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Sample records for double optical spring

  1. Optical spring effect in nanoelectromechanical systems

    Science.gov (United States)

    Tian, Feng; Zhou, Guangya; Du, Yu; Chau, Fook Siong; Deng, Jie

    2014-08-01

    In this Letter, we report a hybrid system consisting of nano-optical and nano-mechanical springs, in which the optical spring effect works to adjust the mechanical frequency of a nanoelectromechanical systems resonator. Nano-scale folded beams are fabricated as the mechanical springs and double-coupled one-dimensional photonic crystal cavities are used to pump the "optical spring." The dynamic characteristics of this hybrid system are measured and analyzed at both low and high input optical powers. This study leads the physical phenomenon of optomechanics in complex nano-opto-electro-mechanical systems (NOEMS) and could benefit the future applications of NOEMS in chip-level communication and sensing.

  2. Thermal noise free opto-mechanics using strong optical springs

    CERN Document Server

    Page, Michael; Zhao, Chunnong; Blair, David; Ju, Li; Pan, Huang-Wei; Chao, Shiuh; Mitrofanov, Valery; Sadeghian, Hamed

    2016-01-01

    Thermal noise generally greatly exceeds quantum noise in optomechanical devices unless the mechanical frequency is very high or the thermodynamic temperature is very low. This paper addresses the design concept for a novel optomechanical device capable of ultrahigh quality factors with negligible thermal noise. The proposed system consists of a minimally supported millimeter scale pendulum mounted in a Double End-Mirror Sloshing (DEMS) cavity that is topologically equivalent to a Membrane-in-the-Middle (MIM) cavity. The radiation pressure inside the high-finesse cavity allows for high optical stiffness, cancellation of terms which lead to unwanted negative damping and suppression of quantum radiation pressure noise. We solve for the optical spring dynamics of the system using the Hamiltonian, find the noise spectral density and show that stable optical trapping is possible. We also assess various loss mechanisms, one of the most important being the acceleration loss due to the optical spring. We show that pra...

  3. Experimental demonstration of coupled optical springs

    Science.gov (United States)

    Gordon, N. A.; Barr, B. W.; Bell, A.; Graef, C.; Hild, S.; Huttner, S. H.; Leavey, S. S.; Macarthur, J.; Sorazu, B.; Wright, J.; Strain, K. A.

    2017-02-01

    Optical rigidity will play an important role in improving the sensitivity of future generations of gravitational wave (GW) interferometers, which employ high laser power in order to reach and exceed the standard quantum limit. Several experiments have demonstrated the combined effect of two optical springs on a single system for very low-weight mirror masses or membranes. In this paper we investigate the complex interactions between multiple optical springs and the surrounding apparatus in a system of comparable dynamics to a large-scale GW detector. Using three 100 g mirrors to form a coupled cavity system capable of sustaining two or more optical springs, we demonstrate a number of different regimes of opto-mechanical rigidity and measurement techniques. Our measurements reveal couplings between each optical spring and the control loops that can affect both the achievable increase in sensitivity and the stability of the system. Hence this work establishes a better understanding of the realisation of these techniques and paves the way to their application in future GW observatories, such as upgrades to Advanced LIGO.

  4. Hot Springs-Garrison Fiber Optic Project

    Energy Technology Data Exchange (ETDEWEB)

    1994-10-01

    Bonneville Power Administration (BPA) is proposing to upgrade its operational telecommunications system between the Hot Springs Substation and the Garrison Substation using a fiber optic system. The project would primarily involve installing 190 kilometers (120 miles) of fiber optic cable on existing transmission structures and installing new fiber optic equipment in BPA`s substation yards and control houses. BPA prepared an environmental assessment (EA) evaluating the proposed action. This EA was published in October 1994. The EA identifies a number of minor impacts that might occur as a result of the proposed action, as well as some recommended mitigation measures. This Mitigation Action Plan (MAP) identifies specific measures to avoid, minimize, or compensate for impacts identified in the EA.

  5. Adaptive Optics Simulations for Siding Spring

    CERN Document Server

    Goodwin, Michael; Lambert, Andrew

    2012-01-01

    Using an observational derived model optical turbulence profile (model-OTP) we have investigated the performance of Adaptive Optics (AO) at Siding Spring Observatory (SSO), Australia. The simulations cover the performance for AO techniques of single conjugate adaptive optics (SCAO), multi-conjugate adaptive optics (MCAO) and ground-layer adaptive optics (GLAO). The simulation results presented in this paper predict the performance of these AO techniques as applied to the Australian National University (ANU) 2.3 m and Anglo-Australian Telescope (AAT) 3.9 m telescopes for astronomical wavelength bands J, H and K. The results indicate that AO performance is best for the longer wavelengths (K-band) and in the best seeing conditions (sub 1-arcsecond). The most promising results are found for GLAO simulations (field of view of 180 arcsecs), with the field RMS for encircled energy 50% diameter (EE50d) being uniform and minimally affected by the free-atmosphere turbulence. The GLAO performance is reasonably good over...

  6. Characterisation of the Optical Turbulence at Siding Spring

    CERN Document Server

    Goodwin, Michael; Lambert, Andrew

    2012-01-01

    Measurements of the optical turbulence profile above Siding Spring Observatory were conducted during 2005 and 2006. This effort was largely motivated by the need to predict the statistical performance of adaptive optics at Siding Spring. The data were collected using a purpose-built instrument based on the slope-detection and ranging method (SLODAR) where observations of a bright double star are imaged by Shack-Hartmann taken with the Australian National University 24 inch and 40 inch telescopes. The analysis of the data yielded a model consisting of a handful of statistically prominent thin layers that are statistically separated into the ground layer (37.5, 250m) and the free atmosphere (1, 3, 6, 9, 13.5 km) for good (25%), typical (50%) and bad (25%) observing conditions. We found that ground-layer turbulence dominates the turbulence profile with up to 80% of the integrated turbulence below 500 m. The turbulence tends to be non-Kolmogorov, especially for the ground-layer with a power law index of $\\beta \\s...

  7. Nonlinear Quantum Optical Springs and Their Nonclassical Properties

    Institute of Scientific and Technical Information of China (English)

    M.J. Faghihi; M.K. Tavassoly

    2011-01-01

    The original idea of quantum optical spring arises from the requirement of quantization of the frequency of oscillations in the Hamiltonian of harmonic oscillator. This purpose is achieved by considering a spring whose constant (and so its frequency) depends on the quantum states ofanother system. Recently, it is realized that by the assumption of frequency modulation of ω to ω √1+ μα+α the mentioned idea can be established. In the present paper, we generalize the approach of quantum optical spring with particular attention to the dependence or trequency to the intensity of radiation field that naturally observes in the nonlinear coherent states, from which we arrive at a physical system has been called by us as nonlinear quantum optical spring. Then, after the introduction of the generalized tlamiltonian of nonlinear quantum optical spring and it's solution, we will investigate the nonclassical properties of the obtained states. Specially, typical collapse and revival in the distribution functions and squeezing parameters, as particular quantum features, will be revealed.

  8. Creating a Double-Spring Model to Teach Chromosome Movement during Mitosis & Meiosis

    Science.gov (United States)

    Luo, Peigao

    2012-01-01

    The comprehension of chromosome movement during mitosis and meiosis is essential for understanding genetic transmission, but students often find this process difficult to grasp in a classroom setting. I propose a "double-spring model" that incorporates a physical demonstration and can be used as a teaching tool to help students understand this…

  9. Creating a Double-Spring Model to Teach Chromosome Movement during Mitosis & Meiosis

    Science.gov (United States)

    Luo, Peigao

    2012-01-01

    The comprehension of chromosome movement during mitosis and meiosis is essential for understanding genetic transmission, but students often find this process difficult to grasp in a classroom setting. I propose a "double-spring model" that incorporates a physical demonstration and can be used as a teaching tool to help students understand this…

  10. Development of silicon microforce sensors integrated with double meander springs for standard hardness test instruments

    Science.gov (United States)

    Wasisto, Hutomo Suryo; Doering, Lutz; Daus, Alwin; Brand, Uwe; Frank, Thomas; Peiner, Erwin

    2015-05-01

    Silicon microforce sensors, to be used as a transferable standard for micro force and depth scale calibrations of hardness testing instruments, are developed using silicon bulk micromachining technologies. Instead of wet chemical etching, inductively coupled plasma (ICP) cryogenic deep reactive ion etching (DRIE) is employed in the sensor fabrication process leading to more precise control of 300 μm deep structures with smooth sidewall profiles. Double meander springs are designed flanking to the boss replacing the conventional rectangular springs and thereby improving the system linearity. Two full p-SOI piezoresistive Wheatstone bridges are added on both clamped ends of the active sensors. To realize passive force sensors two spring-mass elements are stacked using glue and photoresist as joining materials. Correspondingly, although plastic deformation seems to occur when the second spring is contacted, the kink effect (i.e., abrupt increase of stiffness) is obviously observed from the first test of the passive stack sensor.

  11. Optical axis jitter rejection for double overlapped adaptive optics systems

    Science.gov (United States)

    Luo, Qi; Luo, Xi; Li, Xinyang

    2016-04-01

    Optical axis jitters, or vibrations, which arise from wind shaking and structural oscillations of optical platforms, etc., cause a deleterious impact on the performance of adaptive optics systems. When conventional integrators are utilized to reject such high frequency and narrow-band disturbance, the benefits are quite small despite their acceptable capabilities to reject atmospheric turbulence. In our case, two suits of complete adaptive optics systems called double overlapped adaptive optics systems (DOAOS) are used to counteract both optical jitters and atmospheric turbulence. A novel algorithm aiming to remove vibrations is proposed by resorting to combine the Smith predictor and notch filer. With the help of loop shaping method, the algorithm will lead to an effective and stable controller, which makes the characteristics of error transfer function close to notch filters. On the basis of the spectral analysis of observed data, the peak frequency and bandwidth of vibrations can be identified in advance. Afterwards, the number of notch filters and their parameters will be determined using coordination descending method. The relationship between controller parameters and filtering features is discussed, and the robustness of the controller against varying parameters of the control object is investigated. Preliminary experiments are carried out to validate the proposed algorithms. The overall control performance of DOAOS is simulated. Results show that time delays are a limit of the performance, but the algorithm can be successfully implemented on our systems, which indicate that it has a great potential to reject jitters.

  12. Springs

    Institute of Scientific and Technical Information of China (English)

    James J. Kilpatrick

    2006-01-01

    @@ Springs are not always the same. In some years, April bursts upon our Virginia hills in one prodigious leap-and all the stage is filled at once, whole choruses of tulips, arabesques of forsythia, cadenzas of flowering plum. The trees grow leaves overnight

  13. New Structure of Optical Fiber Protection Cable Using Helical Composite Spring

    Science.gov (United States)

    Chung, Seunghwan; Yoon, Youngki; Lee, Woo‑Il; Lee, Byoungho

    2006-07-01

    A new type of cable is introduced for protecting optical fiber from mechanical bending or abrupt temperature changes. It shows superior ability to protect fiber from severe bending and lowers the thermal sensitivity compared with conventional optical fiber cable. It can be used as a protection sleeve or cable in special regions. The proposed device consists of a helical composite spring, a thermal insulator (i.e., polyurethane foam) and a heat-shrinkable tube which coats the outside of the spring. These components can be acquired for a moderate price and manufactured by simple processes.

  14. Simultaneous calibration of optical tweezers spring constant and position detector response.

    Science.gov (United States)

    Le Gall, Antoine; Perronet, Karen; Dulin, David; Villing, André; Bouyer, Philippe; Visscher, Koen; Westbrook, Nathalie

    2010-12-06

    We demonstrate a fast and direct calibration method for systems using a single laser for optical tweezers and particle position detection. The method takes direct advantage of back-focal-plane interferometry measuring not an absolute but a differential position, i.e. the position of the trapped particle relative to the center of the optical tweezers. Therefore, a fast step-wise motion of the optical tweezers yields the impulse response of the trapped particle. Calibration parameters such as the detector's spatial and temporal response and the spring constant of the optical tweezers then follow readily from fitting the measured impulse response.

  15. New Pyrometer with Double X—type Optical Fibers①

    Institute of Scientific and Technical Information of China (English)

    SHIWeidong; LIZhiquantffu

    1997-01-01

    A new pyrometer,which can solve the affection of emissivity change in temperature measuring,has been developed by double Y-type optical fibers.The mathematical model of the new pyrometer is presented and the errors of the new pyrometer are analyzed.

  16. Transmission performance of the double-sideband SCM optical label

    Science.gov (United States)

    Chen, Minghua; Zhou, Weiqing; Jia, Zhensheng; Xie, Shizhong

    2002-09-01

    Transmission performance of the optical label with the double-sideband subcarrier multiplexing is investigated using Volterra transfer function approach. It is shown that the phase shifts of the two sideband signal is induced jointly by the interaction between SCM component and payload component due to fiber dispersion and nonlinearity. This will cause the SCM label fading, and then harm to system performance.

  17. Optical double-image encryption and authentication by sparse representation.

    Science.gov (United States)

    Mohammed, Emad A; Saadon, H L

    2016-12-10

    An optical double-image encryption and authentication method by sparse representation is proposed. The information from double-image encryption can be integrated into a sparse representation. Unlike the traditional double-image encryption technique, only sparse (partial) data from the encrypted data is adopted for the authentication process. Simulation results demonstrate that the correct authentication results are achieved even with partial information from the encrypted data. The randomly selected sparse encrypted information will be used as an effective key for a security system. Therefore, the proposed method is feasible, effective, and can provide an additional security layer for optical security systems. In addition, the method also achieved the general requirements of storage and transmission due to a high reduction of the encrypted information.

  18. Optical and dielectric properties of double helix DNA thin films

    Energy Technology Data Exchange (ETDEWEB)

    Soenmezoglu, Savas, E-mail: svssonmezoglu@kmu.edu.tr [Department of Physics, Faculty of Kamil Ozdag Science, Karamanoglu Mehmetbey University, 70100, Karaman (Turkey); Ates Soenmezoglu, Ozlem [Department of Biology, Faculty of Kamil Ozdag Science, Karamanoglu Mehmetbey University, 70100, Karaman (Turkey)

    2011-12-01

    In this work, the thin film of wheat DNA was deposited by spin-coating technique onto glass substrate, and the optical and dielectric properties of the double helix DNA thin film were investigated. The optical constants such as refractive index, extinction coefficient, dielectric constant, dissipation factor, relaxation time, and optical conductivity were determined from the measured transmittance spectra in the wavelength range 190-1100 nm. Meanwhile, the dispersion behavior of the refractive index was studied in terms of the single oscillator Wemple-DiDomenico (W-D) model, and the physical parameters of the average oscillator strength, average oscillator wavelength, average oscillator energy, the refractive index dispersion parameter and the dispersion energy were achieved. Furthermore, the optical band gap values were calculated by W-D model and Tauc model, respectively, and the values obtained from W-D model are in agreement with those determined from the Tauc model. The analysis of the optical absorption data indicates that the optical band gap E{sub g} was indirect transitions. These results provide some useful references for the potential application of the DNA thin films in fiber optic, solar cell and optoelectronic devices. Highlights: {yields} The optical constants of DNA in full UV-vis spectrum were determined. {yields} The change in optical and dielectric property demonstrates that this material has potential to be used as a novel technology. {yields} DNA shows promise to be more suitable material than other materials currently being used for photonic devices.

  19. Bandgap properties in locally resonant phononic crystal double panel structures with periodically attached spring-mass resonators

    Science.gov (United States)

    Qian, Denghui; Shi, Zhiyu

    2016-10-01

    Bandgap properties of the locally resonant phononic crystal double panel structure made of a two-dimensional periodic array of a spring-mass resonator surrounded by n springs (n equals to zero at the beginning of the study) connected between the upper and lower plates are investigated in this paper. The finite element method is applied to calculate the band structure, of which the accuracy is confirmed in comparison with the one calculated by the extended plane wave expansion (PWE) method and the transmission spectrum. Numerical results and further analysis demonstrate that two bands corresponding to the antisymmetric vibration mode open a wide band gap but is cut narrower by a band corresponding to the symmetric mode. One of the regulation rules shows that the lowest frequency on the symmetric mode band is proportional to the spring stiffness. Then, a new design idea of adding springs around the resonator in a unit cell (n is not equal to zero now) is proposed in the need of widening the bandwidth and lowering the starting frequency. Results show that the bandwidth of the band gap increases from 50 Hz to nearly 200 Hz. By introducing the quality factor, the regulation rules with the comprehensive consideration of the whole structure quality limitation, the wide band gap and the low starting frequency are also discussed.

  20. Optical-optical double-resonant multiphoton ionization spectra of Rydberg states of nitrogen dioxide

    Institute of Scientific and Technical Information of China (English)

    Zhang Gui-Yin; Zhang Lian-Shui; Sun Bo; Han Xiao-Feng; Yu Wei

    2005-01-01

    The optical-optical double-resonant multiphoton ionization(OODR-MPI) technique has been applied to the study of the Rydberg states of nitrogen dioxide. The results show that ,althougy the OODR-MPI spectra of NO2 are composed of regular progression bands at different pump laser intensities, their ionization pathways are different.The NO2 mollecule is ionized through the (3+1+1)double-resonant process as the pump laser intensity is in a high value, or else it is through the (1+2+1)rpocess.The final resonant states in the two ionizing processes have been attributed to different Rydberg states.

  1. Automatic Optical Crack Tracking for Double Cantilever Beam Specimens

    Science.gov (United States)

    2015-01-01

    and Member, R.G., ‘‘Path Planning For Machine Vision Assisted , Teleoperated Pavement Crack Sealer,’’ Journal of Transportation Engineering 124:137...TECHN ICAL ART IC LE Automatic Optical Crack Tracking for Double Cantilever Beam Specimens B. Krull1,2, J. Patrick2,3, K. Hart2,4, S. White2,4, and N...Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 3 Department of Civil and Environmental Engineering, University of

  2. Infrared spectromicroscopy and magneto-optical imaging stations at SPring-8

    CERN Document Server

    Kimura, S; Sada, T; Okuno, M; Matsunami, M; Shinoda, K; Kimura, H; Moriwaki, T; Yamagata, M; Kondo, Y; Yoshimatsu, Y; Takahashi, T; Fukui, K; Kawamoto, T; Ishikawa, T

    2001-01-01

    At the BL43IR of SPring-8, infrared microanalysis on various kinds of solid specimens under multiple environments with a spatial resolution smaller than 10 mu m in diameter is planned in the infrared region. In order to perform such analysis, two different stations, a multipurpose spectromicroscopy apparatus and a magneto-optical imaging one have been constructed. Measurements on the spatial two-dimensional cross-section of the infrared beam at the spectromicroscopy station have proven that the stations have a good prospective feature in the performance.

  3. Double-Teeth-Shaped Plasmonic Waveguide Electro-Optical Switches

    Institute of Scientific and Technical Information of China (English)

    ZHU Jia-Hu; HUANG Xu-Guang; MEI Xian

    2011-01-01

    @@ An electro-optical switch based on a plasmonic T-shaped waveguide structure with a double-teeth-shaped waveguide filled with 4-dimet4ylamino-N-methyl-4stilbazolium tosylate is proposed and numerically investigated.TheFinite-difference time domain simulation results reveal that the structure can operate as a circuit switch by controlling the external voltages V1 and/or V2.The proposed structure can also operate as a variable optical attenuator, which can continuously attenuate the power of a light beam from 6dB to 30dB by an external electrical field.The structure is of small size of a few hundred nanometers.Our results may open a possibility to construct nanoscale high-density photonic integration circuits.

  4. Stable optical spring in the Advanced LIGO detector with unbalanced arms and in the Michelson-Sagnac interferometer

    Science.gov (United States)

    Vostrosablin, Nikita; Vyatchanin, Sergey P.

    2014-03-01

    Optical rigidity in the Advanced LIGO gravitational-wave detector, operated on the dark port regime, is unstable. We show that the same interferometer with excluded symmetric mechanical mode but with unbalanced arms allows us to get stable optical spring for the antisymmetric mechanical mode. The arm detuning necessary to get stability is shown to be a small one—it corresponds to small power in the signal port. We show that stable optical spring may be also obtained in the Michelson-Sagnac interferometer with both power and signal recycling mirrors and unbalanced arms.

  5. Parallel optical evaluation of double-exposure records in optical metrology.

    Science.gov (United States)

    Arnold, W; Hinsch, K D

    1989-02-15

    The evaluation of double-exposure records in optical metrology (speckle photography or particle image velocimetry) is simplified by using two-step optical processing that is performed on many interrogation areas simultaneously by a 2-D array of narrow focused light beams. A first application of this procedure to the original record, if dimensioned properly, produces an array of small nonoverlapping Young's fringe systems. The photographic record of these patterns is subjected to the same operation once more, each beam illuminating precisely one pattern. The resulting output is an array of autocorrelation functions that are a direct representation of the displacement field since the spacing of respective side peaks gives the displacement. A single whole-field interrogation of the array of fringe systems produces an optical representation of accumulated displacement values thus rendering the statistics of the displacement field. The required matrix of light beams is generated by holographic optical elements.

  6. Potassium double tungstate waveguides with high ytterbium concentration for optical amplification

    NARCIS (Netherlands)

    Yong, Yean-Sheng

    2017-01-01

    In this thesis, the research work concerning high ytterbium concentration potassium double tungstate waveguides catered for optical amplification purpose is presented. The scope of the research work includes the investigation of spectroscopic and optical gain properties in epitaxy layers with

  7. Optical image encryption based on a joint Fresnel transform correlator with double optical wedges.

    Science.gov (United States)

    Shen, Xueju; Dou, Shuaifeng; Lei, Ming; Chen, Yudan

    2016-10-20

    An optical cryptosystem based on the joint Fresnel transform correlator (JFTC) with double optical wedges is designed. The designed cryptosystem retains the two major advantages of JTC-based optical cryptosystems. First, the encrypted image is real-valued and therefore is easier to record and transmit. Second, the encryption process is simplified, since it doesn't require accurate alignment of optical elements or the generation of the complex conjugate of the key. Also, the designed optical cryptosystem can produce a decrypted image with higher quality than a JTC-based optical cryptosystem, because the original encrypted image is divided by the Fresnel transform power distribution of the key mask to generate the new encrypted image, which significantly reduces the noise during the decryption process. Simulation results showed that the correlation coefficient of the decrypted image and the original image can reach as large as 0.9819 after denoising and adequately selecting half-central interval a and encrypted image width w. Another improvement relative to JTC-based optical cryptosystems is that the attack resistibility gets enhanced due to the nonlinearity of the encryption process as well as the additional key parameter a, which enlarges the key space.

  8. Control mechanism of double-rotator-structure ternary optical computer

    Science.gov (United States)

    Kai, SONG; Liping, YAN

    2017-03-01

    Double-rotator-structure ternary optical processor (DRSTOP) has two characteristics, namely, giant data-bits parallel computing and reconfigurable processor, which can handle thousands of data bits in parallel, and can run much faster than computers and other optical computer systems so far. In order to put DRSTOP into practical application, this paper established a series of methods, namely, task classification method, data-bits allocation method, control information generation method, control information formatting and sending method, and decoded results obtaining method and so on. These methods form the control mechanism of DRSTOP. This control mechanism makes DRSTOP become an automated computing platform. Compared with the traditional calculation tools, DRSTOP computing platform can ease the contradiction between high energy consumption and big data computing due to greatly reducing the cost of communications and I/O. Finally, the paper designed a set of experiments for DRSTOP control mechanism to verify its feasibility and correctness. Experimental results showed that the control mechanism is correct, feasible and efficient.

  9. Period Doubling in a Fabry-Perot Laser Diode Subject to Optical Pulse Injection

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yue-Peng; WANG Yun-Cai; ZHANG Ming-Jiang; AN Yi; WANG Ji-Long

    2007-01-01

    Experimental study and numerical simulations of the period doubling of injected optical pulses in Fabry-Perot laser diodes are presented. In our experiments, the period doubling is achieved within a wide input frequency range and the period doubling of the injected optical pulses with 6.32 GHz repetition rate is investigated in detail. The obtained experimental results indicate that period doubling occurs at an appropriate injected optical power level when the bias current of the Fabry-Perot laser diode is located in lower ranges. Moreover, the experimental observed features have been numerically demonstrated by using a coupled rate-equation model. Numerical simulations are consistent with the experimental results.

  10. Polarization-maintaining fiber loop with double optical length and its application to fiber optic gyroscope

    Institute of Scientific and Technical Information of China (English)

    Changsheng Li; Chunxi Zhang; Ningfang Song; Hongjie Xu

    2011-01-01

    @@ A novel polarization maintaining fiber (PMP) loop is proposed and used for an interferometric fiber optic gyroscope (FOG). By splicing a conventional PMF loop with two pigtailed polarization beam splitters, polarized light can be guided to propagate along the slow and fast axes of the PMF in sequence to double its effective optical length in the loop. In particular, the resultant optical length in the combined loop is partially self-compensated for some external disturbances, such as transverse strain. Primary experiments on the FOG using the proposed loop demonstrate that the average static bias deviation between -40 and +60 ℃ is less than 0.050 deg./h, and the average bias variation under conventional random vibration test is less than 0.10 deg./h.%A novel polarization maintaining fiber (PMF) loop is proposed and used for an interferometric fiber optic gyroscope (FOG). By splicing a conventional PMF loop with two pigtailed polarization beam splitters,polarized light can be guided to propagate along the slow and fast axes of the PMF in sequence to double its effective optical length in the loop. In particular, the resultant optical length in the combined loop is partially self-compensated for some external disturbances, such as transverse strain. Primary experiments on the FOG using the proposed loop demonstrate that the average static bias deviation between -40 and +60 ℃ is less than 0.050 deg./h, and the average bias variation under conventional random vibration test is less than 0.10 deg./h.

  11. Spherical Refractive Correction With an Electro-Optical Liquid Lens in a Double-Pass System

    Science.gov (United States)

    Sanàbria, F.; Díaz-Doutón, F.; Aldaba, M.; Pujol, J.

    2013-09-01

    In this study we show a novel double-pass configuration to correct the spherical refractive error by means of an electro-optical liquid lens.The proposed method enables spherical correction in the -12 D to +7 D range without movable parts using an electro-optical liquid lens.We have measured the optical performance of the spherical corrector in terms of power, pupil size and optical quality verifying that it fitsthe requirements to be applied to a double-pass system. We have also evaluated the performance of the proposed method in patients bycomparison with a conventional double-pass system using a Badal optometer.

  12. An improved resource allocation algorithm based on double auction for optical networks

    Science.gov (United States)

    Duan, Xiaolin; Yang, Xiaolong; Shen, Huang; Chen, Qianbin

    2007-11-01

    For the resource allocation of optical network, grid economy can be introduced to optimize the utilization of resource. Double auction algorithm is appropriate for grid economy, but the speed of convergence of many algorithms is too slow. In this paper we proposed double auction supported optical resource scheduling framework, and then described an improved algorithm on double auction based resource allocation for optical network. We attempt to speed the course of auction and utilize price parameter to adjust the overlay. Simulation results show that our scheme can optimize the equilibrium of overlay, and optical resource can be allocated and scheduled efficiently.

  13. Automatic alignment of double optical paths in excimer laser amplifier

    Science.gov (United States)

    Wang, Dahui; Zhao, Xueqing; Hua, Hengqi; Zhang, Yongsheng; Hu, Yun; Yi, Aiping; Zhao, Jun

    2013-05-01

    A kind of beam automatic alignment method used for double paths amplification in the electron pumped excimer laser system is demonstrated. In this way, the beams from the amplifiers can be transferred along the designated direction and accordingly irradiate on the target with high stabilization and accuracy. However, owing to nonexistence of natural alignment references in excimer laser amplifiers, two cross-hairs structure is used to align the beams. Here, one crosshair put into the input beam is regarded as the near-field reference while the other put into output beam is regarded as the far-field reference. The two cross-hairs are transmitted onto Charge Coupled Devices (CCD) by image-relaying structures separately. The errors between intersection points of two cross-talk images and centroid coordinates of actual beam are recorded automatically and sent to closed loop feedback control mechanism. Negative feedback keeps running until preset accuracy is reached. On the basis of above-mentioned design, the alignment optical path is built and the software is compiled, whereafter the experiment of double paths automatic alignment in electron pumped excimer laser amplifier is carried through. Meanwhile, the related influencing factors and the alignment precision are analyzed. Experimental results indicate that the alignment system can achieve the aiming direction of automatic aligning beams in short time. The analysis shows that the accuracy of alignment system is 0.63μrad and the beam maximum restoration error is 13.75μm. Furthermore, the bigger distance between the two cross-hairs, the higher precision of the system is. Therefore, the automatic alignment system has been used in angular multiplexing excimer Main Oscillation Power Amplification (MOPA) system and can satisfy the requirement of beam alignment precision on the whole.

  14. Hyperparallel optical quantum computation assisted by atomic ensembles embedded in double-sided optical cavities

    Science.gov (United States)

    Li, Tao; Long, Gui-Lu

    2016-08-01

    We propose an effective, scalable, hyperparallel photonic quantum computation scheme in which photonic qubits are hyperencoded both in the spatial degrees of freedom (DOF) and the polarization DOF of each photon. The deterministic hyper-controlled-not (hyper-cnot) gate on a two-photon system is attainable with our interesting interface between the polarized photon and the collective spin wave (magnon) of an atomic ensemble embedded in a double-sided optical cavity, and it doubles the operations in the conventional quantum cnot gate. Moreover, we present a compact hyper-cnotN gate on N +1 hyperencoded photons with only two auxiliary cavity-magnon systems, not more, and it can be faithfully constituted with current experimental techniques. Our proposal enables various applications with the hyperencoded photons in quantum computing and quantum networks.

  15. Double remote electrochemical addressing and optical readout of electrochemiluminescence at the tip of an optical fiber.

    Science.gov (United States)

    Li, Haidong; Garrigue, Patrick; Bouffier, Laurent; Arbault, Stéphane; Kuhn, Alexander; Sojic, Neso

    2016-07-21

    In this work, we report an original strategy for the wireless electrochemical generation of light at the tip of an optical fiber bundle, coupled with a simultaneous remote readout. An optical fiber bundle coated with a nanometer-thin gold film acts as a dual platform, on the one hand to locally generate electrochemiluminescence (ECL) in a wireless manner by bipolar electrochemistry, and on the other hand to guide the resulting ECL signal. The light emission is triggered and collected at one end, transmitted by the waveguide and remotely detected at the opposite end. Integration of both functionalities at the level of the same miniaturized object leads to an unprecedented bipolar opto-electrode, allowing one to quantify the ECL intensity as a function of different parameters in a double remote approach with interesting potential applications, ranging from high-throughput catalyst screening to massive parallel biochemical analysis.

  16. Experimental study on optical image encryption with asymmetric double random phase and computer-generated hologram.

    Science.gov (United States)

    Xi, Sixing; Wang, Xiaolei; Song, Lipei; Zhu, Zhuqing; Zhu, Bowen; Huang, Shuai; Yu, Nana; Wang, Huaying

    2017-04-03

    Optical image encryption, especially double-random-phase-based, is of great interest in information security. In this work, we experimentally demonstrate the security and feasibility of optical image encryption with asymmetric double random phase and computer-generated hologram (CGH) by using spatial light modulator. First of all, the encrypted image modulated by asymmetric double random phase is numerically encoded into real-value CGH. Then, the encoded real-value CGH is loaded on the spatial light modulator and optically decrypted in self-designed experimental system. Experimental decryption results are in agreement with numerical calculations under the prober/mistaken phase keys condition. This optical decryption technology opens a window of optical encryption practical application and shows great potential for digital multimedia product copyright protection and holographic false trademark.

  17. Algebraic invariants for reflection Mueller polarimetry via uncompensated double pass illumination-collection optics.

    Science.gov (United States)

    Ossikovski, Razvigor; Vizet, Jérémy

    2016-07-01

    We report on the identification of the two algebraic invariants inherent to Mueller matrix polarimetry measurements performed through double pass illumination-collection optics (e.g., an optical fiber or an objective) of unknown polarimetric response. The practical use of the invariants, potentially applicable to the characterization of nonreciprocal media, is illustrated on experimental examples.

  18. Dynamics mechanism of optical-optical double-resonant multiphoton ionization of nitrogen dioxide

    Institute of Scientific and Technical Information of China (English)

    Guiyin Zhang; Yidong Jin

    2007-01-01

    The optical-optical double-resonant multiphoton ionization (OODR-MPI) spectrum of NO2 molecule in the 460-605-nm wavelength region of the probe photon is presented. The mechanism of the OODR-MPI of NO2 molecule is analyzed. The results show that the resonant features can be assigned to the transitions from the first 3sσg Rydberg intermediate resonant state to the final npσu Rydberg series. The ionization pathway is NO2 (X2A1) 3hv1→ 3sσghv2→npσu hv2 or autoionization→NO2+ + e. It is found that the converging potential of the npσu Rydberg series and the quantum defect of np orbit about NO2 are (78803 ± 14) cm-1 and 0.652 ± 0.014, respectively. The bending vibration frequency of 5pσu state is determined also.

  19. Controllable optical bistability and multistability in asymmetric double quantum wells via spontaneously generated coherence

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yuan; Deng, Li [Department of Applied Physics, East China Jiaotong University, Nanchang, 330013 (China); Chen, Aixi, E-mail: aixichen@ecjtu.jx.cn [Department of Applied Physics, East China Jiaotong University, Nanchang, 330013 (China); Institute for Quantum Computing, University of Waterloo, Ontario N2L 3G1 (Canada)

    2015-02-15

    We investigate the nonlinear optical phenomena of the optical bistability and multistability via spontaneously generated coherence in an asymmetric double quantum well structure coupled by a weak probe field and a controlling field. It is shown that the threshold and hysteresis cycle of the optical bistability can be conveniently controlled only by adjusting the intensity of the SGC or the controlling field. Moreover, switching between optical bistability and multistability can be achieved. These studies may have practical significance for the preparation of optical bistable switching device.

  20. Optical properties of multilayered Period-Doubling and Rudin-Shapiro porous silicon dielectric heterostructures

    Science.gov (United States)

    Agarwal, V.; Mora-Ramos, Miguel E.; Alvarado-Tenorio, B.

    2009-05-01

    To investigate the optical properties in quasi-regular porous-silicon-based dielectric Period-Doubling and Rudin-Shapiro multilayer systems, we study here the reflection of light from these structures. The Period-Doubling and Rudin-Shapiro structures are fabricated in such a way that the optical thickness of each layer is one quarter of 600 and 640 nm respectively. We find that porous silicon Period-Doubling dielectric multilayers could demonstrate the optical properties similar to the classical periodic Febry-Perot interference filters with one or multiple resonant peaks, but with an advantage of having total optical thickness much lesser than the periodic structures. Additionally, light propagation in porous silicon Rudin-Shapiro structures is investigated for the first time, both theoretically and experimentally. The reflectance spectra of the structures exhibit photonic band gaps centered at predetermined wavelengths. In both cases, numerical simulation of light transmission is performed using transfer matrix method.

  1. Quartz optical filter for wavelength selection of frequency-doubled laser based on optical rotatory dispersion effect

    Institute of Scientific and Technical Information of China (English)

    Shan Zhang; Fuquan Wu; Wendi Wu; Haifeng Wang

    2007-01-01

    Based on the optical rotatory dispersion effect, an optical filter for selecting the second harmonic of a frequency-doubled laser is constructed from quartz in combination with polarizers. The operating principle is analyzed by matrix formulation, and the result indicates that the second harmonic of a frequency-doubled laser will be obtained when the rotation angle has a difference of (2n + 1)π/2 (n = 0, 1, 2, 3,… ) between the two polarizations of the second-harmonic laser and the fundamental laser. The spectrum of the output laser is taken by the AQ-6315A spectrometer, and the experimental results are in good agreement with the theoretical results.

  2. A simple multipurpose double-beam optical image analyzer

    CERN Document Server

    Popowicz, Adam

    2016-01-01

    In the paper we present a low cost optical device which splits the light in the focal plane into two separate optical paths and collimates it back into a single image plane, and where a selective information processing ca be carried out. The optical system is straightforward and easy implementable as it consists of only three lens and two mirrors. The system is dedicated for imaging in low-light-level conditions in which widely used optical devices, based on beam-splitters or dichroic mirrors, suffer from light loss. We expose examples of applications of our device, using a prototype model. The proposed optical system may be employed for: monitoring the objects located in different distances from observer (1), creating regions of different magnification within a single image plane (2), high dynamic range photometry (3), or imaging in two wavelength bands simultaneously (4).

  3. A simple multipurpose double-beam optical image analyzer

    Science.gov (United States)

    Popowicz, A.; Blachowicz, T.

    2016-07-01

    In the paper we present a low cost optical device which splits the light in the focal plane into two separate optical paths and collimates it back into a single image plane, and where a selective information processing can be carried out. The optical system is straightforward and easily implementable as it consists of only three lenses and two mirrors. The system is dedicated for imaging in low-light-level conditions in which widely used optical devices, based on beam splitters or dichroic mirrors, suffer from light loss. We expose examples of applications of our device, using a prototype model. The proposed optical system may be employed for: monitoring the objects located at different distances from observer (1), creating regions of different magnification within a single image plane (2), high dynamic range photometry (3), or imaging in two wavelength bands simultaneously (4).

  4. Angular resolution measurements at SPring-8 of a hard X-ray optic for the New Hard X-ray Mission

    CERN Document Server

    Spiga, D; Furuzawa, A; Basso, S; Binda, R; Borghi, G; Cotroneo, V; Grisoni, G; Kunieda, H; Marioni, F; Matsumoto, H; Mori, H; Miyazawa, T; Negri, B; Orlandi, A; Pareschi, G; Salmaso, B; Tagliaferri, G; Uesugi, K; Valsecchi, G; Vernani, D

    2015-01-01

    The realization of X-ray telescopes with imaging capabilities in the hard (> 10 keV) X-ray band requires the adoption of optics with shallow (10 m shall be produced and tested. Full-illumination tests of such mirrors are usually performed with on- ground X-ray facilities, aimed at measuring their effective area and the angular resolution; however, they in general suffer from effects of the finite distance of the X-ray source, e.g. a loss of effective area for double reflection. These effects increase with the focal length of the mirror under test; hence a "partial" full-illumination measurement might not be fully representative of the in-flight performances. Indeed, a pencil beam test can be adopted to overcome this shortcoming, because a sector at a time is exposed to the X-ray flux, and the compensation of the beam divergence is achieved by tilting the optic. In this work we present the result of a hard X-ray test campaign performed at the BL20B2 beamline of the SPring-8 synchrotron radiation facility, aime...

  5. Matched Ultra Slow Optical Solitons in Double-A Media

    Institute of Scientific and Technical Information of China (English)

    YANG Xiao-Xue; WU Xuan; WU Ying

    2005-01-01

    @@ We study the four-wave mixing (FWM) in a double-A atomic system where two strong continuous-wave pump lasers and a weak pulsed probe laser produce an FWM generated pulse. We show that both the probe and FWM generated fields may evolve into bright and dark solitons with the same shape and the same ultraslow group velocity.

  6. Dynamics of optical breakdown in air induced by single and double nanosecond laser pulses

    Energy Technology Data Exchange (ETDEWEB)

    Mahdieh, Mohammad Hossein, E-mail: mahdm@iust.ac.ir; Akbari Jafarabadi, Marzieh [Department of Physics, Iran University of Science and Technology, Narmak, Tehran 1684613114 (Iran, Islamic Republic of)

    2015-12-15

    In this paper, an optical breakdown in air induced by single and double nanosecond laser pulses was studied. A high power Nd:YAG laser beam was used for producing optical breakdown plasma in the air. The dynamics of breakdown plasma were studied using an optical probe beam. A portion of the laser beam was used, as the probe beam and was aligned to propagate (perpendicular to the pump beam) through the breakdown region. The transmission of the probe beam (through the breakdown region) was temporally measured for both single and double pulse irradiations. The results were used to describe the evolution of the induced plasma in both conditions. These results show that the plasma formation time and its absorptivity are strongly dependent on the single or double pulse configurations.

  7. Transient Intersubband Optical Absorption in Double Quantum Well Structure

    Institute of Scientific and Technical Information of China (English)

    WU Bin-He

    2005-01-01

    The microscopic equations of motion including many-body effects are derived to study the intersubband polarization in the double quantum well structure induced by an ultrafast pumping infrared light. Based on the selfconsistent field theory, the transient probe absorption coefficient is calculated. These calculations are beyond the previous steady-state assumption. Transient probe absorption spectra are calculated under different pumping intensity and various pump probe delay.

  8. Optical analogue of 2D heteronuclear double-quantum NMR

    CERN Document Server

    Tollerud, Jonathan

    2016-01-01

    Heteronuclear multi-quantum spectroscopy is a powerful part of the NMR toolbox, commonly used to identify specific sequences of atoms in complex pulse sequences designed to determine the structure of complex molecules, including proteins. Optical coherent multidimensional spectroscopy (CMDS) is analogous to multidimensional NMR and many of the techniques of NMR have been adapted for application in the optical regime. This has been highly successful, with CMDS being used to understand energy transfer in photosynthesis and many body effects in semiconductor nanostructures amongst many other scientific breakthroughs. Experimental challenges have, however, prevented the translation of heteronuclear multi-quantum NMR to the optical regime, where capabilities to isolate signals in otherwise congested spectra, reduce acquisition times and enable more incisive probes of multi-particle correlations and complex electronic systems would have great benefit. Here we utilise a diffraction based pulseshaper to impose the tw...

  9. Radical-ion-pair reactions are the biochemical equivalent of the optical double slit experiment

    OpenAIRE

    Kominis, I. K.

    2010-01-01

    Radical-ion-pair reactions were recently shown to represent a rich biophysical laboratory for the application of quantum measurement theory methods and concepts. We here show that radical-ion-pair reactions essentially form a non-linear biochemical double slit interferometer. Quantum coherence effects are visible when "which-path" information is limited, and the incoherent limit is approached when measurement-induced decoherence sets in. Based on this analogy with the optical double slit expe...

  10. Double random fractional Fourier domain encoding for optical security

    Science.gov (United States)

    Unnikrishnan, G.; Singh, Kehar

    2000-11-01

    We propose a new optical encryption technique using the fractional Fourier transform. In this method, the data are encrypted to a stationary white noise by two statistically independent random phase masks in fractional Fourier domains. To decrypt the data correctly, one needs to specify the fractional domains in which the input plane, encryption plane, and output planes exist, in addition to the key used for encryption. The use of an anamorphic fractional Fourier transform for the encryption of 2D data is also discussed. We suggest an optical implementation of the proposed idea. Results of a numerical simulation to analyze the performance of the proposed method are presented.

  11. Optimally enhanced optical emission in laser-induced air plasma by femtosecond double-pulse

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Anmin [Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012 (China); Institute of Theoretical Chemistry, State Key Laboratory of Theoretical and Computational Chemistry, Jilin University, Changchun 130012 (China); Li, Suyu; Li, Shuchang; Jiang, Yuanfei; Ding, Dajun [Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012 (China); Shao, Junfeng; Wang, Tingfeng [State Key Laboratory of Laser Interaction with Matter, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); Huang, Xuri [Institute of Theoretical Chemistry, State Key Laboratory of Theoretical and Computational Chemistry, Jilin University, Changchun 130012 (China); Jin, Mingxing [Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012 (China); State Key Laboratory of Laser Interaction with Matter, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China)

    2013-10-15

    In laser-induced breakdown spectroscopy, a femtosecond double-pulse laser was used to induce air plasma. The plasma spectroscopy was observed to lead to significant increase of the intensity and reproducibility of the optical emission signal compared to femtosecond single-pulse laser. In particular, the optical emission intensity can be optimized by adjusting the delay time of femtosecond double-pulse. An appropriate pulse-to-pulse delay was selected, that was typically about 50 ps. This effect can be especially advantageous in the context of femtosecond laser-induced breakdown spectroscopy, plasma channel, and so on.

  12. Raman Probe Based on Optically-Poled Double-Core Fiber

    DEFF Research Database (Denmark)

    Brunetti, Anna Chiara; Margulis, Walter; Rottwitt, Karsten

    2012-01-01

    A Raman probe based on an optically-poled double-core fiber. In-fiber SHG allows for Raman spectroscopy of DMSO at 532nm when illuminating the fiber with 1064nm light. The fiber structure provides independent excitation and collection paths.......A Raman probe based on an optically-poled double-core fiber. In-fiber SHG allows for Raman spectroscopy of DMSO at 532nm when illuminating the fiber with 1064nm light. The fiber structure provides independent excitation and collection paths....

  13. Investigation on Characteristics and the Improving Method of Double Loop Optical Buffer

    Institute of Scientific and Technical Information of China (English)

    WANG Yong-Jun; WU Chong-Qing; WANG Zhi; YANG Shuang-Shou; ZHAO Shuang; WANG Ya-Ping; SHU Da; ZHAO Xi

    2009-01-01

    @@ We establish an equivalent cascaded semiconductor optical amplifier system model to analyze the characteristics of the double loop optical buffer (DLOB). The theoretical analysis finds that the performance of the DLOB can be improved by inserted amplifying process in an interval of some cycles. The experiment demonstrates that the buffered cycles can be improved from 20 to 50 and the bit error rate is less than 10-9 by inserting amplifying process in an interval of about 10 cycles.

  14. Double-Tubing Encapsulated Fiber Optic Temperature Sensor

    Science.gov (United States)

    Xu, Juncheng; Pickrell, Gary; Huang, Zhengyu; Qi, Bing; Zhang, Po; Duan, Yuhong; Wang, Anbo

    2003-09-01

    Increasing the efficiency of oil production operations requires improved sensors to supply critical information such as mixed-phase fluid flow, pressure and temperature measurements within the down-hole oil environment. In order to provide robust and reliable fiber optic temperature sensors capable of operating in the harsh down-hole oil environment, where temperatures might exceed 250 °C and pressures might reach 20,000 psi (140 Mpa), a novel type of fiber optic temperature sensor has been developed. This temperature sensor functions as an EFPI (extrinsic Fabry-Perot interferometric) sensor. One unique contribution of this work is that the glass tubing used is a borosilicate glass with a relatively high coefficient of thermal expansion (CTE) and long gauge length, allowing a much higher sensitivity to be achieved, without hysteresis. The sensor structure utilizes a dual tubing design (tubing within a tubing) to allow pressure isolation. An LED light beam is used as the signal interrogation source to remotely interrogate the sensor which may be located tens of thousands of meters away, connected by an optical fiber. A white-light interferometer measurement system is utilized to process the returned interference signal and to precisely determine the length of the Fabry-Perot interferometric cavity. Another unique feature of this work is that the sensor has been packaged with a specially developed hermetic protection process to prevent water penetration and to improve the mechanical integrity of the sensor. This protection process has allowed the successful hydraulic deployment of fiber optic sensors through 3 mm ID stainless steel tubing into a functioning oil well. Data on the resolution, repeatability and pressure sensitivity are presented.

  15. Measurement of creep of optical fiber by a low coherent white light double interferometer system

    Institute of Scientific and Technical Information of China (English)

    Farhad; ANSARI

    2009-01-01

    The creep properties of optical fiber used in fiber optical sensors were studied in this paper. A low co- herent white light double interferometer system was designed and calibrated and the creep deforma- tions of optical fibers under static and cyclic loadings were measured with this device. The research results showed that polymer coated optical fibers crept at the beginning when they were under static or cyclic load. As the number of the cyclic loading or the static loading times increased the creep tended to stop. Thus to ensure that the optical fiber keeps pre-stress for long time in pressure transducer, it is recommended that the optical fiber should be tensioned cyclically before being fixed into the sensor device.

  16. Measurement of creep of optical fiber by a low coherent white light double interferometer system

    Institute of Scientific and Technical Information of China (English)

    XU ZhiHong; Farhad ANSARI

    2009-01-01

    The creep properties of optical fiber used in fiber optical sensors were studied in this paper. A low co-herent white light double interferometer system was designed and calibrated and the creep deforma-tions of optical fibers under static and cyclic Ioadings were measured with this device. The research results showed that polymer coated optical fibers crept at the beginning when they were under static or cyclic load. As the number of the cyclic loading or the static loading times increased the creep tended to stop. Thus to ensure that the optical fiber keeps pro-stress for long time in pressure transducer, it is recommended that the optical fiber should be tensioned cyclically before being fixed into the sensor device.

  17. Theoretical modeling of the dynamics of a semiconductor laser subject to double-reflector optical feedback

    Science.gov (United States)

    Bakry, A.; Abdulrhmann, S.; Ahmed, M.

    2016-06-01

    We theoretically model the dynamics of semiconductor lasers subject to the double-reflector feedback. The proposed model is a new modification of the time-delay rate equations of semiconductor lasers under the optical feedback to account for this type of the double-reflector feedback. We examine the influence of adding the second reflector to dynamical states induced by the single-reflector feedback: periodic oscillations, period doubling, and chaos. Regimes of both short and long external cavities are considered. The present analyses are done using the bifurcation diagram, temporal trajectory, phase portrait, and fast Fourier transform of the laser intensity. We show that adding the second reflector attracts the periodic and perioddoubling oscillations, and chaos induced by the first reflector to a route-to-continuous-wave operation. During this operation, the periodic-oscillation frequency increases with strengthening the optical feedback. We show that the chaos induced by the double-reflector feedback is more irregular than that induced by the single-reflector feedback. The power spectrum of this chaos state does not reflect information on the geometry of the optical system, which then has potential for use in chaotic (secure) optical data encryption.

  18. Nanoconstructions on the base of double-stranded DNA molecules and their optical properties

    Science.gov (United States)

    Skuridin, S. G.; Yevdokimov, Yu. M.; Chulkov, D. P.; Gusev, V. M.; Kompanets, O. N.; Vereschagin, F. V.

    2016-12-01

    Experimental results have been presented on studying optical properties of nanoconstructions formed of orientationally ordered neighbouring double-stranded DNA molecules in the structure of their liquid-crystalline phases and dispersion particles of these phases including ones cured with intercalators.

  19. Theoretical modeling of the dynamics of a semiconductor laser subject to double-reflector optical feedback

    Energy Technology Data Exchange (ETDEWEB)

    Bakry, A. [King Abdulaziz University, 80203, Department of Physics, Faculty of Science (Saudi Arabia); Abdulrhmann, S. [Jazan University, 114, Department of Physics, Faculty of Sciences (Saudi Arabia); Ahmed, M., E-mail: mostafa.farghal@mu.edu.eg [King Abdulaziz University, 80203, Department of Physics, Faculty of Science (Saudi Arabia)

    2016-06-15

    We theoretically model the dynamics of semiconductor lasers subject to the double-reflector feedback. The proposed model is a new modification of the time-delay rate equations of semiconductor lasers under the optical feedback to account for this type of the double-reflector feedback. We examine the influence of adding the second reflector to dynamical states induced by the single-reflector feedback: periodic oscillations, period doubling, and chaos. Regimes of both short and long external cavities are considered. The present analyses are done using the bifurcation diagram, temporal trajectory, phase portrait, and fast Fourier transform of the laser intensity. We show that adding the second reflector attracts the periodic and perioddoubling oscillations, and chaos induced by the first reflector to a route-to-continuous-wave operation. During this operation, the periodic-oscillation frequency increases with strengthening the optical feedback. We show that the chaos induced by the double-reflector feedback is more irregular than that induced by the single-reflector feedback. The power spectrum of this chaos state does not reflect information on the geometry of the optical system, which then has potential for use in chaotic (secure) optical data encryption.

  20. Static thermo-optic instability in double-pass fiber amplifiers

    DEFF Research Database (Denmark)

    Lægsgaard, Jesper

    2016-01-01

    A coupled-mode formalism, earlier used to describe transverse mode instabilities in single-pass optical fiber amplifiers, is extended to the case of double-pass amplifiers. Contrary to the single-pass case, it is shown that the thermo-optic nonlinearity can couple light at the same frequency...... between the LP01 and LP11 modes, leading to a static deformation of the output beam profile. This novel phenomenon is caused by the interaction of light propagating in either direction with thermo-optic index perturbations caused by light propagating in the opposite direction. The threshold power...

  1. Optical double-image cryptography based on diffractive imaging with a laterally-translated phase grating.

    Science.gov (United States)

    Chen, Wen; Chen, Xudong; Sheppard, Colin J R

    2011-10-10

    In this paper, we propose a method using structured-illumination-based diffractive imaging with a laterally-translated phase grating for optical double-image cryptography. An optical cryptosystem is designed, and multiple random phase-only masks are placed in the optical path. When a phase grating is laterally translated just before the plaintexts, several diffraction intensity patterns (i.e., ciphertexts) can be correspondingly obtained. During image decryption, an iterative retrieval algorithm is developed to extract plaintexts from the ciphertexts. In addition, security and advantages of the proposed method are analyzed. Feasibility and effectiveness of the proposed method are demonstrated by numerical simulation results.

  2. Frequency-doubled telecom fiber laser for a cold atom interferometer using optical lattices

    Science.gov (United States)

    Theron, Fabien; Bidel, Yannick; Dieu, Emily; Zahzam, Nassim; Cadoret, Malo; Bresson, Alexandre

    2017-06-01

    A compact and robust frequency-doubled telecom laser system at 780 nm is presented for a rubidium cold atom interferometer using optical lattices. Adopting an optical switch at 1.5 μm and a dual-wavelength second harmonic generation system, only one laser amplifier is required for the laser system. Our system delivers a 900 mW laser beam with a detuning of 110 GHz for the optical lattice and a 650 mW laser beam with an adjustable detuning between 0 and -1 GHz for the laser cooling, the detection and the Raman transitions.

  3. Frequency doubled telecom fiber laser for a cold atom interferometer using optical lattices

    CERN Document Server

    Theron, Fabien; Dieu, Emily; Zahzam, Nassim; Cadoret, Malo; Zahzam, Nassim; Bresson, Alexandre

    2016-01-01

    A compact and robust laser system, based on a frequency-doubled telecom laser, providing all the lasers needed for a rubidium cold atom interferometer using optical lattices is presented. Thanks to an optical switch at 1.5 \\mu m and a dual-wavelength second harmonic generation system, only one laser amplifier is needed for all the laser system. Our system delivers at 780 nm a power of 900 mW with a detuning of 110 GHz for the optical lattice and a power of 650 mW with an adjustable detuning between 0 and -1 GHz for the laser cooling, the detection and the Raman transitions.

  4. Application of double-layered skin phantoms for optical flow imaging during laser tattoo treatments

    Science.gov (United States)

    Lee, Byeong-il; Song, Woosub; Kim, Hyejin; Kang, Hyun Wook

    2016-05-01

    The feasible application of double-layered skin phantoms was evaluated to identify artificial blood flow with a Doppler optical coherence tomography (DOCT) system for laser tattoo treatments. Polydimethylsiloxane (PDMS) was used to fabricate the artificial phantoms with flow channels embedded. A double-integrating sphere system with an inverse adding-doubling method quantified both the absorption and the reduced scattering coefficients for epidermis and dermis phantoms. Both OCT and caliper measurements confirmed the double-layered phantom structure (epidermis = 136 ± 17 µm vs. dermis = 3.0 ± 0.1 mm). The DOCT method demonstrated that high flow rates were associated with high image contrast, visualizing the position and the shape of the flow channel. Application of the channel-embedded skin phantoms in conjunction with DOCT can be a reliable technique to assess dynamic variations in the blood flow during and after laser tattoo treatments.

  5. Angular resolution measurements at SPring-8 of a hard x-ray optic for the New Hard X-ray Mission

    Science.gov (United States)

    Spiga, D.; Raimondi, L.; Furuzawa, A.; Basso, S.; Binda, R.; Borghi, G.; Cotroneo, V.; Grisoni, G.; Kunieda, H.; Marioni, F.; Matsumoto, H.; Mori, H.; Miyazawa, T.; Negri, B.; Orlandi, A.; Pareschi, G.; Salmaso, B.; Tagliaferri, G.; Uesugi, K.; Valsecchi, G.; Vernani, D.

    2011-09-01

    The realization of X-ray telescopes with imaging capabilities in the hard (> 10 keV) X-ray band requires the adoption of optics with shallow (=10 m shall be produced and tested. Full-illumination tests of such mirrors are usually performed with onground X-ray facilities, aimed at measuring their effective area and the angular resolution; however, they in general suffer from effects of the finite distance of the X-ray source, e.g. a loss of effective area for double reflection. These effects increase with the focal length of the mirror under test; hence a "partial" full-illumination measurement might not be fully representative of the in-flight performances. Indeed, a pencil beam test can be adopted to overcome this shortcoming, because a sector at a time is exposed to the X-ray flux, and the compensation of the beam divergence is achieved by tilting the optic. In this work we present the result of a hard X-ray test campaign performed at the BL20B2 beamline of the SPring-8 synchrotron radiation facility, aimed at characterizing the Point Spread Function (PSF) of a multilayer-coated Wolter-I mirror shell manufactured by Nickel electroforming. The mirror shell is a demonstrator for the NHXM hard X-ray imaging telescope (0.3 - 80 keV), with a predicted HEW (Half Energy Width) close to 20 arcsec. We show some reconstructed PSFs at monochromatic X-ray energies of 15 to 63 keV, and compare them with the PSFs computed from post-campaign metrology data, self-consistently treating profile and roughness data by means of a method based on the Fresnel diffraction theory. The modeling matches the measured PSFs accurately.

  6. Double peacock eye optical element for extended focal depth imaging with ophthalmic applications.

    Science.gov (United States)

    Romero, Lenny A; Millán, María S; Jaroszewicz, Zbigniew; Kolodziejczyk, Andrzej

    2012-04-01

    The aged human eye is commonly affected by presbyopia, and therefore, it gradually loses its capability to form images of objects placed at different distances. Extended depth of focus (EDOF) imaging elements can overcome this inability, despite the introduction of a certain amount of aberration. This paper evaluates the EDOF imaging performance of the so-called peacock eye phase diffractive element, which focuses an incident plane wave into a segment of the optical axis and explores the element's potential use for ophthalmic presbyopia compensation optics. Two designs of the element are analyzed: the single peacock eye, which produces one focal segment along the axis, and the double peacock eye, which is a spatially multiplexed element that produces two focal segments with partial overlapping along the axis. The performances of the peacock eye elements are compared with those of multifocal lenses through numerical simulations as well as optical experiments in the image space. The results demonstrate that the peacock eye elements form sharper images along the focal segment than the multifocal lenses and, therefore, are more suitable for presbyopia compensation. The extreme points of the depth of field in the object space, which represent the remote and the near object points, have been experimentally obtained for both the single and the double peacock eye optical elements. The double peacock eye element has better imaging quality for relatively short and intermediate distances than the single peacock eye, whereas the latter seems better for far distance vision.

  7. Optical absorption in asymmetric double quantum wells driven by two intense terahertz fields

    Institute of Scientific and Technical Information of China (English)

    Wu Hong-Wei; Mi Xian-Wu

    2013-01-01

    Optical absorption is investigated for asymmetric double quantum wells driven by a resonant terahertz field and a varied terahertz field,both polarized along the growth direction.Rich nonlinear dynamics of the replica peak and the Autler-Townes splitting of various dressed states are systematically studied in undoped asymmetric double quantum wells by taking account of multiple factors,such as the frequency of the varied terahertz field and the strength of the resonant terahertz field.Each electron subband splits into two dressed states when the resonant terahertz field is applied in the absence of the varied terahertz field,the optical absorption spectrum shows the first-order Autler-Townes splitting of the electron subbands.When a varied terahertz field is added into the resonant system,the replica peak and the second-order Autler-Townes splitting of the dressed states near the band edge respectively emerge when the varied terahertz field is non-resonant and resonant with these dressed states.Wben the strength of the resonant terahertz field is increased,the first-order Autler-Townes double peaks and the replica peak in the optical absorption spectrum shift with the shifts of the dressed states.The presented results have potential applications in electro-optical devices.

  8. Hierarchical Supervisor and Agent Routing Algorithm in LEO/MEO Double-layered Optical Satellite Network

    Science.gov (United States)

    Li, Yongjun; Zhao, Shanghong

    2016-09-01

    A novel routing algorithm (Hierarchical Supervisor and Agent Routing Algorithm, HSARA) for LEO/MEO (low earth orbit/medium earth orbit) double-layered optical satellite network is brought forward. The so-called supervisor (MEO satellite) is designed for failure recovery and network management. LEO satellites are grouped according to the virtual managed field of MEO which is different from coverage area of MEO satellite in RF satellite network. In each LEO group, one LEO satellite which has maximal persistent link with its supervisor is called the agent. A LEO group is updated when this optical inter-orbit links between agent LEO satellite and the corresponding MEO satellite supervisor cuts off. In this way, computations of topology changes and LEO group updating can be decreased. Expense of routing is integration of delay and wavelength utilization. HSARA algorithm simulations are implemented and the results are as follows: average network delay of HSARA can reduce 21 ms and 31.2 ms compared with traditional multilayered satellite routing and single-layer LEO satellite respectively; LEO/MEO double-layered optical satellite network can cover polar region which cannot be covered by single-layered LEO satellite and throughput is 1% more than that of single-layered LEO satellite averagely. Therefore, exact global coverage can be achieved with this double-layered optical satellite network.

  9. Optical Tweezers Analysis of Double-Stranded DNA Denaturation in the Presence of Urea

    Science.gov (United States)

    Zhu, Chunli; Li, Jing

    2016-09-01

    Urea is a kind of denaturant prone to form hydrogen bonds with the electronegative centers of the nitrogenous bases, threatening the stability of hydrogen bonds between DNA base pairs. In this paper, the stability and stiffness of DNA double helix influenced by urea are investigated at single-molecule level using optical tweezers. Experimental results show that DNA's double helix stability and stiffness both decrease with increasing urea concentration. In addition, the re-forming of ruptured hydrogen bonds between the base pairs is blocked by urea as the tension on DNA is released.

  10. Reduction of the Shupe effect in interferometric fiber optic gyroscopes: The double cylinder-wound coil

    Science.gov (United States)

    Ling, Weiwei; Li, Xuyou; Yang, Hanrui; Liu, Pan; Xu, Zhenlong; Wei, Yanhui

    2016-07-01

    For the first time, we introduce a novel double-cylinder winding method for reducing the Shupe effect in interferometric fiber optic gyroscopes (IFOGs). Simulation by finite element method (FEM) is performed to calculate the dynamic temperature distribution of fiber coils, which can obtained thermal-induced rate errors in IFOGs with cross-wound coil and double cylinder-wound coil respectively. Simulation results reveal that thermal-induced rate errors in IFOGs by both winding methods can be substantially reduced under the same variable temperature conditions, but the latter has a simpler winding technology. This study is promising for reducing the temperature fragility of IFOGs.

  11. Multi-band optical/IR transmissometry during the VAMPIRA trials, spring 2004

    NARCIS (Netherlands)

    Jong, A.N. de; Cohen, L.H.; Moerman, M.M.

    2004-01-01

    Scattering by atmospheric aerosols is one of the environmental parameters determining the range performance of optical and infrared sensors. Extinction of the target contrast along the path due to scattering is difficult to estimate in real operational conditions due to uncertainties in the size

  12. 双层板簧夹持的直线型超声电机%Study on the Linear Ultrasonic Motor Clamped by Double Leaf Springs

    Institute of Scientific and Technical Information of China (English)

    于会民; 王寅; 陈乾伟; 黄卫清

    2011-01-01

    The existing problems of the linear ultrasonic motor clamping device have been analyized in this paper. A new clamping scheme based on the the doulbe leaf springs has been designed for the V-shape stator with the double amplitude amplifier pole. The double leaf spring structure clamping device can limit the degree of freedom of the stator along the driving direction and accordingly the mechanical properties have been improved significantly,in addition, the two-tier parallel structure was an effective solution to the tortuosity of the stator and accordingly the stability of the motor has been improved significantly. The maximum output force, maximum power and the maximum efficiency of the motor have been up to 17. 7 N,0. 67 W and 19. 7% respectively.%分析了目前直线型超声电机夹持装置存在的问题,并针对双变幅杆V形定子结构提出了双层板簧夹持方案.双层板簧结构可限制定子沿驱动方向的自由度,从而提高了电机的机械性能,其双层平行结构可有效地解决定子工作过程中的扭转,提高了电机的稳定性,电机最大输出力达17.7 N,最大功率为0.67 W.最高效率为19.7%.

  13. Theoretical analysis on double Rayleigh backscattering noise in optical fibre Raman amplifiers and its suppression

    Institute of Scientific and Technical Information of China (English)

    Jiang Wen-Ning; Chen Jian-Ping; Li Xin-Wan; Shang Tao

    2004-01-01

    In this paper, amplified double Rayleigh backscattering noise (DRB) in the optical fibre Raman amplifier is analysed. Expressions are presented for both forward pumping and backward pumping schemes. Calculation is performed to show the effective suppression of DRB noise by employing an optical isolator. The optimal position for the isolator is determined and is found to be insensitive to the power levels of the signals and pumps. The results show that a reduction of the DRB noise by almost 2 to 3 orders can be reached.

  14. High frequency optical pulse generation by frequency doubling using polarization rotation

    Science.gov (United States)

    Liu, Yang

    2016-05-01

    In this work, we propose and experimentally characterize a stable 40 GHz optical pulse generation by frequency doubling using polarization rotation in a phase modulator (PM). Only half the electrical driving frequency is required (i.e. 20 GHz); hence the deployment cost can be reduced. Besides, precise control of the bias of the PM is not required. The generated optical pulses have a high center-mode-suppression-ratio (CMSR) of  >  28 dB. The single sideband (SSB) noise spectrum is also measured, and the time-domain waveforms under different CMSRs are also analyzed and discussed.

  15. Double pass in acousto-optic tunable filter for telecommunication network

    Science.gov (United States)

    Issa, Hadeel; Quintard, Véronique; Pérennou, André; Sakkour, Afif

    2014-07-01

    We investigate an acousto-optic tunable filter setup for wavelength division multiplexing telecommunication applications in wideband C (100 nm around 1550 nm). Anisotropic Bragg diffraction of light in TeO2 bulk crystal is first investigated experimentally and theoretically in a quasi-collinear interaction configuration. Based on those characterizations, we propose a double-pass optical beam which allows us to improve the filter performances in terms of crosstalk and selectivity: the full width at half maximum and the sidelobe level are reduced.

  16. Voltage-controlled wavelength conversion by terahertz electro-optic modulation in double quantum wells

    CERN Document Server

    Su, M Y; Sherwin, M S; Huntington, A S; Coldren, L A

    2002-01-01

    An undoped double quantum well (DQW) was driven with a terahertz (THz) electric field of frequency \\omega_{THz} polarized in the growth direction, while simultaneously illuminated with a near-infrared (NIR) laser at frequency \\omega_{NIR}. The intensity of NIR upconverted sidebands \\omega_{sideband}=\\omega_{NIR} + \\omega_{THz} was maximized when a dc voltage applied in the growth direction tuned the excitonic states into resonance with both the THz and NIR fields. There was no detectable upconversion far from resonance. The results demonstrate the possibility of using gated DQW devices for all-optical wavelength shifting between optical communication channels separated by up to a few THz.

  17. Dynamic Variation in Protein-Small Molecule Interaction Observed by Double-Nanohole Optical Trapping

    CERN Document Server

    Balushi, Ahmed Al

    2014-01-01

    The interaction of proteins with small molecules is fundamental to their function in living organisms and it is widely studied in drug development. Here we compare optical trapping dynamics of streptavidin and biotinylated streptavidin using a double nanohole optical trap in a metal film. Consistent and clearly distinct behavior is seen between the protein with and without the small molecule binding. The real-time dynamics at the single protein level are accessible with this technique, which also has advantages of not requiring tethering to a surface or the need for exogeneous markers.

  18. Negative and positive hysteresis in double-cavity optical bistability in three-level atom

    CERN Document Server

    Babu, H Aswath

    2010-01-01

    We present novel hysteretic behaviour of a three-level ladder atomic system exhibiting double-cavity optical bistability in the mean-field limit. The two fields coupling the atomic system experience feedback via two independent, unidirectional, single mode ring cavities and exhibit cooperative phenomena, simultaneously. The system displays a range of rich dynamical features varying from normal switching to self pulsing and a period-doubling route to chaos for both the fields. We focus our attention to a new hump like feature in the bistable curve arising purely due to cavity induced inversion, which eventually leads to negative hysteresis in the bistable response. This is probably the only all-optical bistable system that exhibits positive as well as negative bistable hysteresis in different input field intensity regimes. For both the fields, the switching times, the associated critical slowing down, the self-pulsing characteristics, and the chaotic behaviour can be controlled to a fair degree, moreover, all ...

  19. Few-Photon All-Optical {\\pi} Phase modulation Based on a Double-{\\Lambda} System

    CERN Document Server

    Chen, Yen-Chun; Lo, Hsiang-Yu; Tsai, Bing-Ru; Yu, Ite A; Chen, Ying-Cheng; Chen, Yong-Fan

    2013-01-01

    We propose an efficient all-optical phase modulation based on a double-{\\Lambda} system and demonstrate a {\\pi} phase shift of a few-photon pulse induced by another few-photon pulse in cold rubidium atoms with this scheme. By changing the phases of the applied laser fields, one can control the property of the double-{\\Lambda} medium. This phase-dependent mechanism makes the double-{\\Lambda} system different form the conventional cross-Kerr-based system which only depends on the applied laser intensities. The proposed scheme provides a new route to generate strong nonlinear interactions between photons, and may have potential for applications in quantum information technologies.

  20. Phytoplankton, sediment and optical observations in Netherlands coastal water in spring

    Science.gov (United States)

    Wild-Allen, Karen; Lane, Andrew; Tett, Paul

    2002-06-01

    Factors controlling the dynamics of suspended particulate matter (SPM), its influence on sea-leaving radiance and in-water optical properties, and the consequences of optical variation for phytoplankton growth, were studied at the 'Processes of Vertical Exchange in Shelf Seas' (PROVESS) project's southern North Sea site during April 1999. The optical properties of Netherlands coastal water were not unexpectedly found to be primarily determined by suspended sediment (Case 2) and were classified as Jerlov type 7 'relatively turbid coastal water'. During the study period, vertical mixing periodically resuspended optically active particles from the bed fluff layer throughout the water column and into the near-surface layer. These particles influenced sea surface radiance reflectance, and the red/green ratio of radiance reflectance, both of which can be observed by remote sensing. Linear relationships between sea surface radiance reflectance and SPM concentration were primarily determined by the inorganic fraction, as organic SPM varied little in concentration throughout the cruise period. The inorganic fraction was an important scatterer of light at all wavelengths, whereas the organic fraction displayed a greater tendency for light absorption at shorter wavelengths. Although the euphotic layer (depth of 1% surface irradiance) was only 8-10 m deep, vertical mixing ensured that phytoplankton throughout the water column (˜18 m) had access to PAR in excess of the estimated compensation illumination. Growth rates of microplankton (which includes pelagic microheterotrophs as well as phytoplankters) were calculated using an algorithm from the PROWQM model. These ranged from 0.1 to 0.3 d -1, and implied loss rates of 3-25% which were mostly attributed to mesozooplankton grazing. Estimated oxygen production, however, was in near equilibrium with oxygen demand observed in dark bottles, and implied a significant oxygen demand due to detrital respiration and nitrification. This

  1. Beyond the Hookean Spring Model: Direct Measurement of Optical Forces Through Light Momentum Changes.

    Science.gov (United States)

    Farré, Arnau; Marsà, Ferran; Montes-Usategui, Mario

    2017-01-01

    The ability to measure forces in the range of 0.1-100 pN is a key feature of optical tweezers used for biophysical and cell biological studies. Analysis of the interactions between biomolecules and the forces that biomolecular motors generate at the single-molecule level has provided valuable insights in the molecular mechanisms that govern key cellular functions such as gene expression and the long-distance transport of organelles. Methods for determining the minute forces that biomolecular motors generate exhibit notable constraints that limit their application for studies other than the well-controlled in vitro experiments (although recent advances have been made that permit more quantitative optical tweezers studies insight living cells). One constraint comes from the linear approximation of the distance vs. force relationship used to extract the force from the position of the bead in the trap. This commonly employed "indirect" approach, although usually sufficiently precise, restricts the use of optical tweezers to a limited range of displacements (typically up to ±150 nm for small beads). Measurements based on the detection of the light-momentum changes, on the other hand, offer a "direct" and precise way to determine forces even when the generated displacements reach the escape point, thus covering the complete force range developed by the trap. In this chapter, we detail the requirements for the design of a force-sensor instrument based on light-momentum changes using a high-numerical-aperture objective lens and provide insights into its construction. We further discuss the calibration of the system and the main steps for its routine operation.

  2. Active Optical Sensing of Spring Maize for In-Season Diagnosis of Nitrogen Status Based on Nitrogen Nutrition Index

    Directory of Open Access Journals (Sweden)

    Tingting Xia

    2016-07-01

    Full Text Available The nitrogen (N nutrition index (NNI is a reliable indicator of crop N status and there is an urgent need to develop efficient technologies for non-destructive estimation of NNI to support the practical applications of precision N management strategies. The objectives of this study were to: (i validate a newly established critical N dilution curve for spring maize in Northeast China; (ii determine the potential of using the GreenSeeker active optical sensor to non-destructively estimate NNI; and (iii evaluate the performance of different N status diagnostic approaches based on estimated NNI via the GreenSeeker sensor measurements. Four field experiments involving six N rates (0, 60, 120,180, 240, and 300 kg·ha−1 were conducted in 2014 and 2015 in Lishu County, Jilin Province in Northeast China. The results indicated that the newly established critical N dilution curve was suitable for spring maize N status diagnosis in the study region. Across site-years and growth stages (V5–V10, GreenSeeker sensor-based vegetation indices (VIs explained 87%–90%, 87%–89% and 83%–84% variability of leaf area index (LAI, aboveground biomass (AGB and plant N uptake (PNU, respectively. However, normalized difference vegetation index (NDVI became saturated when LAI > 2 m2·m−2, AGB > 3 t·ha−1 or PNU > 80 kg·ha−1. The GreenSeeker-based VIs performed better for estimating LAI, AGB and PNU at V5–V6 and V7–V8 than the V9–V10 growth stages, but were very weakly related to plant N concentration. The response index calculated with GreenSeeker NDVI (RI–NDVI and ratio vegetation index (R2 = 0.56–0.68 performed consistently better than the original VIs (R2 = 0.33–0.55 for estimating NNI. The N status diagnosis accuracy rate using RI–NDVI was 81% and 71% at V7–V8 and V9–V10 growth stages, respectively. We conclude that the response indices calculated with the GreenSeeker-based vegetation indices can be used to estimate spring maize NNI non

  3. EXPERIMENTAL STUDIES OF ERROR COMPENSATION FOR OPTICAL SIGNAL COORDINATE DETERMINATION BY DOUBLE SYNTHESIZED APERTURE

    Directory of Open Access Journals (Sweden)

    A. G. Obolenskov

    2016-09-01

    Full Text Available Subject of Research. The paper presents theoretical and experimental analysis of dependence of the determination error of a modulated optical signal under intense background illumination on the value of mutual shift of two current-voltage characteristics if using a double synthesized aperture on multiscan position-sensitive detector. Method. The studies have been carried out on a specially designed setup, that allows scanning photosensitive area of multiscan position-sensitive detector by an optical beam that imitates intense solar illumination. At the same time the position error of determination of weak modulated optical signal coordinate is measured at different relative position of signal and background illumination, and background power. Main Results. Experimental studies have confirmed the theoretical conclusions. It is shown that the use of double synthesized aperture of multiscan position-sensitive detector with the voltage shift of the current-voltage characteristics equal to 0.4 V enables to reduce position determination error of a weak modulated signal by an order of magnitude. Practical Relevance. Research results have opened the opportunity of accuracy increase for position-sensitive systems operating under background illuminations exceeding the level of information optical signal.

  4. A 130 GHz Electro-Optic Ring Modulator with Double-Layer Graphene

    Directory of Open Access Journals (Sweden)

    Lei Wu

    2017-02-01

    Full Text Available The optical absorption coefficient of graphene will change after injecting carriers. Based on this principle, a high-speed double-layer graphene electro-optic modulator with a ring resonator structure was designed in this paper. From the numerical simulations, we designed a modulator. Its optical bandwidth is larger than 130 GHz, the switching energy is 0.358 fJ per bit, and the driven voltage is less than 1.2 V. At the same time, the footprint of the proposed modulator is less than 10 microns squared, which makes the process compatible with the Complementary Metal Oxide Semiconductors (CMOS process. This will provide the possibility for the on-chip integration of the photoelectric device.

  5. Scalable photonic quantum computing assisted by quantum-dot spin in double-sided optical microcavity.

    Science.gov (United States)

    Wei, Hai-Rui; Deng, Fu-Guo

    2013-07-29

    We investigate the possibility of achieving scalable photonic quantum computing by the giant optical circular birefringence induced by a quantum-dot spin in a double-sided optical microcavity as a result of cavity quantum electrodynamics. We construct a deterministic controlled-not gate on two photonic qubits by two single-photon input-output processes and the readout on an electron-medium spin confined in an optical resonant microcavity. This idea could be applied to multi-qubit gates on photonic qubits and we give the quantum circuit for a three-photon Toffoli gate. High fidelities and high efficiencies could be achieved when the side leakage to the cavity loss rate is low. It is worth pointing out that our devices work in both the strong and the weak coupling regimes.

  6. Experimental demonstration of sharp Fano resonance in optical metamaterials composed of asymmetric double bars.

    Science.gov (United States)

    Moritake, Yuto; Kanamori, Yoshiaki; Hane, Kazuhiro

    2014-07-01

    We experimentally demonstrated Fano resonance in metamaterials composed of asymmetric double bars (ADBs) in the optical region. ADB metamaterials were fabricated by a lift-off method, and the optical spectra were measured. Around a wavelength of 1100 nm, measured optical spectra clearly showed sharp Fano resonance due to weak asymmetry of the ADB structures. The highest-quality factor (Q-factor) of the Fano resonance was 7.34. Calculated spectra showed the same tendency as the experimental spectra. Moreover, in a Fano resonant condition, out of phase of induced current flowing along each bar was revealed by electromagnetic field calculations. These antiphase currents decreased radiative loss of the Fano mode, resulting in a high Q-factor of the Fano resonance in ADB metamaterials. As the degree of asymmetry became small, the Q-factor decreased, and the Fano resonance disappeared because the effect of Joule loss became significant.

  7. Research algorithm for synthesis of double conjugation optical systems in the Gauss region

    Directory of Open Access Journals (Sweden)

    A. B. Ostrun

    2014-01-01

    Full Text Available The article focuses on the research of variable magnification optical systems of sophistic class - so-called double conjugation systems. When the magnification changes, they provide two pairs of fixed conjugate planes, namely object and image, as well as entrance and exit pupils. Similar systems are used in microscopy and complex schemes, where it is necessary to conform the pupils of contiguous removable optical components. Synthesis of double conjugation systems in Gauss region is not an easy task. To ensure complete immobility of the exit pupil in the system there should be three movable components or components with variable optical power.Analysis of the literature shows that the design of double conjugation optical system in the paraxial region has been neglected, all methods are not completely universal and suitable for automation.Based on the foregoing, the research and development of a universal method for automated synthesis of double conjugation systems in Gauss region formulated as an objective of the present work seem to be a challenge.To achieve this goal a universal algorithm is used. It is based on the fact that the output coordinates of paraxial rays are multilinear functions of optical surfaces and of axial thicknesses between surfaces. It allows us to create and solve a system of multilinear equations in semi-automatic mode to achieve the chosen values of paraxial characteristics.As a basic scheme for the synthesis a five-component system has been chosen with extreme fixed components and three mobile "internal" ones. The system was considered in two extreme states of moving parts. Initial values of axial thicknesses were taken from Hopkins' patent. Optical force five components were considered unknown. For calculation the system of five equations was created, which allowed us to obtain a certain back focal length, to provide the specified focal length and a fixed position of the exit pupil at a fixed entrance pupil.The scheme

  8. Optical emission studies of plasma induced by single and double femtosecond laser pulses

    Energy Technology Data Exchange (ETDEWEB)

    Pinon, V. [Institute of Electronic Structure and Laser, Foundation for Research and Technology-Hellas (IESL-FORTH), P.O. Box 1385, 71110 Heraklion, Crete (Greece); Universidad de A Coruna, Departamento de Ingenieria Industrial II, E-15403 Ferrol, A Coruna (Spain); Anglos, D., E-mail: anglos@iesl.forth.g [Institute of Electronic Structure and Laser, Foundation for Research and Technology-Hellas (IESL-FORTH), P.O. Box 1385, 71110 Heraklion, Crete (Greece); Department of Chemistry, University of Crete, 71003 Heraklion, Crete (Greece)

    2009-10-15

    Double-pulse femtosecond laser ablation has been shown to lead to significant increase of the intensity and reproducibility of the optical emission signal compared to single-pulse ablation particularly when an appropriate interpulse delay is selected, that is typically in the range of 50-1000 ps. This effect can be especially advantageous in the context of femtosecond laser-induced breakdown spectroscopy analysis of materials. A detailed comparative study of collinear double- over single-pulse femtosecond laser-induced breakdown spectroscopy has been carried out, based on measurements of emission lifetime, temperature and electronic density of plasmas, produced during laser ablation of brass with 450 fs laser pulses at 248 nm. The results obtained show a distinct increase of plasma temperature and electronic density as well as a longer decay time in the double-pulse case. The plasma temperature increase is in agreement with the observed dependence of the emission intensity enhancement on the upper energy level of the corresponding spectral line. Namely, intensity enhancement of emission lines originating from higher lying levels is more profound compared to that of lines arising from lower energy levels. Finally, a substantial decrease of the plasma threshold fluence was observed in the double-pulse arrangement; this enables sensitive analysis with minimal damage on the sample surface.

  9. Steganographic optical image encryption system based on reversible data hiding and double random phase encoding

    Science.gov (United States)

    Chuang, Cheng-Hung; Chen, Yen-Lin

    2013-02-01

    This study presents a steganographic optical image encryption system based on reversible data hiding and double random phase encoding (DRPE) techniques. Conventional optical image encryption systems can securely transmit valuable images using an encryption method for possible application in optical transmission systems. The steganographic optical image encryption system based on the DRPE technique has been investigated to hide secret data in encrypted images. However, the DRPE techniques vulnerable to attacks and many of the data hiding methods in the DRPE system can distort the decrypted images. The proposed system, based on reversible data hiding, uses a JBIG2 compression scheme to achieve lossless decrypted image quality and perform a prior encryption process. Thus, the DRPE technique enables a more secured optical encryption process. The proposed method extracts and compresses the bit planes of the original image using the lossless JBIG2 technique. The secret data are embedded in the remaining storage space. The RSA algorithm can cipher the compressed binary bits and secret data for advanced security. Experimental results show that the proposed system achieves a high data embedding capacity and lossless reconstruction of the original images.

  10. Phase-sensitive microwave optical double resonance in an N system

    Science.gov (United States)

    Preethi, T. M.; Manukumara, M.; Asha, K.; Vijay, J.; Roshi, D. A.; Narayanan, A.

    2011-08-01

    An experimental investigation of a Microwave Optical Double Resonance (MODR) phenomenon is carried out in a four level N system of 85Rb atoms, at room temperature. This N system consists of a closed three level Λ subsystem irradiated with two optical fields and one microwave field. The MODR response is investigated in a separate probe field which drives a resonant transition from one of the ground states of the Λ system to a fourth level. We find that, under two-photon resonance condition for the optical fields, the MODR becomes a function of the relative phase between the beat frequency envelop of the optical fields and the microwave field. The variation in MODR is shown to be correlated with the phase-sensitive variation of the EIT phenomenon seen in such microwave-connected closed Λ systems. We envisage that this phase-sensitive variation in the MODR, can be utilized for a phase-sensitive manipulation of non-linear optical phenomena in N systems.

  11. U-shaped, double-tapered, fiber-optic sensor for effective biofilm growth monitoring

    Science.gov (United States)

    Zhong, Nianbing; Zhao, Mingfu; Li, Yishan

    2016-01-01

    To monitor biofilm growth on polydimethylsiloxane in a photobioreactor effectively, the biofilm cells and liquids were separated and measured using a sensor with two U-shaped, double-tapered, fiber-optic probes (Sen. and Ref. probes). The probes’ Au-coated hemispherical tips enabled double-pass evanescent field absorption. The Sen. probe sensed the cells and liquids inside the biofilm. The polyimide–silica hybrid-film-coated Ref. probe separated the liquids from the biofilm cells and analyzed the liquid concentration. The biofilm structure and active biomass were also examined to confirm the effectiveness of the measurement using a simulation model. The sensor was found to effectively respond to the biofilm growth in the adsorption through exponential phases at thicknesses of 0–536 μm. PMID:26977344

  12. Optical double image encryption employing a pseudo image technique in the Fourier domain

    Science.gov (United States)

    Guo, Changliang; Liu, Shi; Sheridan, John T.

    2014-06-01

    A novel optical encryption method is proposed involving double image encryption in which one image is introduced as the pseudo image while the other is the original object image. The Double Random Phase Encoding technique is used to encrypt both the pseudo and object images into complex images. A unique binary image is then employed to first generate the random phase key for the object image encryption and then to embed the encrypted object image into the encrypted pseudo image, which acts as host image. Both the second random phase mask used for encoding the pseudo image and the binary image act as encryption keys. If an attacker attempts to crack the random phase key and decrypt the original object image, the pseudo image will be obtained instead. Simulation results and robustness tests are performed which demonstrate the feasibility of the algorithm.

  13. U-shaped, double-tapered, fiber-optic sensor for effective biofilm growth monitoring.

    Science.gov (United States)

    Zhong, Nianbing; Zhao, Mingfu; Li, Yishan

    2016-02-01

    To monitor biofilm growth on polydimethylsiloxane in a photobioreactor effectively, the biofilm cells and liquids were separated and measured using a sensor with two U-shaped, double-tapered, fiber-optic probes (Sen. and Ref. probes). The probes' Au-coated hemispherical tips enabled double-pass evanescent field absorption. The Sen. probe sensed the cells and liquids inside the biofilm. The polyimide-silica hybrid-film-coated Ref. probe separated the liquids from the biofilm cells and analyzed the liquid concentration. The biofilm structure and active biomass were also examined to confirm the effectiveness of the measurement using a simulation model. The sensor was found to effectively respond to the biofilm growth in the adsorption through exponential phases at thicknesses of 0-536 μm.

  14. Reconstructing optical parameters from double-integrating-sphere measurements using a genetic algorithm

    Science.gov (United States)

    Böcklin, Christoph; Baumann, Dirk; Stuker, Florian; Klohs, Jan; Rudin, Markus; Fröhlich, Jürg

    2013-02-01

    For the reconstruction of physiological changes in specific tissue layers detected by optical techniques, the exact knowledge of the optical parameters μa, μs and g of different tissue types is of paramount importance. One approach to accurately determine these parameters for biological tissue or phantom material is to use a double-integrating-sphere measurement system. It offers a flexible way to measure various kinds of tissues, liquids and artificial phantom materials. Accurate measurements can be achieved by technical adjustments and calibration of the spheres using commercially available reflection and transmission standards. The determination For the reconstruction of physiological changes in specific tissue layers detected by optical techniques, the exact knowledge of the optical parameters μa, μs and g of different tissue types is of paramount importance. One approach to accurately determine these parameters for biological tissue or phantom material is to use a double-integrating-sphere measurement system. It offers a flexible way to measure various kinds of tissues, liquids and artificial phantom materials. Accurate measurements can be achieved by technical adjustments and calibration of the spheres using commercially available reflection and transmission standards. The determination of the optical parameters of a material is based on two separate steps. Firstly, the reflectance ρs, the total transmittance TsT and the unscattered transmittance TsC of the sample s are measured with the double-integrating-sphere setup. Secondly, the optical parameters μa, μs and g are reconstructed with an inverse search algorithm combined with an appropriate solver for the forward problem (calculating ρs, TsT and TsC from μa, μs and g) has to be applied. In this study a Genetic Algorithm is applied as search heuristic, since it offers the most flexible and general approach without requiring any foreknowledge of the fitness-landscape. Given the challenging

  15. Regional aerosol optical properties and radiative impact of the extreme smoke event in the European Arctic in spring 2006

    Directory of Open Access Journals (Sweden)

    C. Lund Myhre

    2007-11-01

    Full Text Available In spring 2006 a special meteorological situation occurred in the European Arctic region giving record high levels of air pollution. The synoptic situation resulted in extensive transport of pollution predominantly from agricultural fires in Eastern Europe into the Arctic region and record high air-pollution levels were measured at the Zeppelin observatory at Ny-Ålesund (78°54' N, 11°53' E in the period from 25 April to 12 May. In the present study we investigate the optical properties of the aerosols from this extreme event and we estimate the radiative forcing of this episode.

    We examine the aerosol optical properties from the source region and into the European Arctic and explore the evolution of the episode and the changes in the optical properties. A number of sites in Eastern Europe, Northern Scandinavia and Svalbard are included in the study. The observations show that the maximum AOD was from 2–3 May at all sites and varies from 0.52 to 0.87, and the corresponding Ångstrøm exponent was relatively large. Lidar measurements from Minsk, ALOMAR (Arctic Lidar Observatory for Middle Atmosphere Research at Andenes and Ny-Ålesund show that the aerosol layer was below 3 km at all sites the height is decreasing from the source region and into the Arctic. For the AERONET sites included (Minsk, Toravere, Hornsund we have further studied the evolution of the aerosol size. The single scattering albedo at Svalbard is provided for two sites; Ny-Ålesund and Hornsund. Importantly the calculated single scattering albedo based on the aerosol chemical composition and size distribution from Ny-Ålesund and the AERONET measurements at Hornsund are consistent. We have found strong agreement between the satellite daily MODIS AOD and the ground-based AOD observations. This agreement is crucial for accurate radiative forcing calculations. We calculate a strong negative radiative forcing for the most polluted days employing the analysed

  16. Linearized electro-optic racetrack modulator based on double injection method in silicon.

    Science.gov (United States)

    Cohen, Roei Aviram; Amrani, Ofer; Ruschin, Shlomo

    2015-02-09

    Racetrack-based modulator of increased linearity for optical links is presented and analyzed. The modulator is referred to as FLAME - Finer Linearity Amplitude Modulation Element. Linearity is improved via the introduction of a Double Injection approach. Large spurious-free-dynamic-range (SFDR) of 132dB·Hz(4/5) can thus be theoretically obtained. The FLAME is studied for silicon platform and requires small footprint size (100 × 50µm2) and low operation voltage, 2.5V. This makes the FLAME an appealing candidate for large scale integration in RF photonics.

  17. Synthesis and Characterization of Layered Double Hydroxides Containing Optically Active Transition Metal Ion

    Science.gov (United States)

    Tyagi, S. B.; Kharkwal, Aneeta; Nitu; Kharkwal, Mamta; Sharma, Raghunandan

    2017-01-01

    The acetate intercalated layered double hydroxides of Zn and Mn, have been synthesized by chimie douce method. The materials were characterized by XRD, TGA, CHN, IR, XPS, SEM-EDX and UV-visible spectroscopy. The photoluminescence properties was also studied. The optical properties of layered hydroxides are active transition metal ion dependent, particularly d1-10 system plays an important role. Simultaneously the role of host - guest orientation has been considered the basis of photoluminescence. Acetate ion can be exchanged with iodide and sulphate ions. The decomposed product resulted the pure phase Mn doped zinc oxide are also reported.

  18. Optical information authentication via compressed sensing and double random phase encoding

    Science.gov (United States)

    Chen, Junxin; Bao, Nan; Zhu, Zhi-liang

    2017-10-01

    This paper presents a novel information authentication scheme via compressed sensing and double random phase encoding. Two alternative architectures have been investigated, in which significantly compressed data with micro percentage is sufficient for authentication. At the decoder end, a noise-like image with no leakage of the plaintext is recovered and subsequently authenticated using a nonlinear optical correlation approach. The authentication effectiveness, noise resistance and security performance of the proposed scheme have been experimentally validated. This work was supported by the Fundamental Research Funds for the Central Universities (N162410002-4, N151904002), the National Natural Science Foundation of China (No. 61374178).

  19. Four-Wave Mixing of a Laser and Its Frequency-Doubled Version in a Multimode Optical Fiber

    Directory of Open Access Journals (Sweden)

    Hamed Pourbeyram

    2015-08-01

    Full Text Available It is shown that it is possible to couple a laser beam and its frequency-doubled daughter into a multimode optical fiber through the four-wave mixing nonlinear process and generate a new wavelength. The frequency-doubled daughter can be generated in an external crystal with a large second order nonlinearity. It is argued that while this possibility is within the design parameter range of conventional multimode optical fibers, it necessitates a lower-bound for the core-cladding refractive index contrast of the multimode optical fiber.

  20. Research on the methods of optical image hiding based on double random phase encoding and digital holography

    Science.gov (United States)

    Xu, Hongsheng; Sang, Nong

    2011-12-01

    Optical information hiding system has many features such as high processing speed, high parallel, high encryption dimension and high speed of optical transformation and related operations, more advantages than digital method in some way. But it has not adequate security, and enough combination with techniques of digital image processing. So on basis of analyzing existing image hiding and analyzing techniques, we give out the idea. We should adopt idea of virtual optics on the way of all-digital simulation to do research of optical image hiding and analyzing methods based on optical image processing technique especially technique of double random phase encoding and digital holography.

  1. A Novel All-Optical Switch in a Double-Loop Sagnac Ring Coupled with a Nonlinear Ring Resonator

    Institute of Scientific and Technical Information of China (English)

    LI Jun-Qing; LI Li; ZHAO Jia-Qun; LI Chun-Fei

    2004-01-01

    @@ We propose a novel configuration of all-optical switch based on a double-loop Sagnac ring coupled with a nonlinear ring resonator. In the case of self-phase modulation, the reducing switching threshold power down to mW is predicted, which is the improvement of earlier works on all-optical switches. The switch optimization is analysed.A way to increase the response speed of all-optical switches is suggested.

  2. Bandwidth smearing in optical interferometry: Analytic model of the transition to the double fringe packet

    CERN Document Server

    Lachaume, Régis

    2012-01-01

    Bandwidth smearing is a chromatic aberration due to the finite frequency bandwidth. In long-baseline optical interferometry terms, it is when the angular extension of the source is greater than the coherence length of the interferogram. As a consequence, separated parts of the source will contribute to fringe packets that are not fully overlapping; it is a transition from the classical interferometric regime to a double or multiple fringe packet. While studied in radio interferometry, there has been little work on the matter in the optical, where observables are measured and derived in a different manner, and are more strongly impacted by the turbulent atmosphere. We provide here the formalism and a set of usable equations to model and correct for the impact of smearing on the fringe contrast and phase, with the case of multiple stellar systems in mind. The atmosphere is briefly modeled and discussed.

  3. Modifying the optical path in a nonlinear double-slit experiment

    CERN Document Server

    Paltoglou, Vassilis

    2015-01-01

    In this letter, we study a nonlinear interferometric setup based on diffraction rather than beam combining. It consists of a nonlinear analogue of Young's double-slit experiment where a nonlinear material is placed exactly after one of the slits. The presence of nonlinearity breaks the transverse spatial symmetry of the system and thus modifies the optical path. For moderate nonlinearities this leads to a self-induced shift of the intensity pattern in the transverse plane. A simple theoretical model is developed which is surprisingly accurate in predicting the intensity profile of the main lobes for a wide range of parameters. We discuss about possible applications of our model in nonlinear interferometry, for example in measuring the nonlinearities of optical materials.

  4. Choice of optical system is critical for the security of double random phase encryption systems

    Science.gov (United States)

    Muniraj, Inbarasan; Guo, Changliang; Malallah, Ra'ed; Cassidy, Derek; Zhao, Liang; Ryle, James P.; Healy, John J.; Sheridan, John T.

    2017-06-01

    The linear canonical transform (LCT) is used in modeling a coherent light-field propagation through first-order optical systems. Recently, a generic optical system, known as the quadratic phase encoding system (QPES), for encrypting a two-dimensional image has been reported. In such systems, two random phase keys and the individual LCT parameters (α,β,γ) serve as secret keys of the cryptosystem. It is important that such encryption systems also satisfy some dynamic security properties. We, therefore, examine such systems using two cryptographic evaluation methods, the avalanche effect and bit independence criterion, which indicate the degree of security of the cryptographic algorithms using QPES. We compared our simulation results with the conventional Fourier and the Fresnel transform-based double random phase encryption (DRPE) systems. The results show that the LCT-based DRPE has an excellent avalanche and bit independence characteristics compared to the conventional Fourier and Fresnel-based encryption systems.

  5. Magnetic, electronic, and optical properties of double perovskite Bi2FeMnO6

    Science.gov (United States)

    Ahmed, Towfiq; Chen, Aiping; Yarotski, Dmitry A.; Trugman, Stuart A.; Jia, Quanxi; Zhu, Jian-Xin

    2017-03-01

    Double perovskite Bi2FeMnO6 is a potential candidate for the single-phase multiferroic system. In this work, we study the magnetic, electronic, and optical properties in BFMO by performing the density functional theory calculations and experimental measurements of magnetic moment. We also demonstrate the strain dependence of magnetization. More importantly, our calculations of electronic and optical properties reveal that the onsite local correlation on Mn and Fe sites is critical to the gap opening in BFMO, which is a prerequisite condition for the ferroelectric ordering. Finally, we calculate the x-ray magnetic circular dichroism spectra of Fe and Mn ions (L2 and L3 edges) in BFMO.

  6. The design of double wishbone torsion bar spring independent suspension for car%汽车双横臂扭杆弹簧独立悬架设计

    Institute of Scientific and Technical Information of China (English)

    崔敏

    2016-01-01

    This paper is mainly to analysis a light truck’s computing method of the front independent suspension design and testing of design experiment. Firstly, it goes with the stress analysis and the trajectory calculation of the double wishbone independent suspension, and then continues with the suspension design calculation such as the design of torsion bar spring , front suspension’s stiffness, offset frequency calculation, stabilizer bar’s design, roll stiffness calculation, shock absorber’s design, and finally the suspension offset frequency and riding comfort can be verified through the test.%文章主要研究某轻型载货汽车前独立悬架的设计计算方法以及独立悬架的设计试验验证,首先对双横臂式独立悬架进行受力分析、运动轨迹计算,然后对悬架进行设计计算如扭杆弹簧的设计、前悬架的刚度、偏频计算、稳定杆的设计、侧倾刚度计算、减震器的设计,最后通过试验验证悬架的偏频、平顺性。

  7. Nonarteritic Anterior Ischemic Optic Neuropathy and Double Thrombophilic Defect: A New Observation

    Directory of Open Access Journals (Sweden)

    Eleni Papageorgiou

    2012-02-01

    Full Text Available We report the first case of nonarteritic anterior ischemic neuropathy (NAION associated with double thrombophilia: protein S deficiency and prothrombin G20210A mutation. A 58-year-old man is presented including the clinical and laboratory findings, cardiovascular profile and thrombophilia screening. The patient presented with 3/10 vision and an inferior altitudinal defect in the right eye. Funduscopic examination of the right eye revealed a hyperemic optic disk with blurred superior optic disk border and sectoral nerve fiber layer edema. Complete blood count, erythrocyte sedimentation rate and C-reactive protein were normal, suggesting a NAION. A workup of cardiovascular risk factors revealed hyperlipidemia, arterial hypertension and high-risk asymptomatic coronary artery disease. Due to the family history of deep vein thrombosis in the patient’s daughter, a thrombophilia screening was additionally performed. The results revealed a double thrombophilic defect, namely congenital protein S deficiency and heterozygosity for prothrombin G20210A mutation, which were also identified in the patient’s daughter. Anticoagulant warfarin therapy was initiated and the patient underwent a triple bypass surgery. At three-month follow-up, the right optic disk edema had resolved, leaving a pale superior optic nerve head. Visual acuity in the right eye had slightly improved to 4/10; however, the dense inferior altitudinal field defect had remained unchanged. The patient is currently treated with warfarin, atorvastatin, irbesartan and metoprolol. This case suggests that the first line of investigation in all patients with NAION involves assessment of cardiovascular risk factors. However, careful history taking will identify NAION patients who are eligible for additional thrombophilia screening: young patients without vasculopathic risk factors, bilateral or recurrent NAION, idiopathic or recurrent venous thromboembolism (VTE, positive family history of VTE

  8. Nonarteritic anterior ischemic optic neuropathy and double thrombophilic defect: a new observation.

    Science.gov (United States)

    Papageorgiou, Eleni; Karamagkiolis, Spyridon; Dimera, Vasiliki

    2012-01-01

    WE REPORT THE FIRST CASE OF NONARTERITIC ANTERIOR ISCHEMIC NEUROPATHY (NAION) ASSOCIATED WITH DOUBLE THROMBOPHILIA: protein S deficiency and prothrombin G20210A mutation. A 58-year-old man is presented including the clinical and laboratory findings, cardiovascular profile and thrombophilia screening. The patient presented with 3/10 vision and an inferior altitudinal defect in the right eye. Funduscopic examination of the right eye revealed a hyperemic optic disk with blurred superior optic disk border and sectoral nerve fiber layer edema. Complete blood count, erythrocyte sedimentation rate and C-reactive protein were normal, suggesting a NAION. A workup of cardiovascular risk factors revealed hyperlipidemia, arterial hypertension and high-risk asymptomatic coronary artery disease. Due to the family history of deep vein thrombosis in the patient's daughter, a thrombophilia screening was additionally performed. The results revealed a double thrombophilic defect, namely congenital protein S deficiency and heterozygosity for prothrombin G20210A mutation, which were also identified in the patient's daughter. Anticoagulant warfarin therapy was initiated and the patient underwent a triple bypass surgery. At three-month follow-up, the right optic disk edema had resolved, leaving a pale superior optic nerve head. Visual acuity in the right eye had slightly improved to 4/10; however, the dense inferior altitudinal field defect had remained unchanged. The patient is currently treated with warfarin, atorvastatin, irbesartan and metoprolol. This case suggests that the first line of investigation in all patients with NAION involves assessment of cardiovascular risk factors. However, careful history taking will identify NAION patients who are eligible for additional thrombophilia screening: young patients without vasculopathic risk factors, bilateral or recurrent NAION, idiopathic or recurrent venous thromboembolism (VTE), positive family history of VTE, and VTE in young age or

  9. One- and Two-Dimensional Arrays of Double-Well Optical Traps for Cold Atoms or Molecules

    Institute of Scientific and Technical Information of China (English)

    JI Xian-Ming; YIN Jian-Ping

    2004-01-01

    @@ We propose a novel scheme to form one- and two-dimensional arrays of double-well optical dipole traps for cold atoms (or molecules) by using an optical system composed of a binary π-phase grating and a lens illuminated by a plane light wave, and study the relationship between the maximum intensity Imax of each optical well (or the maximum trapping potential Umax for 85Rb atoms) and the relative apertureβ (= a/f) of the lens. We also calculate the intensity gradients of each optical well and their curvatures, and estimate the spontaneous photon-scattering rate of trapped atom in each well, including Rayleigh and Raman scattering rates. Our study shows that the proposed 1D and 2D arrays of double-well traps can be used to prepare 1D and 2D novel optical lattices with cold atoms (or molecules), or form an all-optically integrated atom optical chip, or even to realize an array of all-optical double-well atomic (or molecular) Bose-Einstein condensates by optical-potential evaporative cooling, and so on.

  10. Double-Slot Hybrid Plasmonic Ring Resonator Used for Optical Sensors and Modulators

    Directory of Open Access Journals (Sweden)

    Xu Sun

    2015-11-01

    Full Text Available An ultra-high sensitivity double-slot hybrid plasmonic (DSHP ring resonator, used for optical sensors and modulators, is developed. Due to high index contrast, as well as plasmonic enhancement, a considerable part of the optical energy is concentrated in the narrow slots between Si and plasmonic materials (silver is used in this paper, which leads to high sensitivity to the infiltrating materials. By partial opening of the outer plasmonic circular sheet of the DSHP ring, a conventional side-coupled silicon on insulator (SOI bus waveguide can be used. Experimental results demonstrate ultra-high sensitivity (687.5 nm/RIU of the developed DSHP ring resonator, which is about five-times higher than for the conventional Si ring with the same geometry. Further discussions show that a very low detection limit (5.37 × 10−6 RIU can be achieved after loaded Q factor modifications. In addition, the plasmonic metal structures offer also the way to process optical and electronic signals along the same hybrid plasmonic circuits with small capacitance (~0.275 fF and large electric field, which leads to possible applications in compact high-efficiency electro-optic modulators, where no extra electrodes for electronic signals are required.

  11. Molecular states in double quantum wells: nanochemistry for metatmaterials with new optical properties

    Science.gov (United States)

    Gutierrez, Rafael M.; Castañeda, Arcesio

    2009-08-01

    Quantum mechanics explains the existence and properties of the chemical bond responsible for the formation of molecules from isolated atoms. In this work we study quantum states of Double Quantum Wells, DQW, formed from isolated Single Quantum Wells, SQWs, that can be considered metamaterials. Using the quantum chemistry definition of the covalent bond, we discuss molecular states in DQW as a kind of nanochemistry of metamaterials with new properties, in particular new optical properties. An important particularity of such nanochemistry, is the possible experimental control of the geometrical parameters and effective masses characterizing the semiconductor heterostructures represented by the corresponding DQW. This implies a great potential for new applications of the controlled optical properties of the metamaterials. The use of ab initio methods of intensive numerical calculations permits to obtain macroscopic optical properties of the metamaterials from the fundamental components: the spatial distribution of the atoms and molecules constituting the semiconductor layers. The metamaterial new optical properties emerge from the coexistence of many body processes at atomic and molecular level and complex quantum phenomena such as covalent-like bonds at nanometric dimensions.

  12. Effect of refractive correction on ocular optical quality measurement using double-pass system

    Institute of Scientific and Technical Information of China (English)

    WAN Xiu-hua; CAI Xiao-gu; QIAO Li-ya; ZHANG Ye; TAN Jia-xuan; Jhanji Vishal; WANG Ning-li

    2013-01-01

    Background Optical Quality Analysis System Ⅱ (OQAS,Visiometrics,Terrassa,Spain) that uses double-pass (DP) technique is the only commercially available device that allows objective measurement of ocular retinal image quality.This study aimed to evaluate the impact of spectacle lenses on the ocular optical quality parameters and the validity of the optometer within OQAS.Methods Seventy eyes of healthy volunteers were enrolled.Optical quality measurements were performed using OQAS with an artificial pupil diameter of 4.0 mm.Three consecutive measurements were obtained from spectacle correction corresponding to subjective refraction and from the OQAS built-in optometer separately.The modulation transfer function cutoff frequency,the Strehl ratio,the width of the point spread function (PSF) at 10% of its maximal height (PSF10),and the width of the PSF at 50% of its maximal height (PSF50) were analyzed.Results There was no significant difference in any of the parameters between the spectacle correction and the optometer correction (all P >0.05,paired t-test).A good agreement was found between both the methods and a good intraobserver repeatability in both the correction methods.Difference in best focus between two methods was the only parameter associated significantly with optical quality parameter differences.Best focus difference,built-in optometer correction with or without external cylindrical lens,and age were associated significantly with PSF10 difference.No linear correlation between refractive status and optical quality measurement difference was observed.A hyperopic bias (best focus difference of (0.50±0.44) D) and a relatively better optical quality using spectacle correction in high myopia group were found.Conclusions OQAS based on DP system is a clinically reliable instrument.In patients with high myopia,measurements using built-in optometer correction should be considered and interpreted with caution.

  13. Optical and Electrical Characteristics of Graphene Double Layer Formed by a Double Transfer of Graphene Single Layers.

    Science.gov (United States)

    Kim, Young Jun; Bae, Gi Yoon; Chun, Sungwoo; Park, Wanjun

    2016-03-01

    We demonstrate formation of double layer graphene by means of a double transfer using two single graphene layers grown by a chemical vapor deposition method. It is observed that shiftiness and broadness in the double-resonance of Raman scattering are much weaker than those of bilayer graphene formed naturally. Transport characteristics examined from transmission line measurements and field effect transistors show the similar behavior with those of single layer graphene. It indicates that interlayer separation, in electrical view, is large enough to avoid correlation between layers for the double layer structure. It is also observed from a transistor with the double layer graphene that molecules adsorpted on two inner graphene surfaces in the double layered structure are isolated and conserved from ambient environment.

  14. Nuclear mean field and double-folding model of the nucleus-nucleus optical potential

    CERN Document Server

    Khoa, Dao T; Loan, Doan Thi; Loc, Bui Minh

    2016-01-01

    Realistic density dependent CDM3Yn versions of the M3Y interaction have been used in an extended Hartree-Fock (HF) calculation of nuclear matter (NM), with the nucleon single-particle potential determined from the total NM energy based on the Hugenholtz-van Hove theorem that gives rise naturally to a rearrangement term (RT). Using the RT of the single-nucleon potential obtained exactly at different NM densities, the density- and energy dependence of the CDM3Yn interactions was modified to account properly for both the RT and observed energy dependence of the nucleon optical potential. Based on a local density approximation, the double-folding model of the nucleus-nucleus optical potential has been extended to take into account consistently the rearrangement effect and energy dependence of the nuclear mean-field potential, using the modified CDM3Yn interactions. The extended double-folding model was applied to study the elastic $^{12}$C+$^{12}$C and $^{16}$O+$^{12}$C scattering at the refractive energies, wher...

  15. BER Analysis Using Beat Probability Method of 3D Optical CDMA Networks with Double Balanced Detection

    Directory of Open Access Journals (Sweden)

    Chih-Ta Yen

    2015-01-01

    Full Text Available This study proposes novel three-dimensional (3D matrices of wavelength/time/spatial code for code-division multiple-access (OCDMA networks, with a double balanced detection mechanism. We construct 3D carrier-hopping prime/modified prime (CHP/MP codes by extending a two-dimensional (2D CHP code integrated with a one-dimensional (1D MP code. The corresponding coder/decoder pairs were based on fiber Bragg gratings (FBGs and tunable optical delay lines integrated with splitters/combiners. System performance was enhanced by the low cross correlation properties of the 3D code designed to avoid the beat noise phenomenon. The CHP/MP code cardinality increased significantly compared to the CHP code under the same bit error rate (BER. The results indicate that the 3D code method can enhance system performance because both the beating terms and multiple-access interference (MAI were reduced by the double balanced detection mechanism. Additionally, the optical component can also be relaxed for high transmission scenery.

  16. Optical Tagging of Ion Beams Accelerated by Double Layers in Laboratory Plasma

    Science.gov (United States)

    Good, Timothy; Aguirre, Evan; Thompson, Derek; Scime, Earl

    2016-10-01

    Experiments in helicon sources that investigate plasma expansion into weakly magnetized, low density regions reveal the production of supersonic ion beams attributed to acceleration by spatially localized double layer structures. Current efforts are aimed at mapping the ion velocity flow field utilizing 2D spatially scanning laser induced fluorescence (LIF) probes that yield metastable ion velocity distribution functions (IVDF) for velocities along and perpendicular to the flow. Observation of metastable ion beams by LIF renders plausible a Lagrangian approach to studying the field-ion interaction via optical tagging. We propose a tagging scheme in which metastable state ion populations are modulated by optical pumping upstream of the double layer and the synchronous detection of LIF at the ion beam velocity is recorded downstream. Besides the unambiguous identification of the source of beam ions, this method can provide detailed dynamical information through time of flight analysis. Preliminary results will be presented. Please include this poster in session that includes poster authored by Evan Aguirre et al.

  17. Laser tissue coagulation and concurrent optical coherence tomography through a double-clad fiber coupler.

    Science.gov (United States)

    Beaudette, Kathy; Baac, Hyoung Won; Madore, Wendy-Julie; Villiger, Martin; Godbout, Nicolas; Bouma, Brett E; Boudoux, Caroline

    2015-04-01

    Double-clad fiber (DCF) is herein used in conjunction with a double-clad fiber coupler (DCFC) to enable simultaneous and co-registered optical coherence tomography (OCT) and laser tissue coagulation. The DCF allows a single channel fiber-optic probe to be shared: i.e. the core propagating the OCT signal while the inner cladding delivers the coagulation laser light. We herein present a novel DCFC designed and built to combine both signals within a DCF (>90% of single-mode transmission; >65% multimode coupling). Potential OCT imaging degradation mechanisms are also investigated and solutions to mitigate them are presented. The combined DCFC-based system was used to induce coagulation of an ex vivo swine esophagus allowing a real-time assessment of thermal dynamic processes. We therefore demonstrate a DCFC-based system combining OCT imaging with laser coagulation through a single fiber, thus enabling both modalities to be performed simultaneously and in a co-registered manner. Such a system enables endoscopic image-guided laser marking of superficial epithelial tissues or laser thermal therapy of epithelial lesions in pathologies such as Barrett's esophagus.

  18. Spring Outing

    Institute of Scientific and Technical Information of China (English)

    孙芳

    2011-01-01

    It is springtime.The days are getting warmer and the flowers are in bloom.With the pleasantly warm sunshine,gentle breeze and fresh air,it is high time for spring outing and sightseeing.Are you still hesitating? Let’s see what benefits spring outing brings about and then pay attention to some matters while taking a trip out in spring. Benefits of spring outing Spring outing is especially popular with children and teenagers.But many adults also like to go on spring trips.The reason might be that spring outing can have several benefits.

  19. Spring in the Arab Spring

    NARCIS (Netherlands)

    Borg, G.J.A.

    2011-01-01

    Column Gert Borg | Spring in the Arab Spring door dr. Gert Borg, onderzoeker bij Islam en Arabisch aan de Radboud Universiteit Nijmegen en voormalig directeur van het Nederlands-Vlaams Instituut Caïro Spring If, in Google, you type "Arab Spring" and hit the button, you get more than 14 mill

  20. Double-crystal monochromator as the first optical element in BESSRC-CAT beamlines (abstract)

    Science.gov (United States)

    Beno, Mark A.; Ramanathan, Mohan

    1996-09-01

    The first optical element in the BESSRC-CAT beamlines at the Advanced Photon Source will be a monochromator, so that a standard design for this critical component is advantageous. The monochromator we have designed is a double-crystal, fixed-exit scheme with a constant offset designed for UHV operation, thereby allowing windowless operation of the beamlines. The crystals are mounted on a turntable with the first crystal at the center of rotation. A mechanical linkage is used to correctly position the second crystal and maintain a constant offset. The main drive for the rotary motion is provided by a vacuum-compatible Huber goniometer isolated from the main vacuum chamber. Rotary motion of the primary monochromator stage is accomplished by using two adjacent vacuum chambers connected only by the small annular opening around a hollow stainless steel shaft, which connects the Huber goniometer to the turntable on which the crystals are mounted. The design of the monochromator is such that it can accommodate both water and liquid nitrogen cooling for the crystal optics. The basic design for the monochromator linkage mechanism will be presented along with details of the monochromator chamber. The results of initial optical tests of the monochromator system using tilt sensors and a precision autocollimator will also be given.

  1. Doubling absorption in nanowire solar cells with dielectric shell optical antennas.

    Science.gov (United States)

    Kim, Sun-Kyung; Zhang, Xing; Hill, David J; Song, Kyung-Deok; Park, Jin-Sung; Park, Hong-Gyu; Cahoon, James F

    2015-01-14

    Semiconductor nanowires (NWs) often exhibit efficient, broadband light absorption despite their relatively small size. This characteristic originates from the subwavelength dimensions and high refractive indices of the NWs, which cause a light-trapping optical antenna effect. As a result, NWs could enable high-efficiency but low-cost solar cells using small volumes of expensive semiconductor material. Nevertheless, the extent to which the antenna effect can be leveraged in devices will largely determine the economic viability of NW-based solar cells. Here, we demonstrate a simple, low-cost, and scalable route to dramatically enhance the optical antenna effect in NW photovoltaic devices by coating the wires with conformal dielectric shells. Scattering and absorption measurements on Si NWs coated with shells of SiN(x) or SiO(x) exhibit a broadband enhancement of light absorption by ∼ 50-200% and light scattering by ∼ 200-1000%. The increased light-matter interaction leads to a ∼ 80% increase in short-circuit current density in Si photovoltaic devices under 1 sun illumination. Optical simulations reproduce the experimental results and indicate the dielectric-shell effect to be a general phenomenon for groups IV, II-VI, and III-V semiconductor NWs in both lateral and vertical orientations, providing a simple route to approximately double the efficiency of NW-based solar cells.

  2. Optical absorption analysis of quaternary molybdate- and tungstate-ordered double perovskites

    Energy Technology Data Exchange (ETDEWEB)

    Tablero, C., E-mail: ctablero@etsit.upm.es

    2015-08-05

    Highlights: • These compounds present a high optical absorption. • The absorption coefficients using different DFT + U alternatives have been compared. • The absorption coefficients have been split into different contributions. • The maximum efficiency is near the maximum efficiency for multiple-gap solar cells. - Abstract: Quaternary-ordered double perovskite A{sub 2}MM′O{sub 6} (M = Mo,W) semiconductors are a group of materials with a variety of photocatalytic and optoelectronic applications. An analysis focused on the optoelectronic properties is carried out using first-principles density-functional theory with several U orbital-dependent one-electron potentials applied to different orbital subspaces. The structural non-equivalence of the atoms resulting from the symmetry has been taken in account. In order to analyze optical absorption in these materials deeply, the absorption coefficients have been split into inter- and intra-non-equivalent species contributions. The results indicate that the effect of the A and M′ atoms on the optical properties are minimal whereas the largest contribution comes from the non-equivalent O atoms to M transitions.

  3. Double-way spectral tunability for the control of optical nanocavity resonance.

    Science.gov (United States)

    Baida, Fadi I; Grosjean, Thierry

    2015-12-08

    Scanning Near-field Optical Microscopy (SNOM) has been successful in finely tuning the optical properties of photonic crystal (PC) nanocavities. The SNOM nanoprobes proposed so far allowed for either redshifting or blueshifting the resonance peak of the PC structures. In this paper, we theoretically demonstrate the possibility of a redshifting (up to +0.65 nm) and a blueshifting (up to -5 nm) the PC cavity resonance wavelength with a single perturbation element. As an example, a fiber bowtie-aperture nano-antenna (BNA) engraved at the apex of a SNOM tip is proposed to play this role. The double-way tunability is the result of a competition between an induced electric dipole (BNA at resonance) leading to a redshift and an induced magnetic dipole (the tip metalcoating) giving rise to a blueshift of the resonance wavelength. We demonstrate that the sign of the spectral shift can be simply controlled through the tip-to-cavity distance. This study opens the way to the full postproduction control of the resonance wavelength of high quality-factor optical cavities.

  4. Overlapping double potential wells in a single optical microtube cavity with vernier-scale-like tuning effect

    Science.gov (United States)

    Madani, A.; Bolaños Quiñones, V. A.; Ma, L. B.; Miao, S. D.; Jorgensen, M. R.; Schmidt, O. G.

    2016-04-01

    Spatially and temporally overlapping double potential wells are realized in a hybrid optical microtube cavity due to the coexistence of an aggregate of luminescent quantum dots embedded in the tube wall and the cone-shaped tube's geometry. The double potential wells produce two independent sets of optical modes with different sets of mode numbers, indicating phase velocity separation for the modes overlapping at the same frequency. The overlapping mode position can be tuned by modifying the tube cavity, where these mode sets shift with different magnitudes, allowing for a vernier-scale-like tuning effect.

  5. Differences Between a Single- and a Double-Folding Nucleus-^{9}Be Optical Potential

    Science.gov (United States)

    Bonaccorso, A.; Carstoiu, F.; Charity, R. J.; Kumar, R.; Salvioni, G.

    2016-05-01

    We have recently constructed two very successful n-^9Be optical potentials (Bonaccorso and Charity in Phys Rev C89:024619, 2014). One by the Dispersive Optical Model (DOM) method and the other (AB) fully phenomenological. The two potentials have strong surface terms in common for both the real and the imaginary parts. This feature makes them particularly suitable to build a single-folded (light-) nucleus-^9Be optical potential by using ab-initio projectile densities such as those obtained with the VMC method (Wiringa http://www.phy.anl.gov/theory/research/density/). On the other hand, a VMC density together with experimental nucleon-nucleon cross-sections can be used also to obtain a neutron and/or proton-^9Be imaginary folding potential. We will use here an ab-initio VMC density (Wiringa http://www.phy.anl.gov/theory/research/density/) to obtain both a n-^9Be single-folded potential and a nucleus-nucleus double-folded potential. In this work we report on the cases of ^8B, ^8Li and ^8C projectiles. Our approach could be the basis for a systematic study of optical potentials for light exotic nuclei scattering on such light targets. Some of the projectiles studied are cores of other exotic nuclei for which neutron knockout has been used to extract spectroscopic information. For those cases, our study will serve to make a quantitative assessment of the core-target part of the reaction description, in particular its localization.

  6. NASA thunderstorm overflight program: Atmospheric electricity research. An overview report on the optical lightning detection experiment for spring and summer 1983

    Science.gov (United States)

    Vaughan, O. H., Jr.

    1984-01-01

    This report presents an overview of the NASA Thunderstorm Overflight Program (TOP)/Optical Lightning Experiment (OLDE) being conducted by the Marshall Space Flight Center and university researchers in atmospheric electricity. Discussed in this report are the various instruments flown on the NASA U-2 aircraft, as well as the ground instrumentation used in 1983 to collect optical and electronic signatures from the lightning events. Samples of some of the photographic and electronic signatures are presented. Approximately 4132 electronic data samples of optical pulses were collected and are being analyzed by the NASA and university researchers. A number of research reports are being prepared for future publication. These reports will provide more detailed data analysis and results from the 1983 spring and summer program.

  7. New limit on Lorentz violation using a double-pass optical ring cavity.

    Science.gov (United States)

    Michimura, Yuta; Matsumoto, Nobuyuki; Ohmae, Noriaki; Kokuyama, Wataru; Aso, Yoichi; Ando, Masaki; Tsubono, Kimio

    2013-05-17

    A search for Lorentz violation in electrodynamics was performed by measuring the resonant frequency difference between two counterpropagating directions of an optical ring cavity. Our cavity contains a dielectric element, which makes our cavity sensitive to the violation. The laser frequency is stabilized to the counterclockwise resonance of the cavity, and the transmitted light is reflected back into the cavity for resonant frequency comparison with the clockwise resonance. This double-pass configuration enables a null experiment and gives high common mode rejection of environmental disturbances. We found no evidence for odd-parity anisotropy at the level of δc/c ≲ 10(-14). Within the framework of the standard model extension, our result put more than 5 times better limits on three odd-parity parameters κ(o+)(JK) and a 12 times better limit on the scalar parameter κ(tr) compared with the previous best limits.

  8. Continuously transferring cold atoms in caesium double magneto-optical trap

    Institute of Scientific and Technical Information of China (English)

    Yan Shu-Bin; Geng Tao; Zhang Tian-Cai; Wang Jun-Min

    2006-01-01

    We have established a caesium double magneto-optical trap (MOT) system for cavity-QED experiment, and demonstrated the continuous transfer of cold caesium atoms from the vapour-cell MOT with a pressure of ~ 1 × 10-6 Pa to the ultra-high-vacuum (UHV) MOT with a pressure of ~ 8 × 10-8 Pa via a focused continuous-wave transfer laser beam. The effect of frequency detuning as well as the intensity of the transfer beam is systematically investigated, which makes the transverse cooling adequate before the atoms leak out of the vapour-cell MOT to reduce divergence of the cold atomic beam. The typical cold atomic flux got from vapour-cell MOT is ~ 2 × 107 atoms/s. About 5 × 106 caesium atoms are recaptured in the UHV MOT.

  9. High-Power Blue Light Generation by External Frequency Doubling of an Optical Parametric Oscillator

    Institute of Scientific and Technical Information of China (English)

    毕勇; 张鸿博; 孙志培; 包照日格图; 李惠清; 孔宇鹏; 林学春; 王桂玲; 张杰; 侯玮; 李瑞宁; 崔大复; 许祖彦; 宋立维; 章萍; 崔建峰; 樊仲维

    2003-01-01

    We report on an all-solid-state high-power quasi-continuous blue light source by the frequency doubling of a signal wave from an optical parametric oscillator(OPO).A 50-mm-long LiB3O5(LBO)crystal is used for the OPO,which is pumped by a diode-pumped Nd:YAG green laser(10kHz,50ns).Tunable blue emission in a new nonlinear crystal BiB3O6(BiBO)is obtained with a wavelength range from 450 to 495 nm.The average power of the signal output is as high as 9.3 W from 924 to 970nm.The maximum output of the blue laser with the second harmonic walk-off compensation is 1.3 W average power at 470nm for 6.2 W of OPO signal light at 940nm.

  10. Doubling transmission capacity in optical wireless system by antenna horizontal- and vertical-polarization multiplexing.

    Science.gov (United States)

    Li, Xinying; Yu, Jianjun; Zhang, Junwen; Dong, Ze; Chi, Nan

    2013-06-15

    We experimentally demonstrate 2×56 Gb/s two-channel polarization-division-multiplexing quadrature-phase-shift-keying signal delivery over 80 km single-mode fiber-28 and 2 m Q-band (33-50 GHz) wireless link, adopting antenna horizontal- (H-) and vertical-polarization (V-polarization) multiplexing. At the wireless receiver, classic constant-modulus-algorithm equalization based on digital signal processing can realize polarization demultiplexing and remove the crosstalk at the same antenna polarization. By adopting antenna polarization multiplexing, the signal baud rate and performance requirements for optical and wireless devices can be reduced but at the cost of double antennas and devices, while wireless transmission capacity can also be increased but at the cost of stricter requirements for V-polarization. The isolation is only about 19 dB when V-polarization deviation approaches 10°, which will affect high-speed (>50 Gb/s) wireless delivery.

  11. Optical and electronic properties of double perovskite Ba2ScSbO6

    Science.gov (United States)

    Ray, Rajyavardhan; Himanshu, A. K.; Lahiri, J.; Kumar, Uday; Sen, Pintu; Bandyopadhyay, S. K.; Sinha, T. P.

    2016-05-01

    The ordered double perovskite Ba2ScSbO6 (BSS) has been synthesized in polycrystalline form by solid state reaction at 1400 C for 72 Hrs. Structural characterization of the compound was done through X-ray diffraction (XRD) followed by Rietveld analysis. The crystal structure is cubic, with space group Fm-3m (No. 225) and lattice parameter, a = 8.20 Ǻ. Optical band-gap has been calculated using UV-Vis Spectroscopy and Kubelka-Munk (KM) function, yielding 4.23 eV. A detailed Ab-initio Density Functional Theory (DFT) study of the electronic properties has been carried out using the Full-Potential Linear Augmented Plane Wave (FP-LAPW) as implemented in WIEN2k. BSS is found to be a large band-gap insulator with potential technological applications.

  12. Optical phonon lasing and its detection in transport through semiconduc- tor double quantum dots

    Science.gov (United States)

    Okuyama, Rin; Eto, Mikio; Brandes, Tobias

    2014-03-01

    We theoretically propose optical phonon lasing for a double quantum dot (DQD) fabricated in a semiconductor substrate. No additional cavity or resonator is required. We show that the DQD couples to only two phonon modes that act as a natural cavity. The pumping to the upper level is realized by an electric current through the DQD under a finite bias. Using the rate equation in the Born-Markov-Secular approximation, we analyze the enhanced phonon emission when the level spacing in the DQD is tuned to the phonon energy. We find the phonon lasing when the pumping rate is much larger than the phonon decay rate, whereas anti-bunching of phonon emission is observed when the pumping rate is smaller.[1] Our theory can be also applicable to DQDs embedded in nanomechanical resonators to control the vibrating modes. We discuss detection of amplified modes using the electric current and its noise through the DQD, and another DQD fabricated nearby.

  13. Optical coherence tomography assessment of a complex bifurcation lesion treated with double kissing Crush technique

    Science.gov (United States)

    Cai, Jin-Zan; Zhang, Yao-Jun; Xu, Tian; Zhu, Yong-Xiang; Mao, Chen-Yu; Bourantas, Christos V.; Crake, Tom; Chen, Shao-Liang

    2017-01-01

    Abstract The DEFINITION (Impact of the complexity of bifurcation lesions treated with drug-eluting stents) study has provided a novel classification to evaluate the complexity of coronary bifurcation lesion according to coronary angiography, but angiographic imaging due to its low resolution and inherited limitation may result in an inaccurate adjudication. We used optical coherence tomography (OCT) to further evaluate the coronary characteristics in a patient with “simple” bifurcation lesion which was classified by the DEFINITION criteria. However, a “complex” bifurcation lesion was defined and confirmed according to the OCT results. A double kissing Crush stenting approach was adopted to treat this “complex” case finally. The immediate and long-term angiographic and OCT results were excellent. OCT may be useful imaging modality to classify complexity of coronary bifurcation lesion and subsequently guide its treatment strategy. PMID:28072714

  14. Double nanohole optical tweezers visualize protein p53 suppressing unzipping of single DNA-hairpins.

    Science.gov (United States)

    Kotnala, Abhay; Gordon, Reuven

    2014-06-01

    Here we report on the use of double-nanohole (DNH) optical tweezers as a label-free and free-solution single-molecule probe for protein-DNA interactions. Using this approach, we demonstrate the unzipping of individual 10 base pair DNA-hairpins, and quantify how tumor suppressor p53 protein delays the unzipping. From the Arrhenius behavior, we find the energy barrier to unzipping introduced by p53 to be 2 × 10(-20) J, whereas cys135ser mutant p53 does not show suppression of unzipping, which gives clues to its functional inability to suppress tumor growth. This transformative approach to single molecule analysis allows for ultra-sensitive detection and quantification of protein-DNA interactions to revolutionize the fight against genetic diseases.

  15. Longitudinal polar optical phonons in InN/GaN single and double het- erostructures

    Energy Technology Data Exchange (ETDEWEB)

    Ardali, Sukru; Tiras, Engin [Department of Physics, Faculty of Science, Anadolu University, Yunus Emre Campus, Eskisehir 26470 (Turkey); Gunes, Mustafa; Balkan, Naci [School of Computer Science and Electronic Engineering, University of Essex, Wivenhoe Park, Colchester CO4 3SQ (United Kingdom); Ajagunna, Adebowale Olufunso; Iliopoulos, Eleftherios; Georgakilas, Alexandros [Microelectronics Research Group, IESL, FORTH and Physics Department, University of Crete, P.O. Box 1385, 71110 Heraklion-Crete (Greece)

    2011-05-15

    Longitudinal optical phonon energy in InN epi-layers has been determined independently from the Raman spectroscopy and temperature dependent Hall mobility measurements. Raman spectroscopy technique can be used to obtain directly the LO energy where LO phonon scattering dominates transport at high temperature. Moreover, the Hall mobility is determined by the scattering of electrons with LO phonons so the data for the temperature dependence of Hall mobility have been used to calculate the effective energy of longitudinal optical phonons.The samples investigated were (i) single heterojunction InN with thicknesses of 1.08, 2.07 and 4.7 {mu}m grown onto a 40 nm GaN buffer and (ii) GaN/InN/AlN double heterojunction samples with InN thicknesses of 0.4, 0.6 and 0.8 {mu}m. Hall Effect measurements were carried out as a function of temperature in the range between T = 1.7 and 275 K at fixed magnetic and electric fields. The Raman spectra were obtained at room temperature. In the experiments, the 532 nm line of a nitrogen laser was used as the excitation source and the light was incident onto the samples along of the growth direction (c-axis). The results, obtained from the two independent techniques suggest the following: (1) LO phonon energies obtained from momentum relaxation experiments are generally slightly higher than those obtained from the Raman spectra. (2) LO phonon energy for the single heterojunctions does not depend on the InN thickness. (3) In double heterostructures, with smaller InN thicknesses and hence with increased strain, LO phonon energy increases by 3% (experimental accuracy is < 1%) when the InN layer thickness increases from 400 to 800 nm (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  16. On the Performance of Free-Space Optical Communication Systems over Double Generalized Gamma Channel

    KAUST Repository

    Al-Quwaiee, Hessa

    2015-05-13

    Starting with the double generalized Gamma (GG) model to describe turbulence-induced fading in free-space optical (FSO) systems, we propose a new unified model that accounts for the impact of pointing errors and type of receiver detector. More specifically, we present unified closed-form expressions for the cumulative distribution function, the probability density function, the moment generating function, and the moments of the end-toend signal-to-noise ratio (SNR) of a single link FSO transmission system in terms of the Meijer’s G-function. We then use these unified expressions to evaluate performance measures such as the bit error rate, the outage probability, and the ergodic capacity of (i) a single FSO link operating over double GG fading model (ii) asymmetric RF-FSO dual-hop relay transmission system with fixed gain relay. Using an asymptotic expansion of the Meijer’s G-function at high SNR, we express all the expressions, derived earlier, in terms of elementary functions. All our analytical results are verified using computer based Monte-Carlo simulations.

  17. Probing the electric field in organic double layer-system by optical second harmonic generation

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Eunju; Shibata, Yoshinori; Manaka, Takaaki [Department of Physical Electronics, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8552 (Japan); Iwamoto, Mitsumasa, E-mail: iwamoto@ome.pe.titech.ac.j [Department of Physical Electronics, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8552 (Japan)

    2009-11-30

    Optical electric field induced second harmonic generation (EFISHG) measurements were employed to probe the electric field in the active layer of organic field effect transistors (OFETs) and organic light emitting diodes (OLEDs). The OFETs used were double-layered with an active layer of pentacene/poly (3-hexyl thiophene) P3HT on SiO{sub 2} gate insulator with Au source and drain electrodes. It was shown that SHG from the P3HT bottom layer could be selectively probed at a wavelength of 450 nm. Similarly, by using OLEDs comprised of a double layer of Tris(8-hydroxyquinolinato) aluminium (Alq{sub 3}) and N'-di(1-naphthyl)-N,N'-diphenylbenzidine ({alpha}-NPD) with a device structure of indium-zinc oxide (IZO)/{alpha}-NPD/Alq{sub 3}/Al, it was shown that EFISHG from the Alq{sub 3} layer could be selectively probed at a wavelength of 1000 nm by reflective laser beam irradiation from IZO-side. The results show that the spectroscopic nature of materials allows us to selectively probe the electric field distribution in each layer of multi-layer in organic devices.

  18. Brillouin optical time domain reflectometry for fast detection of dynamic strain incorporating double-edge technique

    Science.gov (United States)

    Shangguan, Mingjia; Wang, Chong; Xia, Haiyun; Shentu, Guoliang; Dou, Xiankang; Zhang, Qiang; Pan, Jian-wei

    2017-09-01

    For the first time, to the best of our knowledge, a direct detection Brillouin optical time-domain reflectometry (BOTDR) is demonstrated for fast distributed dynamic strain sensing incorporating double-edge technique, time-division multiplexing technique and upconversion technique. In order to guarantee the robust stability of the system, the double-edge technique is implemented by using a convert single-channel FPI and a fiber-coupled upconversion single-photon detector, incorporating a time-division multiplexing method. The upconversion single-photon detector is adopted to upconvert the backscattering photons from 1548.1 nm to 863 nm, which is subsequently detected by a Silicon avalanche photodiode (Si-APD). In the experiment, dynamic strain disturbance up to 1.9 mε over 1.5 km of a polarization maintaining fiber is detected at a sampling rate of 30 Hz. An accuracy of ± 30 με and spatial resolution of 0.6 m are realized.

  19. Flux densities of meteoroids derived from optical double-station observations

    Science.gov (United States)

    Koschny, D.; Drolshagen, E.; Drolshagen, S.; Kretschmer, J.; Ott, T.; Drolshagen, G.; Poppe, B.

    2017-09-01

    We have developed a new method to determine flux densities of meteoroids using optical double-station meteor observations. It is based on the assumption that the velocity distribution is constant for all mass bins. By comparing the observed velocity distribution with a model distribution we determine de-biasing factors to correct for meteors too slow to emit a detectable amount of light. We use this method to correct a dataset of about 20000 double-station meteoroids detected over a period of about 3.5 years with the Canary Island Long-Baseline Observatory (CILBO). The resulting cumulative flux density has a slope comparable to the model of Grün et al. (1985). The largest uncertainty is the luminous efficiency. Depending on which values for the luminous efficiency are assumed, the mass estimate deviates by about one to 1.5 orders of magnitude. Using the luminous efficiencies derived by Weryk et al. (2013) results in an excellent agreement of our data with the Grün data.

  20. Groundwater flow cycling between a submarine spring and an inland fresh water spring

    Science.gov (United States)

    Davis, J. Hal; Verdi, Richard

    2014-01-01

    Spring Creek Springs and Wakulla Springs are large first magnitude springs that derive water from the Upper Floridan Aquifer. The submarine Spring Creek Springs are located in a marine estuary and Wakulla Springs are located 18 km inland. Wakulla Springs has had a consistent increase in flow from the 1930s to the present. This increase is probably due to the rising sea level, which puts additional pressure head on the submarine Spring Creek Springs, reducing its fresh water flow and increasing flows in Wakulla Springs. To improve understanding of the complex relations between these springs, flow and salinity data were collected from June 25, 2007 to June 30, 2010. The flow in Spring Creek Springs was most sensitive to rainfall and salt water intrusion, and the flow in Wakulla Springs was most sensitive to rainfall and the flow in Spring Creek Springs. Flows from the springs were found to be connected, and composed of three repeating phases in a karst spring flow cycle: Phase 1 occurred during low rainfall periods and was characterized by salt water backflow into the Spring Creek Springs caves. The higher density salt water blocked fresh water flow and resulted in a higher equivalent fresh water head in Spring Creek Springs than in Wakulla Springs. The blocked fresh water was diverted to Wakulla Springs, approximately doubling its flow. Phase 2 occurred when heavy rainfall resulted in temporarily high creek flows to nearby sinkholes that purged the salt water from the Spring Creek Springs caves. Phase 3 occurred after streams returned to base flow. The Spring Creek Springs caves retained a lower equivalent fresh water head than Wakulla Springs, causing them to flow large amounts of fresh water while Wakulla Springs flow was reduced by about half.

  1. Groundwater flow cycling between a submarine spring and an inland fresh water spring.

    Science.gov (United States)

    Davis, J Hal; Verdi, Richard

    2014-01-01

    Spring Creek Springs and Wakulla Springs are large first magnitude springs that derive water from the Upper Floridan Aquifer. The submarine Spring Creek Springs are located in a marine estuary and Wakulla Springs are located 18 km inland. Wakulla Springs has had a consistent increase in flow from the 1930s to the present. This increase is probably due to the rising sea level, which puts additional pressure head on the submarine Spring Creek Springs, reducing its fresh water flow and increasing flows in Wakulla Springs. To improve understanding of the complex relations between these springs, flow and salinity data were collected from June 25, 2007 to June 30, 2010. The flow in Spring Creek Springs was most sensitive to rainfall and salt water intrusion, and the flow in Wakulla Springs was most sensitive to rainfall and the flow in Spring Creek Springs. Flows from the springs were found to be connected, and composed of three repeating phases in a karst spring flow cycle: Phase 1 occurred during low rainfall periods and was characterized by salt water backflow into the Spring Creek Springs caves. The higher density salt water blocked fresh water flow and resulted in a higher equivalent fresh water head in Spring Creek Springs than in Wakulla Springs. The blocked fresh water was diverted to Wakulla Springs, approximately doubling its flow. Phase 2 occurred when heavy rainfall resulted in temporarily high creek flows to nearby sinkholes that purged the salt water from the Spring Creek Springs caves. Phase 3 occurred after streams returned to base flow. The Spring Creek Springs caves retained a lower equivalent fresh water head than Wakulla Springs, causing them to flow large amounts of fresh water while Wakulla Springs flow was reduced by about half. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

  2. SPRING 2016

    NARCIS (Netherlands)

    Steinberger, Jessica; Unknown, [Unknown

    SPRING 2016, 11th edition of the SPRING series, is a single-track event that was sponsored by the special interest group Security – Intrusion Detection and Response (SIDAR) of the German Informatics Society (GI). The purpose of SPRING is to provide young researchers the opportunity to discuss their

  3. An Optical Wavefront Sensor Based on a Double Layer Microlens Array

    Directory of Open Access Journals (Sweden)

    Hsiang-Chun Wei

    2011-10-01

    Full Text Available In order to determine light aberrations, Shack-Hartmann optical wavefront sensors make use of microlens arrays (MLA to divide the incident light into small parts and focus them onto image planes. In this paper, we present the design and fabrication of long focal length MLA with various shapes and arrangements based on a double layer structure for optical wavefront sensing applications. A longer focal length MLA could provide high sensitivity in determining the average slope across each microlens under a given wavefront, and spatial resolution of a wavefront sensor is increased by numbers of microlenses across a detector. In order to extend focal length, we used polydimethysiloxane (PDMS above MLA on a glass substrate. Because of small refractive index difference between PDMS and MLA interface (UV-resin, the incident light is less refracted and focused in further distance. Other specific focal lengths could also be realized by modifying the refractive index difference without changing the MLA size. Thus, the wavefront sensor could be improved with better sensitivity and higher spatial resolution.

  4. Double Disassociation of Anosognosia for Alexia and Simultanagnosia but Quantitative Awareness of Optic Ataxia.

    Science.gov (United States)

    Williams, Reed C; Patira, Riddhi; Altschuler, Eric L

    2016-03-01

    A 66-yr-old man with a history of atrial fibrillation and a pacemaker developed sudden onset confusion, disorientation, and visual disturbance without motor weakness. Clinically, significant deficits were found in reading (alexia) and simultaneous multiobject perception (simultanagnosia), both of which the patient denied limitation in, and in vision-right hemianopsia-which he readily acknowledged. Visual acuity in the left visual field was normal. The patient also demonstrated a symptom of optic ataxia-a lack of coordination between visual inputs and hand movements-a deficit he also acknowledged. Work-up with computed topography revealed a left posterior cerebral artery infarct affecting the occipital lobe and extending to involve the parietal lobe and the splenium of the corpus callosum. The authors describe and discuss this fascinating case-the first case to their knowledge of a double disassociation of anosognosia for alexia and simultanagnosia but full, indeed quantitative, awareness of hemianopsia and optic ataxia. This case may be informative on the mechanism of anosognosia in general and supports intentional feed-forward and exemplar reafference models. With regard to the rehabilitation process, appreciation that a patient has anosognosia for various deficits is crucial in recovery and health maintenance.

  5. Energy band gap and optical transition of metal ion modified double crossover DNA lattices.

    Science.gov (United States)

    Dugasani, Sreekantha Reddy; Ha, Taewoo; Gnapareddy, Bramaramba; Choi, Kyujin; Lee, Junwye; Kim, Byeonghoon; Kim, Jae Hoon; Park, Sung Ha

    2014-10-22

    We report on the energy band gap and optical transition of a series of divalent metal ion (Cu(2+), Ni(2+), Zn(2+), and Co(2+)) modified DNA (M-DNA) double crossover (DX) lattices fabricated on fused silica by the substrate-assisted growth (SAG) method. We demonstrate how the degree of coverage of the DX lattices is influenced by the DX monomer concentration and also analyze the band gaps of the M-DNA lattices. The energy band gap of the M-DNA, between the lowest unoccupied molecular orbital (LUMO) and the highest occupied molecular orbital (HOMO), ranges from 4.67 to 4.98 eV as judged by optical transitions. Relative to the band gap of a pristine DNA molecule (4.69 eV), the band gap of the M-DNA lattices increases with metal ion doping up to a critical concentration and then decreases with further doping. Interestingly, except for the case of Ni(2+), the onset of the second absorption band shifts to a lower energy until a critical concentration and then shifts to a higher energy with further increasing the metal ion concentration, which is consistent with the evolution of electrical transport characteristics. Our results show that controllable metal ion doping is an effective method to tune the band gap energy of DNA-based nanostructures.

  6. An optical time delay for the double gravitational lens system FBQ 0951+2635

    CERN Document Server

    Jakobsson, P; Burud, I; Letawe, G; Lidman, C E; Courbin, F

    2005-01-01

    We present optical R-band light curves of the double gravitationally lensed quasar FBQ 0951+2635 from observations obtained at the Nordic Optical Telescope between March 1999 and June 2001. A time delay of 16 +/- 2 days (1 sigma) is determined from the light curves. New constraints on the lensing geometry are provided by the position and ellipticity of the lensing galaxy. For a (Omega_m, Omega_Lambda) = (0.3, 0.7) cosmology, the time delay yields a Hubble parameter of H_0 = 60^{+9}_{-7} (random, 1 sigma) +/- 2 (systematic) km/s/Mpc for a singular isothermal ellipsoid model and H_0 = 63^{+9}_{-7} (random, 1 sigma) +/- 1 (systematic) km/s/Mpc for a constant mass-to-light ratio model. In both models, the errors are mainly due to the time-delay uncertainties. Non-parametric models yield H_0 = 64^{+9}_{-7} (random, 1 sigma) +/- 14 (systematic) km/s/Mpc.

  7. Determination of optical properties in dental restorative biomaterials using the inverse-adding-doubling method

    Science.gov (United States)

    Fernández-Oliveras, Alicia; Rubiño, Manuel; Pérez, María. M.

    2013-11-01

    Light propagation in biological media is characterized by the absorption coefficient, the scattering coefficient, the scattering phase function, the refractive index, and the surface conditions (roughness). By means of the inverse-adding-doubling (IAD) method, transmittance and reflectance measurements lead to the determination of the absorption coefficient and the reduced scattering coefficient. The additional measurement of the phase function performed by goniometry allows the separation of the reduced scattering coefficient into the scattering coefficient and the scattering anisotropy factor. The majority of techniques, such as the one utilized in this work, involve the use of integrating spheres to measure total transmission and reflection. We have employed an integrating sphere setup to measure the total transmittance and reflectance of dental biomaterials used in restorative dentistry. Dental biomaterials are meant to replace dental tissues, such as enamel and dentine, in irreversibly diseased teeth. In previous works we performed goniometric measurements in order to evaluate the scattering anisotropy factor for these kinds of materials. In the present work we have used the IAD method to combine the measurements performed using the integrating sphere setup with the results of the previous goniometric measurements. The aim was to optically characterize the dental biomaterials analyzed, since whole studies to assess the appropriate material properties are required in medical applications. In this context, complete optical characterizations play an important role in achieving the fulfillment of optimal quality and the final success of dental biomaterials used in restorative dentistry.

  8. No double-dissociation between optic ataxia and visual agnosia: Multiple sub-streams for multiple visuo-manual integrations

    NARCIS (Netherlands)

    Pisella, L.; Binkofski, F.; Lasek, K.; Toni, I.; Rossetti, Y.

    2006-01-01

    The current dominant view of the visual system is marked by the functional and anatomical dissociation between a ventral stream specialised for perception and a dorsal stream specialised for action. The "double-dissociation" between visual agnosia (VA), a deficit of visual recognition, and optic ata

  9. No double-dissociation between optic ataxia and visual agnosia: Multiple sub-streams for multiple visuo-manual integrations

    NARCIS (Netherlands)

    Pisella, L.; Binkofski, F.; Lasek, K.; Toni, I.; Rossetti, Y.

    2006-01-01

    The current dominant view of the visual system is marked by the functional and anatomical dissociation between a ventral stream specialised for perception and a dorsal stream specialised for action. The "double-dissociation" between visual agnosia (VA), a deficit of visual recognition, and optic

  10. Effects of electromagnetic fields on the nonlinear optical properties of asymmetric double quantum well under intense laser field

    Science.gov (United States)

    Yesilgul, U.; Sari, H.; Ungan, F.; Martínez-Orozco, J. C.; Restrepo, R. L.; Mora-Ramos, M. E.; Duque, C. A.; Sökmen, I.

    2017-03-01

    In this study, the effects of electric and magnetic fields on the optical rectification and second and third harmonic generation in asymmetric double quantum well under the intense non-resonant laser field is theoretically investigated. We calculate the optical rectification and second and third harmonic generation within the compact density-matrix approach. The theoretical findings show that the influence of electric, magnetic, and intense laser fields leads to significant changes in the coefficients of nonlinear optical rectification, second and third harmonic generation.

  11. Excess Loss of the Coupling System to Double-Function Optical Circulators Utilizing Lens Twice and Two-Fiber Tips

    Institute of Scientific and Technical Information of China (English)

    TIAN Yan-ning; FANG Qiang; WANG Yong-chang; SUN Ai-jing; BAI Ju-rong; YANG Yi-fei

    2005-01-01

    A new type of double function optical circulator for double fibers is proposed in this paper. Two fiber tips and lens twice are employed in this kind of device as the coupling system for what is believed to be the first time. Because two fiber tips and lens twice are used, the function of optical circulator is duplicated in comparison with conventional optical circulator with single fiber tip. Thus the optical circulator has a low cost and a small volume comparatively. Excess loss of the coupling system and the misalignment of the lens twice in angular error and the position error to the developed circulator are analyzed and discussed by using Gauss wave and double integral in theory. The analysis results show that the excess loss is zero when each distance is equal to f between every adjacent fraction and without misalignment error in the coupling system. In addition, the excess loss is increasing with increment of the distance error and the angular error. The errors of the angular of the optical axis to lens and the distance between the SL to lens are the main source of the excess loss. The higher the errors are, the higher the excess loss is. It's very important for reducing the misalignment errors in the coupling system with high ratio of coupling to achieve low excess loss. Details of design and excess loss in the coupling system of this circulator are presented.

  12. Achieving strong doubling power by optical phase-locked Ti:sapphire laser and MOPA system

    Institute of Scientific and Technical Information of China (English)

    Yu Peng; Baike Lin; Qiang Wang; Yang Zhao; Ye Li; Jianping Cao; Zhanjun Fang; Erjun Zang

    2012-01-01

    We show two external cavity-enhanced second-harmonic generations of 922 nm with periodically poled potassium titanyl phosphate crystal,whose doubling cavities are locked separately with Hansch-Couillaud and intra-modulation methods.The outputs of second-harmonic generation reach 310 mW,54.8% of the conversion efficiency from the Ti;sapphire laser with the crystal length of 10 mm,and 208 mW,59% of the conversion efficiency from the MOPA system with the crystal length of 30 mm.It consists of heterodyning the Ti;sapphire laser and the MOPA system,and compares the phase of the beat frequency signal with the phase of a reference RF local oscillator.The resulting phase error is used as a feedback signal and fed back to the reference cavity of the Ti;sapphire laser to lock the two lasers in phase.A stable blue power of 520 mW is obtained,which supplies enough power for the cooling and trapping step of the strontium (Sr) optical lattice clock.Four stable isotopes of Sr,84Sr,86Sr,87Sr,and 88Sr,are detected by probing the laser during a strong 460.7-nm cycling transition (5s21S0-5s5p1P1).%We show two external cavity-enhanced second-harmonic generations of 922 nm with periodically poled potassium titanyl phosphate crystal, whose doubling cavities are locked separately with Hansch-Couillaud and intra-modulation methods. The outputs of second-harmonic generation reach 310 mW, 54.8% of the conversion efficiency from the Ti:sapphire laser with the crystal length of 10 mm, and 208 mW, 59% of the conversion efficiency from the MOPA system with the crystal length of 30 mm. It consists of heterodyning the Ti:sapphire laser and the MOPA system, and compares the phase of the beat frequency signal with the phase of a reference RF local oscillator. The resulting phase error is used as a feedback signal and fed back to the reference cavity of the Ti:sapphire laser to lock the two lasers in phase. A stable blue power of 520 mW is obtained, which supplies enough power for the cooling

  13. Spring Tire

    Science.gov (United States)

    Asnani, Vivake M.; Benzing, Jim; Kish, Jim C.

    2011-01-01

    The spring tire is made from helical springs, requires no air or rubber, and consumes nearly zero energy. The tire design provides greater traction in sandy and/or rocky soil, can operate in microgravity and under harsh conditions (vastly varying temperatures), and is non-pneumatic. Like any tire, the spring tire is approximately a toroidal-shaped object intended to be mounted on a transportation wheel. Its basic function is also similar to a traditional tire, in that the spring tire contours to the surface on which it is driven to facilitate traction, and to reduce the transmission of vibration to the vehicle. The essential difference between other tires and the spring tire is the use of helical springs to support and/or distribute load. They are coiled wires that deform elastically under load with little energy loss.

  14. Dynamics of double-pulse laser produced titanium plasma inferred from thin film morphology and optical emission spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Krstulović, N., E-mail: niksak@ifs.hr [Institute of Physics, Bijenička 46, HR-10000 Zagreb (Croatia); Salamon, K., E-mail: ksalamon@ifs.hr [Institute of Physics, Bijenička 46, HR-10000 Zagreb (Croatia); Modic, M., E-mail: martina.modic@ijs.si [Jožef Stefan Institute, Jamova 39, 1001 Ljubljana (Slovenia); Bišćan, M., E-mail: mbiscan@ifs.hr [Institute of Physics, Bijenička 46, HR-10000 Zagreb (Croatia); Milat, O., E-mail: milat@ifs.hr [Institute of Physics, Bijenička 46, HR-10000 Zagreb (Croatia); Milošević, S., E-mail: slobodan@ifs.hr [Institute of Physics, Bijenička 46, HR-10000 Zagreb (Croatia)

    2015-05-01

    In this paper, dynamics of double-pulse laser produced titanium plasma was studied both directly using optical emission spectroscopy (OES) and indirectly from morphological properties of deposited thin films. Both approaches yield consistent results. Ablated material was deposited in a form of thin film on the Si substrate. During deposition, plasma dynamics was monitored using optical emission spectroscopy with spatial and temporal resolutions. The influence of ablation mode (single and double) and delay time τ (delay between first and second pulses in double-pulse mode) on plasma dynamics and consequently on morphology of deposited Ti-films was studied using X-ray reflectivity and atomic force microscopy. Delay time τ was varied from 170 ns to 4 μs. The results show strong dependence of both emission signal and Ti-film properties, such as thickness, density and roughness, on τ. In addition, correlation of average density and thickness of film is observed. These results are discussed in terms of dependency of angular distribution and kinetic energy of plasma plume particles on τ. Advantages of using double-pulse laser deposition for possible application in thin film production are shown. - Highlights: • Ti-thin films produced by single and double pulse laser ablation mode. • Ablation mode and delay time influenced plasma plume and film characteristics. • Films are most compact for optimized delay time (thinnest, smoothest and most dense). • Plasma dynamics can be inferred from film characteristics.

  15. Beginning Spring

    CERN Document Server

    Caliskan, Mert

    2015-01-01

    Get up to speed quickly with this comprehensive guide toSpring Beginning Spring is the complete beginner's guide toJava's most popular framework. Written with an eye towardreal-world enterprises, the book covers all aspects of applicationdevelopment within the Spring Framework. Extensive samples withineach chapter allow developers to get up to speed quickly byproviding concrete references for experimentation, building askillset that drives successful application development byexploiting the full capabilities of Java's latest advances. Spring provides the exact toolset required to build anent

  16. Just Spring

    CERN Document Server

    Konda, Madhusudhan

    2011-01-01

    Get a concise introduction to Spring, the increasingly popular open source framework for building lightweight enterprise applications on the Java platform. This example-driven book for Java developers delves into the framework's basic features, as well as advanced concepts such as containers. You'll learn how Spring makes Java Messaging Service easier to work with, and how its support for Hibernate helps you work with data persistence and retrieval. Throughout Just Spring, you'll get your hands deep into sample code, beginning with a problem that illustrates dependency injection, Spring's co

  17. Optical CDMA with Embedded Spectral-Polarization Coding over Double Balanced Differential-Detector

    Science.gov (United States)

    Huang, Jen-Fa; Yen, Chih-Ta; Chen, Bo-Hau

    A spectral-polarization coding (SPC) optical code-division multiple-access (OCDMA) configuration structured over arrayed-waveguide grating (AWG) router is proposed. The polarization-division double balanced detector is adopted to execute difference detection and enhances system performance. The signal-to-noise ratio (SNR) is derived by taking the effect of PIIN into account. The result indicates that there would be up to 9-dB SNR improvement than the conventional spectral-amplitude coding (SAC) structures with Walsh-Hadamard codes. Mathematical deriving results of the SNR demonstrate the system embedded with the orthogonal state of polarization (SOP) will suppress effectively phase-induced intensity noise (PIIN). In addition, we will analyze the relations about bit error rate (BER) vs. the number of active users under the different encoding schemes and compare them with our proposed scheme. The BER vs. the effective power under the different encoding scheme with the same number of simultaneous active user conditions are also revealed. Finally, the polarization-matched factor and the difference between simulated and experimental values are discussed.

  18. Encrustation of urologic double pigtail catheters-an ex vivo optical coherence tomography (OCT) study.

    Science.gov (United States)

    Bader, Markus J; Zilinberg, Katja; Weidlich, Patrick; Waidelich, Raphaela; Püls, Michaela; Gratzke, Christian; Stief, Christian G; Stepp, Herbert; Sroka, Ronald

    2013-05-01

    This study aims to evaluate whether optical coherence tomography (OCT) using both the surface and the endoluminal technique is feasible to investigate the locations and degree of encrustation process in clinically used ureteral stents. After removal from patients, 14 polyurethane JJ stents were investigated. A fresh JJ served as a control. The external surfaces were examined using an endoscopic surface OCT whereas the intraluminal surfaces were investigated by an endoluminal radial OCT device. The focus was on detection of encrustation or crystalline sedimentation. In 12 female and two male patients, the median indwelling time of the ureteral catheter was 100 days (range, 19-217). Using the endoluminal OCT, the size and grade of intraluminal encrustation could be expressed as a percentage relating to the open lumen of the reference stent. The maximum encrustation observed resulted in a remaining unrestricted lumen of 15-35 % compared to the reference. The luminal reduction caused by encrustation was significantly higher at the proximal end of the ureteral stent as compared to its distal part. The extraluminal OCT investigations facilitated the characterization of extraluminal encrustation. OCT techniques were feasible and facilitated the detection of encrustation of double pigtail catheters on both the extra and intra luminal surface. Quantitative expression of the degree of intraluminal encrustation could be achieved, with the most dense and thickened occurrence of intraluminal incrustation in the upper curl of the JJ stent.

  19. Axial interface optical phonon modes in a double-nanoshell system

    Energy Technology Data Exchange (ETDEWEB)

    Kanyinda-Malu, C; Clares, F J; Cruz, R M de la [Departamento de Fisica, Universidad Carlos III de Madrid, EPS Avenida de la Universidad 30, 28911 Leganes (Madrid) (Spain)], E-mail: clement.kanyindamalu@urjc.es, E-mail: rmc@fis.uc3m.es

    2008-07-16

    Within the framework of the dielectric continuum (DC) model, we analyze the axial interface optical phonon modes in a double system of nanoshells. This system is constituted by two identical equidistant nanoshells which are embedded in an insulating medium. To illustrate our results, typical II-VI semiconductors are used as constitutive polar materials of the nanoshells. Resolution of Laplace's equation in bispherical coordinates for the potentials derived from the interface vibration modes is made. By imposing the usual electrostatic boundary conditions at the surfaces of the two-nanoshell system, recursion relations for the coefficients appearing in the potentials are obtained, which entails infinite matrices. The problem of deriving the interface frequencies is reduced to the eigenvalue problem on infinite matrices. A truncating method for these matrices is used to obtain the interface phonon branches. Dependences of the interface frequencies on the ratio of inter-nanoshell separation to core size are obtained for different systems with several values of nanoshell interdistance. Effects due to the change of shell and embedding materials are also investigated in interface phonon modes.

  20. Spring Festival

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Spring Festival is the most important festival in China. It's to celebrate the lunar calendar's new year. In the evening before the Spring Festival, families get together and have a big meal. In many places people like to set off firecrackers. Dumplings are

  1. Single-frequency and tunable operation of a continuous intracavity-frequency-doubled singly resonant optical parametric oscillator.

    Science.gov (United States)

    My, Thu-Hien; Drag, Cyril; Bretenaker, Fabien

    2008-07-01

    A widely tunable continuous intracavity-frequency-doubled singly resonant optical parametric oscillator based on MgO-doped periodically poled stoichiometric lithium tantalate crystal is described. The idler radiation resonating in the cavity is frequency doubled by an intracavity BBO crystal. Pumped in the green, this system can provide up to 485 mW of single-frequency orange radiation. The system is continuously temperature tunable between 1170 and 1355 nm for the idler, 876 and 975 nm for the signal, and between 585 and 678 nm for the doubled idler. The free-running power and frequency stability of the system have been observed to be better than those for a single-mode dye laser.

  2. On the performance of free-space optical wireless communication systems over double generalized gamma fading channels

    KAUST Repository

    Al-Quwaiee, Hessa

    2014-03-01

    Starting with the double generalized Gamma (GG) model that was proposed in [1] to describe turbulence-induced fading in free-space optical (FSO) systems, we propose a new unified model which accounts for the impact of pointing errors and type of receiver detector. Based on this new unified model, we study the performance of FSO links operating over these kind of channels. All our analytical results are verified using computer based Monte-Carlo simulations. © 2014 IEEE.

  3. Tracking of Single Quantum Dot Labeled EcoRV Sliding along DNA Manipulated by Double Optical Tweezers

    OpenAIRE

    Biebricher, Andreas; Wende, Wolfgang; Escudé, Christophe; Pingoud, Alfred; Desbiolles, Pierre

    2009-01-01

    Fluorescence microscopy provides a powerful method to directly observe single enzymes moving along a DNA held in an extended conformation. In this work, we present results from single EcoRV enzymes labeled with quantum dots which interact with DNA manipulated by double optical tweezers. The application of quantum dots facilitated accurate enzyme tracking without photobleaching whereas the tweezers allowed us to precisely control the DNA extension. The labeling did not affect the biochemical a...

  4. Normal and system lupus erythematosus red blood cell interactions studied by double trap optical tweezers: direct measurements of aggregation forces

    Science.gov (United States)

    Khokhlova, Maria D.; Lyubin, Eugeny V.; Zhdanov, Alexander G.; Rykova, Sophia Yu.; Sokolova, Irina A.; Fedyanin, Andrey A.

    2012-02-01

    Direct measurements of aggregation forces in piconewton range between two red blood cells in pair rouleau are performed under physiological conditions using double trap optical tweezers. Aggregation and disaggregation properties of healthy and pathologic (system lupus erythematosis) blood samples are analyzed. Strong difference in aggregation speed and behavior is revealed using the offered method which is proposed to be a promising tool for SLE monitoring at single cell level.

  5. Investigation of a double barrier resonant tunnelling structure which incorporates an optical window layer in the top contact

    Energy Technology Data Exchange (ETDEWEB)

    Henini, M.; Eaves, L.; Maude, D.K.; Hughes, O.H. (Dept. of Physics, Univ. of Nottingham (UK)); White, C.R.H. (Dept. of Physics, Univ. of Nottingham (UK) RSRE, Great Malvern (UK)); Simmonds, P.E. (Royal Signals and Radar Establishment, Great Malvern (UK) Dept. of Physics, Univ. of Nottingham (UK)); Skolnick, M.S. (Royal Signals and Radar Establishment, Great Malvern (UK)); Portal, J.C. (SNCI-CNRS, 38 - Grenoble (France) LPS-INSA, 31 - Toulouse (France))

    1991-05-01

    The electrical and optical properties of a double barrier resonant tunnelling device based on n-GaAs/(AlGa)As and incorporating a heavily doped (AlGa)As window layer are described. The window layer is located between the quantum well and the top surface and has a band gap which exceeds the energy of the quantum well photoluminescence. The incorporation of this layer does not impair the electrical properties of the device. (orig.).

  6. The parametric spring-mass system, its connection with non-linear optics, and an approach for undergraduate students

    CERN Document Server

    Boscolo, Ilario; Stellato, Marco; Vercellati, Stefano

    2014-01-01

    The spring-mass system studied in undergraduate physics laboratories may exhibit complex dynamics due to the simultaneous action of gravitational and elastic forces in addition to air friction. In the first part of this paper, we describe a laboratory experiment aimed at beginner students which also gives those with a more advanced background an opportunity to explore more complex aspects of the motions involved. If students are not given predefined apparatus but are allowed instead to design their own set-up for the experiment, they may also learn something about the thought processes and experimental procedures used in physics. In the second part of this paper, we present a systematic study of the parametric behavior of the system because teachers have to master its dynamics. The non-linear interaction between the vertical and the pendular oscillations in a vertical spring-mass system depends on the ratio between the frequencies of the two motions and on the motion's excitation. Systematic experimental inve...

  7. Yield and quality prediction using satellite passive imagery and ground-based active optical sensors in sugar beet, spring wheat, corn, and sunflower

    Science.gov (United States)

    Bu, Honggang

    Remote sensing is one possible approach for improving crop nitrogen use efficiency to save fertilizer cost, reduce environmental pollution, and improve crop yield and quality. Feasibility and potential of using remote sensing tools to predict crops yield and quality as well as detect nitrogen requirements, application timing, rate, and places in season were investigated based on 2012-2013 two-year and four-crop (corn, spring wheat, sugar beet, and sunflower) study. Two ground-based active optical sensors, GreenSeeker and Holland Scientific Crop Circle, and the RapidEye satellite imagery were used to collect sensing data. Highly significant statistical relationships between INSEY (NDVI normalized by growing degree days) and crop yield and quality indices were found for all crops, indicating that remote sensing tools may be useful for managing in-season crop yield and quality prediction.

  8. Comparison of aerosol optical properties at the sub-arctic stations ALOMAR-Andenes, Abisko and Sodankylä in late spring and summer 2007

    Science.gov (United States)

    Rodríguez, E.; Toledano, C.; Cachorro, V.; de Leeuw, G.; De Frutos, A.; Gausa, M.; Holben, B.

    2012-04-01

    Aerosol concentration and aerosol type, retrieved from observations with CIMEL sun-photometers at three sub-arctic locations at the Scandinavian Peninsula are presented. The observations were made at ALOMAR-Andenes in Norway, Abisko in Sweden and Sodankylä in Finland. This field campaign took place in late spring and summer 2007 as part of the activities of the International Polar Year (IPY) within the POLARCAT project at ALOMAR and Abisko. Aerosol properties were characterized using the relationship between the aerosol optical depth and the Ångström Exponent. The characteristics of the predominant aerosol type and microphysics are largely determined by the location of the site (continental or coastal). During summer the fine mode particles dominate, as indicated by the fine mode volume fraction and the Ångström Exponent. The aerosol concentration was on average very low, except during an event in which long-range transported aerosols (dust and pollution) were detected.

  9. Potential of a spectroscopic measurement method using adding-doubling to retrieve the bulk optical properties of dense microalgal media.

    Science.gov (United States)

    Bellini, Sarah; Bendoula, Ryad; Latrille, Eric; Roger, Jean-Michel

    2014-01-01

    In the context of algal mass cultivation, current techniques used for the characterization of algal cells require time-consuming sample preparation and a large amount of costly, standard instrumentation. As the physical and chemical properties of the algal cells strongly affect their optical properties, the optical characterization is seen as a promising method to provide an early diagnosis in the context of mass cultivation monitoring. This article explores the potential of a spectroscopic measurement method coupled with the inversion of the radiative transfer theory for the retrieval of the bulk optical properties of dense algal samples. Total transmittance and total reflectance measurements were performed over the 380-1020 nm range on dense algal samples with a double integrating sphere setup. The bulk absorption and scattering coefficients were thus extracted over the 380-1020 nm range by inverting the radiative transfer theory using inverse-adding-doubling computations. The experimental results are presented and discussed; the configuration of the optical setup remains a critical point. The absorption coefficients obtained for the four samples of this study appear not to be more informative about pigment composition than would be classical methods in analytical spectroscopy; however, there is a real added value in measuring the reduced scattering coefficient, as it appears to be strongly correlated to the size distribution of the algal cells.

  10. Electromagnetic and optical characteristics of Nb5+-doped double-crossover and salmon DNA thin films

    Science.gov (United States)

    Babu Mitta, Sekhar; Reddy Dugasani, Sreekantha; Jung, Soon-Gil; Vellampatti, Srivithya; Park, Tuson; Park, Sung Ha

    2017-10-01

    We report the fabrication and physical characteristics of niobium ion (Nb5+)-doped double-crossover DNA (DX-DNA) and salmon DNA (SDNA) thin films. Different concentrations of Nb5+ ([Nb5+]) are coordinated into the DNA molecules, and the thin films are fabricated via substrate-assisted growth (DX-DNA) and drop-casting (SDNA) on oxygen plasma treated substrates. We conducted atomic force microscopy to estimate the optimum concentration of Nb5+ ([Nb5+]O = 0.08 mM) in Nb5+-doped DX-DNA thin films, up to which the DX-DNA lattices maintain their structures without deformation. X-ray photoelectron spectroscopy (XPS) was performed to probe the chemical nature of the intercalated Nb5+ in the SDNA thin films. The change in peak intensities and the shift in binding energy were witnessed in XPS spectra to explicate the binding and charge transfer mechanisms between Nb5+ and SDNA molecules. UV-visible, Raman, and photoluminescence (PL) spectra were measured to determine the optical properties and thus investigate the binding modes, Nb5+ coordination sites in Nb5+-doped SDNA thin films, and energy transfer mechanisms, respectively. As [Nb5+] increases, the absorbance peak intensities monotonically increase until ∼[Nb5+]O and then decrease. However, from the Raman measurements, the peak intensities gradually decrease with an increase in [Nb5+] to reveal the binding mechanism and binding sites of metal ions in the SDNA molecules. From the PL, we observe the emission intensities to reduce them at up to ∼[Nb5+]O and then increase after that, expecting the energy transfer between the Nb5+ and SDNA molecules. The current–voltage measurement shows a significant increase in the current observed as [Nb5+] increases in the SDNA thin films when compared to that of pristine SDNA thin films. Finally, we investigate the temperature dependent magnetization in which the Nb5+-doped SDNA thin films reveal weak ferromagnetism due to the existence of tiny magnetic dipoles in the Nb5+-doped

  11. Ultrafast optical reversible double Feynman logic gate using electro-optic effect in lithium-niobate based Mach Zehnder interferometers

    Science.gov (United States)

    Chauhan, Chanderkanta; Bedi, Amna; Kumar, Santosh

    2017-02-01

    In this ultra fast computing era power optimization is a major technological challenge that requires new computing paradigms. Conservative and reversible logic opens up the possibility of ultralow power computing. In this paper, basic reversible logic gate (double Feynman gate) using the lithium-niobate based Mach-Zehnder interferometer is proposed. The results are verified using beam propagation method and MATLAB simulations.

  12. Retinal optical coherence tomography image enhancement via shrinkage denoising using double-density dual-tree complex wavelet transform.

    Science.gov (United States)

    Chitchian, Shahab; Mayer, Markus A; Boretsky, Adam R; van Kuijk, Frederik J; Motamedi, Massoud

    2012-11-01

    ABSTRACT. Image enhancement of retinal structures, in optical coherence tomography (OCT) scans through denoising, has the potential to aid in the diagnosis of several eye diseases. In this paper, a locally adaptive denoising algorithm using double-density dual-tree complex wavelet transform, a combination of the double-density wavelet transform and the dual-tree complex wavelet transform, is applied to reduce speckle noise in OCT images of the retina. The algorithm overcomes the limitations of commonly used multiple frame averaging technique, namely the limited number of frames that can be recorded due to eye movements, by providing a comparable image quality in significantly less acquisition time equal to an order of magnitude less time compared to the averaging method. In addition, improvements of image quality metrics and 5 dB increase in the signal-to-noise ratio are attained.

  13. Ultra-flat and broad optical frequency combs generation based on novel dispersion-flattened double-slot microring resonator

    Science.gov (United States)

    Wang, Yuanwu; Zhang, Minming; Lu, Luluzi; Li, Meifeng; Wang, Jinghao; Zhou, Feiya; Dai, Jing; Deng, Lei; Liu, Deming

    2016-01-01

    In this paper, a novel double-slot microring resonator is proposed to produce flat dispersion of 0-3.8 ps/(nm km) over 1150 nm wavelength range. Moreover, the dispersion tailoring with different structural parameters of the proposed microring resonator is analyzed and simulated. The simulation results show that the dispersion fluctuation can be tailored by the height of the central and bottom As2S3 layer, and the slope can be adjusted by the waveguide width and lower SiO2 slot thickness. Furthermore, by means of the Lugiato-Lefever equation, an ultra-flat and broad optical frequency comb with 7-dB bandwidth of 1155 nm (1855-3010 nm) is obtained based on such dispersion-optimized resonator. The proposed double-slot microring resonator shows potential application in both telecommunication and mid-infrared research domain.

  14. MgO:PPLN frequency doubling optical chips for green light generation: from lab research to mass production

    Science.gov (United States)

    Xu, Chang-Qing; Gan, Yi; Sun, Jian

    2012-03-01

    Laser displays require red, green and blue (RGB) laser sources each with a low-cost, a high wall-plug efficiency, and a small size. However, semiconductor chips that directly emit green light with sufficient power and efficiency are not currently available on the market. A practical solution to the "green" bottleneck is to employ diode pumped solid state laser (DPSSL) technology, in which a frequency doubling crystal is used. In this paper, recent progress of MgO doped periodically poled lithium niobate (MgO:PPLN) frequency doubling optical chips will be presented. It is shown that MgO:PPLN can satisfy all of the requirements for laser displays and is ready for mass production.

  15. Quantum Spring

    Science.gov (United States)

    Feng, Chao-Jun; Li, Xin-Zhou

    In this paper, we will give a short review on quantum spring, which is a Casimir effect from the helix boundary condition that proposed in our earlier works. The Casimir force parallel to the axis of the helix behaves very much like the force on a spring that obeys the Hooke's law when the ratio r of the pitch to the circumference of the helix is small, but in this case, the force comes from a quantum effect, so we would like to call it quantum spring. On the other hand, the force perpendicular to the axis decreases monotonously with the increasing of the ratio r. Both forces are attractive and their behaviors are the same in two and three dimensions.

  16. Airborne measurements of aerosol optical properties related to early spring transport of mid-latitude sources into the Arctic

    Directory of Open Access Journals (Sweden)

    R. Adam de Villiers

    2009-12-01

    Full Text Available Airborne lidar and in-situ measurements of the aerosol properties were conducted between Svalbard Island and Scandinavia in April 2008. Evidence of aerosol transport from Europe and Asia is given. The analysis of the aerosol optical properties based on a multiwavelength lidar (355, 532, 1064 nm including depolarization at 355 nm aims at distinguishing the role of the different aerosol sources (Siberian wild fires, Eastern Asia and European anthropogenic emissions. Combining, first aircraft measurements, second FLEXPART simulations with a calculation of the PBL air fraction originating from the three different mid-latitude source regions, and third level-2 CALIPSO data products (i.e. backscatter coefficient, depolarisation and color ratio in aerosol layers along the transport pathways, appears a valuable approach to identify the role of the different aerosol sources even after a transport time larger than 4 days. Above Asia, CALIPSO data indicate more depolarisation (up to 15% and largest color ratio (>0.5 for the northeastern Asia emissions (i.e. an expected mixture of Asian pollution and dust, while low depolarisation together with smaller and quasi constant color ratio (≈0.3 are observed for the Siberian biomass burning emissions. A similar difference is visible between two layers observed by the aircraft above Scandinavia. The analysis of the time evolution of the aerosol optical properties revealed by CALIPSO between Asia and Scandinavia shows a gradual decrease of the aerosol backscatter, depolarisation ratio and color ratio which suggests the removal of the largest particles in the accumulation mode. A similar study conducted for a European plume has shown aerosol optical properties intermediate between the two Asian sources with color ratio never exceeding 0.4 and moderate depolarisation ratio being always less than 8%, i.e. less aerosol from the accumulation mode.

  17. Airborne measurements of aerosol optical properties related to early spring transport of mid-latitude sources into the Arctic

    Directory of Open Access Journals (Sweden)

    R. A. de Villiers

    2010-06-01

    Full Text Available Airborne lidar and in-situ measurements of the aerosol properties were conducted between Svalbard Island and Scandinavia in April 2008. Evidence of aerosol transport from Europe and Asia is given. The analysis of the aerosol optical properties based on a multiwavelength lidar (355, 532, 1064 nm including volume depolarization at 355 nm aims at distinguishing the role of the different aerosol sources (Siberian wild fires, Eastern Asia and European anthropogenic emissions. Combining, first aircraft measurements, second FLEXPART simulations with a calculation of the PBL air fraction originating from the three different mid-latitude source regions, and third level-2 CALIPSO data products (i.e. backscatter coefficient 532 nm,volume depolarization and color ratio between 1064 and 532 nm in aerosol layers along the transport pathways, appears a valuable approach to identify the role of the different aerosol sources even after a transport time larger than 4 days. Optical depth of the aerosol layers are always rather small (<4% while transported over the Arctic and ratio of the total attenuated backscatter (i.e. including molecular contribution provide more stable result than conventional aerosol backscatter ratio. Above Asia, CALIPSO data indicate more depolarization (up to 15% and largest color ratio (>0.5 for the northeastern Asia emissions (i.e. an expected mixture of Asian pollution and dust, while low depolarization together with smaller and quasi constant color ratio (≈0.3 are observed for the Siberian biomass burning emissions. A similar difference is visible between two layers observed by the aircraft above Scandinavia. The analysis of the time evolution of the aerosol optical properties revealed by CALIPSO between Asia and Scandinavia shows a gradual decrease of the aerosol backscatter, depolarization ratio and color ratio which suggests the removal of the largest particles in the accumulation mode. A similar study conducted for a European

  18. Estimation of optical properties of neuroendocrine pancreas tumor with double-integrating-sphere system and inverse Monte Carlo model.

    Science.gov (United States)

    Saccomandi, Paola; Larocca, Enza Stefania; Rendina, Veneranda; Schena, Emiliano; D'Ambrosio, Roberto; Crescenzi, Anna; Di Matteo, Francesco Maria; Silvestri, Sergio

    2016-08-01

    The investigation of laser-tissue interaction is crucial for diagnostics and therapeutics. In particular, the estimation of tissue optical properties allows developing predictive models for defining organ-specific treatment planning tool. With regard to laser ablation (LA), optical properties are among the main responsible for the therapy efficacy, as they globally affect the heating process of the tissue, due to its capability to absorb and scatter laser energy. The recent introduction of LA for pancreatic tumor treatment in clinical studies has fostered the need to assess the laser-pancreas interaction and hence to find its optical properties in the wavelength of interest. This work aims at estimating optical properties (i.e., absorption, μ a , scattering, μ s , anisotropy, g, coefficients) of neuroendocrine pancreas tumor at 1064 nm. Experiments were performed using two popular sample storage methods; the optical properties of frozen and paraffin-embedded neuroendocrine tumor of the pancreas are estimated by employing a double-integrating-sphere system and inverse Monte Carlo algorithm. Results show that paraffin-embedded tissue is characterized by absorption and scattering coefficients significantly higher than frozen samples (μ a of 56 cm(-1) vs 0.9 cm(-1), μ s of 539 cm(-1) vs 130 cm(-1), respectively). Simulations show that such different optical features strongly influence the pancreas temperature distribution during LA. This result may affect the prediction of therapeutic outcome. Therefore, the choice of the appropriate preparation technique of samples for optical property estimation is crucial for the performances of the mathematical models which predict LA thermal outcome on the tissue and lead the selection of optimal LA settings.

  19. Optical and photoelectrochemical studies on Ag{sub 2}O/TiO{sub 2} double-layer thin films

    Energy Technology Data Exchange (ETDEWEB)

    Li, Chuan, E-mail: cli10@yahoo.com [Department of Biomedical Engineering, National Yang Ming University, Taipei, Taiwan 11221 (China); Department of Mechanical Engineering, National Central University, Jhongli, Taoyuan, Taiwan 32001 (China); Hsieh, J.H. [Department of Materials Engineering, Ming Chi University of Technology, Taishan, Taipei, Taiwan 24301 (China); Cheng, J.C. [Department of Electronic Engineering, National Taipei University of Technology, Taipei, Taiwan 10608 (China); Huang, C.C. [Department of Biomedical Engineering, National Yang Ming University, Taipei, Taiwan 11221 (China)

    2014-11-03

    When two different oxides films stacked together, if the absorption (upper) layer has both its conduction and valence bands more negatively lower than that of the layer underneath, then the photo-excited electrons can be forwarded to the underneath layer to become an effect of energy storage. Recent studies discovered that the double-layers of Cu{sub 2}O/TiO{sub 2} films possess such capacity. In order to investigate this specific phenomenon, we use a DC magnetron reactive sputtering to deposit a double-layer of Ag{sub 2}O/TiO{sub 2} films on glass substrate. The film thicknesses of the double-layer are 300 nm and 200 nm respectively. X-Ray diffraction (XRD), scanning electron microscope (SEM) and UV–VIS–NIR photospectrometer and photoluminance tests were used to study the structure, morphology, optical absorption and band gaps of the stacked films. From XRD and SEM, we can confirm the microstructures of each layer. The UV–VIS–NIR spectrum revealed that the optical absorption of Ag{sub 2}O/TiO{sub 2} fell in between the single film of Ag{sub 2}O and TiO{sub 2}. Further, two band gaps were estimated for Ag{sub 2}O/TiO{sub 2} films based on the Beer-Lambert law and Tauc plot. Photoluminance and photoelectrochemical tests indicated that delayed emission by electron-hole recombination and photoelectrical current was effectively support the mechanism of electrons transfer from Ag{sub 2}O to TiO{sub 2} at Ag{sub 2}O/TiO{sub 2} interface in the double-layer films. - Highlights: • A double-layer of Ag{sub 2}O/TiO{sub 2} films was deposited on glass substrate by sputtering. • XRD confirms the nanocrystalline structures of the stack deposited films. • UV–VIS–NIR spectroscopy shows the enhanced of optical absorption in Ag{sub 2}O/TiO{sub 2}. • Photoluminance and photoelectrochemical tests show electron-hole separation effect.

  20. Ground States of Ultracold Spin-1 Atoms in a Deep Double-Well Optical Superlattice in a Weak Magnetic Field

    Institute of Scientific and Technical Information of China (English)

    ZHENG Gong-Ping; QIN Shuai-Feng; WANG Shou-Yang; JIAN Wen-Tian

    2013-01-01

    The ground states of the ultracold spin-1 atoms trapped in a deep one-dimensional double-well optical superlattice in a weak magnetic field are obtained.It is shown that the ground-state diagrams of the reduced doublewell model are remarkably different for the antiferromagnetic and ferromagnetic condensates.The transition between the singlet state and nematic state is observed for the antiferromagnetic interaction atoms,which can be realized by modulating the tunneling parameter or the quadratic Zeeman energy.An experiment to distinguish the different spin states is suggested.

  1. Universal quantum gates for hybrid system assisted by atomic ensembles embedded in double-sided optical cavities

    Science.gov (United States)

    Liu, A.-Peng; Cheng, Liu-Yong; Guo, Qi; Zhang, Shou; Zhao, Ming-Xia

    2017-01-01

    We propose deterministic schemes for controlled-NOT (CNOT), Toffoli, and Fredkin gates between flying photon qubits and the collective spin wave (magnon) of an atomic ensemble inside double-sided optical microcavities. All the gates can be accomplished with 100% success probability in principle and no additional qubit is required. Atomic ensemble is employed so that light-matter coupling is remarkably improved by collective enhancement. We qualified the performance of the gates and the results show that they can be faithfully constituted with current experimental techniques. PMID:28272548

  2. Nanosecond Pulse Shaping with Fiber-Based Electro-Optical Modulators and a Double-Pass Tapered Amplifier

    CERN Document Server

    Rogers, Charles E

    2015-01-01

    We describe a system for generating frequency-chirped and amplitude-shaped pulses on time scales from sub-nanosecond to ten nanoseconds. The system starts with cw diode-laser light at 780 nm and utilizes fiber-based electro-optical phase and intensity modulators, driven by an arbitrary waveform generator, to generate the shaped pulses. These pulses are subsequently amplified to several hundred mW with a tapered amplifier in a delayed double-pass configuration. Frequency chirps up to 5 GHz in 2 ns and pulse widths as short as 0.15 ns have been realized.

  3. Scalable quantum computing based on stationary spin qubits in coupled quantum dots inside double-sided optical microcavities.

    Science.gov (United States)

    Wei, Hai-Rui; Deng, Fu-Guo

    2014-12-18

    Quantum logic gates are the key elements in quantum computing. Here we investigate the possibility of achieving a scalable and compact quantum computing based on stationary electron-spin qubits, by using the giant optical circular birefringence induced by quantum-dot spins in double-sided optical microcavities as a result of cavity quantum electrodynamics. We design the compact quantum circuits for implementing universal and deterministic quantum gates for electron-spin systems, including the two-qubit CNOT gate and the three-qubit Toffoli gate. They are compact and economic, and they do not require additional electron-spin qubits. Moreover, our devices have good scalability and are attractive as they both are based on solid-state quantum systems and the qubits are stationary. They are feasible with the current experimental technology, and both high fidelity and high efficiency can be achieved when the ratio of the side leakage to the cavity decay is low.

  4. Synthesis, surface structure and optical properties of double perovskite Sr2NiMoO6 nanoparticles

    Science.gov (United States)

    Xu, Lei; Wan, Yingpeng; Xie, Hongde; Huang, Yanlin; Yang, Li; Qin, Lin; Seo, Hyo Jin

    2016-12-01

    Double perovskite Sr2NiMoO6 nanoparticles were synthesized via the chemical sol-gel route. The phase formation was investigated through X-ray polycrystalline diffraction (XRD) and Rietveld refinements. The perovskite crystallized in worm-like nano-grains with the diameter of 20-50 nm. The optical properties were measured by the optical absorption spectra. The nanoparticles present an indirect allowed transition with a narrow band gap of 2.1 eV. Sr2NiMoO6 nanoparticles have obvious photocatalytic ability on the degradation of Rhodamine B (RhB) solutions under the irradiation of visible light. The transport behaviors of the excitons were investigated from the photoluminescence spectra and the corresponding decay lifetimes. Sr2NiMoO6 nanoparticles present several advantages for photocatalysis such as the appropriate band energy positions, the quenched luminescence, and the coexistence of multivalent ions in the lattices.

  5. Electrical and Optical Properties of InGaN/AIGaN Double Heterostructure Blue Light-Emitting Diodes

    Institute of Scientific and Technical Information of China (English)

    SHEN Bo; SHI Hong-Tao; ZHANG Rong; CHEN Zhi-Zhong; ZHENG You-Dou

    2001-01-01

    Electrical and optical properties of InGaN/AlGaN double heterostructure blue light-emitting diodes were inves tigated. Measurement of the forward bias current-voltage behaviour of the device demonstrated a departure from the Shockley model of a p-n diode, and it was observed that the dominant mechanism of carrier transport across the junction is associated with carrier tunnelling. Electroluminescence experiments indicated that there was a main emission band around 2.80eV and a relatively weaker peak at 3.2eV. A significant blueshift of the optical emission band was observed, which was consistent with the tunnelling character of electrical characteris tics. Furthermore, the degradation in I - V characteristics and the low resistance ohmic short of the device were observed.

  6. A double optical solitary wave in a nonlinear Schr(o)dinger-type equation

    Institute of Scientific and Technical Information of China (English)

    Yin Jiu-Li; Ding Shan-Yu

    2013-01-01

    A qualitative analysis method to efficiently solve the shallow wave equations is improved,so that a more complicated nonlinear Schr(o)dinger equation can be considered.By using the detailed study,some quite strange optical solitary waves are obtained in which the bright and dark optical solitary waves are allowed to coexist.

  7. A double-DD blind equalizer for PolMux QAM optical coherent systems

    Science.gov (United States)

    Zhou, Zhili; Zhan, Yiju; Ruan, Xiukai; Cai, Qibo; Cui, Guihua; Zhu, Guijun

    2017-01-01

    In polarization-multiplexed (PolMux) coherent system, adaptive blind equalization is efficient in demultiplexing and mitigating inter-symbol interference (ISI). We propose a double decision-directed (double-DD) blind algorithm which combines the output of soft decision-directed (SDD) algorithm with that of the equalizer in variable step size decision-directed (VSS-DD) mode. In our scheme, two equalizers can softly switch when the mean-square error (MSE) is sufficiently low and it can achieve fast convergence rate and small steady MSE in steady state. By simulation in PolMux-16QAM/64QAM coherent systems, we show that the double-DD algorithm outperforms existing blind equalizers.

  8. An optical MEMS accelerometer fabricated using double-sided deep reactive ion etching on silicon-on-insulator wafer

    Science.gov (United States)

    Teo, Adrian J. T.; Li, Holden; Tan, Say Hwa; Yoon, Yong-Jin

    2017-06-01

    Optical MEMS devices provide fast detection, electromagnetic resilience and high sensitivity. Using this technology, an optical gratings based accelerometer design concept was developed for seismic motion detection purposes that provides miniaturization, high manufacturability, low costs and high sensitivity. Detailed in-house fabrication procedures of a double-sided deep reactive ion etching (DRIE) on a silicon-on-insulator (SOI) wafer for a micro opto electro mechanical system (MOEMS) device are presented and discussed. Experimental results obtained show that the conceptual device successfully captured motion similar to a commercial accelerometer with an average sensitivity of 13.6 mV G-1, and a highest recorded sensitivity of 44.1 mV G-1. A noise level of 13.5 mV was detected due to experimental setup limitations. This is the first MOEMS accelerometer developed using double-sided DRIE on SOI wafer for the application of seismic motion detection, and is a breakthrough technology platform to open up options for lower cost MOEMS devices.

  9. Double random phase spread spectrum spread space technique for secure parallel optical multiplexing with individual encryption key

    Science.gov (United States)

    Hennelly, B. M.; Javidi, B.; Sheridan, J. T.

    2005-09-01

    A number of methods have been recently proposed in the literature for the encryption of 2-D information using linear optical systems. In particular the double random phase encoding system has received widespread attention. This system uses two Random Phase Keys (RPK) positioned in the input spatial domain and the spatial frequency domain and if these random phases are described by statistically independent white noises then the encrypted image can be shown to be a white noise. Decryption only requires knowledge of the RPK in the frequency domain. The RPK may be implemented using a Spatial Light Modulators (SLM). In this paper we propose and investigate the use of SLMs for secure optical multiplexing. We show that in this case it is possible to encrypt multiple images in parallel and multiplex them for transmission or storage. The signal energy is effectively spread in the spatial frequency domain. As expected the number of images that can be multiplexed together and recovered without loss is proportional to the ratio of the input image and the SLM resolution. Many more images may be multiplexed with some loss in recovery. Furthermore each individual encryption is more robust than traditional double random phase encoding since decryption requires knowledge of both RPK and a lowpass filter in order to despread the spectrum and decrypt the image. Numerical simulations are presented and discussed.

  10. Ultraslow optical solitons in tunnel-coupled double semiconductor quantum well

    Institute of Scientific and Technical Information of China (English)

    Chen Ai-Xi; Xu Yan-Qiu; Deng Li; Zhou Su-Yun

    2009-01-01

    This paper investigates the nonlinear evolution of the pulse probe field in an asymmetric coupled-quantum well driven coherently by a pulse probe field and two controlled fields.This study shows that,by choosing appropriate physical parameters,self-modulation can precisely balance group velocity dispersion in the investigated system,leading to the formation of ultraslow optical solitons of the probe field.The proposed scheme may lead to the development of the controlled technique of optical buffers and optical delay lines.

  11. A double-blind, randomized trial of IV immunoglobulin treatment in acute optic neuritis

    DEFF Research Database (Denmark)

    Roed, H.G; Langkilde, Annika Reynberg; Sellebjerg, F;

    2005-01-01

    OBJECTIVE: To investigate if IV immunoglobulin (IVIG) treatment in the acute phase of optic neuritis (ON) could improve visual outcome and reduce MRI disease activity 6 months after onset of ON. METHODS: Sixty-eight patients with ON were randomized within 4 weeks from onset of symptoms. Thirty...... during follow-up. CONCLUSIONS: There was no effect of IV immunoglobulin (IVIG) on long-term visual function following acute optic neuritis, nor was there an effect of IVIG treatment in reducing latency on visual evoked potentials and thus preserving function of axons of the optic nerve...

  12. Organic double layer element driven by triboelectric nanogenerator: Study of carrier behavior by non-contact optical method

    Science.gov (United States)

    Chen, Xiangyu; Taguchi, Dai; Manaka, Takaaki; Iwamoto, Mitsumasa

    2016-02-01

    By using optical electric-field-induced second-harmonic generation (EFISHG) technique, we studied carrier behavior caused by contact electrification (CE) in an organic double-layer element. This double-layer sample was half suspended in the open air, where one electrode (anode or cathode) was connected with a Cu foil for electrification while the other electrode was floated. Results showed two distinct carrier behaviors, depending on the (anode or cathode) connections to the Cu foil, and these carrier behaviors were analyzed based on the Maxwell-Wagner model. The double-layer sample works as a simple solar cell device. The photovoltaic effect and CE process have been proved to be two paralleled effects without strong interaction with each other, while photoconductivity changing in the sample can enhance the relaxation of CE induced charges. By probing the carrier behavior in this half-suspended device, the EFISHG technique has been demonstrated to be an effective non-contact method for clarifying the CE effect on related energy harvesting devices and electronics devices. Meanwhile, the related physical analysis in this letter is also useful for elucidating the fundamental characteristic of hybrid energy system based on solar cell and triboelectric nanogenerator.

  13. Raman probes based on optically-poled double-clad fiber and coupler

    DEFF Research Database (Denmark)

    Brunetti, Anna Chiara; Margulis, Walter; Rottwitt, Karsten

    2012-01-01

    of a sample of dimethyl sulfoxide (DMSO), when illuminating the waveguide with 1064nm laser light. The Raman signal is collected in the inner cladding, from which it is retrieved with either a bulk dichroic mirror or a double-clad fiber coupler. The coupler allows for a substantial reduction of the fiber...

  14. Study of the optical properties of solid tissue phantoms using single and double integrating sphere systems

    CSIR Research Space (South Africa)

    Monem, S

    2015-12-01

    Full Text Available Tissue simulators, the so-called tissue phantoms, have been used to mimic human tissue for spectroscopic applications. Phantoms’ design depends on patterning the optical properties, namely absorption and scattering coefficients which characterize...

  15. The Cambridge Double Star Atlas

    Science.gov (United States)

    MacEvoy, Bruce; Tirion, Wil

    2015-12-01

    Preface; What are double stars?; The binary orbit; Double star dynamics; Stellar mass and the binary life cycle; The double star population; Detecting double stars; Double star catalogs; Telescope optics; Preparing to observe; Helpful accessories; Viewing challenges; Next steps; Appendices: target list; Useful formulas; Double star orbits; Double star catalogs; The Greek alphabet.

  16. Multianalyte electrochemical biosensor on a monolith electrode by optically scanning the electrical double layer.

    Science.gov (United States)

    Lee, Seung-Woo; Saraf, Ravi F

    2014-07-15

    Redox on an electrode is an interfacial phenomenon that modulates the charge in the electrical double layer (EDL). A novel instrument, the Scanning Electrometer for Electrical Double-layer (SEED) has been developed to measure multiple enzyme reactions on a monolith electrode due to immunospecific binding with a mixture of respective analytes. SEED quantitatively maps the local redox reaction by scanning a laser on the array of enzyme monolayer spots immobilized on the monolith electrode. SEED measures the change in local charge state of the EDL that abruptly changes due to the redox reaction. The measurement spot size defined by the size of the laser beam is ~10 µm. The SEED signal is linearly proportional to the local redox current density and analyte concentration. The specificity is close to 100%. The SEED readout is compatible with microfluidics platform where the signal degrades less than 2% due to the poly(dimethyl siloxane) (PDMS) body.

  17. Raman Spectroscopy of Single Nanoparticles in a Double-Nanohole Optical Tweezer System

    CERN Document Server

    Jones, Steven; Gordon, Reuven

    2015-01-01

    A double nanohole in a metal film was used to trap nanoparticles (20 nm diameter) and simultaneously record their Raman spectrum using the trapping laser as the excitation source. This allowed for the identification of characteristic Stokes lines for titania and polystyrene nanoparticles, showing the capability for material identification of nanoparticles once trapped. Increased Raman signal is observed for the trapping of multiple nanoparticles. This system combines the benefits of nanoparticle isolation and manipulation with unique identification.

  18. Raman spectroscopy of single nanoparticles in a double-nanohole optical tweezer system

    Science.gov (United States)

    Jones, Steven; Balushi, Ahmed A. Al; Gordon, Reuven

    2015-10-01

    A double nanohole in a metal film was used to trap nanoparticles (20 nm diameter) and simultaneously record their Raman spectrum using the trapping laser as the excitation source. This allowed for the identification of characteristic Stokes lines for titania and polystyrene nanoparticles, showing the capability for material identification of nanoparticles once trapped. Increased Raman signal was observed for the trapping of multiple nanoparticles. This system combines the benefits of nanoparticle isolation and manipulation with unique identification.

  19. All-optical production of a large Bose-Einstein condensate in a double compressible crossed dipole trap

    Science.gov (United States)

    Yamashita, Kazuya; Hanasaki, Kouhei; Ando, Akihiro; Takahama, Masahiro; Kinoshita, Toshiya

    2017-01-01

    We report on an all-optical production of a 87Rb Bose-Einstein condensate (BEC) of 106 atoms. We construct a double compressible crossed dipole trap (DCDT) formed by a high-power multimode fiber laser (MCDT) and a single-mode fiber amplifier (SCDT), which are both operated at 1.06 μ m . A very cold dense gas is first cooled by polarization gradient cooling in a three-dimensional optical lattice. More than 2 ×107 atoms are loaded into the enlarged DCDT. Both CDTs are then simultaneously compressed to significantly different sizes followed by evaporation, which is performed by lowering only the MCDT power. The tighter SCDT produces an extremely high collision rate and maintains the trap stiffness, which leads to rapid and efficient evaporation. After 0.4 s, a gas of 5 ×106 atoms with a phase-space density of 0.2 is confined within the SCDT alone. Further evaporation in 2.8 s yields a nearly pure BEC of 1.2 ×106 atoms in the |F mF>=|11 > state. This number is the largest generated among all-optical methods. Our approach significantly improves the atom number of a condensate and circumvents the severe atom loss previously reported for multimode fiber lasers.

  20. Brillouin optical time domain reflectometry for fast detection of dynamic strain incorporating double-edge technique

    CERN Document Server

    Shangguan, Mingjia; Xia, Haiyun; Qiu, Jiawei; Shentu, Guoliang; Dou, Xiankang; Zhang, Qiang; Pan, Jian-wei

    2016-01-01

    For the first time, a direct detection BOTDR is demonstrated for distributed dynamic strain sensing incorporating double-edge technique, time-division multiplexing technique and upconversion technique. The double edges are realized by using the transmission curve and reflection curve of an all-fiber Fabry-Perot interferometer (FPI). Benefiting from the low loss of the fiber at, the time-division multiplexing technique is performed to realize the double-edge technique by using only a single-channel FPI and only one piece of a detector. In order to detect the weak spontaneous Brillouin backscattering signal efficiently, a fiber-coupled upconversion detector is adopted to upconvert the backscattering signal at 1548.1 nm to 863 nm, which is detected by a Si-APD finally. In the experiment, dynamic strain disturbance up to 1.9m{\\epsilon} over 1.5 km of polarization maintaining fiber is detected at a sampling rate of 30 Hz. An accuracy of 30{\\mu}{\\epsilon} and spatial resolution of 0.6 m is realized.

  1. Double acousto-optic deflector system for increased scanning range of laser beams.

    Science.gov (United States)

    Kastelik, J-C; Dupont, S; Yushkov, K B; Molchanov, V Ya; Gazalet, J

    2017-09-01

    A new laser scanning system is presented based on two wide-band acousto-optic deflectors. The interaction medium is tellurium dioxide. Anisotropic interactions take place under two different tangential phase matching configurations in such a way that the acousto-optic bandwidths add up. We demonstrate the feasibility of such a cascade deflection system for the wavelength of λ=514nm. The total frequency bandwidth is Δf=100MHz, equally distributed between the two acousto-optic deflectors. The total angular scan at the output is Δθ=4.4° leading to 125 resolvable spots for a 1mm truncated Gaussian beam. Copyright © 2017. Published by Elsevier B.V.

  2. Standard Practice for Optical Distortion and Deviation of Transparent Parts Using the Double-Exposure Method

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2009-01-01

    1.1 This photographic practice determines the optical distortion and deviation of a line of sight through a simple transparent part, such as a commercial aircraft windshield or a cabin window. This practice applies to essentially flat or nearly flat parts and may not be suitable for highly curved materials. 1.2 Test Method F 801 addresses optical deviation (angluar deviation) and Test Method F 2156 addresses optical distortion using grid line slope. These test methods should be used instead of Practice F 733 whenever practical. 1.3 This standard does not purport to address the safety concerns associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  3. Carotico-clinoid foramina and a double optic canal: A case report with neurosurgical implications

    Directory of Open Access Journals (Sweden)

    Matthew J Zdilla

    2015-01-01

    Conclusion: The presence of an accessory optic canal may be misconstrued as a carotico-clinoid foramen or pneumatization of the anterior clinoid process, lesser sphenoidal wing, or optic strut. The case report documents two clinically important variant structures occurring ipsilaterally, each with the potential to masquerade as the other radiographically and present complications to both neurosurgeons and radiologists. Knowledge of the unique combination of anatomical variants presented in this report may prevent adverse surgical events during anterior clinoidectomy procedures including hemorrhage of the ophthalmic artery or internal carotid artery and subsequent vision loss or death.

  4. Properties of long-term optical variability of active galactic nuclei with double-peaked broad low-ionization emission lines

    Science.gov (United States)

    Zhang, Xue-Guang; Feng, Long-Long

    2017-01-01

    In this paper, we study properties of the long-term optical variability of a large sample of 106 Sloan Digital Sky Survey (SDSS) spectroscopically confirmed active galactic nuclei (AGN) with double-peaked broad low-ionization emission lines (double-peaked emitters). The long-term optical light curves over 8 yr are collected from the Catalina Sky Surveys Data Release 2, and the Damped Random Walk (DRW) process is applied to describe the long-term variability of the double-peaked emitters. Meanwhile, the same DRW process is applied to long-term optical light curves of more than 7000 spectroscopically confirmed normal quasars in the SDSS Stripe82 Database. Then, we can find that the DRW process determined rest-frame intrinsic variability time-scales ln (τ /d) are about 5.8 and about 4.8 for the double-peaked emitters and for the normal quasars, respectively. The statistically longer intrinsic variability time-scales can be confirmed in the double-peaked emitters, after considerations of necessary effects, such as the effects from different distributions of redshift, black hole mass, and accretion rate between the double-peaked emitters and the normal quasars. Moreover, a radial dependence of the accretion rate dot{m}R ∝ R^β with larger values of β could be an acceptable interpretation of the longer intrinsic variability time-scales in the double-peaked emitters. Therefore, there are different intrinsic properties of emission regions between the double-peaked emitters and the normal quasars. The double-peaked emitters can be well treated as an unique subclass of AGN.

  5. The Infrared Imaging Spectrograph (IRIS) for TMT: optical design of IRIS imager with "co-axis double TMA"

    Science.gov (United States)

    Tsuzuki, Toshihiro; Suzuki, Ryuji; Harakawa, Hiroki; Ikenoue, Bungo; Larkin, James; Moore, Anna; Obuchi, Yoshiyuki; Phillips, Andrew C.; Saito, Sakae; Uraguchi, Fumihiro; Wincentsen, James; Wright, Shelley; Hayano, Yutaka

    2016-08-01

    IRIS (InfraRed Imaging Spectrograph) is one of the first-generation instruments for the Thirty Meter Telescope (TMT). IRIS is composed of a combination of near-infrared (0.84-2.4 μm) diffraction limited imager and integral field spectrograph. To achieve near-diffraction limited resolutions in the near-infrared wavelength region, IRIS uses the advanced adaptive optics system NFIRAOS (Narrow Field Infrared Adaptive Optics System) and integrated on-instrument wavefront sensors (OIWFS). However, IRIS itself has challenging specifications. First, the overall system wavefront error should be less than 40 nm in Y, z, J, and H-band and 42 nm in K-band over a 34.0 × 34.0 arcsecond field of view. Second, the throughput of the imager components should be more than 42 percent. To achieve the extremely low wavefront error and high throughput, all reflective design has been newly proposed. We have adopted a new design policy called "Co-Axis double-TMA", which cancels the asymmetric aberrations generated by "collimator/TMA" and "camera/TMA" efficiently. The latest imager design meets all specifications, and, in particular, the wavefront error is less than 17.3 nm and throughput is more than 50.8 percent. However, to meet the specification of wavefront error and throughput as built performance, the IRIS imager requires both mirrors with low surface irregularity after high-reflection coating in cryogenic and high-level Assembly Integration and Verification (AIV). To deal with these technical challenges, we have done the tolerance analysis and found that total pass rate is almost 99 percent in the case of gauss distribution and more than 90 percent in the case of parabolic distribution using four compensators. We also have made an AIV plan and feasibility check of the optical elements. In this paper, we will present the details of this optical system.

  6. Preparation of Layered Double Hydroxide-Immobilized Lipase for High Yield and Optically Active (-)-Menthyl butyrate

    Institute of Scientific and Technical Information of China (English)

    Siti; Salhah; Othman; Mahiran; Basri; Mohd.Zobir; Hussein; Mohd; Basyaruddin; Abdul; Rahman; Raja; Noor; Zaliha; Raja; Abdul; Rahman; Abu; Bakar; Salleh; Salina; Mat; Radzi; Azwani; Sofia; Ahmad; Khiar

    2007-01-01

    1 Results Layered Double Hydroxide (LDH) finds extensive usage in the areas of pharmaceutical sciences and catalysis. In this study, a member of the LDH family, Mg/Al-hydrotalcite (HT), or the so-called anionic clay, was prepared at ratio 4 (HT) by co-precipitating through continuous agitation. X-ray diffraction pattern and thermogravimetric analysis of the material indicated that a pure HT had been successfully synthesized. This matrix was then used as support in the immobilization of lipase from Cand...

  7. Ratiometric, filter-free optical sensor based on a complementary metal oxide semiconductor buried double junction photodiode.

    Science.gov (United States)

    Yung, Ka Yi; Zhan, Zhiyong; Titus, Albert H; Baker, Gary A; Bright, Frank V

    2015-07-16

    We report a complementary metal oxide semiconductor integrated circuit (CMOS IC) with a buried double junction (BDJ) photodiode that (i) provides a real-time output signal that is related to the intensity ratio at two emission wavelengths and (ii) simultaneously eliminates the need for an optical filter to block Rayleigh scatter. We demonstrate the BDJ platform performance for gaseous NH3 and aqueous pH detection. We also compare the BDJ performance to parallel results obtained by using a slew scanned fluorimeter (SSF). The BDJ results are functionally equivalent to the SSF results without the need for any wavelength filtering or monochromators and the BDJ platform is not prone to errors associated with source intensity fluctuations or sensor signal drift.

  8. Double pane windows—elastic deformations, gas thermodynamics, thermal and optical phenomena

    Science.gov (United States)

    Vollmer, M.; Möllmann, K.-P.; Schlichting, H. J.

    2014-07-01

    Double pane windows are common objects which can enrich physics teaching at undergraduate level at least in five different fields. First, having sealed inner spaces filled with gas, one can discuss gas law problems upon changes of pressure and/or temperature. Second, when discussing temperature differences between inside and outside, one needs to take into account the associated heat transfer mechanisms which define the pane temperatures, enclosing the gas. Third, using elastic properties of the glass, one may treat deformations of the window panes upon those changes or additional manually applied external pressure. Fourth, the reflective properties of glass combined with the pane deformations result in concave or convex mirrors, which when illuminated by the Sun, may lead to focal points on projection areas such as facing houses. Fifth, such areas receive an increased irradiance which leads to associated thermal effects. Starting from the most obvious daily life phenomenon, the fascinating caustics of reflected sunlight on streets or walls, all of these double pane window phenomena are investigated experimentally as well as theoretically.

  9. Investigation of optical inhomogeneity of MgO:PPLN crystals for frequency doubling of 1560 nm laser

    Science.gov (United States)

    Guo, Shanlong; Ge, Yulong; Han, Yashuai; He, Jun; Wang, Junmin

    2014-09-01

    The asymmetrical phase-matching temperature tuning curves of periodically-poled 5%-mol MgO-doped lithium niobate (MgO:PPLN) bulk crystals for frequency doubling of 1560 nm telecom laser have been observed experimentally and analyzed theoretically. We find that the asymmetrical phenomena are resulted from the variation in the extraordinary refractive index by the doping concentration inhomogeneity of the crystals. The critical parameters of phase-matching temperature mismatching γ(γ=δTpm/ΔT, in which δTpm is the change of the phase-matching temperature due to the doping concentration inhomogeneity, and ΔT is the temperature acceptance bandwidth) and the thermal refractive index ∂(Δn)/∂T are investigated. Our analysis method is not only a reasonable explanation to the experiment, but also can be a simple evaluation way of optical quality of the given MgO:PPLN bulk crystals. Moreover, the MgO:PPLN bulk crystal is used in single-pass configuration for frequency doubling a 4.4 W Erbium-doped fiber amplifier boosted 1560 nm telecom laser, and 300 mW of tunable 780 nm laser is obtained, corresponding to a conversion efficiency of 6.9%. This source provides a simple and compact laser system for rubidium atom cooling and manipulation experiments.

  10. Study of the 5p3/2 -> 6p3/2 electric dipole forbidden transition in atomic rubidium using optical-optical double resonance spectroscopy

    CERN Document Server

    Ponciano-Ojeda, Francisco; López-Hernández, Oscar; Mojica-Casique, Cristian; Colín-Rodríguez, Ricardo; Ramírez-Martínez, Fernando; Flores-Mijangos, Jesús; Sahagún, Daniel; Jáuregui, Rocío; Jiménez-Mier, José

    2015-01-01

    Direct evidence of excitation of the 5p3/2 -> 6p3/2 electric dipole forbidden transition in atomic rubidium is presented. The experiments were performed in a room temperature rubidium cell with continuous wave extended cavity diode lasers. Optical-optical double resonance spectroscopy with counterpropagating beams allows the detection of the non-dipole transition free of Doppler broadening. The 5p3/2 state is prepared by excitation with a laser locked to the maximum F cyclic transition of the D2 line, and the forbidden transition is produced by excitation with a 911 nm laser. Production of the forbidden transition is monitored by detection of the 420 nm fluorescence that results from decay of the 6p3/2 state. Spectra with three narrow lines (~ 13 MHz FWHM) with the characteristic F - 1, F and F + 1 splitting of the 6p3/2 hyperfine structure in both rubidium isotopes were obtained. The results are in very good agreement with a direct calculation that takes into account the 5s -> 5p3/2 preparation dynamics, the...

  11. The electronic structure and optical properties of ABP 2O 7 ( A = Na, Li) double phosphates

    Science.gov (United States)

    Hizhnyi, Yu. A.; Oliynyk, A.; Gomenyuk, O.; Nedilko, S. G.; Nagornyi, P.; Bojko, R.; Bojko, V.

    2008-01-01

    Partial densities of states and reflection spectra of NaAlP 2O 7, KAlP 2O 7 and LiInP 2O 7 double phosphate crystals are calculated by the full-potential linear-augmented-plane-wave (FLAPW) method. Experimental reflection spectra of KAlP 2O 7, CsAlP 2O 7 and NaInP 2O 7 are measured in the 4-20 eV energy range. The values of band gaps, Eg, are found from a comparison of experiment and calculations to be 6.0 eV for NaAlP 2O 7 and KAlP 2O 7, and 4.6 eV for LiInP 2O 7.

  12. THz Acoustic Spectroscopy by using Double Quantum Wells and Ultrafast Optical Spectroscopy

    Science.gov (United States)

    Wei, Fan Jun; Yeh, Yu-Hsiang; Sheu, Jinn-Kong; Lin, Kung-Hsuan

    2016-06-01

    GaN is a pivotal material for acoustic transducers and acoustic spectroscopy in the THz regime, but its THz phonon properties have not been experimentally and comprehensively studied. In this report, we demonstrate how to use double quantum wells as a THz acoustic transducer for measuring generated acoustic phonons and deriving a broadband acoustic spectrum with continuous frequencies. We experimentally investigated the sub-THz frequency dependence of acoustic attenuation (i.e., phonon mean-free paths) in GaN, in addition to its physical origins such as anharmonic scattering, defect scattering, and boundary scattering. A new upper limit of attenuation caused by anharmonic scattering, which is lower than previously reported values, was obtained. Our results should be noteworthy for THz acoustic spectroscopy and for gaining a fundamental understanding of heat conduction.

  13. Optical double image security using random phase fractional Fourier domain encoding and phase-retrieval algorithm

    Science.gov (United States)

    Rajput, Sudheesh K.; Nishchal, Naveen K.

    2017-04-01

    We propose a novel security scheme based on the double random phase fractional domain encoding (DRPE) and modified Gerchberg-Saxton (G-S) phase retrieval algorithm for securing two images simultaneously. Any one of the images to be encrypted is converted into a phase-only image using modified G-S algorithm and this function is used as a key for encrypting another image. The original images are retrieved employing the concept of known-plaintext attack and following the DRPE decryption steps with all correct keys. The proposed scheme is also used for encryption of two color images with the help of convolution theorem and phase-truncated fractional Fourier transform. With some modification, the scheme is extended for simultaneous encryption of gray-scale and color images. As a proof-of-concept, simulation results have been presented for securing two gray-scale images, two color images, and simultaneous gray-scale and color images.

  14. Low coherence technique to interrogate optical sensors based on selectively filled double-core photonic crystal fiber for temperature measurement

    Science.gov (United States)

    Li, Kun; Jiang, Meng; Zhao, Zhongze; Wang, Zeming

    2017-04-01

    In this paper, an optical fiber sensing system based on low coherence interferometry (LCI) is proposed and demonstrated to interrogate sensors comprised of selectively filled double-core photonic crystal fiber (SFDC-PCF). The sensor used here is made by selectively filling about 1/3 area of air holes in the cladding of photonic crystal fiber with distilled water. So the dual-core in the sensor has different effective refractive indices, resulting in a phase delay between two lights transmitting in the fiber. The phase delay of the sensor can be compensated by a Mach-Zehnder interferometer with a scanning optical tunable delay line in one arm of the interferometer, namely temporal interrogation. By tracking the value of phase delay, the change of the measurand can be detected. Temperature measurement is carried out to testify the system performance. An average sensitivity of 0.9 μm/°C is achieved within the temperature range of 29-92 °C. This work provides a new thinking for fiber sensing technology based on LCI. The proposed all-fiber sensing system, with the merits of cost-effective, stability, and flexibility, can demodulate the SFDC-PCF sensor signals well. Further improvements such as better sensitivity, larger measurement range and multiplexing efficiency can be realized by tailoring the PCF sensor's structure.

  15. Enhanced optical limiting effects in a double-decker bis(phthalocyaninato) rare earth complex using radially polarized beams

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Jia-Lu; Gu, Bing, E-mail: gubing@seu.edu.cn; Liu, Dahui; Cui, Yiping, E-mail: cyp@seu.edu.cn [Advanced Photonics Center, Southeast University, Nanjing 210096 (China); Sheng, Ning [Advanced Photonics Center, Southeast University, Nanjing 210096 (China); Key Laboratory of Inorganic Chemistry in Universities of Shandong, Department of Chemistry and Chemical Engineering, Jining University, Qufu 273155 (China)

    2014-10-27

    Optical limiting (OL) effects can be enhanced by exploiting various limiting mechanisms and by designing nonlinear optical materials. In this work, we present the large enhancement of OL effects by manipulating the polarization distribution of the light field. Theoretically, we develop the Z-scan and nonlinear transmission theories on a two-photon absorber under the excitation of cylindrical vector beams. It is shown that both the sensitivity of Z-scan technique and the OL effect using radially polarized beams have the large enhancement compared with that using linearly polarized beams (LPBs). Experimentally, we investigate the nonlinear absorption properties of a double-decker Pr[Pc(OC{sub 8}H{sub 17}){sub 8}]{sub 2} rare earth complex by performing Z-scan measurements with femtosecond-pulsed radially polarized beams at 800 nm wavelength. The observed two-photon absorption process, which originates from strong intramolecular π–π interaction, is exploited for OL application. The results demonstrate the large enhancement of OL effects using radially polarized beams instead of LPBs.

  16. The Infrared Imaging Spectrograph (IRIS) for TMT: optical design of IRIS imager with "Co-axis double TMA"

    CERN Document Server

    Tsuzuki, Toshihiro; Harakawa, Hiroki; Ikenoue, Bungo; Larkin, James; Moore, Anna; Obuchi, Yoshiyuki; Phillips, Andrew C; Saito, Sakae; Uraguchi, Fumihiro; Wincentsen, James; Wright, Shelley; Hayano, Yutaka

    2016-01-01

    IRIS (InfraRed Imaging Spectrograph) is one of the first-generation instruments for the Thirty Meter Telescope (TMT). IRIS is composed of a combination of near-infrared (0.84--2.4 $\\mu$m) diffraction limited imager and integral field spectrograph. To achieve near-diffraction limited resolutions in the near-infrared wavelength region, IRIS uses the advanced adaptive optics system NFIRAOS (Narrow Field Infrared Adaptive Optics System) and integrated on-instrument wavefront sensors (OIWFS). However, IRIS itself has challenging specifications. First, the overall system wavefront error should be less than 40 nm in Y, z, J, and H-band and 42 nm in K-band over a 34.0 $\\times$ 34.0 arcsecond field of view. Second, the throughput of the imager components should be more than 42 percent. To achieve the extremely low wavefront error and high throughput, all reflective design has been newly proposed. We have adopted a new design policy called "Co-Axis double-TMA", which cancels the asymmetric aberrations generated by "col...

  17. Properties of long-term optical variability of active galactic nuclei with double-peaked broad low-ionization emission lines

    CERN Document Server

    Zhang, XueGuang

    2016-01-01

    In this manuscript, we study properties of long-term optical variability of a large sample of 106 SDSS spectroscopically confirmed AGN with double-peaked broad low-ionization emission lines (double-peaked emitters). The long-term optical light curves over 8 years are collected from the Catalina Sky Surveys Data Release 2. And, the Damped Random Walk (DRW) process is applied to describe the long-term variability of the double-peaked emitters. Meanwhile, the same DRW process is applied to long-term optical light curves of more than 7000 spectroscopically confirmed normal quasars in the SDSS Stripe82 Database. Then, we can find that the DRW process determined rest-frame intrinsic variability timescales $\\ln(\\tau/{\\rm days})$ are about 5.8 and about 4.8 for the double-peaked emitters and for the normal quasars, respectively. The statistically longer intrinsic variability timescales can be confirmed in the double-peaked emitters, after considerations of necessary effects, such as the effects from different distrib...

  18. Flow-dependent double-nanohole optical trapping of 20 nm polystyrene nanospheres

    Science.gov (United States)

    Zehtabi-Oskuie, Ana; Bergeron, Jarrah Gerald; Gordon, Reuven

    2012-01-01

    We study the influence of fluid flow on the ability to trap optically a 20 nm polystyrene particle from a stationary microfluidic environment and then hold it against flow. Increased laser power is required to hold nanoparticles as the flow rate is increased, with an empirical linear dependence of 1 μl/(min×mW). This is promising for the delivery of additional nanoparticles to interact with a trapped nanoparticle; for example, to study protein-protein interactions, and for the ability to move the trapped particle in solution from one location to another. PMID:23236587

  19. A path integral study of the role of correlation in exchange coupling of spins in double quantum dots and optical lattices

    DEFF Research Database (Denmark)

    Pedersen, Jesper Goor; Zhang, Lei; Gilbert, M.J.

    2010-01-01

    We explore exchange coupling of a pair of spins in a double dot and in an optical lattice, using the frequency of exchanges in a bosonic path integral, evaluated using Monte Carlo simulation. The algorithm gives insights into the role of correlation through visualization of two-particle probability...

  20. Preparation and Optical Absorption Performance of Si Single Quantum Dots and Si/Ge Double Quantum Dots Doped TiO2 Films.

    Science.gov (United States)

    Chen, Lixia; He, Fang; Sun, Zuwen; Zhang, Yan; Li, Fengjiao; Huang, Yuan; Gu, Ruisona

    2015-02-01

    Si single quantum dots (QDs) and Si/Ge double QDs doped TiO2 films were successfully fabricated via layer-by-layer ion beam sputtering assisted by annealing treatment, and their morphology and optical absorption performance were analyzed in this paper. TEM images show that Si QDs and Si/Ge double QDs prepared in the TiO2 matrix are in a uniform size distribution and high density, especially after annealed at 500 °C. XPS results indicate that Si in the TiO2 films mainly exists in the form of elemental Si and SiO2, and Ge is in elemental form. From the optical absorption spectra, the optical response of the TiO2 films is shifted from ultraviolet to visible and near infrared region when they are doped by the QDs, and the Si/Ge double QDs co-doped TiO2 films show better optical response compared with the Si QDs doped TiO2 films, suggesting a hybrid enhanced effect of double QDs.

  1. Double resonance fequency light shift compensation in optically oriented laser-pumped alkali atoms

    Energy Technology Data Exchange (ETDEWEB)

    Baranov, A. A., E-mail: lexusbar@gmail.com; Ermak, S. V.; Sagitov, E. A.; Smolin, R. V.; Semenov, V. V. [St. Petersburg Polytechnic University (Russian Federation)

    2015-09-15

    The contributions of the vector and scalar components to the magnetically dependent microwave transition frequency light shift are analyzed and the compensation of these components is experimentally demonstrated for the {sup 87}Rb atoms optically oriented by a laser tuned to the D{sub 2} line of the head doublet. The Allan variance is studied as a function of the averaging time for a tandem of optically pumped quantum magnetometers (OPQMs), one of which is based on a low-frequency spin oscillator while another is based on a quantum microwave discriminator with a resonance frequency that corresponds to magnetically dependent transitions between HFS sublevels with the extremal value of the magnetic quantum number. It is shown that the compensation of the scalar and vector components of the light shift in OPQMs reduces the Allan variance at averaging times that exceed hundreds of seconds compared to a quantum discriminator based on the magnetically independent 0–0 transition. In this case, the minimal Allan variance in OPQMs at the end resonance is achieved at considerably longer averaging times than in the case of the quantum discriminator that is tuned to the 0–0 transition frequency.

  2. Aerosol optical properties derived from the DRAGON-NE Asia campaign, and implications for a single-channel algorithm to retrieve aerosol optical depth in spring from Meteorological Imager (MI) on-board the Communication, Ocean, and Meteorological Satellite (COMS)

    Science.gov (United States)

    Kim, M.; Kim, J.; Jeong, U.; Kim, W.; Hong, H.; Holben, B.; Eck, T. F.; Lim, J. H.; Song, C. K.; Lee, S.; Chung, C.-Y.

    2016-02-01

    An aerosol model optimized for northeast Asia is updated with the inversion data from the Distributed Regional Aerosol Gridded Observation Networks (DRAGON)-northeast (NE) Asia campaign which was conducted during spring from March to May 2012. This updated aerosol model was then applied to a single visible channel algorithm to retrieve aerosol optical depth (AOD) from a Meteorological Imager (MI) on-board the geostationary meteorological satellite, Communication, Ocean, and Meteorological Satellite (COMS). This model plays an important role in retrieving accurate AOD from a single visible channel measurement. For the single-channel retrieval, sensitivity tests showed that perturbations by 4 % (0.926 ± 0.04) in the assumed single scattering albedo (SSA) can result in the retrieval error in AOD by over 20 %. Since the measured reflectance at the top of the atmosphere depends on both AOD and SSA, the overestimation of assumed SSA in the aerosol model leads to an underestimation of AOD. Based on the AErosol RObotic NETwork (AERONET) inversion data sets obtained over East Asia before 2011, seasonally analyzed aerosol optical properties (AOPs) were categorized by SSAs at 675 nm of 0.92 ± 0.035 for spring (March, April, and May). After the DRAGON-NE Asia campaign in 2012, the SSA during spring showed a slight increase to 0.93 ± 0.035. In terms of the volume size distribution, the mode radius of coarse particles was increased from 2.08 ± 0.40 to 2.14 ± 0.40. While the original aerosol model consists of volume size distribution and refractive indices obtained before 2011, the new model is constructed by using a total data set after the DRAGON-NE Asia campaign. The large volume of data in high spatial resolution from this intensive campaign can be used to improve the representative aerosol model for East Asia. Accordingly, the new AOD data sets retrieved from a single-channel algorithm, which uses a precalculated look-up table (LUT) with the new aerosol model, show an

  3. Study of optical reflectance properties in 1D annular photonic crystal containing double negative (DNG) metamaterials

    Science.gov (United States)

    Srivastava, Sanjeev K.; Aghajamali, Alireza

    2016-05-01

    Theoretical investigation of photonic band gaps or reflection bands in one-dimensional annular photonic crystal (APC) containing double negative (DNG) metamaterials and air has been presented. The proposed structure consists of the alternate layers of dispersive DNG material and air immersed in free space. In order to study photonic band gaps we obtain the reflectance spectrum of the annular PC by employing the transfer matrix method (TMM) in the cylindrical waves for both TE and TM polarizations. In this work we study the effect of azimuthal mode number (m) and starting radius (ρ0) on the three band gaps viz. zero averaged refractive index (zero-nbar) gap, zero permittivity (zero- ε) and zero permeability (zero- μ) gaps. It is found that for m ≥ 1 , zero- μ gap appears in TE mode and zero- ε gap appears in TM mode. The width of both zero- μ and zero- ε gap increases by increasing m values, but the enhancement of zero- μ gap is more appreciable. Also, the effect of ρ0 on the three band gaps (reflection bands) of annular PC structure at the given m-number has been studied, for both TE and TM polarizations. The result shows that in both polarizations zero- ε and zero- μ gaps decreases when ρ0 increases, whereas zero-nbar gap remains invariant.

  4. Optical spectra and stokes shift in double-stranded helical supramolecular assemblies.

    Science.gov (United States)

    van Dijk, Leon; Bobbert, Peter A; Spano, Frank C

    2009-07-23

    We study the photoluminescence from helical MOPV4 aggregates using a model that includes excitonic coupling, exciton-phonon coupling, and spatially correlated disorder in the chromophore transition energies. The helical aggregates consist of stacked dimers of MOPV4 chromophores. We have modeled these helical stacks as double-stranded aggregates, allowing us to investigate the effect of correlated disorder within the dimers on emission. We have studied the dependence of the Stokes shift, the emission line widths, and the ratio of the 0-0 to 0-1 emission peaks on the aggregate size and disorder. Our findings show that this peak ratio is quite insensitive to the aggregate size if the latter exceeds the coherence length of the emitting exciton. This makes this ratio a reliable probe for both disorder and the coherence length of the emitting exciton. We have found only a weak dependence of this peak ratio on the degree of correlation between the transition energies within each dimer, whereas such correlation has a large effect on the aggregate-size-dependent Stokes shift. By comparison with experiment, we have estimated the coherence length of the emitting exciton to be only one lattice spacing along the stacking direction. From our analysis of the Stokes shift we conclude that the exciton diffusion length is in the range 6-13 nm.

  5. Search for global oscillations on Jupiter with a double-cell sodium magneto-optical filter

    Science.gov (United States)

    Cacciani, A.; Dolci, M.; Moretti, P. F.; D'Alessio, F.; Giuliani, C.; Micolucci, E.; Di Cianno, A.

    2001-06-01

    Doppler observations on Jupiter are presented and discussed. A two-cells Magneto-Optical Filter (MOF), able to obtain two separate signals, Red and Blue, on the opposite wings of the Sodium D-lines, along with a continuum reference signal, has been used. This set of data permits to discriminate between real oscillations and albedo ``modes" by means of the two algorithms D=(B-R)/(B+R) and S=(B+R)/continuum. No unambiguous oscillation modes were detected with amplitudes above the 1-sigma level of ~ 1.2 m s-1 in the range between 0.5 and 0.7 mHz. However, using refined analysis for signal recovery in a noisy background we notice an increase of power also in the region of the solar 5 min oscillations. The albedo variations on the Jupiter's surface and instrumental effects are addressed to be responsible for the spurious signals.

  6. Double layers liquid-crystal microlens arrays used in optical switches

    Science.gov (United States)

    Wang, Cheng; Fan, Di; Zhang, Bo; Tong, Qing; Luo, Jun; Lei, Yu; Zhang, Xinyu; Xie, Changsheng

    2015-12-01

    Based on our previous works in liquid-crystal microlens arrays (LCMAs), a new kind of optical switches using the 24×24 fiber arrays coupled with the LCMAs, which have a key dual-mode function of the switches about on and off state and work in visible and infrared range, is proposed and fabricated in this paper. Different with other common LCMAs, this new kind of dual-mode LCMAs includes two layers of control electrodes deposited directly over the surface of the top glass substrate in LC microcavity fabricated. The first layer is the patterned electrode, which is designed into basic circular holes with suitable diameter, and the second is the planar electrode. Both layered electrodes are effectively separated by a thin SiO2 film with a typical thickness of about several micrometers, and then the dual-mode microlenses are driven by applied electrical signals with different root mean square (rms) voltage.

  7. Effects of the structure asymmetry on optical responses in GaAs double quantum dots under intense laser and electric fields

    Science.gov (United States)

    Bejan, Doina

    2016-10-01

    The effects of the potential shape asymmetry on the nonlinear optical absorption and optical rectification in GaAs double quantum dots under intense non-resonant laser field and static electric field were investigated comparatively using the effective mass approximation and the compact density-matrix formalism under steady state conditions. The obtained results show that: (i) for both systems, the optical spectra are redshifted with the increase of the laser intensity only in the presence of the electric field, exceptions appearing at the highest considered laser intensity for both systems and at low laser field intensity for the asymmetric system; (ii) the augment of the static field intensity blueshifts the optical spectra of both systems; (iii) the spectra of the asymmetric system are displaced toward higher energies and show a shoulder-like feature at a given electric field value; (iv) the optical rectification spectra are more intense for the symmetric system.

  8. Study of Electrical Conduction Mechanism of Organic Double-Layer Diode Using Electric Field Induced Optical Second Harmonic Generation Measurement.

    Science.gov (United States)

    Nishi, Shohei; Taguchi, Dai; Manaka, Takaaki; Iwamoto, Mitsumasa

    2016-04-01

    By using electric field induced optical second harmonic generation (EFISHG) and current voltage (I-V) measurements, we studied the electrical transport mechanism of organic double-layer diodes with a structure of Au/N, N'-di-[(1-naphthyl)-N, N'-diphenyl]-(1,1'-biphenyl)-4,4'-diamine (a-NPD)/poly(methyl methacrylate) (PMMA)/indium zinc oxide (IZO). Here the α-NPD is a carrier transport layer and the PMMA is an electrical insulating layer. The current level was very low, but the I-V characteristics showed a rectifying behavior. The EFISHG measurement selectively and directly probed the electric field across the α-NPD layer, and showed that the electric field across the a-NPD layer is completely relaxed owing to the charge accumulation at the a-NPD/PMMA interface in the region V > 0, whereas the carrier accumulation was not significant in the region V < 0. On the basis of these experimental results, we proposed a model of the rectification. Further, by coupling the I-V characteristics with the EFISHG measurement, the I-V characteristics of the diodes were well converted into the current-electric field (I-E) characteristics of the α-NPD layer and the PMMA layer. The I-E characteristics suggested the Schottky-type conduction governs the carrier transport. We conclude that the I-V measurement coupled with the EFISHG measurement is very useful to study carrier transport mechanism of the organic double-layer diodes.

  9. 双量子阱中的子带光吸收%Intersubband Optical Absorption in Double Quantum Wells

    Institute of Scientific and Technical Information of China (English)

    邓永晴; 郭康贤; 于凤梅; 俞友宾; 王瑞强

    2005-01-01

    Recently, much attention has been focus on the investigation of the electroabsorption in the GaAs/AlGaAs quantum wells (QW's) because of its possibility of designing new types of electro-optic modulators. Much optical properties of the single QW's with different potential has been and being investigated experimently and theoriticaly with different methods. In these few years, the double quantum wells (DQWs) became the focus of the research. In this paper, by using the density matrix formalism and iterated method, the first-and the third-order intersubband optical absorption of double quantum well with infinit boundary was investigated theoretically. Thereafter, a typical GaAs/AlGaAs DQWs is presented to get the results. The results show that the peak absorption varies with the width of the intermediate potential barrier. And it also shows that the absorption decrease as the incident optical intensity increasing.%由于微制造技术的不断发展,如液相外延(LPE),气相外延(VPE),金属有机化学气相沉积(MOCVD)以及分子束外延技术(MBE)等先进的材料生长技术方法也日趋完善,从而使得各种低维半导体量子器件(如半导体、超晶格、量子阱、量子线和量子点等)制造日趋成熟.由于这些低维半导体量子器件具有很强的非线性光效应,而且随着材料、外形、尺寸等的不同,非线性光效应也有很大的差别,更由于其可能存在的广泛的应用前景,所以近年来,一直是人们研究的重点.近来,由于人们相信,利用GaAs/AlGaAs量子阱有可能制造出一些新型的光学仪器,如光开关、光限幅器、光调制器等,所以,对不同势形的GaAs/AlGaAs量子阱的非线性光学特性一直吸引着人们进行理论和实验的研究.而在最近几年,对双量子阱的研究也成为了人们的研究重点.通过密度矩阵和迭代的方法,得到双量子阱中的第一、第三阶子带光吸收表达式,我们将用一个典型的GaAs/AlGaAs双

  10. An optical sensor based on H-acid/layered double hydroxide composite film for the selective detection of mercury ion.

    Science.gov (United States)

    Sun, Zhiyong; Jin, Lan; Zhang, Shitong; Shi, Wenying; Pu, Min; Wei, Min; Evans, David G; Duan, Xue

    2011-09-19

    A novel optical chemosensor was fabricated based on 1-amino-8-naphthol-3,6-disulfonic acid sodium (H-acid) intercalated layered double hydroxide (LDH) film via the electrophoretic deposition (EPD) method. The film of H-acid/LDH with the thickness of 1 μm possesses a well c-orientation of the LDH microcrystals confirmed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The fluorescence detection for Hg(II) in aqueous solution was performed by using the H-acid/LDH film sensor at pH 7.0, with a linear response range in 1.0 × 10(-7) to 1.0 × 10(-5) mol L(-1) and a detection limit of 6.3 × 10(-8) mol L(-1). Furthermore, it exhibits excellent selectivity for Hg(II) over a large number of competitive cations including alkali, alkaline earth, heavy metal and transitional metals. The specific fluorescence response of the optical sensor is attributed to the coordination between Hg(II) and sulfonic group in the H-acid immobilized in the LDH matrix, which was verified by NMR spectroscopy and UV-vis spectra. In addition, density functional theory (DFT) calculation further confirms that the coordination occurs between one Hg(2+) and two O atoms in the sulfonic group, which is responsible for the significant fluorescence quenching of the H-acid/LDH film. The results indicate that the H-acid/LDH composite film can be potentially used as a chemosensor for the detection of Hg(2+) in the environmental and biomedical field.

  11. Double-layer optical fiber coating analysis in MHD flow of an elastico-viscous fluid using wet-on-wet coating process

    Science.gov (United States)

    Khan, Zeeshan; Islam, Saeed; Shah, Rehan Ali; Khan, Muhammad Altaf; Bonyah, Ebenezer; Jan, Bilal; Khan, Aurangzeb

    Modern optical fibers require a double-layer coating on the glass fiber in order to provide protection from signal attenuation and mechanical damage. The most important plastic resins used in wires and optical fibers are plastic polyvinyl chloride (PVC) and low and high density polyethylene (LDPE/HDPE), nylon and Polysulfone. One of the most important things which affect the final product after processing is the design of the coating die. In the present study, double-layer optical fiber coating is performed using melt polymer satisfying Oldroyd 8-constant fluid model in a pressure type die with the effect of magneto-hydrodynamic (MHD). Wet-on-wet coating process is applied for double-layer optical fiber coating. The coating process in the coating die is modeled as a simple two-layer Couette flow of two immiscible fluids in an annulus with an assigned pressure gradient. Based on the assumptions of fully developed laminar and MHD flow, the Oldroyd 8-constant model of non-Newtonian fluid of two immiscible resin layers is modeled. The governing nonlinear equations are solved analytically by the new technique of Optimal Homotopy Asymptotic Method (OHAM). The convergence of the series solution is established. The results are also verified by the Adomian Decomposition Method (ADM). The effect of important parameters such as magnetic parameter Mi , the dilatant constant α , the Pseodoplastic constant β , the radii ratio δ , the pressure gradient Ω , the speed of fiber optics V , and the viscosity ratio κ on the velocity profiles, thickness of coated fiber optics, volume flow rate, and shear stress on the fiber optics are investigated. At the end the result of the present work is also compared with the experimental results already available in the literature by taking non-Newtonian parameters tends to zero.

  12. The design of double electrostatic-lens optics for resonance enhanced multiphoton ionization and photoelectron imaging experiments

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Zehua; Li, Chunsheng; Qin, Zhengbo, E-mail: wave0403@163.com, E-mail: xfzheng@mail.ahnu.edu.cn; Zheng, Xianfeng, E-mail: wave0403@163.com, E-mail: xfzheng@mail.ahnu.edu.cn; Yao, Guanxin; Zhang, Xianyi; Cui, Zhifeng [Institute of Atomic and Molecular Physics, Anhui Normal University, Wuhu, Anhui 241000 (China)

    2015-06-15

    Compared to single ion/electron-optics for velocity-map imaging, a double-focusing lens assembly designed not only allows for mapping velocity imaging of photoelectrons but also allows for investigating the vibrational structure of the intermediate states of neutral species in resonance enhanced multiphoton ionization (REMPI) spectra. In this presentation, in order to record REMPI and photoelectron spectra separately, we have constructed a compact photoelectron velocity-map imaging (VMI) apparatus combined with an opposite linear Wiley-Mclaren time-of-flight mass spectrometer (TOFMS). A mass resolution (m/Δm) of ∼1300 for TOFMS and electron energy resolution (ΔE/E) of 2.4% for VMI have been achieved upon three-photon ionization of Xe atom at 258.00 nm laser wavelength. As a benchmark, in combination of one-color (1 + 1) REMPI and photoelectron imaging of benzene via 6{sup 1} and 6{sup 1}1{sup 1} vibronic levels in the S{sub 1} state, the vibrational structures of the cation and photoelectron angular anisotropy are unraveled. In addition, two-color (1 + 1′) REMPI and photoelectron imaging of aniline was used to complete the accurate measurement of ionization potential (62 271 ± 3 cm{sup −1}). The results suggest that the apparatus is a powerful tool for studying photoionization dynamics in the photoelectron imaging using vibrational-state selected excitation to the intermediate states of neutrals based on REMPI technique.

  13. Phase correlation between four-wave mixing and optical fields in double Λ-type atomic system.

    Science.gov (United States)

    Jeong, Taek; Moon, Han Seb

    2016-12-12

    We study the spectral features and phase of four-wave mixing (FWM) light according to the relative phase-noise of the optical fields coupled to a double Λ-type atomic system of the 5S1/2-5P1/2 transition of 87Rb atoms. We observe that the spectral shape of the FWM spectrum is identical to that of the two-photon absorption (TPA) spectrum due to two-photon coherence and that it is independent of the relative phase-noise of the pump light. From these results, we clarify that the two-photon coherence plays a very important role in the FWM process. Furthermore, we measure the relative linewidth of the FWM signal to the probe and pump lasers by means of a beat interferometer. We confirmed that the phase of the FWM signal is strongly correlated with that of the pump laser under the condition of phase-locked probe and coupling lasers for two-photon coherence.

  14. Optical time of flight studies of lithium plasma in double pulse laser ablation: Evidence of inverse Bremsstrahlung absorption

    Energy Technology Data Exchange (ETDEWEB)

    Sivakumaran, V.; Joshi, H. C.; Singh, R. K.; Kumar, Ajai, E-mail: ajai@ipr.res.in [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat 382428 (India)

    2014-06-15

    The early stage of formation of lithium plasma in a collinear—double pulse laser ablation mode has been studied using optical time of flight (OTOF) spectroscopy as a function of inter-pulse delay time, the distance from the target surface and the fluence of the ablation lasers. The experimental TOF measurements were carried out for lithium neutral (670.8 nm and 610.3 nm), and ionic (548.4 nm and 478.8 nm) lines. These experimental observations have been compared with that for single pulse laser ablation mode. It is found that depending on the fluence and laser pulse shape of the first pre-ablation laser and the second main ablation laser, the plasma plume formation and its characteristic features can be described in terms of plume-plume or laser-plume interaction processes. Moreover, the enhancement in the intensity of Li neutral and ionic lines is observed when the laser-plume interaction is the dominant process. Here, we see the evidence of the role of inverse Bremsstrahlung absorption process in the initial stage of formation of lithium plasma in this case.

  15. Electronic mobility limited by optical phonons in Al2O3/AlGaN/GaN double heterojunctions

    Science.gov (United States)

    Zhou, X. J.; Gu, Z.; Ban, S. L.; Wang, Z. P.

    2016-09-01

    Applying a finite difference method and modified random-element-isodisplacement model, the mobility of electrons in the two dimensional electron gas in Al2O3/AlGaN/GaN double heterojunctions is calculated in consideration of scattering from interface and half-space optical phonons based on the theory of force balance equation. Considering the effect of ternary mixed crystals and built-in electric fields, the electronic wave functions and corresponding eigen-energies are obtained by solving Schrödinger equations. The results show that electronic mobility decreases with increasing Al from a small component, and then increases with the increasing Al. Other effects such as the size, fixed charges at Al2O3/AlGaN interface, and temperature are also discussed. It is found that the thickness of AlGaN layer increases the mobility, and the fixed charges also increase the mobility but within a certain range, whereas the thickness of Al2O3 layer and temperature reduce the mobility. Some of our results are compared with the experimental data and our conclusion is helpful for designing high electron mobility transistors.

  16. On the Maximum and Minimum of Double Generalized Gamma Variates with Applications to the Performance of Free-space Optical Communication Systems

    KAUST Repository

    Al-Quwaiee, Hessa

    2016-01-07

    In this work, we derive the exact statistical characteristics of the maximum and the minimum of two modified1 double generalized gamma variates in closed-form in terms of Meijer’s G-function, Fox’s H-function, the extended generalized bivariate Meijer’s G-function and H-function in addition to simple closed-form asymptotic results in terms of elementary functions. Then, we rely on these new results to present the performance analysis of (i) a dual-branch free-space optical selection combining diversity and of (ii) a dual-hop free-space optical relay transmission system over double generalized gamma fading channels with the impact of pointing errors. In addition, we provide asymptotic results of the bit error rate of the two systems at high SNR regime. Computer-based Monte-Carlo simulations verify our new analytical results.

  17. Optically active mixed phthalocyaninato-porphyrinato rare-earth double-decker complexes: synthesis, spectroscopy, and solvent-dependent molecular conformations.

    Science.gov (United States)

    Zhang, Xiaomei; Muranaka, Atsuya; Lv, Wei; Zhang, Yuexing; Bian, Yongzhong; Jiang, Jianzhuang; Kobayashi, Nagao

    2008-01-01

    Reaction between the optically active metal-free phthalocyanine with a pi system with noncentrosymmetrical C(2) [corrected] symmetry ((S)- and (R)-H(2){Pc(OBNP)(2)}; OBNP=binaphthylphthalocyanine) and half-sandwich complexes [M(III)(acac)(TClPP)] (M=Y, Eu; TClPP=meso-tetrakis(4-chlorophenyl)porphyrinate; acac=acetylacetonate), which were generated in situ from [M(acac)(3)].n H(2)O and H(2)(TClPP) in n-octanol at reflux, provided the first optically active protonated mixed phthalocyaninato-porphyrinato rare-earth double-decker complexes [M(III)H{Pc(OBNP)(2)}(TClPP)] (M=Y, Eu) in good yield. In addition to electronic absorption spectroscopy and magnetic circular dichroism results, circular dichroism shows different spectroscopic features of these mixed-ring rare-earth double-decker compounds in different solvents, such as DMF and CHCl(3), which was well-reproduced on the basis of time-dependent density functional theory calculation results for the yttrium species (S)-[Y(III){Pc(OBNP)(2)}(Por)](-) (Por=porphyrinate, which is obtained by removing the four chlorophenyl groups from the TClPP ligand) in terms of the change in the rotation angle between the two macrocyclic ligands in the double-decker molecules. These results revealed the solvent-dependent nature of the molecular conformation of mixed-ring rare-earth double-decker complexes, which suggests a new way of tuning the optical and the electrochemical properties of sandwich-type bis(tetrapyrrole)-metal double-decker complexes in solution by changing the solvent.

  18. Optical-optical double resonance, laser induced fluorescence, and revision of the signs of the spin-spin constants of the boron carbide (BC) free radical

    Science.gov (United States)

    Sunahori, Fumie X.; Nagarajan, Ramya; Clouthier, Dennis J.

    2015-12-01

    The cold boron carbide free radical (BC X 4Σ-) has been produced in a pulsed discharge free jet expansion using a precursor mixture of trimethylborane in high pressure argon. High resolution laser induced fluorescence spectra have been obtained for the B 4Σ--X 4Σ- and E 4Π-X 4Σ- band systems of both 11BC and 10BC. An optical-optical double resonance (OODR) scheme was implemented to study the finer details of both band systems. This involved pumping a single rotational level of the B state with one laser and then recording the various allowed transitions from the intermediate B state to the final E state with a second laser by monitoring the subsequent E-X ultraviolet fluorescence. In this fashion, we were able to prove unambiguously that, contrary to previous studies, the spin-spin constant λ is negative in the ground state and positive in the B 4Σ- excited state. It has been shown that λ″ < 0 is in fact expected based on a semiempirical second order perturbation theory calculation of the magnitude of the spin-spin constant. The OODR spectra have also been used to validate our assignments of the complex and badly overlapped E 4Π-X 4Σ- 0-0 and 1-0 bands of 11BC. The E-X 0-0 band of 10BC was found to be severely perturbed. The ground state main electron configuration is …3σ24σ25σ11π22π0 and the derived bond lengths show that there is a 0.03 Å contraction in the B state, due to the promotion of an electron from the 4σ antibonding orbital to the 5σ bonding orbital. In contrast, the bond length elongates by 0.15 Å in the E state, a result of promoting an electron from the 5σ bonding orbital to the 2π antibonding orbitals.

  19. Optical-optical double resonance, laser induced fluorescence, and revision of the signs of the spin-spin constants of the boron carbide (BC) free radical

    Energy Technology Data Exchange (ETDEWEB)

    Sunahori, Fumie X. [Department of Chemistry and Physics, Franklin College, Franklin, Indiana 46131 (United States); Nagarajan, Ramya; Clouthier, Dennis J., E-mail: dclaser@uky.edu [Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506-0055 (United States)

    2015-12-14

    The cold boron carbide free radical (BC X {sup 4}Σ{sup −}) has been produced in a pulsed discharge free jet expansion using a precursor mixture of trimethylborane in high pressure argon. High resolution laser induced fluorescence spectra have been obtained for the B {sup 4}Σ{sup −}–X {sup 4}Σ{sup −} and E {sup 4}Π–X {sup 4}Σ{sup −} band systems of both {sup 11}BC and {sup 10}BC. An optical-optical double resonance (OODR) scheme was implemented to study the finer details of both band systems. This involved pumping a single rotational level of the B state with one laser and then recording the various allowed transitions from the intermediate B state to the final E state with a second laser by monitoring the subsequent E–X ultraviolet fluorescence. In this fashion, we were able to prove unambiguously that, contrary to previous studies, the spin-spin constant λ is negative in the ground state and positive in the B {sup 4}Σ{sup −} excited state. It has been shown that λ″ < 0 is in fact expected based on a semiempirical second order perturbation theory calculation of the magnitude of the spin-spin constant. The OODR spectra have also been used to validate our assignments of the complex and badly overlapped E {sup 4}Π–X {sup 4}Σ{sup −} 0-0 and 1-0 bands of {sup 11}BC. The E–X 0-0 band of {sup 10}BC was found to be severely perturbed. The ground state main electron configuration is …3σ{sup 2}4σ{sup 2}5σ{sup 1}1π{sup 2}2π{sup 0} and the derived bond lengths show that there is a 0.03 Å contraction in the B state, due to the promotion of an electron from the 4σ antibonding orbital to the 5σ bonding orbital. In contrast, the bond length elongates by 0.15 Å in the E state, a result of promoting an electron from the 5σ bonding orbital to the 2π antibonding orbitals.

  20. Optical-optical double resonance, laser induced fluorescence, and revision of the signs of the spin-spin constants of the boron carbide (BC) free radical.

    Science.gov (United States)

    Sunahori, Fumie X; Nagarajan, Ramya; Clouthier, Dennis J

    2015-12-14

    The cold boron carbide free radical (BC X (4)Σ(-)) has been produced in a pulsed discharge free jet expansion using a precursor mixture of trimethylborane in high pressure argon. High resolution laser induced fluorescence spectra have been obtained for the B (4)Σ(-)-X (4)Σ(-) and E (4)Π-X (4)Σ(-) band systems of both (11)BC and (10)BC. An optical-optical double resonance (OODR) scheme was implemented to study the finer details of both band systems. This involved pumping a single rotational level of the B state with one laser and then recording the various allowed transitions from the intermediate B state to the final E state with a second laser by monitoring the subsequent E-X ultraviolet fluorescence. In this fashion, we were able to prove unambiguously that, contrary to previous studies, the spin-spin constant λ is negative in the ground state and positive in the B (4)Σ(-) excited state. It has been shown that λ″ < 0 is in fact expected based on a semiempirical second order perturbation theory calculation of the magnitude of the spin-spin constant. The OODR spectra have also been used to validate our assignments of the complex and badly overlapped E (4)Π-X (4)Σ(-) 0-0 and 1-0 bands of (11)BC. The E-X 0-0 band of (10)BC was found to be severely perturbed. The ground state main electron configuration is …3σ(2)4σ(2)5σ(1)1π(2)2π(0) and the derived bond lengths show that there is a 0.03 Å contraction in the B state, due to the promotion of an electron from the 4σ antibonding orbital to the 5σ bonding orbital. In contrast, the bond length elongates by 0.15 Å in the E state, a result of promoting an electron from the 5σ bonding orbital to the 2π antibonding orbitals.

  1. 春天%Spring

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    @@ Days get longer and warmer in the spring. There are new leaves on the trees. Flowers begin to grow. Spring rain makes the grass green and helps the plants grow. Nature wears new clothes in many colors red, yellow, blue, white and purple. Spring is the time of new life. I love spring.

  2. Optical characterization of double-side-textured silicon wafer based on photonic nanostructures for thin-wafer crystalline silicon solar cells

    Science.gov (United States)

    Tayagaki, Takeshi; Furuta, Daichi; Aonuma, Osamu; Takahashi, Isao; Hoshi, Yusuke; Kurokawa, Yasuyoshi; Usami, Noritaka

    2017-04-01

    Crystalline silicon (c-Si) wafers have found extensive use in photovoltaic applications. In this regard, to enable advanced light manipulation in thin-wafer c-Si solar cells, we demonstrate the fabrication of double-side-textured Si wafers composed of a front-surface photonic nanotexture fabricated with quantum dot arrays and a rear-surface microtexture. The addition of the rear-surface microtexture to a Si wafer with the front-surface photonic nanotexture increases the wafer’s optical absorption in the near-infrared region, thus enabling enhanced light trapping. Excitation spectroscopy reveals that the photoluminescence intensity in the Si wafer with the double-sided texture is higher than that in the Si wafer without the rear-surface microtexture, thus indicating an increase in true optical absorption in the Si wafer with the double-sided texture. Our results indicate that the double-sided textures, i.e., the front-surface photonic nanotexture and rear-surface microtexture, can effectively reduce the surface reflection loss and provide enhanced light trapping, respectively.

  3. No double-dissociation between optic ataxia and visual agnosia: multiple sub-streams for multiple visuo-manual integrations.

    Science.gov (United States)

    Pisella, L; Binkofski, F; Lasek, K; Toni, I; Rossetti, Y

    2006-01-01

    The current dominant view of the visual system is marked by the functional and anatomical dissociation between a ventral stream specialised for perception and a dorsal stream specialised for action. The "double-dissociation" between visual agnosia (VA), a deficit of visual recognition, and optic ataxia (OA), a deficit of visuo-manual guidance, considered as consecutive to ventral and dorsal damage, respectively, has provided the main argument for this dichotomic view. In the first part of this paper, we show that the currently available empirical data do not suffice to support a double-dissociation between OA and VA. In the second part, we review evidence coming from human neuropsychology and monkey data, which cast further doubts on the validity of a simple double-dissociation between perception and action because they argue for a far more complex organisation with multiple parallel visual-to-motor connections: 1. A dorso-dorsal pathway (involving the most dorsal part of the parietal and pre-motor cortices): for immediate visuo-motor control--with OA as typical disturbance. The latest research about OA is reviewed, showing how these patients exhibit deficits restricted to the most direct and fast visuo-motor transformations. We also propose that mild mirror ataxia, consisting of misreaching errors when the controlesional hand is guided to a visual goal though a mirror, could correspond to OA with an isolated "hand effect". 2. A ventral stream-prefrontal pathway (connections from the ventral visual stream to pre-frontal areas, by-passing the parietal areas): for "mediate" control (involving spatial or temporal transpositions [Rossetti, Y., & Pisella, L. (2003). Mediate responses as direct evidence for intention: Neuropsychology of Not to-, Not now- and Not there-tasks. In S. Johnson (Ed.), Cognitive Neuroscience perspectives on the problem of intentional action (pp. 67-105). MIT Press.])--with VA as typical disturbance. Preserved visuo-manual guidance in patients

  4. Multifocal and pattern-reversal visual evoked potentials vs. automated perimetry frequency-doubling technology matrix in optic neuritis

    Directory of Open Access Journals (Sweden)

    Marcella Nebbioso

    2013-01-01

    Full Text Available Background: To compare the usefulness of the traditional pattern-reversal Visual Evoked Potentials (VEP with multifocal VEP (mfVEP and Frequency-Doubling Technology (FDT perimetry in the evaluation of the ocular abnormalities induced by acute or subacute optic neuritis (ON. Materials and Methods: The test results of 24 ON patients were compared with those obtained in 40 normal control subjects. MfVEP recordings were obtained by using an Optoelectronic Stimulator that extracts topographic VEP using a pseudorandom m-sequence stimulus. Receiver operator characteristic (ROC curves were calculated to determine the sensitivity and specificity of abnormal values. Results: The frequency of the abnormal ocular findings differed in the ON patients according to the used technique. Reduced visual sensitivity was demonstrated in 12 eyes (54.5% using FDT perimetry; 17 eyes (77.2% showed decreased amplitude and/or an increase in the implicit time of the P1 wave in mfVEP and 20 eyes (90.9% showed an abnormal decrease in the amplitude and/or an increase in the latency of the P100 peak at VEP examination. The areas under the ROC curves ranged from 0.743 to 0.935, with VEP having the largest areas. The VEP and mfVEP amplitudes and latencies yielded the greatest sensitivity and specificity. Conclusions: The mfVEP and the FDT perimetry can be used for the evaluation and monitoring of visual impairment in patients with ON. The most sensitive and practical diagnostic tool in patients with ON is, however, the traditional VEP. The mfVEP can be utilized in those cases with doubtful or negative VEP results.

  5. Cyanobacterial ecotypes in different optical microenvironments of a 68 C hot spring mat community revealed by 16S-23S rRNA internal transcribed spacer region variation

    DEFF Research Database (Denmark)

    Ferris, Mike J.; Kühl, Michael; Wieland, Andrea

    2003-01-01

    We examined the population of unicellular cyanobacteria (Synechococcus) in the upper 3-mm vertical interval of a 68°C region of a microbial mat in a hot spring effluent channel (Yellowstone National Park, Wyoming). Fluorescence microscopy and microsensor measurements of O2 and oxygenic photosynth......We examined the population of unicellular cyanobacteria (Synechococcus) in the upper 3-mm vertical interval of a 68°C region of a microbial mat in a hot spring effluent channel (Yellowstone National Park, Wyoming). Fluorescence microscopy and microsensor measurements of O2 and oxygenic...... distinct populations over the vertical interval. We were unable to identify patterns in genetic variation in Synechococcus 16S rRNA sequences that correlate with different vertically distributed populations. However, patterns of variation at the internal transcribed spacer locus separating 16S and 23S r...

  6. Steady flow and heat transfer analysis of Phan-Thein-Tanner fluid in double-layer optical fiber coating analysis with Slip Conditions

    Science.gov (United States)

    Khan, Zeeshan; Shah, Rehan Ali; Islam, Saeed; Jan, Bilal; Imran, Muhammad; Tahir, Farisa

    2016-10-01

    Modern optical fibers require double-layer coating on the glass fiber to provide protection from signal attenuation and mechanical damage. The most important plastic resins used in wires and optical fibers are plastic polyvinyl chloride (PVC) and low-high density polyethylene (LDPE/HDPE), nylon and Polysulfone. In this paper, double-layer optical fiber coating is performed using melt polymer satisfying PTT fluid model in a pressure type die using wet-on-wet coating process. The assumption of fully developed flow of Phan-Thien-Tanner (PTT) fluid model, two-layer liquid flows of an immiscible fluid is modeled in an annular die, where the fiber is dragged at a higher speed. The equations characterizing the flow and heat transfer phenomena are solved exactly and the effects of emerging parameters (Deborah and slip parameters, characteristic velocity, radii ratio and Brinkman numbers on the axial velocity, flow rate, thickness of coated fiber optics, and temperature distribution) are reported in graphs. It is shown that an increase in the non-Newtonian parameters increase the velocity in the absence or presence of slip parameters which coincides with related work. The comparison is done with experimental work by taking λ → 0 (non-Newtonian parameter).

  7. Steady flow and heat transfer analysis of Phan-Thein-Tanner fluid in double-layer optical fiber coating analysis with Slip Conditions

    Science.gov (United States)

    Khan, Zeeshan; Shah, Rehan Ali; Islam, Saeed; Jan, Bilal; Imran, Muhammad; Tahir, Farisa

    2016-01-01

    Modern optical fibers require double-layer coating on the glass fiber to provide protection from signal attenuation and mechanical damage. The most important plastic resins used in wires and optical fibers are plastic polyvinyl chloride (PVC) and low-high density polyethylene (LDPE/HDPE), nylon and Polysulfone. In this paper, double-layer optical fiber coating is performed using melt polymer satisfying PTT fluid model in a pressure type die using wet-on-wet coating process. The assumption of fully developed flow of Phan-Thien-Tanner (PTT) fluid model, two-layer liquid flows of an immiscible fluid is modeled in an annular die, where the fiber is dragged at a higher speed. The equations characterizing the flow and heat transfer phenomena are solved exactly and the effects of emerging parameters (Deborah and slip parameters, characteristic velocity, radii ratio and Brinkman numbers on the axial velocity, flow rate, thickness of coated fiber optics, and temperature distribution) are reported in graphs. It is shown that an increase in the non-Newtonian parameters increase the velocity in the absence or presence of slip parameters which coincides with related work. The comparison is done with experimental work by taking λ → 0 (non-Newtonian parameter). PMID:27708412

  8. Thermal springs of Wyoming

    Energy Technology Data Exchange (ETDEWEB)

    Breckenridge, R.M.; Hinckley, B.S.

    1978-01-01

    This bulletin attempts, first, to provide a comprehensive inventory of the thermal springs of Wyoming; second, to explore the geologic and hydrologic factors producing these springs; and, third, to analyze the springs collectively as an indicator of the geothermal resources of the state. A general discussion of the state's geology and the mechanisms of thermal spring production, along with a brief comparison of Wyoming's springs with worldwide thermal features are included. A discussion of geothermal energy resources, a guide for visitors, and an analysis of the flora of Wyoming's springs follow the spring inventory. The listing and analysis of Wyoming's thermal springs are arranged alphabetically by county. Tabulated data are given on elevation, ownership, access, water temperature, and flow rate. Each spring system is described and its history, general characteristics and uses, geology, hydrology, and chemistry are discussed. (MHR)

  9. A Numerical Investigation of the Strain Effect on Saturation Optical Intensity in Electroabsorption Modulators Based on Asymmetric Intra-step-barrier Coupled Double Strained Quantum Wells

    Science.gov (United States)

    Abedi, Kambiz

    2011-12-01

    In this paper, the strain effect on saturation optical intensity in electroabsorption modulators (EAMs) based on asymmetric intra-step-barrier coupled double strained quantum well (AICD-SQWs) active region is theoretically investigated and compared with intra-step quantum well (IQW) structure. For this purpose, the thermionic emission and tunneling escape processes are taken into account and the escape times of photogenerated carriers are calculated. Then, the electroabsorption coefficient is calculated for different well strains for TE input light polarization. Finally, the saturation optical intensity of electroabsorption modulators with AICD-SQW structures in comparison with IQW structure is evaluated. Numerical results show that the tensile strain of well has the most significant effect on the saturation optical intensity of electroabsorption modulators with AICD-SQW structures due to reduction in escape times.

  10. Instant Spring Tool Suite

    CERN Document Server

    Chiang, Geoff

    2013-01-01

    Filled with practical, step-by-step instructions and clear explanations for the most important and useful tasks. A tutorial guide that walks you through how to use the features of Spring Tool Suite using well defined sections for the different parts of Spring.Instant Spring Tool Suite is for novice to intermediate Java developers looking to get a head-start in enterprise application development using Spring Tool Suite and the Spring framework. If you are looking for a guide for effective application development using Spring Tool Suite, then this book is for you.

  11. Optical Design for Photonics. Organization of the 1993 Photonics Science Topical Meetings Held in Palm Springs, California on March 22 - 24, 1993. Technical Digest Series, Volume 9

    Science.gov (United States)

    1993-03-24

    propagat- desip wsing Affractive optics, T. ponents, N. Fabricius, B, Wol~f, In- ing LiNb03. (p. 29) Heydenburg. D. A. Zweig , Hughes Dan- teg-riem-e...of various fabrication technologies. OMA3-1 / 7 Practical Considerations for Optical Design Using Diffractive Optics T. Heydenburg, D.A. Zweig Hughes...OTuA5-1 /53 Fresnel Ping-Pong Algorithm for Two-Plane CGH Display Rainer G. Dorsch, Adolf W. Lohmann, Stefan Sinzinger Physikalisches Institut der

  12. The electronic, magnetic and optical properties of ZnO doped with doubles impurities (Cr, Fe): An LDA-SIC and Monte Carlo study

    Science.gov (United States)

    Salmani, El Mehdi; Laghrissi, Ayoub; Lamouri, Rachida; Ez-Zahraouy, Hamid; Benyoussef, Abdelilah

    2017-01-01

    Electronic structure, magnetic and optical properties of ZnO doped with single and double impurities Zn1-xCrxO, Zn1-xFexO, and Zn1-2xCrxFexO (x=0.03 and 0.06) are investigated using first-principles calculations. Based on the Korringa-Kohn-Rostoker method combined with the coherent potential approximation, we investigated the half-metallic ferromagnetic behavior of doubles impurities (Cr, Fe) doped ZnO. To support our results, we apply the self-interaction-corrected local density approximation (SIC-LDA) to study the electronic structure, optical and magnetic properties of Co-doped ZnO with doubles impurities (Cr, Fe) showing that the half-metallic ferromagnetic state still persists. The stability of the ferromagnetic state compared with the spin-glass state is investigated by comparing their total energies. The exchange interactions obtained from first principle calculations and used in a classical Ising model by a Monte Carlo approach resulted in ferromagnetic states with high Neel temperature.

  13. Comparative analysis of luminescent properties of germanate glass and double-clad optical fibers co-doped with Yb3+/Ho3+ ions

    Science.gov (United States)

    Pietrzycki, Marcin; Kochanowicz, Marcin; Romańczuk, Patryk; Żmojda, Jacek; Miluski, Piotr; Ragiń, Tomasz; Jeleń, Piotr; Sitarz, Maciej; Dorosz, Dominik

    2016-09-01

    The 2 μm and visible emission of low phonon (805 cm-1) germanate glasses and double - clad optical fiber co-doped with 0.7Yb2O3/(0.07-0.7)Ho2O3 ions have been investigated. Luminescence at 2 μm corresponding to Ho3+: 5I7 → 5I8 as well as upconversion luminescence in the visible spectral range corresponding to the Ho3+: 5S2(5F4)→5I8 (545 nm), and Ho3+: 5F5→5I8 (655 nm) transition, respectively were obtained. The optimization of the acceptor content and donor-acceptor ratio were conducted with the purpose of maximizing the luminescence intensity. The highest luminescence intensity in both spectral range was obtained in glass co-doped with 0.7Yb2O3/0.15 Ho2O3. Despite relatively small effective absorption coefficient of the optical fiber comparative analysis of luminescent properties of fabricated glasses (further core) and double - clad optical fiber showed significant contribution of reabsorption process of emitted ASE signal.

  14. Water Treatment Technology - Springs.

    Science.gov (United States)

    Ross-Harrington, Melinda; Kincaid, G. David

    One of twelve water treatment technology units, this student manual on springs provides instructional materials for two competencies. (The twelve units are designed for a continuing education training course for public water supply operators.) The competencies focus on spring basin construction and spring protection. For each competency, student…

  15. Androgenesis in anther culture of Lithuanian spring barley cultivars

    OpenAIRE

    Asakavičiūtė, Rita; Pašakinskienė, Izolda

    2006-01-01

    The method of anther culture was used for the production of doubled haploids in Lithuanian spring barley cultivars. Two methods, (i) regeneration from callus (Szarjeko’s method) and (ii) direct regeneration from embryoids (Caredda’s method) were applied to determine the androgenic potential according to the green regenerant yield and other morphogenetic factors. Green double haploid regenerants were obtained in four Lithuanian spring barley cultivars (‘Aura’, ‘Aidas’, ‘Alsa’ and ‘Auksiniai’) ...

  16. Linkage effects to nonlinear optical properties of porphyrin-appended mixed (porphyrinato)(phthalocyaninato) yttrium(III) double-decker complexes

    Science.gov (United States)

    Li, Yong; Zhang, Xianyao; Yan, Xingzhong; Bian, Yongzhong; Jiang, Jianzhuang

    2011-10-01

    Third-order nonlinear optical properties of three isomeric tetrapyrrole triads, i.e. mixed (porphyrinato)(phthalocyaninato) yttrium double-decker complexes appended with one metal free porphyrin chromophore at the para, meta, and orthoposition, respectively, of one meso-phenyl group of the porphyrin ligand in the double-decker unit through ester linkage, 3-5, were comparatively investigated along with the model compounds metal free meso-tetrakis(4-tert-butylphenyl) porphyrin H2TBPP (1) and mixed [meso-tetrakis(4-tert-butylphenyl)porphyrinato] [1,4,8,11,15,18,22,25-octakis(butyloxyl)phthalocyaninato] yttrium double-decker complex YIIIH(TBPP) [Pc(α-OC4H9)8] (2) by using Z-scan technique with the fundamental (800 nm) laser emission from a Ti:sapphire femtosecond laser system. Strong reverse saturable absorption (RSA) properties of complexes 2-5 were observed. Interestingly, under highly intense irradiation, an RSA-SA-RSA-SA-RSA switch behavior was evolved in the tight focal intensity regime on the Z-scan profiles of complexes 3-5. Under the laser irradiation with focal intensity of 7.48-8.39 GW.cm-2, the triads 3 and 4 with the metal free porphyrin chromophore appended at the para or meta positions of the meso-phenyl group of the porphyrin ligand in the double-decker unit retained a characteristic response of RSA. In contrast, the triad 5 with the metal free porphyrin chromophore appended at the ortho position has already shown a trend of SA peaks at the same intensity range, revealing the effect of the position of porphyrin-substituent on the nonlinear optical properties of the triads.

  17. 扭簧加载双片齿轮消隙机构综合啮合刚度%Research on Synthesis Meshing Stiffness of Torsional Spring-loaded Double-gear Anti-backlash Mechanism

    Institute of Scientific and Technical Information of China (English)

    杨政; 尚建忠; 罗自荣; 王晓明; 于乃辉

    2013-01-01

    Anti-backlash gear can improve the transmission precision via eliminating or controlling the backlash. It is very important to make a study of the dynamic characteristics of anti-backlash mechanism. The law of periodic variation of meshing points is analyzed emphatically in anti-backlash mechanism with the contact ratio 1 ≤ ε < 2. Single or double tooth meshing states of two gear pairs and the transform arithmetic in positive and reversal rotation based on symmetry at anytime are determined, insuring continuity of calculator in reversal rotation and making the further studies on swept resonance characteristic easier. Based on this, the synthesis meshing stiffness model of anti-backlash mechanism is built, including the calculation formula of meshing stiffness based on Hertz contact theory and FE calculation results. The influence of torsional spring stiffness and variations of all gear parameters on synthesis meshing stiffness is analyzed using numerical calculation, and the results show that under the condition of no gear teeth disengaging, anti-backlash mechanism not only can eliminate the backlash, but also can increase the synthesis meshing stiffness comparing with the meshing stiffness of the ordinary gear pair, and by optimizing gear parameters, the synthesis meshing stiffness can be increased much more.%扭簧加载双片齿轮消隙机构(简称消隙齿轮)通过消除或控制回程误差来提高系统的传动精度,对其动态特性的研究具有重要意义.着重分析重合度1≤ε<2的消隙齿轮机构啮合点的周期性变化规律,确定任意时刻各啮合齿轮副的单双齿啮合状态,以及基于对称性的正反转之间的转换关系,保证正反转计算的衔接性,有利于进一步研究系统扫频谐振特性;在此基础上引入基于Hertz接触理论及有限元计算结果的啮合刚度计算公式,建立消隙齿轮机构综合啮合刚度模型;通过数值计算,分析扭簧刚度以及各齿轮参数的

  18. 双季稻田马铃薯不同覆盖栽培对土壤酶活性的影响%Soil enzyme activity in spring potato fields under different mulching practices in double rice cropping area

    Institute of Scientific and Technical Information of China (English)

    林叶春; 曾昭海; 唐海明; 肖小平; 汤文光; 杨光立; 胡跃高

    2011-01-01

    An experiment was designed to explore the effects of different surface mulching practices on soil β-glucosidase, arylamidase, alkalinephosphatase, arylsulfatase and dehydrogenase activities in spring potato fields in double rice cropping areas. Surface mulching practices included zero mulching (CK), rice straw mulching, non-woven fabric mulching, rice straw plus non-woven fabric mulching, black plastic film mulching, and rice straw plus black plastic film mulching. The results indicated that surface mulching significantly affected soil enzyme activity. Compared with CK, the activities of alkaline phosphatase, arylsulfatase and dehydrogenase significantly increased (P<0.05) respectively by 17.55%, 24.77% and 87.2% under rice straw mulching. Arylamidase and dehydrogenase activities increased significantly (P<0.05) by 8.03% and 71.05%, respectively under rice straw plus non-woven fabric mulching. Black plastic film mulching also significant increased (P<0.05) the activities of β-glucosidase, alkaline phosphatase, arylsulfatase and dehydrogenase by 23.44%, 22.70%, 37.43% and 146.30%, respectively. Similarly, rice straw plus black plastic film mulching significantly improved (P<0.05) the activities of β-glucosidase, arylamidase, alkaline phosphatase, arylsulfatase and dehydrogenase by 34.76%, 19.31%, 19.03%, 51.98% and 125.62%, respectively. In conclusion therefore, the activities of soil enzymes related to soil nutrient cycling were significantly enhanced by rice straw plus black plastic film mulching, which in turn enhanced soil fertility and quality.%为探讨双季稻区春马铃薯不同覆盖模式下稻田土壤酶活性的变化情况,在大田条件下,以露地处理为对照,设置稻草、无纺布、稻草+无纺布、黑膜、稻草+黑膜5种覆盖处理.结果表明:地表覆盖显著影响土壤酶活性.其中,稻草覆盖显著(P<0.05)提高碱性磷酸酶、芳基硫酸酯酶和脱氢酶

  19. Pro Spring Batch

    CERN Document Server

    Minella, Michael T

    2011-01-01

    Since its release, Spring Framework has transformed virtually every aspect of Java development including web applications, security, aspect-oriented programming, persistence, and messaging. Spring Batch, one of its newer additions, now brings the same familiar Spring idioms to batch processing. Spring Batch addresses the needs of any batch process, from the complex calculations performed in the biggest financial institutions to simple data migrations that occur with many software development projects. Pro Spring Batch is intended to answer three questions: *What? What is batch processing? What

  20. Coherent manipulation of four-level double lambda-like atomic system by a train of ultra-short few-cycle-optical pulses

    CERN Document Server

    Kumar, Pawan

    2014-01-01

    We have demonstrated that near complete coherence can be achieved in a four level double lambda-like systems using a train of ultra-short optical pulses. The effect of the Doppler broadening has been analyzed and a scheme has been proposed for establishing high and uniform coherence across different velocity groups in the atomic ensemble. We have also presented a novel scheme of excitation using chirped pulses and shown that in addition to generating coherence in the system it is possible to alter the translational states of the atoms.

  1. Widely tunable, narrow line width and low optical noise continuous-wave all fiber Er:Yb co-doped double-clad ring laser

    Science.gov (United States)

    Guesmi, Khmaies; Bahloul, Faouzi; Semaan, Georges; Meng, Yichang; Salhi, Mohamed; Sanchez, François

    2017-01-01

    In this paper, we report a widely tunable, narrow linewidth, low noise continuous-wave double-clad Er:Yb doped fiber ring laser. Tunability is demonstrated in wide range spanning from 1520 to almost 1620 nm covering the C and L spectral bands. The cavity design is optimized in order to achieve the largest tuning range with very high optical signal-to-noise ratio (SNR). The output coupling ratio greatly influences the tuning range of the laser while the position of the spectral filter determines the SNR. The obtained laser exhibits a tuning range over 98 nm with a nearly constant SNR of about 58.5 dB.

  2. Comparative study of optical properties of the one-dimensional multilayer Period-Doubling and Thue-Morse quasi-periodic photonic crystals

    Directory of Open Access Journals (Sweden)

    Yassine Bouazzi

    2012-10-01

    Full Text Available The last decades have witnessed the growing interest in the use of photonic crystal as a new material that can be used to control electromagnetic wave. Actually, not only the periodic structures but also the quasi-periodic systems have become significant structures of photonic crystals. This work deals with optical properties of dielectric Thue-Morse multilayer and Period-Doubling multilayer. We use the so-called Transfer Matrix Method (TMM to determine the transmission spectra of the structures. Based on the representation of the transmittance spectra in the visible range a comparative analysis depending on the iteration number, number of layers and incidence angle is presented.

  3. Electronic structure and magnetic and optical properties of double perovskite Bi2FeCrO6 from first-principles investigation

    Institute of Scientific and Technical Information of China (English)

    Song Zhe-Wen; Liu Bang-Gui

    2013-01-01

    Double perovskite Bi2FeCrO6,related with multiferroic BiFeO3,is very interesting because of its strong ferroelectricity and high magnetic Curie temperature beyond room temperature.We investigate its electronic structure and magnetic and optical properties by using a full-potential density-functional method.Our optimization shows that it is a robust ferrimagnetic semiconductor.This nonmetallic phase is formed due to crystal field splitting and spin exchange splitting,in contrast to previous studies.Spin exchange constants and optical properties are calculated.Our Monte Carlo magnetic Curie temperature is 450 K,much higher than any previously calculated value and consistent with experimental results.Our study and analysis reveal that the main magnetic mechanism is an antiferromagnetic superexchange between Fe and Cr over the intermediate O atom.These results are useful in understanding such perovskite materials and exploring their potential applications.

  4. Exciton-related nonlinear optical absorption and refractive index change in GaAs-Ga{sub 1-x}Al{sub x}As double quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, Guillermo L. [Fisica Teorica y Aplicada, Escuela de Ingenieria de Antioquia, A.A. 7516 Medellin (Colombia); Instituto de Fisica, Universidad de Antioquia, AA 1226 Medellin (Colombia); Mora-Ramos, Miguel E., E-mail: memora@uaem.mx [Fisica Teorica y Aplicada, Escuela de Ingenieria de Antioquia, A.A. 7516 Medellin (Colombia); Facultad de Ciencias, Universidad Autonoma del Estado de Morelos, Av. Universidad 1001, C.P. 62209 Cuernavaca, Morelos (Mexico); Instituto de Fisica, Universidad de Antioquia, AA 1226 Medellin (Colombia); Duque, Carlos A. [Instituto de Fisica, Universidad de Antioquia, AA 1226 Medellin (Colombia)

    2013-01-15

    In this work the variations of the exciton-related optical absorption and the change of the refractive index in a GaAs-(Ga,Al)As double quantum well as functions of the geometric parameters of the heterostructure are investigated. The variational method is applied within the framework of the parabolic band and effective mass approximations, in order to obtain the 1s-like exciton energy spectrum. The outcome for the related optical coefficients shows a quenched and redshifted light absorption as a result of the increment in the inner barrier and right-hand well widths, with the possibility of an enhancement of the excitonic contribution to the relative change in the refractive index.

  5. The duration of fibre-optic intubation is increased by cricoid pressure. A randomised double-blind study

    DEFF Research Database (Denmark)

    Arenkiel, Bjørn; Smitt, M; Olsen, K S

    2013-01-01

    In some categories of patients, a rapid sequence induction using a fibre-optic method may be indicated. The aim of the present study was to examine the effect of cricoid pressure (CP) on the duration of fibre-optic intubation. The hypothesis was that CP would prolong the intubation time....

  6. Comparison of 3D double inversion recovery and 2D STIR FLAIR MR sequences for the imaging of optic neuritis: pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Hodel, Jerome; Bocher, Anne-Laure; Pruvo, Jean-Pierre; Leclerc, Xavier [Hopital Roger Salengro, Department of Neuroradiology, Lille (France); Outteryck, Olivier; Zephir, Helene; Vermersch, Patrick [Hopital Roger Salengro, Department of Neurology, Lille (France); Lambert, Oriane [Fondation Ophtalmologique Rothschild, Department of Neuroradiology, Paris (France); Benadjaoud, Mohamed Amine [Radiation Epidemiology Team, Inserm, CESP Centre for Research in Epidemiology and Population Health, U1018, Villejuif (France); Chechin, David [Philips Medical Systems, Suresnes (France)

    2014-12-15

    We compared the three-dimensional (3D) double inversion recovery (DIR) magnetic resonance imaging (MRI) sequence with the coronal two-dimensional (2D) short tau inversion recovery (STIR) fluid-attenuated inversion recovery (FLAIR) for the detection of optic nerve signal abnormality in patients with optic neuritis (ON). The study group consisted of 31 patients with ON (44 pathological nerves) confirmed by visual-evoked potentials used as the reference. MRI examinations included 2D coronal STIR FLAIR and 3D DIR with 3-mm coronal reformats to match with STIR FLAIR. Image artefacts were graded for each portion of the optic nerves. Each set of MR images (2D STIR FLAIR, DIR reformats and multiplanar 3D DIR) was examined independently and separately for the detection of signal abnormality. Cisternal portion of optic nerves was better delineated with DIR (p < 0.001), while artefacts impaired analysis in four patients with STIR FLAIR. Inter-observer agreement was significantly improved (p < 0.001) on 3D DIR (κ = 0.96) compared with STIR FLAIR images (κ = 0.60). Multiplanar DIR images reached the best performance for the diagnosis of ON (95 % sensitive and 94 % specific). Our study showed a high sensitivity and specificity of 3D DIR compared with STIR FLAIR for the detection of ON. These findings suggest that the 3D DIR sequence may be more useful in patients suspected of ON. (orig.)

  7. Spring 5 & reactive streams

    CERN Document Server

    CERN. Geneva; Clozel, Brian

    2017-01-01

    Spring is a framework widely used by the world-wide Java community, and it is also extensively used at CERN. The accelerator control system is constituted of 10 million lines of Java code, spread across more than 1000 projects (jars) developed by 160 software engineers. Around half of this (all server-side Java code) is based on the Spring framework. Warning: the speakers will assume that people attending the seminar are familiar with Java and Spring’s basic concepts. Spring 5.0 and Spring Boot 2.0 updates (45 min) This talk will cover the big ticket items in the 5.0 release of Spring (including Kotlin support, @Nullable and JDK9) and provide an update on Spring Boot 2.0, which is scheduled for the end of the year. Reactive Spring (1h) Spring Framework 5.0 has been released - and it now supports reactive applications in the Spring ecosystem. During this presentation, we'll talk about the reactive foundations of Spring Framework with the Reactor project and the reactive streams specification. We'll al...

  8. Image Mosaicking Approach for a Double-Camera System in the GaoFen2 Optical Remote Sensing Satellite Based on the Big Virtual Camera.

    Science.gov (United States)

    Cheng, Yufeng; Jin, Shuying; Wang, Mi; Zhu, Ying; Dong, Zhipeng

    2017-06-20

    The linear array push broom imaging mode is widely used for high resolution optical satellites (HROS). Using double-cameras attached by a high-rigidity support along with push broom imaging is one method to enlarge the field of view while ensuring high resolution. High accuracy image mosaicking is the key factor of the geometrical quality of complete stitched satellite imagery. This paper proposes a high accuracy image mosaicking approach based on the big virtual camera (BVC) in the double-camera system on the GaoFen2 optical remote sensing satellite (GF2). A big virtual camera can be built according to the rigorous imaging model of a single camera; then, each single image strip obtained by each TDI-CCD detector can be re-projected to the virtual detector of the big virtual camera coordinate system using forward-projection and backward-projection to obtain the corresponding single virtual image. After an on-orbit calibration and relative orientation, the complete final virtual image can be obtained by stitching the single virtual images together based on their coordinate information on the big virtual detector image plane. The paper subtly uses the concept of the big virtual camera to obtain a stitched image and the corresponding high accuracy rational function model (RFM) for concurrent post processing. Experiments verified that the proposed method can achieve seamless mosaicking while maintaining the geometric accuracy.

  9. Optical Computing. Organization of the 1993 Photonics Science Topical Meetings Held in Palm Springs, California on March 16 - 19, 1993. Technical Digest Series, Volume 7

    Science.gov (United States)

    1993-03-19

    Bruno W Acklin. Jirgen Jahns. AT&T Bell Laboratr-;. We pre- matrix as a photonic backplane, Michel Charier, Bruno Houssay . sent a specific example for...MASSIVELY PARALLEL COMPUTERS USING HOLOGRAPHIC MATRIX AS A PHOTONIC BACKPLANE M. Charrier, B. Houssay , T. Lemoine, S. Paineau - Thomson CSF - RCM Division 178...34International conference on Advances in Interconnection and Packaging" (2) C. Vergnolle, C. Sebillotte, B. Houssay , S. Paineau - "Optical Interconnection

  10. The use of the adding-doubling method for the optical optimization of planar luminescent down shifting layers for solar cells.

    Science.gov (United States)

    Leyre, Sven; Cappelle, Jan; Durinck, Guy; Abass, Aimi; Hofkens, Johan; Deconinck, Geert; Hanselaer, Peter

    2014-05-05

    To enhance the efficiency of solar cells, a luminescent down shifting layer can be applied in order to adapt the solar spectrum to the spectral internal quantum efficiency of the semiconductor. Optimization of such luminescent down shifting layers benefits from quick and direct evaluation methods. In this paper, the potential of the adding-doubling method is investigated to simulate the optical behavior of an encapsulated solar cell including a planar luminescent down shifting layer. The results of the adding-doubling method are compared with traditional Monte Carlo ray tracing simulations. The average relative deviation is found to be less than 1.5% for the absorptance in the active layer and the reflectance from the encapsulated cell, while the computation time can be decreased with a factor 52. Furthermore, the adding-doubling method is adopted to investigate the suitability of the SrB4O7:5%Sm2 + ,5%Eu2 + phosphor as a luminescent down shifting material in combination with a Copper Indium Gallium Selenide solar cell. A maximum increase of 9.0% in the short-circuit current can be expected if precautions are taken to reduce the scattering by matching the refractive index of host material to the phosphor particles. To be useful as luminescent down shifting material, the minimal value of the quantum yield of the phosphor is determined to be 0.64.

  11. Spring integration essentials

    CERN Document Server

    Pandey, Chandan

    2015-01-01

    This book is intended for developers who are either already involved with enterprise integration or planning to venture into the domain. Basic knowledge of Java and Spring is expected. For newer users, this book can be used to understand an integration scenario, what the challenges are, and how Spring Integration can be used to solve it. Prior experience of Spring Integration is not expected as this book will walk you through all the code examples.

  12. Pro Spring Integration

    CERN Document Server

    Lui, M; Chan, Andy; Long, Josh

    2011-01-01

    Pro Spring Integration is an authoritative book from the experts that guides you through the vast world of enterprise application integration (EAI) and application of the Spring Integration framework towards solving integration problems. The book is:. * An introduction to the concepts of enterprise application integration * A reference on building event-driven applications using Spring Integration * A guide to solving common integration problems using Spring Integration What makes this book unique is its coverage of contemporary technologies and real-world information, with a focus on common p

  13. Espectrofotometria de longo caminho óptico em espectrofotômetro de duplo-feixe convencional: uma alternativa simples para investigações de amostras com densidade óptica muito baixa Long optical path length spectrophotometry in conventional double-beam spectrophotometers: a simple alternative for investigating samples of very low optical density

    Directory of Open Access Journals (Sweden)

    André Luiz Galo

    2009-01-01

    Full Text Available We describe the design and tests of a set-up mounted in a conventional double beam spectrophotometer, which allows the determination of optical density of samples confined in a long liquid core waveguide (LCW capillary. Very long optical path length can be achieved with capillary cell, allowing measurements of samples with very low optical densities. The device uses a custom optical concentrator optically coupled to LCW (TEFLON® AF. Optical density measurements, carried out using a LCW of ~ 45 cm, were in accordance with the Beer-Lambert Law. Thus, it was possible to analyze quantitatively samples at concentrations 45 fold lower than that regularly used in spectrophotometric measurements.

  14. Optics

    CERN Document Server

    Fincham, W H A

    2013-01-01

    Optics: Ninth Edition Optics: Ninth Edition covers the work necessary for the specialization in such subjects as ophthalmic optics, optical instruments and lens design. The text includes topics such as the propagation and behavior of light; reflection and refraction - their laws and how different media affect them; lenses - thick and thin, cylindrical and subcylindrical; photometry; dispersion and color; interference; and polarization. Also included are topics such as diffraction and holography; the limitation of beams in optical systems and its effects; and lens systems. The book is recommen

  15. A Combinative Double-Well Optical Trap for Two-Species Cold Atoms%一种新颖的操控冷原子的组合双光学阱方案

    Institute of Scientific and Technical Information of China (English)

    罗坤; 潘小青; 周琦; 陆俊发

    2011-01-01

    提出了一种利用液晶空间光调制器和透镜组合系统产生双光学阱的新颖方案,计算并分析了该双光学阱组的特征参数与几何参数,研究了从双光学阱到单光阱的双向演变过程。讨论了该双光学阱在冷原子、冷分子物理中的潜在的应用前景。%This paper puts forward a kind of using liquid crystal spatial light the combinations of optical trap double novel scheme. Calculates and analyzes the characteristic parameters. The evolutionary process of double optical trap modulator and lens of the double optical trap was studied.

  16. Spring A Developer's Notebook

    CERN Document Server

    Tate, Bruce A

    2009-01-01

    This no-nonsense book quickly gets you up to speed on the new Spring open source framework. Favoring examples and practical application over theory, Spring: A Developer's Notebook features 10 code-intensive labs that'll reveal the many assets of this revolutionary, lightweight architecture. In the end, you'll understand how to produce simple, clean, and effective applications.

  17. Mockito for Spring

    CERN Document Server

    Acharya, Sujoy

    2015-01-01

    If you are an application developer with some experience in software testing and want to learn more about testing frameworks, then this technology and book is for you. Mockito for Spring will be perfect as your next step towards becoming a competent software tester with Spring and Mockito.

  18. Masters of the springs

    DEFF Research Database (Denmark)

    Laursen, Steffen

    2010-01-01

    led to a number of insights into the social organization of the mound cemeteries that will be presented in the paper. It is obvious that there existed a close spatial relation between freshwater springs and the compact mounds cemeteries that emerged c.2050 BC. The mound cemeteries appear to have been...... flanked by villages that relied on these water recourses for agricultural production. The springs emerged in the zone separating the cemeteries from the settlements. The freshwater springs were actively incorporated into the religious landscape of the dead, by consistently erecting mounds of a particular...... high status type right above the head of each spring. These tombs of the masters of the springs are distinguished by their larger size and vertical shaft entrance. It is argued that this particular strategy of power was employed after population growth had intensified conflicts over the rights...

  19. Electric field effects on the intersubband optical absorptions and refractive index in double-electron quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Lu Liangliang; Xie Wenfang, E-mail: lll516946435@126.com [Department of Physics, College of Physics and Electronic Engineering, Guangzhou University, Guangzhou 510006 (China)

    2011-08-01

    The linear and nonlinear optical properties such as optical absorption and refractive index change associated with intersubband transitions in a two-electron quantum dot (QD) in the presence of an external electric field have been investigated theoretically by using the perturbation method. The exchange force, which is a strictly quantum mechanical phenomenon, has also been considered. Numerical results on typical GaAs/AlGaAs materials show that an increase of the electric field decreases the oscillator strengths, the peak positions of absorption coefficients as well as the refractive index changes. Additionally, an increase of the confinement frequency (dot size) increases (decreases) the absorption coefficients but does not significantly affect the refractive index changes. It is also observed that the intensity of the illumination and the relaxation time have drastic effects on nonlinear optical properties. Finally, we note that the optical absorption coefficients and refractive index changes of two electrons are about five times higher than that of a one-electron QD.

  20. Double-Pass Retina Point Imaging for the Evaluation of Optical Light Scatter, Retinal Image Quality, and Staging of Keratoconus.

    Science.gov (United States)

    Leonard, Anthony P; Gardner, Scott D; Rocha, Karolinne M; Zeldin, Evan R; Tremblay, David M; Waring, George O

    2016-11-01

    To measure retinal image quality using point spread function (PSF) analysis by double-pass retina point imaging in patients with keratoconus and to correlate visual quality with disease severity. Patients diagnosed as having keratoconus by clinical examination, topography, and tomography and normal eyes were included in this study. A commercially available double-pass retina point imaging instrument (OQAS 108 II AcuTarget HD; Visiometrics S.L., Terrassa, Spain) was used to collect Objective Scatter Index (OSI) values in 21 keratoconic and 22 normal eyes. Eyes were also subjected to corneal topography and tomography, and staged using the Keratoconus Severity Score (KSS) and Amsler-Krumeich (AK) scales. The OSI was increased in keratoconic eyes (5.85 ± 0.98) versus control eyes (0.83 ± 0.12; mean ± SEM), in AK stages 1 to 4, and KSS stages 3 and 4. Receiver-operator characteristic analysis obtained an area under the curve (AUC) of 0.859 when evaluating the OSI as a unimodal diagnostic indicator for any KSS stage and 0.993 for KSS stages 3 and higher. An AUC of 0.949 was obtained in comparing eyes with lower severity topographic aberrations (KSS 1 and 2) versus mild to moderate keratoconus (KSS 3 and 4). Increasing corneal steepening patterns on tomography and topography were associated with PSF broadening and increased OSI. Double-pass retina point imaging is useful in correlating retinal image quality with keratoconus severity. The OSI may represent a clinically significant parameter for staging keratoconus with a unique ability to directly evaluate quality of vision in this population. [J Refract Surg. 2016;32(11):760-765.]. Copyright 2016, SLACK Incorporated.

  1. Optics

    CERN Document Server

    Fincham, W H A

    2013-01-01

    Optics: Eighth Edition covers the work necessary for the specialization in such subjects as ophthalmic optics, optical instruments and lens design. The text includes topics such as the propagation and behavior of light; reflection and refraction - their laws and how different media affect them; lenses - thick and thin, cylindrical and subcylindrical; photometry; dispersion and color; interference; and polarization. Also included are topics such as diffraction and holography; the limitation of beams in optical systems and its effects; and lens systems. The book is recommended for engineering st

  2. Effect of Injector Geometry on Atomization of a Liquid-Liquid Double Swirl Coaxial Injector Using Non-invasive Laser, Optical and X-ray Techniques

    Science.gov (United States)

    Radke, C. R.; Meyer, T. R.

    2014-01-01

    The spray characteristics of a liquid-liquid double swirl coaxial injector were studied using non-invasive optical, laser, and X-ray diagnostics. A parametric study of injector exit geometry demonstrated that spray breakup time, breakup type and sheet stability could be controlled with exit geometry. Phase Doppler interferometry was used to characterize droplet statistics and non-dimensional droplet parameters over a range of inlet conditions and for various fluids allowing for a study on the role of specific fluid properties in atomization. Further, X-ray radiography allowed for investigation of sheet thickness and breakup length to be quantified for different recess exit diameters and inlet pressures. Finally, computed tomography scans revealed that the spray cone was distinctively non-uniform and comprised of several pockets of increased mass flux.

  3. Anticrossing double Fano resonances generated in metallic/dielectric hybrid nanostructures using nonradiative anapole modes for enhanced nonlinear optical effects.

    Science.gov (United States)

    Zhai, Wu-Chao; Qiao, Tie-Zhu; Cai, Dong-Jin; Wang, Wen-Jie; Chen, Jing-Dong; Chen, Zhi-Hui; Liu, Shao-Ding

    2016-11-28

    Third-harmonic generation with metallic or dielectric nanoparticles often suffer from, respectively, small modal volumes and weak near-field enhancements. This study propose and demonstrate that a metallic/dielectric hybrid nanostructure composed of a silver double rectangular nanoring and a silicon square nanoplate can be used to overcome these obstacles for enhanced third-harmonic generation. It is shown that the nonradiative anapole mode of the Si plate can be used as a localized source to excite the dark subradiant octupole mode of the Ag ring, and the mode hybridization leads to the formation of an antibonding and a bonding subradiant collective mode, thereby forming anticrossing double Fano resonances. With the strong coupling between individual particles and the effectively suppressed radiative losses of the Fano resonances, several strong hot spots are generated around the Ag ring due to the excitation of the octupole mode, and electromagnetic fields within the Si plate are also strongly amplified, making it possible to confine more incident energy inside the dielectric nanoparticle. Calculation results reveal that the confined energy inside the Si plate and the Ag ring for the hybrid structures can be about, respectively, more than three times and four orders stronger than that of the corresponding isolated nanoparticles, which makes the designed hybrid nanostructure a promising platform for enhanced third-harmonic generation.

  4. Spectral optical monitoring of the double peaked emission line AGN Arp 102B: II. Variability of the broad line properties

    CERN Document Server

    Popovic, L C; Ilic, D; Burenkov, A N; Chavushyan, V H; Kollatschny, W; Kovacevic, A; Valdes, J R; Leon-Tavares, J; Bochkarev, N G; Patino-Alvarez, V; Torrealba, J

    2014-01-01

    We investigate a long-term (26 years, from 1987 to 2013) variability in the broad spectral line properties of the radio galaxy Arp 102B, an active galaxy with broad double-peaked emission lines. We use observations presented in Paper I (Shapovalova et al. 2013) in the period from 1987 to 2011, and a new set of observations performed in 2012--2013. To explore the BLR geometry, and clarify some contradictions about the nature of the BLR in Arp 102B we explore variations in the H$\\alpha$ and H$\\beta$ line parameters during the monitored period. We fit the broad lines with three broad Gaussian functions finding the positions and intensities of the blue and red peaks in H$\\alpha$ and H$\\beta$. Additionally we fit averaged line profiles with the disc model. We find that the broad line profiles are double-peaked and have not been changed significantly in shapes, beside an additional small peak that, from time to time can be seen in the blue part of the H$\\alpha$ line. The positions of the blue and red peaks { have n...

  5. Optical properties of double layer thin films zinc oxide doping aluminum (ZnO/Al) were deposited on glass substrates by sol gel method spray coating technique

    Science.gov (United States)

    Permatasari, Anes; Sutanto, Heri; Marito Siagian, Sinta

    2017-01-01

    Thin films of double layer of ZnO/Al has succeeded in deposition on a glass substrate using sol-gel method and spray coating techniques. Variations of doping Al as much as 2%, 4%, 6% and 8%. ZnO precursor synthesized using zinc acetate dehydrate (Zn(COOCH3)2.2H2O), isopropanol ((CH3)2CHOH) and monoethanolamine (MEA) were stirred using a magnetic stirrer for 45 minutes. ZnO precursor get homogeneous and then added of aluminum nitrate nonahydrate predetermined doping concentration and stirred again for 15 minutes. Deposition solution is done by the spray on a glass substrate and then heated at a temperature of 450°C. A layer of ZnO/Al deposited over the ZnO to produce a thin layer of a double layer. Optical properties layer of ZnO/Al characterized using UV-Vis spectrophotometer. Based on data from UV-Vis absorbance was determined the value of the energy band gap. Pure and dopped layers has different energy due the Al dopping. For pure ZnO layer has energy band gap of 3.347 eV and decreased to 3.09 eV for ZnO layer with Al dopant.

  6. Preparation of biomimetic photoresponsive polymer springs.

    Science.gov (United States)

    Iamsaard, Supitchaya; Villemin, Elise; Lancia, Federico; Aβhoff, Sarah-Jane; Fletcher, Stephen P; Katsonis, Nathalie

    2016-10-01

    Polymer springs that twist under irradiation with light, in a manner that mimics how plant tendrils twist and turn under the effect of differential expansion in different sections of the plant, show potential for soft robotics and the development of artificial muscles. The soft springs prepared using this protocol are typically 1 mm wide, 50 μm thick and up to 10 cm long. They are made from liquid crystal polymer networks in which an azobenzene derivative is introduced covalently as a molecular photo-switch. The polymer network is prepared by irradiation of a twist cell filled with a mixture of shape-persistent liquid crystals, liquid crystals having reactive end groups, molecular photo-switches, some chiral dopant and a small amount of photoinitiator. After postcuring, the soft polymer film is removed and cut into springs, the geometry of which is determined by the angle of cut. The material composing the springs is characterized by optical microscopy, scanning electron microscopy and tensile strength measurements. The springs operate at ambient temperature, by mimicking the orthogonal contraction mechanism that is at the origin of plant coiling. They shape-shift under irradiation with UV light and can be pre-programmed to either wind or unwind, as encoded in their geometry. Once illumination is stopped, the springs return to their initial shape. Irradiation with visible light accelerates the shape reversion.

  7. Cavity optomechanical spring sensing of single molecules

    Science.gov (United States)

    Yu, Wenyan; Jiang, Wei C.; Lin, Qiang; Lu, Tao

    2016-07-01

    Label-free bio-sensing is a critical functionality underlying a variety of health- and security-related applications. Micro-/nano-photonic devices are well suited for this purpose and have emerged as promising platforms in recent years. Here we propose and demonstrate an approach that utilizes the optical spring effect in a high-Q coherent optomechanical oscillator to dramatically enhance the sensing resolution by orders of magnitude compared with conventional approaches, allowing us to detect single bovine serum albumin proteins with a molecular weight of 66 kDa at a signal-to-noise ratio of 16.8. The unique optical spring sensing approach opens up a distinctive avenue that not only enables biomolecule sensing and recognition at individual level, but is also of great promise for broad physical sensing applications that rely on sensitive detection of optical cavity resonance shift to probe external physical parameters.

  8. The Spring Festival

    Institute of Scientific and Technical Information of China (English)

    萧平

    2005-01-01

    Everybody likes to have the Spring Festival, so do I.Because during the Spring Festival there are many good things to eat, to drink and to play with. During the last Spring Festival I had a very good time. On the eve of the festival, our family had a big dinner. My uncle, aunt and cousin came back from Canada to celebrate(庆祝) my grandma's eightieth birthday. They also brought many beautiful gifts to me. My cousin and I watched TV and played games the whole night, while the grown-ups had a long talk. I didn't know when I fell asleep.

  9. Asymmetric GaAs n-type double δ-doped quantum wells as a source of intersubband-related nonlinear optical response: Effects of an applied electric field

    Energy Technology Data Exchange (ETDEWEB)

    Rodríguez-Magdaleno, K.A.; Martínez-Orozco, J.C.; Rodríguez-Vargas, I. [Unidad Académica de Física, Universidad Autónoma de Zacatecas, Calz. Solidaridad Esq. Paseo a La Bufa S/N. C.P. 98060 Zacatecas (Mexico); Mora-Ramos, M.E. [Facultad de Ciencias, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, CP 62209 Cuernavaca, Morelos (Mexico); Física Teórica y Aplicada, Escuela de Ingeniería de Antioquia, AA 7516 Medellín (Colombia); Grupo de Materia Condensada-UdeA, Instituto de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín (Colombia); Duque, C.A., E-mail: cduque@fisica.udea.edu.co [Grupo de Materia Condensada-UdeA, Instituto de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín (Colombia)

    2014-03-15

    In this work, the conduction band electron states and the associated intersubband-related linear and nonlinear optical absorption coefficient and relative refractive index change are calculated for an asymmetric double n-type δ-doped quantum well in a GaAs-matrix. The effects of an external applied static electric field are included. Values of the two-dimensional impurities density (N{sub 2d}) of each single δ-doped quantum well are taken to vary within the range of 1.0×10{sup 12} to 7.0×10{sup 12} cm{sup −2}, consistent with the experimental data growth regime. The optical responses are reported as a function of the δ-doped impurities density and the applied electric field. It is shown that single electron states and the related optical quantities are significantly affected by the structural asymmetry of the double δ-doped quantum well system. In addition, a brief comparison with the free-carrier-related optical response is presented. -- Highlights: • Nonlinear optics in asymmetric double n-type δ-doped quantum well in a GaAs-matrix. • The system is considered under external applied electric field in growth direction. • The 2D impurity density is consistent with the experimental data growth regime. • The optical quantities are significantly affected by the structural asymmetry of the system.

  10. Optical quality improvement of MOVPE grown GaAlAs/GaAs double heterostructures on silicon substrates

    Science.gov (United States)

    Draïdia, N.; Azoulay, R.; Dugrand, L.; Papadopoulo, A. C.; Gao, Y.; Sermage, B.; Ossart, P.; Meddeb, J.

    1991-01-01

    We report a study of metalorganic vapour phase epitaxy (MOVPE) grown GaAlAs/GaAs double heterostructures on Si substrates. The main part of this work deals with the influence of post growth annealing conditions on cathodoluminescence (CL) efficiency, defect reduction, Si distribution over the structure, and interfaces state. It has been found by 300 K cathodoluminescence measurements that treatment at high temperature up to 900°C reduces defect and deep level transitions giving rise to larger zones of high near band edge (NBE) emission luminescence in contrast to those observed on unannealed samples. Such improvement has been confirmed by transmission electron microscopy and luminescence decay measurements. Carrier life times as 6 ns have been measured indicating a ten fold increase after annealing.

  11. Optical quality improvement of MOVPE grown GaAlAs/GaAs double heterostructures on silicon substrates

    Energy Technology Data Exchange (ETDEWEB)

    Draidia, N.; Azoulay, R.; Dugrand, L.; Papadopoulo, A.C.; Gao, Y.; Sermage, B.; Ossart, P. (Centre National des Etudes des Telecommunications, Lab. de Bagneux, 92 (France)); Meddeb, J. (Dept. de Physique de la Matiere, Univ. Claude Bernard, 69 - Villeurbanne (France))

    1991-01-01

    We report a study of metalorganic vapour phase epitaxy (MOVPE) grown GaAlAs/GaAs double heterostructures on Si substrates. The main part of this work deals with the influence of post growth annealing conditions on cathodoluminescence (CL) efficiency, defect reduction, Si distribution over the structure, and interfaces state. It has been found by 300 K cathodoluminescence measurements that treatment at high temperature up to 900degC reduces defect and deep level transitions giving rise to larger zones of high near band edge (NBE) emission luminescence in contrast to those observed on unannealed samples. Such improvement has been confirmed by transmission electron microscopy and luminescence decay measurements. Carrier life times as large as 6 ns have been measured indicating a ten fold increase after annealing. (orig.).

  12. 工具式围堰在桥梁墩柱维修中的应用%Operation Method of the Tool-typed Recycling Double Wall Steel Cofferdam in Wate-pier Reinforcement Engineering in the Spring Tide of Poor Water

    Institute of Scientific and Technical Information of China (English)

    刘昂; 吴中鑫; 朱慈祥

    2015-01-01

    In this paper,in the engineering background of detection and reinforcement project of the No.14~18 Pier of a bridge,the construction method of the Tool-Typed Double Wall Steel Cofferdam in the bridge of low clearance flyovers which is removable and recyclable in the spring tide of poor wa-ter is introduced.In the method,the factors,the spring tide of poor water,low clearance flyovers, and details of design and fabrication of the steel cofferdams are considered.An application example shows that the method can reduce construction time,cost,energy conservation and environmental protection..%以某桥梁15~18号桥墩检测加固项目为工程背景,介绍了某桥梁高潮差低净空下的工具式可拆卸循环利用双壁钢围堰使用方法,该工具式可拆卸循环利用双壁钢围堰的施工考虑了涨落潮变化、桥下净空较小等环境因素,以及围堰及辅助措施的设计、制作安装。应用证明,该方法具有减少施工工期、降低成本、节能环保等特点。

  13. Fish Springs pond snail

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Communication scenario between the branch of Listing and Recovery, Fish and Wildlife Enhancement, and Fish Springs National Wildlife Refuge (NWR), in regards to the...

  14. Spring Bottom Trawl Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The standardized NEFSC Spring Bottom Trawl Survey was initiated in 1968 and covered an area from Cape Hatteras, NC, to Nova Scotia, Canada, at depths >27m....

  15. Learning Spring application development

    CERN Document Server

    Soni, Ravi Kant

    2015-01-01

    This book is intended for those who are interested in learning the core features of the Spring Framework. Prior knowledge of Java programming and web development concepts with basic XML knowledge is expected.

  16. Harbingers of Spring

    Science.gov (United States)

    Serrao, John

    1976-01-01

    Emphasizing the spring migration of frogs, toads, and salamanders to their watery breeding sites, this article presents information on numerous amphibians and suggests both indoor and outdoor educational activities appropriate for elementary and/or early secondary instruction. (JC)

  17. 舌簧活动矫治器联合直丝弓矫治器治疗恒牙早期骨性Ⅲ错(牙合)的疗效评价%Treatment effects of double parabolic lingual springs appliance and straight wire appliance therapy in skeletal class Ⅲ malocclusion

    Institute of Scientific and Technical Information of China (English)

    常忠福; 尹传卫

    2010-01-01

    目的 评价舌簧活动矫治器和直丝弓矫治器联合治疗恒牙早期骨性Ⅲ错(牙合)的疗效.方法 舌簧活动矫治器和直丝弓矫治器联合治疗恒牙早期骨性Ⅲ错(牙合)12例患者,在矫治前和矫治后拍摄并分析头颅定位侧位片,比较它们前后的变化.结果 X线片测量显示SNA增加2.80°,SNB减少1.39°,ANB减少4.88°.结论 舌簧活动矫治器和直丝弓矫治器联合治疗恒牙早期骨性Ⅲ错(牙合)的疗效明显,值得推广.%Objective To evaluate the treatment effects of double parabolic lingual springs appliance and straight wire appliance therapy in skeletal class Ⅲ malocclusion. Methods 12 cases with skeletal class Ⅲ malocclusion were treated by double parabolic lingual springs appliance and straight wire appliance, cephalometric tracing measurement were taken in analysis,compared between pretreatment and posttreatment in each case. Results The comparison of before and after orthodontic treatment showed angle SNA increased by 2.80°, angle SNB decreased 1.39°ANB decreased by 4.88°. Conclusion The above metioned technique could be a reliable way to treat mild and moderate skeletal class Ⅲ malocclusion.

  18. Archaeologist Fr Rafael Maglioni and the Stean of Double F Lines in the Spring and Autumn Period Unearthed in Wuhua%考古学家麦兆良与五华出土的春秋夔纹陶罐

    Institute of Scientific and Technical Information of China (English)

    刘向明

    2011-01-01

    1940年至1946年间,考古学家麦兆良对粤东地区开展了大范围的考古调查工作,收获丰硕,也有幸成为目前已知的梅州考古与研究的第一人。他在五华发现的春秋夔纹陶罐,已成为确定夔纹陶存在年代,揭示夔纹陶纹样来源,探讨夔纹陶技术产生、发展和传播的典型器物,具有很高的考古学价值。同时,也充分证明梅州古地是岭南区域考古文化传播和交流的交汇点,有着悠久和丰富的古代文明。%Archaeologist Fr Rafael Maglioni made a big scale of archaeological investigation with fruitful results between 1940 and 1946 and became so far the first ever known person who has engaged in the archaeological studies in Meizhou. The stean of double f lines and he discovered in Wuha has become the typical implement which is used to determine the date of existence of the stean of double F lines, to reveal the source of the double f lines in earthe- nware, and to explore how the technique of the double F lines in earthenware came into being, developed and spread, and is of very high archaeological value. It also well proves that ancient Meizhou which was the meeting point of the spread and communication of the archaeological cultures in the area of south of the Five Ridges has a long- standing and rich ancient civilization.

  19. The Springs at Pipe Spring National Monument, Arizona (pisp_springs)

    Data.gov (United States)

    National Park Service, Department of the Interior — This is an Arc/Info coverage consisting of 5 points representing the springs, natural and man-made, at Pipe Spring National Monument, Arizona. The springs were...

  20. Demonstration system design of double-layered optical satellite network%双层卫星光网络仿真演示系统设计

    Institute of Scientific and Technical Information of China (English)

    李勇军; 赵尚弘; 吴继礼; 朱子行; 王翔; 赵顾灏; 姜晓峰

    2011-01-01

    In order to simulate and demonstrate the maintaining and handover of inter-orbit links of double-layered optical satellite network accurately, a hardware-in-the-loop demonstration system of asynchronous handover optical satellite network was designed in the scale of 1:30. The system was composed of demonstration hardware platform and computer simulation platform which were connected by System-In-the-Loop (SITL) module. Hardware platform was made up of a circular rotor mounted two servo-optical communication terminals and four servo-optical communication terminals which were located on the two sides of the circular rotor. The former demonstrated the LEO satellites and the latter demonstrated the MEO satellites. The system period was 280 s, the rotational velocity of circular rotor was 1.28(°)/s and the handover time from LEO satellites to MEO satellites was 4 s. The software environment was composed of computer virtual networks, in which flexible on board routing and processing may be performed. The demonstration system can achieve automatic tracking, bi-directional handover and automatic pointing. It can model OIOL (optical inter-orbit links) maintaining, data relaying and bi-directional handovers between LEO satellites andMEO satellites. Experiences from the demonstration system would be useful for the realization of LEO/MEO double-layered optical satellite network in engineering.%为了精确模拟、演示验证双层卫星光网络星际激光链路的稳定和切换,按l:30的比例设计了分时切换低/中轨道(LEO/MEO:Low Earth Orbit/Medium Earth Orbit)双层卫星光网络实验演示系统.系统由SITL(System-In-the-Loop)模块将硬件平台和计算机仿真平台互联而组成.硬件平台由中心的圆形往复转台上面的2个伺服终端和两侧的4个伺服终端组成,分别模拟LEO卫星和MEO卫星.转台平台角速度为1.28(°)/s,周期为280s,切换时间为4s.软件部分由虚拟网络组成,具有灵活的星上路由和处理

  1. An acousto-optic Q-switched fiber laser using China-made double-cladding fiber

    Institute of Scientific and Technical Information of China (English)

    Hongming Zhao; Qihong Lou; Jun Zhou; Fangpei Zhang; Jingxing Dong; Yunrong Wei; Libo Li; Zhijiang Wang

    2007-01-01

    @@ A simple laser-diode pumped acoustic-optic Q-switched fiber laser is reported by using China-made largemode-area ytterbium-doped fiber. Q-switched pulses with a beam quality factor of M2 ≈ 2 and several hundred nanoseconds pulse duration are achieved at the repetition rate of 1 - 50 kHz. When the repetition rate is 1 kHz, the pulse energy is 0.93 mJ with the pulse duration of 132 ns. Meanwhile, the profile of laser pulses shows some mode-locking phenomena, the mechanism of the phenomena is discussed.

  2. Experimental investigation of PAM, CAP and DMT modulations efficiency over a double-step-index polymer optical fiber

    Science.gov (United States)

    Stepniak, G.; Siuzdak, J.

    2014-08-01

    Investigated was the transmission over step index POF that is 50 m/100 m long with a red DVD laser as a source and a Si p-i-n commercial photo-detector. The maximum bit rates of three modulation formats: PAM, CAP and DMT were sought. Their constellation sizes and symbol rates were varied in order to maximize FEC limited throughputs for each modulation whereas the laser operating point and relevant optical powers were maintained constant for all the modulations. The maximum throughputs were similar for PAM and CAP, namely 3.3/2 Gbit/s for PAM, and 3.15/2.1 for CAP for 50/100 m fiber, respectively. The bit rates for DMT were 2.65/1.65 Gbit/s for the respective lengths of the fiber. We attribute the inferior performance of DMT to its high value of peak to average power ratio.

  3. Optical and Thermal Properties of Zn/Al-Layered Double Hydroxide Nanocomposite Intercalated with Sodium Dodecyl Sulfate

    Directory of Open Access Journals (Sweden)

    Samaneh Babakhani

    2014-01-01

    Full Text Available Zn/Al-LDH-SDS nanocomposites have been prepared using a coprecipitation method in different molar ratio of Zn2+/Al3+ = 2, 3, and 4 at pH = 10 and different concentrations of sodium dodecyl sulfate solution (0.2 M, 0.4 M, and 0.8 M. The XRD and FTIR data show the successful intercalation of SDS into the LDH interlayer. The XRD diffractogram showed that the basal spacing for Zn/Al–NO3- is 0.89 nm compared to 2.54–2.61 nm for the Zn/Al-SDS nanocomposite. Optical band gap of the samples was calculated using Kubelka-Munk model. Due to the presence of LDH phase, two band gap energies (Eg1 and Eg2 were observed. The values of Eg1 and Eg2 were found around 4.8 eV and 3.75 eV for Zn/Al-LDH (r = 2, 3, and 4. The values of band gap of LDH-SDS nanocomposites were found to increase to around 4.2 eV and 5.2 eV. For Zn4Al-LDH-SDS with 0.4 M and 0.8 M of SDS, only one energy gap at around 3.23 eV was observed. The optical band gap of SO42- phase increased as the amount of SDS increases. Thermal diffusivity of the resulted nanocomposite was also investigated.

  4. JINAN: the City of Springs

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    @@ Attractions Jinan is not a hot tourist destination in China, but it has Something special to offer, such as the 72 springs scattered throughout the city. Jinan has an alias of the Spring City (Quan Cheng)because of ouver 700 natural springs run through the city. Among them,the Baotu Spring is the most famous.

  5. Walking with springs

    Science.gov (United States)

    Sugar, Thomas G.; Hollander, Kevin W.; Hitt, Joseph K.

    2011-04-01

    Developing bionic ankles poses great challenges due to the large moment, power, and energy that are required at the ankle. Researchers have added springs in series with a motor to reduce the peak power and energy requirements of a robotic ankle. We developed a "robotic tendon" that reduces the peak power by altering the required motor speed. By changing the required speed, the spring acts as a "load variable transmission." If a simple motor/gearbox solution is used, one walking step would require 38.8J and a peak motor power of 257 W. Using an optimized robotic tendon, the energy required is 21.2 J and the peak motor power is reduced to 96.6 W. We show that adding a passive spring in parallel with the robotic tendon reduces peak loads but the power and energy increase. Adding a passive spring in series with the robotic tendon reduces the energy requirements. We have built a prosthetic ankle SPARKy, Spring Ankle with Regenerative Kinetics, that allows a user to walk forwards, backwards, ascend and descend stairs, walk up and down slopes as well as jog.

  6. Zn-Al layered double hydroxide prepared at different molar ratios: Preparation, characterization, optical and dielectric properties

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Abdullah Ahmed Ali [Department of Physics, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Talib, Zainal Abidin, E-mail: zainalat@science.upm.edu.my [Department of Physics, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Zobir bin Hussein, Mohd [Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Advanced Materials and Nanotechnology Laboratory, Institute of Advanced Technology (ITMA), Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Zakaria, Azmi [Department of Physics, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Advanced Materials and Nanotechnology Laboratory, Institute of Advanced Technology (ITMA), Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia)

    2012-07-15

    The co-precipitation method was used to prepare Zn-Al-NO{sub 3}-LDH at different Zn{sup 2+}/Al{sup 3+} molar ratios (2, 3, 4, 5 and 6) and pH value of 7.5. The structure, textural, composition and morphological properties were investigated using powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR) and scanning electron microscope (SEM), respectively. The crystallinity of LDH samples were found to improve as molar ratio decreased which is attributed to the distortion of the hydroxide layers networks of the LDH crystal by the larger difference in ionic radii of Zn{sup 2+} and Al{sup 3+}. The optical band gap energy of LDH samples were evaluated using absorbance data from UV-Vis-NIR Diffuse reflectance spectroscopy. Band gaps were affected by the variation of the Zn{sup 2+}/Al{sup 3+} molar ratio is due to the formation of the low crystalline phases (ZnO and ZnAl{sub 2}O{sub 4}). The water molecules and anionic NO{sub 3}{sup -} in the LDH interlayer were responsible for the generation of the dielectric response. This response can be described by an anomalous low frequency dispersion using the second type of Universal Power Law. The dominance of ZnO dipoles and charge carriers (NO{sub 3}{sup -} ions) in the dielectric relaxation increases with the increasing molar ratio. - Graphical abstract: (a) Schematic diagram of Zn-Al- NO{sub 3}-LDH shows the LDH structure, (b) Kubelka-Munk transformed reflectance spectra and c. The dielectric constant versus frequency of Zn-Al- NO{sub 3}-LDH samples. Highlights: Black-Right-Pointing-Pointer Zn-Al-NO{sub 3}-LDH was prepared at different Zn{sup 2+}/Al{sup 3+} molar ratios (2, 3, 4, 5 and 6). Black-Right-Pointing-Pointer The crystallinity of LDH phase decreased with increase of Zn{sup 2+}/Al{sup 3+} molar ratio. Black-Right-Pointing-Pointer The optical band gaps of LDH samples have been measured. Black-Right-Pointing-Pointer Dielectric response of LDH can be described by anomalous low

  7. Simulation study of rotating double optical wedge vectoring optics path based on Matlab%旋转双光楔光路引导系统Matlab仿真研究

    Institute of Scientific and Technical Information of China (English)

    郭云曾; 杨小军; 杨小君; 贾海妮; 王海涛; 刘锋; 姜志

    2014-01-01

    由于光楔在高精度微孔加工中起着对激光光束引导作用,为了提高激光微细孔加工质量,给出了一种提高光楔对激光微加工精度分析的方法。首先提出了单光楔矢量等效概念,基于单光楔矢量定义对双光楔矢量模型进行了建立与分析,并得出了多个光楔进行矢量叠加的新方法;其次,应用Matlab编写了仿真软件,仿真得出了激光束经过两个相同光楔后的轨迹,并指出了由于运动系统的不同步对激光微孔加工中打孔质量的影响,进行了误差定量分析并给出了误差计算公式。文中结论对高精度激光微孔加工控制系统设计时的性能指标提供参考。%The optical wedge plays a guiding and key role on the processing of high-precision micro-hole drilling by laser pulses. In order to improve the laser micro-hole processing quality, a method was presented to improve the analysis on the impact of the optical wedge on accuracy of laser micro-manufacturing. First the concept of the equivalent of a single wedge vector was proposed. The double wedge vector model was established and analyzed based on the definition of a single wedge vector, and the new method of the vector superposition of the multiple wedges was came up with. Secondly, the simulation software was programmed by using Matlab. The simulation results show the trail of the laser pulses through the double optical wedge. The effect of the quality of the micro-hole caused by the un-synchronization of the motion system is investigated. The deviation quantitative analysis is carried and the formula of calculation the deviation is given. The conclusion is of great value to the performance indicators of designing the controlling system in the high-precision micro-hole drilling by laser pulses.

  8. A facile synthesis of strong near infrared fluorescent layered double hydroxide nanovehicles with an anticancer drug for tumor optical imaging and therapy

    Science.gov (United States)

    Chen, Chunping; Yee, Lee Kim; Gong, Hua; Zhang, Yong; Xu, Rong

    2013-05-01

    In this work, a new multifunctional nanovehicle for tumor optical imaging and therapy was developed using Y2O3:Er3+,Yb3+ nanoparticles as near infrared fluorescent nanophosphors, and MgAl-layered double hydroxide (LDH) nanosheets as anticancer drug nanovehicles. Monodispersed Y2O3:Er3+,Yb3+ nanophosphors were readily synthesized by the urea assisted homogenous precipitation method. Hierarchically structured LDH nanosheets intercalated with an anticancer drug, fluorouracil (5FU), were deposited on the surface of Y2O3:Er3+,Yb3+@SiO2 by a simple precipitation method followed by hydrothermal treatment. The resultant Y2O3:Er3+,Yb3+@SiO2@LDH-5FU nanovehicles exhibit strong red upconversion fluorescence under the excitation of a 980 nm laser, which allows tracking of the nanovehicles after localization in cancer cells. A better anticancer efficiency was obtained over the nanovehicles than the free drug which can be attributed to their positively charged surfaces for favorable interaction with the negatively charged cell membranes. The multifunctional nanovehicles designed in this work are expected to be promising material candidates for simultaneous tumor optical imaging and therapy.In this work, a new multifunctional nanovehicle for tumor optical imaging and therapy was developed using Y2O3:Er3+,Yb3+ nanoparticles as near infrared fluorescent nanophosphors, and MgAl-layered double hydroxide (LDH) nanosheets as anticancer drug nanovehicles. Monodispersed Y2O3:Er3+,Yb3+ nanophosphors were readily synthesized by the urea assisted homogenous precipitation method. Hierarchically structured LDH nanosheets intercalated with an anticancer drug, fluorouracil (5FU), were deposited on the surface of Y2O3:Er3+,Yb3+@SiO2 by a simple precipitation method followed by hydrothermal treatment. The resultant Y2O3:Er3+,Yb3+@SiO2@LDH-5FU nanovehicles exhibit strong red upconversion fluorescence under the excitation of a 980 nm laser, which allows tracking of the nanovehicles after

  9. Spring of women?

    Directory of Open Access Journals (Sweden)

    Mónica Castillo

    2012-12-01

    Full Text Available Terms such as “Islamic feminism” and “women’s movement” refer to those social movements of women that seek to assert their rights in Islamic societies. This brief study focuses on theses social movements of women and will presentan overview of the role and participation of women in the Arab Spring by examining news, events, press articles and opinions in order to contextualize the participation of women and feminists in the Arab Spring from a perspective of the social networking phenomenon as apparent drivers of the revolution.

  10. Instant Spring security starter

    CERN Document Server

    Jagielski, Piotr

    2013-01-01

    Get to grips with a new technology, understand what it is and what it can do for you, and then get to work with the most important features and tasks. A concise guide written in an easy-to-follow format following the Starter guide approach.This book is for people who have not used Spring Security before and want to learn how to use it effectively in a short amount of time. It is assumed that readers know both Java and HTTP protocol at the level of basic web programming. The reader should also be familiar with Inversion-of-Control/Dependency Injection, preferably with the Spring framework itsel

  11. Pro Spring security

    CERN Document Server

    Scarioni, Carlo

    2013-01-01

    Security is a key element in the development of any non-trivial application. The Spring Security Framework provides a comprehensive set of functionalities to implement industry-standard authentication and authorization mechanisms for Java applications. Pro Spring Security will be a reference and advanced tutorial that will do the following: Guides you through the implementation of the security features for a Java web application by presenting consistent examples built from the ground-up. Demonstrates the different authentication and authorization methods to secure enterprise-level applications

  12. What's Behind Spring Festival?

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ Similar to what the Christmas Day means for the westerners,the Spring Festival is the most important celebration for Chinese people.This big event according to Chinese traditional lunar calendar relaxes and pleases the whole country as the happiest gathering time of the year.National-wide crusade for going back home,too-difficult-to-get train tickets,generous family-going-out shopping,Miaohui laundering,New Year Eve reunion dinner,visiting friends and relatives,watching annual TV gala……each piece of clue reminds us of the smell of Chinese Spring Festival.

  13. Numerical Optimization of Tunnel-recombination Junction and Optical Absorption Properties of a-Si:H/a-SiGe:H Double-junction Solar Cell

    Institute of Scientific and Technical Information of China (English)

    KE; Shaoying; WANG; Chong; PAN; Tao; WANG; Zhaoqing; YANG; Jie; YANG; Yu

    2015-01-01

    The tunnel-recombination junction(TRJ) and optical absorption properties of a-Si:H/a-Si Ge:H double-junction solar cell were calculated by means of one dimensional simulator named AMPS-1D at the radiation of AM1.5G with a power density of 100 m W/cm2. Since the TRJ is the core component of the tandem solar cell, the optical absorption of the sub-cells and the electronic transport properties at the interface of the sub-cells are affected by the thickness and doping concentration of the TRJ. As a result, the TRJ parameters were optimized. The numerical results indicate that the maximum conversion efficiency(Eff) of 9.862% can be obtained when the thickness and doping concentration of the TRJ are 10 nm and 5*1019 cm–3, respectively. Based on the analysis of the contour map of short circuit current density, the optimal current matching can be achieved for 130 nm-thick top i-layer and 250 nm-thick bottom i-layer. In addition, four kinds of TRJ structures were also simulated for the comparison purpose. According to the calculated resistivity and band structures of the four TRJs, the efficiency of the solar cell with n-type μc-Si:H layer and p-type a-Si:H layer in TRJ structure is greater than that with other TRJ structures. It is assumed that the effect of the band offset that results in the formation of triangular barrier and backscattering behavior at the edge of the TRJ could be responsible to this phenomenon.

  14. Spring bloom onset in the Nordic Seas

    Science.gov (United States)

    Mignot, Alexandre; Ferrari, Raffaele; Mork, Kjell Arne

    2016-06-01

    The North Atlantic spring bloom is a massive annual growth event of marine phytoplankton, tiny free-floating algae that form the base of the ocean's food web and generates a large fraction of the global primary production of organic matter. The conditions that trigger the onset of the spring bloom in the Nordic Seas, at the northern edge of the North Atlantic, are studied using in situ data from six bio-optical floats released north of the Arctic Circle. It is often assumed that spring blooms start as soon as phytoplankton cells daily irradiance is sufficiently abundant that division rates exceed losses. The bio-optical float data instead suggest the tantalizing hypothesis that Nordic Seas blooms start when the photoperiod, the number of daily light hours experienced by phytoplankton, exceeds a critical value, independently of division rates. The photoperiod trigger may have developed at high latitudes where photosynthesis is impossible during polar nights and phytoplankton enters into a dormant stage in winter. While the first accumulation of biomass recorded by the bio-optical floats is consistent with the photoperiod hypothesis, it is possible that some biomass accumulation started before the critical photoperiod but at levels too low to be detected by the fluorometers. More precise observations are needed to test the photoperiod hypothesis.

  15. Band edge tailoring of InGaAs/AlAsSb coupled double quantum wells for a monolithically integrated all-optical switch.

    Science.gov (United States)

    Feng, Jijun; Akimoto, Ryoichi; Gozu, Shin-ichiro; Mozume, Teruo; Hasama, Toshifumi; Ishikawa, Hiroshi

    2013-07-01

    We demonstrate a compact all-optical Michelson interferometer (MI) gating switch with monolithic integration of two different bandgap energies. Based on the ion-induced intermixing in InGaAs/AlAsSb coupled double quantum wells, the blueshift of the band edge can be tailored. Through phosphorus ion implantation with a dose of 5 × 10(14) cm(-2) and subsequent annealing at 720 °C for 60 s, an implanted sample can acquire a high transmittance compared with the as-grown one. Meanwhile, the cross-phase modulation (XPM) efficiency of a non-implanted sample undergoing the same annealing process decreases little. An implanted part for signal propagation and a non-implanted section for XPM are thus monolithically integrated for an MI switch by an area-selective manner. Full switching of a π-rad nonlinear phase shift is achieved with pump pulse energy of 5.6 pJ at a 10-GHz repetition rate.

  16. Gain chip design, power scaling and intra-cavity frequency doubling with LBO of optically pumped red-emitting AlGaInP-VECSELs

    Science.gov (United States)

    Kahle, Hermann; Mateo, Cherry M. N.; Brauch, Uwe; Bek, Roman; Schwarzbäck, Thomas; Jetter, Michael; Graf, Thomas; Michler, Peter

    2016-03-01

    The wide range of applications in biophotonics, television or projectors, spectroscopy and lithography made the optically-pumped semiconductor (OPS) vertical external cavity surface-emitting lasers (VECSELs) an important category of power scalable lasers. The possibility of bandgap engineering, inserting frequency selective and converting elements into the open laser cavity and laser emission in the fundamental Gaussian mode leads to ongoing growth of the area of applications for tuneable laser sources. We present an AlGaInP-VECSEL system with a multi quantum well structure consisting of compressively strained GaInP quantum wells in an AlxGa1-xInP separate confinement heterostructure with an emission wavelength around 665 nm. The VECSEL chip with its n-λ cavity is pumped by a 532nm Nd:YAG laser under an angle to the normal incidence of 50°. In comparison, a gain chip design for high absorption values at pump wavelengths around 640nm with the use of quantum dot layers as active material is also presented. Frequency doubling is now realized with an antireflection coated lithium borate crystal, while a birefringent filter, placed inside the laser cavity under Brewster's angle, is used for frequency tuning. Further, power-scaling methods like in-well pumping as well as embedding the active region of a VECSEL between two transparent ic heaspreaders are under investigation.

  17. Optical, luminescence and thermal properties of radiopure ZnMoO{sub 4} crystals used in scintillating bolometers for double beta decay search

    Energy Technology Data Exchange (ETDEWEB)

    Chernyak, D.M. [Institute for Nuclear Research, MSP 03680 Kyiv (Ukraine); Centre de Sciences Nucléaires et de Sciences de la Matière, 91405 Orsay (France); Danevich, F.A. [Institute for Nuclear Research, MSP 03680 Kyiv (Ukraine); Degoda, V.Ya.; Dmitruk, I.M. [Kyiv National Taras Shevchenko University, MSP 03680 Kyiv (Ukraine); Ferri, F. [Dipartimento di Scienza e Alta Tecnologia dell' Università dell' Insubria, Como I-22100 (Italy); Galashov, E.N. [Nikolaev Institute of Inorganic Chemistry, 630090 Novosibirsk (Russian Federation); Giuliani, A., E-mail: Andrea.Giuliani@csnsm.in2p3.fr [Centre de Sciences Nucléaires et de Sciences de la Matière, 91405 Orsay (France); Dipartimento di Scienza e Alta Tecnologia dell' Università dell' Insubria, Como I-22100 (Italy); Sezione INFN di Milano-Bicocca, I-20126 Italy (Italy); Ivanov, I.M. [Nikolaev Institute of Inorganic Chemistry, 630090 Novosibirsk (Russian Federation); Kobychev, V.V. [Institute for Nuclear Research, MSP 03680 Kyiv (Ukraine); Mancuso, M.; Marnieros, S. [Centre de Sciences Nucléaires et de Sciences de la Matière, 91405 Orsay (France); Dipartimento di Scienza e Alta Tecnologia dell' Università dell' Insubria, Como I-22100 (Italy); Mokina, V.M. [Institute for Nuclear Research, MSP 03680 Kyiv (Ukraine); Nones, C.; Olivieri, E. [Service de Physique des Particules, CEA-Saclay, F-91191 Gif sur Yvette (France); Pessina, G. [Sezione INFN di Milano-Bicocca, I-20126 Italy (Italy); Rusconi, C. [Dipartimento di Scienza e Alta Tecnologia dell' Università dell' Insubria, Como I-22100 (Italy); Sezione INFN di Milano-Bicocca, I-20126 Italy (Italy); and others

    2013-11-21

    Zinc molybdate (ZnMoO{sub 4}) crystals are an excellent candidate material to fabricate scintillating bolometers for the study of neutrinoless double beta decay of {sup 100}Mo, provided that the crystal quality meets strict optical, thermal and radiopurity requirements. This paper addresses the characterization of improved crystalline samples grown by the low-thermal-gradient Czochralski technique. Transmittance measurements confirm significant improvement of the material with respect to previously developed samples. Luminescence properties (emission spectra, dependence of intensity on temperature, thermally stimulated luminescence and phosphorescence) have been studied under X-ray excitation from liquid-helium to room temperature. The index of refraction was measured in the wavelength interval 406–655 nm. Samples of ZnMoO{sub 4} crystals with masses of 5.07 g and 23.8 g were operated as scintillating bolometers at temperatures below 30 mK, with simultaneous detection of scintillation and heat signals, confirming an excellent alpha/beta rejection power. Background measurements allowed encouraging radiopurity level estimations. The light collection from ZnMoO{sub 4} scintillators was Monte Carlo simulated, analysing different crystal size, shape and surface properties and different photodetector sizes.

  18. Large-scale fabrication of linear low density polyethylene/layered double hydroxides composite films with enhanced heat retention, thermal, mechanical, optical and water vapor barrier properties

    Science.gov (United States)

    Xie, Jiazhuo; Zhang, Kun; Zhao, Qinghua; Wang, Qingguo; Xu, Jing

    2016-11-01

    Novel LDH intercalated with organic aliphatic long-chain anion was large-scale synthesized innovatively by high-energy ball milling in one pot. The linear low density polyethylene (LLDPE)/layered double hydroxides (LDH) composite films with enhanced heat retention, thermal, mechanical, optical and water vapor barrier properties were fabricated by melt blending and blowing process. FT IR, XRD, SEM results show that LDH particles were dispersed uniformly in the LLDPE composite films. Particularly, LLDPE composite film with 1% LDH exhibited the optimal performance among all the composite films with a 60.36% enhancement in the water vapor barrier property and a 45.73 °C increase in the temperature of maximum mass loss rate compared with pure LLDPE film. Furthermore, the improved infrared absorbance (1180-914 cm-1) of LLDPE/LDH films revealed the significant enhancement of heat retention. Therefore, this study prompts the application of LLDPE/LDH films as agricultural films with superior heat retention.

  19. Spectral optical monitoring of a double-peaked emission line AGN Arp 102B: I. Variability of spectral lines and continuum

    CERN Document Server

    Shapovalova, A I; Burenkov, A N; Chavushyan, V H; Ilic, D; Kollatschny, W; Kovacevic, A; Bochkarev, N G; Valdes, J R; Torrealba, J; Patino-Alvarez, V; Leon-Tavares, J; Benitez, E; Carrasco, L; Dultzin, D; Mercado, A; Zhdanova, V E

    2013-01-01

    Here we present results of the long-term (1987-2010) optical spectral monitoring of the broad line radio galaxy Arp 102B, a prototype of active galactic nuclei with the double-peaked broad emission lines, usually assumed to be emitted from an accretion disk. To explore the structure of the broad line region (BLR), we analyze the light curves of the broad H\\alpha and H\\beta lines and the continuum flux. We aim to estimate the dimensions of the broad-line emitting regions and the mass of the central black hole. We use the CCF to find lags between the lines and continuum variations. We investigate in more details the correlation between line and continuum fluxes, moreover we explore periodical variations of the red-to-blue line flux ratio using Lomb-Scargle periodograms. The line and continuum light curves show several flare-like events. The fluxes in lines and in the continuum are not showing a big change (around 20%) during the monitoring period. We found a small correlation between the line and continuum flux...

  20. Spring batch essentials

    CERN Document Server

    Rao, P Raja Malleswara

    2015-01-01

    If you are a Java developer with basic knowledge of Spring and some experience in the development of enterprise applications, and want to learn about batch application development in detail, then this book is ideal for you. This book will be perfect as your next step towards building simple yet powerful batch applications on a Java-based platform.

  1. Energy Matters - Spring 2002

    Energy Technology Data Exchange (ETDEWEB)

    None

    2002-03-01

    Quarterly newsletter from DOE's Industrial Technologies Program to promote the use of energy-efficient industrial systems. The focus of the Spring 2002 Issue of Energy Matters focuses on premium energy efficiency systems, with articles on new gas technologies, steam efficiency, the Augusta Newsprint Showcase, and more.

  2. Renaissance Administrator, Spring 1998.

    Science.gov (United States)

    Dowdy, June P., Ed.

    1998-01-01

    This spring 1998 issue of Renaissance Administrator features the following articles: (1) "Servant Leadership and Higher Education--What is Leadership?" (Richard E. Hasselbach); (2) "Teaching Writing in the 90's--Carnivorous Printers and Dying Grandmothers" (Helen Ruggieri); (3) Assignment--Journal Writing" (Lynn Muscato); and (4) "A Business…

  3. Editors' Spring Picks

    Science.gov (United States)

    Library Journal, 2011

    2011-01-01

    While they do not represent the rainbow of reading tastes American public libraries accommodate, Book Review editors are a wildly eclectic bunch. One look at their bedside tables and ereaders would reveal very little crossover. This article highlights an eclectic array of spring offerings ranging from print books to an audiobook to ebook apps. It…

  4. Fish Springs molluscan studies: House and Percy Springs

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the findings of a limited survey of House and Percy Springs molluscan fauna within Fish Springs National Wildlife Refuge. Various...

  5. A double-taper optical fiber-based radiation wave other than evanescent wave in all-fiber immunofluorescence biosensor for quantitative detection of Escherichia coli O157:H7.

    Directory of Open Access Journals (Sweden)

    Zhonghuan Zhang

    Full Text Available Cylindrical or taper-and-cylinder combination optical fiber probe based on evanescent wave has been widely used for immunofluorescence biosensor to detect various analytes. In this study, in contrast to the contradiction between penetration depth and analyte diameter of optical fiber probe-based evanescent wave, we demonstrate that double-taper optical fiber used in a radiation wave-based all-fiber immunofluorescence biosensor (RWAIB can detect micron-scale analytes using Escherichia coli O157:H7 as representative target. Finite-difference time-domain method was used to compare the properties of evanescent wave and radiation wave (RW. Ray-tracing model was formulated to optimize the taper geometry of the probe. Based on a commercial multi-mode fiber, a double-taper probe was fabricated and connected with biosensor through a "ferrule connector" optical fiber connector. The RWAIB configuration was accomplished using commercial multi-mode fibers and fiber-based devices according to the "all-fiber" method. The standard sample tests revealed that the sensitivity of the proposed technique for E. coli O157:H7 detection was 10(3 cfu · mL(-1. Quantitation could be achieved within the concentration range of 10(3 cfu · mL(-1 to 107 cfu · mL(-1. No non-specific recognition to ten kinds of food-borne pathogens was observed. The results demonstrated that based on the double-taper optical fiber RWAIB can be used for the quantitative detection of micron-scale targets, and RW sensing is an alternative for traditional evanescent wave sensing during the fabrication of fiber-optic biosensors.

  6. A double-taper optical fiber-based radiation wave other than evanescent wave in all-fiber immunofluorescence biosensor for quantitative detection of Escherichia coli O157:H7.

    Science.gov (United States)

    Zhang, Zhonghuan; Hua, Fei; Liu, Ting; Zhao, Yong; Li, Jun; Yang, Ruifu; Yang, Changxi; Zhou, Lei

    2014-01-01

    Cylindrical or taper-and-cylinder combination optical fiber probe based on evanescent wave has been widely used for immunofluorescence biosensor to detect various analytes. In this study, in contrast to the contradiction between penetration depth and analyte diameter of optical fiber probe-based evanescent wave, we demonstrate that double-taper optical fiber used in a radiation wave-based all-fiber immunofluorescence biosensor (RWAIB) can detect micron-scale analytes using Escherichia coli O157:H7 as representative target. Finite-difference time-domain method was used to compare the properties of evanescent wave and radiation wave (RW). Ray-tracing model was formulated to optimize the taper geometry of the probe. Based on a commercial multi-mode fiber, a double-taper probe was fabricated and connected with biosensor through a "ferrule connector" optical fiber connector. The RWAIB configuration was accomplished using commercial multi-mode fibers and fiber-based devices according to the "all-fiber" method. The standard sample tests revealed that the sensitivity of the proposed technique for E. coli O157:H7 detection was 10(3) cfu · mL(-1). Quantitation could be achieved within the concentration range of 10(3) cfu · mL(-1) to 107 cfu · mL(-1). No non-specific recognition to ten kinds of food-borne pathogens was observed. The results demonstrated that based on the double-taper optical fiber RWAIB can be used for the quantitative detection of micron-scale targets, and RW sensing is an alternative for traditional evanescent wave sensing during the fabrication of fiber-optic biosensors.

  7. Studying Springs in Series Using a Single Spring

    Science.gov (United States)

    Serna, Juan D.; Joshi, Amitabh

    2011-01-01

    Springs are used for a wide range of applications in physics and engineering. Possibly, one of their most common uses is to study the nature of restoring forces in oscillatory systems. While experiments that verify Hooke's law using springs are abundant in the physics literature, those that explore the combination of several springs together are…

  8. Comparative study of the hydrostatic pressure and temperature effects on the impurity-related optical properties in single and double GaAs-Ga{sub 1-x}Al{sub x}As quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Odhiambo Oyoko, H. [Department of Physics, Westville Campus, University of KwaZulu-Natal, Private Bag X 54001, Durban 4000 (South Africa); Porras-Montenegro, N. [Departamento de Fisica, Universidad del Valle, AA 25360, Cali (Colombia); Lopez, S.Y. [Facultad de Educacion, Universidad de Antioquia, AA 1226, Medellin (Colombia); Duque, C.A. [Instituto de Fisica, Universidad de Antioquia, AA 1226, Medellin (Colombia)

    2007-07-01

    Using a variational technique within the effective mass approximation we have carried out a comparative study of the effect of hydrostatic pressure and temperature on the shallow-impurity related optical absorption spectra in GaAs-Ga{sub 1-x}Al{sub x}As single and double quantum wells. The results show a pressure dependent read-shift and a temperature dependent blue-shift in the optical absorption spectra. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  9. Warm Springs pupfish recovery plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document gives a history of pupfish and focuses on the warm springs pupfish. The warm springs pupfish is endangered, and this is a plan to help recover the...

  10. Generation of high-energy sub-20 fs pulses tunable in the 250-310 nm region by frequency doubling of a high-power noncollinear optical parametric amplifier.

    Science.gov (United States)

    Beutler, Marcus; Ghotbi, Masood; Noack, Frank; Brida, Daniele; Manzoni, Cristian; Cerullo, Giulio

    2009-03-15

    We report on the generation of powerful sub-20 fs deep UV pulses with 10 microJ level energy and broadly tunable in the 250-310 nm range. These pulses are produced by frequency doubling a high-power noncollinear optical parametric amplifier and compressed by a pair of MgF2 prisms to an almost transform-limited duration. Our results provide a power scaling by an order of magnitude with respect to previous works.

  11. Hot Spring Metagenomics

    Directory of Open Access Journals (Sweden)

    Olalla López-López

    2013-04-01

    Full Text Available Hot springs have been investigated since the XIX century, but isolation and examination of their thermophilic microbial inhabitants did not start until the 1950s. Many thermophilic microorganisms and their viruses have since been discovered, although the real complexity of thermal communities was envisaged when research based on PCR amplification of the 16S rRNA genes arose. Thereafter, the possibility of cloning and sequencing the total environmental DNA, defined as metagenome, and the study of the genes rescued in the metagenomic libraries and assemblies made it possible to gain a more comprehensive understanding of microbial communities—their diversity, structure, the interactions existing between their components, and the factors shaping the nature of these communities. In the last decade, hot springs have been a source of thermophilic enzymes of industrial interest, encouraging further study of the poorly understood diversity of microbial life in these habitats.

  12. Magnetic Spring Device

    OpenAIRE

    Hassam, A. B.; Rodgers, J. C.

    2009-01-01

    A cylindrical system is proposed that will store magnetic energy in a localized azimuthal field that can then be quickly released on Alfvenic timescales, accompanied by the formation of a flowing Z-pinch plasma. The magnetized plasma is MHD in character and will have unilateral axial momentum with Alfvenic speeds. Conventional plasma gun injectors (Marshall type) have a limited parameter space of operation. The "magnetic spring" momentum injector differs from Marshall guns in that it has an a...

  13. Linear and nonlinear optical absorption coefficients in GaAs/Ga{sub 1-x}Al{sub x}As concentric double quantum rings: Effects of hydrostatic pressure and aluminum concentration

    Energy Technology Data Exchange (ETDEWEB)

    Baghramyan, H.M. [Department of Solid State Physics, Yerevan State University, Al. Manookian 1, 0025 Yerevan (Armenia); Barseghyan, M.G., E-mail: mbarsegh@ysu.am [Department of Solid State Physics, Yerevan State University, Al. Manookian 1, 0025 Yerevan (Armenia); Kirakosyan, A.A. [Department of Solid State Physics, Yerevan State University, Al. Manookian 1, 0025 Yerevan (Armenia); Restrepo, R.L. [Escuela de Ingenieria de Antioquia, AA 7516 Medellin (Colombia); Duque, C.A. [Instituto de Fisica, Universidad de Antioquia, AA 1226 Medellin (Colombia)

    2013-02-15

    The linear and nonlinear intra-band optical absorption coefficients in GaAs/Ga{sub 1-x}Al{sub x}As two-dimensional concentric double quantum rings are investigated. Taking into account the combined effects of hydrostatic pressure and aluminum concentration the energies of the ground (n=1,l=0) and the first excited state (n=2,l=1) have been found using the effective mass approximation and the transfer matrix formalism. The energies of these states and the corresponding threshold energy of the intra-band optical transitions are examined as a function of hydrostatic pressure and aluminum concentration for different sizes of the structure. We also investigated the dependencies of the linear, nonlinear, and total optical absorption coefficients as functions of the incident photon energy for different values of hydrostatic pressure, aluminum concentration, sizes of the structure, and incident optical intensity. Its is found that the effects of the hydrostatic pressure and the aluminum concentration lead to a shifting of the resonant peaks of the intra-band optical spectrum. - Highlights: Black-Right-Pointing-Pointer Linear and nonlinear intra-band absorption in quantum rings. Black-Right-Pointing-Pointer Threshold energy strongly depends on the hydrostatic pressure. Black-Right-Pointing-Pointer Threshold energy strongly depends on the stoichiometry and sizes of structure. Black-Right-Pointing-Pointer Optical absorption is affected by the incident optical intensity.

  14. Millimeter-wave optical double resonance schemes for rapid assignment of perturbed spectra, with applications to the C{sup ~} {sup 1}B{sub 2} state of SO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Park, G. Barratt, E-mail: barratt@mit.edu, E-mail: barratt.park@gmail.com; Womack, Caroline C.; Jiang, Jun; Field, Robert W., E-mail: rwfield@mit.edu [Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Whitehill, Andrew R.; Ono, Shuhei [Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2015-04-14

    Millimeter-wave detected, millimeter-wave optical double resonance (mmODR) spectroscopy is a powerful tool for the analysis of dense, complicated regions in the optical spectra of small molecules. The availability of cavity-free microwave and millimeter wave spectrometers with frequency-agile generation and detection of radiation (required for chirped-pulse Fourier-transform spectroscopy) opens up new schemes for double resonance experiments. We demonstrate a multiplexed population labeling scheme for rapid acquisition of double resonance spectra, probing multiple rotational transitions simultaneously. We also demonstrate a millimeter-wave implementation of the coherence-converted population transfer scheme for background-free mmODR, which provides a ∼10-fold sensitivity improvement over the population labeling scheme. We analyze perturbations in the C{sup ~} state of SO{sub 2}, and we rotationally assign a b{sub 2} vibrational level at 45 328 cm{sup −1} that borrows intensity via a c-axis Coriolis interaction. We also demonstrate the effectiveness of our multiplexed mmODR scheme for rapid acquisition and assignment of three predissociated vibrational levels of the C{sup ~} state of SO{sub 2} between 46 800 and 47 650 cm{sup −1}.

  15. Developing bulk exchange spring magnets

    Energy Technology Data Exchange (ETDEWEB)

    Mccall, Scott K.; Kuntz, Joshua D.

    2017-06-27

    A method of making a bulk exchange spring magnet by providing a magnetically soft material, providing a hard magnetic material, and producing a composite of said magnetically soft material and said hard magnetic material to make the bulk exchange spring magnet. The step of producing a composite of magnetically soft material and hard magnetic material is accomplished by electrophoretic deposition of the magnetically soft material and the hard magnetic material to make the bulk exchange spring magnet.

  16. Several Moments of the Spring

    Institute of Scientific and Technical Information of China (English)

    毛竹晨

    2003-01-01

    Spring has finally fallen on Cambridge. After a long, wet and dark winter, sky finally brightens up. The first messenger of spring is the daffodil (水仙花). English daffodils are slightly different from the Chinese ones that we are all familiar with. First of all, they bloom in spring, not in winter as the Chinese daffodils do. Second, they do not grow in water, but on the ground, though they

  17. Spring viremia of carp

    Science.gov (United States)

    Ahne, W.; Bjorklund, H.V.; Essbauer, S.; Fijan, N.; Kurath, G.; Winton, J.R.

    2002-01-01

    pring viremia of carp (SVC) is an important disease affecting cyprinids, mainly common carp Cyprinus carpio. The disease is widespread in European carp culture, where it causes significant morbidity and mortality. Designated a notifiable disease by the Office International des Epizooties, SVC is caused by a rhabdovirus, spring viremia of carp virus (SVCV). Affected fish show destruction of tissues in the kidney, spleen and liver, leading to hemorrhage, loss of water-salt balance and impairment of immune response. High mortality occurs at water temperatures of 10 to 17°C, typically in spring. At higher temperatures, infected carp develop humoral antibodies that can neutralize the spread of virus and such carp are protected against re-infection by solid immunity. The virus is shed mostly with the feces and urine of clinically infected fish and by carriers. Waterborne transmission is believed to be the primary route of infection, but bloodsucking parasites like leeches and the carp louse may serve as mechanical vectors of SVCV. The genome of SVCV is composed of a single molecule of linear, negative-sense, single-stranded RNA containing 5 genes in the order 3¹-NPMGL-5¹ coding for the viral nucleoprotein, phosphoprotein, matrix protein, glycoprotein, and polymerase, respectively. Polyacrylamide gel electrophoresis of the viral proteins, and sequence homologies between the genes and gene junctions of SVCV and vesicular stomatitis viruses, have led to the placement of the virus as a tentative member of the genus Vesiculovirus in the family Rhabdoviridae. These methods also revealed that SVCV is not related to fish rhabdoviruses of the genus Novirhabdovirus. In vitro replication of SVCV takes place in the cytoplasm of cultured cells of fish, bird and mammalian origin at temperatures of 4 to 31°C, with an optimum of about 20°C. Spring viremia of carp can be diagnosed by clinical signs, isolation of virus in cell culture and molecular methods. Antibodies directed

  18. Donor impurity-related linear and nonlinear optical absorption coefficients in GaAs/Ga{sub 1−x}Al{sub x}As concentric double quantum rings: Effects of geometry, hydrostatic pressure, and aluminum concentration

    Energy Technology Data Exchange (ETDEWEB)

    Baghramyan, H.M.; Barseghyan, M.G.; Kirakosyan, A.A. [Department of Solid State Physics, Yerevan State University, Al. Manookian 1, 0025 Yerevan (Armenia); Restrepo, R.L. [Física Teórica y Aplicada, Escuela de Ingeniería de Antioquia, AA 7516, Medellín (Colombia); Grupo de Materia Condensada-UdeA, Instituto de Física, Facultadde Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21,Medellín (Colombia); Mora-Ramos, M.E. [Grupo de Materia Condensada-UdeA, Instituto de Física, Facultadde Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21,Medellín (Colombia); Facultad de Ciencias, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, CP 62209, Cuernavaca, Morelos (Mexico); Duque, C.A., E-mail: cduque@fisica.udea.edu.co [Grupo de Materia Condensada-UdeA, Instituto de Física, Facultadde Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21,Medellín (Colombia)

    2014-01-15

    The linear and nonlinear optical absorption associated with the transition between 1s and 2s states corresponding to the electron-donor-impurity complex in GaAs/Ga{sub 1−x}Al{sub x}As three-dimensional concentric double quantum rings are investigated. Taking into account the combined effects of hydrostatic pressure and the variation of the aluminum concentration, the energies of the ground and first excited s-like states of a donor impurity in such a system have been calculated using the effective mass approximation and a variational method. The energies of these states and the corresponding threshold energy of the optical transitions are examined as functions of hydrostatic pressure, aluminum concentration, radial impurity position, as well as the geometrical dimensions of the structure. The dependencies of the linear, nonlinear and total optical absorption coefficients as functions of the incident photon energy are investigated for different values of those mentioned parameters. It is found that the influences mentioned above lead to either redshifts or blueshifts of the resonant peaks of the optical absorption spectrum. It is particularly discussed the unusual property exhibited by the third-order nonlinear of becoming positive for photon energies below the resonant transition one. It is shown that this phenomenon is associated with the particular features of the system under study, which determine the values of the electric dipole moment matrix elements. -- Highlights: • Intra-band optical absorption associated to impurity states in double quantum rings. • Combined effects of hydrostatic pressure and aluminum concentration are studied. • The influences mentioned above lead to shifts of resonant peaks. • It is discussed an unusual property exhibited by the third-order nonlinear absorption.

  19. Spring security 3.x cookbook

    CERN Document Server

    Mankale, Anjana

    2013-01-01

    This book follows a cookbook style exploring various security solutions provided by Spring Security for various vulnerabilities and threat scenarios that web applications may be exposed to at the authentication and session level layers.This book is for all Spring-based application developers as well as Java web developers who wish to implement robust security mechanisms into web application development using Spring Security.Readers are assumed to have a working knowledge of Java web application development, a basic understanding of the Spring framework, and some knowledge of the fundamentals o

  20. Leaky mode suppression in planar optical waveguides written in Er:TeO{sub 2}–WO{sub 3} glass and CaF{sub 2} crystal via double energy implantation with MeV N{sup +} ions

    Energy Technology Data Exchange (ETDEWEB)

    Bányász, I., E-mail: banyasz@sunserv.kfki.hu [Department of Crystal Physics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, P.O.B. 49, H-1525 Budapest (Hungary); Zolnai, Z.; Fried, M. [Research Institute for Technical Physics and Materials Science, Research Centre for Natural Sciences, Hungarian Academy of Sciences, P.O.B. 49, Budapest H-1525 (Hungary); Berneschi, S. [MDF-Lab, “Nello Carrara” Institute of Applied Physics, IFAC-CNR, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); “Enrico Fermi” Center for Study and Research, Piazza del Viminale 2, 00184 Roma (Italy); Pelli, S.; Nunzi-Conti, G. [MDF-Lab, “Nello Carrara” Institute of Applied Physics, IFAC-CNR, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy)

    2014-05-01

    Ion implantation proved to be an universal technique for producing waveguides in most optical materials. Tellurite glasses are good hosts of rare-earth elements for the development of fibre and integrated optical amplifiers and lasers covering all the main telecommunication bands. Er{sup 3+}-doped tellurite glasses are good candidates for the fabrication of broadband amplifiers in wavelength division multiplexing around 1.55 μm, as they exhibit large stimulated cross sections and broad emission bandwidth. Calcium fluoride is an excellent optical material, due to its perfect optical characteristics from UV wavelengths up to near IR. It has become a promising laser host material (doped with rare earth elements). Ion implantation was also applied to optical waveguide fabrication in CaF{sub 2} and other halide crystals. In the present work first single-energy implantations at 3.5 MeV at various fluences were applied. Waveguide operation up to 1.5 μm was observed in Er:Te glass, and up to 980 nm in CaF{sub 2}. Then double-energy implantations at a fixed upper energy of 3.5 MeV and lower energies between 2.5 and 3.2 MeV were performed to suppress leaky modes by increasing barrier width.

  1. Large springs of east Tennessee

    Science.gov (United States)

    Sun, Pao-chang P.; Criner, J.H.; Poole, J.L.

    1963-01-01

    Springs constitute an important source of water in east Tennessee, and many individual springs are capable of supplying the large quantities needed for municipal and industrial supplies. Most of the springs in east Tennessee issue from solution openings and fractured and faulted zones in limestone and dolomite of the Knox Group, Chickamauga Limestone, and Conasauga Group. The ability of these rocks to yield a sustained flow of water to springs is dependent on a system of interconnected openings through which water can infiltrate from the land surface and move to points of natural discharge. Ninety springs were selected for detailed study, and 84 of these are analyzed in terms of magnitude and variability of discharge. Of the 84 springs analyzed, 4 flow at an average rate of 10 to 100 cfs (cubic feet per second), 62 at an average rate of 1 to 10 cfs, and 18 at an average rate of 1 cfs or less. Of the 90 springs, 75 are variable in their discharge; that is, the ratio of their fluctuations to their average discharges exceeds 100 percent. Mathematical analysis of the flow recession curve of Mill Spring near Jefferson City shows that the hydrologic system contributing to the flow of the spring has an effective capacity of about 70 million cubic feet of water. The rate of depletion of this volume of water, in the absence of significant precipitation, averages 0.0056 cfs per day between the time when the hydrologic system is full and the time when the spring ceases to flow. From such a curve it is possible to determine at any time the residual volume of water remaining in the system and the expected rate of decrease in discharge from that time to cessation of flow. Correlation of discharge measurements of 22 springs with those of Mill Spring shows that rough approximations of discharge can be projected for springs for which few measurements are available. Seventeen of the springs analyzed in this manner show good correlation with Mill Spring: that is, their coefficients

  2. Experimenting with Inexpensive Plastic Springs

    Science.gov (United States)

    Perez, Leander; Marques, Adriana; Sánchez, Iván

    2014-01-01

    Acommon undergraduate laboratory experience is the determination of the elastic constant of a spring, whether studying the elongation under a static load or studying the damped harmonic motion of the spring with a suspended mass. An alternative approach to this laboratory experience has been suggested by Menezes et al., aimed at studying the…

  3. Multi-scale and angular analysis of ray-optical light trapping schemes in thin-film solar cells: micro lens array, V-shaped configuration, and double parabolic trapper.

    Science.gov (United States)

    Cho, Changsoon; Lee, Jung-Yong

    2013-03-11

    An efficient light trapping scheme is a key to enhancing the power conversion efficiency (PCE) of thin-film photovoltaic (PV) cells by compensating for the insufficient light absorption. To handle optical components from nano-scale to micro-scale seamlessly, a multi-scale optical simulation is carefully designed in this study and is used to qualitatively analyze the light trapping performances of a micro lens array (MLA), a V-shaped configuration, and the newly proposed scheme, which is termed a double parabolic trapper (DPT) according to both daily and annual movement of the sun. DPT has the potential to enhance the PCE significantly, from 5.9% to 8.9%, for PCDTBT:PC(70)BM-based polymer solar cells by perfectly trapping the incident light between two parabolic PV cells.

  4. Mallow Springs, County Cork, Ireland

    Science.gov (United States)

    Aldwell, C. R.

    1996-03-01

    Because of its copious and reliable rainfall, Ireland has an abundance of springs. Many of the larger ones issue from the Carboniferous limestone that occurs in over 40% of the country. The spring water is mainly a calcium bicarbonate type with a temperature of about 10°C. In the 18th century, warm and cold springs were developed as spas in various parts of Ireland. The popularity of these springs was short and most were in major decline by 1850. Today only one cold spa at Lisdoonvarna, Co. Clare is still operating. Springs in Ireland were places of religious significance for the pre-Christian Druidic religion. In the Christian period they became holy wells, under the patronage of various saints. Cures for many different ailments were attributed to water from these wells.

  5. Double Trouble

    NARCIS (Netherlands)

    Elsaesser, Thomas; Kievit, Robert; Simons, Jan

    1994-01-01

    Double Trouble highlights the career of Dutch scriptwriter and television producer Chiem van Houweninge, well-known for his long-running TV comedy series and as author of episodes for TV detective series. Double Trouble gives Van Houweninge's own views on writing and filming in television prime impo

  6. Double Trouble

    NARCIS (Netherlands)

    Elsaesser, Thomas; Kievit, Robert; Simons, Jan

    1994-01-01

    Double Trouble highlights the career of Dutch scriptwriter and television producer Chiem van Houweninge, well-known for his long-running TV comedy series and as author of episodes for TV detective series. Double Trouble gives Van Houweninge's own views on writing and filming in television prime

  7. Double-Glazing Interferometry

    OpenAIRE

    Toal, Vincent; Mihaylova, Emilia

    2009-01-01

    This note describes how white light interference fringes can be seen by observing the Moon through a double-glazed window. White light interferometric fringes are normally observed only in a well-aligned interferometer whose optical path difference is less than the coherence length of the light source, which is approximately one micrometer for white light. Obtaining such fringes in a Michelson interferometer is not a trivial task.1 The interferometer is typically illuminated with a monochroma...

  8. Spring comes for ATLAS

    CERN Multimedia

    Butin, F.

    2004-01-01

    (First published in the CERN weekly bulletin 24/2004, 7 June 2004.) A short while ago the ATLAS cavern underwent a spring clean, marking the end of the installation of the detector's support structures and the cavern's general infrastructure. The list of infrastructure to be installed in the ATLAS cavern from September 2003 was long: a thousand tonnes of mechanical structures spread over 13 storeys, two lifts, two 65-tonne overhead travelling cranes 25 metres above cavern floor, with a telescopic boom and cradle to access the remaining 10 metres of the cavern, a ventilation system for the 55 000 cubic metre cavern, a drainage system, a standard sprinkler system and an innovative foam fire-extinguishing system, as well as the external cryogenic system for the superconducting magnets and the liquid argon calorimeters (comprising, amongst other things, two helium refrigeration units, a nitrogen refrigeration unit and 5 km of piping for gaseous or liquid helium and nitrogen), not to mention the handling eq...

  9. A bountiful spring harvest

    CERN Multimedia

    2013-01-01

    Although we recently put the clocks forward and spring has officially begun, the view from my window looks more autumnal – befitting of the season of mists and mellow fruitfulness, rather than that of sowing seeds for the future. Which, in a way is appropriate. With the LHC paused, we are reaping a kind of harvest in the form of recognition for our efforts.   Two weeks ago, I was in Edinburgh, on behalf of everyone at CERN, to collect the Edinburgh medal, which we shared with Peter Higgs. I particularly like the citation for this honour: “The Edinburgh Medal is awarded each year to men and women of science and technology whose professional achievements are judged to have made a significant contribution to the understanding and well-being of humanity.” I like this, because it underlines a fact that needs to be shouted louder – that fundamental science does more than build the sum of human knowledge, it is also the foundation of human well-being. A few d...

  10. Double pendulum contact problem

    Directory of Open Access Journals (Sweden)

    Špička J.

    2014-06-01

    Full Text Available The work concerns contact problems focused on biomechanical systems modelled by a multibody approach. The example is modelling of impact between a body and an infrastructure. The paper firstly presents algorithm for minimum distance calculation. An analytical approach using a tangential plain perpendicular to an initial one is applied. Contact force generated during impact is compared by three different continuous force models, namely the Hertz’s model, the spring-dashpot model and the non-linear damping model. In order to identify contact parameters of these particular models, the method of numerical optimization is used. Purpose of this method is to find the most corresponding results of numerical simulation to the original experiment. Numerical optimization principle is put upon a bouncing ball example for the purpose of evaluation of desirable contact force parameters. The contact modelling is applied to a double pendulum problem. The equation of motion of the double pendulum system is derived using Lagrange equation of the second kind with multipliers, respecting the contact phenomena. Applications in biomechanical research are hinted at arm gravity motion and a double pendulum impact example.

  11. Frequency locking to a high-finesse Fabry-Perot cavity of a Frequency doubled Nd YAG laser used as the optical phase modulator

    CERN Document Server

    Bregant, M; Valle, F D; Ruoso, G; Zavattini, G

    2002-01-01

    We report on the frequency locking of a frequency doubled Nd:YAG laser to a 45 000 finesse, 87-cm-long, Fabry-Perot cavity using a modified form of the Pound-Drever-Hall technique. Necessary signals, such as light phase modulation and frequency correction feedback, are fed direcly to the infrared pump laser. This is sufficient to achieve a stable locking of the 532 nm visible beam to the cavity, also showing that the doubling process does not degrade laser performances.

  12. Application of the Jones calculus for a modulated double-refracted light beam propagating in a homogeneous and nondepolarizing electro-optic uniaxial crystal.

    Science.gov (United States)

    Izdebski, Marek; Kucharczyk, Włodzimierz; Raab, Roger E

    2004-01-01

    The Jones matrix calculus is applied to an electro-optic crystal with uniaxial symmetry when the light beam is incident nearly normally on the crystal face. The approach allows one to treat refracted waves and rays that diverge in the crystal and are modulated by an external low-frequency field. The effect of partial interference of overlapping refracted beams is allowed for and calculated for the case of uniform intensity of the beam over its cross section. The method is employed to analyze optical systems containing an imprecisely cut and aligned electro-optic crystal plate.

  13. SPRING FESTIVAL ON THE LOESS PLATEAU

    Institute of Scientific and Technical Information of China (English)

    亦西; 杨延康

    2005-01-01

    How Spring Festival is celebrated Although the date of the Spring Festival was switched from the beginning of spring to the first day of the first lunar month, the main ways of celebrating it, from bygone days, remain popular.

  14. Calculation of Optical Gain and Electron Relaxation Rates in Single- and Double-Phonon Resonant Quantum Cascade Lasers in a Magnetic Field

    Science.gov (United States)

    Radovanović, J.; Mirčetić, A.; Milanović, V.; Ikonić, Z.; Indjin, D.; Harrison, P.; Kelsall, R. W.

    We have explored the possibility of modulating the optical gain in the active region of mid-infrared QCLs by means of external magnetic field, which strongly influences the relaxation processes, in particular the LO phonon assisted intersubband transitions. The additional carrier confinement, induced by the field, leads to an increase in the upper laser level carrier lifetime, which results in pronounced oscillations of the optical gain. The described model was applied to two structures designed for λ˜9µm emission.

  15. Fish Springs weather CY 2011

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Weather data for calendar year 2011 at Fish Springs National Wildlife Refuge. Data is provided for each month and includes maximum temperature, minimum temperature,...

  16. Fish Springs weather CY 2010

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Weather data for calendar year 2010 at Fish Springs National Wildlife Refuge. Data is provided for each month and includes maximum temperature, minimum temperature,...

  17. Steller's Eider spring migration surveys

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Annual spring aerial surveys were conducted most years from 1992 to 2008, to monitor the population status and habitat use of Steller's eiders (Polysticta stelleri)...

  18. Report on Fish Springs - 1958

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document discusses field survey results from several trips to Fish Springs National Wildlife Refuge during the summer of 1958. The following information is...

  19. Evaluation of Optical Properties of Self-Frequency-Doubling Crystal Yb:GdYAl3(BO3)4 for Laser Applications

    Institute of Scientific and Technical Information of China (English)

    LI Jing; LI Qiang; WANG Ji-Yang; ZHAO Hong-Yang

    2007-01-01

    @@ Yb:GdYAl3(BO3)4(Yb:GdYAB) is investigated as a new laser crystal for potential applications in self-frequency doubling. The emission and absorption properties of Yb:GdYAB crystal are studied, and the emission decay times of the upper laser level are measured. The emission cross sections are evaluated using the absorption cross section and principle of reciprocity. The other laser performance parameters, such as the minimum inversion fraction βmin, pump saturation intensity Isat and minimum pump intensity Imin, are also calculated. The results are discussed in the framework of requirements for an effective diode-pumped Yb3+ laser system. Yb:GdYAB is expected to exhibit the most useful laser properties and to be superior to Yb:YAB crystal that has been excellent self-frequency-doubling crystal at present in many key spectroscopic parameter values.

  20. LD side-pumped intracavity frequency-doubled high power Nd:YAG green laser based on acousto-optic Q-switch

    Institute of Scientific and Technical Information of China (English)

    ZHANG Feng-chuan; FAN Xiu-wei; XUE Lin; CHAI Hong-liang; HE Jing-liang

    2006-01-01

    A highly efficient and high power green laser generated by intracavity frequency doubling of a diode-side pumped Q-switched Nd:YAG laser has been demonstrated. In the simple L-shaped cavity geometry,the maximum green output power of 28.5 W was obtained with a pulse width of 95 ns at a pulse repetition rate of 10 kHz by using a LBO crystal for frequency doubling,corresponding to a conversion efficiency of 11% from diode pump power to pulse green power. At a pulse repetition rate of 1 kHz,6.9 mJ of pulse energy,25 ns of pulse duration and 276 kW of peak power were obtained.

  1. The Effect of the Optical Spatial Coherence in Young's Double Silt Experiment%光场空间相干性的杨氏双缝干涉实验研究

    Institute of Scientific and Technical Information of China (English)

    吕泽龙; 董洁丽; 陈丹阳; 姚昊

    2012-01-01

    Based on the method of rotating frosted glass, the coherence of optical fields has been modula-ted and the partially coherent optical source has been obtained. The affecting factors of the coherence of opti- cal fields has been analyzed by making use of Young's double slit experiment. The results show that the opti-cal coherence is affected by the incident facular width in frosted glass and isn't affected by the rotational speed of frosted glass.%利用旋转毛玻璃的方法对激光光场的相干性进行调制,获得空间部分相干的光源.同时利用杨氏双缝干涉实验对影响光场的相干性的因素进行分析.实验分析表明,照射至毛玻璃上的光斑宽度对光场相干性有很大影响,而毛玻璃的旋转速度对光场相干性基本没有影响.

  2. Single- and double energy N{sup +} ion irradiated planar optical waveguides in Er: Tungsten–tellurite oxide glass and sillenite type Bismuth Germanate crystals working up to telecommunications wavelengths

    Energy Technology Data Exchange (ETDEWEB)

    Bányász, I., E-mail: banyasz@sunserv.kfki.hu [Department of Crystal Physics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest (Hungary); Zolnai, Z.; Fried, M.; Lohner, T. [Research Institute for Technical Physics and Materials Science, Research Centre for Natural Sciences, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest (Hungary); Berneschi, S.; Righini, G.C. [MDF-Lab, “Nello Carrara” Institute of Applied Physics, IFAC-CNR, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); “Enrico Fermi” Center for Study and Research, Piazza del Viminale 2, 00184 Roma (Italy); Pelli, S.; Nunzi-Conti, G. [MDF-Lab, “Nello Carrara” Institute of Applied Physics, IFAC-CNR, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy)

    2013-07-15

    Ion implantation proved to be a universal technique for producing waveguides in most optical materials. Tellurite glasses are good hosts of rare-earth elements for the development of fibre and integrated optical amplifiers and lasers covering all the main telecommunication bands. Er{sup 3+}-doped tellurite glasses are good candidates for the fabrication of broadband amplifiers in wavelength division multiplexing around 1.55 μm, as they exhibit large stimulated cross sections and broad emission bandwidth. Fabrication of channel waveguides in such a material via N{sup +} ion implantation was reported recently. Sillenite type Bismuth Germanate (BGO) crystals are good nonlinear optical materials. Parameters of waveguide fabrication in both materials via implantation of MeV-energy N{sup +} ions were optimized. First single-energy implantations at 3.5 MeV at various fluences were applied. Waveguide operation up to 1.5 μm was observed in both materials. Then double-energy implantations at a fixed upper energy of 3.5 MeV and lower energies between 2.5 and 3.1 MeV were performed to suppress leaky modes by increasing barrier width. Improvement of waveguide characteristics was found by m-line spectroscopy and spectroscopic ellipsometry.

  3. The Absorption Characteristics of Inhomogeneous Double-Clad Fibers

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The absorption characteristics of radially inhomogeneous double-clad fiber (DCF) are investigated firstly with the method of caustic radius, combined with the method of WKBJ. The results are significant for double-clad optical fiber lasers and amplifiers.

  4. On the variations of optical property and electronic structure in heavily Al-doped ZnO films during double-step growth process

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Q. C.; Ding, K., E-mail: kding@fjirsm.ac.cn; Zhang, J. Y.; Yan, F. P.; Pan, D. M.; Huang, F., E-mail: fhuang@fjirsm.ac.cn [Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Chiou, J. W., E-mail: jwchiou@nuk.edu.tw [Department of Applied Physics, National University of Kaohsiung, Kaohsiung 811, Taiwan (China)

    2014-01-13

    We have investigated the variations of optical property and electronic structure in heavily Al-doped ZnO (AZO) films during the growth process, which were formed by first creating Zn vacancies in O{sub 2}-rich atmosphere and second filling the vacancies with Zn atoms in Zn-vapor atmosphere. After the first step, the high-resistance AZO films have the same optical bandgap with nominally undoped ZnO, indicating that negligible variations in the fundamental bandgap happened to the AZO films although Al atom was incorporated into the ZnO lattice. After the second step, once free electrons were brought into the lattice by Zn-filling, the optical transition energy blueshifts due to the band-filling effect. X-ray absorption fine structure measurements suggest that Zn-filling process decreased the unoccupied states of the conduction band, but not raised the conduction band minimum.

  5. Effect of amino acid dopants on the spectral, optical, mechanical and thermal properties of potassium acid phthalate crystals for possible optoelectronic and frequency doubling applications

    Science.gov (United States)

    Prakash, J. Thomas Joseph; Gnanaraj, J. Martin Sam; Dhavud, S. Shek; Ekadevasena, S.

    2015-09-01

    Undoped and amino acid (L-Arginine and L-Valine) doped KAP crystals were grown by slow evaporation solution growth technique. The changes in the structural, spectral, optical, mechanical and thermal properties were observed. The sharp prominent peaks in the indexed powder XRD pattern confirms the crystalline nature of the sample. Optical studies reveal that the crystal is transparent in the entire visible light region. Thermal stability was checked by TG/DTA analysis. The mechanical stability was evaluated from Vicker's microhardness test. The SHG efficiency for the title materials was tested with different particle sizes by the Kurtz and Perry powder method, which established the existence of phase matching.

  6. Fossilization Processes in Thermal Springs

    Science.gov (United States)

    Farmer, Jack D.; Cady, Sherry; Desmarais, David J.; Chang, Sherwood (Technical Monitor)

    1995-01-01

    To create a comparative framework for the study of ancient examples, we have been carrying out parallel studies of the microbial biosedimentology, taphonomy and geochemistry of modem and sub-Recent thermal spring deposits. One goal of the research is the development of integrated litho- and taphofacies models for siliceous and travertline sinters. Thermal springs are regarded as important environments for the origin and early evolution of life on Earth, and we seek to utilize information from the fossil record to reconstruct the evolution of high temperature ecosystems. Microbial contributions to the fabric of thermal spring sinters occur when population growth rates keep pace with, or exceed rates of inorganic precipitation, allowing for the development of continuous biofilms or mats. In siliceous thermal springs, microorganisms are typically entombed while viable. Modes of preservation reflect the balance between rates of organic matter degradation, silica precipitation and secondary infilling. Subaerial sinters are initially quite porous and permeable and at temperatures higher than about 20 C, organic materials are usually degraded prior to secondary infilling of sinter frameworks. Thus, organically-preserved microfossils are rare and fossil information consists of characteristic biofabrics formed by the encrustation and underplating of microbial mat surfaces. This probably accounts for the typically low total organic carbon values observed in thermal spring deposits. In mid-temperature, (approx. 35 - 59 C) ponds and outflows, the surface morphology of tufted Phormidium mats is preserved through mat underplating by thin siliceous: crusts. Microbial taxes lead to clumping of ceils and/or preferred filament orientations that together define higher order composite fabrics in thermal spring stromatolites (e.g. network, coniform, and palisade). At lower temperatures (less than 35 C), Calothrix mats cover shallow terracette pools forming flat carpets or pustular

  7. Fabrication of mechanically robust, self-cleaning and optically high-performance hybrid thin films by SiO2&TiO2 double-shelled hollow nanospheres

    Science.gov (United States)

    Yao, Lin; He, Junhui; Geng, Zhi; Ren, Tingting

    2015-07-01

    Low-cost antireflection (AR) thin films on large-area optical surfaces are important for high-performance optical devices, display devices and photovoltaic cells. In the current work, SiO2&TiO2 double-shell hollow nanospheres (DSHNs) were designed, synthesized and utilized as building blocks for fabricating multifunctional AR thin films. By optimizing the porosity of SiO2&TiO2 DSHN and thin film structure, substrates with DSHN thin films attained transmittance as high as 99.4% and average transmittance up to 98.5% in the visible region. The nano-composite SiO2-TiO2 films exhibited intrinsic superhydrophilicity, anti-fogging and high photocatalytic activity. Tape peeling test, sponge washing test, and high temperature and moisture proof test showed favorable robustness and functional durability of the thin films, which make them extremely attractive for applications in lenses, photovoltaic cells and windows of high-rise buildings.Low-cost antireflection (AR) thin films on large-area optical surfaces are important for high-performance optical devices, display devices and photovoltaic cells. In the current work, SiO2&TiO2 double-shell hollow nanospheres (DSHNs) were designed, synthesized and utilized as building blocks for fabricating multifunctional AR thin films. By optimizing the porosity of SiO2&TiO2 DSHN and thin film structure, substrates with DSHN thin films attained transmittance as high as 99.4% and average transmittance up to 98.5% in the visible region. The nano-composite SiO2-TiO2 films exhibited intrinsic superhydrophilicity, anti-fogging and high photocatalytic activity. Tape peeling test, sponge washing test, and high temperature and moisture proof test showed favorable robustness and functional durability of the thin films, which make them extremely attractive for applications in lenses, photovoltaic cells and windows of high-rise buildings. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr02467f

  8. Two Optical Techniques Appropriate for Visualizing the Steady/Unsteady Vortical Flow Past a Highly Swept Delta—Wing Equipped with Double Vortex—Flaps in Low and High Speed Wind—Tunnel

    Institute of Scientific and Technical Information of China (English)

    GongNI; DingdingXIN; 等

    1998-01-01

    For a better understanding of the vortical flow past a highly swept deltawing equipped with double vortex-flaps,two optical techniques including the Laser-light-sheet with artificial particals put in the test-section and the Schlieren photography were used for steady/unsteady flow visualization in the low and high speed wind-tunnel respectively.SIne these techniques are seldom used for vortical flow visualization in the mentioned cases in our country.our success has the significance to indicate that they are appropriate for visualizing the development ,mutual interaction and bresk-down of the vortices appear in the complex flow field.In this paper,besides the experimental procedure,merits and demerits of these two techniques are discussed through comparisons.

  9. Mechanics of anisotropic spring networks

    Science.gov (United States)

    Zhang, T.; Schwarz, J. M.; Das, Moumita

    2014-12-01

    We construct and analyze a model for a disordered linear spring network with anisotropy. The modeling is motivated by, for example, granular systems, nematic elastomers, and ultimately cytoskeletal networks exhibiting some underlying anisotropy. The model consists of a triangular lattice with two different bond occupation probabilities, px and py, for the linear springs. We develop an effective medium theory (EMT) to describe the network elasticity as a function of px and py. We find that the onset of rigidity in the EMT agrees with Maxwell constraint counting. We also find beyond linear behavior in the shear and bulk modulus as a function of occupation probability in the rigid phase for small strains, which differs from the isotropic case. We compare our EMT with numerical simulations to find rather good agreement. Finally, we discuss the implications of extending the reach of effective medium theory as well as draw connections with prior work on both anisotropic and isotropic spring networks.

  10. Motor gasoline assessment, Spring 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-07-01

    The springs of 1996 and 1997 provide an excellent example of contrasting gasoline market dynamics. In spring 1996, tightening crude oil markets pushed up gasoline prices sharply, adding to the normal seasonal gasoline price increases; however, in spring 1997, crude oil markets loosened and crude oil prices fell, bringing gasoline prices down. This pattern was followed throughout the country except in California. As a result of its unique reformulated gasoline, California prices began to vary significantly from the rest of the country in 1996 and continued to exhibit distinct variations in 1997. In addition to the price contrasts between 1996 and 1997, changes occurred in the way in which gasoline markets were supplied. Low stocks, high refinery utilizations, and high imports persisted through 1996 into summer 1997, but these factors seem to have had little impact on gasoline price spreads relative to average spread.

  11. Spring harvest of corn stover

    Energy Technology Data Exchange (ETDEWEB)

    Lizotte, P.L. [Laval Univ., Quebec City, PQ (Canada). Dept. des sols et de genie agroalimentaire; Savoie, P. [Agriculture and Agri-Food Canada, Quebec City, PQ (Canada)

    2010-07-01

    Corn stover is typically left behind in the field after grain harvest. Although part of the stover should remain in the field for soil organic matter renewal and erosion protection, half of the stover could be removed sustainably. This represents about one million t dry matter (DM) of stover per year in the province of Quebec. Stover harvested in the fall is very wet. While there are applications for wet stover, the available markets currently require a dry product. Preliminary measurements have shown that stover left in the field throughout the winter becomes very dry, and a considerable amount would still be harvestable in the spring. In the spring of 2009, corn stover was harvested at 2 sites, each subdivided into 2 parcels. The first parcel was cut and raked in the fall of 2008 (fall parcel), while the second parcel was cut and raked in spring 2009. Fibre from both parcels was baled in the spring 2009. At the first site, a large square baler was used in late April to produce bales measuring 0.8 m x 0.9 m x 1.8 m. On the second site a round baler was used in late May to produce bales of 1.2 m in width by 1.45 m in diameter. On the second site, a small square baler was also used to produce bales of 0.35 m x 0.45 m x 0.60 m (spring cutting only). With the large square baler, an average of 3.9 t DM/ha was harvested equally on the fall parcel and the spring parcel, representing a 48 per cent recovery of biomass based on stover yields.

  12. A 200 kHz Q-Switched Adhesive-Free Bond Composite Nd:YVO4 Laser using a Double-Crystal RTP Electro-optic Modulator

    Institute of Scientific and Technical Information of China (English)

    YU Yong-Ji; CHEN Xin-Yu; WANG Chao; WU Chun-Ting; LIU Rui; JIN Guang-Yong

    2012-01-01

    A diode-end-pumped electro-optic (EO) Q-switched adhesive-free bond composite Nd:YVO4 laser operating at a repetition rate of 200 kHz is reported. A pair of RbTiOPOi (RTP) crystals are used as a high repetition EO Q-switch. At the repetition rate of 200kHz, the maximum average output power of 11.8 W at wavelength 1064 nm and full width at half maximum of pulses of 16.65 ns are achieved at an incident pump power of 27 W, corresponding to an optical conversion efficiency of 43.7% and a slope efficiency of 44.6%, respectively. To the best of our knowledge, this is the highest repetition rate reported on the EO Q-switched laser by using RTP crystals.%A diode-end-pumped electro-optic (EO) Q-switched adhesive-free bond composite Nd:YVO4 laser operating at a repetition rate of 200 kHz is reported.A pair of RbTiOPO4 (RTP) crystals are used as a high repetition EO Q-switch.At the repetition rate of 200kHz,the maximum average output power of 11.8 W at wavelength 1064 nm and full width at half maximum of pulses of 16.65ns are achieved at an incident pump power of 27 W,corresponding to an optical conversion efficiency of 43.7% and a slope efficiency of 44.6%,respectively.To the best of our knowledge,this is the highest repetition rate reported on the EO Q-switched laser by using RTP crystals.

  13. Yarn Expo Spring Concluded the Spring Fair in Beijing Successfully

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    @@ As the 2009 Yarn Expo Spring, organized by Messe Frankfurt (HK) Ltd, the Sub-Council of Textile Industry - CCPIT, China Cotton Textile Association, China Wool Textile Association, China Chemical Fibers Association, China Bast & Leaf Fiber Textiles Association, and China Textile Information Centre, came to an end on 1 April, the organizers had something to smile about.

  14. Instant Spring for Android starter

    CERN Document Server

    Dahanne, Anthony

    2013-01-01

    Packt Instant Starter: get to grips with a new technology, understand what it is and what it can do for you, and then get to work with the most important features and tasks.This is a Starter which gives you an introduction to Spring for Android with plenty of well-explained practical code examples.If you are an Android developer who wants to learn about RESTful web services and OAuth authentication and authorization, and you also want to know how to speed up your development involving those architectures using Spring for Android abstractions, then this book is for you.But core Java developers

  15. SPring-8 twin helical undulator.

    Science.gov (United States)

    Hara, T; Tanaka, T; Tanabe, T; Maréchal, X M; Kumagai, K; Kitamura, H

    1998-05-01

    There are several ways of producing circularly polarized light, such as using asymmetric devices, crossed undulators etc. The SPring-8 helical undulator introduces a simple way of producing both horizontal and vertical fields in one undulator. All the magnet arrays are arranged above and below the plane of the electron orbit, so there is no limitation of access from the sides of the undulator. For the SPring-8 BL25SU, two helical undulators will be installed in tandem, and the helicity of the polarization can be switched at up to 10 Hz using five kicker magnets.

  16. Surface science station of the infrared beamline at SPring-8

    CERN Document Server

    Sakurai, M; Kimura, H; Nishida, S; Nanba, T

    2001-01-01

    An experimental station for surface science has been constructed at the infrared beamline (BL43IR) of SPring-8, Japan. The station utilizes synchrotron radiation in the energy range of 100-20000 cm sup - sup 1 to perform infrared reflection absorption spectroscopy (IRAS) of surfaces. It consists of an experimental section, a preparation chamber, gas handling equipment and a pair of focusing optics. In situ observation of vibrational spectra is possible using both IRAS and high-resolution electron energy loss spectroscopy.

  17. A Biochemical Double Slit

    Science.gov (United States)

    Kominis, Iannis

    2011-03-01

    Radical-ion-pair reactions, fundamental in photosynthesis and at the basis of the avian magnetic compass mechanism, have been recently shown to offer a rich playground for applying methods and concepts from quantum measurement/quantum information science. We will demonstrate that radical-ion-pair reactions are almost the exact analog of the optical double slit experiment, i.e. Nature has already engineered biochemical reactions performing the act of quantum interference. We will further elaborate on the non-trivial quantum effects pertaining in these reactions and the recent debate on their fundamental theoretical description that these effects have sparked.

  18. A compact optical fiber positioner

    Science.gov (United States)

    Hu, Hongzhuan; Wang, Jianping; Liu, Zhigang; Zhou, Zengxiang; Zhai, Chao; Chu, Jiaru

    2016-07-01

    In this paper, a compact optical fiber positioner is proposed, which is especially suitable for small scale and high density optical fiber positioning. Based on the positioning principle of double rotation, positioner's center shaft depends on planetary gear drive principle, meshing with the fixed annular gear central motor gear driving device to rotate, and the eccentric shaft rotated driving by a coaxial eccentric motor, both center and the eccentric shaft are supported by a rolling bearings; center and eccentric shaft are both designed with electrical zero as a reference point, and both of them have position-limiting capability to ensure the safety of fiber positioning; both eccentric and center shaft are designed to eliminating clearance with spring structure, and can eliminate the influence of gear gap; both eccentric and center motor and their driving circuit can be installed in the positioner's body, and a favorable heat sink have designed, the heat bring by positioning operation can be effectively transmit to design a focal plane unit through the aluminum component, on sleeve cooling spiral airway have designed, when positioning, the cooling air flow is inlet into install hole on the focal plate, the cooling air flow can effectively take away the positioning's heat, to eliminate the impact of the focus seeing. By measuring position device's sample results show that: the unit accuracy reached 0.01mm, can meet the needs of fiber positioning.

  19. Enhanced optical properties of InAs/InAlGaAs/InP quantum dots grown by metal-organic chemical vapor deposition using a double-cap technique

    Science.gov (United States)

    Shi, Bei; Lau, Kei May

    2016-01-01

    The effects of a double-cap procedure on the optical properties of an InAs/InAlGaAs quantum dots (QDs) system grown by metal-organic chemical vapor deposition (MOCVD) have been investigated by atomic force microscopy (AFM) and room temperature photoluminescence (RT-PL) spectroscopy. An optimized QD growth condition has been achieved, with an areal density of 4.6×1010 cm-2. It was found that the thickness and lattice constant of the high temperature second cap layer (SCL) were crucial for improving the integrated PL intensity and line-width of the 1.55 μm emission from the InAs/InAlGaAs QD system grown on a semi-insulating InP (100) substrate. With fine-tuned SCL thickness and lattice constant, the optical performance of the five-stack QDs was enhanced. The improvements can be attributed to the smooth growth front, observed from the AFM images, and the well-balanced stress engineering.

  20. Finding Spring on Planet X

    Science.gov (United States)

    Simoson, Andrew J.

    2007-01-01

    For a given orbital period and eccentricity, we determine the maximum time lapse between the winter solstice and the spring equinox on a planet. In addition, given an axial precession path, we determine the effects on the seasons. This material can be used at various levels to illustrate ideas such as periodicity, eccentricity, polar coordinates,…

  1. Sources of antibiotics: Hot springs.

    Science.gov (United States)

    Mahajan, Girish B; Balachandran, Lakshmi

    2017-06-15

    The discovery of antibiotics heralded an era of improved health care. However, the over-prescription and misuse of antibiotics resulted in the development of resistant strains of various pathogens. Since then, there has been an incessant search for discovering novel compounds from bacteria at various locations with extreme conditions. The soil is one of the most explored locations for bioprospecting. In recent times, hypersaline environments and symbiotic associations have been investigated for novel antimicrobial compounds. Among the extreme environments, hot springs are comparatively less explored. Many researchers have reported the presence of microbial life and secretion of antimicrobial compounds by microorganisms in hot springs. A pioneering research in the corresponding author's laboratory resulted in the identification of the antibiotic Fusaricidin B isolated from a hot spring derived eubacteria, Paenibacillus polymyxa, which has been assigned a new application for its anti-tubercular properties. The corresponding author has also reported anti-MRSA and anti-VRE activity of 73 bacterial isolates from hot springs in India. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Finding Spring on Planet X

    Science.gov (United States)

    Simoson, Andrew J.

    2007-01-01

    For a given orbital period and eccentricity, we determine the maximum time lapse between the winter solstice and the spring equinox on a planet. In addition, given an axial precession path, we determine the effects on the seasons. This material can be used at various levels to illustrate ideas such as periodicity, eccentricity, polar coordinates,…

  3. NOVA Spring 2000 Teacher's Guide.

    Science.gov (United States)

    Colombo, Luann; Gregoire, Tanya; Ransick, Kristina; Sammons, Fran Lyons; Sammons, James

    This teacher's guide complements six programs that aired on the Public Broadcasting System (PBS) in the spring of 2000. Programs include: (1) "Lost on Everest"; (2) "Lost Tribes of Israel"; (3) "Crocodiles"; (4) "Lost at Sea: The Search for Longitude"; (5) "Global Warming"; and (6) "Secrets of…

  4. Spring for It: First Novels

    Science.gov (United States)

    Hoffert, Barbara

    2010-01-01

    How do publishers describe the first novels they will be releasing this spring and summer? "Amazing," "fabulous," and "unique" are words that pop up frequently, though hats off to one publicist forthright or cheeky enough to call a work "weird Western/horror." The proof of such praise is in the reading, but why not check out this preview of first…

  5. Spring for It: First Novels

    Science.gov (United States)

    Hoffert, Barbara

    2010-01-01

    How do publishers describe the first novels they will be releasing this spring and summer? "Amazing," "fabulous," and "unique" are words that pop up frequently, though hats off to one publicist forthright or cheeky enough to call a work "weird Western/horror." The proof of such praise is in the reading, but why not check out this preview of first…

  6. The analytical investigation of the super-Gaussian pump source on the thermal, stress and thermo-optics properties of double-clad Yb:glass fiber lasers

    Indian Academy of Sciences (India)

    H Nadgaran; P Elahi

    2005-07-01

    Fiber lasers have attracted considerable attention when their power can realistically be scaled to kilowatt level and beyond. In this paper, we assumed that the fiber core and first clad are exposed to a pump source with a super-Gaussian profile of order four. The effects of this non-uniform heat deposition on thermal, stress and thermo-optics properties such as temperature-dependent change of refractive index and thermally induced stress have been comprehensively studied and their equations analytically derived.

  7. Double lens device for tunable harmonic generation of laser beams in KBBF/RBBF crystals or other non-linear optic materials

    Energy Technology Data Exchange (ETDEWEB)

    Kaminski, Adam

    2017-08-22

    A method and apparatus to generate harmonically related laser wavelengths includes a pair of lenses at opposing faces of a non-linear optical material. The lenses are configured to promote incoming and outgoing beams to be normal to each outer lens surface over a range of acceptance angles of the incoming laser beam. This reduces reflection loss for higher efficiency operation. Additionally, the lenses allow a wider range of wavelengths for lasers for more universal application. Examples of the lenses include plano-cylindrical and plano-spherical form factors.

  8. Double supergeometry

    CERN Document Server

    Cederwall, Martin

    2016-01-01

    A geometry of superspace corresponding to double field theory is developed, with type II supergravity in D=10 as the main example. The formalism is based on an orthosymplectic extension OSp(d,d|2s) of the continuous T-duality group. Covariance under generalised super-diffeomorphisms is manifest. Ordinary superspace is obtained as a solution of the orthosymplectic section condition. A systematic study of curved superspace Bianchi identities is performed, and a relation to a double pure spinor superfield cohomology is established. A Ramond-Ramond superfield is constructed as an infinite-dimensional orthosymplectic spinor. Such objects in minimal orbits under the OSp supergroup ("pure spinors") define super-sections.

  9. Double screening

    Energy Technology Data Exchange (ETDEWEB)

    Gratia, Pierre [Department of Physics, University of Chicago,South Ellis Avenue, Chicago, IL 60637 (United States); Hu, Wayne [Department of Astronomy and Astrophysics, University of Chicago,South Ellis Avenue, Chicago, IL 60637 (United States); Enrico Fermi Institute and Kavli Institute for Cosmological Physics, University of Chicago,South Ellis Avenue, Chicago, IL 60637 (United States); Joyce, Austin [Enrico Fermi Institute and Kavli Institute for Cosmological Physics, University of Chicago,South Ellis Avenue, Chicago, IL 60637 (United States); Ribeiro, Raquel H. [School of Physics and Astronomy, Queen Mary University of London,Mile End Road, London, E1 4NS (United Kingdom)

    2016-06-15

    Attempts to modify gravity in the infrared typically require a screening mechanism to ensure consistency with local tests of gravity. These screening mechanisms fit into three broad classes; we investigate theories which are capable of exhibiting more than one type of screening. Specifically, we focus on a simple model which exhibits both Vainshtein and kinetic screening. We point out that due to the two characteristic length scales in the problem, the type of screening that dominates depends on the mass of the sourcing object, allowing for different phenomenology at different scales. We consider embedding this double screening phenomenology in a broader cosmological scenario and show that the simplest examples that exhibit double screening are radiatively stable.

  10. Identifying anomalously early spring onsets in the CESM large ensemble project

    Science.gov (United States)

    Labe, Zachary; Ault, Toby; Zurita-Milla, Raul

    2016-08-01

    Seasonal transitions from winter to spring impact a wide variety of ecological and physical systems. While the effects of early springs across North America are widely documented, changes in their frequency and likelihood under the combined influences of climate change and natural variability are poorly understood. Extremely early springs, such as March 2012, can lead to severe economical losses and agricultural damage when these are followed by hard freeze events. Here we use the new Community Earth System Model Large Ensemble project and Extended Spring Indices to simulate historical and future spring onsets across the United States and in the particular the Great Lakes region. We found a marked increase in the frequency of March 2012-like springs by midcentury in addition to an overall trend towards earlier spring onsets, which nearly doubles that of observational records. However, changes in the date of last freeze do not occur at the same rate, therefore, causing a potential increase in the threat of plant tissue damage. Although large-scale climate modes, such as the Pacific Decadal Oscillation, have previously dominated decadal to multidecadal spring onset trends, our results indicate a decreased role in natural climate variability and hence a greater forced response by the end of the century for modulating trends. Without a major reduction in greenhouse gas emissions, our study suggests that years like 2012 in the US could become normal by mid-century.

  11. A Low Frequency FBG Accelerometer with Symmetrical Bended Spring Plates

    Directory of Open Access Journals (Sweden)

    Fufei Liu

    2017-01-01

    Full Text Available To meet the requirements for low-frequency vibration monitoring, a new type of FBG (fiber Bragg grating accelerometer with a bended spring plate is proposed. Two symmetrical bended spring plates are used as elastic elements, which drive the FBG to produce axial strains equal in magnitude but opposite in direction when exciting vibrations exist, leading to doubling the wavelength shift of the FBG. The mechanics model and a numerical method are presented in this paper, with which the influence of the structural parameters on the sensitivity and the eigenfrequency are discussed. The test results show that the sensitivity of the accelerometer is more than 1000 pm/g when the frequency is within the 0.7–20 Hz range.

  12. A Low Frequency FBG Accelerometer with Symmetrical Bended Spring Plates

    Science.gov (United States)

    Liu, Fufei; Dai, Yutang; Karanja, Joseph Muna; Yang, Minghong

    2017-01-01

    To meet the requirements for low-frequency vibration monitoring, a new type of FBG (fiber Bragg grating) accelerometer with a bended spring plate is proposed. Two symmetrical bended spring plates are used as elastic elements, which drive the FBG to produce axial strains equal in magnitude but opposite in direction when exciting vibrations exist, leading to doubling the wavelength shift of the FBG. The mechanics model and a numerical method are presented in this paper, with which the influence of the structural parameters on the sensitivity and the eigenfrequency are discussed. The test results show that the sensitivity of the accelerometer is more than 1000 pm/g when the frequency is within the 0.7–20 Hz range. PMID:28117740

  13. Portrait of a Geothermal Spring, Hunter's Hot Springs, Oregon.

    Science.gov (United States)

    Castenholz, Richard W

    2015-01-27

    Although alkaline Hunter's Hot Springs in southeastern Oregon has been studied extensively for over 40 years, most of these studies and the subsequent publications were before the advent of molecular methods. However, there are many field observations and laboratory experiments that reveal the major aspects of the phototrophic species composition within various physical and chemical gradients of these springs. Relatively constant temperature boundaries demark the upper boundary of the unicellular cyanobacterium, Synechococcus at 73-74 °C (the world-wide upper limit for photosynthesis), and 68-70 °C the upper limit for Chloroflexus. The upper limit for the cover of the filamentous cyanobacterium, Geitlerinema (Oscillatoria) is at 54-55 °C, and the in situ lower limit at 47-48 °C for all three of these phototrophs due to the upper temperature limit for the grazing ostracod, Thermopsis. The in situ upper limit for the cyanobacteria Pleurocapsa and Calothrix is at ~47-48 °C, which are more grazer-resistant and grazer dependent. All of these demarcations are easily visible in the field. In addition, there is a biosulfide production in some sections of the springs that have a large impact on the microbiology. Most of the temperature and chemical limits have been explained by field and laboratory experiments.

  14. Optical security system using jigsaw transforms of the second random phase mask and the encrypted image in a double random phase encoding system

    Science.gov (United States)

    Singh, Madan; Kumar, Arvind; Singh, Kehar

    2008-10-01

    In this paper, we have described a simple and secure double random phase encoding and decoding system to encrypt and decrypt a two-dimensional gray scale image. We have used jigsaw transforms of the second random phase mask and the encrypted image. The random phase mask placed in the Fourier plane is broken into independent non-overlapping segments by applying the jigsaw transform. To make the system more secure, a jigsaw transform on the encrypted image is also carried out. The encrypted image is also broken into independent non-overlapping segments. The jigsaw transform indices of random phase code and the encrypted image form the keys for the successful retrieval of the data. Encrypting with this technique makes it almost impossible to retrieve the image without using both the right keys. Results of computer simulation have been presented in support of the proposed idea. Mean square error (MSE) between the decrypted and the original image has also been calculated in support of the technique.

  15. RPR-SDH双光纤通信传输系统的设计及应用%RPR'SDH Double Optical Fiber Communication System Design and Application

    Institute of Scientific and Technical Information of China (English)

    周磊; 李扬

    2011-01-01

    In this paper, for a single set of power optical fiber communication system in various faults and security risks,we integrate the most widely used RPR and SDH technology ,upgrade and optimize the network through computer technology.The successful applicat%本文针对电力通信中单套光纤传输系统存在的各种故障和安全风险,融合应用最广泛的RPR和SDH技术,综合运用计算机技术对网络进行升级和优化,成功应用了RPR-SDH双光纤通信传输系统。这对提高电力通信的安全可靠性具有十分重要的指导意义。

  16. Numerical Optimization of Tunnel-recombination Junction and Optical Absorption Properties of a-Si:H/a-SiGe:H Double-junction Solar Cell

    Institute of Scientific and Technical Information of China (English)

    KE Shaoying; WANG Chong; PAN Tao; WANG Zhaoqing; YANG Jie; YANG Yu

    2015-01-01

    The tunnel-recombination junction (TRJ) and optical absorption properties of a-Si:H/a-SiGe:H dou-ble-junction solar cell were calculated by means of one dimensional simulator named AMPS-1D at the radiation of AM1.5G with a power density of 100 mW/cm2. Since the TRJ is the core component of the tandem solar cell, the optical absorption of the sub-cells and the electronic transport properties at the interface of the sub-cells are affected by the thickness and doping concentration of the TRJ. As a result, the TRJ parameters were optimized. The numerical results indicate that the maximum conversion efficiency (Ef) of 9.862% can be obtained when the thickness and doping con-centration of the TRJ are 10 nm and 5´1019 cm–3, respectively. Based on the analysis of the contour map of short circuit current density, the optimal current matching can be achieved for 130 nm-thick topi-layer and 250 nm-thick bottom i-layer. In addition, four kinds of TRJ structures were also simulated for the comparison purpose. According to the cal-culated resistivity and band structures of the four TRJs, the efficiency of the solar cell withn-typeμc-Si:H layer and p-type a-Si:H layer in TRJ structure is greater than that with other TRJ structures. It is assumed that the effect of the band offset that results in the formation of triangular barrier and backscattering behavior at the edge of the TRJ could be responsible to this phenomenon.

  17. Colloidal Double Quantum Dots.

    Science.gov (United States)

    Teitelboim, Ayelet; Meir, Noga; Kazes, Miri; Oron, Dan

    2016-05-17

    Pairs of coupled quantum dots with controlled coupling between the two potential wells serve as an extremely rich system, exhibiting a plethora of optical phenomena that do not exist in each of the isolated constituent dots. Over the past decade, coupled quantum systems have been under extensive study in the context of epitaxially grown quantum dots (QDs), but only a handful of examples have been reported with colloidal QDs. This is mostly due to the difficulties in controllably growing nanoparticles that encapsulate within them two dots separated by an energetic barrier via colloidal synthesis methods. Recent advances in colloidal synthesis methods have enabled the first clear demonstrations of colloidal double quantum dots and allowed for the first exploratory studies into their optical properties. Nevertheless, colloidal double QDs can offer an extended level of structural manipulation that allows not only for a broader range of materials to be used as compared with epitaxially grown counterparts but also for more complex control over the coupling mechanisms and coupling strength between two spatially separated quantum dots. The photophysics of these nanostructures is governed by the balance between two coupling mechanisms. The first is via dipole-dipole interactions between the two constituent components, leading to energy transfer between them. The second is associated with overlap of excited carrier wave functions, leading to charge transfer and multicarrier interactions between the two components. The magnitude of the coupling between the two subcomponents is determined by the detailed potential landscape within the nanocrystals (NCs). One of the hallmarks of double QDs is the observation of dual-color emission from a single nanoparticle, which allows for detailed spectroscopy of their properties down to the single particle level. Furthermore, rational design of the two coupled subsystems enables one to tune the emission statistics from single photon

  18. Fish Springs NWR Water Use Report : 2010

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Fish Springs National Wildlife Refuge (NWR) for 2010. A general background is presented on historical spring water...

  19. Double Imbalance

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The government has been introducing a string of policies to stabilize the economy and cushion the impact of the global eco-nomic slowdown since October.These policies are generally deemed"timely"and"necessary,"but not a long-term cure for problems in China’s economy.Renowned economist Wu Jinglian says the country must address its"double imbalance"and further reform its economic growth mode.He made his comments at the First Annual Global Management Forum on December 6 in Shanghai.Excerptsf ollow:

  20. Top 5 Spring Festival Customs in China

    Institute of Scientific and Technical Information of China (English)

    梁小明

    2016-01-01

    The Spring Festival is the largest and most important festival in China.It is the first day of the lunar calendar~1 and usually occurs somewhere between January30 and February 20,heralding~2 the beginning of spring,thus it is known as the Spring Festival.1.Spring Couplets On the Chinese New Year,families in China decorate their front doors with poetic couplets

  1. An Evaluation of Chinese Spring Festival

    Institute of Scientific and Technical Information of China (English)

    李艳蕊

    2012-01-01

    Nowadays,many Chinese people felt that Spring Festival is bored;feeling of celebrating Spring Festival is not as strong as before.Some experts stated that the physical part of Spring Festival shrouded the cultural celebrations.This article analysis the phenomenon through comparing how Chinese people had Spring Festivals in the past and now,and comparing different economic status Chinese people have in these two periods.

  2. Qatar and the Arab Spring

    KAUST Repository

    Coates Ulrichsen, Kristian

    2014-11-15

    This chapter examines how Qatar assumed an extraordinarily visible and interventionist role during the Arab Spring upheaval in 2011. It argues that, after an initial period of caution in January 2011, Qatari officials quickly recognised the changing contours of the Arab Spring and pragmatically readjusted their policy-responses. The lack of domestic constraints on decision-making enabled officials, led by the Emir and the Prime minister, to reposition Qatar (somewhat improbably) as a champion of the popular uprisings in North Africa and later as a key external player in the Syrian Civil War. The chapter also provides historical context to Qatar’s close relationship with the Muslim Brotherhood, and documents why Qatari officials saw the outbreak of the uprisings as far more of an opportunity than a challenge.

  3. ELVES Research at the Pierre Auger Observatory: Optical Emission Simulation and Time Evolution, WWLLN-LIS-Auger Correlations, and Double ELVES Observations and Simulation.

    Science.gov (United States)

    Merenda, K. D.

    2016-12-01

    Since 2013, the Pierre Auger Cosmic Ray Observatory in Mendoza, Argentina, extended its trigger algorithm to detect emissions of light consistent with the signature from very low frequency perturbations due to electromagnetic pulse sources (ELVES). Correlations with the World Wide Lightning Location Network (WWLLN), the Lightning Imaging Sensor (LIS) and simulated events were used to assess the quality of the reconstructed data. The FD is a pixel array telescope sensitive to the deep UV emissions of ELVES. The detector provides the finest time resolution of 100 nanoseconds ever applied to the study of ELVES. Four eyes, separated by approximately 40 kilometers, consist of six telescopes and span a total of 360 degrees of azimuth angle. The detector operates at night when storms are not in the field of view. An existing 3D EMP Model solves Maxwell's equations using a three dimensional finite-difference time-domain model to describe the propagation of electromagnetic pulses from lightning sources to the ionosphere. The simulation also provides a projection of the resulting ELVES onto the pixel array of the FD. A full reconstruction of simulated events is under development. We introduce the analog signal time evolution comparison between Auger reconstructed data and simulated events on individual FD pixels. In conjunction, we will present a study of the angular distribution of light emission around the vertical and above the causative lightning source. We will also contrast, with Monte Carlo, Auger double ELVES events separated by at most 5 microseconds. These events are too short to be explained by multiple return strokes, ground reflections, or compact intra-cloud lightning sources. Reconstructed ELVES data is 40% correlated to WWLLN data and an analysis with the LIS database is underway.

  4. KUNMING: The City of Spring

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    @@ Kunming is the political, economic and cultural center of Yunnan province and the most popular center for tourism in Southwest China. Kunming enjoys a pleasant climate and does its best to live up to its title of "the City of Spring". Whenever you are planning to go, the temperature is always pleasant. With its convenient transport links in and out of the city, Kunming welcomes tens of thousands of tourists every day.

  5. The Arab Spring in Jordan

    OpenAIRE

    Eriksson, Elsa Annaklara; Hansen, Ditte Ingemann

    2013-01-01

    This project contains analysis and discussion of several social movements in Jordan. The uprising in Jordan and demands for more democratization are inspired by the Arab Spring observed in the Middle East. The most highlighted Jordanian social movements being the religious Muslim Brotherhood, the radical Salafi Movement and the newly proclaimed Popular Mobilization. Questions concerning the identification of them, their goals and ways of mobilizing and the hindrances for these movements to mo...

  6. Spring Framework 5: Themes & Trends

    CERN Document Server

    CERN. Geneva

    2017-01-01

    Spring Framework 5.0/5.1, scheduled for release in early/late 2017, focuses on several key themes: reactive web applications based on Reactive Streams, comprehensive support for JDK 9 and HTTP/2, as well as the latest API generations in the Enterprise Java ecosystem. This talk presents the overall story in the context of wider industry trends, highlighting Spring’s unique programming model strategy.

  7. Controlling proteins through molecular springs.

    Science.gov (United States)

    Zocchi, Giovanni

    2009-01-01

    We argue that the mechanical control of proteins-the notion of controlling chemical reactions and processes by mechanics-is conceptually interesting. We give a brief review of the main accomplishments so far, leading to our present approach of using DNA molecular springs to exert controlled stresses on proteins. Our focus is on the physical principles that underlie both artificial mechanochemical devices and natural mechanisms of allostery.

  8. Strategic Studies Quarterly- Spring 2016

    Science.gov (United States)

    2016-01-01

    Khyber Pakhtunkhwa, bordering Afghanistan. A number of analysts agree that if conflict breaks out with India, Pakistan would immediately rede - ploy...the military should not risk its capacity to fight just to become an instrument of social progress but at the same rook pride in ending the...the " social experiments" conducted during his tenure are not yet known. The former Secretary STRATEGIC STUDIES QuARTERLY + SPRING 2016 [ 149] Book

  9. 14 CFR 27.687 - Spring devices.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Spring devices. 27.687 Section 27.687... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Control Systems § 27.687 Spring devices. (a) Each control system spring device whose failure could cause flutter or other unsafe...

  10. 14 CFR 23.687 - Spring devices.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Spring devices. 23.687 Section 23.687 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... Systems § 23.687 Spring devices. The reliability of any spring device used in the control system must...

  11. 14 CFR 29.687 - Spring devices.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Spring devices. 29.687 Section 29.687... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Control Systems § 29.687 Spring devices. (a) Each control system spring device whose failure could cause flutter or other unsafe...

  12. Spring-forward in composite plate elements

    NARCIS (Netherlands)

    Wijskamp, Sebastiaan; Lamers, E.A.D.; Akkerman, Remko; Banabic, D.

    2005-01-01

    Spring-forward is a distortion of corner sections in continuous fibre reinforced composite products. The linear thermoelastic prediction for the spring-forward of single curved geometries is incorporated in a FE formulation for plate elements in order to simulate the spring-forward of doubly curved

  13. Radon in Himalayan springs: a geohydrological control

    Energy Technology Data Exchange (ETDEWEB)

    Choubey, V.M.; Bartarya, S.K. [Wadia Inst. of Himalayan Geology, Dehra Dun (India); Ramola, R.C. [Garhwal Univ., Srinagar, Uttar Pradesh (India). Dept. of Physics

    2000-04-01

    This paper presents the results of radon measurements in springs of the Himalayan region by using radon emanometry technique. The radon was measured in different springs, draining from different geohydrological setups, and from stream water in order to find the geohydrological control over radon concentration in groundwater emanating in the form of spring. The radon values were found to vary from 0.4 Bq/l to 887 Bq/l, being observed lowest for a turbulent stream and highest for the spring. The radon values were recorded highest in the springs draining through gneiss, granite, mylonite, etc. Radon concentrations have been related with four spring types viz. fracture-joint related spring, fault-lineament related spring, fluvial related spring and colluvial related spring, showing geohydrological characteristics of the rocks through which they are emanating. The high radon concentration in fracture-joint and fault-lineament springs is related to increased ratio of rock surface area to water volume and uranium mineralisation in the shear zones present in the close vicinity of fault and thrust. The low concentration of radon in fluvial and colluvial springs is possibly because of high transmissivity and turbulent flow within such deposits leading to natural de-emanation of gases. (orig.)

  14. Spring-forward in composite plate elements

    NARCIS (Netherlands)

    Wijskamp, S.; Lamers, E.A.D.; Akkerman, R.

    2005-01-01

    Spring-forward is a distortion of corner sections in continuous fibre reinforced composite products. The linear thermoelastic prediction for the spring-forward of single curved geometries is incorporated in a FE formulation for plate elements in order to simulate the spring-forward of doubly curved

  15. 49 CFR 236.822 - Switch, spring.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Switch, spring. 236.822 Section 236.822 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Switch, spring. A switch equipped with a spring device which forces the points to their original...

  16. Skillful Use of Imagery in Two Odes to Spring--Comment on The Soote Season and Spring, the Sweet Spring

    Institute of Scientific and Technical Information of China (English)

    冯海荣

    2002-01-01

    The Soote Season and Spring, the Sweet Spring are two lyrics that sing the praise of spring. The common feature of the two lyrics is that the two poets depict a series of pictures of the sweet spring by rich and varied imagery for readers.When these pictures are presented to readers ,readers feel as if they are participating in them,and the enchanting beauty of spring makes readers feel intoxicated with happiness. The two poets express their different feelings toward nature.

  17. The first CERN Spring Campus

    CERN Multimedia

    CERN Bulletin

    2014-01-01

    From 14 to 16 April, the first edition of the CERN Spring Campus took place in Spain. Taking place over three intensive days, this event brought experts from CERN together at the University of Oviedo, where they met the engineers and scientists of the future in a programme of scientific and technological dissemination and cultural exchange.   The young participants of the first CERN Spring Campus and their instructors show their enthusiasm after the intensive three-day course. “This three-day school focuses on preparing young engineers for the job market, with a particular emphasis on computing,” explains Derek Mathieson, Advanced Information Systems Group Leader in the GS Department and Head of the CERN Spring Campus organising committee. “We organised talks on entrepreneurship and IT, as well as on job interviews and CV writing. It was also an important opportunity for the participants to meet CERN computing engineers to find out what it is like to work in I...

  18. Disaggregation modelling of spring discharges

    Directory of Open Access Journals (Sweden)

    Kirilova Bojilova Elena

    2004-12-01

    Full Text Available Disaggregation models are basically divided into three main groups: temporal, spatial and temporal-spatial. The focus of this paper is the application of temporal disaggregation models to disaggregate the seasonal flow in some large time intervals to sub-seasonal flows in some shorter time intervals. Two basic models are applied: the original model of Mejia and Rousselle and the corrected extended Lin model one-stage disaggregation. The flow totals from some karstic springs are used. Data for five springs in different areas of Bulgaria for the aims of the study are executed. The synthetic data generation for the chosen spring stations for a new realisation of thirty years is obtained. The multi-variate lag-one auto regressive model (AR(1 model is applied for generation of the annual flow sequences. The Lin model single- site is performed for thirty years generation period. The Lin model is an improvement compared to the original extended model. The new Lin approach succeeds in the preservation of the additivity as well as the moments. Applying the Lin model one-stage disaggregation results in consistent model parameter estimates. As a second step in the research multi-site disaggregation schemes are also applied.

  19. Analysis of carrier behavior in C60/P(VDF-TrFE) double-layer capacitor by using electric-field-induced optical second-harmonic generation measurement

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Xiaojin [Department of Physical Electronics, Tokyo Institute of Technology 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8552 (Japan); State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Taguchi, Dai; Manaka, Takaaki; Iwamoto, Mitsumasa, E-mail: iwamoto@pe.titech.ac.jp [Department of Physical Electronics, Tokyo Institute of Technology 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8552 (Japan)

    2013-12-21

    By using displacement current measurement (DCM) and electric-field-induced optical second-harmonic generation (EFISHG) measurement, we studied the carrier behavior in the indium-tin oxide (ITO)/Poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE))/C60/Au(or Al) capacitors. Two DCM peaks appeared asymmetrically at around −35.5 V and +30.0 V in the dark. Correspondingly, the EFISHG response from the C60 layer was observed, but the peak positions were different with respect to DCM ones. The results show that the spontaneous polarization of the ferroelectric P(VDF-TrFE) polymeric layer directly affects the electric field in the C60 layer, and thus governs the carrier motion in this layer. As a result, the C60 layer serves like an insulator in the dark, while electrons and holes are captured and released at the interface in response to the turn-over of spontaneous polarization of ferroelectric layer. On the other hand, under white light illumination, C60 layer serves like a conductor due to the increase of photogenerated mobile carriers, and these carriers dominate the carrier motions therein. Our findings here will be helpful for analyzing carrier behaviors in organic electronic devices using ferroelectric polymers.

  20. Effects of long-term fertilization on spring season weed community in winter fallow paddy field in red soil area under double-rice cropping system%长期施肥对红壤双季稻冬闲田春季杂草群落的影响

    Institute of Scientific and Technical Information of China (English)

    董春华; 曾希柏; 石林; 高菊生

    2015-01-01

    利用始于1982年的红壤双季稻田长期施肥定位试验,于2012年采用田间调查法研究了在无机肥(化肥 NPK)与有机肥(M)氮磷钾养分等量条件下,长期施用有机肥、无机化肥和有机肥无机肥配施模式下红壤双季稻冬闲田春季杂草生物量及群落密度和群落多样性的变化。结果表明:有机肥无机肥配施改变了优势杂草种类,增加了杂草总密度和总生物量。化肥氮钾配施有机肥(NKM)处理的杂草种类数量最多,化肥氮磷配施有机肥(NPM)处理的最少。施肥处理中, M处理的杂草群落多样性指数、均匀度指数和优势度指数均最高,分别为1.1186、0.7323和0.6297;其杂草总密度最低,为297.0株×0.25m-2。NPK处理的杂草总生物量最低,为58.0 g×0.25m-2。NPM处理的杂草群落多样性指数值、均匀度及优势度指数值均显著低于其他处理;其杂草总密度和杂草总生物量均最高,分别为539.7株×0.25m-2和109.5 g×0.25m-2;其优势杂草日本看麦娘的密度为428.0株×0.25m-2,相对密度为79.31%,明显高于其他处理优势杂草的密度和相对密度。春季杂草总干物质量与土壤碱解氮正相关(相关系数为0.703),与土壤 pH 负相关(相关系数为0.697),相关性不显著;与土壤有效磷显著正相关(相关系数为0.758*)。长期不同施肥模式下红壤稻田磷素是导致田间春季杂草群落特征变化的主要因素,通过改变土壤有效磷和碱解氮含量及土壤pH,能有效调控红壤双季稻冬闲田春季杂草生物量及群落密度和生物多样性。%An investigation in winter fallow field of double-rice cropping system in the red soil area was carried out in 2012 in a long-term fertilization experiment (started in 1982) site in Hengyang Red Soil Experiment Station of Chinese Academy of Agricultural Sciences to study the species, biomass and biodiversity of weed communities during spring season. The investigated long

  1. Spring Recipes A Problem-solution Approach

    CERN Document Server

    Long, Josh; Mak, Gary

    2010-01-01

    With over 3 Million users/developers, Spring Framework is the leading "out of the box" Java framework. Spring addresses and offers simple solutions for most aspects of your Java/Java EE application development, and guides you to use industry best practices to design and implement your applications. The release of Spring Framework 3 has ushered in many improvements and new features. Spring Recipes: A Problem-Solution Approach, Second Edition continues upon the bestselling success of the previous edition but focuses on the latest Spring 3 features for building enterprise Java applications.

  2. Double acting bit holder

    Science.gov (United States)

    Morrell, Roger J.; Larson, David A.; Ruzzi, Peter L.

    1994-01-01

    A double acting bit holder that permits bits held in it to be resharpened during cutting action to increase energy efficiency by reducing the amount of small chips produced. The holder consist of: a stationary base portion capable of being fixed to a cutter head of an excavation machine and having an integral extension therefrom with a bore hole therethrough to accommodate a pin shaft; a movable portion coextensive with the base having a pin shaft integrally extending therefrom that is insertable in the bore hole of the base member to permit the moveable portion to rotate about the axis of the pin shaft; a recess in the movable portion of the holder to accommodate a shank of a bit; and a biased spring disposed in adjoining openings in the base and moveable portions of the holder to permit the moveable portion to pivot around the pin shaft during cutting action of a bit fixed in a turret to allow front, mid and back positions of the bit during cutting to lessen creation of small chip amounts and resharpen the bit during excavation use.

  3. Comparative spring mechanics in mantis shrimp.

    Science.gov (United States)

    Patek, S N; Rosario, M V; Taylor, J R A

    2013-04-01

    Elastic mechanisms are fundamental to fast and efficient movements. Mantis shrimp power their fast raptorial appendages using a conserved network of exoskeletal springs, linkages and latches. Their appendages are fantastically diverse, ranging from spears to hammers. We measured the spring mechanics of 12 mantis shrimp species from five different families exhibiting hammer-shaped, spear-shaped and undifferentiated appendages. Across species, spring force and work increase with size of the appendage and spring constant is not correlated with size. Species that hammer their prey exhibit significantly greater spring resilience compared with species that impale evasive prey ('spearers'); mixed statistical results show that species that hammer prey also produce greater work relative to size during spring loading compared with spearers. Disabling part of the spring mechanism, the 'saddle', significantly decreases spring force and work in three smasher species; cross-species analyses show a greater effect of cutting the saddle on the spring force and spring constant in species without hammers compared with species with hammers. Overall, the study shows a more potent spring mechanism in the faster and more powerful hammering species compared with spearing species while also highlighting the challenges of reconciling within-species and cross-species mechanical analyses when different processes may be acting at these two different levels of analysis. The observed mechanical variation in spring mechanics provides insights into the evolutionary history, morphological components and mechanical behavior, which were not discernible in prior single-species studies. The results also suggest that, even with a conserved spring mechanism, spring behavior, potency and component structures can be varied within a clade with implications for the behavioral functions of power-amplified devices.

  4. Electro-optical properties, decomposition pathways and the hydrostatic pressure-dependent behaviours of a double-cation hydrogen storage material of Al$_3$Li$_4$(BH$_4$)$_{13}$

    Indian Academy of Sciences (India)

    MEHMET SIMSEK

    2017-09-01

    Electro-optical properties, the decomposition pathways and the pressure-dependent behaviours of Al$_3$Li$_4$(BH$_4$)$_{13}$ have been investigated using a first-principle plane-wave pseudopotential method. Al$_3$Li$_4$(BH$_4$)$_{13}$ is a kindof double-cation borohydride, consisting of distorted tetrahedral anions [Al(BH$_4$)$_4$]$^−$ and cations [Li$_4$(BH$_4$)]$^{3+}$, which obeys the stability criteria of decomposition reactions. Herein, two possible decomposition reactions of the compound are proposed, which release 18 hydrogen molecules (about 12.03 wt%) in the first reaction and 24 hydrogen molecules (about16.04 wt%) in the second reaction. On increasing the pressure on the structure, the lattice parameter, the volume of unitcell, the quasiparticle band gap and also enthalpy of the system decrease nearly monotonically; therefore, the acceptor levelsgradually get filled and the Fermi level shifts upward. Results of computational investigations of the structural, electronic andthermodynamic parameters and their pressure-dependent behaviours indicate that Al$_3$Li$_4$(BH$_4$)$_{13}$ has intriguing properties. Therefore, it would be a very promising material for hydrogen storage technology.

  5. Electronic, magnetic, and optical characteristics of half-semiconductor double perovskite oxide Sr2CrOsO6 governed by 3d (t2g3)-5d (t2g3) antiferromagnetic coupling

    Science.gov (United States)

    H.-E., M. Musa Saad

    2016-07-01

    In this study, motivated by observations of the remarkable magnetic insulating nature and high Curie temperature (TC=725 K) of double perovskite oxide Sr2CrOsO6, the electronic, magnetic, and optical characteristics of Sr2CrOsO6 were determined using the full potential linear muffin-tin orbital method according to density functional theory. The spin-orbit coupling contribution was included in the local spin density approximation (LSDA) and generalized gradient approximation (GGA). In addition, the Coulomb repulsion (U) and Hund's exchange (J) energies were considered in both methods (LSDA+U and GGA+U). Full structural optimization confirmed that the ground state of Sr2CrOsO6 is face-centered cubic (Fm-3m symmetry). Calculations predicted that Sr2CrOsO6 is ferrimagnetic half-semiconductive (HSC) due to the vertical hopping of t2g electrons via antiferromagnetic coupling [Cr3+ (t2g3↑)-O (2pπ)-Os5+ (t2g3↓)], which agreed with the experimental results. The HSC energy-gaps originate from the splitting of three partially occupied Os5+ (5d) bands into two fully filled bands and one empty spin-down band. The real ε1 (ω) and imaginary ε2 (ω) parts of the dielectric function ε (ω) and energy-loss spectrum L (ω) were calculated, analyzed, and compared with the electronic results.

  6. Application of Double Ether CAT and Optical Fiber Interlock Network in Short Circuit Protection%双层Ether CAT与光纤联锁在井下短路保护中的应用

    Institute of Scientific and Technical Information of China (English)

    赵战伟; 张伟

    2013-01-01

    Short circuit protection of high-voltage power grid in coal mine cannot realize selectivity by existing protection sys-tems. To solve the problem, a scheme based on real-time Ethernet Ether CAT and optical fiber interlock network was proposed. The system is mainly composed of double real-time Ethernet Ether CAT, optical fiber interlock network and integrated protec-tion device with Ether CAT communication interface and interlock interface. Real time Ethernet Ether CAT and optical fiber in-terlock network cooperate with each other, when one is interrupted by the failure, the other network can complete the work of system independently. Experiments show that the system can achieve short circuit protection selectivity reliably, determine the position of fault quickly, shorten troubleshooting time and improve safety and reliability of power grid system.%针对现有保护系统无法可靠实现煤矿井下高压电网短路保护的选择性,提出了一种由实时以太网Ether CAT与光纤联锁相互配合的井下短路保护方案。系统主要由双层实时以太网Ether CAT、光纤联锁网、具有Ether CAT通讯接口和联锁接口的综合保护装置等构成。实时以太网Ether CAT与光纤联锁网协同工作并互为后备,当Ether CAT或光纤联锁网通讯因故障中断时,后备网络独立实现系统功能。试验表明,系统可靠实现了井下短路保护的选择性,并能够迅速确定故障点位置,缩短故障排查时间,提高了供电网的安全性与可靠性。

  7. CACTUS SPRING ROADLESS AREA, CALIFORNIA.

    Science.gov (United States)

    Matti, Jonathan C.; Kuizon, Lucia

    1984-01-01

    Geologic, geochemical, and geophysical studies together with a review of historic mining and prospecting activities indicate that the Cactus Spring Roadless Area in California has little promise for the occurrence of mineral or energy resources. Marble bodies occur in the northern part of the roadless area and are possible resources for building stone, crushed and quarried aggregate, and lime and magnesium for Portland cement and industrial applications. It is recommended that the terrane of marble be mapped and sampled carefully in order to evaluate the quantity and quality of the carbonate resources.

  8. Corrective action investigation plan: Cactus Spring Waste Trenches. Revision 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-02-01

    This Correction Action Investigation Plan (CAIP) contains environmental sample collection objectives and logic for the Corrective Action Unit No. 426, which includes the Cactus Spring Waste Trenches, located at the Tonopah Test Range. The purpose of this investigation is to generate sufficient data to establish the types of waste buried in the trenches, identify the presence and nature of contamination, determine the vertical extent of contaminant migration below the Cactus Spring Waste Trenches, and determine the appropriate course of action for the site. The potential courses of action for the site are clean closure, closure in place (with or without remediation), or no further action. The scope of this investigation will include drilling and collecting subsurface samples from within and below the trenches. Sampling locations will be biased toward the areas most likely to be contaminated. The Cactus Spring Waste Trenches Site is identified as one of three potential locations for buried, radioactively contaminated materials from the Double Tracks Test. This test was the first of four storage-transportation tests conducted in 1963 as part of Operation Roller Coaster. The experiment involved the use of live animals to assess the inhalation intake of a plutonium aerosol.

  9. Efficient Method for Calculating the Composite Stiffness of Parabolic Leaf Springs with Variable Stiffness for Vehicle Rear Suspension

    OpenAIRE

    Wen-ku Shi; Cheng Liu; Zhi-yong Chen; Wei He; Qing-hua Zu

    2016-01-01

    The composite stiffness of parabolic leaf springs with variable stiffness is difficult to calculate using traditional integral equations. Numerical integration or FEA may be used but will require computer-aided software and long calculation times. An efficient method for calculating the composite stiffness of parabolic leaf springs with variable stiffness is developed and evaluated to reduce the complexity of calculation and shorten the calculation time. A simplified model for double-leaf spr...

  10. Slightly thermal springs and non-thermal springs at Mount Shasta, California: Chemistry and recharge elevations

    Science.gov (United States)

    Nathenson, M.; Thompson, J.M.; White, L.D.

    2003-01-01

    Temperature measurements, isotopic contents, and dissolved constituents are presented for springs at Mount Shasta to understand slightly thermal springs in the Shasta Valley based on the characteristics of non-thermal springs. Non-thermal springs on Mount Shasta are generally cooler than mean annual air temperatures for their elevation. The specific conductance of non-thermal springs increases linearly with discharge temperature. Springs at higher and intermediate elevations on Mount Shasta have fairly limited circulation paths, whereas low-elevation springs have longer paths because of their higher-elevation recharge. Springs in the Shasta Valley are warmer than air temperatures for their elevation and contain significant amounts of chloride and sulfate, constituents often associated with volcanic hydrothermal systems. Data for the Shasta Valley springs generally define mixing trends for dissolved constituents and temperature. The isotopic composition of the Shasta Valley springs indicates that water fell as precipitation at a higher elevation than any of the non-thermal springs. It is possible that the Shasta Valley springs include a component of the outflow from a proposed 210??C hydrothermal system that boils to supply steam for the summit acid-sulfate spring. In order to categorize springs such as those in the Shasta Valley, we introduce the term slightly thermal springs for springs that do not meet the numerical criterion of 10??C above air temperature for thermal springs but have temperatures greater than non-thermal springs in the area and usually also have dissolved constituents normally found in thermal waters. ?? 2002 Elsevier Science B.V. All rights reserved.

  11. Optics/Optical Diagnostics Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Optics/Optical Diagnostics Laboratory supports graduate instruction in optics, optical and laser diagnostics and electro-optics. The optics laboratory provides...

  12. Double Conditional Expectation

    Institute of Scientific and Technical Information of China (English)

    HU Di-he

    2004-01-01

    The concept of double conditional expectation is introduced. A series of properties for the double conditional expectation are obtained several convergence theorems and Jensen inequality are proved. Finally we discuss the special cases and application for double conditional expectation.

  13. Running springs: speed and animal size.

    Science.gov (United States)

    Farley, C T; Glasheen, J; McMahon, T A

    1993-12-01

    Trotting and hopping animals use muscles, tendons and ligaments to store and return elastic energy as they bounce along the ground. We examine how the musculoskeletal spring system operates at different speeds and in animals of different sizes. We model trotting and hopping as a simple spring-mass system which consists of a leg spring and a mass. We find that the stiffness of the leg spring (k(leg)) is nearly independent of speed in dogs, goats, horses and red kangaroos. As these animals trot or hop faster, the leg spring sweeps a greater angle during the stance phase, and the vertical excursion of the center of mass during the ground contact phase decreases. The combination of these changes to the spring system causes animals to bounce off the ground more quickly at higher speeds. Analysis of a wide size range of animals (0.1-140 kg) at equivalent speeds reveals that larger animals have stiffer leg springs (k(leg) [symbol: see text] M0.67, where M is body mass), but that the angle swept by the leg spring is nearly independent of body mass. As a result, the resonant period of vertical vibration of the spring-mass system is longer in larger animals. The length of time that the feet are in contact with the ground increases with body mass in nearly the same way as the resonant period of vertical vibration.

  14. Work Term Assignment Spring 2017

    Science.gov (United States)

    Sico, Mallory

    2017-01-01

    My tour in the Engineering Robotics directorate exceeded my expectations. I learned lessons about Creo, manufacturing and assembly, collaboration, and troubleshooting. During my first tour, last spring, I used Creo on a smaller project, but had limited experience with it before starting in the Dynamic Systems Test branch this spring. I gained valuable experience learning assembly design, sheet metal design and designing with intent for manufacturing and assembly. These skills came from working both on the hatch and the floor. I also learned to understand the intent of other designers on models I worked with. While redesigning the floor, I was modifying an existing part and worked to understand what the previous designer had done to make it fit with the new model. Through working with the machine shop and in the mock-up, I learned much more about manufacturing and assembly. I used a Dremel, rivet gun, belt sander, and countersink for the first time. Through taking multiple safety training for different machine shops, I learned new machine shop safety skills specific to each one. This semester also gave me new collaborative opportunities. I collaborated with engineers within my branch as well as with Human Factors and the building 10 machine shop. This experience helped me learn how to design for functionality and assembly, not only for what would be easiest in my designs. In addition to these experiences, I learned many lessons in troubleshooting. I was the first person in my office to use a Windows 10 computer. This caused unexpected issues with NASA services and programs, such as the Digital Data Management Server (DDMS). Because of this, I gained experience finding solutions to lockout and freeze issues as well as Creo specific settings. These will be useful skills to have in the future and will be implemented in future rotations. This co-op tour has motivated me more to finish my degree and pursue my academic goals. I intend to take a machining Career Gateway

  15. Synthesis of optical spring potentials in optomechanical systems

    CERN Document Server

    Slatyer, Harry J; Cho, Young-Wook; Buchler, Ben C; Lam, Ping Koy

    2016-01-01

    We propose a method to tailor the potential experienced by a moveable end mirror in a cavity optomechanical system by specifying the spectral properties of the input field. We show that by engineering the power spectral density of the cavity input field a desired force function can be approximated, with the accuracy of the approximation limited only by the linewidth of the cavity. The very general technique presented here could have applications in many kinds of optomechanical systems, particularly those used for sensing and metrology. We demonstrate the method by applying it to improve the sensitivity of a particular gravity measurement.

  16. 75 FR 39241 - Hooper Springs Project

    Science.gov (United States)

    2010-07-08

    ... of a 115-kilovolt (kV) transmission line and a 138/115-kV substation (collectively referred to as the Hooper Springs Project). The new BPA substation would be called Hooper Springs Substation and would be located adjacent to PacifiCorp's existing 345/ 138-kV Threemile Knoll Substation, located near the City of...

  17. Spring Flowers: Harvest of a Sensitive Eye

    Science.gov (United States)

    Clark, Eloise; Levin, Ted

    1978-01-01

    Defining and describing a number of spring flowers, this article includes illustrations and explanations that demonstrate "art and science are born of the same parents". The flowers discussed are skunk cabbage, bellwort, spring beauty, jack-in-the-pulpit, Solomon's seal, wild geranium, showy orchids, moccasin flower, bluets, apple, and Indian…

  18. 1988 Hanford riverbank springs characterization report

    Energy Technology Data Exchange (ETDEWEB)

    Dirkes, R.L.

    1990-12-01

    This reports presents the results of a special study undertaken to characterize the riverbank springs (i.e., ground-water seepage) entering the Columbia River along the Hanford Site. Radiological and nonradiological analyses were performed. River water samples were also analyzed from upstream and downstream of the Site as well as from the immediate vicinity of the springs. In addition, irrigation return water and spring water entering the river along the shoreline opposite Hanford were analyzed. Hanford-origin contaminants were detected in spring water entering the Columbia River along the Hanford Site. The type and concentrations of contaminants in the spring water were similar to those known to exist in the ground water near the river. The location and extent of the contaminated discharges compared favorably with recent ground-water reports and predictions. Spring discharge volumes remain very small relative to the flow of the Columbia. Downstream river sampling demonstrates the impact of ground-water discharges to be minimal, and negligible in most cases. Radionuclide concentrations were below US Department of Energy Derived Concentration Guides (DCGs) with the exception {sup 90}Sr near the 100-N Area. Tritium, while below the DCG, was detected at concentrations above the US Environmental Protection Agency drinking water standards in several springs. All other radionuclide concentrations were below drinking water standards. Nonradiological contaminants were generally undetectable in the spring water. River water contaminant concentrations, outside of the immediate discharge zones, were below drinking water standards in all cases. 19 refs., 5 figs., 12 tabs.

  19. Joystick With Cable Springs Offers Better Feel

    Science.gov (United States)

    Kerley, James; Ecklund, Wayne

    1992-01-01

    Improved joystick allows motion in 6 degrees of freedom, biased toward central position and orientation by 16 segments of cable serving as springs. Improvement in feel and control results from nonlinear compliance of cable-spring assembly. Nonlinear variations accommodate natural reactions of hand and brain. Operator functions as part of feedback control loop. More comfortable, increases ability to exert control and reduces fatigue.

  20. Stabilising springs for fixed lingual retainer.

    Science.gov (United States)

    Karthikeyan, M K; Ramachandraprabhakar; Saravanan, R; Rajvikram, N; Kuppuchamy

    2013-11-01

    Most treated malocclusion needs fixed lingual retention. To stabilise fixed lingual retainer in the exact location needs proper stabilisation. Proper stabilization requires a holding spring. This Stabilising Spring should be easy to fabricate and help the clinician to stabilise the retainer quickly and save the chair side time. More over it should not irritate the mucosa and should be easy to insert and remove.

  1. Efficient Method for Calculating the Composite Stiffness of Parabolic Leaf Springs with Variable Stiffness for Vehicle Rear Suspension

    Directory of Open Access Journals (Sweden)

    Wen-ku Shi

    2016-01-01

    Full Text Available The composite stiffness of parabolic leaf springs with variable stiffness is difficult to calculate using traditional integral equations. Numerical integration or FEA may be used but will require computer-aided software and long calculation times. An efficient method for calculating the composite stiffness of parabolic leaf springs with variable stiffness is developed and evaluated to reduce the complexity of calculation and shorten the calculation time. A simplified model for double-leaf springs with variable stiffness is built, and a composite stiffness calculation method for the model is derived using displacement superposition and material deformation continuity. The proposed method can be applied on triple-leaf and multileaf springs. The accuracy of the calculation method is verified by the rig test and FEA analysis. Finally, several parameters that should be considered during the design process of springs are discussed. The rig test and FEA analytical results indicate that the calculated results are acceptable. The proposed method can provide guidance for the design and production of parabolic leaf springs with variable stiffness. The composite stiffness of the leaf spring can be calculated quickly and accurately when the basic parameters of the leaf spring are known.

  2. Rocky Mountain Carbonate Spring Deposit development

    Science.gov (United States)

    Rainey, Dustin Kyle

    Relict Holocene carbonate spring deposits containing diverse biotic and abiotic depositional textures are present at Fall Creek cold sulphur springs, Alberta, Fairmont Hot Springs, British Columbia, and Hot Creek cold springs, British Columbia. The relict deposits are formed mainly of low-magnesium crystalline calcite contained in laterally continuous strata. Paleo-flow regimes were characterized by extensive sheet flow that increased the surface area of spring water exposed to the atmosphere. Calcite precipitated inorganically from spring water that attained CaCO3 supersaturation through agitation-induced CO2 degassing that was facilitated by elevated flow rates and a large surface area as spring water flowed down-slope. Thus, the deposits contain only minor amounts of detrital, mechanically deposited, and biogenic carbonate. Evaporation was only a minor contributor to CaCO3 supersaturation, mainly in quiescent environments. Photosynthetic CO2 removal did not measurably contribute to CaCO3 supersaturation. Calcite crystals precipitated in biotic facies formed from low to moderately supersaturated spring water, whereas abiotic dendrite crystals formed rapidly from highly supersaturated spring water. Calcite passively nucleated on cyanobacteria, bryophytes and macrophytes, and was probably facilitated by cyanobacterial extracellular polymeric substances. Cyanobacterial filaments and stromatolites are integral parts of all three deposits, whereas bryophytes were restricted to the Fall Creek and Hot Creek deposits. Diagenetic microbial degradation of crystalline calcite was common to all three deposits, but recrystallization was limited to the Fall Creek deposit. The amount and location of calcite precipitation relative to the vents was controlled by the concentrations of Ca2+ and HCO3- in solution, and discharge volume fluctuations. Spring water with high [Ca2+] and [HCO 3-] precipitated large amounts of calcite proximal to the vents (e.g. Fairmont), whereas spring

  3. Distribution map of hot springs in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Sumi, K.

    1975-01-01

    This map (scale 1:2,000,000) provides the distribution and locations of hot springs in Japan. A hot spring is defined as hot water, mineral water, vapor or other gases (excluding natural gases containing hydrocarbons as the major component) issuing from underground at a temperature of 25/sup 0/C or higher and/or containing substances listed on the map in specific concentrations. Springs are classified according to their chemical composition. Each class of spring is assigned one of five different symbols (per class) according to its temperature. Where appropriate, the geologic age of the spring location is identified. A comprehensive place name index is provided in both Japanese and English transliteration. The map is also isothermically graduated in HFU and references are given for descriptive textual materials that may be used as supplements.

  4. Enhanced nonlinear susceptibility via double-double electromagnetically induced transparency

    Science.gov (United States)

    Alotaibi, Hessa M. M.; Sanders, Barry C.

    2016-11-01

    We investigate the nonlinear optical susceptibility of an alkali-metal atom with tripod electronic configuration responsible for generating cross-phase modulation and self-phase modulation under the condition of double-double electromagnetically induced transparency. Our investigation demonstrates an enhancement in the nonlinear optical susceptibility of an alkali-metal atom by a factor of 1000 in the region of the second transparency window. This enhancement is in comparison with the atom's susceptibility in the first transparency window for the same parameters under the same conditions. Nonlinear-absorption enhancement arises by canceling Raman-gain generation, which arises when the probe and signal fields have equal intensities. At the center of the second transparency window, we obtain the condition required to attain a nonvanishing nonlinear optical susceptibility. In the bare-state picture, the coupling field must be off resonant from a bare-to-bare-state transition, while working in the semiclassical dressed picture required the signal field to be tuned off resonantly with a bare-to-dressed-state transition. The relation that governs the values of coupling- and signal-field detuning are also obtained. Our scheme exhibits the fact that the second transparency window has advantages over the first transparency window with respect to obtaining an enhanced Kerr effect, and our calculation includes simulation of both low-temperature and Doppler-broadened regimes.

  5. Nonlinear Dynamics in Double Square Well Potential

    CERN Document Server

    Khomeriki, Ramaz; Ruffo, Stefano; Wimberger, Sandro; 10.1007/s11232-007-0096-y

    2009-01-01

    Considering the coherent nonlinear dynamics in double square well potential we find the example of coexistence of Josephson oscillations with a self-trapping regime. This macroscopic bistability is explained by proving analytically the simultaneous existence of symmetric, antisymmetric and asymmetric stationary solutions of the associated Gross-Pitaevskii equation. The effect is illustrated and confirmed by numerical simulations. This property allows to make suggestions on possible experiments using Bose-Einstein condensates in engineered optical lattices or weakly coupled optical waveguide arrays.

  6. Spring plant phenology and false springs in the conterminous US during the 21st century

    Science.gov (United States)

    Allstadt, Andrew J.; Vavrus, Stephen J.; Heglund, Patricia J.; Pidgeon, Anna M.; Thogmartin, Wayne E.; Radeloff, Volker C.

    2015-01-01

    The onset of spring plant growth has shifted earlier in the year over the past several decades due to rising global temperatures. Earlier spring onset may cause phenological mismatches between the availability of plant resources and dependent animals, and potentially lead to more false springs, when subsequent freezing temperatures damage new plant growth. We used the extended spring indices to project changes in spring onset, defined by leaf out and by first bloom, and predicted false springs until 2100 in the conterminous United States (US) using statistically-downscaled climate projections from the Coupled Model Intercomparison Project 5 ensemble. Averaged over our study region, the median shift in spring onset was 23 days earlier in the Representative Concentration Pathway 8.5 scenario with particularly large shifts in the Western US and the Great Plains. Spatial variation in phenology was due to the influence of short-term temperature changes around the time of spring onset versus season long accumulation of warm temperatures. False spring risk increased in the Great Plains and portions of the Midwest, but remained constant or decreased elsewhere. We conclude that global climate change may have complex and spatially variable effects on spring onset and false springs, making local predictions of change difficult.

  7. Genetic Algorithms Based Approach for Designing Spring Brake Orthosis – Part I: Spring Parameters

    Directory of Open Access Journals (Sweden)

    M. S. Huq

    2012-01-01

    Full Text Available Spring brake orthosis (SBO concentrates purely on the knee to generate the swing phase of the paraplegic gait with the required hip flexion occurring passively as a consequence of the ipsilateral knee flexion, generated by releasing the torsion spring mounted at the knee joint. Electrical stimulation then drives the knee back to full extension, as well as restores the spring potential energy. In this paper, genetic algorithm (GA and its variant multi-objective GA (MOGA is used to perform the search operation for the ‘best’ spring parameters for the SBO spring mounted on an average sized subject simulated in the sagittal plane. Conventional torsion spring is tested against constant torque type spring in terms of swing duration as, based on first principles, it is hypothesized that constant torque spring would be able to produce slower SBO swing phase as might be preferred in assisted paraplegic gait. In line with the hypothesis, it is found that it is not possible to delay the occurrence of the flexion peak of the SBO swing phase further than its occurrence in the natural gait. The use of conventional torsion spring causes the swing knee flexion peak to appear rather faster than that of the natural gait, resulting in a potentially faster swing phase and hence gait cycle. The constant torque type spring on the other hand is able to stretch duration of the swing phase to some extent, rendering it the preferable spring type in SBO.

  8. Weldon Spring historical dose estimate

    Energy Technology Data Exchange (ETDEWEB)

    Meshkov, N.; Benioff, P.; Wang, J.; Yuan, Y.

    1986-07-01

    This study was conducted to determine the estimated radiation doses that individuals in five nearby population groups and the general population in the surrounding area may have received as a consequence of activities at a uranium processing plant in Weldon Spring, Missouri. The study is retrospective and encompasses plant operations (1957-1966), cleanup (1967-1969), and maintenance (1969-1982). The dose estimates for members of the nearby population groups are as follows. Of the three periods considered, the largest doses to the general population in the surrounding area would have occurred during the plant operations period (1957-1966). Dose estimates for the cleanup (1967-1969) and maintenance (1969-1982) periods are negligible in comparison. Based on the monitoring data, if there was a person residing continually in a dwelling 1.2 km (0.75 mi) north of the plant, this person is estimated to have received an average of about 96 mrem/yr (ranging from 50 to 160 mrem/yr) above background during plant operations, whereas the dose to a nearby resident during later years is estimated to have been about 0.4 mrem/yr during cleanup and about 0.2 mrem/yr during the maintenance period. These values may be compared with the background dose in Missouri of 120 mrem/yr.

  9. The Spring 2016 Observing Program of Brilliant Sky Observatory: Measurements of 313 Pairs

    Science.gov (United States)

    Harshaw, Richard

    2017-01-01

    Until approximately a decade ago, speckle interferometry, a double star measurement technique that is capable of high accuracy, had been the domain of professional astronomers using large telescopes, high-end cameras, and high-powered computing systems. But with the advent of relatively low-cost CCD cameras and powerful speckle reduction software that runs on a desktop PC, amateurs can now do high quality research and contribute valuable measurements of close double stars. This paper presents the measurement of 313 pairs based on the Spring 2016 observing program at Brilliant Sky Observatory, located in Cave Creek, Arizona.

  10. Thermal springs of Malaysia and their potentialdevelopment

    Science.gov (United States)

    Rahim Samsudin, Abdul; Hamzah, Umar; Rahman, Rakmi Ab.; Siwar, Chamhuri; Fauzi Mohd. Jani, Mohd; Othman, Redzuan

    The study on the potential development of hot springs for the tourism industry in Malaysiawas conducted. Out of the 40 hot springs covered, the study identified 9 hot springs having a high potential for development, 14 having medium potential and the remaining 17 having low or least potential for development. This conclusion was arrived at after considering the technical and economic feasibility of the various hot springs. Technical feasibility criteria includes geological factors, water quality, temperature and flow rate. The economic feasibility criteria considers measures such as accessibility, current and market potentials in terms of visitors, surrounding attractions and existing inventory and facilities available. A geological input indicates that high potential hot springs are located close to or within the granite body and associated with major permeable fault zones. They normally occur at low elevation adjacent to topographic highs. High potential hot springs are also characterised by high water temperature, substantial flowrate and very good water quality which is important for water-body contact activities such as soaking. Economic criteria for high potential hot springs are associated with good accessibility, good market, good surrounding attractions like rural and village setting and well developed facilities and infrastructures.

  11. Fabrication and experimentation of FRP helical spring

    Science.gov (United States)

    Ekanthappa, J.; Shiva Shankar, G. S.; Amith, B. M.; Gagan, M.

    2016-09-01

    In present scenario, the automobile industry sector is showing increased interest in reducing the unsprung weight of the automobile & hence increasing the fuel Efficiency. One of the feasible sub systems of a vehicle where weight reduction may be attempted is vehicle- suspension system. Usage of composite material is a proven way to lower the component weight without any compromise in strength. The composite materials are having high specific strength, more elastic strain energy storage capacity in comparison with those of steel. Therefore, helical coil spring made of steel is replaceable by composite cylindrical helical coil spring. This research aims at preparing a re-usable mandrel (mould) of Mild steel, developing a setup for fabrication, fabrication of FRP helical spring using continuous glass fibers and Epoxy Resin (Polymer). Experimentation has been conducted on fabricated FRP helical spring to determine its strength parameters & for failure analysis. It is found that spring stiffness (K) of Glass/Epoxy helical-spring is greater than steel-coil spring with reduced weight.

  12. Double-slit Quantum Eraser

    CERN Document Server

    Walborn, S P; Pádua, S; Monken, C H

    2002-01-01

    We report a quantum eraser experiment which actually uses a Young double-slit to create interference. The experiment can be considered an optical analogy of an experiment proposed by Scully, Englert and Walther. One photon of an entangled pair is incident on a Young double-slit of appropriate dimensions to create an interference pattern in a distant detection region. Quarter-wave plates, oriented so that their fast axes are orthogonal, are placed in front of each slit to serve as which-path markers. The quarter-wave plates mark the polarization of the interfering photon and thus destroy the interference pattern. To recover interference, we measure the polarization of the other entangled photon. In addition, we perform the experiment under delayed erasure circumstances.

  13. The X-Ray Beam Imager for Transversal Profiling of Low-Emittance Electron Beam at the SPring-8

    CERN Document Server

    Takano, S; Ohkuma, H

    2005-01-01

    We have developed the X-ray beam imager (XBI) at the accelerator diagnostics beamline I of the SPring-8 to observe transverse profiles of small electron beam of a low-emittance synchrotron light source. The XBI is based on a single Fresnel zone plate (FZP) and an X-ray zooming tube (XZT). The electron beam moving in a bending magnet is imaged by the FZP. Monochromatic X-ray is selected by a double crystal monochromator to avoid the effect of chromatic aberration of the FZP. The X-ray images of the electron beam obtained are converted by the XZT to enlarged images in visible light. The XBI has achieved a superior 1 σ spatial resolution in the micron range, and a fast time resolution of 1 ms. It has also realized a vignetting-free field of view larger than 1.5 mm in diameter on the coordinates of the electron beam, which is not easily obtained by imaging optics using two FZPs. With the XBI, we have successfully measured the profiles of the small electron beam having low vertical emittance in the pm ra...

  14. Effect of free-carrier concentration and optical injection on carrier lifetimes in undoped and iodine doped CdMgTe/CdSeTe double heterostructures grown by molecular beam epitaxy

    Science.gov (United States)

    Sohal, S.; Edirisooriya, M.; Ogedengbe, O. S.; Petersen, J. E.; Swartz, C. H.; LeBlanc, E. G.; Myers, T. H.; Li, J. V.; Holtz, M.

    2016-12-01

    Time-resolved and time integrated photoluminescence (PL) studies are reported for undoped and doped CdMgTe/CdSeTe double heterostructures (DHs) grown by molecular beam epitaxy. Undoped DHs are studied with absorber layer thickness varying from 0.5 to 2.5 µm. The n-type free-carrier concentration is varied ~7  ×  1015, 8.4  ×  1016, and 8.4  ×  1017 cm-3 using iodine as a dopant in different absorber layer thicknesses (0.25-2.0 µm). Optical injection is varied from 1  ×  1010 to 3  ×  1011 photons/pulse/cm2, corresponding to the initial injection of photo-carriers up to ~8  ×  1015 cm-3, to examine the effects of excess carrier concentration on the PL lifetimes. Undoped DHs exhibit an initial rapid decay followed by a slower dependence with carrier lifetimes up to ~485 ns. The dependence of carrier lifetimes on the thickness of the absorber layers (0.5-2.5 µm) suggests interface recombination velocities ({{v}\\operatorname{int}}~ ) ~ 1288 and 238 cm s-1 in the initial and later decay times, respectively, corresponding to high and low photo-carrier concentrations. The Shockley-Read-Hall model is used to describe the results in which variations are observed in {{v}\\operatorname{int}}~ for undoped DHs. The lifetimes of doped DHs show a consistent trend with thickness. The {{v}\\operatorname{int}}~ ~ 80-200 cm s-1 is estimated for doping n ~ 7  ×  1015 cm-3 and 240-410 cm s-1 for n ~ 8.4  ×  1016 cm-3. The observed decrease in carrier lifetimes with increasing n is consistent with growing importance of the radiative recombination rate due to the excess carrier concentration. The effect of carrier concentration on the PL spectrum is also discussed.

  15. Biogeochemistry of hypersaline springs supporting a mid-continent marine ecosystem: an analogue for martian springs?

    Science.gov (United States)

    Grasby, Stephen E; Londry, Kathleen L

    2007-08-01

    Hypersaline springs that host unique mid-continent marine ecosystems were examined in central Manitoba, Canada. The springs originate from a reflux of glacial meltwater that intrudes into underlying bedrock and dissolved buried salt beds. Two spring types were distinguished based both on flow rate and geochemistry. High flow springs (greater than 10 L/s) hosted extensive marine microbial mats, which were dominated by algae but also included diverse microbes. These varied somewhat between springs as indicated by changes in profiles of fatty acid methyl esters. Culture studies confirmed the presence of sulfate-reducing bacteria in sediments at the high flow sites. In contrast, low flow springs were affected by solar evaporation, increasing salinity, and temperature. These low flow springs behaved more like closed nutrient-limited systems and did not support microbial mats. Direct comparison of the high and low flow springs revealed interesting implications for the potential to record biosignatures in the rock record. High flow springs have abundant, well-developed microbial mats, which desiccate and are cemented along the edges of the spring pools; however, the high mass flux overwhelms any geochemical signature of microbial activity. In contrast, the nutrient-limited low flow sites develop strong geochemical signatures of sulfate reduction, even in the absence of microbial mats, due to less dilution with the lower flows. Geochemical and physical evidence for life did not correlate with the abundance of microbial life but, rather, with the extent to which the biological system formed a closed ecosystem.

  16. Numerical bifurcation analysis of the bipedal spring-mass model

    Science.gov (United States)

    Merker, Andreas; Kaiser, Dieter; Hermann, Martin

    2015-01-01

    The spring-mass model and its numerous extensions are currently one of the best candidates for templates of human and animal locomotion. However, with increasing complexity, their applications can become very time-consuming. In this paper, we present an approach that is based on the calculation of bifurcations in the bipedal spring-mass model for walking. Since the bifurcations limit the region of stable walking, locomotion can be studied by computing the corresponding boundaries. Originally, the model was implemented as a hybrid dynamical system. Our new approach consists of the transformation of the series of initial value problems on different intervals into a single boundary value problem. Using this technique, discontinuities can be avoided and sophisticated numerical methods for studying parametrized nonlinear boundary value problems can be applied. Thus, appropriate extended systems are used to compute transcritical and period-doubling bifurcation points as well as turning points. We show that the resulting boundary value problems can be solved by the simple shooting method with sufficient accuracy, making the application of the more extensive multiple shooting superfluous. The proposed approach is fast, robust to numerical perturbations and allows determining complete manifolds of periodic solutions of the original problem.

  17. Single Spring Joint Element Based on the Mixed Coordinate System

    Directory of Open Access Journals (Sweden)

    Lanhao Zhao

    2015-01-01

    Full Text Available As a FEM for reinforced concrete bond-slip problems, one important feature of the typical double spring joint element method is the selection of the normal stiffness, which may cause the mutual embedding problem and bring challenges to the calculation. In this paper, a novel single spring joint element method based on the mixed coordinate system is proposed to simulate the interaction of two materials. Instead of choosing the normal stiffness arbitrarily, the proposed method makes DOFs of two materials in the normal direction equal to ensure deformation compatibility. And its solid elements for the concrete are solved in global coordinate system, while the beam elements for the steel bar are solved in local coordinate system. In addition, the proposed method can also be applied to RC structures with irregular arrangements of steel bars. Numerical examples demonstrate the validity and accuracy of the proposed approach. Furthermore, the bond model is applied to RC beams with the description of the damage process.

  18. Process for Forming a High Temperature Single Crystal Canted Spring

    Science.gov (United States)

    DeMange, Jeffrey J (Inventor); Ritzert, Frank J (Inventor); Nathal, Michael V (Inventor); Dunlap, Patrick H (Inventor); Steinetz, Bruce M (Inventor)

    2017-01-01

    A process for forming a high temperature single crystal canted spring is provided. In one embodiment, the process includes fabricating configurations of a rapid prototype spring to fabricate a sacrificial mold pattern to create a ceramic mold and casting a canted coiled spring to form at least one canted coil spring configuration based on the ceramic mold. The high temperature single crystal canted spring is formed from a nickel-based alloy containing rhenium using the at least one coil spring configuration.

  19. Executive summary: Weldon Spring Site Environmental Report for calendar year 1992. Weldon Spring Site Remedial Action Project, Weldon Spring, Missouri

    Energy Technology Data Exchange (ETDEWEB)

    1993-06-01

    This report has been prepared to provide information about the public safety and environmental protection programs conducted by the Weldon Spring Site Remedial Action Project. The Weldon Spring site is located in southern St. Charles County, Missouri, approximately 48 km (30 mi) west of St. Louis. The site consists of two main areas, the Weldon Spring Chemical Plant and raffinate pits and the Weldon Spring Quarry. The objectives of the Site Environmental Report are to present a summary of data from the environmental monitoring program, to characterize trends and environmental conditions at the site, and to confirm compliance with environmental and health protection standards and requirements. The report also presents the status of remedial activities and the results of monitoring these activities to assess their impacts on the public and environment. The scope of the environmental monitoring program at the Weldon Spring site has changed since it was initiated. Previously, the program focused on investigations of the extent and level of contaminants in the groundwater, surface waters, buildings, and air at the site. In 1992, the level of remedial activities required monitoring for potential impacts of those activities, particularly on surface water runoff and airborne effluents. This report includes monitoring data from routine radiological and nonradiological sampling activities. These data include estimates of dose to the public from the Weldon Spring site; estimates of effluent releases; and trends in groundwater contaminant levels. Also, applicable compliance requirements, quality assurance programs, and special studies conducted in 1992 to support environmental protection programs are reviewed.

  20. The double identity of linguistic doubling.

    Science.gov (United States)

    Berent, Iris; Bat-El, Outi; Brentari, Diane; Dupuis, Amanda; Vaknin-Nusbaum, Vered

    2016-11-29

    Does knowledge of language consist of abstract principles, or is it fully embodied in the sensorimotor system? To address this question, we investigate the double identity of doubling (e.g., slaflaf, or generally, XX; where X stands for a phonological constituent). Across languages, doubling is known to elicit conflicting preferences at different levels of linguistic analysis (phonology vs. morphology). Here, we show that these preferences are active in the brains of individual speakers, and they are demonstrably distinct from sensorimotor pressures. We first demonstrate that doubling in novel English words elicits divergent percepts: Viewed as meaningless (phonological) forms, doubling is disliked (e.g., slaflaf linguistic preferences doubly dissociate from sensorimotor demands: A single stimulus can elicit diverse percepts, yet these percepts are invariant across stimulus modality--for speech and signs. These conclusions are in line with the possibility that some linguistic principles are abstract, and they apply broadly across language modality.

  1. Spring Enterprise Recipes A Problem-solution Approach

    CERN Document Server

    Mak, Gary

    2010-01-01

    The Spring Framework is a widely adopted enterprise and general Java framework. The release of Spring Framework 3.0 has added many improvements and new features for Spring development. Written by Gary Mak of the best-selling Spring Recipes and Josh Long, an expert Spring user and developer, Spring Enterprise Recipes is one of the first books on the new Spring 3. This key book focuses on Spring Framework 3.0, the latest version available, and a framework-related suite of tools, extensions, plug-ins, modules, and more-all of which you may want and need for building three-tier Java EE application

  2. Comparison of Shikani optical stylet and Macintosh laryngoscope for double-lumen endotracheal tube intubation%Shikani 喉镜与 Macintosh 喉镜在双腔气管导管插管中的比较

    Institute of Scientific and Technical Information of China (English)

    许挺; 李民; 郭向阳

    2015-01-01

    Objective:To compare the efficacy and safety of Shikani ( S) optical stylet and Macintosh (M) laryngoscope for double-lumen endotracheal tube intubation .Methods:In the study, 60 patients undergoing elective thoracic surgery were randomly allocated to group S ( n=30 ) and group M ( n=30 ) . After general anesthesia induction , the patients in group S and group M were intubated double-lumen en-dotracheal tube ( DLT) by Shikani optical stylet ( SOS) and macintosh laryngoscope respectively .Intuba-tion time, intubation attempts , cuff broken and oral mucosal or dental injury were recorded;Blood pres-sure and heart rate at baseline ( T0 ) , at the time of intubaiton onset ( T1 ) , 1 minute after intubaiton (T2), 3 minutes after intubation (T3) and 5 minutes after intubation (T3) were also recorded;Hoarse-ness and throat sore of the patients 24 hours after surgery were evaluated .Results:The intubaiton time with the SOS was faster than with the Macintosh [(37.4 ±9.7) s vs.(43.9 ±13.7) s, P=0.039] and the first attempt success rate (87%vs.80%, P=0.488) did not differ between the groups; No tube cuff broke in both the groups;Group S had fewer patients who suffered oral mucosal or dental injury than group M (8 vs.2, P=0.038);The blood pressure and heart rate at T0,T1,T2,T3 and T4 did not differ between the groups;Throat sore(7 vs.10, P=0.390) and hoarseness (5 vs.7, P=0.519) incidence did not differ between the groups .Conclusion:By comparison of the Macintosh laryngoscope , the SOS provides faster DLT intubation and causes less oral Mucosal or dental injury .%目的:比较Shikani喉镜和Macintosh喉镜在双腔气管导管插管中的有效性和安全性。方法:60例择期行胸外科手术的患者随机分为Shikani喉镜组(S组,n=30)和Macintosh喉镜组(M组,n=30),在全麻诱导后分别采用Shikani喉镜和Macintosh喉镜插入双腔气管导管,记录患者插管时间,插管次数,是否发生导管套囊破裂及口唇、牙

  3. 2012 Fish Springs NWR predator report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Report on a 2012 study to determine a relative index of predator populations, primarily coyote, on fish Springs National Wildlife refuge. Scat deposition transects...

  4. Status report on Fish Springs pond snail

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report provides a life history of the pond snail (Lymnaea Hinkleyia pilsbryi) at Fish Springs National Wildlife Refuge. The following information is included;...

  5. Fish Springs pond snail : Refuge communication scenario

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Communication scenario between the branch of Listing and Recovery, Fish and Wildlife Enhancement, and Fish Springs National Wildlife Refuge (NWR), in regards to the...

  6. Fish Springs National Wildlife Refuge habitat map

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Habitat map for Fish Springs National Wildlife Refuge. This habitat map was created along with the National Vegetation Classification (NVC) map of the refuge. Refuge...

  7. Coastal Energy Corporation, Willow Springs, MO

    Science.gov (United States)

    notice of a proposed Administrative Penalty Assessment against Coastal Energy Corporation, located at 232 Burnham Road, Willow Springs, Missouri, for alleged violations at the facility located at or near that facility.

  8. Spring staging waterfowl on the Naknek River

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Alaska Peninsula/Becharof National Wildlife Refuge staff conducted a survey of spring staging waterfowl on the Naknek River in the Bristol Bay drainage, Alaska...

  9. Seney Wildlife Refuge Spring migration report -- 1938

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The purpose of this report is to compare the numbers of migratory waterfowl using the Seney National Wildlife Refuge area during the spring of 1938 with the numbers...

  10. SPring-8 and application of nuclear scattering

    Energy Technology Data Exchange (ETDEWEB)

    Harami, Taikan [Japan Atomic Energy Research Inst., Kamigori, Hyogo (Japan). Kansai Research Establishment

    1997-03-01

    The SPring-8 has Linac synchrotron, incidence type facility and an accumulation ring. By preparing a beam line to take out light at the accumulation ring, the SPring-8 is supplied for common applications. Development of science adopting new method to study of properties and organisms by using high brightness source is expected. Construction of the SPring-8 accelerator was finished and adjusting test and commissioning of apparatuses are now in proceeding. At pre-use inspection of the accumulation ring on March, 1997, beam lines for R and D and crystalline structure analysis are applied to the Science and Technology Agency to inspect them simultaneously. And, by activating character of the SPring-8 radiation facility of high brightness and high energy X-ray generator, property study using Moessbauer nuclide to a probe can be conducted. (G.K.)

  11. EASTER- a floating holiday in spring

    Institute of Scientific and Technical Information of China (English)

    周雷生

    2004-01-01

    Approximately 260 million North Americans(85%) are Christians. As in other Christian lands,the greatest religious festival of the year in Canada and the United States is Easter. Easter is a joyous spring day commemorating the res-

  12. Fish Springs National Wildlife Refuge : Wildlife list

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This checklist is a comprehensive list of Fish Springs National Wildlife Refuge wildlife species. The checklist contains all wildlife species documented on the...

  13. Stravinsky: The Rite of Spring. Canticum sacrum

    Index Scriptorium Estoniae

    1996-01-01

    Uuest heliplaadist "Stravinsky: The Rite of Spring. Canticum sacrum. Requiem canticles. Choral Variations on "Vom Himmel hoch". Lausanne Pro Arte Choir, Suisse Romande Chamber Choir and Orchestra, Neeme Järvi" Chandos CHAN 9408 (75 minutes:DDD)

  14. Coffee Cravings May Spring from Your DNA

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_160628.html Coffee Cravings May Spring From Your DNA Genes appear ... research suggests that your genes influence how much coffee you drink. Researchers analyzed genetic data from more ...

  15. Stravinsky: The Rite of Spring. Canticum sacrum

    Index Scriptorium Estoniae

    1996-01-01

    Uuest heliplaadist "Stravinsky: The Rite of Spring. Canticum sacrum. Requiem canticles. Choral Variations on "Vom Himmel hoch". Lausanne Pro Arte Choir, Suisse Romande Chamber Choir and Orchestra, Neeme Järvi" Chandos CHAN 9408 (75 minutes:DDD)

  16. Spring Creek Common Allotment habitat management plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Management plan for the Spring Creek Common Allotment on Charles M. Russell National Wildlife Refuge, in McCone and Garfield Counties, Montana. This plan discusses...

  17. Fish Springs NWR Water Use Report : 1980

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Annual Water Management Plan for water use on Fish Springs National Wildlife Refuge in 1981. This plan discusses expected water levels of management units and the...

  18. Inspection report: Fish Springs National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report discusses results of a reconnaissance trip conducted at Fish Springs National Wildlife Refuge. The following is outlined; land condition, presence of...

  19. Pagosa Springs geothermal project. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    1984-10-19

    This booklet discusses some ideas and methods for using Colorado geothermal energy. A project installed in Pagosa Springs, which consists of a pipeline laid down 8th street with service to residences retrofitted to geothermal space heating, is described. (ACR)

  20. Double outlet right ventricle

    Science.gov (United States)

    ... medlineplus.gov/ency/article/007328.htm Double outlet right ventricle To use the sharing features on this page, please enable JavaScript. Double outlet right ventricle (DORV) is a heart disease that is ...

  1. Spring-back deformation in tube bending

    Institute of Scientific and Technical Information of China (English)

    Da-xin E; Hua-hui He; Xiao-yi Liu; Ru-xin Ning

    2009-01-01

    The spring-back of a bending metal tube was studied through extensive experiments and finite element method (FEM) analysis. An approximate equation for the spring-back angle of bending was deduced. It is noted that the mechanical properties of the material (in a tubular form) are quite different from those found in the standard tensile tests (when the materials are in bar forms). This is one of the major reasons that result in the discrepancies in the outcomes of experimental study, FEM calculations, and spring-back analysis. It is therefore of crucial importance to study the mechanical properties of the materials in their tubular forms. The experiments and FEM simulations prove that the spring-back angle is significantly affected by the mechanical properties of the materials. The angle decreases accordingly with plastic modulus, but changes inversely with the hardening index and elastic modulus. The spring-back angle is also affected by the conditions of tube deformation: it increases accordingly with the relative bending radius but changes inversely with the relative wall thickness. In addition, the spring-back angle increases nonlinearly with the bending an-gle.

  2. Optic glioma

    Science.gov (United States)

    Glioma - optic; Optic nerve glioma; Juvenile pilocytic astrocytoma; Brain cancer - optic glioma ... Optic gliomas are rare. The cause of optic gliomas is unknown. Most optic gliomas are slow-growing ...

  3. Chromosome doubling method

    Science.gov (United States)

    Kato, Akio

    2006-11-14

    The invention provides methods for chromosome doubling in plants. The technique overcomes the low yields of doubled progeny associated with the use of prior techniques for doubling chromosomes in plants such as grasses. The technique can be used in large scale applications and has been demonstrated to be highly effective in maize. Following treatment in accordance with the invention, plants remain amenable to self fertilization, thereby allowing the efficient isolation of doubled progeny plants.

  4. High power double-scale pulses from a gain-guided double-clad fiber laser

    Science.gov (United States)

    Zhang, Haitao; Gao, Gan; Li, Qinghua; Gong, Mali

    2017-03-01

    Generation of high power double-scale pulses from a gain-guided double-clad fiber laser is experimentally demonstrated. By employing the Yb-doped 10/130 double-clad fiber as the gain medium, the laser realizes an output power of 5.1 W and pulse energy of 0.175 µJ at repetition rate of 29.14 MHz. To the best of our knowledge, this average output power is the highest among the reported double-scale pulse oscillators. The autocorrelation trace of pulses contains the short (98 fs) and long (29.5 ps) components, and the spectral bandwidth of the pulse is 27.3 nm. Such double-scale pulses are well suited for seeding the high power MOPA (master oscillator power amplifier) systems, nonlinear frequency conversion and optical coherence tomography.

  5. Geochemical and hydrologic data for wells and springs in thermal-spring areas of the Appalachians

    Energy Technology Data Exchange (ETDEWEB)

    Hobba, W.A. Jr.; Chemerys, J.C.; Fisher, D.W.; Pearson, F.J. Jr.

    1976-07-01

    Current interest in geothermal potential of thermal-spring areas in the Appalachians makes all data on thermal springs and wells in these areas valuable. Presented here without interpretive comment are maps showing selected springs and wells and tables of physical and chemical data pertaining to these wells and springs. The chemical tables show compositions of gases (oxygen, nitrogen, argon, methane, carbon dioxide, and helium), isotope contents (tritium, carbon (13), and oxygen (18)), trace and minor element chemical data, and the usual complete chemical data.

  6. 扩展Spring MVC模块的Web应用%Web Application of Extended Spring MVC

    Institute of Scientific and Technical Information of China (English)

    廖福保

    2012-01-01

    This paper described the application of Spring MVC framework. It analyzed the controller, model, and view of MVC framework. To compensate for the deficiency of Spring MVC, it introduced the AJAX technology into Spring MVC to have it extended. The extended Spring MVC is easier to maintain, and has been proved to be feasible and valid in a typical Web application.%叙述了Spring MVC模块的应用,对MVC模块中的控制器、模型和视图进行了分析,然后针对目前Spring MVC模块的不足,对此模块进行了扩展,并将AJAX技术引入到Spring MVC模块中,具有易维护性.在扩展Spring MVC模块的基础上设计了1个典型的Web应用,表明了扩展Spring MVC模块的可行性和有效性.

  7. The source, discharge, and chemical characteristics of water from Agua Caliente Spring, Palm Springs, California

    Science.gov (United States)

    : Martin, Peter; Contributors: Brandt, Justin; Catchings, Rufus D.; Christensen, Allen H.; Flint, Alan L.; Gandhok, Gini; Goldman, Mark R.; Halford, Keith J.; Langenheim, V.E.; Martin, Peter; Rymer, Michael J.; Schroeder, Roy A.; Smith, Gregory A.; Sneed, Michelle

    2011-01-01

    Agua Caliente Spring, in downtown Palm Springs, California, has been used for recreation and medicinal therapy for hundreds of years and currently (2008) is the source of hot water for the Spa Resort owned by the Agua Caliente Band of the Cahuilla Indians. The Agua Caliente Spring is located about 1,500 feet east of the eastern front of the San Jacinto Mountains on the southeast-sloping alluvial plain of the Coachella Valley. The objectives of this study were to (1) define the geologic structure associated with the Agua Caliente Spring; (2) define the source(s), and possibly the age(s), of water discharged by the spring; (3) ascertain the seasonal and longer-term variability of the natural discharge, water temperature, and chemical characteristics of the spring water; (4) evaluate whether water-level declines in the regional aquifer will influence the temperature of the spring discharge; and, (5) estimate the quantity of spring water that leaks out of the water-collector tank at the spring orifice.

  8. Comparison of spring characteristics of titanium-molybdenum alloy and stainless steel

    Science.gov (United States)

    Salehi, Anahita; Asatourian, Armen

    2017-01-01

    Background Titanium-molybdenum alloy (TMA) and stainless steel (SS) wires are commonly used in orthodontics as arch-wires for tooth movement. However, plastic deformation phenomenon in these arch-wires seems to be a major concern among orthodontists. This study aimed to compare the mechanical properties of TMA and SS wires with different dimensions. Material and Methods Seventy-two wire samples (36 TMA and 36 SS) of three different sizes (19×25, 17×25 and 16×22) were analyzed in vitro, with 12 samples in each group. Various mechanical properties of the wires, including spring-back, bending moment and stiffness were determined using a universal testing machine. Student’s t-test showed statistically significant differences in the mean values of all the groups. In addition, metallographic comparison of SS and TMA wires was conducted under an optical microscope. Results The degree of stiffness of 16×22-sized SS and TMA springs was found to be 12±2 and 5±0.4, respectively, while the bending moment was estimated to be 1927±352 (gm-mm) and 932±16 (gm-mm), respectively; the spring-back index was determined to be 0.61±0.2 and 0.4±.09, respectively (p<0.001). There were no statistically significant differences in spring-back index in larger dimensions of the wires. Conclusions Systematic analysis indicated that springs made of TMA were superior compared to those made of SS. Although both from economic and functionality viewpoints the use of TMA is suggested, further clinical investigations are recommended. Key words:Bending moment, optical microscope, spring-back, stainless steel, stiffness, titanium‒molybdenum alloy. PMID:28149469

  9. The Cultural Impact on the Traditional Spring Festival Activities

    Institute of Scientific and Technical Information of China (English)

    刘琳琳

    2015-01-01

    Spring Festival will surely be considered as the most important festival among Chinese colorful occasions.This study attempts to analyze several typical rituals of Spring Festival from the cultural aspects,digging out the cultural factors and cultur-al connotation from the activity like the Family Reunion Dinner,Spring Couplets,the Spring Festival Gala,etc.

  10. Epitaxial Halide Perovskite Lateral Double Heterostructure.

    Science.gov (United States)

    Wang, Yiping; Chen, Zhizhong; Deschler, Felix; Sun, Xin; Lu, Toh-Ming; Wertz, Esther A; Hu, Jia-Mian; Shi, Jian

    2017-03-28

    Epitaxial III-V semiconductor heterostructures are key components in modern microelectronics, electro-optics, and optoelectronics. With superior semiconducting properties, halide perovskite materials are rising as promising candidates for coherent heterostructure devices. In this report, spinodal decomposition is proposed and experimentally implemented to produce epitaxial double heterostructures in halide perovskite system. Pristine epitaxial mixed halide perovskites rods and films were synthesized via van der Waals epitaxy by chemical vapor deposition method. At room temperature, photon was applied as a knob to regulate the kinetics of spinodal decomposition and classic coarsening. By this approach, halide perovskite double heterostructures were created carrying epitaxial interfaces and outstanding optical properties. Reduced Fröhlich electron-phonon coupling was discovered in coherent halide double heterostructure, which is hypothetically attributed to the classic phonon confinement effect widely existing in III-V double heterostructures. As a proof-of-concept, our results suggest that halide perovskite-based epitaxial heterostructures may be promising for high-performance and low-cost optoelectronics, electro-optics, and microelectronics. Thus, ultimately, for practical device applications, it may be worthy to pursue these heterostructures via conventional vapor phase epitaxy approaches widely practised in III-V field.

  11. A Portable Double-Slit Quantum Eraser with Individual Photons

    Science.gov (United States)

    Dimitrova, T. L.; Weis, A.

    2011-01-01

    The double-slit experiment has played an important role in physics, from supporting the wave theory of light, via the discussions of the wave-particle duality of light (and matter) to the foundations of modern quantum optics. Today it keeps playing an active role in the context of quantum optics experiments involving single photons. In this paper,…

  12. All-optical switching in optically induced nonlinear waveguide couplers

    Energy Technology Data Exchange (ETDEWEB)

    Diebel, Falko, E-mail: falko.diebel@uni-muenster.de; Boguslawski, Martin; Rose, Patrick; Denz, Cornelia [Institut für Angewandte Physik and Center for Nonlinear Science (CeNoS), Westfälische Wilhelms-Universität Münster, 48149 Münster (Germany); Leykam, Daniel; Desyatnikov, Anton S. [Nonlinear Physics Centre, Research School of Physics and Engineering, The Australian National University, Canberra ACT 0200 (Australia)

    2014-06-30

    We experimentally demonstrate all-optical vortex switching in nonlinear coupled waveguide arrays optically induced in photorefractive media. Our technique is based on multiplexing of nondiffracting Bessel beams to induce various types of waveguide configurations. Using double- and quadruple-well potentials, we demonstrate precise control over the coupling strength between waveguides, the linear and nonlinear dynamics and symmetry-breaking bifurcations of guided light, and a power-controlled optical vortex switch.

  13. Experimental Investigation Of Polymeric Compound Cross Section Springs

    Directory of Open Access Journals (Sweden)

    Mayas Al-Mahasne

    2007-01-01

    Full Text Available This paper presents an experimental investigation of the characteristic of the compound cross section springs on models made from polymeric materials (organic glass. Two constructive variants of the compound spring sections were specified with the help of criteria of similarity. The criterion of similarity of natural and model springs was determined by the simulation method at particular spring deflection. The problem of simulation was brought to accurate determination of the magnitudes that characterize the physical and mechanical properties of materials for natural and model springs. It was experimentally proved that the use of the proposed new type of springs significantly increases the spring stiffness.

  14. Characterization of the hydrogeology of the sacred Gihon Spring, Jerusalem: a deteriorating urban karst spring

    Science.gov (United States)

    Amiel, Ronit Benami; Grodek, Tamir; Frumkin, Amos

    2010-09-01

    The Gihon Spring, Jerusalem, is important for the major monotheistic religions. Its hydrogeology and hydrochemistry is studied here in order to understand urbanization effects on karst groundwater resources, and promote better water management. High-resolution monitoring of the spring discharge, temperature and electrical conductivity, was performed, together with chemical and bacterial analysis. All these demonstrate a rapid response of the spring to rainfall events and human impact. A complex karst system is inferred, including conduit flow, fissure flow and diffuse flow. Electrical conductivity, Na+ and K+ values (2.0 mS/cm, 130 and 50 mg/l respectively) are very high compared to other nearby springs located at the town margins (0.6 mS/cm, 15 and <1 mg/l respectively), indicating considerable urban pollution in the Gihon area. The previously cited pulsating nature of the spring was not detected during the present high-resolution monitoring. This phenomenon may have ceased due to additional water sources from urban leakage and irrigation feeding the spring. The urbanization of the recharge catchment thus affects the spring water dramatically, both chemically and hydrologically. Appropriate measures should therefore be undertaken to protect the Gihon Spring and other karst aquifers threatened by rapid urbanization.

  15. Spring Bird Migration Phenology in Eilat, Israel

    Directory of Open Access Journals (Sweden)

    Reuven Yosef

    2009-12-01

    Full Text Available Analysis of the mean date of first captures and median arrival dates of spring migration for 34 species of birds at Eilat, Israel, revealed that the earlier a species migrates through Eilat, the greater is the inter-annual variation in the total time of its passage. Birds arrive during spring migration in Eilat in four structured and independent waves. The annual fluctuation in the initial arrival dates (initial capture dates and median dates (median date of all captures, not including recaptures, did not depend on the length of the migratory route. This implies that migrants crossing the Sahara desert depart from their winter quarters on different Julian days in different years. We suggest that negative correlations between the median date of the spring migration of early and late migrants depends upon the easterly (Hamsin wind period. Moreover, we believe that the phenology of all birds during spring migration in Eilat is possibly also determined by external factors such as weather conditions on the African continent or global climatic processes in the Northern hemisphere. Orphean Warblers (Sylvia hortensis show a strong positive correlation (rs=-0.502 of initial capture date with calendar years, whereas other species such as Barred Warbler (S. nisoria; rs = -0.391 and Spotted Flycatcher (Muscicapa striata; rs = -0.398 display an insignificant trend. The Dead Sea Sparrow (Passer moabiticus and Red-Backed Shrike (Lanius collurio are positively correlated regarding initial arrival date and medians of spring migration.

  16. Geothermal energy and hot springs in Ethiopia

    Energy Technology Data Exchange (ETDEWEB)

    Koga, T. (Hot Springs Therapeutics Research Institute, Kyushu, Univ., Japan)

    1971-01-01

    The hot springs in Ethiopia are concentrated in two areas: the North Afar depression and adjacent Red Sea shore, and a geothermal field 100 km from northeast to southwest in the central part of Ethiopia. The latter extends not only to the Great Rift Valley but also to the Aden Gulf. In the lake district in the central Great Rift Valley, there are a number of hot springs on the lake shore. These are along NE-SW fault lines, and the water is a sodium bicarbonate-type rich in HCO/sub 3/ and Na but low in C1 and Ca. In Dallol in the North Afar depression, CO/sub 2/-containing hot springs with high temperatures (110/sup 0/C) and a specific gravity of 1.4, were observed. In the South Afar depression, located in the northeastern part of the Rift Valley, there are many active volcanoes and hot springs between the lake district and the Danakil depression. The spring water is a sodium bicarbonate saline type. Nine graphs and maps are included.

  17. Prediction of Spring Rate and Initial Failure Load due to Material Properties of Composite Leaf Spring

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Sung Ha [Maxoft Inc., Seongnam (Korea, Republic of); Choi, Bok Lok [Gangneung-Wonju National University, Gangneung (Korea, Republic of)

    2014-12-15

    This paper presented analysis methods for adapting E-glass fiber/epoxy composite (GFRP) materials to an automotive leaf spring. It focused on the static behaviors of the leaf spring due to the material composition and its fiber orientation. The material properties of the GFRP composite were directly measured based on the ASTM standard test. A reverse implementation was performed to obtain the complete set of in-situ fiber and matrix properties from the ply test results. Next, the spring rates of the composite leaf spring were examined according to the variation of material parameters such as the fiber angles and resin contents of the composite material. Finally, progressive failure analysis was conducted to identify the initial failure load by means of an elastic stress analysis and specific damage criteria. As a result, it was found that damage first occurred along the edge of the leaf spring owing to the shear stresses.

  18. Comparison of spring characteristics of titanium-molybdenum alloy and stainless steel.

    Science.gov (United States)

    Sheibaninia, Ahmad; Salehi, Anahita; Asatourian, Armen

    2017-01-01

    Titanium-molybdenum alloy (TMA) and stainless steel (SS) wires are commonly used in orthodontics as arch-wires for tooth movement. However, plastic deformation phenomenon in these arch-wires seems to be a major concern among orthodontists. This study aimed to compare the mechanical properties of TMA and SS wires with different dimensions. Seventy-two wire samples (36 TMA and 36 SS) of three different sizes (19×25, 17×25 and 16×22) were analyzed in vitro, with 12 samples in each group. Various mechanical properties of the wires, including spring-back, bending moment and stiffness were determined using a universal testing machine. Student's t-test showed statistically significant differences in the mean values of all the groups. In addition, metallographic comparison of SS and TMA wires was conducted under an optical microscope. The degree of stiffness of 16×22-sized SS and TMA springs was found to be 12±2 and 5±0.4, respectively, while the bending moment was estimated to be 1927±352 (gm-mm) and 932±16 (gm-mm), respectively; the spring-back index was determined to be 0.61±0.2 and 0.4±.09, respectively (pBending moment, optical microscope, spring-back, stainless steel, stiffness, titanium‒molybdenum alloy.

  19. ANALYSIS OF COMPOSITE LEAF SPRING BY USING ANALYTICAL & FEA

    OpenAIRE

    Ranjeet Mithari; Amar Patil; Prof. E. N. Aitavade

    2012-01-01

    Leaf spring are of the oldest suspension component they are still frequently used. The current leaf spring is multiple leaf spring types with a steel material. It has high weight, low natural frequency, high corrosion, more noise. Therefore current multiple leaf spring is replaced by mono composite (E- Glass epoxy) leaf spring which has high natural frequency, low weight etc. The maximum stress produced at the cylindrically joint than fixed joint. Therefore stress analysis of composite materi...

  20. Archaeal diversity in Icelandic hot springs

    DEFF Research Database (Denmark)

    Kvist, Thomas; Ahring, Birgitte Kiær; Westermann, Peter

    2007-01-01

    Whole-cell density gradient extractions from three solfataras (pH 2.5) ranging in temperature from 81 to 90 degrees C and one neutral hot spring (81 degrees C, pH 7) from the thermal active area of Hveragerethi (Iceland) were analysed for genetic diversity and local geographical variation...... of Archaea by analysis of amplified 16S rRNA genes. In addition to the three solfataras and the neutral hot spring, 10 soil samples in transects of the soil adjacent to the solfataras were analysed using terminal restriction fragment length polymorphism (t-RFLP). The sequence data from the clone libraries...... enzymes AluI and BsuRI. The sequenced clones from this solfatara belonged to Sulfolobales, Thermoproteales or were most closest related to sequences from uncultured Archaea. Sequences related to group I.1b were not found in the neutral hot spring or the hyperthermophilic solfatara (90 degrees C)....