 crianças incluídas no estudo transversal foi de 2 a 10 anos de idade. A associação entre asma e ascaridíase foi estudada pelo índice Kappa. As análises das variáveis demográficas e clínicas, comparando os dois grupos, foram realizadas pelo teste do qui-quadrado (chi² ou o teste t de Student para os dados quantitativos (contínuos. RESULTADOS: nas 742 crianças, as proporções dos sexos foram semelhantes: 51,9% (n = 385 do masculino e 48,1% (n = 357 do feminino. Nessas crianças, a prevalência de asma foi de 59,7% (n = 443 e da ascaridíase de 56,3% (n = 418, sendo semelhante (chi² = 0,27; p > 0,60 a freqüência de asma no grupo portador de ascaridíase (60,5% ou sem essa helmintíase (58,6%. CONCLUSÃO: apesar da elevada freqüência dos agravos estudados, não há aparente associação entre asma e ascaridíase na população estudada.OBJECTIVE: to assess the relation between children with asthma and ascariasis in the low income neighborhood of Pedregal, in Campina Grande (Paraíba, Brazil. MATERIAL AND METHOD: the International Study of Asthma and Allergies in Childhood (ISSAC standard questionnaire was distributed to 1,095 children but only 742 of them answered it and provided stool samples for parasite examination. The cross-sectional study included those 742 children, whose age ranged from 2 to 10 years. The association between asthma and ascariasis was studied through Kappa rating. Demographic and clinic variants comparing the two groups were analyzed by chi-square test