WorldWideScience

Sample records for causing light interference

  1. Colours and metallic sheen in beetle shells - A biomimetic search for material structuring principles causing light interference

    DEFF Research Database (Denmark)

    Lenau, Torben Anker; Barfoed, Michael

    2008-01-01

    mechanisms that generate them. The metallic and bright colours of beetle shells are structural colours deriving from at least two different internal shell structures with different light reflecting properties. One nano-structure is the multilayer stack which is composed of layered pairs with different......Visual aesthetic has always played a vital role for the success of many products. This includes colours and glossiness and metal appearance which is often achieved using surface coatings. Present coating techniques do, however, have limitations. It is difficult to reach very bright and brilliant...... colours, colours tend to fade over time and many of the materials and coating technologies pollute and have other environmental problems. Beetles in nature have many of the desired properties: They have appealing brilliant colours and some even with metallic appearance. It is noticeable that the colours...

  2. Nonlocal Double-Slit Interference with Pseudothermal Light

    OpenAIRE

    Gao, Lu; Xiong, Jun; Lin, Lu-Fang; Wang, Wei; Zhang, Su-Heng; Wang, Kaige

    2007-01-01

    We perform a nonlocal double-slit interference experiment with pseudothermal light. The experimental result exhibits a typical double-slit interference fringe in the intensity correlation measurement, in agreement with the theoretical analysis by means of the property of the second-order spatial correlation of field.

  3. Quantum Interference and Entanglement Induced by Multiple Scattering of Light

    DEFF Research Database (Denmark)

    Ott, Johan Raunkjær; Mortensen, Asger; Lodahl, Peter

    2010-01-01

    We report on the effects of quantum interference induced by the transmission of an arbitrary number of optical quantum states through a multiple-scattering medium. We identify the role of quantum interference on the photon correlations and the degree of continuous variable entanglement between two...... output modes. It is shown that quantum interference survives averaging over all ensembles of disorder and manifests itself as increased photon correlations due to photon antibunching. Furthermore, the existence of continuous variable entanglement correlations in a volume speckle pattern is predicted. Our...... results suggest that multiple scattering provides a promising way of coherently interfering many independent quantum states of light of potential use in quantum information processing....

  4. Phase control of light propagation via Fano interference in asymmetric double quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Wen-Xing, E-mail: wenxingyang2@126.com [Department of Physics, Southeast University, Nanjing 210096 (China); Institute of Photonics Technologies, National Tsing-Hua University, Hsinchu 300, Taiwan (China); Lu, Jia-Wei; Zhou, Zhi-Kang; Yang, Long [Department of Physics, Southeast University, Nanjing 210096 (China); Lee, Ray-Kuang [Institute of Photonics Technologies, National Tsing-Hua University, Hsinchu 300, Taiwan (China)

    2014-05-28

    We investigate the light propagation and dynamical control of a weak pulsed probe field in asymmetric double quantum wells via Fano interference, which is caused by tunneling from the excited subbands to the same continuum. Our results show that the system can produce anomalous and normal dispersion regions with negligible absorption by choosing appropriate coupling strength of the tunneling and the Fano interference. Interesting enough, the dispersion can be switched between normal and anomalous by adjusting the relative phase between the pulsed probe and coherent control fields owing to the existence of the perfectly Fano interference. Thus, the relative phase can be regarded as a switch to manipulate light propagation with subluminal or superluminal. The temporal and spatial dynamics of the pulsed probe field with hyperbolic secant envelope are analyzed.

  5. Phase control of light propagation via Fano interference in asymmetric double quantum wells

    International Nuclear Information System (INIS)

    We investigate the light propagation and dynamical control of a weak pulsed probe field in asymmetric double quantum wells via Fano interference, which is caused by tunneling from the excited subbands to the same continuum. Our results show that the system can produce anomalous and normal dispersion regions with negligible absorption by choosing appropriate coupling strength of the tunneling and the Fano interference. Interesting enough, the dispersion can be switched between normal and anomalous by adjusting the relative phase between the pulsed probe and coherent control fields owing to the existence of the perfectly Fano interference. Thus, the relative phase can be regarded as a switch to manipulate light propagation with subluminal or superluminal. The temporal and spatial dynamics of the pulsed probe field with hyperbolic secant envelope are analyzed.

  6. Light interference detection on-chip by integrated SNSPD counters

    Directory of Open Access Journals (Sweden)

    Paul Cavalier

    2011-12-01

    Full Text Available A SWIFTS device (Stationary Wave Integrated Fourier Transform Spectrometer has been realized with an array of 24 Superconducting Nanowire Single Photon Detectors (SNSPD, on-chip integrated under a Si3N4 monomode rib-waveguide interferometer. Colored light around 1.55μm wavelength is introduced through end-fire coupling, producing a counter-propagative stationary interferogram over the 40nm wide, 120nm spaced, 4nm thick epi-NbN nanowire array. Modulations in the source bandwidth have been detected using individual waveguide coupled SNSPDs operating in single photon counting mode, which is a step towards light spectrum reconstruction by inverse Fourier transform of the stationary wave intensity. We report the design, fabrication process and in-situ measurement at 4.2K of light power modulation in the interferometer, obtained with variable laser wavelength. Such micro-SWIFTS configuration with 160nm sampling period over 3.84μm distance allows a spectral bandwidth of 2μm and a wavelength resolution of 170nm. The light interferences direct sampling ability is unique and raises wide interest with several potential applications like fringe-tracking, metrology, cryptography or optical tomography.

  7. Does predator interference cause alternative stable states in multispecies communities?

    NARCIS (Netherlands)

    Feng, J.; Dakos, V.; Nes, van E.H.

    2012-01-01

    Whereas it is well known that simple ecological mechanisms may promote stability in simple species models, their consequences for stability and resilience in multispecies communities are largely unexplored. Here, we studied the effect of predator interference on the occurrence of alternative attract

  8. Breast cancer diagnosis using spatial light interference microscopy

    Science.gov (United States)

    Majeed, Hassaan; Kandel, Mikhail E.; Han, Kevin; Luo, Zelun; Macias, Virgilia; Tangella, Krishnarao; Balla, Andre; Popescu, Gabriel

    2015-11-01

    The standard practice in histopathology of breast cancers is to examine a hematoxylin and eosin (H&E) stained tissue biopsy under a microscope to diagnose whether a lesion is benign or malignant. This determination is made based on a manual, qualitative inspection, making it subject to investigator bias and resulting in low throughput. Hence, a quantitative, label-free, and high-throughput diagnosis method is highly desirable. We present here preliminary results showing the potential of quantitative phase imaging for breast cancer screening and help with differential diagnosis. We generated phase maps of unstained breast tissue biopsies using spatial light interference microscopy (SLIM). As a first step toward quantitative diagnosis based on SLIM, we carried out a qualitative evaluation of our label-free images. These images were shown to two pathologists who classified each case as either benign or malignant. This diagnosis was then compared against the diagnosis of the two pathologists on corresponding H&E stained tissue images and the number of agreements were counted. The agreement between SLIM and H&E based diagnosis was 88% for the first pathologist and 87% for the second. Our results demonstrate the potential and promise of SLIM for quantitative, label-free, and high-throughput diagnosis.

  9. Disease-Causing Allele-Specific Silencing by RNA Interference

    Directory of Open Access Journals (Sweden)

    Hirohiko Hohjoh

    2013-04-01

    Full Text Available Small double-stranded RNAs (dsRNAs of approximately 21-nucleotides in size, referred to as small interfering RNA (siRNA duplexes, can induce sequence-specific posttranscriptional gene silencing, or RNA interference (RNAi. Since chemically synthesized siRNA duplexes were found to induce RNAi in mammalian cells, RNAi has become a powerful reverse genetic tool for suppressing the expression of a gene of interest in mammals, including human, and its application has been expanding to various fields. Recent studies further suggest that synthetic siRNA duplexes have the potential for specifically inhibiting the expression of an allele of interest without suppressing the expression of other alleles, i.e., siRNA duplexes likely confer allele-specific silencing. Such gene silencing by RNAi is an advanced technique with very promising applications. In this review, I would like to discuss the potential utility of allele-specific silencing by RNAi as a therapeutic method for dominantly inherited diseases, and describe possible improvements in siRNA duplexes for enhancing their efficacy.

  10. Characterization of two distant double-slits by chaotic light second-order interference

    CERN Document Server

    D'Angelo, Milena; Pepe, Francesco V; Garuccio, Augusto; Tamma, Vincenzo

    2016-01-01

    We present the experimental characterization of two distant double-slit masks illuminated by chaotic light, in the absence of first-order imaging and interference. The scheme exploits second-order interference of light propagating through two indistinguishable pairs of disjoint optical paths passing through the masks of interest. The proposed technique leads to a deeper understanding of biphoton interference and coherence, and opens the way to the development of novel schemes for retrieving information on the relative position and the spatial structure of distant objects, which is of interest in remote sensing, biomedical imaging, as well as monitoring of laser ablation, when first-order imaging and interference are not feasible.

  11. Super-resolving multi-photon interferences with independent light sources

    CERN Document Server

    Oppel, Steffen; Kok, Pieter; von Zanthier, Joachim

    2012-01-01

    Multi-photon interferences with indistinguishable photons from independent light sources are at the focus of current research owing to their potential in optical quantum computing, creating remote entanglement for quantum computation and communication, and quantum metrology. The paradigmatic states for multi-photon interference are the highly entangled NOON states, which can be used to achieve increased resolution in spectroscopy, interferometry, lithography, and microscopy. Multi-photon interferences from independent, uncorrelated emitters can also lead to enhanced resolution in metrology and imaging. So far, such interferences have been observed with maximally two independent emitters. Here, we report multi-photon interferences with up to five independent emitters, displaying interference patterns equivalent to those of NOON states. Experimental results with independent thermal light sources confirm this NOON-like modulation. The experiment is an extension of the landmark measurement by Hanbury Brown and Tw...

  12. Direct laser interference patterning of polystyrene films doped with azo dyes, using 355 nm laser light

    International Nuclear Information System (INIS)

    Highlights: • We describe the first use of Direct Laser Interference Patterning on PS at 355 nm. . • The structured areas of regular lines are produced in several square millimeters. • The method, Direct Laser Interference Patterning (DLIP) uses a single laser pulse. • DLIP is applied at room temperature and atmospheric pressure. • DLIP is easier to use than other lithographic techniques. • The topography contrasts with the usual Polystyrene ablation at lower wavelengths. - Abstract: The generation of line-like periodic patterns by direct laser interference patterning (DLIP) of polystyrene films (PS) at a wavelength of 355 nm has been investigated. No structuration is achieved in plain PS due to the weak absorption of the polymer at 355 nm. On the other hand, patterning is achieved on films doped (PSd) with an azo dye (2-anisidine → 2-anisidine) which is incorporated in the polymer solution used for film preparation. Periodic micro-structures are generated. DLIP on PSd results in the swelling of the surface at low fluences, while at high laser intensities it causes the ablation of the regions at the interference maxima positions. The results contrast with the usual process of DLIP on PS (at shorter wavelengths, like 266 nm) where only ablation is detected. The results suggest that decomposition of the azo dye is the driving force of the patterning which therefore differ from the patterning obtained when plain PS is irradiated with laser light able to be absorbed by the aromatic ring in PS (e.g. 266 nm). The biocompatibility of these materials and adhesion of cells was tested, the data from in vitro assays shows that fibroblast cells are attached and proliferate extensively on the PSd films

  13. Signal-to-noise ratio of lensless ghost interference with thermal incoherent light

    Institute of Scientific and Technical Information of China (English)

    Zhang Er-Feng; Dai Hong-Yi; Chen Ping-Xing

    2011-01-01

    Factors influencing the signal-to-noise ratio (SNR) of lensless ghost interference with thermal incoherent light are investigated. Our result shows that the SNR of lensless ghost interference is related to the transverse length of the object, the position of the object in the imaging system and the transverse size of the light source. Furthermore, the effects of these factors on the SNR are discussed in detail by numerical simulations.

  14. Optical Interference Effects by Metal Cathode in Organic Light-Emitting Diodes

    Institute of Scientific and Technical Information of China (English)

    WU Zhao-Xin; WANG Li-Duo; QIU Yong

    2004-01-01

    The dependence of light intensities of organic light-emitting diodes (OLEDs) on the distance of emission zone to metal cathode is investigated numerically. The investigation is based on the half-space optical model that accounts for optical interference effects of metal cathode. We find that light intensities of OLEDs are functions of the distance of emission zone from the metal cathode because of the effect of interference of the metal cathode.This interference leads to an optimal location of emission zone in OLEDs for the maximum of light intensities.Optimal locations of emission zone are numerically shown in various emitting colour OLEDs with different metal cathodes and these results are expected to give insight into the preparation of high efficiency full colour or white light OLEDs.

  15. Interference and dynamics of light from a distance-controlled atom pair in an optical cavity

    CERN Document Server

    Neuzner, Andreas; Morin, Olivier; Ritter, Stephan; Rempe, Gerhard

    2016-01-01

    Interference is central to quantum physics and occurs when indistinguishable paths exist, like in a double-slit experiment. Replacing the two slits with two single atoms introduces optical non-linearities for which nontrivial interference phenomena are predicted. Their observation, however, has been hampered by difficulties in preparing the required atomic distribution, controlling the optical phases and detecting the faint light. Here we overcome all of these experimental challenges by combining an optical lattice for atom localisation, an imaging system with single-site resolution, and an optical resonator for light steering. We observe resonator-induced saturation of resonance fluorescence for constructive interference of the scattered light and nonzero emission with huge photon bunching for destructive interference. The latter is explained by atomic saturation and photon pair generation. Our experimental setting is scalable and allows one to realize the Tavis-Cummings model for any number of atoms and pho...

  16. Low-Power Photoplethysmogram Acquisition Integrated Circuit with Robust Light Interference Compensation

    OpenAIRE

    Jongpal Kim; Jihoon Kim; Hyoungho Ko

    2015-01-01

    To overcome light interference, including a large DC offset and ambient light variation, a robust photoplethysmogram (PPG) readout chip is fabricated using a 0.13-μm complementary metal–oxide–semiconductor (CMOS) process. Against the large DC offset, a saturation detection and current feedback circuit is proposed to compensate for an offset current of up to 30 μA. For robustness against optical path variation, an automatic emitted light compensation method is adopted. To prevent ambient light...

  17. Proposed experiment to test the non-locality hypothesis in transient light-interference phenomena

    OpenAIRE

    Sato, Masanori

    2006-01-01

    The transient phenomena of the Mach-Zender interferometer are discussed. To test the non-locality hypothesis, a single mode laser with a large coherence length is used. The behavior of a photon and its wave packets in the paths of the interferometer are discussed. Coherent photons have wave packets that overlap, thus their interference pattern is influenced by the overlap of the wave packets of other photons in transient phenomena. The proposed transient light-interference experiment will pro...

  18. Interference pattern generation and simulation in the single beam of a white light continuum

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    We demonstrate the interference phenomenon in the White Light Continuum(WLC) generated by a single femtosecond laser beam. Different kinds of spatial interference patterns of the WLC generation under various conditions were investigated. The spatial patterns were attributed to interference between the filaments in the WLC generated by the fundamental laser beam yielding the diffraction effect from spatial confinement. Simulations of different patterns were performed. By comparing the results of simulation with those of experiments,the distances of several micrometers between the neighboring filaments can be derived,which agree with the literature values from direct measurements.

  19. Note: Experimental observation of nano-channel pattern in light sheet laser interference nanolithography system

    Science.gov (United States)

    Mohan, Kavya; Mondal, Partha Pratim

    2016-06-01

    We experimentally observed nano-channel-like pattern in a light-sheet based interference nanolithography system. The optical system created nano-channel-like patterned illumination. Coherent counter-propagating light sheets are made to interfere at and near geometrical focus along the propagation z-axis. This results in the formation of nano-channel-like pattern (of size ≈ 300 nm and inter-channel periodicity of ≈337.5 nm) inside the sample due to constructive and destructive interference. In addition, the technique has the ability to generate large area patterning using larger light-sheets. Exciting applications are in the broad field of nanotechnology (nano-electronics and nano-fluidics).

  20. Light pipe design method and stepper experimentation for interference effects reduction in laser illumination

    Science.gov (United States)

    Poyet, Jean-Michel; Lutz, Yves

    2016-07-01

    The use of light pipes is an efficient and low-cost technique to get a homogeneous illumination for laser-gated viewing systems. However, this technique suffers from drawbacks when used with coherent sources like solid-state lasers. Compacting light pipe-based laser illuminators involves working with small light pipe sections, and experiments show that interference fringes appear on the laser illumination profiles. The principle of light pipe homogenization has been reviewed using geometrical optics to understand the phenomenon better, and a pragmatic light pipe design method, based on laser-gated viewing system parameters, is proposed. Another original solution based on optical stepper is studied to reduce both interference fringes and speckle noise to increase the homogeneity of laser illumination profiles.

  1. The interference aerodynamics caused by the wing elasticity during store separation

    Science.gov (United States)

    Lei, Yang; Zheng-yin, Ye

    2016-04-01

    Air-launch-to-orbit is the technology that has stores carried aloft and launched the store from the plane to the orbit. The separation between the aircraft and store is one of the most important and difficult phases in air-launch-to-orbit technology. There exists strong aerodynamic interference between the aircraft and the store in store separation. When the aspect ratio of the aircraft is large, the elastic deformations of the wing must be considered. The main purpose of this article is to study the influence of the interference aerodynamics caused by the elastic deformations of the wing to the unsteady aerodynamics of the store. By solving the coupled functions of unsteady Navier-Stokes equations, six degrees of freedom dynamic equations and structural dynamic equations simultaneously, the store separation with the elastic deformation of the aircraft considered is simulated numerically. And the interactive aerodynamic forces are analyzed. The study shows that the interference aerodynamics is obvious at earlier time during the separation, and the dominant frequency of the elastic wing determines the aerodynamic forces frequencies of the store. Because of the effect of the interference aerodynamics, the roll angle response and pitch angle response increase. When the store is mounted under the wingtip, the additional aerodynamics caused by the wingtip vortex is obvious, which accelerate the divergence of the lateral force and the lateral-directional attitude angle of the store. This study supports some beneficial conclusions to the engineering application of the air-launch-to-orbit.

  2. White-light interference fringe detection using color CCD camera

    Czech Academy of Sciences Publication Activity Database

    Buchta, Zdeněk; Jedlička, Petr; Matějka, Milan; Kolařík, Vladimír; Mikel, Břetislav; Lazar, Josef; Číp, Ondřej

    Los Alamitos : IEEE, 2009, 5308093: 1-5. ISBN 978-1-4244-3918-8. [Africon 2009. Nairobi (KE), 23.09.2009-25.09.2009] R&D Projects: GA MŠk(CZ) LC06007; GA MŠk 2C06012; GA AV ČR KAN311610701; GA MPO 2A-1TP1/127; GA MPO FT-TA3/133; GA MPO 2A-3TP1/113; GA ČR GA102/07/1179; GA ČR GP102/09/P293; GA ČR GP102/09/P630; GA ČR GA102/09/1276 Institutional research plan: CEZ:AV0Z20650511 Keywords : white- light source * phase-crossing algorithm * gauge block * color CCD camera Subject RIV: BH - Optics, Masers, Lasers

  3. Low-Power Photoplethysmogram Acquisition Integrated Circuit with Robust Light Interference Compensation.

    Science.gov (United States)

    Kim, Jongpal; Kim, Jihoon; Ko, Hyoungho

    2015-01-01

    To overcome light interference, including a large DC offset and ambient light variation, a robust photoplethysmogram (PPG) readout chip is fabricated using a 0.13-μm complementary metal-oxide-semiconductor (CMOS) process. Against the large DC offset, a saturation detection and current feedback circuit is proposed to compensate for an offset current of up to 30 μA. For robustness against optical path variation, an automatic emitted light compensation method is adopted. To prevent ambient light interference, an alternating sampling and charge redistribution technique is also proposed. In the proposed technique, no additional power is consumed, and only three differential switches and one capacitor are required. The PPG readout channel consumes 26.4 μW and has an input referred current noise of 260 pArms. PMID:26729122

  4. Low-Power Photoplethysmogram Acquisition Integrated Circuit with Robust Light Interference Compensation

    Directory of Open Access Journals (Sweden)

    Jongpal Kim

    2015-12-01

    Full Text Available To overcome light interference, including a large DC offset and ambient light variation, a robust photoplethysmogram (PPG readout chip is fabricated using a 0.13-μm complementary metal–oxide–semiconductor (CMOS process. Against the large DC offset, a saturation detection and current feedback circuit is proposed to compensate for an offset current of up to 30 μA. For robustness against optical path variation, an automatic emitted light compensation method is adopted. To prevent ambient light interference, an alternating sampling and charge redistribution technique is also proposed. In the proposed technique, no additional power is consumed, and only three differential switches and one capacitor are required. The PPG readout channel consumes 26.4 μW and has an input referred current noise of 260 pArms.

  5. Topography and refractometry of nanostructures using spatial light interference microscopy (SLIM)

    OpenAIRE

    Wang, Zhuo; Chun, Ik Su; Li, Xiuling; Ong, Zhun-Yong; Pop, Eric; Millet, Larry; Gillette, Martha; Popescu, Gabriel

    2010-01-01

    Spatial Light Interference Microscopy (SLIM) is a novel method developed in our laboratory that provides quantitative phase images of transparent structures with 0.3 nm spatial and 0.03 nm temporal accuracy owing to the white light illumination and its common path interferometric geometry. We exploit these features and demonstrate SLIM's ability to perform topography at a single atomic layer in graphene. Further, using a decoupling procedure that we developed for cylindrical structures, we ex...

  6. Cardiomyocyte Imaging Using Real-Time Spatial Light Interference Microscopy (SLIM)

    OpenAIRE

    Bhaduri, Basanta; Wickland, David; Wang, Ru; Chan, Vincent; Bashir, Rashid; Popescu, Gabriel

    2013-01-01

    Spatial light interference microscopy (SLIM) is a highly sensitive quantitative phase imaging method, which is capable of unprecedented structure studies in biology and beyond. In addition to the π/2 shift introduced in phase contrast between the scattered and unscattered light from the sample, 4 phase shifts are generated in SLIM, by increments of π/2 using a reflective liquid crystal phase modulator (LCPM). As 4 phase shifted images are required to produce a quantitative phase image, the sw...

  7. Coplanarity inspection of BGA solder balls based on laser interference structure light

    Science.gov (United States)

    Wei, Zhe; Xiao, Zexin; Zhang, Xuefei; Zhou, Haiying

    2011-11-01

    Using laser interference structure light for profilometry is a rapid, non-contact, full-field profile and high accuracy measuring method.And it has been a promising technique in complicated geometrical shape measurement. In this paper, a fast and cost-effective measurement method of coplanarity inspection of ball grid array (BGA) solder balls is proposed. Laser interference structure light can be obtained by using the principle of shearing interferometry. The collimated and beam expanded laser produced interference fringe by the high reflection rate optical flat. After laser interference fringe project on the surface of object and the structured light would modulated. The light signal pass through the image optical grabber and captured by the CCD image sensor. The height of each point on object can be demodulated by the imaging processing software.This method to construct the measurement appliance for coplanarity inspection of ball grid array (BGA) chip solder ball. Experiments have shown that the coplanarity measurement of BGA solder balls is very efficient and effective with the measurement. The measurement accuracy achieve micrometer level. The processing time of the measurement accuracy is less than 3s on a personal computer. This measurement appliance could completely meet the demand of measure.

  8. Effect of interferences on indoor visible light car-to-car communication systems

    Science.gov (United States)

    Kim, Jong-Young; Park, Bong-Seok; Choi, Hyun-Sik; Kim, So Eun; Moon, Inkyu; Lee, Chung Ghiu

    2016-04-01

    We report the effect of interferences on visible light car-to-car communication system. The interferences from floor reflections and fluorescent lamps are taken into account for indoor car-to-car visible light communication (VLC) systems. The system is composed of a white LED lamp as a VLC transmitter and a photo-receiver with an appropriate optical filter as a VLC receiver. The signal power distribution patterns are measured and analyzed at a transmission distance, considering the positions of the transmitter and receiver. Generally, the light from fluorescent lamps in indoor environment affects the DC level of the received signal power, which is more significant at higher receiver positions. The measurements show that the indoor VLC communication performance can be varied depending on floor reflections. Also, the fluorescent ceiling illuminations affect the DC level change of the received VLC signal waveforms.

  9. Submicrometer photonic structure fabrication by phase spatial-light-modulator-based interference lithography.

    Science.gov (United States)

    Behera, Saraswati; Kumar, Manish; Joseph, Joby

    2016-04-15

    We present a large-area and single-step fabrication approach based on phase spatial light modulator (SLM)-assisted interference lithography for the realization of submicrometer photonic structures on photoresist. A multimirror beam steering unit is used to reflect the SLM-generated phase-engineered beams leading to a large angle between interfering beams while also preserving the large area of the interfering plane beams. Both translational and rotational periodic submicrometer structures are experimentally realized. This approach increases the flexibility of interference lithography to fabricate more complex submicrometer photonic structures and photonic metamaterial structures for future applications. PMID:27082372

  10. Calibration of wavefront distortion in light modulator setup by Fourier analysis of multi-beam interference

    CERN Document Server

    Leszczyński, Adam

    2015-01-01

    We present a method to calibrate wavefront distortion of the spatial light modulator setup by registering far field images of several gaussian beams diffracted off the modulator. The Fourier transform of resulting interference images reveals phase differences between typically 5 movable points on the modulator. Repeating this measurement yields wavefront surface. Next, the amplitude efficiency is calibrated be registering near field image. As a verification we produced a superposition of 7th and 8th Bessel beams with different phase velocities and observed their interference.

  11. Studying the optical second-order interference pattern formation process with classical light in the photon counting regime.

    Science.gov (United States)

    He, Yuchen; Liu, Jianbin; Zhang, Songlin; Wang, Wentao; Bai, Bin; Le, Mingnan; Xu, Zhuo

    2015-12-01

    The formation process of the second-order interference pattern is studied experimentally in the photon counting regime by superposing two independent single-mode continuous-wave lasers. Two-photon interference based on the superposition principle in Feynman's path integral theory is employed to interpret the experimental results. The second-order interference pattern of classical light can be formulated when, with high probability, there are only two photons in the interferometer at one time. The studies are helpful in understanding the second-order interference of classical light in the language of photons. The method and conclusions can be generalized to the third- and higher-order interference of light and interference of massive particles. PMID:26831397

  12. Orbital angular momentum light frequency conversion and interference with quasi-phase matching crystals

    CERN Document Server

    Zhou, Zhi-Yuan; Jiang, Yun-Kun; Li, Yan; Shi, Shuai; Wang, Xi-Shi; Shi, Bao-Sen; Guo, Guang-Can

    2014-01-01

    Light with helical phase structures, carrying quantized orbital angular momentum (OAM), has many applications in both classical and quantum optics, such as high-capacity optical communications and quantum information processing. Frequency conversion is a basic technique to expand the frequency range of fundamental light. The frequency conversion of OAM-carrying light gives rise to new physics and applications such as up-conversion detection of images and high dimensional OAM entanglements. Quasi-phase matching (QPM) nonlinear crystals are good candidates for frequency conversion, particularly for their high-valued effective nonlinear coefficients and no walk-off effect. Here we report the first experimental second-harmonic generation (SHG) of OAM light with a QPM crystal, where a UV light with OAM of 100 is generated. OAM conservation is verified using a specially designed interferometer. With a pump beam carrying an OAM superposition of opposite sign, we observed interesting interference phenomena in the SHG...

  13. Interference and dynamics of light from a distance-controlled atom pair in an optical cavity

    Science.gov (United States)

    Neuzner, A.; Körber, M.; Morin, O.; Ritter, S.; Rempe, G.

    2016-05-01

    Interference is central to quantum physics and occurs when indistinguishable paths exist, as in a double-slit experiment. Replacing the two slits with single atoms introduces optical nonlinearities for which non-trivial interference phenomena are predicted. Their observation, however, has been hampered by difficulties in preparing the required atomic distribution, controlling the optical phases and detecting the faint light. Here we overcome all of these experimental challenges by combining an optical lattice for atom localization, an imaging system with single-site resolution and an optical resonator for light steering. We observe resonator-induced saturation of resonance fluorescence for constructive interference and non-zero emission with huge photon bunching for destructive interference. The latter is explained by atomic saturation and photon-pair generation, similar to predictions for free-space atoms. Our experimental setting allows realization of the Tavis–Cummings model for any number of atoms and photons, exploration of fundamental aspects of light–matter interaction and implementation of new quantum information processing protocols.

  14. Interference and shadow effects in the production of light by charged particles in optical fibers

    International Nuclear Information System (INIS)

    A charged particle passing through or near a narrow optical fiber induces, by polarisation, coherent light guided by the fiber. In the limit of zero crossing angle, the radiation tends towards a Cherenkov radiation with a discrete spectrum, studied by different authors. If the particle crosses a bent fiber at regularly spaced points, interference gives quasi-monochromatic lines. If the particle passes near an end of the fiber, light is produced by the capture of virtual photons through the end face. An alternative way consists in sticking a metallic ball to the fiber: the passing particle induces plasmons which are then evacuated as light in the fiber. Interferences can occur between lights from several ends or balls. Applications of these various light signals to beam diagnostics are discussed. The shadow effect, which reduces the photon yield when the particle runs parallel to a row of balls, is pointed out and an upper bound -dE/dz≤C(Ze/b)2 for the particle energy loss is conjectured (Ze is the particle charge, b the impact parameter and C a numerical constant). This bound should also apply to other kinds of light sources, in particular to Smith-Purcell radiation

  15. Enhanced Transmission of Light and Particle Waves through Subwavelength Nanoapertures by Far-Field Interference

    CERN Document Server

    Kukhlevsky, S V

    2007-01-01

    Subwavelength aperture arrays in thin metal films can enable enhanced transmission of light and matter (atom) waves. The phenomenon relies on resonant excitation of the plasmon or matter surface waves. We show another mechanism that provides a great transmission enhancement of the light and de Broglie particle waves not by coupling to the surface waves but by the interference of diffracted evanescent waves in the far-field zone. Verification of the mechanism is presented by comparison with recently published data. The Wood anomalies in transmission spectra of gratings, a long standing problem in optics, follow naturally from interference properties of the model. The new point, in comparison to other models, is the prediction of the Wood anomaly in a classical Young-type two-slit system.

  16. Anisotropic expansion of the Universe and generation of quantum interference in light propagation

    OpenAIRE

    Fanizza, G.; Tedesco, L.

    2015-01-01

    We investigate the electrodynamic in a Bianchi type I cosmological model. This scenario reveals the possibility that photons, during their traveling, can make quantum interference. This effect is only due to the presence of two different axes of expansion in the cosmic evolution. In other word, it is possible to conclude that a purely metrical - or, equivalently, gravitational - phenomenon gives rise up to a quantum effect that manifests itself in the light propagation.

  17. Measurement of Berry Phase Associated with Higher Dimensional Orbital Angular Momentum of Light by Interference Method

    International Nuclear Information System (INIS)

    Berry phase of higher-dimensional orbital angular momentum of light is studied. When an Nth order orbital state, described by a vector in (N + 1)-dimensional space, evolves through a closed path in space of orbital states, there will exist a higher order orbital Berry phase. We calculate this phase by using the matrix transformation theory. A direct measurement of the higher-order orbital Berry phase is also carried out by the interference method. The experimental results are in good agreement with the theoretical description, which shows that the Berry phase is proportional to the orbital angular momentum of light

  18. Protection of Hawaii’s observatories from light pollution and radio frequency interference

    Science.gov (United States)

    Wainscoat, Richard

    2015-08-01

    The island of Hawaii is home to Maunakea Observatory, the largest collection of optical and infrared telescopes in the world. Haleakala Observatory on Maui is also an excellent observing site, and is home to the Pan-STARRS telescopes, the Faulkes Telescope North, solar telescopes, and military telescopes.The dark night sky over Maunakea has been well protected by a strong lighting ordinance, and remains very dark. The National Park Service night sky team recently visited Maunakea, and found it to have a darker night sky than any of the US National Parks that they have visited.Haleakala is more threatened, because Maui has a weaker lighting ordinance, and it is a smaller island, meaning that people live and work closer to the telescopes. Haleakala is also closer to Honolulu, and the urban glow from Honolulu contributes to an artificially bright sky in the northwest direction. Although there is no astronomical research done on the island of Kauai, it has some of the best lighting in the world, because endangered birds on Kauai become confused and disoriented by unshielded lights.The county and state lighting regulations will be described in detail. Enforcement issues will also be discussed.The efforts that have been made to protect Maunakea observatory from radio frequency interference, and to reduce radio frequency interference on Haleakala will also be described.

  19. Shielding and filtering techniques to protect sensitive instrumentation from electromagnetic interference caused by arc welding

    International Nuclear Information System (INIS)

    Electromagnetic interference (EMI) caused by arc welding is a concern for sensitive CANDU instrumentation and control equipment, especially start-up instrumentation (SUI) and ion chamber instruments used to measure neutron flux at low power. Measurements of the effectiveness of simple shielding and filtering techniques that may be applied to limit arc welding electromagnetic emissions below the interference threshold are described. Shielding configurations investigated include an arrangement in which the welding power supply, torch (electrode holder), interconnecting cables and welder operator were housed in a single enclosure and a more practical configuration of separate shields for the power supply, cables and operator with torch. The two configuration were found to provide 30 dB and 26 dB attenuation, respectively, for arc welder electric-field emissions and were successful in preventing EMI in SUI set up just outside the shielding enclosures. Practical improvements that may be incorporated in the shielding arrangement to facilitate quick setup in the field in a variety of application environments, while maintaining adequate EMI protection, are discussed. (author)

  20. Radio and television interference caused by corona discharges from high-voltage transmission lines

    International Nuclear Information System (INIS)

    Increase in power utility loads in industrialized countries, as well as developing countries, demands a higher level of transmission line voltage. Radio interference (RI) problems have been determined to be a limiting factor in selecting the size of transmission line conductors. Transmission line noise is primarily caused by corona discharges in the immediate vicinity of the conductor. It has been observed that discharges occur during both half-cycles of the applied voltage, but positive corona is usually predominant at AM radio frequencies range with practical high-voltage and extra high-voltage transmission lines. The corona radio noise effect is highly dependent upon the presence of particles on the surface of the conductor and the increase of the electrical gradient beyond the breakdown value of the air. Therefore, corona radio noise varies significantly with the weather and atmospheric conditions and generally increases by 10 to 30 dB in foul weather

  1. Quantum interference effects in an ensemble of $^{229}$Th nuclei interacting with coherent light

    CERN Document Server

    Das, Sumanta; Keitel, Christoph H

    2013-01-01

    As a unique feature, the $^{229}$Th nucleus has an isomeric transition in the vacuum ultraviolet that can be accessed by optical lasers. The interference effects occurring in the interaction between coherent optical light and an ensemble of $^{229}$Th nuclei are investigated theoretically. We consider the scenario of nuclei doped in vacuum ultraviolet-vacuum ultraviolet transparent crystals and take into account the effect of different doping sites and therefore different lattice fields that broaden the nuclear transition width. This effect is shown to come in interplay with interference effects due to the hyperfine splitting of the ground and isomeric nuclear states. We investigate possible experimentally available situations involving two-, three- and four-level schemes of quadrupole sublevels of the ground and isomeric nuclear states coupling to one or two coherent fields. Specific configurations which offer clear signatures of the isomer excitation advantageous for the more precise experimental determinat...

  2. Orbital angular momentum light frequency conversion and interference with quasi-phase matching crystals.

    Science.gov (United States)

    Zhou, Zhi-Yuan; Ding, Dong-Sheng; Jiang, Yun-Kun; Li, Yan; Shi, Shuai; Wang, Xi-Shi; Shi, Bao-Sen

    2014-08-25

    Light with helical phase structures, carrying quantized orbital angular momentum (OAM), has many applications in both classical and quantum optics, such as high-capacity optical communications and quantum information processing. Frequency conversion is a basic technique to expand the frequency range of the fundamental light. The frequency conversion of OAM-carrying light gives rise to new physics and applications such as up-conversion detection of images and generation of high dimensional OAM entanglements. Quasi-phase matching (QPM) nonlinear crystals are good candidates for frequency conversion, particularly due to their high-valued effective nonlinear coefficients and no walk-off effect. Here we report the first experimental second-harmonic generation (SHG) of an OAM-carried light with a QPM crystal, where a UV light with OAM of 100 ℏ is generated. OAM conservation is verified using a specially designed interferometer. With a pump beam carrying an OAM superposition of opposite sign, we observe interesting interference phenomena in the SHG light; specifically, a photonics gear-like structure is obtained that gives direct evidence of OAM conservation, which will be very useful for ultra-sensitive angular measurements. Besides, we also develop a theory to reveal the underlying physics of the phenomena. The methods and theoretical analysis shown here are also applicable to other frequency conversion processes, such as sum frequency generation and difference-frequency generation, and may also be generalized to the quantum regime for single photons. PMID:25321240

  3. Superresolving Imaging of Irregular Arrays of Thermal Light Sources using Multiphoton Interferences

    CERN Document Server

    Classen, Anton; Giebel, Sebastian; Schneider, Raimund; Bhatti, Daniel; Mehringer, Thomas; von Zanthier, Joachim

    2016-01-01

    We propose to use multiphoton interferences of photons emitted from statistically independent thermal light sources in combination with linear optical detection techniques to reconstruct, i.e., image, arbitrary source geometries in one dimension with subclassical resolution. The scheme is an extension of earlier work [Phys. Rev. Lett. 109, 233603 (2012)] where N regularly spaced sources in one dimension were imaged by use of the Nth-order intensity correlation function. Here, we generalize the scheme to reconstruct any number of independent thermal light sources at arbitrary separations in one dimension exploiting intensity correlation functions of order $m \\geq 3$. We present experimental results confirming the imaging protocol and provide a rigorous mathematical proof for the obtained subclassical resolution.

  4. Wavelength monitoring of DWDM systems using a polarization interference filter without reference light

    Science.gov (United States)

    Chen, Xiyao; Chen, Shengyu; Lin, Guimin; Xie, Jianping; Ming, Hai

    2006-09-01

    A novel scheme for wavelength monitoring of DWDM systems was proposed in which the two transmission spectra of a polarization interference filter (PIF) are employed. The filter consists of a polarizer, a polarizing beamsplitter (PBS) and a birefringent plate sandwiched between them. The birefringent plate used is made of yttrium orthovanadate (YVO 4) crystal. The two transmission spectra with perpendicular polarization directions are complementary in light transmittivity. By designing the filter and controlling its temperature appropriately, the intersections of the two transmission spectra can be utilized to monitor operating wavelengths in a DWDM network. This scheme doesn't need reference light for wavelength sensing. In addition, the monitoring sensitivity is twice as large as that in the way that only one transmission spectrum is utilized.

  5. A review of digital flight control system upsets caused by electromagnetic interference

    Science.gov (United States)

    Clough, Bruce T.

    Examinations of the MIL-STD-461C data base, operational experience, and specific tests show that upsets of digital flight-control systems are caused by low-frequency amplitude modulated signals corrupting the sensor inputs. Studies show that the current digital (and analog) flight-control systems are susceptible to electromagnetic radiation, that is, continuous wave, AM signal of 0 to 3 Hz modulation content, and has carrier frequencies of between 1 and 250 MHz. When the systems are placed in an airframe the frequency region constricts to 3 to 30 MHz, reflecting the influence of airframe/wire coupling. Field levels vary according to the electromagnetic interference susceptibility specifications the system was built to. Most current systems respond to average field levels of 200 V/m over some part of the carrier-frequency range. Steps to reduce the upset potential of analog portions are required if average field levels greater than 200 V/m are experienced during operation. Then, harder analog sensors and sensor/flight computer interfaces are required.

  6. Role of intensity fluctuations in third-order correlation double-slit interference of thermal light.

    Science.gov (United States)

    Chen, Xi-Hao; Chen, Wen; Meng, Shao-Ying; Wu, Wei; Wu, Ling-An; Zhai, Guang-Jie

    2013-07-01

    A third-order double-slit interference experiment with a pseudothermal light source in the high-intensity limit has been performed by actually recording the intensities in three optical paths. It is shown that not only can the visibility be dramatically enhanced compared to the second-order case as previously theoretically predicted and shown experimentally, but also that the higher visibility is a consequence of the contribution of third-order correlation interaction terms, which is equal to the sum of all contributions from second-order correlation. It is interesting that, when the two reference detectors are scanned in opposite directions, negative values for the third-order correlation term of the intensity fluctuations may appear. The phenomenon can be completely explained by the theory of classical statistical optics and is the first concrete demonstration of the influence of the third-order correlation terms. PMID:24323159

  7. From Hanbnry-Brown and Twiss Experiment to the Second-Order Double-Slit Interference for Incoherent Light

    Institute of Scientific and Technical Information of China (English)

    WANG Kai-ge; XIONG Jun; GAO Lu

    2006-01-01

    In this review article,we discuss both experimentally and theoretically the second-order double-siR interference for a thermal light source which is random in transverse propagating direction.We show that when the bandwidth of the noise spectrum is increased,the first-order interference pattem disappears while the sub-wavelength pattern fringe emerges in the intensity correlation measurement.Our theoretical description,which is carried out in contrast with coherent light and two-photon state sources,demonstrates that this effect can be explained in accordance with the Hanbury-Brown and Twiss experiment.

  8. Cardiomyocyte imaging using real-time spatial light interference microscopy (SLIM.

    Directory of Open Access Journals (Sweden)

    Basanta Bhaduri

    Full Text Available Spatial light interference microscopy (SLIM is a highly sensitive quantitative phase imaging method, which is capable of unprecedented structure studies in biology and beyond. In addition to the π/2 shift introduced in phase contrast between the scattered and unscattered light from the sample, 4 phase shifts are generated in SLIM, by increments of π/2 using a reflective liquid crystal phase modulator (LCPM. As 4 phase shifted images are required to produce a quantitative phase image, the switching speed of the LCPM and the acquisition rate of the camera limit the acquisition rate and, thus, SLIM's applicability to highly dynamic samples. In this paper we present a fast SLIM setup which can image at a maximum rate of 50 frames per second and provide in real-time quantitative phase images at 50/4 = 12.5 frames per second. We use a fast LCPM for phase shifting and a fast scientific-grade complementary metal oxide semiconductor (sCMOS camera (Andor for imaging. We present the dispersion relation, i.e. decay rate vs. spatial mode, associated with dynamic beating cardiomyocyte cells from the quantitative phase images obtained with the real-time SLIM system.

  9. Optical compensation of distorted data image caused by interference fringe distortion in holographic data storage.

    Science.gov (United States)

    Muroi, Tetsuhiko; Kinoshita, Nobuhiro; Ishii, Norihiko; Kamijo, Koji; Shimidzu, Naoki

    2009-07-01

    Photopolymer materials shrink because of photopolymerization. This shrinkage distorts the recorded interference fringes in a medium made of such material, which in turn degrades the reconstructed image quality. Adaptive optics controlled by a genetic algorithm was developed to optimize the wavefront of the reference beam while reproducing in order to compensate for the interference fringe distortion. We defined a fitness measure for this genetic algorithm that involves the mean brightness and coefficients of the variations of bit data "1" and "0". In an experiment, the adaptive optics improved the reconstructed image to the extent that data could be reproduced from the entire area of the image, and the signal to noise ratio of the reproduced data could be improved. PMID:19571923

  10. Light Chain Amyloid Fibrils Cause Metabolic Dysfunction in Human Cardiomyocytes.

    Directory of Open Access Journals (Sweden)

    Helen P McWilliams-Koeppen

    Full Text Available Light chain (AL amyloidosis is the most common form of systemic amyloid disease, and cardiomyopathy is a dire consequence, resulting in an extremely poor prognosis. AL is characterized by the production of monoclonal free light chains that deposit as amyloid fibrils principally in the heart, liver, and kidneys causing organ dysfunction. We have studied the effects of amyloid fibrils, produced from recombinant λ6 light chain variable domains, on metabolic activity of human cardiomyocytes. The data indicate that fibrils at 0.1 μM, but not monomer, significantly decrease the enzymatic activity of cellular NAD(PH-dependent oxidoreductase, without causing significant cell death. The presence of amyloid fibrils did not affect ATP levels; however, oxygen consumption was increased and reactive oxygen species were detected. Confocal fluorescence microscopy showed that fibrils bound to and remained at the cell surface with little fibril internalization. These data indicate that AL amyloid fibrils severely impair cardiomyocyte metabolism in a dose dependent manner. These data suggest that effective therapeutic intervention for these patients should include methods for removing potentially toxic amyloid fibrils.

  11. A Combined Light Sheet Fluorescence and Differential Interference Contrast Microscope for Live Imaging of Multicellular Specimens

    Science.gov (United States)

    Baker, Ryan; Taormina, Michael; Jemielita, Matthew; Parthasarathy, Raghuveer

    2015-03-01

    We present a microscope capable of both light sheet fluorescence microscopy (LSFM) and differential interference contrast microscopy (DICM). The two imaging modes, which to the best of our knowledge have not previously been combined, are complementary: LSFM provides high speed three-dimensional imaging of fluorescently labeled components of multicellular systems, large fields of view, and low phototoxicity, while DICM reveals the unlabeled neighborhood of tissues, organs, and other structures with high contrast and inherent optical sectioning. Use of a shared detection path for both imaging modes enables simple integration of the two techniques in one microscope. To demonstrate the instrument's utility, we provide several examples which focus on the digestive tract of the larval zebrafish. We show that DICM can sometimes circumvent the need for fluorescent based techniques, augmenting the number of parameters obtainable per experiment when used alongside LSFM, and that DICM can be used to augment each experiment by imaging complementary features, such as non-fluorescent local environments near fluorescent samples (e.g. fluorescent enteric neurons imaged alongside the non-fluorescent gut wall), interactions between fluorescent and non-fluorescent samples (e.g. bacteria), and more. NSF Award 0922951, NIH Award 1P50 GM098911

  12. Gradient light interference microscopy (GLIM) for imaging thick specimens (Conference Presentation)

    Science.gov (United States)

    Nguyen, Tan H.; Kandel, Mikhail E.; Popescu, Gabriel

    2016-03-01

    Compared to the Phase Contrast, Differential Interference Contrast (DIC) has been known to give higher depth sectioning as well as a halo-free images when investigating transparent specimens. Thanks to relying on generating two slightly shifted replicas with a small amount of shift, within the coherence area, DIC is able to operate with very low coherence light. More importantly, the method is able to work with very large numerical aperture of the illumination, which offer comparable sectioning capability to bright field microscopy. However, DIC is still a qualitative method, which limits potential applications of the technique. In this paper, we introduce a method that extends the capability of DIC by combining it with a phase shifting module to extract the phase gradient information. A theoretical model of the image formation is developed and the possibility of integrating the gradient function is analyzed.. Our method is benchmarked on imaging embryos during their 7-day development, HeLa cells during mitosis, and control samples.

  13. Direct periodic patterning of GaN-based light-emitting diodes by three-beam interference laser ablation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jeomoh; Ji, Mi-Hee; Detchprohm, Theeradetch [Center for Compound Semiconductors and School of Electrical and Computer Engineering, Georgia Institute of Technology, 777 Atlantic Dr. NW, Atlanta, Georgia 30332-0250 (United States); Yuan, Dajun; Guo, Rui [Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0405 (United States); Liu, Jianping [Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou, Jiangsu 215125 (China); Asadirad, Mojtaba [Materials Engineering Program, University of Houston, Houston, Texas 77204-4005 (United States); Kwon, Min-Ki [Department of Photonic Engineering, Chosun University, Seosuk-dong, Gwangju 501-759 (Korea, Republic of); Dupuis, Russell D. [Center for Compound Semiconductors and School of Electrical and Computer Engineering, Georgia Institute of Technology, 777 Atlantic Dr. NW, Atlanta, Georgia 30332-0250 (United States); School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0245 (United States); Das, Suman [Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0405 (United States); School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0245 (United States); Ryou, Jae-Hyun, E-mail: jryou@uh.edu [Materials Engineering Program, University of Houston, Houston, Texas 77204-4005 (United States); Department of Mechanical Engineering and Texas Center for Superconductivity at the University of Houston (TcSUH), University of Houston, Houston, Texas 77204-4006 (United States)

    2014-04-07

    We report on the direct patterning of two-dimensional periodic structures in GaN-based light-emitting diodes (LEDs) through laser interference ablation for the fast and reliable fabrication of periodic micro- and nano-structures aimed at enhancing light output. Holes arranged in a two-dimensional hexagonal lattice array having an opening size of 500 nm, depth of 50 nm, and a periodicity of 1 μm were directly formed by three-beam laser interference without photolithography or electron-beam lithography processes. The laser-patterned LEDs exhibit an enhancement in light output power of 20% compared to conventional LEDs having a flat top surface without degradation of electrical and optical properties of the top p-GaN layer and the active region, respectively.

  14. Direct periodic patterning of GaN-based light-emitting diodes by three-beam interference laser ablation

    International Nuclear Information System (INIS)

    We report on the direct patterning of two-dimensional periodic structures in GaN-based light-emitting diodes (LEDs) through laser interference ablation for the fast and reliable fabrication of periodic micro- and nano-structures aimed at enhancing light output. Holes arranged in a two-dimensional hexagonal lattice array having an opening size of 500 nm, depth of 50 nm, and a periodicity of 1 μm were directly formed by three-beam laser interference without photolithography or electron-beam lithography processes. The laser-patterned LEDs exhibit an enhancement in light output power of 20% compared to conventional LEDs having a flat top surface without degradation of electrical and optical properties of the top p-GaN layer and the active region, respectively

  15. CERN’s light guide sold for a good cause

    CERN Multimedia

    2009-01-01

    On 26 March, a light guide donated by CERN received the lion’s share at a prestigious Sotheby’s auction in favour of the WISH foundation (Women in Science and Humanities). The WISH foundation, created by EPFL (Ecole polytechnique fédérale de Lausanne) professors, with the support of the Lombard-Odier bank, is aimed at promoting women’s careers in science, engineering and architecture. Among their numerous dedicated projects, scholarships and special events, the yearly gala dinner ending in a special auction organised by Sotheby’s is definitely the most glamorous. This year, CERN was asked by EPFL to contribute to the cause of women in science by donating a symbolic or historical object. The choice of a light guide was a winning one. Polished and "lit" by CERN’s central workshops, CERN’s light guide (probably coming from the UA1 or UA2 experiments) got the lion’s share at the auction, defying the competition of eight d...

  16. Electron-phonon interaction in boron-doped silicon nanocrystals: effect of Fano interference on combined light scattering

    International Nuclear Information System (INIS)

    The arrays of the silicon nanocrystals in the boron-doped amorphous silicon films are studied by the method of the light combined scattering spectroscopy. The nanocrystals were formed in the initial amorphous films under the pulse effect of the excimer laser. The effects of the electron-phonon interaction were experimentally identified in the silicon nanocrystal/amorphous matrix heterostructure. These effects may be described within the frames of the known Fano interference model

  17. Effect of Toll-Like Receptor 4 on Synovial Injury of Temporomandibular Joint in Rats Caused by Occlusal Interference

    Directory of Open Access Journals (Sweden)

    Jingjing Kong

    2016-01-01

    Full Text Available Synovitis is an important disease that causes intractable pain in TMJ. Some investigations suggested that the increasing expression of IL-1β secreted by synovial lining cells plays an important role in synovial inflammation and cartilage destruction in TMJ. In our previous research, the results demonstrated that TLR4 is involved in the expression of IL-1β in SFs from TMJ with lipopolysaccharide stimulation. However, the inflammatory response that occurred in synovial membrane is not caused by bacterial infection. In the current study, we investigated whether or not TLR4 participates in the inflammatory responses and the expression of IL-1β in synovial membrane of rats induced by occlusal interference. The results showed that obvious inflammation changes were observed in the synovial membranes and the expression of TLR4 and IL-1β was increased at both mRNA and protein levels in the occlusal interference rats. In addition, the inflammation reactions and the increased expression of IL-1β could be restrained by treatment with TAK-242, a blocker of TLR4 signaling. The results prompted us that the activation of TLR4 may be involved in the inflammatory reactions and increased expression of IL-1β in patients with synovitis and participate in the mechanisms of the initiation and development of synovial injury by regulating the expression of inflammatory mediators like IL-1β in synovial membranes.

  18. Increasing Reliability by Means of Root Cause Aware HARQ and Interference Coordination

    DEFF Research Database (Denmark)

    Soret, Beatriz; Gerardino, Guillermo Andrés Pocovi; Pedersen, Klaus I.;

    2015-01-01

    network. Combined with a ROot Cause Aware HARQ (ROCA-HARQ), which provides additional information when a transmission fails, the joint mechanism is relevant for any LTE/LTE-A deployment and can be easily implemented in a real network. System-level simulations show attractive BLER reductions up to 80% with...

  19. Hereditary spastic paraplegia-causing mutations in atlastin-1 interfere with BMPRII trafficking

    OpenAIRE

    Zhao, Jiali; Hedera, Peter

    2012-01-01

    Disruption of the bone morphogenic protein (BMP)-linked signaling pathway has been suggested as an important factor in the development of hereditary spastic paraplegia (HSP). HSP-causing proteins spastin, spartin and NIPA1 were reported to inhibit the BMP pathway. We have previously shown a strong interaction of NIPA1 and atlastin-1 proteins. Hence, we investigated the role of another HSP-associated protein atlastin-1 in this signaling cascade. Endogenous and expressed atlastin-1 showed a str...

  20. Spatial interference of light: transverse coherence and Alford and Gold effect

    CERN Document Server

    Jefferson, Flórez; Omar, Calderón-Losada; Luis-José, Salazar-Serrano; Alejandra, Valencia

    2015-01-01

    We study the interference between two parallel-propagating Gaussian beams, originated from the same source, as their transverse separation is tuned. The interference pattern as a function of such separation lead us to determine the spatial coherence of the original beam, in a similar way that a Michelson-Morley interferometer can be employed to measure the temporal coherence of a transform limited pulse. Moreover, performing a Fourier transform of the two-beam transverse plane, we observe an intensity modulation in the transverse momentum variable. This observation resembles the Alford and Gold Effect reported in time and frequency variables so far.

  1. Human alteration of natural light cycles: causes and ecological consequences

    OpenAIRE

    Gaston, Kevin J; Duffy, James P.; Gaston, Sian; Bennie, Jonathan; Davies, Thomas W

    2014-01-01

    Artificial light at night is profoundly altering natural light cycles, particularly as perceived by many organisms, over extensive areas of the globe. This alteration comprises the introduction of light at night at places and times at which it has not previously occurred, and with different spectral signatures. Given the long geological periods for which light cycles have previously been consistent, this constitutes a novel environmental pressure, and one for which there is evidence for biolo...

  2. Highly sensitive biosensing based on interference from light scattering in capillary tubes

    DEFF Research Database (Denmark)

    Sørensen, H.S.; Larsen, N.B.; Latham, J.C.;

    2006-01-01

    Human IgG interactions with surface bound protein A are monitored label-free using microinterferometric backscatter detection. An electromagnetic wave-based model is developed and used to quantitatively describe the change in interference pattern as a consequence of the molecular interaction with...

  3. Reduced graphene oxides: light-weight and high-efficiency electromagnetic interference shielding at elevated temperatures.

    Science.gov (United States)

    Wen, Bo; Cao, Maosheng; Lu, Mingming; Cao, Wenqiang; Shi, Honglong; Liu, Jia; Wang, Xixi; Jin, Haibo; Fang, Xiaoyong; Wang, Wenzhong; Yuan, Jie

    2014-06-01

    Chemical graphitized r-GOs, as the thinnest and lightest material in the carbon family, exhibit high-efficiency electromagnetic interference (EMI) shielding at elevated temperature, attributed to the cooperation of dipole polarization and hopping conductivity. The r-GO composites show different temperature-dependent imaginary permittivities and EMI shielding performances with changing mass ratio. PMID:24648151

  4. Observation of Quantum Interferences via Light Induced Conical Intersections in Diatomic Molecules

    CERN Document Server

    Natan, Adi; Bucksbaum, Philip H

    2015-01-01

    We observe energy-dependent angle-resolved diffraction patterns in protons from strong-field dissociation of the molecular hydrogen ion H$_2^+$. The interference is a characteristic of dissociation around a laser-induced conical intersection (LICI), which is a point of contact between two surfaces in the dressed 2-dimensional Born-Oppenheimer potential energy landscape of a diatomic molecule in a strong laser field. The interference magnitude and angular period depend strongly on the energy difference between the initial state and the LICI, consistent with coherent diffraction around a cone-shaped potential barrier whose width and thickness depend on the relative energy of the initial state and the cone apex. These findings are supported by numerical solutions of the time-dependent Schr\\"{o}dinger equation for similar experimental conditions.

  5. Observation of Quantum Interferences via Light-Induced Conical Intersections in Diatomic Molecules

    Science.gov (United States)

    Natan, Adi; Ware, Matthew R.; Prabhudesai, Vaibhav S.; Lev, Uri; Bruner, Barry D.; Heber, Oded; Bucksbaum, Philip H.

    2016-04-01

    We observe energy-dependent angle-resolved diffraction patterns in protons from strong-field dissociation of the molecular hydrogen ion H2+ . The interference is a characteristic of dissociation around a laser-induced conical intersection (LICI), which is a point of contact between two surfaces in the dressed two-dimensional Born-Oppenheimer potential energy landscape of a diatomic molecule in a strong laser field. The interference magnitude and angular period depend strongly on the energy difference between the initial state and the LICI, consistent with coherent diffraction around a cone-shaped potential barrier whose width and thickness depend on the relative energy of the initial state and the cone apex. These findings are supported by numerical solutions of the time-dependent Schrödinger equation for similar experimental conditions.

  6. Controlling light pulse in triangular quantum well nanostructure via quantum interference

    International Nuclear Information System (INIS)

    We study numerically the optical properties of the intersubband transitions in AlGaAs/GaAs triangular quantum well nanostructure. The Schrödinger equation is being solved numerically for this structure using homemade codes. Afterward the refractive index and the absorption coefficient are calculated for general triangular quantum well using the density matrix formalism. The density matrix equations are being solved numerically for calculation of linear susceptibility. The effect of quantum interference between spontaneous emission decays on the refractive index, absorption coefficient and group velocity is studied for purposed triangular quantum well nanostructure. The result shows the linear optical properties and group index can be controlled via quantum interference between spontaneous emission decays

  7. Optical biosensors. Monitoring studies of glycopeptide antibiotic fermentation using white light interference.

    Science.gov (United States)

    Tünnemann, R; Mehlmann, M; Süssmuth, R D; Bühler, B; Pelzer, S; Wohlleben, W; Fiedler, H P; Wiesmüller, K H; Gauglitz, G; Jung, G

    2001-09-01

    This paper describes the design, characterization, and use of an optical biosensor suited for the process control of biotechnological processes. The detector principle is based on reflectometric interference spectroscopy (RIfS). RIfS enables a label-free, product-specific monitoring, with a future outline for on-line process control. The potential of the RIfS biosensor is exemplified by the qualitative and quantitative monitoring of the microbial production of vancomycin-type glycopeptide antibiotics. PMID:11569825

  8. Teager-Kaiser Energy and Higher-Order Operators in White-Light Interference Microscopy for Surface Shape Measurement

    Directory of Open Access Journals (Sweden)

    Abdel-Ouahab Boudraa

    2005-10-01

    Full Text Available In white-light interference microscopy, measurement of surface shape generally requires peak extraction of the fringe function envelope. In this paper the Teager-Kaiser energy and higher-order energy operators are proposed for efficient extraction of the fringe envelope. These energy operators are compared in terms of precision, robustness to noise, and subsampling. Flexible energy operators, depending on order and lag parameters, can be obtained. Results show that smoothing and interpolation of envelope approximation using spline model performs better than Gaussian-based approach.

  9. Laser-frequency locking to a whispering-gallery-mode cavity by spatial interference of scattered light.

    Science.gov (United States)

    Zullo, R; Giorgini, A; Avino, S; Malara, P; De Natale, P; Gagliardi, G

    2016-02-01

    We present a simple and effective method for frequency locking a laser source to a free-space-coupled whispering-gallery-mode cavity. The scheme relies on the interference of spatial modes contained in the light scattered by the cavity, where low- and high-order modes are simultaneously excited. A dispersion-shaped signal proportional to the imaginary component of the resonant optical field is simply generated by spatial filtering of the scattered light. Locking of a diode laser to the equatorial modes of a liquid droplet resonator is demonstrated using this scheme, and its performance is compared to the Pound-Drever-Hall technique. This new approach makes laser-frequency locking straightforward and shows a number of advantages, including robustness, low cost, and no need for sophisticated optical and electronic components. PMID:26907446

  10. Highly sensitive biosensing based on interference from light scattering in capillary tubes

    Science.gov (United States)

    Sørensen, Henrik S.; Larsen, Niels B.; Latham, Joey C.; Bornhop, Darryl J.; Andersen, Peter E.

    2006-10-01

    Human IgG interactions with surface bound protein A are monitored label-free using microinterferometric backscatter detection. An electromagnetic wave-based model is developed and used to quantitatively describe the change in interference pattern as a consequence of the molecular interaction with the affinity layer on the fused silica capillary. Within the framework of the model it is of paramount importance to establish a valid stop criterion for the infinite summations involved in the fringe pattern computations. The high sensitivity towards surface changes, ease of changing the surface chemistry to other specific interacting layers, and simplicity of the optical sensor make this technique a powerful tool in biosensing.

  11. LIGHT PRESSURE: Theoretical study of the light pressure force acting on a spherical dielectric particle of an arbitrary size in the interference field of two plane monochromatic electromagnetic waves

    Science.gov (United States)

    Guzatov, D. V.; Gaida, L. S.; Afanas'ev, Anatolii A.

    2008-12-01

    The light pressure force acting on a spherical dielectric particle in the interference field of two plane monochromatic electromagnetic waves is studied in detail for different particle radii and angles of incidence of waves.

  12. Spatial Light Interference Microscopy (SLIM) using twisted-nematic liquid-crystal modulation

    OpenAIRE

    Nguyen, Tan H.; Popescu, Gabriel

    2013-01-01

    We report the use of a twisted nematic liquid-crystal spatial light modulator (TNLC-SLM) for quantitative phase imaging. The experimental setup is a new implementation of the SLIM principle, which is a phase shifting, white light method for quantitative phase imaging. The approach is based on switching between the phase and amplitude modulation modes of the SLM. Our system is able to deliver a 0.99 nm spatial and 1.33 nm temporal pathlength sensitivity while retaining the optical transverse r...

  13. Application of Asymptotic and Rigorous Techniques for the Characterization of Interferences Caused by a Wind Turbine in Its Neighborhood

    Directory of Open Access Journals (Sweden)

    Maria Jesús Algar

    2013-01-01

    Full Text Available This paper presents a complete assessment to the interferences caused in the nearby radio systems by wind turbines. Three different parameters have been considered: the scattered field of a wind turbine, its radar cross-section (RCS, and the Doppler shift generated by the rotating movements of the blades. These predictions are very useful for the study of the influence of wind farms in radio systems. To achieve this, both high-frequency techniques, such as Geometrical Theory of Diffraction/Uniform Theory of Diffraction (GTD/UTD and Physical Optics (PO, and rigorous techniques, like Method of Moments (MoM, have been used. In the analysis of the scattered field, conductor and dielectric models of the wind turbine have been analyzed. In this way, realistic results can be obtained. For all cases under analysis, the wind turbine has been modeled with NURBS (Non-Uniform Rational B-Spline surfaces since they allow the real shape of the object to be accurately replicated with very little information.

  14. Interference of light, temperature, depth of sowing and straw on germination and emergency of Murdannia nudiflora

    Directory of Open Access Journals (Sweden)

    Flávia Nayane Luz

    2014-03-01

    Full Text Available Murdannia nudiflora, also known as trapoerabinha has been reported in recent years, as an important weed in soybean crops under no-tillage in Brasil, due to its highly competitive with crops, poor control and rapid infestation. The present work was to study germination of seeds under light conditions (and without and temperature (20, 25 and 30 °C, and the emergence in straw (with and without and sowing depth (0, 0, 1.0, 2.0, 3.0, 4.0 and 8.0 cm. The experimental design was completely randomized for all experiments. The species studied presents photoblastism referred, with higher germination under light. Depths greater than 1.0 cm and the presence of mulch on the soil surface affect the emergence of seedlings of this species.

  15. What causes the superluminal propagation of light pulses

    Institute of Scientific and Technical Information of China (English)

    ShiYao Zhu(朱诗尧); LiGang Wang(王立刚)

    2003-01-01

    In this paper, we discuss what causes the superluminal propagation of a pulse through dispersion by solving Maxwell's equations without any approximation. The coherence of the pulse plays an important role for superluminal propagation. When the pulse becomes partially coherent, the propagation changes from superluminal to subluminal. The energy velocity is always less than the vacuum velocity. The shape of the pulse is changed during the propagation.

  16. Low-light-level four-wave mixing by quantum interference

    CERN Document Server

    Chiu, Chang-Kai; Chen, Yen-Chun; Yu, Ite A; Chen, Ying-Cheng; Chen, Yong-Fan

    2013-01-01

    We observed electromagnetically-induced-transparency-based four-wave mixing (FWM) in the pulsed regime at low light levels. The FWM conversion efficiency of 3.8(9)% was observed in a four-level system of cold 87Rb atoms using a driving laser pulse with a peak intensity of approximately 80 {\\mu}W/cm^2, corresponding to an energy of approximately 60 photons per atomic cross section. Comparison between the experimental data and the theoretical predictions proposed by Harris and Hau [Phys. Rev. Lett. 82, 4611 (1999)] showed strong agreement. Additionally, a high conversion efficiency of 46(2)% was demonstrated when applying this scheme using a driving laser intensity of approximately 1.8 mW/cm^2. According to our theoretical predictions, this FWM scheme can achieve a conversion efficiency of nearly 100% when using a dense medium with an optical depth of 500.

  17. A Novel Observation of 'a Sharp Absorption Line' Using Much More Broad Laser Lights: Quantum Interference in the Autoionization Spectra of Sc

    International Nuclear Information System (INIS)

    The most accurate measurements in physical sciences will be precision spectroscopic experiments which are based on the usage of most narrow lines in cooperation with interference phenomena. We present a novel experimental observation of 'a sharp absorption resonance line' with much more broad laser lights. The mechanism of such a novel phenomenon will be elucidated and its implications will be discussed

  18. Intronic L1 retrotransposons and nested genes cause transcriptional interference by inducing intron retention, exonization and cryptic polyadenylation.

    Directory of Open Access Journals (Sweden)

    Kristel Kaer

    Full Text Available BACKGROUND: Transcriptional interference has been recently recognized as an unexpectedly complex and mostly negative regulation of genes. Despite a relatively few studies that emerged in recent years, it has been demonstrated that a readthrough transcription derived from one gene can influence the transcription of another overlapping or nested gene. However, the molecular effects resulting from this interaction are largely unknown. METHODOLOGY/PRINCIPAL FINDINGS: Using in silico chromosome walking, we searched for prematurely terminated transcripts bearing signatures of intron retention or exonization of intronic sequence at their 3' ends upstream to human L1 retrotransposons, protein-coding and noncoding nested genes. We demonstrate that transcriptional interference induced by intronic L1s (or other repeated DNAs and nested genes could be characterized by intron retention, forced exonization and cryptic polyadenylation. These molecular effects were revealed from the analysis of endogenous transcripts derived from different cell lines and tissues and confirmed by the expression of three minigenes in cell culture. While intron retention and exonization were comparably observed in introns upstream to L1s, forced exonization was preferentially detected in nested genes. Transcriptional interference induced by L1 or nested genes was dependent on the presence or absence of cryptic splice sites, affected the inclusion or exclusion of the upstream exon and the use of cryptic polyadenylation signals. CONCLUSIONS/SIGNIFICANCE: Our results suggest that transcriptional interference induced by intronic L1s and nested genes could influence the transcription of the large number of genes in normal as well as in tumor tissues. Therefore, this type of interference could have a major impact on the regulation of the host gene expression.

  19. Skin Hypersensitivity to Sun Light Due to Doxycycline Ingestion Causing Hand Partial-Thickness Burn

    OpenAIRE

    Simman, Richard; Raynolds, David

    2013-01-01

    Drugs hypersensitivity should be remembered when placing patients on any form of medications. In this case we present skin hypersensitivity to sun light due to doxycycline ingestion causing hand partial-thickness burn.

  20. Light spectrum regulates cell accumulation during daytime in the raphidophyte Chattonella antiqua causing noxious red tides.

    Science.gov (United States)

    Shikata, Tomoyuki; Matsunaga, Shigeru; Kuwahara, Yusuke; Iwahori, Sho; Nishiyama, Yoshitaka

    2016-07-01

    Most marine raphidophyte species cause noxious red tides in temperate coastal areas around the world. It is known that swimming abilities enable raphidophytes to accumulation of cells and to actively acquire light at surface layers and nutrients over a wide depth range. However, it remains unclear how the swimming behavior is affected by environmental conditions, especially light condition. In the present study, we observed the accumulation of the harmful red-tide raphidophyte Chattonella antiqua under various light conditions during the daytime in the laboratory. When exposed to ultraviolet-A/blue light (320-480nm) or red light (640-680nm) from above, cells moved downward. In the case of blue light (455nm), cells started to swim downward after 5-15min of irradiation at a photon flux density≥10μmolm(-2)s(-1). When exposed to monochromatic lights (400-680nm) from the side, cells moved away from the blue light source and then descended, but just moved downward under red light. However, mixing of green/orange light (520-630nm) diminished the effects of blue light. When exposed to a mixture of 30μmolm(-2)s(-1) of blue light (440nm) and ≥6μmolm(-2)s(-1) of yellow light (560nm) from above, cells did not move downward. These results indicate that blue light induces negative phototaxis and ultraviolet-A/blue and red lights induce descending, and green/orange light cancels out their effects in C. antiqua. PMID:27107332

  1. Application of optical interference methods to minimize the failure rate of LSI-chips caused by mechanical or thermal loads

    International Nuclear Information System (INIS)

    Efficient cooling required to achieve low working temperatures of highly integrated chips with high heat generation is obtained by pressing bare TAB-mounted chips against a cold plate. In order to minimize the thermal resistance of the contact surface, the forces necessary to straighten the initially curved chips and the minimum thickness of the remaining air gap were determined by two optical interference techniques. This showed the mechanical conditions required for good thermal contact, and thus for ensuring a prolonged life for the chip. (orig.)

  2. RNA interference gene therapy in dominant retinitis pigmentosa and cone-rod dystrophy mouse models caused by GCAP1 mutations

    OpenAIRE

    JIANG Li; Frederick, Jeanne M.; Baehr, Wolfgang

    2014-01-01

    RNA interference (RNAi) knockdown is an efficacious therapeutic strategy for silencing genes causative for dominant retinal dystrophies. To test this, we used self-complementary (sc) AAV2/8 vector to develop an RNAi-based therapy in two dominant retinal degeneration mouse models. The allele-specific model expresses transgenic bovine GCAP1(Y99C) establishing a rapid RP-like phenotype, whereas the nonallele-specific model expresses mouse GCAP1(L151F) producing a slowly progressing cone-rod dyst...

  3. RNA interference gene therapy in dominant retinitis pigmentosa and cone-rod dystrophy mouse models caused by GCAP1 mutations

    OpenAIRE

    Wolfgang Baehr

    2014-01-01

    RNA interference (RNAi) knockdown is an efficacious therapeutic strategy for silencing genes causative for dominant retinal dystrophies. To test this, we used self-complementary (sc) AAV2/8 vector to develop an RNAi-based therapy in two dominant retinal degeneration mouse models. The allele-specific model expresses transgenic bovine GCAP1(Y99C) establishing a rapid RP-like phenotype, whereas the nonallele-specific model expresses mouse GCAP1(L151F) producing a slowly progressing cone/rod dyst...

  4. Radiation-damage-free quantum crystallography and resolution-enhanced x-ray imaging techniques using quantum multipath interference of thermal light

    CERN Document Server

    Li, Zheng; Medvedev, Nikita; Wang, Fenglin; Chapman, Henry N; Shih, Yanhua

    2016-01-01

    Using higher order coherence of thermal light sources, we can achieve enhancement of resolution of standard x-ray imaging techniques, such as x-ray diffraction and phase contrast imaging. The cost of implementing such schemes is minimal comparing to the schemes using entangled two-photon pairs. The proposed diffractive quan- tum crystallography using multipath interference of thermal light can be eventually free of radiation damage, because the diffraction pattern could be formed by using low energy photons of optical wavelength. Thus it is promising to apply the proposed quantum crystallography scheme to nanocrystalline or non-crystalline samples that are too difficult to be crystallized.

  5. Influences of wide-angle and multi-beam interference on the chromaticity and efficiency of top-emitting white organic light-emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Lingling; Zhou, Hongwei; Chen, Shufen, E-mail: iamsfchen@njupt.edu.cn; Liu, Bin; Wang, Lianhui [Key Laboratory for Organic Electronics and Information Displays and Institute of Advanced Materials, Nanjing University of Posts and Telecommunications, Nanjing 210023 (China); Shi, Hongying [Jiangsu-Singapore Joint Research Center for Organic/Bio- Electronics and Information Displays and Institute of Advanced Materials, Nanjing Tech University, Nanjing 211816 (China); Huang, Wei, E-mail: iamdirector@njupt.edu.cn [Key Laboratory for Organic Electronics and Information Displays and Institute of Advanced Materials, Nanjing University of Posts and Telecommunications, Nanjing 210023 (China); Jiangsu-Singapore Joint Research Center for Organic/Bio- Electronics and Information Displays and Institute of Advanced Materials, Nanjing Tech University, Nanjing 211816 (China)

    2015-02-28

    Wide-angle interference (WI) and multi-beam interference (MI) in microcavity are analyzed separately to improve chromaticity and efficiency of the top-emitting white organic light-emitting diodes (TWOLEDs). A classic electromagnetic theory is used to calculate the resonance intensities of WI and MI in top-emitting organic light-emitting diodes (TOLEDs) with influence factors (e.g., electrodes and exciton locations) being considered. The role of WI on the performances of TOLEDs is revealed through using δ-doping technology and comparing blue and red EML positions in top-emitting and bottom-emitting devices. The blue light intensity significantly increases and the chromaticity of TWOLEDs is further improved with the use of enhanced WI (the blue emitting layer moving towards the reflective electrode) in the case of a weak MI. In addition, the effect of the thicknesses of light output layer and carrier transport layers on WI and MI are also investigated. Apart from the microcavity effect, other factors, e.g., carrier balance and carrier recombination regions are considered to obtain TWOLEDs with high efficiency and improved chromaticity near white light equal-energy point.

  6. Fiber refractive index sensor based on dual polarized Mach-Zehnder interference caused by a single-mode fiber loop.

    Science.gov (United States)

    Chen, Lei; Zhang, Wei-Gang; Wang, Li; Zhou, Quan; Sieg, Jonathan; Zhao, De-Long; Wang, Biao; Yan, Tie-Yi; Wang, Song

    2016-01-01

    A novel refractive index (RI) sensor head is proposed and experimentally demonstrated in this paper. The proposed sensor head is composed of a segment of bared single-mode fiber and a fiber holder that is fabricated by a 3D printer. The mechanism of the sensor head is based on dual polarized Mach-Zehnder interference. According to the aforementioned mechanism, we derived that the RI responses of the resonance dips possess an exponential functional manner when the E field is along the fast or slow axes. In addition, based on the finite element method, we found that the resonance dips wavelength responses are more sensitive when the input E field is along the fast axis. A confirmation experiment was performed, and the results confirmed our hypothesis. The maximum arithmetic mean value of RI response is about 657.895  nm/RIU for the proposed sensor head when the ambient RI changes from 1.3350 to 1.4110. Moreover, in the case of the proposed liquid RI sensor head, aligning the E field along the fast axis is the potentially needed condition for polarization. PMID:26835622

  7. RNA interference gene therapy in dominant retinitis pigmentosa and cone-rod dystrophy mouse models caused by GCAP1 mutations

    Directory of Open Access Journals (Sweden)

    Wolfgang Baehr

    2014-04-01

    Full Text Available RNA interference (RNAi knockdown is an efficacious therapeutic strategy for silencing genes causative for dominant retinal dystrophies. To test this, we used self-complementary (sc AAV2/8 vector to develop an RNAi-based therapy in two dominant retinal degeneration mouse models. The allele-specific model expresses transgenic bovine GCAP1(Y99C establishing a rapid RP-like phenotype, whereas the nonallele-specific model expresses mouse GCAP1(L151F producing a slowly progressing cone/rod dystrophy (CORD. The late onset GCAP1(L151F-CORD mimics the dystrophy observed in human GCAP1-CORD patients. Subretinal injection of scAAV2/8 carrying shRNA expression cassettes specific for bovine or mouse GCAP1 showed strong expression at one week post-injection. In both allele-specific (GCAP1(Y99C-RP and nonallele-specific (GCAP1(L151F-CORD models of dominant retinal dystrophy, RNAi-mediated gene silencing enhanced photoreceptor survival, delayed onset of degeneration and improved visual function. Such results provide a “proof of concept” toward effective RNAi-based gene therapy mediated by scAAV2/8 for dominant retinal disease based on GCAP1 mutation. Further, nonallele-specific RNAi knockdown of GCAP1 may prove generally applicable toward the rescue of any human GCAP1-based dominant cone-rod dystrophy.

  8. Light

    CERN Document Server

    Ditchburn, R W

    2011-01-01

    This classic study, available for the first time in paperback, clearly demonstrates how quantum theory is a natural development of wave theory, and how these two theories, once thought to be irreconcilable, together comprise a single valid theory of light. Aimed at students with an intermediate-level knowledge of physics, the book first offers a historical introduction to the subject, then covers topics such as wave theory, interference, diffraction, Huygens' Principle, Fermat's Principle, and the accuracy of optical measurements. Additional topics include the velocity of light, relativistic o

  9. Impaired Mitochondrial Energy Production Causes Light-Induced Photoreceptor Degeneration Independent of Oxidative Stress.

    Science.gov (United States)

    Jaiswal, Manish; Haelterman, Nele A; Sandoval, Hector; Xiong, Bo; Donti, Taraka; Kalsotra, Auinash; Yamamoto, Shinya; Cooper, Thomas A; Graham, Brett H; Bellen, Hugo J

    2015-07-01

    Two insults often underlie a variety of eye diseases including glaucoma, optic atrophy, and retinal degeneration--defects in mitochondrial function and aberrant Rhodopsin trafficking. Although mitochondrial defects are often associated with oxidative stress, they have not been linked to Rhodopsin trafficking. In an unbiased forward genetic screen designed to isolate mutations that cause photoreceptor degeneration, we identified mutations in a nuclear-encoded mitochondrial gene, ppr, a homolog of human LRPPRC. We found that ppr is required for protection against light-induced degeneration. Its function is essential to maintain membrane depolarization of the photoreceptors upon repetitive light exposure, and an impaired phototransduction cascade in ppr mutants results in excessive Rhodopsin1 endocytosis. Moreover, loss of ppr results in a reduction in mitochondrial RNAs, reduced electron transport chain activity, and reduced ATP levels. Oxidative stress, however, is not induced. We propose that the reduced ATP level in ppr mutants underlies the phototransduction defect, leading to increased Rhodopsin1 endocytosis during light exposure, causing photoreceptor degeneration independent of oxidative stress. This hypothesis is bolstered by characterization of two other genes isolated in the screen, pyruvate dehydrogenase and citrate synthase. Their loss also causes a light-induced degeneration, excessive Rhodopsin1 endocytosis and reduced ATP without concurrent oxidative stress, unlike many other mutations in mitochondrial genes that are associated with elevated oxidative stress and light-independent photoreceptor demise. PMID:26176594

  10. Weak-Light, Zero to -\\pi Lossless Kerr-Phase Gate in Quantum-well System via Tunneling Interference Effect

    CERN Document Server

    Shi, Y L; Wu, J X; Zhu, C J; Xu, J P; Yang, Y P

    2015-01-01

    We examine a Kerr phase gate in a semiconductor quantum well structure based on the tunnelling interference effect. We show that there exist a specific signal field detuning, at which the absorption/amplification of the probe field will be eliminated with the increase of the tunnelling interference. Simultaneously, the probe field will acquire a -\\pi phase shift at the exit of the medium. We demonstrate with numerical simulations that a complete 180^\\circ phase rotation for the probe field at the exit of the medium is achieved, which may result in many applications in information science and telecommunication.

  11. A model for direct laser interference patterning of ZnO:Al - predicting possible sample topographies to optimize light trapping in thin-film silicon solar cells

    Science.gov (United States)

    Dyck, Tobias; Haas, Stefan

    2016-04-01

    We present a novel approach to obtaining a quick prediction of a sample's topography after the treatment with direct laser interference patterning (DLIP) . The underlying model uses the parameters of the experimental setup as input, calculates the laser intensity distribution in the interference volume and determines the corresponding heat intake into the material as well as the subsequent heat diffusion within the material. The resulting heat distribution is used to determine the topography of the sample after the DLIP treatment . This output topography is in good agreement with corresponding experiments. The model can be applied in optimization algorithms in which a sample topography needs to be engineered in order to suit the needs of a given device. A prominent example for such an application is the optimization of the light scattering properties of the textured interfaces in a solar cell.

  12. Light

    CERN Document Server

    Robertson, William C

    2003-01-01

    Why is left right and right left in the mirror? Baffled by the basics of reflection and refraction? Wondering just how the eye works? If you have trouble teaching concepts about light that you don t fully grasp yourself, get help from a book that s both scientifically accurate and entertaining with Light. By combining clear explanations, clever drawings, and activities that use easy-to-find materials, this book covers what science teachers and parents need to know to teach about light with confidence. It uses ray, wave, and particle models of light to explain the basics of reflection and refraction, optical instruments, polarization of light, and interference and diffraction. There s also an entire chapter on how the eye works. Each chapter ends with a Summary and Applications section that reinforces concepts with everyday examples. Whether you need a deeper understanding of how light bends or a good explanation of why the sky is blue, you ll find Light more illuminating and accessible than a college textbook...

  13. Graphene quantum interference photodetector

    Directory of Open Access Journals (Sweden)

    Mahbub Alam

    2015-03-01

    Full Text Available In this work, a graphene quantum interference (QI photodetector was simulated in two regimes of operation. The structure consists of a graphene nanoribbon, Mach–Zehnder interferometer (MZI, which exhibits a strongly resonant transmission of electrons of specific energies. In the first regime of operation (that of a linear photodetector, low intensity light couples two resonant energy levels, resulting in scattering and differential transmission of current with an external quantum efficiency of up to 5.2%. In the second regime of operation, full current switching is caused by the phase decoherence of the current due to a strong photon flux in one or both of the interferometer arms in the same MZI structure. Graphene QI photodetectors have several distinct advantages: they are of very small size, they do not require p- and n-doped regions, and they exhibit a high external quantum efficiency.

  14. GaN-based light emitting diodes on nano-hole patterned sapphire substrate prepared by three-beam laser interference lithography

    Science.gov (United States)

    Sang, Wei-hua; Lin, Lu; Wang, Long; Min, Jia-hua; Zhu, Jian-jun; Wang, Min-rui

    2016-05-01

    Nano-hole patterned sapphire substrates (NHPSSs) were successfully prepared using a low-cost and high-efficiency approach, which is the laser interference lithography (LIL) combined with reactive ion etching (RIE) and inductively coupled plasma (ICP) techniques. Gallium nitride (GaN)-based light emitting diode (LED) structure was grown on NHPSS by metal organic chemical vapor deposition (MOCVD). Photoluminescence (PL) measurement was conducted to compare the luminescence efficiency of the GaN-based LED structure grown on NHPSS (NHPSS-LED) and that on unpatterned sapphire substrates (UPSS-LED). Electroluminescence (EL) measurement shows that the output power of NHPSS-LED is 2.3 times as high as that of UPSS-LED with an injection current of 150 mA. Both PL and EL results imply that NHPSS has an advantage in improving the crystalline quality of GaN epilayer and light extraction efficiency of LEDs at the same time.

  15. Properties of light induced EPR signals in enamel and their possible interference with gamma-induced signals

    International Nuclear Information System (INIS)

    Exposure of tooth enamel to natural and artificial UV light results in stable EPR signals with g-factors of 1.9985, 2.0018, 2.0045, 2.0052 and 2.0110. The first three signals correspond to the parallel and perpendicular components of the radiation induced or dosimetric signal and the native signal reported in dosimetry and dating studies. The latter two signals were found to be sensitive to both gamma-ray and sunlight exposure, however, their responses to light differed from that to radiation, giving rise to the possibility of using them as indicators of the dose-equivalent resulting from light exposure

  16. Fatal Injuries in Light Vehicle Crashes - Time to Death and Cause of Death

    OpenAIRE

    Luchter, Stephen; Smith, Andrew; Wang, Jing

    1998-01-01

    FARS and NASS CDS data were analyzed to determine time and cause of occupant deaths resulting from light vehicle crashes in the early 1990s. The results shows 46 percent of the deaths occurred within half an hour, 24 percent between half an hour and an hour and a half and a total of 90 percent within 24 hours. Of the deaths occurring during the 1.5 hours following injury 52 percent were the result of head injuries and 36 percent were the result of thorax injuries. When compared with the class...

  17. Can the Hypothesis 'Photon Interferes only with Itself' be Reconciled with Superposition of Light from Multiple Beams or Sources?

    Science.gov (United States)

    Roychoudhuri, Chandrasekhar; Prasad, Narasimha S.; Peng, Qing

    2007-01-01

    Any superposition effect as measured (SEM) by us is the summation of simultaneous stimulations experienced by a detector due to the presence of multiple copies of a detectee each carrying different values of the same parameter. We discus the cases with light beams carrying same frequency for both diffraction and multiple beam Fabry-Perot interferometer and also a case where the two superposed light beams carry different frequencies. Our key argument is that if light really consists of indivisible elementary particle, photon, then it cannot by itself create superposition effect since the state vector of an elementary particle cannot carry more than one values of any parameter at the same time. Fortunately, semiclassical model explains all light induced interactions using quantized atoms and classical EM wave packet. Classical physics, with its deeper commitment to Reality Ontology, was better prepared to nurture the emergence of Quantum Mechanics and still can provide guidance to explore nature deeper if we pay careful attention to successful classical formulations like Huygens-Fresnel diffraction integral.

  18. An investigation of pupil-based cognitive load measurement with low cost infrared webcam under light reflex interference.

    Science.gov (United States)

    Chen, Siyuan; Epps, Julien; Chen, Fang

    2013-01-01

    Using the task-evoked pupillary response (TEPR) to index cognitive load can contribute significantly to the assessment of memory function and cognitive skills in patients. However, the measurement of pupillary response is currently limited to a well-controlled lab environment due to light reflex and also relies heavily on expensive video-based eye trackers. Furthermore, commercial eye trackers are usually dedicated to gaze direction measurement, and their calibration procedure and computing resource are largely redundant for pupil-based cognitive load measurement (PCLM). In this study, we investigate the validity of cognitive load measurement with (i) pupil light reflex in a less controlled luminance background; (ii) a low-cost infrared (IR) webcam for the TEPR in a controlled luminance background. ANOVA results show that with an appropriate baseline selection and subtraction, the light reflex is significantly reduced, suggesting the possibility of less constrained practical applications of PCLM. Compared with the TEPR from a commercial remote eye tracker, a low-cost IR webcam achieved a similar TEPR pattern and no significant difference was found between the two devices in terms of cognitive load measurement across five induced load levels. PMID:24110409

  19. Interference Spins

    DEFF Research Database (Denmark)

    Popovski, Petar; Simeone, Osvaldo; Nielsen, Jimmy Jessen;

    2015-01-01

    traffic load and interference condition leads to performance gains. In this letter, a general network of multiple interfering two-way links is studied under the assumption of a balanced load in the two directions for each link. Using the notion of interference spin, we introduce an algebraic framework for...

  20. Neurofilament light mutation causes hereditary motor and sensory neuropathy with pyramidal signs.

    Science.gov (United States)

    Hashiguchi, Akihiro; Higuchi, Yujiro; Nomura, Miwa; Nakamura, Tomonori; Arata, Hitoshi; Yuan, Junhui; Yoshimura, Akiko; Okamoto, Yuji; Matsuura, Eiji; Takashima, Hiroshi

    2014-12-01

    To identify novel mutations causing hereditary motor and sensory neuropathy (HMSN) with pyramidal signs, a variant of Charcot-Marie-Tooth disease (CMT), we screened 28 CMT and related genes in four members of an affected Japanese family. Clinical features included weakness of distal lower limb muscles, foot deformity, and mild sensory loss, then late onset of progressive spasticity. Electrophysiological studies revealed widespread neuropathy. Electron microscopic analysis showed abnormal mitochondria and mitochondrial accumulation in the neurons and Schwann cells. Brain magnetic resonance imaging (MRI) revealed an abnormally thin corpus callosum. In all four, microarrays detected a novel heterozygous missense mutation c.1166A>G (p.Y389C) in the gene encoding the light-chain neurofilament protein (NEFL), indicating that NEFL mutations can result in a HMSN with pyramidal signs phenotype. PMID:25583183

  1. On-chip copper-dielectric interference filters for manufacturing of ambient light and proximity CMOS sensors.

    Science.gov (United States)

    Frey, Laurent; Masarotto, Lilian; D'Aillon, Patrick Gros; Pellé, Catherine; Armand, Marilyn; Marty, Michel; Jamin-Mornet, Clémence; Lhostis, Sandrine; Le Briz, Olivier

    2014-07-10

    Filter technologies implemented on CMOS image sensors for spectrally selective applications often use a combination of on-chip organic resists and an external substrate with multilayer dielectric coatings. The photopic-like and near-infrared bandpass filtering functions respectively required by ambient light sensing and user proximity detection through time-of-flight can be fully integrated on chip with multilayer metal-dielectric filters. Copper, silicon nitride, and silicon oxide are the materials selected for a technological proof-of-concept on functional wafers, due to their immediate availability in front-end semiconductor fabs. Filter optical designs are optimized with respect to specific performance criteria, and the robustness of the designs regarding process errors are evaluated for industrialization purposes. PMID:25090070

  2. Tysnd1 deficiency in mice interferes with the peroxisomal localization of PTS2 enzymes, causing lipid metabolic abnormalities and male infertility.

    Directory of Open Access Journals (Sweden)

    Yumi Mizuno

    Full Text Available Peroxisomes are subcellular organelles involved in lipid metabolic processes, including those of very-long-chain fatty acids and branched-chain fatty acids, among others. Peroxisome matrix proteins are synthesized in the cytoplasm. Targeting signals (PTS or peroxisomal targeting signal at the C-terminus (PTS1 or N-terminus (PTS2 of peroxisomal matrix proteins mediate their import into the organelle. In the case of PTS2-containing proteins, the PTS2 signal is cleaved from the protein when transported into peroxisomes. The functional mechanism of PTS2 processing, however, is poorly understood. Previously we identified Tysnd1 (Trypsin domain containing 1 and biochemically characterized it as a peroxisomal cysteine endopeptidase that directly processes PTS2-containing prethiolase Acaa1 and PTS1-containing Acox1, Hsd17b4, and ScpX. The latter three enzymes are crucial components of the very-long-chain fatty acids β-oxidation pathway. To clarify the in vivo functions and physiological role of Tysnd1, we analyzed the phenotype of Tysnd1(-/- mice. Male Tysnd1(-/- mice are infertile, and the epididymal sperms lack the acrosomal cap. These phenotypic features are most likely the result of changes in the molecular species composition of choline and ethanolamine plasmalogens. Tysnd1(-/- mice also developed liver dysfunctions when the phytanic acid precursor phytol was orally administered. Phyh and Agps are known PTS2-containing proteins, but were identified as novel Tysnd1 substrates. Loss of Tysnd1 interferes with the peroxisomal localization of Acaa1, Phyh, and Agps, which might cause the mild Zellweger syndrome spectrum-resembling phenotypes. Our data established that peroxisomal processing protease Tysnd1 is necessary to mediate the physiological functions of PTS2-containing substrates.

  3. Optical interference with digital holograms

    Science.gov (United States)

    Gossman, David; Perez-Garcia, Benjamin; Hernandez-Aranda, Raul I.; Forbes, Andrew

    2016-07-01

    In 1804, Thomas Young reported the observation of fringes in the intensity of light, and attributed it to the concept of interference between coherent sources. In this paper, we revisit this famous experiment and show how it can easily be demonstrated with digital holography. We look closely at the concept of interference with light and ask, "fringes in what?" We then show that depending on how light interferes, fringe patterns in observables other than intensity can be seen. We explain this conceptually and demonstrate it experimentally. We provide a holistic approach to the topic, aided by modern laboratory practices for a straightforward demonstration of the underlying physics.

  4. The Performance of a Dual Header Pulse Interval Modulation in the Presence of Artificial Light Interferences in an Indoor Optical Wireless Communications Channel with Wavelet Denoising

    Directory of Open Access Journals (Sweden)

    S. Rajbhandari

    2011-01-01

    Full Text Available Problem statement: Similar to other baseband modulation schemes, the performance of the Dual Header Pulse Interval Modulation (DH-PIM is adversely affected by Artificial Light Interferences (ALI in an indoor Optical Wireless Communications (OWC channel. Approach: The Discrete Wavelet Transform (DWT based denoising is studied for reducing the effect of the ALI. Computer simulation is carried out to demonstrate the effectiveness of the proposed system. The Baseline Wander (BLW affects for a range of bit resolutions is also analyzed. Results: The normalized optical power requirement in the presence of ALI is high in the range of 9-15 dB depending upon the bit resolution. A significant reduction in the optical power penalty is observed with the DWT denoising scheme. Conclusion: The DWT based denoising scheme is effective in reducing the consequence of the ALI. The optical power penalty decreases with an increase in the data rate and the bit resolution, which is due to reduction of the DC values and low frequency spectrum.

  5. Quantum Erasure: Quantum Interference Revisited

    OpenAIRE

    Walborn, Stephen P.; Cunha, Marcelo O Terra; Pádua, Sebastião; Monken, Carlos H.

    2005-01-01

    Recent experiments in quantum optics have shed light on the foundations of quantum physics. Quantum erasers - modified quantum interference experiments - show that quantum entanglement is responsible for the complementarity principle.

  6. The Spiegelmer NOX-A12, a novel CXCL12 inhibitor, interferes with chronic lymphocytic leukemia cell motility and causes chemosensitization

    OpenAIRE

    Hoellenriegel, Julia; Zboralski, Dirk; Maasch, Christian; Rosin, Nathalie Y.; Wierda, William G.; Keating, Michael J.; Kruschinski, Anna; Burger, Jan A.

    2014-01-01

    NOX-A12, a structured mirror-image RNA oligonucleotide that neutralizes CXCL12, interferes with CLL migration and drug resistance.NOX-A12 inhibits chemotaxis and sensitizes CLL cells toward cytotoxic drugs, providing a rationale for NOX-A12 combination therapy.

  7. Germline Defects Caused by Smed-boule RNA-Interference Reveal That Egg Capsule Deposition Occurs Independently of Fertilization, Ovulation, Mating, or the Presence of Gametes in Planarian Flatworms

    OpenAIRE

    Jessica Kathryne Steiner; Junichi Tasaki; Labib Rouhana

    2016-01-01

    Few animals are known to lay eggs in the absence of ovulation or copulation, as it is presumably energetically wasteful and subjected to negative selection. Characterization of Smed-boule, a member of the DAZ family of germline RNA-binding proteins, revealed that egg capsule (or capsule) production and deposition occurs independently of the presence of gametes in the planarian flatworm Schmidtea mediterranea. Reduction of Smed-boule expression by RNA-interference (RNAi) causes ablation of spe...

  8. An explanation of interference effects in the double slit experiment: Classical trajectories plus ballistic diffusion caused by zero-point fluctuations

    OpenAIRE

    Groessing, Gerhard; Fussy, Siegfried; Pascasio, Johannes Mesa; Schwabl, Herbert

    2011-01-01

    A classical explanation of interference effects in the double slit experiment is proposed. We claim that for every single "particle" a thermal context can be defined, which reflects its embedding within boundary conditions as given by the totality of arrangements in an experimental apparatus. To account for this context, we introduce a "path excitation field", which derives from the thermodynamics of the zero-point vacuum and which represents all possible paths a "particle" can take via therm...

  9. Interference in immunoassay

    International Nuclear Information System (INIS)

    Interfering factors are evident in both limited reagent (radioimmunoassay) and excess reagent (immunometric assay) technologies and should be suspected whenever there is a discrepancy between analytical results and clinical findings in the investigation of particular diseases. The overall effect of interference in immunoassay is analytical bias in result, either positive or negative of variable magnitude. The interference maybe caused by a wide spectrum of factors from poor sample collection and handling to physiological factors e.g. lipaemia, heparin treatment, binding protein abnormalities, autoimmunity and drug treatments. The range of interfering factors is extensive and difficult to discuss effectively in a short review

  10. Bending of light caused by gravitation: the same result via totally different philosophies

    OpenAIRE

    Yarman, Tolga; Kholmetskii, Alexander; Arik, Metin

    2014-01-01

    We offer a concise and direct way to derive the bending angle of light (i.e. as generally called, gravitational lensing), while light grazes a star, through the approach suggested earlier by the first author, which is fundamentally based on the energy conservation law and the weak equivalence principle. We come out with the same result as that of the general theory of relativity (GTR), although the philosophies behind are totally different from each other. We emphasize that in our approach, t...

  11. Resin polymerization problems--are they caused by resin curing lights, resin formulations, or both?

    Science.gov (United States)

    Christensen, R P; Palmer, T M; Ploeger, B J; Yost, M P

    1999-01-01

    Negative effects of rapid, high-intensity resin curing have been predicted for both argon lasers and plasma-arc curing lights. To address these questions, six different resin restorative materials were cured with 14 different resin curing lights representing differences in intensities ranging from 400 mW/cm2 to 1,900 mW/cm2; delivery modes using constant, ramped, and stepped methods; cure times ranging from 1 second to 40 seconds; and spot sizes of 6.7 mm to 10.9 mm. Two lasers, five plasma-arc lights, and seven halogen lights were used. Shrinkage, modulus, heat generation, strain, and physical changes on the teeth and resins during strain testing were documented. Results showed effects associated with lights were not statistically significant, but resin formulation was highly significant. Microfill resins had the least shrinkage and the lowest modulus. An autocure resin had shrinkage and modulus as high as or higher than the light-cured hybrid resins. Lasers and plasma-arc lights produced the highest heat increases on the surface (up to 21 degrees C) and within the resin restorations (up to 14 degrees C), and the halogen lights produced the most heat within the pulp chamber (up to 2 degrees C). Strain within the tooth was least with Heliomolar and greatest with Z100 Restorative and BISFIL II autocure resin. Clinical effects of strain relief were evident as white lines at the tooth-resin interface and cracks in enamel adjacent to the margins. This work implicates resin formulation, rather than light type or curing mode, as the important factor in polymerization problems. Lower light intensity and use of ramped and stepped curing modes did not provide significant lowering of shrinkage, modulus, or strain, and did not prevent enamel cracking adjacent to margins and formation of "white line" defects at the margins. Until materials with lower shrinkage and modulus are available, use of low-viscosity surface sealants as a final step in resin placement is suggested to

  12. Hydroxyl radicals cause fluctuation in intracellular ferrous ion levels upon light exposure during photoreceptor cell death.

    Science.gov (United States)

    Imamura, Tomoyo; Hirayama, Tasuku; Tsuruma, Kazuhiro; Shimazawa, Masamitsu; Nagasawa, Hideko; Hara, Hideaki

    2014-12-01

    Iron accumulation is a potential pathogenic event often seen in age-related macular degeneration (AMD) patients. In this study, we focused on the relationship between AMD pathology and concentrations of ferrous ion, which is a highly reactive oxygen generator in biological systems. Murine cone-cells-derived 661 W cells were exposed to white fluorescence light at 2500 lx for 1, 3, 6, or 12 h. Levels of ferrous ions, reactive oxygen species (ROS), and hydroxyl radicals were detected by RhoNox-1, a novel fluorescent probe for the selective detection of ferrous ion, 5-(and-6)-chloromethyl-2',7'-dichlorodihydrofluorescein diacetate, acetyl ester (CM-H2DCFDA), and 3'-p-(aminophenyl) fluorescein, respectively. Reduced glutathione, total iron levels and photoreceptor cell death were also measured. Two genes related to iron metabolism, transferrin receptor 1 (TfR1) and H ferritin (HFt), were quantified by RT-PCR. The effects of ferrous ion on cell death and hydroxyl radical production were determined by treatment with a ferrous ion chelating agent, 2,2'-bipyridyl. We found that the ferrous ion level decreased with light exposure in the short time frame, whereas it was upregulated during a 6-h light exposure. Total iron, ROS, cell death rate, and expression of TfR and HFt genes were significantly increased in a time-dependent manner in 661 W cells exposed to light. Chelation with 2,2'-bipyridyl reduced the level of hydroxyl radicals and protected against light-induced cell death. These results suggest that light exposure decreases ferrous ion levels and enhances iron uptake in photoreceptor cells. Ferrous ion may be involved in light-induced photoreceptor cell death through production of hydroxyl radicals. PMID:25447561

  13. Interference in ballistic motor learning - is motor interference really sensory?

    DEFF Research Database (Denmark)

    Lundbye-Jensen, Jesper; Petersen, Tue Hvass; Rothwell, John C;

    Skill gained after a short period of practice in one motor task can be abolished if a second task is learned shortly afterwards. We hypothesised that interference requires the same circuits to be engaged in the two tasks and provoke competing processes of synaptic plasticity. To test this, subjects...... not require learning. Repeated transcranial magnetic stimulation (rTMS) of corticospinal motor output at intensities below ankle movement threshold did not cause interference, whereas suprathreshold rTMS did. Furthermore, electrical stimulation of the peripheral nerve to the plantarflexors (but not...... extensors) caused interference. We conclude that interference is remarkably specific for circuits involved in a specific movement direction / activation of individual muscles and depends crucially on sensory error signals. One possible mechanism of interference may be disruption of early motor memory...

  14. Light Vector Meson Photoproduction off of 1H at Jefferson Lab and p-w Interference in the Leptonic Decay Channel

    Energy Technology Data Exchange (ETDEWEB)

    Djalali, Chaden [University of Iowa; Paolone, Michael [Temple University, JLAB; Weygand, Dennis; Wood, Mike H. [USC LA, JLAB

    2014-09-01

    Although the phenomena of r – w interference has been studied at great length in pionic decay channel over the past 50 years, a study of the interference in a purely electromagnetic production and decay channel has never been performed on an elementary proton target until now. The only published photo-production data of the r - w leptonic decay channel was obtained in the early seventies on C and Be. An investigation of the r - w interference on a Hydrogen was recently completed at Jefferson Lab with the CLAS detector. The di-lepton spectra was fit with two inter- fering relativistic Breit-Wigner functions, and the interference phase was extracted. Preliminary results will be compared to the previous experimental studies in nuclei.

  15. An explanation of interference effects in the double slit experiment: Classical trajectories plus ballistic diffusion caused by zero-point fluctuations

    International Nuclear Information System (INIS)

    A classical explanation of interference effects in the double slit experiment is proposed. We claim that for every single “particle” a thermal context can be defined, which reflects its embedding within boundary conditions as given by the totality of arrangements in an experimental apparatus. To account for this context, we introduce a “path excitation field”, which derives from the thermodynamics of the zero-point vacuum and which represents all possible paths a “particle” can take via thermal path fluctuations. The intensity distribution on a screen behind a double slit is calculated, as well as the corresponding trajectories and the probability density current. The trajectories are shown to obey a “no crossing” rule with respect to the central line, i.e., between the two slits and orthogonal to their connecting line. This agrees with the Bohmian interpretation, but appears here without the necessity of invoking the quantum potential. - Highlights: ► We model quantum mechanical interference with classical means. ► The intensity distribution on a screen behind a double slit is calculated. ► Also, the corresponding trajectories and the probability density current are obtained.

  16. Quantitative analysis with advanced compensated polarized light microscopy on wavelength dependence of linear birefringence of single crystals causing arthritis

    International Nuclear Information System (INIS)

    To improve our ability to identify single crystals causing arthritis, we have developed a practical measurement system of polarized light microscopy called advanced compensated polarized light microscopy (A-CPLM). The A-CPLM system is constructed by employing a conventional phase retardation plate, an optical fibre and a charge-coupled device spectrometer in a polarized light microscope. We applied the A-CPLM system to measure linear birefringence (LB) in the visible region, which is an optical anisotropic property, for tiny single crystals causing arthritis, i.e. monosodium urate monohydrate (MSUM) and calcium pyrophosphate dihydrate (CPPD). The A-CPLM system performance was evaluated by comparing the obtained experimental data using the A-CPLM system with (i) literature data for a standard sample, MgF2, and (ii) experimental data obtained using an established optical method, high-accuracy universal polarimeter, for the MSUM. The A-CPLM system was found to be applicable for measuring the LB spectra of the single crystals of MSUM and CPPD, which cause arthritis, in the visible regions. We quantitatively reveal the large difference in LB between MSUM and CPPD crystals. These results demonstrate the usefulness of the A-CPLM system for distinguishing the crystals causing arthritis. (paper)

  17. Bending of light caused by gravitation: the same result via totally different philosophies

    CERN Document Server

    Yarman, Tolga; Arik, Metin

    2014-01-01

    We offer a concise and direct way to derive the bending angle of light (i.e. as generally called, gravitational lensing), while light grazes a star, through the approach suggested earlier by the first author, which is fundamentally based on the energy conservation law and the weak equivalence principle. We come out with the same result as that of the general theory of relativity (GTR), although the philosophies behind are totally different from each other. We emphasize that in our approach, there is no need to draw a distinction between light and ordinary matter, which makes our approach of gravity potentially compatible with quantum mechanics. Furthermore, our equation that furnishes gravitational lensing, also furnishes the result about the precession of the perihelion of a planet. The results obtained are discussed.

  18. Interference of a Narrowband Biphoton with Double Electromagnetically Induced Transparency in an N-Type System

    Institute of Scientific and Technical Information of China (English)

    CHEN Peng; QIAN Jun; CHEN Dong-Yuan; HU Zheng-Feng; WANG Yu-Zhu

    2012-01-01

    We predict the possibility of the interference of narrow-hand biphotons generated by spontaneous four-wave mixing with double electromagnetically induced transparency configuration in cold atoms. In an N-type four-level system, an auxiliary optical field Ωm can create double transparency windows for anti-Stokes photons. When the slow light effects in the double transparency windows are very strong, two four-wave mixing channels could exist due to the splitting of the phase matching condition. The biphoton generated from the two four-wave mixing channels can cause interference and shows Rabi oscillations in two-photon correlation. This interference mechanism will complement the understanding of interference at the two-photon level.%We predict the possibility of the interference of narrow-band biphotons generated by spontaneous four-wave mixing with double electromagnetically induced transparency configuration in cold atoms.In an N-type fourlevel system,an auxiliary optical field Ωm can create double transparency windows for anti-Stokes photons.When the slow light effects in the double transparency windows are very strong,two four-wave mixing channels could exist due to the splitting of the phase matching condition.The biphoton generated from the two four-wave mixing channels can cause interference and shows Rabi oscillations in two-photon correlation.This interference mechanism will complement the understanding of interference at the two-photon level.

  19. Designing the Color of Hot-Dip Galvanized Steel Sheet Through Destructive Light Interference Using a Zn-Ti Liquid Metallic Bath

    Science.gov (United States)

    Levai, Gabor; Godzsák, Melinda; Török, Tamas I.; Hakl, Jozsef; Takáts, Viktor; Csik, Attila; Vad, Kalman; Kaptay, George

    2016-05-01

    The color of hot-dip galvanized steel sheet was adjusted in a reproducible way using a liquid Zn-Ti metallic bath, air atmosphere, and controlling the bath temperature as the only experimental parameter. Coloring was found only for samples cooled in air and dipped into Ti-containing liquid Zn. For samples dipped into a 0.15 wt pct Ti-containing Zn bath, the color remained metallic (gray) below a 792 K (519 °C) bath temperature; it was yellow at 814 K ± 22 K (541 °C ± 22 °C), violet at 847 K ± 10 K (574 °C ± 10 °C), and blue at 873 K ± 15 K (600 °C ± 15 °C). With the increasing bath temperature, the thickness of the adhered Zn-Ti layer gradually decreased from 52 to 32 micrometers, while the thickness of the outer TiO2 layer gradually increased from 24 to 69 nm. Due to small Al contamination of the Zn bath, a thin (around 2 nm) alumina-rich layer is found between the outer TiO2 layer and the inner macroscopic Zn layer. It is proven that the color change was governed by the formation of thin outer TiO2 layer; different colors appear depending on the thickness of this layer, mostly due to the destructive interference of visible light on this transparent nano-layer. A complex model was built to explain the results using known relationships of chemical thermodynamics, adhesion, heat flow, kinetics of chemical reactions, diffusion, and optics. The complex model was able to reproduce the observations and allowed making predictions on the color of the hot-dip galvanized steel sample, as a function of the following experimental parameters: temperature and Ti content of the Zn bath, oxygen content, pressure, temperature and flow rate of the cooling gas, dimensions of the steel sheet, velocity of dipping the steel sheet into the Zn-Ti bath, residence time of the steel sheet within the bath, and the velocity of its removal from the bath. These relationships will be valuable for planning further experiments and technologies on color hot-dip galvanization of steel

  20. Designing the Color of Hot-Dip Galvanized Steel Sheet Through Destructive Light Interference Using a Zn-Ti Liquid Metallic Bath

    Science.gov (United States)

    Levai, Gabor; Godzsák, Melinda; Török, Tamas I.; Hakl, Jozsef; Takáts, Viktor; Csik, Attila; Vad, Kalman; Kaptay, George

    2016-07-01

    The color of hot-dip galvanized steel sheet was adjusted in a reproducible way using a liquid Zn-Ti metallic bath, air atmosphere, and controlling the bath temperature as the only experimental parameter. Coloring was found only for samples cooled in air and dipped into Ti-containing liquid Zn. For samples dipped into a 0.15 wt pct Ti-containing Zn bath, the color remained metallic (gray) below a 792 K (519 °C) bath temperature; it was yellow at 814 K ± 22 K (541 °C ± 22 °C), violet at 847 K ± 10 K (574 °C ± 10 °C), and blue at 873 K ± 15 K (600 °C ± 15 °C). With the increasing bath temperature, the thickness of the adhered Zn-Ti layer gradually decreased from 52 to 32 micrometers, while the thickness of the outer TiO2 layer gradually increased from 24 to 69 nm. Due to small Al contamination of the Zn bath, a thin (around 2 nm) alumina-rich layer is found between the outer TiO2 layer and the inner macroscopic Zn layer. It is proven that the color change was governed by the formation of thin outer TiO2 layer; different colors appear depending on the thickness of this layer, mostly due to the destructive interference of visible light on this transparent nano-layer. A complex model was built to explain the results using known relationships of chemical thermodynamics, adhesion, heat flow, kinetics of chemical reactions, diffusion, and optics. The complex model was able to reproduce the observations and allowed making predictions on the color of the hot-dip galvanized steel sample, as a function of the following experimental parameters: temperature and Ti content of the Zn bath, oxygen content, pressure, temperature and flow rate of the cooling gas, dimensions of the steel sheet, velocity of dipping the steel sheet into the Zn-Ti bath, residence time of the steel sheet within the bath, and the velocity of its removal from the bath. These relationships will be valuable for planning further experiments and technologies on color hot-dip galvanization of steel

  1. Light-induced temperature jump causes power-dependent ultrafast kinetics of electrons generated in multiphoton ionization of liquid water

    OpenAIRE

    Crowell, Robert A.; Lian, Rui; Shkrob, Ilya A.; Qian, Jun; Oulianov, Dmitri A.; Pommeret, Stanislas

    2004-01-01

    Picosecond geminate recombination kinetics for electrons generated by multiphoton ionization of liquid water become power dependent when the radiance of the excitation light is greater than 0.3-0.5 TW/cm^2 (the terawatt regime). To elucidate the mechanism of this power dependence, tri- 400 nm photon ionization of water has been studied using pump-probe laser spectroscopy on the pico- and femtosecond time scales. We suggest that the observed kinetic transformations are caused by a rapid temper...

  2. Ti-O-O coordination bond caused visible light photocatalytic property of layered titanium oxide

    Science.gov (United States)

    Kong, Xingang; Zeng, Chaobin; Wang, Xing; Huang, Jianfeng; Li, Cuiyan; Fei, Jie; Li, Jiayin; Feng, Qi

    2016-01-01

    The layered titanium oxide is a useful and unique precursor for the facile and rapid preparation of the peroxide layered titanium oxide H1.07Ti1.73O4·nH2O (HTO) crystal with enhanced visible light photoactivity. The H2O2 molecules as peroxide chemicals rapidly enter into the interlayers of HTO crystal, and coordinate with Ti within TiO6 octahedron to form a mass of Ti-O-O coordination bond in the interlayers. The introduction of these Ti-O-O coordination bonds result in lowering the band gap of HTO, and promoting the separation efficiency of the photo induced electron–hole pairs. Meanwhile, the photocatalytic investigation indicates that such peroxide HTO crystal has the enhanced photocatalytic performance for RhB degradation and water splitting to generate oxygen under visible light irradiating. PMID:27350285

  3. Phase collapse caused by blue-light irradiation in a cyanobridged coordination polymer

    International Nuclear Information System (INIS)

    In this work, we report a photoinduced phase transition, light-induced phase collapse, using rubidium manganese hexacyanoferrate, RbI0.43MnII[FeIII(CN)6]0.81·3H2O, which does not exhibit a phase transition upon changing the temperature. However, when this material is irradiated with blue light at temperature around 100-200 K, the MnII-FeIII phase collapses and the valence isomer MnIII-FeII phase appears. The MnII-FeIII phase is perfectly recovered as the temperature increased. Theoretical analysis suggests that the initial MnII-FeIII phase is a thermodynamically metastable phase, trapped at a local free-energy minimum, while the photogenerated MnIII-FeII phase is the true thermodynamically stable phase below 230 K

  4. Artificial Lighting as a Vector Attractant and Cause of Disease Diffusion

    OpenAIRE

    Barghini, Alessandro; de Medeiros, Bruno A. S.

    2010-01-01

    Background Traditionally, epidemiologists have considered electrification to be a positive factor. In fact, electrification and plumbing are typical initiatives that represent the integration of an isolated population into modern society, ensuring the control of pathogens and promoting public health. Nonetheless, electrification is always accompanied by night lighting that attracts insect vectors and changes people’s behavior. Although this may lead to new modes of infection and increased tra...

  5. Lighting

    Data.gov (United States)

    Federal Laboratory Consortium — Lighting Systems Test Facilities aid research that improves the energy efficiency of lighting systems. • Gonio-Photometer: Measures illuminance from each portion of...

  6. Causes of variability in light absorption by particles in snow at sites in Idaho and Utah

    Science.gov (United States)

    Doherty, Sarah J.; Hegg, Dean A.; Johnson, James E.; Quinn, Patricia K.; Schwarz, Joshua P.; Dang, Cheng; Warren, Stephen G.

    2016-05-01

    A characterization of black carbon (BC) and other light-absorbing particles in snow is presented for three mountain valley sites in Idaho in early 2014 and for one site near Vernal, Utah, in early 2013 and 2014. The focus of the study was on constraining the magnitude and drivers of variations in particulate absorbers in midlatitude U.S. seasonal snow. Mass mixing ratios of BC in newly fallen snow were similar at all three Idaho sites, with a median of 4.7 ± 4.2 ng BC per gram of snow. The median total light-absorbing particulate mixing ratios in new snow, expressed as an equivalent mixing ratio of BC, was 18 ± 23 ng g-1. At the Utah site, which is near sources of both fossil fuel and dust, the mixing ratios of BC varied from 7 to 45 ng g-1 across seven new snowfall samples, and the BC-equivalent mixing ratios varied from 9 to 1500 ng g-1. At all sites, dry deposition and in-snow processes increase the mixing ratio of BC by up to an order of magnitude and increase the mixing ratio of all light-absorbing particulates by up to 2 orders of magnitude, highlighting the importance of capturing these processes for accurately representing snow albedo in climate models. Spatial variability at a range of scales is found to be considerably smaller than the temporal variations at a given site, with implications for the representativeness of field samples used in observation/model comparisons.

  7. Light deflection with torsion effects caused by a spinning cosmic string

    Science.gov (United States)

    Jusufi, Kimet

    2016-06-01

    Using a new geometrical method introduced by Werner, we find the deflection angle in the weak limit approximation by a spinning cosmic string in the context of the Einstein-Cartan (EC) theory of gravity. We begin by adopting the String-Randers optical metric, then we apply the Gauss-Bonnet theorem to the optical geometry and derive the leading terms of the deflection angle in the equatorial plane. Calculation shows that light deflection is affected by the intrinsic spin of the cosmic string and torsion.

  8. Light Deflection with Torsion Effects Caused by a Spinning Cosmic String

    CERN Document Server

    Jusufi, Kimet

    2016-01-01

    Using a new geometrical method introduced by Werner, we find the deflection angle in the weak limit approximation by a spinning cosmic string in the context of the Einstein-Cartan (EC) theory of gravity. We begin by adopting the String-Randers optical metric, then we apply the Gauss-Bonnet theorem to the optical geometry and derive the leading terms of the deflection angle in the equatorial plane. Calculations shows that light deflection is affected by the intrinsic spin of the cosmic string and torsion.

  9. Long-Term Reduction in Infrared Autofluorescence Caused by Infrared Light Below the Maximum Permissible Exposure

    OpenAIRE

    Masella, Benjamin D.; Williams, David R.; Fischer, William S.; Rossi, Ethan A.; Hunter, Jennifer J.

    2014-01-01

    Exposure to infrared illumination at irradiances well below current safety limits can cause a long-lasting decrease in infrared autofluorescence from the retina. It is unclear whether this effect is benign or indicative of a subcellular change that could be cumulatively harmful.

  10. Assessment of Electromagnetic Interference with Active Cardiovascular Implantable Electronic Devices (CIEDs Caused by the Qi A13 Design Wireless Charging Board

    Directory of Open Access Journals (Sweden)

    Tobias Seckler

    2015-05-01

    Full Text Available Electromagnetic interference is a concern for people wearing cardiovascular implantable electronic devices (CIEDs. The aim of this study was to assess the electromagnetic compatibility between CIEDs and the magnetic field of a common wireless charging technology. To do so the voltage induced in CIEDs by Qi A13 design magnetic fields were measured and compared with the performance limits set by ISO 14117. In order to carry this out a measuring circuit was developed which can be connected with unipolar or bipolar pacemaker leads. The measuring system was positioned at the four most common implantation sites in a torso phantom filled with physiological saline solution. The phantom was exposed by using Helmholtz coils from 5 µT to 27 µT with 111 kHz sine‑bursts or by using a Qi A13 design wireless charging board (Qi‑A13‑Board in two operating modes “power transfer” and “pinging”. With the Helmholtz coils the lowest magnetic flux density at which the performance limit was exceeded is 11 µT. With the Qi‑A13‑Board in power transfer mode 10.8% and in pinging mode 45.7% (2.2% at 10 cm distance of the performance limit were reached at maximum. In neither of the scrutinized cases, did the voltage induced by the Qi‑A13‑Board exceed the performance limits.

  11. Assessment of Electromagnetic Interference with Active Cardiovascular Implantable Electronic Devices (CIEDs) Caused by the Qi A13 Design Wireless Charging Board.

    Science.gov (United States)

    Seckler, Tobias; Jagielski, Kai; Stunder, Dominik

    2015-06-01

    Electromagnetic interference is a concern for people wearing cardiovascular implantable electronic devices (CIEDs). The aim of this study was to assess the electromagnetic compatibility between CIEDs and the magnetic field of a common wireless charging technology. To do so the voltage induced in CIEDs by Qi A13 design magnetic fields were measured and compared with the performance limits set by ISO 14117. In order to carry this out a measuring circuit was developed which can be connected with unipolar or bipolar pacemaker leads. The measuring system was positioned at the four most common implantation sites in a torso phantom filled with physiological saline solution. The phantom was exposed by using Helmholtz coils from 5 µT to 27 µT with 111 kHz sine‑bursts or by using a Qi A13 design wireless charging board (Qi‑A13‑Board) in two operating modes "power transfer" and "pinging". With the Helmholtz coils the lowest magnetic flux density at which the performance limit was exceeded is 11 µT. With the Qi‑A13‑Board in power transfer mode 10.8% and in pinging mode 45.7% (2.2% at 10 cm distance) of the performance limit were reached at maximum. In neither of the scrutinized cases, did the voltage induced by the Qi‑A13‑Board exceed the performance limits. PMID:26024360

  12. Multipolar interference effects in nanophotonics

    CERN Document Server

    Liu, Wei

    2016-01-01

    Scattering of electromagnetic waves by an arbitrary nanoscale object can be characterized by a multipole decomposition of the electromagnetic field that allows to describe the scattering intensity and radiation pattern through interferences of dominating excited multipole modes. In modern nanophotonics, both generation and interference of multipole modes start to play an indispensable role, and they enable nanoscale manipulation of light with many related applications. Here we review the multipolar interference effects in metallic, metal-dielectric, and dielectric nanostructures, and suggest a comprehensive view on many phenomena involving the interferences of electric, magnetic and toroidal multipoles, which drive a number of recently discussed effects in nanophotonics such as unidirectional scattering, effective optical antiferromagnetism, generalized Kerker scattering with controlled angular patterns, generalized Brewster angle, and nonradiating optical anapoles. We further discuss other types of possible ...

  13. TNF causes changes in glomerular endothelial permeability and morphology through a Rho and myosin light chain kinase-dependent mechanism.

    Science.gov (United States)

    Xu, Chang; Wu, Xiaoyan; Hack, Bradley K; Bao, Lihua; Cunningham, Patrick N

    2015-12-01

    A key function of the endothelium is to serve as a regulated barrier between tissue compartments. We have previously shown that tumor necrosis factor (TNF) plays a crucial role in lipopolysaccharide (LPS)-induced acute kidney injury, in part by causing injury to the renal endothelium through its receptor TNFR1. Here, we report that TNF increased permeability to albumin in primary culture mouse renal endothelial cells, as well as human glomerular endothelial cells. This process occurred in association with changes in the actin cytoskeleton and was associated with gaps between previously confluent cells in culture and decreases in the tight junction protein occludin. This process was dependent on myosin light chain activation, as seen by its prevention with Rho-associated kinase and myosin light chain kinase (MLCK) inhibitors. Surprisingly, permeability was not blocked by inhibition of apoptosis with caspase inhibitors. Additionally, we found that the renal glycocalyx, which plays an important role in barrier function, was also degraded by TNF in a Rho and MLCK dependent fashion. TNF treatment caused a decrease in the size of endothelial fenestrae, dependent on Rho and MLCK, although the relevance of this to changes in permeability is uncertain. In summary, TNF-induced barrier dysfunction in renal endothelial cells is crucially dependent upon the Rho/MLCK signaling pathway. PMID:26634902

  14. Reproductive interference between animal species.

    Science.gov (United States)

    Gröning, Julia; Hochkirch, Axel

    2008-09-01

    Although sexual interactions between species (reproductive interference) have been reported from a wide range of animal taxa, their potential for determining species coexistence is often disregarded. Here, we review evidence from laboratory and field studies illustrating that heterospecific sexual interactions are frequently associated with fitness loss and can have severe ecological and evolutionary consequences. We define reproductive interference as any kind of interspecific interaction during the process of mate acquisition that adversely affects the fitness of at least one of the species involved and that is caused by incomplete species recognition. We distinguish seven types of reproductive interference: signal jamming, heterospecific rivalry, misdirected courtship, heterospecific mating attempts, erroneous female choice, heterospecific mating, and hybridization. We then discuss the sex-specific costs of these types and highlight two typical features of reproductive interference: density-dependence and asymmetry. Similar to competition, reproductive interference can lead to displacement of one species (sexual exclusion), spatial, temporal, or habitat segregation, changes in life history parameters, and reproductive character displacement. In many cases, patterns of coexistence might be shaped by reproductive interference rather than by resource competition, as the presence of a few heterospecifics might substantially decrease reproductive success. Therefore, interspecific sexual interactions should receive more attention in ecological research. Reproductive interference has mainly been discussed in the context of invasive species or hybrid zones, whereas its influence on naturally-occurring sympatric species pairs has rarely been addressed. To improve our knowledge of the ecological significance of reproductive interference, findings from laboratory experiments should be validated in the field. Future studies should also focus on ecological mechanisms, such

  15. Interference in motor learning - is motor interference sensory?

    DEFF Research Database (Denmark)

    Jensen, Jesper Lundbye; Petersen, Tue Hvass; Rothwell, John C;

    Skill gained after a short period of practice in one motor task can be abolished if a second task is learned shortly afterwards, but not all motor activities cause interference. After all it is not necessary to remain completely still after practicing a task for learning to occur. Here we ask which...... mechanisms determine whether or not interference occurs. We hypothesised that interference requires the same neural circuits to be engaged in the two tasks and provoke competing processes of synaptic plasticity. To test this, subjects learned a ballistic ankle plantarflexion task. Early motor memory was...... learning of the primary task, no interference was observed. Previous studies have suggested that primary motor cortex (M1) may be involved in early motor memory consolidation. 1Hz Repetitive Transcranial Magnetic Stimulation (rTMS) of corticospinal motor output at intensities below ankle movement threshold...

  16. Multi-wavelength phase-shifting interferometry for micro-structures measurement based on color image processing in white light interference

    Science.gov (United States)

    Guo, Tong; Li, Feng; Chen, Jinping; Fu, Xing; Hu, Xiaotang

    2016-07-01

    Conventional multi-wavelength phase-shifting interferometry utilizes two or three monochromatic light sources, such as lasers, to realize the measurement of the surface topography with large discontinuity. In this paper, the white light source, with a single-chip CCD color camera, is used to accomplish multi-wavelength phase-shifting interferometry. In addition, we propose an algorithm which combines white light phase-shifting algorithm, equivalent wavelength method and fringe order method to achieve measuring and calibrating the micro-structures ranging from nanometer scale to micrometer scale. Finally, the proposed method is validated by a traceable step height standard.

  17. Quantum Interference of Multiple Beams Induced by Multiple Scattering

    DEFF Research Database (Denmark)

    Ott, Johan Raunkjær; Mortensen, N. Asger; Lodahl, Peter

    2011-01-01

    We report on quantum interference induced by the transmission of quantized light through a multiple-scattering medium. We show that entangled states can be created by multiple-scattering and that quantum interference survives disorder averaging.......We report on quantum interference induced by the transmission of quantized light through a multiple-scattering medium. We show that entangled states can be created by multiple-scattering and that quantum interference survives disorder averaging....

  18. Topical and Intradermal Efficacy of Photodynamic Therapy with Methylene Blue and Light-Emitting Diode in the Treatment of Cutaneous Leishmaniasis Caused by Leishmania braziliensis

    OpenAIRE

    Sbeghen, Mônica Raquel; Voltarelli, Evandra Maria; Campois, Tácito Graminha; Kimura, Elza; Aristides, Sandra Mara Alessi; Hernandes, Luzmarina; Caetano, Wilker; Hioka, Noboru; Lonardoni, Maria Valdrinez Campana; Silveira, Thaís Gomes Verzignassi

    2015-01-01

    Introduction: The topical and intradermal photodynamic therapy (PDT) effect of methylene blue (MB) using light-emitting diode (LED) as light source (MB/LED-PDT) in the treatment of lesions of American cutaneous leishmaniasis (ACL) caused by Leishmania braziliensis in hamsters were investigated.

  19. Light-induced temperature jump causes power-dependent ultrafast kinetics of electrons generated in multiphoton ionization of liquid water

    CERN Document Server

    Crowell, Robert A; Shkrob, Ilya A; Qian, Jun; Oulianov, Dmitri A; Pommeret, Stanislas

    2004-01-01

    Picosecond geminate recombination kinetics for electrons generated by multiphoton ionization of liquid water become power dependent when the radiance of the excitation light is greater than 0.3-0.5 TW/cm^2 (the terawatt regime). To elucidate the mechanism of this power dependence, tri- 400 nm photon ionization of water has been studied using pump-probe laser spectroscopy on the pico- and femtosecond time scales. We suggest that the observed kinetic transformations are caused by a rapid temperature jump in the sample. Such a jump is inherent to multiphoton ionization in the terawatt regime, when the absorption of the pump light along the optical path becomes very nonuniform. The heating of water is substantial (tens of degrees C) because the 3-photon quantum yield of the ionization is relatively low, ca. 0.42, and a large fraction of the excitation energy is released into the solvent bulk as heat. Evidence of the temperature jump is the observation of a red shift in the absorption spectrum of (thermalized) ele...

  20. Bringing the magic of light to remote areas where resources are scarce: beautiful demonstrations of interference patterns using laser pens and fibres

    Science.gov (United States)

    Mignard, D.

    2016-09-01

    The training of physics teachers in remote areas in the developing world requires dedicated trainers (who typically are volunteers), as well as robust logistics. The latter must include the supply of equipment for experiments in the classroom. This task is greatly aided by the use of cheap, safe and readily available consumer goods that do not require local power supplies. In this paper, a simple experiment using a laser pointer pen and samples of hair as well as wire and transparent thin fibre is presented, reproducing a variant of Thomas Youngs’ famed double slit experiment. The spread of the interference pattern as it projects itself on a screen is sufficiently large to catch the interest of students, and its orientation being perpendicular to that of the hair is also strikingly counter-intuitive. The students are then encouraged to apply the simplified Fraunhofer equation to the various samples to find out the width of their hair. Ideally, these samples would also include calibrating materials like fibres and wires of known diameters, the use of which should give confidence in the model by confirming that it can predict the sample diameter. A fruitful discussion supported by diagrams can also be conducted on the differences that could be expected between a straight edge and a rounded edge, the latter throwing an unexpected challenge to the initial model. However, the use of a transparent fibre also clearly illustrate the limitations of this model, a perception that is amplified by the particularly wide and bright interference pattern that it produces. This mismatch between the model and the real system should prompt the students to further refine their description of the physical system and the resulting model. Throughout the session, their reasoning may be helped by encouraging them to produce diagrams showing the path of optical rays.

  1. Blind Known Interference Cancellation

    CERN Document Server

    Zhang, Shengli; Wang, Hui

    2011-01-01

    This paper investigates interference-cancellation schemes at the receiver, in which the original data of the interference is known a priori. Such a priori knowledge is common in wireless relay networks. For example, a transmitting relay could be relaying data that was previously transmitted by a node, in which case the interference received by the node now is actually self information. Besides the case of self information, the node could also have overheard or received the interference data in a prior transmission by another node. Directly removing the known interference requires accurate estimate of the interference channel, which may be difficult in many situations. In this paper, we propose a novel scheme, Blind Known Interference Cancellation (BKIC), to cancel known interference without interference channel information. BKIC consists of two steps. The first step combines adjacent symbols to cancel the interference, exploiting the fact that the channel coefficients are almost the same between successive sy...

  2. IETS and quantum interference

    DEFF Research Database (Denmark)

    Jørgensen, Jacob Lykkebo; Gagliardi, Alessio; Pecchia, Alessandro;

    2014-01-01

    Destructive quantum interference in single molecule electronics is an intriguing phenomenon; however, distinguishing quantum interference effects from generically low transmission is not trivial. In this paper, we discuss how quantum interference effects in the transmission lead to either low...... suppressed when quantum interference effects dominate. That is, we expand the understanding of propensity rules in inelastic electron tunneling spectroscopy to molecules with destructive quantum interference....

  3. Interference Resilient Sigma Delta-Based Pulse Oximeter.

    Science.gov (United States)

    Shokouhian, Mohsen; Morling, Richard; Kale, Izzet

    2016-06-01

    Ambient light and optical interference can severely affect the performance of pulse oximeters. The deployment of a robust modulation technique to drive the pulse oximeter LEDs can reduce these unwanted effects and increases the resilient of the pulse oximeter against artificial ambient light. The time division modulation technique used in conventional pulse oximeters can not remove the effect of modulated light coming from surrounding environment and this may cause huge measurement error in pulse oximeter readings. This paper presents a novel cross-coupled sigma delta modulator which ensures that measurement accuracy will be more robust in comparison with conventional fixed-frequency oximeter modulation technique especially in the presence of pulsed artificial ambient light. Moreover, this novel modulator gives an extra control over the pulse oximeter power consumption leading to improved power management. PMID:26742140

  4. Laser self-mixing interference fiber sensor

    Institute of Scientific and Technical Information of China (English)

    Zhu Jun; Zhao Yan; Jin Guo-fan

    2008-01-01

    Fibre sensors exhibit a number of advantages over other sensors such as high sensitivity, electric insulation, corrosion resistance, interference rejection and so on. And laser elf-mixing interference can accurately detect the phase difference of feedback light. In this paper, a novel laser self-mixing interference fibre sensor that combines the advantages of fibre sensors with those of laser self-mixing interference is presented. Experimental configurations are set up to study the relationship between laser power output and phase of laser feedback light when the fibre trembles or when the fibre is stretched or pressed. The theoretical analysis of pressure sensors based on laser self-mixing interference is indicated to accord with the experimental results.

  5. Interference of spontaneously emitted photons

    CERN Document Server

    Beige, A; Pachos, J; Beige, Almut; Schoen, Christian; Pachos, Jiannis

    2002-01-01

    We discuss an experimental setup where two laser-driven atoms spontaneously emit photons and every photon causes a ``click'' at a point on a screen. By deriving the probability density for an emission into a certain direction from basic quantum mechanical principles we predict a spatial interference pattern. Similarities and differences with the classical double-slit experiment are discussed.

  6. Interference of spontaneously emitted photons

    OpenAIRE

    Beige, Almut; Schoen, Christian; Pachos, Jiannis

    2001-01-01

    We discuss an experimental setup where two laser-driven atoms spontaneously emit photons and every photon causes a ``click'' at a point on a screen. By deriving the probability density for an emission into a certain direction from basic quantum mechanical principles we predict a spatial interference pattern. Similarities and differences with the classical double-slit experiment are discussed.

  7. Opportunistic Interference Alignment in MIMO Interference Channels

    CERN Document Server

    Perlaza, Samir Medina; Lasaulce, Samson; Chaufray, Jean Marie

    2008-01-01

    We present two interference alignment techniques such that an opportunistic point-to-point multiple input multiple output (MIMO) link can reuse, without generating any additional interference, the same frequency band of a similar pre-existing primary link. In this scenario, we exploit the fact that under power constraints, although each radio maximizes independently its rate by water-filling on their channel transfer matrix singular values, frequently, not all of them are used. Therefore, by aligning the interference of the opportunistic radio it is possible to transmit at a significant rate while insuring zero-interference on the pre-existing link. We propose a linear pre-coder for a perfect interference alignment and a power allocation scheme which maximizes the individual data rate of the secondary link. Our numerical results show that significant data rates are achieved even for a reduced number of antennas.

  8. Artificial light at night causes diapause inhibition and sex-specific life history changes in a moth

    OpenAIRE

    Geffen, van, J; Grunsven, van, ECE; Ruijven, van, L.J.; Berendse, F.; Veenendaal, E. M.

    2014-01-01

    Rapidly increasing levels of light pollution subject nocturnal organisms to major alterations of their habitat, the ecological consequences of which are largely unknown. Moths are well-known to be attracted to light at night, but effects of light on other aspects of moth ecology, such as larval development and life-history, remain unknown. Such effects may have important consequences for fitness and thus for moth population sizes. To study the effects of artificial night lighting on developme...

  9. Gene expression patterns in transgenic mouse models of hypertrophic cardiomyopathy caused by mutations in myosin regulatory light chain.

    Science.gov (United States)

    Huang, Wenrui; Kazmierczak, Katarzyna; Zhou, Zhiqun; Aguiar-Pulido, Vanessa; Narasimhan, Giri; Szczesna-Cordary, Danuta

    2016-07-01

    Using microarray and bioinformatics, we examined the gene expression profiles in transgenic mouse hearts expressing mutations in the myosin regulatory light chain shown to cause hypertrophic cardiomyopathy (HCM). We focused on two malignant RLC-mutations, Arginine 58→Glutamine (R58Q) and Aspartic Acid 166 → Valine (D166V), and one benign, Lysine 104 → Glutamic Acid (K104E)-mutation. Datasets of differentially expressed genes for each of three mutants were compared to those observed in wild-type (WT) hearts. The changes in the mutant vs. WT samples were shown as fold-change (FC), with stringency FC ≥ 2. Based on the gene profiles, we have identified the major signaling pathways that underlie the R58Q-, D166V- and K104E-HCM phenotypes. The correlations between different genotypes were also studied using network-based algorithms. Genes with strong correlations were clustered into one group and the central gene networks were identified for each HCM mutant. The overall gene expression patterns in all mutants were distinct from the WT profiles. Both malignant mutations shared certain classes of genes that were up or downregulated, but most similarities were noted between D166V and K104E mice, with R58Q hearts showing a distinct gene expression pattern. Our data suggest that all three HCM mice lead to cardiomyopathy in a mutation-specific manner and thus develop HCM through diverse mechanisms. PMID:26906074

  10. Germline Defects Caused by Smed-boule RNA-Interference Reveal That Egg Capsule Deposition Occurs Independently of Fertilization, Ovulation, Mating, or the Presence of Gametes in Planarian Flatworms.

    Science.gov (United States)

    Steiner, Jessica Kathryne; Tasaki, Junichi; Rouhana, Labib

    2016-05-01

    Few animals are known to lay eggs in the absence of ovulation or copulation, as it is presumably energetically wasteful and subjected to negative selection. Characterization of Smed-boule, a member of the DAZ family of germline RNA-binding proteins, revealed that egg capsule (or capsule) production and deposition occurs independently of the presence of gametes in the planarian flatworm Schmidtea mediterranea. Reduction of Smed-boule expression by RNA-interference (RNAi) causes ablation of spermatogonial stem cells and the inability of ovarian germline stem cells to undergo oogenesis. Although animals subjected to Smed-boule RNAi lose their gametes and become sterile, they continue to lay egg capsules. Production of sterile capsules is even observed in virgin Smed-boule(RNAi) and control planarians maintained in complete isolation, demonstrating that egg production in S. mediterranea occurs independently of ovulation, fertilization, or mating. Evidence suggests that this is a conserved feature amongst Platyhelminthes, and therefore relevant to the pathology and dissemination of parasitic flatworms. These findings demonstrate that Smed-boule functions at different stages during male and female germline stem cell development, and also demonstrate that egg capsule production by planarian flatworms occurs independently of signals produced by mating or ova. PMID:27149082

  11. Germline Defects Caused by Smed-boule RNA-Interference Reveal That Egg Capsule Deposition Occurs Independently of Fertilization, Ovulation, Mating, or the Presence of Gametes in Planarian Flatworms.

    Directory of Open Access Journals (Sweden)

    Jessica Kathryne Steiner

    2016-05-01

    Full Text Available Few animals are known to lay eggs in the absence of ovulation or copulation, as it is presumably energetically wasteful and subjected to negative selection. Characterization of Smed-boule, a member of the DAZ family of germline RNA-binding proteins, revealed that egg capsule (or capsule production and deposition occurs independently of the presence of gametes in the planarian flatworm Schmidtea mediterranea. Reduction of Smed-boule expression by RNA-interference (RNAi causes ablation of spermatogonial stem cells and the inability of ovarian germline stem cells to undergo oogenesis. Although animals subjected to Smed-boule RNAi lose their gametes and become sterile, they continue to lay egg capsules. Production of sterile capsules is even observed in virgin Smed-boule(RNAi and control planarians maintained in complete isolation, demonstrating that egg production in S. mediterranea occurs independently of ovulation, fertilization, or mating. Evidence suggests that this is a conserved feature amongst Platyhelminthes, and therefore relevant to the pathology and dissemination of parasitic flatworms. These findings demonstrate that Smed-boule functions at different stages during male and female germline stem cell development, and also demonstrate that egg capsule production by planarian flatworms occurs independently of signals produced by mating or ova.

  12. Cryptic interference competition in swans foraging on cryptic prey

    NARCIS (Netherlands)

    Gyimesi, A.; Stillman, R.A.; Nolet, B.A.

    2010-01-01

    Interference can be defined as the reduction of intake rate caused by the presence of congeneric individuals. However, surrounding congeneric individuals may also accelerate food depletion. Therefore, it is difficult to quantify interference (contest) and exploitative (scramble) competition separate

  13. Modulation of the light-harvesting chlorophyll antenna size in Chlamydomonas reinhardtii by TLA1 gene over-expression and RNA interference

    Science.gov (United States)

    Mitra, Mautusi; Kirst, Henning; Dewez, David; Melis, Anastasios

    2012-01-01

    Truncated light-harvesting antenna 1 (TLA1) is a nuclear gene proposed to regulate the chlorophyll (Chl) antenna size in Chlamydomonas reinhardtii. The Chl antenna size of the photosystems and the chloroplast ultrastructure were manipulated upon TLA1 gene over-expression and RNAi downregulation. The TLA1 over-expressing lines possessed a larger chlorophyll antenna size for both photosystems and contained greater levels of Chl b per cell relative to the wild type. Conversely, TLA1 RNAi transformants had a smaller Chl antenna size for both photosystems and lower levels of Chl b per cell. Western blot analyses of the TLA1 over-expressing and RNAi transformants showed that modulation of TLA1 gene expression was paralleled by modulation in the expression of light-harvesting protein, reaction centre D1 and D2, and VIPP1 genes. Transmission electron microscopy showed that modulation of TLA1 gene expression impacts the organization of thylakoid membranes in the chloroplast. Over-expressing lines showed well-defined grana, whereas RNAi transformants possessed loosely held together and more stroma-exposed thylakoids. Cell fractionation suggested localization of the TLA1 protein in the inner chloroplast envelope and potentially in association with nascent thylakoid membranes, indicating a role in Chl antenna assembly and thylakoid membrane biogenesis. The results provide a mechanistic understanding of the Chl antenna size regulation by the TLA1 gene. PMID:23148270

  14. Artificial light at night causes diapause inhibition and sex-specific life history changes in a moth.

    Science.gov (United States)

    van Geffen, Koert G; van Grunsven, Roy H A; van Ruijven, Jasper; Berendse, Frank; Veenendaal, Elmar M

    2014-06-01

    Rapidly increasing levels of light pollution subject nocturnal organisms to major alterations of their habitat, the ecological consequences of which are largely unknown. Moths are well-known to be attracted to light at night, but effects of light on other aspects of moth ecology, such as larval development and life-history, remain unknown. Such effects may have important consequences for fitness and thus for moth population sizes. To study the effects of artificial night lighting on development and life-history of moths, we experimentally subjected Mamestra brassicae (Noctuidae) caterpillars to low intensity green, white, red or no artificial light at night and determined their growth rate, maximum caterpillar mass, age at pupation, pupal mass and pupation duration. We found sex-specific effects of artificial light on caterpillar life-history, with male caterpillars subjected to green and white light reaching a lower maximum mass, pupating earlier and obtaining a lower pupal mass than male caterpillars under red light or in darkness. These effects can have major implications for fitness, but were absent in female caterpillars. Moreover, by the time that the first adult moth from the dark control treatment emerged from its pupa (after 110 days), about 85% of the moths that were under green light and 83% of the moths that were under white light had already emerged. These differences in pupation duration occurred in both sexes and were highly significant, and likely result from diapause inhibition by artificial night lighting. We conclude that low levels of nocturnal illumination can disrupt life-histories in moths and inhibit the initiation of pupal diapause. This may result in reduced fitness and increased mortality. The application of red light, instead of white or green light, might be an appropriate measure to mitigate negative artificial light effects on moth life history. PMID:25360250

  15. Interference of composite bosons

    OpenAIRE

    Brougham, Thomas; Barnett, Stephen M.; Jex, Igor

    2010-01-01

    We investigate multi-boson interference. A Hamiltonian is presented that treats pairs of bosons as a single composite boson. This Hamiltonian allows two pairs of bosons to interact as if they were two single composite bosons. We show that this leads to the composite bosons exhibiting novel interference effects such as Hong-Ou-Mandel interference. We then investigate generalizations of the formalism to the case of interference between two general composite bosons. Finally, we show how one can ...

  16. Communication and interference coordination

    OpenAIRE

    Blasco-Serrano, Ricardo; Thobaben, Ragnar; Skoglund, Mikael

    2014-01-01

    We study the problem of controlling the interference created to an external observer by a communication processes. We model the interference in terms of its type (empirical distribution), and we analyze the consequences of placing constraints on the admissible type. Considering a single interfering link, we characterize the communication-interference capacity region. Then, we look at a scenario where the interference is jointly created by two users allowed to coordinate their actions prior to...

  17. Hurricane Andrew causes major oil spill at Florida Power ampersand Light Company's Turkey Point Power Plant, Homestead, Florida

    International Nuclear Information System (INIS)

    On August 24, 1992, Hurricane Andrew slammed into South Florida with wind gusts in excess of 160 mph. At 4:00 a.m. that day, the eye of this category four storm passed over Florida Power ampersand Light Company's Turkey Point power plant, south of Miami. Although the plant's two nuclear units escaped any significant damage, the storm caused extensive destruction to buildings and transmission facilities, and damaged two 400 foot tall emission stacks associated with the site's two fossil fuel generating units. In addition, a 90,000 to 110,000 gallon spill of No. 6 fuel oil resulted when a piece of wind-blown debris punctured the steel of the unit One 12,000 barrel fuel oil metering tank approximately 30 feet up from the tank bottom. Despite the presence of a secondary containment structure around the tank, the intense wind blew oil throughout the plant site. The damage to the metering tank apparently occurred during the first half hour of the hurricane. As the tank's oil level fell due to the puncture, transfer pumps from the bulk oil storage tanks received a low level alarm which automatically began transferring oil to the damaged metering tank. To prevent the further discharge of oil, plant personnel entered the power block and secured the pumps during the passage of the hurricane eye. Immediately following the storm, facility personnel deployed booms across the barge canal and the Units 1 and 2 intake canal to contain the oil which had entered the water. The response strategy and implementation is described in detail. The remediation costs were approximately $14/gallon spilled, including 54,000 gallons recovered for electricity generation

  18. Phonon-Mediated Nonclassical Interference in Diamond

    Science.gov (United States)

    England, Duncan G.; Fisher, Kent A. G.; MacLean, Jean-Philippe W.; Bustard, Philip J.; Heshami, Khabat; Resch, Kevin J.; Sussman, Benjamin J.

    2016-08-01

    Quantum interference of single photons is a fundamental aspect of many photonic quantum processing and communication protocols. Interference requires that the multiple pathways through an interferometer be temporally indistinguishable to within the coherence time of the photon. In this Letter, we use a diamond quantum memory to demonstrate interference between quantum pathways, initially temporally separated by many multiples of the optical coherence time. The quantum memory can be viewed as a light-matter beam splitter, mapping a THz-bandwidth single photon to a variable superposition of the output optical mode and stored phononic mode. Because the memory acts both as a beam splitter and as a buffer, the relevant coherence time for interference is not that of the photon, but rather that of the memory. We use this mechanism to demonstrate nonclassical single-photon and two-photon interference between quantum pathways initially separated by several picoseconds, even though the duration of the photons themselves is just ˜250 fs .

  19. Interference patterns and extinction ratio of the diatom Coscinodiscus granii

    DEFF Research Database (Denmark)

    Maibohm, Christian; Friis, Søren Michael Mørk; Ellegaard, M.; Rottwitt, Karsten

    2015-01-01

    We report experimental and theoretical verification of the nature and position of multiple interference points of visible light transmitted through the valve of the centric diatom species Coscinodiscus granii. Furthermore, by coupling the transmitted light into an optical fiber and moving the dia...... diatom valve between constructive and destructive interference points, an extinction ratio of 20 dB is shown...

  20. Sleep disturbances are related to decreased transmission of blue light to the retina caused by lens yellowing

    DEFF Research Database (Denmark)

    Kessel, Line; Siganos, Galatios; Jørgensen, Torben;

    2011-01-01

    Sleep pattern and circadian rhythms are regulated via the retinohypothalamic tract in response to stimulation of a subset of retinal ganglion cells, predominantly by blue light (450-490 nm). With age, the transmission of blue light to the retina is reduced because of the aging process of the human...... lens, and this may impair the photoentrainment of circadian rhythm leading to sleep disorders. The aim of the study was to examine the association between lens aging and sleep disorders....

  1. Seed germination of Pinus koraiensis Siebold and Zucc. in response to light regimes caused by shading and seed positions

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, M.; Zhu, J.; Yan, Q.

    2012-07-01

    Pinus koraiensis Siebold and Zucc. (Korean pine), the dominant tree species in the mixed broadleaved Korean pine forests (regional climax), is severely restricted by its regeneration failure. To determine the effects of light regimes on P. koraiensis regeneration, the seed germination process was examined in shade houses and forest stands (before and after leaf expansion) with various light levels created by shading and seed positions. Despite the large size of P. koraiensis seeds (500-600 mg), both light intensity and quality significantly affected the germination percentage in both shade houses and forests. Substantial changes in light intensity and quality led the majority of seeds (80%) to germinate in leafless forests and shade houses, while only a minority ({<=}20%) germinated after leaf expansion in the forests. Moreover, seed germination in shade houses and leafless forests exhibited similar patterns; they consistently reached a 70% shading degree, which was optimal for the seed germination of P. koraiensis on topsoil. Seed positioning significantly affected germination for each shading degree, especially when litter and soil coverings drastically inhibited germination. In conclusion, (1) when seeds were not stressed by temperature and moisture, light irradiance played a critical role in the seed germination of P. koraiensis; (2) seed positioning, in relation to alterations in light intensity and quality, affected the germination of P. koraiensis; (3) a shade house experiment using neutral cloth provided an applicable and controllable way to monitor the P. koraiensis seed germination in early spring before leaf expansion. The light requirement for the germination of P. koraiensis played a key role in the regeneration of P. koraiensis throughout the temperate secondary forests. (Author) 41 refs.

  2. Interference Fit Life Factors for Roller Bearings

    Science.gov (United States)

    Oswald, Fred B.; Zaretsky, Erwin V.; Poplawski, Joseph V.

    2008-01-01

    The effect of hoop stresses in reducing cylindrical roller bearing fatigue life was determined for various classes of inner ring interference fit. Calculations were performed for up to seven interference fit classes for each of ten bearing sizes. Each fit was taken at tightest, average and loosest values within the fit class for RBEC-5 tolerance, thus requiring 486 separate analyses. The hoop stresses were superimposed on the Hertzian principal stresses created by the applied radial load to calculate roller bearing fatigue life. The method was developed through a series of equations to calculate the life reduction for cylindrical roller bearings based on interference fit. All calculated lives are for zero initial bearing internal clearance. Any reduction in bearing clearance due to interference fit was compensated by increasing the initial (unmounted) clearance. Results are presented as tables and charts of life factors for bearings with light, moderate and heavy loads and interference fits ranging from extremely light to extremely heavy and for bearing accuracy class RBEC 5 (ISO class 5). Interference fits on the inner bearing ring of a cylindrical roller bearing can significantly reduce bearing fatigue life. In general, life factors are smaller (lower life) for bearings running under light load where the unfactored life is highest. The various bearing series within a particular bore size had almost identical interference fit life factors for a particular fit. The tightest fit at the high end of the RBEC-5 tolerance band defined in ANSI/ABMA shaft fit tables produces a life factor of approximately 0.40 for an inner-race maximum Hertz stress of 1200 MPa (175 ksi) and a life factor of 0.60 for an inner-race maximum Hertz stress of 2200 MPa (320 ksi). Interference fits also impact the maximum Hertz stress-life relation.

  3. Isolation and Identification of Active Compound Cause Light Emmitting of Bacterial Photobacterium phosphoreum Isolated from the Indonesia Jepara Marine Squid

    Directory of Open Access Journals (Sweden)

    Idam Arif

    2005-04-01

    Full Text Available This research carried out to study the bioluminescence process of bacterial Photobacterium phosphoreum isolated from Indonesia marine squid. The method used in the present study involved isolation, purification, electrophoresis, and the absorbance and light intensity measurement. This result show that the luciferace enzyme of bacterial Photobacterium phosphoreum or called LBPP catalyzes the emission of visible light from the reaction of reduced flavin mononucleotide (FMNH2, molecular oxygen (O2, and an aldehyde (RCOH. The electrophoresis data show that LBPP comprised of two different subunits α and βwith 41kD and 38 kD molecular weights. The absorb pattern showed that the bioluminescence process centered around 516 nm and are consistent with the fluorescence data. This result concluded that the excitation state formed after LBPP bind subtracts and the ground state formed after LBPP releases product and visible light.

  4. Noise caused by a finite extinction ratio of the light modulator in CW cavity ring-down spectroscopy

    Science.gov (United States)

    Huang, H.; Lehmann, K. K.

    2009-02-01

    A model is presented for the effect of a finite extinction ratio of the light modulator used in continuous wave cavity ring-down spectroscopy (CW-CRDS) experiments. We present a simple analytical expression for the minimum isolation required to prevent a significant increase in the fluctuations of the cavity decay rate, which determine the sensitivity of the method. We also present systematic measurements of the signal to noise in CW-CRDS as a function of the effective isolation of the light modulator, and excellent agreement with the model is found.

  5. Dark Matter Interference

    DEFF Research Database (Denmark)

    Del Nobile, Eugenio; Kouvaris, Christoforos; Sannino, Francesco;

    2012-01-01

    We study different patterns of interference in WIMP-nuclei elastic scattering that can accommodate the DAMA and CoGeNT experiments via an isospin violating ratio $f_n/f_p=-0.71$. We study interference between the following pairs of mediators: Z and Z', Z' and Higgs, and two Higgs fields. We show ...

  6. Two-photon interference with non-identical photons

    Science.gov (United States)

    Liu, Jianbin; Zhou, Yu; Zheng, Huaibin; Chen, Hui; Li, Fu-li; Xu, Zhuo

    2015-11-01

    Two-photon interference with non-identical photons is studied based on the superposition principle in Feynman's path integral theory. The second-order temporal interference pattern is observed by superposing laser and pseudothermal light beams with different spectra. The reason why there is two-photon interference for photons of different spectra is that non-identical photons can be indistinguishable for the detection system when Heisenberg's uncertainty principle is taken into account. These studies are helpful to understand the second-order interference of light in the language of photons.

  7. Inter-WBAN Coexistence and Interference Mitigation

    Institute of Scientific and Technical Information of China (English)

    Bin Liu; Xiaosong Zhao; Lei Zou; Chang Wen Chen

    2015-01-01

    With promising applications in e⁃health and entertainment, wireless body area networks (WBANs) have attracted the in⁃terest of both academia and industry. If WBANs are densely deployed within a small area, serious problems may arise be⁃tween the WBANs. In this paper, we discuss issues related to the coexistence of WBANs and investigate the main fac⁃tors that cause inter⁃WBAN interference. We survey inter⁃WBAN interference mitigation strategies and track recent re⁃search developments. We also discuss unresolved issues re⁃lated to inter⁃WBAN interference mitigation and propose fu⁃ture research directions.

  8. Infrared temperature measurement and interference analysis of magnesium alloys in hybrid laser-TIG welding process

    Energy Technology Data Exchange (ETDEWEB)

    Huang, R.-S. [State Key Laboratory of Materials Modification and School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Liu, L.-M. [State Key Laboratory of Materials Modification and School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China)]. E-mail: liulm@dlut.edu.cn; Song, G. [State Key Laboratory of Materials Modification and School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China)

    2007-02-25

    Infrared (IR) temperature measurement, as a convenient, non-contact method for making temperature field measurements, has been widely used in the fields of welding, but the problem of interference from radiant reflection is a complicating factor in applying IR temperature sensing to welding. The object of this research is to make a deep understand about the formation of interference, explore a new method to eliminate the interfering radiation during laser-TIG hybrid welding of magnesium alloys and to obtain the distribution of temperature field accurately. The experimental results showed that the interferences caused by radiant specular reflection of arc light, ceramic nozzle, electrode and laser nozzle were transferred out of welding seam while the IR thermography system was placed perpendicularly to welding seam. And the welding temperature distribution captured by IR termography system which had been calibrated by thermocouple was reliable by using this method in hybrid laser-TIG welding process of AZ31B magnesium alloy.

  9. Fast forward genetics to identify mutations causing a high light tolerant phenotype in Chlamydomonas reinhardtii by whole-genome-sequencing

    OpenAIRE

    Schierenbeck, Lisa; Ries, David; Rogge, Kristin; Grewe, Sabrina; Weisshaar, Bernd; Kruse, Olaf

    2015-01-01

    Background: High light tolerance of microalgae is a desired phenotype for efficient cultivation in large scale production systems under fluctuating outdoor conditions. Outdoor cultivation requires the use of either wild-type or non-GMO derived mutant strains due to safety concerns. The identification and molecular characterization of such mutants derived from untagged forward genetics approaches was limited previously by the tedious and time-consuming methods involving techniques such as ...

  10. Comparison of tissue damage caused by various laser systems with tissue tolerable plasma by light and laser scan microscopy

    International Nuclear Information System (INIS)

    Tissue tolerable plasma (TTP) represents a novel therapeutic method with promising capabilities in the field of dermatological interventions, in particular disinfection but also wound antisepsis and regeneration. The energy transfer by plasma into living tissue is not easily educible, as a variety of features such as the medium’s actual molecule-stream, the ions, electrons and free radicals involved, as well as the emission of ultraviolet, visible and infrared light contribute to its increasingly well characterized effects. Thus, relating possible adversary effects, especially of prolonged exposure to a single component of the plasma’s mode of action, is difficult. Until now, severe adverse events connected to plasma exposure have not been reported when conducted according to existing therapeutic protocols. In this study, we have compared the tissue damage-potential of CO2 and dye lasers with TTP in a porcine model. After exposure of pig ear skin to the three treatment modalities, all specimens were examined histologically and by means of laser scan microscopy (LSM). Light microscopical tissue damage could only be shown in the case of the CO2 laser, whereas dye laser and plasma treatment resulted in no detectable impairment of the specimens. In the case of TTP, LSM examination revealed only an impairment of the uppermost corneal layers of the skin, thus stressing its safety when used in vivo. (letter)

  11. Comparison of tissue damage caused by various laser systems with tissue tolerable plasma by light and laser scan microscopy

    Science.gov (United States)

    Vandersee, Staffan; Lademann, Jürgen; Richter, Heike; Patzelt, Alexa; Lange-Asschenfeldt, Bernhard

    2013-10-01

    Tissue tolerable plasma (TTP) represents a novel therapeutic method with promising capabilities in the field of dermatological interventions, in particular disinfection but also wound antisepsis and regeneration. The energy transfer by plasma into living tissue is not easily educible, as a variety of features such as the medium’s actual molecule-stream, the ions, electrons and free radicals involved, as well as the emission of ultraviolet, visible and infrared light contribute to its increasingly well characterized effects. Thus, relating possible adversary effects, especially of prolonged exposure to a single component of the plasma’s mode of action, is difficult. Until now, severe adverse events connected to plasma exposure have not been reported when conducted according to existing therapeutic protocols. In this study, we have compared the tissue damage-potential of CO2 and dye lasers with TTP in a porcine model. After exposure of pig ear skin to the three treatment modalities, all specimens were examined histologically and by means of laser scan microscopy (LSM). Light microscopical tissue damage could only be shown in the case of the CO2 laser, whereas dye laser and plasma treatment resulted in no detectable impairment of the specimens. In the case of TTP, LSM examination revealed only an impairment of the uppermost corneal layers of the skin, thus stressing its safety when used in vivo.

  12. Intercollisional interference effects

    International Nuclear Information System (INIS)

    First, some qualitative aspects of intercollisional interference effects are discussed. These effects are closely related to what is sometimes called 'shielding by Newton's second law', as outlined in Section 3. Finally, some phenomenological models are introduced. (KBE)

  13. Real Interference Alignment

    CERN Document Server

    Motahari, Abolfazl Seyed; Maddah-Ali, Mohammad-Ali; Khandani, Amir Keyvan

    2010-01-01

    In this paper, we show that the total Degrees-Of-Freedoms (DOF) of the $K$-user Gaussian Interference Channel (GIC) can be achieved by incorporating a new alignment technique known as \\emph{real interference alignment}. This technique compared to its ancestor \\emph{vector interference alignment} performs on a single real line and exploits the properties of real numbers to provide optimal signaling. The real interference alignment relies on a new coding scheme in which several data streams having fractional multiplexing gains are sent by transmitters and interfering streams are aligned at receivers. The coding scheme is backed up by a recent result in the field of Diophantine approximation, which states that the convergence part of the Khintchine-Groshev theorem holds for points on non-degenerate manifolds.

  14. The investigation of the light radiation caused polyethylene based materials deterioration by means of atomic force microscopy

    Science.gov (United States)

    Sikora, A.; Grabarek, A.; Moroń, L.; Wałecki, M.; Kryla, P.

    2016-02-01

    The impact of the environmental conditions on the materials used in various devices and constructions, in particular in electrotechnical applications, has an critical impact in terms of their reliability and utilization range in specific climatic conditions. Due to increasing utilitarian requirements, technological processes complexity and introducing new materials (for instance nanomaterials), advanced diagnostic techniques are desired. One of such techniques is atomic force microscopy (AFM), which allows to study the changes of the roughness and mechanical properties of the surface at the submicrometer scale, enabling the investigation of the degradation processes. In this work the deterioration of selected group of polyethylene based materials have been measured by means of AFM, as the samples were exposed to the simulated solar light and UV-C radiation. Such an analysis of the environmental conditions impact on the deterioration process using AFM methods for various versions of specific material was not presented before.

  15. Embracing interference in wireless systems

    CERN Document Server

    Gollakota, Shyamnath

    2014-01-01

    The wireless medium is a shared resource. If nearby devices transmit at thesame time, their signals interfere, resulting in a collision. In traditionalnetworks, collisions cause the loss of the transmitted information. For thisreason, wireless networks have been designed with the assumption thatinterference is intrinsically harmful and must be avoided.This book, a revised version of the author's award-winning Ph.D.dissertation, takes an alternate approach: Instead of viewing interferenceas an inherently counterproductive phenomenon that should to be avoided, wedesign practical systems that tra

  16. Multiple scattering mechanisms causing interference effects in the differential cross sections of H + D2 → HD(v' = 4, j') + D at 3.26 eV collision energy

    Science.gov (United States)

    Sneha, Mahima; Gao, Hong; Zare, Richard N.; Jambrina, P. G.; Menéndez, M.; Aoiz, F. J.

    2016-07-01

    Differential cross sections (DCSs) for the H + D2 → HD(v' = 4, j') + D reaction at 3.26 eV collision energy have been measured using the photoloc technique, and the results have been compared with those from quantum and quasiclassical scattering calculations. The quantum mechanical DCSs are in good overall agreement with the experimental measurements. In common with previous results at 1.97 eV, clear interference patterns which appear as fingerlike structures have been found at 3.26 eV but in this case for vibrational states as high as v' = 4. The oscillatory structure is prominent for low rotational states and progressively disappears as j' increases. A detailed analysis, similar to that carried out at 1.97 eV, shows that the origin of these structures could be traced to interferences between well defined classical mechanisms. In addition, at this energy, we do not observe the anomalous positive j'-θ trend found for the v' = 4 manifold at lower collision energies, thus reinforcing our explanation that the anomalous distribution for HD(v' = 4, j') at 1.97 eV only takes place for those states associated with low product recoil energies.

  17. Carbon nanostructure composite for electromagnetic interference shielding

    Indian Academy of Sciences (India)

    Anupama Joshi; Suwarna Datar

    2015-06-01

    This communication reviews current developments in carbon nanostructure-based composite materials for electromagnetic interference (EMI) shielding. With more and more electronic gadgets being used at different frequencies, there is a need for shielding them from one another to avoid interference. Conventionally, metal-based shielding materials have been used. But due to the requirement of light weight, corrosion resistive materials, lot of work is being done on composite materials. In this research the forerunner is the nanocarbon-based composite material whose different forms add different characteristics to the composite. The article focusses on composites based on graphene, graphene oxide, carbon nanotubes, and several other novel forms of carbon.

  18. Cognitive Aware Interference Mitigation Scheme for LTE Femtocells

    KAUST Repository

    AlQerm, Ismail

    2015-04-21

    Femto-cells deployment in today’s cellular networks came into practice to fulfill the increasing demand for data services. However, interference to other femto and macro-cells users remains an unresolved challenge. In this paper, we propose an interference mitigation scheme to control the cross-tier interference caused by femto-cells to the macro users and the co-tier interference among femtocells. Cognitive radio spectrum sensing capability is utilized to determine the non-occupied channels or the ones that cause minimal interference to the macro users. An awareness based channel allocation scheme is developed with the assistance of the graph-coloring algorithm to assign channels to the femto-cells base stations with power optimization, minimal interference, maximum throughput, and maximum spectrum efficiency. In addition, the scheme exploits negotiation capability to match traffic load and QoS with the channel capacity, and to maintain efficient utilization of the available channels.

  19. Ramsey interference with single photons

    CERN Document Server

    Clemmen, Stéphane; Ramelow, Sven; Gaeta, Alexander L

    2016-01-01

    Interferometry using discrete energy levels in nuclear, atomic or molecular systems is the foundation for a wide range of physical phenomena and enables powerful techniques such as nuclear magnetic resonance, electron spin resonance, Ramsey-based spectroscopy and laser/maser technology. It also plays a unique role in quantum information processing as qubits are realized as energy superposition states of single quantum systems. Here, we demonstrate quantum interference of different energy states of single quanta of light in full analogy to energy levels of atoms or nuclear spins and implement a Ramsey interferometer with single photons. We experimentally generate energy superposition states of a single photon and manipulate them with unitary transformations to realize arbitrary projective measurements, which allows for the realization a high-visibility single-photon Ramsey interferometer. Our approach opens the path for frequency-encoded photonic qubits in quantum information processing and quantum communicati...

  20. Interference cancellation technique under imperfect synchronization in cellular systems

    Institute of Scientific and Technical Information of China (English)

    WANG; Xin; WU; Zhuo

    2009-01-01

    In this paper, an asynchronous cooperative cellular system applied with space-time block coding(STBC)is investigated. A signal detector is proposed based on parallel interference cancellation(PIC), to cancel the inter-symbol interference(ISI)caused by the imperfect synchronization. Simulation results show that the proposed PIC detector can effectively suppress the ISI, but there is still a comparatively high error floor, due to the co-channel interference(CCI)of the cellular system.

  1. Kvantová interference

    Czech Academy of Sciences Publication Activity Database

    Peřina, Jan

    2003-01-01

    Roč. 48, č. 4 (2003), s. 99-103. ISSN 0447-6441 R&D Projects: GA MŠk LN00A015 Institutional research plan: CEZ:AV0Z1010921 Keywords : interference * quantum cryptography * quantum computing * quantum teleportation Subject RIV: BH - Optics, Masers, Lasers

  2. Quantum interference in polyenes

    Energy Technology Data Exchange (ETDEWEB)

    Tsuji, Yuta; Hoffmann, Roald, E-mail: rh34@cornell.edu [Department of Chemistry and Chemical Biology, Cornell University, Baker Laboratory, Ithaca, New York 14853 (United States); Movassagh, Ramis [Department of Mathematics, Northeastern University, Boston, Massachusetts 02115, USA and Department of Mathematics, Massachusetts Institute of Technology, Building E18, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139-4307 (United States); Datta, Supriyo [School of Electrical and Computer Engineering, Purdue University, Electrical Engineering Building, 465 Northwestern Ave., West Lafayette, Indiana 47907-2035 (United States)

    2014-12-14

    The explicit form of the zeroth Green's function in the Hückel model, approximated by the negative of the inverse of the Hückel matrix, has direct quantum interference consequences for molecular conductance. We derive a set of rules for transmission between two electrodes attached to a polyene, when the molecule is extended by an even number of carbons at either end (transmission unchanged) or by an odd number of carbons at both ends (transmission turned on or annihilated). These prescriptions for the occurrence of quantum interference lead to an unexpected consequence for switches which realize such extension through electrocyclic reactions: for some specific attachment modes the chemically closed ring will be the ON position of the switch. Normally the signs of the entries of the Green's function matrix are assumed to have no physical significance; however, we show that the signs may have observable consequences. In particular, in the case of multiple probe attachments – if coherence in probe connections can be arranged – in some cases new destructive interference results, while in others one may have constructive interference. One such case may already exist in the literature.

  3. Disentangling posterror and postconflict reduction of interference.

    Science.gov (United States)

    Van der Borght, Liesbet; Braem, Senne; Notebaert, Wim

    2014-12-01

    Conflict monitoring theory (CMT; Botvinick, Braver, Barch, Carter, & Cohen Psychological Review, 108, 624-652, 2001) states that response conflict, the simultaneous activation of two competing responses, increases task focus and reduces interference from irrelevant information. CMT also defines errors as conflict, and reduced interference effects have consistently been reported following errors (Ridderinkhof Psychological Research, 66, 312-323, 2002). However, previous computations of this posterror reduction of interference (PERI) have overlooked the congruency of the previous trial. This is problematic, because most errors are made on incongruent trials, creating a confound between (previous) accuracy and (previous) congruency. Therefore, it is likely that reduced interference following errors is in fact the congruency sequence effect (i.e., reduced interference following incongruent, relative to congruent, trials). Our results corroborate this idea by demonstrating that participants indeed showed significant PERI following a congruent trial, but inverse PERI following an incongruent trial. These findings are discussed in light of the adaptation-by-binding account (Verguts & Notebaert Psychological Review, 115, 518-525, 2008, Trends in Cognitive Sciences, 13, 252-257, 2009). PMID:24740696

  4. Multiple-Antenna Interference Cancellation for WLAN with MAC Interference Avoidance in Open Access Networks

    Directory of Open Access Journals (Sweden)

    Kuzminskiy Alexandr M

    2007-01-01

    Full Text Available The potential of multiantenna interference cancellation receiver algorithms for increasing the uplink throughput in WLAN systems such as 802.11 is investigated. The medium access control (MAC in such systems is based on carrier sensing multiple-access with collision avoidance (CSMA/CA, which itself is a powerful tool for the mitigation of intrasystem interference. However, due to the spatial dependence of received signal strengths, it is possible for the collision avoidance mechanism to fail, resulting in packet collisions at the receiver and a reduction in system throughput. The CSMA/CA MAC protocol can be complemented in such scenarios by interference cancellation (IC algorithms at the physical (PHY layer. The corresponding gains in throughput are a result of the complex interplay between the PHY and MAC layers. It is shown that semiblind interference cancellation techniques are essential for mitigating the impact of interference bursts, in particular since these are typically asynchronous with respect to the desired signal burst. Semiblind IC algorithms based on second- and higher-order statistics are compared to the conventional no-IC and training-based IC techniques in an open access network (OAN scenario involving home and visiting users. It is found that the semiblind IC algorithms significantly outperform the other techniques due to the bursty and asynchronous nature of the interference caused by the MAC interference avoidance scheme.

  5. Multiple-Antenna Interference Cancellation for WLAN with MAC Interference Avoidance in Open Access Networks

    Directory of Open Access Journals (Sweden)

    Alexandr M. Kuzminskiy

    2007-10-01

    Full Text Available The potential of multiantenna interference cancellation receiver algorithms for increasing the uplink throughput in WLAN systems such as 802.11 is investigated. The medium access control (MAC in such systems is based on carrier sensing multiple-access with collision avoidance (CSMA/CA, which itself is a powerful tool for the mitigation of intrasystem interference. However, due to the spatial dependence of received signal strengths, it is possible for the collision avoidance mechanism to fail, resulting in packet collisions at the receiver and a reduction in system throughput. The CSMA/CA MAC protocol can be complemented in such scenarios by interference cancellation (IC algorithms at the physical (PHY layer. The corresponding gains in throughput are a result of the complex interplay between the PHY and MAC layers. It is shown that semiblind interference cancellation techniques are essential for mitigating the impact of interference bursts, in particular since these are typically asynchronous with respect to the desired signal burst. Semiblind IC algorithms based on second- and higher-order statistics are compared to the conventional no-IC and training-based IC techniques in an open access network (OAN scenario involving home and visiting users. It is found that the semiblind IC algorithms significantly outperform the other techniques due to the bursty and asynchronous nature of the interference caused by the MAC interference avoidance scheme.

  6. Gyroscopic effects in interference of matter waves

    International Nuclear Information System (INIS)

    A new gyroscopic interference effect stemming from the Galilean translational factor in the matter wave function is pointed out. In contrast to the well-known Sagnac effect that stems from the geometric phase and leads to a shift of interference fringes, this effect causes slanting of the fringes. We illustrate it by calculations for two split cigar-shaped Bose-Einstein condensates under the conditions of a recent experiment, see Y. Shin et al., Phys. Rev. Lett. 92, 050405 (2004). Importantly, the measurement of slanting obviates the need of a third reference cloud

  7. Gyroscopic effects in interference of matter waves

    OpenAIRE

    Tolstikhin, Oleg I.; Morishita, Toru; Watanabe, Shinichi

    2005-01-01

    A new gyroscopic interference effect stemming from the Galilean translational factor in the matter wave function is pointed out. In contrast to the well-known Sagnac effect that stems from the geometric phase and leads to a shift of interference fringes, this effect causes slanting of the fringes. We illustrate it by calculations for two split cigar-shaped Bose-Einstein condensates under the conditions of a recent experiment, see Y.Shin et al., Phys. Rev. Lett. 92, 050405 (2004). Importantly,...

  8. Inertial and interference effects in optical spectroscopy

    Science.gov (United States)

    Karstens, W.; Y Smith, D.

    2015-04-01

    Interference between free-space and material components of the displacement current plays a key role in determining optical properties. This is illustrated by an analogy between the Lorentz optical model and a-c circuits. Phase shifts in material-polarization currents, which are inertial, relative to the non-inertial vacuum-polarization current cause interference in the total displacement current and, hence, variation in E-M wave propagation. If the displacement-current is reversed, forward propagation is inhibited yielding the semimetallic reflectivity exhibited by intrinsic silicon. Complete cancellation involves material currents offsetting free-space currents to form current-loops that correspond to plasmons.

  9. Interference Reconsidered: The Role of Similarity in Second Language Acquisition.

    Science.gov (United States)

    Young-Scholten, Martha

    1985-01-01

    The validity of the theory of crucial similarity in language interference is investigated. The theory proposes that when a first and a second language are structurally similar in some aspects, the second language learner will assume similarity in other aspects, causing interference. In this study, the German of first grade students whose teacher…

  10. Transparency induced by two photon interference in a beam splitter

    Institute of Scientific and Technical Information of China (English)

    Wang Kai-Ge; Yang Guo-Jian

    2004-01-01

    We propose a special two-photon state which is completely transparent in a 50/50 beam splitter. This effect is caused by the destructive two-photon interference and shows the signature of photon entanglement. We find that the symmetry of the two-photon spectrum plays the key role for the properties of two-photon interference.

  11. Carrier recombination spatial transfer by reduced potential barrier causes blue/red switchable luminescence in C8 carbon quantum dots/organic hybrid light-emitting devices

    Science.gov (United States)

    Chen, Xifang; Yan, Ruolin; Zhang, Wenxia; Fan, Jiyang

    2016-04-01

    The underlying mechanism behind the blue/red color-switchable luminescence in the C8 carbon quantum dots (CQDs)/organic hybrid light-emitting devices (LEDs) is investigated. The study shows that the increasing bias alters the energy-level spatial distribution and reduces the carrier potential barrier at the CQDs/organic layer interface, resulting in transition of the carrier transport mechanism from quantum tunneling to direct injection. This causes spatial shift of carrier recombination from the organic layer to the CQDs layer with resultant transition of electroluminescence from blue to red. By contrast, the pure CQDs-based LED exhibits green-red electroluminescence stemming from recombination of injected carriers in the CQDs.

  12. DNA-to-protein crosslinks and backbone breaks caused by far- and near-ultraviolet, and visible light radiations in mammalian cells

    International Nuclear Information System (INIS)

    Spectral responses for DNA damages caused by far-uv, near-uv, and visible light radiations have been studied. The near congruence of the spectra for far-uv damages and the spectrum of DNA is good evidence that the mechanism is the same for the induction of breaks, crosslinks, and pyrimidine dimers. For near-uv, the different spectra imply that at least several nonDNA sensitizer molecules act as primary chromophores, but that DNA damage eventually results. With the understanding that near-uv and visible radiations produce a variety of chemically potent reactive oxygen species within the cell, we recognize the possibility for many types of DNA damage. If we assume that SSBs and DNA-to-protein crosslinks are random single events along the genome, it is possible to compute the number of events per cell genome per lethal event caused by the different energies used. In the near-uv and visible region, many more breaks and crosslinks are formed per lethal event than by far-uv. About 20 times more SSBs per lethal event are caused by 365-nm radiation than by x-rays, strong evidence that these breaks are effectively repaired. It is therefore likely that SSBs are not a serious event with regard to cellular lethality. The role of crosslinks and their repair in lethal events is less clear. The lack of any correlation at all between the action spectra for SSBs, or crosslinks, and lethality and mutagenesis in the same cells is evidence that another lesion or lesions are involved in these events. The multitude of chemical events that can be caused in cellular metabolites by the reactive species generated by these long wavelengths of radiation means that death is attributable to the total spectrum of changed chemicals delivered by a lethal dose, only some of which are DNA changes leading to SSBs and crosslinks. 43 refs., 3 figs., 2 tabs

  13. Lecture-Room Interference Demo Using a Glass Plate and a Laser Beam Focused on It

    Science.gov (United States)

    Ageev, Leonid A.; Yegorenkov, Vladimir D.

    2010-01-01

    We describe a simple case of non-localized interference produced with a glass plate and a laser beam focused on it. The proposed setup for observing interference is compact when semiconductor lasers are employed, and it is well suited for demonstration and comparison of interference in reflected and transmitted light in a large lecture-room. This…

  14. Laser Interference Lithography

    OpenAIRE

    Wolferen, van, Henk A.G.M.; Abelmann, Leon; Hennessy, Theodore C.

    2011-01-01

    In this chapter we explain how submicron gratings can be prepared by Laser Interference Lithography (LIL). In this maskless lithography technique, the standing wave pattern that exists at the intersection of two coherent laser beams is used to expose a photosensitive layer. We show how to build the basic setup, with special attention for the optical aspects. The pros and cons of different types of resist as well as the limitations and errors of the setup are discussed. The bottleneck in Laser...

  15. RNA Interference in livestock

    OpenAIRE

    Merkl, Claudia

    2010-01-01

    RNA Interference (RNAi) allows experimental reduction of gene expression, providing a tool for the investigation of gene function, disease therapy and the generation of animal models for human diseases. RNAi offers an opportunity to carry out precise genetic manipulations in a wide variety of species. This thesis describes the use of RNAi to downregulate two porcine genes, the whey protein Beta-Lactoglobulin (BLG) and the tumor suppressor protein p53. BLG is a major component in porcine and r...

  16. Quantum Confined Fano Interference

    International Nuclear Information System (INIS)

    We study the transition from a dense continuum to a sparse quasicontinuum in the Fano problem. Transmission measurements on epitaxial layers of GaAs in a high magnetic field and calculations of the optical absorption show how the Fano interference disappears as quantum confinement discretizes the continuum states. The transition between quasi-one-dimensional and quasi-zero-dimensional systems occurs at length scales which are unusually large for optical experiments. copyright 1997 The American Physical Society

  17. Interference checking approach with tolerance based on assembly dimension chain

    Institute of Scientific and Technical Information of China (English)

    Wang Lei; Li Yingguang; Wang Wei; and Liao Wenhe

    2012-01-01

    CAD model with nominal dimension is implemented in interference checking of assembly simulation of aircraft complex parts at present, which causes inadequate availability. In order to address this challenging issue, interference checking method with tolerance based on assembly dimension chain was proposed. Worst case and maximum error probability of tolerance of composing loop were used, and CAD models were respectively re-constructed and inserted into simulation system. Before dynamic interference checking, engineering semantic interference condition was set to assembly requirements. Finally, the interface checking result was a basis for reasonability of assembly process and tolerance. A prototype system was developed based on the above research.

  18. Ghost Interference and Quantum Erasure

    OpenAIRE

    Chingangbam, Pravabati; Qureshi, Tabish

    2005-01-01

    The two-photon ghost interference experiment, generalized to the case of massive particles, is theoretically analyzed. It is argued that the experiment is intimately connected to a double-slit interference experiment where, the which-path information exists. The reason for not observing first order interference behind the double-slit, is clarified.It is shown that the underlying mechanism for the appearance of ghost interference is, the more familiar, quantum erasure.

  19. Interference competition and species coexistence.

    OpenAIRE

    Amarasekare, Priyanga

    2002-01-01

    Interference competition is ubiquitous in nature. Yet its effects on resource exploitation remain largely unexplored for species that compete for dynamic resources. Here, I present a model of exploitative and interference competition with explicit resource dynamics. The model incorporates both biotic and abiotic resources. It considers interference competition both in the classical sense (i.e. each species suffers a net reduction in per capita growth rate via interference from, and interferen...

  20. Epulis and pyogenic granuloma with occlusal interference

    Directory of Open Access Journals (Sweden)

    Widowati Witjaksono

    2005-06-01

    Full Text Available In dental clinic of Hospital University Science Malaysia (HUSM, there were cases with Localized Gingival Enlargement (LGE in the oral cavity with occlusal interference. In this study, three cases were observed. They were a 13 - year- old female with fibrous lge around 31 and 32 with occlusal interference in protrusive movement due to X bite, a 15 - year – old female with pyogenic granuloma near 11 & 21 with occlusal interference due to deep bite; and a 24 – year – old female who was eight months in pregnancy with pyogenic granuloma on the 34-35 and severe generalized pregnancy gingivitis with occlusal interference in centric occlusion and lateral movement. Clinical and histopathological diagnosis of the first case showed fibrous epulis, whereas the second and third cases disclosed pyogenic granuloma. Chronic trauma of the gingiva due to occlusal interference was assumed to be the cause of those LGE in case 1 and 2, while in case 3 poor oral hygiene and chronic trauma were assumed to be the etiologic factors.

  1. Dependency-dependent interference: NPI interference, agreement attraction, and global pragmatic inferences

    Directory of Open Access Journals (Sweden)

    MingXiang

    2013-10-01

    Full Text Available Previous psycholinguistics studies have shown that when forming a long distance dependency in online processing, the parser sometimes accepts a sentence even though the required grammatical constraints are only partially met. A mechanistic account of how such errors arise sheds light on both the underlying linguistic representations involved and the processing mechanisms that put such representations together. In the current study, we contrast the NPI (negative polarity items interference effect, as shown by the acceptance of an ungrammatical sentence like “The bills that democratic senators have voted for will ever become law”, with the well-known phenomenon of agreement attraction (“The key to the cabinets are…”. On the surface, these two types of errors look alike and thereby can be explained as being driven by the same source: similarity based memory interference. However, we argue that the linguistic representations involved in NPI licensing are substantially different from those of subject-verb agreement, and therefore the interference effects in each domain potentially arise from distinct sources. In particular, we show that NPI interference at least partially arises from pragmatic inferences. In a self-paced reading study with an acceptability judgment task, we showed NPI interference was modulated by participants’ general pragmatic communicative skills, as quantified by the Autism-Spectrum Quotient (Baron-Cohen 2001, especially in offline tasks. Participants with more autistic traits were actually less prone to the NPI interference effect than those with fewer autistic traits. This result contrasted with agreement attraction conditions, which were not influenced by individual pragmatic skill differences. We also show that different NPI licensors have distinct interference profiles. We discuss two kinds of interference effects for NPI licensing: memory-retrieval based and pragmatically triggered.

  2. Orientation of Red Blood Cells and Rouleaux Disaggregation in Interference Laser Fields

    OpenAIRE

    Kruchenok, J. V.; Bushuk, S. B.; Kurilo, G. I.; Nemkovich, N. A.; Rubinov, A. N.

    2005-01-01

    The effect of interference laser fields on red blood cells (RBCs) was investigated both theoretically and experimentally. The optical trapping and orientation of individual RBC in interference fringes were observed. It was found that RBC rouleaux undergo disaggregation under the action of interference laser fields. To describe the effect of RBC orientation in interference fringes, we used the equation for torque exerted on a discoid dielectric particle in a gradient light field. The experimen...

  3. Importance of light smoking and inhalation habits on risk of myocardial infarction and all cause mortality. A 22 year follow up of 12 149 men and women in The Copenhagen City Heart Study

    DEFF Research Database (Denmark)

    Prescott, E; Scharling, H; Osler, M;

    2002-01-01

    STUDY OBJECTIVE: To determine risk of myocardial infarction (MI) and all cause mortality associated with light smoking and inhalation habits in men and women. DESIGN: Prospective cohort study with follow up of MI and all cause mortality through record linkage. SETTING: The Copenhagen City Heart...

  4. Engineering light outcoupling in 2D materials

    KAUST Repository

    Lien, Derhsien

    2015-02-11

    When light is incident on 2D transition metal dichalcogenides (TMDCs), it engages in multiple reflections within underlying substrates, producing interferences that lead to enhancement or attenuation of the incoming and outgoing strength of light. Here, we report a simple method to engineer the light outcoupling in semiconducting TMDCs by modulating their dielectric surroundings. We show that by modulating the thicknesses of underlying substrates and capping layers, the interference caused by substrate can significantly enhance the light absorption and emission of WSe2, resulting in a ∼11 times increase in Raman signal and a ∼30 times increase in the photoluminescence (PL) intensity of WSe2. On the basis of the interference model, we also propose a strategy to control the photonic and optoelectronic properties of thin-layer WSe2. This work demonstrates the utilization of outcoupling engineering in 2D materials and offers a new route toward the realization of novel optoelectronic devices, such as 2D LEDs and solar cells.

  5. Interference from a nonlocal double-slit through one-photon process.

    Science.gov (United States)

    Gan, Shu; Zhang, Su-Heng; Xiong, Jun; Wang, Kaige

    2009-12-21

    In this paper, we report an interference experiment in which a spatially incoherent light source illuminates two spatially separated apertures, whose superposition at the same place forms a double-slit. The experimental result exhibits a well-defined interference fringe solely through intensity measurements, in agreement with the theoretical analysis by means of the first-order spatial interference of the incoherent light. Consequently, the nonlocal double-slit interference with thermal light should be attributed to the first-order spatial correlation of incoherent field. PMID:20052077

  6. Entanglement and quantum interference

    OpenAIRE

    O'Hara, Paul

    2006-01-01

    In the history of quantum mechanics, much has been written about the double-slit experiment, and much debate as to its interpretation has ensued. Indeed, to explain the interference patterns for sub-atomic particles, explanations have been given not only in terms of the principle of complementarity and wave-particle duality but also in terms of quantum consciousness and parallel universes. In this paper, the topic will be discussed from the perspective of spin-coupling in the hope of further ...

  7. RNA interference in Lepidoptera

    DEFF Research Database (Denmark)

    Terenius, Ole; Papanicolaou, Alexie; Garbutt, Jennie S.;

    2011-01-01

    Gene silencing through RNA interference (RNAi) has revolutionized the study of gene function, particularly in non-model insects. However, in Lepidoptera (moths and butterflies) RNAi has many times proven to be difficult to achieve. Most of the negative results have been anecdotal and the positive...... in RNAi experiments in Lepidoptera are discussed. The review also points to a need to further investigate the mechanism of RNAi in lepidopteran insects and its possible connection to the innate immune response. Our general understanding of RNAi in Lepidoptera will be further aided in the future as...

  8. Precise packet loss pattern generation by intentional interference

    OpenAIRE

    He Z.; Voigt T

    2011-01-01

    Abstract—Intermediate-quality links often cause vulnerable connectivity in wireless sensor networks, but packet losses caused by such volatile links are not easy to trace. In order to equip link layer protocol designers with a reliable test and debugging tool, we develop a reactive interferer to generate packet loss patterns precisely. By using intentional interference to emulate parameterized lossy links with very low intrusiveness, our tool facilitates both robustness evaluation of proto...

  9. Interference layer metallography

    International Nuclear Information System (INIS)

    Refractory metallic materials for application in Gas Cooled High Temperature Reactors are age-hardened nickel or iron base alloys. To control their behaviour and to adapt it to realistic load conditions, these materials have to be subjected to suitable informing tests and characterized. In the past few years, interference layer metallography has proved to be a highly flexible characterization procedure, suitable as an independent investigation method as well as an outstanding way of sample preparation for application of automatic quantitative image analysis to refractory alloys. This paper reports the problems of characterization of the Ni and Fe base alloys to be solved by interference layer metallography and the physical background of this method. The procedure of chromatic contrasting is discussed. From these considerations arises the result that for technical applications the optimum layer material for each special sample should be selected a priori. For that purpose it is necessary to measure the optical constants of the respective structural elements of the alloys as well as those of the candidate layer materials. The measuring procedures are discussed in detail. A routine procedure is deduced which allows to determine a priori the layer material and thickness fitting best to a given problem. (orig.)

  10. Beamforming design with proactive interference cancelation in MISO interference channels

    Science.gov (United States)

    Li, Yang; Tian, Yafei; Yang, Chenyang

    2015-12-01

    In this paper, we design coordinated beamforming at base stations (BSs) to facilitate interference cancelation at users in interference networks, where each BS is equipped with multiple antennas and each user is with a single antenna. By assuming that each user can select the best decoding strategy to mitigate the interference, either canceling the interference after decoding when it is strong or treating it as noise when it is weak, we optimize the beamforming vectors that maximize the sum rate for the networks under different interference scenarios and find the solutions of beamforming with closed-form expressions. The inherent design principles are then analyzed, and the performance gain over passive interference cancelation is demonstrated through simulations in heterogeneous cellular networks.

  11. Development of Studies on RNA Interference

    Institute of Scientific and Technical Information of China (English)

    Li ZHANG; Yaqiong ZHANG; Lina SHE; Wenting XU; Yangying JIA; Shiqing XIE; WenliSUN; Quan LIANG

    2012-01-01

    RNA interference (RNAi), caused by endogenous or exogenous double- stranded RNA (dsRNA) homologous with target genes, refers to gene silencing widely existing in animals and plants. It was first found in plants, and now it has developed into a kind of biotechnology as well as an important approach in post- genome era. This paper is to summarize the achievements of studies on RNAi tech- nology in basic biology, medicine, pharmacy, botany and other fields.

  12. Single-plasmon interferences.

    Science.gov (United States)

    Dheur, Marie-Christine; Devaux, Eloïse; Ebbesen, Thomas W; Baron, Alexandre; Rodier, Jean-Claude; Hugonin, Jean-Paul; Lalanne, Philippe; Greffet, Jean-Jacques; Messin, Gaétan; Marquier, François

    2016-03-01

    Surface plasmon polaritons are electromagnetic waves coupled to collective electron oscillations propagating along metal-dielectric interfaces, exhibiting a bosonic character. Recent experiments involving surface plasmons guided by wires or stripes allowed the reproduction of quantum optics effects, such as antibunching with a single surface plasmon state, coalescence with a two-plasmon state, conservation of squeezing, or entanglement through plasmonic channels. We report the first direct demonstration of the wave-particle duality for a single surface plasmon freely propagating along a planar metal-air interface. We develop a platform that enables two complementary experiments, one revealing the particle behavior of the single-plasmon state through antibunching, and the other one where the interferences prove its wave nature. This result opens up new ways to exploit quantum conversion effects between different bosonic species as shown here with photons and polaritons. PMID:26998521

  13. Sensing via optical interference

    Directory of Open Access Journals (Sweden)

    Ryan C. Bailey

    2005-04-01

    Full Text Available Chemical and biological sensing are problems of tremendous contemporary technological importance in multiple regulatory and human health contexts, including environmental monitoring, water quality assurance, workplace air quality assessment, food quality control, many aspects of biodiagnostics, and, of course, homeland security. Frequently, what is needed, or at least wanted, are sensors that are simultaneously cheap, fast, reliable, selective, sensitive, robust, and easy to use. Unfortunately, these are often conflicting requirements. Over the past few years, however, a number of promising ideas based on optical interference effects have emerged. Each is based to some extent on advances in the design and fabrication of functional materials. Generally, the advances are of two kinds: chemo- and bio-selective recognition and binding, and efficient methods for micropatterning or microstructuring.

  14. Interferences in Photodetachment of a Negative Molecular Ion Model

    Institute of Scientific and Technical Information of China (English)

    A. Afaq; DU Meng-Li

    2008-01-01

    By employing a two-center model, the total and differential cross sections in the photodetachment of "a negative molecular ion" are studied theoretically and obtained for the case of light polarization parallel to the molecular axis. We find that in contrast to the smooth behavior of the total cross section for perpendicular polarized light, the cross section for parallel polarized light shows an interesting oscillatory structure. The oscillations in the total cross section may provide a method to determine the distance between the two centers. We explain the oscillation in the total cross section as an interference effect using closed-orbit theory. We also calculated the detached-electron flux distributions on a screen placed at a large distance from the negative molecular ion. The distributions display multiple-ring-like interference patterns. Such interference patterns are similar to those in the photodetachment microscopy experiments.

  15. Quantum Interference in Graphene Nanoconstrictions.

    Science.gov (United States)

    Gehring, Pascal; Sadeghi, Hatef; Sangtarash, Sara; Lau, Chit Siong; Liu, Junjie; Ardavan, Arzhang; Warner, Jamie H; Lambert, Colin J; Briggs, G Andrew D; Mol, Jan A

    2016-07-13

    We report quantum interference effects in the electrical conductance of chemical vapor deposited graphene nanoconstrictions fabricated using feedback controlled electroburning. The observed multimode Fabry-Pérot interferences can be attributed to reflections at potential steps inside the channel. Sharp antiresonance features with a Fano line shape are observed. Theoretical modeling reveals that these Fano resonances are due to localized states inside the constriction, which couple to the delocalized states that also give rise to the Fabry-Pérot interference patterns. This study provides new insight into the interplay between two fundamental forms of quantum interference in graphene nanoconstrictions. PMID:27295198

  16. Jam-X: Wireless Agreement under Interference

    CERN Document Server

    Boano, Carlo Alberto; Zúñiga, Marco Antonio; Voigt, Thiemo

    2012-01-01

    Wireless low-power transceivers used in sensor networks such as IEEE 802.15.4 typically operate in unlicensed frequency bands that are subject to external interference from devices transmitting at much higher power. Communication protocols should therefore be designed to be robust against such interference. A critical building block of many protocols at all layers is agreement on a piece of information among a set of nodes. At the MAC layer, nodes may need to agree on a new time slot or frequency channel; at the application layer nodes may need to agree on handing over a leader role from one node to another. Message loss caused by interference may break agreement in two different ways: none of the nodes use the new information (time slot, channel, leader) and stick with the previous assignment, or - even worse - some nodes use the new information and some do not. This may lead to reduced performance or failures. In this paper we investigate the problem of agreement under interference and point out the limitat...

  17. Comparative molecular docking analysis of cytoplasmic dynein light chain DYNLL1 with pilin to explore the molecular mechanism of pathogenesis caused by Pseudomonas aeruginosa PAO.

    Directory of Open Access Journals (Sweden)

    Samina Kausar

    Full Text Available Cytoplasmic dynein light chain 1 (DYNLL1 is a component of large protein complex, which is implicated in cargo transport processes, and is known to interact with many cellular and viral proteins through its short consensus motif (K/RXTQT. Still, it remains to be explored that bacterial proteins also exhibit similar recognition sequences to make them vulnerable to host defense mechanism. We employed multiple docking protocols including AUTODOCK, PatchDock, ZDOCK, DOCK/PIERR and CLUSPRO to explore the DYNLL1 and Pilin interaction followed by molecular dynamics simulation assays. Subsequent structural comparison of the predicted binding site for DYNLL1-Pilin complex against the experimentally verified DYNLL1 binding partners was performed to cross check the residual contributions and to determine the binding mode. On the basis of in silico analysis, here we describe a novel interaction of DYNLL1 and receptor binding domain of Pilin (the main protein constituent of bacterial type IV Pili of gram negative bacteria Pseudomonas aeruginosa (PAO, which is the third most common nosocomial pathogen associated with the life-threatening infections. Evidently, our results underscore that Pilin specific motif (KSTQD exhibits a close structural similarity to that of Vaccinia virus polymerase, P protein Rabies and P protein Mokola viruses. We speculate that binding of DYNLL1 to Pilin may trigger an uncontrolled inflammatory response of the host immune system during P. aeruginosa chronic infections thereby opening a new pioneering area to investigate the role of DYNLL1 in gram negative bacterial infections other than viral infections. Moreover, by manifesting a strict correspondence between sequence and function, our study anticipates a novel drug target site to control the complications caused by P. aeruginosa infections.

  18. 不纯流动相对离子色谱法分析无机阴离子的影响%Investigation of Interferences Caused by Extraneous Chloride in the Analysis of Inorganic Anions with Ion Chromatography

    Institute of Scientific and Technical Information of China (English)

    刘勇建; HEBERLINGShawn; 等

    2002-01-01

    采用离子色谱模拟研究了流动相不纯对样品中无机阴离子测定造成的干扰.结果表明,在流动相中加入Cl-,使得其他6种阴离子响应值增加.这主要是由于Cl-加入的同时也带来了相应的阳离子,在通过抑制器时可带来等量的H+,H+伴随着各个阴离子样品一起通过检测器,使总的样品离子响应值增加.在6种阴离子中,F-和NO-2对AS14色谱柱的亲和力和Cl-相近,其响应值随Cl-加入量的变化趋势相似;Br-,NO-3,PO3-4及SO2-4因其对色谱柱的亲和力大于Cl-,它们的响应值随Cl-加入量的变化趋势也相同.对Cl-本身,当流动相中Cl-加入浓度不大于样品中Cl-的浓度(3 mgL-1)时,由流动相中Cl-造成的负系统峰小于样品中Cl-产生的正峰,其响应值基本没有变化.当流动相中Cl-浓度大于样品中Cl-浓度时,流动相中Cl-的负系统峰大于样品中Cl-的正峰,Cl-样品峰被系统峰覆盖.%A series of experiments were conducted by adding Cl- to the eluent to simulate the contaminated eluent. It was found that the added Cl- would cause the peak response of the anions increase largely. Because of the introduction of the superfluous H+, the total conductivity of each anion band was enhanced, and it was regarded as the increase of the sample anion. In the anions except Cl-, for the low affinities of F- and NO-2 for an AS14 column that were close to Cl-, they had the similar variation trends according to the amount of Cl- added to the eluent, and the two anions had the maximal responses when the concentration of Cl- in the eluent was 3 mg*L-1 that was just equal to the content in the sample. As to Br-, NO-3, PO3-4 and SO2-4 whose variation trends were the same, all of the peak responses of the anions reached the maximum when the concentration of Cl- in the eluent was 6 mg*L-1. For Cl-, the peak response hardly changed when the amount of Cl- added was less than or equal to the concentration of 3 mg*L-1 in the sample. When

  19. The RNA interference revolution

    Directory of Open Access Journals (Sweden)

    G. Lenz

    2005-12-01

    Full Text Available The discovery of double-stranded RNA-mediated gene silencing has rapidly led to its use as a method of choice for blocking a gene, and has turned it into one of the most discussed topics in cell biology. Although still in its infancy, the field of RNA interference has already produced a vast array of results, mainly in Caenorhabditis elegans, but recently also in mammalian systems. Micro-RNAs are short hairpins of RNA capable of blocking translation, which are transcribed from genomic DNA and are implicated in several aspects from development to cell signaling. The present review discusses the main methods used for gene silencing in cell culture and animal models, including the selection of target sequences, delivery methods and strategies for a successful silencing. Expected developments are briefly discussed, ranging from reverse genetics to therapeutics. Thus, the development of the new paradigm of RNA-mediated gene silencing has produced two important advances: knowledge of a basic cellular mechanism present in the majority of eukaryotic cells and access to a potent and specific new method for gene silencing.

  20. Serum indices: managing assay interference.

    Science.gov (United States)

    Farrell, Christopher-John L; Carter, Andrew C

    2016-09-01

    Clinical laboratories frequently encounter samples showing significant haemolysis, icterus or lipaemia. Technical advances, utilizing spectrophotometric measurements on automated chemistry analysers, allow rapid and accurate identification of such samples. However, accurate quantification of haemolysis, icterus and lipaemia interference is of limited value if laboratories do not set rational alert limits, based on sound interference testing experiments. Furthermore, in the context of increasing consolidation of laboratories and the formation of laboratory networks, there is an increasing requirement for harmonization of the handling of haemolysis, icterus and lipaemia-affected samples across different analytical platforms. Harmonization may be best achieved by considering both the analytical aspects of index measurement and the possible variations in the effects of haemolysis, icterus and lipaemia interferences on assays from different manufacturers. Initial verification studies, followed up with ongoing quality control testing, can help a laboratory ensure the accuracy of haemolysis, icterus and lipaemia index results, as well as assist in managing any biases in index results from analysers from different manufacturers. Similarities, and variations, in the effect of haemolysis, icterus and lipaemia interference in assays from different manufacturers can often be predicted from the mechanism of interference. Nevertheless, interference testing is required to confirm expected similarities or to quantify differences. It is important that laboratories are familiar with a number of interference testing protocols and the particular strengths and weaknesses of each. A rigorous approach to all aspects of haemolysis, icterus and lipaemia interference testing allows the analytical progress in index measurement to be translated into improved patient care. PMID:27147624

  1. FUNGICIDAL INTERFERENCE DURING INFECTION RELATED DEVELOPMENTAL STAGES INMAGNAPORTHE GRISEA

    Directory of Open Access Journals (Sweden)

    Anil S. Kotasthane

    2012-12-01

    Full Text Available Rice blast, a serious epidemic disease that limits grain yield worldwide is caused by fungal pathogen Magnaporthe grisea. The present investigation was carried out to identify the probable avenues of interference by different fungicides during the critical stages of infection related morphogenesis of M. grisea. Effect of six fungicides at different stages of infection related morphogenesis showed variable results like interference in conidial germination, distortion of surface structure of the spores,  interference in the germ tube elongation, interference in the transfer of the cell contents from spore to appresorrium, deformity in appressorial dome, interference in the melanin deposition. We speculate the critical stages at which these fungicides may interfere. The activity of immunosuppressive drug cyclosporin A (CsA which is a potential antifungal agent was equated with all the fungicides used. We hypothesize that the exposure of the M. grisea spore to the fungicide may lead to the formation of a cyclophilin CYP1-fungicide complex, which inactivates calcineurin and prevents calcium/ calmodulin-dependent protein phosphatase signaling and is therefore one of the target of fungicidal interference. An understanding of how fungal pathogens break the protective barrier that comprise the surface of the host plant as well as precise identification of avenues of fungicidal interference during infection related development in M. grisea will lead to novel approach for controlling plant diseases.

  2. Communications in interference limited networks

    CERN Document Server

    2016-01-01

    This book offers means to handle interference as a central problem of operating wireless networks. It investigates centralized and decentralized methods to avoid and handle interference as well as approaches that resolve interference constructively. The latter type of approach tries to solve the joint detection and estimation problem of several data streams that share a common medium. In fact, an exciting insight into the operation of networks is that it may be beneficial, in terms of an overall throughput, to actively create and manage interference. Thus, when handled properly, "mixing" of data in networks becomes a useful tool of operation rather than the nuisance as which it has been treated traditionally. With the development of mobile, robust, ubiquitous, reliable and instantaneous communication being a driving and enabling factor of an information centric economy, the understanding, mitigation and exploitation of interference in networks must be seen as a centrally important task.

  3. PROBABILISTIC-STATISTICAL MODELING THE INTERFERENCES FROM ELECTRIC LOCOMOTIVES

    Directory of Open Access Journals (Sweden)

    Orlov A. I.

    2015-02-01

    Full Text Available The movements of electric locomotives create the interferences affecting the wired link. The creation of sufficiently technical effective and at the same time cost-effective means of protection from wireline interferences generated traction networks assumes as a preparatory phase to develop mathematical models of interference caused by electric locomotives. We have developed a probabilistic-statistical model of interferences caused by electric locomotives. The asymptotic distribution of the total interference is the distribution of the length of the two-dimensional random vector whose coordinates - independent normally distributed random variables with mean 0 and variance 1. Limit theorem is proved for the expectation of the total amplitude of the interferences. Monte-Carlo method is used to study the rate of convergence of the expectation of the total amplitude of the interferences to the limiting value. We used an algorithm of mixing developed by MacLaren-Marsaglia (M-algorithm. Five sets of amplitudes are analyzed, selected in accordance with the recommendations of experts in the field of traction AC networks. The most rapid convergence to the limit takes place in the case of equal amplitudes. It was found that the maximum possible average value of the amplitude of the random noise by 7.4% less than the previously used value, which promises a significant economic impact

  4. Optical Realization of Double-Continuum Fano Interference and Coherent Control in Plasmonic Metasurfaces

    Science.gov (United States)

    Arju, Nihal; Ma, Tzuhsuan; Khanikaev, Alexander; Purtseladze, David; Shvets, Gennady

    2015-06-01

    Classical realization of a ubiquitous quantum mechanical phenomenon of double-continuum Fano interference using metasurfaces is experimentally demonstrated by engineering the near-field interaction between two bright and one dark plasmonic modes. The competition between the bright modes, one of them effectively suppressing the Fano interference for the orthogonal light polarization, is discovered. Coherent control of optical energy concentration and light absorption by the ellipticity of the incident light is theoretically predicted.

  5. Identification of a single base-pair mutation of TAA (Stop codon) → GAA (Glu) that causes light chain extension in a CHO cell derived IgG1

    Science.gov (United States)

    Zhang, Taylor; Huang, Yungfu; Chamberlain, Scott; Romeo, Tony; Zhu-Shimoni, Judith; Hewitt, Daniel; Zhu, Mary; Katta, Viswanatham; Mauger, Brad; Kao, Yung-Hsiang

    2012-01-01

    We describe here the identification of a stop codon TAA (Stop) → GAA (Glu) = Stop221E mutation on the light chain of a recombinant IgG1 antibody expressed in a Chinese hamster ovary (CHO) cell line. The extended light chain variants, which were caused by translation beyond the mutated stop codon to the next alternative in-frame stop codon, were observed by mass spectra analysis. The abnormal peptide peaks present in tryptic and chymotryptic LC–MS peptide mapping were confirmed by N-terminal sequencing as C-terminal light chain extension peptides. Furthermore, LC-MS/MS of Glu-C peptide mapping confirmed the stop221E mutation, which is consistent with a single base-pair mutation in TAA (stop codon) to GAA (Glu). The light chain variants were approximately 13.6% of wild type light chain as estimated by RP-HPLC analysis. DNA sequencing techniques determined a single base pair stop codon mutation, instead of a stop codon read-through, as the cause of this light chain extension. To our knowledge, the stop codon mutation has not been reported for IgGs expressed in CHO cells. These results demonstrate orthogonal techniques should be implemented to characterize recombinant proteins and select appropriate cell lines for production of therapeutic proteins because modifications could occur at unexpected locations. PMID:23018810

  6. Improved Interference Suppression Algorithm Against Broadband BPSK Interference

    Institute of Scientific and Technical Information of China (English)

    AN Jian-ping; XIA Cai-jie; WANG Ai-hua

    2008-01-01

    An improved polar exciser (IMPE) interference suppression method against broadband constant envelope binary phase shift keying (BPSK) interference is proposed. The disadvantage of traditional polar exciser (PE) is the performance degradation when the power of interference is low, i.e., the threshold effect. The proposed improved PE (IMPE) algorithm can overcome the threshold effect of PE by introducing compression gain (CG) metric, which forces PE suppressor active only at larger jammer-to-signal ratio (JSR) and switch to matched filter (MF) at lower JSR. Theoretical analysis and numerical simulations show the exactness of CG as a switching metric and the validity of the IMPE algorithm.

  7. Quantum interference of molecules -- probing the wave nature of matter

    CERN Document Server

    Venugopalan, Anu

    2012-01-01

    The double slit interference experiment has been famously described by Richard Feynman as containing the "only mystery of quantum mechanics". The history of quantum mechanics is intimately linked with the discovery of the dual nature of matter and radiation. While the double slit experiment for light is easily undertsood in terms of its wave nature, the very same experiment for particles like the electron is somewhat more difficult to comprehend. By the 1920s it was firmly established that electrons have a wave nature. However, for a very long time, most discussions pertaining to interference experiments for particles were merely gedanken experiments. It took almost six decades after the establishment of its wave nature to carry out a 'double slit interference' experiment for electrons. This set the stage for interference experiments with larger particles. In the last decade there has been spectacular progress in matter-wave interefernce experiments. Today, molecules with over a hundred atoms can be made to i...

  8. 248 nm imaging photolithography assisted by surface plasmon polariton interference

    Science.gov (United States)

    Tian, Man-man; Mi, Jia-jia; Shi, Jian-ping; Wei, Nan-nan; Zhan, Ling-li; Huang, Wan-xia; Zuo, Ze-wen; Wang, Chang-tao; Luo, Xian-gang

    2014-01-01

    A new photolithography technique for 248 nm based on the interference of surface plasmon waves is proposed and demonstrated by using computer simulations. The basic structure consists of surface plasmon polariton (SPP) interference mask and multi-layer film superlens. Using the amplification effect of superlens on evanescent wave, the near field SPP interference pattern is imaged to the far field, and then is exposed on photo resist (PR). The simulation results based on finite difference time domain (FDTD) method show that the full width at half maximum (FWHM) of the interference pattern is about 19 nm when the p-polarization light from 248 nm source is vertically incident to the structure. Meanwhile, the focal depth is 150 nm for negative PR and 60 nm for positive PR, which is much greater than that in usual SPP photolithography.

  9. Metasurface-Enabled Remote Quantum Interference.

    Science.gov (United States)

    Jha, Pankaj K; Ni, Xingjie; Wu, Chihhui; Wang, Yuan; Zhang, Xiang

    2015-07-10

    An anisotropic quantum vacuum (AQV) opens novel pathways for controlling light-matter interaction in quantum optics, condensed matter physics, etc. Here, we theoretically demonstrate a strong AQV over macroscopic distances enabled by a judiciously designed array of subwavelength-scale nanoantennas-a metasurface. We harness the phase-control ability and the polarization-dependent response of the metasurface to achieve strong anisotropy in the decay rate of a quantum emitter located over distances of hundreds of wavelengths. Such an AQV induces quantum interference among radiative decay channels in an atom with orthogonal transitions. Quantum vacuum engineering with metasurfaces holds promise for exploring new paradigms of long-range light-matter interaction for atom optics, solid-state quantum optics, quantum information processing, etc. PMID:26207477

  10. Asymmetric interference in molecular photoprocesses

    International Nuclear Information System (INIS)

    For the first time, the Coulomb continuum effects in asymmetric molecular interference have been studied analytically in photoionization, photorecombination, bremsstrahlung and Compton ionization. Simple, closed-form factors describe the interference not only in monochromatic photoprocesses, but also in the continuous photoelectron spectra generated by attosecond x-ray pulses with a frequency-dependent phase and broad bandwidth. Using HeH2+ molecular ion as an example, we show how the plane wave interference pattern is strongly modified by the two-centre Coulomb continuum. Asymmetric Coulomb continuum introduces qualitative changes in a photoionization process

  11. A New Approach to Interference Excision in Radio Astronomy: Real-Time Adaptive Cancellation

    Science.gov (United States)

    Barnbaum, Cecilia; Bradley, Richard F.

    1998-11-01

    Every year, an increasing amount of radio-frequency (RF) spectrum in the VHF, UHF, and microwave bands is being utilized to support new commercial and military ventures, and all have the potential to interfere with radio astronomy observations. Such services already cause problems for radio astronomy even in very remote observing sites, and the potential for this form of light pollution to grow is alarming. Preventive measures to eliminate interference through FCC legislation and ITU agreements can be effective; however, many times this approach is inadequate and interference excision at the receiver is necessary. Conventional techniques such as RF filters, RF shielding, and postprocessing of data have been only somewhat successful, but none has been sufficient. Adaptive interference cancellation is a real-time approach to interference excision that has not been used before in radio astronomy. We describe here, for the first time, adaptive interference cancellation in the context of radio astronomy instrumentation, and we present initial results for our prototype receiver. In the 1960s, analog adaptive interference cancelers were developed that obtain a high degree of cancellation in problems of radio communications and radar. However, analog systems lack the dynamic range, noised performance, and versatility required by radio astronomy. The concept of digital adaptive interference cancellation was introduced in the mid-1960s as a way to reduce unwanted noise in low-frequency (audio) systems. Examples of such systems include the canceling of maternal ECG in fetal electrocardiography and the reduction of engine noise in the passenger compartments of automobiles. These audio-frequency applications require bandwidths of only a few tens of kilohertz. Only recently has high-speed digital filter technology made high dynamic range adaptive canceling possible in a bandwidth as large as a few megahertz, finally opening the door to application in radio astronomy. We have

  12. Solar lighting

    CERN Document Server

    Pode, Ramchandra

    2011-01-01

    Limited availability of grid-based electricity is a major challenge faced by many developing countries, particularly the rural population. Fuel-based lighting, such as the kerosene lantern, is widespread in these areas, but it is a poor alternative, contributing to global warming and causing serious health problems. Several developing countries are therefore now encouraging the use of sustainable lighting. ""Solar Lighting"" gives an in-depth analysis of energy-efficient light production through the use of solar-powered LED systems. The authors pay particular attention to the interplay between

  13. Electromagnetic Interference In New Aircraft

    Science.gov (United States)

    Larsen, William E.

    1991-01-01

    Report reviews plans to develop tests and standards to ensure that digital avionics systems in new civil aircraft immune to electromagnetic interference (EMI). Updated standards reflect more severe environment and vulnerabilities of modern avionics.

  14. Interference of Quantum Market Strategies

    OpenAIRE

    Piotrowski, Edward W.; Jan Sladkowski; Jacek Syska

    2002-01-01

    Recent development in quantum computation and quantum information theory allows to extend the scope of game theory for the quantum world. The paper is devoted to the analysis of interference of quantum strategies in quantum market games.

  15. Exploiting Interference through Algebraic Structure

    OpenAIRE

    Nazer, Bobak Anthony

    2009-01-01

    In a network, interference between transmitters is usually viewed as highly undesirable and clever algorithms and protocols have been devised to avoid it. Collectively, these strategies transform the physical layer into a set of reliable bit pipes which can then be used seamlessly by higher layers in the protocol stack. Unfortunately, interference avoidance results in sharply decreasing rates as the number of users increases. In this thesis, we develop a new tool, computation coding, that all...

  16. Interference between gestures and words

    OpenAIRE

    Langton, Stephen R. H.

    1996-01-01

    This thesis explores the idea that a speaker's gestural and verbal behaviours are mutually influential in the comprehension process. A Stroop-type interference paradigm was adopted as a tool for investigating whether or not listeners process to-be-ignored gestural information and how this information influences the processing of spoken words. In Experiments 1-4, static pointing (deictic) gestures and corresponding spoken and written words showed symmetrical interference. Incongruent words ...

  17. Advanced Interference Management Technique: Potentials and Limitations

    OpenAIRE

    Lee, Namyoon; Heath Jr, Robert W.

    2014-01-01

    Interference management has the potential to improve spectrum efficiency in current and next generation wireless systems (e.g. 3GPP LTE and IEEE 802.11). Recently, new paradigms for interference management have emerged to tackle interference in a general class of wireless networks: interference shaping and interference exploitation. Both approaches offer better performance in interference-limited communication regimes than traditionally thought possible. This article provides a high-level ove...

  18. Light Pollution and Wildlife

    Science.gov (United States)

    Duffek, J.

    2008-12-01

    for Educational Program IYA Dark Skies Education Session Fall American Geophysical Union San Francisco, December 15-19, 2008 Light Pollution and Wildlife This is a very exciting time to be a part of the mission to keep the nighttime skies natural. The International Year of Astronomy (IYA) 2009 is developing programs for all areas of Dark Skies Awareness. For many years the issue of light pollution focused on the impact to the astronomy industry. While this is an important area, research has shown that light pollution negatively impacts wildlife, their habitat, human health, and is a significant waste of energy. Since the message and impact of the effects of light pollution are much broader now, the message conveyed to the public must also be broader. Education programs directed at youth are a new frontier to reach out to a new audience about the adverse effects of too much artificial light at night. The International Dark-Sky Association (IDA) has developed educational presentations using the National Science Teachers Association Education Standards. These programs focus on youth between the ages of 5 to 17exploring new territory in the education of light pollution. The IDA education programs are broken down into three age groups; ages 5-9, 8-13, 12 and older. The presentations come complete with PowerPoint slides, discussion notes for each slide, and workbooks including age appropriate games to keep young audiences involved. A new presentation reflects the growing area of interest regarding the effects of too much artificial light at night on wildlife. This presentation outlines the known problems for ecosystems caused by artificial light at night. Insects are attracted to artificial lights and may stay near that light all night. This attraction interferes with their ability to migrate, mate, and look for food. Such behavior leads to smaller insect populations. Fewer insects in turn affect birds and bats, because they rely on insects as a food source. The IDA

  19. Interference-Assisted Secret Communication

    CERN Document Server

    Tang, Xiaojun; Spasojevic, Predrag; Poor, H Vincent

    2008-01-01

    Wireless communication is susceptible to adversarial eavesdropping due to the broadcast nature of the wireless medium. In this paper it is shown how eavesdropping can be alleviated by exploiting the superposition property of the wireless medium. A wiretap channel with a helping interferer (WT-HI), in which a transmitter sends a confidential message to its intended receiver in the presence of a passive eavesdropper, and with the help of an independent interferer, is considered. The interferer, which does not know the confidential message, helps in ensuring the secrecy of the message by sending independent signals. An achievable secrecy rate for the WT-HI is given. The results show that interference can be exploited to assist secrecy in wireless communications. An important example of the Gaussian case, in which the interferer has a better channel to the intended receiver than to the eavesdropper, is considered. In this situation, the interferer can send a (random) codeword at a rate that ensures that it can be...

  20. Identification of a single base-pair mutation of TAA (Stop codon) → GAA (Glu) that causes light chain extension in a CHO cell derived IgG1

    OpenAIRE

    Zhang, Taylor; Huang, Yungfu; Chamberlain, Scott; Romeo, Tony; Zhu-Shimoni, Judith; Hewitt, Daniel; Zhu, Mary; Katta, Viswanatham; Mauger, Brad; Kao, Yung-Hsiang

    2012-01-01

    We describe here the identification of a stop codon TAA (Stop) → GAA (Glu) = Stop221E mutation on the light chain of a recombinant IgG1 antibody expressed in a Chinese hamster ovary (CHO) cell line. The extended light chain variants, which were caused by translation beyond the mutated stop codon to the next alternative in-frame stop codon, were observed by mass spectra analysis. The abnormal peptide peaks present in tryptic and chymotryptic LC–MS peptide mapping were confirmed by N-terminal s...

  1. Cognitive Aware Interference Mitigation Scheme for OFDMA Femtocells

    KAUST Repository

    Alqerm, Ismail

    2015-04-09

    Femto-cells deployment in today’s cellular networks came into practice to fulfill the increasing demand for data services. It also extends the coverage in the indoor areas. However, interference to other femto and macro-cells users remains an unresolved challenge. In this paper, we propose an interference mitigation scheme to control the cross-tier interference caused by femto-cells to the macro users and the co-tier interference among femtocells. Cognitive radio spectrum sensing capability is utilized to determine the non-occupied channels or the ones that cause minimal interference to the macro users. An awareness based channel allocation scheme is developed with the assistance of the graph-coloring algorithm to assign channels to the femto-cells base stations with power optimization, minimal interference, maximum throughput, and maximum spectrum efficiency. In addition, the scheme exploits negotiation capability to match traffic load and QoS with the channel, and to maintain efficient utilization of the available channels.

  2. CRISPR interference directs strand specific spacer acquisition.

    Directory of Open Access Journals (Sweden)

    Daan C Swarts

    Full Text Available BACKGROUND: CRISPR/Cas is a widespread adaptive immune system in prokaryotes. This system integrates short stretches of DNA derived from invading nucleic acids into genomic CRISPR loci, which function as memory of previously encountered invaders. In Escherichia coli, transcripts of these loci are cleaved into small RNAs and utilized by the Cascade complex to bind invader DNA, which is then likely degraded by Cas3 during CRISPR interference. RESULTS: We describe how a CRISPR-activated E. coli K12 is cured from a high copy number plasmid under non-selective conditions in a CRISPR-mediated way. Cured clones integrated at least one up to five anti-plasmid spacers in genomic CRISPR loci. New spacers are integrated directly downstream of the leader sequence. The spacers are non-randomly selected to target protospacers with an AAG protospacer adjacent motif, which is located directly upstream of the protospacer. A co-occurrence of PAM deviations and CRISPR repeat mutations was observed, indicating that one nucleotide from the PAM is incorporated as the last nucleotide of the repeat during integration of a new spacer. When multiple spacers were integrated in a single clone, all spacer targeted the same strand of the plasmid, implying that CRISPR interference caused by the first integrated spacer directs subsequent spacer acquisition events in a strand specific manner. CONCLUSIONS: The E. coli Type I-E CRISPR/Cas system provides resistance against bacteriophage infection, but also enables removal of residing plasmids. We established that there is a positive feedback loop between active spacers in a cluster--in our case the first acquired spacer--and spacers acquired thereafter, possibly through the use of specific DNA degradation products of the CRISPR interference machinery by the CRISPR adaptation machinery. This loop enables a rapid expansion of the spacer repertoire against an actively present DNA element that is already targeted, amplifying the

  3. Nonmonotonic quantum-to-classical transition in multiparticle interference.

    Science.gov (United States)

    Ra, Young-Sik; Tichy, Malte C; Lim, Hyang-Tag; Kwon, Osung; Mintert, Florian; Buchleitner, Andreas; Kim, Yoon-Ho

    2013-01-22

    Quantum-mechanical wave-particle duality implies that probability distributions for granular detection events exhibit wave-like interference. On the single-particle level, this leads to self-interference--e.g., on transit across a double slit--for photons as well as for large, massive particles, provided that no which-way information is available to any observer, even in principle. When more than one particle enters the game, their specific many-particle quantum features are manifested in correlation functions, provided the particles cannot be distinguished. We are used to believe that interference fades away monotonically with increasing distinguishability--in accord with available experimental evidence on the single- and on the many-particle level. Here, we demonstrate experimentally and theoretically that such monotonicity of the quantum-to-classical transition is the exception rather than the rule whenever more than two particles interfere. As the distinguishability of the particles is continuously increased, different numbers of particles effectively interfere, which leads to interference signals that are, in general, nonmonotonic functions of the distinguishability of the particles. This observation opens perspectives for the experimental characterization of many-particle coherence and sheds light on decoherence processes in many-particle systems. PMID:23297196

  4. On Feasibility of Interference Alignment in MIMO Interference Networks

    CERN Document Server

    Yetis, Cenk M; Jafar, Syed A; Kayran, Ahmet H

    2009-01-01

    We explore the feasibility of interference alignment in signal vector space -- based only on beamforming -- for K-user MIMO interference channels. Our main contribution is to relate the feasibility issue to the problem of determining the solvability of a multivariate polynomial system, considered extensively in algebraic geometry. It is well known, e.g. from Bezout's theorem, that generic polynomial systems are solvable if and only if the number of equations does not exceed the number of variables. Following this intuition, we classify signal space interference alignment problems as either proper or improper based on the number of equations and variables. Rigorous connections between feasible and proper systems are made through Bernshtein's theorem for the case where each transmitter uses only one beamforming vector. The multi-beam case introduces dependencies among the coefficients of a polynomial system so that the system is no longer generic in the sense required by both theorems. In this case, we show tha...

  5. Interference-Fit Life Factors for Roller Bearings

    Science.gov (United States)

    Oswald, Fred B.; Zaretsky, Erwin V.; Poplawski, Joseph V.

    2009-01-01

    The effect of hoop stresses in reducing cylindrical roller bearing fatigue life was determined for various classes of inner-ring interference fit. Calculations were performed for up to 7 fit classes for each of 10 bearing sizes. The hoop stresses were superimposed on the Hertzian principal stresses created by the applied radial load to calculate roller bearing fatigue life. A method was developed through a series of equations to calculate the life reduction for cylindrical roller bearings. All calculated lives are for zero initial internal clearance. Any reduction in bearing clearance due to interference fit would be compensated by increasing the initial (unmounted) clearance. Results are presented as tables and charts of life factors for bearings with light, moderate, and heavy loads and interference fits ranging from extremely light to extremely heavy for bearing accuracy class RBEC-5 (ISO class 5). Interference fits on the inner ring of a cylindrical roller bearing can significantly reduce bearing fatigue life. In general, life factors are smaller (lower life) for bearings running under light load where the unfactored life is highest. The various bearing series within a particular bore size had almost identical interference-fit life factors for a particular fit. The tightest fit at the high end of the tolerance band produces a life factor of approximately 0.40 for an inner-race maximum Hertz stress of 1200 MPa (175 ksi) and a life factor of 0.60 for an inner-race maximum Hertz stress of 2200 MPa (320 ksi). Interference fits also impact the maximum Hertz stress-life relation.

  6. Xenopus laevis P23H rhodopsin transgene causes rod photoreceptor degeneration that is more severe in the ventral retina and is modulated by light

    OpenAIRE

    Zhang, Rui; Oglesby, Ericka; Marsh-Armstrong, Nicholas

    2008-01-01

    Rhodopsin transgenes carrying mutations that cause autosomal dominant retinitis pigmentosa in humans have been used to study rod photoreceptor degeneration in various model organisms including Xenopus laevis. To date, the only transgenes shown to cause rod photoreceptor degeneration in Xenopus laevis have been either mammalian rhodopsins or chimeric versions of rhodopsin based mainly on Xenopus laevis rhodopsin sequences but with a mammalian C-terminus. Since the C-terminal sequence of rhodop...

  7. UHV交流输电线路有源干扰下无方向信标台功率限值的分析%Analysis of Non-directional Radio Beacon Power Limit Under the Condition of Active Interference Caused by UHV AC Transmission Line

    Institute of Scientific and Technical Information of China (English)

    周铖路; 翁木云; 陈凤

    2015-01-01

    有关UHV交流输电线路与无方向信标台电磁兼容方面的研究主要集中在防护距离的分析,对间距无法满足要求时的兼容问题研究较少。为此,从台站频谱参数入手,分析特高压交流输电线路有源干扰下无方向信标台的发射功率限值。首先介绍无方向信标台的工作原理及配置区域,然后分析UHV交流输电线路对台站的干扰机理,最后根据飞行航迹,以防护率为干扰判别依据,结合防护距离的研究,分别针对航路无方向信标台、近距无方向信标台和远距无方向信标台进行有效辐射功率的分析。结果表明,在给定条件下,对于航路和远距无方向信标台,有效辐射功率分别大于5.298 W、5.273 W时,机载无线电罗盘不受干扰;对于近距无方向信标台,与输电线路始终满足兼容的要求,无需分析限值。%The EMC research between UHV AC transmission line and non-directional radio beacon mainly focused on the protection distance while the study of EMC is little when the protection distance cannot meet the requirements. Therefore, the non-directional radio beacon power limit under the condition of active interference caused by UHV AC transmission line is analyzed from the aspect of spectrum parameters. Firstly, the working principle and configuration area of non-directional radio beacon are introduced. Then the interference mechanism of non-directional radio beacon from UHV AC transmission line is analyzed. Finally, the effective radiated power (ERP) of route non-directional radio beacon, close non-directional radio beacon and distance non-directional radio beacon are analyzed according to the flight path and protection ratio in combination with protection distance research. The results show that under the given conditions, route non-directional radio beacon and distance non-directional radio beacon’s ERP should be greater than 5.298 W and 5.273 W respectively to keep

  8. The Promoter Structure Differentiation of a MYB Transcription Factor RLC1 Causes Red Leaf Coloration in Empire Red Leaf Cotton under Light

    OpenAIRE

    Gao, Zhenrui; Liu, Chuanliang; Zhang, Yanzhao; Li, Ying; Yi, Keke; Zhao, Xinhua; Cui, Min-Long

    2013-01-01

    The red leaf coloration of Empire Red Leaf Cotton (ERLC) (Gossypium hirsutum L.), resulted from anthocyanin accumulation in light, is a well known dominant agricultural trait. However, the underpin molecular mechanism remains elusive. To explore this, we compared the molecular biological basis of anthocyanin accumulation in both ERLC and the green leaf cotton variety CCRI 24 (Gossypium hirsutum L.). Introduction of R2R3-MYB transcription factor Rosea1, the master regulator anthocyanin biosynt...

  9. Whirling waves in Interference experiments

    Science.gov (United States)

    Sinha, Urbasi; Sawant, Rahul; Samuel, Joseph; Sinha, Aninda; Sinha, Supurna

    2014-03-01

    In a double slit interference experiment, the wave function at the screen with both slits open is not exactly the sum of the wave functions with the slits individually open one at a time. The three scenarios represent three different boundary conditions and as such, the superposition principle should not be applicable. However, most well- known text books in quantum mechanics implicitly and/or explicitly use this assumption, the wave function hypothesis, which is only approximately true. In our present study, we have used the Feynman path integral formalism to quantify contributions from non-classical paths in interference experiments which provide a measurable deviation from the wave function hypothesis. A direct experimental demonstration for the existence of these non-classical paths is hard. We find that contributions from such paths can be significant and we propose simple three-slit interference experiments to directly confirm their existence. I will also describe some ongoing experimental efforts towards testing our theoretical findings.

  10. Ultrawideband Electromagnetic Interference to Aircraft Radios

    Science.gov (United States)

    Ely, Jay J.; Fuller, Gerald L.; Shaver, Timothy W.

    2002-01-01

    A very recent FCC Final Rule now permits marketing and operation of new products that incorporate Ultrawideband (UWB) technology into handheld devices. Wireless product developers are working to rapidly bring this versatile, powerful and expectedly inexpensive technology into numerous consumer wireless devices. Past studies addressing the potential for passenger-carried portable electronic devices (PEDs) to interfere with aircraft electronic systems suggest that UWB transmitters may pose a significant threat to aircraft communication and navigation radio receivers. NASA, United Airlines and Eagles Wings Incorporated have performed preliminary testing that clearly shows the potential for handheld UWB transmitters to cause cockpit failure indications for the air traffic control radio beacon system (ATCRBS), blanking of aircraft on the traffic alert and collision avoidance system (TCAS) displays, and cause erratic motion and failure of instrument landing system (ILS) localizer and glideslope pointers on the pilot horizontal situation and attitude director displays. This paper provides details of the preliminary testing and recommends further assessment of aircraft systems for susceptibility to UWB electromagnetic interference.

  11. Orientation of red blood cells and rouleaux disaggregation in interference laser fields.

    Science.gov (United States)

    Kruchenok, J V; Bushuk, S B; Kurilo, G I; Nemkovich, N A; Rubinov, A N

    2005-01-01

    The effect of interference laser fields on red blood cells (RBCs) was investigated both theoretically and experimentally. The optical trapping and orientation of individual RBC in interference fringes were observed. It was found that RBC rouleaux undergo disaggregation under the action of interference laser fields. To describe the effect of RBC orientation in interference fringes, we used the equation for torque exerted on a discoid dielectric particle in a gradient light field. The experimental results are in agreement with the predictions of the developed theoretical model. PMID:23345885

  12. Alternate transmission with half-duplex relaying in MIMO interference relay networks

    KAUST Repository

    Park, Seongho

    2013-12-01

    In this paper, we consider an alternate transmission scheme for a multiple-input multiple-output interference relay channel where multiple sources transmit their own signals to their corresponding destinations via one of two relaying groups alternately every time phase. Each of the relaying groups has arbitrary number of relays, and each relay operates in half-duplex amplify-and-forward mode. In our scheme, the received signals at the relay nodes consist of desired signals and two different interference signals such as the inter-source interferences and the inter-group interferences which are caused by the phase incoherence of relaying. As such, we propose an iterative interference alignment algorithm to mitigate the interferences. We show that our proposed scheme achieves additional degrees of freedom compared to the conventional half-duplex relaying system in the interference relay channels. © 2013 IEEE.

  13. "Quantum Interference with Slits" Revisited

    CERN Document Server

    Rothman, Tony

    2010-01-01

    Marcella [arXiv:quant-ph/0703126] has presented a straightforward technique employing the Dirac formalism to calculate single- and double-slit interference patterns. He claims that no reference is made to classical optics or scattering theory and that his method therefore provides a purely quantum mechanical description of these experiments. He also presents his calculation as if no approximations are employed. We show that he implicitly makes the same approximations found in classical treatments of interference and that no new physics has been introduced. At the same time, some of the quantum mechanical arguments Marcella gives are, at best, misleading.

  14. Interference of probabilities in dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Zak, Michail, E-mail: michail.zak@gmail.com [Jet Propulsion Laboratory California Institute of Technology, Pasadena, CA 91109 (United States)

    2014-08-15

    A new class of dynamical systems with a preset type of interference of probabilities is introduced. It is obtained from the extension of the Madelung equation by replacing the quantum potential with a specially selected feedback from the Liouville equation. It has been proved that these systems are different from both Newtonian and quantum systems, but they can be useful for modeling spontaneous collective novelty phenomena when emerging outputs are qualitatively different from the weighted sum of individual inputs. Formation of language and fast decision-making process as potential applications of the probability interference is discussed.

  15. Role of dressed-state interference in electromagnetically induced transparency

    CERN Document Server

    Khan, Sumanta; Natarajan, Vasant

    2016-01-01

    Electromagnetically induced transparency (EIT) in three-level systems uses a strong control laser on one transition to modify the absorption of a weak probe laser on a second transition. The control laser creates dressed states whose decay pathways show interference. We study the role of dressed-state interference in causing EIT in the three types of three-level systems - lambda ({\\Lambda}), ladder ({\\Xi}), and vee (V). In order to get realistic values for the linewidths of the energy levels involved, we consider appropriate hyperfine levels of 87 Rb. For such realistic systems, we find that dressed-state interference causes probe absorption (and hence EIT) to go to zero in a {\\Lambda} system, but plays a negligible role in {\\Xi} and V systems.

  16. Spectral anomalies of the effect of light-induced drift of caesium atoms caused by the velocity dependence of transport collision frequencies

    International Nuclear Information System (INIS)

    The spectral features of the light-induced drift (LID) velocity of caesium atoms in inert buffer gases are studied theoretically. A strong temperature dependence of the spectral LID line shape of Cs atoms in Ar or Kr atmosphere in the vicinity of T ∼ 1000 K is predicted. It is shown that the anomalous LID of Cs atoms in binary buffer mixtures of two different inert gases can be observed at virtually any (including ambient) temperature, depending on the content of the components in these mixtures. The results obtained make it possible to precisely test the interatomic interaction potentials in the experiments on the anomalous LID. (quantum optics)

  17. Electromagnetic interference reduction by dynamic impedance balancing applied in biosensors

    International Nuclear Information System (INIS)

    Electromagnetic interference, caused by the electric power line, affects the signals of electronic instruments, specifically those with low levels of amplitude. This type of signal is known as Common Mode Interference. There are many methods and architectures used to minimize or eliminate the influence of these interferences in electronic instrumentation, the most common is the use of band reject filters to eliminate them. With this objective, we present the analysis, prototyping, developing and testing of a new architecture reconfigurable filter with application in biomedical instrumentation, applied to the reduction of interference in common mode and conservation of components of the useful signal in the same range of noise, by the principle of balancing impedance dynamic using the hardware description software and simulation electronics software. The methodology was tested using a sinusoidal signal in the same standard frequency of an electrocardiogram signal in the same frequency interference (50/60 Hz). Excellent results were obtained in simulation with noise reduction of approximately 97%, while the results of experimental tests showed around 50% reduction. In both cases, the useful signal was preserved, confirming the efficiency of the proposed architecture. The method can be applied to eliminate the interference, which are in the same band the of the useful signal components.

  18. Biomedical Applications Of Interference Reflection Microscopy

    Science.gov (United States)

    Opas, Michal

    1990-04-01

    The relationship between cell adhesiveness and motility is being studied extensively for its paramount importance in the normal development of an organism and in pathological conditions such as tumour metastasis. Although they have been intensively studied at both the cellular and molecular levels, correlative studies of cell structure and adhesiveness, and the precise determination of cell adhesion to a substratum in living cells have been hampered by the fact that cell adhesion has been very difficult to visualize. Two techniques have emerged recently which have allowed successful visualization of cell adhesion. The most recent one, total internal reflection fluorescence, is technically complicated and thus not widespread and so it will not be dealt with here. The other one is a variant of incident light interferometry of thin layers, known as interference reflection microscopy (IRM).

  19. Multipolar interference for non-reciprocal nonlinear generation

    CERN Document Server

    Poutrina, Ekaterina

    2015-01-01

    We show that nonlinear multipolar interference allows achieving not only unidirectional, but also non-reciprocal nonlinear generation from a nanoelement, with the direction of the nonlinearly produced light decoupled from that of at least one or several of the excitation beams. Alternatively, it may allow inhibiting the specified nonlinear response in a nanoelement or in its periodic arrangement by reversing the direction of one of the pumps. The described phenomena exploit the fact that, contrary to the linear response case, nonlinear magneto-electric interference stems from a combination of additive and multiplicative processes and includes an interference between various terms within the electric and magnetic partial waves themselves. We demonstrate the introduced concept numerically using an example of a plasmonic dimer geometry with realistic material parameters.

  20. Multipolar interference for non-reciprocal nonlinear generation

    Science.gov (United States)

    Poutrina, Ekaterina; Urbas, Augustine

    2016-01-01

    We show that nonlinear multipolar interference allows achieving not only unidirectional, but also non-reciprocal nonlinear generation from a nanoelement, with the direction of the produced light decoupled from the direction of at least one of the excitation beams. Alternatively, it may allow inhibiting the specified nonlinear response in a nanoelement or in its periodic arrangement by reversing the direction of one of the pumps. These general phenomena exploit the fact that, contrary to the linear response case, nonlinear magneto-electric interference stems from a combination of additive and multiplicative processes and includes an interference between various terms within the electric and magnetic partial waves themselves. We demonstrate the introduced concept numerically using an example of a plasmonic dimer geometry with realistic material parameters. PMID:27126209

  1. Double-slit interference of radially polarized vortex beams

    Science.gov (United States)

    Qi, Junli; Wang, Weihua; Li, Xiujian; Wang, Xiaofeng; Sun, Wenchao; Liao, Jiali; Nie, Yongming

    2014-04-01

    Both radially polarized (RP) and radially polarized vortex (RPV) beams are generated by an experimental setup with one phase-only liquid crystal spatial light modulator which efficiently modulates the phase retardation distributions of input beam by twice reflections. The polarizing properties and double-slit interference of both RP and RPV beams are investigated in detail. Misplacement and tilt appear in double-slit interference fringes of both RP beams and RPV beams in simulations and experiments. The fringe tilt number F in the intermediate region is proportional to the topological charge l of RPV beams with the approximate relation Fs(l)=0.8125l in simulations and Fe(l)=0.8182l in experiments. The double-slit interference method can be utilized to determine and analyze the topological charge of the beams.

  2. Interpreting Stroop interference: an analysis of differences between task versions.

    Science.gov (United States)

    Salo, R; Henik, A; Robertson, L C

    2001-10-01

    The present study investigated methodological differences between the clinical version of the Stroop Color and Word Test and the computerized single-trial version. Three experiments show that different presentations of the Stroop task can produce different levels of interference. The 1st experiment examined the effect of blocking; the 2nd experiment examined different control conditions. Greater interference in the blocked clinical version appears to result from lower response times (RTs) in the neutral condition, not from greater RTs in the incongruent condition. Experiment 3 examined the impact of shifting attention across locations while responding to Stroop stimuli. The present set of findings sheds light on the inconsistency in the clinical literature and demonstrates that the method and selection of neutral stimuli (that provide the baseline by which interference is measured) are critical because they clearly can change performance. PMID:11761035

  3. "Quantum Interference with Slits" Revisited

    Science.gov (United States)

    Rothman, Tony; Boughn, Stephen

    2011-01-01

    Marcella has presented a straightforward technique employing the Dirac formalism to calculate single- and double-slit interference patterns. He claims that no reference is made to classical optics or scattering theory and that his method therefore provides a purely quantum mechanical description of these experiments. He also presents his…

  4. Fano Interference in Classical Oscillators

    Science.gov (United States)

    Satpathy, S.; Roy, A.; Mohapatra, A.

    2012-01-01

    We seek to illustrate Fano interference in a classical coupled oscillator by using classical analogues of the atom-laser interaction. We present an analogy between the dressed state picture of coherent atom-laser interaction and a classical coupled oscillator. The Autler-Townes splitting due to the atom-laser interaction is analogous to the…

  5. Final report about research project SR2521 ''Analysis and assessment of the risk potentials caused by corrosion in German Light Water Reactor (LWR) plants''

    International Nuclear Information System (INIS)

    Following the reports about incidents in nuclear facilities between 1995 and 2004 that were caused by corrosion, it was the purpose of this research project to systematically analyze the risk potentials of the existing types of corrosion, except expansion crack corrosion, transgranular stress-corrosion with sensitization, intergranular stress corrosion with sensitization and the corrosion of alloys based on nickel. The share of such incidents due to corrosion in the total number of reportable incidents in German LWR plants amounted to approx. 12.5 % (annual average). Some 90 % of the incidents caused by corrosion both in Germany and abroad were identified during scheduled maintenance, inspection or test measures, which include regular inspections. The remaining incidents due to corrosion were identified by the internal monitoring equipment. The further analysis of the incidents, which took into account the erection period of the German LWR plants, did not show any significant correlation between the age of the plant and the found corrosion effects. As a tendency, less incidents caused by corrosion occurred in the PWR or BWR plants of a more advanced design. This can be attributed to the requirements contained in the BMU-BMI safety criteria which were implemented in the 1980s, to the RSK guidelines, to the general specification concerning the fundamental safety of pressurized vessels and to the KTA regulations. A deterministic assessment of systems and components affected by corrosion showed that it was impossible to exclude specific corrosion types from any further considerations merely for system-related reasons. The assessment with probabilistic methods did not lead to any other results. The following aspects were taken into account in the subsequent assessments:. characteristic features, peripheral conditions and the propagation of the individual types of corrosion,. possible influences of changes of the material caused by corrosion on the leakbefore- break

  6. ELISA reader does not interfere by mobile phone radiofrequency radiation

    OpenAIRE

    Mortazavi, Seyyed Mohammad Javad; Baradaran-Ghahfarokhi, Hamid Reza; Abdi, Mohammad Reza; Baradaran-Ghahfarokhi, Milad; Mostafavi, Nayyer Sadat; Mahmoudi, Golshan; Berenjkoub, Nafiseh; Akmali, Zahra; Hossein-Beigi, Fahimeh; Arsang, Vajiheh

    2016-01-01

    Background: The increasing number of mobile phones can physically cause electromagnetic interference (EMI) in medical environments; can also cause errors in immunoassays in laboratories. The ELISA readers are widely used as a useful diagnostic tool for Enzymun colorimetric assay in medicine. The aim of this study was to investigate whether the ELISA reader could be interfered by the exposure to the 900 MHz cell phones in the laboratory. Materials and Methods: Human serum samples were collecte...

  7. An Inexpensive LED Light Sensor

    Science.gov (United States)

    Kutzner, Mickey; Wright, Richard; Kutzner, Emily

    2010-01-01

    Light irradiance measurements are important for students grappling with abstract optical phenomena such as the inverse square law, polarization, diffraction, interference, and spectroscopy. A variety of commercial light sensors are available from scientific vendors such as the CI-6504A from PASCO scientific and the LS-BTA from Vernier Software and…

  8. Understanding causes and effects of non-uniform light distributions on multi-junction solar cells: Procedures for estimating efficiency losses

    Science.gov (United States)

    Herrero, Rebeca; Victoria, Marta; Domínguez, César; Askins, Stephen; Antón, Ignacio; Sala, Gabriel

    2015-09-01

    This paper presents the mechanisms of efficiency losses that have to do with the non-uniformity of the irradiance over the multi-junction solar cells and different measurement techniques used to investigate them. To show the capabilities of the presented techniques, three different concentrators (that consist of an acrylic Fresnel lens, different SOEs and a lattice matched multi-junction cell) are evaluated. By employing these techniques is possible to answer some critical questions when designing concentrators as for example which degree of non-uniformity the cell can withstand, how critical the influence of series resistance is, or what kind of non-uniformity (spatial or spectral) causes more losses.

  9. Relay self interference minimisation using tapped filter

    KAUST Repository

    Jazzar, Saleh

    2013-05-01

    In this paper we introduce a self interference (SI) estimation and minimisation technique for amplify and forward relays. Relays are used to help forward signals between a transmitter and a receiver. This helps increase the signal coverage and reduce the required transmitted signal power. One problem that faces relays communications is the leaked signal from the relay\\'s output to its input. This will cause an SI problem where the new received signal at the relay\\'s input will be added with the unwanted leaked signal from the relay\\'s output. A Solution is proposed in this paper to estimate and minimise this SI which is based upon using a tapped filter at the destination. To get the optimum weights for this tapped filter, some channel parameters must be estimated first. This is performed blindly at the destination without the need of any training. This channel parameter estimation method is named the blind-self-interference-channel-estimation (BSICE) method. The next step in the proposed solution is to estimate the tapped filter\\'s weights. This is performed by minimising the mean squared error (MSE) at the destination. This proposed method is named the MSE-Optimum Weight (MSE-OW) method. Simulation results are provided in this paper to verify the performance of BSICE and MSE-OW methods. © 2013 IEEE.

  10. Evaluation of a Mobile Phone for Aircraft GPS Interference

    Science.gov (United States)

    Nguyen, Truong X.

    2004-01-01

    Measurements of spurious emissions from a mobile phone are conducted in a reverberation chamber for the Global Positioning System (GPS) radio frequency band. This phone model was previously determined to have caused interference to several aircraft GPS receivers. Interference path loss (IPL) factors are applied to the emission data, and the outcome compared against GPS receiver susceptibility. The resulting negative safety margins indicate there are risks to aircraft GPS systems. The maximum emission level from the phone is also shown to be comparable with some laptop computer's emissions, implying that laptop computers can provide similar risks to aircraft GPS receivers.

  11. Inappropriate shock delivery due to interference between a washing machine and an implantable cardioverter defibrillator.

    Science.gov (United States)

    Kolb, Christof; Schmieder, Sebastian; Schmitt, Claus

    2002-12-01

    Electromagnetic interference with implantable cardioverter defibrillators (ICD) can cause inappropriate delivery of therapies or temporary inhibition of ICD functions. The presented case describes electromagnetic interference between a washing machine and an ICD resulting in an inappropriate discharge of the device due to false detection of ventricular fibrillation. PMID:12510137

  12. Prediction of shipboard electromagnetic interference (EMI) problems using artificial intelligence (AI) technology

    Science.gov (United States)

    Swanson, David J.

    1990-01-01

    The electromagnetic interference prediction problem is characteristically ill-defined and complicated. Severe EMI problems are prevalent throughout the U.S. Navy, causing both expected and unexpected impacts on the operational performance of electronic combat systems onboard ships. This paper focuses on applying artificial intelligence (AI) technology to the prediction of ship related electromagnetic interference (EMI) problems.

  13. Multi-user interference cancellation schemes for carrier frequency offset compensation in uplink OFDMA

    DEFF Research Database (Denmark)

    Nguyen, Huan Cong; De Carvalho, Elisabeth; Prasad, Ramjee

    2014-01-01

    Each user in the uplink of an Orthogonal Frequency Division Multiple Access (OFDMA) system may experience a different carrier frequency offset (CFO). These uncorrected CFOs destroy the orthogonality among subcarriers, causing inter-carrier interference and multi-user interference, which degrade t...... cancellation techniques for Orthogonal Frequency Division Multiple Access (OFDMA) available in literature with comparable or lower complexity....

  14. Jung's views on causes and treatments of schizophrenia in light of current trends in cognitive neuroscience and psychotherapy research I. Aetiology and phenomenology.

    Science.gov (United States)

    Silverstein, Steven M

    2014-02-01

    Jung's writings on schizophrenia are almost completely ignored or forgotten today. The purpose of this paper, along with a follow-up article, is to review the primary themes found in Jung's writings on schizophrenia, and to assess the validity of his theories about the disorder in light of our current knowledge base in the fields of psychopathology, cognitive neuroscience and psychotherapy research. In this article, five themes related to the aetiology and phenomenology of schizophrenia from Jung's writings are discussed:1) abaissement du niveau mental; 2) the complex; 3) mandala imagery; 4) constellation of archetypes and 5) psychological versus toxic aetiology. Reviews of the above areas suggest three conclusions. First, in many ways, Jung's ideas on schizophrenia anticipated much current thinking and data about the disorder. Second, with the recent (re)convergence of psychological and biological approaches to understanding and treating schizophrenia, the pioneering ideas of Jung regarding the importance of both factors and their interaction remain a useful and rich, but still underutilized resource. Finally, a more concerted effort to understand and evaluate the validity of Jung's concepts in terms of evidence from neuroscience could lead both to important advances in analytical psychology and to developments in therapeutic approaches that would extend beyond the treatment of schizophrenia. PMID:24467355

  15. Task duration in contextual interference.

    Science.gov (United States)

    Smith, Peter J K

    2002-12-01

    Duration of practice trial on a pursuit rotor task in contextual interference was investigated. Participants practiced at each of 4 angular velocities, with 24 participants completing 28 trials lasting 20 sec., and 24 participants completing 112 trials of 5 sec. Half of the participants in each trial-duration condition practiced in a blocked format and half practiced in a random format. After random practice posttest performance was better than blocked practice when practice-trial duration was 20 sec., but worse when practice-trial duration was 5 sec. This result is not consistent with theoretical explanations of the contextual interference effect and is discussed with reference to the task characteristics and demands of the pursuit rotor. PMID:12578255

  16. Parasitic interference in nulling interferometry

    CERN Document Server

    Matter, Alexis; Danchi, William C; Lopez, Bruno; Absil, Olivier

    2013-01-01

    Nulling interferometry aims to detect faint objects close to bright stars. Its principle is to produce a destructive interference along the line-of-sight so that the stellar flux is rejected, while the flux of the off-axis source can be transmitted. In practice, various instrumental perturbations can degrade the nulling performance. Any imperfection in phase, amplitude, or polarization produces a spurious flux that leaks to the interferometer output and corrupts the transmitted off-axis flux. One of these instrumental pertubations is the crosstalk phenomenon, which occurs because of multiple parasitic reflections inside transmitting optics, and/or diffraction effects related to beam propagation along finite size optics. It can include a crosstalk of a beam with itself, and a mutual crosstalk between different beams. This can create a parasitic interference pattern, which degrades the intrinsic transmission map - or intensity response - of the interferometer. In this context, we describe how this instrumental ...

  17. Fano interference in classical oscillators

    International Nuclear Information System (INIS)

    We seek to illustrate Fano interference in a classical coupled oscillator by using classical analogues of the atom-laser interaction. We present an analogy between the dressed state picture of coherent atom-laser interaction and a classical coupled oscillator. The Autler-Townes splitting due to the atom-laser interaction is analogous to the splitting of normal-mode frequencies of a coupled oscillator. Using this analogy, we simulate and experimentally demonstrate Fano interference and the associated phenomena in three-level atoms in a coupled electrical resonator circuit. This work aims to highlight analogies between classical and quantum systems for students at the postgraduate and graduate levels. Also, the reported technique can be easily realized in undergraduate laboratories. (paper)

  18. Targeted Cancer Therapy: Correlative Light-Electron Microscopy Shows RGD-Targeted ZnO Nanoparticles Dissolve in the Intracellular Environment of Triple Negative Breast Cancer Cells and Cause Apoptosis with Intratumor Heterogeneity (Adv. Healthcare Mater. 11/2016).

    Science.gov (United States)

    Othman, Basmah A; Greenwood, Christina; Abuelela, Ayman F; Bharath, Anil A; Chen, Shu; Theodorou, Ioannis; Douglas, Trevor; Uchida, Maskai; Ryan, Mary; Merzaban, Jasmeen S; Porter, Alexandra E

    2016-06-01

    On page 1310 J. S. Merzaban, A. E. Porter, and co-workers present fluorescently labeled RGD-targeted ZnO nanoparticles (NPs; green) for the targeted delivery of cytotoxic ZnO to integrin αvβ3 receptors expressed on triple negative breast cancer cells. Correlative light-electron microscopy shows that NPs dissolve into ionic Zn(2+) (blue) upon uptake and cause apoptosis (red) with intra-tumor heterogeneity, thereby providing a possible strategy for targeted breast cancer therapy. Cover design by Ivan Gromicho. PMID:27275627

  19. Distractor interference during a choice limb reaching task.

    Directory of Open Access Journals (Sweden)

    Matthew Ray

    Full Text Available According to action-centered models of attention, the patterns of distractor interference that emerge in selective reaching tasks are related to the time and effort required to resolve a race for activation between competing target and non-target response producing processes. Previous studies have only used unimanual aiming tasks and, as such, only examined the effects of competition that occurs within a limb. The results of studies using unimanual aiming movements often reveal an "ipsilateral effect"--distractors on the same side of space as the effector cause greater interference than distractors on the opposite side of space. The cost of the competition when response selection is between the limbs has yet to be addressed. Participants in the present study executed reaching movements to 1 of 4 (2 left, 2 right possible target locations with and without a distractor. Participants made ipsilateral reaches (left hand to left targets, right hand to right targets. In contrast to studies using unimanual aiming movements, a "contralateral effect" was observed; distractors affording responses for the other hand (in contralateral space caused more interference than distractors affording responses for the same hand. The findings from the present research demonstrate that when certain portions of response planning must be resolved prior to response initiation, distractors that code for that dimension cause the greatest interference.

  20. Quantum interference of molecules -- probing the wave nature of matter

    OpenAIRE

    Venugopalan, Anu

    2012-01-01

    The double slit interference experiment has been famously described by Richard Feynman as containing the "only mystery of quantum mechanics". The history of quantum mechanics is intimately linked with the discovery of the dual nature of matter and radiation. While the double slit experiment for light is easily undertsood in terms of its wave nature, the very same experiment for particles like the electron is somewhat more difficult to comprehend. By the 1920s it was firmly established that el...

  1. Quantum Interference Mechanism of Cooperative Optical Phenomena in Extended Media

    OpenAIRE

    Valery I Rupasov

    2000-01-01

    In the quantum process of stimulated Raman scattering (SRS), a laser photon propagating in a resonance medium undergoes multifold conversions into a Stokes photon and back. The nontrivial ``cooperative'' behavior of the Stokes component of light transmitted through the medium is proven to be completely determined by the interference of scattering amplitudes in different sub-channels of the Stokes channel, which obviously combines all the sub-channels with an odd number of photon conversions. ...

  2. Interference in multilayer relativistic mirrors

    Science.gov (United States)

    Mirzanejhad, Saeed; Sohbatzadeh, Farshad; Babaei, Javad; Taghipour, Meisam; Mohammadzadeh, Zahra

    2015-10-01

    In this paper, reflection coefficient of a relativistic ultra-thin electron multilayer is calculated using electromagnetic interference procedures. The relativistic electron layers are assumed to be formed by nonlinear plasma wake waves that constitute the electron density cusps. It is shown that the interference between successive relativistic mirrors is restricted by the condition, τ p ≫ ( 2 γ 0 ) 5 / 2 / ω p 0 , where τp is the laser pulse duration. The results showed that tailoring the pulse amplitude, incident wave frequency value, incidence angle, and plasma density leads to increasing reflection coefficient a few orders of magnitudes. This constructive interference condition can be used for increasing conversion efficiency in the reflected energy from relativistic mirrors for the purpose of generating ultra-short coherence pulses in the extreme ultraviolet and x-ray regions. We also performed reflection from relativistic thin electron layers using relativistic 1D3V electromagnetic particle-in-cell (PIC) simulation. It was found that the results of PIC simulation are in agreement with analytical considerations.

  3. Continuous Time Channels with Interference

    CERN Document Server

    Ivan, Ioana; Thaler, Justin; Yuen, Henry

    2012-01-01

    Khanna and Sudan studied a natural model of continuous time channels where signals are corrupted by the effects of both noise and delay, and showed that, surprisingly, in some cases both are not enough to prevent such channels from achieving unbounded capacity. Inspired by their work, we consider channels that model continuous time communication with adversarial delay errors. The sender is allowed to subdivide time into arbitrarily large number $M$ of micro-units in which binary symbols may be sent, but the symbols are subject to unpredictable delays and may interfere with each other. We model interference by having symbols that land in the same micro-unit of time be summed, and a $k$-interference channels allows receivers to distinguish sums up to the value $k$. We consider both a channel adversary that has a limit on the maximum number of steps it can delay each symbol, and a more powerful adversary that only has a bound on the average delay. We give precise characterizations of the threshold between finite...

  4. Local form interference in biological motion perception.

    Science.gov (United States)

    Kerr-Gaffney, Jess E; Hunt, Amelia R; Pilz, Karin S

    2016-07-01

    Replacing the local dots of point-light walkers with complex images leads to significant detriments to performance in biological motion detection and discrimination tasks. This detriment has previously been shown to be larger when the local elements match the global shape in object category and facing direction. In contrast, studies using Navon stimuli have demonstrated that local interference on global processing primarily occurs when local elements are dissimilar to the global form. In 3 experiments, we investigated this contradiction by replacing the local dots of a point-light walker with human images or stick figures. Participants were significantly faster and more accurate at discriminating the facing and walking direction of a walker when the local images were facing in the same direction as the global walker than when they were facing in the opposite direction. These results provide support for the idea that organization of biological motion depends on allocation of limited processing resources to the global motion information when the local elements are complex. However, there is more disruption to global form processing when the local elements and global form conflict in task-related properties. PMID:27016343

  5. Cooperative Algorithms for MIMO Interference Channels

    CERN Document Server

    Peters, Steven W

    2010-01-01

    Interference alignment is a transmission technique for exploiting all available degrees of freedom in the interference channel with an arbitrary number of users. Most prior work on interference alignment, however, neglects interference from other nodes in the network not participating in the alignment operation. This paper proposes three generalizations of interference alignment for the multiple-antenna interference channel with multiple users that account for colored noise, which models uncoordinated interference. First, a minimum interference-plus-noise leakage algorithm is presented, and shown to be equivalent to previous subspace methods when noise is spatially white or negligible. A joint minimum mean squared error design is then proposed that jointly optimizes the transmit precoders and receive spatial filters, whereas previous designs neglect the receive spatial filter. This algorithm is shown to be a generalization of previous joint MMSE designs for other system configurations such as the broadcast ch...

  6. Devices That May Interfere with Pacemakers

    Science.gov (United States)

    ... group of cellphone companies is studying that possibility. Bluetooth® headsets do not appear to interfere with pacemakers. ... group of cellphone companies is studying that possibility. Bluetooth® headsets do not appear to interfere with pacemakers. ...

  7. Measurement of step height by traceable interference microscope

    International Nuclear Information System (INIS)

    A Traceable Interference Microscope (TIM) to calibrate the step height standards is presented. The construction of the TIM includes an interference microscope, a stabilized He-Ne laser, and a rotated ground glass. The instrument's original white light source is replaced by the stabilized laser through an optical fiber. The step height is measured by calculating the phase difference of two fringe patterns both on the upper and lower surfaces of the specimen. A new methodology called Double-Tilt Imaging (DTI) method is proposed to determine the Numerical Aperture Correction Factor (NACF). The wavelength of the light source and the difference both in angles and in spatial frequencies between the positive and negative tilts would reveal sufficient information to allow for the determination of the NACF directly. The light source used is a stabilized He-Ne laser traceable to the definition of the meter and the angle measurement to the angle standards by an autocollimator. The calculation of the aperture correction factor for the interference microscope with a 10x Mirau-type objective lens yields a traceable average value of 1.01936 with a relative standard uncertainty of about 5.74 x 10-4. The expanded uncertainty of this step height calibration system is determined to be approximately 3 nm

  8. Rheumatoid factor and its interference with cytokine measurements

    DEFF Research Database (Denmark)

    Bartels, Else Marie; Falbe Wätjen, Inger; Littrup Andersen, Eva;

    2011-01-01

    Use of cytokines as biomarkers for disease is getting more widespread. Cytokines are conveniently determined by immunoassay, but interference from present antibodies is known to cause problems. In rheumatoid arthritis (RA), interference of rheumatoid factor (RF) may be problematic. RF covers a...... group of autoantibodies from immunoglobulin subclasses and is present in 65-80% of RA patients. Partly removal of RF is possible by precipitation. This study aims at determining the effects of presence of RF in blood and synovial fluid on cytokine measurements in samples from RA patients and finding...... possible solutions for recognized problems. IL-1β, IL-4, IL-6, and IL-8 were determined with multiplex immunoassays (MIA) in samples from RA patients prior to and after polyethylene glycol (PEG 6000) precipitation. Presence of RF does interfere with MIA. PEG 6000 precipitation abolishes this RF...

  9. Rheumatoid factor and its interference with cytokine measurements

    DEFF Research Database (Denmark)

    Bartels, Else Marie; Falbe Wätjen, Inger; Littrup Andersen, Eva;

    2011-01-01

    Use of cytokines as biomarkers for disease is getting more widespread. Cytokines are conveniently determined by immunoassay, but interference from present antibodies is known to cause problems. In rheumatoid arthritis (RA), interference of rheumatoid factor (RF) may be problematic. RF covers a...... group of autoantibodies from immunoglobulin subclasses and is present in 65-80% of RA patients. Partly removal of RF is possible by precipitation. This study aims at determining the effects of presence of RF in blood and synovial fluid on cytokine measurements in samples from RA patients and finding...... possible solutions for recognized problems. IL-1ß, IL-4, IL-6, and IL-8 were determined with multiplex immunoassays (MIA) in samples from RA patients prior to and after polyethylene glycol (PEG 6000) precipitation. Presence of RF does interfere with MIA. PEG 6000 precipitation abolishes this RF...

  10. PARASITIC INTERFERENCE IN LONG BASELINE OPTICAL INTERFEROMETRY: REQUIREMENTS FOR HOT JUPITER-LIKE PLANET DETECTION

    International Nuclear Information System (INIS)

    The observable quantities in optical interferometry, which are the modulus and the phase of the complex visibility, may be corrupted by parasitic fringes superimposed on the genuine fringe pattern. These fringes are due to an interference phenomenon occurring from stray light effects inside an interferometric instrument. We developed an analytical approach to better understand this phenomenon when stray light causes cross talk between beams. We deduced that the parasitic interference significantly affects the interferometric phase and thus the associated observables including the differential phase and the closure phase. The amount of parasitic flux coupled to the piston between beams appears to be very influential in this degradation. For instance, considering a point-like source and a piston ranging from λ/500 to λ/5 in the L band (λ = 3.5 μm), a parasitic flux of about 1% of the total flux produces a parasitic phase reaching at most one-third of the intrinsic phase. The piston, which can have different origins (instrumental stability, atmospheric perturbations, etc.), thus amplifies the effect of parasitic interference. According to the specifications of piston correction in space or at ground level (respectively λ/500 ∼ 2 nm and λ/30 ∼ 100 nm), the detection of hot Jupiter-like planets, one of the most challenging aims for current ground-based interferometers, limits parasitic radiation to about 5% of the incident intensity. This was evaluated by considering different types of hot Jupiter synthetic spectra. Otherwise, if no fringe tracking is used, the detection of a typical hot Jupiter-like system with a solar-like star would admit a maximum level of parasitic intensity of 0.01% for piston errors equal to λ/15. If the fringe tracking specifications are not precisely observed, it thus appears that the allowed level of parasitic intensity dramatically decreases and may prevent the detection. In parallel, the calibration of the parasitic phase by a

  11. Photon wave functions and quantum interference experiments

    OpenAIRE

    Lapaire, G. G.; Sipe, J. E.

    2006-01-01

    We present a general theory to describe two-photon interference, including a formal description of few photon intereference in terms of single-photon amplitudes. With this formalism, it is possible to describe both frequency entangled and separable two-photon interference in terms of single-photon wave functions. Using this description, we address issues related to the physical interpretation of two-photon interference experiments. We include a discussion on how few-photon interference can be...

  12. Single-photon interference experiment for high schools

    Science.gov (United States)

    Bondani, Maria

    2014-07-01

    We follow the reductio ad absurdum reasoning described in the book "Sneaking a Look at God's Cards" by Giancarlo Ghirardi to demonstrate the wave-particle duality of light in a Mach-Zehnder interferometric setup analog to the conventional Young double-slit experiment. We aim at showing the double nature of light by measuring the existence of interference fringes down to the single-photon level. The setup includes a strongly attenuated laser, polarizing beam splitters, half-waveplates, polarizers and single-photon detectors.

  13. Heavy Higgs signal-background interference in gg → VV in the Standard Model plus real singlet

    International Nuclear Information System (INIS)

    For the Standard Model extended with a real scalar singlet field, the modification of the heavy Higgs signal due to interference with the continuum background and the off-shell light Higgs contribution is studied for gg → ZZ, WW @→ 4 lepton processes at the Large Hadron Collider. Interference effects can range from O(10%) to O(1) effects for integrated cross sections. Despite a strong cancellation between the heavy Higgs-continuum and the heavy Higgs-light Higgs interference, the full interference is clearly non-negligible and modifies the heavy Higgs line shape. A vertical stroke MVV - Mh2 vertical stroke < Γh2 cut mitigates interference effects to O(10%) or less. A public program that allows one to simulate the full interference is presented. (orig.)

  14. Heavy Higgs signal-background interference in gg → VV in the Standard Model plus real singlet

    Energy Technology Data Exchange (ETDEWEB)

    Kauer, Nikolas; O' Brien, Claire [Royal Holloway, University of London, Department of Physics, Egham (United Kingdom)

    2015-08-15

    For the Standard Model extended with a real scalar singlet field, the modification of the heavy Higgs signal due to interference with the continuum background and the off-shell light Higgs contribution is studied for gg → ZZ, WW @→ 4 lepton processes at the Large Hadron Collider. Interference effects can range from O(10%) to O(1) effects for integrated cross sections. Despite a strong cancellation between the heavy Higgs-continuum and the heavy Higgs-light Higgs interference, the full interference is clearly non-negligible and modifies the heavy Higgs line shape. A vertical stroke M{sub VV} - M{sub h2} vertical stroke < Γ{sub h2} cut mitigates interference effects to O(10%) or less. A public program that allows one to simulate the full interference is presented. (orig.)

  15. Effects of garlic on cellular doubling time and DNA strand breaks caused by UV light and BPL, enhanced with catechol and TPA

    International Nuclear Information System (INIS)

    3T3 cell cultures were exposed to UV light and Beta-Propiolactone. Neoplastic cell transformation (TF) was demonstrated after concurrent addition of catechol, or repeated addition of TPA. Addition of garlic to all fluences/concentrations of the carcinogen/cocarcinogen/promoter groups reduced the number of transformed foci/dish by at least 40%. Since the cell cycle is prolonged following exposure to carcinogens, it is likely the cell requires a longer time to repair this damage. The doubling time (DT) was extended from 12 to 36 hrs. when cells were exposed to BPL and from 12 o 28 hrs. when cells were exposed to 3.0J/M2/sec. If an anticarcinogenic compound is also added, it is reasonable to assume that the cell cycle may be further elongated. The cell cycle, denoted by DT was lengthened from 12 to 47 hrs and from 12 to 86 hrs for BPL and UVC, respectively. The extensions occurred in a dope dependent manner. The concentrations of the cocarcinogen and promoter remained constant throughout the experiment. When strand breaks were determined at the same dose sequences, by alkaline elution, more repair was seen with garlic where the lowest and middle doses of BPL were used and almost no decrease in % DNA eluted was seen with UVC exposed cells. With catechol, there was a two-fold decrease in % DNA eluted at the lowest and middle fluences. When TPA was added, all three fluences of UVC showed more than a threefold decrease in % DNA eluted. BPS with both TPA and catechol, again showed a reduction in strand breaks only low and middle doses. Both a direct-acting alkylating agent, BPL, and a physical carcinogen, UVC, were homogeneously affected, in terms of doubling time, but not when strand break repair was examined. A separate mechanism may be responsible for repair, and the mechanism associated with combinations of physical carcinogen enhancing agents combined with some non-carcinogens may be more profoundly affected by some natural products

  16. Interference Alignment Using Variational Mean Field Annealing

    DEFF Research Database (Denmark)

    Badiu, Mihai Alin; Guillaud, Maxime; Fleury, Bernard Henri

    2014-01-01

    We study the problem of interference alignment in the multiple-input multiple- output interference channel. Aiming at minimizing the interference leakage power relative to the receiver noise level, we use the deterministic annealing approach to solve the optimization problem. In the corresponding...

  17. Interference-Fit Life Factors for Ball Bearings

    Science.gov (United States)

    Oswald, Fred B.; Zaretsky, Erwin V.; Poplawski, Joseph V.

    2010-01-01

    The effect of hoop stresses on the rolling-element fatigue life of angular-contact and deep-groove ball bearings was determined for common inner-ring interference fits at the ABEC-5 tolerance level. The analysis was applied to over 1150 bearing configurations and load cases. Hoop stresses were superimposed on the Hertzian principal stresses created by the applied bearing load to calculate the inner-race maximum shearing stress. The resulting fatigue life of the bearing was recalculated through a series of equations. The reduction in the fatigue life is presented as life factors that are applied to the unfactored bearing life. The life factors found in this study ranged from 1.00 (no life reduction)--where there was no net interface pressure--to a worst case of 0.38 (a 62-percent life reduction). For a given interference fit, the reduction in life is different for angular-contact and deep-groove ball bearings. Interference fits also affect the maximum Hertz stress-life relation. Experimental data of Czyzewski, showing the effect of interference fit on rolling-element fatigue life, were reanalyzed to determine the shear stress-life exponent. The Czyzewski data shear stress-life exponent c equals 8.77, compared with the assumed value of 9. Results are presented as tables and charts of life factors for angular-contact and deep-groove ball bearings with light, normal, and heavy loads and interference fits ranging from extremely light to extremely heavy.

  18. Codebook-based interference alignment for uplink MIMO interference channels

    KAUST Repository

    Lee, Hyun Ho

    2014-02-01

    In this paper, we propose a codebook-based interference alignment (IA) scheme in the constant multiple-input multipleoutput (MIMO) interference channel especially for the uplink scenario. In our proposed scheme, we assume cooperation among base stations (BSs) through reliable backhaul links so that global channel knowledge is available for all BSs, which enables BS to compute the transmit precoder and inform its quantized index to the associated user via limited rate feedback link.We present an upper bound on the rate loss of the proposed scheme and derive the scaling law of the feedback load tomaintain a constant rate loss relative to IA with perfect channel knowledge. Considering the impact of overhead due to training, cooperation, and feedback, we address the effective degrees of freedom (DOF) of the proposed scheme and derive the maximization of the effective DOF. From simulation results, we verify our analysis on the scaling law to preserve the multiplexing gain and confirm that the proposed scheme is more effective than the conventional IA scheme in terms of the effective DOF. © 2014 KICS.

  19. INTERFERENCE OF UNIDIRECTIONAL SHOCK WAVES

    Directory of Open Access Journals (Sweden)

    P. V. Bulat

    2015-05-01

    Full Text Available Subject of study.We consider interference of unidirectional shock waves or, as they are called, catching up shock waves. The scope of work is to give a classification of the shock-wave structures that arise in this type of interaction of shock waves, and the area of their existence. Intersection of unidirectional shock waves results in arising of a shock-wave structure at the intersection point, which contains the main shock wave, tangential discontinuity and one more reflected gas-dynamic discontinuity of unknown beforehand type. The problem of determining the type of reflected discontinuity is the main problem that one has to solve in the study of catching shock waves interference. Main results.The paper presents the pictures of shock-wave structures arising at the interaction of catching up shock waves. The areas with a regular and irregular unidirectional interaction of shocks are described. Characteristic shock-wave structures are of greatest interest, where reflected gas-dynamic discontinuity degenerates into discontinuous characteristics. Such structures have a number of extreme properties. We have found the areas of existence for such shock-wave structures. There are also areas in which the steady-state solution is not available. The latter has determined revival of interest for the theoretical study of the problem, because the facts of sudden shock-wave structure destruction inside the air intake of supersonic aircrafts at high Mach numbers have been discovered. Practical significance.The theory of interference for unidirectional shock waves and design procedure are usable in the design of supersonic air intakes. It is also relevant for application possibility investigation of catching up oblique shock waves to create overcompressed detonation in perspective detonation air-jet and rocket engines.

  20. IETS and quantum interference: propensity rules in the presence of an interference feature.

    Science.gov (United States)

    Lykkebo, Jacob; Gagliardi, Alessio; Pecchia, Alessandro; Solomon, Gemma C

    2014-09-28

    Destructive quantum interference in single molecule electronics is an intriguing phenomenon; however, distinguishing quantum interference effects from generically low transmission is not trivial. In this paper, we discuss how quantum interference effects in the transmission lead to either low current or a particular line shape in current-voltage curves, depending on the position of the interference feature. Second, we consider how inelastic electron tunneling spectroscopy can be used to probe the presence of an interference feature by identifying vibrational modes that are selectively suppressed when quantum interference effects dominate. That is, we expand the understanding of propensity rules in inelastic electron tunneling spectroscopy to molecules with destructive quantum interference. PMID:25273424

  1. IETS and quantum interference: Propensity rules in the presence of an interference feature

    Energy Technology Data Exchange (ETDEWEB)

    Lykkebo, Jacob; Solomon, Gemma C., E-mail: gsolomon@nano.ku.dk [Nano-Science Center and Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen Ø (Denmark); Gagliardi, Alessio [Technische Universität München, Electrical Engineering and Information Tech., Arcisstr. 21, 80333 München (Germany); Pecchia, Alessandro [Consiglio Nazionale delle Ricerche, ISMN, Via Salaria km 29.6, 00017 Monterotondo (Rome) (Italy)

    2014-09-28

    Destructive quantum interference in single molecule electronics is an intriguing phenomenon; however, distinguishing quantum interference effects from generically low transmission is not trivial. In this paper, we discuss how quantum interference effects in the transmission lead to either low current or a particular line shape in current-voltage curves, depending on the position of the interference feature. Second, we consider how inelastic electron tunneling spectroscopy can be used to probe the presence of an interference feature by identifying vibrational modes that are selectively suppressed when quantum interference effects dominate. That is, we expand the understanding of propensity rules in inelastic electron tunneling spectroscopy to molecules with destructive quantum interference.

  2. IETS and quantum interference: Propensity rules in the presence of an interference feature

    International Nuclear Information System (INIS)

    Destructive quantum interference in single molecule electronics is an intriguing phenomenon; however, distinguishing quantum interference effects from generically low transmission is not trivial. In this paper, we discuss how quantum interference effects in the transmission lead to either low current or a particular line shape in current-voltage curves, depending on the position of the interference feature. Second, we consider how inelastic electron tunneling spectroscopy can be used to probe the presence of an interference feature by identifying vibrational modes that are selectively suppressed when quantum interference effects dominate. That is, we expand the understanding of propensity rules in inelastic electron tunneling spectroscopy to molecules with destructive quantum interference

  3. Long working distance interference microscope

    Science.gov (United States)

    Sinclair, Michael B.; DeBoer, Maarten P.; Smith, Norman F.

    2004-04-13

    Disclosed is a long working distance interference microscope suitable for three-dimensional imaging and metrology of MEMS devices and test structures on a standard microelectronics probe station. The long working distance of 10-30 mm allows standard probes or probe cards to be used. This enables nanometer-scale 3-D height profiles of MEMS test structures to be acquired across an entire wafer. A well-matched pair of reference/sample objectives is not required, significantly reducing the cost of this microscope, as compared to a Linnik microinterferometer.

  4. Interference Mitigation in Cognitive Femtocells

    DEFF Research Database (Denmark)

    Da Costa, Gustavo Wagner Oliveira; Cattoni, Andrea Fabio; Alvarez Roig, Victor;

    2010-01-01

    , management and optimization can be prohibitive. Instead, self-optimization of an uncoordinated deployment should be considered. Cognitive Radio enabled femtocells are considered to be a promising solution to enable self-optimizing femtocells to effectively manage the inter-cell interference, especially in...... densely deployed femto scenarios. In this paper, two key elements of cognitive femtocells are combined: a power control algorithm and a fully distributed dynamic spectrum allocation method. The resulting solution was evaluated through system-level simulations and compared to the separate algorithms and...

  5. Admission Control and Interference Management in Dynamic Spectrum Access Networks

    Directory of Open Access Journals (Sweden)

    Jorge Martinez-Bauset

    2010-01-01

    Full Text Available We study two important aspects to make dynamic spectrum access work in practice: the admission policy of secondary users (SUs to achieve a certain degree of quality of service and the management of the interference caused by SUs to primary users (PUs. In order to limit the forced termination probability of SUs, we evaluate the Fractional Guard Channel reservation scheme to give priority to spectrum handovers over new arrivals. We show that, contrary to what has been proposed, the throughput of SUs cannot be maximized by configuring the reservation parameter. We also study the interference caused by SUs to PUs. We propose and evaluate different mechanisms to reduce the interference, which are based on simple spectrum access algorithms for both PUs and SUs and channel repacking algorithms for SUs. Numerical results show that the reduction can be of one order of magnitude or more with respect to the random access case. Finally, we propose an adaptive admission control scheme that is able to limit simultaneously the forced termination probability of SUs and what we define as the probability of interference. Our scheme does not require any configuration parameters beyond the probability objectives. Besides, it is simple to implement and it can operate with any arrival process and distribution of the session duration.

  6. An Efficient Inter Carrier Interference Cancellation Schemes for OFDM Systems

    Directory of Open Access Journals (Sweden)

    B. Sathish Kumar

    2009-12-01

    Full Text Available Orthogonal Frequency Division Multiplexing (OFDM has recently been used widely in wireless communication systems. OFDM is very effective in combating inter-symbol interference and can achieve high data rate in frequency selective channel. For OFDM communication systems, the frequency offsets in mobile radio channels distort the orthogonality between subcarriers resulting in Inter Carrier Interference (ICI. ICI causes power leakage among subcarriers thus degrading the system performance. A well-known problem of OFDM is its sensitivity to frequency offset between the transmitted and received carrier frequencies. There are two deleterious effects caused by frequency offset one is the reduction of signal amplitude in the output of the filters matched to each of the carriers and the second is introduction of ICI from the other carriers. This research work investigates three effective methods for combating the effects of ICI: ICI Self Cancellation (SC, Maximum Likelihood (ML estimation, and Extended Kalman Filter (EKF method. These three methods are compared in terms of bit error rate performance and bandwidth efficiency. Through simulations, it is shown that the three techniques are effective in mitigating the modulation schemes, the ML and EKF methods perform better than the SC method.Keywords- Orthogonal frequency Division Multiplexing (OFDM; Inter Carrier Interference(ICI; Carrier to Interference Power Ratio (CIR;Self Cancellation(SC;Carrier Frequency Offset (CFO; Maximum Likelihood(ML; Extended Kalman Filtering(EKF.

  7. Interference Mitigation in Large Random Wireless Networks

    CERN Document Server

    Aldridge, Matthew

    2011-01-01

    A central problem in the operation of large wireless networks is how to deal with interference -- the unwanted signals being sent by transmitters that a receiver is not interested in. This thesis looks at ways of combating such interference. In Chapters 1 and 2, we outline the necessary information and communication theory background, including the concept of capacity. We also include an overview of a new set of schemes for dealing with interference known as interference alignment, paying special attention to a channel-state-based strategy called ergodic interference alignment. In Chapter 3, we consider the operation of large regular and random networks by treating interference as background noise. We consider the local performance of a single node, and the global performance of a very large network. In Chapter 4, we use ergodic interference alignment to derive the asymptotic sum-capacity of large random dense networks. These networks are derived from a physical model of node placement where signal strength d...

  8. Tailoring double Fano profiles with plasmon-assisted quantum interference in hybrid exciton-plasmon system

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Dongxing; Wu, Jiarui [State Key Laboratory for Mesoscopic Physics, Department of Physics, Peking University, Beijing 100871 (China); Gu, Ying, E-mail: ygu@pku.edu.cn; Gong, Qihuang [State Key Laboratory for Mesoscopic Physics, Department of Physics, Peking University, Beijing 100871 (China); Collaborative Innovation Center of Quantum Matter, Beijing (China)

    2014-09-15

    We propose tailoring of the double Fano profiles via plasmon-assisted quantum interference in a hybrid exciton-plasmon system. Tailoring is performed by the interference between two exciton channels interacting with a common localized surface plasmon. Using an applied field of low intensity, the absorption spectrum of the hybrid system reveals a double Fano lineshape with four peaks. For relatively large field intensity, a broad flat window in the absorption spectrum appears which results from the destructive interference between excitons. Because of strong constructive interference, this window vanishes as intensity is further increased. We have designed a nanometer bandpass optical filter for visible light based on tailoring of the optical spectrum. This study provides a platform for quantum interference that may have potential applications in ultracompact tunable quantum devices.

  9. Tailoring double Fano profiles with plasmon-assisted quantum interference in hybrid exciton-plasmon system

    International Nuclear Information System (INIS)

    We propose tailoring of the double Fano profiles via plasmon-assisted quantum interference in a hybrid exciton-plasmon system. Tailoring is performed by the interference between two exciton channels interacting with a common localized surface plasmon. Using an applied field of low intensity, the absorption spectrum of the hybrid system reveals a double Fano lineshape with four peaks. For relatively large field intensity, a broad flat window in the absorption spectrum appears which results from the destructive interference between excitons. Because of strong constructive interference, this window vanishes as intensity is further increased. We have designed a nanometer bandpass optical filter for visible light based on tailoring of the optical spectrum. This study provides a platform for quantum interference that may have potential applications in ultracompact tunable quantum devices.

  10. Spatially and spectrally resolved quantum path interference with chirped driving pulses

    CERN Document Server

    Preclíková, Jana; Lorek, Eleonora; Larsen, Esben Witting; Heyl, Christoph M; Paleček, David; Zigmantas, Donatas; Schafer, Kenneth J; Gaarde, Mette B; Mauritsson, Johan

    2016-01-01

    We measure spectrally and spatially resolved high-order harmonics generated in argon using chirped multi-cycle laser pulses. Using a very stable, high-repetition rate laser we are able to clearly observe the interference between light emitted from the two shortest trajectories and study this interference structure systematically. The interference structure is clearly observed over a large range of harmonic orders, ranging from harmonic 11, which is below the ionization threshold of argon, to harmonic 25. The interference pattern contains more information than just the relative phase of the light from the two trajectories, since it is both spatially and spectrally resolved. We can access this additional information by changing the chirp of the driving laser pulses which affects both the spatial and the spectral phases of the two trajectories differently, allowing us to reconstruct the dipole phase parameters for the short ($\\alpha_s$) and long ($\\alpha_l$) trajectories from the data. The reconstruction is done...

  11. Radio-Frequency Field-Induced Quantum Interference Effects in Cold Atoms

    Institute of Scientific and Technical Information of China (English)

    龙全; 周蜀渝; 周善钰; 王育竹

    2001-01-01

    We propose constructing a quantum interference configuration for cold atoms in a magneto-optical trap by applying a radio frequency field, which coherently couples adjacent Zeeman sublevels, in combination with a repumping laser field. One effect of this interference is that a dip exists in the absorption of the repumping light when the radio frequency is scanned. Our prediction has been indirectly detected through the fluorescence of cold atoms in a preliminary experiment.

  12. Ramsey method for Auger-electron interference induced by an attosecond twin pulse

    OpenAIRE

    Buth, Christian; Schafer, Kenneth J.

    2010-01-01

    We examine the archetype of an interference experiment for Auger electrons: two electron wave packets are launched by inner-shell ionizing a krypton atom using two attosecond light pulses with a variable time delay. This setting is an attosecond realization of the Ramsey method of separated oscillatory fields. Interference of the two ejected Auger-electron wave packets is predicted, indicating that the coherence between the two pulses is passed to the Auger electrons. For the detection of the...

  13. Quantum interference and manipulation of entanglement in silicon wire waveguide quantum circuits

    International Nuclear Information System (INIS)

    Integrated quantum photonic waveguide circuits are a promising approach to realizing future photonic quantum technologies. Here, we present an integrated photonic quantum technology platform utilizing the silicon-on-insulator material system, where quantum interference and the manipulation of quantum states of light are demonstrated in components orders of magnitude smaller than previous implementations. Two-photon quantum interference is presented in a multi-mode interference coupler, and the manipulation of entanglement is demonstrated in a Mach-Zehnder interferometer, opening the way to an all-silicon photonic quantum technology platform. (paper)

  14. Cognitive declines in healthy aging: evidence from multiple aspects of interference resolution.

    Science.gov (United States)

    Pettigrew, Corinne; Martin, Randi C

    2014-06-01

    The present study tested the hypothesis that older adults show age-related deficits in interference resolution, also referred to as inhibitory control. Although oftentimes considered as a unitary aspect of executive function, various lines of work support the notion that interference resolution may be better understood as multiple constructs, including resistance to proactive interference (PI) and response-distractor inhibition (e.g., Friedman & Miyake, 2004). Using this dichotomy, the present study assessed whether older adults (relative to younger adults) show impaired performance across both, 1, or neither of these interference resolution constructs. To do so, we used multiple tasks to tap each construct and examined age effects at both the single task and latent variable levels. Older adults consistently demonstrated exaggerated interference effects across resistance to PI tasks. Although the results for the response-distractor inhibition tasks were less consistent at the individual task level analyses, age effects were evident on multiple tasks, as well as at the latent variable level. However, results of the latent variable modeling suggested declines in interference resolution are best explained by variance that is common to the 2 interference resolution constructs measured herein. Furthermore, the effect of age on interference resolution was found to be both distinct from declines in working memory, and independent of processing speed. These findings suggest multiple cognitive domains are independently sensitive to age, but that declines in the interference resolution constructs measured herein may originate from a common cause. PMID:24955989

  15. Pulse Tube Interference in Cryogenic Sensors - Oral Presentation

    Energy Technology Data Exchange (ETDEWEB)

    Lam, Tyler [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-08-24

    Transition edge sensors (TES) are extremely sensitive superconducting sensors, operating at 100 mK, which can be used to detect X-rays and Cosmic Microwave Background. The goal of our project is to design the electronics to read out an array of 10000 of these sensors by using microwave signals. However, we noticed the pulse tube used to maintain cryogenic temperatures caused interference in our readout. To determine the cause of the signal distortions, we used a detector with a 370 MHz sampling rate to collect and analyze sensor data. Although this data provided little information towards the nature of the noise, it was determined through a maintenance procedure than the 0.3 mm stainless steel wires were being vibrated due to acoustic waves, which distorted the signal. Replacing this wire appeared to cease the interference from the sensor data.

  16. Pulse Tube Interference in Cryogenic Sensor Resonant Circuits - Final Paper

    Energy Technology Data Exchange (ETDEWEB)

    Lam, Tyler [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-08-27

    Transition edge sensors (TES) are extremely sensitive superconducting sensors, operating at 100 mK, which can be used to detect X-rays and Cosmic Microwave Background. The goal of our project is to design the electronics to read out an array of 10000 of these sensors by using microwave signals. However, we noticed the pulse tube used to maintain cryogenic temperatures caused interference in our readout. To determine the cause of the signal distortions, we used a detector with a 370 MHz sampling rate to collect and analyze sensor data. Although this data provided little information towards the nature of the noise, it was determined through a maintenance procedure than the 0.3 mm stainless steel wires were being vibrated due to acoustic waves, which distorted the signal. Replacing this wire appeared to cease the interference from the sensor data.

  17. Environmental Factors that Interfere in the Germination

    Directory of Open Access Journals (Sweden)

    Lisiane de Souza

    2014-12-01

    Full Text Available This paper refers to the application of experiments with sixth graders of elementary school, aiming motivation, skills development focused on observation, interpersonal relationships in teams, related to the various forms of language skills, as well to identify and resume misconceptions about the external (environmental factors required for seed germination, in order that the contents developed this year refer to the study of the earth, soil, water and air, among others, and that many students do not understand all the concepts and the importance of these factors for the existence of living beings. The experiments were organized in two stages, first to observe the influence of soil and another moment to observe the interference of water, air and light. The temperature impractical activities were conducted, however, during the observation period (three weeks experiments remained in a controlled environment in the science laboratory. For the experiments we used materials easily found in commerce, some recycled; students were organized into six teams, which improved the data collection, the maintenance of the experiments, the calculations of the percentages, and the producing of report. Many of these contents had not yet been studied in other disciplines, but were developed in the discipline of science, respecting prior knowledge and cognitive abilities. The use of experiments was effective for the construction of new knowledge and to develop skills necessary to start the search.

  18. RNA interference and antiviral therapy

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    RNA interference (RNAi) is an evolutionally conserved gene silencing mechanism present in a variety of eukaryotic species. RNAi uses short double-stranded RNA (dsRNA) to trigger degradation or translation repression of homologous RNA targets in a sequence-specific manner. This system can be induced effectively in vitro and in vivo by direct application of small interfering RNAs (siRNAs), or by expression of short hairpin RNA (shRNA) with non-viral and viral vectors. To date, RNAi has been extensively used as a novel and effective tool for functional genomic studies, and has displayed great potential in treating human diseases, including human genetic and acquired disorders such as cancer and viral infections. In the present review, we focus on the recent development in the use of RNAi in the prevention and treatment of viral infections. The mechanisms,strategies, hurdles and prospects of employing RNAi in the pharmaceutical industry are also discussed.

  19. Graphene Superconducting Quantum Interference Device

    Science.gov (United States)

    Girit, Çaǧlar; Bouchiat, Vincent; Naaman, Ofer; Zhang, Yuanbo; Crommie, Michael; Zettl, Alex; Siddiqi, Irfan

    2010-03-01

    Graphene can support Cooper pair transport when contacted with two superconducting electrodes, resulting in the well-known Josephson effect. By depositing aluminum/palladium electrodes in the geometry of a loop onto a single graphene sheet, we fabricate a two junction dc superconducting quantum interference device (SQUID). Not only an the supercurrent in this device be increased by moving the electrostatic gate away from the Dirac point, but it can also be modulated periodically by an applied magnetic field---a potentially powerful probe of electronic transport in graphene. We analyze the magnetic field modulation of the critical current with the asymmetric/inductive SQUID model of Fulton and Dynes and discuss the variation of the fitting parameters with gate voltage.

  20. Quasiparticle interference from magnetic impurities

    Science.gov (United States)

    Derry, Philip G.; Mitchell, Andrew K.; Logan, David E.

    2015-07-01

    Fourier transform scanning tunneling spectroscopy (FT-STS) measures the scattering of conduction electrons from impurities and defects, giving information about the electronic structure of both the host material and adsorbed impurities. We interpret such FT-STS measurements in terms of the quasiparticle interference (QPI), here investigating in detail the QPI due to single magnetic impurities adsorbed on a range of representative nonmagnetic host surfaces, and contrasting with the case of a simple scalar impurity or point defect. We demonstrate how the electronic correlations present for magnetic impurities markedly affect the QPI, showing, e.g., a large intensity enhancement due to the Kondo effect, and universality at low temperatures/scanning energies. The commonly used joint density of states interpretation of FT-STS measurements is also considered, and shown to be insufficient in many cases, including that of magnetic impurities.

  1. Dissolved organic carbon interferences in UV nitrate measurements and possible mitigation methods

    Science.gov (United States)

    Thomas, R. G.; Foster, C. R.; Cohen, M. J.; Martin, J. B.; Delfino, J. J.

    2010-12-01

    Nitrate can be the limiting nutrient in many aquatic ecosystems and has been implicated in the degradation of surface and ground water quality. Understanding its fate and transport requires measurements at high temporal resolution in situ for extended periods of time to observe a range of natural and anthropogenic inputs. These measurements are most efficiently made by in situ sensors, preferably without chemical manipulation. The development of in situ ultraviolet spectrometers with high spectral resolution (0.8 nm) and short response time (1 s) have provided the ability to make in situ measurements of nitrate concentration by measuring its absorbance in the UV wavelengths (200nm-400nm). Like many other regions, springs in Florida have shown increasing nitrate levels in recent years. Because many spring runs in Florida ultimately enter highly colored rivers with high humic DOC content, UV nitrate analyzers cannot operate according to specifications under such light limiting conditions and can result in erroneous or even unattainable readings. Here we present an analysis of interferences caused by dissolved organic carbon (DOC) on the measured nitrate concentration by the Satlantic SUNA (Submersible Ultraviolet Nitrate Analyzer). Dissolved organic carbon absorption of UV irradiation is well documented in the literature and the results of this study clearly demonstrate that high DOC concentrations impact in situ sensor nitrate concentration measurements. Interferences caused by DOC were estimated through bench tests of natural water collected from the upper reaches of the Santa Fe River (USGS Monitoring Station 2322700) and found to have DOC concentration of approximately 50 mg/L and N03 concentration of 0.04 mg/L. The SUNA was operated in a continuous sample mode (about 1 sample per second) to measure nitrate concentrations in this water that was diluted to DOC concentrations of 2.5, 5.0, 10.0, and 12.5 mg/L DOC and nitrate concentrations of 0.05, 0.10, 0.20, 0

  2. An application of differential interference contrast in metallographic examination

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    As one of the most exciting inspection and powerful analysis methods in modern materials metallographic examinations, the difference interference contrast (DIC) method has many advantages, including relatively low requirement for specimen preparation, obvious relief senses observed under microscope. Details such as fine structures or defects that are not or barely visible in incident-light bright field, could be easily revealed and thus make materials analysis more reliable. Differential interference contrast produces an image that can be readily manipulated using digital and video imaging techniques to further enhance contrast. But, studies of material metallography based on DIC method have rarely carried out. Based on the fundamental principle of the DIC method combing with the computer image analysis, applications of DIC method in materials metallographic examination were investigated in this study.

  3. High-order dispersion effects in two-photon interference

    CERN Document Server

    Mazzotta, Z; Cipriani, D; Olivares, S; Paris, M G A

    2016-01-01

    Two-photon interference and Hong-Ou-Mandel (HOM) effect are relevant tools for quantum metrology and quantum information processing. In optical coherence tomography, HOM effect is exploited to achieve high-resolution measurements with the width of the HOM dip being the main parameter. On the other hand, applications like dense coding require high-visibility performances. Here we address high-order dispersion effects in two-photon interference and study, theoretically and experimentally, the dependence of the visibility and the width of the HOM dip on both the pump spectrum and the downconverted photon spectrum. In particular, a spatial light modulator is exploited to experimentally introduce and manipulate a custom phase function to simulate the high-order dispersion effects.

  4. Coping with Radio Frequency Interference

    Science.gov (United States)

    Lewis, B. M.

    2009-01-01

    The radio spectrum is a finite resource, on which humanity makes many demands. And pressure on it is ever increasing with the development of new technology and ideas for radio services. After all, we all benefit from wifi and cell phones. Radio astronomers have a small percentage of the spectrum allocated to them at octave intervals in the metre-centimetre bands, and at important frequencies, such as that of the 21cm line of HI. Signals from other services, as well as from our own poorly-engineered equipment, sometimes contaminate our bands: these signals constitute RFI. These may totally obliterate the astronomical signal, or, in the case of CLOUDSAT, may be capable of completely destroying a receiver, which introduces us to the new possibility of 'destructive interference'. A geo-stationary satellite can block access to a piece of sky from one site. Good equipment design eliminates self-inflicted interference, while physical separation often provides adequate practical mitigation at many frequencies. However, new observatories end up being located in the West Australian desert or Antarctica. In future they may be on the back side of the Moon. But there is no Earth-bound protection via physical separation against satellite signals. Some mitigation can be achieved by frequent data dumps and the excision of RFI, or by real-time detection and blanking of the receiver, or by more sophisticated algoriths. Astronomers of necessity aim to achieve mitigation via coordination, at the local level, and by participating in spectrum management at the national and international levels. This involves them spending a lot of time in Geneva at the International Telegraphic Union protecting their access to spectrum, and access to clean spectrum from the L3 point and the far side of the Moon.

  5. Parasitic interference in nulling interferometry

    Science.gov (United States)

    Matter, A.; Defrère, D.; Danchi, W. C.; Lopez, B.; Absil, O.

    2013-05-01

    Nulling interferometry aims to detect faint objects close to bright stars. Its principle is to produce a destructive interference along the line of sight so that the stellar flux is rejected, while the flux of the off-axis source can be transmitted. In practice, various instrumental perturbations can degrade the nulling performance. Any imperfection in phase, amplitude or polarization produces a spurious flux that leaks to the interferometer output and corrupts the transmitted off-axis flux. One of these instrumental perturbations is the crosstalk phenomenon, which occurs because of multiple parasitic reflections inside transmitting optics, and/or diffraction effects related to beam propagation along finite size optics. It can include a crosstalk of a beam with itself, and a mutual crosstalk between different beams. This can create a parasitic interference pattern, which degrades the intrinsic transmission map - or intensity response - of the interferometer. In this context, we describe how this instrumental effect impairs the performance of a Bracewell interferometer. A simple formalism is developed to derive the corresponding modified intensity response of the interferometer, as a function of the two parameters of interest: the crosstalk level (or contamination rate) and the phase shift between the primary and secondary - parasitic - beams. We then apply our mathematical approach to a few scientific cases, both analytically and using the GENIESIM simulation software, adapted to handle coherent crosstalk. Our results show that a coherent crosstalk level of about 1 per cent implies a 20 per cent drop of the signal-to-noise ratio at most. Careful attention should thus be paid to reduce the crosstalk level inside an interferometric instrument and ensure an instrumental stability that provides the necessary sensitivity through calibration procedures.

  6. Measurement-Based Interference in Quantum Computation

    International Nuclear Information System (INIS)

    The interference has been measured by the visibility in two-level systems, which, however, does not work for multi-level systems. We generalize a measure of the interference based on decoherence process, consistent with the visibility in qubit systems. By taking cluster states as examples, we show in the one-way quantum computation that the gate fidelity is proportional to the interference of the measured qubit and is inversely proportional to the interference of all register qubits. We also find that the interference increases with the number of the computing steps. So we conjecture that the interference may be the source of the speedup of the one-way quantum computation. (general)

  7. Measurement-Based Interference in Quantum Computation

    Science.gov (United States)

    Xu, You-Yang

    2013-09-01

    The interference has been measured by the visibility in two-level systems, which, however, does not work for multi-level systems. We generalize a measure of the interference based on decoherence process, consistent with the visibility in qubit systems. By taking cluster states as examples, we show in the one-way quantum computation that the gate fidelity is proportional to the interference of the measured qubit and is inversely proportional to the interference of all register qubits. We also find that the interference increases with the number of the computing steps. So we conjecture that the interference may be the source of the speedup of the one-way quantum computation.

  8. CDMA with interference cancellation for multiprobe missions

    Science.gov (United States)

    Divsalar, D.; Simon, M. K.

    1995-01-01

    Code division multiple-access spread spectrum has been proposed for use in future multiprobe/multispacecraft missions. This article considers a general parallel interference-cancellation scheme that significantly reduces the degradation effect of probe (user) interference but with a lesser implementation complexity than the maximum-likelihood technique. The scheme operates on the fact that parallel processing simultaneously removes from each probe (user) the total interference produced by the remaining most reliably received probes (users) accessing the channel. The parallel processing can be done in multiple stages. The proposed scheme uses tentative decision devices with different optimum thresholds at the multiple stages to produce the most reliably received data for generation and cancellation of probe/spacecraft interference. The one-stage interference cancellation was analyzed for two types of tentative decision devices, namely, hard and null zone decisions. Simulation results are given for one- and two-stage interference cancellation for equal as well as unequal received power probes.

  9. Collision-induced constructive quantum interference

    International Nuclear Information System (INIS)

    We theoretically study the collision-induced constructive quantum interference in an open four-level system with the density-matrix approach based on the experimental observation of constructive quantum interference between two transition pathways 3P1/2-5S (or 4D) and 3P3/2-5S (or 4D) via equal-frequency hybrid excitation in the Na2-Na system. The effects of the collision-induced coherent and incoherent decay rates and the ratio of the two transition dipole moments on the interference are analyzed. It is shown that through the incoherent process (collision), the coherence between a widely separated doublet and subsequent constructive quantum interference can be realized. The physical origin of the constructive interference can be seen clearly in the dressed-atom picture. The theoretical results can also be used to qualitatively explain the dependence of quantum interference on the experimental buffer gas pressure and sample temperature

  10. A method for describe the image of interference and diffraction

    Science.gov (United States)

    Zheng, Sheng

    2013-05-01

    In the process of exploring essence of light, Newton initially agreed with the particle interpretation of light while Huygens supported the wave theory. These two doctrines had been disputed in Newton's time. Until today this dispute has been carrying on. Why one particle has two forms. For solve this question, I do some experiments discover that the moving photons produce gravitation, and know that the light wave phenomenon is produced by gravitation. Then I came up with a new method to draw images of multi-pinhole diffraction patterns and their interference fringes.: given the perpendicular line for the line which links the nearest two pinholes, the point of intersection of this vertical line is quite right the image become on the screen. The more detail see below website: https://www.lap-publishing.com/catalog/details/store/gb/book/978-3-8473-2658-8/mechanism-of-interaction-in-moving-matter.

  11. GPS and GLONASS Radio Interference in Germany

    OpenAIRE

    Butsch, Felix

    1997-01-01

    The goal of the work described here was to search for interference sources that could pose a threat to the application of GPS for automatic airport approach and landing of aircraft. For this purpose field measurements were conducted in the vicinity of airports, radar facilities andother radio frequency transmitters throughout Germany,and interference resistance measurements of commercial GPS receivers were taken. An additional aim was to examine the interference problems of GLONASS signals. T...

  12. Modelling transcriptional interference and DNA looping in gene regulation.

    Science.gov (United States)

    Dodd, Ian B; Shearwin, Keith E; Sneppen, Kim

    2007-06-22

    We describe a hybrid statistical mechanical and dynamical approach for modelling the formation of closed, open and elongating complexes of RNA polymerase, the interactions of these polymerases to produce transcriptional interference, and the regulation of these processes by a DNA-binding and DNA-looping regulatory protein. As a model system, we have used bacteriophage 186, for which genetic, biochemical and structural studies have suggested that the CI repressor binds as a 14-mer to form alternative DNA-looped complexes, and activates lysogenic transcription indirectly by relieving transcriptional interference caused by the convergent lytic promoter. The modelling showed that the original mechanisms proposed to explain this relief of transcriptional interference are not consistent with the available in vivo reporter data. However, a good fit to the reporter data was given by a revised model that incorporates a novel predicted regulatory mechanism: that RNA polymerase bound at the lysogenic promoter protects itself from transcriptional interference by recruiting CI to the lytic promoter. This mechanism and various estimates of in vivo biochemical parameters for the 186 CI system should be testable. Our results demonstrate the power of mathematical modelling for the extraction of detailed biochemical information from in vivo data. PMID:17498740

  13. Coalitional Game Theory for Cooperative Interference Management in Femtocell Networks

    Directory of Open Access Journals (Sweden)

    Yuanyuan Shi

    2015-01-01

    Full Text Available Dense deployment of femtocells can cause serious intra-tier interference in femtocell networks. In this paper, a new cooperative interference management approach which allows the femtocell user equipment (FUE to merge into cooperative groups, that is, coalitions, for the uplink transmissions in a femtocell network is proposed, so as to reduce the intra-tier interference and improve the system performance. Taking into account the power cost for cooperation, we claim that all the FUEs are impossible to merge together, and we formulate the proposed cooperative problem as a coalitional game in partition form with an externality due to the interference between the formed coalitions. To get the solution, a novel distributed coalition formation algorithm that takes advantage of the characteristics of femtocell network and allows the FUEs to interact and individually decide on which coalitions to participate in is proposed. Furthermore, we analyze the convergence and stability of the proposed algorithm. Simulations are conducted to illustrate the behavior and the performance of the proposed coalition formation algorithm among FUEs. Results show that the proposed algorithm can improve the system performance with much lower complexity than some previously proposed coalition formation algorithms.

  14. Studies on aerodynamic interferences between the components of transport airplane using unstructured Navier-Stokes simulations

    International Nuclear Information System (INIS)

    It is well known that the aerodynamic interference flows widely exist between the components of conventional transport airplane, for example, the wing-fuselage juncture flow, wing-pylon-nacelle flow and tail-fuselage juncture flow. The main characteristic of these aerodynamic interferences is flow separation, which will increase the drag, reduce the lift and cause adverse influence on the stability and controllability of the airplane. Therefore, the modern civil transport designers should do their best to eliminate negative effects of aerodynamic interferences, which demands that the aerodynamic interferences between the aircraft components should be predicted and analyzed accurately. Today's CFD techniques provide us powerful and efficient analysis tools to achieve this objective. In this paper, computational investigations of the interferences between transport aircraft components have been carried out by using a viscous flow solver based on mixed element type unstructured meshes. (author)

  15. Magneto-induced Fano-like cavity interference in three-dimensional metamaterials

    Science.gov (United States)

    Pan, Xun-Yong; Wang, Gaofeng

    2016-08-01

    Fano-like cavity interference due to magneto-inductive coupling in metamaterial structure is demonstrated via a double Fabry–Perot cavity (DFPC) that consists of stacked multi-layered resonators. The induced magnetic field based destructive interference is observed in the transmission response of the DFPC system, which exhibits the Fano line shaped resonance. The retrieved real and imaginary parts of effective permeability and permittivity indicate strong magneto-induced dispersion with a group delay leading to the slow light effect. This finding provides an interesting mechanism to excite Fano resonances in metamaterial systems via magnetic interaction between resonators, which may enable new devices for slow light and sensing applications.

  16. INTERFERENCE OF COUNTERPROPAGATING SHOCK WAVES

    Directory of Open Access Journals (Sweden)

    P. V. Bulat

    2015-03-01

    -dynamic discontinuities, the intensities corresponding to the transition from regular to irregular interference were described. Numerical calculations of the shock-wave structure transformation in the conditions of hysteresis were performed. The results were compared with the experiments carried out by hydraulic analogy method. Practical significance. Results of the work complement well the theory of stationary gas-dynamic discontinuities interference and can be used at designing of perspective images of supersonic and hypersonic aircraft.

  17. Toosendanin interferes with pore formation of botulinum toxin type A in PC12 cell membrane

    Institute of Scientific and Technical Information of China (English)

    Mu-feng LI; Yu-liang SHI

    2006-01-01

    Aim: Botulinum neurotoxins (BoNT) abort the process of neurotransmitter release at presynaptic motor nerve terminals, causing muscle paralysis. The ability of botulinum toxin to produce its effect is dependent on the ability of the light chain to cleave the SNARE proteins associated with transmitter release. Translocation of the light chain protease through the heavy chain-formed channel is a pivotal step in the intoxication process. Toosendanin (TSN), a triterpenoid derivative extracted from a Chinese traditional medicine, has been demonstrated to be an effective cure for experimental botulism. This study was designed to explore the antibotulismic mechanisms of toosendanin. Methods: The inside-out singlechannel recording patch-clamp technique was used to record the BoNT/A-induced currents in the presence and absence of TSN. Results: Channel formation was delayed and the sizes of the channels were reduced in the TSN-treated PC12cell membrane. Conclusion: The antibotulismic effect of TSN might occur via interference with toxin translocation.

  18. IETS and quantum interference: propensity rules in the presence of an interference feature

    OpenAIRE

    Lykkebo, Jacob; Gagliardi, Alessio; Pecchia, Alessandro; Gemma C. Solomon

    2014-01-01

    Destructive quantum interference in single molecule electronics is an intriguing phe- nomenon; however, distinguishing quantum interference effects from generically low transmission is not trivial. In this paper, we discuss how quantum interference ef- fects in the transmission lead to either low current or a particular line shape in current-voltage curves, depending on the position of the interference feature. Sec- ondly, we consider how inelastic electron tunneling spectroscopy can be used ...

  19. A conclusive experiment to throw more light on 'light'

    International Nuclear Information System (INIS)

    We describe a new realization of Ghose, Home, Agarwal experiment on wave particle duality of light where some limitations of the former experiment, realized by Mizobuchi and Ohtake, are overcome. Our results clearly indicate that wave-particle complementarity must be understood between interference and 'whelcher weg' knowledge and not in a more general sense

  20. Asymptomatic Bacteriuria and Bacterial Interference.

    Science.gov (United States)

    Nicolle, Lindsay E

    2015-10-01

    Asymptomatic bacteriuria is very common. In healthy women, asymptomatic bacteriuria increases with age, from asymptomatic bacteriuria, irrespective of age or gender. The prevalence is very high in residents of long-term-care facilities, from 25% to 50% of women and 15% to 40% of men. Escherichia coli is the most frequent organism isolated, but a wide variety of other organisms may occur. Bacteriuria may be transient or persist for a prolonged period. Pregnant women with asymptomatic bacteriuria identified in early pregnancy and who are untreated have a risk of pyelonephritis later in pregnancy of 20% to 30%. Bacteremia is frequent in bacteriuric subjects following mucosal trauma with bleeding, with 5% to 10% of patients developing severe sepsis or septic shock. These two groups with clear evidence of negative outcomes should be screened for bacteriuria and appropriately treated. Asymptomatic bacteriuria in other populations is benign and screening and treatment are not indicated. Antimicrobial treatment has no benefits but is associated with negative outcomes including reinfection with antimicrobial resistant organisms and a short-term increased frequency of symptomatic infection post-treatment. The observation of increased symptomatic infection post-treatment, however, has led to active investigation of bacterial interference as a strategy to prevent symptomatic episodes in selected high risk patients. PMID:26542046

  1. Quantum theory of two-photon interference

    OpenAIRE

    Wu, Xiang-Yao; Zhang, Bo-Jun; Liu, Xiao-Jing; LI Hong; Zhang, Si-Qi; Jing WANG; Wu, Yi-Heng; Li, Jing-Wu

    2012-01-01

    In this paper, we study two-photon interference with the approach of photon quantum theory, with specific attention to the two-photon interference experiment carried out by Milena D'Angelo et al. (Phys. Rev. Lett 87:013602, 2001). We find the theoretical result is accordance with experiment data.

  2. Partial interference subspace rejection in CDMA systems

    DEFF Research Database (Denmark)

    Hansen, Henrik; Affes, Sofiene; Mewelstein, Paul

    2001-01-01

    Previously presented interference subspace rejection (ISR) proposed a family of new efficient multiuser detectors for CDMA. We reconsider in this paper the modes of ISR using decision feedback (DF). DF modes share similarities with parallel interference cancellation (PIC) but attempt to cancel...

  3. Interference and the Law of Energy Conservation

    Science.gov (United States)

    Drosd, Robert; Minkin, Leonid; Shapovalov, Alexander S.

    2014-01-01

    Introductory physics textbooks consider interference to be a process of redistribution of energy from the wave sources in the surrounding space resulting in constructive and destructive interferences. As one can expect, the total energy flux is conserved. However, one case of apparent non-conservation energy attracts great attention. Imagine that…

  4. Using Interference to Block RFID Tags

    DEFF Research Database (Denmark)

    Krigslund, Rasmus; Popovski, Petar; Pedersen, Gert Frølund;

    We propose a novel method to block RFID tags from responding, using intentional interference. We focus on the experimental evaluation, where we impose interference on the download and uplink, respectively. The results are positive, where modulated CCI shows most effective to block a tag....

  5. Electromagnetic Interference from the ILC Beams

    Energy Technology Data Exchange (ETDEWEB)

    Brown, LaVonda N.; /Norfolk State U. /SLAC

    2007-11-07

    Electromagnetic interference is an emerging problem of the future. This investigation analyzed the data collected from airborne radiation waves that caused electronic devices to fail. This investigation was set up at SLAC in End Station A and the data collected from the electromagnetic waves were received from antennas. In order to calibrate the antennas it required a signal generator to transmit the signals to the antenna and a digital oscilloscope to receive the radiation waves from the other antenna. The signal generator that was used was only able to generate signals between 1 and 1.45 GHz; therefore, the calibrations were not able to be completed. Instead, excel was used to create a curve fitting for the attenuation factors that were already factory calibrated. The function from the curve fitting was then used to extend the calibrations on the biconical and yagi antennas. A fast Fourier Transform was then ran in Matlab on the radiation waves received by the oscilloscope; in addition, the attenuation factors were calculated into the program to show the actual amplitudes of these radiation waves. For future research, the antennas will be manually calibrated and the results will be reanalyzed.

  6. Impulsive interference in communication channels and its mitigation by SPART and other nonlinear filters

    Science.gov (United States)

    Nikitin, Alexei V.; Epard, Marc; Lancaster, John B.; Lutes, Robert L.; Shumaker, Eric A.

    2012-12-01

    A strong digital communication transmitter in close physical proximity to a receiver of a weak signal can noticeably interfere with the latter even when the respective channels are tens or hundreds of megahertz apart. When time domain observations are made in the signal chain of the receiver between the first mixer and the baseband, this interference is likely to appear impulsive. The impulsive nature of this interference provides an opportunity to reduce its power by nonlinear filtering, improving the quality of the receiver channel. This article describes the mitigation, by a particular nonlinear filter, of the impulsive out-of-band (OOB) interference induced in High Speed Downlink Packet Access (HSDPA) by WiFi transmissions, protocols which coexist in many 3G smartphones and mobile hotspots. Our measurements show a decrease in the maximum error-free bit rate of a 1.95 GHz HSDPA receiver caused by the impulsive interference from an OOB 2.4 GHz WiFi transmission, sometimes down to a small fraction of the rate observed in the absence of the interference. We apply a nonlinear SPART filter to recover a noticeable portion of the lost rate and maintain an error-free connection under much higher levels of the WiFi interference than a receiver that does not contain such a filter. These measurements support our wider investigation of OOB interference resulting from digital modulation, which appears impulsive in a receiver, and its mitigation by nonlinear filters.

  7. Fundamental studies of interferences in ICP-MS

    International Nuclear Information System (INIS)

    Methods of temperature measurement by mass spectrometry have been critically reviewed. It was concluded that the most appropriate method depended critically on the availability of fundamental data, hence a database of fundamental spectroscopic constants, for diatomic ions which cause interferences in ICP-MS, was compiled. The equilibration temperature, calculated using the different methods and using various diatomic ions as the thermometric probes, was between c.a. 400 - 10,000 K in the central channel, and between c.a. 600 - 16,000 K when the plasma was moved 1.8 mm off-centre. The wide range in temperature reflected the range of temperature measurement methods and uncertainty in the fundamental data. Optical studies using a fibre optic connected to a monochromator were performed in order to investigate the presence of interferences both in the plasma and the interface region of the ICP-MS, and the influence of a shielded torch on these interferences. It was possible to determine the presence of some species in the plasma, such as the strongly bound metal oxides, however, no species other than OH were detected in the interface region of the ICP-MS. The OH rotational temperature within the interface region of the ICP-MS was calculated to be between 2,000 - 4,000 K. The effect of sampling depth, operating power, radial position and solvent loading, with and without the shielded torch, on the dissociation temperature of a variety of polyatomic interferences was investigated. These calculated temperatures were then used to elucidate the site of formation for different polyatomic interferences. Results confirmed that strongly bound ions such as MO+ were formed in the plasma, whereas weakly bound ions such as ArO+ were formed in the interface region due to gross deviation of the calculated temperatures from those expected for a system in thermal equilibrium. (author)

  8. Understanding quantum interference in General Nonlocality

    CERN Document Server

    Wanng, Hai-Jhun

    2010-01-01

    In this paper we attempt to give an understanding of quantum double-slit interference of fermions in the framework of General Nonlocality (GN) [J. Math. Phys. 49, 033513 (2008)] by studying the self-interaction of matter wave. From the metric of the GN, we derive a special formalism to interpret the interference contrast when the self-interaction is perturbative. According to the formalism, the characteristic of interference pattern is in agreement with experiment qualitatively. As examples, we apply the formalism to the cases governed by Schr\\"odinger current and Dirac current respectively, both of which are relevant to topology. The gap between these two cases corresponds to a spin-current effect, which is possible to test in the near future. In addition, a general interference formalism for both perturbative and non-perturbative self-interactions is presented. By analyzing the general formalism we predict that in the nonperturbative limit there is no interference at all.

  9. Improved CDMA Performance Using Parallel Interference Cancellation

    Science.gov (United States)

    Simon, Marvin; Divsalar, Dariush

    1995-01-01

    This report considers a general parallel interference cancellation scheme that significantly reduces the degradation effect of user interference but with a lesser implementation complexity than the maximum-likelihood technique. The scheme operates on the fact that parallel processing simultaneously removes from each user the interference produced by the remaining users accessing the channel in an amount proportional to their reliability. The parallel processing can be done in multiple stages. The proposed scheme uses tentative decision devices with different optimum thresholds at the multiple stages to produce the most reliably received data for generation and cancellation of user interference. The 1-stage interference cancellation is analyzed for three types of tentative decision devices, namely, hard, null zone, and soft decision, and two types of user power distribution, namely, equal and unequal powers. Simulation results are given for a multitude of different situations, in particular, those cases for which the analysis is too complex.

  10. Reproductive interference explains persistence of aggression between species

    Science.gov (United States)

    Drury, Jonathan P.; Okamoto, Kenichi W.; Anderson, Christopher N.; Grether, Gregory F.

    2015-01-01

    Interspecific territoriality occurs when individuals of different species fight over space, and may arise spontaneously when populations of closely related territorial species first come into contact. But defence of space is costly, and unless the benefits of excluding heterospecifics exceed the costs, natural selection should favour divergence in competitor recognition until the species no longer interact aggressively. Ordinarily males of different species do not compete for mates, but when males cannot distinguish females of sympatric species, females may effectively become a shared resource. We model how reproductive interference caused by undiscriminating males can prevent interspecific divergence, or even cause convergence, in traits used to recognize competitors. We then test the model in a genus of visually orienting insects and show that, as predicted by the model, differences between species pairs in the level of reproductive interference, which is causally related to species differences in female coloration, are strongly predictive of the current level of interspecific aggression. Interspecific reproductive interference is very common and we discuss how it may account for the persistence of interspecific aggression in many taxonomic groups. PMID:25740887

  11. Heterophilic antibody interference affecting multiple hormone assays: Is it due to rheumatoid factor?

    Science.gov (United States)

    Mongolu, Shiva; Armston, Annie E; Mozley, Erin; Nasruddin, Azraai

    2016-05-01

    Assay interference with heterophilic antibodies has been well described in literature. Rheumatoid factor is known to cause similar interference leading to falsely elevated hormone levels when measured by immunometric methods like enzyme-linked immunosorbent assay (ELISA) or multiplex immunoasays (MIA). We report a case of a 60-year-old male patient with a history of rheumatoid arthritis referred to our endocrine clinic for investigation of hypogonadism and was found to have high serum levels of LH, FSH, SHBG, Prolactin, HCG and TSH. We suspected assay interference and further tests were performed. We used Heteroblock tubes and PEG precipitation to eliminate the interference and the hormone levels post treatment were in the normal range. We believe the interference was caused by high serum levels of rheumatoid factor. Although he was treated with thyroxine for 3 years, we believe he may have been treated inappropriately as his Free T4 level was always normal despite high TSH due to assay interference. Our case illustrates the phenomenon of heterophilic antibody interference likely due to high levels of rheumatoid factor. It is essential for clinicians and endocrinologists in particular to be aware of this possibility when making treatment decisions in these groups of patients. PMID:26924790

  12. Preliminary study fo the interference of proteic compounds of radiopharmaceuticals in the test of lisadode amebocitos de limulus (LAL)

    CERN Document Server

    Aldana, C

    1997-01-01

    In this thesis the objective was evaluate the interference of proteic compounds of the radiopharmaceuticals in the test LAL (lisado of amebocitos de limulus) for this, macroagregates of albumina (MAA) was used with metilendifosfonato (MDP) as control that is the radiopharmaceutical more used in the nuclear medicine centers of the country. Initially preliminary test were carried out to assess if some of two radiopharmaceuticals would cause interference with LAL test, after the test was validated and finally routine tests were made. With the preliminary assays was concluded that proteic compounds did not cause interference (albumina with a concentration of 2 md/dl) with the MAA. However with the MDP cause interference with LAL test. The interference was eliminated with a dilution of 1:8 of the sample. Was concluded that the success of LAL test depends on conditions such as temperature, pH, constant incubation (no minimum variations) and that is a good test for quality control of the radiopharmaceuticals.

  13. Preliminary study fo the interference of proteic compounds of radiopharmaceuticals in the test of lisadode amebocitos de limulus (LAL)

    International Nuclear Information System (INIS)

    In this thesis the objective was evaluate the interference of proteic compounds of the radiopharmaceuticals in the test LAL (lisado of amebocitos de limulus) for this, macroagregates of albumina (MAA) was used with metilendifosfonato (MDP) as control that is the radiopharmaceutical more used in the nuclear medicine centers of the country. Initially preliminary test were carried out to assess if some of two radiopharmaceuticals would cause interference with LAL test, after the test was validated and finally routine tests were made. With the preliminary assays was concluded that proteic compounds did not cause interference (albumina with a concentration of 2 md/dl) with the MAA. However with the MDP cause interference with LAL test. The interference was eliminated with a dilution of 1:8 of the sample. Was concluded that the success of LAL test depends on conditions such as temperature, pH, constant incubation (no minimum variations) and that is a good test for quality control of the radiopharmaceuticals

  14. Improvement of Resonance Interference Treatment in STREAM

    Energy Technology Data Exchange (ETDEWEB)

    CHoi, Sooyoung; Khassenov, Azamat; Lee Deokjung [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2014-10-15

    The conventional resonance interference model simply adds the absorption XSs of resonance isotopes to the background XS. The Bondarenko iteration method performs iteration on it till effective XSs converge. However, the conventional models are not enough to consider the interference effects, which results in nonnegligible errors in computing effective XSs. The conventional methods assume that the absorption XSs are flat within an energy group, but the resonance interference occurs complicatedly within a coarse MG, therefore a way to solve this problem is to increase the number of resonance energy groups sufficiently, such as with the ultra-fine group (UFG) method. Recently research has been performed on UFG methods which solve the slowing down equation and then calculate the MG XS or the correction factor, but the UFG transport calculations cannot be practically used due to limited computing capacity. In addition, there are still problems such as geometric limitations and long computation time. In this paper, a new practical resonance interference method is presented which uses the resonance interference factor (RIF) method. However, unlike the original RIF method, this new method interpolates the RIFs in a pre-generated RIF library and corrects the effective XS, rather than solving the time consuming slowing down calculation. The new RIF method and conventional resonance interference methods have been implemented and compared in STREAM. The verification results using the proposed method show significant improvements of accuracy in treating the interference effect. A new resonance interference model based on the RIF library has been developed and verified. The method interpolates the RIF in the RIF library and uses it to treat the resonance interference effect. The RIF library method has been compared to the conventional resonance interference method and the Bondarenko iteration method. From the verification results, the RIF library method shows less than 73 pcm of

  15. Improvement of Resonance Interference Treatment in STREAM

    International Nuclear Information System (INIS)

    The conventional resonance interference model simply adds the absorption XSs of resonance isotopes to the background XS. The Bondarenko iteration method performs iteration on it till effective XSs converge. However, the conventional models are not enough to consider the interference effects, which results in nonnegligible errors in computing effective XSs. The conventional methods assume that the absorption XSs are flat within an energy group, but the resonance interference occurs complicatedly within a coarse MG, therefore a way to solve this problem is to increase the number of resonance energy groups sufficiently, such as with the ultra-fine group (UFG) method. Recently research has been performed on UFG methods which solve the slowing down equation and then calculate the MG XS or the correction factor, but the UFG transport calculations cannot be practically used due to limited computing capacity. In addition, there are still problems such as geometric limitations and long computation time. In this paper, a new practical resonance interference method is presented which uses the resonance interference factor (RIF) method. However, unlike the original RIF method, this new method interpolates the RIFs in a pre-generated RIF library and corrects the effective XS, rather than solving the time consuming slowing down calculation. The new RIF method and conventional resonance interference methods have been implemented and compared in STREAM. The verification results using the proposed method show significant improvements of accuracy in treating the interference effect. A new resonance interference model based on the RIF library has been developed and verified. The method interpolates the RIF in the RIF library and uses it to treat the resonance interference effect. The RIF library method has been compared to the conventional resonance interference method and the Bondarenko iteration method. From the verification results, the RIF library method shows less than 73 pcm of

  16. Improper Signaling on the Two-user SISO Interference Channel

    CERN Document Server

    Ho, Zuleita

    2012-01-01

    On a single-input-single-out (SISO) interference channel (IC), conventional non-cooperative strategies encourage players selfishly maximizing their transmit data rates, neglecting the deficit of performance caused by and to other players. In the case of proper complex Gaussian noise, the maximum entropy theorem shows that the best-response strategy is to transmit with proper signals (symmetric complex Gaussian symbols). However, such equilibrium leads to degrees-of-freedom zero due to the saturation of interference. With improper signals (asymmetric complex Gaussian symbols), an extra freedom of optimization is available. In this paper, we study the impact of improper signaling on the 2-user SISO IC. We explore the achievable rate region with non-cooperative strategies by computing a Nash equilibrium of a non-cooperative game with improper signaling. Then, assuming cooperation between players, we study the achievable rate region of improper signals. We propose the usage of improper rank one signals for their ...

  17. Anisotropic photoconductivity and current deflection induced in Bi12SiO20 by high contrast interference pattern

    DEFF Research Database (Denmark)

    Kukhtarev, N.V.; Lyuksyutov, S; Buchhave, Preben; Caulfield, H.J.; Vasnetsov, M.

    1996-01-01

    We have predicted and observed an anisotropic photocurrent induced in the cubic crystal Bi/sub 12/SiO/sub 20/ by a high-contrast interference pattern. The transverse current detected when the interference pattern is tilted is caused by deflection of the direct current generated by an external...... voltage applied to the crystal...

  18. Young-type interferences with electrons basics and theoretical challenges in molecular collision systems

    CERN Document Server

    Frémont, François

    2014-01-01

    Since the discovery that atomic-size particles can be described as waves, many interference experiments have been realized with electrons to demonstrate their wave behavior. In this book, after describing the different steps that led to the present knowledge, we focus on the strong link existing between photon and electron interferences, highlighting the similarities and the differences. For example, the atomic centers of a hydrogen molecule are used to mimic the slits in the Young's famous interference experiment with light. We show, however, that the basic time-dependent ionization theories that describe these Young-type electron interferences are not able to reproduce the experiment. This crucial point remains a real challenge for theoreticians in atomic collision physics.

  19. Dynamic control of coherent pulses via Fano-type interference in asymmetric double quantum wells

    International Nuclear Information System (INIS)

    We study the temporal and spatial dynamics of two light pulses, a probe and a switch, propagating through an asymmetric double quantum well where tunneling-induced quantum interference may be observed. When such an interference takes place, in the absence of the switch, the quantum well is transparent to the probe which propagates over sufficiently long distances at very small group velocities. In the presence of a relatively strong switch, however, the probe pulse is absorbed due to the quenching of tunneling-induced quantum interference. The probe may be made to vanish even when switch and probe are somewhat delayed with respect to one another. Conversely, our asymmetric double quantum well may be rendered either opaque or transparent to the switch pulse. Such a probe-switch 'reciprocity' can be used to devise a versatile all-optical quantum interference-based solid-state switch for optical communication devices

  20. Applying contextual interference to the Pawlata roll.

    Science.gov (United States)

    Smith, P J; Davies, M

    1995-12-01

    Contextual interference is manipulated by changing the practice order of a number of similar motor tasks, so that the learning context of each interferes with that of the other. The effect has been found to generalize to baseball batting, badminton serving and volleyball skills. The present study examined whether this practice technique could be applied to a Pawlata roll in a kayak. The study was further motivated by the fact that many instructors in Britain currently advocate learning the Pawlata roll in one direction only to a criterion of accuracy, thereafter transferring to the opposite direction. Contextual interference literature predicts that skill retention would be better served by practising on alternate sides. Accordingly, 16 undergraduate students with no kayaking experience were randomly allocated to either a low contextual interference group, which followed U'ren's (1993) recommendations, or a high contextual interference group, which practised the skill on alternate sides. The high contextual interference group took less time to acquire the skill, and were also quicker to achieve successful performance in retention (full roll) and transfer (half roll) tests, regardless of the direction of the roll, 1 week later. The time savings in practice were not expected, as acquisition under high contextual interference was improved rather than impaired. This finding suggests that bilateral transfer was increased by randomizing practice. These results are worthy of further investigation, in that they suggest that the recommended training methods may not be optimal. PMID:8850571

  1. Wave and Particle in Molecular Interference Lithography

    CERN Document Server

    Juffmann, Thomas; Geyer, Philipp; Major, Andras G; Deachapunya, Sarayut; Ulbricht, Hendrik; Arndt, Markus; 10.1103/PhysRevLett.103.263601

    2010-01-01

    The wave-particle duality of massive objects is a cornerstone of quantum physics and a key property of many modern tools such as electron microscopy, neutron diffraction or atom interferometry. Here we report on the first experimental demonstration of quantum interference lithography with complex molecules. Molecular matter-wave interference patterns are deposited onto a reconstructed Si(111) 7x7 surface and imaged using scanning tunneling microscopy. Thereby both the particle and the quantum wave character of the molecules can be visualized in one and the same image. This new approach to nanolithography therefore also represents a sensitive new detection scheme for quantum interference experiments.

  2. Multiple Beam Interference in a Relativistic Medium

    CERN Document Server

    Rakshit, Supantho

    2016-01-01

    In this paper the effects of movement of optical medium on the conditions of interference, transmission pattern and performance of spectroscopes like Febry Perot are investigated. Firstly, the conditions of constructive and destructive interference of two beams in a moving thin film is derived. Then the idea is expanded to multiple beam interference and a new modified equation of the transmission pattern is formulated with the help of basic Lorentz transformation of space and time co-ordinates and electromagnetic field. Further the new effective resolving power of a Febry Perot spectroscope is determined using this idea, which has a moving dielectric medium in its etalon.

  3. Sub-wavelength interference in macroscopic observation

    International Nuclear Information System (INIS)

    We study the generalized Young's double-slit interference for the beam produced in the spontaneous parametric down-conversion (SPDC). It has been found that the sub-wavelength interference can occur macroscopically in both the two-photon intensity measurement and the single-photon spatial intensity-correlation measurement. The former refers to the quantum entanglement and the latter originates from the thermal spatial correlation. We show the visibility and the strength of the interference fringe related to the SPDC interaction, which may provide a strong sub-wavelength lithography with a moderate visibility in practical application

  4. Coulomb continuum effects in molecular interference

    International Nuclear Information System (INIS)

    We study analytically the interference in photoionization of molecules by monochromatic and attosecond x-ray pulses. Using the hydrogen molecule ion as a test case, we obtain simple analytical factors describing the Coulomb continuum molecular interference. We show how chirped attosecond pulse with a frequency-dependent phase and broad bandwidth creates the continuous photoelectron spectra. Due to the long-range Coulomb forces, the plane wave interference patterns are strongly modified by two-centre Coulomb continuum even at large internuclear distances. (letter to the editor)

  5. Interference of Fano-Rashba conductance dips

    International Nuclear Information System (INIS)

    We study the interference of two tunable Rashba regions in a quantum wire with one propagating mode. The transmission dips (Fano-Rashba dips) of the two regions either cross or anti-cross, depending on the distance between the two regions. For large separations we find Fabry-Perot oscillations due to the interference of forwards and backwards propagating modes. At small separations overlapping evanescent modes play a prominent role, leading to an enhanced transmission and destroying the conductance dip. Analytical expressions in scattering matrix theory are given and the relevance of the interference effect in a device is discussed.

  6. Gas Interference in Sucker Rod Pump

    Science.gov (United States)

    Samad, Abdus

    2010-10-01

    Commonly used artificial lift or dewatering system is sucker rod pump and gas interference of the pump is the biggest issue in the oil and gas industry. Gas lock or fluid pound problems occur due to the gas interference when the pump has partially or completely unfilled plunger barrel. There are several techniques available in the form of patents to solve these problems but those techniques have positive as well as negative aspects. Some of the designs rely on the leakage and some of the designs rely on the mechanical arrangements etc to break the gas lock. The present article compares the existing gas interference handling techniques.

  7. CORRELATED INTERFERENCE CANCELLATION FOR IR-UWB

    Institute of Scientific and Technical Information of China (English)

    Zhang Zaichen; Yu Xutao; Bi Guangguo

    2008-01-01

    In this letter,we propose a hybrid analog/digital detection algorithm,the Correlated Interference Cancellation (CIC) algorithm,for Impulse Radio Ultra-WideBand (IR-UWB) system. The CIC algorithm correlates received signal with its delayed versions in the analog domain and samples the correlation output at the symbol rate. The symbol rate samples are processed in the digital domain to perform interference cancellation. Therefore,CIC works for high data rate systems with heavy InterSymbol Interference (ISI). Simulation results show that CIC achieves good performance in typical UWB channels.

  8. Stack emission monitoring using non-dispersive infrared spectroscopy with an optimized nonlinear absorption cross interference correction algorithm

    Directory of Open Access Journals (Sweden)

    Y. W. Sun

    2013-08-01

    Full Text Available In this paper, we present an optimized analysis algorithm for non-dispersive infrared (NDIR to in situ monitor stack emissions. The proposed algorithm simultaneously compensates for nonlinear absorption and cross interference among different gases. We present a mathematical derivation for the measurement error caused by variations in interference coefficients when nonlinear absorption occurs. The proposed algorithm is derived from a classical one and uses interference functions to quantify cross interference. The interference functions vary proportionally with the nonlinear absorption. Thus, interference coefficients among different gases can be modeled by the interference functions whether gases are characterized by linear or nonlinear absorption. In this study, the simultaneous analysis of two components (CO2 and CO serves as an example for the validation of the proposed algorithm. The interference functions in this case can be obtained by least-squares fitting with third-order polynomials. Experiments show that the results of cross interference correction are improved significantly by utilizing the fitted interference functions when nonlinear absorptions occur. The dynamic measurement ranges of CO2 and CO are improved by about a factor of 1.8 and 3.5, respectively. A commercial analyzer with high accuracy was used to validate the CO and CO2 measurements derived from the NDIR analyzer prototype in which the new algorithm was embedded. The comparison of the two analyzers show that the prototype works well both within the linear and nonlinear ranges.

  9. Near-field imaging of interference pattern of counterpropagating evanescent waves

    DEFF Research Database (Denmark)

    Bozhevolnyi, Sergey I.; Bozhevolnaya, Elena A.

    1999-01-01

    It is generally accepted that measurement of of the contrast of the intensity interference pattern formed by two counterpropagating evanescent waves can be used to characterize the resolving power of a collection near-field microscope. We argue that, if the light collected by a fiber probe...

  10. Interference Channels with One Cognitive Transmitter

    CERN Document Server

    Cao, Yi

    2009-01-01

    This paper studies the problem of interference channels with one cognitive transmitter (ICOCT) where "cognitive" is defined from both the noncausal and causal perspectives. For the noncausal ICOCT, referred to as interference channels with degraded message sets (IC-DMS), we propose a new achievable rate region that generalizes existing achievable rate regions for IC-DMS. In the absence of the noncognitive transmitter, the proposed region coincides with Marton's region for the broadcast channel. Based on this result, the capacity region of a class of semi-deterministic IC-DMS is established. For the causal ICOCT, due to the complexity of the channel model, we focus primarily on the cognitive Z interference channel (ZIC), where the interference link from the cognitive transmitter to the primary receiver is assumed to be absent due to practical design considerations. Capacity bounds for such channels in different parameter regimes are obtained and the impact of such causal cognitive ability is carefully studied....

  11. Fight plant pests using RNA interference

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ CAS plant physiologists have recently invented a plant-mediated RNA interference (RNAi) technique to effectively and specifically control the gene expression of the cotton bollworm (Helicoverpa armigera) and stunt its growth.

  12. Small Aircraft RF Interference Path Loss Measurements

    Science.gov (United States)

    Nguyen, Truong X.; Koppen, Sandra V.; Ely, Jay J.; Szatkowski, George N.; Mielnik, John J.; Salud, Maria Theresa P.

    2007-01-01

    Interference to aircraft radio receivers is an increasing concern as more portable electronic devices are allowed onboard. Interference signals are attenuated as they propagate from inside the cabin to aircraft radio antennas mounted on the outside of the aircraft. The attenuation level is referred to as the interference path loss (IPL) value. Significant published IPL data exists for transport and regional category airplanes. This report fills a void by providing data for small business/corporate and general aviation aircraft. In this effort, IPL measurements are performed on ten small aircraft of different designs and manufacturers. Multiple radio systems are addressed. Along with the typical worst-case coupling values, statistical distributions are also reported that could lead to more meaningful interference risk assessment.

  13. Small Aircraft RF Interference Path Loss

    Science.gov (United States)

    Nguyen, Truong X.; Koppen, Sandra V.; Ely, Jay J.; Szatkowski, George N.; Mielnik, John J.; Salud, Maria Theresa P.

    2007-01-01

    Interference to aircraft radio receivers is an increasing concern as more portable electronic devices are allowed onboard. Interference signals are attenuated as they propagate from inside the cabin to aircraft radio antennas mounted on the outside of the aircraft. The attenuation level is referred to as the interference path loss (IPL) value. Significant published IPL data exists for transport and regional category airplanes. This report fills a void by providing data for small business/corporate and general aviation aircraft. In this effort, IPL measurements are performed on ten small aircraft of different designs and manufacturers. Multiple radio systems are addressed. Along with the typical worst-case coupling values, statistical distributions are also reported that could lead to better interference risk assessment.

  14. Signal interference RF photonic bandstop filter.

    Science.gov (United States)

    Aryanfar, Iman; Choudhary, Amol; Shahnia, Shayan; Pagani, Mattia; Liu, Yang; Marpaung, David; Eggleton, Benjamin J

    2016-06-27

    In the microwave domain, signal interference bandstop filters with high extinction and wide stopbands are achieved through destructive interference of two signals. Implementation of this filtering concept using RF photonics will lead to unique filters with high performance, enhanced tuning range and reconfigurability. Here we demonstrate an RF photonic signal interference filter, achieved through the combination of precise synthesis of stimulated Brillouin scattering (SBS) loss with advanced phase and amplitude tailoring of RF modulation sidebands. We achieve a square-shaped, 20-dB extinction RF photonic filter over a tunable bandwidth of up to 1 GHz with a central frequency tuning range of 16 GHz using a low SBS loss of ~3 dB. Wideband destructive interference in this novel filter leads to the decoupling of the filter suppression from its bandwidth and shape factor. This allows the creation of a filter with all-optimized qualities. PMID:27410650

  15. Parallel interference cancellation for CDMA applications

    Science.gov (United States)

    Divsalar, Dariush (Inventor); Simon, Marvin K. (Inventor); Raphaeli, Dan (Inventor)

    1997-01-01

    The present invention provides a method of decoding a spread spectrum composite signal, the composite signal comprising plural user signals that have been spread with plural respective codes, wherein each coded signal is despread, averaged to produce a signal value, analyzed to produce a tentative decision, respread, summed with other respread signals to produce combined interference signals, the method comprising scaling the combined interference signals with a weighting factor to produce a scaled combined interference signal, scaling the composite signal with the weighting factor to produce a scaled composite signal, scaling the signal value by the complement of the weighting factor to produce a leakage signal, combining the scaled composite signal, the scaled combined interference signal and the leakage signal to produce an estimate of a respective user signal.

  16. Assessment of life interference in anxious children

    DEFF Research Database (Denmark)

    Rapee, Ronald; Thastum, Mikael; Chavira, Denise

    associated with mental disorders arguably the key issue of relevance to both sufferers and therapists. Yet among both childhood and adult disorders the primary focus in terms of assessment and treatment is on symptoms, with far less attention paid to the impact of these symptoms on the sufferer's life. This...... imbalance has particularly characterised research on child anxiety where few studies have examined either the impact of anxiety disorders on children's lives or the effects of treatments on life interference. To some extent this lack of attention has come from a lack of well developed measures to assess...... life interference derived from symptoms of anxiety. Broader and more general life interference measures tend to have minimal relevance for children with anxiety disorders. The current paper will describe two measures of life interference that have been developed at the Centre for Emotional Health...

  17. Radio VLBI and the quantum interference paradox

    CERN Document Server

    Singal, Ashok K

    2016-01-01

    We address here the question of interference of radio signals from astronomical sources like distant quasars, in a very long baseline interferometer (VLBI), where two (or more) distantly located radio telescopes (apertures), receive simultaneous signal from the sky. In an equivalent optical two-slit experiment, it is generally argued that for the photons involved in the interference pattern on the screen, it is not possible, even in principle, to ascertain which of the two slits a particular photon went through. It is argued that any procedure to ascertain this destroys the interference pattern. But in the case of the modern radio VLBI, it is a routine matter to record the phase and amplitude of the voltage outputs from the two radio antennas on a recording media separately and then do the correlation between the two recorded signals later in an offline manner. Does this not violate the quantum interference principle? We provide a resolution of this problem here.

  18. Conducted Electromagnetic Interference (EMI) in Smart Grids

    CERN Document Server

    Smolenski, Robert

    2012-01-01

    As power systems develop to incorporate renewable energy sources, the delivery systems may be disrupted by the changes involved. The grid’s technology and management must be developed to form Smart Grids between consumers, suppliers and producers. Conducted Electromagnetic Interference (EMI) in Smart Grids considers the specific side effects related to electromagnetic interference (EMI) generated by the application of these Smart Grids. Conducted Electromagnetic Interference (EMI) in Smart Grids presents specific EMI conducted phenomena as well as effective methods to filter and handle them once identified. After introduction to Smart Grids, the following sections cover dedicated methods for EMI reduction and potential avenues for future development including chapters dedicated to: •potential system services, •descriptions of the EMI spectra shaping methods, •methods of interference voltage compensation, and theoretical analysis of experimental results.  By focusing on these key aspects, Conducted El...

  19. Automotive radar - investigation of mutual interference mechanisms

    Science.gov (United States)

    Goppelt, M.; Blöcher, H.-L.; Menzel, W.

    2010-09-01

    In the past mutual interference between automotive radar sensors has not been regarded as a major problem. With an increasing number of such systems, however, this topic is receiving more and more attention. The investigation of mutual interference and countermeasures is therefore one topic of the joint project "Radar on Chip for Cars" (RoCC) funded by the German Federal Ministry of Education and Research (BMBF). RoCC's goal is to pave the way for the development of high-performance, low-cost 79 GHz radar sensors based on Silicon-Germanium (SiGe) Monolithic Microwave Integrated Circuits (MMICs). This paper will present some generic interference scenarios and report on the current status of the analysis of interference mechanisms.

  20. Optical Layout Analysis of Polarization Interference Imaging Spectrometer by Jones Calculus in View of both Optical Throughput and Interference Fringe Visibility

    Science.gov (United States)

    Zhang, Xuanni; Zhang, Chunmin

    2013-01-01

    A polarization interference imaging spectrometer based on Savart polariscope was presented. Its optical throughput was analyzed by Jones calculus. The throughput expression was given, and clearly showed that the optical throughput mainly depended on the intensity of incident light, transmissivity, refractive index and the layout of optical system. The simulation and analysis gave the optimum layout in view of both optical throughput and interference fringe visibility, and verified that the layout of our former design was optimum. The simulation showed that a small deviation from the optimum layout influenced interference fringe visibility little for the optimum one, but influenced severely for others, so a small deviation is admissible in the optimum, and this can mitigate the manufacture difficulty. These results pave the way for further research and engineering design.

  1. Interference Alignment with Analog Channel State Feedback

    OpenAIRE

    Ayach, Omar El; Heath Jr, Robert W.

    2010-01-01

    Interference alignment (IA) is a multiplexing gain optimal transmission strategy for the interference channel. While the achieved sum rate with IA is much higher than previously thought possible, the improvement often comes at the cost of requiring network channel state information at the transmitters. This can be achieved by explicit feedback, a flexible yet potentially costly approach that incurs large overhead. In this paper we propose analog feedback as an alternative to limited feedback ...

  2. Visual Working Memory Capacity and Proactive Interference

    OpenAIRE

    Hartshorne, Joshua K.

    2008-01-01

    BACKGROUND: Visual working memory capacity is extremely limited and appears to be relatively immune to practice effects or the use of explicit strategies. The recent discovery that visual working memory tasks, like verbal working memory tasks, are subject to proactive interference, coupled with the fact that typical visual working memory tasks are particularly conducive to proactive interference, suggests that visual working memory capacity may be systematically under-estimated. METHODOLOGY/P...

  3. Fading and interference mitigation in wireless communications

    CERN Document Server

    Panic, Stefan; Anastasov, Jelena; Spalevic, Petar

    2013-01-01

    The rapid advancement of various wireless communication system services has created the need to analyze the possibility of their performance improvement. Introducing the basic principles of digital communications performance analysis and its mathematical formalization, Fading and Interference Mitigation in Wireless Communications will help you stay up to date with recent developments in the performance analysis of space diversity reception over fading channels in the presence of cochannel interference.The book presents a unified method for computing the performance of digital communication sys

  4. Quantified Interference for a While Language

    OpenAIRE

    Clark, D. (David); Hunt, S.; Malacaria, P.

    2005-01-01

    We show how information theory can be used to give a quantitative definition of interference between variables in imperative programming languages. In this paper we focus on a particular case of this definition of interference: leakage of information from private variables to public ones in While language programs. The major result of the paper is a quantitative analysis for this language that employs a use-definition graph to calculate bounds on the leakage into each variable.

  5. Indonesian Young Adults’ Interference in Translating

    Directory of Open Access Journals (Sweden)

    Indra Nugraha

    2013-09-01

    Full Text Available Interference has become a crucial matter to recognize in bilingual and multilingual communities. The phenomenon of interference has affected how we as at least members of bilingual or even multilingual communities speak to the others. As the members of multilingual communities, the Indonesian young adults receive many influences in the way they speak and understand languages. However, these influences often lead to the wrong way. In this case, many Indonesian young adults understand English cursing inappropriately. This misunderstanding may lead to the abuse of English cursing in daily conversations. This article provides the insight of how interference affects the way the Indonesian young adults understand English cursing. Using the questionnaire-based research method, this articles tends to find out the attitudes of Indonesian young adults towards translating English cursing to Indonesian, which interference that affects the translation process of English cursing resulting to the inappropriate understanding of English cursing among Indonesian young adults, and which suitable translation method for translating English cursing to Indonesian. Apparently, the present writer has found out that there are two attitudes towards translating English cursing to Indonesian, that is, first, the English cursing is translated to the Indonesian cursing and second, the English cursing is translated literaly to Indonesian. Further, the present writer has found out that the interlingual interference has affected the translation process of English cursing to Indonesian and the suitable method for translating English cursing to Indonesian is adaptation based on Newmark (1988.Keywords: Interference, Multilingual communities, Translating English cursing, Indonesian young adults

  6. Investigation of Interference Models for RFID Systems.

    Science.gov (United States)

    Zhang, Linchao; Ferrero, Renato; Gandino, Filippo; Rebaudengo, Maurizio

    2016-01-01

    The reader-to-reader collision in an RFID system is a challenging problem for communications technology. In order to model the interference between RFID readers, different interference models have been proposed, mainly based on two approaches: single and additive interference. The former only considers the interference from one reader within a certain range, whereas the latter takes into account the sum of all of the simultaneous interferences in order to emulate a more realistic behavior. Although the difference between the two approaches has been theoretically analyzed in previous research, their effects on the estimated performance of the reader-to-reader anti-collision protocols have not yet been investigated. In this paper, the influence of the interference model on the anti-collision protocols is studied by simulating a representative state-of-the-art protocol. The results presented in this paper highlight that the use of additive models, although more computationally intensive, is mandatory to improve the performance of anti-collision protocols. PMID:26861326

  7. Investigation of Interference Models for RFID Systems

    Directory of Open Access Journals (Sweden)

    Linchao Zhang

    2016-02-01

    Full Text Available The reader-to-reader collision in an RFID system is a challenging problem for communications technology. In order to model the interference between RFID readers, different interference models have been proposed, mainly based on two approaches: single and additive interference. The former only considers the interference from one reader within a certain range, whereas the latter takes into account the sum of all of the simultaneous interferences in order to emulate a more realistic behavior. Although the difference between the two approaches has been theoretically analyzed in previous research, their effects on the estimated performance of the reader-to-reader anti-collision protocols have not yet been investigated. In this paper, the influence of the interference model on the anti-collision protocols is studied by simulating a representative state-of-the-art protocol. The results presented in this paper highlight that the use of additive models, although more computationally intensive, is mandatory to improve the performance of anti-collision protocols.

  8. Cross-limb interference during motor learning.

    Directory of Open Access Journals (Sweden)

    Benedikt Lauber

    Full Text Available It is well known that following skill learning, improvements in motor performance may transfer to the untrained contralateral limb. It is also well known that retention of a newly learned task A can be degraded when learning a competing task B that takes place directly after learning A. Here we investigate if this interference effect can also be observed in the limb contralateral to the trained one. Therefore, five different groups practiced a ballistic finger flexion task followed by an interfering visuomotor accuracy task with the same limb. Performance in the ballistic task was tested before the training, after the training and in an immediate retention test after the practice of the interference task for both the trained and the untrained hand. After training, subjects showed not only significant learning and interference effects for the trained limb but also for the contralateral untrained limb. Importantly, the interference effect in the untrained limb was dependent on the level of skill acquisition in the interfering motor task. These behavioural results of the untrained limb were accompanied by training specific changes in corticospinal excitability, which increased for the hemisphere ipsilateral to the trained hand following ballistic training and decreased during accuracy training of the ipsilateral hand. The results demonstrate that contralateral interference effects may occur, and that interference depends on the level of skill acquisition in the interfering motor task. This finding might be particularly relevant for rehabilitation.

  9. Ethical Perspectives on RNA Interference Therapeutics

    Directory of Open Access Journals (Sweden)

    Mette Ebbesen, Thomas G. Jensen, Svend Andersen, Finn Skou Pedersen

    2008-01-01

    Full Text Available RNA interference is a mechanism for controlling normal gene expression which has recently begun to be employed as a potential therapeutic agent for a wide range of disorders, including cancer, infectious diseases and metabolic disorders. Clinical trials with RNA interference have begun. However, challenges such as off-target effects, toxicity and safe delivery methods have to be overcome before RNA interference can be considered as a conventional drug. So, if RNA interference is to be used therapeutically, we should perform a risk-benefit analysis. It is ethically relevant to perform a risk-benefit analysis since ethical obligations about not inflicting harm and promoting good are generally accepted. But the ethical issues in RNA interference therapeutics not only include a risk-benefit analysis, but also considerations about respecting the autonomy of the patient and considerations about justice with regard to the inclusion criteria for participation in clinical trials and health care allocation. RNA interference is considered a new and promising therapeutic approach, but the ethical issues of this method have not been greatly discussed, so this article analyses these issues using the bioethical theory of principles of the American bioethicists, Tom L. Beauchamp and James F. Childress.

  10. Power and Contention Control Scheme: As a Good Candidate for Interference Modeling in Cognitive Radio Network

    Directory of Open Access Journals (Sweden)

    Ireyuwa E. Igbinosa

    2015-10-01

    Full Text Available Due to the ever growing need for spectrum, the cognitive radio (CR has been proposed to improve the radio spectrum utilization. In this scenario, the secondary users (SU are permitted to share spectrum with the licensed primary users (SU with a strict condition that they do not cause harmful interference to the cognitive network. In this work, we have proposed an interference model for cognitive radio network that utilizes power or contention control interference management schemes. We derived the probability density function (PDF with the power control scheme, where the power of transmission of the CR transmitter is guided by the power control law and also with contention control scheme that has a fixed transmission power for all CR transmitter controlled by a contention control protocol. This protocol makes a decision on which CR transmitter can transmit at any point in time. In this work, we have shown that power and contention control schemes are good candidates for interference modeling in cognitive radio system. The impact of the unknown location of the primary receiver on the resulting interference generated by the CR transmitters was investigated and the results shows that the challenges of the hidden primary receivers lead to higher CR-primary interference in respect to higher mean and variance. Finally, the presented results show power control and the contention control scheme are good candidates in reducing the interference generated by the cognitive radio network.

  11. Scalar Potential Model of light

    Science.gov (United States)

    Hodge, John

    2008-04-01

    Some observations of light are inconsistent with a wave--like model. Other observations of light are inconsistent with a particle--like model. A model of light is proposed wherein Newton's and Democritus's speculations are combined with the cosmological scalar potential model (SPM). The SPM was tested by confrontation with observations of galaxy HI rotation curves (RCs), asymmetric RCs, redshift, discrete redshift, galaxy central mass, and central velocity dispersion; and with observations of the Pioneer Anomaly. The resulting model of light will be tested by numerical simulation of a photon behaving in a wave-like manner such as diffusion, interference, reflection, spectrography, and the Afshar experiment. Although the SPM light model requires more work, early results are beginning to emerge that suggest possible tests because a few predictions are inconsistent with both the current particle and wave models of light and that suggest a re-interpretation of the equations of quantum mechanics.

  12. On the Feasibility of Linear Interference Alignment for MIMO Interference Broadcast Channels with Constant Coefficients

    OpenAIRE

    Liu, Tingting; Yang, Chenyang

    2012-01-01

    In this paper, we analyze the feasibility of linear interference alignment (IA) for multi-input-multi-output (MIMO) interference broadcast channel (MIMO-IBC) with constant coefficients. We pose and prove the necessary conditions of linear IA feasibility for general MIMO-IBC. Except for the proper condition, we find another necessary condition to ensure a kind of irreducible interference to be eliminated. We then prove the necessary and sufficient conditions for a special class of MIMO-IBC, wh...

  13. Interference with the host haemostatic system by schistosomes.

    Directory of Open Access Journals (Sweden)

    Mirjam M Mebius

    Full Text Available Schistosomes, parasitic flatworms that cause the tropical disease schistosomiasis, are still a threat. They are responsible for 200 million infections worldwide and an estimated 280,000 deaths annually in sub-Saharan Africa alone. The adult parasites reside as pairs in the mesenteric or perivesicular veins of their human host, where they can survive for up to 30 years. The parasite is a potential activator of blood coagulation according to Virchow's triad, because it is expected to alter blood flow and endothelial function, leading to hypercoagulability. In contrast, hepatosplenic schistosomiasis patients are in a hypocoagulable and hyperfibrinolytic state, indicating that schistosomes interfere with the haemostatic system of their host. In this review, the interactions of schistosomes with primary haemostasis, secondary haemostasis, fibrinolysis, and the vascular tone will be discussed to provide insight into the reduction in coagulation observed in schistosomiasis patients. Interference with the haemostatic system by pathogens is a common mechanism and has been described for other parasitic worms, bacteria, and fungi as a mechanism to support survival and spread or enhance virulence. Insight into the mechanisms used by schistosomes to interfere with the haemostatic system will provide important insight into the maintenance of the parasitic life cycle within the host. This knowledge may reveal new potential anti-schistosome drug and vaccine targets. In addition, some of the survival mechanisms employed by schistosomes might be used by other pathogens, and therefore, these mechanisms that interfere with host haemostasis might be a broad target for drug development against blood-dwelling pathogens. Also, schistosome antithrombotic or thrombolytic molecules could form potential new drugs in the treatment of haemostatic disorders.

  14. Outage analysis of interference-limited systems using STBC with co-channel MIMO interferers

    Institute of Scientific and Technical Information of China (English)

    Yongzhao LI; Leonard J.CIMINI,JR.; Nageen HIMAYAT

    2009-01-01

    The performance of Space-Time Block Coding (STBC) with co-channel MIMO interference is investigated.For an interference-limited environment, the closed-form ex-pressions for the probability density functions of the signal-to-interference ratio are derived and applied to analyze the outage probability with three typical types of co-channel MIMO interferers: STBC, open-loop spatial multiplexing and closed-loop spatial multiplexing. Both theoretical anal-yses and simulation results show that the performance of STBC is independent of the MIMO modes used in the in-terfering links.

  15. Calculating Model of Interference Amount for Miniaturized Gear and Shaft Shrink Fit

    Institute of Scientific and Technical Information of China (English)

    JIN Xin; ZHANG Zhi-jing; YE Xin; LI Zhong-xin

    2006-01-01

    Based on miniaturized components' characteristics, the method of assembling miniaturized gear and shaft together with corresponding calculating model of the interference amount are proposed. On the basis of main effecting factors analysis on the gear and shaft assembling interference amount, calculating formula including all factors effective on the interference amount necessary for reliable system running was built up. The methods of reverse calculating theoretical model was used to build up the equivalent simulation model of the theoretical one, together with simulation verification and case study for calculating formula. The results show that the cold assembling method is applicable for miniaturized gear and shaft, but in the assembling process,the interference amount compensating the shape error of contacting surfaces takes a large proportion, which is the main cause of stress variance on contacting surfaces.

  16. Analysis and improvements of module incidental interference faults of water level control system pressurize NPP

    International Nuclear Information System (INIS)

    In Daya Bay nuclear power plant, there have been many times that the module used to value the water level outputs a small pulse interference when the pressurizer water level control system is in operation, and the interference exists only in analog storage operation module, which can directly impact the control of the water level of the pressurizer, causing the water level fluctuations and adversely affecting the safe operation of the reactor. This paper analyzes the module incidental interference faults of the water level control system of the NPP pressurizer from the point view of the system control and design of module hardware, and finds out the reasons by the system simulation experiment and power supply circuit test. It is suggested to further improve on the design of hardware loops, add more inductance and capacity to eliminate the interference. (authors)

  17. Interference removals on Pd, Ru and Au with ICP-QQQ-MS in PGE RM

    Science.gov (United States)

    Nadeem Hussain Bokhari, Syed; Meisel, Thomas; Walkner, Christoph

    2015-04-01

    Gold and platinum group elements (PGE) are essential industrial precious metals with high world demand due to their unique properties. Struggle for natural exploration of PGE is on great pace and recycling from industrial wastes, electronics and catalytic convertor is on the rise for PGE supply chain. Along with these developments it is becoming more challenging for analytical chemists to determine gold and PGE out of complex matrix which causes severe interferences. The current state of art is online analysis coupled with chromatographic separation of interferences. The ICP-QQQ-MS Agilent 8800 has the capability of using multi tunes and mass shifts. We aim to remove interferences on Pd+ (for direct and isotope dilution analysis) Au+ and Ru+ in lieu of chemical separations. YO+, SrOH+, ZnAr+, NiAr+, ZrO+, CuAr+, MoO+ , Ru+and Cd+ are expected interferences on Pd+ while Au+ is interfered by TaO+, HfOH+, GdAr+ and 102Ru+ ,104Ru+ by 102Pd+ ,104Pd+ etc. Initial test were performed on pure solutions of 1mg/l (interfering elements): 1 ng/l (Pd, Ru & Au) respectively. The outcomes of initial tests were applied on PGE reference material (RM) WMG-1 and SARM-7 (digested with Na2O2 sintering). The results obtained show that YO+, SrOH+ interfere (104Pd,105Pd), 104 Ru+ on (104Pd), ZnAr+ has slight interference on (104Pd and106Pd), ZrO+, NiAr+, CuAr+ interferences are negligible, MoO+ has severe interference on (108Pd, 110Pd) and that Cd+ has severe isobaric interference on (106Pd,108Pd, 110Pd). These interference have been removed by formation of Pd(NH3)3+complex. The TaO+, HfOH+ and GdAr+ interferences on Au+ are best removed by formation of Au(NH3)+ and Au(NH3)2+ complexes. 102Pd+,104Pd+interference on 102Ru+ ,104Ru+ can be removed by formation of Ru(NH3)4+ and RuO+ compounds. The results obtained comply with certified values of RM. The developed method is being tested on low concentration PGE reference materials. References: Sugiyama, N. " Removal of complex spectral

  18. Lens-fibre interference proposed to monitor a transparent sheet's thickness variations

    Science.gov (United States)

    Ramadan, W. A.; Shams El-Din, M. A.; Wahba, H. H.; El-Tawargy, A. S.; Hamza, A. A.

    2014-12-01

    The lens-fibre interference (LFI) technique is used for monitoring thickness variations of a known refractive index transparent sheet. The sheet is inserted in the light path between the cylindrical lens and the fibre, in the LFI optical arrangement. A phase change and a geometrical shift for the beam passed through the sheet are observed. The presence of the sheet is considered in the ray tracing model which explained LFI (J. Opt. A: Pure Appl. Opt. 2:234-238, 2000). So, we are able to reproduce the interference pattern, in the presence of the sheet, theoretically. Depending on the width of the incident light spot on the cylindrical lens, a three beams interference could be observed. A development of the previous model is presented taking into account the third interfered beam. The produced interference pattern is a good indicator to the sheet's thickness variations, especially when we considered the occurred three beams interference. Some investigations about the uncertainty analyses in our measurements are presented.

  19. Longitudinal correlation properties of an optical field with broad angular and frequency spectra and their manifestation in interference microscopy

    International Nuclear Information System (INIS)

    The results of theoretical and experimental studies of the longitudinal correlation properties of an optical field with broad angular and frequency spectra and manifestations of these properties in interference microscopy are presented. The joint and competitive influence of the angular and frequency spectra of the object-probing field on the longitudinal resolution and on the amplitude of the interference microscope signals from the interfaces between the media inside a multilayer object is demonstrated. The method of compensating the so-called defocusing effect that arises in the interference microscopy using objectives with a large numerical aperture is experimentally demonstrated, which consists in using as a light source in the interference microscope an illuminating interferometer with a frequency-broadband light source. This method of compensation may be used as the basis of simultaneous determination of geometric thickness and refractive index of media forming a multilayer object. (optical fields)

  20. Simulation of Genetic Algorithm: Traffic Light Efficiency

    OpenAIRE

    Lienert, Eric

    2015-01-01

    Traffic is a problem in many urban areas worldwide. Traffic flow is dictated by certain devices such as traffic lights. The traffic lights signal when each lane is able to pass through the intersection. Often, static schedules interfere with ideal traffic flow. The purpose of this project was to find a way to make intersections controlled with traffic lights more efficient. This goal was accomplished through the creation of a genetic algorithm, which enhances an input algorithm through geneti...

  1. Interference Mitigation for Cyber-Physical Wireless Body Area Network System Using Social Networks.

    Science.gov (United States)

    Zhang, Zhaoyang; Wang, Honggang; Wang, Chonggang; Fang, Hua

    2013-06-01

    Wireless body area networks (WBANs) are cyber-physical systems (CPS) that have emerged as a key technology to provide real-time health monitoring and ubiquitous healthcare services. WBANs could operate in dense environments such as in a hospital and lead to a high mutual communication interference in many application scenarios. The excessive interferences will significantly degrade the network performance including depleting the energy of WBAN nodes more quickly, and even eventually jeopardize people's lives due to unreliable (caused by the interference) healthcare data collections. Therefore, It is critical to mitigate the interference among WBANs to increase the reliability of the WBAN system while minimizing the system power consumption. Many existing approaches can deal with communication interference mitigation in general wireless networks but are not suitable for WBANs due to their ignoring the social nature of WBANs. Unlike the previous research, we for the first time propose a power game based approach to mitigate the communication interferences for WBANs based on the people's social interaction information. Our major contributions include: (1) model the inter-WBANs interference, and determine the distance distribution of the interference through both theoretical analysis and Monte Carlo simulations; (2) develop social interaction detection and prediction algorithms for people carrying WBANs; (3) develop a power control game based on the social interaction information to maximize the system's utility while minimize the energy consumption of WBANs system. The extensive simulation results show the effectiveness of the power control game for inter-WBAN interference mitigation using social interaction information. Our research opens a new research vista of WBANs using social networks. PMID:25436180

  2. A simple method of measuring profiles of thin liquid films for microfluidics experiments by means of interference reflection microscopy

    OpenAIRE

    Berejnov, V.; Li, D.

    2010-01-01

    A simple method was developed to observe the interference patterns of the light reflected by the interfaces of thin liquid films. Employing a fluorescent microscope with epi-illumination, we collected the 2D patterns of interference fringes containing information of the liquid film topography at microscale. To demonstrate the utility of the proposed visualization method we developed a framework for reconstructing the profiles of liquid films by analysing the reflected interferograms numerical...

  3. Enhanced quantitative phase imaging in self-interference digital holographic microscopy using an electrically focus tunable lens

    OpenAIRE

    Schubert, Robin; Vollmer, Angelika; Ketelhut, Steffi; Kemper, Björn

    2014-01-01

    Self-interference digital holographic microscopy (DHM) has been found particular suitable for simplified quantitative phase imaging of living cells. However, a main drawback of the self-interference DHM principle are scattering patterns that are induced by the coherent nature of the laser light which affect the resolution for detection of optical path length changes. We present a simple and efficient technique for the reduction of coherent disturbances in quantitative phase images. Therefore,...

  4. Interference of wedge-shaped protrusions on the faces of a Griffith crack in biaxial stress. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Boulet, J.A.M. [Tennessee Univ., Knoxville, TN (United States)

    1992-04-01

    An initial investigation of the influence of protrusion interference on the fracture toughness required to prevent unstable propagation of a Griffith crack in a brittle material is described. The interference is caused by relative shear displacement of the crack faces when subjected to remote biaxial stress with neither principal stress parallel to the crack. It is shown that for room temperature cracks smaller than about one centimeter in silicon carbide, or about one millimeter in silicon nitride, the presence of interference changes the fracture stress. A mathematical model based on linear elasticity solutions and including multiple interference sites at arbitrarily specified positions on the crack is presented. Computations of the change in required fracture toughness and its dependence on wedge geometry (size and vertex angle), applied stresses (orientation and magnitude), and location of the interference site are discussed. Results indicate that a single interference site has only a slight effect on required toughness. However, the influence of interference increases monotonically with the number of interference sites. The two-dimensional model described herein is not accurate when the interference sites are closely spaced.

  5. Remote sensing of nearshore wave interference

    Science.gov (United States)

    Smit, P. B.; Bland, R.; Janssen, T. T.; Laughlin, B.

    2016-05-01

    Wave focusing of energetic swell fields can result in small-scale variations associated with coherent interference that can be important for nearshore circulation and beach dynamics. However, coherent interference is difficult to measure with conventional in situ instruments and is not accounted for in operational wave models. As a result, such effects are generally ignored. In this work, we analyze X-band radar observations collected at Ocean Beach, San Francisco using a Wigner-Ville or coupled-mode spectrum, to show how long-dwell remote sensing technology allows us to identify coherent wave interference. Our analysis demonstrates that during energetic swell events, the nearshore wave field consists of two noncollinear, but coherent, swell patterns that originate from the same offshore source but are directionally separated due to refraction over the San Francisco Bar. The length scale of the associated alongshore wave height variability (200 m) is consistent with the wavenumber separation obtained from the coupled mode analysis. This confirms that the small-scale variability is primarily due to coherent interference. In addition, our analysis shows that the shoreline exhibits a strong localized response near the radar site on the 200 m scale, which suggests that coherent interference effects can affect wave-driven nearshore transport processes and localized erosion.

  6. General Quantum Interference Principle and Duality Computer

    Institute of Scientific and Technical Information of China (English)

    LONG Gui-Lu

    2006-01-01

    In this article, we propose a general principle of quantum interference for quantum system, and based on this we propose a new type of computing machine, the duality computer, that may outperform in principle both classical computer and the quantum computer. According to the general principle of quantum interference, the very essence of quantum interference is the interference of thesub-waves of the quantum system itself. A quantum system considered here can be any quantum system: a single microscopic particle, a composite quantum system such as an atom or a molecule, or a loose collection of a few quantum objects such as two independent photons. In the duality computer,the wave of the duality computer is split into several sub-waves and they pass through different routes, where different computing gate operations are performed. These sub-waves are then re-combined to interfere to give the computational results. The quantum computer, however, has only used the particle nature of quantum object. In a duality computer,it may be possible to find a marked item from an unsorted database using only a single query, and all NP-complete problems may have polynomial algorithms. Two proof-of-the-principle designs of the duality computer are presented:the giant molecule scheme and the nonlinear quantum optics scheme. We also propose thought experiment to check the related fundamental issues, the measurement efficiency of a partial wave function.

  7. Multiple Fano interferences in a plasmonic metamolecule consisting of asymmetric metallic nanodimers

    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, Minnesota 55812 (United States); Alù, Andrea [Department of Electrical and Computer Engineering, University of Texas at Austin, Austin, Texas 77812 (United States); Bai, Jing [Department of Electrical Engineering, University of Minnesota, Duluth, Minnesota 55812 (United States)

    2015-01-14

    We theoretically explore signatures of plasmonic Fano interferences in a subwavelength plasmonic metamolecule consisting of closely packed asymmetric gold nanodimers, which lead to the possibility of generating multiple Fano resonances in the scattering spectrum. This spectral feature is attributed to the interference between bright and dark plasmonic modes sustained by the constituent nanodimers. The excited Fano dips are highly sensitive in both wavelength and amplitude to geometry and background dielectric medium. The tunability of induced Fano resonances associated with enhanced electric fields from the visible to infrared region provides promising applications, particularly in refractive index sensing, light-trapping, and photon up-converting.

  8. Young-type interference in projectile-electron loss in energetic ion-molecule collisions

    International Nuclear Information System (INIS)

    We propose an alternative and very promising scenario for studying the Young-type-interference phenomena in energetic ion-molecule collisions. In such a scenario, we focus on the energy spectra of electrons that are ionized from the bound states of fast moving projectiles. We argue that under certain conditions these (projectile) electrons interact mainly with the nuclei and inner-shell electrons of atoms forming the molecule. Due to their compact localization in space and distinct separation from each other, these molecular centers play a role similar to that of optical slits in light scattering leading to pronounced interference patterns in electron energy distributions.

  9. Multiple Fano interferences in a plasmonic metamolecule consisting of asymmetric metallic nanodimers

    International Nuclear Information System (INIS)

    We theoretically explore signatures of plasmonic Fano interferences in a subwavelength plasmonic metamolecule consisting of closely packed asymmetric gold nanodimers, which lead to the possibility of generating multiple Fano resonances in the scattering spectrum. This spectral feature is attributed to the interference between bright and dark plasmonic modes sustained by the constituent nanodimers. The excited Fano dips are highly sensitive in both wavelength and amplitude to geometry and background dielectric medium. The tunability of induced Fano resonances associated with enhanced electric fields from the visible to infrared region provides promising applications, particularly in refractive index sensing, light-trapping, and photon up-converting

  10. Hanbury-Brown and Twiss effect without quantum interference in photon counting regime

    CERN Document Server

    Bai, Bin; Chen, Hui; Zheng, Huai bin; Liu, Jian bin; Liu, Rui feng; Wang, Yun long; Xu, Zhuo; Li, Fuli

    2016-01-01

    Usually HBT effect can be interpreted by classical (intensity fluctuation correlation) and quantum (interference of two-photon probability amplitudes) theories properly at the same time. In this manuscript, we report a deliberately designed experiment in which two chaotic light beams has the same intensity fluctuation but mutual-orthogonal polarizations to each other so there will be no interference of two-photon probability amplitudes. Classical and quantum theory give different predictions on if there should be HBT (photon bunching) effect or not in the experiment. The experiment results are used to test the two different predictions. At the end, both the temporal and spatial HBT effects are observed.

  11. Light Pollution

    Science.gov (United States)

    Riegel, Kurt W.

    1973-01-01

    Outdoor lighting is light pollution which handicaps certain astronomical programs. Protective measures must be adopted by the government to aid observational astronomy without sacrificing legitimate outdoor lighting needs. (PS)

  12. Digital Light

    OpenAIRE

    Cubitt, Sean; Palmer, Daniel; Tkacz, Nathaniel

    2015-01-01

    Light symbolises the highest good, it enables all visual art, and today it lies at the heart of billion-dollar industries. The control of light forms the foundation of contemporary vision. Digital Light brings together artists, curators, technologists and media archaeologists to study the historical evolution of digital light-based technologies. Digital Light provides a critical account of the capacities and limitations of contemporary digital light-based technologies and techniques by tracin...

  13. Analysing Self Interference Cancellation in Full Duplex Radios

    DEFF Research Database (Denmark)

    Mahmood, Nurul Huda; Shafique Ansari, Imran; Berardinelli, Gilberto;

    2016-01-01

    interference power is modelled as a noise-like constant level interference floor. However, experimental validations have shown that the self interference power is in practice a random variable depending on a number of factors such as the surrounding wireless environment and the degree of interference...

  14. Collisional quantum interference on rotational energy transfer: physical interpretation of the differential interference angle

    Institute of Scientific and Technical Information of China (English)

    Li Yong-Qing; Li Jian; Ma Feng-Cai

    2006-01-01

    Collisional quantum interference (CQI) on the intramolecular rotational energy transfer is observed in an experiment with a static cell, and the integral interference angles are measured. To obtain more accurate information, an experiment with a molecular beam is carried out, and thereby the relationship between the differential interference angle and the scattering angle is obtained. Based on the first-Born approximation of time-dependent perturbation theory,the theoretical model of CQI is developed in an atom-diatom system in the condition of the molecular beam, with the long-range interaction potential taken into account. The method of measuring correctly the differential interference angle is presented. The tendencies of the differential interference angle changing with the impact parameter and relative velocity are discussed. The theoretical model presented here is important for understanding or performing the experiment in the molecular beam.

  15. Cross-limb Interference during motor learning

    DEFF Research Database (Denmark)

    Lauber, Benedikt; Jensen, Jesper Lundbye; Keller, Martin;

    2013-01-01

    It is well known that following skill learning, improvements in motor performance may transfer to the untrained contralateral limb. It is also well known that retention of a newly learned task A can be degraded when learning a competing task B that takes place directly after learning A. Here we...... investigate if this interference effect can also be observed in the limb contralateral to the trained one. Therefore, five different groups practiced a ballistic finger flexion task followed by an interfering visuomotor accuracy task with the same limb. Performance in the ballistic task was tested before the...... training, after the training and in an immediate retention test after the practice of the interference task for both the trained and the untrained hand. After training, subjects showed not only significant learning and interference effects for the trained limb but also for the contralateral untrained limb...

  16. Time and interference: Effects on working memory.

    Science.gov (United States)

    Botto, Marta; Palladino, Paola

    2016-05-01

    This study tested predictions from the time-based resource-sharing (TBRS) model with a classical verbal working memory (WM) task, where target and non-target information interfere strongly with each other. Different predictions can be formulated according to the dominant perspectives (TBRS and interference hypothesis) on the role of inhibitory control in WM task performance. Here, we aimed to trace the activation of irrelevant information, examining priming effects in a lexical decision task immediately following WM recall. Results indicate the roles of both time and interference constraints in determining task performance. In particular, the role of time available seemed crucial at the highest WM loads (i.e., 3 and 4 memoranda). These were also associated with a higher activation of no-longer-relevant information but, in this case, independently from time available for processing. PMID:26085338

  17. Nonclassical Paths in Quantum Interference Experiments

    Science.gov (United States)

    Sawant, Rahul; Samuel, Joseph; Sinha, Aninda; Sinha, Supurna; Sinha, Urbasi

    2014-09-01

    In a double slit interference experiment, the wave function at the screen with both slits open is not exactly equal to the sum of the wave functions with the slits individually open one at a time. The three scenarios represent three different boundary conditions and as such, the superposition principle should not be applicable. However, most well-known text books in quantum mechanics implicitly and/or explicitly use this assumption that is only approximately true. In our present study, we have used the Feynman path integral formalism to quantify contributions from nonclassical paths in quantum interference experiments that provide a measurable deviation from a naive application of the superposition principle. A direct experimental demonstration for the existence of these nonclassical paths is difficult to present. We find that contributions from such paths can be significant and we propose simple three-slit interference experiments to directly confirm their existence.

  18. Non-classical paths in interference experiments

    CERN Document Server

    Sawant, Rahul; Sinha, Aninda; Sinha, Supurna; Sinha, Urbasi

    2014-01-01

    In a double slit interference experiment, the wave function at the screen with both slits open is not exactly equal to the sum of the wave functions with the slits individually open one at a time. The three scenarios represent three different boundary conditions and as such, the superposition principle should not be applicable. However, most well known text books in quantum mechanics implicitly and/or explicitly use this assumption which is only approximately true. In our present study, we have used the Feynman path integral formalism to quantify contributions from non-classical paths in quantum interference experiments which provide a measurable deviation from a naive application of the superposition principle. A direct experimental demonstration for the existence of these non-classical paths is hard. We find that contributions from such paths can be significant and we propose simple three-slit interference experiments to directly confirm their existence.

  19. Interference Channels with Correlated Receiver Side Information

    CERN Document Server

    Liu, Nan; Goldsmith, Andrea J; Poor, H Vincent

    2008-01-01

    The problem of joint source-channel coding in transmitting independent sources over interference channels with correlated receiver side information is studied. When each receiver has side information correlated with its own desired source, it is shown that source-channel code separation is optimal. When each receiver has side information correlated with the interfering source, sufficient conditions for reliable transmission are provided based on a joint source-channel coding scheme using the superposition encoding and partial decoding idea of Han and Kobayashi. When the receiver side information is a deterministic function of the interfering source, source-channel code separation is again shown to be optimal. As a special case, for a class of Z-interference channels, when the side information of the receiver facing interference is a deterministic function of the interfering source, necessary and sufficient conditions for reliable transmission are provided in the form of single letter expressions. As a byprodu...

  20. Electromagnetic Interference on Large Wind Turbines

    Directory of Open Access Journals (Sweden)

    Florian Krug

    2009-11-01

    Full Text Available Electromagnetic interference (EMI can both affect and be transmitted by mega-watt wind turbines. This paper provides a general overview on EMI with respect to mega-watt wind turbines. Possibilities of measuring all types of electromagnetic interference are shown. Electromagnetic fields resulting from a GSM transmitter mounted on a mega-watt wind turbine will be analyzed in detail. This cellular system operates as a real-time communication link. The method-of-moments is used to analytically describe the electro-magnetic fields. The electromagnetic interference will be analyzed under the given boundary condition with a commercial simulation tool. Different transmitter positions are judged on the basis of their radiation patterns. The principal EMI mechanisms are described and taken into consideration.

  1. On Interference of Chinese with ELL

    Institute of Scientific and Technical Information of China (English)

    九曼

    2011-01-01

    It is popularly admitted that the foreign language learning is strongly influenced by learners' first language.Generally speaking,the interference of Chinese with ELL is divided into negative transfer and positive transfer,which are manifested at various levels during ELL.The thesis aims to show the interference of Chinese with ELL,with the approach of qualitative analysis,the paper is arranged into Part Ⅰ:Introduction; Part Ⅱ:The Contrast between ELL and Chinese Language Acquisition; Part Ⅲ:The Influence of Chinese on ELL:Part Ⅵ:Conclusion.Being aware of the interference of Chinese with ELL will help students overcome the obstacles and promote ELL.

  2. Multichannel interference mitigation methods in radio astronomy

    CERN Document Server

    Leshem, A; Boonstra, A J; Leshem, Amir; Veen, Alle-Jan van der; Boonstra, Albert-Jan

    2000-01-01

    Radio-astronomical observations are increasingly corrupted by RF interference, and online detection and filtering algorithms are becoming essential. To facilitate the introduction of such techniques into radio astronomy, we formulate the astronomical problem in an array signal processing language, and give an introduction to some elementary algorithms from that field. We consider two topics in detail: interference detection by rank estimation of short-term covariance matrices, and spatial filtering by subspace estimation and projection. We discuss experimental data collected at the Westerbork radio telescope, and illustrate the effectiveness of the space-time detection and blanking process on the recovery of a 3C48 absorption line in the presence of GSM mobile telephony interference.

  3. Bargaining and the MISO Interference Channel

    Directory of Open Access Journals (Sweden)

    Matthew Nokleby

    2009-01-01

    Full Text Available We examine the MISO interference channel under cooperative bargaining theory. Bargaining approaches such as the Nash and Kalai-Smorodinsky solutions have previously been used in wireless networks to strike a balance between max-sum efficiency and max-min equity in users' rates. However, cooperative bargaining for the MISO interference channel has only been studied extensively for the two-user case. We present an algorithm that finds the optimal Kalai-Smorodinsky beamformers for an arbitrary number of users. We also consider joint scheduling and beamformer selection, using gradient ascent to find a stationary point of the Kalai-Smorodinsky objective function. When interference is strong, the flexibility allowed by scheduling compensates for the performance loss due to local optimization. Finally, we explore the benefits of power control, showing that power control provides nontrivial throughput gains when the number of transmitter/receiver pairs is greater than the number of transmit antennas.

  4. Frequent video game players resist perceptual interference.

    Directory of Open Access Journals (Sweden)

    Aaron V Berard

    Full Text Available Playing certain types of video games for a long time can improve a wide range of mental processes, from visual acuity to cognitive control. Frequent gamers have also displayed generalized improvements in perceptual learning. In the Texture Discrimination Task (TDT, a widely used perceptual learning paradigm, participants report the orientation of a target embedded in a field of lines and demonstrate robust over-night improvement. However, changing the orientation of the background lines midway through TDT training interferes with overnight improvements in overall performance on TDT. Interestingly, prior research has suggested that this effect will not occur if a one-hour break is allowed in between the changes. These results have suggested that after training is over, it may take some time for learning to become stabilized and resilient against interference. Here, we tested whether frequent gamers have faster stabilization of perceptual learning compared to non-gamers and examined the effect of daily video game playing on interference of training of TDT with one background orientation on perceptual learning of TDT with a different background orientation. As a result, we found that non-gamers showed overnight performance improvement only on one background orientation, replicating previous results with the interference in TDT. In contrast, frequent gamers demonstrated overnight improvements in performance with both background orientations, suggesting that they are better able to overcome interference in perceptual learning. This resistance to interference suggests that video game playing not only enhances the amplitude and speed of perceptual learning but also leads to faster and/or more robust stabilization of perceptual learning.

  5. Interference Alignment with Incomplete CSIT Sharing

    OpenAIRE

    De Kerret, Paul; Gesbert, David

    2012-01-01

    In this work, we study the impact of having only incomplete channel state information at the transmitters (CSIT) over the feasibility of interference alignment (IA) in a K-user MIMO interference channel (IC). Incompleteness of CSIT refers to the perfect knowledge at each transmitter (TX) of only a sub-matrix of the global channel matrix, where the sub-matrix is specific to each TX. This paper investigates the notion of IA feasibility for CSIT configurations being as incomplete as possible, as...

  6. Sensorimotor Interference When Reasoning About Described Environments

    Science.gov (United States)

    Avraamides, Marios N.; Kyranidou, Melina-Nicole

    The influence of sensorimotor interference was examined in two experiments that compared pointing with iconic arrows and verbal responding in a task that entailed locating target-objects from imagined perspectives. Participants studied text narratives describing objects at locations around them in a remote environment and then responded to targets from memory. Results revealed only minor differences between the two response modes suggesting that bodily cues do not exert severe detrimental interference on spatial reasoning from imagined perspective when non-immediate described environments are used. The implications of the findings are discussed.

  7. Interference-free ultrasonic level measuring sensor

    International Nuclear Information System (INIS)

    To avoid interference phenomena depending on the level, an ultrasonic level measuring sensor is proposed, which has an envelope tube around the path of the ultrasonic signal to prevent reflection. An ultrasonic transducer suspended by means of a linkage on a flange is additionally provided with a corrugated hose or a sintered metal tube around the path of the ultrasonic signal. A reference element necessary to raise the accuracy can be fitted in a cutout of the envelope tube. This device makes very precise measurement of the level possible without variations in the accuracy of measurement depending on the level, as interference due to shunt reflection is prevented. (orig./HP)

  8. Gathering algorithms on paths under interference constraints

    OpenAIRE

    Bermond, Jean-Claude; Correa, Ricardo; Yu, Min-Li

    2006-01-01

    International audience We study the problem of gathering information from the nodes of a multi-hop radio network into a pre-determined destination node under interference constraints which are modeled by an integer d 1, so that any node within distance d of a sender cannot receive calls from any other sender. A set of calls which do not interfere with each other is referred to as a round. We give algorithms and lower bounds on the minimum number of rounds for this problem, when the network...

  9. Control of exciton transport using quantum interference

    Science.gov (United States)

    Lusk, Mark T.; Stafford, Charles A.; Zimmerman, Jeramy D.; Carr, Lincoln D.

    2015-12-01

    It is shown that quantum interference can be employed to create an exciton transistor. An applied potential gates the quasiparticle motion and also discriminates between quasiparticles of differing binding energy. When implemented within nanoscale assemblies, such control elements could mediate the flow of energy and information. Quantum interference can also be used to dissociate excitons as an alternative to using heterojunctions. A finite molecular setting is employed to exhibit the underlying discrete, two-particle, mesoscopic analog to Fano antiresonance. Selected entanglement measures are shown to distinguish regimes of behavior which cannot be resolved from population dynamics alone.

  10. Phonon interference effects in molecular junctions

    International Nuclear Information System (INIS)

    We study coherent phonon transport through organic, π-conjugated molecules. Using first principles calculations and Green's function methods, we find that the phonon transmission function in cross-conjugated molecules, like meta-connected benzene, exhibits destructive quantum interference features very analogous to those observed theoretically and experimentally for electron transport in similar molecules. The destructive interference features observed in four different cross-conjugated molecules significantly reduce the thermal conductance with respect to linear conjugated analogues. Such control of the thermal conductance by chemical modifications could be important for thermoelectric applications of molecular junctions

  11. Phonon interference effects in molecular junctions

    Energy Technology Data Exchange (ETDEWEB)

    Markussen, Troels, E-mail: troels.markussen@gmail.com [Center for Atomic-scale Materials Design (CAMD), Department of Physics, Technical University of Denmark, DK-2800 Kgs. Lyngby (Denmark)

    2013-12-28

    We study coherent phonon transport through organic, π-conjugated molecules. Using first principles calculations and Green's function methods, we find that the phonon transmission function in cross-conjugated molecules, like meta-connected benzene, exhibits destructive quantum interference features very analogous to those observed theoretically and experimentally for electron transport in similar molecules. The destructive interference features observed in four different cross-conjugated molecules significantly reduce the thermal conductance with respect to linear conjugated analogues. Such control of the thermal conductance by chemical modifications could be important for thermoelectric applications of molecular junctions.

  12. Visualizing light with electrons

    Science.gov (United States)

    Fitzgerald, J. P. S.; Word, R. C.; Koenenkamp, R.

    2014-03-01

    In multiphoton photoemission electron microscopy (nP-PEEM) electrons are emitted from surfaces at a rate proportional to the surface electromagnetic field amplitude. We use 2P-PEEM to give nanometer scale visualizations of light of diffracted and waveguide fields around various microstructures. We use Fourier analysis to determine the phase and amplitude of surface fields in relation to incident light from the interference patterns. To provide quick and intuitive simulations of surface fields, we employ two dimensional Fresnel-Kirchhoff integration, a technique based on freely propagating waves and Huygens' principle. We find generally good agreement between simulations and experiment. Additionally diffracted wave simulations exhibit greater phase accuracy, indicating that these waves are well represented by a two dimensional approximation. The authors gratefully acknowledge funding of this research by the US-DOE Basic Science Office under Contract DE-FG02-10ER46406.

  13. Teaching Diffraction of Light and Electrons: Classroom Analogies to Classic Experiments

    Science.gov (United States)

    Velentzas, Athanasios

    2014-01-01

    Diffraction and interference are phenomena that demonstrate the wave nature of light and of particles. Experiments relating to the diffraction/interference of light can easily be carried out in an educational lab, but it may be impossible to perform experiments involving electrons because of the lack of specialized equipment needed for such…

  14. WOW: light print, light propel, light point

    DEFF Research Database (Denmark)

    Glückstad, Jesper; Bañas, Andrew Rafael; Aabo, Thomas;

    2012-01-01

    anywhere in a sample at any orientation using real-time 3D optical micromanipulation with six degrees of freedom. One of the key aspects of our demonstrated WOWs is the change in direction of in-coupled light and the marked increase in numerical aperture of the out-coupled light. Hence, each light...... propelled WOW can tap from a relatively broad incident beam and generate a much more tightly confined light at its tip. The presentation contains both numerical simulations related to the propagation of light through a WOW and preliminary experimental demonstrations on our BioPhotonics Workstation...

  15. Cue-independent memory impairment by reactivation-coupled interference in human declarative memory.

    Science.gov (United States)

    Zhu, Zijian; Wang, Yingying; Cao, Zhijun; Chen, Biqing; Cai, Huaqian; Wu, Yanhong; Rao, Yi

    2016-10-01

    Memory is a dynamic process. While memory becomes increasingly resistant to interference after consolidation, a brief reactivation renders it unstable again. Previous studies have shown that interference, when applied upon reactivation, impairs the consolidated memory, presumably by disrupting the reconsolidation of the memory. However, attempts have failed in disrupting human declarative memory, raising a question about whether declarative memory becomes unstable upon reactivation. Here, we used a double-cue/one-target paradigm, which associated the same target with two different cues in initial memory formation. Only one cue/target association was later reactivated and treated with behavioral interference. Our results showed, for the first time, that reactivation-coupled interference caused cue-independent memory impairment that generalized to other cues associated with the memory. Critically, such memory impairment appeared immediately after interference, before the reconsolidation process was completed, suggesting that common manipulations of reactivation-coupled interference procedures might disrupt other processes in addition to the reconsolidation process in human declarative memory. PMID:27389345

  16. Perspectives for quantum interference with biomolecules and biomolecular clusters

    Science.gov (United States)

    Geyer, P.; Sezer, U.; Rodewald, J.; Mairhofer, L.; Dörre, N.; Haslinger, P.; Eibenberger, S.; Brand, C.; Arndt, M.

    2016-06-01

    Modern quantum optics encompasses a wide field of phenomena that are either related to the discrete quantum nature of light, the quantum wave nature of matter or light–matter interactions. We here discuss new perspectives for quantum optics with biological nanoparticles. We focus in particular on the prospects of matter-wave interferometry with amino acids, nucleotides, polypeptides or DNA strands. We motivate the challenge of preparing these objects in a ‘biomimetic’ environment and argue that hydrated molecular beam sources are promising tools for quantum-assisted metrology. The method exploits the high sensitivity of matter-wave interference fringes to dephasing and shifts in the presence of external perturbations to access and determine molecular properties.

  17. Quantum interference-enhanced deep sub-Doppler cooling of 39 K atoms beyond gray molasses

    CERN Document Server

    Nath, Dipankar; Rajalakshmi, G; Unnikrishnan, C S

    2013-01-01

    We report enhanced sub-Doppler cooling of the bosonic atoms of 39 K facilitated by formation of dark states due to the quantum interference of excitation amplitudes in the Raman configuration for the cooling and repumping lasers tuned around the D1 resonance. The temperature of about 12 {\\mu}K achieved in the two stage D2-D1 molasses is the lowest ever reported for 39 K and spans a very large parameter region where quantum interference persists robustly. We also present results on enhanced radiation heating with sub-natural linewidth (0.1{\\Gamma}) and Fano like profile, following the quantum features of 3-level coherently driven atomic system with complexities associated with optical pumping to dark states and Sisyphus effect in standing wave light fields, over and above the Raman quantum interference.

  18. Perfect interference-less absorption at infrared frequencies by a van der Waal's crystal

    CERN Document Server

    Baranov, D G; Hoffman, Tim; Bassim, Nabil; Caldwell, Joshua D

    2015-01-01

    Traditionally, efforts to achieve perfect absorption have required the use of complicated metamaterial-based structures as well as relying on destructive interference to eliminate back reflections. Here, we have demonstrated both theoretically and experimentally that such perfect absorption can be achieved using a naturally occurring material, hexagonal boron nitride (hBN) due to its high optical anisotropy without the requirement of interference effects to absorb the incident field. This effect was observed for p-polarized light within the mid-infrared spectral range, and we provide the full theory describing the origin of the perfect absorption as well as the methodology for achieving this effect with other materials. Furthermore, while this is reported for the uniaxial crystal hBN, this is equally applicable to biaxial crystals and more complicated crystal structures. Interference-less absorption is of fundamental interest to the field of optics; moreover, such materials may provide additional layers of fl...

  19. The high-order quantum coherence of thermal light

    Science.gov (United States)

    Chen, Hui

    Thermal light, such as sunlight, is usually considered classical light. In a macroscopic picture, classical theory successfully explained the first-order coherence phenomena of thermal light. The macroscopic theory, based on the statistical behavior of light intensity fluctuations, however, can only phenomenologically explain the second- or higher-order coherence phenomena of thermal light. This thesis introduces a microscopic quantum picture, based on the interferences of a large number of randomly distributed and randomly radiated subfields, wavepackets or photons, to the study of high-order coherence of thermal light. This thesis concludes that the second-order intensity fluctuation correlation is caused by nonlocal interference: a pair of wavepackets, which are randomly paired together, interferes with the pair itself at two distant space-time coordinates. This study has the following practical motivations: (1) to simulate N-qbits. Practical quantum computing requires quantum bits(qubits) of N-digit to represent all possible integers from 0 to 2N-1 simultaneously. A large number of independent particles can be prepared to represent a large set of N orthogonal |0> and |1> bits. In fact, based on our recent experiments of simulating the high-order correlation of entangled photons, thermal radiation is suggested as a promising source for quantum information processing. (2) to achieve sunlight ghost imaging. Ghost imaging has three attractive non-classical features: (a) the ghost camera can "see" targets that can never be seen by a classic camera; (2) it is turbulence-free; and (3) its spatial resolution is mainly determined by the angular diameter of the light source. For example, a sunlight ghost image of an object on earth may achieve a spatial resolution of 200 micrometer because the angular diameter of sun is 0.53 degree with respect to Earth. Although ghost imaging has been experimental demonstrated by using entangled photon pairs and "pseudo-thermal light

  20. "Tangible Lights"

    DEFF Research Database (Denmark)

    Sørensen, Tor; Merritt, Timothy; Andersen, Oskar

    2015-01-01

    While there has been much focus on tangible lighting interfaces embedded in physical objects and smartphones as remote control, there has not been sufficient attention on how the expressivity of bodily movement can be used when designing interactions with light. Therefore, we investigate...... interaction with lighting technology beyond the smartphone and physical controllers. We examine the usefulness of the in-air gestural interaction style for lighting control. We bring forward "Tangible Lights", which serves as a novel interface for in-air interaction with lighting, drawing on existing...... knowledge from the tangible world. Tangible Lights has been subject to initial evaluations....

  1. Influence of spectral interferences on the results of quartz determination by infrared spectrometry

    Directory of Open Access Journals (Sweden)

    Aleksandra Maciejewska

    2015-07-01

    Full Text Available Background: Determination of quartz by Fourier transform infrared spectrometry (FTIR is not specific: the obtained results are influenced by matrix components, some of which cause spectral interference. The aim of the study was to evaluate the effect of dust components responsible for spectral interference with quartz on the results of its determinations, and to develop methods to minimize the effects of interferences. Material and Methods: Investigation of interferent effects were conducted using respirable dusts: quartz SRM 1878a, cristobalite SRM 1879a, synthetic amorphous silica (Zeosil and feldspar, albite and kaolinite. For the study 17 mixtures with quartz and interferents at concentrations from 10 to 90% were prepared. Determinations of quartz were carried out by the KBr disc method. Results: In mixtures of quartz with interferents, the results based on bands 798–779 cm–1 were overestimated by 10–55%, while those based on band 695 cm–1 were closer to the true content of quartz. It was found that the best methods able to decrease the impact of spectral interference are: scaled subtraction of IR spectra of feldspar or kaolinite analysed in nonashed samples, correction curve for kaolinite also investigated in nonashed samples with quartz-content calculation based on band 695 cm–1 in mixtures with cristobalite, amorphous silica or kaolinite in ashed samples. Conclusions: The study indicates the need to identify spectral interferences in dust when determining crystalline silica by FT-IR and to take actions to minimize their impact on the obtained results. Med Pr 2015;66(4:497–509

  2. Neutron Interference Experiments and Quantum Measurement Theory

    Science.gov (United States)

    Namiko, M.; Otake, Y.; Soshi, H.

    1987-03-01

    Physical and epistemological implications of recent experiments on the neutron interference are discussed from the viewpoint of the Machida-Namiki theory of measurement in quantum mechanics, without resort to discussion on the number-phase uncertainty relation. The same idea is also applied to the neutrino oscillation problem.

  3. Bacteria interfere with A-actinomycetemcomitans colonization

    OpenAIRE

    Teughels, Wim; Haake, S. Kinder; Sliepen, Isabelle; Pauwels, Martine; Van Eldere, Johan; Cassiman, Jean-Jacques; Quirynen, Marc

    2007-01-01

    It is known that beneficial bacteria can suppress the emergence of pathogenic bacteria, particularly in the gastrointestinal tract. This study examined the potential for a similar suppression of Aggregatibacter (formerly Actinobacillus) actinomycetemcomitans colonization of epithelial cells, due to its potential relevance in periodontal diseases. Seven presumed beneficial bacteria were examined for their ability to interfere, exclude, or displace A. actinomycetemcomitans from epithelial cells...

  4. Photon number conservation and photon interference

    OpenAIRE

    Koniorczyk, Matyas; Janszky, Jozsef

    2001-01-01

    The group theoretical aspect of the description of passive lossless optical four-ports (beam splitters) is revisited. It is shown through an example, that this approach can be useful in understanding interferometric schemes where a low number of photons interfere. The formalism is extended to passive lossless optical six-ports, their SU(3)-theory is outlined.

  5. On optimization of interference fit assembly

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard

    2016-01-01

    Assembly of shaft and hub by an interference fitis a classical connection with known advantages and disadvantages.The advantage being the level of possible torque transfer while the disadvantage is a possible fretting fatigue failure at the points of stress concentration. To improve the assembly ...

  6. Engine Power Effects on Support Interference

    NARCIS (Netherlands)

    Horsten, B.J.C.; Veldhuis, L.L.M.

    2009-01-01

    Renewed interest in propeller propulsion on aircraft configurations combined with higher propeller loads lead to the question how the effects of the propulsion on model support disturbances should be accounted for. In this paper, the determination of engine power effects on support interference of s

  7. Phase-Modulation Laser Interference Microscopy

    DEFF Research Database (Denmark)

    Brazhe, Alexey; Brazhe, Nadezda; Maximov, G. V.;

    2008-01-01

    We describe how phase-modulation laser interference microscopy and wavelet analysis can be applied to noninvasive nonstained visualization and study of the structural and dynamical properties of living cells. We show how phase images of erythrocytes can reveal the difference between various...

  8. Exploiting Genetic Interference for Antiviral Therapy

    Science.gov (United States)

    Kirkegaard, Karla A.; Weinberger, Leor S.

    2016-01-01

    Rapidly evolving viruses are a major threat to human health. Such viruses are often highly pathogenic (e.g., influenza virus, HIV, Ebola virus) and routinely circumvent therapeutic intervention through mutational escape. Error-prone genome replication generates heterogeneous viral populations that rapidly adapt to new selection pressures, leading to resistance that emerges with treatment. However, population heterogeneity bears a cost: when multiple viral variants replicate within a cell, they can potentially interfere with each other, lowering viral fitness. This genetic interference can be exploited for antiviral strategies, either by taking advantage of a virus’s inherent genetic diversity or through generating de novo interference by engineering a competing genome. Here, we discuss two such antiviral strategies, dominant drug targeting and therapeutic interfering particles. Both strategies harness the power of genetic interference to surmount two particularly vexing obstacles—the evolution of drug resistance and targeting therapy to high-risk populations—both of which impede treatment in resource-poor settings. PMID:27149616

  9. Two-order Interference of Single Photon

    Institute of Scientific and Technical Information of China (English)

    JIANG Yunkun; LI Jian; SHI Baosen; FAN Xiaofeng; GUO Guangcan

    2000-01-01

    A pair of photons called signal and idler photons, respectively, are produced through the nonlinear process of type-I spontaneous parametric downconversion in BBO crystal pumped by the second-harmonic wave of a Ti:sapphire femtosecond laser pulse. The two-order interference phenomenon of the signal photon in Michelson interferometer is observed and give an analysis in detail.

  10. Electron Interference in Ballistic Graphene Nanoconstrictions

    DEFF Research Database (Denmark)

    Baringhaus, Jens; Settnes, Mikkel; Aprojanz, Johannes;

    2016-01-01

    We realize nanometer size constrictions in ballistic graphene nanoribbons grown on sidewalls of SiC mesa structures. The high quality of our devices allows the observation of a number of electronic quantum interference phenomena. The transmissions of Fabry-Perot-like resonances are probed...

  11. Interference Fragmentation Functions and the Nucleon's Transversity

    OpenAIRE

    Jaffe, R. L.; Jin, Xuemin; Tang, Jian

    1997-01-01

    We introduce twist-two quark interference fragmentation functions in helicity density matrix formalism and study their physical implications. We show how the nucleon's transversity distribution can be probed through the final state interaction between two mesons ($\\pi^+\\pi^-$, $K\\bar K$, or $\\pi K$) produced in the current fragmentation region in deep inelastic scattering on a transversely polarized nucleon.

  12. Impact of MIMO Co-Channel Interference

    DEFF Research Database (Denmark)

    Rahman, Muhammad Imadur; De Carvalho, Elisabeth; Prasad, Ramjee

    2007-01-01

    In a real cellular system, existence of a number of multi-antenna schemes in neighboring cells means that different multi-antenna schemes will experience Co-Channel Interference (CCI) from the same or other multi-antenna schemes. In this work, we have summarized our analysis and simulations relat...

  13. Phonon interference effects in molecular junctions

    DEFF Research Database (Denmark)

    Markussen, Troels

    2013-01-01

    We study coherent phonon transport through organic, p-conjugated molecules. Using first principles calculations and Green's function methods, we find that the phonon transmission function in cross-conjugated molecules, like meta-connected benzene, exhibits destructive quantum interference features...

  14. Exploiting Genetic Interference for Antiviral Therapy.

    Science.gov (United States)

    Tanner, Elizabeth J; Kirkegaard, Karla A; Weinberger, Leor S

    2016-05-01

    Rapidly evolving viruses are a major threat to human health. Such viruses are often highly pathogenic (e.g., influenza virus, HIV, Ebola virus) and routinely circumvent therapeutic intervention through mutational escape. Error-prone genome replication generates heterogeneous viral populations that rapidly adapt to new selection pressures, leading to resistance that emerges with treatment. However, population heterogeneity bears a cost: when multiple viral variants replicate within a cell, they can potentially interfere with each other, lowering viral fitness. This genetic interference can be exploited for antiviral strategies, either by taking advantage of a virus's inherent genetic diversity or through generating de novo interference by engineering a competing genome. Here, we discuss two such antiviral strategies, dominant drug targeting and therapeutic interfering particles. Both strategies harness the power of genetic interference to surmount two particularly vexing obstacles-the evolution of drug resistance and targeting therapy to high-risk populations-both of which impede treatment in resource-poor settings. PMID:27149616

  15. Exploiting Genetic Interference for Antiviral Therapy.

    Directory of Open Access Journals (Sweden)

    Elizabeth J Tanner

    2016-05-01

    Full Text Available Rapidly evolving viruses are a major threat to human health. Such viruses are often highly pathogenic (e.g., influenza virus, HIV, Ebola virus and routinely circumvent therapeutic intervention through mutational escape. Error-prone genome replication generates heterogeneous viral populations that rapidly adapt to new selection pressures, leading to resistance that emerges with treatment. However, population heterogeneity bears a cost: when multiple viral variants replicate within a cell, they can potentially interfere with each other, lowering viral fitness. This genetic interference can be exploited for antiviral strategies, either by taking advantage of a virus's inherent genetic diversity or through generating de novo interference by engineering a competing genome. Here, we discuss two such antiviral strategies, dominant drug targeting and therapeutic interfering particles. Both strategies harness the power of genetic interference to surmount two particularly vexing obstacles-the evolution of drug resistance and targeting therapy to high-risk populations-both of which impede treatment in resource-poor settings.

  16. Feshbach Resonance Induced Fano Interference in Photoassociation

    CERN Document Server

    Deb, Bimalendu

    2009-01-01

    We consider photoassociation from a state of two free atoms when the continuum state is close to a magnetic field induced Feshbach resonance and demonstrate the possibility of Fano interference in photoassociation. We introduce an analog of Fano asymmetry parameter which characterizes the minimum in photoassociation profiles. We further show a nonlinear analog of Fano effect, which was recently observed in quantum dots.

  17. Interference Coordination for Dense Wireless Networks

    DEFF Research Database (Denmark)

    Soret, Beatriz; Pedersen, Klaus I.; Jørgensen, Niels T.K.;

    2015-01-01

    The promise of ubiquitous and super-fast connectivity for the upcoming years will be in large part fulfilled by the addition of base stations and spectral aggregation. The resulting very dense networks (DenseNets) will face a number of technical challenges. Among others, the interference emerges as...

  18. Identical particle interference in $D^{+}$ meson lifetime

    CERN Document Server

    Altarelli, Guido

    1982-01-01

    A calculation is presented of the contribution to the D^{+} non- leptonic decay rate of the interference between the active and spectator d antiquarks, relating this effect to the shape of the electron energy spectrum in D semi-leptonic decay. Predictions for the D^{+} life-time and semi-leptonic branching ratio are also derived and discussed.

  19. Non-locality and destructive interference of matter waves

    International Nuclear Information System (INIS)

    Quantum mechanics with massive particles becomes an important tool for fundamental research and applied science since many previously named 'Gedanken' experiments become feasible. Neutrons are massive particles which couple to gravitational, nuclear and electro-magnetic interactions and they are sensitive to topological effects as well. Therefore they are proper tools for testing quantum mechanics where several previously named 'hidden' parameters become measurable. Widely separated coherent beams can be produced by means of perfect crystal interferometers and they can be influenced individually. Spinor symmetry, spin superposition and quantum beat effect experiments have been performed and topological phases have been observed. Recent experiments related to the decoherence problem have shown that interference effects can be revived even when the overall interference pattern seems to be incoherent. All retrieval processes involve inherently unavoidable losses which stem partly from the theory itself and partly from an imperfect environment. Related post-selection experiments shed a new light on questions of quantum non-locality and support the request for more complete quantum measurements in the future. A more rational explanation of non-locality effects may be obtained when the plane wave components outside the wave packets are included in the discussion. This can also help to discuss entanglement and contextuality effects in a new light. In all quantum experiments more information can be extracted by more complete quantum experiments which will be important in the future to get a better understanding of quantum physics. An example may be the consideration of the Compton frequency and of proper time effects of matter waves.

  20. Interference between Cues Requires a Causal Scenario: Favorable Evidence for Causal Reasoning Models in Learning Processes

    Science.gov (United States)

    Luque, David; Cobos, Pedro L.; Lopez, Francisco J.

    2008-01-01

    In an interference-between-cues design (IbC), the expression of a learned Cue A-Outcome 1 association has been shown to be impaired if another cue, B, is separately paired with the same outcome in a second learning phase. The present study examined whether IbC could be caused by associative mechanisms independent of causal reasoning processes.…

  1. When Bees Hamper the Production of Honey: Lexical Interference from Associates in Speech Production

    Science.gov (United States)

    Rahman, Rasha Abdel; Melinger, Alissa

    2007-01-01

    In this article, the authors explore semantic context effects in speaking. In particular, the authors investigate a marked discrepancy between categorically and associatively induced effects; only categorical relationships have been reported to cause interference in object naming. In Experiments 1 and 2, a variant of the semantic blocking paradigm…

  2. Task Interference in Time-Based, Event-Based, and Dual Intention Prospective Memory Conditions

    Science.gov (United States)

    Hicks, Jason L.; Marsh, Richard L.; Cook, Gabriel I.

    2005-01-01

    Forming the intention to complete an activity later is the standard definition of a prospective memory task. Recently, a debate has arisen concerning the degree to which near-term intentions usurp resources away from other ongoing activities. In four experiments the authors tested how much interference was caused by holding a variety of different…

  3. Inkjet Color Printing by Interference Nanostructures.

    Science.gov (United States)

    Yakovlev, Aleksandr V; Milichko, Valentin A; Vinogradov, Vladimir V; Vinogradov, Alexandr V

    2016-03-22

    Color printing technology is developing rapidly; in less than 40 years, it moved from dot matrix printers with an ink-soaked cloth ribbon to 3D printers used to make three-dimensional color objects. Nevertheless, what remained unchanged over this time is the fact that in each case, dye inks (CMYK or RGB color schemes) were exclusively used for coloring, which inevitably limits the technological possibilities and color reproduction. As a next step in printing color images and storing information, we propose the technology of producing optical nanostructures. In this paper, we report use of inkjet technology to create colored interference layers with high accuracy without the need for high-temperature fixing. This was made possible due to using titania-based colloidal ink yielding monolithic coatings with a high refractive index (2.00 ± 0.08 over the entire visible range) when naturally dried. By controlling the film thickness by using inkjet deposition, we produced images based on controlled interference and implementing color printing with one ink. The lack of dyes in the proposed method has good environmental prospects, because applied systems based on a crystalline anatase sol are nontoxic and biologically inert. The paper explains in detail the principle of producing interference images by the classical inkjet method and shows the advantages of this technique in depositing coatings with uniform thickness, which are required for large-scale interference color imaging even on unprepared polymer films. This article demonstrates the possibility of inkjet printing of nanostructures with a precision in thickness of up to 50 nm, we believe that the proposed approach will be the groundwork for developing interference color printing approach and allow to implement new methods of forming optical nano-objects by widely available techniques. PMID:26805775

  4. Interference effects of categorization on decision making.

    Science.gov (United States)

    Wang, Zheng; Busemeyer, Jerome R

    2016-05-01

    Many decision making tasks in life involve a categorization process, but the effects of categorization on subsequent decision making has rarely been studied. This issue was explored in three experiments (N=721), in which participants were shown a face stimulus on each trial and performed variations of categorization-decision tasks. On C-D trials, they categorized the stimulus and then made an action decision; on X-D trials, they were told the category and then made an action decision; on D-alone trials, they only made an action decision. An interference effect emerged in some of the conditions, such that the probability of an action on the D-alone trials (i.e., when there was no explicit categorization before the decision) differed from the total probability of the same action on the C-D or X-D trials (i.e., when there was explicit categorization before the decision). Interference effects are important because they indicate a violation of the classical law of total probability, which is assumed by many cognitive models. Across all three experiments, a complex pattern of interference effects systematically occurred for different types of stimuli and for different types of categorization-decision tasks. These interference effects present a challenge for traditional cognitive models, such as Markov and signal detection models, but a quantum cognition model, called the belief-action entanglement (BAE) model, predicted that these results could occur. The BAE model employs the quantum principles of superposition and entanglement to explain the psychological mechanisms underlying the puzzling interference effects. The model can be applied to many important and practical categorization-decision situations in life. PMID:26896726

  5. Acoustic and electromagnetic noise from lighting in classrooms

    Science.gov (United States)

    Laszlo, Charles A.; Lashin, Jonathan; Hodgson, Murray R.

    2005-04-01

    Following complaints by hard-of-hearing students using assistive-listening devices, and their teachers, the hum-like noise generated by fluorescent lighting was investigated in classrooms and the school library in a typical school. This hum is caused by vibrations in the core of the magnetic ballasts. Measurements were made in several rooms without students present. Noise levels increased between 7 and 15 dB when fixtures using magnetic ballasts were switched on. Spectral analysis showed the presence of 30, 60, 120, and 240 Hz components. In rooms where electronic ballasts were installed, there was no increase in noise level when the lights were switched on. Since hearing aids and assistive-listening devices worn by students may also be influenced by magnetic fields, these were also surveyed in these classrooms. The magnetic fields generated by the lights were not significant, but near some wiring and electrical panels the interference was strong. In rooms with electronic ballasts some infrared assistive-listening devices picked up strong high-frequency hum. It is recommended that the effect of lighting fixtures and the electrical-distribution system be taken into account in the acoustical and communication design of classrooms.

  6. Interference by amplitude division with extended sources by paraxial boundary conditions

    International Nuclear Information System (INIS)

    We present a wave-optics paraxial approach to the interference by amplitude division produced by plane-parallel films (or plates) and non-plane-parallel films, or by equivalent optical devices such as a Michelson interferometer, when they are illuminated with extended (spatially incoherent) quasi-monochromatic sources. To the best of our knowledge, the most common approaches to the study of interference are based, for simplicity, on the combined use of geometrical optics concepts, such as the optical path length along a ray, together with some wave-optics concepts such as optical phases. However, interference phenomena have been the means by which the wave nature of light has been established and therefore geometrical and wave concepts are so far-off that their simultaneous use can give rise to misleading concepts. Therefore, the primary aim of this work is to provide an analytical homogeneous description of interference by amplitude division using only paraxial spherical waves and boundary conditions at smooth interfaces or discontinuities in such a way that the calculation of the total optical field, interference irradiance, fringe visibility, coherence degree, localization of the interference and so on, can be made in a unified way by taking a fully wave-optics approach. The paraxial regime is enough in most cases and, moreover, interference is generally collected by an optical instrument such as a lens or the eye itself, in which a paraxial approximation is required. This work is particularly aimed at university physics teachers and undergraduate and first year postgraduate students. (papers)

  7. Light intensity compressor

    Science.gov (United States)

    Rushford, Michael C.

    1990-01-01

    In a system for recording images having vastly differing light intensities over the face of the image, a light intensity compressor is provided that utilizes the properties of twisted nematic liquid crystals to compress the image intensity. A photoconductor or photodiode material that is responsive to the wavelength of radiation being recorded is placed adjacent a layer of twisted nematic liquid crystal material. An electric potential applied to a pair of electrodes that are disposed outside of the liquid crystal/photoconductor arrangement to provide an electric field in the vicinity of the liquid crystal material. The electrodes are substantially transparent to the form of radiation being recorded. A pair of crossed polarizers are provided on opposite sides of the liquid crystal. The front polarizer linearly polarizes the light, while the back polarizer cooperates with the front polarizer and the liquid crystal material to compress the intensity of a viewed scene. Light incident upon the intensity compressor activates the photoconductor in proportion to the intensity of the light, thereby varying the field applied to the liquid crystal. The increased field causes the liquid crystal to have less of a twisting effect on the incident linearly polarized light, which will cause an increased percentage of the light to be absorbed by the back polarizer. The intensity of an image may be compressed by forming an image on the light intensity compressor.

  8. Fano type transparency and other multimode interference effects in all-dielectric nanoshells

    CERN Document Server

    Garg, Srishti

    2015-01-01

    Recently, the coupling of two different modes of a homogeneous plasmonic particle and their sharply varying spectra were elucidated as Fano resonances; an 'interference' of two spatially orthogonal modes driving each other. On the other hand, the scattering (and extinction) cross-section of a non-absorbing dielectric particle is always the sum of the cross-sections of all mode numbers; and this rules out any such Fano type interference between two different mode numbers. So delectric particles exhibit an interference structure in their extinction spectra only if it manifests in the individual modes describing the scattered field of the particle. We show that in a all-dielectric core-shell particle such strong interferences in multiple mode numbers can be attained, and notably even as a spectral region of transparency and directional scattering of incident light. Here interference between the complementary normal modes of the nanoshell and core regions can be realized for each mode number, resulting in a sharp...

  9. Theory and simulation of multi-channel interference (MCI) widely tunable lasers.

    Science.gov (United States)

    Chen, Quanan; Lu, Qiaoyin; Guo, Weihua

    2015-07-13

    A novel design of an InP-based monolithic widely tunable laser, multi-channel interference (MCI) laser, is proposed and presented for the first time. The device is comprised of a gain section, a common phase section and a multi-channel interference section. The multi-channel interference section contains a 1x8 splitter based on cascaded 1 × 2 multi-mode interferometers (MMIs) and eight arms with unequal length difference. The rear part of each arm is integrated with a one-port multi-mode interference reflector (MIR). Mode selection of the MCI laser is realized by the constructive interference of the lights reflected back by the eight arms. Through optimizing the arm length difference, a tuning range of more than 40 nm covering the whole C band, a threshold current around 11.5 mA and an side-mode-suppression-ratio (SMSR) up to 48 dB have been predicted for this widely tunable laser. Detailed design principle and numerical simulation results are presented. PMID:26191863

  10. Investigations of several interference effects in high frequency plasmas of analytical importance

    International Nuclear Information System (INIS)

    Investigations of the extent to which certain inter-element or interference effects occur in a radiofrequency-excited inductively coupled plasma (ICP) are reported. Under conditions normally employed for analytical purposes, it is shown that: (a) two solute vaporization interferences often observed in flames are eliminated or reduced to negligible proportions in the plasma; (b) increasing concentrations of an easily ionizable element (Na) up to concentrations of 6900 μg/ml exerted an unusually low influence on the observed emission intensities of three selected elements (Ca, Cr, and Cd) of widely differing degrees of ionization. The high degree of freedom from interelement effects of this analytical technique is further documented by the observation that a variety of matrices did not affect the emission intensity of Mo to a significant extent. A comparison of the degree to which several interference effects are observed in a microwave-excited single electrode plasma (SEP) and in an ICP shows that the severe changes observed in the SEP are small or negligible in the ICP. The spectral interferences arising from stray light and from the wings of broadened emission lines in atomic emission spectrometry are discussed. Experimental evidence is presented showing various forms of stray light originating from defects in the optical components, design and engineering of optical spectrometers. Experimental evidence is also presented demonstrating that the wings of certain spectral lines emitted by high temperature sources may contribute a significant continuum at wavelengths as far removed as 10 nm or more from the line center

  11. Receive Diversity and Ergodic Performance of Interference Alignment on the MIMO Gaussian Interference Channel

    CERN Document Server

    Guillaud, Maxime

    2010-01-01

    We consider interference alignment (IA) over K-user Gaussian MIMO interference channel (MIMO-IC) when the SNR is not asymptotically high. We introduce a generalization of IA which enables receive diversity inside the interference-free subspace. We generalize the existence criterion of an IA solution proposed by Yetis et al. to this case, thereby establishing a multi-user diversity-multiplexing trade-off (DMT) for the interference channel. Furthermore, we derive a closed-form tight lower-bound for the ergodic mutual information achievable using IA over a Gaussian MIMO-IC with Gaussian i.i.d. channel coefficients at arbitrary SNR, when the transmitted signals are white inside the subspace defined by IA. Finally, as an application of the previous results, we compare the performance achievable by IA at various operating points allowed by the DMT, to a recently introduced distributed method based on game theory.

  12. Elements of Cellular Blind Interference Alignment --- Aligned Frequency Reuse, Wireless Index Coding and Interference Diversity

    CERN Document Server

    Jafar, Syed A

    2012-01-01

    We explore degrees of freedom (DoF) characterizations of partially connected wireless networks, especially cellular networks, with no channel state information at the transmitters. Specifically, we introduce three fundamental elements --- aligned frequency reuse, wireless index coding and interference diversity --- through a series of examples, focusing first on infinite regular arrays, then on finite clusters with arbitrary connectivity and message sets, and finally on heterogeneous settings with asymmetric multiple antenna configurations. Aligned frequency reuse refers to the optimality of orthogonal resource allocations in many cases, but according to unconventional reuse patterns that are guided by interference alignment principles. Wireless index coding highlights both the intimate connection between the index coding problem and cellular blind interference alignment, as well as the added complexity inherent to wireless settings. Interference diversity refers to the observation that in a wireless network ...

  13. The differential interference angle in collisional quantum interference on rotational energy transfer

    Institute of Scientific and Technical Information of China (English)

    Wang Wei-Li; Miao Gang; Chen Yue-Hui; Tang Dan; Ma Feng-Cai

    2008-01-01

    Collisional quantum interference (CQI) in the intramolecular rotational energy transfer was observed in experiment by Sha and co-workers.[1] The interference angle, which measuring the degree of the coherence, were measured in the experiment of the static cell. Based on the first Born approximation of time dependent perturbation theory, taking into accounts the anisotropic Lennard-Jones interaction potentials, this paper describes the theoretical model of CQI in intramolecular rotational energy transfer in an atom-diatom collision system. In the model, the differential interference angle for the experiment of the molecular beam is calculated, the changing tendencies of the differential interference angle with the impact parameter and collision partners are obtained. This theoretical model is important for understanding or performing this kind of experiments.

  14. Feedback-Topology Designs for Interference Alignment in MIMO Interference Channels

    CERN Document Server

    Cho, Sungyoon; Huang, Kaibin; Kim, Dongku; Lau, Vincent K N; Seo, Hanbyul; Kim, Byounghoon

    2011-01-01

    Interference alignment (IA) is a joint-transmission technique that achieves the capacity of the interference channel for high signal-to-noise ratios (SNRs). Most prior work on IA is based on the impractical assumption that perfect and global channel-state information(CSI) is available at all transmitters. To implement IA, each receiver has to feed back CSI to all interferers, resulting in overwhelming feedback overhead. In particular, the sum feedback rate of each receiver scales quadratically with the number of users even if the quantized CSI is fed back. To substantially suppress feedback overhead, this paper focuses on designing efficient arrangements of feedback links, called feedback topologies, under the IA constraint. For the multiple-input-multiple-output (MIMO) K-user interference channel, we propose the feedback topology that supports sequential CSI exchange (feedback and feedforward) between transmitters and receivers so as to achieve IA progressively. This feedback topology is shown to reduce the ...

  15. Interference Mitigation by Statistical Interference Modeling in an Impulse Radio UWB Receiver

    OpenAIRE

    Flury, Manuel; Le Boudec, Jean-Yves

    2006-01-01

    Some impulse radio UWB (IR-UWB) networks may allow concurrent transmissions without power control (for example MAC protocols that do not use power control, or co-exisiting, non-coordinated piconets). In such cases, it has been proposed to mitigate multi-user interference (MUI) at the physical layer, but existing proposals for interference mitigation do not account for the multipath nature of UWB channels. We address this problem and propose a receiver that employs a combination of statistical...

  16. Multiple-Antenna Interference Cancellation for WLAN with MAC Interference Avoidance in Open Access Networks

    OpenAIRE

    Alexandr M. Kuzminskiy; Hamid Reza Karimi

    2007-01-01

    The potential of multiantenna interference cancellation receiver algorithms for increasing the uplink throughput in WLAN systems such as 802.11 is investigated. The medium access control (MAC) in such systems is based on carrier sensing multiple-access with collision avoidance (CSMA/CA), which itself is a powerful tool for the mitigation of intrasystem interference. However, due to the spatial dependence of received signal strengths, it is possible for the collision avoidance mechanism to fa...

  17. Exploiting Spatial Interference Alignment and Opportunistic Scheduling in the Downlink of Interference Limited Systems

    OpenAIRE

    Kuchi, Kiran

    2013-01-01

    In this paper we analyze the performance of single stream and multi-stream spatial multiplexing (SM) systems employing opportunistic scheduling in the presence of interference. In the proposed downlink framework, every active user reports the post-processing signal-to-interference-plus-noise-power-ratio (post-SINR) or the receiver specific mutual information (MI) to its own transmitter using a feedback channel. The combination of scheduling and multi-antenna receiver processing leads to subst...

  18. Lightness functions

    DEFF Research Database (Denmark)

    Campi, Stefano; Gardner, Richard; Gronchi, Paolo;

    2012-01-01

    Variants of the brightness function of a convex body K in n-dimensional Euclidean are investigated. The Lambertian lightness function L(K; v , w ) gives the total reflected light resulting from illumination by a light source at infinity in the direction w that is visible when looking in the...... direction v . The partial brightness function R( K ; v , w ) gives the area of the projection orthogonal to v of the portion of the surface of K that is both illuminated by a light source from the direction w and visible when looking in the direction v . A class of functions called lightness functions is...... lightness functions....

  19. The Approximate Capacity Region of the Symmetric $K$-user Gaussian Interference Channel with Strong Interference

    KAUST Repository

    Chaaban, Anas

    2016-03-01

    The symmetric K-user interference channel is studied with the goal of characterizing its capacity region in the strong interference regime within a constant gap. The achievable rate region of a scheme combining rate-splitting at the transmitters and interference alignment and successive decoding/computation at the receivers is derived. Next it is shown that this scheme achieves the so-called greedy-max corner points of the capacity region within a constant gap. By combining this result with previous results by Ordentlich et al. on the sum-capacity of the symmetric interference channel, a constant gap characterization of the capacity region for the strong interference regime is obtained. This leads to the first approximate characterization of the capacity region of the symmetric K-user IC. Furthermore, a new scheme that achieves the sum-capacity of the channel in the strong interference regime within a constant gap is also proposed, and the corresponding gap is calculated. The advantage of the new scheme is that it leads to a characterization within a constant gap without leaving an outage set contrary to the scheme by Ordentlich et al..

  20. (Sub-)Optimality of Treating Interference as Noise in the Cellular Uplink With Weak Interference

    KAUST Repository

    Gherekhloo, Soheil

    2015-11-09

    Despite the simplicity of the scheme of treating interference as noise (TIN), it was shown to be sum-capacity optimal in the Gaussian interference channel (IC) with very-weak (noisy) interference. In this paper, the two-user IC is altered by introducing an additional transmitter that wants to communicate with one of the receivers of the IC. The resulting network thus consists of a point-to-point channel interfering with a multiple access channel (MAC) and is denoted by PIMAC. The sum-capacity of the PIMAC is studied with main focus on the optimality of TIN. It turns out that TIN in its naive variant, where all transmitters are active and both receivers use TIN for decoding, is not the best choice for the PIMAC. In fact, a scheme that combines both time division multiple access and TIN (TDMA-TIN) strictly outperforms the naive-TIN scheme. Furthermore, it is shown that in some regimes, TDMA-TIN achieves the sum-capacity for the deterministic PIMAC and the sum-capacity within a constant gap for the Gaussian PIMAC. In addition, it is shown that, even for very-weak interference, there are some regimes where a combination of interference alignment with power control and TIN at the receiver side outperforms TDMA-TIN. As a consequence, on the one hand, TIN in a cellular uplink is approximately optimal in certain regimes. On the other hand, those regimes cannot be simply described by the strength of interference.

  1. Avoiding Dangerous Anthropogenic Interference with the Climate System

    Energy Technology Data Exchange (ETDEWEB)

    Keller, K. [Department of Geosciences, Penn State, PA (United States); Hall, M. [Brookings Institution, Washington, DC (United States); Kim, Seung-Rae [Woodrow Wilson School of Public and International Affairs, Princeton University, Princeton, NJ (United States); Bradford, D.F. [Department of Economics, Princeton University, Princeton, NJ (United States); Oppenheimer, M. [Woodrow Wilson School and Department of Geosciences, Princeton University, Robertson Hall 448, Princeton, NJ, 08544 (United States)

    2005-12-01

    The UN Framework Convention on Climate Change calls for the avoidance of 'dangerous anthropogenic interference with the climate system'. Among the many plausible choices, dangerous interference with the climate system may be interpreted as anthropogenic radiative forcing causing distinct and widespread climate change impacts such as a widespread demise of coral reefs or a disintegration of the West Antarctic ice sheet. The geological record and numerical models suggest that limiting global warming below critical temperature thresholds significantly reduces the likelihood of these eventualities. Here we analyze economically optimal policies that may ensure this risk-reduction. Reducing the risk of a widespread coral reef demise implies drastic reductions in greenhouse gas emissions within decades. Virtually unchecked greenhouse gas emissions to date (combined with the inertia of the coupled natural and human systems) may have already committed future societies to a widespread demise of coral reefs. Policies to reduce the risk of a West Antarctic ice sheet disintegration allow for a smoother decarbonization of the economy within a century and may well increase consumption in the long run.

  2. Domain motions of Argonaute, the catalytic engine of RNA interference

    Directory of Open Access Journals (Sweden)

    Wall Michael E

    2007-11-01

    Full Text Available Abstract Background The Argonaute protein is the core component of the RNA-induced silencing complex, playing the central role of cleaving the mRNA target. Visual inspection of static crystal structures already has enabled researchers to suggest conformational changes of Argonaute that might occur during RNA interference. We have taken the next step by performing an all-atom normal mode analysis of the Pyrococcus furiosus and Aquifex aeolicus Argonaute crystal structures, allowing us to quantitatively assess the feasibility of these conformational changes. To perform the analysis, we begin with the energy-minimized X-ray structures. Normal modes are then calculated using an all-atom molecular mechanics force field. Results The analysis reveals low-frequency vibrations that facilitate the accommodation of RNA duplexes – an essential step in target recognition. The Pyrococcus furiosus and Aquifex aeolicus Argonaute proteins both exhibit low-frequency torsion and hinge motions; however, differences in the overall architecture of the proteins cause the detailed dynamics to be significantly different. Conclusion Overall, low-frequency vibrations of Argonaute are consistent with mechanisms within the current reaction cycle model for RNA interference.

  3. Renewable Energy, Photovoltaic Systems Near Airfields. Electromagnetic Interference

    Energy Technology Data Exchange (ETDEWEB)

    Deline, Chris [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Dann, Geoff [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2015-04-01

    Recent increases in photovoltaic (PV) systems on Department of the Navy (DON) land and potential siting near airfields prompted Commander, Naval Installations Command to fund the Naval Facilities Engineering Command to evaluate the impact of electromagnetic interference (EMI) from PV systems on airfield electronic equipment. Naval Facilities Engineering and Expeditionary Warfare Center tasked Department of Energy National Renewable Energy laboratory (NREL) to conduct the assessment. PV systems often include high-speed switching semiconductor circuits to convert the voltage produced by the PV arrays to the voltage needed by the end user. Switching circuits inherently produce electromagnetic radiation at harmonics of the switching frequency. In this report, existing literature is summarized and tests to measure emissions and mitigation methods are discussed. The literature shows that the emissions from typical PV systems are low strength and unlikely to cause interference to most airfield electronic systems. With diligent procurement and siting of PV systems, including specifications for FCC Part 15 Class A compliant equipment and a 250-foot setback from communication equipment, NREL anticipates little to no EMI impact on nearby communications or telemetry equipment.

  4. FIBER OPTIC LIGHTING SYSTEMS

    OpenAIRE

    Munir BATUR; Parali, Ufuk; Osman Nuri UCAN

    2013-01-01

    Recently there have been many important and valuable developments in the communication industry. The huge increase in the sound, data and visual communications has caused a parallel increase in the demand for systems with wider capacity, higher speed and higher quality. Communication systems that use light to transfer data are immensely increased. There have recently many systems in which glass or plastic fiber cables were developed for light wave to be transmitted from a source to a target p...

  5. Experimental evaluation of high speed impulse radio UWB interference on WiMAX narrowband systems

    DEFF Research Database (Denmark)

    Yu, Xianbin; Yin, Xiaoli; Tafur Monroy, Idelfonso

    2010-01-01

    Interference of high speed impulse radio ultrawideband (IR-UWB) on 5.735GHz single carrier 64/256-QAM WiMAX narrowband signals is experimentally investigated. The experimental results indicate that the coexistence of 625Mbps and 2Gbps IR-UWB signals causes penalties of 3dB and 0.5dB respectively to...... the WiMAX channel. At higher bit rates, IR-UWB technology is therefore expected to reduce its interference on WiMAX signals. This work serves as further motivation for the exploration of IR-UWB systems with higher speed and higher capacity....

  6. Time-division phase modulated single-photon interference in a Sagnac interferometer

    Institute of Scientific and Technical Information of China (English)

    WU Guang; ZHOU Chunyuan; ZENG Heping

    2003-01-01

    We introduce a stable, long-distance single- photon Sagnac interferometer, which has a balanced configuration to efficiently compensate phase drift caused by change of the fiber-optic path. By using time-division phase modulation, single-photon interference was realized at 1550 nm in a 5-km-long as well as 27-km-long Sagnac fiber loops, with a fringe visibility higher than 90% and long-term stability. The stable performance of the single-photon interference indicated that the time-division phase-modulated Sag- nac interferometer might readily lead to practical applications in single-photon routing and quantum cryptography.

  7. Beyond Quantum interference and Optical pumping: invoking a Closed-loop phase

    CERN Document Server

    Kani, A

    2016-01-01

    Atomic coherence effects arising from coherent light-atom interaction are conventionally known to be governed by quantum interference and optical pumping mechanisms. However, anisotropic nonlinear response driven by optical field involves another fundamental effect arising from closed-loop multiphoton transitions. This closed-loop phase dictates the tensorial structure of the nonlinear susceptibility as it governs the principal coordinate system in determining, whether the light field will either compete or cooperate with the external magnetic field stimulus. Such a treatment provides deeper understanding of all magneto-optical anisotropic response. The magneto-optical response in all atomic systems is classified using closed-loop phase. The role of quantum interference in obtaining electromagnetically induced transparency or electromagnetically induced absorption in multi-level systems is identified.

  8. Detecting orbital angular momentum through division-of-amplitude interference with a circular plasmonic lens

    Science.gov (United States)

    Liu, Ai-Ping; Xiong, Xiao; Ren, Xi-Feng; Cai, Yong-Jing; Rui, Guang-Hao; Zhan, Qi-Wen; Guo, Guang-Can; Guo, Guo-Ping

    2013-01-01

    We demonstrate a novel detection scheme for the orbital angular momentum (OAM) of light using circular plasmonic lens. Owing to a division-of-amplitude interference phenomenon between the surface plasmon waves and directly transmitted light, specific intensity distributions are formed near the plasmonic lens surface under different OAM excitations. Due to different phase behaviors of the evanescent surface plasmon wave and the direct transmission, interference patterns rotate as the observation plane moves away from the lens surface. The rotation direction is a direct measure of the sign of OAM, while the amount of rotation is linked to the absolute value of the OAM. This OAM detection scheme is validated experimentally and numerically. Analytical expressions are derived to provide insights and explanations of this detection scheme. This work forms the basis for the realization of a compact and integrated OAM detection architect that may significantly benefit optical information processing with OAM states. PMID:23929189

  9. Detecting orbital angular momentum through division-of-amplitude interference with a circular plasmonic lens

    CERN Document Server

    Liu, Ai-Ping; Ren, Xi-Feng; Cai, Yong-Jing; Rui, Guang-Hao; Zhan, Qi-Wen; Guo, Guang-Can; Guo, Guo-Ping

    2013-01-01

    We demonstrate a novel detection scheme for the orbital angular momentum (OAM) of light using circular plasmonic lens. Owing to a division-of-amplitude interference phenomenon between the surface plasmon waves and directly transmitted light, specific intensity distributions are formed near the plasmonic lens surface under different OAM excitations. Due to different phase behaviors of the evanescent surface plasmon wave and the direct transmission, interference patterns rotate as the observation plane moves away from the lens surface. The rotation direction is a direct measure of the sign of OAM, while the amount of rotation is linked to the absolute value of the OAM. This OAM detection scheme is validated experimentally and numerically. Analytical expressions are derived to provide insights and explanations of this detection scheme. This work forms the basis for the realization of a compact and integrated OAM detection architect that may significantly benefit optical information processing with OAM states.

  10. Analysis of beam interference reflected from atomic force microscope tip and periodic silicon surface under various humidity conditions

    Science.gov (United States)

    Banerjee, Hans P.; Weerasinghe, Asanka T.; Lyuksyutov, Sergei F.

    2012-10-01

    Dynamical sensing based on combination of classical optical effects and atomic force microscopy (AFM) presents challenge for analysis of the forces at the nanoscale and beyond. An interference effect between light reflected from an AFM cantilever and highly reflective silicon surface of the calibration grating was studied for relative humidity (RH) varied between 9 and 60%. Force-distance analysis indicates on separation of capillary, van der Waals, adhesion, and electrostatic forces. The measurements performed in contact AFM mode suggest that the period of interference pattern observed in displacement curves is a function of humidity and varies between 293 nm at RH = 9% and 335 nm at RH > 50% with standard deviation less than 8 nm. Clear change of the interference period suggests that other than hardwarerelated factors may be involved in the formation of the interference in force-distance curves.

  11. Colloquium: Quantum interference of clusters and molecules

    CERN Document Server

    Hornberger, Klaus; Haslinger, Philipp; Nimmrichter, Stefan; Arndt, Markus

    2011-01-01

    We review recent progress and future prospects of matter wave interferometry with complex organic molecules and inorganic clusters. Three variants of a near-field interference effect, based on diffraction by material nanostructures, at optical phase gratings, and at ionizing laser fields are considered. We discuss the theoretical concepts underlying these experiments and the experimental challenges. This includes optimizing interferometer designs as well as understanding the role of decoherence. The high sensitivity of matter wave interference experiments to external perturbations is demonstrated to be useful for accurately measuring internal properties of delocalized nanoparticles. We conclude by investigating the prospects for probing the quantum superposition principle in the limit of high particle mass and complexity.

  12. On interference types in electrolyte solutions

    International Nuclear Information System (INIS)

    A brief analysis of component interference types in electrolyte aqueous solutions is presented. On the example of studying ClO4- ion state in different (lithium, sodium, magnesium, cadmium, europium...) perchlorate solutions using molecular spectroscopy methods it is shown that ion-water interaction essentially depends on counterion nature. For deep understanding of interference processes in solutions with ion-molecular level usefulness of considering the system solubility isotherms is marked. On the example of solubility isotherms of several ternary systems (PrCl3-LiCl-H2O; Sc(ClO4)3-HClO4-H2O; PrCl3-RbCl-H2O; CdCl2-KCl-H2O) it is shown that different chemical nature of components results in various dominating interactions (mutual dehydration of electrolytes, dehydration of one of the components etc.). 6 refs.; 4 figs

  13. Adaptive transmit selection with interference suppression

    KAUST Repository

    Radaydeh, Redha Mahmoud Mesleh

    2010-01-01

    This paper studies the performance of adaptive transmit channel selection in multipath fading channels. The adaptive selection algorithms are configured for single-antenna bandwidth-efficient or power-efficient transmission with as low transmit channel estimations as possible. Due to the fact that the number of active co-channel interfering signals and their corresponding powers experience random behavior, the adaptation to channels conditions, assuming uniform buffer and traffic loading, is proposed to be jointly based on the transmit channels instantaneous signal-to-noise ratios (SNRs) and signal-to- interference-plus- noise ratios (SINRs). Two interference cancelation algorithms, which are the dominant cancelation and the less complex arbitrary cancelation, are considered, for which the receive antenna array is assumed to have small angular spread. Analytical formulation for some performance measures in addition to several processing complexity and numerical comparisons between various adaptation schemes are presented. ©2010 IEEE.

  14. Canceling Interference in Acupuncture Points Signal

    Directory of Open Access Journals (Sweden)

    Yanexy San Martín Reyes

    2012-07-01

    Full Text Available The present paper propose the cancellation of interference or artifacts by the method of Allen in signals captured in different acupuncture points (Small Intestine Meridian, points ID1-ID2 and ID1-ID19. It is considered that the biosignal under study should be able to be characterized after its acquisition by subtracting the different interference variables that may coexist in the measurement zone, as it is in the case of ECG or any other artifact. The biosignal obtained as a result of the cancellation will be the acupuncture signal or from its imperfection another wave can be obtained as from a bioelectrical point of view such imperfection can be characterized and at the same time can bb useful to establish a long-term correspondence between the behavior of the signals on various acupuncture points and different diseases.

  15. Unruh effect and macroscopic quantum interference

    CERN Document Server

    Steane, Andrew

    2015-01-01

    We investigate the influence of Unruh radiation on matter-wave interferometry experiments using neutral objects modeled as dielectric spheres. The Unruh effect leads to a loss of coherence through momentum diffusion. This is a fundamental source of decoherence that affects all objects having electromagnetic interactions. However, the effect is not large enough to prevent the observation of interference for objects of any size, even when the path separation is larger than the size of the object. When the acceleration in the interferometer arms is large, inertial tidal forces will disrupt the material integrity of the interfering objects before the Unruh decoherence of the centre of mass motion is sufficient to prevent observable interference.

  16. Electron Interference in Ballistic Graphene Nanoconstrictions

    Science.gov (United States)

    Baringhaus, Jens; Settnes, Mikkel; Aprojanz, Johannes; Power, Stephen R.; Jauho, Antti-Pekka; Tegenkamp, Christoph

    2016-05-01

    We realize nanometer size constrictions in ballistic graphene nanoribbons grown on sidewalls of SiC mesa structures. The high quality of our devices allows the observation of a number of electronic quantum interference phenomena. The transmissions of Fabry-Perot-like resonances are probed by in situ transport measurements at various temperatures. The energies of the resonances are determined by the size of the constrictions, which can be controlled precisely using STM lithography. The temperature and size dependence of the measured conductances are in quantitative agreement with tight-binding calculations. The fact that these interference effects are visible even at room temperature makes the reported devices attractive as building blocks for future carbon based electronics.

  17. Quantum interference between resonant and nonresonant photorecombination

    Science.gov (United States)

    Tu, B.; Xiao, J.; Yao, K.; Shen, Y.; Yang, Y.; Lu, D.; Li, W. X.; Qiu, M. L.; Wang, X.; Chen, C. Y.; Fu, Y.; Wei, B.; Zheng, C.; Huang, L. Y.; Zhang, B. H.; Tang, Y. J.; Hutton, R.; Zou, Y.

    2016-03-01

    In this paper, we present experimental and theoretical studies on the interference between resonant and nonresonant photorecombinations for the main resonances of ground-state He-, Be-, B-, C-, N-, and O-like W ions. Experiments were done using a fast electron energy scanning technique at the upgraded Shanghai electron-beam ion trap. Asymmetric resonances were observed, and their Fano factors, which measure the interference degree, were determined. The calculations were done under the framework of Fano's theory by using the flexible atomic code, in which the relativistic configuration interaction method was employed. Among the nine resonances studied in this work, eight experimental results agree with the calculation within experimental uncertainties. But the experimental result for the resonance of Be-like W ions, through the intermediate state of [(1s2s22p 1 /2) 12 p3 /2] 5 /2, deviates from its corresponding theoretical result by 1.3 times experimental uncertainty.

  18. Parametric constraints in multi-beam interference

    Science.gov (United States)

    Burrow, Guy M.; Gaylord, Thomas K.

    2012-10-01

    Multi-beam interference (MBI) represents a method of producing one-, two-, and three-dimensional submicron periodic optical-intensity distributions for applications including micro- and nano-electronics, photonic crystals, metamaterial, biomedical structures, optical trapping, and numerous other subwavelength structures. Accordingly, numerous optical configurations have been developed to implement MBI. However, these configurations typically provide limited ability to condition the key parameters of each interfering beam. Constraints on individual beam amplitudes and polarizations are systematically considered to understand their effects on lithographically useful MBI periodic patterning possibilities. A method for analyzing parametric constraints is presented and used to compare the optimized optical-intensity distributions for representative constrained systems. Case studies are presented for both square and hexagonal-lattices produced via three-beam interference. Results demonstrate that constraints on individual-beam polarizations significantly impact patterning possibilities and must be included in the systematic design of an MBI system.

  19. Multiscale Investigation of Chemical Interference in Proteins

    CERN Document Server

    Samiotakis, Antonios; Cheung, Margaret S

    2010-01-01

    We developed a multiscale approach (MultiSCAAL) that integrates the potential of mean force (PMF) obtained from all-atomistic molecular dynamics simulations with a knowledge-based energy function for coarse-grained molecular simulations in better exploring the energy landscape of a small protein under chemical interference such as chemical denaturation. An excessive amount of water molecules in all-atomistic molecular dynamics simulations often negatively impacts the sampling efficiency of some advanced sampling techniques such as the replica exchange method and it makes the investigation of chemical interferences on protein dynamics difficult. Thus, there is a need to develop an effective strategy that focuses on sampling structural changes in protein conformations rather than solvent molecule fluctuations. In this work, we address this issue by devising a multiscale simulation scheme (MultiSCAAL) that bridges the gap between all-atomistic molecular dynamics simulation and coarse-grained molecular simulation...

  20. Blood interference in fluorescence spectrum : Experiment, analysis and comparison with intraoperativemeasurements on brain tumor

    OpenAIRE

    Lowndes, Shannely

    2010-01-01

    The optical touch pointer (OTP), a fluorescence spectroscopy based system, assists brain surgeons during guided brain tumor resection in patients with glioblastoma multiforme (GBM). After recording and analyzing the autofluorescence spectrum of the tissue, it is possible to distinguish malignant from healthy brain tissue. A challenge during the intraoperative measurements is the interference of blood. If it gets in contact with the laser pointer, the blood blocks the light transmission to and...