WorldWideScience

Sample records for carrier lifetime

  1. Insight into carrier lifetime impact on band-modulation devices

    Science.gov (United States)

    Parihar, Mukta Singh; Lee, Kyung Hwa; Park, Hyung Jin; Lacord, Joris; Martinie, Sébastien; Barbé, Jean-Charles; Xu, Yue; El Dirani, Hassan; Taur, Yuan; Cristoloveanu, Sorin; Bawedin, Maryline

    2018-05-01

    A systematic study to model and characterize the band-modulation Z2-FET device is developed bringing light to the relevance of the carrier lifetime influence. This work provides guidelines to optimize the Z2-FETs for sharp switching, ESD protection, and 1T-DRAM applications. Lower carrier lifetime in the Z2-FET helps in attaining the sharp switch. We provide new insights into the correlation between generation/recombination, diffusion, electrostatic barriers and carrier lifetime.

  2. Self-scaling minority carrier lifetime imaging using periodically modulated electroluminescence

    Science.gov (United States)

    Kropp, Timo; Berner, Marcel; Werner, Jürgen H.

    2017-11-01

    We present a straightforward self-scaling imaging technique to extract the effective minority carrier lifetime image of silicon solar cells using periodically modulated electroluminescence. This novel modulation technique overcomes main limiting factors linked to camera integration time. Our approach is based on comparing three luminescence images taken during current modulation. One image is taken while periodically injecting excess charge carriers with a pulsed current stimulation followed by an open-circuit luminescence decay. A second image with the same injection profile is taken while additionally extracting excess charge carriers at the falling edge, accelerating the luminescence decay. Both images are normalized to a steady-state image. The camera integration time is several orders of magnitude longer than the modulation period length, and no synchronization of image acquisition is needed. The intensity difference between both modulated images is used for determining a calibration factor to convert the steady-state image into the effective minority carrier lifetime image: Our modulation method enables carrier lifetime images completely independent of the image integration time. First carrier lifetime images show good agreement with data from time resolved electroluminescence.

  3. Minority-carrier lifetime in InP as a function of light bias

    Science.gov (United States)

    Yater, Jane A.; Weinberg, I.; Jenkins, Phillip P.; Landis, Geoffrey A.

    1995-01-01

    Minority-carrier lifetime in InP is studied as a function of doping level and laser intensity using time-resolved photoluminescence. A continuous wave diode laser illuminates bulk InP and acts as a light bias, injecting a steady-state concentration of carriers. A 200 ps laser pulse produces a small transient signal on top of the steady-state luminescence, allowing lifetime to be measured directly as a function of incident intensity. For p-InP, lifetime increases with light bias up to a maximum value. Bulk recombination centers are presumably filled to saturation, allowing minority carriers to live longer. The saturation bias scales with dopant concentration for a particular dopant species. As light bias is increased for n-InP, minority-carrier lifetime increases slightly but then decreases, suggesting radiative recombination as a dominant decay mechanism.

  4. Minority Carrier Lifetime Studies of Narrow Bandgap Antimonide Superlattices

    Science.gov (United States)

    Hoglund, Linda; Ting, David Z.; Khoshakhlagh, Arezou; Soibel, Alexander; Hill, Cory J.; Fisher, Anita; Keo, Sam; Gunapala, Sarath D.

    2014-01-01

    In this study optical modulation response and photoluminescence spectroscopy were used to study mid-wave Ga-free InAs/InAsSb superlattices. The minority carrier lifetimes in the different samples varied from 480 ns to 4700 ns, partly due to different background doping concentrations. It was shown that the photoluminescence intensity can be used as a fast non-destructive tool to predict the material quality. It was also demonstrated that it is crucial to use a low excitation power in the photoluminescence measurements in order to get a good correlation between the photoluminescence intensity and the minority carrier lifetime.

  5. Contactless Spectral-dependent Charge Carrier Lifetime Measurements in Silicon Photovoltaic Materials

    Science.gov (United States)

    Roller, John; Hamadani, Behrang; Dagenais, Mario

    Charge carrier lifetime measurements in bulk or unfinished photovoltaic (PV) materials allow for a more accurate estimate of power conversion efficiency in completed solar cells. In this work, carrier lifetimes in PV-grade silicon wafers are obtained by way of quasi-steady state photoconductance measurements. These measurements use a contactless RF system coupled with varying narrow spectrum input LEDs, ranging in wavelength from 460 nm to 1030 nm. Spectral dependent lifetime measurements allow for determination of bulk and surface properties of the material, including the intrinsic bulk lifetime and the surface recombination velocity. The effective lifetimes are fit to an analytical physics-based model to determine the desired parameters. Passivated and non-passivated samples are both studied and are shown to have good agreement with the theoretical model.

  6. Origin of long lifetime of band-edge charge carriers in organic-inorganic lead iodide perovskites.

    Science.gov (United States)

    Chen, Tianran; Chen, Wei-Liang; Foley, Benjamin J; Lee, Jooseop; Ruff, Jacob P C; Ko, J Y Peter; Brown, Craig M; Harriger, Leland W; Zhang, Depei; Park, Changwon; Yoon, Mina; Chang, Yu-Ming; Choi, Joshua J; Lee, Seung-Hun

    2017-07-18

    Long carrier lifetime is what makes hybrid organic-inorganic perovskites high-performance photovoltaic materials. Several microscopic mechanisms behind the unusually long carrier lifetime have been proposed, such as formation of large polarons, Rashba effect, ferroelectric domains, and photon recycling. Here, we show that the screening of band-edge charge carriers by rotation of organic cation molecules can be a major contribution to the prolonged carrier lifetime. Our results reveal that the band-edge carrier lifetime increases when the system enters from a phase with lower rotational entropy to another phase with higher entropy. These results imply that the recombination of the photoexcited electrons and holes is suppressed by the screening, leading to the formation of polarons and thereby extending the lifetime. Thus, searching for organic-inorganic perovskites with high rotational entropy over a wide range of temperature may be a key to achieve superior solar cell performance.

  7. Measurement of minority carrier lifetime in silicon solar cells using an a. c. light source

    Energy Technology Data Exchange (ETDEWEB)

    Nagpal, A.; Gupta, R.S.; Srivastava, G.P. (Delhi Univ., New Delhi (India). Dept. of Electronic Sciences); Jain, V.K. (Solid State Physics Lab., Delhi (India)); Chilana, G.S. (Delhi Univ. (India). Dept. of Physics and Astrophysics)

    1990-06-01

    A simple technique for the measurement of minority carriers lifetimes is proposed. It is based on the modification of the junction structure by the addition of a d.c. bias to the a.c. source. This always keeps the solar cell in the forward biased condition and also keeps it in the operating range. This method provides a direct measurement of minority carriers lifetimes. The lifetime is found to increase from 2.89 {mu}s at 30deg C to 4.55 {mu}s at 120deg C. The lifetime reduces to 1.45 {mu}s at liquid air temperature. Based on these lifetime measurements, the diffusion length of the carriers has also been calculated. (orig.).

  8. Enhancing Charge Carrier Lifetime in Metal Oxide Photoelectrodes through Mild Hydrogen Treatment

    KAUST Repository

    Jang, Ji-Wook

    2017-08-25

    Widespread application of solar water splitting for energy conversion is largely dependent on the progress in developing not only efficient but also cheap and scalable photoelectrodes. Metal oxides, which can be deposited with scalable techniques and are relatively cheap, are particularly interesting, but high efficiency is still hindered by the poor carrier transport properties (i.e., carrier mobility and lifetime). Here, a mild hydrogen treatment is introduced to bismuth vanadate (BiVO4), which is one of the most promising metal oxide photoelectrodes, as a method to overcome the carrier transport limitations. Time-resolved microwave and terahertz conductivity measurements reveal more than twofold enhancement of the carrier lifetime for the hydrogen-treated BiVO4, without significantly affecting the carrier mobility. This is in contrast to the case of tungsten-doped BiVO4, although hydrogen is also a donor type dopant in BiVO4. The enhancement in carrier lifetime is found to be caused by significant reduction of trap-assisted recombination, either via passivation or reduction of deep trap states related to vanadium antisite on bismuth or vanadium interstitials according to density functional theory calculations. Overall, these findings provide further insights on the interplay between defect modulation and carrier transport in metal oxides, which benefit the development of low-cost, highly-efficient solar energy conversion devices.

  9. Variation of minority charge carrier lifetime in high-resistance p-type silicon under irradiation

    International Nuclear Information System (INIS)

    Basheleishvili, Z.V.; Garnyk, V.S.; Gorin, S.N.; Pagava, T.A.

    1984-01-01

    The minority carrier lifetime (tau) variation was studied in the process of p-type silicon bombardment with fast 8 MeV electrons. The irradiation and all measurements were carried out at room temperature. The tau quantity was measured by the photoconductivity attenuation method at a low injection level 20% measurement error; the resistivity was measured by the four-probe method (10% error). The resistivity and minority charge carrier lifetime tau are shown to increase with the exposure dose. It is supposed that as radiation dose increases, the rearrangement of the centres responsible for reducing the lifetime occurs and results in a tau increase in the material being irradiated, however the tau value observed in the original samples is not attained. The restoration of the minority carrier lifetime in p-type high-resistance silicon with a growing exposure dose might proceed due to reduction in the free carrier concentration

  10. Measurement of carrier lifetime and linewidth enhancement factor for 1.5- mu m ridge-waveguide laser amplifier

    DEFF Research Database (Denmark)

    Storkfelt, Niels; Mikkelsen, B.; Olesen, D. S.

    1991-01-01

    Semiconductor optical amplifiers are used for investigation of the effective carrier lifetime and the linewidth enhancement factor. Contrary to semiconductor lasers, semiconductor optical amplifiers allow measurement at high levels of injected carrier density. The carrier lifetime and the linewid...

  11. Minority Carrier Lifetime and Photoluminescence Studies of Antimony-Based Superlattices

    Science.gov (United States)

    Hoglund, Linda; Soibel, Alexander; Ting, David Z.; Khoshakhlagh, Arezou; Hill, Cory J.; Gunapala, Sarath D.

    2012-01-01

    In this paper, we have used the OMR technique to study the minority carrier lifetimes in three InAs/GaSb-photoluminescence (PL) structures with different number of periods in the absorber: 300, 400 and 600 periods respectively. The feasibility of using a visible 643 nm laser source with short penetration depth for lifetime measurements was studied by comparing the achieved results to measurements performed on the same samples with a 1550 nm IR laser source, which penetrates much deeper into the sample. Despite the differences in excitation wavelengths and penetration depths, the results from both measurements were very similar. This indicates that the diffusion length is long enough to facilitate a homogeneous distribution of excess carriers in the material.

  12. Steady state minority carrier lifetime and defect level occupation in thin film CdTe solar cells

    International Nuclear Information System (INIS)

    Cheng, Zimeng; Delahoy, Alan E.; Su, Zhaoqian; Chin, Ken K.

    2014-01-01

    A model consisting of Shockley Read Hall (SRH) recombination under steady state conditions of constant photon injection is proposed in this work to study the steady state minority carrier lifetime in CdS/CdTe thin film solar cells. The SRH recombination rate versus optical injection level is analytically approximated in the junction and neutral regions. In the neutral region, it is found that the recombination rate through certain defect levels has one constant value under lower optical injection conditions and another constant value under higher optical injection conditions with the transition occurring at a critical optical injection level. By simultaneously solving the equations of charge neutrality, charge conservation and SRH recombination in the neutral region, it is found that the compensation of doping and the reduction of minority carrier lifetime by donors in the p-type semiconductor can each be remedied by optical injection. It is also demonstrated that this optical-dependent SRH recombination is significant in large bandgap thin films. The measured minority carrier diffusion length in a CdS/CdTe solar cells, as determined from the steady-state photo-generated carrier collection efficiency, shows the predicted transition of minority carrier lifetime versus optical injection level. A numerical fitting of the indirectly-measured minority carrier lifetime by assuming the minority carrier mobility gives a non-intuitive picture of the p–n junction with a low free hole concentration but a narrow depletion region width. - Highlights: • Minority carrier lifetimes under different optical injections are solved. • Simplifications of Shockley–Read–Hall recombination equation are discussed. • The compensation of donor can be remedied with optical injection. • The recombination efficiency of donor can be remedied with optical injection. • The minority carrier lifetime transition under illumination was experimentally observed

  13. Enhancing Charge Carrier Lifetime in Metal Oxide Photoelectrodes through Mild Hydrogen Treatment

    KAUST Repository

    Jang, Ji-Wook; Friedrich, Dennis; Mü ller, Sö nke; Lamers, Marlene; Hempel, Hannes; Lardhi, Sheikha F.; Cao, Zhen; Harb, Moussab; Cavallo, Luigi; Heller, René ; Eichberger, Rainer; van de Krol, Roel; Abdi, Fatwa F.

    2017-01-01

    and are relatively cheap, are particularly interesting, but high efficiency is still hindered by the poor carrier transport properties (i.e., carrier mobility and lifetime). Here, a mild hydrogen treatment is introduced to bismuth vanadate (BiVO4), which is one

  14. Mathematical analysis of the Photovoltage Decay (PVD) method for minority carrier lifetime measurements

    Science.gov (United States)

    Vonroos, O. H.

    1982-01-01

    When the diffusion length of minority carriers becomes comparable with or larger than the thickness of a p-n junction solar cell, the characteristic decay of the photon-generated voltage results from a mixture of contributions with different time constants. The minority carrier recombination lifetime tau and the time constant l(2)/D, where l is essentially the thickness of the cell and D the minority carrier diffusion length, determine the signal as a function of time. It is shown that for ordinary solar cells (n(+)-p junctions), particularly when the diffusion length L of the minority carriers is larger than the cell thickness l, the excess carrier density decays according to exp (-t/tau-pi(2)Dt/4l(2)), tau being the lifetime. Therefore, tau can be readily determined by the photovoltage decay method once D and L are known.

  15. Carrier mobility and scattering lifetime in electric double-layer gated few-layer graphene

    Energy Technology Data Exchange (ETDEWEB)

    Piatti, E.; Galasso, S.; Tortello, M.; Nair, J.R.; Gerbaldi, C. [Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, 10129 Torino (Italy); Bruna, M.; Borini, S. [Istituto Nazionale di Ricerca Metrologica (INRIM), 10135 Torino (Italy); Daghero, D. [Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, 10129 Torino (Italy); Gonnelli, R.S., E-mail: renato.gonnelli@polito.it [Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, 10129 Torino (Italy)

    2017-02-15

    Highlights: • We fabricated few-layer graphene FETs by mechanical exfoliation and standard microfabrication techniques. • We employed a Li-TFSI based ion gel to induce carrier densities as high as ≈6e14 e{sup −}/cm{sup 2} in the devices' channel. • We found a strong asymmetry in the sheet conductance and mobility doping dependences between electron and hole doping. • We combined the experimental results with ab initio DFT calculations to obtain the average scattering lifetime of the charge carriers. • We found that the increase in the carrier density and an unexpected increase in the density of charged scattering centers compete in determining the scattering lifetime. - Abstract: We fabricate electric double-layer field-effect transistor (EDL-FET) devices on mechanically exfoliated few-layer graphene. We exploit the large capacitance of a polymeric electrolyte to study the transport properties of three, four and five-layer samples under a large induced surface charge density both above and below the glass transition temperature of the polymer. We find that the carrier mobility shows a strong asymmetry between the hole and electron doping regime. We then employ ab initio density functional theory (DFT) calculations to determine the average scattering lifetime from the experimental data. We explain its peculiar dependence on the carrier density in terms of the specific properties of the electrolyte we used in our experiments.

  16. Three-dimensional minority carrier lifetime mapping of thin film semiconductors for solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Hardin, Brian [PLANT PV, Inc., Belmont, CA (United States); Peters, Craig [PLANT PV, Inc., Belmont, CA (United States); Barnard, Edward [PLANT PV, Inc., Belmont, CA (United States)

    2015-09-30

    This project addresses the difficulty of accurately measuring charge carrier dynamics in novel semiconductor materials for thin film photovoltaic cells. We have developed a two- photon lifetime tomography technique to separate bulk minority carrier lifetime from surface recombination effects and effects of recombination at sub-surface defects. This technique also enables us to characterize how local defects such as grain boundaries– buried below the surface of a sample–affect carrier lifetimes in the active layer, dynamics that have been previously inaccessible. We have applied this newly developed technique to illuminate how CdCl2 treatment improves CdTe PV efficiency. From striking 3D lifetime tomography maps, a clear, sub- surface understanding emerges of the photophysical changes that occur in CdTe active medium following exposure to CdCl2, a standard step in the fabrication of high-efficiency CdTe-based solar cells. This work demonstrates a well-defined method to quantify grain-boundary, interface, and bulk recombination in CdTe and other optically-active polycrystalline semiconductor materials; information that can provide critical information to the development of next- generation photovoltaics and many other semiconductor technologies.

  17. Analysis of the photo voltage decay /PVD/ method for measuring minority carrier lifetimes in P-N junction solar cells

    Science.gov (United States)

    Von Roos, O.

    1981-01-01

    The photo voltage decay (PVD) method for the measurement of minority carrier lifetimes in P-N junction solar cells with cell thickness comparable to or even less than the minority carrier diffusion length is examined. The method involves the generation of free carriers in the quasi-neutral bulk material by flashes of light and the monitoring of the subsequent decay of the induced open-circuit voltages as the carriers recombine, which is dependent on minority carrier recombination lifetime. It is shown that the voltage versus time curve for an ordinary solar cell (N(+)-P junction) is proportional to the inverse minority carrier lifetime plus a factor expressing the ratio of diffusion length to cell thickness. In the case of an ideal back-surface-field cell (N(+)-P-P(+) junction) however, the slope is directly proportional to the inverse minority carrier lifetime. It is noted that since most BSF cells are not ideal, possessing a sizable back surface recombination velocity, the PVD measurements must be treated with caution and supplemented with other nonstationary methods.

  18. Measurement of Minority-Carrier Lifetime in Silicon Solar Cells by ...

    African Journals Online (AJOL)

    This manuscript describes the measurement of minority - carrier lifetime of silicon solar cells, at room temperature, by photoconductive decay method. The Holobeam, Model 655 Double-Pulsed Holographic system, is used as the light source. This consists of a Q-switched, pulsed ruby laser oscillator with two ruby laser ...

  19. Effect of Thermal Annealing on Light-Induced Minority Carrier Lifetime Enhancement in Boron-Doped Czochralski Silicon

    International Nuclear Information System (INIS)

    Wang Hong-Zhe; Zheng Song-Sheng; Chen Chao

    2015-01-01

    The effect of thermal annealing on the light-induced effective minority carrier lifetime enhancement (LIE) phenomenon is investigated on the p-type Czochralski silicon (Cz-Si) wafer passivated by a phosphorus-doped silicon nitride (P-doped SiN_x) thin film. The experimental results show that low temperature annealing (below 300°C) can not only increase the effective minority carrier lifetime of P-doped SiN_x passivated boron-doped Cz-Si, but also improve the LIE phenomenon. The optimum annealing temperature is 180°C, and its corresponding effective minority carrier lifetime can be increased from initial 7.5 μs to maximum 57.7 μs by light soaking within 15 min after annealing. The analysis results of high-frequency dark capacitance-voltage characteristics reveal that the mechanism of the increase of effective minority carrier lifetime after low temperature annealing is due to the sharp enhancement of field effect passivation induced by the negative fixed charge density, while the mechanism of the LIE phenomenon after low temperature annealing is attributed to the enhancement of both field effect passivation and chemical passivation. (paper)

  20. Guanidinium: A Route to Enhanced Carrier Lifetime and Open-Circuit Voltage in Hybrid Perovskite Solar Cells.

    Science.gov (United States)

    De Marco, Nicholas; Zhou, Huanping; Chen, Qi; Sun, Pengyu; Liu, Zonghao; Meng, Lei; Yao, En-Ping; Liu, Yongsheng; Schiffer, Andy; Yang, Yang

    2016-02-10

    Hybrid perovskites have shown astonishing power conversion efficiencies owed to their remarkable absorber characteristics including long carrier lifetimes, and a relatively substantial defect tolerance for solution-processed polycrystalline films. However, nonradiative charge carrier recombination at grain boundaries limits open circuit voltages and consequent performance improvements of perovskite solar cells. Here we address such recombination pathways and demonstrate a passivation effect through guanidinium-based additives to achieve extraordinarily enhanced carrier lifetimes and higher obtainable open circuit voltages. Time-resolved photoluminescence measurements yield carrier lifetimes in guanidinium-based films an order of magnitude greater than pure-methylammonium counterparts, giving rise to higher device open circuit voltages and power conversion efficiencies exceeding 17%. A reduction in defect activation energy of over 30% calculated via admittance spectroscopy and confocal fluorescence intensity mapping indicates successful passivation of recombination/trap centers at grain boundaries. We speculate that guanidinium ions serve to suppress formation of iodide vacancies and passivate under-coordinated iodine species at grain boundaries and within the bulk through their hydrogen bonding capability. These results present a simple method for suppressing nonradiative carrier loss in hybrid perovskites to further improve performances toward highly efficient solar cells.

  1. Differential carrier lifetime and transport effects in electrically injected III-nitride light-emitting diodes

    Science.gov (United States)

    Rashidi, A.; Nami, M.; Monavarian, M.; Aragon, A.; DaVico, K.; Ayoub, F.; Mishkat-Ul-Masabih, S.; Rishinaramangalam, A.; Feezell, D.

    2017-07-01

    This work describes a small-signal microwave method for determining the differential carrier lifetime and transport effects in electrically injected InGaN/GaN light-emitting diodes (LEDs). By considering the carrier diffusion, capture, thermionic escape, and recombination, the rate equations are used to derive an equivalent small-signal electrical circuit for the LEDs, from which expressions for the input impedance and modulation response are obtained. The expressions are simultaneously fit to the experimental data for the input impedance and modulation response for nonpolar InGaN/GaN micro-LEDs on free-standing GaN substrates. The fittings are used to extract the transport related circuit parameters and differential carrier lifetimes. The dependence of the parameters on the device diameter and current density is reported. We also derive approximations for the modulation response under low and high injection levels and show that the transport of carriers affects the modulation response of the device, especially at low injection levels. The methods presented are relevant to the design of high-speed LEDs for visible-light communication.

  2. Minority carrier lifetime in mid-wavelength infrared InAs/InAsSb superlattices: Photon recycling and the role of radiative and Shockley-Read-Hall recombination mechanisms

    International Nuclear Information System (INIS)

    Höglund, L.; Ting, D. Z.; Soibel, A.; Fisher, A.; Khoshakhlagh, A.; Hill, C. J.; Keo, S.; Gunapala, S. D.

    2014-01-01

    The influence of radiative recombination on the minority carrier lifetime in mid-wavelength InAs/InAsSb superlattices was investigated. From the lifetime's dependence on temperature, photon recycling, and carrier concentration, it was demonstrated that radiative lifetime dominates for carrier concentrations >5 × 10 14  cm −3 , and Shockley-Read-Hall recombination starts to dominate the minority carrier lifetime for carrier concentrations <5 × 10 14  cm −3 . An observed increase of the minority carrier lifetime with increasing superlattice thickness was attributed to photon recycling, and good agreement between measured and theoretical values of the photon recycling factor was obtained

  3. Effect of Copper on the Carrier Lifetime in Black Silicon

    DEFF Research Database (Denmark)

    Porte, Henrik; Turchinovich, Dmitry; Persheyev, Saydulla

    2011-01-01

    Black silicon is produced by laser annealing of a-Si:H films. During annealing, silicon microstructures are formed on the surface. We use time-resolved terahertz spectroscopy to study the photoconductivity dynamics in black silicon. We find that when a copper film is deposited on top of the a......-Si:H layer prior to laser annealing, the carrier lifetime of black silicon is significantly reduced....

  4. Lower reflectivity and higher minority carrier lifetime of hand-tailored porous silicon

    International Nuclear Information System (INIS)

    Zhang Nansheng; Ma Zhongquan; Zhou Chengyue; He Bo

    2009-01-01

    Solar cell grade crystalline silicon with very low reflectivity has been obtained by electrochemically selective erosion. The porous silicon (PS) structure with a mixture of nano- and micro-crystals shows good antireflection properties on the surface layer, which has potential for application in commercial silicon photovoltaic devices after optimization. The morphology and reflectivity of the PS layers are easily modulated by controlling the electrochemical formation conditions (i.e., the current density and the anodization time). It has been shown that much a lower reflectivity of approximately 1.42% in the range 380-1100 nm is realized by using optimized conditions. In addition, the minority carrier lifetime of the PS after removing the phosphorus silicon layer is measured to be ∼3.19 μs. These values are very close to the reflectivity and the minority carrier lifetime of Si 3 N 4 as a passivation layer on a bulk silicon-based solar cell (0.33% and 3.03 μs, respectively).

  5. Hot carrier degradation and a new lifetime prediction model in ultra-deep sub-micron pMOSFET

    International Nuclear Information System (INIS)

    Lei Xiao-Yi; Liu Hong-Xia; Zhang Kai; Zhang Yue; Zheng Xue-Feng; Ma Xiao-Hua; Hao Yue

    2013-01-01

    The hot carrier effect (HCE) of an ultra-deep sub-micron p-channel metal—oxide semiconductor field-effect transistor (pMOSFET) is investigated in this paper. Experiments indicate that the generation of positively charged interface states is the predominant mechanism in the case of the ultra-deep sub-micron pMOSFET. The relation of the pMOSFET hot carrier degradation to stress time (t), channel width (W), channel length (L), and stress voltage (V d ) is then discussed. Based on the relation, a lifetime prediction model is proposed, which can predict the lifetime of the ultra-deep sub-micron pMOSFET accurately and reflect the influence of the factors on hot carrier degradation directly. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  6. Influence of stain etching on low minority carrier lifetime areas of multicrystalline silicon for solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Montesdeoca-Santana, A. [Departamento de Fisica Basica, Universidad de La Laguna, Avda. Astrofisico Francisco Sanchez, 38206 La Laguna (Spain); Fraunhofer Institute for Solar Energy Systems, Laboratory and Servicecenter Gelsenkirchen, Auf der Reihe 2, 45884 Gelsenkirchen (Germany); Gonzalez-Diaz, B. [Departamento de Fisica Basica, Universidad de La Laguna, Avda. Astrofisico Francisco Sanchez, 38206 La Laguna (Spain); Departamento de Energia Fotovoltaica, Instituto Tecnologico y de Energias Renovables. Poligono Industrial de Granadilla s/n, 38600 San Isidro-Granadilla de Abona (Spain); Jimenez-Rodriguez, E. [Departamento de Fisica Basica, Universidad de La Laguna, Avda. Astrofisico Francisco Sanchez, 38206 La Laguna (Spain); Ziegler, J. [Fraunhofer Institute for Solar Energy Systems, Laboratory- and Servicecenter Gelsenkirchen. Auf der Reihe 2, 45884 Gelsenkirchen (Germany); Velazquez, J.J. [Departamento de Fisica Fundamental y Experimental, Electronica y Sistemas, Universidad de La Laguna. Avda. Astrofisico Francisco Sanchez, 38206 La Laguna (Spain); Hohage, S.; Borchert, D. [Fraunhofer Institute for Solar Energy Systems, Laboratory and Servicecenter Gelsenkirchen. Auf der Reihe 2, 45884 Gelsenkirchen (Germany); Guerrero-Lemus, R., E-mail: rglemus@ull.es [Departamento de Fisica Basica, Universidad de La Laguna, Avda. Astrofisico Francisco Sanchez, 38206 La Laguna (Spain)

    2011-11-15

    Highlights: > An enhanced minority carrier lifetime at extended defects in multicrystalline silicon is observed with the use of HF/HNO{sub 3} stain etching to texture the surface. > FTIR analysis shows no influence of oxide passivation in this effect. > SEM images show a preferential etching at extended defects suggesting smoothing at defects as one of the causes for the reduced recombination activity. > LBIC images show a reduction in IQE at extended defects in HF/HNO{sub 3} textured multicrystalline solar cells. - Abstract: In this work the use of HF/HNO{sub 3} solutions for texturing silicon-based solar cell substrates by stain etching and the influence of texturing on minority carrier lifetimes are studied. Stain etching is currently used to decrease the reflectance and, subsequently improve the photogenerated current of the cells, but also produces nanostructures on the silicon surface. In the textured samples it has been observed that an improvement on the minority carrier lifetime with respect to the samples treated with a conventional saw damage etching process is produced on grain boundaries and defects, and the origin of this effect has been discussed.

  7. Influence of stain etching on low minority carrier lifetime areas of multicrystalline silicon for solar cells

    International Nuclear Information System (INIS)

    Montesdeoca-Santana, A.; Gonzalez-Diaz, B.; Jimenez-Rodriguez, E.; Ziegler, J.; Velazquez, J.J.; Hohage, S.; Borchert, D.; Guerrero-Lemus, R.

    2011-01-01

    Highlights: → An enhanced minority carrier lifetime at extended defects in multicrystalline silicon is observed with the use of HF/HNO 3 stain etching to texture the surface. → FTIR analysis shows no influence of oxide passivation in this effect. → SEM images show a preferential etching at extended defects suggesting smoothing at defects as one of the causes for the reduced recombination activity. → LBIC images show a reduction in IQE at extended defects in HF/HNO 3 textured multicrystalline solar cells. - Abstract: In this work the use of HF/HNO 3 solutions for texturing silicon-based solar cell substrates by stain etching and the influence of texturing on minority carrier lifetimes are studied. Stain etching is currently used to decrease the reflectance and, subsequently improve the photogenerated current of the cells, but also produces nanostructures on the silicon surface. In the textured samples it has been observed that an improvement on the minority carrier lifetime with respect to the samples treated with a conventional saw damage etching process is produced on grain boundaries and defects, and the origin of this effect has been discussed.

  8. Dependence of InGaN solar cell performance on polarization-induced electric field and carrier lifetime

    International Nuclear Information System (INIS)

    Yang Jing; Zhao De-Gang; Jiang De-Sheng; Liu Zong-Shun; Chen Ping; Li Liang; Wu Liang-Liang; Le Ling-Cong; Li Xiao-Jing; He Xiao-Guang; Yang Hui; Wang Hui; Zhu Jian-Jun; Zhang Shu-Ming; Zhang Bao-Shun

    2013-01-01

    The effects of Mg-induced net acceptor doping concentration and carrier lifetime on the performance of a p—i—n InGaN solar cell are investigated. It is found that the electric field induced by spontaneous and piezoelectric polarization in the i-region could be totally shielded when the Mg-induced net acceptor doping concentration is sufficiently high. The polarization-induced potential barriers are reduced and the short circuit current density is remarkably increased from 0.21 mA/cm 2 to 0.95 mA/cm 2 by elevating the Mg doping concentration. The carrier lifetime determined by defect density of i-InGaN also plays an important role in determining the photovoltaic properties of solar cell. The short circuit current density severely degrades, and the performance of InGaN solar cell becomes more sensitive to the polarization when carrier lifetime is lower than the transit time. This study demonstrates that the crystal quality of InGaN absorption layer is one of the most important challenges in realizing high efficiency InGaN solar cells. (interdisciplinary physics and related areas of science and technology)

  9. Increased carrier lifetimes in epitaxial silicon layers on buried silicon nitride produced by ion implantation

    International Nuclear Information System (INIS)

    Skorupa, W.; Kreissig, U.; Hensel, E.; Bartsch, H.

    1984-01-01

    Carrier lifetimes were measured in epitaxial silicon layers deposited on buried silicon nitride produced by high-dose nitrogen implantation at 330 keV. The values were in the range 20-200 μs. The results are remarkable taking into account the high density of crystal defects in the epitaxial layers. Comparing with other SOI technologies the measured lifetimes are higher by 1-2 orders of magnitude. (author)

  10. The Role of Polymer Fractionation in Energetic Losses and Charge Carrier Lifetimes of Polymer: Fullerene Solar Cells

    KAUST Repository

    Baran, Derya

    2015-08-10

    Non-radiative recombination reduces the open-circuit voltage relative to its theoretical limit and leads to reduced luminescence emission at a given excitation. Therefore it is possible to correlate changes in luminescence emission with changes in open-circuit voltage and in the charge carrier lifetime. Here we use luminescence studies combined with transient photovoltage and differential charging analyses to study the effect of polymer fractionation in indacenoedithiophene-co-benzothiadiazole (IDTBT):fullerene solar cells. In this system, polymer fractionation increases electroluminescence and reduces non-radiative recombination. High molecular weight and fractionated IDTBT polymers exhibit higher carrier lifetime-mobility product compared to their non-fractionated analogues, resulting in improved solar cell performance.

  11. The Role of Polymer Fractionation in Energetic Losses and Charge Carrier Lifetimes of Polymer: Fullerene Solar Cells

    KAUST Repository

    Baran, Derya; Vezie, Michelle S; Gasparini, Nicola; Deledalle, Florent; Yao, Jizhong; Schroeder, Bob C.; Bronstein, Hugo; Ameri, Tayebeh; Kirchartz, Thomas; McCulloch, Iain; Nelson, Jenny; Brabec, Christoph J

    2015-01-01

    Non-radiative recombination reduces the open-circuit voltage relative to its theoretical limit and leads to reduced luminescence emission at a given excitation. Therefore it is possible to correlate changes in luminescence emission with changes in open-circuit voltage and in the charge carrier lifetime. Here we use luminescence studies combined with transient photovoltage and differential charging analyses to study the effect of polymer fractionation in indacenoedithiophene-co-benzothiadiazole (IDTBT):fullerene solar cells. In this system, polymer fractionation increases electroluminescence and reduces non-radiative recombination. High molecular weight and fractionated IDTBT polymers exhibit higher carrier lifetime-mobility product compared to their non-fractionated analogues, resulting in improved solar cell performance.

  12. Light-induced enhancement of the minority carrier lifetime in boron-doped Czochralski silicon passivated by doped silicon nitride

    International Nuclear Information System (INIS)

    Wang, Hongzhe; Chen, Chao; Pan, Miao; Sun, Yiling; Yang, Xi

    2015-01-01

    Graphical abstract: - Highlights: • The phosphorus-doped SiN x with negative fixed charge was deposited by PECVD. • The increase of lifetime was observed on P-doped SiN x passivated Si under illumination. • The enhancement of lifetime was caused by the increase of negative fixed charges. - Abstract: This study reports a doubling of the effective minority carrier lifetime under light soaking conditions, observed in a boron-doped p-type Czochralski grown silicon wafer passivated by a phosphorus-doped silicon nitride thin film. The analysis of capacitance–voltage curves revealed that the fixed charge in this phosphorus-doped silicon nitride film was negative, which was unlike the well-known positive fixed charges observed in traditional undoped silicon nitride. The analysis results revealed that the enhancement phenomenon of minority carrier lifetime was caused by the abrupt increase in the density of negative fixed charge (from 7.2 × 10 11 to 1.2 × 10 12 cm −2 ) after light soaking.

  13. Theoretical insights into the minority carrier lifetime of doped Si—A computational study

    Science.gov (United States)

    Iyakutti, K.; Lavanya, R.; Rajeswarapalanichamy, R.; Mathan Kumar, E.; Kawazoe, Y.

    2018-04-01

    Using density functional theory, we have analyzed the ways and means of improving the minority carrier lifetime (MCL) by calculating the band structure dependent quantities contributing to the MCL. We have computationally modeled silicon doped with different elements like B, C, N, O, P, Ti, Fe, Ga, Ge, As, In, Sn, Sb, and Pt and looked at the effect of doping on MCL. In co-doping, the systems Si-B-Ga, Si-B-Ge, Si-B-2Ge, Si-B-Pt, Si-Ga-Ge, Si-Ga-2Ge, and Si-Ga-Pt are investigated. From our calculation, it is found that by doping and co-doping of Si with suitable elements having "s" and "p" electrons, there is a decrease in the recombination activity. The predicted effective minority carrier lifetime indicates the possibility of significant improvements. Based on the above studies, it is now maybe possible, with suitable choice of dopant and co-dopant material, to arrive at part of a standard production process for solar grade Si material.

  14. Effective lifetime of minority carriers in black silicon nano-textured by cones and pyramids

    DEFF Research Database (Denmark)

    Onyshchenko, V.F.; Karachevtseva, L.A.; Lytvynenko, O.O.

    2017-01-01

    We calculated the dependence of effective lifetime of minority carriers in black silicon nano-textured by cones and pyramids on the diameter of the cone base, the side of the pyramid base, the height of cone and pyramid. The numerical calculation shows that n-type polished plate of single crystal...

  15. Carrier Lifetimes in Fluorescent 6H-SiC for LEDs Application

    DEFF Research Database (Denmark)

    Grivickas, Vytautas; Gulbinas, Karolis; Jokubavičius, Valdas

    Recently it was shown a new approach based on all-semiconductor material technology which is composed with a near ultra-violet GaN LED excitation source and fluorescent silicon carbide (f-6H-SiC) substrate which generates a visible broad spectral light by N and B dopants and an efficient donor...... to acceptor pair recombination [1,2]. This combination can achieve higher electric-light conversion efficiency and high color rendering in comparison with today’s used blue GaN LED based and phosphors. The devices are promising candidates for general lightning applications and may obtain stability...... under co-linear and orthogonal probe geometry was used to measure carrier lifetimes in the layers under variable injection conditions. Same results are shown in Fig. 1 exaggerating the fact that longer electron lifetime responsible for higher emission and n-type doping should prevail the p-type doping...

  16. Minority carrier lifetime and dark current measurements in mid-wavelength infrared InAs0.91Sb0.09 alloy nBn photodetectors

    Science.gov (United States)

    Olson, B. V.; Kim, J. K.; Kadlec, E. A.; Klem, J. F.; Hawkins, S. D.; Leonhardt, D.; Coon, W. T.; Fortune, T. R.; Cavaliere, M. A.; Tauke-Pedretti, A.; Shaner, E. A.

    2015-11-01

    Carrier lifetime and dark current measurements are reported for a mid-wavelength infrared InAs0.91Sb0.09 alloy nBn photodetector. Minority carrier lifetimes are measured using a non-contact time-resolved microwave technique on unprocessed portions of the nBn wafer and the Auger recombination Bloch function parameter is determined to be |F1F2|=0.292 . The measured lifetimes are also used to calculate the expected diffusion dark current of the nBn devices and are compared with the experimental dark current measured in processed photodetector pixels from the same wafer. Excellent agreement is found between the two, highlighting the important relationship between lifetimes and diffusion currents in nBn photodetectors.

  17. A new approach to determine accurately minority-carrier lifetime

    International Nuclear Information System (INIS)

    Idali Oumhand, M.; Mir, Y.; Zazoui, M.

    2009-01-01

    Electron or proton irradiations introduce recombination centers, which tend to affect solar cell parameters by reducing the minority-carrier lifetime (MCLT). Because this MCLT plays a fundamental role in the performance degradation of solar cells, in this work we present a new approach that allows us to get accurate values of MCLT. The relationship between MCLT in p-region and n-region both before and after irradiation has been determined by the new method. The validity and accuracy of this approach are justified by the fact that the degradation parameters that fit the experimental data are the same for both short-circuit current and the open-circuit voltages. This method is applied to the p + /n-InGaP solar cell under 1 MeV electron irradiation

  18. Carrier Lifetime in Exfoliated Few-Layer Graphene Determined from Intersubband Optical Transitions

    Science.gov (United States)

    Limmer, Thomas; Feldmann, Jochen; Da Como, Enrico

    2013-05-01

    We report a femtosecond transient spectroscopy study in the near to middle infrared range, 0.8-0.35 eV photon energy, on graphene and few layer graphene single flakes. The spectra show an evolving structure of photoinduced absorption bands superimposed on the bleaching caused by Pauli blocking of the interband optically coupled states. Supported by tight-binding model calculations, we assign the photoinduced absorption features to intersubband transitions as the number of layers is increased. Interestingly, the intersubband photoinduced resonances show a longer dynamics than the interband bleaching, because of their independence from the absolute energy of the carriers with respect to the Dirac point. The dynamic of these intersubband transitions reflects the lifetime of the hot carriers and provides an elegant method to access it in this important class of semimetals.

  19. Carrier lifetime in exfoliated few-layer graphene determined from intersubband optical transitions.

    Science.gov (United States)

    Limmer, Thomas; Feldmann, Jochen; Da Como, Enrico

    2013-05-24

    We report a femtosecond transient spectroscopy study in the near to middle infrared range, 0.8-0.35 eV photon energy, on graphene and few layer graphene single flakes. The spectra show an evolving structure of photoinduced absorption bands superimposed on the bleaching caused by Pauli blocking of the interband optically coupled states. Supported by tight-binding model calculations, we assign the photoinduced absorption features to intersubband transitions as the number of layers is increased. Interestingly, the intersubband photoinduced resonances show a longer dynamics than the interband bleaching, because of their independence from the absolute energy of the carriers with respect to the Dirac point. The dynamic of these intersubband transitions reflects the lifetime of the hot carriers and provides an elegant method to access it in this important class of semimetals.

  20. Effects of Radiative Recombination and Photon Recycling on Minority Carrier Lifetime in Epitaxial GaINAsSb Lattice-matched to GaSb

    International Nuclear Information System (INIS)

    S Anikeev; D Donetsky; G Belenky; S Luryl; CA Wang; DA Shiau; M Dashiell; J Beausang; G Nichols

    2004-01-01

    Radiative coefficient (B) is a fundamental recombination parameter which is of importance for a variety of optoelectronic minority carrier devices. Radiative recombination was comprehensively studied for wide-bandgap III-V compounds, while for 0.5-0.6 eV materials experimental data are quite limited and demonstrate significant spreading. Here we report excess carrier lifetime in isotype double heterostructures (DHs) of 0.54-eV p-GaInAsSb capped with p-AlGaAsSb, and grown lattice-matched to GaSb. Lifetime was measured by time-resolved photoluminescence (dynamic lifetime) as well as by optical response to sinusoidal excitation (static lifetime). Wide range of GaInAsSb layer thickness was used to separate contributions from interface and radiative recombination processes. Radiative coefficient and recombination velocity at GaInAsSb/AlGaAsSb heterointerface were determined. Temperature dependence of lifetime demonstrated significant contribution of radiative effects to the total recombination

  1. Carrier-lifetime-controlled selective etching process for semiconductors using photochemical etching

    International Nuclear Information System (INIS)

    Ashby, C.I.H.; Myers, D.R.

    1992-01-01

    This patent describes a process for selectively photochemically etching a semiconductor material. It comprises introducing at least one impurity into at least one selected region of a semiconductor material to be etched to increase a local impurity concentration in the at least one selected region relative to an impurity concentration in regions of the semiconductor material adjacent thereto, for reducing minority carrier lifetimes within the at least one selected region relative to the adjacent regions for thereby providing a photochemical etch-inhibiting mask at the at least one selected region; and etching the semiconductor material by subjecting the surface of the semiconductor material to a carrier-driven photochemical etching reaction for selectively etching the regions of the semiconductor material adjacent the at least one selected region having the increase impurity concentration; wherein the step of introducing at least one impurity is performed so as not to produce damage to the at least one selected region before any etching is performed

  2. Deep level transient spectroscopy and minority carrier lifetime study on Ga-doped continuous Czochralski silicon

    Science.gov (United States)

    Yoon, Yohan; Yan, Yixin; Ostrom, Nels P.; Kim, Jinwoo; Rozgonyi, George

    2012-11-01

    Continuous-Czochralski (c-Cz) crystal growth has been suggested as a viable technique for the fabrication of photovoltaic Si wafers due to its low resistivity variation of any dopant, independent of segregation, compared to conventional Cz. In order to eliminate light induced degradation due to boron-oxygen traps in conventional p-type silicon wafers, gallium doped wafers have been grown by c-Cz method and investigated using four point probe, deep level transient spectroscopy (DLTS), and microwave-photoconductance decay. Iron-gallium related electrically active defects were identified using DLTS as the main lifetime killers responsible for reduced non-uniform lifetimes in radial and axial positions of the c-Cz silicon ingot. A direct correlation between minority carrier lifetime and the concentration of electrically active Fe-Ga pairs was established.

  3. Kerfless epitaxial silicon wafers with 7 ms carrier lifetimes and a wide lift-off process window

    Science.gov (United States)

    Gemmel, Catherin; Hensen, Jan; David, Lasse; Kajari-Schröder, Sarah; Brendel, Rolf

    2018-04-01

    Silicon wafers contribute significantly to the photovoltaic module cost. Kerfless silicon wafers that grow epitaxially on porous silicon (PSI) and are subsequently detached from the growth substrate are a promising lower cost drop-in replacement for standard Czochralski (Cz) wafers. However, a wide technological processing window appears to be a challenge for this process. This holds in particularly for the etching current density of the separation layer that leads to lift-off failures if it is too large or too low. Here we present kerfless PSI wafers of high electronic quality that we fabricate on weakly reorganized porous Si with etch current densities varying in a wide process window from 110 to 150 mA/cm2. We are able to detach all 17 out of 17 epitaxial wafers. All wafers exhibit charge carrier lifetimes in the range of 1.9 to 4.3 ms at an injection level of 1015 cm-3 without additional high-temperature treatment. We find even higher lifetimes in the range of 4.6 to 7.0 ms after applying phosphorous gettering. These results indicate that a weak reorganization of the porous layer can be beneficial for a large lift-off process window while still allowing for high carrier lifetimes.

  4. Mapping Charge Carrier Density in Organic Thin-Film Transistors by Time-Resolved Photoluminescence Lifetime Studies

    DEFF Research Database (Denmark)

    Leißner, Till; Jensen, Per Baunegaard With; Liu, Yiming

    2017-01-01

    The device performance of organic transistors is strongly influenced by the charge carrier distribution. A range of factors effect this distribution, including injection barriers at the metal-semiconductor interface, the morphology of the organic film, and charge traps at the dielectric/organic...... interface or at grain boundaries. In our comprehensive experimental and analytical work we demonstrate a method to characterize the charge carrier density in organic thin-film transistors using time-resolved photoluminescence spectroscopy. We developed a numerical model that describes the electrical...... and optical responses consistently. We determined the densities of free and trapped holes at the interface between the organic layer and the SiO2 gate dielectric by comparison to electrical measurements. Furthermore by applying fluorescence lifetime imaging microscopy we determine the local charge carrier...

  5. Depth distribution of carrier lifetime in 65 MeV oxygen ion irradiated silicon wafers

    Energy Technology Data Exchange (ETDEWEB)

    Shinde, N.S. [Ecotopia Science Institute, Division of Energy Science, Nagoya University, Nagoya (Japan); Dahiwale, S.S. [Department of Physics, University of Pune, Pune 411 007 (India); Kanjilal, D. [Nuclear Science Centre, New Delhi (India); Bhoraskar, V.N. [Department of Physics, University of Pune, Pune 411 007 (India); Dhole, S.D. [Department of Physics, University of Pune, Pune 411 007 (India)]. E-mail: sanjay@physics.unipune.ernet.in

    2006-03-15

    CZ-grown, n-doped crystalline Si(1 1 1) of resistivity 60 {omega} cm and 140 {omega} cm were irradiated with 65 MeV energy oxygen ions, in the fluence range of 2 x 10{sup 1}-10{sup 14} ions/cm{sup 2}. The depth and spatial profile of excess minority carrier recombination time {tau} (lifetime) was measured using photoconductive decay (PCD) method. Lifetime measurements were carried out before the stopping range of impinging ions. Results show a monotonous decrease in lifetime with fluence, which is attributed to defect creation mechanism by electronic energy loss based on the thermal spike model. Also, surface modification is expected with a small loss in crystalline quality. This surface is considered to be a multi-crystalline surface with large grain boundaries that act as trapping sites for excess holes in n-Si(1 1 1). Annealing of the irradiated samples showed a near complete recovery at 750 deg. C for a period of 1 h.

  6. The Impact of Metallic Impurities on Minority Carrier Lifetime in High Purity N-type Silicon

    Science.gov (United States)

    Yoon, Yohan

    Boron-doped p-type silicon is the industry standard silicon solar cell substrate. However, it has serious limitations: iron boron (Fe-B) pairs and light induced degradation (LID). To suppress LID, the replacement of boron by gallium as a p-type dopant has been proposed. Although this eliminates B-O related defects, gallium-related pairing with iron, oxygen, and carbon can reduce lifetime in this material. In addition resistivity variations are more pronounced in gallium doped ingots, however Continuous-Czochralski (c-Cz) growth technologies are being developed to overcome this problem. In this work lifetime limiting factors and resistivity variations have been investigated in this material. The radial and axial variations of electrically active defects were observed using deep level transient spectroscopy (DLTS) these have been correlated to lifetime and resistivity variations. The DLTS measurements demonstrated that iron-related pairs are responsible for the lifetime variations. Specifically, Fe-Ga pairs were found to be important recombination sites and are more detrimental to lifetime than Fei. Typically n-type silicon has a higher minority carrier lifetime than p-type silicon with similar levels of contamination. That is because n-type silicon is more tolerant to metallic impurities, especially Fe. Also, it has no serious issues in relation to lifetime degradation, such as FeB pairs and light-induced degradation (LID). However, surface passivation of the p + region in p+n solar cells is much more problematic than the n+p case where silicon nitride provides very effective passivation of the cell. SiO2 is the most effective passivation for n type surfaces, but it does not work well on B-doped surfaces, resulting in inadequate performance. Al2O3 passivation layer suggested for B-doped emitters. With this surface passivation layer a 23.2 % conversion efficiency has been achieved. After this discovery n-type silicon is now being seriously considered for

  7. Effect of Rapid Thermal Processing on Light-Induced Degradation of Carrier Lifetime in Czochralski p-Type Silicon Bare Wafers

    Science.gov (United States)

    Kouhlane, Y.; Bouhafs, D.; Khelifati, N.; Belhousse, S.; Menari, H.; Guenda, A.; Khelfane, A.

    2016-11-01

    The electrical properties of Czochralski silicon (Cz-Si) p-type boron-doped bare wafers have been investigated after rapid thermal processing (RTP) with different peak temperatures. Treated wafers were exposed to light for various illumination times, and the effective carrier lifetime ( τ eff) measured using the quasi-steady-state photoconductance (QSSPC) technique. τ eff values dropped after prolonged illumination exposure due to light-induced degradation (LID) related to electrical activation of boron-oxygen (BO) complexes, except in the sample treated with peak temperature of 785°C, for which the τ eff degradation was less pronounced. Also, a reduction was observed when using the 830°C peak temperature, an effect that was enhanced by alteration of the wafer morphology (roughness). Furthermore, the electrical resistivity presented good stability under light exposure as a function of temperature compared with reference wafers. Additionally, the optical absorption edge shifted to higher wavelength, leading to increased free-carrier absorption by treated wafers. Moreover, a theoretical model is used to understand the lifetime degradation and regeneration behavior as a function of illumination time. We conclude that RTP plays an important role in carrier lifetime regeneration for Cz-Si wafers via modification of optoelectronic and structural properties. The balance between an optimized RTP cycle and the rest of the solar cell elaboration process can overcome the negative effect of LID and contribute to achievement of higher solar cell efficiency and module performance.

  8. In situ monitoring of stacking fault formation and its carrier lifetime mediation in p-type 4H-SiC

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Bin, E-mail: chenbinmse@gmail.com; Chen, Jun; Yao, Yuanzhao; Sekiguchi, Takashi [National Institute for Materials Science, Tsukuba, Ibaraki 305-0044 (Japan); Matsuhata, Hirofumi; Okumura, Hajime [National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8568 (Japan)

    2014-07-28

    Using the fine control of an electron beam (e-beam) in scanning electron microscopy with the capabilities of both electrical and optical imaging, the stacking fault (SF) formation together with its tuning of carrier lifetime was in situ monitored and investigated in p-type 4H-SiC homoepitaxial films. The SFs were formed through engineering basal plane dislocations with the energy supplied by the e-beam. The e-beam intensity required for the SF formation in the p-type films was ∼100 times higher than that in the n-type ones. The SFs reduced the minority-carrier lifetime in the p-type films, which was opposite to that observed in the n-type case. The reason for the peculiar SF behavior in the p-type 4H-SiC is discussed with the cathodoluminescence results.

  9. Oxygen and minority carrier lifetimes in N-and P-type AL0.2GA0.8AS grown by metal organics vapor phase epitaxy

    International Nuclear Information System (INIS)

    Zahraman, Khaled; Leroux, M.; Gibart, P.; Zaidi, M.A.; Bremond, G.; Guillot, G.

    2000-01-01

    author.The minority carrier lifetimes in Al x Ga 1-x As grown by Metal-Organics Vapor Phase Epitaxy (MOVPE) is generally lower than in GaAs. This is believed to be due to oxygen incorporation in the layers. We describe a study of radiative and non radiative minority carriers lifetimes in n-and p-type Al 0.2 Ga 0.8 As as a function of growth parameters, in correlation with oxygen concentration measurements and deep level transient spectroscopy (DLTS) studies. Long non radiative lifetimes and low oxygen contents are achieved using temperature growth. A main minority hole lifetime killer appears to be 0.4 eV deep O related electron trap detected by DLTS at concentrations three orders of magnitude lower than the atomic oxygen one. Record lifetimes in MOVPE grown n-and p-type Al 0.2 Ga 0.8 As are obtained. An Al 0.85 Ga 0.15 As/Al 0.2 Ga 0.8 As surface recombination velocity lower than 4.5x10 3 cm.s -1 is measured

  10. Simultaneous determination of effective carrier lifetime and resistivity of Si wafers using the nonlinear nature of photocarrier radiometric signals

    Science.gov (United States)

    Sun, Qiming; Melnikov, Alexander; Wang, Jing; Mandelis, Andreas

    2018-04-01

    A rigorous treatment of the nonlinear behavior of photocarrier radiometric (PCR) signals is presented theoretically and experimentally for the quantitative characterization of semiconductor photocarrier recombination and transport properties. A frequency-domain model based on the carrier rate equation and the classical carrier radiative recombination theory was developed. The derived concise expression reveals different functionalities of the PCR amplitude and phase channels: the phase bears direct quantitative correlation with the carrier effective lifetime, while the amplitude versus the estimated photocarrier density dependence can be used to extract the equilibrium majority carrier density and thus, resistivity. An experimental ‘ripple’ optical excitation mode (small modulation depth compared to the dc level) was introduced to bypass the complicated ‘modulated lifetime’ problem so as to simplify theoretical interpretation and guarantee measurement self-consistency and reliability. Two Si wafers with known resistivity values were tested to validate the method.

  11. The effects of inorganic surface treatments on photogenerated carrier mobility and lifetime in PbSe quantum dot thin films

    Energy Technology Data Exchange (ETDEWEB)

    Goodwin, E.D.; Straus, Daniel B. [Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104 (United States); Gaulding, E. Ashley [Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA 19104 (United States); Murray, Christopher B. [Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104 (United States); Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA 19104 (United States); Kagan, Cherie R., E-mail: kagan@seas.upenn.edu [Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104 (United States); Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA 19104 (United States); Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA 19104 (United States)

    2016-06-01

    Highlights: • Na{sub 2}Se and PbCl{sub 2} treatments modified the surface chemistry of PbSe quantum dots. • Excess Se (Pb) p-doped (n-doped) PbSe quantum dot thin films. • Carrier mobility and lifetime were studied using time-resolved microwave conductivity. • Mobility increased as the Fermi level approached the band edges. - Abstract: We used flash-photolysis, time-resolved microwave conductivity (TRMC) to probe the carrier mobility and lifetime in PbSe quantum dot (QD) thin films treated with solutions of the metal salts of Na{sub 2}Se and PbCl{sub 2}. The metal salt treatments tuned the Pb:Se stoichiometry and swept the Fermi energy throughout the QD thin film bandgap. A stoichiometric imbalance favoring excess Se heavily p-doped the QD thin film, shifted the Fermi energy toward the valence band, and yielded the highest TRMC mobility and lifetime. Introducing Pb first compensated the p-doping and shifted the Fermi level through mid-gap, decreasing the TRMC mobility. Further Pb addition created an excess of Pb, n-doped the QD thin film, moved the Fermi level to near the conduction band, and again increased the TRMC mobility. The increase in TRMC mobility as the Fermi energy was shifted toward the band edges by non-stoichiometry is consistent with the QD thin film density of states.

  12. Analytic 1D pn junction diode photocurrent solutions following ionizing radiation and including time-dependent changes in the carrier lifetime.

    Energy Technology Data Exchange (ETDEWEB)

    Axness, Carl L.; Keiter, Eric Richard; Kerr, Bert (New Mexico Tech, Socorro, NM)

    2011-04-01

    Circuit simulation tools (e.g., SPICE) have become invaluable in the development and design of electronic circuits in radiation environments. These codes are often employed to study the effect of many thousands of devices under transient current conditions. Device-scale simulation tools (e.g., MEDICI) are commonly used in the design of individual semiconductor components, but require computing resources that make their incorporation into a circuit code impossible for large-scale circuits. Analytic solutions to the ambipolar diffusion equation, an approximation to the carrier transport equations, may be used to characterize the transient currents at nodes within a circuit simulator. We present new transient 1D excess carrier density and photocurrent density solutions to the ambipolar diffusion equation for low-level radiation pulses that take into account a finite device geometry, ohmic fields outside the depleted region, and an arbitrary change in the carrier lifetime due to neutron irradiation or other effects. The solutions are specifically evaluated for the case of an abrupt change in the carrier lifetime during or after, a step, square, or piecewise linear radiation pulse. Noting slow convergence of the raw Fourier series for certain parameter sets, we use closed-form formulas for some of the infinite sums to produce 'partial closed-form' solutions for the above three cases. These 'partial closed-form' solutions converge with only a few tens of terms, which enables efficient large-scale circuit simulations.

  13. Lifetime measurements by open circuit voltage decay in GaAs and InP diodes

    International Nuclear Information System (INIS)

    Bhimnathwala, H.G.; Tyagi, S.D.; Bothra, S.; Ghandhi, S.K.; Borrego, J.M.

    1990-01-01

    Minority carrier lifetimes in the base of solar cells made in GaAs and InP are measured by open circuit voltage decay method. This paper describes the measurement technique and the conditions under which the minority carrier lifetimes can be measured. Minority carrier lifetimes ranging from 1.6 to 34 ns in InP of different doping concentrations are measured. A minority carrier lifetime of 6 ns was measured in n-type GaAs which agrees well with the lifetime of 5.7 ns measured by transient microwave reflection

  14. Theoretical optimization of base doping concentration for radiation resistance of InGaP subcells of InGaP/GaAs/Ge based on minority-carrier lifetime

    International Nuclear Information System (INIS)

    Elfiky, Dalia; Yamaguchi, Masafumi; Sasaki, Takuo

    2010-01-01

    One of the fundamental objectives for research and development of space solar cells is to improve their radiation resistance. InGaP solar cells with low base carrier concentrations under low-energy proton irradiations have shown high radiation resistances. In this study, an analytical model for low-energy proton radiation damage to InGaP subcells based on a fundamental approach for radiative and nonradiative recombinations has been proposed. The radiation resistance of InGaP subcells as a function of base carrier concentration has been analyzed by using the radiative recombination lifetime and damage coefficient K for the minority-carrier lifetime of InGaP. Numerical analysis shows that an InGaP solar cell with a lower base carrier concentration is more radiation-resistant. Satisfactory agreements between analytical and experimental results have been obtained, and these results show the validity of the analytical procedure. The damage coefficients for minority-carrier diffusion length and carrier removal rate with low-energy proton irradiations have been observed to be dependent on carrier concentration through this study. As physical mechanisms behind the difference observed between the radiation-resistant properties of various base doping concentrations, two mechanisms, namely, the effect of a depletion layer as a carrier collection layer and generation of the impurity-related complex defects due to low-energy protons stopping within the active region, have been proposed. (author)

  15. Effect of 1.5 MeV electron irradiation on β-Ga2O3 carrier lifetime and diffusion length

    Science.gov (United States)

    Lee, Jonathan; Flitsiyan, Elena; Chernyak, Leonid; Yang, Jiancheng; Ren, Fan; Pearton, Stephen J.; Meyler, Boris; Salzman, Y. Joseph

    2018-02-01

    The influence of 1.5 MeV electron irradiation on minority transport properties of Si doped β-Ga2O3 vertical Schottky rectifiers was observed for fluences up to 1.43 × 1016 cm-2. The Electron Beam-Induced Current technique was used to determine the minority hole diffusion length as a function of temperature for each irradiation dose. This revealed activation energies related to shallow donors at 40.9 meV and radiation-induced defects with energies at 18.1 and 13.6 meV. Time-resolved cathodoluminescence measurements showed an ultrafast 210 ps decay lifetime and reduction in carrier lifetime with increased irradiation.

  16. Identification of deep trap energies and influences of oxygen plasma ashing on semiconductor carrier lifetime

    International Nuclear Information System (INIS)

    Koprowski, A; Humbel, O; Plappert, M; Krenn, H

    2015-01-01

    We have performed an analytical study of the effects of oxygen plasma ashing processes in semiconductor device fabrication and its impact on minority carrier lifetime in high voltage semiconductor devices. Our work includes a critical background study of life time killing mechanisms by deep traps imparted into the semiconductor by barrel plasma ashing. The Elymat technique provides the opportunity to measure lifetime and diffusion length of minority carriers and surface photo voltage (SPV) measurement was used to analyse influences of process parameters such as photoresist, time budget and positioning in the process chamber. It was shown that in microwave plasma processes the diffusion length changes severely with tempering at 200 °C, whereas RF-plasma processes show a significant process time-dependence. Batch tools in general suffer from a strong first wafer effect which could be correlated with the static electrical parameters of the semiconductor devices. The trap identities were detected by using deep level transient spectroscopy and the chemical species of the traps has been proven by inductive coupled plasma mass spectrometry. The deep-bandgap trap energies are reliable fingerprints of the chosen process parameters such as process time and of resist-influences. By microwave plasma processes intrinsic Fe and FeB-complex levels were identified and a good agreement with the SPV-measurement and electrical device characteristic was shown. RF-plasma processes impart levels attributed to Pt levels and an additional level, which could be identified as a trap level probably forming a complex of Pt and H. (paper)

  17. Computer based system for measuring the minority carrier lifetime in the solar cells

    International Nuclear Information System (INIS)

    Morales A, A.; Casados C, G.

    1994-01-01

    We show the development of a computer based system for measuring the minority carrier lifetime in the base of silicon solar cells. The system allows using two different techniques for such kind of measurements:the open circuit voltage decay (OCVD) and the surface voltage decay SVD. The equipment is based on internal cards for IBM-Pc or compatible computers that work as an oscilloscope and as a function generator, in addition to a synchronization and signal conditioning circuit. The system is fully controlled by a 'c' language program that optimizes the used of the instrument built in this way, and makes the analysis of the measurement data by curve fitting techniques. We show typical results obtained with silicon solar cells made in our laboratories. (Author)

  18. Lifetime of charge carriers in intrinsic indium antimonide

    International Nuclear Information System (INIS)

    Bruhns, H.; Kruse, H.

    1980-01-01

    The lifetime of additional photoinjected electron-hole pairs in intrinsic InSb at 291 K is investigated by measuring the photoconductive (PC) decay. Apart from studying the usual PC-decay an arangement is used with superimposed magnetic field transverse to the electric field. Depending on the direction of the magnetic field the photoinjected plasma is either driven into the sample's bulk or travels parallel to the illuminated surface. The Auger-lifetime is evaluated from the measurements by a numerical magnetohydrodynamical simulation taking into account surface recombination as well as the Suhl profile of the intrinsic plasma. A lifetime of tau = (57+-3) ns is found which is independent of the magnetic field up to 2.3 T. (author)

  19. Identification of the limiting factors for high-temperature GaAs, GaInP, and AlGaInP solar cells from device and carrier lifetime analysis

    Science.gov (United States)

    Perl, E. E.; Kuciauskas, D.; Simon, J.; Friedman, D. J.; Steiner, M. A.

    2017-12-01

    We analyze the temperature-dependent dark saturation current density and open-circuit voltage (VOC) for GaAs, GaInP, and AlGaInP solar cells from 25 to 400 °C. As expected, the intrinsic carrier concentration, ni, dominates the temperature dependence of the dark currents. However, at 400 °C, we measure VOC that is ˜50 mV higher for the GaAs solar cell and ˜60-110 mV lower for the GaInP and AlGaInP solar cells compared to what would be expected from commonly used solar cell models that consider only the ni2 temperature dependence. To better understand these deviations, we measure the carrier lifetimes of p-type GaAs, GaInP, and AlGaInP double heterostructures (DHs) from 25 to 400 °C using time-resolved photoluminescence. Temperature-dependent minority carrier lifetimes are analyzed to determine the relative contributions of the radiative recombination, interface recombination, Shockley-Read-Hall recombination, and thermionic emission processes. We find that radiative recombination dominates for the GaAs DHs with the effective lifetime approximately doubling as the temperature is increased from 25 °C to 400 °C. In contrast, we find that thermionic emission dominates for the GaInP and AlGaInP DHs at elevated temperatures, leading to a 3-4× reduction in the effective lifetime and ˜40× increase in the surface recombination velocity as the temperature is increased from 25 °C to 400 °C. These observations suggest that optimization of the minority carrier confinement layers for the GaInP and AlGaInP solar cells could help to improve VOC and solar cell efficiency at elevated temperatures. We demonstrate VOC improvement at 200-400 °C in GaInP solar cells fabricated with modified AlGaInP window and back surface field layers.

  20. Gettering improvements of minority-carrier lifetimesin solar grade silicon

    DEFF Research Database (Denmark)

    Osinniy, Viktor; Nylandsted Larsen, Arne; Dahl, Espen

    2012-01-01

    The minority-carrier lifetime in p-type solar-grade silicon (SoG-Si) produced by Elkem Solar was investigated after different types of heat treatment. Two groups of samples differing by the as-grown lifetimes were exposed to internal and phosphorus gettering using constant and variable temperature...... processes. Optimal heat-treatment parameters for each group of samples were then identified which improved the minority-carrier lifetimes to values higher than the minimum value needed for solar cells. Phosphorus gettering using a variable temperature process enhanced in particular the lifetime within each...

  1. Long-wavelength stimulated emission and carrier lifetimes in HgCdTe-based waveguide structures with quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Rumyantsev, V. V., E-mail: rumyantsev@ipm.sci-nnov.ru; Fadeev, M. A.; Morozov, S. V.; Dubinov, A. A.; Kudryavtsev, K. E.; Kadykov, A. M. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation); Tuzov, I. V. [Lobachevsky State University of Nizhny Novgorod (NNSU) (Russian Federation); Dvoretskii, S. A.; Mikhailov, N. N. [Russian Academy of Sciences, Institute for Semiconductor Physics, Siberian Branch (Russian Federation); Gavrilenko, V. I. [Novosibirsk State University (Russian Federation); Teppe, F. [Universite Montpellier II, Laboratoire Charles Coulomb (L2C) (France)

    2016-12-15

    The interband photoconductivity and photoluminescence in narrow-gap HgCdTe-based waveguide structures with quantum wells (QWs) (designed for long-wavelength stimulated emission under optical pumping) are investigated. The photoconductivity relaxation times in n-type structures reach several microseconds, due to which stimulated emission at a wavelength of 10.2 μm occurs at a low threshold pump intensity (~100 W/cm{sup 2}) at 20 K. In the p-type structures obtained by annealing (to increase the mercury vacancy concentration), even spontaneous emission from the QWs is not detected because of a dramatic decrease in the carrier lifetime with respect to Shockley–Read–Hall nonradiative recombination.

  2. Lifetime control of the minority carrier in PiN diodes by He+ ion implantation

    International Nuclear Information System (INIS)

    Tanaka, Y.; Kojima, K.; Takao, K.; Okamoto, M.; Kawasaki, M.; Takatsuka, A.; Yatsuo, T.; Arai, K.

    2005-01-01

    This paper reports the first demonstration of the lifetime control of the minority carrier in 4H-SiC PiN diodes by He + ion implantation. In this work, we fabricated 4H-SiC PiN diodes with the epitaxial junction and the blocking voltage of 2.6 kV, precisely corresponding to the theoretical blocking voltage calculated from the doping concentration (4.0 x 10 15 /cm 2 ) and the thickness of the drift layer (16.5 μm). He + ion implantation was performed with the energy and the dose of 400 kV and 1.0 x 10 13 -2.0 x 10 14 /cm 2 , respectively. We observed no different characteristics in the blocking voltage (2.6kV) and leakage current ( + ion implantation. However, we confirmed the improvement of the current recovery characteristics in the diodes with He + ion implantation. (orig.)

  3. Effective carrier sweepout in a silicon waveguide by a metal-semiconductor-metal structure

    DEFF Research Database (Denmark)

    Ding, Yunhong; Hu, Hao; Ou, Haiyan

    2015-01-01

    We demonstrate effective carrier depletion by metal-semiconductor-metal junctions for a silicon waveguide. Photo-generated carriers are efficiently swept out by applying bias voltages, and a shortest carrier lifetime of only 55 ps is demonstrated.......We demonstrate effective carrier depletion by metal-semiconductor-metal junctions for a silicon waveguide. Photo-generated carriers are efficiently swept out by applying bias voltages, and a shortest carrier lifetime of only 55 ps is demonstrated....

  4. The impact of ultra-thin titania interlayers on open circuit voltage and carrier lifetime in thin film solar cells

    International Nuclear Information System (INIS)

    Moerman, David; Colbert, Adam E.; Ginger, David S.; Kim, Hyungchul; Graham, Samuel

    2016-01-01

    We study the effects of modifying indium tin oxide electrodes with ultrathin titania (TiO_2) layers grown via plasma-enhanced atomic layer deposition (PE-ALD). We find an optimal thickness of PE-ALD-grown titania by tracking performance, which initially increases, peaks, and eventually decreases with increasing TiO_2 thickness. We use scanning Kelvin probe microscopy (SKPM) to measure both the local work function and its distribution as a function of TiO_2 thickness. We find that the variance in contact potential difference across the surface of the film is related to either the amorphous or anatase TiO_2 form. Finally, we use local SKPM recombination rate experiments, supported by bulk transient photovoltage and charge extraction measurements. We show that the optimum TiO_2 thickness is the one for which the carrier lifetime is the longest and the charge carrier density is the highest, when the TiO_2 is amorphous, in agreement with the device measurements.

  5. Development of an In-Line Minority-Carrier Lifetime Monitoring Tool for Process Control during Fabrication of Crystalline Silicon Solar Cells: Annual Subcontract Report, June 2003 (Revised)

    Energy Technology Data Exchange (ETDEWEB)

    Sinton, R. A.

    2004-04-01

    Under the PV Manufacturing R&D subcontract''Development of an In-Line, Minority-Carrier Lifetime Monitoring Tool for Process Control during Fabrication of Crystalline Silicon Solar Cells'', Sinton Consulting developed prototypes for several new instruments for use in the manufacture of silicon solar cells. These instruments are based on two families of R&D instruments that were previously available, an illumination vs. open-circuit-voltage technique and the quasi-steady state RF photoconductance technique for measuring minority-carrier lifetime. Compared to the previous instruments, the new prototypes are about 20 times faster per measurement, and have automated data analysis that does not require user intervention even when confronted by challenging cases. For example, un-passivated multi-crystalline wafers with large variations in lifetime and trapping behavior can be measured sequentially without error. Five instruments have been prototyped in this project to date, including a block tester for evaluating cast or HEM silicon blocks, a CZ ingot tester, an FZ boule tester for use with long-lifetime silicon, and an in-line sample head for measuring wafers. The CZ ingot tester and the FZ boule tester are already being used within industry and there is interest in the other prototypes. For each instrument, substantial R&D work was required in developing the device physics and analysis as well as for the hardware. This work has been documented in a series of application notes and conference publications, and will result in significant improvements for both the R&D and the industrial types of instruments.

  6. Impact of Interface States and Bulk Carrier Lifetime on Photocapacitance of Metal/Insulator/GaN Structure for Ultraviolet Light Detection

    Science.gov (United States)

    Bidzinski, Piotr; Miczek, Marcin; Adamowicz, Boguslawa; Mizue, Chihoko; Hashizume, Tamotsu

    2011-04-01

    The influence of interface state density and bulk carrier lifetime on the dependencies of photocapacitance versus wide range of gate bias (-0.1 to -3 V) and light intensity (109 to 1020 photon cm-2 s-1) was studied for metal/insulator/n-GaN UV light photodetector by means of numerical simulations. The light detection limit and photocapacitance saturation were analyzed in terms of the interface charge and interface Fermi level for electrons and holes and effective interface recombination velocity. It was proven that the excess carrier recombination through interface states is the main reason of photocapacitance signal quenching. It was found that the photodetector can work in various modes (on-off or quantitative light measurement) adjusted by the gate bias. A comparison between experimental data and theoretical capacitance-light intensity characteristics was made. A new method for the determination of the interface state density distribution from capacitance-voltage-light intensity measurements was also proposed.

  7. The impact of ultra-thin titania interlayers on open circuit voltage and carrier lifetime in thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Moerman, David; Colbert, Adam E.; Ginger, David S., E-mail: ginger@chem.washington.edu [Department of Chemistry, University of Washington, Seattle, Washington 98195 (United States); Kim, Hyungchul; Graham, Samuel, E-mail: sgraham@gatech.edu [School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)

    2016-03-14

    We study the effects of modifying indium tin oxide electrodes with ultrathin titania (TiO{sub 2}) layers grown via plasma-enhanced atomic layer deposition (PE-ALD). We find an optimal thickness of PE-ALD-grown titania by tracking performance, which initially increases, peaks, and eventually decreases with increasing TiO{sub 2} thickness. We use scanning Kelvin probe microscopy (SKPM) to measure both the local work function and its distribution as a function of TiO{sub 2} thickness. We find that the variance in contact potential difference across the surface of the film is related to either the amorphous or anatase TiO{sub 2} form. Finally, we use local SKPM recombination rate experiments, supported by bulk transient photovoltage and charge extraction measurements. We show that the optimum TiO{sub 2} thickness is the one for which the carrier lifetime is the longest and the charge carrier density is the highest, when the TiO{sub 2} is amorphous, in agreement with the device measurements.

  8. Carrier recombination in mid-wave infrared InAs/InAsSb superlattices

    Science.gov (United States)

    Aytac, Yigit; Olson, Benjamin Varberg; Kim, Jin K.; Shaner, Eric A.; Hawkins, Sam D.; Klem, John F.; Flatté, Michael E.; Boggess, Thomas F.

    2014-03-01

    Measurements of carrier recombination rates using a temperature-dependent time-resolved differential transmission technique are reported for mid-wave infrared InAs / InAs1 - x Sbx type-2 superlattices (T2SLs). By engineering the layer widths and antimony compositions a 16K band-gap of ~ 238 meV was achieved for all five unintentionally doped T2SLs. Carrier recombination rates were determined for all five samples by fitting a rate equation model to the density and temperature dependent data. Minority-carrier lifetimes as long as 22 μs were measured at 14K, while lifetimes in excess of 2 μs were measured for all five samples at 200K. The minority-carrier lifetimes were observed to generally increase with increasing antimony content. While minority-carrier lifetimes are much longer than those observed in InAs/Ga(In)Sb T2SLs, Auger recombination processes were found to be more prominent in the Ga-free T2SLs. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under Contract No. DE-AC04-94AL85000. This research was funded by the U.S. Government.

  9. Carrier Decay and Diffusion Dynamics in Single-Crystalline CdTe as seen via Microphotoluminescence

    Science.gov (United States)

    Mascarenhas, Angelo; Fluegel, Brian; Alberi, Kirstin; Zhang, Yong-Hang

    2015-03-01

    The ability to spatially resolve the degree to which extended defects impact carrier diffusion lengths and lifetimes is important for determining upper limits for defect densities in semiconductor devices. We show that a new spatially and temporally resolved photoluminescence (PL) imaging technique can be used to accurately extract carrier lifetimes in the immediate vicinity of dark-line defects in CdTe/MgCdTe double heterostructures. A series of PL images captured during the decay process show that extended defects with a density of 1.4x10-5 cm-2 deplete photogenerated charge carriers from the surrounding semiconductor material on a nanosecond time scale. The technique makes it possible to elucidate the interplay between nonradiative carrier recombination and carrier diffusion and reveals that they both combine to degrade the PL intensity over a fractional area that is much larger than the physical size of the defects. Carrier lifetimes are correctly determined from numerical simulations of the decay behavior by taking these two effects into account. Our study demonstrates that it is crucial to measure and account for the influence of local defects in the measurement of carrier lifetime and diffusion, which are key transport parameters for the design and modeling of advanced solar-cell and light-emitting devices. We acknowledge the financial support of the Department of Energy Office of Science under Grant No. DE-AC36-08GO28308.

  10. Improvement of minority carrier lifetime and conversion efficiency by Na incorporation in Cu2ZnSnSe4 solar cells

    Science.gov (United States)

    Tampo, Hitoshi; Kim, Kang Min; Kim, Shinho; Shibata, Hajime; Niki, Shigeru

    2017-07-01

    The effect of Na incorporation in Cu2ZnSnSe4 (CZTSe) solar cells grown by the coevaporation method was investigated via photoluminescence (PL) and time-resolved PL (TRPL) measurements as well as photovoltaic properties. The TRPL decay curves showed a monotonic increase in CZTSe lifetime from 2 to 15 ns with increasing Na incorporation, which corresponds to the increase in the correction length estimated by quantum efficiency measurements. The TRPL decay curves included two decay components, fast and slow, which were discussed and concluded as originating from the recombination at the surface and bulk of CZTSe, respectively, which is also supported by TPRL measurements with various excitation wavelengths. The lifetime of CZTSe is limited by the surface-related nonradiative recombination compared to Cu(In,Ga)Se2 devices which are fabricated with the same device structure except for the absorber, and at present, it is concluded that the surface recombination of the CZTSe limits the cell performance. In addition to the above investigations, the relationship between the CZTSe bulk lifetime and carrier concentration is discussed; deep nonradiative recombination centers in the CZTSe bulk were found to decrease by one order of magnitude with Na incorporation. The Na incorporation primarily resulted in improvement in the short circuit current density and fill factor and not in the open circuit voltage, and the results are discussed. The best performing CZTSe solar cell with Na incorporation showed a conversion efficiency of 9.57%.

  11. Measurement of the drift mobilities and the mobility-lifetime products of charge carriers in a CdZnTe crystal by using a transient pulse technique

    International Nuclear Information System (INIS)

    Cho, H Y; Kwon, Y K; Lee, C S; Lee, J H; Moon, J Y

    2011-01-01

    In this work we present results on the measurement of the drift mobility and the mobility-lifetime product of charge carriers in a 16-pixellated CdZnTe detector. For the determination of an interaction position based on the pulse rise-time method in a CZT detector, it is necessary to characterize the transport properties governed by drift mobility and lifetime for electrons and holes. In order to extract the transport properties of an electron and a hole, we bombarded 5.5-MeV alpha particles from a 241 Am source and 81-keV gamma rays emitted from a 133 Ba source on the negatively biased contact of the CZT detector. A time-of-flight (TOF) method was used to measure the electron drift mobility at room temperature whose value turned out to be 906.4 cm 2 /Vc s. With the Hecht's equation, the electron mobility-lifetime product was also determined from the bias-dependent alpha response and was equal to (9.88 ± 2.33) x 10 -3 cm 2 /V. On the other hand, the hole mobility-lifetime product was evaluated by a model based on the average charge collection efficiency which accounts for the absorption probability with a given photon energy. By using a single parameter fitting of the model, we obtained the hole mobility-lifetime product of (8.28 ± 0.17) x 10 -4 cm 2 /V.

  12. Inkjet printable-photoactive all inorganic perovskite films with long effective photocarrier lifetimes

    Science.gov (United States)

    Ilie, C. C.; Guzman, F.; Swanson, B. L.; Evans, I. R.; Costa, P. S.; Teeter, J. D.; Shekhirev, M.; Benker, N.; Sikich, S.; Enders, A.; Dowben, P. A.; Sinitskii, A.; Yost, A. J.

    2018-05-01

    Photoactive perovskite quantum dot films, deposited via an inkjet printer, have been characterized by x-ray diffraction and x-ray photoelectron spectroscopy. The crystal structure and bonding environment are consistent with CsPbBr3 perovskite quantum dots. The current–voltage (I–V) and capacitance–voltage (C–V) transport measurements indicate that the photo-carrier drift lifetime can exceed 1 ms for some printed perovskite films. This far exceeds the dark drift carrier lifetime, which is below 50 ns. The printed films show a photocarrier density 109 greater than the dark carrier density, making these printed films ideal candidates for application in photodetectors. The successful printing of photoactive-perovskite quantum dot films of CsPbBr3, indicates that the rapid prototyping of various perovskite inks and multilayers is realizable.

  13. Pressure-Induced Bandgap Optimization in Lead-Based Perovskites with Prolonged Carrier Lifetime and Ambient Retainability

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Gang [Center for High Pressure Science and Technology Advanced Research, Shanghai 201203 China; Geophysical Laboratory, Carnegie Institution of Washington, Washington DC 20015 USA; Kong, Lingping [Center for High Pressure Science and Technology Advanced Research, Shanghai 201203 China; Geophysical Laboratory, Carnegie Institution of Washington, Washington DC 20015 USA; Gong, Jue [Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb IL 60115 USA; Yang, Wenge [Center for High Pressure Science and Technology Advanced Research, Shanghai 201203 China; Geophysical Laboratory, Carnegie Institution of Washington, Washington DC 20015 USA; Mao, Ho-kwang [Center for High Pressure Science and Technology Advanced Research, Shanghai 201203 China; Geophysical Laboratory, Carnegie Institution of Washington, Washington DC 20015 USA; Hu, Qingyang [Geophysical Laboratory, Carnegie Institution of Washington, Washington DC 20015 USA; Liu, Zhenxian [Geophysical Laboratory, Carnegie Institution of Washington, Washington DC 20015 USA; Schaller, Richard D. [Center for Nanoscale Materials, Argonne National Laboratory, Argonne IL 60439 USA; Zhang, Dongzhou [Hawai' i Institute of Geophysics and Planetology, School of Ocean and Earth Science and Technology, University of Hawai' i at Manoa, Honolulu HI 96822 USA; Xu, Tao [Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb IL 60115 USA

    2016-12-05

    Bond length and bond angle exhibited by valence electrons is essential to the core of chemistry. Using lead-based organic–inorganic perovskite compounds as an exploratory platform, it is demonstrated that the modulation of valence electrons by compression can lead to discovery of new properties of known compounds. Yet, despite its unprecedented progress, further efficiency boost of lead-based organic–inorganic perovskite solar cells is hampered by their wider bandgap than the optimum value according to the Shockley–Queisser limit. By modulating the valence electron wavefunction with modest hydraulic pressure up to 2.1 GPa, the optimized bandgap for single-junction solar cells in lead-based perovskites, for the first time, is achieved by narrowing the bandgap of formamidinium lead triiodide (HC(NH2)2PbI3) from 1.489 to 1.337 eV. Strikingly, such bandgap narrowing is partially retained after the release of pressure to ambient, and the bandgap narrowing is also accompanied with double-prolonged carrier lifetime. With First-principles simulation, this work opens a new dimension in basic chemical understanding of structural photonics and electronics and paves an alternative pathway toward better photovoltaic materials-by-design.

  14. Pressure-Induced Bandgap Optimization in Lead-Based Perovskites with Prolonged Carrier Lifetime and Ambient Retainability

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Gang [Center for High Pressure Science and Technology Advanced Research, Shanghai 201203 China; Geophysical Laboratory, Carnegie Institution of Washington, Washington DC 20015 USA; Kong, Lingping [Center for High Pressure Science and Technology Advanced Research, Shanghai 201203 China; Geophysical Laboratory, Carnegie Institution of Washington, Washington DC 20015 USA; Gong, Jue [Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb IL 60115 USA; Yang, Wenge [Center for High Pressure Science and Technology Advanced Research, Shanghai 201203 China; Geophysical Laboratory, Carnegie Institution of Washington, Washington DC 20015 USA; Mao, Ho-kwang [Center for High Pressure Science and Technology Advanced Research, Shanghai 201203 China; Geophysical Laboratory, Carnegie Institution of Washington, Washington DC 20015 USA; Hu, Qingyang [Geophysical Laboratory, Carnegie Institution of Washington, Washington DC 20015 USA; Liu, Zhenxian [Geophysical Laboratory, Carnegie Institution of Washington, Washington DC 20015 USA; Schaller, Richard D. [Center for Nanoscale Materials, Argonne National Laboratory, Argonne IL 60439 USA; Zhang, Dongzhou [Hawai' i Institute of Geophysics and Planetology, School of Ocean and Earth Science and Technology, University of Hawai' i at Manoa, Honolulu HI 96822 USA; Xu, Tao [Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb IL 60115 USA

    2016-12-05

    Bond length and bond angle exhibited by valence electrons is essential to the core of chemistry. Using lead-based organic–inorganic perovskite compounds as an exploratory platform, it is demonstrated that the modulation of valence electrons by compression can lead to discovery of new properties of known compounds. Yet, despite its unprecedented progress, further efficiency boost of lead-based organic–inorganic perovskite solar cells is hampered by their wider bandgap than the optimum value according to the Shockley–Queisser limit. By modulating the valence electron wavefunction with modest hydraulic pressure up to 2.1 GPa, the optimized bandgap for single-junction solar cells in lead-based perovskites, for the first time, is achieved by narrowing the bandgap of formamidinium lead triiodide (HC(NH2)2PbI3) from 1.489 to 1.337 eV. Strikingly, such bandgap narrowing is partially retained after the release of pressure to ambient, and the bandgap narrowing is also accompanied with double-prolonged carrier lifetime. With First-principles simulation, this work opens a new dimension in basic chemical understanding of structural photonics and electronics and paves an alternative pathway toward better photovoltaic materials-by-design.

  15. Carrier quenching in InGaP/GaAs double heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Wells, Nathan P., E-mail: nathan.p.wells@aero.org; Driskell, Travis U.; Hudson, Andrew I.; LaLumondiere, Stephen D.; Lotshaw, William T. [The Aerospace Corporation, Physical Sciences Laboratories, P.O. Box 92957, Los Angeles, California 90009 (United States); Forbes, David V.; Hubbard, Seth M. [NanoPower Research Labs, Rochester Institute of Technology, 156 Lomb Memorial Dr., Rochester, New York 14623 (United States)

    2015-08-14

    Photoluminescence measurements on a series of GaAs double heterostructures demonstrate a rapid quenching of carriers in the GaAs layer at irradiance levels below 0.1 W/cm{sup 2} in samples with a GaAs-on-InGaP interface. These results indicate the existence of non-radiative defect centers at or near the GaAs-on-InGaP interface, consistent with previous reports showing the intermixing of In and P when free As impinges on the InGaP surface during growth. At low irradiance, these defect centers can lead to sub-ns carrier lifetimes. The defect centers involved in the rapid carrier quenching can be saturated at higher irradiance levels and allow carrier lifetimes to reach hundreds of nanoseconds. To our knowledge, this is the first report of a nearly three orders of magnitude decrease in carrier lifetime at low irradiance in a simple double heterostructure. Carrier quenching occurs at irradiance levels near the integrated Air Mass Zero (AM0) and Air Mass 1.5 (AM1.5) solar irradiance. Additionally, a lower energy photoluminescence band is observed both at room and cryogenic temperatures. The temperature and time dependence of the lower energy luminescence is consistent with the presence of an unintentional InGaAs or InGaAsP quantum well that forms due to compositional mixing at the GaAs-on-InGaP interface. Our results are of general interest to the photovoltaic community as InGaP is commonly used as a window layer in GaAs based solar cells.

  16. Ultrafast carrier dynamics in bimetallic nanostructure-enhanced methylammonium lead bromide perovskites.

    Science.gov (United States)

    Zarick, Holly F; Boulesbaa, Abdelaziz; Puretzky, Alexander A; Talbert, Eric M; DeBra, Zachary R; Soetan, Naiya; Geohegan, David B; Bardhan, Rizia

    2017-01-26

    In this work, we examine the impact of hybrid bimetallic Au/Ag core/shell nanostructures on the carrier dynamics of methylammonium lead tribromide (MAPbBr 3 ) mesoporous perovskite solar cells (PSCs). Plasmon-enhanced PSCs incorporated with Au/Ag nanostructures demonstrated improved light harvesting and increased power conversion efficiency by 26% relative to reference devices. Two complementary spectral techniques, transient absorption spectroscopy (TAS) and time-resolved photoluminescence (trPL), were employed to gain a mechanistic understanding of plasmonic enhancement processes. TAS revealed a decrease in the photobleach formation time, which suggests that the nanostructures improve hot carrier thermalization to an equilibrium distribution, relieving hot phonon bottleneck in MAPbBr 3 perovskites. TAS also showed a decrease in carrier decay lifetimes, indicating that nanostructures enhance photoinduced carrier generation and promote efficient electron injection into TiO 2 prior to bulk recombination. Furthermore, nanostructure-incorporated perovskite films demonstrated quenching in steady-state PL and decreases in trPL carrier lifetimes, providing further evidence of improved carrier injection in plasmon-enhanced mesoporous PSCs.

  17. Hot carrier dynamics in plasmonic transition metal nitrides

    Science.gov (United States)

    Habib, Adela; Florio, Fred; Sundararaman, Ravishankar

    2018-06-01

    Extraction of non-equilibrium hot carriers generated by plasmon decay in metallic nano-structures is an increasingly exciting prospect for utilizing plasmonic losses, but the search for optimum plasmonic materials with long-lived carriers is ongoing. Transition metal nitrides are an exciting class of new plasmonic materials with superior thermal and mechanical properties compared to conventional noble metals, but their suitability for plasmonic hot carrier applications remains unknown. Here, we present fully first principles calculations of the plasmonic response, hot carrier generation and subsequent thermalization of all group IV, V and VI transition metal nitrides, fully accounting for direct and phonon-assisted transitions as well as electron–electron and electron–phonon scattering. We find the largest frequency ranges for plasmonic response in ZrN, HfN and WN, between those of gold and silver, while we predict strongest absorption in the visible spectrum for the VN, NbN and TaN. Hot carrier generation is dominated by direct transitions for most of the relevant energy range in all these nitrides, while phonon-assisted processes dominate only below 1 eV plasmon energies primarily for the group IV nitrides. Finally, we predict the maximum hot carrier lifetimes to be around 10 fs for group IV and VI nitrides, a factor of 3–4 smaller than noble metals, due to strong electron–phonon scattering. However, we find longer carrier lifetimes for group V nitrides, comparable to silver for NbN and TaN, while exceeding 100 fs (twice that of silver) for VN, making them promising candidates for efficient hot carrier extraction.

  18. Carrier Modulation Layer-Enhanced Organic Light-Emitting Diodes

    Directory of Open Access Journals (Sweden)

    Jwo-Huei Jou

    2015-07-01

    Full Text Available Organic light-emitting diode (OLED-based display products have already emerged in the market and their efficiencies and lifetimes are sound at the comparatively low required luminance. To realize OLED for lighting application sooner, higher light quality and better power efficiency at elevated luminance are still demanded. This review reveals the advantages of incorporating a nano-scale carrier modulation layer (CML, also known as a spacer, carrier-regulating layer, or interlayer, among other terms, to tune the chromaticity and color temperature as well as to markedly improve the device efficiency and color rendering index (CRI for numerous OLED devices. The functions of the CML can be enhanced as multiple layers and blend structures are employed. At proper thickness, the employment of CML enables the device to balance the distribution of carriers in the two emissive zones and achieve high device efficiencies and long operational lifetime while maintaining very high CRI. Moreover, we have also reviewed the effect of using CML on the most significant characteristics of OLEDs, namely: efficiency, luminance, life-time, CRI, SRI, chromaticity, and the color temperature, and see how the thickness tuning and selection of proper CML are crucial to effectively control the OLED device performance.

  19. Increasing minority carrier lifetime in as-grown multicrystalline silicon by low temperature internal gettering

    Energy Technology Data Exchange (ETDEWEB)

    Al-Amin, M., E-mail: m.al-amin@warwick.ac.uk; Murphy, J. D., E-mail: john.d.murphy@warwick.ac.uk [School of Engineering, University of Warwick, Coventry, CV4 7AL (United Kingdom)

    2016-06-21

    We report a systematic study into the effects of long low temperature (≤500 °C) annealing on the lifetime and interstitial iron distributions in as-grown multicrystalline silicon (mc-Si) from different ingot height positions. Samples are characterised in terms of dislocation density, and lifetime and interstitial iron concentration measurements are made at every stage using a temporary room temperature iodine-ethanol surface passivation scheme. Our measurement procedure allows these properties to be monitored during processing in a pseudo in situ way. Sufficient annealing at 300 °C and 400 °C increases lifetime in all cases studied, and annealing at 500 °C was only found to improve relatively poor wafers from the top and bottom of the block. We demonstrate that lifetime in poor as-grown wafers can be improved substantially by a low cost process in the absence of any bulk passivation which might result from a dielectric surface film. Substantial improvements are found in bottom wafers, for which annealing at 400 °C for 35 h increases lifetime from 5.5 μs to 38.7 μs. The lifetime of top wafers is improved from 12.1 μs to 23.8 μs under the same conditions. A correlation between interstitial iron concentration reduction and lifetime improvement is found in these cases. Surprisingly, although the interstitial iron concentration exceeds the expected solubility values, low temperature annealing seems to result in an initial increase in interstitial iron concentration, and any subsequent decay is a complex process driven not only by diffusion of interstitial iron.

  20. Determination of Carrier Lifetimes in Organic-Inorganic Hybrid Solar Cells Based on Sb2S3 by Using the Time-Resolved Photocurrent

    Science.gov (United States)

    Jo, Hyun-Jun; Mun, Young Hee; Kim, Jong Su; Kim, Seung Hyun; Lee, Sang-Ju; Sung, Shi-Joon; Kim, Dae-Hwan

    2018-03-01

    This paper presents organic-inorganic hybrid solar cells (SCs) based on ZnO/Sb2S3/P3HT heterojunctions. The ZnO and the Sb2S3 layers were grown using atomic layer deposition (ALD). Although four cells were fabricated on one substrate by using the same process, their open-circuit voltages ( V OC ) and short-circuit current densities ( J SC ) were different. The SC with a high V OC has a low J SC . The causes of the changes in the V OC and the JSC were investigated by using photoluminescence (PL) spectroscopy and optically-biased time-resolved photocurrent (TRPC) measurements. The PL results at 300 K showed that the emission positions of the Sb2S3 layers in all cells were similar at approximately 1.71 eV. The carrier lifetime of the SCs was calculated from the TRPC results. The lifetime of cell 4 with the highest J SC decreased drastically with increasing intensity of the continuous-wave optical bias beam. Therefore, the defect states in the ZnO layer contribute to the J SC , but degrade the V OC .

  1. Multiple-level defect species evaluation from average carrier decay

    Science.gov (United States)

    Debuf, Didier

    2003-10-01

    An expression for the average decay is determined by solving the the carrier continuity equations, which include terms for multiple defect recombination. This expression is the decay measured by techniques such as the contactless photoconductance decay method, which determines the average or volume integrated decay. Implicit in the above is the requirement for good surface passivation such that only bulk properties are observed. A proposed experimental configuration is given to achieve the intended goal of an assessment of the type of defect in an n-type Czochralski-grown silicon semiconductor with an unusually high relative lifetime. The high lifetime is explained in terms of a ground excited state multiple-level defect system. Also, minority carrier trapping is investigated.

  2. Extracting hot carriers from photoexcited semiconductor nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Xiaoyang

    2014-12-10

    This research program addresses a fundamental question related to the use of nanomaterials in solar energy -- namely, whether semiconductor nanocrystals (NCs) can help surpass the efficiency limits, the so-called “Shockley-Queisser” limit, in conventional solar cells. In these cells, absorption of photons with energies above the semiconductor bandgap generates “hot” charge carriers that quickly “cool” to the band edges before they can be utilized to do work; this sets the solar cell efficiency at a limit of ~31%. If instead, all of the energy of the hot carriers could be captured, solar-to-electric power conversion efficiencies could be increased, theoretically, to as high as 66%. A potential route to capture this energy is to utilize semiconductor nanocrystals. In these materials, the quasi-continuous conduction and valence bands of the bulk semiconductor become discretized due to confinement of the charge carriers. Consequently, the energy spacing between the electronic levels can be much larger than the highest phonon frequency of the lattice, creating a “phonon bottleneck” wherein hot-carrier relaxation is possible via slower multiphonon emission. For example, hot-electron lifetimes as long as ~1 ns have been observed in NCs grown by molecular beam epitaxy. In colloidal NCs, long lifetimes have been demonstrated through careful design of the nanocrystal interfaces. Due to their ability to slow electronic relaxation, semiconductor NCs can in principle enable extraction of hot carriers before they cool to the band edges, leading to more efficient solar cells.

  3. Long-lived hot-carrier light emission and large blue shift in formamidinium tin triiodide perovskites

    NARCIS (Netherlands)

    Fang, Hong-Hua; Adjokatse, Sampson; Shao, Shuyan; Even, Jacky; Loi, Maria Antonietta

    2018-01-01

    A long-lived hot carrier population is critical in order to develop working hot carrier photovoltaic devices with efficiencies exceeding the Shockley-Queisser limit. Here, we report photoluminescence from hot-carriers with unexpectedly long lifetime (a few ns) in formamidinium tin triiodide. An

  4. Explanation of low efficiency droop in semipolar $(20\\bar 2\\bar 1)$ InGaN/GaN LEDs through evaluation of carrier recombination coefficients

    OpenAIRE

    Monavarian, Morteza; Rashidi, Arman; Aragon, Andrew A.; Oh, Sang H.; Nami, Mohsen; DenBaars, Steve P.; Feezell, Daniel F.

    2017-01-01

    We report the carrier dynamics and recombination coefficients in single-quantum-well semipolar $(20\\bar 2\\bar 1)$ InGaN/GaN light-emitting diodes emitting at 440 nm with 93% peak internal quantum efficiency. The differential carrier lifetime is analyzed for various injection current densities from 5 $A/cm^2$ to 10 $kA/cm^2$, and the corresponding carrier densities are obtained. The coupling of internal quantum efficiency and differential carrier lifetime vs injected carrier density ($n$) enab...

  5. Controlling of carrier movement on gamma irradiator ISG-500

    International Nuclear Information System (INIS)

    Achmad Suntoro

    2010-01-01

    Gamma irradiator ISG-500 is being designed. One of the design objects in the gamma irradiator is carrier movement and its controlling. Many possibilities of carrier movements can be implemented in the set-up design, such as using discrete or continuous mode. In this paper, selected discrete carriers movement and their controlling for the basic-design of the ISG-500 will be discussed. Nine stopper locations for nineteen carriers in operation will be controlled their carriers movement so that the movements have maximum positive transient load (increasing load) two carriers only. The controlling of the movement uses a train of pulses counting system as a one-dimension coordinate reference of a point on the rotated chain pulling the carrier. Every stopper location has a specific counting number in which will be used by the controlling system to let the carrier in the stopper location moving. By this movement, it is expected to prolong the life-time of the in use carrier mover motor. (author)

  6. Development of an In-line Minority-Carrier Lifetime Monitoring Tool for Process Control during Fabrication of Crystalline Silicon Solar Cells: Final Technical Report, 2 August 2002-15 November 2004

    Energy Technology Data Exchange (ETDEWEB)

    Sinton, R. A.

    2004-12-01

    The objective of this subcontract over its two-phase, two-year duration was to design and develop improvements to the existing Sinton Consulting R&D minority-carrier lifetime testers. The improvements enable the possibilities for performing various in-line diagnostics on crystalline silicon wafers and cells for solar cell manufacturing lines. This facilitates manufacturing optimization and improved process control. The scope of work for Phase I was to prototype industrial applications for the improved instruments. A small-sample-head version of the instrument was designed and developed in this effort. This new instrument was complemented by detailed application notes detailing the productive use of minority-carrier lifetime measurements for process optimization and routine process control. In Phase II, the results from the first year were applied to design new instruments for industrial applications. These instruments were then characterized and documented. We report here on four new instruments, each optimized for a specific application as demanded by industrial customers. The documentation for these instruments was very technical and involved considerable R&D. Applications were developed that applied the latest in R&D on industrial silicon materials. By investigating the compromises that would be necessary to measure industrial material directly without the sample preparation that is commonly done for good research, we were able to develop several very innovative applications that can now be done directly in the production line for process control.

  7. Dual-lifetime referencing (DLR: a powerful method for on-line measurement of internal pH in carrier-bound immobilized biocatalysts

    Directory of Open Access Journals (Sweden)

    Boniello Caterina

    2012-03-01

    Full Text Available Abstract Background Industrial-scale biocatalytic synthesis of fine chemicals occurs preferentially as continuous processes employing immobilized enzymes on insoluble porous carriers. Diffusional effects in these systems often create substrate and product concentration gradients between bulk liquid and the carrier. Moreover, some widely-used biotransformation processes induce changes in proton concentration. Unlike the bulk pH, which is usually controlled at a suitable value, the intraparticle pH of immobilized enzymes may deviate significantly from its activity and stability optima. The magnitude of the resulting pH gradient depends on the ratio of characteristic times for enzymatic reaction and on mass transfer (the latter is strongly influenced by geometrical features of the porous carrier. Design and selection of optimally performing enzyme immobilizates would therefore benefit largely from experimental studies of the intraparticle pH environment. Here, a simple and non-invasive method based on dual-lifetime referencing (DLR for pH determination in immobilized enzymes is introduced. The technique is applicable to other systems in which particles are kept in suspension by agitation. Results The DLR method employs fluorescein as pH-sensitive luminophore and Ru(II tris(4,7-diphenyl-1,10-phenantroline, abbreviated Ru(dpp, as the reference luminophore. Luminescence intensities of the two luminophores are converted into an overall phase shift suitable for pH determination in the range 5.0-8.0. Sepabeads EC-EP were labeled by physically incorporating lipophilic variants of the two luminophores into their polymeric matrix. These beads were employed as carriers for immobilization of cephalosporin C amidase (a model enzyme of industrial relevance. The luminophores did not interfere with the enzyme immobilization characteristics. Analytical intraparticle pH determination was optimized for sensitivity, reproducibility and signal stability under

  8. Influence of interface preparation on minority carrier lifetime for low bandgap tandem solar cell materials

    Energy Technology Data Exchange (ETDEWEB)

    Szabo, Nadine; Sagol, B. Erol; Seidel, Ulf; Schwarzburg, Klaus; Hannappel, Thomas [Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Berlin (Germany)

    2010-07-01

    III-V semiconductor compounds grown by MOVPE are implemented in todays state-of-the-art third generation multi-junction solar cells. The current record multi junction solar cell grown on germanium, having Ge, Ga(In)As and GaInP as subcells, reached a record efficiency of 41.6%. The efficiency of these multi junction solar cells could be significantly increased, if its low bandgap Ge subcell would be replaced by a more efficient tandem. For this purpose the low bandgap materials InGaAs and InGaAsP are suitable. The bandgap composition of these materials allows a better yield of the solar spectrum. Based on InGaAs/InGaAsP absorber materials we have developed a low bandgap tandem solar cell with optimized bandgaps. Results of time resolved photoluminescence (TRPL) for the IR-bandgap compounds InGaAsP (1.03 eV)/InGaAs (0.73 eV) are presented. The lifetime of minority carriers is one of the most important properties of solar cell absorber materials. We show on the example of the low band gap tandem cell how the choice of the materials, the quality of the bulk, the optimization of the band gap energies and the preparation of the critical interfaces are essential to build a high efficiency solar cell. The quality of the bulk and the preparation of the critical interfaces are essential for the growth of the double heterostructure (DHS).

  9. Anomalous carrier life-time relaxation mediated by head group interaction in surface anchored MnSe quantum dots conjugated with albumin proteins

    Energy Technology Data Exchange (ETDEWEB)

    Sarma, Runjun; Mohanta, Dambarudhar, E-mail: best@tezu.ernet.in

    2017-02-01

    We report on the radiative emission decay dynamics of a less known, γ-phase manganese selenide quantum dot system (MnSe QDs) subjected to bio-functionalization. A short-ligand thioglycolic acid (TGA), and a long-chain sodium dodecyl sulfate (SDS) surfactants were used as surface anchors prior bioconjugation with albumin proteins (BSA). Time resolved photoluminescence (TR-PL) spectra of the QDs have revealed bi-exponential decay trends with the fast (τ{sub 1}) and slow (τ{sub 2}) decay parameters assigned to the core state recombination and surface trapped excitons; respectively. The average lifetime (τ{sub avg}) was found to get shortened from a value of ∼0.87 ns–0.72 ns in unconjugated and BSA conjugated MnSe-TGA QDs; respectively. Conversely, MnSe-SDS QDs with BSA conjugation exhibited nearly four-fold enhancement of τ{sub avg} with respect to its unconjugated counterpart. Moreover, a considerable amount of Förster resonance energy transfer (FRET) was found to occur from the TGA coated MnSe QDs to BSA and with an ensuing efficiency of ∼61%. The origin of anomalous carrier life-time relaxation features has also been encountered through a simplified model as regards head group interaction experienced by the MnSe QDs with different surfactant types. Exploiting luminescence decay characteristics of a magneto-fluorescent candidate could find immense scope in diverse biological applications including assays, labeling and imaging. - Highlights: • Surface anchored manganese selenide quantum dots (MnSe QDs) have been synthesized via a physico-chemical reduction route. • Time resolved luminescence spectra of the QDs have displayed bi-exponential decay trend. • Thioglycolic acid (TGA) coated QDs exhibited shorter lifetime as compared to sodium dodecyl sulfo-succinate (SDS) coated ones. • Upon BSA conjugation, the average life time is four-fold enhanced in MnSe-SDS QDs. • An efficient FRET process has been revealed in BSA conjugated TGA coated MnSe QDs.

  10. Theory of lifetime measurements with the scanning electron microscope: transient analysis

    NARCIS (Netherlands)

    Kuiken, H.K.

    1976-01-01

    A transient analysis of an SEM experiment is given with the purpose of determining directly the lifetime of minority carriers in a semiconductor material. The injection takes place below a surface normal to the junction and expressions are derived for the current-decay which ensues when the electron

  11. Hall effect and photoconductivity lifetime studies of gallium nitride, indium nitride, and mercury cadmium telluride

    Science.gov (United States)

    Swartz, Craig H.

    A deep understanding of both carrier recombination and transport is necessary for semiconductor engineering, particularly in defining the ultimate limits of performance for a given device before spending the resources to perfect its fabrication. Hall effect measurements utilizing a variable magnetic field are necessary to discriminate between conduction in epitaxial layers and conduction originating at the surface or at an interfacial layer. For thick hydride vapor phase epitaxy (HVPE) grown GaN, variable field Hall measurements revealed the presence of small but significant lower mobility surface and interface electrons which would otherwise lead to errors in interpreting the electrical properties. In addition, QMSA analysis of the measurements indicates that thick GaN samples contain a large spread in electron mobility values, most likely with depth. For molecular beam epitaxial InN, it was found that electrical measurements are affected by surface charge conduction, as well as the non-uniformity of mobility and carrier concentration with depth. Both of these effects mask the surprisingly high quality of the material close to the surface. Photoconductance lifetime and variable-magnetic-field Hall and transient measurements were performed on a series of undoped, In-doped and As-doped HgCdTe grown by MBE and MOCVD. N-type layers often significantly influence the interpretation of the electrical measurements. Even the best Low Wavelength Infrared (LWIR) n-type material still appears to be dominated by defect-related recombination, as intrinsic lifetimes calculated with full band structure can be well above those measured. Mid-Wavelength Infrared (MWIR) lifetimes increase somewhat with carrier concentration, as if the n-type doping process were passivating Schockley-Read-Hall (SRH) defects. P-type MWIR films lie mainly below the predicted values, and their relationship between concentration and lifetime is essentially unchanged by growth technique, indicating that a

  12. Lifetime degradation of n-type Czochralski silicon after hydrogenation

    Science.gov (United States)

    Vaqueiro-Contreras, M.; Markevich, V. P.; Mullins, J.; Halsall, M. P.; Murin, L. I.; Falster, R.; Binns, J.; Coutinho, J.; Peaker, A. R.

    2018-04-01

    Hydrogen plays an important role in the passivation of interface states in silicon-based metal-oxide semiconductor technologies and passivation of surface and interface states in solar silicon. We have shown recently [Vaqueiro-Contreras et al., Phys. Status Solidi RRL 11, 1700133 (2017)] that hydrogenation of n-type silicon slices containing relatively large concentrations of carbon and oxygen impurity atoms {[Cs] ≥ 1 × 1016 cm-3 and [Oi] ≥ 1017 cm-3} can produce a family of C-O-H defects, which act as powerful recombination centres reducing the minority carrier lifetime. In this work, evidence of the silicon's lifetime deterioration after hydrogen injection from SiNx coating, which is widely used in solar cell manufacturing, has been obtained from microwave photoconductance decay measurements. We have characterised the hydrogenation induced deep level defects in n-type Czochralski-grown Si samples through a series of deep level transient spectroscopy (DLTS), minority carrier transient spectroscopy (MCTS), and high-resolution Laplace DLTS/MCTS measurements. It has been found that along with the hydrogen-related hole traps, H1 and H2, in the lower half of the gap reported by us previously, hydrogenation gives rise to two electron traps, E1 and E2, in the upper half of the gap. The activation energies for electron emission from the E1 and E2 trap levels have been determined as 0.12, and 0.14 eV, respectively. We argue that the E1/H1 and E2/H2 pairs of electron/hole traps are related to two energy levels of two complexes, each incorporating carbon, oxygen, and hydrogen atoms. Our results show that the detrimental effect of the C-O-H defects on the minority carrier lifetime in n-type Si:O + C materials can be very significant, and the carbon concentration in Czochralski-grown silicon is a key parameter in the formation of the recombination centers.

  13. High p-type doping, mobility, and photocarrier lifetime in arsenic-doped CdTe single crystals

    Science.gov (United States)

    Nagaoka, Akira; Kuciauskas, Darius; McCoy, Jedidiah; Scarpulla, Michael A.

    2018-05-01

    Group-V element doping is promising for simultaneously maximizing the hole concentration and minority carrier lifetime in CdTe for thin film solar cells, but there are roadblocks concerning point defects including the possibility of self-compensation by AX metastability. Herein, we report on doping, lifetime, and mobility of CdTe single crystals doped with As between 1016 and 1020 cm-3 grown from the Cd solvent by the travelling heater method. Evidence consistent with AX instability as a major contributor to compensation in samples doped below 1017 cm-3 is presented, while for higher-doped samples, precipitation of a second phase on planar structural defects is also observed and may explain spatial variation in properties such as lifetime. Rapid cooling after crystal growth increases doping efficiency and mobility for times up to 20-30 days at room temperature with the highest efficiencies observed close to 45% and a hole mobility of 70 cm2/Vs at room temperature. A doping limit in the low 1017/cm3 range is observed for samples quenched at 200-300 °C/h. Bulk minority carrier lifetimes exceeding 20 ns are observed for samples doped near 1016 cm-3 relaxed in the dark and for unintentionally doped samples, while a lifetime of nearly 5 ns is observed for 1018 cm-3 As doping. These results help us to establish limits on properties expected for group-V doped CdTe polycrystalline thin films for use in photovoltaics.

  14. Ultrafast recombination in H+ bombarded InP and GaAs: Consequences for the carrier distribution functions

    International Nuclear Information System (INIS)

    Lamprecht, K.F.; Juen, S.; Hoepfel, R.A.; Palmetshofer, L.

    1992-01-01

    The authors studied the lifetimes and the luminescence spectra of photoexcited carriers in H + bombarded InP and GaAs for different damage doses by means of femtosecond luminescence spectroscopy. For InP the lifetime decreases down to 95 fs for the highest dose, whereas for GaAs no shorter lifetime than 650 fs could be observed. With decreasing lifetime they observe an increase of the high energy tail of the time-integrated luminescence spectrum which is even inverted for the 95 fs InP sample

  15. Charge Carrier Dynamics at Silver Nanocluster-Molecular Acceptor Interfaces

    KAUST Repository

    Almansaf, Abdulkhaleq

    2017-07-01

    A fundamental understanding of interfacial charge transfer at donor-acceptor interfaces is very crucial as it is considered among the most important dynamical processes for optimizing performance in many light harvesting systems, including photovoltaics and photo-catalysis. In general, the photo-generated singlet excitons in photoactive materials exhibit very short lifetimes because of their dipole-allowed spin radiative decay and short diffusion lengths. In contrast, the radiative decay of triplet excitons is dipole forbidden; therefore, their lifetimes are considerably longer. The discussion in this thesis primarily focuses on the relevant parameters that are involved in charge separation (CS), charge transfer (CT), intersystem crossing (ISC) rate, triplet state lifetime, and carrier recombination (CR) at silver nanocluster (NCs) molecular-acceptors interfaces. A combination of steady-state and femto- and nanosecond broadband transient absorption spectroscopies were used to investigate the charge carrier dynamics in various donor-acceptor systems. Additionally, this thesis was prolonged to investigate some important factors that influence the charge carrier dynamics in Ag29 silver NCs donor-acceptor systems, such as the metal doping and chemical structure of the nanocluster and molecular acceptors. Interestingly, clear correlations between the steady-state measurements and timeresolved spectroscopy results are found. In the first study, we have investigated the interfacial charge transfer dynamics in positively charged meso units of 5, 10, 15, 20-tetra (1- methyl-4-pyridino)-porphyrin tetra (p-toluene sulfonate) (TMPyP) and neutral charged 5, 10, 15, 20-tetra (4-pyridyl)-porphyrin (TPyP), with negatively charged undoped and gold (Au)- doped silver Ag29 NCs. Moreover, this study showed the impact of Au doping on the charge carrier dynamics of the system. In the second study, we have investigated the interfacial charge transfer dynamics in [Pt2 Ag23 Cl7 (PPh3

  16. All-optical measurements of carrier dynamics in bulk-GaN LEDs: Beyond the ABC approximation

    Science.gov (United States)

    David, Aurelien; Young, Nathan G.; Hurni, Christophe A.; Craven, Michael D.

    2017-06-01

    An all-optical measurement of differential carrier lifetimes is performed in a specially designed single-quantum-well structure. The measurement reveals the complex carrier-dependence of radiative and non-radiative recombinations, which directly manifest wavefunction-overlap and field-screening effects. This analysis clarifies the range of applicability of the common ABC model and its limitations.

  17. Cryogenic Lifetime Studies of 130 nm and 65 nm CMOS Technologies for High-Energy Physics Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Hoff, James R. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Deptuch, G. W. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Wu, Guoying [Southern Methodist Univ., Dallas, TX (United States); Gui, Ping [Southern Methodist Univ., Dallas, TX (United States)

    2015-06-04

    The Long Baseline Neutrino Facility intends to use unprecedented volumes of liquid argon to fill a time projection chamber in an underground facility. Research is under way to place the electronics inside the cryostat. For reasons of efficiency and economics, the lifetimes of these circuits must be well in excess of 20 years. The principle mechanism for lifetime degradation of MOSFET devices and circuits operating at cryogenic temperatures is hot carrier degradation. Choosing a process technology that is, as much as possible, immune to such degradation and developing design techniques to avoid exposure to such damage are the goals. This, then, requires careful investigation and a basic understanding of the mechanisms that underlie hot carrier degradation and the secondary effects they cause in circuits. In this work, commercially available 130 nm and 65 nm nMOS transistors operating at cryogenic temperatures are investigated. Our results show that both technologies achieve the lifetimes required by the experiment. Minimal design changes are necessary in the case of the 130 nm process and no changes whatsoever are necessary for the 65 nm process.

  18. Tracking Ultrafast Carrier Dynamics in Single Semiconductor Nanowire Heterostructures

    Directory of Open Access Journals (Sweden)

    Taylor A.J.

    2013-03-01

    Full Text Available An understanding of non-equilibrium carrier dynamics in silicon (Si nanowires (NWs and NW heterostructures is very important due to their many nanophotonic and nanoelectronics applications. Here, we describe the first measurements of ultrafast carrier dynamics and diffusion in single heterostructured Si nanowires, obtained using ultrafast optical microscopy. By isolating individual nanowires, we avoid complications resulting from the broad size and alignment distribution in nanowire ensembles, allowing us to directly probe ultrafast carrier dynamics in these quasi-one-dimensional systems. Spatially-resolved pump-probe spectroscopy demonstrates the influence of surface-mediated mechanisms on carrier dynamics in a single NW, while polarization-resolved femtosecond pump-probe spectroscopy reveals a clear anisotropy in carrier lifetimes measured parallel and perpendicular to the NW axis, due to density-dependent Auger recombination. Furthermore, separating the pump and probe spots along the NW axis enabled us to track space and time dependent carrier diffusion in radial and axial NW heterostructures. These results enable us to reveal the influence of radial and axial interfaces on carrier dynamics and charge transport in these quasi-one-dimensional nanosystems, which can then be used to tailor carrier relaxation in a single nanowire heterostructure for a given application.

  19. Screening in crystalline liquids protects energetic carriers in hybrid perovskites

    Science.gov (United States)

    Zhu, Haiming; Miyata, Kiyoshi; Fu, Yongping; Wang, Jue; Joshi, Prakriti; Niesner, Daniel; Williams, Kristopher; Jin, Song; Zhu, Xiaoyang

    Hybrid lead halide perovskites exhibit carrier properties that resemble those of pristine nonpolar semiconductors despite static and dynamic disorder, but how carriers are protected from efficient scattering with charged defects and optical phonons is unknown. Here, we reveal the carrier protection mechanism by comparing three single-crystal lead bromide perovskites: CH3NH3PbBr3, CH(NH2)2PbBr3, and CsPbBr3. We observed hot fluorescence emission from energetic carriers with 102 picosecond lifetimes in CH3NH3PbBr3 or CH(NH,SUB>2)2PbBr3, but not in CsPbBr3. The hot fluorescence is correlated with liquid-like molecular reorientational motions, suggesting that dynamic screening protects energetic carriers via solvation or large polaron formation on time scales competitive with that of ultrafast cooling. Similar protections likely exist for band-edge carriers. The long-lived energetic carriers may enable hot-carrier solar cells with efficiencies exceeding the Shockley-Queisser limit. This work was supported by U.S. Department of Energy Grant ER46980, National Science Foundation, Grant DMR 1420634 (MRSEC), and Department of Energy Award DE-FG02-09ER46664.

  20. Ultrafast carrier dynamics in Br.sup.+./sup.-bombarded InP studied by time-resolved terahertz spectroscopy

    Czech Academy of Sciences Publication Activity Database

    Němec, Hynek; Fekete, Ladislav; Kadlec, Filip; Kužel, Petr

    2008-01-01

    Roč. 78, č. 23 (2008), 235206/1-235206/7 ISSN 1098-0121 R&D Projects: GA MŠk LC512 Institutional research plan: CEZ:AV0Z10100520 Keywords : InP * carrier lifetime * carrier mobility * ultrafast * ion-bombardment * terahertz Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.322, year: 2008

  1. High p-Type Doping, Mobility, and Photocarrier Lifetime in Arsenic-Doped CdTe Single Crystals

    Energy Technology Data Exchange (ETDEWEB)

    Kuciauskas, Darius [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Nagaoka, Akira [Kyoto University; University of Utah; McCoy, Jedidiah [Washington State University; Scarpulla, Michael A. [University of Utah

    2018-05-08

    Group-V element doping is promising for simultaneously maximizing the hole concentration and minority carrier lifetime in CdTe for thin film solar cells, but there are roadblocks concerning point defects including the possibility of self-compensation by AX metastability. Herein, we report on doping, lifetime, and mobility of CdTe single crystals doped with As between 10^16 and 10^20 cm-3 grown from the Cd solvent by the travelling heater method. Evidence consistent with AX instability as a major contributor to compensation in samples doped below 10^17 cm-3 is presented, while for higher-doped samples, precipitation of a second phase on planar structural defects is also observed and may explain spatial variation in properties such as lifetime. Rapid cooling after crystal growth increases doping efficiency and mobility for times up to 20-30 days at room temperature with the highest efficiencies observed close to 45% and a hole mobility of 70 cm2/Vs at room temperature. A doping limit in the low 10^17/cm3 range is observed for samples quenched at 200-300 degrees C/h. Bulk minority carrier lifetimes exceeding 20 ns are observed for samples doped near 10^16 cm-3 relaxed in the dark and for unintentionally doped samples, while a lifetime of nearly 5 ns is observed for 10^18 cm-3 As doping. These results help us to establish limits on properties expected for group-V doped CdTe polycrystalline thin films for use in photovoltaics.

  2. Study of excess carrier dynamics in polar, semi-polar, and non-polar (In,Ga)N epilayers and QWs

    Energy Technology Data Exchange (ETDEWEB)

    Aleksiejunas, R. [Institute of Applied Research, Vilnius University, Sauletekio Ave. 9-III, 10222 Vilnius (Lithuania); Laser Research Center, Vilnius University, Sauletekio Ave. 10, 10222 Vilnius (Lithuania); Lubys, L.; Jarasiunas, K. [Institute of Applied Research, Vilnius University, Sauletekio Ave. 9-III, 10222 Vilnius (Lithuania); Vengris, M. [Laser Research Center, Vilnius University, Sauletekio Ave. 10, 10222 Vilnius (Lithuania); Wernicke, T.; Hoffmann, V.; Netzel, C.; Knauer, A.; Weyers, M. [Ferdinand-Braun-Institut, Leibniz-Institut fuer Hoechstfrequenztechnik, Gustav-Kirchhoff-Str. 4, 12498 Berlin (Germany); Kneissl, M. [Ferdinand-Braun-Institut, Leibniz-Institut fuer Hoechstfrequenztechnik, Gustav-Kirchhoff-Str. 4, 12498 Berlin (Germany); Institute of Solid State Physics, Technische Universitaet Berlin, Hardenbergstr. 36, 10623 Berlin (Germany)

    2011-07-15

    We studied carrier recombination and diffusion in GaN/sapphire templates, (In,Ga)N layers, and (In,Ga)N quantum well structures oriented along the polar [0001], semi-polar [11-22], and non-polar [11-20] orientations by means of light induced transient grating, differential transmission, and photoluminescence optical techniques. We show that the lifetime of excess carriers drops by orders of magnitude when changing the orientation from polar to non-polar, both in GaN templates and (In,Ga)N layers. We attribute the shorter lifetime to carrier trapping by extended structural defects that are more abundant in non-polar grown samples. In addition, we observe pronounced carrier localization effects in the semi- and non-polar layers. We show that thick (In,Ga)N layers inherit the properties of the GaN templates. However, the thin quantum well structures show a lower carrier trapping activity. So, a better electrical quality can be assumed as compared to the thick (In,Ga)N layers. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  3. Long-lived hot-carrier light emission and large blue shift in formamidinium tin triiodide perovskites

    OpenAIRE

    Fang, Hong-Hua; Adjokatse, Sampson; Shao, Shuyan; Even, Jacky; Loi, Maria Antonietta

    2018-01-01

    A long-lived hot carrier population is critical in order to develop working hot carrier photovoltaic devices with efficiencies exceeding the Shockley-Queisser limit. Here, we report photoluminescence from hot-carriers with unexpectedly long lifetime (a few ns) in formamidinium tin triiodide. An unusual large blue shift of the time-integrated photoluminescence with increasing excitation power (150 meV at 24 K and 75 meV at 293 K) is displayed. On the basis of the analysis of energy-resolved an...

  4. Spatial carrier distribution in InP/GaAs type II quantum dots and quantum posts

    Science.gov (United States)

    Iikawa, F.; Donchev, V.; Ivanov, Ts; Dias, G. O.; Tizei, L. H. G.; Lang, R.; Heredia, E.; Gomes, P. F.; Brasil, M. J. S. P.; Cotta, M. A.; Ugarte, D.; Martinez Pastor, J. P.; de Lima, M. M., Jr.; Cantarero, A.

    2011-02-01

    We performed a detailed investigation of the structural and optical properties of multi-layers of InP/GaAs quantum dots, which present a type II interface arrangement. Transmission electronic microscopy analysis has revealed relatively large dots that coalesce forming so-called quantum posts when the GaAs layer between the InP layers is thin. We observed that the structural properties and morphology affect the resulting radiative lifetime of the carriers in our systems. The carrier lifetimes are relatively long, as expected for type II systems, as compared to those observed for single layer InP/GaAs quantum dots. The interface intermixing effect has been pointed out as a limiting factor for obtaining an effective spatial separation of electrons and holes in the case of single layer InP/GaAs quantum-dot samples. In the present case this effect seems to be less critical due to the particular carrier wavefunction distribution along the structures.

  5. Spatial carrier distribution in InP/GaAs type II quantum dots and quantum posts

    International Nuclear Information System (INIS)

    Iikawa, F; Donchev, V; Dias, G O; Tizei, L H G; Lang, R; Gomes, P F; Brasil, M J S P; Cotta, M A; Ugarte, D; Ivanov, Ts; Heredia, E; Martinez Pastor, J P; De Lima, M M Jr; Cantarero, A

    2011-01-01

    We performed a detailed investigation of the structural and optical properties of multi-layers of InP/GaAs quantum dots, which present a type II interface arrangement. Transmission electronic microscopy analysis has revealed relatively large dots that coalesce forming so-called quantum posts when the GaAs layer between the InP layers is thin. We observed that the structural properties and morphology affect the resulting radiative lifetime of the carriers in our systems. The carrier lifetimes are relatively long, as expected for type II systems, as compared to those observed for single layer InP/GaAs quantum dots. The interface intermixing effect has been pointed out as a limiting factor for obtaining an effective spatial separation of electrons and holes in the case of single layer InP/GaAs quantum-dot samples. In the present case this effect seems to be less critical due to the particular carrier wavefunction distribution along the structures.

  6. Spatial carrier distribution in InP/GaAs type II quantum dots and quantum posts

    Energy Technology Data Exchange (ETDEWEB)

    Iikawa, F; Donchev, V; Dias, G O; Tizei, L H G; Lang, R; Gomes, P F; Brasil, M J S P; Cotta, M A; Ugarte, D [Instituto de Fisica ' Gleb Wataghin' , Unicamp, CP-6165, 13083-970, Campinas-SP (Brazil); Ivanov, Ts [Faculty of Physics, Sofia University, 5, Boulevard J.Bourchier, Sofia-1164 (Bulgaria); Heredia, E [Laboratorio Associado de Sensores e Materiais, Instituto Nacional de Pesquisas Espaciais, CP 515, 12245-970, Sao Jose dos Campos-SP (Brazil); Martinez Pastor, J P; De Lima, M M Jr; Cantarero, A, E-mail: iikawa@ifi.unicamp.br [Materials Science Institute, University of Valencia, PO Box 22085, 46071 Valencia (Spain)

    2011-02-11

    We performed a detailed investigation of the structural and optical properties of multi-layers of InP/GaAs quantum dots, which present a type II interface arrangement. Transmission electronic microscopy analysis has revealed relatively large dots that coalesce forming so-called quantum posts when the GaAs layer between the InP layers is thin. We observed that the structural properties and morphology affect the resulting radiative lifetime of the carriers in our systems. The carrier lifetimes are relatively long, as expected for type II systems, as compared to those observed for single layer InP/GaAs quantum dots. The interface intermixing effect has been pointed out as a limiting factor for obtaining an effective spatial separation of electrons and holes in the case of single layer InP/GaAs quantum-dot samples. In the present case this effect seems to be less critical due to the particular carrier wavefunction distribution along the structures.

  7. Advances in Contactless Silicon Defect and Impurity Diagnostics Based on Lifetime Spectroscopy and Infrared Imaging

    Directory of Open Access Journals (Sweden)

    Jan Schmidt

    2007-01-01

    Full Text Available This paper gives a review of some recent developments in the field of contactless silicon wafer characterization techniques based on lifetime spectroscopy and infrared imaging. In the first part of the contribution, we outline the status of different lifetime spectroscopy approaches suitable for the identification of impurities in silicon and discuss—in more detail—the technique of temperature- and injection-dependent lifetime spectroscopy. The second part of the paper focuses on the application of infrared cameras to analyze spatial inhomogeneities in silicon wafers. By measuring the infrared signal absorbed or emitted from light-generated free excess carriers, high-resolution recombination lifetime mappings can be generated within seconds to minutes. In addition, mappings of non-recombination-active trapping centers can be deduced from injection-dependent infrared lifetime images. The trap density has been demonstrated to be an important additional parameter in the characterization and assessment of solar-grade multicrystalline silicon wafers, as areas of increased trap density tend to deteriorate during solar cell processing.

  8. Model of hot-carrier induced degradation in ultra-deep sub-micrometer nMOSFET

    International Nuclear Information System (INIS)

    Lei Xiao-Yi; Liu Hong-Xia; Zhang Yue; Ma Xiao-Hua; Hao Yue

    2014-01-01

    The degradation produced by hot carrier (HC) in ultra-deep sub-micron n-channel metal oxide semiconductor field effect transistor (nMOSFET) has been analyzed in this paper. The generation of negatively charged interface states is the predominant mechanism for the ultra-deep sub-micron nMOSFET. According to our lifetime model of p-channel MOFET (pMOFET) that was reported in a previous publication, a lifetime prediction model for nMOSFET is presented and the parameters in the model are extracted. For the first time, the lifetime models of nMOFET and pMOSFET are unified. In addition, the model can precisely predict the lifetime of the ultra-deep sub-micron nMOSFET and pMOSFET. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  9. Carrier dynamics in epilayers and nanocolumns of ternary AlGaN with a tunable bandgap

    International Nuclear Information System (INIS)

    Aleksiejunas, R; Šcajev, P; Nargelas, S; Miasojedovas, S; Jarašiunas, K; Trinkler, L; Grigorjeva, J; Berzina, B; Chen, K H; Chen, Y T; Chen, M W; Chen, L C

    2012-01-01

    We apply several optical time-resolved techniques to investigate the dynamics of excess carriers in Al x Ga 1−x N nanocolumns grown on (111) silicon substrates and in thick Al x Ga 1−x N epitaxial layers deposited on sapphire. We demonstrate that carrier lifetime drops in nanocolumns by several times if compared to epilayers with similar Al content; in addition, recombination rate displays a strong nonlinearity on excitation. On the other hand, carrier localization effects observed in the epilayers completely disappear in nanocolumns.

  10. Effect of carrier relaxation lifetime on the performance of InAs/InP quantum-dash lasers

    KAUST Repository

    Khan, Mohammed Zahed Mustafa

    2011-12-01

    The effect of carrier relaxation process into the quantum dash (Qdash) ground state (GS) is examined theoretically by carrier-photon rate equation model incorporating the inhomogeneous broadening. Increase in the relaxation time and the inhomogeneous broadening degrades the threshold current density. Moreover, our results show that a relaxation time of less than 2 ps gives optimum laser performance. © 2011 IEEE.

  11. Photoconductance-calibrated photoluminescence lifetime imaging of crystalline silicon

    International Nuclear Information System (INIS)

    Herlufsen, Sandra; Schmidt, Jan; Hinken, David; Bothe, Karsten; Brendel, Rolf

    2008-01-01

    We use photoluminescence (PL) measurements by a silicon charge-coupled device camera to generate high-resolution lifetime images of multicrystalline silicon wafers. Absolute values of the excess carrier density are determined by calibrating the PL image by means of contactless photoconductance measurements. The photoconductance setup is integrated in the camera-based PL setup and therefore identical measurement conditions are realised. We demonstrate the validity of this method by comparison with microwave-detected photoconductance decay measurements. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (Abstract Copyright [2008], Wiley Periodicals, Inc.)

  12. Variations in the electrical short-circuit current decay for recombination lifetime and velocity measurements

    Science.gov (United States)

    Jung, Tae-Won; Lindholm, Fredrik A.; Neugroschel, Arnost

    1987-01-01

    An improved measurement system for electrical short-circuit current decay is presented that extends applicability of the method to silicon solar cells having an effective lifetime as low as 1 microsec. The system uses metal/oxide/semiconductor transistors as voltage-controlled switches. Advances in theory developed here increase precision and sensitivity in the determination of the minority-carrier recombination lifetime and recombination velocity. A variation of the method, which exploits measurements made on related back-surface field and back-ohmic contact devices, further improves precision and sensitivity. The improvements are illustrated by application to 15 different silicon solar cells.

  13. Active tuning of surface phonon polariton resonances via carrier photoinjection

    Science.gov (United States)

    Dunkelberger, Adam D.; Ellis, Chase T.; Ratchford, Daniel C.; Giles, Alexander J.; Kim, Mijin; Kim, Chul Soo; Spann, Bryan T.; Vurgaftman, Igor; Tischler, Joseph G.; Long, James P.; Glembocki, Orest J.; Owrutsky, Jeffrey C.; Caldwell, Joshua D.

    2018-01-01

    Surface phonon polaritons (SPhPs) are attractive alternatives to infrared plasmonics for subdiffractional confinement of infrared light. Localized SPhP resonances in semiconductor nanoresonators are narrow, but that linewidth and the limited extent of the Reststrahlen band limit spectral coverage. To address this limitation, we report active tuning of SPhP resonances in InP and 4H-SiC by photoinjecting free carriers into nanoresonators, taking advantage of the coupling between the carrier plasma and optic phonons to blueshift SPhP resonances. We demonstrate state-of-the-art tuning figures of merit upon continuous-wave excitation (in InP) or pulsed excitation (in 4H-SiC). Lifetime effects cause the tuning to saturate in InP, and carrier redistribution leads to rapid (electronic and phononic excitations.

  14. Explanation of low efficiency droop in semipolar (202¯1¯) InGaN/GaN LEDs through evaluation of carrier recombination coefficients

    Science.gov (United States)

    Monavarian, Morteza; Rashidi, Arman; Aragon, Andrew; Oh, Sang H.; Nami, Mohsen; DenBaars, Steve P.; Feezell, Daniel

    2017-08-01

    We report the carrier dynamics and recombination coefficients in single-quantum-well semipolar $(20\\bar 2\\bar 1)$ InGaN/GaN light-emitting diodes emitting at 440 nm with 93% peak internal quantum efficiency. The differential carrier lifetime is analyzed for various injection current densities from 5 $A/cm^2$ to 10 $kA/cm^2$, and the corresponding carrier densities are obtained. The coupling of internal quantum efficiency and differential carrier lifetime vs injected carrier density ($n$) enables the separation of the radiative and nonradiative recombination lifetimes and the extraction of the Shockley-Read-Hall (SRH) nonradiative ($A$), radiative ($B$), and Auger ($C$) recombination coefficients and their $n$-dependency considering the saturation of the SRH recombination rate and phase-space filling. The results indicate a three to four-fold higher $A$ and a nearly two-fold higher $B_0$ for this semipolar orientation compared to that of $c$-plane reported using a similar approach [A. David and M. J. Grundmann, Appl. Phys. Lett. 96, 103504 (2010)]. In addition, the carrier density in semipolar $(20\\bar 2\\bar 1)$ is found to be lower than the carrier density in $c$-plane for a given current density, which is important for suppressing efficiency droop. The semipolar LED also shows a two-fold lower $C_0$ compared to $c$-plane, which is consistent with the lower relative efficiency droop for the semipolar LED (57% vs. 69%). The lower carrier density, higher $B_0$ coefficient, and lower $C_0$ (Auger) coefficient are directly responsible for the high efficiency and low efficiency droop reported in semipolar $(20\\bar 2\\bar 1)$ LEDs.

  15. Direct femtosecond observation of charge carrier recombination in ternary semiconductor nanocrystals: The effect of composition and shelling

    KAUST Repository

    Bose, Riya

    2015-02-12

    Heavy-metal free ternary semiconductor nanocrystals are emerging as key materials in photoactive applications. However, the relative abundance of intra-bandgap defect states and lack of understanding of their origins within this class of nanocrystals are major factors limiting their applicability. To remove these undesirable defect states which considerably shorten the lifetimes of photogenerated excited carriers, a detailed understanding about their origin and nature is required. In this report, we monitor the ultrafast charge carrier dynamics of CuInS2 (CIS), CuInSSe (CISSe), and CuInSe2 (CISe) nanocrystals, before and after ZnS shelling, using state-of-the-art time-resolved laser spectroscopy with broadband capabilities. The experimental results demonstrate the presence of both electron and hole trapping intra-bandgap states in the nanocrystals which can be removed significantly by ZnS shelling, and the carrier dynamics is slowed down. Another important observation remains the reduction of carrier lifetime in the presence of Se, and the shelling strategy is observed to be less effective at suppressing trap states. This study provides quantitative physical insights into the role of anion composition and shelling on the charge carrier dynamics in ternary CIS, CISSe, and CISe nanocrystals which are essential to improve their applicability for photovoltaics and optoelectronics.

  16. PbCl2-tuned inorganic cubic CsPbBr3(Cl) perovskite solar cells with enhanced electron lifetime, diffusion length and photovoltaic performance

    Science.gov (United States)

    Li, Bo; Zhang, Yanan; Zhang, Luyuan; Yin, Longwei

    2017-08-01

    Inorganic CsPbBr3 perovskite is arousing great interest following after organic-inorganic hybrid halide perovskites, and is found as a good candidate for photovoltaic devices for its prominent photoelectric property and stability. Herein, we for the first time report on PbCl2-tuned inorganic Cl-doped CsPbBr3(Cl) perovskite solar cells with adjustable crystal structure and Cl doping for enhanced carrier lifetime, extraction rate and photovoltaic performance. The effect of PbCl2 on the morphologies, structures, optical, and photovoltaic performance of CsPbBr3 perovskite solar cells is investigated systemically. Compared with orthorhombic CsPbBr3, cubic CsPbBr3 demonstrates a significant improvement for electron lifetime (from 6.7 ns to 12.3 ns) and diffusion length (from 69 nm to 197 nm), as well as the enhanced electron extraction rate from CsPbBr3 to TiO2. More importantly, Cl doping benefits the further enhancement of carrier lifetime (14.3 ns) and diffusion length (208 nm). The Cl doped cubic CsPbBr3(Cl) perovskite solar cell exhibits a Jsc of 8.47 mA cm-2 and a PCE of 6.21%, superior to that of pure orthorhombic CsPbBr3 (6.22 mA cm-2 and 3.78%). The improvement of photovoltaic performance can be attributed to enhanced carrier lifetime, diffusion length and extraction rates, as well as suppressed nonradiative recombination.

  17. Efficient photogeneration of charge carriers in silicon nanowires with a radial doping gradient

    International Nuclear Information System (INIS)

    Murthy, D H K; Houtepen, A J; Savenije, T J; Siebbeles, L D A; Xu, T; Nys, J P; Krzeminski, C; Grandidier, B; Stievenard, D; Chen, W H; Pareige, P; Jomard, F; Patriarche, G; Lebedev, O I

    2011-01-01

    by performing electrodeless time-resolved microwave conductivity measurements, the efficiency of charge carrier generation, their mobility, and the decay kinetics on photoexcitation were studied in arrays of Si nanowires grown by the vapor-liquid-solid mechanism. Large enhancements in the magnitude of the photoconductance and charge carrier lifetime are found depending on the incorporation of impurities during the growth. They are explained by the internal electric field that builds up, due to higher doped sidewalls, as revealed by detailed analysis of the nanowire morphology and chemical composition.

  18. Lifetime of excess electrons in Cu–Zn–Sn–Se powders

    Energy Technology Data Exchange (ETDEWEB)

    Novikov, G. F., E-mail: ngf@icp.ac.ru; Gapanovich, M. V. [Russian Academy of Sciences, Institute of Problems in Chemical Physics (Russian Federation); Gremenok, V. F. [National Academy of Sciences of Belarus, Scientific and Practical Center for Materials Science (Belarus); Bocharov, K. V. [Russian Academy of Sciences, Institute of Problems in Chemical Physics (Russian Federation); Tsai, W.-T.; Jeng, Ming-Jer; Chang, Liann-Be [Chang Gung University, Department of Electronic Engineering (China)

    2017-01-15

    The method of time-resolved microwave photoconductivity at a frequency of 36 GHz in the range of temperatures of 200–300 K is used to study the kinetics of the annihilation of charge carriers in Cu–Zn–Sn–Se powders obtained by the solid-phase method of synthesis in cells. The lifetime of excess electrons at room temperature is found to be shorter than 5 ns. The activation energy for the process of recombination amounted to E{sub a} ~ 0.054 eV.

  19. Two dimensional numerical simulations of carrier dynamics during time-resolved photoluminescence decays in two-photon microscopy measurements in semiconductors

    International Nuclear Information System (INIS)

    Kanevce, Ana; Kuciauskas, Darius; Levi, Dean H.; Johnston, Steven W.; Allende Motz, Alyssa M.

    2015-01-01

    We use two-dimensional numerical simulations to analyze high spatial resolution time-resolved spectroscopy data. This analysis is applied to two-photon excitation time-resolved photoluminescence (2PE-TRPL) but is broadly applicable to all microscopic time-resolved techniques. By solving time-dependent drift-diffusion equations, we gain insight into carrier dynamics and transport characteristics. Accurate understanding of measurement results establishes the limits and potential of the measurement and enhances its value as a characterization method. Diffusion of carriers outside of the collection volume can have a significant impact on the measured decay but can also provide an estimate of carrier mobility as well as lifetime. In addition to material parameters, the experimental conditions, such as spot size and injection level, can impact the measurement results. Although small spot size provides better resolution, it also increases the impact of diffusion on the decay; if the spot size is much smaller than the diffusion length, it impacts the entire decay. By reproducing experimental 2PE-TRPL decays, the simulations determine the bulk carrier lifetime from the data. The analysis is applied to single-crystal and heteroepitaxial CdTe, material important for solar cells, but it is also applicable to other semiconductors where carrier diffusion from the excitation volume could affect experimental measurements

  20. Enhanced Mobility-Lifetime Products in PbS Colloidal Quantum Dot Photovoltaics

    KAUST Repository

    Jeong, Kwang S.

    2012-01-24

    Figure Persented: Colloidal quantum dot (CQD) photovoltaics offer a promising approach to harvest the near-IR region of the solar spectrum, where half of the sun\\'s power reaching the earth resides. High external quantum efficiencies have been obtained in the visible region in lead chalcogenide CQD photovoltaics. However, the corresponding efficiencies for band gap radiation in the near-infrared lag behind because the thickness of CQD photovoltaic layers from which charge carriers can be extracted is limited by short carrier diffusion lengths. Here, we investigate, using a combination of electrical and optical characterization techniques, ligand passivation strategies aimed at tuning the density and energetic distribution of charge trap states at PbS nanocrystal surfaces. Electrical and optical measurements reveal a more than 7-fold enhancement of the mobility-lifetime product of PbS CQD films treated with 3-mercaptopropionic acid (MPA) in comparison to traditional organic passivation strategies that have been examined in the literature. We show by direct head-to-head comparison that the greater mobility-lifetime products of MPA-treated devices enable markedly greater short-circuit current and higher power conversion efficiency under AM1.5 illumination. Our findings highlight the importance of selecting ligand treatment strategies capable of passivating a diversity of surface states to enable shallower and lower density trap distributions for better transport and more efficient CQD solar cells. © 2011 American Chemical Society.

  1. Accelerated carrier recombination by grain boundary/edge defects in MBE grown transition metal dichalcogenides

    Science.gov (United States)

    Chen, Ke; Roy, Anupam; Rai, Amritesh; Movva, Hema C. P.; Meng, Xianghai; He, Feng; Banerjee, Sanjay K.; Wang, Yaguo

    2018-05-01

    Defect-carrier interaction in transition metal dichalcogenides (TMDs) plays important roles in carrier relaxation dynamics and carrier transport, which determines the performance of electronic devices. With femtosecond laser time-resolved spectroscopy, we investigated the effect of grain boundary/edge defects on the ultrafast dynamics of photoexcited carrier in molecular beam epitaxy (MBE)-grown MoTe2 and MoSe2. We found that, comparing with exfoliated samples, the carrier recombination rate in MBE-grown samples accelerates by about 50 times. We attribute this striking difference to the existence of abundant grain boundary/edge defects in MBE-grown samples, which can serve as effective recombination centers for the photoexcited carriers. We also observed coherent acoustic phonons in both exfoliated and MBE-grown MoTe2, indicating strong electron-phonon coupling in this materials. Our measured sound velocity agrees well with the previously reported result of theoretical calculation. Our findings provide a useful reference for the fundamental parameters: carrier lifetime and sound velocity and reveal the undiscovered carrier recombination effect of grain boundary/edge defects, both of which will facilitate the defect engineering in TMD materials for high speed opto-electronics.

  2. Accelerated carrier recombination by grain boundary/edge defects in MBE grown transition metal dichalcogenides

    Directory of Open Access Journals (Sweden)

    Ke Chen

    2018-05-01

    Full Text Available Defect-carrier interaction in transition metal dichalcogenides (TMDs plays important roles in carrier relaxation dynamics and carrier transport, which determines the performance of electronic devices. With femtosecond laser time-resolved spectroscopy, we investigated the effect of grain boundary/edge defects on the ultrafast dynamics of photoexcited carrier in molecular beam epitaxy (MBE-grown MoTe2 and MoSe2. We found that, comparing with exfoliated samples, the carrier recombination rate in MBE-grown samples accelerates by about 50 times. We attribute this striking difference to the existence of abundant grain boundary/edge defects in MBE-grown samples, which can serve as effective recombination centers for the photoexcited carriers. We also observed coherent acoustic phonons in both exfoliated and MBE-grown MoTe2, indicating strong electron-phonon coupling in this materials. Our measured sound velocity agrees well with the previously reported result of theoretical calculation. Our findings provide a useful reference for the fundamental parameters: carrier lifetime and sound velocity and reveal the undiscovered carrier recombination effect of grain boundary/edge defects, both of which will facilitate the defect engineering in TMD materials for high speed opto-electronics.

  3. A cost-benefit analysis of preimplantation genetic diagnosis for carrier couples of cystic fibrosis.

    Science.gov (United States)

    Davis, Lynn B; Champion, Sara J; Fair, Steve O; Baker, Valerie L; Garber, Alan M

    2010-04-01

    To perform a cost-benefit analysis of preimplantation genetic diagnosis (PGD) for carrier couples of cystic fibrosis (CF) compared with the alternative of natural conception (NC) followed by prenatal testing and termination of affected pregnancies. Cost-benefit analysis using a decision analytic model. Outpatient reproductive health practices. A simulated cohort of 1,000 female patients. We calculated the net benefit of giving birth to a child as the present value of lifetime earnings minus lifetime medical costs. Net benefits in dollars. When used for women younger than 35 years of age, the net benefit of PGD over NC was $182,000 ($715,000 vs. $532,000, respectively). For women aged 35-40 years, the net benefit of PGD over NC was $114,000 ($634,000 vs. $520,000, respectively). For women older than 40 years, however, the net benefit of PGD over NC was -$148,000 ($302,000 vs. $450,000, respectively). Preimplantation genetic diagnosis provides net economic benefits when used by carrier couples of CF. Although there is an upper limit of maternal age at which economic benefit can be demonstrated, carrier couples of CF should be offered PGD for prevention of an affected child. Copyright 2010 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  4. Long-lived hot-carrier light emission and large blue shift in formamidinium tin triiodide perovskites.

    Science.gov (United States)

    Fang, Hong-Hua; Adjokatse, Sampson; Shao, Shuyan; Even, Jacky; Loi, Maria Antonietta

    2018-01-16

    A long-lived hot carrier population is critical in order to develop working hot carrier photovoltaic devices with efficiencies exceeding the Shockley-Queisser limit. Here, we report photoluminescence from hot-carriers with unexpectedly long lifetime (a few ns) in formamidinium tin triiodide. An unusual large blue shift of the time-integrated photoluminescence with increasing excitation power (150 meV at 24 K and 75 meV at 293 K) is displayed. On the basis of the analysis of energy-resolved and time-resolved photoluminescence, we posit that these phenomena are associated with slow hot carrier relaxation and state-filling of band edge states. These observations are both important for our understanding of lead-free hybrid perovskites and for an eventual future development of efficient lead-free perovskite photovoltaics.

  5. Nuclear lifetimes

    International Nuclear Information System (INIS)

    Caraca, J.M.G.

    1976-01-01

    The importance of the results obtained in experiments of measurement of lifetimes for a detailed knowledge of nuclear structure is referred. Direct methods of measurement of nuclear lifetimes are described, namely, electronic methods, recoil-distance method, doppler shift atenuation method and blocking-method. A brief reference is made to indirect methods for measurement of life-times

  6. Suicidal ideation and suicidal behavior according to the C-SSRS in a European cohort of Huntington's disease gene expansion carriers.

    Science.gov (United States)

    van Duijn, Erik; Vrijmoeth, Eslie M; Giltay, Erik J; Bernhard Landwehrmeyer, G

    2018-03-01

    Huntington's disease (HD) gene expansion carriers are at an increased risk of suicide, but so far, no studies have investigated the full spectrum of suicidality, including suicidal ideation, suicidal behavior and self-injurious behavior. We included 1451 HD gene expansion carriers (age 48.4 years (SD 14.0), 54.8% female) of the REGISTRY study of the European Huntington's Disease Network. Lifetime suicidal ideation and suicidal behavior were assessed with the Columbia-Suicidal Severity Rating Scale. Motor symptoms and disease stage were assessed using subscales of the Unified Huntington's Disease Rating Scale, and depressed mood and irritability were assessed by the Problem Behaviors Assessment. Lifetime passive suicidal ideation was reported by 21.2%. Participants in stage II showed the highest prevalence rate of suicidal ideation, while participants in stage IV/V showed the highest prevalence of suicidal behavior. A lifetime suicide attempt was reported by 6.5% of the HD gene expansion carriers. In multivariate regression analyses, both suicidal ideation and suicidal behavior were associated with a depressed mood, and to a lesser extend to irritability. Results may have been affected by denial or recall bias and no conclusions can be made about the temporal and causal relationships with depressed mood and irritability because of the cross-sectional analyses. Given the high prevalence of suicidal ideation and suicidal behavior in all stages of HD, it is important to screen HD gene expansion carriers for suicidal ideation and suicidal behavior on a regular basis in clinical practice. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. How High Local Charge Carrier Mobility and an Energy Cascade in a Three-Phase Bulk Heterojunction Enable >90% Quantum Efficiency

    KAUST Repository

    Burke, Timothy M.

    2013-12-27

    Charge generation in champion organic solar cells is highly efficient in spite of low bulk charge-carrier mobilities and short geminate-pair lifetimes. In this work, kinetic Monte Carlo simulations are used to understand efficient charge generation in terms of experimentally measured high local charge-carrier mobilities and energy cascades due to molecular mixing. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. How High Local Charge Carrier Mobility and an Energy Cascade in a Three-Phase Bulk Heterojunction Enable >90% Quantum Efficiency

    KAUST Repository

    Burke, Timothy M.; McGehee, Michael D.

    2013-01-01

    Charge generation in champion organic solar cells is highly efficient in spite of low bulk charge-carrier mobilities and short geminate-pair lifetimes. In this work, kinetic Monte Carlo simulations are used to understand efficient charge generation in terms of experimentally measured high local charge-carrier mobilities and energy cascades due to molecular mixing. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Separation of Olefin/Paraffin Mixtures with Carrier Facilitated Membrane Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Merkel, T.C.; Blanc, R.; Zeid, J.; Suwarlim, A.; Firat, B.; Wijmans, H.; Asaro, M. (SRI); Greene, M.(Lummus)

    2007-03-12

    This document describes the results of a DOE funded joint effort of Membrane Technology and Research Inc. (MTR), SRI International (SRI), and ABB Lummus (ABB) to develop facilitated transport membranes for olefin/paraffin separations. Currently, olefin/paraffin separation is done by distillation—an extremely energy-intensive process because of the low relative volatilities of olefins and paraffins. If facilitated transport membranes could be successfully commercialized, the potential energy savings achievable with this membrane technology are estimated to be 48 trillion Btu per year by the year 2020. We discovered in this work that silver salt-based facilitated transport membranes are not stable even in the presence of ideal olefin/paraffin mixtures. This decline in membrane performance appears to be caused by a previously unrecognized phenomenon that we have named olefin conditioning. As the name implies, this mechanism of performance degradation becomes operative once a membrane starts permeating olefins. This project is the first study to identify olefin conditioning as a significant factor impacting the performance of facilitated olefin transport membranes. To date, we have not identified an effective strategy to mitigate the impact of olefin conditioning. other than running at low temperatures or with low olefin feed pressures. In our opinion, this issue must be addressed before further development of facilitated olefin transport membranes can proceed. In addition to olefin conditioning, traditional carrier poisoning challenges must also be overcome. Light, hydrogen, hydrogen sulfide, and acetylene exposure adversely affect membrane performance through unwanted reaction with silver ions. Harsh poisoning tests with these species showed useful membrane lifetimes of only one week. These tests demonstrate a need to improve the stability of the olefin complexing agent to develop membranes with lifetimes satisfactory for commercial application. A successful effort

  10. Nonradiative lifetime extraction using power-dependent relative photoluminescence of III-V semiconductor double-heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Walker, A. W., E-mail: alexandre.walker@ise.fraunhofer.de; Heckelmann, S.; Karcher, C.; Höhn, O.; Went, C.; Niemeyer, M.; Bett, A. W.; Lackner, D. [Fraunhofer Institute for Solar Energy Systems ISE, Heidenhofstraße 2, 79110 Freiburg (Germany)

    2016-04-21

    A power-dependent relative photoluminescence measurement method is developed for double-heterostructures composed of III-V semiconductors. Analyzing the data yields insight into the radiative efficiency of the absorbing layer as a function of laser intensity. Four GaAs samples of different thicknesses are characterized, and the measured data are corrected for dependencies of carrier concentration and photon recycling. This correction procedure is described and discussed in detail in order to determine the material's Shockley-Read-Hall lifetime as a function of excitation intensity. The procedure assumes 100% internal radiative efficiency under the highest injection conditions, and we show this leads to less than 0.5% uncertainty. The resulting GaAs material demonstrates a 5.7 ± 0.5 ns nonradiative lifetime across all samples of similar doping (2–3 × 10{sup 17 }cm{sup −3}) for an injected excess carrier concentration below 4 × 10{sup 12 }cm{sup −3}. This increases considerably up to longer than 1 μs under high injection levels due to a trap saturation effect. The method is also shown to give insight into bulk and interface recombination.

  11. Lifetime measurements

    International Nuclear Information System (INIS)

    Fossan, D.B.; Warburton, E.K.

    1974-01-01

    Lifetime measurements are discussed, concentrating on the electronic technique, the recoil distance method (RDM), and the Doppler shift attenuation method (DSAM). A brief review of several indirect timing techniques is given, and their specific advantages and applicability are considered. The relationship between lifetimes of nuclear states and the nuclear structure information obtained from them is examined. A short discussion of channeling and microwave methods of lifetime measurement is presented. (23 figures, 171 references) (U.S.)

  12. Effect of thermal annealing on carrier localization and efficiency of spin detection in GaAsSb epilayers grown on InP

    Science.gov (United States)

    Zhang, Bin; Chen, Cheng; Han, Junbo; Jin, Chuan; Chen, Jianxin; Wang, Xingjun

    2018-04-01

    The effect of the thermal annealing on the optical and spin properties in GaAs0.44Sb0.56 epilayers grown on InP was investigated via photoreflectance, power-dependent and time-resolved photoluminescence spectroscopy as well as optical orientation measurement. The carrier's localization and the optical spin detection efficiency increase with an increase of annealing temperature up to 600 °C. The enhancement of the spin detection efficiency is attributed to both the shortening of the electron lifetime and the prolonging of the spin lifetime as a result of the enhanced carriers' localization induced by the annealing process. Our results provided an approach to enhance spin detection efficiency of GaAsSb with its PL emission in the 1.55 μm region.

  13. Ultrafast Carrier Trapping of a Metal-Doped Titanium Dioxide Semiconductor Revealed by Femtosecond Transient Absorption Spectroscopy

    KAUST Repository

    Sun, Jingya; Yang, Yang; Khan, Jafar I.; Alarousu, Erkki; Guo, Zaibing; Zhang, Xixiang; Zhang, Qiang; Mohammed, Omar F.

    2014-01-01

    We explored for the first time the ultrafast carrier trapping of a metal-doped titanium dioxide (TiO2) semiconductor using broad-band transient absorption (TA) spectroscopy with 120 fs temporal resolution. Titanium dioxide was successfully doped layer-by-layer with two metal ions, namely tungsten and cobalt. The time-resolved data demonstrate clearly that the carrier trapping time decreases progressively as the doping concentration increases. A global-fitting procedure for the carrier trapping suggests the appearance of two time components: a fast one that is directly associated with carrier trapping to the defect state in the vicinity of the conduction band and a slow one that is attributed to carrier trapping to the deep-level state from the conduction band. With a relatively long doping deposition time on the order of 30 s, a carrier lifetime of about 1 ps is obtained. To confirm that the measured ultrafast carrier dynamics are associated with electron trapping by metal doping, we explored the carrier dynamics of undoped TiO2. The findings reported here may be useful for the implementation of high-speed optoelectronic applications and fast switching devices.

  14. Ultrafast Carrier Trapping of a Metal-Doped Titanium Dioxide Semiconductor Revealed by Femtosecond Transient Absorption Spectroscopy

    KAUST Repository

    Sun, Jingya

    2014-06-11

    We explored for the first time the ultrafast carrier trapping of a metal-doped titanium dioxide (TiO2) semiconductor using broad-band transient absorption (TA) spectroscopy with 120 fs temporal resolution. Titanium dioxide was successfully doped layer-by-layer with two metal ions, namely tungsten and cobalt. The time-resolved data demonstrate clearly that the carrier trapping time decreases progressively as the doping concentration increases. A global-fitting procedure for the carrier trapping suggests the appearance of two time components: a fast one that is directly associated with carrier trapping to the defect state in the vicinity of the conduction band and a slow one that is attributed to carrier trapping to the deep-level state from the conduction band. With a relatively long doping deposition time on the order of 30 s, a carrier lifetime of about 1 ps is obtained. To confirm that the measured ultrafast carrier dynamics are associated with electron trapping by metal doping, we explored the carrier dynamics of undoped TiO2. The findings reported here may be useful for the implementation of high-speed optoelectronic applications and fast switching devices.

  15. Minority carrier diffusion length extraction in Cu2ZnSn(Se,S)4 solar cells

    Science.gov (United States)

    Gokmen, Tayfun; Gunawan, Oki; Mitzi, David B.

    2013-09-01

    We report measurement of minority carrier diffusion length (Ld) for high performance Cu2ZnSn(S,Se)4 (CZTSSe) solar cells in comparison with analogous Cu(In,Ga)(S,Se)2 (CIGSSe) devices. Our Ld extraction method involves performing systematic measurements of the internal quantum efficiency combined with separate capacitance-voltage measurement. This method also enables the measurement of the absorption coefficient of the absorber material as a function of wavelength in a finished device. The extracted values of Ld for CZTSSe samples are at least factor of 2 smaller than those for CIGSSe samples. Combined with minority carrier lifetime (τ) data measured by time-resolved photoluminescence, we deduce the minority carrier mobility (μe), which is also relatively low for the CZTSSe samples.

  16. Investigation of carrier dynamics in InAs/GaAsSb quantum dots with different silicon delta-doping levels

    Energy Technology Data Exchange (ETDEWEB)

    Ban, Keun-Yong [Arizona State Univ., Tempe, AZ (United States). School of Electrical, Computer and Energy Engineering; Kim, Yeongho [Korea Research Inst. of Chemistry Technology (KRICT), Daejeon (Korea, Republic of). Division of Metrology for Future Technology; Kuciauskas, Darius [National Renewable Energy Lab. (NREL), Golden, CO (United States); Bremner, Stephen P. [Univ. of New South Wales, Sydney, NSW (Australia). School of Photovoltaic and Renewable Energy Engineering; Honsberg, Christiana B. [Arizona State Univ., Tempe, AZ (United States). School of Electrical, Computer and Energy Engineering

    2016-11-10

    The optical properties of InAs quantum dots (QDs) embedded in a GaAsSb matrix with different delta (d)-doping levels of 0, 2, 4, and 6 electrons per dot (e-/dot), incorporated to control the occupation of QD electronic states, are studied by photoluminescence (PL) spectroscopy. The time-resolved PL data taken at 10 K reveal that the increase of δ-doping density from 2 to 6 e-/dot decreases the recombination lifetime of carriers at ground states of the QDs from 996 ± 36 to 792 ± 19 ps, respectively. Furthermore, the carrier lifetime of the sample with 4 e-/dot is found to increase at a slower rate than that of the undoped sample as temperature increases above 70 K. An Arrhenius plot of the temperature dependent PL intensity indicates that the thermal activation energy of electrons in the QDs, required for carrier escape from the dot ground state to continuum state, is increased when the d-doping density is high enough (>4 e-/dot). These results are attributed to the enhanced Coulomb interaction of electrons provided by the d-doping, leading to reduced thermal quenching of the PL.

  17. Elastic scattering by hot electrons and apparent lifetime of longitudinal optical phonons in gallium nitride

    Energy Technology Data Exchange (ETDEWEB)

    Khurgin, Jacob B., E-mail: jakek@jhu.edu [Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Bajaj, Sanyam; Rajan, Siddharth [Department of Electrical and Computer Engineering, The Ohio State University, Columbus, Ohio 43210 (United States)

    2015-12-28

    Longitudinal optical (LO) phonons in GaN generated in the channel of high electron mobility transistors (HEMT) are shown to undergo nearly elastic scattering via collisions with hot electrons. The net result of these collisions is the diffusion of LO phonons in the Brillouin zone causing reduction of phonon and electron temperatures. This previously unexplored diffusion mechanism explicates how an increase in electron density causes reduction of the apparent lifetime of LO phonons, obtained from the time resolved Raman studies and microwave noise measurements, while the actual decay rate of the LO phonons remains unaffected by the carrier density. Therefore, the saturation velocity in GaN HEMT steadily declines with increased carrier density, in a qualitative agreement with experimental results.

  18. Genome-wide association study in BRCA1 mutation carriers identifies novel loci associated with breast and ovarian cancer risk.

    Directory of Open Access Journals (Sweden)

    Fergus J Couch

    Full Text Available BRCA1-associated breast and ovarian cancer risks can be modified by common genetic variants. To identify further cancer risk-modifying loci, we performed a multi-stage GWAS of 11,705 BRCA1 carriers (of whom 5,920 were diagnosed with breast and 1,839 were diagnosed with ovarian cancer, with a further replication in an additional sample of 2,646 BRCA1 carriers. We identified a novel breast cancer risk modifier locus at 1q32 for BRCA1 carriers (rs2290854, P = 2.7 × 10(-8, HR = 1.14, 95% CI: 1.09-1.20. In addition, we identified two novel ovarian cancer risk modifier loci: 17q21.31 (rs17631303, P = 1.4 × 10(-8, HR = 1.27, 95% CI: 1.17-1.38 and 4q32.3 (rs4691139, P = 3.4 × 10(-8, HR = 1.20, 95% CI: 1.17-1.38. The 4q32.3 locus was not associated with ovarian cancer risk in the general population or BRCA2 carriers, suggesting a BRCA1-specific association. The 17q21.31 locus was also associated with ovarian cancer risk in 8,211 BRCA2 carriers (P = 2×10(-4. These loci may lead to an improved understanding of the etiology of breast and ovarian tumors in BRCA1 carriers. Based on the joint distribution of the known BRCA1 breast cancer risk-modifying loci, we estimated that the breast cancer lifetime risks for the 5% of BRCA1 carriers at lowest risk are 28%-50% compared to 81%-100% for the 5% at highest risk. Similarly, based on the known ovarian cancer risk-modifying loci, the 5% of BRCA1 carriers at lowest risk have an estimated lifetime risk of developing ovarian cancer of 28% or lower, whereas the 5% at highest risk will have a risk of 63% or higher. Such differences in risk may have important implications for risk prediction and clinical management for BRCA1 carriers.

  19. PGD for all cystic fibrosis carrier couples: novel strategy for preventive medicine and cost analysis.

    Science.gov (United States)

    Tur-Kaspa, I; Aljadeff, G; Rechitsky, S; Grotjan, H E; Verlinsky, Y

    2010-08-01

    Over 1000 children affected with cystic fibrosis (CF) are born annually in the USA. Since IVF with preimplantation genetic diagnosis (PGD) is an alternative to raising a sick child or to aborting an affected fetus, a cost-benefit analysis was performed for a national IVF-PGD program for preventing CF. The amount spent to deliver healthy children for all CF carrier-couples by IVF-PGD was compared with the average annual and lifetime direct medical costs per CF patient avoided. Treating annually about 4000 CF carrier-couples with IVF-PGD would result in 3715 deliveries of non-affected children at a cost of $57,467 per baby. Because the average annual direct medical cost per CF patient was $63,127 and life expectancy is 37 years, savings would be $2.3 million per patient and $2.2 billion for all new CF patients annually in lifetime treatment costs. Cumulated net saving of an IVF-PGD program for all carrier-couples for 37 years would be $33.3 billion. A total of 618,714 cumulative years of patients suffering because of CF and thousands of abortions could be prevented. A national IVF-PGD program is a highly cost-effective novel modality of preventive medicine and would avoid most births of individuals affected with debilitating genetic disease. 2010 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

  20. Direct minority carrier transport characterization of InAs/InAsSb superlattice nBn photodetectors

    International Nuclear Information System (INIS)

    Zuo, Daniel; Liu, Runyu; Wasserman, Daniel; Mabon, James; He, Zhao-Yu; Liu, Shi; Zhang, Yong-Hang; Kadlec, Emil A.; Olson, Benjamin V.; Shaner, Eric A.

    2015-01-01

    We present an extensive characterization of the minority carrier transport properties in an nBn mid-wave infrared detector incorporating a Ga-free InAs/InAsSb type-II superlattice as the absorbing region. Using a modified electron beam induced current technique in conjunction with time-resolved photoluminescence, we were able to determine several important transport parameters of the absorber region in the device, which uses a barrier layer to reduce dark current. For a device at liquid He temperatures, we report a minority carrier diffusion length of 750 nm and a minority carrier lifetime of 200 ns, with a vertical diffusivity of 3 × 10 −2  cm 2 /s. We also report on the device's optical response characteristics at 78 K

  1. Nuclear lifetime measurement

    International Nuclear Information System (INIS)

    Guillaume, Georges

    Three direct techniques of lifetime measurement are emphasized: electronic methods and two methods based on the Doppler effect (the recoil distance methods or RDM, the Doppler shift attenuation methods or DSAM). Said direct methods are concerned with the direct measurement of the radioactive decay constants of nuclear excited states. They allow lifetimes of nucleus bound states whose deexcitations occur by electromagnetic transitions, to be determined. Other methods for measuring lifetimes are also examined: microwave techniques and those involving the blocking effect in crystals (direct methods) and also various indirect methods of obtaining lifetimes (γ resonance scattering, capture reactions, inelastic electron and nucleus scattering, and Coulomb deexcitation) [fr

  2. Hadronization, spin and lifetimes

    International Nuclear Information System (INIS)

    Grossman, Yuval; Nachshon, Itay

    2008-01-01

    Measurements of lifetimes can be done in two ways. For very short lived particles, the width can be measured. For long lived ones, the lifetime can be directly measured, for example, using a displaced vertex. Practically, the lifetime cannot be extracted for particles with intermediate lifetimes. We show that for such cases information about the lifetime can be extracted for heavy colored particles that can be produced with known polarization. For example, a t-like particle with intermediate lifetime hadronizes into a superposition of the lowest two hadronic states, T* and T (the equivalent of B* and B). Depolarization effects are governed by time scales that are much longer than the hadronization time scale, Λ QCD -1 . After a time of order 1/Δm, with Δm≡m(T*)-m(T), half of the initial polarization is lost. The polarization is totally lost after a time of order 1/Γ γ , with Γ γ = Γ(T* → Tγ). Thus, by comparing the initial and final polarization, we get information on the particle's lifetime.

  3. Lifetime-management and lifetime-extension at PAKS nuclear power plant

    International Nuclear Information System (INIS)

    Katona, Tamas; Ratkai, Sandor; Janosi, Agnes Biro

    2002-01-01

    Paks Nuclear Power Plant provides 38-40% of domestic generation at lowest price. It has an important energy-policy role in Hungary. NPP Paks shall be a decisive and perspectively permanent element of the domestic electricity generation during the next two decades, which shall be ensured by plant safe operation, the lifetime extension and power uprating. Paks Nuclear Power Plant investigated the nuclear power plant's lifetime extension possibilities and alternatives, as well as technical and business feasibility of such alternatives. The feasibility study is based on the evaluation of a representative set of systems, structures and components, operational, test, in-service inspection and maintenance practice, experience and findings of the Periodic Safety Review. The most important results of this study showing the feasibility of 20 years lifetime extension is summarised in the paper. It was found that there are no technical or safety issues or limits, which may inhibit the operation of the Nuclear Power Plant Paks up to 50 years. In case of most systems and equipment the recent monitoring, maintenance and regular reconstruction practice of the NPP Paks allows the lifetime extension without outstanding cost. Replacement or reconstruction of a few equipment and systems requires significant investment costs. Material of reactor vessels of VVER/213 incorporated at Paks, compared to vessels of the similar units, is less sensitive to the embrittlement. At units 3-4 reactor vessels do not require any measure, consequently, any additional cost, even in case of a lifetime of 50 years. At unit 2 to extend the lifetime of the reactor vessel, only heating-up of emergency core cooling tanks is needed in order to decrease thermal stress levels caused by pressure thermal shock (PST) transients. For this purpose cost-effective technical solutions are available. At unit 1, beside the heating-up of the emergency core cooling tanks annealing of the welded joint No. 5/6 close to the

  4. Genome-Wide Association Study in BRCA1 Mutation Carriers Identifies Novel Loci Associated with Breast and Ovarian Cancer Risk

    Science.gov (United States)

    Wang, Xianshu; McGuffog, Lesley; Lee, Andrew; Olswold, Curtis; Kuchenbaecker, Karoline B.; Soucy, Penny; Fredericksen, Zachary; Barrowdale, Daniel; Dennis, Joe; Gaudet, Mia M.; Dicks, Ed; Kosel, Matthew; Healey, Sue; Sinilnikova, Olga M.; Lee, Adam; Bacot, François; Vincent, Daniel; Hogervorst, Frans B. L.; Peock, Susan; Stoppa-Lyonnet, Dominique; Jakubowska, Anna; Investigators, kConFab; Radice, Paolo; Schmutzler, Rita Katharina; Domchek, Susan M.; Piedmonte, Marion; Singer, Christian F.; Friedman, Eitan; Thomassen, Mads; Hansen, Thomas V. O.; Neuhausen, Susan L.; Szabo, Csilla I.; Blanco, Ignacio; Greene, Mark H.; Karlan, Beth Y.; Garber, Judy; Phelan, Catherine M.; Weitzel, Jeffrey N.; Montagna, Marco; Olah, Edith; Andrulis, Irene L.; Godwin, Andrew K.; Yannoukakos, Drakoulis; Goldgar, David E.; Caldes, Trinidad; Nevanlinna, Heli; Osorio, Ana; Terry, Mary Beth; Daly, Mary B.; van Rensburg, Elizabeth J.; Hamann, Ute; Ramus, Susan J.; Ewart Toland, Amanda; Caligo, Maria A.; Olopade, Olufunmilayo I.; Tung, Nadine; Claes, Kathleen; Beattie, Mary S.; Southey, Melissa C.; Imyanitov, Evgeny N.; Tischkowitz, Marc; Janavicius, Ramunas; John, Esther M.; Kwong, Ava; Diez, Orland; Balmaña, Judith; Barkardottir, Rosa B.; Arun, Banu K.; Rennert, Gad; Teo, Soo-Hwang; Ganz, Patricia A.; Campbell, Ian; van der Hout, Annemarie H.; van Deurzen, Carolien H. M.; Seynaeve, Caroline; Gómez Garcia, Encarna B.; van Leeuwen, Flora E.; Meijers-Heijboer, Hanne E. J.; Gille, Johannes J. P.; Ausems, Margreet G. E. M.; Blok, Marinus J.; Ligtenberg, Marjolijn J. L.; Rookus, Matti A.; Devilee, Peter; Verhoef, Senno; van Os, Theo A. M.; Wijnen, Juul T.; Frost, Debra; Ellis, Steve; Fineberg, Elena; Platte, Radka; Evans, D. Gareth; Izatt, Louise; Eeles, Rosalind A.; Adlard, Julian; Eccles, Diana M.; Cook, Jackie; Brewer, Carole; Douglas, Fiona; Hodgson, Shirley; Morrison, Patrick J.; Side, Lucy E.; Donaldson, Alan; Houghton, Catherine; Rogers, Mark T.; Dorkins, Huw; Eason, Jacqueline; Gregory, Helen; McCann, Emma; Murray, Alex; Calender, Alain; Hardouin, Agnès; Berthet, Pascaline; Delnatte, Capucine; Nogues, Catherine; Lasset, Christine; Houdayer, Claude; Leroux, Dominique; Rouleau, Etienne; Prieur, Fabienne; Damiola, Francesca; Sobol, Hagay; Coupier, Isabelle; Venat-Bouvet, Laurence; Castera, Laurent; Gauthier-Villars, Marion; Léoné, Mélanie; Pujol, Pascal; Mazoyer, Sylvie; Bignon, Yves-Jean; Złowocka-Perłowska, Elżbieta; Gronwald, Jacek; Lubinski, Jan; Durda, Katarzyna; Jaworska, Katarzyna; Huzarski, Tomasz; Spurdle, Amanda B.; Viel, Alessandra; Peissel, Bernard; Bonanni, Bernardo; Melloni, Giulia; Ottini, Laura; Papi, Laura; Varesco, Liliana; Tibiletti, Maria Grazia; Peterlongo, Paolo; Volorio, Sara; Manoukian, Siranoush; Pensotti, Valeria; Arnold, Norbert; Engel, Christoph; Deissler, Helmut; Gadzicki, Dorothea; Gehrig, Andrea; Kast, Karin; Rhiem, Kerstin; Meindl, Alfons; Niederacher, Dieter; Ditsch, Nina; Plendl, Hansjoerg; Preisler-Adams, Sabine; Engert, Stefanie; Sutter, Christian; Varon-Mateeva, Raymonda; Wappenschmidt, Barbara; Weber, Bernhard H. F.; Arver, Brita; Stenmark-Askmalm, Marie; Loman, Niklas; Rosenquist, Richard; Einbeigi, Zakaria; Nathanson, Katherine L.; Rebbeck, Timothy R.; Blank, Stephanie V.; Cohn, David E.; Rodriguez, Gustavo C.; Small, Laurie; Friedlander, Michael; Bae-Jump, Victoria L.; Fink-Retter, Anneliese; Rappaport, Christine; Gschwantler-Kaulich, Daphne; Pfeiler, Georg; Tea, Muy-Kheng; Lindor, Noralane M.; Kaufman, Bella; Shimon Paluch, Shani; Laitman, Yael; Skytte, Anne-Bine; Gerdes, Anne-Marie; Pedersen, Inge Sokilde; Moeller, Sanne Traasdahl; Kruse, Torben A.; Jensen, Uffe Birk; Vijai, Joseph; Sarrel, Kara; Robson, Mark; Kauff, Noah; Mulligan, Anna Marie; Glendon, Gord; Ozcelik, Hilmi; Ejlertsen, Bent; Nielsen, Finn C.; Jønson, Lars; Andersen, Mette K.; Ding, Yuan Chun; Steele, Linda; Foretova, Lenka; Teulé, Alex; Lazaro, Conxi; Brunet, Joan; Pujana, Miquel Angel; Mai, Phuong L.; Loud, Jennifer T.; Walsh, Christine; Lester, Jenny; Orsulic, Sandra; Narod, Steven A.; Herzog, Josef; Sand, Sharon R.; Tognazzo, Silvia; Agata, Simona; Vaszko, Tibor; Weaver, Joellen; Stavropoulou, Alexandra V.; Buys, Saundra S.; Romero, Atocha; de la Hoya, Miguel; Aittomäki, Kristiina; Muranen, Taru A.; Duran, Mercedes; Chung, Wendy K.; Lasa, Adriana; Dorfling, Cecilia M.; Miron, Alexander; Benitez, Javier; Senter, Leigha; Huo, Dezheng; Chan, Salina B.; Sokolenko, Anna P.; Chiquette, Jocelyne; Tihomirova, Laima; Friebel, Tara M.; Agnarsson, Bjarni A.; Lu, Karen H.; Lejbkowicz, Flavio; James, Paul A.; Hall, Per; Dunning, Alison M.; Tessier, Daniel; Cunningham, Julie; Slager, Susan L.; Wang, Chen; Hart, Steven; Stevens, Kristen; Simard, Jacques; Pastinen, Tomi; Pankratz, Vernon S.; Offit, Kenneth; Antoniou, Antonis C.

    2013-01-01

    BRCA1-associated breast and ovarian cancer risks can be modified by common genetic variants. To identify further cancer risk-modifying loci, we performed a multi-stage GWAS of 11,705 BRCA1 carriers (of whom 5,920 were diagnosed with breast and 1,839 were diagnosed with ovarian cancer), with a further replication in an additional sample of 2,646 BRCA1 carriers. We identified a novel breast cancer risk modifier locus at 1q32 for BRCA1 carriers (rs2290854, P = 2.7×10−8, HR = 1.14, 95% CI: 1.09–1.20). In addition, we identified two novel ovarian cancer risk modifier loci: 17q21.31 (rs17631303, P = 1.4×10−8, HR = 1.27, 95% CI: 1.17–1.38) and 4q32.3 (rs4691139, P = 3.4×10−8, HR = 1.20, 95% CI: 1.17–1.38). The 4q32.3 locus was not associated with ovarian cancer risk in the general population or BRCA2 carriers, suggesting a BRCA1-specific association. The 17q21.31 locus was also associated with ovarian cancer risk in 8,211 BRCA2 carriers (P = 2×10−4). These loci may lead to an improved understanding of the etiology of breast and ovarian tumors in BRCA1 carriers. Based on the joint distribution of the known BRCA1 breast cancer risk-modifying loci, we estimated that the breast cancer lifetime risks for the 5% of BRCA1 carriers at lowest risk are 28%–50% compared to 81%–100% for the 5% at highest risk. Similarly, based on the known ovarian cancer risk-modifying loci, the 5% of BRCA1 carriers at lowest risk have an estimated lifetime risk of developing ovarian cancer of 28% or lower, whereas the 5% at highest risk will have a risk of 63% or higher. Such differences in risk may have important implications for risk prediction and clinical management for BRCA1 carriers. PMID:23544013

  5. Relation of lifetime to surface passivation for atomic-layer-deposited Al2O3 on crystalline silicon solar cell

    International Nuclear Information System (INIS)

    Cho, Young Joon; Song, Hee Eun; Chang, Hyo Sik

    2015-01-01

    Highlights: • We investigated the relation of potassium contamination on Si solar wafer to lifetime. • We deposited Al 2 O 3 layer by atomic layer deposition (ALD) on Si solar wafer after several cleaning process. • Potassium can be left on Si surface by incomplete cleaning process and degrade the Al 2 O 3 passivation quality. - Abstract: We investigated the relation of potassium contamination on a crystalline silicon (c-Si) surface after potassium hydroxide (KOH) etching to the lifetime of the c-Si solar cell. Alkaline solution was employed for saw damage removal (SDR), texturing, and planarization of a textured c-Si solar wafer prior to atomic layer deposition (ALD) Al 2 O 3 growth. In the solar-cell manufacturing process, ALD Al 2 O 3 passivation is utilized to obtain higher conversion efficiency. ALD Al 2 O 3 shows excellent surface passivation, though minority carrier lifetime varies with cleaning conditions. In the present study, we investigated the relation of potassium contamination to lifetime in solar-cell processing. The results showed that the potassium-contaminated samples, due to incomplete cleaning of KOH, had a short lifetime, thus establishing that residual potassium can degrade Al 2 O 3 surface passivation

  6. Lifetime measurements

    International Nuclear Information System (INIS)

    Poletti, A.R.

    1976-01-01

    Recent developments in experimental methods of measuring the lifetimes of excited nuclear states is reviewed in three main areas. (a) Doppler Shift Attenuation Measurements (DSAM) Times: 10 -14 - 10 -11 sec.; (b) Recoil Distance Measurements (RDM) Times: 10 -9 - 10 -12 sec.; (c) Direct Electronic Timing Times: down to 10 -10 sec.; A measurement of an excited state lifetime can answer a large number of different questions. Two examples are discussed: (a) The determination of the lifetime of an isomeric transition in 93 Tc and its use in determining an upper limit for the magnitude of the parity non-conserving matrix element - /Hsub(PN)/17/2 + >. (b) The dependence of the strength of M2 transitions on isospin in nuclei in the 1dsub(3/2) -1fsub(7/2) region. (author)

  7. Carrier-inside-carrier: polyelectrolyte microcapsules as reservoir for drug-loaded liposomes.

    Science.gov (United States)

    Maniti, Ofelia; Rebaud, Samuel; Sarkis, Joe; Jia, Yi; Zhao, Jie; Marcillat, Olivier; Granjon, Thierry; Blum, Loïc; Li, Junbai; Girard-Egrot, Agnès

    2015-01-01

    Conventional liposomes have a short life-time in blood, unless they are protected by a polymer envelope, most often polyethylene glycol. However, these stabilizing polymers frequently interfere with cellular uptake, impede liposome-membrane fusion and inhibit escape of liposome content from endosomes. To overcome such drawbacks, polymer-based systems as carriers for liposomes are currently developed. Conforming to this approach, we propose a new and convenient method for embedding small size liposomes, 30-100 nm, inside porous calcium carbonate microparticles. These microparticles served as templates for deposition of various polyelectrolytes to form a protective shell. The carbonate particles were then dissolved to yield hollow polyelectrolyte microcapsules. The main advantage of using this method for liposome encapsulation is that carbonate particles can serve as a sacrificial template for deposition of virtually any polyelectrolyte. By carefully choosing the shell composition, bioavailability of the liposomes and of the encapsulated drug can be modulated to respond to biological requirements and to improve drug delivery to the cytoplasm and avoid endosomal escape.

  8. Charmed particle lifetimes

    International Nuclear Information System (INIS)

    Rosner, J.L.

    1979-01-01

    Conventional estimates are reviewed for charmed particle lifetimes. Free-quark models give values of (a few) x 10 -13 sec to (a few) x 10 -12 sec. The shorter of these values also follows from an extrapolation based on D → Ke/sup nu/. Possible differences among the lifetimes and production rates of D 0 , D + , F + , C 0 + , the heavy lepton tau, and the fifth quark b are discussed. Extreme values of mixing angles in a six-quark model could extend charmed particle lifetimes by a factor of at most three from the above estimates, while shorter lifetimes than those predicted could occur for some species like D 0 or F + if their nonleptonic decays were enhanced. The predictions are discussed in the light of some current experimental results, and it is estimated that sigma(pp → charm) approx. = 10 μb at 400 GeV/c. 95 references

  9. Lifetimes of heavy flavour particles

    International Nuclear Information System (INIS)

    Forty, R.

    1994-01-01

    The lifetimes of heavy-flavour hadrons are reviewed. After a brief discussion of the theoretical predictions, the problem of averaging lifetime measurements is discussed. The various experimental measurements are then presented and suitable averages performed. Charmed meson lifetimes are now measured to the few percent level, better that theory can predict, whilst for charmed baryons the lifetime hierarchy has been established for the first time. For beauty hadrons the lifetimes are measured at the 6-10 % level, and are in reasonable agreement with theoretical expectations. Beauty baryon studies ar just beginning. (author)

  10. The prospects for hydrogen as an energy carrier: an overview of hydrogen energy and hydrogen energy systems

    International Nuclear Information System (INIS)

    Rosen, Marc A.; Koohi-Fayegh, Seama

    2016-01-01

    Hydrogen is expected to play a key role as an energy carrier in future energy systems of the world. As fossil-fuel supplies become scarcer and environmental concerns increase, hydrogen is likely to become an increasingly important chemical energy carrier and eventually may become the principal chemical energy carrier. When most of the world's energy sources become non-fossil based, hydrogen and electricity are expected to be the two dominant energy carriers for the provision of end-use services. In such a ''hydrogen economy,'' the two complementary energy carriers, hydrogen and electricity, are used to satisfy most of the requirements of energy consumers. A transition era will bridge the gap between today's fossil-fuel economy and a hydrogen economy, in which non-fossil-derived hydrogen will be used to extend the lifetime of the world's fossil fuels - by upgrading heavy oils, for instance - and the infrastructure needed to support a hydrogen economy is gradually developed. In this paper, the role of hydrogen as an energy carrier and hydrogen energy systems' technologies and their economics are described. Also, the social and political implications of hydrogen energy are examined, and the questions of when and where hydrogen is likely to become important are addressed. Examples are provided to illustrate key points. (orig.)

  11. Lifetime costs of cerebral palsy

    DEFF Research Database (Denmark)

    Kruse, Marie; Michelsen, Susan Ishøy; Flachs, Esben Meulengracht

    2009-01-01

    This study quantified the lifetime costs of cerebral palsy (CP) in a register-based setting. It was the first study outside the US to assess the lifetime costs of CP. The lifetime costs attributable to CP were divided into three categories: health care costs, productivity costs, and social costs....... social care costs and productivity costs associated with CP point to a potential gain from labour market interventions that benefit individuals with CP.......This study quantified the lifetime costs of cerebral palsy (CP) in a register-based setting. It was the first study outside the US to assess the lifetime costs of CP. The lifetime costs attributable to CP were divided into three categories: health care costs, productivity costs, and social costs...... in 2000. The prevalence of CP in eastern Denmark was approximately 1.7 per 1000. Information on productivity and the use of health care was retrieved from registers. The lifetime cost of CP was about euro860 000 for men and about euro800 000 for women. The largest component was social care costs...

  12. Three-dimensional fluorescence lifetime tomography

    International Nuclear Information System (INIS)

    Godavarty, Anuradha; Sevick-Muraca, Eva M.; Eppstein, Margaret J.

    2005-01-01

    Near-infrared fluorescence tomography using molecularly targeted lifetime-sensitive, fluorescent contrast agents have applications for early-stage cancer diagnostics. Yet, although the measurement of fluorescent lifetime imaging microscopy (FLIM) is extensively used in microscopy and spectroscopy applications, demonstration of fluorescence lifetime tomography for medical imaging is limited to two-dimensional studies. Herein, the feasibility of three-dimensional fluorescence-lifetime tomography on clinically relevant phantom volumes is established, using (i) a gain-modulated intensified charge coupled device (CCD) and modulated laser diode imaging system, (ii) two fluorescent contrast agents, e.g., Indocyanine green and 3-3'-Diethylthiatricarbocyanine iodide differing in their fluorescence lifetime by 0.62 ns, and (iii) a two stage approximate extended Kalman filter reconstruction algorithm. Fluorescence measurements of phase and amplitude were acquired on the phantom surface under different target to background fluorescence absorption (70:1, 100:1) and fluorescence lifetime (1:1, 2.1:1) contrasts at target depths of 1.4-2 cm. The Bayesian tomography algorithm was employed to obtain three-dimensional images of lifetime and absorption owing to the fluorophores

  13. Anisotropic mobility and carrier dynamics in the β-type BEDT-TTF salts as studied by inter-layer transverse magnetoresistance

    Directory of Open Access Journals (Sweden)

    Shigeharu Sugawara and Masafumi Tamura

    2013-01-01

    Full Text Available A new method to estimate an in-plane conduction anisotropy in a quasi-two-dimensional (q2D layered conductor by measuring the inter-layer transverse magnetoresistance is proposed. We applied this method to layered organic conductors β-(BEDT-TTF2X (BEDT-TTF = bis(ethylenedithiotetrathiafulvalene, C10H8S8; X = IBr2, I2Br by applying magnetic field rotating within the basal plane at 4.2 K. We found the anisotropic behaviour of carrier mobility μ. From this, anomalous distribution of carrier lifetime τ on the Fermi surface is derived, by the use of Fermi surface data reported for the materials. Calculations of the non-uniform susceptibility χ0(q suggest that carrier scattering is enhanced at specific k-points related to partial nesting of the Fermi surface. The present method is thus demonstrated to be an efficient experimental tool to elucidate anisotropic carrier dynamics in q2D conductors.

  14. Precision lifetime measurements

    International Nuclear Information System (INIS)

    Tanner, C.E.

    1994-01-01

    Precision measurements of atomic lifetimes provide important information necessary for testing atomic theory. The authors employ resonant laser excitation of a fast atomic beam to measure excited state lifetimes by observing the decay-in-flight of the emitted fluorescence. A similar technique was used by Gaupp, et al., who reported measurements with precisions of less than 0.2%. Their program includes lifetime measurements of the low lying p states in alkali and alkali like systems. Motivation for this work comes from a need to test the atomic many-body-perturbation theory (MBPT) that is necessary for interpretation of parity nonconservation experiments in atomic cesium. The authors have measured the cesium 6p 2 P 1/2 and 6p 2 P 3/2 state lifetimes to be 34.934±0.094 ns and 30.499±0.070 ns respectively. With minor changes to the apparatus, they have extended their measurements to include the lithium 2p 2 P 1/2 and 2p 2 P 3/2 states

  15. Mining the bulk positron lifetime

    International Nuclear Information System (INIS)

    Aourag, H.; Guittom, A.

    2009-01-01

    We introduce a new approach to investigate the bulk positron lifetimes of new systems based on data-mining techniques. Through data mining of bulk positron lifetimes, we demonstrate the ability to predict the positron lifetimes of new semiconductors on the basis of available semiconductor data already studied. Informatics techniques have been applied to bulk positron lifetimes for different tetrahedrally bounded semiconductors in order to discover computational design rules. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  16. Lifetime prediction of InGaZnO thin film transistor for the application of display device and BEOL-transistors

    Science.gov (United States)

    Kim, Sang Min; Cho, Won Ju; Yu, Chong Gun; Park, Jong Tae

    2018-04-01

    In this work, the lifetime prediction models of amorphous InGaZnO thin film transistors (a-IGZO TFTs) were suggested for the application of display device and BEOL (Back End Of line) transistors with embedded a-IGZO TFTs. Four different types of test devices according to the active layer thickness, source/drain electrode materials and thermal treatments have been used to verify the suggested model. The device lifetimes under high gate bias stress and hot carrier stress were extracted through fittings of the stretched-exponential equation for threshold voltage shifts and the current estimation method for drain current degradations. Our suggested lifetime prediction models could be used in any kinds of structures of a-IGZO TFTs for the application of display device and BEOL transistors. The a-IGZO TFTs with embedded ITO local conducting layer under source/drain is better for BEOL transistor application and a-IGZO TFTs with InGaZnO thin film as source/drain electrodes may be better for the application of display devices. From 1983 to 1985, he was a Researcher at Gold-Star Semiconductor, Inc., Korea, where he worked on the development of SRAM. He joined the Department of Electronics Engineering, University of Incheon, Incheon, Korea, in 1987, where he is a Professor. As a visiting scientist at Massachusetts Institute of Technology, Cambridge, in 1991, he conducted research in hot carrier reliability of CMOS. As a visiting scholar at University of California, Davis, in 2001, he conducted research on the device structure of Nano-scale SOI CMOS. His recent interests are device structure and reliability of Nano-scale CMOS devices, flash memory, and thin film transistors.

  17. Positron lifetimes in deformed copper

    International Nuclear Information System (INIS)

    Hinode, Kenji; Tanigawa, Shoichiro; Doyama, Masao

    1976-01-01

    Positron lifetime measurements were performed for Cu samples with different densities of lattice defects. The lifetime spectra were successfully resolved into two components with the help of the well established analysis program. Obtained results were quite consistent with those expected from the trapping model. The positron trapping mechanism from free to trapped states and the initial condition of the model were especially checked. Deduced values obtained for tau sub(c) (lifetime of free positrons) and tau sub(t) (lifetime of trapped positrons) were 122+-5 psec and 176+-5 psec, respectively. (auth.)

  18. Accelerated lifetime testing methodology for lifetime estimation of Lithium-ion batteries used in augmented wind power plants

    DEFF Research Database (Denmark)

    Stroe, Daniel Ioan; Swierczynski, Maciej Jozef; Stan, Ana-Irina

    2013-01-01

    The development of lifetime estimation models for Lithium-ion battery cells, which are working under highly variable mission profiles characteristic for wind power plant applications, requires a lot of expenditures and time resources. Therefore, batteries have to be tested under accelerated...... lifetime ageing conditions. This paper presents a three-stage methodology used for accelerated lifetime testing of Lithium-ion batteries. The results obtained at the end of the accelerated ageing process can be used for the parametrization of a performance-degradation lifetime model. In the proposed...... methodology both calendar and cycling lifetime tests are considered since both components are influencing the lifetime of Lithium-ion batteries. The methodology proposes also a lifetime model verification stage, where Lithium-ion battery cells are tested at normal operating conditions using an application...

  19. Lifetime results from heavy quark systems

    International Nuclear Information System (INIS)

    Papadimitriou, V.

    1997-11-01

    We present the latest measurements of weakly decaying b-hadrons from experiments at e + e - and p anti p colliders. These measurements include the average lifetime of b-hadrons, lifetimes of the B - , B 0 and B 0 s mesons, the average lifetime of b-baryons and lifetimes of the Λ b and Ξ b baryons

  20. The prospects for hydrogen as an energy carrier: an overview of hydrogen energy and hydrogen energy systems

    Energy Technology Data Exchange (ETDEWEB)

    Rosen, Marc A.; Koohi-Fayegh, Seama [Ontario Univ., Oshawa, ON (Canada). Inst. of Technology

    2016-02-15

    Hydrogen is expected to play a key role as an energy carrier in future energy systems of the world. As fossil-fuel supplies become scarcer and environmental concerns increase, hydrogen is likely to become an increasingly important chemical energy carrier and eventually may become the principal chemical energy carrier. When most of the world's energy sources become non-fossil based, hydrogen and electricity are expected to be the two dominant energy carriers for the provision of end-use services. In such a ''hydrogen economy,'' the two complementary energy carriers, hydrogen and electricity, are used to satisfy most of the requirements of energy consumers. A transition era will bridge the gap between today's fossil-fuel economy and a hydrogen economy, in which non-fossil-derived hydrogen will be used to extend the lifetime of the world's fossil fuels - by upgrading heavy oils, for instance - and the infrastructure needed to support a hydrogen economy is gradually developed. In this paper, the role of hydrogen as an energy carrier and hydrogen energy systems' technologies and their economics are described. Also, the social and political implications of hydrogen energy are examined, and the questions of when and where hydrogen is likely to become important are addressed. Examples are provided to illustrate key points. (orig.)

  1. Degradation and lifetime estimation of n-MOS SLS ELA polycrystalline TFTs during hot carrier stressing: effect of channel width in the region Vth ≤ VGS,stress ≤ VDS,stress/2

    International Nuclear Information System (INIS)

    Kontogiannopoulos, G P; Farmakis, F V; Kouvatsos, D N; Papaioannou, G J; Voutsas, A T

    2009-01-01

    The voltage bias stress induced degradation of sequential lateral solidification (SLS) polysilicon thin film transistors (TFTs) is studied. The aim of this work is the investigation of the types of damage arising from the electrical stressing in the gate voltage range around V th ≤ V GS,stress ≤ V DS,stress /2 and for different drain-bias voltages. It is shown that the drain on-current variation (%) with stressing time for a defined gate voltage obeys a power–time-dependent law of the form At n . The parameters A and n of this law were determined in order to gain insight on degradation mechanisms in different stress regimes and to estimate the time to failure of our devices. Devices with different channel widths were compared, and their lifetime to failure was extracted. It was found that the magnitude of stress was lower for devices with narrower channel widths. By monitoring the threshold voltage variation and the percentage change of transconductance maximum in the linear regime of operation, it was verified that the threshold voltage degradation was mainly due to the contribution of G m,max to V th rather than severe carrier trapping

  2. Lifetime of organic photovoltaics

    DEFF Research Database (Denmark)

    Corazza, Michael; Krebs, Frederik C; Gevorgyan, Suren A.

    2015-01-01

    tests. Comparison of the indoor and outdoor lifetimes was performed by means of the o-diagram, which constitutes the initial steps towards establishing a method for predicting the lifetime of an organic photovoltaic device under real operational conditions based on a selection of accelerated indoor...

  3. Accelerated Lifetime Testing Methodology for Lifetime Estimation of Lithium-ion Batteries used in Augmented Wind Power Plants

    DEFF Research Database (Denmark)

    Stroe, Daniel Ioan; Swierczynski, Maciej Jozef; Stan, Ana-Irina

    2014-01-01

    The development of lifetime estimation models for Lithium-ion battery cells, which are working under highly variable mission profiles characteristic for wind power plant applications, requires a lot of expenditures and time resources. Therefore, batteries have to be tested under accelerated...... lifetime ageing conditions. This paper presents a three-stage methodology used for accelerated lifetime testing of Lithium ion batteries. The results obtained at the end of the accelerated ageing process were used for the parametrization of a performance-degradation lifetime model, which is able to predict...... both the capacity fade and the power capability decrease of the selected Lithium-ion battery cells. In the proposed methodology both calendar and cycling lifetime tests were considered since both components are influencing the lifetime of Lithium-ion batteries. Furthermore, the proposed methodology...

  4. Charge carrier dynamics in thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Strothkaemper, Christian

    2013-06-24

    the other hand, the charge carrier lifetime in Cu-poor CIS is orders of magnitude higher as in stoichiometric CIS. This is explained by assuming that the CuIn antisite is the most effective recombination center.

  5. Quantitative analysis of fluorescence lifetime measurements of the macula using the fluorescence lifetime imaging ophthalmoscope in healthy subjects.

    Science.gov (United States)

    Dysli, Chantal; Quellec, Gwénolé; Abegg, Mathias; Menke, Marcel N; Wolf-Schnurrbusch, Ute; Kowal, Jens; Blatz, Johannes; La Schiazza, Olivier; Leichtle, Alexander B; Wolf, Sebastian; Zinkernagel, Martin S

    2014-04-03

    Fundus autofluorescence (FAF) cannot only be characterized by the intensity or the emission spectrum, but also by its lifetime. As the lifetime of a fluorescent molecule is sensitive to its local microenvironment, this technique may provide more information than fundus autofluorescence imaging. We report here the characteristics and repeatability of FAF lifetime measurements of the human macula using a new fluorescence lifetime imaging ophthalmoscope (FLIO). A total of 31 healthy phakic subjects were included in this study with an age range from 22 to 61 years. For image acquisition, a fluorescence lifetime ophthalmoscope based on a Heidelberg Engineering Spectralis system was used. Fluorescence lifetime maps of the retina were recorded in a short- (498-560 nm) and a long- (560-720 nm) spectral channel. For quantification of fluorescence lifetimes a standard ETDRS grid was used. Mean fluorescence lifetimes were shortest in the fovea, with 208 picoseconds for the short-spectral channel and 239 picoseconds for the long-spectral channel, respectively. Fluorescence lifetimes increased from the central area to the outer ring of the ETDRS grid. The test-retest reliability of FLIO was very high for all ETDRS areas (Spearman's ρ = 0.80 for the short- and 0.97 for the long-spectral channel, P macula in healthy subjects. By using a custom-built software, we were able to quantify fluorescence lifetimes within the ETDRS grid. Establishing a clinically accessible standard against which to measure FAF lifetimes within the retina is a prerequisite for future studies in retinal disease.

  6. Energy Savings Lifetimes and Persistence

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, Ian M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Schiller, Steven R. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Todd, Annika [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Billingsley, Megan A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Goldman, Charles A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Schwartz, Lisa C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-02-01

    This technical brief explains the concepts of energy savings lifetimes and savings persistence and discusses how program administrators use these factors to calculate savings for efficiency measures, programs and portfolios. Savings lifetime is the length of time that one or more energy efficiency measures or activities save energy, and savings persistence is the change in savings throughout the functional life of a given efficiency measure or activity. Savings lifetimes are essential for assessing the lifecycle benefits and cost effectiveness of efficiency activities and for forecasting loads in resource planning. The brief also provides estimates of savings lifetimes derived from a national collection of costs and savings for electric efficiency programs and portfolios.

  7. Coupled modeling of the competitive gettering of transition metals and impact on performance of lifetime sensitive devices

    Science.gov (United States)

    Yazdani, Armin; Chen, Renyu; Dunham, Scott T.

    2017-03-01

    This work models competitive gettering of metals (Cu, Ni, Fe, Mo, and W) by boron, phosphorus, and dislocation loops, and connects those results directly to device performance. Density functional theory calculations were first performed to determine the binding energies of metals to the gettering sites, and based on that, continuum models were developed to model the redistribution and trapping of the metals. Our models found that Fe is most strongly trapped by the dislocation loops while Cu and Ni are most strongly trapped by the P4V clusters formed in high phosphorus concentrations. In addition, it is found that none of the mentioned gettering sites are effective in gettering Mo and W. The calculated metal redistribution along with the associated capture cross sections and trap energy levels are passed to device simulation via the recombination models to calculate carrier lifetime and the resulting device performance. Thereby, a comprehensive and predictive TCAD framework is developed to optimize the processing conditions to maximize performance of lifetime sensitive devices.

  8. Network degeneration and dysfunction in presymptomatic C9ORF72 expansion carriers

    Directory of Open Access Journals (Sweden)

    Suzee E. Lee

    2017-01-01

    Full Text Available Hexanucleotide repeat expansions in C9ORF72 are the most common known genetic cause of familial and sporadic frontotemporal dementia and amyotrophic lateral sclerosis. Previous work has shown that patients with behavioral variant frontotemporal dementia due to C9ORF72 show salience and sensorimotor network disruptions comparable to those seen in sporadic behavioral variant frontotemporal dementia, but it remains unknown how early in the lifespan these and other changes in brain structure and function arise. To gain insights into this question, we compared 15 presymptomatic carriers (age 43.7 ± 10.2 years, nine females to matched healthy controls. We used voxel-based morphometry to assess gray matter, diffusion tensor imaging to interrogate white matter tracts, and task-free functional MRI to probe the salience, sensorimotor, default mode, and medial pulvinar thalamus-seeded networks. We further used a retrospective chart review to ascertain psychiatric histories in carriers and their non-carrier family members. Carriers showed normal cognition and behavior despite gray matter volume and brain connectivity deficits that were apparent as early as the fourth decade of life. Gray matter volume deficits were topographically similar though less severe than those in patients with behavioral variant frontotemporal dementia due to C9ORF72, with major foci in cingulate, insula, thalamus, and striatum. Reduced white matter integrity was found in the corpus callosum, cingulum bundles, corticospinal tracts, uncinate fasciculi and inferior longitudinal fasciculi. Intrinsic connectivity deficits were detected in all four networks but most prominent in salience and medial pulvinar thalamus-seeded networks. Carrier and control groups showed comparable relationships between imaging metrics and age, suggesting that deficits emerge during early adulthood. Carriers and non-carrier family members had comparable lifetime histories of psychiatric symptoms. Taken

  9. Validity of LIDAS (LIfetime Depression Assessment Self-report): a self-report online assessment of lifetime major depressive disorder.

    Science.gov (United States)

    Bot, M; Middeldorp, C M; de Geus, E J C; Lau, H M; Sinke, M; van Nieuwenhuizen, B; Smit, J H; Boomsma, D I; Penninx, B W J H

    2017-01-01

    There is a paucity of valid, brief instruments for the assessment of lifetime major depressive disorder (MDD) that can be used in, for example, large-scale genomics, imaging or biomarker studies on depression. We developed the LIfetime Depression Assessment Self-report (LIDAS), which assesses lifetime MDD diagnosis according to DSM criteria, and is largely based on the widely used Composite International Diagnostic Interview (CIDI). Here, we tested the feasibility and determined the sensitivity and specificity for measuring lifetime MDD with this new questionnaire, with a regular CIDI as reference. Sensitivity and specificity analyses of the online lifetime MDD questionnaire were performed in adults with (n = 177) and without (n = 87) lifetime MDD according to regular index CIDIs, selected from the Netherlands Study of Depression and Anxiety (NESDA) and Netherlands Twin Register (NTR). Feasibility was tested in an additional non-selective, population-based sample of NTR participants (n = 245). Of the 753 invited persons, 509 (68%) completed the LIDAS, of which 419 (82%) did this online. User-friendliness of the instrument was rated high. Median completion time was 6.2 min. Sensitivity and specificity for lifetime MDD were 85% [95% confidence interval (CI) 80-91%] and 80% (95% CI 72-89%), respectively. This LIDAS instrument gave a lifetime MDD prevalence of 20.8% in the population-based sample. Measuring lifetime MDD with an online instrument was feasible. Sensitivity and specificity were adequate. The instrument gave a prevalence of lifetime MDD in line with reported population prevalences. LIDAS is a promising tool for rapid determination of lifetime MDD status in large samples, such as needed for genomics studies.

  10. Review of charm and beauty lifetimes

    International Nuclear Information System (INIS)

    Cheung, Harry W. K.

    1999-01-01

    A review of the latest experimental results on charm and beauty particle lifetimes is presented together with a brief summary of measurement methods used for beauty particle lifetime measurements. There have been significant updates to the D s + /D 0 , B + /B d 0 and Λ b 0 /B d 0 lifetime ratios which have some theoretical implications. However more precise measurements are still needed before one can make conclusive statements about the theory used to calculate the particle lifetimes

  11. The Susquehanna plant lifetime excellence program

    International Nuclear Information System (INIS)

    McNamara, R.W.

    1988-01-01

    This paper discusses how the Susquehanna plant lifetime excellence program (SPLEX) blends many of the objectives of a new managing for excellence program with plant life extension objectives to achieve excellence in the lifetime operation and availability of the two-unit Susquehanna steam electric station. Investments in lifetime excellence improvements will provide near-term, as well as plant life extension, benefits. A high-quality lifetime experience record, together with extensive, periodic technical assessments and cost-benefit analyses, will provide conclusive justification for future extensions of the unit operating licenses

  12. Measurement of Charm Meson Lifetimes

    International Nuclear Information System (INIS)

    Bonvicini, G.; Cinabro, D.; Greene, R.; Perera, L.P.; Zhou, G.J.; Chan, S.; Eigen, G.; Lipeles, E.; Schmidtler, M.; Shapiro, A.; Sun, W.M.; Urheim, J.; Weinstein, A.J.; Wuerthwein, F.; Jaffe, D.E.; Masek, G.; Paar, H.P.; Potter, E.M.; Prell, S.; Sharma, V.; Asner, D.M.; Eppich, A.; Gronberg, J.; Hill, T.S.; Korte, C.M.; Lange, D.J.; Morrison, R.J.; Nelson, H.N.; Nelson, T.K.; Roberts, D.; Tajima, H.; Behrens, B.H.; Ford, W.T.; Gritsan, A.; Krieg, H.; Roy, J.; Smith, J.G.; Alexander, J.P.; Baker, R.; Bebek, C.; Berger, B.E.; Berkelman, K.; Boisvert, V.; Cassel, D.G.; Crowcroft, D.S.; Dickson, M.; Dombrowski, S. von; Drell, P.S.; Dumas, D.J.; Ecklund, K.M.; Ehrlich, R.; Foland, A.D.; Gaidarev, P.; Gibbons, L.; Gittelman, B.; Gray, S.W.; Hartill, D.L.; Heltsley, B.K.; Henderson, S.; Hopman, P.I.; Katayama, N.; Kreinick, D.L.; Lee, T.; Liu, Y.; Meyer, T.O.; Mistry, N.B.; Ng, C.R.; Nordberg, E.; Ogg, M.; Patterson, J.R.; Peterson, D.; Riley, D.; Soffer, A.; Thayer, J.G.; Thies, P.G.; Valant-Spaight, B.; Warburton, A.; Ward, C.; Athanas, M.; Avery, P.; Jones, C.D.; Lohner, M.; Prescott, C.; Rubiera, A.I.; Yelton, J.; Zheng, J.; Brandenburg, G.; Briere, R.A.; Ershov, A.; Gao, Y.S.; Kim, D.Y.; Wilson, R.; Browder, T.E.; Li, Y.; Rodriguez, J.L.; Yamamoto, H.; Bergfeld, T.; Eisenstein, B.I.; Ernst, J.; Gladding, G.E.; Gollin, G.D

    1999-01-01

    We report measurements of the D 0 , D + , and D + s meson lifetimes using 3.7 fb -1 of e + e - annihilation data collected near the Υ(4S) resonance with the CLEO detector. The measured lifetimes of the D 0 , D + , and D + s mesons are 408.5±4.1 +3.5 -3.4 fs , 1033.6±22.1 +9.9 -12.7 fs , and 486.3±15.0 +4.9 -5.1 fs . The precision of these lifetimes are comparable to those of the best previous measurements, and the systematic errors are very different. In a single experiment we find that the ratio of the D + s and D 0 lifetimes is 1.19±0.04 . copyright 1999 The American Physical Society

  13. Role of defects in the carrier-tunable topological-insulator (Bi1 -xSbx )2Te3 thin films

    Science.gov (United States)

    Scipioni, Kane L.; Wang, Zhenyu; Maximenko, Yulia; Katmis, Ferhat; Steiner, Charlie; Madhavan, Vidya

    2018-03-01

    Alloys of Bi2Te3 and Sb2Te3[(Bi1-xSbx) 2Te3] have played an essential role in the exploration of topological surface states, allowing us to study phenomena that would otherwise be obscured by bulk contributions to conductivity. Despite intensive transport and angle resolved photoemission (ARPES) studies, important questions about this system remain unanswered. For example, previous studies reported the chemical tuning of the Fermi level to the Dirac point by controlling the Sb:Bi composition ratio, but the optimum ratio varies widely across various studies. Moreover, it is unclear how the quasiparticle lifetime is affected by the disorder resulting from Sb/Bi alloying. In this work, we use scanning tunneling microscopy and spectroscopy to study the electronic structure of epitaxially grown (Bi,Sb) 2Te3 thin films at the nanoscale. We study Landau levels (LLs) to determine the effect of disorder on the quasiparticle lifetime as well as the position of the Dirac point with respect to the Fermi energy. A plot of the LL peak widths shows that despite the intrinsic disorder, the quasiparticle lifetime is not significantly degraded. We further determine that the ideal Sb concentration to place the Fermi energy to within a few meV of the Dirac point is x ˜0.7 , but that postannealing temperatures can have a significant effect on the crystallinity and Fermi level position. Specifically, high postgrowth annealing temperature can result in better crystallinity and surface roughness, but also produces a larger Te defect density which adds n -type carriers. Finally, in combination with quasiparticle interference imaging, the dispersion is revealed over a large energy range above the Fermi energy, in a regime inaccessible to ARPES. Interestingly, the surface state dispersion for the x ˜0.7 sample shows great similarity to pristine Bi2Te3 . This work provides microscopic information on the role of disorder and composition in determining carrier concentration, surface state

  14. Temperature behavior and annealing of insulated gate transistors subjected to localized lifetime control by proton implantation

    International Nuclear Information System (INIS)

    Mogro-Campero, A.; Love, R.P.; Chang, M.F.; Dyer, R.F.

    1987-01-01

    Localized lifetime control by proton implantation can result in a considerable improvement (as much as an order of magnitude or more) in the trade-off between device turn-off time and forward voltage when compared with the unlocalized method of electron irradiation. The physical mechanisms responsible for the qualitative temperature dependences are identified: MOS channel resistance for forward voltage, carrier capture cross-section for turn-off time, and generation and diffusion components of leakage current. Since no catastrophic or unrecoverable behavior is observed, normal device operation within the tested temperature range is possible. Isothermal annealing curves of turn-off time measured after annealing, and corresponding to a few hours annealing time, reveal that a constant turn-off time is reached after about an hour. The constant value increases with temperature, but is still below the unimplanted value after 4 h at 525 0 C. The turn-off time was verified to be constant even after 24 h of annealing at 200 0 C. Lifetime control by proton implantation seems to be more thermally stable than that caused by electron irradiation. (author)

  15. Fluorescence lifetime imaging of skin cancer

    Science.gov (United States)

    Patalay, Rakesh; Talbot, Clifford; Munro, Ian; Breunig, Hans Georg; König, Karsten; Alexandrov, Yuri; Warren, Sean; Neil, Mark A. A.; French, Paul M. W.; Chu, Anthony; Stamp, Gordon W.; Dunsby, Chris

    2011-03-01

    Fluorescence intensity imaging and fluorescence lifetime imaging microscopy (FLIM) using two photon microscopy (TPM) have been used to study tissue autofluorescence in ex vivo skin cancer samples. A commercially available system (DermaInspect®) was modified to collect fluorescence intensity and lifetimes in two spectral channels using time correlated single photon counting and depth-resolved steady state measurements of the fluorescence emission spectrum. Uniquely, image segmentation has been used to allow fluorescence lifetimes to be calculated for each cell. An analysis of lifetime values obtained from a range of pigmented and non-pigmented lesions will be presented.

  16. Charge Carrier Conduction Mechanism in PbS Quantum Dot Solar Cells: Electrochemical Impedance Spectroscopy Study.

    Science.gov (United States)

    Wang, Haowei; Wang, Yishan; He, Bo; Li, Weile; Sulaman, Muhammad; Xu, Junfeng; Yang, Shengyi; Tang, Yi; Zou, Bingsuo

    2016-07-20

    With its properties of bandgap tunability, low cost, and substrate compatibility, colloidal quantum dots (CQDs) are becoming promising materials for optoelectronic applications. Additionally, solution-processed organic, inorganic, and hybrid ligand-exchange technologies have been widely used in PbS CQDs solar cells, and currently the maximum certified power conversion efficiency of 9.9% has been reported by passivation treatment of molecular iodine. Presently, there are still some challenges, and the basic physical mechanism of charge carriers in CQDs-based solar cells is not clear. Electrochemical impedance spectroscopy is a monitoring technology for current by changing the frequency of applied alternating current voltage, and it provides an insight into its electrical properties that cannot be measured by direct current testing facilities. In this work, we used EIS to analyze the recombination resistance, carrier lifetime, capacitance, and conductivity of two typical PbS CQD solar cells Au/PbS-TBAl/ZnO/ITO and Au/PbS-EDT/PbS-TBAl/ZnO/ITO, in this way, to better understand the charge carriers conduction mechanism behind in PbS CQD solar cells, and it provides a guide to design high-performance quantum-dots solar cells.

  17. Ultrafast carrier dynamics and third-order nonlinear optical properties of AgInS2/ZnS nanocrystals

    Science.gov (United States)

    Yu, Kuai; Yang, Yang; Wang, Junzhong; Tang, Xiaosheng; Xu, Qing-Hua; Wang, Guo Ping

    2018-06-01

    Broad photoluminescence (PL) emission, a large Stokes shift and extremely long-lived radiative lifetimes are the characteristics of ternary I–III–VI semiconductor nanocrystals (NCs), such as CuInS2 and AgInS2. However, the lack of understanding regarding the intriguing PL mechanisms and photo-carrier dynamics limits their further applications. Here, AgInS2 and AgInS2/ZnS NCs were chemically synthesized and their carrier dynamics were studied by time-resolved PL spectroscopy. The results demonstrated that the surface defect state, which contributed dominantly to the non-radiative decay processes, was effectively passivated through ZnS alloying. Femtosecond transient absorption spectroscopy was also used to investigate the carrier dynamics, revealing the electron storage at the surface state and donor state. Furthermore, the two photon absorption properties of AgInS2 and AgInS2/ZnS NCs were measured using an open-aperture Z-scan technique. The improved third-order nonlinear susceptibility {χ }(3) of AgInS2 through ZnS alloying demonstrates potential application in two photon PL biological imaging.

  18. Lifetimes of charm and beauty hadrons

    International Nuclear Information System (INIS)

    Bellini, G.; Dornan, P.J.

    1997-01-01

    Major breakthroughs have been achieved in the determination of the lifetimes of charm and beauty hadrons. Much larger data samples than previously have become available and new experimental devices and techniques have been developed and employed. The lifetimes of all weakly decaying singly charmed hadrons have been measured, some with an accuracy of a few percent. The difference in the shortest lifetime - τ(Ω c ) - and the longest one - τ(D + ) - is given by a factor of close to ten. The experimental status of beauty lifetimes, while less complete, has still reached a new level of quality and is now better than 5% for the commoner states. New theoretical tools, based mainly on heavy quark expansions, have been developed; they incorporate as well as transcend earlier phenomenological descriptions. The observed pattern in the charm lifetime ratios is reproduced in a semi-quantitative manner as well as could be expected; as far as the beauty lifetime ratios are concerned some problems may well be emerging. The maturity level achieved in the measurements bodes quite well for future challenges where reliable and efficient tracking of the decay vertices will be crucial. (orig.)

  19. Theoretical calculations of positron lifetimes for metal oxides

    International Nuclear Information System (INIS)

    Mizuno, Masataka; Araki, Hideki; Shirai, Yasuharu

    2004-01-01

    Our recent positron lifetime measurements for metal oxides suggest that positron lifetimes of bulk state in metal oxides are shorter than previously reported values. We have performed theoretical calculations of positron lifetimes for bulk and vacancy states in MgO and ZnO using first-principles electronic structure calculations and discuss the validity of positron lifetime calculations for insulators. By comparing the calculated positron lifetimes to the experimental values, it wa found that the semiconductor model well reproduces the experimental positron lifetime. The longer positron lifetime previously reported can be considered to arise from not only the bulk but also from the vacancy induced by impurities. In the case of cation vacancy, the calculated positron lifetime based on semiconductor model is shorter than the experimental value, which suggests that the inward relaxation occurs around the cation vacancy trapping the positron. (author)

  20. Lifetime of Organic Photovoltaics: Status and Predictions

    DEFF Research Database (Denmark)

    Gevorgyan, Suren; Madsen, Morten Vesterager; Roth, Bérenger

    2016-01-01

    The results of a meta-analysis conducted on organic photovoltaics (OPV) lifetime data reported in the literature is presented through the compilation of an extensive OPV lifetime database based on a large number of articles, followed by analysis of the large body of data. We fully reveal the prog......The results of a meta-analysis conducted on organic photovoltaics (OPV) lifetime data reported in the literature is presented through the compilation of an extensive OPV lifetime database based on a large number of articles, followed by analysis of the large body of data. We fully reveal...... the progress of reported OPV lifetimes. Furthermore, a generic lifetime marker has been defi ned, which helps with gauging and comparing the performance of different architectures and materials from the perspective of device stability. Based on the analysis, conclusions are drawn on the bottlenecks...

  1. Electricite de France: Lifetime Project

    International Nuclear Information System (INIS)

    Combes, Jean-Pierre

    1991-01-01

    Electricite de France produces almost 80% of its electricity by means of standardized PWR nuclear power stations. Starting in 1986, therefore, a project known as the 'Lifetime Project' was developed, whose aim was initially to ensure that the lifetime defined at design stage (40 years in general) could be attained without major difficulty (follow up of the aging process). It then became apparent that it would be useful to know just how far it would be technically and economically possible to go. As a result, the project is now working towards increasing the lifetime of power stations. (author)

  2. Lifetime studies of self-activated photoluminescence in heavily silicon-doped GaAs

    Science.gov (United States)

    Sauncy, T.; Palsule, C. P.; Holtz, M.; Gangopadhyay, S.; Massie, S.

    1996-01-01

    We report results of a detailed temperature dependence study of photoluminescence lifetime and continuous emission properties in silicon-doped GaAs. The primary focus is on a defect-related emission at 1.269 eV (T=20 K). GaAs crystals were grown using molecular-beam epitaxy with most of the experiments conducted on a sample having a carrier concentration of 4.9×1018 cm-3. The intensity is seen to decrease above 100 K, with no corresponding decrease in the measured lifetime of 9.63+/-0.25 ns. The intensity decrease implies an activation energy of 19+/-2 meV, which is approximately one order of magnitude smaller than what was previously obtained for similar defects in Czochralski-grown GaAs with other dopants. We interpret our results in terms of a configuration coordinate model and obtain a more complete picture of the energy-level structure. The experiments indicate that the upper level in the recombination process is about 20 meV below the conduction-band continuum, with the lower state approximately 300 meV above the valence band. Our results are consistent with the identification of the corresponding defect complex microstructure as being a silicon-at-gallium substitution, weakly interacting with a gallium vacancy second-nearest neighbor, known as the Si-Y defect complex.

  3. Observation of interface carrier states in no-common-atom heterostructures ZnSe/BeTe

    Science.gov (United States)

    Gurevich, A. S.; Kochereshko, V. P.; Bleuse, J.; Mariette, H.; Waag, A.; Akimoto, R.

    2011-09-01

    The existence of intrinsic carrier interface states in heterostructures with no common atom at the interface (such as ZnSe/BeTe) is shown experimentally by ellipsometry and photoluminescence spectroscopy. These states are located on interfaces and lie inside the effective bandgap of the structure; they are characterized by a high density and a long lifetime. A tight binding model confirms theoretically the existence of these states in ZnSe/BeTe heterostructures for a ZnTe-type interface, in contrast to the case of the BeSe-type interface for which they do not exist.

  4. Observation of interface carrier states in no-common-atom heterostructures ZnSe/BeTe

    Energy Technology Data Exchange (ETDEWEB)

    Gurevich, A S; Kochereshko, V P [A F Ioffe Physical-Technical Institute, St Petersburg 194021 (Russian Federation); Bleuse, J; Mariette, H [CEA-CNRS Group ' Nanophysique et Semiconducteurs' , CEA, INAC/SP2M, and Institut Neel, 17 rue des Martyrs, F-38054 Grenoble (France); Waag, A [Braunschweig Technical University, Hans-Sommer-Strasse 66, D-38106 Braunschweig (Germany); Akimoto, R, E-mail: vladimir.kochereshko@mail.ioffe.ru [National Institute of Advanced Industrial Science and Technology (AIST), AIST Tsukuba Central 2-1, Tsukuba 305-8568 (Japan)

    2011-09-07

    The existence of intrinsic carrier interface states in heterostructures with no common atom at the interface (such as ZnSe/BeTe) is shown experimentally by ellipsometry and photoluminescence spectroscopy. These states are located on interfaces and lie inside the effective bandgap of the structure; they are characterized by a high density and a long lifetime. A tight binding model confirms theoretically the existence of these states in ZnSe/BeTe heterostructures for a ZnTe-type interface, in contrast to the case of the BeSe-type interface for which they do not exist.

  5. Lifetime Improvement by Battery Scheduling

    NARCIS (Netherlands)

    Jongerden, M.R.; Schmitt, Jens B.; Haverkort, Boudewijn R.H.M.

    The use of mobile devices is often limited by the lifetime of their batteries. For devices that have multiple batteries or that have the option to connect an extra battery, battery scheduling, thereby exploiting the recovery properties of the batteries, can help to extend the system lifetime. Due to

  6. FUNDUS AUTOFLUORESCENCE LIFETIMES AND CENTRAL SEROUS CHORIORETINOPATHY.

    Science.gov (United States)

    Dysli, Chantal; Berger, Lieselotte; Wolf, Sebastian; Zinkernagel, Martin S

    2017-11-01

    To quantify retinal fluorescence lifetimes in patients with central serous chorioretinopathy (CSC) and to identify disease specific lifetime characteristics over the course of disease. Forty-seven participants were included in this study. Patients with central serous chorioretinopathy were imaged with fundus photography, fundus autofluorescence, optical coherence tomography, and fluorescence lifetime imaging ophthalmoscopy (FLIO) and compared with age-matched controls. Retinal autofluorescence was excited using a 473-nm blue laser light and emitted fluorescence light was detected in 2 distinct wavelengths channels (498-560 nm and 560-720 nm). Clinical features, mean retinal autofluorescence lifetimes, autofluorescence intensity, and corresponding optical coherence tomography (OCT) images were further analyzed. Thirty-five central serous chorioretinopathy patients with a mean visual acuity of 78 ETDRS letters (range, 50-90; mean Snellen equivalent: 20/32) and 12 age-matched controls were included. In the acute stage of central serous chorioretinopathy, retinal fluorescence lifetimes were shortened by 15% and 17% in the respective wavelength channels. Multiple linear regression analysis showed that fluorescence lifetimes were significantly influenced by the disease duration (P autofluorescence lifetimes, particularly in eyes with retinal pigment epithelial atrophy, were associated with poor visual acuity. This study establishes that autofluorescence lifetime changes occurring in central serous chorioretinopathy exhibit explicit patterns which can be used to estimate perturbations of the outer retinal layers with a high degree of statistical significance.

  7. Real-time monitoring of luminescent lifetime changes of PtOEP oxygen sensing film with LED/photodiode-based time-domain lifetime device.

    Science.gov (United States)

    Ji, Shaomin; Wu, Wanhua; Wu, Yubo; Zhao, Taiyang; Zhou, Fuke; Yang, Yubin; Zhang, Xin; Liang, Xiaofen; Wu, Wenting; Chi, Lina; Wang, Zhonggang; Zhao, Jianzhang

    2009-05-01

    A cost-effective LED/photodiode(PD)-based time-domain luminescent lifetime measuring device with rugged electronics and simplified algorithms was assembled and successfully used to characterize oxygen sensing films, by continuously monitoring phosphorescence lifetime changes of phosphorescent platinum octaethylporphyrin (PtOEP) in cardo poly(aryl ether ketone) polymer (IMPEK-C) vs. variation of the oxygen partial pressure in a gas mixture (O(2)/N(2)). The results determined by both phosphorescence lifetime and intensity monitoring were compared and the lifetime mode gave results which are in good agreement with the intensity mode. The lifetime-based linear Stern-Volmer plot indicates that the PtOEP molecules are nearly homogeneously distributed in the sensing film. The phosphorescent lifetime of the PtOEP film changes from 75 micros in neat N(2) to less than 2 micros in neat O(2). The sensing system (by combination of the PtOEP sensing film with the home-assembled lifetime device) gives a high lifetime-based O(2) sensing resolution, e.g. about 2 micros Torr(-1) for low O(2) concentration (below 3.5% O(2), V/V). This feasible lifetime device configuration is affordable to most sensor laboratories and the device may facilitate the study of O(2) sensing material with the continuous lifetime monitoring method.

  8. Revealing charge carrier dynamics in squaraine:[6, 6]-phenyl-C 71-butyric acid methyl ester based organic solar cells

    Science.gov (United States)

    Rana, Aniket; Sharma, Chhavi; Prabhu, Deepak D.; Kumar, Mahesh; Karuvath, Yoosaf; Das, Suresh; Chand, Suresh; Singh, Rajiv K.

    2018-04-01

    Ultrafast charge carrier dynamics as well as the generation of polaron pair in squaraine (SQ) and squaraine:[6,6]-phenyl-C 71-butyric acid methyl ester (SQ:PCBM71) have been studied using ultrafast transient absorption spectroscopy (UTAS). The current study reveals that the pure SQ exhibits the creation of singlet and triplet states; however, incorporation of PCBM71 in SQ results in the formation of polaron pairs with ˜550ps lifetime, which in turn leads to the creation of free electrons in the device. We show that the considerable increment in monomolecular and bimolecular recombination in SQ:PCBM71 compared to pure SQ which describes the interfacial compatibility of SQ and PCBMC71 molecules. The present work not only provides the information about the carrier generation in SQ and SQ:PCBM71 but also gives the facts relating to the effect of PCBM71 mixing into the SQ which is very significant because the SQ has donor-acceptor-donor (D-A-D) structure and mixing one more acceptor can introduce more complex recombinations in the blend. These findings have been complimented by the charge transport study in the device using impedance spectroscopy. The various important transport parameters are transit time (τt), diffusion constant (Dn), global mobility (μ) and carrier lifetime (τr). The values of these parameters are 26.38 μs, 4.64x10-6 cm2s-1, 6.12x10-6 cm2V-1s-1 and 399 μs, respectively. To the best of our knowledge such study related to SQ is not present in the literature comprehensively.

  9. Charge carrier transport and collection enhancement of copper indium diselenide photoactive nanoparticle-ink by laser crystallization

    Energy Technology Data Exchange (ETDEWEB)

    Nian, Qiong; Cheng, Gary J., E-mail: gjcheng@purdue.edu [Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47906 (United States); School of Industrial Engineering, Purdue University, West Lafayette, Indiana 47906 (United States); Zhang, Martin Y. [School of Industrial Engineering, Purdue University, West Lafayette, Indiana 47906 (United States); Wang, Yuefeng [Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47906 (United States); School of Materials Engineering, Purdue University, West Lafayette, Indiana 47906 (United States); Das, Suprem R.; Bhat, Venkataprasad S. [Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47906 (United States); Huang, Fuqiang [Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai 200050 (China)

    2014-09-15

    There has been increasing needs for cost-effective and high performance thin film deposition techniques for photovoltaics. Among all deposition techniques, roll-to-roll printing of nanomaterials has been a promising method. However, the printed thin film contains many internal imperfections, which reduce the charge-collection performance. Here, direct pulse laser crystallization (DPLC) of photoactive nanoparticles-inks is studied to meet this challenge. In this study, copper indium selenite (CIS) nanoparticle-inks is applied as an example. Enhanced crystallinity, densified structure in the thin film is resulted after DLPC under optimal conditions. It is found that the decreased film internal imperfections after DPLC results in reducing scattering and multi-trapping effects. Both of them contribute to better charge-collection performance of CIS absorber material by increasing extended state mobility and carrier lifetime, when carrier transport and kinetics are coupled. Charge carrier transport was characterized after DPLC, showing mobility increased by 2 orders of magnitude. Photocurrent under AM1.5 illumination was measured and shown 10 times enhancement of integrated power density after DPLC, which may lead to higher efficiency in photo-electric energy conversion.

  10. Measurement of the $\\Omega_{c}^{0}$ lifetime

    CERN Document Server

    Adamovich, M.I.; Alexandrov, Yu.A.; Barberis, D.; Beck, M.; Berat, C.; Beusch, W.; Boss, M.; Brons, S.; Bruckner, W.; Buenerd, M.; Buscher, C.; Charignon, F.; Chauvin, J.; Chudakov, E.A.; Dropmann, F.; Engelfried, J.; Faller, F.; Fournier, A.; Gerasimov, S.; Godbersen, M.; Grafstrom, P.; Haller, T.; Heidrich, M.; Hurst, R.B.; Konigsmann, Kay; Konorov, I.; Martens, K.; Martin, P.; Masciocchi, S.; Michaels, R.; Muller, U.; Newsom, C.; Paul, S.; Povh, B.; Ren, Z.; Rey-Campagnolle, M.; Rosner, G.; Rossi, L.; Rudolph, H.; Schmitt, L.; Siebert, H.W.; Simon, A.; Smith, V.J.; Thilmann, O.; Trombini, A.; Vesin, E.; Volkemer, B.; Vorwalter, K.; Walcher, T.; Walder, G.; Werding, R.; Wittmann, E.; Zavertyaev, M.V.

    1995-01-01

    We present the measurement of the lifetime of the Omega_c we have performed using three independent data samples from two different decay modes. Using a Sigma- beam of 340 GeV/c we have obtained clean signals for the Omega_c decaying into Xi- K- pi+ pi+ and Omega- pi+ pi- pi+, avoiding topological cuts normally used in charm analysis. The short but measurable lifetime of the Omega_c is demonstrated by a clear enhancement of the signals at short but finite decay lengths. Using a continuous maximum likelihood method we determined the lifetime to be tau(Omega_c) = 55 +13-11(stat) +18-23(syst) fs. This makes the Omega_c the shortest living weakly decaying particle observed so far. The short value of the lifetime confirms the predicted pattern of the charmed baryon lifetimes and demonstrates that the strong interaction plays a vital role in the lifetimes of charmed hadrons.

  11. Lifetime improvement by battery scheduling

    NARCIS (Netherlands)

    Jongerden, M.R.; Haverkort, Boudewijn R.H.M.

    The use of mobile devices is often limited by the lifetime of its battery. For devices that have multiple batteries or that have the option to connect an extra battery, battery scheduling, thereby exploiting the recovery properties of the batteries, can help to extend the system lifetime. Due to the

  12. 300% Enhancement of Carrier Mobility in Uniaxial-Oriented Perovskite Films Formed by Topotactic-Oriented Attachment.

    Science.gov (United States)

    Kim, Dong Hoe; Park, Jaehong; Li, Zhen; Yang, Mengjin; Park, Ji-Sang; Park, Ik Jae; Kim, Jin Young; Berry, Joseph J; Rumbles, Garry; Zhu, Kai

    2017-06-01

    Organic-inorganic perovskites with intriguing optical and electrical properties have attracted significant research interests due to their excellent performance in optoelectronic devices. Recent efforts on preparing uniform and large-grain polycrystalline perovskite films have led to enhanced carrier lifetime up to several microseconds. However, the mobility and trap densities of polycrystalline perovskite films are still significantly behind their single-crystal counterparts. Here, a facile topotactic-oriented attachment (TOA) process to grow highly oriented perovskite films, featuring strong uniaxial-crystallographic texture, micrometer-grain morphology, high crystallinity, low trap density (≈4 × 10 14 cm -3 ), and unprecedented 9 GHz charge-carrier mobility (71 cm 2 V -1 s -1 ), is demonstrated. TOA-perovskite-based n-i-p planar solar cells show minimal discrepancies between stabilized efficiency (19.0%) and reverse-scan efficiency (19.7%). The TOA process is also applicable for growing other state-of-the-art perovskite alloys, including triple-cation and mixed-halide perovskites. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Quantum lifetime in electron storage rings

    International Nuclear Information System (INIS)

    Chao, A.W.

    1977-02-01

    One of the mechanisms which contribute to beam lifetime in electron storage rings is the quantum emission of energetic photons causing particles to be lost from the rf bucket. This quantum lifetime is among other things important in defining the required aperture in a storage ring. An approximate expression of quantum lifetime, predicted by a one-dimensional model which takes into account only the betatron motion, has been used in most storage ring designs. If the beam is aperture-limited at a position with nonzero dispersion, both the betatron and synchrotron motions have to be included and a two-dimensional model must be used. An exact expression of quantum lifetime for the one-dimensional case and an approximate expression for the two-dimensional case are given

  14. Quantum lifetime in electron storage rings

    International Nuclear Information System (INIS)

    Chao, A.W.

    1977-01-01

    One of the mechanisms which contributes to beam lifetime in electron storage rings is the quantum emission of energetic photons causing particles to be lost from the rf bucket. This quantum lifetime is among other things important in defining the required aperture in a storage ring. An approximate expression of quantum lifetime, predicted by a one-dimensional model which takes into account only the betatron motion, has been used in most storage ring designs. If the beam is aperture-limited at a position with nonzero dispersion, both the betatron and synchrotron motions have to be included, and a two-dimensional model must be used. An exact expression of quantum lifetime for the one-dimensional case and an approximate expression for the two-dimensional case are given

  15. Measuring Charge Carrier Diffusion in Coupled Colloidal Quantum Dot Solids

    KAUST Repository

    Zhitomirsky, David

    2013-06-25

    Colloidal quantum dots (CQDs) are attractive materials for inexpensive, room-temperature-, and solution-processed optoelectronic devices. A high carrier diffusion length is desirable for many CQD device applications. In this work we develop two new experimental methods to investigate charge carrier diffusion in coupled CQD solids under charge-neutral, i.e., undepleted, conditions. The methods take advantage of the quantum-size-effect tunability of our materials, utilizing a smaller-bandgap population of quantum dots as a reporter system. We develop analytical models of diffusion in 1D and 3D structures that allow direct extraction of diffusion length from convenient parametric plots and purely optical measurements. We measure several CQD solids fabricated using a number of distinct methods and having significantly different doping and surface ligand treatments. We find that CQD materials recently reported to achieve a certified power conversion efficiency of 7% with hybrid organic-inorganic passivation have a diffusion length of 80 ± 10 nm. The model further allows us to extract the lifetime, trap density, mobility, and diffusion coefficient independently in each material system. This work will facilitate further progress in extending the diffusion length, ultimately leading to high-quality CQD solid semiconducting materials and improved CQD optoelectronic devices, including CQD solar cells. © 2013 American Chemical Society.

  16. Visible light carrier generation in co-doped epitaxial titanate films

    Energy Technology Data Exchange (ETDEWEB)

    Comes, Ryan B.; Smolin, Sergey Y.; Kaspar, Tiffany C.; Gao, Ran; Apgar, Brent A.; Martin, Lane W.; Bowden, Mark E.; Baxter, Jason; Chambers, Scott A.

    2015-03-02

    Perovskite titanates such as SrTiO3 (STO) exhibit a wide range of important functional properties, including high electron mobility, ferroelectricity—which may be valuable in photovoltaic applications—and excellent photocatalytic performance. The wide optical band gap of titanates limits their use in these applications, however, making them ill-suited for integration into solar energy harvesting technologies. Our recent work has shown that by doping STO with equal concentrations of La and Cr we can enhance visible light absorption in epitaxial thin films while avoiding any compensating defects. In this work, we explore the optical properties of photoexcited carriers in these films. Using spectroscopic ellipsometry, we show that the Cr3+ dopants, which produce electronic states immediately above the top of the O 2p valence band in STO reduce the direct band gap of the material from 3.75 eV to between 2.4 and 2.7 eV depending on doping levels. Transient reflectance measurements confirm that optically generated carriers have a recombination lifetime comparable to that of STO and are in agreement with the observations from ellipsometry. Finally, through photoelectrochemical yield measurements, we show that these co-doped films exhibit enhanced visible light photocatalysis when compared to pure STO.

  17. Low-complexity Joint Sub-carrier Phase Noise Compensation for Digital Multi-carrier Systems

    DEFF Research Database (Denmark)

    Yankov, Metodi Plamenov; Barletta, Luca; Zibar, Darko

    2017-01-01

    Joint sub-carrier phase noise processing is proposed which recovers the SNR penalty related to decreased sub-carrier baudrate w.r.t. single carrier systems. The method enables digital sub-banding to be safely employed for nonlinear mitigation for modulation formats of up to 256-QAM.......Joint sub-carrier phase noise processing is proposed which recovers the SNR penalty related to decreased sub-carrier baudrate w.r.t. single carrier systems. The method enables digital sub-banding to be safely employed for nonlinear mitigation for modulation formats of up to 256-QAM....

  18. The Lifetime of a beautiful and charming meson: Bc lifetime measured using the D0 detector

    International Nuclear Information System (INIS)

    Welty-Rieger, Leah Christine

    2008-01-01

    Using approximately 1.3 fb -1 of data collected by the D0 detector between 2002 and 2006, the lifetime of the B c ± meson is studied in the B c ± → J/ψμ ± + X final state. Using an unbinned likelihood simultaneous fit to J/ψ + μ invariant mass and lifetime distributions, a signal of 810 ± 80(stat.) candidates is estimated and a lifetime measurement made of: τ(B c ± ) = 0.448 -0.036 +0.038 (stat) ± 0.032(sys) ps

  19. Carrier-interleaved orthogonal multi-electrode multi-carrier resistivity-measurement tool

    International Nuclear Information System (INIS)

    Cai, Yu; Sha, Shuang

    2016-01-01

    This paper proposes a new carrier-interleaved orthogonal multi-electrode multi-carrier resistivity-measurement tool used in a cylindrical borehole environment during oil-based mud drilling processes. The new tool is an orthogonal frequency division multiplexing access-based contactless multi-measurand detection tool. The tool can measure formation resistivity in different azimuthal angles and elevational depths. It can measure many more measurands simultaneously in a specified bandwidth than the legacy frequency division multiplexing multi-measurand tool without a channel-select filter while avoiding inter-carrier interference. The paper also shows that formation resistivity is not sensitive to frequency in certain frequency bands. The average resistivity collected from N subcarriers can increase the measurement of the signal-to-noise ratio (SNR) by N times given no amplitude clipping in the current-injection electrode. If the clipping limit is taken into account, with the phase rotation of each single carrier, the amplitude peak-to-average ratio can be reduced by 3 times, and the SNR can achieve a 9/ N times gain over the single-carrier system. The carrier-interleaving technique is also introduced to counter the carrier frequency offset (CFO) effect, where the CFO will cause inter-pad interference. A qualitative analysis and simulations demonstrate that block-interleaving performs better than tone-interleaving when coping with a large CFO. The theoretical analysis also suggests that increasing the subcarrier number can increase the measurement speed or enhance elevational resolution without sacrificing receiver performance. The complex orthogonal multi-pad multi-carrier resistivity logging tool, in which all subcarriers are complex signals, can provide a larger available subcarrier pool than other types of transceivers. (paper)

  20. Hybrid Perovskites for Photovoltaics: Charge-Carrier Recombination, Diffusion, and Radiative Efficiencies.

    Science.gov (United States)

    Johnston, Michael B; Herz, Laura M

    2016-01-19

    values extracted from OPTP measurements and their dependence on perovskite composition and morphology. The significance of the reviewed charge-carrier recombination and mobility parameters is subsequently evaluated in terms of the charge-carrier diffusion lengths and radiative efficiencies that may be obtained for such hybrid perovskites. We particularly focus on calculating such quantities in the limit of ultra-low trap-related recombination, which has not yet been demonstrated but could be reached through further advances in material processing. We find that for thin films of hybrid lead iodide perovskites with typical charge-carrier mobilities of ∼30cm(2)/(V s), charge-carrier diffusion lengths at solar (AM1.5) irradiation are unlikely to exceed ∼10 μm even if all trap-related recombination is eliminated. We further examine the radiative efficiency for hybrid lead halide perovskite films and show that if high efficiencies are to be obtained for intermediate charge-carrier densities (n ≈ 10(14) cm(-3)) trap-related recombination lifetimes will have to be enhanced well into the microsecond range.

  1. Lifetime value in business process

    Directory of Open Access Journals (Sweden)

    Martin Souček

    2011-01-01

    Full Text Available The paper focuses on lifetime value assessment and its implementation and application in business processes. The lifetime value is closely connected to customer relationship management. The paper presents results of three consecutive researches devoted to issues of customer relationship management. The first two from 2008 and 2010 were conducted as quantitative ones; the one from 2009 had qualitative nature. The respondents were representatives of particular companies. The means for data collection was provided by ReLa system. We will focus on individual attributes of lifetime value of a customer, and relate them to approaches of authors mentioned in introduction. Based on the qualitative research data, the paper focuses on individual customer lifetime value parameters. These parameters include: the cost to the customer relationship acquisition and maintenance, profit generated from a particular customer, customer awareness value, the level of preparedness to adopt new products, the value of references and customer loyalty level. For each of these parameters, the paper provides specific recommendations. Moreover, it is possible to learn about the nature of these parameter assessments in the Czech environment.

  2. Models for Battery Reliability and Lifetime

    Energy Technology Data Exchange (ETDEWEB)

    Smith, K.; Wood, E.; Santhanagopalan, S.; Kim, G. H.; Neubauer, J.; Pesaran, A.

    2014-03-01

    Models describing battery degradation physics are needed to more accurately understand how battery usage and next-generation battery designs can be optimized for performance and lifetime. Such lifetime models may also reduce the cost of battery aging experiments and shorten the time required to validate battery lifetime. Models for chemical degradation and mechanical stress are reviewed. Experimental analysis of aging data from a commercial iron-phosphate lithium-ion (Li-ion) cell elucidates the relative importance of several mechanical stress-induced degradation mechanisms.

  3. Masses of charmed particles, decay modes and lifetimes

    International Nuclear Information System (INIS)

    Vajsenberg, A.O.

    1982-01-01

    Basic characteristics of charmed particles obtained up to the middle of 1981 are discussed in the survey. Stated in brief are main predictions of the theory on charmed particles properties. Experimental data on masses, decay modes and lifetimes of D and F mesons as well as charmed baryons are considered. Basic experiments are described. It is pointed out that in the experiments single and pair production events as well as charmed particle decay have been observed. The charmed particles lifetime lies within the limits of 10 -12 - 10 -13 C. The lifetime of D +- mesons is approximately three times longer than the D 0 mesons lifetime. The lifetime of F mesons and Λsub(e) baryons is close to D 0 mesons lifetime [ru

  4. Reactor pressure vessel embrittlement of NPP borssele: Design lifetime and lifetime extension

    International Nuclear Information System (INIS)

    Blom, F.J.

    2007-01-01

    Embrittlement of the reactor pressure vessel of the Borssele nuclear power plant has been investigated taking account of the design lifetime of 40 years and considering 20 years subsequent lifetime extension. The paper presents the current licensing status based on considerations of material test data and of US nuclear regulatory standards. Embrittlement status is also evaluated against German and French nuclear safety standards. Results from previous fracture toughness and Charpy tests are investigated by means of the Master curve toughness transition approach. Finally, state of the art insights are investigated by means of literature research. Regarding the embrittlement status of the reactor pressure vessel of Borssele nuclear power plant it is concluded that there is a profound basis for the current license up to the original end of the design life in 2013. The embrittlement temperature changes only slightly with respect to the acceptance criterion adopted postulating further operation up to 2033. Continued safe operation and further lifetime extension are therefore not restricted by reactor pressure vessel embrittlement

  5. Do methicillin resistant staphylococcus (MRSA) carrier patients influence MRSA infection more than MRSA-carrier medical officers and MRSA-carrier family?

    Science.gov (United States)

    Dilogo, Ismail H; Arya, Abikara; Phedy; Loho, Tony

    2013-07-01

    to determine the rate of MRSA-carrier among patients, family members and health care providers, and the association between MRSA-carrier family members and health care providers on MRSA infection patient after orthopaedic surgery. this is a cross-sectional analytical study. Samples were taken consecutively during December 2010 to December 2011, consisting of postoperative patients infected with MRSA, attending family members, and the medical officers with history of contact with the patient. Swab culture were taken from nasal and axilla of all subjects. The incidence of MRSA infection, and MRSA-carrier on the patient, family members and medical officers were presented descriptively, while their association with MRSA infection was statistically tested using Fischer exact test. during the study period, there were 759 surgeries, with 4 (0.5%) patients were identified to have MRSA infection. Of these four cases, 48 subjects were enrolled. The rate of MRSA-carrier among patients, family and health care providers were 50%, 25% and 0% respectively. There were no significant association between MRSA and the rates of MRSA-carrier on the family member or health care providers. the incidence of MRSA infection, MRSA-carrier patient, MRSA-carrier health care providers, and family member carrier were 0.5%, 50%, 0%, and 25% respectively. No significant association found between MRSA-carrier on the family member or health care providers and MRSA infection patient. There were no MRSA infection found on the health care provider.

  6. Study on the mechanism of using IR illumination to improve the carrier transport performance of CdZnTe detector

    Science.gov (United States)

    Mao, Yifei; Zhang, Jijun; Lin, Liwen; Lai, Jianming; Min, Jiahua; Liang, Xiaoyan; Huang, Jian; Tang, Ke; Wang, Linjun

    2018-04-01

    Different wavelength IR light (770-1150 nm) was used to evaluate the effect of IR light on the carrier transport performance of CdZnTe detector. The effective mobility-lifetime product (μτ*) of CdZnTe achieved 10-2 cm2 V-1 when the IR wavelength was in the range of 820-920 nm, but decreased to 1 × 10-4 cm2 V-1 when the wavelength was longer than 920 nm. The mechanism about how IR light affecting the carrier transport property of CdZnTe detector was analyzed with Shockley-Read-Hall model. The defect of doubly ionized Cd vacancy ([VCd]2-) was found to be the main factor that assist IR light affecting the μτ of CdZnTe detector. The photoconductive experiment under 770-1150 nm IR illumination was carried out, and three kinds of photocurrent curve were detected and analyzed by solving the Hecht equation. The experiments demonstrated the effect of [VCd]2- defect on the carrier transport property of CdZnTe detector under IR illumination.

  7. Occupational risk and lifetime exposure

    International Nuclear Information System (INIS)

    Lapp, R.E.

    1991-01-01

    Any lowering of annual radiation limits for occupational exposure should be based on industry experience with lifetime doses and not on a worst case career exposure of 47 years. Two decades of experience show a lifetime accumulation of less than 1.5 rem for workers with measurable exposure. This is 5% of the normal lifetime exposure of Americans to natural and medical radiation. Any epidemiology of the US nuclear power workforce's two decade long exposure would have to focus on excess leukemia. Application of the Hiroshima and Nagasaki cancer mortality shows that too few leukemias would be expressed to permit a feasible epidemiology. Ionizing radiation appears to be a mild carcinogen as compared to physical and chemical agents presented in the occupational environment. A realistic factor in determining any change in occupational exposure limits for ionizing radiation should take into account the past performance of the licensee and potential health effects applicable to the workplace. Specifically, the lifetime exposure data for workers at nuclear power plants and naval shipyards should be considered. The nuclear industry and the US Navy have detailed data on the annual exposure of workers with a combined collective exposure approaching 1 million worker-rem. The lifetime dose for naval personnel and shipyard workers averages 1.1 rem J 1990. Shipyard workers have an annual dose of 0.28 rem per work-year and a mean exposure time of 4.4 years. The data apply to workers with measurable dose

  8. The association of lifetime insight and cognition in psychosis.

    Science.gov (United States)

    Sánchez-Torres, Ana M; Zarzuela, Amalia; Peralta, Victor; Cuesta, Manuel J

    2015-03-01

    Poor insight has been related to poor course in psychosis. However, the role of cognition in insight remains unclear. The aim of this study was to examine the influence of cognition and lifetime psychopathological dimensions on insight in psychosis. We followed up 42 patients with psychotic disorders over 10years. Lifetime psychopathological dimensions and cognitive performance were assessed. Patients were divided into two groups by lifetime patterns of insight and compared with 42 healthy volunteers. Lower IQ and poorer social cognition were associated with higher risks of poorer lifetime insight of feeling ill and global insight respectively. Lifetime negative symptoms were associated with a higher risk of poorer lifetime insight into symptoms. Lifetime lack of insight is independent of cognitive impairment in specific domains, except for social cognition. Higher IQ may contribute to better lifetime awareness of illness, while better ability to manage emotions is involved in lifetime global insight. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. ''LIFETIME'': a computer program for analyzing Doppler-shift recoil-distance nuclear lifetime data

    International Nuclear Information System (INIS)

    Wells, J.C.; Fewell, M.P.; Johnson, N.R.

    1985-10-01

    The program LIFETIME is designed to extract lifetimes of nuclear levels from Doppler-shift recoil-distance experiments by performing a least-square fit to the experimental data (shifted and unshifted photopeak intensities and branching ratios). Initial populations of levels and transition rates between levels are treated as variable parameters. In terms of these parameters the population of each level as a function of time is determined by the Bateman equations, and the shifted and unshifted intensities are calculated. 19 refs., 5 figs

  10. Control of polythiophene film microstructure and charge carrier dynamics through crystallization temperature

    KAUST Repository

    Marsh, Hilary S.; Reid, Obadiah G.; Barnes, George; Heeney, Martin; Stingelin, Natalie; Rumbles, Garry

    2014-01-01

    The microstructure of neat conjugated polymers is crucial in determining the ultimate morphology and photovoltaic performance of polymer/fullerene blends, yet until recently, little work has focused on controlling the former. Here, we demonstrate that both the long-range order along the (100)-direction and the lamellar crystal thickness along the (001)-direction in neat poly(3-hexylthiophene) (P3HT) and poly[(3,3″-didecyl[2,2′:5′, 2″-terthiophene]-5,5″-diyl)] (PTTT-10) thin films can be manipulated by varying crystallization temperature. Changes in crystalline domain size impact the yield and dynamics of photogenerated charge carriers. Time-resolved microwave conductivity measurements show that neat polymer films composed of larger crystalline domains have longer photoconductance lifetimes and charge carrier yield decreases with increasing crystallite size for P3HT. Our results suggest that the classical polymer science description of temperature-dependent crystallization of polymers from solution can be used to understand thin-film formation in neat conjugated polymers, and hence, should be considered when discussing the structural evolution of organic bulk heterojunctions. © 2014 Wiley Periodicals, Inc.

  11. Control of polythiophene film microstructure and charge carrier dynamics through crystallization temperature

    KAUST Repository

    Marsh, Hilary S.

    2014-03-22

    The microstructure of neat conjugated polymers is crucial in determining the ultimate morphology and photovoltaic performance of polymer/fullerene blends, yet until recently, little work has focused on controlling the former. Here, we demonstrate that both the long-range order along the (100)-direction and the lamellar crystal thickness along the (001)-direction in neat poly(3-hexylthiophene) (P3HT) and poly[(3,3″-didecyl[2,2′:5′, 2″-terthiophene]-5,5″-diyl)] (PTTT-10) thin films can be manipulated by varying crystallization temperature. Changes in crystalline domain size impact the yield and dynamics of photogenerated charge carriers. Time-resolved microwave conductivity measurements show that neat polymer films composed of larger crystalline domains have longer photoconductance lifetimes and charge carrier yield decreases with increasing crystallite size for P3HT. Our results suggest that the classical polymer science description of temperature-dependent crystallization of polymers from solution can be used to understand thin-film formation in neat conjugated polymers, and hence, should be considered when discussing the structural evolution of organic bulk heterojunctions. © 2014 Wiley Periodicals, Inc.

  12. Electrical and Structural Characterization of Web Dendrite Crystals

    Science.gov (United States)

    Schwuttke, G. H.; Koliwad, K.; Dumas, K. A.

    1985-01-01

    Minority carrier lifetime distributions in silicon web dendrites are measured. Emphasis is placed on measuring areal homogeneity of lifetime, show its dependency on structural defects, and its unique change during hot processing. The internal gettering action of defect layers present in web crystals and their relation to minority carrier lifetime distributions is discussed. Minority carrier lifetime maps of web dendrites obtained before and after high temperature heat treatment are compared to similar maps obtained from 100 mm diameter Czochralski silicon wafers. Such maps indicate similar or superior areal homogeneity of minority carrier lifetime in webs.

  13. 14 CFR 399.82 - Passing off of carrier identity by affiliation between carriers.

    Science.gov (United States)

    2010-01-01

    ... forth in paragraph (c) of this section. In such cases the Board may determine in an adjudicatory... carrier shall not engage in joint public relations activities at points served by both carriers which tend... either carrier are performed in common with the other carrier or as part of a single system. In cases...

  14. The EPDS-Lifetime: assessment of lifetime prevalence and risk factors for perinatal depression in a large cohort of depressed women

    NARCIS (Netherlands)

    Meltzer-Brody, S.; Boschloo, L.; Jones, I.; Sullivan, P.F.; Penninx, B.W.J.H.

    2013-01-01

    Perinatal depression (PND) is a common complication of pregnancy and postpartum associated with significant morbidity. We had three goals: (1) to explore the performance of a new lifetime version of the Edinburgh Postnatal Depression Scale (EPDS-Lifetime) to assess lifetime prevalence of PND; (2) to

  15. The EPDS-Lifetime : assessment of lifetime prevalence and risk factors for perinatal depression in a large cohort of depressed women

    NARCIS (Netherlands)

    Meltzer-Brody, Samantha; Boschloo, Lynn; Jones, Ian; Sullivan, Patrick F.; Penninx, Brenda W.

    2013-01-01

    Perinatal depression (PND) is a common complication of pregnancy and postpartum associated with significant morbidity. We had three goals: (1) to explore the performance of a new lifetime version of the Edinburgh Postnatal Depression Scale (EPDS-Lifetime) to assess lifetime prevalence of PND; (2) to

  16. Lifetime of B hadrons from CDF

    International Nuclear Information System (INIS)

    Miao, Ting.

    1996-08-01

    A review of the lifetimes of B hadrons measured by the CDF collaboration at Fermilab is presented. The data corresponds to 110 pb -1 of p anti p collisions at √s = 1.8 TeV. The inclusive B hadron lifetime is measured using a high statistics sample of B → J/ΨΧ decays. Species specific lifetimes of the B + , B 0 , B 0 s , and Λ 0 b are determined using both fully reconstructed decays and partially reconstructed decays consisting of a lepton associated with a charm hadron

  17. Maintenance engineering of lifetime management programs

    International Nuclear Information System (INIS)

    Hervia Ruperez, F.

    1997-01-01

    The complexity of nuclear power plants obliges to stablish the adecuated management of its lifetime. This article describes the methodologies and the improvement the evaluation of lifetime programs and specially in Garona and Vandellos II Nuclear Power Plants. (Author)

  18. Heritability of lifetime ecstasy use.

    Science.gov (United States)

    Verweij, Karin J H; Treur, Jorien L; Vreeker, Annabel; Brunt, Tibor M; Willemsen, Gonneke; Boomsma, Dorret I; Vink, Jacqueline M

    2017-09-01

    Ecstasy is a widely used psychoactive drug that users often take because they experience positive effects such as increased euphoria, sociability, elevated mood, and heightened sensations. Ecstasy use is not harmless and several immediate and long term side effects have been identified. Lifetime ecstasy use is likely to be partly influenced by genetic factors, but no twin study has determined the heritability. Here, we apply a classical twin design to a large sample of twins and siblings to estimate the heritability of lifetime ecstasy use. The sample comprised 8500 twins and siblings aged between 18 and 45 years from 5402 families registered at the Netherlands Twin Registry. In 2013-2014 participants filled out a questionnaire including a question whether they had ever used ecstasy. We used the classical twin design to partition the individual differences in liability to ecstasy use into that due to genetic, shared environmental, and residual components. Overall, 10.4% of the sample had used ecstasy during their lifetime, with a somewhat higher prevalence in males than females. Twin modelling indicated that individual differences in liability to lifetime ecstasy use are for 74% due to genetic differences between individuals, whereas shared environmental and residual factors explain a small proportion of its liability (5% and 21%, respectively). Although heritability estimates appeared to be higher for females than males, this difference was not significant. Lifetime ecstasy use is a highly heritable trait, which indicates that some people are genetically more vulnerable to start using ecstasy than others. Copyright © 2017. Published by Elsevier B.V.

  19. Nuclear Power Plant Lifetime Management Study (I)

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Sung Yull; Jeong, Ill Seok; Jang, Chang Heui; Song, Taek Ho; Song, Woo Young [Korea Electric Power Research Institute, Taejon (Korea, Republic of); Jin, Tae Eun [Korea Power Engineering Company Consulting and Architecture Engineers, (Korea, Republic of); Kim, Woo Chul [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1997-12-31

    As the operation-year of nuclear power plant increases and finding sites for new nuclear power plant becomes harder, a comprehensive and systematic nuclear plant lifetime management(PLIM) program including life extension has to be established for stable and safe supply of electricity. A feasibility study was conducted to systematically evaluate technical, economic and regulatory aspect of plant lifetime managements and plant life extension for Kori-1 nuclear power plant. For technical evaluation of nuclear power plant, 13 major components were selected for lifetime evaluation by screening system. structure, and components(SSCs) of the plant. It was found that except reactor pressure vessel, which needs detailed integrity analysis, and low pressure turbine, which is scheduled to be replaced, 11 out of 13 major components have sufficient service life, for more than 40 years. Because domestic rules and regulations related to license renewal has not yet been written, review on the regulatory aspect of life extensions was conducted using US NRC rules and regulations. A cooperative effort with nuclear regulatory body is needed for early completion of license renewal rules and regulations. For economic evaluation of plant lifetime extension, a computer program was developed and used. It was found that 10 to 20 year of extension operation of Kori-1 nuclear power plant was proved. Based on the results, next phase of plant lifetime management program for detailed lifetime evaluation and presenting detailed implementation schedule for plant refurbishment for lifetime extension should be followed. (author). 74 refs., figs.

  20. Nuclear Power Plant Lifetime Management Study (I)

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Sung Yull; Jeong, Ill Seok; Jang, Chang Heui; Song, Taek Ho; Song, Woo Young [Korea Electric Power Research Institute, Taejon (Korea, Republic of); Jin, Tae Eun [Korea Power Engineering Company Consulting and Architecture Engineers, (Korea, Republic of); Kim, Woo Chul [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1996-12-31

    As the operation-year of nuclear power plant increases and finding sites for new nuclear power plant becomes harder, a comprehensive and systematic nuclear plant lifetime management(PLIM) program including life extension has to be established for stable and safe supply of electricity. A feasibility study was conducted to systematically evaluate technical, economic and regulatory aspect of plant lifetime managements and plant life extension for Kori-1 nuclear power plant. For technical evaluation of nuclear power plant, 13 major components were selected for lifetime evaluation by screening system. structure, and components(SSCs) of the plant. It was found that except reactor pressure vessel, which needs detailed integrity analysis, and low pressure turbine, which is scheduled to be replaced, 11 out of 13 major components have sufficient service life, for more than 40 years. Because domestic rules and regulations related to license renewal has not yet been written, review on the regulatory aspect of life extensions was conducted using US NRC rules and regulations. A cooperative effort with nuclear regulatory body is needed for early completion of license renewal rules and regulations. For economic evaluation of plant lifetime extension, a computer program was developed and used. It was found that 10 to 20 year of extension operation of Kori-1 nuclear power plant was proved. Based on the results, next phase of plant lifetime management program for detailed lifetime evaluation and presenting detailed implementation schedule for plant refurbishment for lifetime extension should be followed. (author). 74 refs., figs.

  1. Both Hemophilia Health Care Providers and Hemophilia A Carriers Report that Carriers have Excessive Bleeding

    Science.gov (United States)

    Paroskie, Allison; Oso, Olatunde; DeBaun, Michael R.; Sidonio, Robert F

    2014-01-01

    Introduction Hemophilia A, the result of reduced factor VIII (FVIII) activity, is an X-linked recessive bleeding disorder. Previous reports of Hemophilia A carriers suggest an increased bleeding tendency. Our objective was to determine the attitudes and understanding of the Hemophilia A carrier bleeding phenotype, and opinions regarding timing of carrier testing from the perspective of both medical providers and affected patients. Data from this survey was used as preliminary data for an ongoing prospective study. Material and Methods An electronic survey was distributed to physicians and nurses employed at Hemophilia Treatment Centers (HTC), and Hemophilia A carriers who were members of Hemophilia Federation of America. Questions focused on the clinical understanding of bleeding symptoms and management of Hemophilia A carriers, and the timing and intensity of carrier testing. Results Our survey indicates that 51% (36/51) of providers compared to 78% (36/46) of carriers believe that Hemophilia A carriers with normal FVIII activity have an increased bleeding tendency (pHemophilia A carriers report a high frequency of bleeding symptoms. Regarding carrier testing, 72% (50/69) of medical providers recommend testing after 14 years of age, conversely 65% (29/45) of Hemophilia A carriers prefer testing to be done prior to this age (pHemophilia A carriers self-report a higher frequency of bleeding than previously acknowledged, and have a preference for earlier testing to confirm carrier status. PMID:24309601

  2. Vibrational lifetimes of protein amide modes

    International Nuclear Information System (INIS)

    Peterson, K.A.; Rella, C.A.

    1995-01-01

    Measurement of the lifetimes of vibrational modes in proteins has been achieved with a single frequency infrared pump-probe technique using the Stanford Picosecond Free-electron Laser, These are the first direct measurements of vibrational dynamics in the polyamide structure of proteins. In this study, modes associated with the protein backbone are investigated. Results for the amide I band, which consists mainly of the stretching motion of the carbonyl unit of the amide linkage, show that relaxation from the first vibrational excited level (v=1) to the vibrational ground state (v=0) occurs within 1.5 picoseconds with apparent first order kinetics. Comparison of lifetimes for myoglobin and azurin, which have differing secondary structures, show a small but significant difference. The lifetime for the amide I band of myoglobin is 300 femtoseconds shorter than for azurin. Further measurements are in progress on other backbone vibrational modes and on the temperature dependence of the lifetimes. Comparison of vibrational dynamics for proteins with differing secondary structure and for different vibrational modes within a protein will lead to a greater understanding of energy transfer and dissipation in biological systems. In addition, these results have relevance to tissue ablation studies which have been conducted with pulsed infrared lasers. Vibrational lifetimes are necessary for calculating the rate at which the energy from absorbed infrared photons is converted to equilibrium thermal energy within the irradiated volume. The very fast vibrational lifetimes measured here indicate that mechanisms which involve direct vibrational up-pumping of the amide modes with consecutive laser pulses, leading to bond breakage or weakening, are not valid

  3. Photovoltaic investigation of minority carrier lifetime in the heavily-doped emitter layer of silicon junction solar cell

    Science.gov (United States)

    Ho, C.-T.

    1982-01-01

    The results of experiments on the recombination lifetime in a phosphorus diffused N(+) layer of a silicon solar cell are reported. The cells studied comprised three groups of Czochralski grown crystals: boron doped to one ohm-cm, boron doped to 6 ohm-cm, and aluminum doped to one ohm-cm, all with a shunt resistance exceeding 500 kilo-ohms. The characteristic bulk diffusion length of a cell sample was determined from the short circuit current response to light at a wavelength of one micron. The recombination rates were obtained by measurement of the open circuit voltage as a function of the photogeneration rate. The recombination rate was found to be dependent on the photoinjection level, and is positive-field controlled at low photoinjection, positive-field influence Auger recombination at a medium photoinjection level, and negative-field controlled Auger recombination at a high photoinjection level.

  4. Spectrally-resolved internal quantum efficiency and carrier dynamics of semipolar (10\\bar{1}1) core-shell triangular nanostripe GaN/InGaN LEDs

    Science.gov (United States)

    Okur, Serdal; Rishinaramangalam, Ashwin K.; Mishkat-Ul-Masabih, Saadat; Nami, Mohsen; Liu, Sheng; Brener, Igal; Brueck, Steven R. J.; Feezell, Daniel F.

    2018-06-01

    We investigate the spectrally resolved internal quantum efficiency (IQE) and carrier dynamics in semipolar (10\\bar{1}1) core–shell triangular nanostripe light-emitting diodes (TLEDs) using temperature-dependent photoluminescence (TDPL) and time-resolved photoluminescence (TRPL) at various excitation energy densities. Using electroluminescence, photoluminescence, and cathodoluminescence measurements, we verify the origins of the broad emission spectra from the nanostructures and confirm that localized regions of high-indium-content InGaN exist along the apex of the nanostructures. Spectrally resolved IQE measurements are then performed, with the spectra integrated from 400–450 nm and 450–500 nm to obtain the IQE of the QWs mainly near the sidewalls and apex of the TLEDs, respectively. TDPL and TRPL are used to decouple the radiative and non-radiative carrier lifetimes for different regions of the emission spectra. We observe that the IQE is higher for the spectral region between 450 nm and 500 nm compared to the IQE between 400 and 450 nm. This result is in contrast to the typical observation that the IQE of planar GaN-based LEDs is lower for longer wavelengths (i.e., higher indium contents). We also observe a longer non-radiative recombination lifetime for the longer wavelength portion of the spectrum. Several explanations are proposed for the improved IQE and longer non-radiative lifetime observed near the apex of the nanostructures. The results show that nanostructures may be leveraged to design more efficient green LEDs, potentially addressing a long-standing challenge in GaN-based materials.

  5. Improved b lifetime measurement from MAC

    International Nuclear Information System (INIS)

    Ford, W.T.

    1984-03-01

    Two recent publications, from the MAC and Mark II collaborations, have reported the somewhat surprising result that the lifetime of particles made up of b quarks is in the 1 to 2 picosecond range, or somewhat longer than the lifetimes of charm particles. Although the charm decays are favored transitions while those of b particles depend upon off-diagonal elements of the weak flavor mixing matrix, the smallness of the b decay rates in face of the large available phase space indicates that the off-diagonal elements are indeed very small. The possibility for complete determination of the mixing matrix was brought significantly nearer by the availability of the lifetime information; what is needed now is to reduce the uncertainty of the measurements, which was about 33% for both experiments. We describe here an extension of the b lifetime study with the MAC detector, incorporating some new data and improvements in the analysis. 12 references

  6. Cosmological constraints on the neutron lifetime

    Energy Technology Data Exchange (ETDEWEB)

    Salvati, L.; Pagano, L.; Melchiorri, A. [Physics Department, Università di Roma ' ' La Sapienza' ' , Piazzale Aldo Moro 2, 00185, Rome (Italy); Consiglio, R., E-mail: laura.salvati@roma1.infn.it, E-mail: luca.pagano@roma1.infn.it, E-mail: rconsiglio@na.infn.it, E-mail: alessandro.melchiorri@roma1.infn.it [Physics Department, Università di Napoli ' ' Federico II' ' , Complesso Universitario Monte S. Angelo, Via Cintia, I-80126 Napoli (Italy)

    2016-03-01

    We derive new constraints on the neutron lifetime based on the recent Planck 2015 observations of temperature and polarization anisotropies of the CMB. Under the assumption of standard Big Bang Nucleosynthesis, we show that Planck data constrains the neutron lifetime to τ{sub n} = (907±69) [s] at 68% c.l.. Moreover, by including the direct measurements of primordial Helium abundance of Aver et al. (2015) and Izotov et al. (2014), we show that cosmological data provide the stringent constraints τ{sub n} = (875±19) [s] and τ{sub n} = (921±11) [s] respectively. The latter appears to be in tension with neutron lifetime value quoted by the Particle Data Group (τ{sub n} = (880.3±1.1) [s]). Future CMB surveys as COrE+, in combination with a weak lensing survey as EUCLID, could constrain the neutron lifetime up to a ∼ 6 [s] precision.

  7. InP quantum dots embedded in GaP: Optical properties and carrier dynamics

    International Nuclear Information System (INIS)

    Hatami, F.; Masselink, W.T.; Schrottke, L.; Tomm, J.W.; Talalaev, V.; Kristukat, C.; Goni, A.R.

    2003-01-01

    The optical emission and dynamics of carriers in Stranski-Krastanow self-organized InP quantum dots embedded in a GaP matrix are studied. InP deposited on GaP (001) using gas-source molecular-beam epitaxy forms quantum dots for InP coverage greater than 1.8 monolayers. Strong photoluminescence from the quantum dots is observed up to room temperature at about 2 eV; photoluminescence from the two-dimensional InP wetting layer is measured at about 2.2 eV. Modeling based on the 'model-solid theory' indicates that the band alignment for the InP quantum dots is direct and type I. Furthermore, low-temperature time-resolved photoluminescence measurements indicate that the carrier lifetime in the quantum dots is about 2 ns, typical for type-I quantum dots. Pressure-dependent photoluminescence measurements provide further evidence for a type-I band alignment for InP/GaP quantum dots at normal pressure with the GaP X states lying about 30 meV higher than the Γ states in the InP quantum dots, but indicate that they become type II under hydrostatic pressures of about 1.2 GPa

  8. Lifetime measurement of ATF damping ring

    International Nuclear Information System (INIS)

    Okugi, T.; Hayano, H.; Kubo, K.; Naito, T.; Terunuma, N.; Urakawa, J.; Zimmermann, F.

    1998-06-01

    The purpose of the ATF damping ring is the development of technologies for producing a low emittance beam required in future linear colliders such as JLC. The lifetime of the damping ring is very short (typically a few minutes). It is limited by elastic beam-gas scattering along with a small dynamic aperture, and by single intra-beam scattering (Touschek effect). The Touschek lifetime strongly depends upon the charge density of the beam, especially, the size of the vertical emittance. In this paper, the authors report the results of beam lifetime measurements in the ATF damping ring and the estimation of the vertical emittance from these measurements

  9. Lifetime measurements of hadrons containing heavy quarks

    International Nuclear Information System (INIS)

    Forden, G.E.

    1985-01-01

    Recent lifetime measurements of heavy particles at PETRA and PEP are reviewed. A comparison of the methods used is given. The world averages for the lifetimes of the D 0 and D +- mesons are found to be (tau/dub D/ 0 ) - 3.97 +/- 0.3 x 10 -13 sec and (tau/dub D +-/) = 8.6 +/- 0.7 x 10 -13 sec. This difference in lifetimes is discussed in light of recent information about exclusive decays. The world average for the lifetime of bottom hadrons is determined to be (tau/sub b/) = 11.0 +/- 1.5 x 10 -13 sec and new estimates for the b quark mixing elements, absolute value V/sub bu/ and absolute value V/sub bc/, are given

  10. Maximizing System Lifetime by Battery Scheduling

    NARCIS (Netherlands)

    Jongerden, M.R.; Haverkort, Boudewijn R.H.M.; Bohnenkamp, H.C.; Katoen, Joost P.

    2009-01-01

    The use of mobile devices is limited by the battery lifetime. Some devices have the option to connect an extra battery, or to use smart battery-packs with multiple cells to extend the lifetime. In these cases, scheduling the batteries over the load to exploit recovery properties usually extends the

  11. Lifetime obtained by ion beam assisted deposition

    Energy Technology Data Exchange (ETDEWEB)

    Chakaroun, M. [XLIM-MINACOM-UMR 6172, Faculte des Sciences et Techniques, 123 av. Albert Thomas, 87060 Limoges cedex (France); Antony, R. [XLIM-MINACOM-UMR 6172, Faculte des Sciences et Techniques, 123 av. Albert Thomas, 87060 Limoges cedex (France)], E-mail: remi.antony@unilim.fr; Taillepierre, P.; Moliton, A. [XLIM-MINACOM-UMR 6172, Faculte des Sciences et Techniques, 123 av. Albert Thomas, 87060 Limoges cedex (France)

    2007-09-15

    We have fabricated green organic light-emitting diodes based on tris-(8-hydroxyquinoline)aluminium (Alq3) thin films. In order to favor the charge carriers transport from the anode, we have deposited a N,N'-diphenyl-N,N'-bis (3-methylphenyl)-1,1'-diphenyl-4,4'-diamine (TPD) layer (hole transport layer) on a ITO anode. Cathode is obtained with a calcium layer covered with a silver layer. This silver layer is used to protect the other layers against oxygen during the OLED use. All the depositions are performed under vacuum and the devices are not exposed to air during their realisation. In order to improve the silver layer characteristics, we have realized this layer with the ion beam assisted deposition process. The aim of this process is to densify the layer and then reduce the permeation of H{sub 2}O and O{sub 2}. We have used argon ions to assist the silver deposition. All the OLEDs optoelectronic characterizations (I = f(V), L = f(V)) are performed in the ambient air. We compare the results obtained with the assisted layer with those obtained with a classical cathode realized by thermal unassisted evaporation. We have realized lifetime measurements in the ambient air and we discuss about the assisted layer influence on the OLEDs performances.

  12. Improving, characterizing and predicting the lifetime of organic photovoltaics

    DEFF Research Database (Denmark)

    Gevorgyan, Suren A.; Heckler, Ilona Maria; Bundgaard, Eva

    2017-01-01

    This review summarizes the recent progress in the stability and lifetime of organic photovoltaics (OPVs). In particular, recently proposed solutions to failure mechanisms in different layers of the device stack are discussed comprising both structural and chemical modifications. Upscaling...... characterization reported recently. Lifetime testing and determination is another challenge in the field of organic solar cells and the final sections of this review discuss the testing protocols as well as the generic marker for device lifetime and the methodology for comparing all the lifetime landmarks in one...... common diagram. These tools were used to determine the baselines for OPV lifetime tested under different ageing conditions. Finally, the current status of lifetime for organic solar cells is presented and predictions are made for progress in the near future....

  13. Sealed substrate carrier for electroplating

    Science.gov (United States)

    Ganti, Kalyana Bhargava [Fremont, CA

    2012-07-17

    One embodiment relates to a substrate carrier for use in electroplating a plurality of substrates. The substrate carrier includes a non-conductive carrier body on which the substrates are held, and conductive lines are embedded within the carrier body. A conductive bus bar is embedded into a top side of the carrier body and is conductively coupled to the conductive lines. A thermoplastic overmold covers a portion of the bus bar, and there is a plastic-to-plastic bond between the thermoplastic overmold and the non-conductive carrier body. Other embodiments, aspects and features are also disclosed.

  14. Cancer risk in MLH1, MSH2 and MSH6 mutation carriers; different risk profiles may influence clinical management

    Directory of Open Access Journals (Sweden)

    Ramsoekh Dewkoemar

    2009-12-01

    Full Text Available Abstract Background Lynch syndrome (LS is associated with a high risk for colorectal cancer (CRC and extracolonic malignancies, such as endometrial carcinoma (EC. The risk is dependent of the affected mismatch repair gene. The aim of the present study was to calculate the cumulative risk of LS related cancers in proven MLH1, MSH2 and MSH6 mutation carriers. Methods The studypopulation consisted out of 67 proven LS families. Clinical information including mutation status and tumour diagnosis was collected. Cumulative risks were calculated and compared using Kaplan Meier survival analysis. Results MSH6 mutation carriers, both males and females had the lowest risk for developing CRC at age 70 years, 54% and 30% respectively and the age of onset was delayed by 3-5 years in males. With respect to endometrial carcinoma, female MSH6 mutation carriers had the highest risk at age 70 years (61% compared to MLH1 (25% and MSH2 (49%. Also, the age of EC onset was delayed by 5-10 years in comparison with MLH1 and MSH2. Conclusions Although the cumulative lifetime risk of LS related cancer is similar, MLH1, MSH2 and MSH6 mutations seem to cause distinguishable cancer risk profiles. Female MSH6 mutation carriers have a lower CRC risk and a higher risk for developing endometrial carcinoma. As a consequence, surveillance colonoscopy starting at age 30 years instead of 20-25 years is more suitable. Also, prophylactic hysterectomy may be more indicated in female MSH6 mutation carriers compared to MLH1 and MSH2 mutation carriers.

  15. Refractive index sensing using Fluorescence Lifetime Imaging (FLIM)

    International Nuclear Information System (INIS)

    Jones, Carolyn; Suhling, Klaus

    2006-01-01

    The fluorescence lifetime is a function of the refractive index of the fluorophore's environment, for example in the case of the biologically important green fluorescent protein (GFP). In order to address the question whether this effect can be exploited to image the local environment of specific proteins in cell biology, we need to determine the distance over which the fluorophore's lifetime is sensitive to the refractive index. To this end, we employ Fluorescence Lifetime Imaging (FLIM) of fluorescein in NaOH buffer at an interface. This approach allows us to map the fluorescence lifetime as a function of distance from a buffer/air and buffer/oil interface. Preliminary data show that the fluorescence lifetime of fluorescein increases near a buffer/air interface and decreases near a buffer/oil interface. The range over which this fluorescence lifetime change occurs is found to be of the order several μm which is consistent with a theoretical model based on the full width at half maximum of the emission spectrum proposed by Toptygin

  16. Exits in order: How crowding affects particle lifetimes

    Energy Technology Data Exchange (ETDEWEB)

    Penington, Catherine J.; Simpson, Matthew J. [School of Mathematical Sciences, Queensland University of Technology, Brisbane (Australia); Baker, Ruth E. [Mathematical Institute, University of Oxford, Radcliffe Observatory Quarter, Woodstock Road, Oxford (United Kingdom)

    2016-06-28

    Diffusive processes are often represented using stochastic random walk frameworks. The amount of time taken for an individual in a random walk to intersect with an absorbing boundary is a fundamental property that is often referred to as the particle lifetime, or the first passage time. The mean lifetime of particles in a random walk model of diffusion is related to the amount of time required for the diffusive process to reach a steady state. Mathematical analysis describing the mean lifetime of particles in a standard model of diffusion without crowding is well known. However, the lifetime of agents in a random walk with crowding has received much less attention. Since many applications of diffusion in biology and biophysics include crowding effects, here we study a discrete model of diffusion that incorporates crowding. Using simulations, we show that crowding has a dramatic effect on agent lifetimes, and we derive an approximate expression for the mean agent lifetime that includes crowding effects. Our expression matches simulation results very well, and highlights the importance of crowding effects that are sometimes overlooked.

  17. Carrier-carrier relaxation kinetics in quantum well semiconductor structures with nonparabolic energy bands

    DEFF Research Database (Denmark)

    Dery, H.; Tromborg, Bjarne; Eisenstein, G.

    2003-01-01

    We describe carrier-carrier scattering dynamics in an inverted quantum well structure including the nonparabolic nature of the valance band. A solution of the semiconductor Bloch equations yields strong evidence to a large change in the temporal evolution of the carrier distributions compared to ...

  18. Positron annihilation lifetime in float-zone n-type silicon irradiated by fast electrons: a thermally stable vacancy defect

    International Nuclear Information System (INIS)

    Arutyunov, Nikolay; Emtsev, Vadim; Oganesyan, Gagik; Krause-Rehberg, Reinhard; Elsayed, Mohamed; Kozlovskii, Vitalii

    2016-01-01

    Temperature dependency of the average positron lifetime has been investigated for n-type float-zone silicon, n-FZ-Si(P), subjected to irradiation with 0.9 MeV electrons at RT. In the course of the isochronal annealing a new defect-related temperature-dependent pattern of the positron lifetime spectra has been revealed. Beyond the well known intervals of isochronal annealing of acceptor-like defects such as E-centers, divacancies and A-centers, the positron annihilation at the vacancy defects has been observed in the course of the isochronal annealing from ∝ 320 C up to the limit of reliable detecting of the defect-related positron annihilation lifetime at ≥ 500 C. These data correlate with the ones of recovery of the concentration of the charge carriers and their mobility which is found to continue in the course of annealing to ∝ 570 C; the annealing is accomplished at ∝650 C. A thermally stable complex consisting of the open vacancy volume and the phosphorus impurity atom, V_o_p-P, is suggested as a possible candidate for interpreting the data obtained by the positron annihilation lifetime spectroscopy. An extended couple of semi-vacancies, 2V_s_-_e_x_t, as well as a relaxed inwards a couple of vacancies, 2V_i_n_w, are suggested as the open vacancy volume V_o_p to be probed with the positron. It is argued that a high thermal stability of the V_s_-_e_x_t PV_s_-_e_x_t (or V_i_n_wPV_i_n_w_.) configuration is contributed by the efficiency of PSi_5 bonding. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. 29 CFR 1201.1 - Carrier.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 4 2010-07-01 2010-07-01 false Carrier. 1201.1 Section 1201.1 Labor Regulations Relating to Labor (Continued) NATIONAL MEDIATION BOARD DEFINITIONS § 1201.1 Carrier. The term carrier includes any express company, sleeping car company, carrier by railroad, subject to the Interstate Commerce Act...

  20. Organic scintillators with long luminescent lifetimes for radiotherapy dosimetry

    DEFF Research Database (Denmark)

    Beierholm, Anders Ravnsborg; Lindvold, Lars René; Andersen, Claus Erik

    2011-01-01

    of experiments performed using two organic scintillators, one commercially available and one custom made. The luminescent lifetimes of the scintillators have been measured using i) optical excitation by pulsed UV light, and ii) irradiative excitation using high-energy X-rays from a linac. A luminescent lifetime...... component on the order of 20 μs was estimated for the custom-made organic scintillator, while the commercial scintillator exhibited a fast component of approximately 5 ns lifetime (7 ns as stated by the manufacturer) and an approximate 10 μs lifetime slow component. Although these lifetimes are not long...

  1. Measurement of the $\\tau$ lepton lifetime

    CERN Document Server

    Buskulic, Damir; De Bonis, I; Décamp, D; Ghez, P; Goy, C; Lees, J P; Lucotte, A; Minard, M N; Odier, P; Pietrzyk, B; Ariztizabal, F; Chmeissani, M; Crespo, J M; Efthymiopoulos, I; Fernández, E; Fernández-Bosman, M; Gaitan, V; Garrido, L; Martínez, M; Orteu, S; Pacheco, A; Padilla, C; Palla, Fabrizio; Pascual, A; Perlas, J A; Sánchez, F; Teubert, F; Colaleo, A; Creanza, D; De Palma, M; Farilla, A; Gelao, G; Girone, M; Iaselli, Giuseppe; Maggi, G; Maggi, M; Marinelli, N; Natali, S; Nuzzo, S; Ranieri, A; Raso, G; Romano, F; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Bonvicini, G; Cattaneo, M; Comas, P; Coyle, P; Drevermann, H; Engelhardt, A; Forty, Roger W; Frank, M; Hagelberg, R; Harvey, J; Jacobsen, R; Janot, P; Jost, B; Kneringer, E; Knobloch, J; Lehraus, Ivan; Markou, C; Martin, E B; Mato, P; Minten, Adolf G; Miquel, R; Oest, T; Palazzi, P; Pater, J R; Pusztaszeri, J F; Ranjard, F; Rensing, P E; Rolandi, Luigi; Schlatter, W D; Schmelling, M; Schneider, O; Tejessy, W; Tomalin, I R; Venturi, A; Wachsmuth, H W; Wiedenmann, W; Wildish, T; Witzeling, W; Wotschack, J; Ajaltouni, Ziad J; Bardadin-Otwinowska, Maria; Barrès, A; Boyer, C; Falvard, A; Gay, P; Guicheney, C; Henrard, P; Jousset, J; Michel, B; Monteil, S; Pallin, D; Perret, P; Podlyski, F; Proriol, J; Rossignol, J M; Saadi, F; Fearnley, Tom; Hansen, J B; Hansen, J D; Hansen, J R; Hansen, P H; Nilsson, B S; Kyriakis, A; Simopoulou, Errietta; Siotis, I; Vayaki, Anna; Zachariadou, K; Blondel, A; Bonneaud, G R; Brient, J C; Bourdon, P; Passalacqua, L; Rougé, A; Rumpf, M; Tanaka, R; Valassi, Andrea; Verderi, M; Videau, H L; Candlin, D J; Parsons, M I; Focardi, E; Parrini, G; Corden, M; Delfino, M C; Georgiopoulos, C H; Jaffe, D E; Antonelli, A; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Chiarella, V; Felici, G; Laurelli, P; Mannocchi, G; Murtas, F; Murtas, G P; Pepé-Altarelli, M; Dorris, S J; Halley, A W; ten Have, I; Knowles, I G; Lynch, J G; Morton, W T; O'Shea, V; Raine, C; Reeves, P; Scarr, J M; Smith, K; Smith, M G; Thompson, A S; Thomson, F; Thorn, S; Turnbull, R M; Becker, U; Braun, O; Geweniger, C; Graefe, G; Hanke, P; Hepp, V; Kluge, E E; Putzer, A; Rensch, B; Schmidt, M; Sommer, J; Stenzel, H; Tittel, K; Werner, S; Wunsch, M; Beuselinck, R; Binnie, David M; Cameron, W; Colling, D J; Dornan, Peter J; Konstantinidis, N P; Moneta, L; Moutoussi, A; Nash, J; San Martin, G; Sedgbeer, J K; Stacey, A M; Dissertori, G; Girtler, P; Kuhn, D; Rudolph, G; Bowdery, C K; Brodbeck, T J; Colrain, P; Crawford, G; Finch, A J; Foster, F; Hughes, G; Sloan, Terence; Whelan, E P; Williams, M I; Galla, A; Greene, A M; Kleinknecht, K; Quast, G; Raab, J; Renk, B; Sander, H G; Wanke, R; Van Gemmeren, P; Zeitnitz, C; Aubert, Jean-Jacques; Bencheikh, A M; Benchouk, C; Bonissent, A; Bujosa, G; Calvet, D; Carr, J; Diaconu, C A; Etienne, F; Thulasidas, M; Nicod, D; Payre, P; Rousseau, D; Talby, M; Abt, I; Assmann, R W; Bauer, C; Blum, Walter; Brown, D; Dietl, H; Dydak, Friedrich; Ganis, G; Gotzhein, C; Jakobs, K; Kroha, H; Lütjens, G; Lutz, Gerhard; Männer, W; Moser, H G; Richter, R H; Rosado-Schlosser, A; Schael, S; Settles, Ronald; Seywerd, H C J; Saint-Denis, R; Wolf, G; Alemany, R; Boucrot, J; Callot, O; Cordier, A; Courault, F; Davier, M; Duflot, L; Grivaz, J F; Heusse, P; Jacquet, M; Kim, D W; Le Diberder, F R; Lefrançois, J; Lutz, A M; Musolino, G; Nikolic, I A; Park, H J; Park, I C; Schune, M H; Simion, S; Veillet, J J; Videau, I; Abbaneo, D; Azzurri, P; Bagliesi, G; Batignani, G; Bettarini, S; Bozzi, C; Calderini, G; Carpinelli, M; Ciocci, M A; Ciulli, V; Dell'Orso, R; Fantechi, R; Ferrante, I; Fidecaro, F; Foà, L; Forti, F; Giassi, A; Giorgi, M A; Gregorio, A; Ligabue, F; Lusiani, A; Marrocchesi, P S; Messineo, A; Rizzo, G; Sanguinetti, G; Sciabà, A; Spagnolo, P; Steinberger, Jack; Tenchini, Roberto; Tonelli, G; Triggiani, G; Vannini, C; Verdini, P G; Walsh, J; Betteridge, A P; Blair, G A; Bryant, L M; Cerutti, F; Gao, Y; Green, M G; Johnson, D L; Medcalf, T; Mir, L M; Perrodo, P; Strong, J A; Bertin, V; Botterill, David R; Clifft, R W; Edgecock, T R; Haywood, S; Edwards, M; Maley, P; Norton, P R; Thompson, J C; Bloch-Devaux, B; Colas, P; Emery, S; Kozanecki, Witold; Lançon, E; Lemaire, M C; Locci, E; Marx, B; Pérez, P; Rander, J; Renardy, J F; Roussarie, A; Schuller, J P; Schwindling, J; Trabelsi, A; Vallage, B; Johnson, R P; Kim, H Y; Litke, A M; McNeil, M A; Taylor, G; Beddall, A; Booth, C N; Boswell, R; Cartwright, S L; Combley, F; Dawson, I; Köksal, A; Letho, M; Newton, W M; Rankin, C; Thompson, L F; Böhrer, A; Brandt, S; Cowan, G D; Feigl, E; Grupen, Claus; Lutters, G; Minguet-Rodríguez, J A; Rivera, F; Saraiva, P; Smolik, L; Stephan, F; Apollonio, M; Bosisio, L; Della Marina, R; Giannini, G; Gobbo, B; Ragusa, F; Rothberg, J E; Wasserbaech, S R; Armstrong, S R; Bellantoni, L; Elmer, P; Feng, Z; Ferguson, D P S; Gao, Y S; González, S; Grahl, J; Harton, J L; Hayes, O J; Hu, H; McNamara, P A; Nachtman, J M; Orejudos, W; Pan, Y B; Saadi, Y; Schmitt, M; Scott, I J; Sharma, V; Turk, J; Walsh, A M; Wu Sau Lan; Wu, X; Yamartino, J M; Zheng, M; Zobernig, G

    1996-01-01

    The mean lifetime of the \\tau lepton is measured in a sample of 25700 \\tau pairs collected in 1992 with the ALEPH detector at LEP. A new analysis of the 1-1 topology events is introduced. In this analysis, the dependence of the impact parameter sum distribution on the daughter track momenta is taken into account, yielding improved precision compared to other impact parameter sum methods. Three other analyses of the one- and three-prong \\tau decays are updated with increased statistics. The measured lifetime is 293.5 \\pm 3.1 \\pm 1.7 \\fs. Including previous (1989--1991) ALEPH measurements, the combined \\tau lifetime is 293.7 \\pm 2.7 \\pm 1.6 \\fs.

  2. Characterisation of multicrystalline silicon solar cells. Development of characterisation method for the combined effect of dislocations and grain boundaries on the minority carrier lifetime

    Energy Technology Data Exchange (ETDEWEB)

    Stokkan, Gaute

    2004-07-01

    The thesis has sections on theoretical background, mathematical models, experimental work such as lifetime measurements, dislocation density and grain boundary mapping, simulation of electrical activity mapping and conclusions and future work. Various mathematical models and nafion surface passivation are studied as well.

  3. Study of the Bulk Charge Carrier Dynamics in Anatase and Rutile TiO2 Single Crystals by Femtosecond Time Resolved Spectroscopy

    KAUST Repository

    Maity, Partha

    2018-04-02

    Understanding of the fundamentals behind charge carriers of photo-catalytic materials are still illusive hindering progress in our quest for renewable energy. TiO2 anatase and rutile are the most understood phases in photo-catalysis and serve as the best model for fundamental studies. Their ultrafast charge carrier dynamics especially on TiO2 anatase single crystal (the most active phase) are unresolved. Here femtosecond time resolved spectroscopy (TRS) was carried out to explore the dynamics of photo-excited charge carriers’ recombination in anatase single crystal, for the first time using pump fluence effects, and compares it to that of the rutile single crystal. A significant difference in charge carrier recombination rates between both crystals is observed. We found that the time constants for carrier recombination are two orders of magnitude slower for anatase (101) when compared to those of rutile (110). Moreover, bulk defects introduced by reduction of the samples via annealing in ultra-high vacuum resulted in faster recombination rates for both polymorphs. Both states (fresh and reduced) probed by pump fluence dependence measurements revealed that the major recombination channel in fresh and reduced anatase and reduced rutile is the first-order Shockley–Reed mediated. However, for fresh rutile, third-body Auger recombination was observed, attributed to the presence of higher density of intrinsic charge carriers. At all excitation wavelengths and fluence investigated, anatase (101) single crystal show longer charge carrier lifetime when compared to rutile (110) single. This may explain the superiority of the anatase phase for the electron transfer H+ reduction to molecular hydrogen.

  4. A Satellite Mortality Study to Support Space Systems Lifetime Prediction

    Science.gov (United States)

    Fox, George; Salazar, Ronald; Habib-Agahi, Hamid; Dubos, Gregory

    2013-01-01

    Estimating the operational lifetime of satellites and spacecraft is a complex process. Operational lifetime can differ from mission design lifetime for a variety of reasons. Unexpected mortality can occur due to human errors in design and fabrication, to human errors in launch and operations, to random anomalies of hardware and software or even satellite function degradation or technology change, leading to unrealized economic or mission return. This study focuses on data collection of public information using, for the first time, a large, publically available dataset, and preliminary analysis of satellite lifetimes, both operational lifetime and design lifetime. The objective of this study is the illustration of the relationship of design life to actual lifetime for some representative classes of satellites and spacecraft. First, a Weibull and Exponential lifetime analysis comparison is performed on the ratio of mission operating lifetime to design life, accounting for terminated and ongoing missions. Next a Kaplan-Meier survivor function, standard practice for clinical trials analysis, is estimated from operating lifetime. Bootstrap resampling is used to provide uncertainty estimates of selected survival probabilities. This study highlights the need for more detailed databases and engineering reliability models of satellite lifetime that include satellite systems and subsystems, operations procedures and environmental characteristics to support the design of complex, multi-generation, long-lived space systems in Earth orbit.

  5. Positron lifetime study of neutron-irradiated molybdenum

    International Nuclear Information System (INIS)

    Hinode, Kenji; Tanigawa, Shoichiro; Kumakura, Hiroaki; Doyama, Masao; Shiraishi, Kensuke.

    1978-01-01

    Annealing behavior of fast-neutron-irradiated molybdenum was studied by means of positron lifetime technique. It was found that Stage III annealing can be mainly identified as the vacancy migration process from the detailed analyses of data. The void growth after successive high temperature annealings was clearly detected through the changes of positron lifetime parameters. An attempt to analyse the size distribution of voids from positron lifetime spectra was presented, and discussions on the evaluation of void concentration from positron data are also given. (author)

  6. Statistical Models and Methods for Lifetime Data

    CERN Document Server

    Lawless, Jerald F

    2011-01-01

    Praise for the First Edition"An indispensable addition to any serious collection on lifetime data analysis and . . . a valuable contribution to the statistical literature. Highly recommended . . ."-Choice"This is an important book, which will appeal to statisticians working on survival analysis problems."-Biometrics"A thorough, unified treatment of statistical models and methods used in the analysis of lifetime data . . . this is a highly competent and agreeable statistical textbook."-Statistics in MedicineThe statistical analysis of lifetime or response time data is a key tool in engineering,

  7. Lifetime assessment and lifetime management for key components of nuclear power plants

    International Nuclear Information System (INIS)

    Dou Yikang; Sun Hanhong; Qu Jiadi

    2000-01-01

    On the bases of investigation on recent development of plant lifetime management in the world, the author gives some points of view on how to establish plant lifetime assessment (PLA) and management (PLM) systems for Chinese nuclear power plants. The main points lie in: 1) safety regulatory organizations, utilities and R and D institutes work cooperatively for PLA and PLM; 2) PLA and PLM make a interdependent cycle, which means that a good PLM system ensures authentic input for PLA, while veritable PLA provides valuable feedback for PLM improvement; 3) PLA and PLM should be initiated for some key components. The author also analyzes some important problems to be tackled in PLA and PLM from the view angle of a R and D institute

  8. Surface passivation and carrier selectivity of the thermal-atomic-layer-deposited TiO2 on crystalline silicon

    DEFF Research Database (Denmark)

    Plakhotnyuk, Maksym; Schüler, Nadine; Shkondin, Evgeniy

    2017-01-01

    Here, we demonstrate the use of an ultrathin TiO2 film as a passivating carrier-selective contact for silicon photovoltaics. The effective lifetime, surface recombination velocity, and diode quality dependence on TiO2 deposition temperature with and without a thin tunneling oxide interlayer (SiO2...... heterojunction with optimized photovoltage, interface quality, and electron extraction to maximize the photovoltage of TiO2–Si heterojunction photovoltaic cells are formulated. Diode behaviour was analysed with the help of experimental, analytical, and simulation methods. It is predicted that TiO2 with a high...

  9. c, b, and tau lifetime measurements in e+e- interactions

    International Nuclear Information System (INIS)

    Jaros, J.A.

    1983-01-01

    Experiments at e + e - storage rings have successfully measured the tau and D 0 lifetimes and set interesting limits on the B lifetime. So far, the conventional wisdom has prevailed. The tau lifetime is consistent with prediction; there is no sign (but little sensitivity) of a violation of universality. The charmed particle lifetimes are roughly as expected, but richer in their phenomenology than anticipated. The B lifetime is still unknown. The experimental art is developing rapidly. Several experiments have by now installed vertex detectors. Measurements of charmed particle lifetimes from e + e - experiments will complement the work that has been done at fixed target machines. Measurements of tau and B lifetimes may be the exclusive province of e + e - experiments for the next few years

  10. LHCb: Measurement of $b$-hadron lifetimes at LHCb

    CERN Multimedia

    Amhis, Y

    2014-01-01

    Lifetimes are among the most fundamental properties of elementary particles. Precision Measurements of $b$-hadron lifetimes are an important tool to test theoretical models such as HQET. These models allow to predict various observables related to B-mixing. Using data collected during Run 1 at the LHC, LHCb measured the lifetime of B-decays including a $J/\\psi$ in the final state.

  11. Differential Analysis of the Nasal Microbiome of Pig Carriers or Non-Carriers of Staphylococcus aureus

    DEFF Research Database (Denmark)

    Espinosa-Gongora, Carmen; Larsen, Niels; Schonning, Kristian

    2016-01-01

    pathogen in animal carriers. The aim of this study was to determine whether the nasal microbiome of pig S. aureus carriers differs from that of non-carriers. The V3-V5 region of the 16S rRNA gene was sequenced from nasal swabs of 44 S. aureus carriers and 56 non-carriers using the 454 GS FLX titanium...... microbiome of pigs that are not colonized with S. aureus harbours several species/taxa that are significantly less abundant in pig carriers, suggesting that the nasal microbiota may play a role in the individual predisposition to S. aureus nasal carriage in pigs. Further research is warranted to isolate...

  12. Measurements of heavy quark and lepton lifetimes

    International Nuclear Information System (INIS)

    Jaros, J.A.

    1985-02-01

    The PEP/PETRA energy range has proved to be well-suited for the study of the lifetimes of hadrons containing the b and c quarks and the tau lepton for several reasons. First, these states comprise a large fraction of the total interaction rate in e + e - annihilation and can be cleanly identified. Second, the storage rings have operated at high luminosity and so produced these exotic states copiously. And finally, thanks to the interplay of the Fermi coupling strength, the quark and lepton masses, and the beam energy, the expected decay lengths are in the 1/2 mm range and so are comparatively easy to measure. This pleasant coincidence of cleanly identified and abundant signal with potentially large effects has made possible the first measurements of two fundamental weak couplings, tau → nu/sub tau/W and b → cW. These measurements have provided a sharp test of the standard model and allowed, for the first time, the full determination of the magnitudes of the quark mixing matrix. This paper reviews the lifetime studies made at PEP during the past year. It begins with a brief review of the three detectors, DELCO, MAC and MARK II, which have reported lifetime measurements. Next it discusses two new measurements of the tau lifetime, and briefly reviews a measurement of the D 0 lifetime. Finally, it turns to measurements of the B lifetime, which are discussed in some detail. 18 references, 14 figures, 1 table

  13. Lifetime measurements of excited Co I levels

    CERN Document Server

    Klotz, W D; Gobel, L H

    1977-01-01

    In the region of 3500 AA the lifetimes of eight excited Cobalt I levels have been measured by means of the zero field level crossing method. The measured lifetimes belong to the odd configurations 3d/sup 7/4s4p and 3d/sup 8/4p and are of the accuracy of about 5%. The hyperfine structure of levels with I not=J has to be taken into account in evaluating lifetimes from level crossing data, because the nuclear spin of the natural isotope /sup 59/Co is I=7/2. Therefore the influence of the line profile of the exciting resonance lines on the lifetimes has been investigated. The results are compared with those of other authors. Furthermore absolute oscillator strengths were calculated with known branching ratios and a new absolute scale has been established. (23 refs).

  14. Personality traits in Huntington's disease: An exploratory study of gene expansion carriers and non-carriers.

    Science.gov (United States)

    Larsen, Ida Unmack; Mortensen, Erik Lykke; Vinther-Jensen, Tua; Nielsen, Jørgen Erik; Knudsen, Gitte Moos; Vogel, Asmus

    2016-12-01

    Huntington's disease (HD) is associated with risk for developing psychiatric symptoms. Vulnerability or resilience to psychiatric symptoms may be associated with personality traits. This exploratory study, aimed to investigate personality traits in a large cohort of HD carriers and at risk gene-expansion negative individuals (HD non-carriers), exploring whether carrying the HD gene or growing up in an HD family influences personality traits. Forty-seven HD carriers, Thirty-nine HD non-carriers, and 121 healthy controls answered the Danish version of the revised NEO personality inventory. Comparisons between HD carriers and HD non-carriers were mostly non-significant but the combined group of HD carriers and non-carriers showed significantly higher scores on the facets: "hostility," "assertiveness," and "activity" and on the trait "Conscientiousness" relative to controls, "Conscientiousness" have been associated with resilience to psychiatric symptoms. Twelve HD carriers and non-carriers were classified as depressed and showed significantly lower scores on "Extraversion" and "Conscientiousness" and significantly higher scores on "Neuroticism," which are associated with vulnerability to psychiatric symptoms. Our findings suggest that, there is no direct effect of the HD gene on personality traits, but that personality assessment may be relevant to use when identifying individuals from HD families who are vulnerable to develop psychiatric symptoms. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  15. Modeling and optimization of membrane lifetime in dead-end ultra filtration

    NARCIS (Netherlands)

    Zondervan, E.; Roffel, B.

    2008-01-01

    In this paper, a membrane lifetime model is developed and experimentally validated. The lifetime model is based on the Weibull probability density function. The lifetime model can be used to determine an unambiguous characteristic membrane lifetime. Experimental results showed that membrane lifetime

  16. Lifetime physical activity and female stress urinary incontinence.

    Science.gov (United States)

    Nygaard, Ingrid E; Shaw, Janet M; Bardsley, Tyler; Egger, Marlene J

    2015-07-01

    We sought to estimate whether moderate/severe stress urinary incontinence (SUI) in middle-aged women is associated with overall lifetime physical activity (including leisure, household, outdoor, and occupational), as well as lifetime leisure (recreational), lifetime strenuous, and strenuous activity during the teen years. Recruitment for this case-control study was conducted in primary-care-level family medicine and gynecology clinics. A total of 1538 enrolled women ages 39-65 years underwent a Pelvic Organ Prolapse Quantification examination to assess vaginal support. Based on Incontinence Severity Index scores, cases had moderate/severe and controls had no/mild SUI. We excluded 349 with vaginal descent at/below the hymen (pelvic organ prolapse), 194 who did not return questionnaires, and 110 with insufficient activity data for analysis. In all, 213 cases were frequency matched 1:1 by age group to controls. Physical activity was measured using the Lifetime Physical Activity Questionnaire, in which women recall activity from menarche to present. We created separate multivariable logistic regression models for activity measures. SUI odds increased slightly with overall lifetime activity (odds ratio [OR], 1.20 per 70 additional metabolic equivalent of task-h/wk; 95% confidence interval [CI], 1.02-1.41), and were not associated with lifetime strenuous activity (OR, 1.11; 95% CI, 0.99-1.25). In quintile analysis of lifetime leisure activity, which demonstrated a nonlinear pattern, all quintiles incurred about half the odds of SUI compared to reference (second quintile; P = .009). Greater strenuous activity in teen years modestly increased SUI odds (OR, 1.37 per 7 additional h/wk; 95% CI, 1.09-1.71); OR, 1.75; 95% CI, 1.15-2.66 in sensitivity analysis adjusting for measurement error. The predicted probability of SUI rose linearly in women exceeding 7.5 hours of strenuous activity/wk during teen years. Teen strenuous activity had a similar effect on SUI odds when

  17. Peptide-Carrier Conjugation

    DEFF Research Database (Denmark)

    Hansen, Paul Robert

    2015-01-01

    To produce antibodies against synthetic peptides it is necessary to couple them to a protein carrier. This chapter provides a nonspecialist overview of peptide-carrier conjugation. Furthermore, a protocol for coupling cysteine-containing peptides to bovine serum albumin is outlined....

  18. Lifetime for the Ti X spectrum

    International Nuclear Information System (INIS)

    Singh, Jagjit; Jha, A K S; Mohan, M

    2010-01-01

    We present configuration interaction calculations for the lifetime of 294 fine-structure levels of the Ti X spectrum in the LSJ coupling scheme. The calculations include all the major correlation effects. The relativistic effects are included by adding the mass correction term, Darwin term and spin-orbit interaction term to the non-relativistic Hamiltonian in the Breit-Pauli approximation. The calculated lifetime values are in very close agreement with other available experimental and theoretical results. We have predicted new lifetime results for levels belonging to 3p 2 3d, 3s 2 4p, 3s3p4s, 3s3p4p and various other configurations of Ti X, where no other theoretical and experimental results are available.

  19. The neutron lifetime experiment PENeLOPE

    Energy Technology Data Exchange (ETDEWEB)

    Schreyer, Wolfgang [Technische Universitaet Muenchen (Germany); Collaboration: PENeLOPE-Collaboration

    2015-07-01

    The neutron lifetime τ{sub n}=880.3±1.1 s is an important parameter in the Standard Model of particle physics and in Big Bang cosmology. Several systematic corrections of previously published results reduced the PDG world average by several σ in the last years and call for a new experiment with complementary systematics. The experiment PENeLOPE, currently under construction at the Physik-Department of Technische Universitaet Muenchen, aims to determine the neutron lifetime with a precision of 0.1 s. It will trap ultra-cold neutrons in a magneto-gravitational trap using a large superconducting magnet and will measure their lifetime by both neutron counting and online proton detection. This presentation gives an overview over the latest developments of the experiment.

  20. Optimizing design of converters using power cycling lifetime models

    DEFF Research Database (Denmark)

    Nielsen, Rasmus Ørndrup; Munk-Nielsen, Stig

    2015-01-01

    Converter power cycling lifetime depends heavily on converter operation point. A lifetime model of a single power module switched mode power supply with wide input voltage range is shown. A lifetime model is created using a power loss model, a thermal model and a model for power cycling capability...... with a given mission profile. A method to improve the expected lifetime of the converter is presented, taking into account switching frequency, input voltage and transformer turns ratio....

  1. 7 CFR 35.4 - Carrier.

    Science.gov (United States)

    2010-01-01

    ... AND PLUMS Definitions § 35.4 Carrier. Carrier means any common or private carrier, including, but not being limited to, trucks, rail, airplanes, vessels, tramp or chartered steamers, whether carrying for...

  2. Lifetime sedentary living accelerates some aspects of secondary aging

    DEFF Research Database (Denmark)

    Booth, Frank W; Laye, Matthew J; Roberts, Michael D

    2011-01-01

    accelerates secondary aging (e.g., speeding the reduction in bone mineral density, maximal oxygen consumption, and skeletal muscle strength and power), but does not alter the primary aging of these systems. Third, a lifetime of physical activity to the age of ∼60-70 yr old totally prevents decrements in some...... role in the secondary aging of many essential physiological functions, and this aging can be prevented through a lifetime of physical activity.......Lifetime physical inactivity interacts with secondary aging (i.e., aging caused by diseases and environmental factors) in three patterns of response. First, lifetime physical inactivity confers no apparent effects on a given set of physiological functions. Second, lifetime physical inactivity...

  3. Ultrafast carrier dynamics in a p-type GaN wafer under different carrier distributions

    Science.gov (United States)

    Fang, Yu; Yang, Junyi; Yang, Yong; Wu, Xingzhi; Xiao, Zhengguo; Zhou, Feng; Song, Yinglin

    2016-02-01

    The dependence of the carrier distribution on photoexcited carrier dynamics in a p-type Mg-doped GaN (GaN:Mg) wafer were systematically measured by femtosecond transient absorption (TA) spectroscopy. The homogeneity of the carrier distribution was modified by tuning the wavelength of the UV pulse excitation around the band gap of GaN:Mg. The TA kinetics appeared to be biexponential for all carrier distributions, and only the slower component decayed faster as the inhomogeneity of the carrier distribution increased. It was concluded that the faster component (50-70 ps) corresponded to the trap process of holes by the Mg acceptors, and the slower component (150-600 ps) corresponded to the combination of non-radiative surface recombination and intrinsic carrier recombination via dislocations. Moreover, the slower component increased gradually with the incident fluence due to the saturation of surface states.

  4. Moisture dependence of positron lifetime in Kevlar-49

    Science.gov (United States)

    Singh, Jag J.; Holt, William H.; Mock, Willis, Jr.

    1984-01-01

    Because of filamentary character of Kevlar-49 aramid fibers, there is some concern about the moisture uptake and its effect on plastic composites reinforced with Kevlar-49 fibers. As part of continuing studies of positron lifetime in polymers, we have measured positron lifetime spectra in Kevlar-49 fibers as a function of their moisture content. The long lifetime component intensities are rather low, being only of the order of 2-3 percent. The measured values of long component lifetimes at various moisture levels in the specimens are as follows: 2072 +/- 173 ps (dry); 2013 +/- 193 ps (20.7 percent saturation); 1665 +/- 85 ps (25.7 percent saturation); 1745 +/- 257 ps (32.1 percent saturation); and 1772 +/- 217 ps (100 percent saturation). It is apparent that the long component lifetime at first decreases and then increases as the specimen moisture content increases. These results have been compared with those inferred from Epon-815 and Epon-815/K-49 composite data.

  5. Nanoparticle discrimination based on wavelength and lifetime-multiplexed cathodoluminescence microscopy.

    Science.gov (United States)

    Garming, Mathijs W H; Weppelman, I Gerward C; de Boer, Pascal; Martínez, Felipe Perona; Schirhagl, Romana; Hoogenboom, Jacob P; Moerland, Robert J

    2017-08-31

    Nanomaterials can be identified in high-resolution electron microscopy images using spectrally-selective cathodoluminescence. Capabilities for multiplex detection can however be limited, e.g., due to spectral overlap or availability of filters. Also, the available photon flux may be limited due to degradation under electron irradiation. Here, we demonstrate single-pass cathodoluminescence-lifetime based discrimination of different nanoparticles, using a pulsed electron beam. We also show that cathodoluminescence lifetime is a robust parameter even when the nanoparticle cathodoluminescence intensity decays over an order of magnitude. We create lifetime maps, where the lifetime of the cathodoluminescence emission is correlated with the emission intensity and secondary-electron images. The consistency of lifetime-based discrimination is verified by also correlating the emission wavelength and the lifetime of nanoparticles. Our results show how cathodoluminescence lifetime provides an additional channel of information in electron microscopy.

  6. Hot carrier degradation in semiconductor devices

    CERN Document Server

    2015-01-01

    This book provides readers with a variety of tools to address the challenges posed by hot carrier degradation, one of today’s most complicated reliability issues in semiconductor devices.  Coverage includes an explanation of carrier transport within devices and book-keeping of how they acquire energy (“become hot”), interaction of an ensemble of colder and hotter carriers with defect precursors, which eventually leads to the creation of a defect, and a description of how these defects interact with the device, degrading its performance. • Describes the intricacies of hot carrier degradation in modern semiconductor technologies; • Covers the entire hot carrier degradation phenomenon, including topics such as characterization, carrier transport, carrier-defect interaction, technological impact, circuit impact, etc.; • Enables detailed understanding of carrier transport, interaction of the carrier ensemble with the defect precursors, and an accurate assessment of how the newly created defects imp...

  7. Lifetime income inequality with taxation and public benefits

    OpenAIRE

    Kemptner, Daniel; Haan, Peter; Prowse, Victoria

    2016-01-01

    In this paper, we show how taxation, unemployment insurance, welfare, disability benefits and public pensions affect the inequality of lifetime income. Using results from a dynamic life-cycle model estimated using German panel data, we show that taxation and public benefits combined reduce the inequality of lifetime income, measured by the Gini coefficient, by 22\\%. Pensions only slightly reduce inequality in lifetime income. Welfare benefits, meanwhile, make persistent transfers to individua...

  8. Possible evidence for the quantization of particle lifetimes

    International Nuclear Information System (INIS)

    Ehrlich, R.

    1976-01-01

    An analysis of widths of resonant states supports the hypothesis that particle lifetimes are quantized in units of 1/2 or possibly 1/4 the lifetime of the rho meson: (4.40 +- 0.06) x 10 -24 seconds. The probability that the observed regularity in resonance widths (lifetimes) is simply due to chance is estimated to be less than 2 x 10 -4 . Possible ramifications of this result are considered

  9. Λc photoproduction and lifetime measurement

    International Nuclear Information System (INIS)

    Amendolia, S.R.; Bagliesi, G.; Batignani, G.; Bertolucci, E.; Bettoni, D.; Bizetti, A.; Bosisio, L.; Bottigli, U.; Bradaschia, C.; Dell'Orso, M.; Fidecaro, F.; Foa, L.; Focardi, E.; Giannetti, P.; Giorgi, M.A.; Marrocchesi, P.S.; Menzione, A.; Raso, G.; Ristori, L.; Scribano, A.; Stefanini, A.; Tenchini, R.; Tonelli, G.; Triggiani, G.; Beck, G.A.; Bologna, G.; D'Ettorre Piazzoli, B.; Picchi, P.; Budinich, M.; Liello, F.; Milotti, E.; Rolandi, L.; Carter, J.; Green, M.G.; Landon, M.P.J.; March, P.V.; Sacks, L.; Sanjari, A.H.; Strong, J.A.; Ciocci, M.A.; Enorini, M.; Fabbri, F.L.; Laurelli, P.; Mannocchi, G.; Simonelli, L.; Spillantini, P.; Zallo, A.

    1987-01-01

    A measurement of the lifetime of the Λ c baryon photoproduced coherently of a germanium-silicon target is presented. A signal of Λ c → ΔΚ * → pKππ 0 has been observed and the two different decay diagrams for this process are compared. A sample of 9 Λ c decays give a lifetime of 1.1(+0.8-0.4)10 13 s. (orig.)

  10. Maintainable substrate carrier for electroplating

    Science.gov (United States)

    Chen, Chen-An [Milpitas, CA; Abas, Emmanuel Chua [Laguna, PH; Divino, Edmundo Anida [Cavite, PH; Ermita, Jake Randal G [Laguna, PH; Capulong, Jose Francisco S [Laguna, PH; Castillo, Arnold Villamor [Batangas, PH; Ma,; Xiaobing, Diana [Saratoga, CA

    2012-07-17

    One embodiment relates to a substrate carrier for use in electroplating a plurality of substrates. The carrier includes a non-conductive carrier body on which the substrates are placed and conductive lines embedded within the carrier body. A plurality of conductive clip attachment parts are attached in a permanent manner to the conductive lines embedded within the carrier body. A plurality of contact clips are attached in a removable manner to the clip attachment parts. The contact clips hold the substrates in place and conductively connecting the substrates with the conductive lines. Other embodiments, aspects and features are also disclosed.

  11. Baselines for Lifetime of Organic Solar Cells

    DEFF Research Database (Denmark)

    Gevorgyan, Suren; Espinosa Martinez, Nieves; Ciammaruchi, Laura

    2016-01-01

    The process of accurately gauging lifetime improvements in organic photovoltaics (OPVs) or other similar emerging technologies, such as perovskites solar cells is still a major challenge. The presented work is part of a larger effort of developing a worldwide database of lifetimes that can help...

  12. Digital positron lifetime spectroscopy: present status and outlook

    International Nuclear Information System (INIS)

    Becvar, F.

    2007-01-01

    This contribution summarizes achievements in instrumentation for positron lifetime measurements with emphasis on digital spectrometric systems. A significant part of the data presented are based on a long-term exploitation of a conventional positron lifetime spectrometer developed at Charles University in early 90s, on bench-mark testing measurements with this spectrometer working temporarily in conjunction with a pair of 8-bit, 4 GS/s digitizers and on analogous measurements with a recently assembled digital positron lifetime spectrometer. In addition, results from testing experiments with microchannel plate photomultipliers are briefly reported. Further development of positron lifetime technique is discussed. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  13. Study on lifetime of C stripping foils

    International Nuclear Information System (INIS)

    Zhang Hongbin; Lu Ziwei; Zhao Yongtao; Li Zhankui; Xu Hushan; Xiao Guoqing; Wang Yuyu; Zhang Ling; Li Longcai; Fang Yan

    2007-01-01

    The carbon stripping foils can be prepared with the AC and DC arc discharge methods, or even sandwiched with AC-DC alternative layers. The lifetime of the carbon stripping foils of 19 μg/cm 2 prepared with different methods and/or structures was measured. The factors affecting the bombarding lifetime of the carbon stripping foils, especially the method of the foil preparation and the structure of the carbon stripping foils, were discussed. It is observed that the foils prepared with the DC arc discharge method have a longer bombarding lifetime than those prepared with the AC arc discharge method. (authors)

  14. Correlation between excited d-orbital electron lifetime in polaron dynamics and coloration of WO3 upon ultraviolet exposure

    Science.gov (United States)

    Lee, Young-Ahn; Han, Seung-Ik; Rhee, Hanju; Seo, Hyungtak

    2018-05-01

    Polarons have been suggested to explain the mechanism of the coloration of WO3 induced by UV light. However, despite the many experimental results that support small polarons as a key mechanism, direct observation of the carrier dynamics of polarons have yet to be reported. Here, we investigate the correlation between the electronic structure and the coloration of WO3 upon exposure to UV light in 5% H2/N2 gas and, more importantly, reveal photon-induced excited d-electron generation/relaxation via the W5+ oxidation state. The WO3 is fabricated by radio-frequency magnetron sputtering. X-ray diffraction patterns show that prepared WO3 is amorphous. Optical bandgap of 3.1 eV is measured by UV-vis before and after UV light. The results of Fourier transform infrared and Raman exhibit pristine WO3 is formed with surface H2O. The colored WO3 shows reduced state of W5+ state (34.3 eV) by using X-ray photoelectron spectroscopy. The valence band maximum of WO3 after UV light in H2 is shifted from mid gap to shallow donor by using ultraviolet photoelectron spectroscopy. During the exploration of the carrier dynamics, pump (700 nm)-probe (1000 nm) spectroscopy at the femtosecond scale was used. The results indicated that electron-phonon relaxation of UV-irradiated WO3, which is the origin of the polaron-induced local surface plasmonic effect, is dominant, resulting in slow decay (within a few picoseconds); in contrast, pristine WO3 shows fast decay (less than a picosecond). Accordingly, the long photoinduced carrier relaxation is ascribed to the prolonged hot-carrier lifetime in reduced oxides resulting in a greater number of free d-electrons and, therefore, more interactions with the W5+ sub-gap states.

  15. Fluorescence lifetime imaging of oxygen in dental biofilm

    Science.gov (United States)

    Gerritsen, Hans C.; de Grauw, Cees J.

    2000-12-01

    Dental biofilm consists of micro-colonies of bacteria embedded in a matrix of polysaccharides and salivary proteins. pH and oxygen concentration are of great importance in dental biofilm. Both can be measured using fluorescence techniques. The imaging of dental biofilm is complicated by the thickness of the biofilms that can be up to several hundred micrometers thick. Here, we employed a combination of two-photon excitation microscopy with fluorescence lifetime imaging to quantify the oxygen concentration in dental biofilm. Collisional quenching of fluorescent probes by molecular oxygen leads to a reduction of the fluorescence lifetime of the probe. We employed this mechanism to measure the oxygen concentration distribution in dental biofilm by means of fluorescence lifetime imaging. Here, TRIS Ruthenium chloride hydrate was used as an oxygen probe. A calibration procedure on buffers was use to measure the lifetime response of this Ruthenium probe. The results are in agreement with the Stern-Volmer equation. A linear relation was found between the ratio of the unquenched and the quenched lifetime and the oxygen concentration. The biofilm fluorescence lifetime imaging results show a strong oxygen gradient at the buffer - biofilm interface and the average oxygen concentration in the biofilm amounted to 50 μM.

  16. Improved lifetime of microchannel-plate PMTs

    Energy Technology Data Exchange (ETDEWEB)

    Lehmann, A., E-mail: lehmann@physik.uni-erlangen.de [Physikalisches Institut IV, Friedrich Alexander-University of Erlangen-Nuremberg, Erlangen (Germany); Britting, A.; Eyrich, W.; Uhlig, F. [Physikalisches Institut IV, Friedrich Alexander-University of Erlangen-Nuremberg, Erlangen (Germany); Dzhygadlo, R.; Gerhardt, A.; Götzen, K.; Höhler, R.; Kalicy, G.; Kumawat, H.; Lehmann, D.; Lewandowski, B.; Patsyuk, M.; Peters, K.; Schepers, G.; Schmitt, L.; Schwarz, C.; Schwiening, J.; Traxler, M.; Zühlsdorf, M. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt (Germany); and others

    2014-12-01

    The charged particle identification at the PANDA experiment will be mainly performed with DIRC detectors. Because of their advantageous properties the preferred photon sensors are MCP-PMTs. However, until recently these devices showed serious aging problems which resulted in a diminishing quantum efficiency (QE) of the photo cathode. By applying innovative countermeasures against the aging causes, the manufacturers recently succeeded in drastically improving the lifetime of MCP-PMTs. Especially the application of an ALD coating technique to seal the material of the micro-channels proves very powerful and results in a lifetime of ≈6C/cm{sup 2} integrated anode charge without a substantial QE degradation for the latest PHOTONIS XP85112. This paper will present a comparative measurement of the lifetime of several older and recent MCP-PMTs demonstrating this progress.

  17. Non-permeable substrate carrier for electroplating

    Science.gov (United States)

    Abas, Emmanuel Chua; Chen, Chen-An; Ma, Diana Xiaobing; Ganti, Kalyana Bhargava

    2012-11-27

    One embodiment relates to a substrate carrier for use in electroplating a plurality of substrates. The substrate carrier comprises a non-conductive carrier body on which the substrates are to be held. Electrically-conductive lines are embedded within the carrier body, and a plurality of contact clips are coupled to the electrically-conductive lines embedded within the carrier body. The contact clips hold the substrates in place and electrically couple the substrates to the electrically-conductive lines. The non-conductive carrier body is continuous so as to be impermeable to flow of electroplating solution through the non-conductive carrier body. Other embodiments, aspects and features are also disclosed.

  18. Behind the Nature of Titanium Oxide Excellent Surface Passivation and Carrier Selectivity of c-Si

    DEFF Research Database (Denmark)

    Plakhotnyuk, Maksym; Crovetto, Andrea; Hansen, Ole

    We present an expanded study of the passivation properties of titanium dioxide (TiO2) on p-type crystalline silicon (c-Si). We report a low surface recombination velocity (16 cm/s) for TiO2 passivation layers with a thin tunnelling oxide interlayer (SiO2 or Al2O3) on p-type crystalline silicon (c-Si......), and post-deposition annealing temperature were investigated. We have observed that that SiO2 and Al2O3 interlayers enhance the TiO2 passivation of c-Si. TiO2 thin film passivation layers alone result in lower effective carrier lifetime. Further annealing at 200  ̊C in N2 gas enhances the surface...

  19. Filter replacement lifetime prediction

    Science.gov (United States)

    Hamann, Hendrik F.; Klein, Levente I.; Manzer, Dennis G.; Marianno, Fernando J.

    2017-10-25

    Methods and systems for predicting a filter lifetime include building a filter effectiveness history based on contaminant sensor information associated with a filter; determining a rate of filter consumption with a processor based on the filter effectiveness history; and determining a remaining filter lifetime based on the determined rate of filter consumption. Methods and systems for increasing filter economy include measuring contaminants in an internal and an external environment; determining a cost of a corrosion rate increase if unfiltered external air intake is increased for cooling; determining a cost of increased air pressure to filter external air; and if the cost of filtering external air exceeds the cost of the corrosion rate increase, increasing an intake of unfiltered external air.

  20. SIRTF thermal design modifications to increase lifetime

    Science.gov (United States)

    Petrick, S. W.

    1993-01-01

    An effort was made to increase the predicted lifetime of the SIRTF dewar by lowering the exterior shell temperature, increasing the radiated energy from the vapor cooled shields and reconfiguring the vapor cooled shields. The lifetime increases can be used to increase the scientific return from the mission and as a trade-off against mass and cost. This paper describes the configurations studied, the steady state thermal model used, the analytical methods and the results of the analysis. Much of the heat input to the outside dewar shell is radiative heat transfer from the solar panel. To lower the shell temperature, radiative cooled shields were placed between the solar panel and the dewar shell and between the bus and the dewar shell. Analysis showed that placing a radiator on the outer vapor cooled shield had a significant effect on lifetime. Lengthening the distance between the outer shell and the point where the vapor cooled shields are attached to the support straps also improved lifetime.

  1. Extending the Lifetime of Sensor Networks through Adaptive Reclustering

    Directory of Open Access Journals (Sweden)

    Gianluigi Ferrari

    2007-06-01

    Full Text Available We analyze the lifetime of clustered sensor networks with decentralized binary detection under a physical layer quality-of-service (QoS constraint, given by the maximum tolerable probability of decision error at the access point (AP. In order to properly model the network behavior, we consider four different distributions (exponential, uniform, Rayleigh, and lognormal for the lifetime of a single sensor. We show the benefits, in terms of longer network lifetime, of adaptive reclustering. We also derive an analytical framework for the computation of the network lifetime and the penalty, in terms of time delay and energy consumption, brought by adaptive reclustering. On the other hand, absence of reclustering leads to a shorter network lifetime, and we show the impact of various clustering configurations under different QoS conditions. Our results show that the organization of sensors in a few big clusters is the winning strategy to maximize the network lifetime. Moreover, the observation of the phenomenon should be frequent in order to limit the penalties associated with the reclustering procedure. We also apply the developed framework to analyze the energy consumption associated with the proposed reclustering protocol, obtaining results in good agreement with the performance of realistic wireless sensor networks. Finally, we present simulation results on the lifetime of IEEE 802.15.4 wireless sensor networks, which enrich the proposed analytical framework and show that typical networking performance metrics (such as throughput and delay are influenced by the sensor network lifetime.

  2. Extending the Lifetime of Sensor Networks through Adaptive Reclustering

    Directory of Open Access Journals (Sweden)

    Ferrari Gianluigi

    2007-01-01

    Full Text Available We analyze the lifetime of clustered sensor networks with decentralized binary detection under a physical layer quality-of-service (QoS constraint, given by the maximum tolerable probability of decision error at the access point (AP. In order to properly model the network behavior, we consider four different distributions (exponential, uniform, Rayleigh, and lognormal for the lifetime of a single sensor. We show the benefits, in terms of longer network lifetime, of adaptive reclustering. We also derive an analytical framework for the computation of the network lifetime and the penalty, in terms of time delay and energy consumption, brought by adaptive reclustering. On the other hand, absence of reclustering leads to a shorter network lifetime, and we show the impact of various clustering configurations under different QoS conditions. Our results show that the organization of sensors in a few big clusters is the winning strategy to maximize the network lifetime. Moreover, the observation of the phenomenon should be frequent in order to limit the penalties associated with the reclustering procedure. We also apply the developed framework to analyze the energy consumption associated with the proposed reclustering protocol, obtaining results in good agreement with the performance of realistic wireless sensor networks. Finally, we present simulation results on the lifetime of IEEE 802.15.4 wireless sensor networks, which enrich the proposed analytical framework and show that typical networking performance metrics (such as throughput and delay are influenced by the sensor network lifetime.

  3. Lifetime measurement in {sup 195}Po

    Energy Technology Data Exchange (ETDEWEB)

    Grahn, T.; Page, R.D. [University of Liverpool, Department of Physics, Oliver Lodge Laboratory, Liverpool (United Kingdom); Dewald, A.; Jolie, J.; Melon, B.; Pissulla, T. [Universitaet zu Koeln, Institut fuer Kernphysik, Koeln (Germany); Greenlees, P.T.; Jakobsson, U.; Jones, P.; Julin, R.; Juutinen, S.; Ketelhut, S.; Leino, M.; Nyman, M.; Peura, P.; Rahkila, P.; Saren, J.; Scholey, C.; Sorri, J.; Uusitalo, J. [University of Jyvaeskylae, Department of Physics, P.O. Box 35, Jyvaeskylae (Finland); Kroell, T.; Kruecken, R.; Maierbeck, P. [TU Muenchen, Physik-Department E12, Garching (Germany)

    2009-03-15

    The lifetime of the 17/2{sup +} yrast state in {sup 195}Po has been measured using the recoil distance Doppler-shift technique to be {tau}=43(11) ps. The lifetime was extracted from the singles {gamma}-ray spectra obtained by using the recoil-decay tagging method. The present work provides more information of the coupling schemes, shapes and configuration mixing in neutron-deficient odd-mass Po nuclei. (orig.)

  4. Reliability-based assessment of polyethylene pipe creep lifetime

    International Nuclear Information System (INIS)

    Khelif, Rabia; Chateauneuf, Alaa; Chaoui, Kamel

    2007-01-01

    Lifetime management of underground pipelines is mandatory for safe hydrocarbon transmission and distribution systems. The use of high-density polyethylene tubes subjected to internal pressure, external loading and environmental variations requires a reliability study in order to define the service limits and the optimal operating conditions. In service, the time-dependent phenomena, especially creep, take place during the pipe lifetime, leading to significant strength reduction. In this work, the reliability-based assessment of pipe lifetime models is carried out, in order to propose a probabilistic methodology for lifetime model selection and to determine the pipe safety levels as well as the most important parameters for pipeline reliability. This study is enhanced by parametric analysis on pipe configuration, gas pressure and operating temperature

  5. Reliability-based assessment of polyethylene pipe creep lifetime

    Energy Technology Data Exchange (ETDEWEB)

    Khelif, Rabia [LaMI-UBP and IFMA, Campus de Clermont-Fd, Les Cezeaux, BP 265, 63175 Aubiere Cedex (France); LR3MI, Departement de Genie Mecanique, Universite Badji Mokhtar, BP 12, Annaba 23000 (Algeria)], E-mail: rabia.khelif@ifma.fr; Chateauneuf, Alaa [LGC-University Blaise Pascal, Campus des Cezeaux, BP 206, 63174 Aubiere Cedex (France)], E-mail: alaa.chateauneuf@polytech.univ-bpclermont.fr; Chaoui, Kamel [LR3MI, Departement de Genie Mecanique, Universite Badji Mokhtar, BP 12, Annaba 23000 (Algeria)], E-mail: chaoui@univ-annaba.org

    2007-12-15

    Lifetime management of underground pipelines is mandatory for safe hydrocarbon transmission and distribution systems. The use of high-density polyethylene tubes subjected to internal pressure, external loading and environmental variations requires a reliability study in order to define the service limits and the optimal operating conditions. In service, the time-dependent phenomena, especially creep, take place during the pipe lifetime, leading to significant strength reduction. In this work, the reliability-based assessment of pipe lifetime models is carried out, in order to propose a probabilistic methodology for lifetime model selection and to determine the pipe safety levels as well as the most important parameters for pipeline reliability. This study is enhanced by parametric analysis on pipe configuration, gas pressure and operating temperature.

  6. Modulated electron-multiplied fluorescence lifetime imaging microscope: all-solid-state camera for fluorescence lifetime imaging.

    Science.gov (United States)

    Zhao, Qiaole; Schelen, Ben; Schouten, Raymond; van den Oever, Rein; Leenen, René; van Kuijk, Harry; Peters, Inge; Polderdijk, Frank; Bosiers, Jan; Raspe, Marcel; Jalink, Kees; Geert Sander de Jong, Jan; van Geest, Bert; Stoop, Karel; Young, Ian Ted

    2012-12-01

    We have built an all-solid-state camera that is directly modulated at the pixel level for frequency-domain fluorescence lifetime imaging microscopy (FLIM) measurements. This novel camera eliminates the need for an image intensifier through the use of an application-specific charge coupled device design in a frequency-domain FLIM system. The first stage of evaluation for the camera has been carried out. Camera characteristics such as noise distribution, dark current influence, camera gain, sampling density, sensitivity, linearity of photometric response, and optical transfer function have been studied through experiments. We are able to do lifetime measurement using our modulated, electron-multiplied fluorescence lifetime imaging microscope (MEM-FLIM) camera for various objects, e.g., fluorescein solution, fixed green fluorescent protein (GFP) cells, and GFP-actin stained live cells. A detailed comparison of a conventional microchannel plate (MCP)-based FLIM system and the MEM-FLIM system is presented. The MEM-FLIM camera shows higher resolution and a better image quality. The MEM-FLIM camera provides a new opportunity for performing frequency-domain FLIM.

  7. Genotypic-specific variance in Caenorhabditis elegans lifetime fecundity.

    Science.gov (United States)

    Diaz, S Anaid; Viney, Mark

    2014-06-01

    Organisms live in heterogeneous environments, so strategies that maximze fitness in such environments will evolve. Variation in traits is important because it is the raw material on which natural selection acts during evolution. Phenotypic variation is usually thought to be due to genetic variation and/or environmentally induced effects. Therefore, genetically identical individuals in a constant environment should have invariant traits. Clearly, genetically identical individuals do differ phenotypically, usually thought to be due to stochastic processes. It is now becoming clear, especially from studies of unicellular species, that phenotypic variance among genetically identical individuals in a constant environment can be genetically controlled and that therefore, in principle, this can be subject to selection. However, there has been little investigation of these phenomena in multicellular species. Here, we have studied the mean lifetime fecundity (thus a trait likely to be relevant to reproductive success), and variance in lifetime fecundity, in recently-wild isolates of the model nematode Caenorhabditis elegans. We found that these genotypes differed in their variance in lifetime fecundity: some had high variance in fecundity, others very low variance. We find that this variance in lifetime fecundity was negatively related to the mean lifetime fecundity of the lines, and that the variance of the lines was positively correlated between environments. We suggest that the variance in lifetime fecundity may be a bet-hedging strategy used by this species.

  8. Positron lifetime studies of electron irradiated copper

    International Nuclear Information System (INIS)

    Hadnagy, T.D.

    1976-01-01

    Single-crystal copper was irradiated with 4.5-MeV electrons producing simple Frenkel defects as well as a significant concentration of divacancies. Mean positron lifetime characteristics, which are sensitive to the presence of vacancies and multivacancies in copper, was monitored after isochronal anneals between 80 and 800 0 K to determine the relative change of characteristic mean lifetimes and their associated intensities. Also a study of the dependence of the mean positron lifetime on the total electron fluence was made and compared with existing theories relating these lifetimes to vacancy or multivacancy concentrations. Numerical data from curve fitting procedures using a conventional trapping model for defect-induced changes in positron lifetimes indicate that upon irradiation with 4.5-MeV electrons at 80 0 K, about 8 percent of the defects produced are divacancy units. Divacancy units appear to be several times more effective in trapping positrons than are monovacancies. Further, the experimental data suggest that the stage III annealing processes in electron-irradiated copper most probably involve the motion and removal of both monovacancies and divacancies. A conglomerate (multivacancy) unit appears to exist as a stable entity even after annealing procedures are carried out at temperatures slightly above the stage III region. Such a stable unit could serve as a nucleation center for the appearance of voids

  9. Spectroscopy and lifetime of bottom and charm hadrons

    International Nuclear Information System (INIS)

    F. Ukegawa

    2000-01-01

    There are several motivations for studying masses and lifetimes of the hadrons containing a heavy quark, either the bottom or the charm quark. First, the mass and the lifetime are fundamental properties of an elementary particle. Second, the spectroscopy of hadrons gives insights into the QCD potential between quarks. In particular, a symmetry exists for heavy hadrons when the heavy quark mass is taken to be infinite, providing a powerful tool to predict and understand properties of those heavy hadrons. Third, studies of the lifetimes of heavy hadrons probe their decay mechanisms. A measurement of the lifetime, or the total decay width, is necessary when the authors extract magnitudes of elements of the Kobayashi-Maskawa matrix. Again, in the limit of an infinite heavy quark mass things become simple and decay of a heavy hadron should be the decay of the heavy quark Q. This leads to a prediction that all hadrons containing the heavy quark Q should have the same lifetime, that of the quark Q. This is far from reality in the case of charm hadrons, where the D + meson lifetime is about 2.5 times longer than the D 0 meson lifetime. Perhaps the charm quark is not heavy enough. The simple quark decay picture should be a better approximation for the bottom hadrons because of the larger b quark mass. On the experimental side, the measurements and knowledge of the heavy hadrons (in particular bottom hadrons) have significantly improved over the last decade, thanks to high statistics data accumulated by various experiments. The authors shall review recent developments in these studies in the remainder of this manuscript

  10. 42 CFR 409.65 - Lifetime reserve days.

    Science.gov (United States)

    2010-10-01

    ... HOSPITAL INSURANCE BENEFITS Scope of Hospital Insurance Benefits § 409.65 Lifetime reserve days. (a... private insurance coverage that begins after the first 90 inpatient days in a benefit period, or if the... 42 Public Health 2 2010-10-01 2010-10-01 false Lifetime reserve days. 409.65 Section 409.65 Public...

  11. The Lifetime of a beautiful and charming meson: Bc lifetime measured using the D0 detector

    Energy Technology Data Exchange (ETDEWEB)

    Welty-Rieger, Leah Christine [Indiana Univ., Bloomington, IN (United States)

    2008-09-01

    Using approximately 1.3 fb-1 of data collected by the D0 detector between 2002 and 2006, the lifetime of the Bc± meson is studied in the Bc± → J/Ψμ± + X final state. Using an unbinned likelihood simultaneous fit to J/Ψ + μ invariant mass and lifetime distributions, a signal of 810 ± 80(stat.) candidates is estimated and a lifetime measurement made of: τ(Bc±) = 0.448-0.036+0.038(stat) ± 0.032(sys) ps.

  12. Micellar effects on positronium lifetime in aqueous SDS solutions

    International Nuclear Information System (INIS)

    Vass, Sz.; Kajcsos, Zs.; Molnar, B.; Stergiopoulos, Ch.

    1981-09-01

    Positron lifetime measurements have been performed in aqueous SDS (Sodium Dodecyl Sulphate) solutions. The lifetime distributions measured by fast-slow coincidence technique have been found to be influenced by surfactant concentration, which varied in the range of 1.25x10 -3 - 3.2x10 -1 mol/dm 3 (i.e. 2.27x10 -5 - 5.82x10 -3 mole fractions). The lifetime of the long living component connected to positronium formation and decay increases with increasing surfactant concentration. Lifetime data suggest that a direct positronium-micelle electron-exchange reaction leading to pick-off annihilation is contraindicated. (author)

  13. Clinical results of fluorescence lifetime imaging in ophthalmology

    Science.gov (United States)

    Schweitzer, D.; Quick, S.; Klemm, M.; Hammer, M.; Jentsch, S.; Dawczynski, J.; Becker, W.

    2009-07-01

    A laser scanner ophthalmoscope was developed for in vivo fluorescence lifetime measurements at the human retina. Measurements were performed in 30 degree fundus images. The fundus was excited by pulses of 75 ps (FWHM). The dynamic fluorescence was detected in two spectral channels K1(490-560nm), K2(560-700 nm) by time-correlated single photon counting. The decay of fluorescence was three-exponentially. Local and global alterations in lifetimes were found between healthy subjects and patients suffering from age-related macular degeneration, diabetic retinopathy, and vessel occlusion. The lifetimes T1, T2, and T3 in both channels are changed to longer values in AMD and diabetic retinopathy in comparison with healthy subjects. The lifetime T2 in K1 is most sensitive to metabolic alterations in branch arterial vessel occlusion.

  14. 7 CFR 33.4 - Carrier.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Carrier. 33.4 Section 33.4 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... ISSUED UNDER AUTHORITY OF THE EXPORT APPLE ACT Definitions § 33.4 Carrier. Carrier means any common or...

  15. Low-cost carriers fare competition effect

    NARCIS (Netherlands)

    Carmona Benitez, R.B.; Lodewijks, G.

    2010-01-01

    This paper examines the effects that low-cost carriers (LCC’s) produce when entering new routes operated only by full-service carriers (FSC’s) and routes operated by low-cost carriers in competition with full-service carriers. A mathematical model has been developed to determine what routes should

  16. Estimating Motor Carrier Management Information System Crash File Underreporting from Carrier Records.

    Science.gov (United States)

    2017-08-01

    This FMCSA-sponsored research investigated the claim that motor carriers have a substantial number of crashes in their own records that are not contained in the Motor Carrier Management Information System (MCMIS) crash file. Based on the results of t...

  17. Fluorescence lifetime imaging using light emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, Gordon T; Munro, Ian; Poher, Vincent; French, Paul M W; Neil, Mark A A [Blackett Laboratory, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom); Elson, Daniel S [Institute of Biomedical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom); Hares, Jonathan D [Kentech Instruments Ltd, Unit 9, Hall Farm Workshops, South Moreton, Didcot, Oxfordshire, OX11 9AG (United Kingdom)], E-mail: gordon.kennedy@imperial.ac.uk

    2008-05-07

    We demonstrate flexible use of low cost, high-power light emitting diodes as illumination sources for fluorescence lifetime imaging (FLIM). Both time-domain and frequency-domain techniques have been implemented at wavelengths spanning the range 450-640 nm. Additionally, we demonstrate optically sectioned fluorescence lifetime imaging by combining structured illumination with frequency-domain FLIM.

  18. Fluorescence lifetime measurement of radical ions

    International Nuclear Information System (INIS)

    Ichinose, Nobuyuki; Kinugasa, Jun-ichiro; Hagiri, Masahide; Nakayama, Toshihiro; Murakami, Hiroshi; Kishimoto, Maki; Daido, Hiroyuki

    2004-01-01

    One-photonic excitation of a charge transfer complex of hexamethoxybenzene (HMB) and nitrosonium tetrafluoroborate (NO + BF 4 - ) in acetonitrile afforded fluorescences emission from excited radical cation of HMB (HMB + *). Lifetime of the excited radical ion species was measured to be 7 ps by the pump-probe transient absorption technique. The lifetime was much shorter than that of free radical ion (63 ps), indicating the presence of an interaction between HMB + * and NO in the excited complex. (author)

  19. Rapid calculation of maximum particle lifetime for diffusion in complex geometries

    Science.gov (United States)

    Carr, Elliot J.; Simpson, Matthew J.

    2018-03-01

    Diffusion of molecules within biological cells and tissues is strongly influenced by crowding. A key quantity to characterize diffusion is the particle lifetime, which is the time taken for a diffusing particle to exit by hitting an absorbing boundary. Calculating the particle lifetime provides valuable information, for example, by allowing us to compare the timescale of diffusion and the timescale of the reaction, thereby helping us to develop appropriate mathematical models. Previous methods to quantify particle lifetimes focus on the mean particle lifetime. Here, we take a different approach and present a simple method for calculating the maximum particle lifetime. This is the time after which only a small specified proportion of particles in an ensemble remain in the system. Our approach produces accurate estimates of the maximum particle lifetime, whereas the mean particle lifetime always underestimates this value compared with data from stochastic simulations. Furthermore, we find that differences between the mean and maximum particle lifetimes become increasingly important when considering diffusion hindered by obstacles.

  20. Radiation lifetimes and failure mechanisms of carbon stripper foils

    International Nuclear Information System (INIS)

    Auble, R.L.

    1981-01-01

    Measurements of lifetimes of thin carbon foils under heavy-ion irradiation are compiled and recent advances in stripper foil technology are reviewed. The impact of recent foil lifetime improvements, many by more than an order of magnitude, on heavy-ion electrostatic accelerators is discussed. Foil inhomogeneities, particularly those caused by sputtering are suggested to be a prime factor in usable foil lifetimes

  1. Carrier transport uphill. I. General

    DEFF Research Database (Denmark)

    Rosenberg, T; Wilbrandt, W

    1963-01-01

    A quantitative treatment of a carrier pump operating with two carrier forms C and Z is presented. Asymmetric metabolic reactions are assumed to transform Z into C on one and C into Z on the other side of the membrane, establishing a carrier cycle. The kinetical consequences of this mechanism...

  2. Measurement of the D/sup 0/ lifetime

    Energy Technology Data Exchange (ETDEWEB)

    Althoff, M; Braunschweig, W; Gerhards, R; Kirschfink, F J; Martyn, H U; Rosskamp, R; Wallraff, W; Bock, B; Eisenmann, J; Fischer, H M

    1986-10-01

    We have determined the D/sup 0/ lifetime from reconstructed vertices of D/sup 0/ mesons produced in e/sup +/e/sup -/ annihilations at an average center of mass energy of 42.2 GeV. From fifteen events the D/sup 0/ lifetime was determined to be (4.3+-1.7+-0.8)x10/sup -13/s.

  3. Direct measurements of the lifetime of medium-heavy hypernuclei

    Science.gov (United States)

    Qiu, X.; Tang, L.; Chen, C.; Margaryan, A.; Wood, S. A.; Achenbach, P.; Ahmidouch, A.; Albayrak, I.; Androic, D.; Asaturyan, A.; Asaturyan, R.; Ates, O.; Badui, R.; Baturin, P.; Boeglin, W.; Bono, J.; Brash, E.; Carter, P.; Chen, X.; Chiba, A.; Christy, M. E.; Dalton, M. M.; Danagoulian, S.; De Leo, R.; Doi, D.; Elaasar, M.; Ent, R.; Fenker, H.; Fujii, Y.; Furic, M.; Gabrielyan, M.; Gan, L.; Garibaldi, F.; Gaskell, D.; Gasparian, A.; Gogami, T.; Hashimoto, O.; Horn, T.; Hu, B.; Hungerford, Ed V.; Jones, M.; Kanda, H.; Kaneta, M.; Kawama, D.; Khanal, H.; Kohl, M.; Liyanage, A.; Luo, W.; Maeda, K.; Markowitz, P.; Marikyan, G.; Maruta, T.; Matsumura, A.; Maxwell, V.; Mkrtchyan, A.; Mkrtchyan, H.; Nagao, S.; Nakamura, S. N.; Narayan, A.; Neville, C.; Niculescu, G.; Niculescu, M. I.; Nunez, A.; Nuruzzaman; Okayasu, Y.; Petkovic, T.; Pochodzalla, J.; Reinhold, J.; Rodriguez, V. M.; Samanta, C.; Sawatzky, B.; Seva, T.; Shichijo, A.; Tadevosyan, V.; Taniya, N.; Tsukada, K.; Veilleux, M.; Vulcan, W.; Wesselmann, F. R.; Yamamoto, T.; Ye, Z.; Yokota, K.; Yuan, L.; Zhamkochyan, S.; Zhu, L.; HKS (JLab E02-017) Collaboration

    2018-05-01

    The lifetime of a Λ particle embedded in a nucleus (hypernucleus) decreases from that of free Λ decay mainly due to the opening of the ΛN → NN weak decay channel. However, it is generally believed that the lifetime of a hypernucleus attains a constant value (saturation) for medium to heavy hypernuclear masses, yet this hypothesis has been difficult to verify. This paper presents a direct measurement of the lifetime of medium-heavy hypernuclei that were hyper-fragments produced by fission or break-up from heavy hypernuclei initially produced with a 2.34 GeV photon-beam incident on thin Fe, Cu, Ag, and Bi target foils. For each event, fragments were detected in coincident pairs by a low-pressure multi-wire proportional chamber system. The lifetime was extracted from decay time spectrum formed by the difference of the time zeros between the pairs. The measured lifetime from each target is actually a statistical average over a range of mass with mean about 1/2 of the target mass and appears to be a constant of about 200 ps. Although this result cannot exclude unexpected shorter or longer lifetimes for some specific hypernuclei or hypernuclear states, it shows that a systematic decrease in lifetime as hypernuclear mass increases is not a general feature for hypernuclei with mean mass up to A ≈ 130. On the other hand, the success of this experiment and its technique shows that the time delayed fissions observed and used by all the lifetime measurements done so far on heavy hypernuclei could likely have originated from hyper-fragments lighter than the assumed masses.

  4. Fluorescence lifetime imaging microscopy using near-infrared contrast agents.

    Science.gov (United States)

    Nothdurft, R; Sarder, P; Bloch, S; Culver, J; Achilefu, S

    2012-08-01

    Although single-photon fluorescence lifetime imaging microscopy (FLIM) is widely used to image molecular processes using a wide range of excitation wavelengths, the captured emission of this technique is confined to the visible spectrum. Here, we explore the feasibility of utilizing near-infrared (NIR) fluorescent molecular probes with emission >700 nm for FLIM of live cells. The confocal microscope is equipped with a 785 nm laser diode, a red-enhanced photomultiplier tube, and a time-correlated single photon counting card. We demonstrate that our system reports the lifetime distributions of NIR fluorescent dyes, cypate and DTTCI, in cells. In cells labelled separately or jointly with these dyes, NIR FLIM successfully distinguishes their lifetimes, providing a method to sort different cell populations. In addition, lifetime distributions of cells co-incubated with these dyes allow estimate of the dyes' relative concentrations in complex cellular microenvironments. With the heightened interest in fluorescence lifetime-based small animal imaging using NIR fluorophores, this technique further serves as a bridge between in vitro spectroscopic characterization of new fluorophore lifetimes and in vivo tissue imaging. © 2012 The Author Journal of Microscopy © 2012 Royal Microscopical Society.

  5. Determination of the D mesons lifetimes

    International Nuclear Information System (INIS)

    Josa Mutuberria, M.I.

    1990-01-01

    The results from the experiment NA27, performed in the North Area of the Super Proton Synchrotron at CERN are presented. The experimental set up was the small, high resolution, rapid cyling bubble chamber LEBC coupled with the European Hybrid Spectrometer (EHS). More than 2 millions pictures were taken, with 1015000 in teractions in hydrogen. The stastistical sensitivity of the experiment was 38.5 events/μb. A clean sample of 700 charm particle decays was obtained. Estimators with minimal systematic and statistical errors are developed for the determination of the lifetimes of short-lived particles whose individual momenta are unknown. These estimators make use of the measured decay lengths and the a priori known production characteristics. In this way, it is possible to include identified but not fully reconstructed charm decays in the sample to determine their lifetime. The properties of these estimators were extensively studied by means of Montecarlo simulation. The detection of the short-lived particles through the impact parameter of their charged decay products leads to additional complications which are taken into account. The biases and statistical errors inherent in using simpler approximate lifetime estimators are also discussed. These estimators are applied to determine the lifetime of the D o and D +- mesons using the charm data sample from NA27. (Author)

  6. Recoil distance lifetime measurements in 122,124Xe

    Science.gov (United States)

    Govil, I. M.; Kumar, A.; Iyer, H.; Li, H.; Garg, U.; Ghugre, S. S.; Johnson, T.; Kaczarowski, R.; Kharraja, B.; Naguleswaran, S.; Walpe, J. C.

    1998-02-01

    Lifetimes of the lower-excited states in 122,124Xe are measured using the recoil-distance Doppler-shift technique. The reactions 110Pd(16O,4n)122Xe and 110Pd(18O,4n)124Xe at a beam energy of 66 MeV were used for this experiment. The lifetimes of the 2+, 4+, 6+, and 8+ states of the ground state band were extracted using the computer code LIFETIME including the corrections due to the side feeding and the nuclear deorientation effects. The lifetime of the 2+ state in 122Xe agrees with the recoil distance method (RDM) measurements but for the 124Xe it does not agree with the RDM measurements but agrees with the Coulomb-excitation experiment. The measured B(E2) values for both the nuclei are compared with the standard algebraic and the multishell models.

  7. Plant lifetime management at Jose Cabrera NPP

    International Nuclear Information System (INIS)

    Martin, Jorge; Garcia, Piedad

    1998-01-01

    This paper presents the results obtained during the development and implementation of the Jose Cabrera NPP Lifetime Management Program according to the methodology applied in the Plant. The implementation of the Lifetime Management Program began in 1995 with the elaboration of the annual revision document 'Lifetime Management Plan', which describes the level of development of the Lifetime Management activities, the results that have been obtained during the implementation of the Program, and the schedule of the upcoming activities. The drawing up of a weighted list of 135 important components and the elaboration of 17 dossiers integrating the ageing mechanisms analysis and its corresponding evaluation, control and mitigation methods, were the result of the activities completed during 1996. A group of 62 component/degradation phenomena pairs with a high degradation risk classification has been considered within the scope of the activity 'Assessment of Maintenance Practices. Improvement Proposal', performed by the plant during 1997 and the first term of 1998 in parallel with other Lifetime Management related activities. The results obtained within this activity have revealed for the components included in the scope of the assessment that the associated degradation phenomena are practically covered by the current maintenance, inspection and testing practices. Recommendations and improvements of the maintenance practices have been particularly proposed from a technical, supporting, proceeding and documentary point of view, and currently an analysis is being made in relation to the feasibility of implementing them at the Jose Cabrera NPP. (author)

  8. Inert carriers for column extraction chromatography

    International Nuclear Information System (INIS)

    Katykhin, G.S.

    1978-01-01

    Inert carriers used in column extraction chromatography are reviewed. Such carriers are devided into two large groups: hydrophilic carriers which possess high surface energy and are well wetted only with strongly polar liquids (kieselguhrs, silica gels, glasses, cellulose, Al 2 O 3 ) and water-repellent carriers which possess low surface energy and are well wetted with various organic solvents (polyethylene, polytetrafluorethylene polytrifluorochlorethylene). Properties of various carriers are presented: structure, chemical and radiation stability, adsorption properties, extracting agent capacity. The effect of structure and sizes of particles on the efficiency of chromatography columns is considered. Ways of immovable phase deposition on the carrier and the latter's regeneration. Peculiarities of column packing for preparative and continuous chromatography are discussed

  9. The measurement of subnanosecond nuclear lifetimes

    International Nuclear Information System (INIS)

    White, D.C.S.

    1974-01-01

    This research dealt with the measurement of subnanosecond nuclear lifetimes using the pulsed beam delayed-coincidence technique. Measurements were performed on isotopes in the f7/2 shell and specifically the isotopes of titanium and vanadium. Experimental investigations were also pursued in 59 Ni and 65 Zn. Several new lifetimes were determined and confirmation was obtained for some previous values which were measured with different techniques. More information was also obtained on certain levels where previous results are in disagreement. (author)

  10. Masses and lifetimes of B hadrons

    International Nuclear Information System (INIS)

    Kkkroll, I.J.

    1996-02-01

    The latest measurements of the masses and lifetimes of weakly decaying B hadrons from experiments at e + e - and p bar p colliders are presented. These measurements include the lifetimes of the bar B o , bar B o s , B - and b baryons, as well as searches for the B c meson. The observation of B*, p-wave B mesons (B**), and excited b baryons using inclusive and exclusive B hadron reconstruction are discussed. Results on b quark flavour tagging are given

  11. The total lifetime costs of smoking

    DEFF Research Database (Denmark)

    Rasmussen, S.R.; Prescott, E.; Sørensen, T.I.A.

    2004-01-01

    Net costs of smoking in a lifetime perspective and, hence, the economic interests in antismoking policies have been questioned. It has been proposed that the health-related costs of smoking are balanced by smaller expenditure due to shorter life expectancy.......Net costs of smoking in a lifetime perspective and, hence, the economic interests in antismoking policies have been questioned. It has been proposed that the health-related costs of smoking are balanced by smaller expenditure due to shorter life expectancy....

  12. Measurement of the Bs0 lifetime

    Science.gov (United States)

    Buskulic, D.; de Bonis, I.; Decamp, D.; Ghez, P.; Goy, C.; Lees, J.-P.; Minard, M.-N.; Odier, P.; Pietrzyk, B.; Ariztizabal, F.; Comas, P.; Crespo, J. M.; Efthymiopoulos, I.; Fernandez, E.; Fernandez-Bosman, M.; Gaitan, V.; Garrido, Ll.; Martinez, M.; Mattison, T.; Orteu, S.; Pacheco, A.; Padilla, C.; Pascual, A.; Creanza, D.; de Palma, M.; Farilla, A.; Iaselli, G.; Maggi, G.; Marinelli, N.; Natali, S.; Nuzzo, S.; Ranieri, A.; Raso, G.; Romano, F.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Zito, G.; Chai, Y.; Hu, H.; Huang, D.; Huang, X.; Lin, J.; Wang, T.; Xie, Y.; Xu, D.; Xu, R.; Zhang, J.; Zhang, L.; Zhao, W.; Bonvicini, G.; Boudreau, J.; Casper, D.; Drevermann, H.; Forty, R. W.; Ganis, G.; Gay, C.; Girone, M.; Hagelberg, R.; Harvey, J.; Hilgart, J.; Jacobsen, R.; Jost, B.; Knobloch, J.; Lehraus, I.; Maggi, M.; Markou, C.; Mato, P.; Meinhard, H.; Minten, A.; Miquel, R.; Moser, H.-G.; Palazzi, P.; Pater, J. R.; Perlas, J. A.; Perrodo, P.; Pusztaszeri, J.-F.; Ranjard, F.; Rolandi, L.; Rothberg, J.; Ruan, T.; Saich, M.; Schlatter, D.; Schmelling, M.; Sefkow, F.; Tejessy, W.; Tomalin, I. R.; Veenhof, R.; Wachsmuth, H.; Wasserbaech, S.; Wiedenmann, W.; Wildish, T.; Witzeling, W.; Wotschack, J.; Ajaltouni, Z.; Bardadin-Otwinowska, M.; Barres, A.; Boyer, C.; Falvard, A.; Gay, P.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Montret, J.-C.; Pallin, D.; Perret, P.; Podlyski, F.; Proriol, J.; Saadi, F.; Fearnley, T.; Hansen, J. B.; Hansen, J. D.; Hansen, J. R.; Hansen, P. H.; Johnson, S. D.; Møllerud, R.; Nilsson, B. S.; Kyriakis, A.; Simopoulou, E.; Siotis, I.; Vayaki, A.; Zachariadou, K.; Badier, J.; Blondel, A.; Bonneaud, G.; Brient, J. C.; Bourdon, P.; Fouque, G.; Passalacqua, L.; Rougé, A.; Rumpf, M.; Tanaka, R.; Verderi, M.; Videau, H.; Candlin, D. J.; Parsons, M. I.; Veitch, E.; Focardi, E.; Moneta, L.; Parrini, G.; Corden, M.; Delfino, M.; Georgiopoulos, C.; Jaffe, D. E.; Levinthal, D.; Antonelli, A.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Cerutti, F.; Chiarella, V.; Felici, G.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G. P.; Pepe-Altarelli, M.; Salomone, S.; Colrain, P.; Ten Have, I.; Knowles, I. G.; Lynch, J. G.; Maitland, W.; Morton, W. T.; Raine, C.; Reeves, P.; Scarr, J. M.; Smith, K.; Smith, M. G.; Thompson, A. S.; Thorn, S.; Turnbull, R. M.; Brandl, B.; Braun, O.; Geweniger, C.; Graefe, G.; Hanke, P.; Hepp, V.; Karger, C.; Kluge, E. E.; Maumary, Y.; Putzer, A.; Rensch, B.; Stahl, A.; Tittel, K.; Wunsch, M.; Beuselinck, R.; Binnie, D. M.; Cameron, W.; Cattaneo, M.; Colling, D. J.; Dornan, P. J.; Hassard, J. F.; Lieske, N. M.; Moutoussi, A.; Nash, J.; Patton, S.; Payne, D. G.; Phillips, M. J.; San Martin, G.; Sedgbeer, J. K.; Wright, A. G.; Girtler, P.; Kuhn, D.; Rudolph, G.; Vogl, R.; Bowdery, C. K.; Brodbeck, T. J.; Finch, A. J.; Foster, F.; Hughes, G.; Jackson, D.; Keemer, N. R.; Nuttall, M.; Patel, A.; Sloan, T.; Snow, S. W.; Whelan, E. P.; Galla, A.; Greene, A. M.; Kleinknecht, K.; Raab, J.; Renk, B.; Sander, H.-G.; Schmidt, H.; Walther, S. M.; Wanke, R.; Wolf, B.; Bencheikh, A. M.; Benchouk, C.; Bonissent, A.; Calvet, D.; Carr, J.; Coyle, P.; Diaconu, C.; Drinkard, J.; Etienne, F.; Nicod, D.; Payre, P.; Ross, L.; Rousseau, D.; Schwemling, P.; Talby, M.; Adlung, S.; Assmann, R.; Bauer, C.; Blum, W.; Brown, D.; Cattaneo, P.; Dehning, B.; Dietl, H.; Dydak, F.; Frank, M.; Halley, A. W.; Jakobs, K.; Lauber, J.; Lütjens, G.; Lutz, G.; Männer, W.; Richter, R.; Schröder, J.; Schwarz, A. S.; Settles, R.; Seywerd, H.; Stierlin, U.; Stiegler, U.; Denis, R. St.; Wolf, G.; Alemany, R.; Boucrot, J.; Callot, O.; Cordier, A.; Davier, M.; Duflot, L.; Grivaz, J.-F.; Heusse, Ph.; Janot, P.; Kimfn 19, D. W.; Le Diberder, F.; Lefrançois, J.; Lutz, A.-M.; Musolino, G.; Schune, M.-H.; Veillet, J.-J.; Videau, I.; Abbaneo, D.; Bagliesi, G.; Batignani, G.; Bottigli, U.; Bozzi, C.; Calderini, G.; Carpinelli, M.; Ciocci, M. A.; Ciulli, V.; Dell'Orso, R.; Ferrante, I.; Fidecaro, F.; Foà, L.; Forti, F.; Giassi, A.; Giorgi, M. A.; Gregorio, A.; Ligabue, F.; Lusiani, A.; Mannelli, E. B.; Marrocchesi, P. S.; Messineo, A.; Palla, F.; Rizzo, G.; Sanguinetti, G.; Spagnolo, P.; Steinberger, J.; Tenchini, R.; Tonelli, G.; Triggiani, G.; Valassi, A.; Vannini, C.; Venturi, A.; Verdini, P. G.; Walsh, J.; Betteridge, A. P.; Gao, Y.; Green, M. G.; Johnson, D. L.; March, P. V.; Medcalf, T.; Mir, Ll. M.; Quazi, I. S.; Strong, J. A.; Bertin, V.; Botterill, D. R.; Clifft, R. W.; Edgecock, T. R.; Haywood, S.; Edwards, M.; Norton, P. R.; Thompson, J. C.; Bloch-Devaux, B.; Colas, P.; Duarte, H.; Emery, S.; Kozanecki, W.; Lançon, E.; Lemaire, M. C.; Locci, E.; Marx, B.; Perez, P.; Rander, J.; Renardy, J.-F.; Rosowsky, A.; Roussarie, A.; Schuller, J.-P.; Schwindling, J.; Si Mohand, D.; Vallage, B.; Johnson, R. P.; Litke, A. M.; Taylor, G.; Wear, J.; Babbage, W.; Booth, C. N.; Buttar, C.; Cartwright, S.; Combley, F.; Dawson, I.; Thompson, L. F.; Barberio, E.; Böhrer, A.; Brandt, S.; Cowan, G.; Grupen, C.; Lutters, G.; Rivera, F.; Schäfer, U.; Smolik, L.; Bosisio, L.; Della Marina, R.; Giannini, G.; Gobbo, B.; Pitis, L.; Ragusa, F.; Bellantoni, L.; Chen, W.; Conway, J. S.; Feng, Z.; Ferguson, D. P. S.; Gao, Y. S.; Grahl, J.; Harton, J. L.; Hayes, O. J.; Nachtman, J. M.; Pan, Y. B.; Saadi, Y.; Schmitt, M.; Scott, I.; Sharma, V.; Shi, Z. H.; Turk, J. D.; Walsh, A. M.; Weber, F. V.; Lan Wu, Sau; Wu, X.; Zheng, M.; Zobernig, G.; Aleph Collaboration

    1994-02-01

    The lifetime of the Bs0 has been measured in a data sample of 8890000 hadronic events recorded with the ALEPH detector at LEP. After background subtraction 30.8 ± 6.9 events are attributed to the semileptonic decay of the Bs0 to a Ds- and an opposite-sign lepton. A maximum-likelihood fit to the distribution of the proper times of these events yields a Bs0 lifetime of τBs = 1.92 -0.35+0.45 ± 0.04 ps.

  13. Time variation of fluorescence lifetime in enhanced cyan fluorescence protein

    International Nuclear Information System (INIS)

    Lee, Soonhyouk; Kim, Soo Yong; Park, Kyoungsook; Jeong, Jinyoung; Chung, Bong Hyun; Kim, Sok Won

    2010-01-01

    The lifetime variations of enhanced cyan fluorescence protein (ECFP) in relatively short integration time bins were studied via time-correlated single photon counting (TCSPC) measurement. We observed that minimum photon counts are necessary for the lifetime estimation to achieve a certain range of variance. The conditions to decrease the variance of lifetime were investigated and the channel width of the measurement of TCSPC data was found to be another important factor for the variance of lifetime. Though the lifetime of ECFP is best fit by a double exponential, a mono exponential fit for the same integration time is more stable. The results may be useful in the analysis of photophysical dynamics for ensemble molecules in short measurement time windows.

  14. Measurement of the D/sup 0/ lifetime

    Energy Technology Data Exchange (ETDEWEB)

    Althoff, M; Braunschweig, W; Gerhards, R; Kirschfink, F J; Martyn, H U; Rosskamp, P; Wallraff, W; Bock, B; Eisenmann, J; Fischer, H M

    1986-04-01

    We have determined the D/sup 0/ lifetime from reconstructed vertices of D/sup 0/ mesons produced in e/sup +/e/sup -/ annihilations at an average center of mass energy of 42.2 GeV. From fifteen events the D/sup 0/ lifetime was determined to be (4.3/sup +2.0//sub -1.4/ +- 0.8) . 10/sup -13/s.

  15. An improved $\\pi$K atom lifetime measurement

    CERN Document Server

    Yazkov, V

    2016-01-01

    This note describes details of analysis of data samples collected by DIRAC experiment on a Pt target in 2007 and Ni targets in 2008–2010 in order to estimate the lifetime of πK atoms. Experimental results consist of eight distinct data samples: both charge combinations ( π + K − and K + π − atoms) obtained in different experimental conditions corresponding to each year of data taking. Estimations of systematic errors are presented. Taking into account both statistical and systematic uncertainties, the lifetime of πK atoms is estimated by the maximum likelihood method. The above sample comprises the total statistics, available for the analysis, thus the improvement over the previous estimation [1,3] of the πK atom lifetime is achieved.

  16. Joint Iterative Carrier Synchronization and Signal Detection for Dual Carrier 448 Gb/s PDM 16-QAM

    DEFF Research Database (Denmark)

    Zibar, Darko; Carvalho, Luis; Estaran Tolosa, Jose Manuel

    2013-01-01

    Soft decision driven joint carrier synchronization and signal detection, employing expectation maximization, is experimentally demonstrated. Employing soft decisions offers an improvement of 0.5 dB compared to hard decision digital PLL based carrier synchronization and demodulation.......Soft decision driven joint carrier synchronization and signal detection, employing expectation maximization, is experimentally demonstrated. Employing soft decisions offers an improvement of 0.5 dB compared to hard decision digital PLL based carrier synchronization and demodulation....

  17. 42 CFR 409.62 - Lifetime maximum on inpatient psychiatric care.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Lifetime maximum on inpatient psychiatric care. 409....62 Lifetime maximum on inpatient psychiatric care. There is a lifetime maximum of 190 days on inpatient psychiatric hospital services available to any beneficiary. Therefore, once an individual receives...

  18. LIQUIFIED NATURAL GAS (LNG CARRIERS

    Directory of Open Access Journals (Sweden)

    Daniel Posavec

    2010-12-01

    Full Text Available Modern liquefied natural gas carriers are double-bottom ships classified according to the type of LNG tank. The tanks are specially designed to store natural gas cooled to -161°C, the boiling point of methane. Since LNG is highly flammable, special care must be taken when designing and operating the ship. The development of LNG carriers has begun in the middle of the twentieth century. LNG carrier storage space has gradually grown to the current maximum of 260000 m3. There are more than 300 LNG carriers currently in operation (the paper is published in Croatian.

  19. Predicting sample lifetimes in creep fracture of heterogeneous materials

    Science.gov (United States)

    Koivisto, Juha; Ovaska, Markus; Miksic, Amandine; Laurson, Lasse; Alava, Mikko J.

    2016-08-01

    Materials flow—under creep or constant loads—and, finally, fail. The prediction of sample lifetimes is an important and highly challenging problem because of the inherently heterogeneous nature of most materials that results in large sample-to-sample lifetime fluctuations, even under the same conditions. We study creep deformation of paper sheets as one heterogeneous material and thus show how to predict lifetimes of individual samples by exploiting the "universal" features in the sample-inherent creep curves, particularly the passage to an accelerating creep rate. Using simulations of a viscoelastic fiber bundle model, we illustrate how deformation localization controls the shape of the creep curve and thus the degree of lifetime predictability.

  20. Lifetime Extension Report: Progress on the SAVY-4000 Lifetime Extension Program

    International Nuclear Information System (INIS)

    Welch, Cynthia F.; Smith, Paul Herrick; Weis, Eric M.; Blair, Michael W.; Stone, Timothy Amos; Veirs, Douglas Kirk; Reeves, Kirk Patrick; Karns, Tristan; Oka, Jude M.; Keller, Jennie; Meincke, Linda Jeanne; Torres, Joseph Angelo; Herman, Matthew Joseph; Weaver, Brian Phillip; Adams, Jillian Cathleen; Trautschold, Olivia Carol

    2016-01-01

    The 3-year accelerated aging study of the SAVY-4000 O-ring shows very little evidence of significant degradation to samples subjected to aggressive elevated temperature and radiation conditions. Whole container thermal aging studies followed by helium leakage testing and compression set measurements were used to establish an estimate for a failure criterion for O-ring compression set of ?65 %. The whole container aging studies further show that the air flow and efficiency functions of the filter do not degrade significantly after thermal aging. However, the degradation of the water-resistant function leads to water penetration failure after four months at 210°C, but does not cause failure after 10 months at 120°C (130°C is the maximum operating temperature for the PTFE membrane). The thermal aging data for O-ring compression set do not meet the assumptions of standard time-temperature superposition analysis for accelerated aging studies. Instead, the data suggest that multiple degradation mechanisms are operative, with a reversible mechanism operative at low aging temperatures and an irreversible mechanism dominating at high aging temperatures. To distinguish between these mechanisms, we have measured compression set after allowing the sample to physically relax, thereby minimizing the effect of the reversible mechanism. The resulting data were analyzed using two distinct mathematical methods to obtain a lifetime estimate based on chemical degradation alone. Both methods support a lifetime estimate of greater than 150 years at 80°C. Although the role of the reversible mechanism is not fully understood, it is clear that the contribution to the total compression set is small in comparison to that due to the chemical degradation mechanism. To better understand the chemical degradation mechanism, thermally aged O-ring samples have been characterized by Fourier Transform Infrared (FTIR), Electron Paramagnetic Resonance (EPR), Gel Permeation Chromatography (GPC), and

  1. Lifetime Extension Report: Progress on the SAVY-4000 Lifetime Extension Program

    Energy Technology Data Exchange (ETDEWEB)

    Welch, Cynthia F. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Materials Science and Technology. Engineered Materials; Smith, Paul Herrick [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Nuclear Process Infrastructure; Weis, Eric M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Materials Science and Technology. Engineered Materials; Blair, Michael W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Materials Science and Technology. Engineered Materials; Stone, Timothy Amos [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Nuclear Process Infrastructure; Veirs, Douglas Kirk [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Manufacturing Engineering and Technology; Reeves, Kirk Patrick [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Nuclear Process Infrastructure; Karns, Tristan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Nuclear Process Infrastructure; Oka, Jude M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Nuclear Process Infrastructure; Keller, Jennie [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Materials Science and Technology. Engineered Materials; Meincke, Linda Jeanne [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Materials Science and Technology. Engineered Materials; Torres, Joseph Angelo [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Materials Science and Technology. Engineered Materials; Herman, Matthew Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Materials Science and Technology. Engineered Materials; Weaver, Brian Phillip [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Computer, Computational, and Statistical Sciences. Statistical Sciences; Adams, Jillian Cathleen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Materials Science and Technology. Engineered Materials; Trautschold, Olivia Carol [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Materials Science and Technology. Engineered Materials

    2016-09-20

    The 3-year accelerated aging study of the SAVY-4000 O-ring shows very little evidence of significant degradation to samples subjected to aggressive elevated temperature and radiation conditions. Whole container thermal aging studies followed by helium leakage testing and compression set measurements were used to establish an estimate for a failure criterion for O-ring compression set of ≥65 %. The whole container aging studies further show that the air flow and efficiency functions of the filter do not degrade significantly after thermal aging. However, the degradation of the water-resistant function leads to water penetration failure after four months at 210°C, but does not cause failure after 10 months at 120°C (130°C is the maximum operating temperature for the PTFE membrane). The thermal aging data for O-ring compression set do not meet the assumptions of standard time-temperature superposition analysis for accelerated aging studies. Instead, the data suggest that multiple degradation mechanisms are operative, with a reversible mechanism operative at low aging temperatures and an irreversible mechanism dominating at high aging temperatures. To distinguish between these mechanisms, we have measured compression set after allowing the sample to physically relax, thereby minimizing the effect of the reversible mechanism. The resulting data were analyzed using two distinct mathematical methods to obtain a lifetime estimate based on chemical degradation alone. Both methods support a lifetime estimate of greater than 150 years at 80°C. Although the role of the reversible mechanism is not fully understood, it is clear that the contribution to the total compression set is small in comparison to that due to the chemical degradation mechanism. To better understand the chemical degradation mechanism, thermally aged O-ring samples have been characterized by Fourier Transform Infrared (FTIR), Electron Paramagnetic Resonance (EPR), Gel Permeation Chromatography (GPC

  2. Air Carrier Traffic Statistics.

    Science.gov (United States)

    2013-11-01

    This report contains airline operating statistics for large certificated air carriers based on data reported to U.S. Department of Transportation (DOT) by carriers that hold a certificate issued under Section 401 of the Federal Aviation Act of 1958 a...

  3. Air Carrier Traffic Statistics.

    Science.gov (United States)

    2012-07-01

    This report contains airline operating statistics for large certificated air carriers based on data reported to U.S. Department of Transportation (DOT) by carriers that hold a certificate issued under Section 401 of the Federal Aviation Act of 1958 a...

  4. Lifetimes of charmed hadrons revisited. Facts and fancy

    International Nuclear Information System (INIS)

    Blok, B.

    1994-01-01

    The problem of the hierarchy of lifetimes of charmed hadrons is reviewed. The QCD-based theory of pre asymptotic effects in inclusive weak decays dating back to the beginning of the eighties is now entering its mature phase. Combining recent and old results it is shown that the observed hierarchy reflects most intimate features of the hadronic structure. The problem of a wide spread of lifetimes of charmed hadrons is addressed. A number of predictions is given for the hierarchy of lifetimes in the family of the beautiful hadrons. (author). 29 refs., 3 figs., 1 tab

  5. Lifetime of the phonons in the PLT ceramic

    Energy Technology Data Exchange (ETDEWEB)

    Barba-Ortega, J., E-mail: jjbarba@unal.edu.co; Joya, M. R., E-mail: mrinconj@unal.edu.co [Departamento de Física, Universidad Nacional de Colombia, carrera 30 # 45-03, Bogotá 1149 (Colombia); Londoño, F. A., E-mail: flondono@fisica.udea.edu.co [Instituto de Física, Universidad de Antioquia, Calle 67 #53-108 Of.6-105, Medellin (Colombia)

    2014-11-05

    The lifetimes at higher temperatures on lanthanum-modified lead titanate (PLT) are mainly due to the anharmonic decay of optical phonons into low-energy phonons. The temperature-independent contributions from inherent crystal defects and from boundary scattering become comparable to the phonon scattering contribution at lower temperatures. The thermal interaction is large at higher temperatures which decreases the phonon mean free path, and so the decay lifetime decreases as the temperature of the system is increased. This leads to the increased line width at higher temperatures. We made an estimate of the lifetimes for different concentrations and temperatures in PLT.

  6. Angular distributions as lifetime probes

    Energy Technology Data Exchange (ETDEWEB)

    Dror, Jeff Asaf; Grossman, Yuval [Department of Physics, LEPP, Cornell University,Ithaca, NY 14853 (United States)

    2014-06-27

    If new TeV scale particles are discovered, it will be important to determine their width. There is, however, a problematic region, where the width is too small to be determined directly, and too large to generate a secondary vertex. For a collection of colored, spin polarized particles, hadronization depolarizes the particles prior to their decay. The amount of depolarization can be used to probe the lifetime in the problematic region. In this paper we apply this method to a realistic scenario of a top-like particle that can be produced at the LHC. We study how depolarization affects the angular distributions of the decay products and derive an equation for the distributions that is sensitive to the lifetime.

  7. Principal and secondary luminescence lifetime components in annealed natural quartz

    International Nuclear Information System (INIS)

    Chithambo, M.L.; Ogundare, F.O.; Feathers, J.

    2008-01-01

    Time-resolved luminescence spectra from quartz can be separated into components with distinct principal and secondary lifetimes depending on certain combinations of annealing and measurement temperature. The influence of annealing on properties of the lifetimes related to irradiation dose and temperature of measurement has been investigated in sedimentary quartz annealed at various temperatures up to 900 deg. C. Time-resolved luminescence for use in the analysis was pulse stimulated from samples at 470 nm between 20 and 200 deg. C. Luminescence lifetimes decrease with measurement temperature due to increasing thermal effect on the associated luminescence with an activation energy of thermal quenching equal to 0.68±0.01eV for the secondary lifetime but only qualitatively so for the principal lifetime component. Concerning the influence of annealing temperature, luminescence lifetimes measured at 20 deg. C are constant at about 33μs for annealing temperatures up to 600 0 C but decrease to about 29μs when the annealing temperature is increased to 900 deg. C. In addition, it was found that lifetime components in samples annealed at 800 deg. C are independent of radiation dose in the range 85-1340 Gy investigated. The dependence of lifetimes on both the annealing temperature and magnitude of radiation dose is described as being due to the increasing importance of a particular recombination centre in the luminescence emission process as a result of dynamic hole transfer between non-radiative and radiative luminescence centres

  8. Positron lifetime studies on thorium oxide powders

    International Nuclear Information System (INIS)

    Upadhyaya, D.D.; Muraleedharan, R.V.; Sharma, B.D.

    1982-01-01

    Positron lifetime spectra have been studied for ThO 2 powders, calcined at different temperatures and having different particle sizes. Three lifetime components could be resolved, the longest component being of low intensity. An observed strong dependence on the particle size of the annihilation process and the variation of positronium diffusion constant is explained on the basis of defect density variations in these powders. (author)

  9. Efficient carrier relaxation and fast carrier recombination of N-polar InGaN/GaN light emitting diodes

    International Nuclear Information System (INIS)

    Feng, Shih-Wei; Liao, Po-Hsun; Leung, Benjamin; Han, Jung; Yang, Fann-Wei; Wang, Hsiang-Chen

    2015-01-01

    Based on quantum efficiency and time-resolved electroluminescence measurements, the effects of carrier localization and quantum-confined Stark effect (QCSE) on carrier transport and recombination dynamics of Ga- and N-polar InGaN/GaN light-emitting diodes (LEDs) are reported. The N-polar LED exhibits shorter ns-scale response, rising, delay, and recombination times than the Ga-polar one does. Stronger carrier localization and the combined effects of suppressed QCSE and electric field and lower potential barrier acting upon the forward bias in an N-polar LED provide the advantages of more efficient carrier relaxation and faster carrier recombination. By optimizing growth conditions to enhance the radiative recombination, the advantages of more efficient carrier relaxation and faster carrier recombination in a competitive performance N-polar LED can be realized for applications of high-speed flash LEDs. The research results provide important information for carrier transport and recombination dynamics of an N-polar InGaN/GaN LED

  10. Efficient carrier relaxation and fast carrier recombination of N-polar InGaN/GaN light emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Shih-Wei, E-mail: swfeng@nuk.edu.tw; Liao, Po-Hsun [Department of Applied Physics, National University of Kaohsiung, No. 700, Kaohsiung University Rd., Nan Tzu Dist., 811 Kaohsiung, Taiwan (China); Leung, Benjamin; Han, Jung [Department of Electrical Engineering, Yale University, New Haven, Connecticut 06520 (United States); Yang, Fann-Wei [Department of Electronic Engineering, Southern Taiwan University of Science and Technology, Tainan, Taiwan (China); Wang, Hsiang-Chen [Graduate Institute of Opto-Mechatronics and Advanced Institute of Manufacturing with High-Tech Innovations (AIM-HI), National Chung Cheng University, Chia-Yi, Taiwan (China)

    2015-07-28

    Based on quantum efficiency and time-resolved electroluminescence measurements, the effects of carrier localization and quantum-confined Stark effect (QCSE) on carrier transport and recombination dynamics of Ga- and N-polar InGaN/GaN light-emitting diodes (LEDs) are reported. The N-polar LED exhibits shorter ns-scale response, rising, delay, and recombination times than the Ga-polar one does. Stronger carrier localization and the combined effects of suppressed QCSE and electric field and lower potential barrier acting upon the forward bias in an N-polar LED provide the advantages of more efficient carrier relaxation and faster carrier recombination. By optimizing growth conditions to enhance the radiative recombination, the advantages of more efficient carrier relaxation and faster carrier recombination in a competitive performance N-polar LED can be realized for applications of high-speed flash LEDs. The research results provide important information for carrier transport and recombination dynamics of an N-polar InGaN/GaN LED.

  11. Estimation of the Service Lifetime of Concrete Bridges

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    In this paper estimation of the service lifetime of concrete bridges is discussed. The main reason for deterioration of concrete bridges is corrosion of the reinforcement. Therefore, modelling of the corrosion process is an important aspect of the estimation of the service lifetime. In this paper...

  12. The Lifetime Prediction of LED Drivers and Lamps

    NARCIS (Netherlands)

    Sun, B.

    2017-01-01

    Light-Emitting Diodes (LEDs) have become a very promising alternative lighting source with the main advantages of a longer lifetime and a higher efficiency than traditional ones. However, the LED lamp’s lifetime is compromised by its driver’s reliability. Although extensive studies have been made on

  13. 50 CFR 600.760 - Fishery Negotiation Panel lifetime.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Fishery Negotiation Panel lifetime. 600... ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MAGNUSON-STEVENS ACT PROVISIONS Fishery Negotiation Panels § 600.760 Fishery Negotiation Panel lifetime. (a) An FNP shall terminate upon either: (1) Submission of...

  14. Fluorophore:dendrimer ratio impacts cellular uptake and intracellular fluorescence lifetime.

    Science.gov (United States)

    Dougherty, Casey A; Vaidyanathan, Sriram; Orr, Bradford G; Banaszak Holl, Mark M

    2015-02-18

    G5-NH2-TAMRAn (n = 1-4, 5+, and 1.5(avg)) were prepared with n = 1-4 as a precise dye:dendrimer ratio, 5+ as a mixture of dendrimers with 5 or more dye per dendrimer, and 1.5(avg) as a Poisson distribution of dye:dendrimer ratios with a mean of 1.5 dye per dendrimer. The absorption intensity increased sublinearly with n whereas the fluorescence emission and lifetime decreased with an increasing number of dyes per dendrimer. Flow cytometry was employed to quantify uptake into HEK293A cells. Dendrimers with 2-4 dyes were found to have greater uptake than dendrimer with a single dye. Fluorescence lifetime imaging microscopy (FLIM) showed that the different dye:dendrimer ratio alone was sufficient to change the fluorescence lifetime of the material observed inside cells. We also observed that the lifetime of G5-NH2-TAMRA5+ increased when present in the cell as compared to solution. However, cells treated with G5-NH2-TAMRA1.5(avg) did not exhibit the high lifetime components present in G5-NH2-TAMRA1 and G5-NH2-TAMRA5+. In general, the effects of the dye:dendrimer ratio on fluorescence lifetime were of similar magnitude to environmentally induced lifetime shifts.

  15. Lifetimes of some b-flavored hadrons

    International Nuclear Information System (INIS)

    Stone, S.

    2014-06-01

    Recent measurements of lifetimes of some b-flavored hadrons are presented and interpreted in the context of theoretical models, especially the Heavy Quark Expansion. Decay widths and decay width differences in the B s 0 - B-bar s 0 system are discussed from the studies of decays into the final states J/ψK + K - , J/ψπ + π - , D s + D s - , K + K - and D s ± π ± . Lifetime measurements of the baryons Λ b 0 , Ξ b - , Ξ b 0 , and Ω b - are also shown. (author)

  16. Positron lifetime in vanadium oxide bronzes

    International Nuclear Information System (INIS)

    Dryzek, J.; Dryzek, E.

    2003-01-01

    The positron lifetime (PL) and Doppler broadening (DB) of annihilation line measurements have been performed in vanadium oxide bronzes M x V 2 O 5 . The dependence of these annihilation characteristics on the kind and concentration of the metal M donor has been observed. In the PL spectrum only one lifetime component has been detected in all studied bronzes. The results indicate the positron localization in the structural tunnels present in the crystalline lattice of the vanadium oxide bronzes. (copyright 2003 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  17. An approach for longer lifetime MCFCs

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Masaru; Tatsumi, Masahiko; Hayano, Takuro [MCFC Research Association, Tokyo (Japan)] [and others

    1996-12-31

    For entering into commercialization of MCFC power plants in the beginning of the 21st century, we will devote to research for increasing lifetime as long as 40,000 hours with cell performance decay rate of 0.25 %/1000hrs as the target in FY 1999. This paper will discuss on our approach for longer lifetime MCFCs through electrolyte-loss management and NiO precipitation management as well as micro-structural control of electrodes and matrix plates. Cell voltage decay rate will be estimated by simulation through series of experiments on accelerated conditions.

  18. DC photogun vacuum characterization through photocathode lifetime studies

    International Nuclear Information System (INIS)

    Marcy Stutzman; Joseph Grames; Matt Poelker; Kenneth Surles-Law; Philip Adderley

    2007-01-01

    Excellent vacuum is essential for long photocathode lifetimes in DC high voltage photoelectron guns. Vacuum Research at Thomas Jefferson National Accelerator Facility has focused on characterizing the existing vacuum systems at the CEBAF polarized photoinjector and on quantifying improvements for new systems. Vacuum chamber preprocessing, full activation of NEG pumps and NEG coating the chamber walls should improve the vacuum within the electron gun, however, pressure measurement is difficult at pressures approaching the extreme-high-vacuum (XHV) region and extractor gauge readings are not significantly different between the improved and original systems. The ultimate test of vacuum in a DC high voltage photogun is the photocathode lifetime, which is limited by the ionization and back-bombardment of residual gasses. Discussion will include our new load-locked gun design as well as lifetime measurements in both our operational and new photo-guns, and the correlations between measured vacuum and lifetimes will be investigated

  19. Study of straw chamber lifetime with argon ethane

    International Nuclear Information System (INIS)

    Adler, J.; Bolton, T.; Bunnell, K.; Cheu, E.; Grab, C.; Mazaheri, G.; Odian, A.; Pitman, D.; Stockhausen, W.; Toki, W.; Wadley, W.; Wood, C.; Mir, R.

    1989-01-01

    We present detailed laboratory measurements of the lifetime of a small test chamber, simulating the Mark III straw vertex chamber conditions. The tests were carried out with an argon-ethane 50/50 gas mixture at 3 atm absolute pressure and 3.9 kV applied to the wires. After the accumulation of ≅ 0.02 C/cm on a single straw, continuous discharges began. The addition of alcohol or water vapor to the gas mixture was found to extend the lifetime of the straws. Continuous flow of the gas mixture with water vapor through the straws prolonged the lifetime significantly. We present results on the effects of changing the gas mixture inside the straws at regular time intervals. Adding a small percentage of water vapor to the argon-ethane gas and flowing the gas mixture in the straws can improve the lifetime by more than an order of magnitude. An accumulated charge of 1.0 C/cm on a single straw has been obtained. (orig.)

  20. Lifetime of {sup 44}Ti as probe for supernova models

    Energy Technology Data Exchange (ETDEWEB)

    Goerres, J; Meissner, J; Schatz, H; Stech, E; Tischhauser, P; Wiescher, M [Univ. of Notre Dame, Notre Dame, IN (United States); Bazin, D; Harkewicz, R; Hellstroem, M; Sherrill, B; Steiner, M [Michigan State Univ., East Lansing, MI (United States); Boyd, R N [Ohio State Univ., Columbus, OH (United States); Buchmann, L [TRIUMF, Vancouver, BC (Canada); Hartmann, D H [Clemson Univ., Clemson, SC (United States); Hinnefeld, J D [Indiana Univ. South Bend, South Bend, IN (United States)

    1998-06-01

    The recent observation of {sup 44}Ti radioactivity in the supernova remnant Cassiopeia A with the Compton Gamma Ray Observatory allows the determination of the absolute amount of {sup 44}Ti. This provides a test for current supernova models. The main uncertainty is the lifetime of {sup 44}Ti. We report a new measurement of the lifetime of {sup 44}Ti applying a novel technique. A mixed radioactive beam containing {sup 44}Ti as well as {sup 22}Na was implanted and the resulting {gamma}-activity was measured. This allowed the determination of the lifetime of {sup 44}Ti relative to the lifetime of {sup 22}Na, {tau} = (87.0 {+-} 1.9) y. With this lifetime, the {sup 44}Ti abundance agrees with theoretical predictions within the remaining observational uncertainties. (orig.)

  1. Positron annihilation lifetime study of low temperature irradiated metals

    Energy Technology Data Exchange (ETDEWEB)

    Kuramoto, Eiichi [Kyushu Univ., Kasuga, Fukuoka (Japan). Research Inst. for Applied Mechanics

    1997-11-01

    Positron annihilation lifetime measurements have been made for electron and neutron irradiated Fe, Fe-Cr, Fe-Cu, Fe-Si, Fe-16Cr-17Ni specimens, and isochronal annealing behaviors were obtained for these metals and alloys. It was found that vacancies start to migrate at about 200 K in Fe and form microvoids, but by the addition of small amount of alloying elements this behavior was changed depending on the alloying elements. Positron lifetime calculations were made to explain the experimental results using EAM (embedded atom method) type potential for the lattice relaxation and the atomic superposition method for the lifetime calculation. Fairly good agreements were obtained for the positron lifetime in a vacancy in Fe and other alloys. (author)

  2. Positron annihilation lifetime spectroscopy study of Kapton thin foils

    Science.gov (United States)

    Kanda, G. S.; Ravelli, L.; Löwe, B.; Egger, W.; Keeble, D. J.

    2016-01-01

    Variable energy positron annihilation lifetime spectroscopy (VE-PALS) experiments on polyimide material Kapton are reported. Thin Kapton foils are widely used in a variety of mechanical, electronic applications. PALS provides a sensitive probe of vacancy-related defects in a wide range of materials, including open volume in polymers. Varying the positron implantation energy enables direct measurement of thin foils. Thin Kapton foils are also commonly used to enclose the positron source material in conventional PALS measurements performed with unmoderated radionuclide sources. The results of depth-profiled positron lifetime measurements on 7.6 μm and 25 μm Kapton foils are reported and determine a dominant 385(1) ps lifetime component. The absence of significant nanosecond lifetime component due to positronium formation is confirmed.

  3. Lifetime-Aware Cloud Data Centers: Models and Performance Evaluation

    Directory of Open Access Journals (Sweden)

    Luca Chiaraviglio

    2016-06-01

    Full Text Available We present a model to evaluate the server lifetime in cloud data centers (DCs. In particular, when the server power level is decreased, the failure rate tends to be reduced as a consequence of the limited number of components powered on. However, the variation between the different power states triggers a failure rate increase. We therefore consider these two effects in a server lifetime model, subject to an energy-aware management policy. We then evaluate our model in a realistic case study. Our results show that the impact on the server lifetime is far from negligible. As a consequence, we argue that a lifetime-aware approach should be pursued to decide how and when to apply a power state change to a server.

  4. CO2 absorption of perovskites as seen by positron lifetime spectroscopy

    International Nuclear Information System (INIS)

    Suevegh, K.; Nomura, K.; Juhasz, G.; Homonnay, Z.; Vertes, A.

    2000-01-01

    The CO 2 absorption of several ABO 3 type perovskites was studied by positron lifetime spectroscopy. The longer positron lifetime was associated with positrons trapped by A site vacancies. The evaluated positron lifetime data indicated the relative stability of the crystal structure of Sr(Co 0.5 Fe 0.5 )O 3-δ against Ca doping at low Ca concentrations. Oxygen desorption and CO 2 absorption/desorption could also be followed by positron lifetime spectroscopy. It was shown that the concentration of oxygen vacancies has a large effect on positron lifetime data through the electron density of A site vacancies.

  5. Measurements of b-hadron lifetimes with the Delphi detector

    International Nuclear Information System (INIS)

    Demaria, N.

    1996-01-01

    The Delphi collaboration has measured the lifetime of b-hadrons using several different methods. In this talk those exploited only by Delphi and that employ original ideas are presented: for the b-baryons lifetime the p-μ correlation; for the B 0 s the φ-μ, D s -h correlations and D s inclusive analysis. The measurement of the average lifetime of b- hadrons using the impact parameters and the vertices of hadronic final states is also presented. (orig.)

  6. Positron lifetime calculation for defects and defect clusters in graphite

    International Nuclear Information System (INIS)

    Onitsuka, T.; Ohkubo, H.; Takenaka, M.; Tsukuda, N.; Kuramoto, E.

    2000-01-01

    Calculations of positron lifetime have been made for vacancy type defects in graphite and compared with experimental results. Defect structures were obtained in a model graphite lattice after including relaxation of whole lattice as determined by the molecular dynamics method, where the interatomic potential given by Pablo Andribet, Dominguez-Vazguez, Mari Carmen Perez-Martin, Alonso, Jimenez-Rodriguez [Nucl. Instrum. and Meth. 115 (1996) 501] was used. For the defect structures obtained via lattice relaxation positron lifetime was calculated under the so-called atomic superposition method. Positron lifetimes 204 and 222 ps were obtained for the graphite matrix and a single vacancy, respectively, which can be compared with the experimental results 208 and 233 ps. For planar vacancy clusters, e.g., vacancy loops, lifetime calculation was also made and indicated that lifetime increases with the number of vacancies in a cluster. This is consistent with the experimental result in the region of higher annealing temperature (above 1200 deg. C), where the increase of positron lifetime is seen, probably corresponding to the clustering of mobile vacancies

  7. Lifetime measurements of the strange beauty meson and beauty baryons at LEP

    International Nuclear Information System (INIS)

    Romero, A.

    1994-01-01

    Last experimental results on the lifetimes of B s 0 mesons and beauty baryons from the LEP experiments ALEPH, DELPHI and OPAL are presented. LEP averages for the lifetimes of B s 0 and Λ b are compared to lifetimes of B d 0 and B + and to the average b hadron lifetime. The precision of these measurements begins to be suitable to test the theoretical predictions of 10-15% differences between the lifetimes of b baryons and mesons, but does not allow a test of the few percent difference expected between B d 0 and B + lifetimes. The data show a significant evidence (3 σ) for lifetime differences between b mesons and b baryons. (author). 4 refs., 9 figs

  8. Autofluorescence Lifetimes in Geographic Atrophy in Patients With Age-Related Macular Degeneration.

    Science.gov (United States)

    Dysli, Chantal; Wolf, Sebastian; Zinkernagel, Martin S

    2016-05-01

    To investigate fluorescence lifetime characteristics in patients with geographic atrophy (GA) in eyes with age-related macular degeneration and to correlate the measurements with clinical data and optical coherence tomography (OCT) findings. Patients with GA were imaged with a fluorescence lifetime imaging ophthalmoscope. Retinal autofluorescence lifetimes were measured in a short and a long spectral channel (498-560 nm and 560-720 nm). Mean retinal fluorescence lifetimes were analyzed within GA and the surrounding retina, and data were correlated with best corrected visual acuity and OCT measurements. Fluorescence lifetime maps of 41 eyes of 41 patients (80 ± 7 years) with GA were analyzed. Mean lifetimes within areas of atrophy were prolonged by 624 ± 276 ps (+152%) in the short spectral channel and 418 ± 186 ps (+83%) in the long spectral channel compared to the surrounding tissue. Autofluorescence lifetime abnormalities in GA occurred with particular patterns, similar to those seen in fundus autofluorescence intensity images. Within the fovea short mean autofluorescence lifetimes were observed, presumably representing macular pigment. Short lifetimes were preserved even in the absence of foveal sparing but were decreased in patients with advanced retinal atrophy in OCT. Short lifetimes in the fovea correlated with better best corrected visual acuity in both spectral channels. This study established that autofluorescence lifetime changes in GA present with explicit patterns. We hypothesize that the short lifetimes seen within the atrophy may be used to estimate damage induced by atrophy and to monitor disease progression in the context of natural history or interventional therapeutic studies.

  9. A positron annihilation lifetime spectroscopy study of porous silicon using a continuous lifetime fitting algorithm

    International Nuclear Information System (INIS)

    Derlet, P.M.; Choy, T.C.

    1996-01-01

    In the present work we report on a positron annihilation lifetime spectroscopy (PALS) investigation of porous silicon using a continuous lifetime fitting algorithm. Our motivation lies in the underlying disadvantage in discrete lifetime fitting algorithms where the number of components must initially be assumed since in general a realistic spectrum does not uniquely determine this number. This becomes particularly apparent when looking at highly disordered systems where the notion of a discrete spectrum may be invalid and indeed crucial to an understanding of the optical absorption and photo-luminescence properties. Using the PALS data collected from different porous silicon samples in conjunction with other methods of characterisation, we have extended the findings of previous work. In particular we resolve three rather than two ortho-positronium components, suggesting that there may be an additional intermediary scale of porosity in which ortho-positronium annihilates. We also establish the existence of a very weak ortho-positronium component in the pre-anodised wafers at a time scale approximately equal to the longest time ortho-positronium component seen in porous silicon, suggesting that irregularities of a particular magnitude exist before anodisation and that these may, in part, be the catalyst for the initial pore formation process

  10. Fluorescence Lifetime Imaging in Stargardt Disease: Potential Marker for Disease Progression

    OpenAIRE

    Dysli Chantal; Wolf Sebastian; Hatz Katja; Zinkernagel Martin

    2016-01-01

    PURPOSE The purpose of this study was to describe autofluorescence lifetime characteristics in Stargardt disease (STGD) using fluorescence lifetime imaging ophthalmoscopy (FLIO) and to investigate potential prognostic markers for disease activity and progression. METHODS Fluorescence lifetime data of 16 patients with STGD (mean age, 40 years; range, 22-56 years) and 15 age-matched controls were acquired using a fluorescence lifetime imaging ophthalmoscope based on a Heidelberg Eng...

  11. Impact of carriers in oral absorption

    DEFF Research Database (Denmark)

    Gram, Luise Kvisgaard; Rist, Gerda Marie; Lennernäs, Hans

    2009-01-01

    Carriers may mediate the permeation across enterocytes for drug substances being organic anions. Carrier mediated permeation for the organic anions estrone-3-sulfate (ES) and glipizide across Caco-2 cells were investigated kinetically, and interactions on involved carriers evaluated. Initial...

  12. Lifetime and Path Length of the Virtual Particle

    International Nuclear Information System (INIS)

    Lyuboshitz, V.L.; Lyuboshitz, V.V.

    2005-01-01

    The concepts of the lifetime and path length of a virtual particle are introduced. It is shown that, near the mass surface of the real particle, these quantities constitute a 4-vector. At very high energies, the virtual particle can propagate over considerable (even macroscopic) distances. The formulas for the lifetime and path length of an ultrarelativistic virtual electron in the process of bremsstrahlung in the Coulomb field of a nucleus are obtained. The lifetime and path length of the virtual photon at its conversion into an electron-positron pair are discussed. The connection between the path length of the virtual particle and the coherence length (formation length) is analyzed

  13. Atmospheric lifetimes of CFC 11 and CFC 12

    International Nuclear Information System (INIS)

    Owens, A.J.; Steed, J.M.; Miller, C.; Filkin, D.L.; Jesson, J.P.

    1982-01-01

    A two-dimensional (2-D) chemical model of the atmosphere is used to investigate the stratospheric removal rates of the chlorofluorocarbons CFC 11 (CFCl 3 ) and CFC 12 (CF 2 Cl 2 ). Assuming equivalent vertical transport rates, one-dimensional (1-D) models are shown to overestimate the atmospheric lifetime of CFC 11 by approx.10% because of their neglect of latitudinal effects. The present Du Pont 1-D and 2-D models have somewhat different effective transport rates and give steady state CFC 11 atmospheric lifetimes of 75 and 60 years, respectively, assuming no tropospheric destructive mechanism. For CFC 12, the corresponding calculated lifetimes are 140 and 120 years

  14. Carrier-added and no-carrier-added syntheses of [18F]spiroperidol and [18F]haloperidol

    International Nuclear Information System (INIS)

    Kilbourn, M.R.; Welch, M.J.; Dence, C.S.; Tewson, T.J.; Saji, H.; Maeda, M.

    1984-01-01

    Syntheses of [ 18 F]haloperidol and [ 18 F]spiroperidol in both no-carrier-added and carrier-added forms have been accomplished. The no-carrier-added [ 18 F]butyrophenone neuroleptics were prepared in low ( 18 F-neuroleptics were prepared in better (5-17%) yields by 18 F-for- 19 F nucleophilic aromatic substitution. The preparation of all synthetic precursors, and procedures for radiolabeling are fully described. (author)

  15. Temperature and phase dependence of positron lifetimes in solid cyclohexane

    DEFF Research Database (Denmark)

    Eldrup, Morten Mostgaard

    1985-01-01

    The temperature dependence of position lifetimes in both the brittle and plastic phases of cyclohaxane has been examined. Long-lived components in both phases are associated with the formation of positronium (Ps). Two long lifetimes attributable to ortho-Ps are resolvable in the plastic phase....... The longer of these (≈ 2.5 ns), which is temperature dependent, is ascribed to ortho-Ps trapped at vacancies. The shorter lifetime (≈ 0.9 ns), shows little temperature dependence. In contrast to most other plastic crystals, no sigmoidal behaviour of the average ortho-Ps lifetime is observed. A possibility...

  16. Singlet Exciton Lifetimes in Conjugated Polymer Films for Organic Solar Cells

    KAUST Repository

    Dimitrov, Stoichko

    2016-01-13

    The lifetime of singlet excitons in conjugated polymer films is a key factor taken into account during organic solar cell device optimization. It determines the singlet exciton diffusion lengths in polymer films and has a direct impact on the photocurrent generation by organic solar cell devices. However, very little is known about the material properties controlling the lifetimes of singlet excitons, with most of our knowledge originating from studies of small organic molecules. Herein, we provide a brief summary of the nature of the excited states in conjugated polymer films and then present an analysis of the singlet exciton lifetimes of 16 semiconducting polymers. The exciton lifetimes of seven of the studied polymers were measured using ultrafast transient absorption spectroscopy and compared to the lifetimes of seven of the most common photoactive polymers found in the literature. A plot of the logarithm of the rate of exciton decay vs. the polymer optical bandgap reveals a medium correlation between lifetime and bandgap, thus suggesting that the Energy Gap Law may be valid for these systems. This therefore suggests that small bandgap polymers can suffer from short exciton lifetimes, which may limit their performance in organic solar cell devices. In addition, the impact of film crystallinity on the exciton lifetime was assessed for a small bandgap diketopyrrolopyrrole co-polymer. It is observed that the increase of polymer film crystallinity leads to reduction in exciton lifetime and optical bandgap again in agreement with the Energy Gap Law.

  17. Effect of the final-state interaction on the initial core-hole lifetime: the case of the 4s-hole lifetime of Sn metal

    International Nuclear Information System (INIS)

    Ohno, Masahide

    2003-01-01

    The first theoretical study of the effect of the final-state interaction on the initial core-hole lifetime is presented. The 4s-hole lifetime width of Sn metal is calculated by an ab-initio atomic many-body theory (Green's function method). When the final-state interaction in the 4p4d two-hole state, created by the 4s -1 -4p -1 4d -1 εf super Coster-Kronig (CK) transition of the initial 4s hole, is explicitly taken into account, the ab-initio atomic many-body calculation of the 4s-hole X-ray photoelectron spectroscopy (XPS) spectrum of Sn atom can provide excellent agreement with experiment in both the 4s-hole energy and the 4s-hole lifetime width. Otherwise, the many-body calculation underestimates considerably the 4s-hole lifetime width. The 4p4d two-hole state interacts strongly with the 4d triple-hole state by the 4p -1 4d -1 -4d -3 εf super CK transition. The interaction affects greatly the initial 4s-hole lifetime width

  18. 14 CFR 271.4 - Carrier costs.

    Science.gov (United States)

    2010-01-01

    ... Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS GUIDELINES FOR SUBSIDIZING AIR CARRIERS PROVIDING ESSENTIAL AIR TRANSPORTATION § 271.4 Carrier costs. (a) The reasonable costs projected for a carrier providing essential air service at an eligible...

  19. 14 CFR 271.5 - Carrier revenues.

    Science.gov (United States)

    2010-01-01

    ... Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS GUIDELINES FOR SUBSIDIZING AIR CARRIERS PROVIDING ESSENTIAL AIR TRANSPORTATION § 271.5 Carrier revenues. (a) The projected passenger revenue for a carrier providing essential air service at an eligible...

  20. Facilitated transport of hydrophilic salts by mixtures of anion and cation carriers and by ditopic carriers

    NARCIS (Netherlands)

    Chrisstoffels, L.A.J.; de Jong, Feike; Reinhoudt, David; Sivelli, Stefano; Gazzola, Licia; Casnati, Alessandro; Ungaro, Rocco

    1999-01-01

    Anion transfer to the membrane phase affects the extraction efficiency of salt transport by cation carriers 1 and 3. Addition of anion receptors 5 or 6 to cation carriers 1, 3, or 4 in the membrane phase enhances the transport of salts under conditions in which the cation carriers alone do not

  1. Remaining lifetime modeling using State-of-Health estimation

    Science.gov (United States)

    Beganovic, Nejra; Söffker, Dirk

    2017-08-01

    Technical systems and system's components undergo gradual degradation over time. Continuous degradation occurred in system is reflected in decreased system's reliability and unavoidably lead to a system failure. Therefore, continuous evaluation of State-of-Health (SoH) is inevitable to provide at least predefined lifetime of the system defined by manufacturer, or even better, to extend the lifetime given by manufacturer. However, precondition for lifetime extension is accurate estimation of SoH as well as the estimation and prediction of Remaining Useful Lifetime (RUL). For this purpose, lifetime models describing the relation between system/component degradation and consumed lifetime have to be established. In this contribution modeling and selection of suitable lifetime models from database based on current SoH conditions are discussed. Main contribution of this paper is the development of new modeling strategies capable to describe complex relations between measurable system variables, related system degradation, and RUL. Two approaches with accompanying advantages and disadvantages are introduced and compared. Both approaches are capable to model stochastic aging processes of a system by simultaneous adaption of RUL models to current SoH. The first approach requires a priori knowledge about aging processes in the system and accurate estimation of SoH. An estimation of SoH here is conditioned by tracking actual accumulated damage into the system, so that particular model parameters are defined according to a priori known assumptions about system's aging. Prediction accuracy in this case is highly dependent on accurate estimation of SoH but includes high number of degrees of freedom. The second approach in this contribution does not require a priori knowledge about system's aging as particular model parameters are defined in accordance to multi-objective optimization procedure. Prediction accuracy of this model does not highly depend on estimated SoH. This model

  2. Lifetimes and masses of b-hadrons at LEP

    International Nuclear Information System (INIS)

    Lesiak, T.

    1994-07-01

    Latest LEP results concerning hadrons containing b-quarks are reviewed. The average lifetime of the b-hadrons together with the lifetimes of the B u + , B d 0 , B s and Λ b and first mass measurements of the B s and Λ b are presented. (author). 34 refs, 7 figs, 4 tabs

  3. Measurement of the Omega0(c) lifetime

    International Nuclear Information System (INIS)

    Iori, M.

    2007-01-01

    The authors report a precise measurement of the (Omega) c 0 lifetime. The data were taken by the SELEX (E781) experiment using 600 GeV/c Σ - , π - and p beams. The measurement has been made using 83 ± 19 reconstructed (Omega) c 0 in the (Omega) - π - π + π + and (Omega) - π + decay modes. The lifetime of the (Omega) c 0 is measured to be 65 ± 13(stat) ± 9(sys) fs

  4. Femtosecond tracking of carrier relaxation in germanium with extreme ultraviolet transient reflectivity

    Science.gov (United States)

    Kaplan, Christopher J.; Kraus, Peter M.; Ross, Andrew D.; Zürch, Michael; Cushing, Scott K.; Jager, Marieke F.; Chang, Hung-Tzu; Gullikson, Eric M.; Neumark, Daniel M.; Leone, Stephen R.

    2018-05-01

    Extreme ultraviolet (XUV) transient reflectivity around the germanium M4 ,5 edge (3 d core-level to valence transition) at 30 eV is advanced to obtain the transient dielectric function of crystalline germanium [100] on femtosecond to picosecond time scales following photoexcitation by broadband visible-to-infrared (VIS/NIR) pulses. By fitting the transient dielectric function, carrier-phonon induced relaxations are extracted for the excited carrier distribution. The measurements reveal a hot electron relaxation rate of 3.2 ±0.2 ps attributed to the X -L intervalley scattering and a hot hole relaxation rate of 600 ±300 fs ascribed to intravalley scattering within the heavy hole (HH) band, both in good agreement with previous work. An overall energy shift of the XUV dielectric function is assigned to a thermally induced band gap shrinkage by formation of acoustic phonons, which is observed to be on a timescale of 4-5 ps, in agreement with previously measured optical phonon lifetimes. The results reveal that the transient reflectivity signal at an angle of 66∘ with respect to the surface normal is dominated by changes to the real part of the dielectric function, due to the near critical angle of incidence of the experiment (66∘-70∘) for the range of XUV energies used. This work provides a methodology for interpreting XUV transient reflectivity near core-level transitions, and it demonstrates the power of the XUV spectral region for measuring ultrafast excitation dynamics in solids.

  5. Carrier-added and no-carrier-added syntheses of (/sup 18/F)spiroperidol and (/sub 18/F)haloperidol

    Energy Technology Data Exchange (ETDEWEB)

    Kilbourn, M R; Welch, M J; Dence, C S; Tewson, T J; Saji, H; Maeda, M

    1984-07-01

    Syntheses of (18F)haloperidol and (18F)spiroperidol in both no-carrier-added and carrier-added forms have been accomplished. The no-carrier-added (18F)butyrophenone neuroleptics were prepared in low (less than 2%) yield by acid decomposition of aryl piperidine triazenes. Carrier-added 18F-neuroleptics were prepared in better (5-17%) yields by 18F-for-19F nucleophilic aromatic substitution. The preparation of all synthetic precursors, and procedures for radiolabeling are fully described.

  6. A lifetime prediction method for LEDs considering mission profiles

    DEFF Research Database (Denmark)

    Qu, Xiaohui; Wang, Huai; Zhan, Xiaoqing

    2016-01-01

    and to benchmark the cost-competitiveness of different lighting technologies. The existing lifetime data released by LED manufacturers or standard organizations are usually applicable only for specific temperature and current levels. Significant lifetime discrepancies may be observed in field operations due...... to the varying operational and environmental conditions during the entire service time (i.e., mission profiles). To overcome the challenge, this paper proposes an advanced lifetime prediction method, which takes into account the field operation mission profiles and the statistical properties of the life data...

  7. Interlaboratory comparison of positron and positronium lifetimes in polymers

    DEFF Research Database (Denmark)

    Wastlund, C.; Eldrup, Morten Mostgaard; Maurer, F.H.J.

    1998-01-01

    A comparison of the results of a series of positron annihilation lifetime measurements performed in 12 laboratories is presented. The measurements were conducted on three different polymer samples, all prepared in one laboratory under standard conditions. The objective of the work was to gain...... insight into the variation in derived positron and positronium lifetimes and intensities measured in the different laboratories on identical specimens. Lifetime data were collected at room temperature by each laboratory following their own standard measurement and data evaluation procedures. The polymers...

  8. Study of variables for accelerating lifetime testing of SOFCs

    DEFF Research Database (Denmark)

    Ploner, Alexandra; Hagen, Anke; Hauch, Anne

    Solid oxide fuel cell (SOFC) applications require lifetimes of several years on the system level. A big challenge is to proof/confirm/demonstrate such exceptionally long lifetimes.Accelerated or compressed testing are possible methods. Activities in this area have been carried out without arriving...... at different current load cycling profiles revealed a strong deviation between predicted and measured lifetime [3].In this study, we present a detailed analysis of durability results for degradation mechanisms of single SOFC components as function of operating conditions. Electrochemical impedance data...

  9. Prediction of the lifetime productive and reproductive performance of Holstein cows managed for different lactation durations, using a model of lifetime nutrient partitioning

    DEFF Research Database (Denmark)

    Gaillard, Charlotte; Martin, O; Blavy, P

    2016-01-01

    The GARUNS model is a lifetime performance model taking into account the changing physiological priorities of an animal during its life and through repeated reproduction cycles. This dynamic and stochastic model has been previously used to predict the productive and reproductive performance...... of various genotypes of cows across feeding systems. In the present paper, we used this model to predict the lifetime productive and reproductive performance of Holstein cows for different lactation durations, with the aim of determining the lifetime scenario that optimizes cows' performance defined...... by lifetime efficiency (ratio of total milk energy yield to total energy intake) and pregnancy rate. To evaluate the model, data from a 16-mo extended lactation experiment on Holstein cows were used. Generally, the model could consistently fit body weight, milk yield, and milk components of these cows...

  10. Two-dimensional fluorescence lifetime correlation spectroscopy. 2. Application.

    Science.gov (United States)

    Ishii, Kunihiko; Tahara, Tahei

    2013-10-03

    In the preceding article, we introduced the theoretical framework of two-dimensional fluorescence lifetime correlation spectroscopy (2D FLCS). In this article, we report the experimental implementation of 2D FLCS. In this method, two-dimensional emission-delay correlation maps are constructed from the photon data obtained with the time-correlated single photon counting (TCSPC), and then they are converted to 2D lifetime correlation maps by the inverse Laplace transform. We develop a numerical method to realize reliable transformation, employing the maximum entropy method (MEM). We apply the developed actual 2D FLCS to two real systems, a dye mixture and a DNA hairpin. For the dye mixture, we show that 2D FLCS is experimentally feasible and that it can identify different species in an inhomogeneous sample without any prior knowledge. The application to the DNA hairpin demonstrates that 2D FLCS can disclose microsecond spontaneous dynamics of biological molecules in a visually comprehensible manner, through identifying species as unique lifetime distributions. A FRET pair is attached to the both ends of the DNA hairpin, and the different structures of the DNA hairpin are distinguished as different fluorescence lifetimes in 2D FLCS. By constructing the 2D correlation maps of the fluorescence lifetime of the FRET donor, the equilibrium dynamics between the open and the closed forms of the DNA hairpin is clearly observed as the appearance of the cross peaks between the corresponding fluorescence lifetimes. This equilibrium dynamics of the DNA hairpin is clearly separated from the acceptor-missing DNA that appears as an isolated diagonal peak in the 2D maps. The present study clearly shows that newly developed 2D FLCS can disclose spontaneous structural dynamics of biological molecules with microsecond time resolution.

  11. Neutron lifetime and generation time by KENO IV

    International Nuclear Information System (INIS)

    Hayashi, Masatoshi

    1991-01-01

    It is believed that Monte Carlo method is suitable to the calculation of neutron lifetime and generation time with reference to the life cycle viewpoint. This paper illustrates that those times obtained by Monte Carlo method are quite different from the results by perturbation method. The neutron lifetime and the generation time for bare and reflected reactors were investigated by the Monte Carlo program, KENO IV. the Monte Carlo procedure is based on tracking and recording the life history of neutrons in a realistic fashion in a fissionable system with minimum nuclear and geometric approximations. The KENO IV provides the multiplication factor, neutron lifetime and generation time simultaneously. The thermal spherical reactors for both bare and reflected reactors were studied using the KENO IV. The reflected reactor is surrounded with 30 cm thick light water. The atomic densities in the regions and the calculated results of the multiplication factor, neutron lifetime and generation time are given. The different definitions of these times between the Monte Carlo method and perturbation theory caused the difference of the results. (K.I.)

  12. Optimized inspection techniques and structural analysis in lifetime management

    International Nuclear Information System (INIS)

    Aguado, M.T.; Marcelles, I.

    1993-01-01

    Preservation of the option of extending the service lifetime of a nuclear power plant beyond its normal design lifetime requires correct remaining lifetime management from the very beginning of plant operation. The methodology used in plant remaining lifetime management is essentially based on the use of standard inspections, surveillance and monitoring programs and calculations, such as thermal-stress and fracture mechanics analysis. The inspection techniques should be continuously optimized, in order to be able to detect and dimension existing defects with the highest possible degree of accuracy. The information obtained during the inspection is combined with the historical data of the components: design, quality, operation, maintenance, and transients, and with the results of destructive testing, fracture mechanics and thermal fatigue analysis. These data are used to estimate the remaining lifetime of nuclear power plant components, systems and structures with the highest degree possible of accuracy. The use of this methodology allows component repairs and replacements to be reduced or avoided and increases the safety levels and availability of the nuclear power plant. Use of this strategy avoids the need for heavy investments at the end of the licensing period

  13. Carrier-added and no-carrier-added syntheses of (/sup 18/F)spiroperidol and (/sup 18/F)haloperidol

    Energy Technology Data Exchange (ETDEWEB)

    Kilbourn, M R; Welch, M J; Dence, C S; Tewson, T J; Saji, H; Maeda, M [Washington Univ., St. Louis, MO (USA). Edward Mallinckrodt Inst. of Radiology

    1984-07-01

    Syntheses of (/sup 18/F)haloperidol and (/sup 18/F)spiroperidol in both no-carrier-added and carrier-added forms have been accomplished. The no-carrier-added (/sup 18/F)butyrophenone neuroleptics were prepared in low (<2%) yield by acid decomposition of aryl piperidine triazenes. Carrier-added /sup 18/F-neuroleptics were prepared in better (5-17%) yields by /sup 18/F-for-/sup 19/F nucleophilic aromatic substitution. The preparation of all synthetic precursors, and procedures for radiolabeling are fully described.

  14. Charge Carrier Dynamics and pH Effect on Optical Properties of Anionic and Cationic Porphyrin-Graphene Oxide Composites

    Science.gov (United States)

    Bajjou, O.; Bakour, A.; Khenfouch, M.; Baitoul, M.; Mothudi, B.; Maaza, M.; Faulques, E.

    2018-02-01

    Composites of graphene oxide (GO) functionalized with Sn(V) tetrakis (4-pyridyl)porphyrin (SnTPyP2+) and meso-tetrakis(4-phenylsulfonic acid)porphyrin (H4TPPS4 2- ) were prepared at different pH values.Successful synthesis of water-soluble stable suspension of GO-SnTPyP2+ and GO-H4TPPS4 2-was confirmed using various spectroscopic techniques, including scanning electronic microscopy (SEM), Raman spectroscopy, and ultraviolet-visible (UV-Vis) absorption. Variation of the pH was found to strongly influence the optical properties of the GO-SnTPyP2+ and GO-H4TPPS4 2-composites, as demonstrated by the UV-Vis absorption results. Steady-state photoluminescence (PL) and time-resolved PL (TRPL) results for both composites showed PL quenching and decrease in the exciton mean lifetime, suggesting strong excited-state interactions between the different components. Moreover, charge carrier dynamics study revealed that insertion of GO into both porphyrin derivatives led to faster mean lifetime for excitons with a slight advantage in the case of the cationic porphyrin-GO composite, making it a better choice for charge separation applications thanks to the higher efficiency of charge/energy transfer interactions.

  15. Superconducting quasiparticle lifetimes due to spin-fluctuation scattering

    International Nuclear Information System (INIS)

    Quinlan, S.M.; Scalapino, D.J.; Bulut, N.

    1994-01-01

    Superconducting quasiparticle lifetimes associated with spin-fluctuation scattering are calculated. A Berk-Schrieffer interaction with an irreducible susceptibility given by a BCS form is used to model the quasiparticle damping due to spin fluctuations. Results are presented for both s-wave and d-wave gaps. Also, quasiparticle lifetimes due to impurity scattering are calculated for a d-wave superconductor

  16. Level lifetimes of Au52+ in Au plasma

    International Nuclear Information System (INIS)

    Liu Bo; Zhu Zhiyan; Jiang Gang; Zhu Zhenghe

    2003-01-01

    Based on the extended relativistic multiconfiguration Dirac-Fock theory, the level lifetimes, level widths and wavelengths of Au 52+ have been calculated using the General-purpose Relativistic Atomic Structure Program. The wavelengths obtained are in good agreement with the experimental data available. The relationship between the level lifetimes and the level widths satisfies the Heisenberg uncertainty principle

  17. Optimal Taxation and Social Insurance in a Lifetime Perspective

    DEFF Research Database (Denmark)

    Bovenberg, A. Lans; Sørensen, Peter Birch

    Advances in information technology have improved the administrative feasibility of redistribution based on lifetime earnings recorded at the time of retirement. We study optimal lifetime income taxation and social insurance in an economy in which redistributive taxation and social insurance serve...... to insure (ex ante) against skill heterogeneity as well as disability risk. Optimal disability benefits rise with previous earnings so that public transfers depend not only on current earnings but also on earnings in the past. Hence, lifetime taxation rather than annual taxation is optimal. The optimal tax...

  18. 8 CFR 217.6 - Carrier agreements.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Carrier agreements. 217.6 Section 217.6 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS VISA WAIVER PROGRAM § 217... may notify a carrier of the existence of a basis for termination of a carrier agreement under this...

  19. Octanol reduces end-plate channel lifetime

    Science.gov (United States)

    Gage, Peter W.; McBurney, Robert N.; Van Helden, Dirk

    1978-01-01

    1. Post-synaptic effects of n-octanol at concentrations of 0·1-1 mM were examined in toad sartorius muscles by use of extracellular and voltage-clamp techniques. 2. Octanol depressed the amplitude and duration of miniature end-plate currents and hence depressed neuromuscular transmission. 3. The decay of miniature end-plate currents remained exponential in octanol solutions even when the time constant of decay (τD) was decreased by 80-90%. 4. The lifetime of end-plate channels, obtained by analysis of acetylcholine noise, was also decreased by octanol. The average lifetime measured from noise spectra agreed reasonably well with the time constant of decay of miniature end-plate currents, both in control solution and in octanol solutions. 5. Octanol caused a reduction in the conductance of end-plate channels. Single channel conductance was on average about 25 pS in control solution and 20 pS in octanol. 6. In most cells the normal voltage sensitivity of the decay of miniature end-plate currents was retained in octanol solutions. The lifetime of end-plate channels measured from acetylcholine noise also remained voltage-sensitive in octanol solutions. In some experiments in which channel lifetime was exceptionally reduced the voltage sensitivity was less than normal. 7. In octanol solutions, τD was still very sensitive to temperature changes in most cells although in some the temperature sensitivity of τD was clearly reduced. Changes in τD with temperature could generally be fitted by the Arrhenius equation suggesting that a single step reaction controlled the decay of currents both in control and in octanol solutions. In some cells in which τD became less than 0·3 ms, the relationship between τD and temperature became inconsistent with the Arrhenius equation. 8. As the decay of end-plate currents in octanol solutions remains exponential, and the voltage and temperature sensitivity can be unchanged even when τD is significantly reduced, it seems likely that

  20. Carrier dynamics in silicon nanowires studied using optical-pump terahertz-probe spectroscopy

    Science.gov (United States)

    Beaudoin, Alexandre; Salem, Bassem; Baron, Thierry; Gentile, Pascal; Morris, Denis

    2014-03-01

    The advance of non-contact measurements involving pulsed terahertz radiation presents great interests for characterizing electrical properties of a large ensemble of nanowires. In this work, N-doped and undoped silicon nanowires (SiNWs) grown by chemical vapour deposition (CVD) on quartz substrate were characterized using optical-pump terahertz probe (OPTP) transmission experiments. Our results show that defects and ionized impurities introduced by N-doping the CVD-grown SiNWs tend to reduce the photoexcited carrier lifetime and degrade their conductivity properties. Capture mechanisms by the surface trap states play a key role on the photocarrier dynamics in theses small diameters' (~100 nm) SiNWs and the doping level is found to alter this dynamics. We propose convincing capture and recombination scenarios that explain our OPTP measurements. Fits of our photoconductivity data curves, from 0.5 to 2 THz, using a Drude-plasmon conductivity model allow determining photocarrier mobility values of 190 and 70 cm2/V .s, for the undoped and N-doped NWs samples, respectively.

  1. Magnetic moments and lifetime measurements with a piezoelectrically driven plunger

    International Nuclear Information System (INIS)

    Rutten, A.J.

    1980-01-01

    Experiments are described leading to precise values for magnetic dipole moments of excited nuclear states and their mean lifetimes. A plunger system is described especially developed for g-factor and lifetime measurements with the coincidence time-differential recoil-into-vacuum technique. Measurements of the g-factors and lifetimes for the 2 1 + state of 20 O and the 5/2 1 + state of 13 C are described. (Auth.)

  2. Inequivalence of single-particle and population lifetimes in a cuprate superconductor

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Shuolong [SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., Stanford, CA (United States); Sobota, J. A. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Leuenberger, D. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., Stanford, CA (United States); He, Y. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., Stanford, CA (United States); Hashimoto, M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Lu, D. H. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Eisaki, H. [National Institute of Advanced Industrial Science and Technology, Ibaraki (Japan); Kirchmann, P. S. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Shen, Z. -X. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., Stanford, CA (United States)

    2015-06-15

    We study optimally doped Bi-2212 (Tc=96 K) using femtosecond time- and angle-resolved photoelectron spectroscopy. Energy-resolved population lifetimes are extracted and compared with single-particle lifetimes measured by equilibrium photoemission. The population lifetimes deviate from the single-particle lifetimes in the low excitation limit by 1–2 orders of magnitude. Fundamental considerations of electron scattering unveil that these two lifetimes are in general distinct, yet for systems with only electron-phonon scattering they should converge in the low-temperature, low-fluence limit. As a result, the qualitative disparity in our data, even in this limit, suggests that scattering channels beyond electron-phonon interactions play a significant role in the electron dynamics of cuprate superconductors.

  3. Estimating motor carrier management information system crash file underreporting from carrier records : research brief.

    Science.gov (United States)

    2017-08-01

    This study estimated a significant amount of underreporting to the MCMIS crash file by the States, for the carriers who cooperated in the study. For the study carriers, it appears that the MCMIS file contained about 66 percent of their reportable cra...

  4. Condition analysis and operating lifetime extension concepts for wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Korzeniewski, Thomas [GMA-Engineering GmbH, Hamburg (Germany). Business Unit Wind Energy

    2014-11-01

    In Germany the basis for the expansion of wind energy was already laid at the beginning of the 1990s. Hence, the first wind turbines already started to reach the end of their permitted lifetime. At that time as today the different wind turbine types were engineered for an operational lifetime of 20 years. As reliable wind turbines types were already available in the 1990s, it is technically and commercially reasonable to consider the extension of their operational lifetime. Of particular interest is the lifetime extension of wind turbine types installed in the beginning of the 2000s. During that period many wind turbine types were launched which absolutely correspond to state-of-the-art technology.

  5. Lifetime measurements using the Jefferson Lad Load-Lock Electron Gun

    International Nuclear Information System (INIS)

    J. Grames; P. Adderley; M. Baylac; J. Brittian; D. Charles; J. Clark; J. Hansknecht; M. Poelker; M. Stutzman; K. Surles-Law

    2000-01-01

    Lifetime measurements of bulk GaAs using a 100 kV load-lock electron gun and beam line were made. Initial tests used anodized samples to study lifetime under various conditions (gun vacuum, laser spot location, activated area). Subsequent tests used a mechanical mask to limit the active area and included improved monitoring of the gun chamber and beam line vacuum pressure. Results of these measurements support claims made at past workshops, namely photocathode lifetime improves when gun vacuum is enhanced and when electron emission from the edge of the photocathode is eliminated. The dependence upon laser spot location is less certain. Tests studying lifetime at higher beam intensity (I ∼ 8 mA) have begun

  6. Positron lifetime calculation for the elements of the periodic table.

    Science.gov (United States)

    Campillo Robles, J M; Ogando, E; Plazaola, F

    2007-04-30

    Theoretical positron lifetime values have been calculated systematically for most of the elements of the periodic table. Self-consistent and non-self-consistent schemes have been used for the calculation of the electronic structure in the solid, as well as different parametrizations for the positron enhancement factor and correlation energy. The results obtained have been studied and compared with experimental data, confirming the theoretical trends. As is known, positron lifetimes in bulk show a periodic behaviour with atomic number. These calculations also confirm that monovacancy lifetimes follow the same behaviour. The effects of enhancement factors used in calculations have been commented upon. Finally, we have analysed the effects that f and d electrons have on positron lifetimes.

  7. Positron lifetime calculation for the elements of the periodic table

    International Nuclear Information System (INIS)

    Robles, J M Campillo; Ogando, E; Plazaola, F

    2007-01-01

    Theoretical positron lifetime values have been calculated systematically for most of the elements of the periodic table. Self-consistent and non-self-consistent schemes have been used for the calculation of the electronic structure in the solid, as well as different parametrizations for the positron enhancement factor and correlation energy. The results obtained have been studied and compared with experimental data, confirming the theoretical trends. As is known, positron lifetimes in bulk show a periodic behaviour with atomic number. These calculations also confirm that monovacancy lifetimes follow the same behaviour. The effects of enhancement factors used in calculations have been commented upon. Finally, we have analysed the effects that f and d electrons have on positron lifetimes

  8. Lifetime, money and cost-benefit analysis

    International Nuclear Information System (INIS)

    Bengtsson, G.

    1984-01-01

    The paper describes briefly many methods for explicit or implicit valuation of the loss of lifetime expectancy due to radiation exposures or other hazards. The health gain from investment in protection is compared with the health gain from a general increase in wealth. It is concluded that in many instances lifetime is valued at 1 to 10 times the gross national product produced in this time. This seems to be reasonable for rich countries whereas it may be questionable for poorer countries. Here, any investment that raises the level of living of the poorer segment of the population may have a greater effect on life expectancy. (author)

  9. Quantum system lifetimes and measurement perturbations

    International Nuclear Information System (INIS)

    Najakov, E.

    1977-05-01

    The recently proposed description of quantum system decay in terms of repeated measurement perturbations is modified. The possibility of retarded reductions to a unique quantum state, due to ineffective localization of the decay products at initial time measurements, is simply taken into account. The exponential decay law is verified again. A modified equation giving the observed lifetime in terms of unperturbed quantum decay law, measurement frequency and reduction law is derived. It predicts deviations of the observed lifetime from the umperturbed one, together with a dependence on experimental procedures. The influence of different model unperturbed decay laws and reduction laws on this effect is studied

  10. The Kinetics of Carrier Transport Inhibition

    DEFF Research Database (Denmark)

    Rosenberg, T.; Wilbrandt, Robert Walter

    1962-01-01

    The kinetical treatment of enzymatic carrier transports as given in previous communications has been extended to conditions of inhibition. Various possible types of inhibitors have been considered differing in the site of attack (enzyme or carrier), in the mode of action (competing with the subst......The kinetical treatment of enzymatic carrier transports as given in previous communications has been extended to conditions of inhibition. Various possible types of inhibitors have been considered differing in the site of attack (enzyme or carrier), in the mode of action (competing...... with the substrate for the enzyme or the carrier or for both, competing with the carrier for the enzyme, or non-competitive) and in the ability of penetrating the membrane. Experiments are reported on the inhibition of glucose and fructose transport across the human red cell membrane by phlorizine, phloretine...... and polyphloretinephosphate. The results of the analysis for these inhibitors indicate a substrate competitive mode of action. The effect of reversing the transport direction by interchanging the substrate concentration has been treated for the case of a non-penetrating substrate competitive inhibitor in the external medium...

  11. Fluorescence lifetime evaluation of whole soils from the Amazon rainforest.

    Science.gov (United States)

    Nicolodelli, Gustavo; Tadini, Amanda Maria; Nogueira, Marcelo Saito; Pratavieira, Sebastião; Mounier, Stephane; Huaman, Jose Luis Clabel; Dos Santos, Cléber Hilário; Montes, Célia Regina; Milori, Débora Marcondes Bastos Pereira

    2017-08-20

    Time-resolved fluorescence spectroscopy (TRFS) is a new tool that can be used to investigate processes of interaction between metal ions and organic matter (OM) in soils, providing a specific analysis of the structure and dynamics of macromolecules. To the best of our knowledge, there are no studies in the literature reporting the use of this technique applied to whole/non-fractionated soil samples, making it a potential method for use in future studies. This work describes the use of TRFS to evaluate the fluorescence lifetimes of OM of whole soils from the Amazon region. Analysis was made of pellets of soils from an oxisol-spodosol system, collected in São Gabriel da Cachoeira (Amazonas, Brazil). The fluorescence lifetimes in the oxisol-spodosol system were attributed to two different fluorophores. One was related to complexation of an OM fraction with metals, resulting in a shorter fluorophore lifetime. A short fluorescence lifetime (2-12 ns) could be associated with simpler structures of the OM, while a long lifetime (19-66 ns) was associated with more complex OM structures. This new TRFS technique for analysis of the fluorescence lifetime in whole soil samples complies with the principles of green chemistry.

  12. Empirical membrane lifetime model for heavy duty fuel cell systems

    Science.gov (United States)

    Macauley, Natalia; Watson, Mark; Lauritzen, Michael; Knights, Shanna; Wang, G. Gary; Kjeang, Erik

    2016-12-01

    Heavy duty fuel cells used in transportation system applications such as transit buses expose the fuel cell membranes to conditions that can lead to lifetime-limiting membrane failure via combined chemical and mechanical degradation. Highly durable membranes and reliable predictive models are therefore needed in order to achieve the ultimate heavy duty fuel cell lifetime target of 25,000 h. In the present work, an empirical membrane lifetime model was developed based on laboratory data from a suite of accelerated membrane durability tests. The model considers the effects of cell voltage, temperature, oxygen concentration, humidity cycling, humidity level, and platinum in the membrane using inverse power law and exponential relationships within the framework of a general log-linear Weibull life-stress statistical distribution. The obtained model is capable of extrapolating the membrane lifetime from accelerated test conditions to use level conditions during field operation. Based on typical conditions for the Whistler, British Columbia fuel cell transit bus fleet, the model predicts a stack lifetime of 17,500 h and a membrane leak initiation time of 9200 h. Validation performed with the aid of a field operated stack confirmed the initial goal of the model to predict membrane lifetime within 20% of the actual operating time.

  13. Predicting a future lifetime through Box-Cox transformation.

    Science.gov (United States)

    Yang, Z

    1999-09-01

    In predicting a future lifetime based on a sample of past lifetimes, the Box-Cox transformation method provides a simple and unified procedure that is shown in this article to meet or often outperform the corresponding frequentist solution in terms of coverage probability and average length of prediction intervals. Kullback-Leibler information and second-order asymptotic expansion are used to justify the Box-Cox procedure. Extensive Monte Carlo simulations are also performed to evaluate the small sample behavior of the procedure. Certain popular lifetime distributions, such as Weibull, inverse Gaussian and Birnbaum-Saunders are served as illustrative examples. One important advantage of the Box-Cox procedure lies in its easy extension to linear model predictions where the exact frequentist solutions are often not available.

  14. Lifetime measurements in the picosecond range: Achievements and Perspectives

    International Nuclear Information System (INIS)

    Kruecken, Reiner

    1999-01-01

    This contribution will review the recoil distance method (RDM), its current range of applications as well as future perspectives for the measurement of lifetimes in the picosecond range of excited nuclear levels. Recent Doppler-shift lifetime experiments with large gamma-ray spectrometers have achieved a new level of precision and sensitivity, providing new insights into nuclear structure physics. High precision RDM measurements of near-yrast states in various mass regions have revealed dynamic shape effects beyond the framework of collective models and have also allowed to study the interaction between coexisting shapes. The measurement of lifetimes in superdeformed bands has shown that lifetimes can be measured for nuclear excitations, which are only populated with a few percent of the production cross-section of a nucleus. These experiments have also enabled us to study the mechanism of the decay-out of superdeformed bands. Another example for the need of precise lifetime measurements is the recent verifications of the concept of 'magnetic rotation' in nuclei by the experimental observation of the characteristic drop of B(M1) values as a function of angular momentum. These recent breakthroughs have also opened new perspectives for the use of the RDM technique for more exotic regions of nuclei and nuclear excitations. Here the measurement of lifetimes in neutron rich nuclei, which are not accessible with conventional nuclear reactions using stable beams and targets, is of special interest. Possible experimental approaches and simple estimates for the feasibility of such experiments will be presented. (author)

  15. Charge-carrier mobilities in disordered semiconducting polymers : effects of carrier density and electric field

    NARCIS (Netherlands)

    Meisel, K.D.; Pasveer, W.F.; Cottaar, J.; Tanase, C.; Coehoorn, R.; Bobbert, P.A.; Blom, P.W.M.; Leeuw, D.M. de; Michels, M.A.J.

    2006-01-01

    We model charge transport in disordered semiconducting polymers by hopping of charge carriers on a square lattice of sites with Gaussian on-site energy disorder, using Fermi-Dirac statistics. From numerically exact solutions of the Master equation, we study the dependence of the charge-carrier

  16. LIQUIFIED NATURAL GAS (LNG) CARRIERS

    OpenAIRE

    Daniel Posavec; Katarina Simon; Matija Malnar

    2010-01-01

    Modern liquefied natural gas carriers are double-bottom ships classified according to the type of LNG tank. The tanks are specially designed to store natural gas cooled to -161°C, the boiling point of methane. Since LNG is highly flammable, special care must be taken when designing and operating the ship. The development of LNG carriers has begun in the middle of the twentieth century. LNG carrier storage space has gradually grown to the current maximum of 260000 m3. There are more than 300 L...

  17. The programs for lifetime extension by AREVA

    International Nuclear Information System (INIS)

    Knoche, P.

    2014-01-01

    In 2011 AREVA launched 2 worldwide programs to meet the demands of its customers: 'AREVA Safety Alliance' that proposes a set of measures for post-Fukushima safety upgrading and 'AREVA Forward Alliance' that is dedicated to lifetime extension projects. Concerning 'AREVA Safety Alliance' about 150 projects have been carried out for 53 customers in 19 countries, as for 'AREVA Forward Alliance' 60% of the lifetime extension projects in the US have been performed by AREVA. In the framework of lifetime extension projects, upgrading measures and services are proposed such as the installation of hydrogen recombiner units, of filtered ventilation systems for severe accidents, or the upgrading of the reactor control system through the implementation of the digital Teleperm XS technology, or recommendations about the methodology to follow for the repair or replacement of important components. The replacement of steam generators and of the pressurizer and with other upgrading works led to a gain of 18.5% on the output power of the Ringhals-4 unit. (A.C.)

  18. Effect of pharmacologically induced retinal degeneration on retinal autofluorescence lifetimes in mice.

    Science.gov (United States)

    Dysli, Chantal; Dysli, Muriel; Zinkernagel, Martin S; Enzmann, Volker

    2016-12-01

    Fluorescence lifetime imaging ophthalmoscopy (FLIO) was used to investigate retinal autofluorescence lifetimes in mouse models of pharmacologically induced retinal degeneration over time. Sodium iodate (NaIO 3 , 35 mg/kg intravenously) was used to induce retinal pigment epithelium (RPE) degeneration with subsequent loss of photoreceptors (PR) whereas N-methyl-N-nitrosourea (MNU, 45 mg/kg intraperitoneally) was employed for degeneration of the photoreceptor cell layer alone. All mice were measured at day 3, 7, 14, and 28 after the respective injection of NaIO 3 , MNU or NaCl (control). Fluorescence lifetime imaging was performed using a fluorescence lifetime imaging ophthalmoscope (Heidelberg Engineering, Heidelberg, Germany). Fluorescence was excited at 473 nm and fluorescence lifetimes were measured in a short and a long spectral channel (498-560 nm and 560-720 nm). Corresponding optical coherence tomography (OCT) images were consecutively acquired and histology was performed at the end of the experiments. Segmentation of OCT images and histology verified the cell type-specific degeneration process over time. Retinal autofluorescence lifetimes increased from day 3 to day 28 in mice after NaIO 3 treatment. Finally, at day 28, fluorescence lifetimes were prolonged by 8% in the short and 61% in the long spectral channel compared to control animals (p = 0.21 and p = 0.004, respectively). In mice after MNU treatment, the mean retinal autofluorescence lifetimes were already decreased at day 3 and retinal lifetimes were finally shortened by 27% in the short and 51% in the long spectral channel at day 28 (p = 0.0028). In conclusion, degeneration of the RPE with subsequent photoreceptor degeneration by NaIO 3 lead to longer mean fluorescence lifetimes of the retina compared to control mice, whereas during specific degeneration of the photoreceptor layer induced by MNU shorter lifetimes were measured. Therefore, short retinal fluorescence lifetimes may originate

  19. Positron lifetime spectroscopy of internally oxidised Ag-In alloys

    International Nuclear Information System (INIS)

    Wegner, D.; Lieb, K.P.

    1989-01-01

    The effects of In 2 O 3 precipitates on positron lifetimes after internal oxidation of α-Ag-In alloys have been investigated. A positron trap associated with the lifetime τ 205(3) ps was detected. On the basis of the experimental results obtained for different oxidation kinetics parameters, a trapping model is proposed according to which positrons thermalised in a dislocation field around oxide precipitates are trapped at the oxide/metal phase boundary. The transition from internal to external oxidation of Ag-In was also studied. The positron lifetime in In 2 O 3 was measured to be τ = 263(8) ps. (author)

  20. Integrated tool for NPP lifetime management in Spain

    Energy Technology Data Exchange (ETDEWEB)

    Francia, L. [UNESA, Madrid (Spain); Lopez de Santa Maria, J. [ASCO-Vandellos 2 NPPs l' Hospitalet de l' Infant, Tarragona (Spain); Cardoso, A. [Tecnatom SA, Madrid (Spain)

    2001-07-01

    The project for the Integrated Nuclear Power Plant Lifetime Management System SIGEVI (Sistema Integrado de GEstion de VIda de Centrales Nucleares) was initiated in April 1998 and finalized in December 2000, the main objective of the project being to develop a computer application facilitating the assessment of the condition and lifetime of nuclear power plant components. This constituted the second phase of a further-reaching project on NPP Lifetime Management. During the first phase of this project, carried out between 1992 and 1995, the methodology and strategy for the lifetime management of the Spanish NPP's were developed. Among others, degradation phenomena were assessed and the most adequate methods for their monitoring were defined. The SIGEVI Project has been performed under the management of UNESA (Spanish Electricity Association) and with the collaboration of different engineering firms and research institutes (Tecnatom, Empresarios Agrupados, Ufisa, Initec and IIT), with Vandellos II as the pilot plant. The rest of the Spanish NPP's have also actively participated through the Project Steering Committee. The following sections describe the scope, the structure and the main functionalities of the system SIGEVI. (authors)

  1. Integrated tool for NPP lifetime management in Spain

    International Nuclear Information System (INIS)

    Francia, L.; Lopez de Santa Maria, J.; Cardoso, A.

    2001-01-01

    The project for the Integrated Nuclear Power Plant Lifetime Management System SIGEVI (Sistema Integrado de GEstion de VIda de Centrales Nucleares) was initiated in April 1998 and finalized in December 2000, the main objective of the project being to develop a computer application facilitating the assessment of the condition and lifetime of nuclear power plant components. This constituted the second phase of a further-reaching project on NPP Lifetime Management. During the first phase of this project, carried out between 1992 and 1995, the methodology and strategy for the lifetime management of the Spanish NPP's were developed. Among others, degradation phenomena were assessed and the most adequate methods for their monitoring were defined. The SIGEVI Project has been performed under the management of UNESA (Spanish Electricity Association) and with the collaboration of different engineering firms and research institutes (Tecnatom, Empresarios Agrupados, Ufisa, Initec and IIT), with Vandellos II as the pilot plant. The rest of the Spanish NPP's have also actively participated through the Project Steering Committee. The following sections describe the scope, the structure and the main functionalities of the system SIGEVI. (authors)

  2. Bacterial Carriers for Glioblastoma Therapy

    Directory of Open Access Journals (Sweden)

    Nalini Mehta

    2017-03-01

    Full Text Available Treatment of aggressive glioblastoma brain tumors is challenging, largely due to diffusion barriers preventing efficient drug dosing to tumors. To overcome these barriers, bacterial carriers that are actively motile and programmed to migrate and localize to tumor zones were designed. These carriers can induce apoptosis via hypoxia-controlled expression of a tumor suppressor protein p53 and a pro-apoptotic drug, Azurin. In a xenograft model of human glioblastoma in rats, bacterial carrier therapy conferred a significant survival benefit with 19% overall long-term survival of >100 days in treated animals relative to a median survival of 26 days in control untreated animals. Histological and proteomic analyses were performed to elucidate the safety and efficacy of these carriers, showing an absence of systemic toxicity and a restored neural environment in treated responders. In the treated non-responders, proteomic analysis revealed competing mechanisms of pro-apoptotic and drug-resistant activity. This bacterial carrier opens a versatile avenue to overcome diffusion barriers in glioblastoma by virtue of its active motility in extracellular space and can lead to tailored therapies via tumor-specific expression of tumoricidal proteins.

  3. Basic Stand Alone Carrier Line Items PUF

    Data.gov (United States)

    U.S. Department of Health & Human Services — This release contains the Basic Stand Alone (BSA) Carrier Line Items Public Use Files (PUF) with information from Medicare Carrier claims. The CMS BSA Carrier Line...

  4. Fine-structure energy levels, oscillator strengths and lifetimes of ...

    Indian Academy of Sciences (India)

    with the experimental results compiled in the NIST Data Base. Many new ... Keywords. Relativistic fine-structure levels; oscillator strengths; lifetimes. ... have calculated oscillator strengths and lifetimes using the Briet–Pauli R-Matrix ..... [2] The Opacity Project Team, The Opacity Project (Institute of Physics Publishing,. Bristol ...

  5. Calculation of the Touschek lifetime in electron storage rings

    International Nuclear Information System (INIS)

    Walker, R.P.

    1987-01-01

    Various formulae for calculating the Touschek lifetime of a ribbon beam of electrons are examined. It is shown that two commonly used approximations can give inaccurate results in certain circumstances. A method is suggested for calculating the lifetime accurately and efficiently using a combination of formulae

  6. Nasal carriers are more likely to acquire exogenous Staphylococcus aureus strains than non-carriers.

    Science.gov (United States)

    Ghasemzadeh-Moghaddam, H; Neela, V; van Wamel, W; Hamat, R A; Shamsudin, M Nor; Hussin, N Suhaila Che; Aziz, M N; Haspani, M S Mohammad; Johar, A; Thevarajah, S; Vos, M; van Belkum, A

    2015-11-01

    We performed a prospective observational study in a clinical setting to test the hypothesis that prior colonization by a Staphylococcus aureus strain would protect, by colonization interference or other processes, against de novo colonization and, hence, possible endo-infections by newly acquired S. aureus strains. Three hundred and six patients hospitalized for >7 days were enrolled. For every patient, four nasal swabs (days 1, 3, 5, and 7) were taken, and patients were identified as carriers when a positive nasal culture for S. aureus was obtained on day 1 of hospitalization. For all patients who acquired methicillin-resistant S. aureus (MRSA) or methicillin-susceptible S. aureus via colonization and/or infection during hospitalization, strains were collected. We note that our study may suffer from false-negative cultures, local problems with infection control and hospital hygiene, or staphylococcal carriage at alternative anatomical sites. Among all patients, 22% were prior carriers of S. aureus, including 1.9% whom carried MRSA upon admission. The overall nasal staphylococcal carriage rate among dermatology patients was significantly higher than that among neurosurgery patients (n = 25 (55.5%) vs. n = 42 (16.1%), p 0.005). This conclusion held when the carriage definition included individuals who were nasal culture positive on day 1 and day 3 of hospitalization (p 0.0001). All MRSA carriers were dermatology patients. There was significantly less S. aureus acquisition among non-carriers than among carriers during hospitalization (p 0.005). The mean number of days spent in the hospital before experiencing MRSA acquisition in nasal carriers was 5.1, which was significantly lower than the score among non-carriers (22 days, p 0.012). In conclusion, we found that nasal carriage of S. aureus predisposes to rather than protects against staphylococcal acquisition in the nose, thereby refuting our null hypothesis. Copyright © 2015 European Society of Clinical

  7. Precision measurement of the $\\Lambda_b^0$ baryon lifetime

    CERN Document Server

    INSPIRE-00258707; Adeva, B; Adinolfi, M; Adrover, C; Affolder, A; Ajaltouni, Z; Albrecht, J; Alessio, F; Alexander, M; Ali, S; Alkhazov, G; Alvarez Cartelle, P; Alves Jr, A A; Amato, S; Amerio, S; Amhis, Y; Anderlini, L; Anderson, J; Andreassen, R; Andrews, J E; Appleby, R B; Aquines Gutierrez, O; Archilli, F; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Baalouch, M; Bachmann, S; Back, J J; Baesso, C; Balagura, V; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Bauer, Th; Bay, A; Beddow, J; Bedeschi, F; Bediaga, I; Belogurov, S; Belous, K; Belyaev, I; Ben-Haim, E; Bencivenni, G; Benson, S; Benton, J; Berezhnoy, A; Bernet, R; Bettler, M -O; van Beuzekom, M; Bien, A; Bifani, S; Bird, T; Bizzeti, A; Bjørnstad, P M; Blake, T; Blanc, F; Blouw, J; Blusk, S; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borgia, A; Bowcock, T J V; Bowen, E; Bozzi, C; Brambach, T; van den Brand, J; Bressieux, J; Brett, D; Britsch, M; Britton, T; Brook, N H; Brown, H; Burducea, I; Bursche, A; Busetto, G; Buytaert, J; Cadeddu, S; Callot, O; Calvi, M; Calvo Gomez, M; Camboni, A; Campana, P; Campora Perez, D; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carranza-Mejia, H; Carson, L; Carvalho Akiba, K; Casse, G; Castillo Garcia, L; Cattaneo, M; Cauet, Ch; Cenci, R; Charles, M; Charpentier, Ph; Chen, P; Chiapolini, N; Chrzaszcz, M; Ciba, K; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coca, C; Coco, V; Cogan, J; Cogneras, E; Collins, P; Comerma-Montells, A; Contu, A; Cook, A; Coombes, M; Coquereau, S; Corti, G; Couturier, B; Cowan, G A; Craik, D C; Cunliffe, S; Currie, R; D'Ambrosio, C; David, P; David, P N Y; Davis, A; De Bonis, I; De Bruyn, K; De Capua, S; De Cian, M; De Miranda, J M; De Paula, L; De Silva, W; De Simone, P; Decamp, D; Deckenhoff, M; Del Buono, L; Déléage, N; Derkach, D; Deschamps, O; Dettori, F; Di Canto, A; Dijkstra, H; Dogaru, M; Donleavy, S; Dordei, F; Dosil Suárez, A; Dossett, D; Dovbnya, A; Dupertuis, F; Durante, P; Dzhelyadin, R; Dziurda, A; Dzyuba, A; Easo, S; Egede, U; Egorychev, V; Eidelman, S; van Eijk, D; Eisenhardt, S; Eitschberger, U; Ekelhof, R; Eklund, L; El Rifai, I; Elsasser, Ch; Falabella, A; Färber, C; Fardell, G; Farinelli, C; Farry, S; Ferguson, D; Fernandez Albor, V; Ferreira Rodrigues, F; Ferro-Luzzi, M; Filippov, S; Fiore, M; Fitzpatrick, C; Fontana, M; Fontanelli, F; Forty, R; Francisco, O; Frank, M; Frei, C; Frosini, M; Furcas, S; Furfaro, E; Gallas Torreira, A; Galli, D; Gandelman, M; Gandini, P; Gao, Y; Garofoli, J; Garosi, P; Garra Tico, J; Garrido, L; Gaspar, C; Gauld, R; Gersabeck, E; Gersabeck, M; Gershon, T; Ghez, Ph; Gibson, V; Giubega, L; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gorbounov, P; Gordon, H; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graziani, G; Grecu, A; Greening, E; Gregson, S; Griffith, P; Grünberg, O; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Hadjivasiliou, C; Haefeli, G; Haen, C; Haines, S C; Hall, S; Hamilton, B; Hampson, T; Hansmann-Menzemer, S; Harnew, N; Harnew, S T; Harrison, J; Hartmann, T; He, J; Head, T; Heijne, V; Hennessy, K; Henrard, P; Hernando Morata, J A; van Herwijnen, E; Hicheur, A; Hicks, E; Hill, D; Hoballah, M; Hombach, C; Hopchev, P; Hulsbergen, W; Hunt, P; Huse, T; Hussain, N; Hutchcroft, D; Hynds, D; Iakovenko, V; Idzik, M; Ilten, P; Jacobsson, R; Jaeger, A; Jans, E; Jaton, P; Jawahery, A; Jing, F; John, M; Johnson, D; Jones, C R; Joram, C; Jost, B; Kaballo, M; Kandybei, S; Kanso, W; Karacson, M; Karbach, T M; Kenyon, I R; Ketel, T; Keune, A; Khanji, B; Kochebina, O; Komarov, I; Koopman, R F; Koppenburg, P; Korolev, M; Kozlinskiy, A; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Kucharczyk, M; Kudryavtsev, V; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanciotti, E; Lanfranchi, G; Langenbruch, C; Latham, T; Lazzeroni, C; Le Gac, R; van Leerdam, J; Lees, J -P; Lefèvre, R; Leflat, A; Lefrançois, J; Leo, S; Leroy, O; Lesiak, T; Leverington, B; Li, Y; Li Gioi, L; Liles, M; Lindner, R; Linn, C; Liu, B; Liu, G; Lohn, S; Longstaff, I; Lopes, J H; Lopez-March, N; Lu, H; Lucchesi, D; Luisier, J; Luo, H; Machefert, F; Machikhiliyan, I V; Maciuc, F; Maev, O; Malde, S; Manca, G; Mancinelli, G; Maratas, J; Marconi, U; Marino, P; Märki, R; Marks, J; Martellotti, G; Martens, A; Martín Sánchez, A; Martinelli, M; Martinez Santos, D; Martins Tostes, D; Massafferri, A; Matev, R; Mathe, Z; Matteuzzi, C; Maurice, E; Mazurov, A; Mc Skelly, B; McCarthy, J; McNab, A; McNulty, R; Meadows, B; Meier, F; Meissner, M; Merk, M; Milanes, D A; Minard, M -N; Molina Rodriguez, J; Monteil, S; Moran, D; Morawski, P; Mordà, A; Morello, M J; Mountain, R; Mous, I; Muheim, F; Müller, K; Muresan, R; Muryn, B; Muster, B; Naik, P; Nakada, T; Nandakumar, R; Nasteva, I; Needham, M; Neubert, S; Neufeld, N; Nguyen, A D; Nguyen, T D; Nguyen-Mau, C; Nicol, M; Niess, V; Niet, R; Nikitin, N; Nikodem, T; Nomerotski, A; Novoselov, A; Oblakowska-Mucha, A; Obraztsov, V; Oggero, S; Ogilvy, S; Okhrimenko, O; Oldeman, R; Orlandea, M; Otalora Goicochea, J M; Owen, P; Oyanguren, A; Pal, B K; Palano, A; Palczewski, T; Palutan, M; Panman, J; Papanestis, A; Pappagallo, M; Parkes, C; Parkinson, C J; Passaleva, G; Patel, G D; Patel, M; Patrick, G N; Patrignani, C; Pavel-Nicorescu, C; Pazos Alvarez, A; Pellegrino, A; Penso, G; Pepe Altarelli, M; Perazzini, S; Perez Trigo, E; Pérez-Calero Yzquierdo, A; Perret, P; Perrin-Terrin, M; Pescatore, L; Pesen, E; Pessina, G; Petridis, K; Petrolini, A; Phan, A; Picatoste Olloqui, E; Pietrzyk, B; Pilař, T; Pinci, D; Playfer, S; Plo Casasus, M; Polci, F; Polok, G; Poluektov, A; Polycarpo, E; Popov, A; Popov, D; Popovici, B; Potterat, C; Powell, A; Prisciandaro, J; Pritchard, A; Prouve, C; Pugatch, V; Puig Navarro, A; Punzi, G; Qian, W; Rademacker, J H; Rakotomiaramanana, B; Rangel, M S; Raniuk, I; Rauschmayr, N; Raven, G; Redford, S; Reid, M M; dos Reis, A C; Ricciardi, S; Richards, A; Rinnert, K; Rives Molina, V; Roa Romero, D A; Robbe, P; Roberts, D A; Rodrigues, E; Rodriguez Perez, P; Roiser, S; Romanovsky, V; Romero Vidal, A; Rouvinet, J; Ruf, T; Ruffini, F; Ruiz, H; Ruiz Valls, P; Sabatino, G; Saborido Silva, J J; Sagidova, N; Sail, P; Saitta, B; Salustino Guimaraes, V; Sanmartin Sedes, B; Sannino, M; Santacesaria, R; Santamarina Rios, C; Santovetti, E; Sapunov, M; Sarti, A; Satriano, C; Satta, A; Savrie, M; Savrina, D; Schaack, P; Schiller, M; Schindler, H; Schlupp, M; Schmelling, M; Schmidt, B; Schneider, O; Schopper, A; Schune, M -H; Schwemmer, R; Sciascia, B; Sciubba, A; Seco, M; Semennikov, A; Senderowska, K; Sepp, I; Serra, N; Serrano, J; Seyfert, P; Shapkin, M; Shapoval, I; Shatalov, P; Shcheglov, Y; Shears, T; Shekhtman, L; Shevchenko, O; Shevchenko, V; Shires, A; Silva Coutinho, R; Sirendi, M; Skwarnicki, T; Smith, N A; Smith, E; Smith, J; Smith, M; Sokoloff, M D; Soler, F J P; Soomro, F; Souza, D; Souza De Paula, B; Spaan, B; Sparkes, A; Spradlin, P; Stagni, F; Stahl, S; Steinkamp, O; Stevenson, S; Stoica, S; Stone, S; Storaci, B; Straticiuc, M; Straumann, U; Subbiah, V K; Sun, L; Swientek, S; Syropoulos, V; Szczekowski, M; Szczypka, P; Szumlak, T; T'Jampens, S; Teklishyn, M; Teodorescu, E; Teubert, F; Thomas, C; Thomas, E; van Tilburg, J; Tisserand, V; Tobin, M; Tolk, S; Tonelli, D; Topp-Joergensen, S; Torr, N; Tournefier, E; Tourneur, S; Tran, M T; Tresch, M; Tsaregorodtsev, A; Tsopelas, P; Tuning, N; Ubeda Garcia, M; Ukleja, A; Urner, D; Ustyuzhanin, A; Uwer, U; Vagnoni, V; Valenti, G; Vallier, A; Van Dijk, M; Vazquez Gomez, R; Vazquez Regueiro, P; Vázquez Sierra, C; Vecchi, S; Velthuis, J J; Veltri, M; Veneziano, G; Vesterinen, M; Viaud, B; Vieira, D; Vilasis-Cardona, X; Vollhardt, A; Volyanskyy, D; Voong, D; Vorobyev, A; Vorobyev, V; Voß, C; Voss, H; Waldi, R; Wallace, C; Wallace, R; Wandernoth, S; Wang, J; Ward, D R; Watson, N K; Webber, A D; Websdale, D; Whitehead, M; Wicht, J; Wiechczynski, J; Wiedner, D; Wiggers, L; Wilkinson, G; Williams, M P; Williams, M; Wilson, F F; Wimberley, J; Wishahi, J; Wislicki, W; Witek, M; Wotton, S A; Wright, S; Wu, S; Wyllie, K; Xie, Y; Xing, Z; Yang, Z; Young, R; Yuan, X; Yushchenko, O; Zangoli, M; Zavertyaev, M; Zhang, F; Zhang, L; Zhang, W C; Zhang, Y; Zhelezov, A; Zhokhov, A; Zhong, L; Zvyagin, A

    2013-01-01

    The ratio of the $\\Lambda_b^0$ baryon lifetime to that of the $\\overline{B}^0$ meson is measured using 1.0 fb$^{-1}$ of integrated luminosity in 7 TeV center-of-mass energy $pp$ collisions at the LHC. The $\\Lambda_b^0$ baryon is observed for the first time in the decay mode $\\Lambda_b^0 \\to J/\\psi p K^-$, while the $\\overline{B}^0$ meson decay used is the well known $\\overline{B}^0 \\to J/\\psi \\pi^+ K^-$ mode, where the $\\pi^+K^-$ mass is consistent with that of the $\\bar{K}^{*0}(892)$ meson. The ratio of lifetimes is measured to be $0.976\\pm0.012\\pm0.006$, in agreement with theoretical expectations based on the heavy quark expansion. Using previous determinations of the $\\overline{B}^0$ meson lifetime, the $\\Lambda_b^0$ lifetime is found to be $1.482 \\pm 0.018 \\pm 0.012$ ps. In both cases the first uncertainty is statistical and the second systematic.

  8. Precision measurement of the Λb(0) baryon lifetime.

    Science.gov (United States)

    Aaij, R; Adeva, B; Adinolfi, M; Adrover, C; Affolder, A; Ajaltouni, Z; Albrecht, J; Alessio, F; Alexander, M; Ali, S; Alkhazov, G; Alvarez Cartelle, P; Alves, A A; Amato, S; Amerio, S; Amhis, Y; Anderlini, L; Anderson, J; Andreassen, R; Andrews, J E; Appleby, R B; Aquines Gutierrez, O; Archilli, F; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Baalouch, M; Bachmann, S; Back, J J; Baesso, C; Balagura, V; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Bauer, Th; Bay, A; Beddow, J; Bedeschi, F; Bediaga, I; Belogurov, S; Belous, K; Belyaev, I; Ben-Haim, E; Bencivenni, G; Benson, S; Benton, J; Berezhnoy, A; Bernet, R; Bettler, M-O; van Beuzekom, M; Bien, A; Bifani, S; Bird, T; Bizzeti, A; Bjørnstad, P M; Blake, T; Blanc, F; Blouw, J; Blusk, S; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borgia, A; Bowcock, T J V; Bowen, E; Bozzi, C; Brambach, T; van den Brand, J; Bressieux, J; Brett, D; Britsch, M; Britton, T; Brook, N H; Brown, H; Burducea, I; Bursche, A; Busetto, G; Buytaert, J; Cadeddu, S; Callot, O; Calvi, M; Calvo Gomez, M; Camboni, A; Campana, P; Campora Perez, D; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carranza-Mejia, H; Carson, L; Carvalho Akiba, K; Casse, G; Castillo Garcia, L; Cattaneo, M; Cauet, Ch; Cenci, R; Charles, M; Charpentier, Ph; Chen, P; Chiapolini, N; Chrzaszcz, M; Ciba, K; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coca, C; Coco, V; Cogan, J; Cogneras, E; Collins, P; Comerma-Montells, A; Contu, A; Cook, A; Coombes, M; Coquereau, S; Corti, G; Couturier, B; Cowan, G A; Craik, D C; Cunliffe, S; Currie, R; D'Ambrosio, C; David, P; David, P N Y; Davis, A; De Bonis, I; De Bruyn, K; De Capua, S; De Cian, M; De Miranda, J M; De Paula, L; De Silva, W; De Simone, P; Decamp, D; Deckenhoff, M; Del Buono, L; Déléage, N; Derkach, D; Deschamps, O; Dettori, F; Di Canto, A; Dijkstra, H; Dogaru, M; Donleavy, S; Dordei, F; Dosil Suárez, A; Dossett, D; Dovbnya, A; Dupertuis, F; Durante, P; Dzhelyadin, R; Dziurda, A; Dzyuba, A; Easo, S; Egede, U; Egorychev, V; Eidelman, S; van Eijk, D; Eisenhardt, S; Eitschberger, U; Ekelhof, R; Eklund, L; El Rifai, I; Elsasser, Ch; Falabella, A; Färber, C; Fardell, G; Farinelli, C; Farry, S; Ferguson, D; Fernandez Albor, V; Ferreira Rodrigues, F; Ferro-Luzzi, M; Filippov, S; Fiore, M; Fitzpatrick, C; Fontana, M; Fontanelli, F; Forty, R; Francisco, O; Frank, M; Frei, C; Frosini, M; Furcas, S; Furfaro, E; Gallas Torreira, A; Galli, D; Gandelman, M; Gandini, P; Gao, Y; Garofoli, J; Garosi, P; Garra Tico, J; Garrido, L; Gaspar, C; Gauld, R; Gersabeck, E; Gersabeck, M; Gershon, T; Ghez, Ph; Gibson, V; Giubega, L; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gorbounov, P; Gordon, H; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graziani, G; Grecu, A; Greening, E; Gregson, S; Griffith, P; Grünberg, O; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Hadjivasiliou, C; Haefeli, G; Haen, C; Haines, S C; Hall, S; Hamilton, B; Hampson, T; Hansmann-Menzemer, S; Harnew, N; Harnew, S T; Harrison, J; Hartmann, T; He, J; Head, T; Heijne, V; Hennessy, K; Henrard, P; Hernando Morata, J A; van Herwijnen, E; Hicheur, A; Hicks, E; Hill, D; Hoballah, M; Hombach, C; Hopchev, P; Hulsbergen, W; Hunt, P; Huse, T; Hussain, N; Hutchcroft, D; Hynds, D; Iakovenko, V; Idzik, M; Ilten, P; Jacobsson, R; Jaeger, A; Jans, E; Jaton, P; Jawahery, A; Jing, F; John, M; Johnson, D; Jones, C R; Joram, C; Jost, B; Kaballo, M; Kandybei, S; Kanso, W; Karacson, M; Karbach, T M; Kenyon, I R; Ketel, T; Keune, A; Khanji, B; Kochebina, O; Komarov, I; Koopman, R F; Koppenburg, P; Korolev, M; Kozlinskiy, A; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Kucharczyk, M; Kudryavtsev, V; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanciotti, E; Lanfranchi, G; Langenbruch, C; Latham, T; Lazzeroni, C; Le Gac, R; van Leerdam, J; Lees, J-P; Lefèvre, R; Leflat, A; Lefrançois, J; Leo, S; Leroy, O; Lesiak, T; Leverington, B; Li, Y; Li Gioi, L; Liles, M; Lindner, R; Linn, C; Liu, B; Liu, G; Lohn, S; Longstaff, I; Lopes, J H; Lopez-March, N; Lu, H; Lucchesi, D; Luisier, J; Luo, H; Machefert, F; Machikhiliyan, I V; Maciuc, F; Maev, O; Malde, S; Manca, G; Mancinelli, G; Maratas, J; Marconi, U; Marino, P; Märki, R; Marks, J; Martellotti, G; Martens, A; Martín Sánchez, A; Martinelli, M; Martinez Santos, D; Martins Tostes, D; Massafferri, A; Matev, R; Mathe, Z; Matteuzzi, C; Maurice, E; Mazurov, A; Mc Skelly, B; McCarthy, J; McNab, A; McNulty, R; Meadows, B; Meier, F; Meissner, M; Merk, M; Milanes, D A; Minard, M-N; Molina Rodriguez, J; Monteil, S; Moran, D; Morawski, P; Mordà, A; Morello, M J; Mountain, R; Mous, I; Muheim, F; Müller, K; Muresan, R; Muryn, B; Muster, B; Naik, P; Nakada, T; Nandakumar, R; Nasteva, I; Needham, M; Neubert, S; Neufeld, N; Nguyen, A D; Nguyen, T D; Nguyen-Mau, C; Nicol, M; Niess, V; Niet, R; Nikitin, N; Nikodem, T; Nomerotski, A; Novoselov, A; Oblakowska-Mucha, A; Obraztsov, V; Oggero, S; Ogilvy, S; Okhrimenko, O; Oldeman, R; Orlandea, M; Otalora Goicochea, J M; Owen, P; Oyanguren, A; Pal, B K; Palano, A; Palczewski, T; Palutan, M; Panman, J; Papanestis, A; Pappagallo, M; Parkes, C; Parkinson, C J; Passaleva, G; Patel, G D; Patel, M; Patrick, G N; Patrignani, C; Pavel-Nicorescu, C; Pazos Alvarez, A; Pellegrino, A; Penso, G; Pepe Altarelli, M; Perazzini, S; Perez Trigo, E; Pérez-Calero Yzquierdo, A; Perret, P; Perrin-Terrin, M; Pescatore, L; Pesen, E; Pessina, G; Petridis, K; Petrolini, A; Phan, A; Picatoste Olloqui, E; Pietrzyk, B; Pilař, T; Pinci, D; Playfer, S; Plo Casasus, M; Polci, F; Polok, G; Poluektov, A; Polycarpo, E; Popov, A; Popov, D; Popovici, B; Potterat, C; Powell, A; Prisciandaro, J; Pritchard, A; Prouve, C; Pugatch, V; Puig Navarro, A; Punzi, G; Qian, W; Rademacker, J H; Rakotomiaramanana, B; Rangel, M S; Raniuk, I; Rauschmayr, N; Raven, G; Redford, S; Reid, M M; dos Reis, A C; Ricciardi, S; Richards, A; Rinnert, K; Rives Molina, V; Roa Romero, D A; Robbe, P; Roberts, D A; Rodrigues, E; Rodriguez Perez, P; Roiser, S; Romanovsky, V; Romero Vidal, A; Rouvinet, J; Ruf, T; Ruffini, F; Ruiz, H; Ruiz Valls, P; Sabatino, G; Saborido Silva, J J; Sagidova, N; Sail, P; Saitta, B; Salustino Guimaraes, V; Sanmartin Sedes, B; Sannino, M; Santacesaria, R; Santamarina Rios, C; Santovetti, E; Sapunov, M; Sarti, A; Satriano, C; Satta, A; Savrie, M; Savrina, D; Schaack, P; Schiller, M; Schindler, H; Schlupp, M; Schmelling, M; Schmidt, B; Schneider, O; Schopper, A; Schune, M-H; Schwemmer, R; Sciascia, B; Sciubba, A; Seco, M; Semennikov, A; Senderowska, K; Sepp, I; Serra, N; Serrano, J; Seyfert, P; Shapkin, M; Shapoval, I; Shatalov, P; Shcheglov, Y; Shears, T; Shekhtman, L; Shevchenko, O; Shevchenko, V; Shires, A; Silva Coutinho, R; Sirendi, M; Skwarnicki, T; Smith, N A; Smith, E; Smith, J; Smith, M; Sokoloff, M D; Soler, F J P; Soomro, F; Souza, D; Souza De Paula, B; Spaan, B; Sparkes, A; Spradlin, P; Stagni, F; Stahl, S; Steinkamp, O; Stevenson, S; Stoica, S; Stone, S; Storaci, B; Straticiuc, M; Straumann, U; Subbiah, V K; Sun, L; Swientek, S; Syropoulos, V; Szczekowski, M; Szczypka, P; Szumlak, T; T'Jampens, S; Teklishyn, M; Teodorescu, E; Teubert, F; Thomas, C; Thomas, E; van Tilburg, J; Tisserand, V; Tobin, M; Tolk, S; Tonelli, D; Topp-Joergensen, S; Torr, N; Tournefier, E; Tourneur, S; Tran, M T; Tresch, M; Tsaregorodtsev, A; Tsopelas, P; Tuning, N; Ubeda Garcia, M; Ukleja, A; Urner, D; Ustyuzhanin, A; Uwer, U; Vagnoni, V; Valenti, G; Vallier, A; Van Dijk, M; Vazquez Gomez, R; Vazquez Regueiro, P; Vázquez Sierra, C; Vecchi, S; Velthuis, J J; Veltri, M; Veneziano, G; Vesterinen, M; Viaud, B; Vieira, D; Vilasis-Cardona, X; Vollhardt, A; Volyanskyy, D; Voong, D; Vorobyev, A; Vorobyev, V; Voß, C; Voss, H; Waldi, R; Wallace, C; Wallace, R; Wandernoth, S; Wang, J; Ward, D R; Watson, N K; Webber, A D; Websdale, D; Whitehead, M; Wicht, J; Wiechczynski, J; Wiedner, D; Wiggers, L; Wilkinson, G; Williams, M P; Williams, M; Wilson, F F; Wimberley, J; Wishahi, J; Wislicki, W; Witek, M; Wotton, S A; Wright, S; Wu, S; Wyllie, K; Xie, Y; Xing, Z; Yang, Z; Young, R; Yuan, X; Yushchenko, O; Zangoli, M; Zavertyaev, M; Zhang, F; Zhang, L; Zhang, W C; Zhang, Y; Zhelezov, A; Zhokhov, A; Zhong, L; Zvyagin, A

    2013-09-06

    The ratio of the Λb(0) baryon lifetime to that of the B(0) meson is measured using 1.0  fb(-1) of integrated luminosity in 7 TeV center-of-mass energy pp collisions at the LHC. The Λb(0) baryon is observed for the first time in the decay mode Λb(0)→J/ψpK-, while the B(0) meson decay used is the well known B(0)→J/ψπ+ K- mode, where the π+ K- mass is consistent with that of the K(*0)(892) meson. The ratio of lifetimes is measured to be 0.976±0.012±0.006, in agreement with theoretical expectations based on the heavy quark expansion. Using previous determinations of the B(0) meson lifetime, the Λb(0) lifetime is found to be 1.482±0.018±0.012  ps. In both cases, the first uncertainty is statistical and the second systematic.

  9. Deconvolution of Positrons' Lifetime spectra

    International Nuclear Information System (INIS)

    Calderin Hidalgo, L.; Ortega Villafuerte, Y.

    1996-01-01

    In this paper, we explain the iterative method previously develop for the deconvolution of Doppler broadening spectra using the mathematical optimization theory. Also, we start the adaptation and application of this method to the deconvolution of positrons' lifetime annihilation spectra

  10. Analysis of Orbital Lifetime Prediction Parameters in Preparation for Post-Mission Disposal

    Directory of Open Access Journals (Sweden)

    Ha–Yeon Choi

    2015-12-01

    Full Text Available Atmospheric drag force is an important source of perturbation of Low Earth Orbit (LEO orbit satellites, and solar activity is a major factor for changes in atmospheric density. In particular, the orbital lifetime of a satellite varies with changes in solar activity, so care must be taken in predicting the remaining orbital lifetime during preparation for post-mission disposal. In this paper, the System Tool Kit (STK® Long-term Orbit Propagator is used to analyze the changes in orbital lifetime predictions with respect to solar activity. In addition, the STK® Lifetime tool is used to analyze the change in orbital lifetime with respect to solar flux data generation, which is needed for the orbital lifetime calculation, and its control on the drag coefficient control. Analysis showed that the application of the most recent solar flux file within the Lifetime tool gives a predicted trend that is closest to the actual orbit. We also examine the effect of the drag coefficient, by performing a comparative analysis between varying and constant coefficients in terms of solar activity intensities.

  11. Lifetime and spin measurements in 40Ar

    International Nuclear Information System (INIS)

    Southon, J.

    1976-01-01

    Lifetimes of levels in 40 Ar populated by the 40 Ar(p,p') reaction have been measured using the Doppler shift attenuation method with a p-γ coincidence technique. A solid argon target was used. The lifetimes determined were (in psec.): 1461 keV level, 1.95 +- 0.15; 2121 keV, >25; 2524 keV, 0.53 +- 0.06; 2893 keV, 4.4 [+2.6,-1.3]; 3208 keV, 0.27. A comprehensive set of branching ratios was also derived and the spins and parities of the 3208 and 4481 keV states were determined to be 2 + and 1 +- respectively. Some of these results suggest that 2 particle -2 hole and 4 particle - 4 hole components are strongly mixed in the low-lying positive parity states in a manner similar to the 2 particle and 4 particle - 2 hole mixing that occurs in 42 Ca. An additional lifetime measurement for the recently discovered high spin state at 3464 keV was carried out using direct electronic timing. The level was excited by the 37 Cl(α,p) reaction and was found to have a lifetime of 1.00 +- 0.03 nsec, which taken together with other evidence indicates that its spin and parity are 6 + . The E2 transition strengths of the 40 Ar 6 + - 4 + - 2 + - 0 + cascade can be simply interpreted in terms of a weak coupling model. (author)

  12. Ultrafast carrier dynamics in tetrahedral amorphous carbon: carrier trapping versus electron-hole recombination

    International Nuclear Information System (INIS)

    Carpene, E; Mancini, E; Dallera, C; Schwen, D; Ronning, C; Silvestri, S De

    2007-01-01

    We report the investigation of the ultrafast carrier dynamics in thin tetrahedral amorphous carbon films by means of femtosecond time-resolved reflectivity. We estimated the electron-phonon relaxation time of a few hundred femtoseconds and we observed that under low optical excitation photo-generated carriers decay according to two distinct mechanisms attributed to trapping by defect states and direct electron-hole recombination. With high excitation, when photo-carrier and trap densities are comparable, a unique temporal evolution develops, as the time dependence of the trapping process becomes degenerate with the electron-hole recombination. This experimental evidence highlights the role of defects in the ultrafast electronic dynamics and is not specific to this particular form of carbon, but has general validity for amorphous and disordered semiconductors

  13. No differences in brain microstructure between young KIBRA-C carriers and non-carriers.

    Science.gov (United States)

    Hu, Li; Xu, Qunxing; Li, Jizhen; Wang, Feifei; Xu, Xinghua; Sun, Zhiyuan; Ma, Xiangxing; Liu, Yong; Wang, Qing; Wang, Dawei

    2018-01-02

    KIBRA rs17070145 polymorphism is associated with variations in memory function and the microstructure of related brain areas. Diffusion kurtosis imaging (DKI) as an extension of diffusion tensor imaging that can provide more information about changes in microstructure, based on the idea that water diffusion in biological tissues is heterogeneous due to structural hindrance and restriction. We used DKI to explore the relationship between KIBRA gene polymorphism and brain microstructure in young adults. We recruited 100 healthy young volunteers, including 53 TT carriers and 47 C allele carriers. No differences were detected between the TT homozygotes and C-allele carriers for any diffusion and kurtosis parameter. These results indicate KIBRA rs17070145 polymorphism likely has little or no effect on brain microstructure in young adults.

  14. CO sub 2 absorption of perovskites as seen by positron lifetime spectroscopy

    CERN Document Server

    Suevegh, K; Juhasz, G; Homonnay, Z; Vertes, A

    2000-01-01

    The CO sub 2 absorption of several ABO sub 3 type perovskites was studied by positron lifetime spectroscopy. The longer positron lifetime was associated with positrons trapped by A site vacancies. The evaluated positron lifetime data indicated the relative stability of the crystal structure of Sr(Co sub 0 sub . sub 5 Fe sub 0 sub . sub 5)O sub 3 sub - subdelta against Ca doping at low Ca concentrations. Oxygen desorption and CO sub 2 absorption/desorption could also be followed by positron lifetime spectroscopy. It was shown that the concentration of oxygen vacancies has a large effect on positron lifetime data through the electron density of A site vacancies.

  15. Theoretical lifetimes and fluorescence yields for multiply-ionized fluorine

    International Nuclear Information System (INIS)

    Tunnell, T.W.; Can, C.; Bhalla, C.P.

    1978-01-01

    Theoretical lifetimes and multiplet partial fluorescence yields for various fluorine ions with a single K-shell vacancy were calculated. For few-electron systems, the lifetimes and line fluorescence yields were computed in the intermediate coupling scheme with the inclusion of the effects arising from configuration interactions. 6 references

  16. Accelerated lifetime test of vibration isolator made of Metal Rubber material

    Science.gov (United States)

    Ao, Hongrui; Ma, Yong; Wang, Xianbiao; Chen, Jianye; Jiang, Hongyuan

    2017-01-01

    The Metal Rubber material (MR) is a kind of material with nonlinear damping characteristics for its application in the field of aerospace, petrochemical industry and so on. The study on the lifetime of MR material is impendent to its application in engineering. Based on the dynamic characteristic of MR, the accelerated lifetime experiments of vibration isolators made of MR working under random vibration load were conducted. The effects of structural parameters of MR components on the lifetime of isolators were studied and modelled with the fitting curves of degradation data. The lifetime prediction methods were proposed based on the models.

  17. Positron lifetime studies of 100-MeV oxygen irradiated Pb-doped Bi-2223 superconductors

    NARCIS (Netherlands)

    Banerjee, T.; Viswanath, R.N.; Kanjilal, D.; Kumar, R.; Ramasamy, S.

    2000-01-01

    Positron lifetime studies have been carried out for unirradiated and 100-MeV oxygen ion irradiated Pb-doped Bi-2223 superconductors. The analysis of positron lifetime spectra revealed three lifetime components: a short lifetime, τ1 = 153–196 ps; an intermediate lifetime, τ2 = 269–339 ps; and a long

  18. Safety requirements for the Pu carriers

    International Nuclear Information System (INIS)

    Mishima, H.

    1993-01-01

    Ministry of Transport of Japan has now set about studying requirements for Pu carriers to ensure safety. It was first studied what the basic concept of safe carriage of Pu should be, and the basic ideas have been worked out. Next the requirements for the Pu carriers were studied based on the above. There are at present no international requirements of construction and equipment for the nuclear-material carriers, but MOT of Japan has so far required special construction and equipment for the nuclear-material carriers which carry a large amount of radioactive material, such as spent fuel or low level radioactive waste, corresponding to the level of the respective potential hazard. The requirements of construction and equipment of the Pu carriers have been established considering the difference in heat generation between Pu and spent fuel, physical protection, and so forth, in addition to the above basic concept. (J.P.N.)

  19. Lifetime depression history and sexual function in women at midlife.

    Science.gov (United States)

    Cyranowski, Jill M; Bromberger, Joyce; Youk, Ada; Matthews, Karen; Kravitz, Howard M; Powell, Lynda H

    2004-12-01

    We examined the association between lifetime depression history and sexual function in a community-based sample of midlife women. Specifically, 914 women aged 42-52 who were participants in the Study of Women's Health Across the Nation completed a self-report assessment of their sexual behaviors, sexual desire, sexual arousal, and sexual satisfaction over the past 6 months. On the basis of the Structured Clinical Interview for the DSM-IV , participants were categorized into 1 of 3 lifetime major depressive disorder (MDD) history groups: no MDD history, single episode MDD, and recurrent MDD. In line with previous reports, women with a history of recurrent MDD reported experiencing less frequent sexual arousal, less physical pleasure, and less emotional satisfaction within their current sexual relationships. Although the groups did not differ in their reported frequency of sexual desire or partnered sexual behaviors, lifetime depression history was associated with increased rates of self-stimulation (masturbation). Associations between lifetime depression history and lower levels of physical pleasure within partnered sexual relationships and higher rates of masturbation remained significant following control for current depressive symptoms, study site, marital status, psychotropic medication use, and lifetime history of anxiety or substance abuse/dependence disorder. Future research is needed to characterize the temporal and etiologic relationships among lifetime depressive disorder, current mood state, and sexual function in women across the lifespan.

  20. Preparation of microorganism free carrier for biofertilizer product

    International Nuclear Information System (INIS)

    Latiffah Norddin; Maizatul Akmam Mhd Nasir; Phua Choo Kwai Hoe

    2007-01-01

    Biofertilizer has been identified as an alternative or complementary to chemical fertilizer to increase soil fertility and crop production in sustainable farming. Biofertilizers are products containing living cells of different types of known microorganisms that may increase crop productivity through N2 fixation, phosphate solubilization or stimulation of plant growth by synthesising phytohormones. A good biofertilizer product needs a good carrier or substrate. A good carrier is free from microbial contamination and can optimise the growth of the biofertilizer microorganisms. Compost is commonly used as carrier or substrate for biofertilizer microorganisms. In the present study, compost produced by Nuclear Malaysia using the Natural Farming was used as a carrier for the biofertilizer products. Gamma irradiation has been used to produce a ?clean? or sterile carrier. The sterilization effect of the carrier was checked by using serial dilution technique. Carriers that were irradiated at 50 kGy of gamma irradiation were found to be sterile. The shelf life of the sterile carriers was also determined. After six months the compost carriers were still free from microbial contamination. (Author)

  1. Carrier-mediated transport of peptides by the kidney

    International Nuclear Information System (INIS)

    Skopicki, H.A.

    1988-01-01

    Small peptide transport was characterized to determine if: (1) Multiple carriers are present in the luminal membrane of renal proximal tubular cells; (2) Carrier-mediated peptide transport is limited by size; and (3) Gentamicin inhibits carrier-mediated reabsorption of peptides. Uptake of glycyl-[ 3 H]proline (Gly-Pro) into renal brush border membrane vesicles demonstrated a dual affinity carrier system. Whether multiple carriers are present was further investigated by characterizing the uptake of [ 3 H]pyroglutamyl-histidine. To determine if carrier-mediated transport of peptides is limited by size of the molecule, uptake of the hydrolytically resistant tripeptide, [ 3 H]pryroglutamyl-histidyl-tryptophan (pGlu-His-Trp), and tetrapeptide, [ 3 H]pyroglutamyl-histidyl-tryptophyl-serine (pGlu-His-Trp-Ser) were assessed. These data indicate: multiple carriers exist on the luminal membrane of renal proximal tubular cells for the transport of dipeptides, and tripeptide pGlu-His-Trp and the tetrapeptide pGlu-His-Trp-Ser are not taken up by a carrier-mediated mechanism, suggesting that the carrier may be limited by the size of the substrate

  2. Lifetime Economic Burden of Rape Among U.S. Adults.

    Science.gov (United States)

    Peterson, Cora; DeGue, Sarah; Florence, Curtis; Lokey, Colby N

    2017-06-01

    This study estimated the per-victim U.S. lifetime cost of rape. Data from previous studies was combined with current administrative data and 2011 U.S. National Intimate Partner and Sexual Violence Survey data in a mathematical model. Rape was defined as any lifetime completed or attempted forced penetration or alcohol- or drug-facilitated penetration, measured among adults not currently institutionalized. Costs included attributable impaired health, lost productivity, and criminal justice costs from the societal perspective. Average age at first rape was assumed to be 18 years. Future costs were discounted by 3%. The main outcome measures were the average per-victim (female and male) and total population discounted lifetime cost of rape. Secondary outcome measures were marginal outcome probabilities among victims (e.g., suicide attempt) and perpetrators (e.g., incarceration) and associated costs. Analysis was conducted in 2016. The estimated lifetime cost of rape was $122,461 per victim, or a population economic burden of nearly $3.1 trillion (2014 U.S. dollars) over victims' lifetimes, based on data indicating >25 million U.S. adults have been raped. This estimate included $1.2 trillion (39% of total) in medical costs; $1.6 trillion (52%) in lost work productivity among victims and perpetrators; $234 billion (8%) in criminal justice activities; and $36 billion (1%) in other costs, including victim property loss or damage. Government sources pay an estimated $1 trillion (32%) of the lifetime economic burden. Preventing sexual violence could avoid substantial costs for victims, perpetrators, healthcare payers, employers, and government payers. These findings can inform evaluations of interventions to reduce sexual violence. Published by Elsevier Inc.

  3. Temperature dependence of positron lifetime in ordered porous silica (SBA-3)

    International Nuclear Information System (INIS)

    Kunishige, S.; Koshimizu, M.; Asai, K.

    2009-01-01

    The temperature dependence of positron lifetime in uniform mesopores was analyzed. We used SBA-3 as the sample material, which possesses an ordered porous structure with uniform cylindrical mesopores. The positron lifetime corresponding to the annihilation in the mesopores increased gradually with a decrease in temperature down to 100 K, and its relative intensity also increased concomitantly. This result was attributed to the lower probability of the escape of the ortho-positronium (o-Ps) from the mesopores into the intergrain space at lower temperatures. An anomalous and sudden increase in the lifetime was observed at around 100 K; this result was in agreement with an increase in the positron lifetime reported in a previous study. It was revealed that the increase in the lifetime is very steep in cases of uniform mesopores, suggesting that the temperature dependence is influenced by the pore size.

  4. Permeability log using new lifetime measurements

    International Nuclear Information System (INIS)

    Dowling, D.J.; Boyd, J.F.; Fuchs, J.A.

    1975-01-01

    Comparative measurements of thermal neutron decay time are obtained for a formation after irradiation with a pulsed neutron source. Chloride ions in formation fluids are concentrated by the electrosmosis effect using charged poles on a well logging sonde. The formation is irradiated with fast neutrons and a first comparative measure of the thermal neutron decay time or neutron lifetime is taken. The chloride ions are then dispersed by acoustic pumping with a magnetostrictive transducer. The formation is then again irradiated with fast neutrons and a comparative measure of neutron lifetime is taken. The comparison is a function of the variation in chloride concentration between the two measurements which is related to formation permeability

  5. Positron lifetime experiments in indium selenide

    International Nuclear Information System (INIS)

    Cruz, R.M. de la; Pareja, R.

    1988-01-01

    Positron lifetime experiments have been performed on as-grown samples which had been isochronally annealed up to 820 K and plastically deformed and these experiments yield a constant lifetime of 282 ± 2 ps which is attributed to bulk positron states in InSe. Electron-irradiated samples exhibit a two-component spectrum, revealing the presence of positron traps which anneal out at about 330 K. The nature of the native shallow donors in InSe is discussed in the light of the results, which support the idea that native donor centres are probably interstitial In atoms rather than Se vacancies. Positron trapping observed in the electron-irradiated samples is attributed to defects related to In vacancies. (author)

  6. Dedicated Carrier Deployment in Heterogeneous Networks with Inter-site Carrier Aggregation

    DEFF Research Database (Denmark)

    Wang, Hua; Rosa, Claudio; Pedersen, Klaus I.

    2013-01-01

    the macrocell or the picocell using simple cell range expansion (RE). Extensive system-level simulations have been conducted to investigate the performance gains that can be achieved with inter-site CA under different traffic models and user distributions. Results show that using inter-site CA between......) or picos with dedicated carrier deployment. Collaborative inter-site carrier aggregation (CA) is proposed in scenarios with macro+RRH deployment to make an efficient use of the fragmented spectrum from multiple cells. While in scenarios with macro+pico deployment, UEs can only connect to either...

  7. Lifetime of piezoceramic multilayer actuators : interplay of material properties and actuator design

    NARCIS (Netherlands)

    Ende, D.A. van den; Bos, B.; Groen, W.A.; Dortmans, L.M.J.G.

    2009-01-01

    We report an investigation into factors limiting the functional lifetime of multilayer piezoceramic actuators. The study consists of a combination of lifetime experiments by means of an accelerated lifetime test, inspection of the actuator microstructure at different stages of the accelerated

  8. Lifetimes for some excited states of sodium

    International Nuclear Information System (INIS)

    Thomas, P.; Campos, J.

    1979-01-01

    The lifetimes of some s,p and d levels of sodium have been measured by the delayed coincidence method, using a single-photon counting technique. The results are compared with the calculated values of the present work, and with other results. The lifetimes of the ns, np, and levels up to n10; of the nf levels up to n-9;and of the ng, nh,n1 and nk levels up to n-8, have been calculated and the transition probabilities of lines with origin in these levels are given. (Author) 38 refs

  9. A study of lifetime within the -12 sec range

    International Nuclear Information System (INIS)

    Dorobantu, V.

    1977-01-01

    Lifetimes of excited nuclear states are studied with a particular emphasis on the determination of nuclear lifetimes by means of the Doppler shift decomposition attenuation method - DSAM - which is based on the mathematical theory of stochastic processes; by its own nature, the emission of recoil nuclei, their motion through an amorphous medium and the detection of gamma rays resulting from these nuclei are all stochastic processes as well. Measurements of lifetimes together with other measurements can supply nuclear structure data, as well as information on the slowing-down process of an energetic ion through a certain material. The experimental tests have been carried out on the Tandem accelerator - IFIN, Bucharest. (author)

  10. Mean lifetime of the B$_{s}^{0}$ meson

    CERN Document Server

    Abreu, P; Adye, T; Agasi, E; Ajinenko, I; Aleksan, Roy; Alekseev, G D; Alemany, R; Allport, P P; Almehed, S; Amaldi, Ugo; Amato, S; Andreazza, A; Andrieux, M L; Antilogus, P; Apel, W D; Arnoud, Y; Åsman, B; Augustin, J E; Augustinus, A; Baillon, Paul; Bambade, P; Barão, F; Barate, R; Barbi, M S; Barbiellini, Guido; Bardin, Dimitri Yuri; Baroncelli, A; Bärring, O; Barrio, J A; Bartl, Walter; Bates, M J; Battaglia, Marco; Baubillier, M; Baudot, J; Becks, K H; Begalli, M; Beillière, P; Belokopytov, Yu A; Benvenuti, Alberto C; Berggren, M; Bertrand, D; Bianchi, F; Bigi, M; Bilenky, S M; Billoir, P; Bloch, D; Blume, M; Blyth, S; Bolognese, T; Bonesini, M; Bonivento, W; Booth, P S L; Borisov, G; Bosio, C; Bosworth, S; Botner, O; Boudinov, E; Bouquet, B; Bourdarios, C; Bowcock, T J V; Bozzo, M; Branchini, P; Brand, K D; Brenke, T; Brenner, R A; Bricman, C; Brillault, L; Brown, R C A; Brückman, P; Brunet, J M; Bugge, L; Buran, T; Burgsmüller, T; Buschmann, P; Buys, A; Cabrera, S; Caccia, M; Calvi, M; Camacho-Rozas, A J; Camporesi, T; Canale, V; Canepa, M; Cankocak, K; Cao, F; Carena, F; Carroll, L; Caso, Carlo; Castillo-Gimenez, M V; Cattai, A; Cavallo, F R; Cerrito, L; Chabaud, V; Chapkin, M M; Charpentier, P; Chaussard, L; Chauveau, J; Checchia, P; Chelkov, G A; Chen, M; Chierici, R; Chliapnikov, P V; Chochula, P; Chorowicz, V; Chudoba, J; Cindro, V; Collins, P; Contreras, J L; Contri, R; Cortina, E; Cosme, G; Cossutti, F; Crawley, H B; Crennell, D J; Crosetti, G; Cuevas-Maestro, J; Czellar, S; Dahl-Jensen, Erik; Dahm, J; D'Almagne, B; Dam, M; Damgaard, G; Dauncey, P D; Davenport, Martyn; Da Silva, W; Defoix, C; Deghorain, A; Della Ricca, G; Delpierre, P A; Demaria, N; De Angelis, A; de Boer, Wim; De Brabandere, S; De Clercq, C; La Vaissière, C de; De Lotto, B; De Min, A; De Paula, L S; De Saint-Jean, C; Dijkstra, H; Di Ciaccio, Lucia; Djama, F; Dolbeau, J; Dönszelmann, M; Doroba, K; Dracos, M; Drees, J; Drees, K A; Dris, M; Edsall, D M; Ehret, R; Eigen, G; Ekelöf, T J C; Ekspong, Gösta; Elsing, M; Engel, J P; Ershaidat, N; Erzen, B; Espirito-Santo, M C; Falk, E; Fassouliotis, D; Feindt, Michael; Fenyuk, A; Ferrer, A; Filippas-Tassos, A; Firestone, A; Fischer, P A; Föth, H; Fokitis, E; Fontanelli, F; Formenti, F; Franek, B J; Frenkiel, P; Fries, D E C; Frodesen, A G; Frühwirth, R; Fulda-Quenzer, F; Fuster, J A; Galloni, A; Gamba, D; Gandelman, M; García, C; García, J; Gaspar, C; Gasparini, U; Gavillet, P; Gazis, E N; Gelé, D; Gerber, J P; Gibbs, M; Gokieli, R; Golob, B; Gopal, Gian P; Gorn, L; Górski, M; Guz, Yu; Gracco, Valerio; Graziani, E; Grosdidier, G; Grzelak, K; Gumenyuk, S A; Gunnarsson, P; Günther, M; Guy, J; Hahn, F; Hahn, S; Hajduk, Z; Hallgren, A; Hamacher, K; Hao, W; Harris, F J; Hedberg, V; Henriques, R P; Hernández, J J; Herquet, P; Herr, H; Hessing, T L; Higón, E; Hilke, Hans Jürgen; Hill, T S; Holmgren, S O; Holt, P J; Holthuizen, D J; Hoorelbeke, S; Houlden, M A; Huet, K; Hultqvist, K; Jackson, J N; Jacobsson, R; Jalocha, P; Janik, R; Jarlskog, C; Jarlskog, G; Jarry, P; Jean-Marie, B; Johansson, E K; Jönsson, L B; Jönsson, P E; Joram, Christian; Juillot, P; Kaiser, M; Kapusta, F; Karafasoulis, K; Karlsson, M; Karvelas, E; Katsanevas, S; Katsoufis, E C; Keränen, R; Khomenko, B A; Khovanskii, N N; King, B J; Kjaer, N J; Klein, H; Klovning, A; Kluit, P M; Köne, B; Kokkinias, P; Koratzinos, M; Korcyl, K; Kostyukhin, V; Kourkoumelis, C; Kuznetsov, O; Kramer, P H; Krammer, Manfred; Kreuter, C; Kronkvist, I J; Krumshtein, Z; Krupinski, W; Kubinec, P; Kucewicz, W; Kurvinen, K L; Lacasta, C; Laktineh, I; Lamblot, S; Lamsa, J; Lanceri, L; Lane, D W; Langefeld, P; Lapin, V; Last, I; Laugier, J P; Lauhakangas, R; Leder, Gerhard; Ledroit, F; Lefébure, V; Legan, C K; Leitner, R; Lemoigne, Y; Lemonne, J; Lenzen, Georg; Lepeltier, V; Lesiak, T; Liko, D; Lindner, R; Lipniacka, A; Lippi, I; Lörstad, B; Loken, J G; López, J M; Loukas, D; Lutz, P; Lyons, L; MacNaughton, J N; Maehlum, G; Maio, A; Malychev, V; Mandl, F; Marco, J; Marco, R P; Maréchal, B; Margoni, M; Marin, J C; Mariotti, C; Markou, A; Maron, T; Martínez-Rivero, C; Martínez-Vidal, F; Martí i García, S; Masik, J; Matorras, F; Matteuzzi, C; Matthiae, Giorgio; Mazzucato, M; McCubbin, M L; McKay, R; McNulty, R; Medbo, J; Merk, M; Meroni, C; Meyer, S; Meyer, W T; Michelotto, M; Migliore, E; Mirabito, L; Mitaroff, Winfried A; Mjörnmark, U; Moa, T; Møller, R; Mönig, K; Monge, M R; Morettini, P; Müller, H; Mundim, L M; Murray, W J; Muryn, B; Myatt, Gerald; Naraghi, F; Navarria, Francesco Luigi; Navas, S; Nawrocki, K; Negri, P; Neumann, W; Neumeister, N; Nicolaidou, R; Nielsen, B S; Nieuwenhuizen, M; Nikolaenko, V; Niss, P; Nomerotski, A; Normand, Ainsley; Novák, M; Oberschulte-Beckmann, W; Obraztsov, V F; Olshevskii, A G; Onofre, A; Orava, Risto; Ostankov, A P; Österberg, K; Ouraou, A; Paganini, P; Paganoni, M; Pagès, P; Palka, H; Papadopoulou, T D; Papageorgiou, K; Pape, L; Parkes, C; Parodi, F; Passeri, A; Pegoraro, M; Pernegger, H; Pernicka, Manfred; Perrotta, A; Petridou, C; Petrolini, A; Petrovykh, M; Phillips, H T; Piana, G; Pierre, F; Pimenta, M; Pindo, M; Plaszczynski, S; Podobrin, O; Pol, M E; Polok, G; Poropat, P; Pozdnyakov, V; Prest, M; Privitera, P; Pukhaeva, N; Pullia, Antonio; Radojicic, D; Ragazzi, S; Rahmani, H; Ratoff, P N; Read, A L; Reale, M; Rebecchi, P; Redaelli, N G; Regler, Meinhard; Reid, D; Renton, P B; Resvanis, L K; Richard, F; Richardson, J; Rídky, J; Rinaudo, G; Ripp, I; Romero, A; Roncagliolo, I; Ronchese, P; Roos, L; Rosenberg, E I; Rosso, E; Roudeau, Patrick; Rovelli, T; Rückstuhl, W; Ruhlmann-Kleider, V; Ruiz, A; Rybicki, K; Saarikko, H; Sacquin, Yu; Sadovskii, A; Sajot, G; Salt, J; Sánchez, J; Sannino, M; Schimmelpfennig, M; Schneider, H; Schwickerath, U; Schyns, M A E; Sciolla, G; Scuri, F; Seager, P; Sedykh, Yu; Segar, A M; Seitz, A; Sekulin, R L; Shellard, R C; Siccama, I; Siegrist, P; Simonetti, S; Simonetto, F; Sissakian, A N; Sitár, B; Skaali, T B; Smadja, G; Smirnov, N; Smirnova, O G; Smith, G R; Sosnowski, R; Souza-Santos, D; Spassoff, Tz; Spiriti, E; Sponholz, P; Squarcia, S; Stanescu, C; Stapnes, Steinar; Stavitski, I; Stichelbaut, F; Stocchi, A; Strauss, J; Strub, R; Stugu, B; Szczekowski, M; Szeptycka, M; Tabarelli de Fatis, T; Tavernet, J P; Chikilev, O G; Tilquin, A; Timmermans, J; Tkatchev, L G; Todorov, T; Todorova, S; Toet, D Z; Tomaradze, A G; Tomé, B; Tonazzo, A; Tortora, L; Tranströmer, G; Treille, D; Trischuk, W; Tristram, G; Trombini, A; Troncon, C; Tsirou, A L; Turluer, M L; Tyapkin, I A; Tyndel, M; Tzamarias, S; Überschär, B; Ullaland, O; Uvarov, V; Valenti, G; Vallazza, E; Van der Velde, C; van Apeldoorn, G W; van Dam, P; Van Doninck, W K; Van Eldik, J; Vassilopoulos, N; Vegni, G; Ventura, L; Venus, W A; Verbeure, F; Verlato, M; Vertogradov, L S; Vilanova, D; Vincent, P; Vitale, L; Vlasov, E; Vodopyanov, A S; Vrba, V; Wahlen, H; Walck, C; Weierstall, M; Weilhammer, Peter; Weiser, C; Wetherell, Alan M; Wicke, D; Wickens, J H; Wielers, M; Wilkinson, G R; Williams, W S C; Winter, M; Witek, M; Woschnagg, K; Yip, K; Zach, F; Zaitsev, A; Zalewska-Bak, A; Zalewski, Piotr; Zavrtanik, D; Zevgolatakos, E; Zimin, N I; Zito, M; Zontar, D; Zuberi, R; Zucchelli, G C; Zumerle, G

    1996-01-01

    This paper presents an update of the measurement of the mean lifetime of the B^0_s meson. Combining D_s - \\ell, D_s-h, \\phi - \\ell and inclusive D_s final states from the 3.2 million hadronic \\Zz decays collected by DELPHI between 1991 and 1994, the B^0_s mean lifetime was measured to be: \\tau(B^0_s) = 1.67 ~\\pm 0.14, M014AU

  11. Observation of rotating nuclear molecules and determination of their lifetimes

    Energy Technology Data Exchange (ETDEWEB)

    Comas, V.; Heinz, S.; Ackermann, D.; Heredia, J.; Hessberger, F.P.; Khuyagbaatar, J.; Kindler, B.; Lommel, B.; Mann, R. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Hofmann, S. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Goethe-Universitaet Frankfurt, Institut fuer Physik, Frankfurt (Germany)

    2012-12-15

    Long-living rotating nuclear molecules (or ''dinuclear systems'') have been observed at the velocity filter SHIP at GSI in reactions of {sup 64}Ni + {sup 207}Pb at Coulomb barrier energies. The rotation was directly revealed by the velocity spectra of deep inelastic target-like transfer products which are formed during the lifetime of the nuclear molecule and emitted after its breakup. The corresponding rotation angles were about 180 degree pointing to long nuclear interaction times or lifetimes of the system, respectively. We deduced the lifetimes from the lines in the velocity spectra originating from two different rotation angles. Further, the unambiguous correlation of a certain transfer product with its individual velocity spectrum allowed us to study the lifetimes as a function of the number of transferred protons. (orig.)

  12. A Humidity-Dependent Lifetime Derating Factor for DC Film Capacitors

    DEFF Research Database (Denmark)

    Wang, Huai; Reigosa, Paula Diaz; Blaabjerg, Frede

    2015-01-01

    accelerated testing of film capacitors under different humidity conditions, enabling a more justified lifetime prediction of film capacitors for DC-link applications under specific climatic environments. The analysis of the testing results and the detailed discussion on the derating factor with different......Film capacitors are widely assumed to have superior reliability performance than Aluminum electrolytic capacitors in DC-link design of power electronic converters. However, the assumption needs to be critically judged especially for applications under high humidity environments. This paper proposes...... a humidity-dependent lifetime derating factor for a type of plastic-boxed metallized DC film capacitors. It overcomes the limitation that the humidity impact is not considered in the state-of-the-art DC film capacitor lifetime models. The lifetime derating factor is obtained based on a total of 8,700 hours...

  13. Carrier-carrier scattering in the gain dynamics of InxGa1-xAs/AlyGa1-yAs diode lasers

    DEFF Research Database (Denmark)

    Sanders, Gary D; Sun, C.-K.; Golubovic, B.

    1996-01-01

    Ultrafast optical nonlinearities in semiconductors play a central role in determining transient amplification and pulse-dependent gain saturation in diode lasers. Both carrier-phonon and carrier-carrier scattering are expected to determine the gain dynamics in these systems. We present a relaxation......-Dirac function where the chemical potential and temperature are self-consistently chosen so that both particle number and energy are conserved in the carrier-carrier scattering process. The relaxation approximation makes the problem an effective one-dimensional problem which can then be solved directly...

  14. Luminosity lifetime in the Tevatron

    International Nuclear Information System (INIS)

    Jackson, G.; Finley, D.; Johnson, R.P.; Kerns, Q.; McCarthy, J.; Siemann, R.; Zhang, P.

    1988-01-01

    Since the inauguration of colliding proton-antiproton operations in 1987, the Tevatron has exhibited luminosity lifetimes shorter than expected. During a typical colliding beam storage period, called a store, luminosity is calculated periodically by measuring the charge and emittances of each bunch. The growth of the transverse bunch emittances is the dominant cause of luminosity deterioration. Throughout, this period, the position spectrum of the bunches exhibited betatron signals larger than expected from Schottky noise. A model assuming externally driven betatron oscillations explains both the betatron signals and the emittance growth. A program is underway to improve the Tevatron luminosity lifetime. The abort kickers have been identified as sources of emittance growth, and some quadrupole power supplies are further candidates. Because the horizontal dispersion through the RF cavities is nonzero, RF phase noise has been investigated. Noise in the main dipole regulation circuit has also been studied. 13 refs., 4 figs

  15. 14 CFR 271.3 - Carrier subsidy need.

    Science.gov (United States)

    2010-01-01

    ... Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS GUIDELINES FOR SUBSIDIZING AIR CARRIERS PROVIDING ESSENTIAL AIR TRANSPORTATION § 271.3 Carrier subsidy need. In establishing the subsidy for an air carrier providing essential air service at an...

  16. Origin of localized states in zinc-blende ZnCdSe thin films and the influence on carrier relaxation of self-assembled ZnTe/ZnCdSe quantum dots

    International Nuclear Information System (INIS)

    Lee, Ling; Dai, Yue-Ru; Yang, Chu-Shou; Fan, Wen-Chung; Chou, Wu-Ching

    2015-01-01

    Highlights: • The localized emission in zinc-blende ZnCdSe is induced by excess selenium. • An optimized growth is demonstrated as the VI/II ratio approaches unity. • Size-independent lifetimes are observed in ZnTe/ZnCdSe quantum dots. • Localized electrons in the capping layer dominate size-independent lifetimes. - Abstract: This study discovered the origin of deep level emission in zinc-blende ZnCdSe thin films grown by molecular beam epitaxy, in which a localization behavior was noticed. Pronounced deep level emission observed in films grown under a VI/II ratio of 1.74 (Se-accumulated regime) could be suppressed by a lower VI/II ratio of 1.04 (intermediate regime) and 0.74 (metal-rich regime). Hence the localized states could be correlated to excess selenium accumulated at the growth surface. The localized states also influence the carrier relaxation process of self-assembled ZnTe quantum dots embedded in a ZnCdSe matrix. Once quantum dots surmount the wetting layer, localized electrons in the capping layer dominate the type-II transition and exhibit size-independent lifetimes

  17. Carbon: Hydrogen carrier or disappearing skeleton?

    International Nuclear Information System (INIS)

    De Jong, K.P.; Van Wechem, H.M.H.

    1994-01-01

    The use of liquid hydrocarbons as energy carriers implies the use of carbon as a carrier for hydrogen to facilitate hydrogen transport and storage. The current trend for liquid energy carriers used in the transport sector is to maximize the load of hydrogen on the carbon carrier. The recently developed Shell Middle Distillate Hydrogenation process for the manufacture of high quality diesel from aromatic refinery streams fits this picture. In the future, the hydrogen required to raise the product H/C ratio will be increasingly produced via gasification of large amounts of heavy residues. In the light of the strong preference towards using liquid fuels in the transport sector, the Shell Middle Distillate Synthesis process to convert natural gas into diesel of very high quality is discussed. Finally, a few comments on the use of hydrogen without a carbon carrier are made. Long lead times and the likelihood of producing the 'first' hydrogen from fossil fuel are highlighted. 13 figs., 6 tabs., 5 refs

  18. Calculating excess lifetime risk in relative risk models

    International Nuclear Information System (INIS)

    Vaeth, M.; Pierce, D.A.

    1990-01-01

    When assessing the impact of radiation exposure it is common practice to present the final conclusions in terms of excess lifetime cancer risk in a population exposed to a given dose. The present investigation is mainly a methodological study focusing on some of the major issues and uncertainties involved in calculating such excess lifetime risks and related risk projection methods. The age-constant relative risk model used in the recent analyses of the cancer mortality that was observed in the follow-up of the cohort of A-bomb survivors in Hiroshima and Nagasaki is used to describe the effect of the exposure on the cancer mortality. In this type of model the excess relative risk is constant in age-at-risk, but depends on the age-at-exposure. Calculation of excess lifetime risks usually requires rather complicated life-table computations. In this paper we propose a simple approximation to the excess lifetime risk; the validity of the approximation for low levels of exposure is justified empirically as well as theoretically. This approximation provides important guidance in understanding the influence of the various factors involved in risk projections. Among the further topics considered are the influence of a latent period, the additional problems involved in calculations of site-specific excess lifetime cancer risks, the consequences of a leveling off or a plateau in the excess relative risk, and the uncertainties involved in transferring results from one population to another. The main part of this study relates to the situation with a single, instantaneous exposure, but a brief discussion is also given of the problem with a continuous exposure at a low-dose rate

  19. Simulation of lifetime radon exposures using observation data

    International Nuclear Information System (INIS)

    Janssen, I.; Stebbings, J.H.

    1990-01-01

    The frequency distribution of lifetime risk of radon-induced lung cancer is a function of the frequency distribution of lifetime radon exposure, which differs from the frequency distribution of radon in homes because of residential mobility. Cumulative personal exposures are averages of a variable number of house radon values, weighted according to duration of occupancy and recency of residence. We simulated a distribution of individual, cumulative Working Level Month (WLM) exposures using observed residence histories from lung cancer cases from Eastern Pennsylvania and (basement) Working Levels (WL) from a survey of Reading Prong, Pennsylvania. The measurements for basement-level houses have a higher skewed distribution, well-approximated by a Gamma distribution with small shape parameter for this high-radon area, where 30% of the houses have basement radon levels that exceed 9 pCi/ell. Using the BEIR IV model and assuming a 50% occupancy factor, we assigned either lifetime residence in a single house or a real residence history at random for women randomly selected from the age distribution of female lung cancer cases. Averaging over houses reduces the exposure of the most highly exposed 5% of the population but increases it for 95%: the upper 25% attains lifetime exposure of ≥ 74 WLM, yielding a relative risk (RR) ≥ 2.1. Ignoring mobility and basing the calculations on the distribution of radon in houses, the corresponding values would be 48.0 WLM and a RR of 1.7. The 50th percentile of the population has an estimated WLM exposure of 34.6 (RR = 1.5); this estimate would be 16.8 (RR = 1.2) if we assume one house per lifetime

  20. Positron lifetime study of copper irradiated by energetic protons or energetic neutrons

    International Nuclear Information System (INIS)

    Howell, R.H.

    1979-03-01

    Positron lifetime measurements of pure copper damaged by irradiation with energetic protons and neutrons are presented. Lifetime determinations of the bulk material and various traps were made, and the dependence of the trapping rate on dose and irradiation energy were investigated. The results from the neutron- and proton-irradiated samples point to the existence of traps with similar but distinct lifetime parameters, not varying greatly from values reported in deformation studies. Also, a trap with long lifetime is seen for some proton irradiations, but is never seen for the neutron irradiations. The trapping rate of the short-lifetime trap is a linear function of dose for proton-irradiated samples and nearly so for the neutron irradiation. 1 figure

  1. Lifetimes of metastable levels of singly ionized titanium: theory and experiment

    International Nuclear Information System (INIS)

    Palmeri, P; Quinet, P; Biemont, E; Gurell, J; Lundin, P; Royen, P; Mannervik, S; Norlin, L-O; Blagoev, K

    2008-01-01

    This paper presents new theoretical lifetimes of metastable levels in singly ionized titanium, Ti II. Along with the lifetimes, transition probabilities for several decay channels from these metastable levels are presented. The calculations are supported by experimental lifetime determinations of the 3d 3 b 2 D 5/2 and 3d 2 ( 3 P)4s b 2 P 3/2 levels along with revised values of the previously published lifetimes of the 3d 2 ( 3 P)4s b 4 P 5/2 and 3d 2 ( 3 P)4s b 2 P 1/2 levels originating partly from a reanalysis utilizing a recently developed method applied on the previously recorded data and partly from new measurements. The presented theoretical investigation of lifetimes of metastable levels in Ti II shows that the HFR calculations are in general compatible with measurements performed using the ion storage ring CRYRING of Stockholm University. The transition probabilities of forbidden lines derived from the new lifetime values will be useful for the diagnostics of low density laboratory or astrophysical plasmas, particularly those encountered in the strontium filament found in the ejecta of η Carinae

  2. Benchmarking of Touschek Beam Lifetime Calculations for the Advanced Photon Source

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, A.; Yang, B.

    2017-06-25

    Particle loss from Touschek scattering is one of the most significant issues faced by present and future synchrotron light source storage rings. For example, the predicted, Touschek-dominated beam lifetime for the Advanced Photon Source (APS) Upgrade lattice in 48-bunch, 200-mA timing mode is only ~ 2 h. In order to understand the reliability of the predicted lifetime, a series of measurements with various beam parameters was performed on the present APS storage ring. This paper first describes the entire process of beam lifetime measurement, then compares measured lifetime with the calculated one by applying the measured beam parameters. The results show very good agreement.

  3. Extraction of minority carrier diffusion length of MWIR Type-II superlattice nBp detector

    Science.gov (United States)

    Taghipour, Zahra; Kazemi, Alireza; Myers, Stephen; Wijewarnasuriya, Priyalal; Mathews, Sen; Steenbergen, Elizabeth H.; Morath, Christian; Cowan, Vincent M.; Ariyawansa, Gamini; Scheihing, John; Krishna, Sanjay

    2017-08-01

    We present a model for the spectral external quantum efficiency (EQE) to extract the minority carrier diffusion length (Ln) of a unipolar nBp InAs/GaSb Type-II superlattice (T2SL) mid-wave infrared (MWIR) detector. The detector consists of a 4 μm thick p-doped 10ML InAs/10ML GaSb SL absorber with a 50% cut-off wavelength of 5 μm at 80 K and zero bias. The n-type doped InAs/AlSb SL barrier in the structure was included to reduce the GR dark current. By fitting the experimentally measured EQE data to the theoretically calculated QE based on the solution of the drift-diffusion equation, the p-type absorber was found the have Ln = 10 +/- 0.5 μm at 80K, and Ln = 12 +/- 0.5 μm at 120K and 150K. We performed the absorption coefficient measurement at different temperatures of interest. Also, we estimated the reduced background concentration and the built-in potential by utilizing a capacitance-voltage measurement technique. We used time-resolved-photoluminescence (TRPL) to determine the lifetime at 80K. With the result of the model and the lifetime measurement, we calculated the diffusion coefficient and the mobility in the T2SL detector at various temperatures. Also, we studied the behavior of different dark current mechanisms by fitting the experimentally measured and simulated dark current density under different operating temperatures and biases.

  4. Lifetime of heavy flavour particles

    International Nuclear Information System (INIS)

    Lueth, V.

    1985-10-01

    Recent measurements of the lifetime of the tau leptons and charm and beauty hadrons are reviewed and their significance for the couplings of the charged weak current, flavour mixing, and models relating quarks to hadron decay are discussed. 70 refs., 17 figs., 5 tabs

  5. Motor carrier evaluation program plan

    International Nuclear Information System (INIS)

    Portsmouth, J.H.; Maxwell, J.E.; Boness, G.O.; Rice, L.E.

    1991-04-01

    The US Department of Energy (DOE) Transportation Management Program (TMP) has established a program to assist the DOE field offices and their contractors in evaluating the motor carriers used to transport DOE-owned hazardous and radioactive materials. This program was initiated to provide the DOE field offices with the tools necessary to help ensure, during this period of motor carrier deregulation, that only highly qualified carriers transport radioactive and hazardous commodities for the DOE. This program will assist DOE in maintaining their excellent performance record in the safe transportation of hazardous commodities. The program was also developed in response to public concern surrounding the transportation of hazardous materials. Representatives of other federal agencies, states, and tribal governments, as well as the news media, have expressed concern about the selection and qualification of carriers engaged in the transportation of Highway Route-Controlled Quantities (HRCQ) and Truckload (TL) quantities of radioactive material for the DOE. 8 refs

  6. A novel experimental technique of nuclear lifetime measurements

    International Nuclear Information System (INIS)

    Yuminov, O.A.; D'Arrigo, A.; Giardina, G.; Taccone, A.; Vannini, G.; Moroni, A.; Ricci, R.A.; Vannucci, L.

    1995-01-01

    In the present paper a new experimental method to measure nuclear reaction time in the 10 -15 -10 -10 s region is presented. Measurements of the lifetimes of low-lying and long-lived states of 19 F and 20 Ne decaying via α-channel were carried out with the aim of checking the feasibility of the method. The results obtained in this way are compared with the lifetimes known from different techniques. ((orig.))

  7. Radionuclide carrier

    International Nuclear Information System (INIS)

    Hartman, F.A.; Kretschmar, H.C.; Tofe, A.J.

    1978-01-01

    A physiologically acceptable particulate radionuclide carrier is described. It comprises a modified anionic starch derivative with 0.1% to 1.5% by weight of a reducing agent and 1 to 20% by weight of anionic substituents

  8. Carrier Screening

    Science.gov (United States)

    ... How accurate is carrier screening? No test is perfect. In a small number of cases, test results ... in which an egg is removed from a woman’s ovary, fertilized in a laboratory with the man’s ...

  9. Lifetime Traumatic Experiences and Leisure Physical Inactivity among Adolescent Boys.

    Science.gov (United States)

    Malinauskas, Romualdas; Malinauskiene, Vilija; Malinauskas, Mindaugas

    2018-03-01

    The aim of this study was to examine the associations between lifetime traumatic experiences and leisure physical inactivity among adolescent boys and to determine to what extent those associations are mediated by posttraumatic stress symptoms, unhealthy behaviors (smoking, alcohol use), the daily consumption of fresh fruit, and sense of coherence. A self-administered questionnaire combining 3 instruments measured leisure physical activity level (Godin and Shephard), symptoms of posttraumatic stress (IES-revised), lifetime traumatic experiences, sense of coherence (SOC-13, from Antonovsky), and behavioral and dietary patterns in a representative sample of eighth grade boys from a number of Kaunas, Lithuania, secondary schools (N = 885; response rate 88.6%). Fifty-six point eight percent of boys had experienced at least 1 lifetime traumatic event, with a 20.5% prevalence of PTS symptoms, and 5.4% were inactive during leisure time. In the logistic regression models, leisure physical inactivity was associated with lifetime traumatic experiences (adjusted OR = 2.33; 95% CI: 1.09-4.98). Sense of coherence and posttraumatic stress symptoms did not mediate those associations. Less-than-daily consumption of fresh fruit showed an independent effect, while smoking and weekly consumption of alcohol did not. Consistent associations between lifetime traumatic experiences and leisure physical inactivity among adolescent boys indicate that the presence of lifetime traumatic events should be taken into account when employing intervention and prevention programs on unhealthy lifestyles (physical inactivity, smoking, and alcohol).

  10. Life-time resolved emission spectra in CdCl2 crystals

    International Nuclear Information System (INIS)

    Kawabata, S.; Nakagawa, H.; Kitaura, M.

    2005-01-01

    The emission spectrum of CdCl 2 is composed of ultraviolet (UV) and yellow (Y) bands peaking at 3.70 and 2.30 eV, respectively. In order to determine the initial states of the Y-luminescence, decay curves of the Y-emission were measured at 8K by varying emission energy in the range from 1.64 eV to 3.13 eV. The observed decay curves are composed of two or three exponential components. The values of lifetime for them were 900, 460 and 60 μs. The emission spectrum for each decay component, i.e., life-time resolved emission spectrum, was analyzed by the observed decay curves. The emission spectrum for the component of 460 μs lifetime exhibits a dominant band at 2.30 eV and a satellite band at 3.03 eV. The emission spectrum for the component of 60 μs lifetime is reproduced by the three Gaussian bands peaking at 2.21, 2.65 and 2.87 eV. For the component of 900 μs lifetime, only a single band appears at 1.73 eV. The origin of the emission bands in life-time resolved emission spectra is briefly discussed, and the initial states of Y-luminescence are explained by the excited states of a [Cd 2+ Cl - 6 ] 4- complex molecular ion. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  11. Fluorescence lifetime based bioassays

    Science.gov (United States)

    Meyer-Almes, Franz-Josef

    2017-12-01

    Fluorescence lifetime (FLT) is a robust intrinsic property and material constant of fluorescent matter. Measuring this important physical indicator has evolved from a laboratory curiosity to a powerful and established technique for a variety of applications in drug discovery, medical diagnostics and basic biological research. This distinct trend was mainly driven by improved and meanwhile affordable laser and detection instrumentation on the one hand, and the development of suitable FLT probes and biological assays on the other. In this process two essential working approaches emerged. The first one is primarily focused on high throughput applications employing biochemical in vitro assays with no requirement for high spatial resolution. The second even more dynamic trend is the significant expansion of assay methods combining highly time and spatially resolved fluorescence data by fluorescence lifetime imaging. The latter approach is currently pursued to enable not only the investigation of immortal tumor cell lines, but also specific tissues or even organs in living animals. This review tries to give an actual overview about the current status of FLT based bioassays and the wide range of application opportunities in biomedical and life science areas. In addition, future trends of FLT technologies will be discussed.

  12. Maximizing Lifetime of Wireless Sensor Networks with Mobile Sink Nodes

    Directory of Open Access Journals (Sweden)

    Yourong Chen

    2014-01-01

    Full Text Available In order to maximize network lifetime and balance energy consumption when sink nodes can move, maximizing lifetime of wireless sensor networks with mobile sink nodes (MLMS is researched. The movement path selection method of sink nodes is proposed. Modified subtractive clustering method, k-means method, and nearest neighbor interpolation method are used to obtain the movement paths. The lifetime optimization model is established under flow constraint, energy consumption constraint, link transmission constraint, and other constraints. The model is solved from the perspective of static and mobile data gathering of sink nodes. Subgradient method is used to solve the lifetime optimization model when one sink node stays at one anchor location. Geometric method is used to evaluate the amount of gathering data when sink nodes are moving. Finally, all sensor nodes transmit data according to the optimal data transmission scheme. Sink nodes gather the data along the shortest movement paths. Simulation results show that MLMS can prolong network lifetime, balance node energy consumption, and reduce data gathering latency under appropriate parameters. Under certain conditions, it outperforms Ratio_w, TPGF, RCC, and GRND.

  13. Lifetime measurement in neutron-rich A ∝ 100 nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Ansari, Saba; Jolie, Jan; Regis, Jean-Marc; Saed-Samii, Nima; Warr, Nigel [Institute for Nuclear Physics, University of Cologne, Cologne (Germany); Collaboration: EXILL-FATIMA-Collaboration

    2016-07-01

    Rapid shape changes are observed in the region of neutron rich nuclei with a mass around A=100. Precise lifetime measurements are a key ingredient in the systematic study of the evolution of nuclear deformation and the degree of collectivity in this region. Nuclear lifetimes of excited states can be obtained using the fast-timing technique with LaBr{sub 3}(Ce)-scintillators. We used neutron induced fission of {sup 241}Pu in order to study lifetimes of excited states of fission fragments in the A∝100 region. The EXILL-FATIMA array located at the PF1B cold neutron beam line at the Institut Laue-Langevin comprises of 8 BGO-shielded EXOGAM clover detectors and 16 very fast LaBr{sub 3}(Ce)-scintillator detectors, which were installed around the fission target. We have studied the lifetimes of low lying states for the nuclei {sup 98}Zr, {sup 100}Zr and {sup 102}Zr by applying the generalized centroid difference method. In this contribution we report on the used fast-timing setup and present preliminary results for the studied isotopes.

  14. Positron annihilation lifetime study of oxide dispersion strengthened steels

    International Nuclear Information System (INIS)

    Krsjak, V.; Szaraz, Z.; Hähner, P.

    2012-01-01

    A comparative positron annihilation lifetime study has been performed on various commercial ferritic and ferritic/martensitic oxide dispersion strengthened (ODS) steels. Both as-extruded and recrystallized materials were investigated. In the materials with recrystallized coarse-grained microstructures, only the positron trapping at small vacancy clusters and yttria nanofeatures was observed. Materials which had not undergone recrystallization treatment clearly showed additional positron trapping which is associated with dislocations. Dislocation densities were calculated from a two-component decomposition of the positron lifetime spectra by assuming the first component to be a superposition of the bulk controlled annihilation rate and the dislocation controlled trapping rate. The second component (which translates into lifetimes of 240–260 ps) was found to be well separated in all those ODS materials. This paper presents the potentialities and limitations of the positron annihilation lifetime spectroscopy, and discusses the results of the experimental determination of the defect concentrations and sensitivity of this technique to the material degradation due to thermally induced precipitation of chromium-rich α′ phases.

  15. Positron annihilation lifetime spectroscopy source correction determination: A simulation study

    Energy Technology Data Exchange (ETDEWEB)

    Kanda, Gurmeet S.; Keeble, David J., E-mail: d.j.keeble@dundee.ac.uk

    2016-02-01

    Positron annihilation lifetime spectroscopy (PALS) can provide sensitive detection and identification of vacancy-related point defects in materials. These measurements are normally performed using a positron source supported, and enclosed by, a thin foil. Annihilation events from this source arrangement must be quantified and are normally subtracted from the spectrum before analysis of the material lifetime components proceeds. Here simulated PALS spectra reproducing source correction evaluation experiments have been systematically fitted and analysed using the packages PALSfit and MELT. Simulations were performed assuming a single lifetime material, and for a material with two lifetime components. Source correction terms representing a directly deposited source and various foil supported sources were added. It is shown that in principle these source terms can be extracted from suitably designed experiments, but that fitting a number of independent, nominally identical, spectra is recommended.

  16. Multiphoton autofluorescence lifetime imaging of induced pluripotent stem cells

    Science.gov (United States)

    Uchugonova, Aisada

    2017-06-01

    The multiphoton fluorescence lifetime imaging tomograph MPTflex with its flexible 360-deg scan head, articulated arm, and tunable femtosecond laser source was employed to study induced pluripotent stem cell (iPS) cultures. Autofluorescence (AF) lifetime imaging was performed with 250-ps temporal resolution and submicron spatial resolution using time-correlated single-photon counting. The two-photon excited AF was based on the metabolic coenzymes NAD(P)H and flavin adenine dinucleotide/flavoproteins. iPS cells generated from mouse embryonic fibroblasts (MEFs) and cocultured with growth-arrested MEFs as feeder cells have been studied. Significant differences on AF lifetime signatures were identified between iPS and feeder cells as well as between their differentiating counterparts.

  17. RDM lifetime measurements in 107Cd

    International Nuclear Information System (INIS)

    Andgren, K; Ashley, S F; Regan, P H

    2005-01-01

    Lifetimes for decays linking near-yrast states in 107 Cd have been measured using the recoil distance method (RDM). The nucleus of interest was populated via the 98 Mo( 12 C,3n) 107 Cd fusion-evaporation reaction at an incident beam energy of 60 MeV. From the measured lifetimes, transition probabilities have been deduced and compared with the theoretical B(E2) values for limiting cases of harmonic vibrational and axially deformed rotational systems. Our initial results suggest a rotor-like behaviour for the structure based on the unnatural-parity, h 11/2 orbital in 107 Cd, providing further evidence for the role of this 'shape-polarizing' orbital in stabilizing the nuclear deformation in the A ∼ 100 transitional region

  18. RDM lifetime measurements in 107Cd

    Science.gov (United States)

    Andgren, K.; Ashley, S. F.; Regan, P. H.; McCutchan, E. A.; Zamfir, N. V.; Amon, L.; Cakirli, R. B.; Casten, R. F.; Clark, R. M.; Gürdal, G.; Keyes, K. L.; Meyer, D. A.; Erduran, M. N.; Papenberg, A.; Pietralla, N.; Plettner, C.; Rainovski, G.; Ribas, R. V.; Thomas, N. J.; Vinson, J.; Warner, D. D.; Werner, V.; Williams, E.

    2005-10-01

    Lifetimes for decays linking near-yrast states in 107Cd have been measured using the recoil distance method (RDM). The nucleus of interest was populated via the 98Mo(12C,3n)107Cd fusion-evaporation reaction at an incident beam energy of 60 MeV. From the measured lifetimes, transition probabilities have been deduced and compared with the theoretical B(E2) values for limiting cases of harmonic vibrational and axially deformed rotational systems. Our initial results suggest a rotor-like behaviour for the structure based on the unnatural-parity, h11/2 orbital in 107Cd, providing further evidence for the role of this 'shape-polarizing' orbital in stabilizing the nuclear deformation in the A ~ 100 transitional region.

  19. On random age and remaining lifetime for populations of items

    DEFF Research Database (Denmark)

    Finkelstein, M.; Vaupel, J.

    2015-01-01

    We consider items that are incepted into operation having already a random (initial) age and define the corresponding remaining lifetime. We show that these lifetimes are identically distributed when the age distribution is equal to the equilibrium distribution of the renewal theory. Then we...... develop the population studies approach to the problem and generalize the setting in terms of stationary and stable populations of items. We obtain new stochastic comparisons for the corresponding population ages and remaining lifetimes that can be useful in applications. Copyright (c) 2014 John Wiley...

  20. Spatial mapping of exciton lifetimes in single ZnO nanowires

    Directory of Open Access Journals (Sweden)

    J. S. Reparaz

    2013-07-01

    Full Text Available We investigate the spatial dependence of the exciton lifetimes in single ZnO nanowires. We have found that the free exciton and bound exciton lifetimes exhibit a maximum at the center of nanowires, while they decrease by 30% towards the tips. This dependence is explained by considering the cavity-like properties of the nanowires in combination with the Purcell effect. We show that the lifetime of the bound-excitons scales with the localization energy to the power of 3/2, which validates the model of Rashba and Gurgenishvili at the nanoscale.

  1. Measurement of the b hadron lifetime with the dipole method

    Science.gov (United States)

    Buskulic, D.; de Bonis, I.; Decamp, D.; Ghez, P.; Goy, C.; Lees, J.-P.; Minard, M.-N.; Pietrzyk, B.; Ariztizabal, F.; Comas, P.; Crespo, J. M.; Delfino, M.; Efthymiopoulos, I.; Fernandez, E.; Fernandez-Bosman, M.; Gaitan, V.; Garrido, Ll.; Mattison, T.; Pacheco, A.; Padilla, C.; Pascual, A.; Creanza, D.; de Palma, M.; Farilla, A.; Iaselli, G.; Maggi, G.; Marinelli, N.; Natali, S.; Nuzzo, S.; Ranieri, A.; Raso, G.; Romano, F.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Zito, G.; Chai, Y.; Hu, H.; Huang, D.; Huang, X.; Lin, J.; Wang, T.; Xie, Y.; Xu, D.; Xu, R.; Zhang, J.; Zhang, L.; Zhao, W.; Bonvicini, G.; Boudreau, J.; Casper, D.; Drevermann, H.; Forty, R. W.; Ganis, G.; Gay, C.; Hagelberg, R.; Harvey, J.; Hilgart, J.; Jacobsen, R.; Jost, B.; Knobloch, J.; Lehraus, I.; Maggi, M.; Markou, C.; Martinez, M.; Mato, P.; Meinhard, H.; Minten, A.; Miquel, R.; Moser, H.-G.; Palazzi, P.; Pater, J. R.; Perlas, J. A.; Pusztaszeri, J.-F.; Ranjard, F.; Rolandi, L.; Rothberg, J.; Ruan, T.; Saich, M.; Schlatter, D.; Schmelling, M.; Sefkow, F.; Tejessy, W.; Tomalin, I. R.; Veenhof, R.; Wachsmuth, H.; Wasserbaech, S.; Wiedenmann, W.; Wildish, T.; Witzeling, W.; Wotschack, J.; Ajaltouni, Z.; Badaud, F.; Bardadin-Otwinowska, M.; El Fellous, R.; Falvard, A.; Gay, P.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Montret, J.-C.; Pallin, D.; Perret, P.; Podlyski, F.; Proriol, J.; Prulhière, F.; Saadi, F.; Fearnley, T.; Hansen, J. B.; Hansen, J. D.; Hansen, J. R.; Hansen, P. H.; Møllerud, R.; Nilsson, B. S.; Kyriakis, A.; Simopoulou, E.; Siotis, I.; Vayaki, A.; Zachariadou, K.; Badier, J.; Blondel, A.; Bonneaud, G.; Brient, J. C.; Bourdon, P.; Fouque, G.; Orteu, S.; Rougé, A.; Rumpf, M.; Tanaka, R.; Verderi, M.; Videau, H.; Candlin, D. J.; Parsons, M. I.; Veitch, E.; Focardi, E.; Moneta, L.; Parrini, G.; Corden, M.; Georgiopoulos, C.; Ikeda, M.; Levinthal, D.; Antonelli, A.; Baldini, R.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Cerutti, F.; Chiarella, V.; D'Ettorre-Piazzoli, B.; Felici, G.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G. P.; Passalacqua, L.; Pepe-Altarelli, M.; Picchi, P.; Colrain, P.; Ten Have, I.; Lynch, J. G.; Maitland, W.; Morton, W. T.; Raine, C.; Reeves, P.; Scarr, J. M.; Smith, K.; Smith, M. G.; Thompson, A. S.; Turnbull, R. M.; Brandl, B.; Braun, O.; Geweniger, C.; Hanke, P.; Hepp, V.; Kluge, E. E.; Maumary, Y.; Putzer, A.; Rensch, B.; Stahl, A.; Tittel, K.; Wunsch, M.; Beuselinck, R.; Binnie, D. M.; Cameron, W.; Cattaneo, M.; Colling, D. J.; Dornan, P. J.; Greene, A. M.; Hassard, J. F.; Lieske, N. M.; Moutoussi, A.; Nash, J.; Patton, S.; Payne, D. G.; Phillips, M. J.; San Martin, G.; Sedgbeer, J. K.; Wright, A. G.; Girtler, P.; Kuhn, D.; Rudolph, G.; Vogl, R.; Bowdery, C. K.; Brodbeck, T. J.; Finch, A. J.; Foster, F.; Hughes, G.; Jackson, D.; Keemer, N. R.; Nuttall, M.; Patel, A.; Sloan, T.; Snow, S. W.; Whelan, E. P.; Kleinknecht, K.; Raab, J.; Renk, B.; Sander, H.-G.; Schmidt, H.; Walther, S. M.; Wanke, R.; Wolf, B.; Zimmermann, A.; Bencheikh, A. M.; Benchouk, C.; Bonissent, A.; Carr, J.; Coyle, P.; Drinkard, J.; Etienne, F.; Nicod, D.; Papalexiou, S.; Payre, P.; Roos, L.; Rousseau, D.; Schwemling, P.; Talby, M.; Adlung, S.; Assmann, R.; Bauer, C.; Blum, W.; Brown, D.; Cattaneo, P.; Dehning, B.; Dietl, H.; Dydak, F.; Frank, M.; Halley, A. W.; Jakobs, K.; Lauber, J.; Lütjens, G.; Lutz, G.; Männer, W.; Richter, R.; Schröder, J.; Schwarz, A. S.; Settles, R.; Seywerd, H.; Stierlin, U.; Stiegler, U.; St. Denis, R.; Wolf, G.; Alemany, R.; Boucrot, J.; Callot, O.; Cordier, A.; Davier, M.; Duflot, L.; Grivaz, J.-F.; Heusse, Ph.; Jaffe, D. E.; Janot, P.; Kim, D. W.; Le Diberder, F.; Lefrançois, J.; Lutz, A.-M.; Schune, M.-H.; Veillet, J.-J.; Videau, I.; Zhang, Z.; Abbaneo, D.; Bagliesi, G.; Batignani, G.; Bottigli, U.; Bozzi, C.; Calderini, G.; Carpinelli, M.; Ciocci, M. A.; Ciulli, V.; Dell'Orso, R.; Ferrante, I.; Fidecaro, F.; Foà, L.; Forti, F.; Giassi, A.; Giorgi, M. A.; Gregorio, A.; Ligabue, F.; Lusiani, A.; Mannelli, E. B.; Marrocchesi, P. S.; Messineo, A.; Palla, F.; Rizzo, G.; Sanguinetti, G.; Spagnolo, P.; Steinberger, J.; Tenchini, R.; Tonelli, G.; Triggiani, G.; Valassi, A.; Vannini, C.; Venturi, A.; Verdini, P. G.; Walsh, J.; Betteridge, A. P.; Gao, Y.; Green, M. G.; March, P. V.; Mir, Ll. M.; Medcalf, T.; Quazi, I. S.; Strong, J. A.; West, L. R.; Botterill, D. R.; Clifft, R. W.; Edgecock, T. R.; Haywood, S.; Norton, P. R.; Thompson, J. C.; Bloch-Devaux, B.; Colas, P.; Duarte, H.; Emery, S.; Kozanecki, W.; Lançon, E.; Lemaire, M. C.; Locci, E.; Marx, B.; Perez, P.; Rander, J.; Renardy, J.-F.; Rosowsky, A.; Roussarie, A.; Schuller, J.-P.; Schwindling, J.; Si Mohand, D.; Vallage, B.; Johnson, R. P.; Litke, A. M.; Taylor, G.; Wear, J.; Ashman, J. G.; Babbage, W.; Booth, C. N.; Buttar, C.; Cartwright, S.; Combley, F.; Dawson, I.; Thompson, L. F.; Barbeiro, E.; Böhrer, A.; Brandt, S.; Cowan, G.; Grupen, C.; Lutters, G.; Rivera, F.; Schäfer, U.; Smolik, L.; Bosisio, L.; Della Marina, R.; Giannini, G.; Gobbo, B.; Ragusa, F.; Bellantoni, L.; Chen, W.; Conway, J. S.; Feng, Z.; Ferguson, D. P. S.; Gao, Y. S.; Grahl, J.; Harton, J. L.; Hayes, O. J.; Nachtman, J. M.; Pan, Y. B.; Saadi, Y.; Schmitt, M.; Scott, I.; Sharma, V.; Shi, Z. H.; Turk, J. D.; Walsh, A. M.; Weber, F. V.; Sau Lan Wu; Wu, X.; Zheng, M.; Zobernig, G.; Aleph Collaboration

    1993-09-01

    A measurement of the average lifetime of b hadrons has been performed with dipole method on a sample of 260 000 hadronic Z decays recorded with the ALEPH detector during 1991. The dipole is the distance between the vertices built in the opposite hemispheres. The mean dipole is extracted from all the events without attempting b enrichment. Comparing the average of the data dipole distribution with a Monte Carlo calibration curve obtained with different b lifetimes, an average b hadron lifetime of 1.51±0.08 ps is extracted.

  2. STAT FAQs Part 2: Lifetime of PV Panels | State, Local, and Tribal

    Science.gov (United States)

    Governments | NREL STAT FAQs Part 2: Lifetime of PV Panels STAT FAQs Part 2: Lifetime of PV Panels April 23, 2018 by Benjamin Mow The Solar Technical Assistance Team (STAT) receives many is the productive lifetime and degradation rate of solar PV panels. Question: What is the productive

  3. Bias Correction Methods Explain Much of the Variation Seen in Breast Cancer Risks of BRCA1/2 Mutation Carriers.

    Science.gov (United States)

    Vos, Janet R; Hsu, Li; Brohet, Richard M; Mourits, Marian J E; de Vries, Jakob; Malone, Kathleen E; Oosterwijk, Jan C; de Bock, Geertruida H

    2015-08-10

    Recommendations for treating patients who carry a BRCA1/2 gene are mainly based on cumulative lifetime risks (CLTRs) of breast cancer determined from retrospective cohorts. These risks vary widely (27% to 88%), and it is important to understand why. We analyzed the effects of methods of risk estimation and bias correction and of population factors on CLTRs in this retrospective clinical cohort of BRCA1/2 carriers. The following methods to estimate the breast cancer risk of BRCA1/2 carriers were identified from the literature: Kaplan-Meier, frailty, and modified segregation analyses with bias correction consisting of including or excluding index patients combined with including or excluding first-degree relatives (FDRs) or different conditional likelihoods. These were applied to clinical data of BRCA1/2 families derived from our family cancer clinic for whom a simulation was also performed to evaluate the methods. CLTRs and 95% CIs were estimated and compared with the reference CLTRs. CLTRs ranged from 35% to 83% for BRCA1 and 41% to 86% for BRCA2 carriers at age 70 years width of 95% CIs: 10% to 35% and 13% to 46%, respectively). Relative bias varied from -38% to +16%. Bias correction with inclusion of index patients and untested FDRs gave the smallest bias: +2% (SD, 2%) in BRCA1 and +0.9% (SD, 3.6%) in BRCA2. Much of the variation in breast cancer CLTRs in retrospective clinical BRCA1/2 cohorts is due to the bias-correction method, whereas a smaller part is due to population differences. Kaplan-Meier analyses with bias correction that includes index patients and a proportion of untested FDRs provide suitable CLTRs for carriers counseled in the clinic. © 2015 by American Society of Clinical Oncology.

  4. Charge-carrier mobilities in disordered semiconducting polymers: effects of carrier density and electric field [refereed

    NARCIS (Netherlands)

    Meisel, K.D.; Pasveer, W.F.; Cottaar, J.; Tanase, C.; Coehoorn, R.; Bobbert, P.A.; Blom, P.W.M.; Leeuw, de D.M.; Michels, M.A.J.

    2006-01-01

    We model charge transport in disordered semiconducting polymers by hopping of charge carriers on a square lattice of sites with Gaussian on-site energy disorder, using Fermi-Dirac statistics. From numerically exact solns. of the Master equation, we study the dependence of the charge-carrier mobility

  5. Extension of the nuclear power plant lifetime

    International Nuclear Information System (INIS)

    Keramsi, Alain

    2011-01-01

    After a presentation of the French nuclear context (history of the reactor fleet, choice of reactor type, PWR operation principle, competitiveness, environmental performance), this Power Point presentation addresses the context and challenges of the operation lifetime (average fleet age in different countries, examples of extensions, case of the United States, what is at stake with lifetime extension, decennial visits, EDF strategy), discusses the EDF's safety objectives (definition of the three main safety functions, impact of the operation duration and of the coexistence of two generations for the safety functions), discusses how to manage the ageing phenomenon for replaceable and non-replaceable components

  6. Magnon lifetimes in terbium at low temperatures

    International Nuclear Information System (INIS)

    Bjerrum Moeller, H.; Mackintosh, A.R.

    1979-01-01

    The lifetimes of magnons propagating in the c-direction of Tb at 4.2 K have been measured by inelastic neutron scattering. In contrast to the behaviour at higher temperatures, where magnon-magnon scattering predominates, the broadening of the magnons increases towards the boundary of the single Brillouin zone, both in the acoustic and optical branches. This suggests that the scattering of the magnons by conduction electrons is important, and the observed lifetimes are consistent with a recent estimate of the magnitude of this effect. The acoustic magnons of very long wavelength behave anomalously, presumably due to dipolar interactions

  7. Prompt Neutron Lifetime for the NBSR Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, A.L.; Diamond, D.

    2012-06-24

    In preparation for the proposed conversion of the National Institute of Standards and Technology (NIST) research reactor (NBSR) from high-enriched uranium (HEU) to low-enriched uranium (LEU) fuel, certain point kinetics parameters must be calculated. We report here values of the prompt neutron lifetime that have been calculated using three independent methods. All three sets of calculations demonstrate that the prompt neutron lifetime is shorter for the LEU fuel when compared to the HEU fuel and longer for the equilibrium end-of-cycle (EOC) condition when compared to the equilibrium startup (SU) condition for both the HEU and LEU fuels.

  8. Robust D-optimal designs under correlated error, applicable invariantly for some lifetime distributions

    International Nuclear Information System (INIS)

    Das, Rabindra Nath; Kim, Jinseog; Park, Jeong-Soo

    2015-01-01

    In quality engineering, the most commonly used lifetime distributions are log-normal, exponential, gamma and Weibull. Experimental designs are useful for predicting the optimal operating conditions of the process in lifetime improvement experiments. In the present article, invariant robust first-order D-optimal designs are derived for correlated lifetime responses having the above four distributions. Robust designs are developed for some correlated error structures. It is shown that robust first-order D-optimal designs for these lifetime distributions are always robust rotatable but the converse is not true. Moreover, it is observed that these designs depend on the respective error covariance structure but are invariant to the above four lifetime distributions. This article generalizes the results of Das and Lin [7] for the above four lifetime distributions with general (intra-class, inter-class, compound symmetry, and tri-diagonal) correlated error structures. - Highlights: • This paper presents invariant robust first-order D-optimal designs under correlated lifetime responses. • The results of Das and Lin [7] are extended for the four lifetime (log-normal, exponential, gamma and Weibull) distributions. • This paper also generalizes the results of Das and Lin [7] to more general correlated error structures

  9. Lifetime improvement mechanism in organic light-emitting diodes with mixed materials at a heterojunction interface

    Science.gov (United States)

    Minagawa, Masahiro; Takahashi, Noriko

    2016-02-01

    To investigate the lifetime improvement mechanism caused by mixing at the heterojunction interface, organic light-emitting diodes (OLEDs) with stacked and mixed 4,4‧-bis[N-(1-naphthyl)-N-phenyl-amino]-biphenyl (α-NPD)/tris(8-hydroxyquinoline)aluminum (Alq3) interfaces were fabricated, and changes in their displacement current due to continuous operation were measured. A decrease in accumulated holes at the α-NPD/Alq3 interface was observed in the stacked configuration devices over longer operations. These results indicate that the injected hole density was reduced during continuous operation, implying that the carrier balance became uneven in the emission region. However, few accumulated holes and changes in the displacement current due to continuous operation were observed in the devices having the mixed layer. Therefore, it was deduced that the number of holes concentrated between the α-NPD and Alq3 layers was decreased by mixing at the heterojunction interface, and that the change in the number of holes was smaller during continuous operation, resulting in less degradation.

  10. Lifetime of a black hole

    International Nuclear Information System (INIS)

    Carlitz, R.D.; Willey, R.S.

    1987-01-01

    We study the constraints placed by quantum mechanics upon the lifetime of a black hole. In the context of a moving-mirror analog model for the Hawking radiation process, we conclude that the period of Hawking radiation must be followed by a much longer period during which the remnant mass (of order m/sub P/) may be radiated away. We are able to place a lower bound on the time required for this radiation process, which translates into a lower bound for the lifetime of the black hole. Particles which are emitted during the decay of the remnant, like the particles which comprise the Hawking flux, may be uncorrelated with each other. But each particle emitted from the decaying remnant is correlated with one particle emitted as Hawking radiation. The state which results after the remnant has evaporated is one which locally appears to be thermal, but which on a much larger scale is marked by extensive correlations

  11. Fine tuning power diodes with irradiation

    International Nuclear Information System (INIS)

    Tarneja, K.S.; Bartko, J.; Johnson, J.E.

    1976-01-01

    Diodes of a particular type are fine tuned with irradiation to optimize the reverse recovery time while minimizing forward voltage drop and providing more uniform electrical characcteristics. The initial and desired minority carrier lifetimes in the anode region of the type are determined as a function of forward voltage drop and reverse recovery time, and the minority carrier radiation damage factor is determined for a desired type of diode and radiation source. The radiation dosage to achieve the desired carrier lifetime with the radiation source is thereafter determined from the function 1/tau = 1/tau 0 + K phi, where tau is the desired minority carrier lifetime, tau 0 is the initial minority carrier lifetime, K is the determined minority carrier radiation damage factor and phi is the radiation dosage. A major surface and preferably the major surface adjoining the anode region of the diodes is then irradiated with the radiation source to the determined radiation dosage. Preferably, the radiation dosage is between about 1 X 10 12 and 5 X 10 13 e/cm 2 , with electron radiation of intensity between 1 and 3 MeV

  12. A new measurement of the Ξc+ lifetime

    Science.gov (United States)

    FOCUS Collaboration; Link, J. M.; Reyes, M.; Yager, P. M.; Anjos, J. C.; Bediaga, I.; Göbel, C.; Magnin, J.; Massafferri, A.; de Miranda, J. M.; Pepe, I. M.; Dos Reis, A. C.; Carrillo, S.; Casimiro, E.; Sánchez-Hernández, A.; Uribe, C.; Vázquez, F.; Cinquini, L.; Cumalat, J. P.; O'Reilly, B.; Ramirez, J. E.; Vaandering, E. W.; Butler, J. N.; Cheung, H. W. K.; Gaines, I.; Garbincius, P. H.; Garren, L. A.; Gottschalk, E.; Kasper, P. H.; Kreymer, A. E.; Kutschke, R.; Bianco, S.; Fabbri, F. L.; Zallo, A.; Cawlfield, C.; Kim, D. Y.; Rahimi, A.; Wiss, J.; Gardner, R.; Kryemadhi, A.; Chung, Y. S.; Kang, J. S.; Ko, B. R.; Kwak, J. W.; Lee, K. B.; Park, H.; Alimonti, G.; Boschini, M.; Chiodini, G.; D'Angelo, P.; DiCorato, M.; Dini, P.; Giammarchi, M.; Inzani, P.; Leveraro, F.; Malvezzi, S.; Menasce, D.; Mezzadri, M.; Milazzo, L.; Moroni, L.; Pedrini, D.; Pontoglio, C.; Prelz, F.; Rovere, M.; Sala, S.; Davenport, T. F.; Agostino, L.; Arena, V.; Boca, G.; Bonomi, G.; Gianini, G.; Liguori, G.; Merlo, M. M.; Pantea, D.; Ratti, S. P.; Riccardi, C.; Segoni, I.; Vitulo, P.; Hernandez, H.; Lopez, A. M.; Mendez, H.; Mendez, L.; Mirles, A.; Montiel, E.; Olaya, D.; Paris, A.; Quinones, J.; Rivera, C.; Xiong, W.; Zhang, Y.; Wilson, J. R.; Cho, K.; Handler, T.; Mitchell, R.; Engh, D.; Hosack, M.; Johns, W. E.; Nehring, M.; Sheldon, P. D.; Stenson, K.; Webster, M.; Sheaff, M.

    2001-12-01

    A precise determination of the charm-strange baryon Ξc+ lifetime is presented. The data were accumulated by the Fermilab high-energy photoproduction experiment FOCUS. The measurement is made with 300Ξc+-->Ξ- π+π+ decays, 130Ξc+-->Σ+K- π+ decays, 45Ξc+-->pK-π+ decays and 58Ξc+-->Λ0K- π+π+ decays. The Ξc+ lifetime is measured to be 0.439+/-0.022+/-0.009 ps.

  13. Positron lifetime measurements on electron irradiated amorphous alloys

    International Nuclear Information System (INIS)

    Moser, P.; Hautojaervi, P.; Chamberod, A.; Yli-Kauppila, J.; Van Zurk, R.

    1981-08-01

    Great advance in understanding the nature of point defects in crystalline metals has been achieved by employing positron annihilation technique. Positrons detect vacancy-type defects and the lifetime value of trapped positrons gives information on the size of submicroscopic vacancy aglomerates and microvoids. In this paper it is shown that low-temperature electron irradiations can result in a considerable increase in the positron lifetimes in various amorphous alloys because of the formation of vacancy-like defects which, in addition of the pre-existing holes, are able to trap positrons. Studied amorphous alloys were Fe 80 B 20 , Pd 80 Si 20 , Cu 50 Ti 50 , and Fe 40 Ni 40 P 14 B 6 . Electron irradiations were performed with 3 MeV electrons at 20 K to doses around 10 19 e - /cm 2 . After annealing positron lifetime spectra were measured at 77 K

  14. Carrier dynamics in graphene. Ultrafast many-particle phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Malic, E.; Brem, S.; Jago, R. [Department of Physics, Chalmers University of Technology, Goeteborg (Sweden); Winzer, T.; Wendler, F.; Knorr, A. [Institut fuer Theoretische Physik, Technische Universitaet Berlin (Germany); Mittendorff, M.; Koenig-Otto, J.C.; Schneider, H.; Helm, M.; Winnerl, S. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Ploetzing, T.; Neumaier, D. [Advanced Microelectronic Center Aachen, AMO GmbH, Aachen (Germany)

    2017-11-15

    Graphene is an ideal material to study fundamental Coulomb- and phonon-induced carrier scattering processes. Its remarkable gapless and linear band structure opens up new carrier relaxation channels. In particular, Auger scattering bridging the valence and the conduction band changes the number of charge carriers and gives rise to a significant carrier multiplication - an ultrafast many-particle phenomenon that is promising for the design of highly efficient photodetectors. Furthermore, the vanishing density of states at the Dirac point combined with ultrafast phonon-induced intraband scattering results in an accumulation of carriers and a population inversion suggesting the design of graphene-based terahertz lasers. Here, we review our work on the ultrafast carrier dynamics in graphene and Landau-quantized graphene is presented providing a microscopic view on the appearance of carrier multiplication and population inversion. (copyright 2017 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. Solid state cloaking for electrical charge carrier mobility control

    Science.gov (United States)

    Zebarjadi, Mona; Liao, Bolin; Esfarjani, Keivan; Chen, Gang

    2015-07-07

    An electrical mobility-controlled material includes a solid state host material having a controllable Fermi energy level and electrical charge carriers with a charge carrier mobility. At least one Fermi level energy at which a peak in charge carrier mobility is to occur is prespecified for the host material. A plurality of particles are distributed in the host material, with at least one particle disposed with an effective mass and a radius that minimize scattering of the electrical charge carriers for the at least one prespecified Fermi level energy of peak charge carrier mobility. The minimized scattering of electrical charge carriers produces the peak charge carrier mobility only at the at least one prespecified Fermi level energy, set by the particle effective mass and radius, the charge carrier mobility being less than the peak charge carrier mobility at Fermi level energies other than the at least one prespecified Fermi level energy.

  16. Measuring upconversion nanoparticles photoluminescence lifetime with FastFLIM and phasor plots

    Science.gov (United States)

    Sun, Yuansheng; Lee, Hsien-Ming; Qiu, Hailin; Liao, Shih-Chu Jeff; Coskun, Ulas; Barbieri, Beniamino

    2018-02-01

    Photon upconversion is a nonlinear process in which the sequential of absorption of two or more photons leads to the anti-stoke emission. Different than the conventional multiphoton excitation process, upconversion can be efficiently performed at low excitation densities. Recent developments in lanthanide-doped upconversion nanoparticles (UCNPs) have led to a diversity of applications, including detecting and sensing of biomolecules, imaging of live cells, tissues and animals, cancer diagnostic and therapy, etc. Measuring the upconversion lifetime provides a new dimension of its imaging and opens a new window for its applications. Due to the long metastable intermediate excited state, UCNP typically has a long excited state lifetime ranging from sub-microseconds to milliseconds. Here, we present a novel development using the FastFLIM technique to measure UCNP lifetime by laser scanning confocal microscopy. FastFLIM is capable of measuring lifetime from 100 ps to 100 ms and features the high data collection efficiency (up to 140-million counts per second). Other than the traditional nonlinear least-square fitting analysis, the raw data acquired by FastFLIM can be directly processed by the model-free phasor plots approach for instant and unbiased lifetime results, providing the ideal routine for the UCNP photoluminescence lifetime microscopy imaging.

  17. Low lifetime stress exposure is associated with reduced stimulus–response memory

    Science.gov (United States)

    Goldfarb, Elizabeth V.; Shields, Grant S.; Daw, Nathaniel D.; Slavich, George M.; Phelps, Elizabeth A.

    2017-01-01

    Exposure to stress throughout life can cumulatively influence later health, even among young adults. The negative effects of high cumulative stress exposure are well-known, and a shift from episodic to stimulus–response memory has been proposed to underlie forms of psychopathology that are related to high lifetime stress. At the other extreme, effects of very low stress exposure are mixed, with some studies reporting that low stress leads to better outcomes, while others demonstrate that low stress is associated with diminished resilience and negative outcomes. However, the influence of very low lifetime stress exposure on episodic and stimulus–response memory is unknown. Here we use a lifetime stress assessment system (STRAIN) to assess cumulative lifetime stress exposure and measure memory performance in young adults reporting very low and moderate levels of lifetime stress exposure. Relative to moderate levels of stress, very low levels of lifetime stress were associated with reduced use and retention (24 h later) of stimulus–response (SR) associations, and a higher likelihood of using context memory. Further, computational modeling revealed that participants with low levels of stress exhibited worse expression of memory for SR associations than those with moderate stress. These results demonstrate that very low levels of stress exposure can have negative effects on cognition. PMID:28298555

  18. Spectrum Fatigue Lifetime and Residual Strength for Fiberglass Laminates; TOPICAL

    International Nuclear Information System (INIS)

    WAHL, NEIL K.; MANDELL, JOHN F.; SAMBORSKY, DANIEL D.

    2002-01-01

    This report addresses the effects of spectrum loading on lifetime and residual strength of a typical fiberglass laminate configuration used in wind turbine blade construction. Over 1100 tests have been run on laboratory specimens under a variety of load sequences. Repeated block loading at two or more load levels, either tensile-tensile, compressive-compressive, or reversing, as well as more random standard spectra have been studied. Data have been obtained for residual strength at various stages of the lifetime. Several lifetime prediction theories have been applied to the results. The repeated block loading data show lifetimes that are usually shorter than predicted by the most widely used linear damage accumulation theory, Miner's sum. Actual lifetimes are in the range of 10 to 20 percent of predicted lifetime in many cases. Linear and nonlinear residual strength models tend to fit the data better than Miner's sum, with the nonlinear providing a better fit of the two. Direct tests of residual strength at various fractions of the lifetime are consistent with the residual strength models. Load sequencing effects are found to be insignificant. The more a spectrum deviates from constant amplitude, the more sensitive predictions are to the damage law used. The nonlinear model provided improved correlation with test data for a modified standard wind turbine spectrum. When a single, relatively high load cycle was removed, all models provided similar, though somewhat non-conservative correlation with the experimental results. Predictions for the full spectrum, including tensile and compressive loads were slightly non-conservative relative to the experimental data, and accurately captured the trend with varying maximum load. The nonlinear residual strength based prediction with a power law S-N curve extrapolation provided the best fit to the data in most cases. The selection of the constant amplitude fatigue regression model becomes important at the lower stress, higher

  19. Accurate Rapid Lifetime Determination on Time-Gated FLIM Microscopy with Optical Sectioning.

    Science.gov (United States)

    Silva, Susana F; Domingues, José Paulo; Morgado, António Miguel

    2018-01-01

    Time-gated fluorescence lifetime imaging microscopy (FLIM) is a powerful technique to assess the biochemistry of cells and tissues. When applied to living thick samples, it is hampered by the lack of optical sectioning and the need of acquiring many images for an accurate measurement of fluorescence lifetimes. Here, we report on the use of processing techniques to overcome these limitations, minimizing the acquisition time, while providing optical sectioning. We evaluated the application of the HiLo and the rapid lifetime determination (RLD) techniques for accurate measurement of fluorescence lifetimes with optical sectioning. HiLo provides optical sectioning by combining the high-frequency content from a standard image, obtained with uniform illumination, with the low-frequency content of a second image, acquired using structured illumination. Our results show that HiLo produces optical sectioning on thick samples without degrading the accuracy of the measured lifetimes. We also show that instrument response function (IRF) deconvolution can be applied with the RLD technique on HiLo images, improving greatly the accuracy of the measured lifetimes. These results open the possibility of using the RLD technique with pulsed diode laser sources to determine accurately fluorescence lifetimes in the subnanosecond range on thick multilayer samples, providing that offline processing is allowed.

  20. Radiation damage and life-time evaluation of RBMK graphite stack

    Energy Technology Data Exchange (ETDEWEB)

    Platonov, P A; Chugunov, O K; Manevsky, V N; Karpukhin, V I [Russian Research Centre Kurchatov Inst., Moscow (Russian Federation). Reactor Material Div.

    1996-08-01

    At the present time there are 11 NPP units with RBMK reactors in operation in Russia, with the oldest now in operation 22 years. Design life-time of the RBMK-1000 reactor is 30 years. This paper addresses the evaluation of RBMK graphite stack life-time. It is the practice in Russia to evaluate the reliability of the channel reactor graphite stack using at least three criteria: degradation of physical-mechanical properties of graphite, preservation of the graphite brick integrity, and degradation of the graphite stack as a structure. Stack life-time evaluation by different criteria indicates that the most realistic approach may be realized on the basis of the criteria of brick cracking and degradation of the graphite stack as a structure. The RBMK reactor graphite stack life-time depends on its temperature and for different units it may be different. (author). 2 refs, 10 figs.

  1. Wake Effects on Lifetime Distribution in DFIG-based Wind Farms

    DEFF Research Database (Denmark)

    Tian, Jie; Zhou, Dao; Su, Chi

    2017-01-01

    With the increasing size of the wind farms, the impact of the wake effect on the energy yields and lifetime consumption of wind turbine can no longer be neglected. In this paper, the affecting factors like the wind speed and wind direction are investigated in terms of the single wake and multiple...... wakes. As the power converter is the most fragile component among the turbine system, its lifetime estimation can be calculated seen from the thermal stress of the power semiconductor. On the basis of the relationship of the power converter in a 5 MW Doubly-Fed Induction Generator (DFIG) wind turbine...... system and the wind speed, the lifetime consumption of the individual turbine in a 10-turbine and an 80-turbine wind farms can be calculated by considering the real distributions of the wind speed and direction. It can be seen that there is significant lifetime difference among individual turbines...

  2. Duchenne muscular dystrophy carriers

    International Nuclear Information System (INIS)

    Matsumura, K.; Nakano, I.

    1989-01-01

    By means of magnetic resonance imaging (MRI), the proton spin-lattice relaxation times (T1 values) of the skeletal muscles were measured in Duchenne muscular dystrophy (DMD) carriers and normal controls. The bound water fraction (BWF) was calculated from the T1 values obtained, according to the fast proton diffusion model. In the DMD carriers, T1 values of the gluteus maximus and quadriceps femoris muscles were significantly higher, and BWFs of these muscles were significantly lower than in normal control. Degenerative muscular changes accompanied by interstitial edema were presumed responsible for this abnormality. No correlation was observed between the muscle T1 and serum creatine kinase values. The present study showed that MRI could be a useful method for studying the dynamic state of water in both normal and pathological skeletal muscles. Its possible utility for DMD carrier detection was discussed briefly. (orig.)

  3. Understanding the prevalence of lifetime abstinence from alcohol: An ecological study.

    Science.gov (United States)

    Probst, Charlotte; Manthey, Jakob; Rehm, Jürgen

    2017-09-01

    The level of alcohol consumption and related burden in a country are strongly impacted by the prevalence of abstinence from alcohol use. The objective of this study was to characterize the association of lifetime abstinence from alcohol use with economic wealth (as measured in the gross domestic product [GDP]) and Muslim religion on a country level. An ecological study was performed using aggregate data of 183 countries for the year 2010. Lifetime abstinence among men and women was predicted using fractional response regression models with the natural logarithm of GDP-PPP (purchasing power parity) and the proportion of Muslim population as predictors. The models were further adjusted by the country's median age and World Health Organization region. Precision of prediction was investigated. Descriptive analyses showed a strong negative association between GDP-PPP and lifetime abstinence in countries without a Muslim majority and a GDP-PPP up to 20,000 international dollars. Regression models confirmed the negative association with GDP-PPP and showed a strong positive association between lifetime abstinence and the proportion of Muslim population. Stratified sensitivity analyses showed that in countries without a Muslim majority only GDP-PPP showed a statistically significant association whereas in Muslim majority countries only the proportion of Muslims was associated with the prevalence of lifetime abstinence. Particularly in countries with a lower GDP and without Muslim majority the prevalence of lifetime abstinence from alcohol use is strongly negatively associated with GDP-PPP. Future research should analyze the accordance in trends of GDP and lifetime abstinence over time. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Multiphoton fluorescence lifetime imaging of chemotherapy distribution in solid tumors

    Science.gov (United States)

    Carlson, Marjorie; Watson, Adrienne L.; Anderson, Leah; Largaespada, David A.; Provenzano, Paolo P.

    2017-11-01

    Doxorubicin is a commonly used chemotherapeutic employed to treat multiple human cancers, including numerous sarcomas and carcinomas. Furthermore, doxorubicin possesses strong fluorescent properties that make it an ideal reagent for modeling drug delivery by examining its distribution in cells and tissues. However, while doxorubicin fluorescence and lifetime have been imaged in live tissue, its behavior in archival samples that frequently result from drug and treatment studies in human and animal patients, and murine models of human cancer, has to date been largely unexplored. Here, we demonstrate imaging of doxorubicin intensity and lifetimes in archival formalin-fixed paraffin-embedded sections from mouse models of human cancer with multiphoton excitation and multiphoton fluorescence lifetime imaging microscopy (FLIM). Multiphoton excitation imaging reveals robust doxorubicin emission in tissue sections and captures spatial heterogeneity in cells and tissues. However, quantifying the amount of doxorubicin signal in distinct cell compartments, particularly the nucleus, often remains challenging due to strong signals in multiple compartments. The addition of FLIM analysis to display the spatial distribution of excited state lifetimes clearly distinguishes between signals in distinct compartments such as the cell nuclei versus cytoplasm and allows for quantification of doxorubicin signal in each compartment. Furthermore, we observed a shift in lifetime values in the nuclei of transformed cells versus nontransformed cells, suggesting a possible diagnostic role for doxorubicin lifetime imaging to distinguish normal versus transformed cells. Thus, data here demonstrate that multiphoton FLIM is a highly sensitive platform for imaging doxorubicin distribution in normal and diseased archival tissues.

  5. Measurement of B_{s}^{0} and D_{s}^{-} Meson Lifetimes.

    Science.gov (United States)

    Aaij, R; Adeva, B; Adinolfi, M; Ajaltouni, Z; Akar, S; Albrecht, J; Alessio, F; Alexander, M; Ali, S; Alkhazov, G; Alvarez Cartelle, P; Alves, A A; Amato, S; Amerio, S; Amhis, Y; An, L; Anderlini, L; Andreassi, G; Andreotti, M; Andrews, J E; Appleby, R B; Archilli, F; d'Argent, P; Arnau Romeu, J; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Baalouch, M; Babuschkin, I; Bachmann, S; Back, J J; Badalov, A; Baesso, C; Baker, S; Balagura, V; Baldini, W; Baranov, A; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Baryshnikov, F; Baszczyk, M; Batozskaya, V; Batsukh, B; Battista, V; Bay, A; Beaucourt, L; Beddow, J; Bedeschi, F; Bediaga, I; Beiter, A; Bel, L J; Bellee, V; Belloli, N; Belous, K; Belyaev, I; Ben-Haim, E; Bencivenni, G; Benson, S; Beranek, S; Berezhnoy, A; Bernet, R; Bertolin, A; Betancourt, C; Betti, F; Bettler, M-O; van Beuzekom, M; Bezshyiko, Ia; Bifani, S; Billoir, P; Birnkraut, A; Bitadze, A; Bizzeti, A; Blake, T; Blanc, F; Blouw, J; Blusk, S; Bocci, V; Boettcher, T; Bondar, A; Bondar, N; Bonivento, W; Bordyuzhin, I; Borgheresi, A; Borghi, S; Borisyak, M; Borsato, M; Bossu, F; Boubdir, M; Bowcock, T J V; Bowen, E; Bozzi, C; Braun, S; Britton, T; Brodzicka, J; Buchanan, E; Burr, C; Bursche, A; Buytaert, J; Cadeddu, S; Calabrese, R; Calvi, M; Calvo Gomez, M; Camboni, A; Campana, P; Campora Perez, D H; Capriotti, L; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carniti, P; Carson, L; Carvalho Akiba, K; Casse, G; Cassina, L; Castillo Garcia, L; Cattaneo, M; Cavallero, G; Cenci, R; Chamont, D; Charles, M; Charpentier, Ph; Chatzikonstantinidis, G; Chefdeville, M; Chen, S; Cheung, S-F; Chobanova, V; Chrzaszcz, M; Chubykin, A; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coco, V; Cogan, J; Cogneras, E; Cogoni, V; Cojocariu, L; Collins, P; Comerma-Montells, A; Contu, A; Cook, A; Coombs, G; Coquereau, S; Corti, G; Corvo, M; Costa Sobral, C M; Couturier, B; Cowan, G A; Craik, D C; Crocombe, A; Cruz Torres, M; Cunliffe, S; Currie, R; D'Ambrosio, C; Da Cunha Marinho, F; Dall'Occo, E; Dalseno, J; David, P N Y; Davis, A; De Bruyn, K; De Capua, S; De Cian, M; De Miranda, J M; De Paula, L; De Serio, M; De Simone, P; Dean, C T; Decamp, D; Deckenhoff, M; Del Buono, L; Dembinski, H-P; Demmer, M; Dendek, A; Derkach, D; Deschamps, O; Dettori, F; Dey, B; Di Canto, A; Di Nezza, P; Dijkstra, H; Dordei, F; Dorigo, M; Dosil Suárez, A; Dovbnya, A; Dreimanis, K; Dufour, L; Dujany, G; Dungs, K; Durante, P; Dzhelyadin, R; Dziewiecki, M; Dziurda, A; Dzyuba, A; Déléage, N; Easo, S; Ebert, M; Egede, U; Egorychev, V; Eidelman, S; Eisenhardt, S; Eitschberger, U; Ekelhof, R; Eklund, L; Ely, S; Esen, S; Evans, H M; Evans, T; Falabella, A; Farley, N; Farry, S; Fay, R; Fazzini, D; Ferguson, D; Fernandez, G; Fernandez Prieto, A; Ferrari, F; Ferreira Rodrigues, F; Ferro-Luzzi, M; Filippov, S; Fini, R A; Fiore, M; Fiorini, M; Firlej, M; Fitzpatrick, C; Fiutowski, T; Fleuret, F; Fohl, K; Fontana, M; Fontanelli, F; Forshaw, D C; Forty, R; Franco Lima, V; Frank, M; Frei, C; Fu, J; Funk, W; Furfaro, E; Färber, C; Gallas Torreira, A; Galli, D; Gallorini, S; Gambetta, S; Gandelman, M; Gandini, P; Gao, Y; Garcia Martin, L M; García Pardiñas, J; Garra Tico, J; Garrido, L; Garsed, P J; Gascon, D; Gaspar, C; Gavardi, L; Gazzoni, G; Gerick, D; Gersabeck, E; Gersabeck, M; Gershon, T; Ghez, Ph; Gianì, S; Gibson, V; Girard, O G; Giubega, L; Gizdov, K; Gligorov, V V; Golubkov, D; Golutvin, A; Gomes, A; Gorelov, I V; Gotti, C; Govorkova, E; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graverini, E; Graziani, G; Grecu, A; Greim, R; Griffith, P; Grillo, L; Gruberg Cazon, B R; Grünberg, O; Gushchin, E; Guz, Yu; Gys, T; Göbel, C; Hadavizadeh, T; Hadjivasiliou, C; Haefeli, G; Haen, C; Haines, S C; Hamilton, B; Han, X; Hansmann-Menzemer, S; Harnew, N; Harnew, S T; Harrison, J; Hatch, M; He, J; Head, T; Heister, A; Hennessy, K; Henrard, P; Henry, L; van Herwijnen, E; Heß, M; Hicheur, A; Hill, D; Hombach, C; Hopchev, H; Huard, Z-C; Hulsbergen, W; Humair, T; Hushchyn, M; Hutchcroft, D; Idzik, M; Ilten, P; Jacobsson, R; Jalocha, J; Jans, E; Jawahery, A; Jiang, F; John, M; Johnson, D; Jones, C R; Joram, C; Jost, B; Jurik, N; Kandybei, S; Karacson, M; Kariuki, J M; Karodia, S; Kecke, M; Kelsey, M; Kenzie, M; Ketel, T; Khairullin, E; Khanji, B; Khurewathanakul, C; Kirn, T; Klaver, S; Klimaszewski, K; Klimkovich, T; Koliiev, S; Kolpin, M; Komarov, I; Kopecna, R; Koppenburg, P; Kosmyntseva, A; Kotriakhova, S; Kozachuk, A; Kozeiha, M; Kravchuk, L; Kreps, M; Krokovny, P; Kruse, F; Krzemien, W; Kucewicz, W; Kucharczyk, M; Kudryavtsev, V; Kuonen, A K; Kurek, K; Kvaratskheliya, T; Lacarrere, D; Lafferty, G; Lai, A; Lanfranchi, G; Langenbruch, C; Latham, T; Lazzeroni, C; Le Gac, R; van Leerdam, J; Leflat, A; Lefrançois, J; Lefèvre, R; Lemaitre, F; Lemos Cid, E; Leroy, O; Lesiak, T; Leverington, B; Li, T; Li, Y; Li, Z; Likhomanenko, T; Lindner, R; Lionetto, F; Liu, X; Loh, D; Longstaff, I; Lopes, J H; Lucchesi, D; Lucio Martinez, M; Luo, H; Lupato, A; Luppi, E; Lupton, O; Lusiani, A; Lyu, X; Machefert, F; Maciuc, F; Maev, O; Maguire, K; Malde, S; Malinin, A; Maltsev, T; Manca, G; Mancinelli, G; Manning, P; Maratas, J; Marchand, J F; Marconi, U; Marin Benito, C; Marinangeli, M; Marino, P; Marks, J; Martellotti, G; Martin, M; Martinelli, M; Martinez Santos, D; Martinez Vidal, F; Martins Tostes, D; Massacrier, L M; Massafferri, A; Matev, R; Mathad, A; Mathe, Z; Matteuzzi, C; Mauri, A; Maurice, E; Maurin, B; Mazurov, A; McCann, M; McNab, A; McNulty, R; Meadows, B; Meier, F; Melnychuk, D; Merk, M; Merli, A; Michielin, E; Milanes, D A; Minard, M-N; Mitzel, D S; Mogini, A; Molina Rodriguez, J; Monroy, I A; Monteil, S; Morandin, M; Morello, M J; Morgunova, O; Moron, J; Morris, A B; Mountain, R; Muheim, F; Mulder, M; Mussini, M; Müller, D; Müller, J; Müller, K; Müller, V; Naik, P; Nakada, T; Nandakumar, R; Nandi, A; Nasteva, I; Needham, M; Neri, N; Neubert, S; Neufeld, N; Neuner, M; Nguyen, T D; Nguyen-Mau, C; Nieswand, S; Niet, R; Nikitin, N; Nikodem, T; Nogay, A; Novoselov, A; O'Hanlon, D P; Oblakowska-Mucha, A; Obraztsov, V; Ogilvy, S; Oldeman, R; Onderwater, C J G; Ossowska, A; Otalora Goicochea, J M; Owen, P; Oyanguren, A; Pais, P R; Palano, A; Palutan, M; Papanestis, A; Pappagallo, M; Pappalardo, L L; Pappenheimer, C; Parker, W; Parkes, C; Passaleva, G; Pastore, A; Patel, M; Patrignani, C; Pearce, A; Pellegrino, A; Penso, G; Pepe Altarelli, M; Perazzini, S; Perret, P; Pescatore, L; Petridis, K; Petrolini, A; Petrov, A; Petruzzo, M; Picatoste Olloqui, E; Pietrzyk, B; Pikies, M; Pinci, D; Pistone, A; Piucci, A; Placinta, V; Playfer, S; Plo Casasus, M; Poikela, T; Polci, F; Poli Lener, M; Poluektov, A; Polyakov, I; Polycarpo, E; Pomery, G J; Ponce, S; Popov, A; Popov, D; Popovici, B; Poslavskii, S; Potterat, C; Price, E; Prisciandaro, J; Prouve, C; Pugatch, V; Puig Navarro, A; Punzi, G; Qian, C; Qian, W; Quagliani, R; Rachwal, B; Rademacker, J H; Rama, M; Ramos Pernas, M; Rangel, M S; Raniuk, I; Ratnikov, F; Raven, G; Redi, F; Reichert, S; Dos Reis, A C; Remon Alepuz, C; Renaudin, V; Ricciardi, S; Richards, S; Rihl, M; Rinnert, K; Rives Molina, V; Robbe, P; Rodrigues, A B; Rodrigues, E; Rodriguez Lopez, J A; Rodriguez Perez, P; Rogozhnikov, A; Roiser, S; Rollings, A; Romanovskiy, V; Romero Vidal, A; Ronayne, J W; Rotondo, M; Rudolph, M S; Ruf, T; Ruiz Valls, P; Saborido Silva, J J; Sadykhov, E; Sagidova, N; Saitta, B; Salustino Guimaraes, V; Sanchez Gonzalo, D; Sanchez Mayordomo, C; Sanmartin Sedes, B; Santacesaria, R; Santamarina Rios, C; Santimaria, M; Santovetti, E; Sarti, A; Satriano, C; Satta, A; Saunders, D M; Savrina, D; Schael, S; Schellenberg, M; Schiller, M; Schindler, H; Schlupp, M; Schmelling, M; Schmelzer, T; Schmidt, B; Schneider, O; Schopper, A; Schreiner, H F; Schubert, K; Schubiger, M; Schune, M-H; Schwemmer, R; Sciascia, B; Sciubba, A; Semennikov, A; Sergi, A; Serra, N; Serrano, J; Sestini, L; Seyfert, P; Shapkin, M; Shapoval, I; Shcheglov, Y; Shears, T; Shekhtman, L; Shevchenko, V; Siddi, B G; Silva Coutinho, R; Silva de Oliveira, L; Simi, G; Simone, S; Sirendi, M; Skidmore, N; Skwarnicki, T; Smith, E; Smith, I T; Smith, J; Smith, M; Soares Lavra, L; Sokoloff, M D; Soler, F J P; Souza De Paula, B; Spaan, B; Spradlin, P; Sridharan, S; Stagni, F; Stahl, M; Stahl, S; Stefko, P; Stefkova, S; Steinkamp, O; Stemmle, S; Stenyakin, O; Stevens, H; Stoica, S; Stone, S; Storaci, B; Stracka, S; Stramaglia, M E; Straticiuc, M; Straumann, U; Sun, L; Sutcliffe, W; Swientek, K; Syropoulos, V; Szczekowski, M; Szumlak, T; T'Jampens, S; Tayduganov, A; Tekampe, T; Tellarini, G; Teubert, F; Thomas, E; van Tilburg, J; Tilley, M J; Tisserand, V; Tobin, M; Tolk, S; Tomassetti, L; Tonelli, D; Topp-Joergensen, S; Toriello, F; Tourinho Jadallah Aoude, R; Tournefier, E; Tourneur, S; Trabelsi, K; Traill, M; Tran, M T; Tresch, M; Trisovic, A; Tsaregorodtsev, A; Tsopelas, P; Tully, A; Tuning, N; Ukleja, A; Ustyuzhanin, A; Uwer, U; Vacca, C; Vagnoni, V; Valassi, A; Valat, S; Valenti, G; Vazquez Gomez, R; Vazquez Regueiro, P; Vecchi, S; van Veghel, M; Velthuis, J J; Veltri, M; Veneziano, G; Venkateswaran, A; Verlage, T A; Vernet, M; Vesterinen, M; Viana Barbosa, J V; Viaud, B; Vieira, D; Vieites Diaz, M; Viemann, H; Vilasis-Cardona, X; Vitti, M; Volkov, V; Vollhardt, A; Voneki, B; Vorobyev, A; Vorobyev, V; Voß, C; de Vries, J A; Vázquez Sierra, C; Waldi, R; Wallace, C; Wallace, R; Walsh, J; Wang, J; Ward, D R; Wark, H M; Watson, N K; Websdale, D; Weiden, A; Whitehead, M; Wicht, J; Wilkinson, G; Wilkinson, M; Williams, M; Williams, M P; Williams, M; Williams, T; Wilson, F F; Wimberley, J; Winn, M A; Wishahi, J; Wislicki, W; Witek, M; Wormser, G; Wotton, S A; Wraight, K; Wyllie, K; Xie, Y; Xing, Z; Xu, Z; Yang, Z; Yang, Z; Yao, Y; Yin, H; Yu, J; Yuan, X; Yushchenko, O; Zarebski, K A; Zavertyaev, M; Zhang, L; Zhang, Y; Zhelezov, A; Zheng, Y; Zhu, X; Zhukov, V; Zucchelli, S

    2017-09-08

    We report on a measurement of the flavor-specific B_{s}^{0} lifetime and of the D_{s}^{-} lifetime using proton-proton collisions at center-of-mass energies of 7 and 8 TeV, collected by the LHCb experiment and corresponding to 3.0  fb^{-1} of integrated luminosity. Approximately 407 000 B_{s}^{0}→D_{s}^{(*)-}μ^{+}ν_{μ} decays are partially reconstructed in the K^{+}K^{-}π^{-}μ^{+} final state. The B_{s}^{0} and D_{s}^{-} natural widths are determined using, as a reference, kinematically similar B^{0}→D^{(*)-}μ^{+}ν_{μ} decays reconstructed in the same final state. The resulting differences between widths of B_{s}^{0} and B^{0} mesons and of D_{s}^{-} and D^{-} mesons are Δ_{Γ}(B)=-0.0115±0.0053(stat)±0.0041(syst)  ps^{-1} and Δ_{Γ}(D)=1.0131±0.0117(stat)±0.0065(syst)  ps^{-1}, respectively. Combined with the known B^{0} and D^{-} lifetimes, these yield the flavor-specific B_{s}^{0} lifetime, τ_{B_{s}^{0}}^{fs}=1.547±0.013(stat)±0.010(syst)±0.004(τ_{B})  ps and the D_{s}^{-} lifetime, τ_{D_{s}^{-}}=0.5064±0.0030(stat)±0.0017(syst)±0.0017(τ_{D})  ps. The last uncertainties originate from the limited knowledge of the B^{0} and D^{-} lifetimes. The results improve upon current determinations.

  6. Relaxation of a kinetic hole due to carrier-carrier scattering in multisubband single-quantum-well semiconductors

    DEFF Research Database (Denmark)

    Dery, H.; Tromborg, Bjarne; Eisenstein, G.

    2003-01-01

    We describe a theoretical model for carrier-carrier scattering in an inverted semiconductor quantum well structure using a multisubband diagram. The model includes all possible nonvanishing interaction terms within the static screening approximation, and it enables one to calculate accurately...

  7. Ultralong Radiative States in Hybrid Perovskite Crystals: Compositions for Submillimeter Diffusion Lengths

    KAUST Repository

    Alarousu, Erkki

    2017-08-29

    Organic-inorganic hybrid perovskite materials have recently evolved into the leading candidate solution-processed semiconductor for solar cells due to their combination of desirable optical and charge transport properties. Chief among these properties is the long carrier diffusion length, which is essential to optimizing the device architecture and performance. Herein, we used time-resolved photoluminescence (at low excitation fluence, 10.59 μJ·cm upon two-photon excitation), which is the most accurate and direct approach to measure the radiative charge carrier lifetime and diffusion lengths. Lifetimes of about 72 and 4.3 μs for FAPbBr and FAPbI perovskite single crystals have been recorded, presenting the longest radiative carrier lifetimes reported to date for perovskite materials. Subsequently, carrier diffusion lengths of 107.2 and 19.7 μm are obtained. In addition, we demonstrate the key role of the organic cation units in modulating the carrier lifetime and its diffusion lengths, in which the defect formation energies for FA cations are much higher than those with the MA ones.

  8. 26 CFR 1.25A-4 - Lifetime Learning Credit.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 1 2010-04-01 2010-04-01 true Lifetime Learning Credit. 1.25A-4 Section 1.25A-4... Rates During A Taxable Year § 1.25A-4 Lifetime Learning Credit. (a) Amount of the credit—(1) Taxable years beginning before January 1, 2003. Subject to the phaseout of the education tax credit described in...

  9. Lifetime of chaotic attractors in a multidimensional laser system

    International Nuclear Information System (INIS)

    Pando L, C.L.; Cerdeira, H.A.

    1995-01-01

    We study the lifetimes of chaotic attractors at crises in a multidimensional laser system. This system describes the CO 2 laser with modulated losses and is known as the four-level model. The critical exponents which are related to the lifetimes of the attractors are estimated in terms of the corresponding eigenvalues and the measured characteristic lifetime in the model. The critical exponents in this model and those of its center manifold version are in good agreement. We conjecture that generically in the four-level model the critical exponents are close to 1/2 at crises. In addition, we compare predictions of a simpler and popular model known as the two-level model with those of the above mentioned models. (author). 21 refs, 2 figs, 3 tabs

  10. Development of a remaining lifetime management system for NPPS

    International Nuclear Information System (INIS)

    Galvan, J.C.; Regano, M.; Hevia Ruperez, F.

    1994-01-01

    The interest evinced by Spain nuclear power plants in providing a tool to support remaining lifetime management led to UNESA's application to OCIDE in 1992, and the latter's approval, for financing the project to develop a Remaining Lifetime Evaluation System for LWR nuclear power plants. This project is currently being developed under UNESA leadership, and the collaboration of three Spanish engineering companies and a research centre. The paper will describe its objectives, activities, current status and prospects. The project is defined in two phases, the first consisting of the identification and analysis of the main ageing phenomena and their significant parameters and specification of the Remaining Lifetime Evaluation System (RLES), and the second implementation of a pilot application of the RLES to verify its effectiveness. (Author)

  11. Lifetime measurement of excited atomic and ionic states of some

    Indian Academy of Sciences (India)

    High-frequency deflection (HFD) technique with a delayed coincidence single photon counting arrangement is an efficient technique for radiative lifetime measurement. An apparatus for measurement of the radiative lifetime of atoms and molecules has been developed in our laboratory and measurements have been ...

  12. Measurement of the Lifetime of the $\\tau$ Lepton

    CERN Document Server

    Acciarri, M; Aguilar-Benítez, M; Ahlen, S P; Alpat, B; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alverson, G; Alviggi, M G; Ambrosi, G; Anderhub, H; Andreev, V P; Angelescu, T; Anselmo, F; Antreasyan, D; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Baksay, L; Ball, R C; Banerjee, S; Banicz, K; Barillère, R; Barone, L; Bartalini, P; Baschirotto, A; Basile, M; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Bhattacharya, S; Biasini, M; Biland, A; Bilei, G M; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böck, R K; Böhm, A; Borgia, B; Boucham, A; Bourilkov, D; Bourquin, Maurice; Boutigny, D; Branson, J G; Brigljevic, V; Brock, I C; Buffini, A; Buijs, A; Burger, J D; Burger, W J; Busenitz, J K; Buytenhuijs, A O; Cai, X D; Campanelli, M; Capell, M; Cara Romeo, G; Caria, M; Carlino, G; Cartacci, A M; Casaus, J; Castellini, G; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada-Canales, M; Cesaroni, F; Chamizo-Llatas, M; Chan, A; Chang, Y H; Chaturvedi, U K; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chen, M; Chiefari, G; Chien, C Y; Choi, M T; Cifarelli, Luisa; Cindolo, F; Civinini, C; Clare, I; Clare, R; Cohn, H O; Coignet, G; Colijn, A P; Colino, N; Costantini, S; Cotorobai, F; de la Cruz, B; Csilling, Akos; Dai, T S; D'Alessandro, R; De Asmundis, R; De Boeck, H; Degré, A; Deiters, K; Denes, P; De Notaristefani, F; DiBitonto, Daryl; Diemoz, M; Van Dierendonck, D N; Di Lodovico, F; Dionisi, C; Dittmar, Michael; Dominguez, A; Doria, A; Dorne, I; Dova, M T; Drago, E; Duchesneau, D; Duinker, P; Durán, I; Dutta, S; Easo, S; Efremenko, Yu V; El-Mamouni, H; Engler, A; Eppling, F J; Erné, F C; Ernenwein, J P; Extermann, Pierre; Fabre, M; Faccini, R; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, Marta; Fenyi, B; Ferguson, T; Fernández, D; Ferroni, F; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, Frank; Fisher, P H; Forconi, G; Fredj, L; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gau, S S; Gentile, S; Gerald, J; Gheordanescu, N; Giagu, S; Goldfarb, S; Goldstein, J; Gong, Z F; Gougas, Andreas; Gratta, Giorgio; Grünewald, M W; Gupta, V K; Gurtu, A; Gutay, L J; Hangarter, K; Hartmann, B; Hasan, A; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Van Hoek, W C; Hofer, H; Hoorani, H; Hou, S R; Hu, G; Innocente, Vincenzo; Janssen, H; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Kasser, A; Khan, R A; Kamyshkov, Yu A; Kapinos, P; Kapustinsky, J S; Karyotakis, Yu; Kaur, M; Kienzle-Focacci, M N; Kim, D; Kim, J K; Kim, S C; Kim, Y G; Kinnison, W W; Kirkby, A; Kirkby, D; Kirkby, Jasper; Kiss, D; Kittel, E W; Klimentov, A; König, A C; Korolko, I; Koutsenko, V F; Krämer, R W; Krenz, W; Kuijten, H; Kunin, A; Ladrón de Guevara, P; Landi, G; Lapoint, C; Lassila-Perini, K M; Laurikainen, P; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Lee Jae Sik; Lee, K Y; Leggett, C; Le Goff, J M; Leiste, R; Leonardi, E; Levchenko, P M; Li Chuan; Lieb, E H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lu, W; Lü, Y S; Lübelsmeyer, K; Luci, C; Luckey, D; Luminari, L; Lustermann, W; Ma Wen Gan; Maity, M; Majumder, G; Malgeri, L; Malinin, A; Maña, C; Mangla, S; Marchesini, P A; Marin, A; Martin, J P; Marzano, F; Massaro, G G G; McNally, D; Mele, S; Merola, L; Meschini, M; Metzger, W J; Von der Mey, M; Mi, Y; Mihul, A; Van Mil, A J W; Mirabelli, G; Mnich, J; Molnár, P; Monteleoni, B; Moore, R; Morganti, S; Moulik, T; Mount, R; Müller, S; Muheim, F; Nagy, E; Nahn, S; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Nippe, A; Nowak, H; Organtini, G; Ostonen, R; Pandoulas, D; Paoletti, S; Paolucci, P; Park, H K; Pascale, G; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Peach, D; Pei, Y J; Pensotti, S; Perret-Gallix, D; Petrak, S; Pevsner, A; Piccolo, D; Pieri, M; Pinto, J C; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Postema, H; Produit, N; Prokofev, D; Prokofiev, D O; Rahal-Callot, G; Rancoita, P G; Rattaggi, M; Raven, G; Razis, P A; Read, K; Ren, D; Rescigno, M; Reucroft, S; Van Rhee, T; Riemann, S; Riemers, B C; Riles, K; Rind, O; Ro, S; Robohm, A; Rodin, J; Rodríguez-Calonge, F J; Roe, B P; Röhner, S; Romero, L; Rosier-Lees, S; Rosselet, P; Van Rossum, W; Roth, S; Rubio, Juan Antonio; Rykaczewski, H; Salicio, J; Sánchez, E; Santocchia, A; Sarakinos, M E; Sarkar, S; Sassowsky, M; Sauvage, G; Schäfer, C; Shchegelskii, V; Schmidt-Kärst, S; Schmitz, D; Schmitz, P; Schneegans, M; Schöneich, B; Scholz, N; Schopper, Herwig Franz; Schotanus, D J; Schwenke, J; Schwering, G; Sciacca, C; Sciarrino, D; Sens, Johannes C; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shukla, J; Shumilov, E; Shvorob, A V; Siedenburg, T; Son, D; Sopczak, André; Soulimov, V; Smith, B; Spillantini, P; Steuer, M; Stickland, D P; Stone, H; Stoyanov, B; Strässner, A; Strauch, K; Sudhakar, K; Sultanov, G G; Sun, L Z; Susinno, G F; Suter, H; Swain, J D; Tang, X W; Tauscher, Ludwig; Taylor, L; Ting, Samuel C C; Ting, S M; Tonisch, F; Tonutti, M; Tonwar, S C; Tóth, J; Tully, C; Tuchscherer, H; Tung, K L; Ulbricht, J; Uwer, U; Valente, E; Van de Walle, R T; Vesztergombi, G; Vetlitskii, I; Viertel, Gert M; Vivargent, M; Völkert, R; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Vorvolakos, A; Wadhwa, M; Wallraff, W; Wang, J C; Wang, X L; Wang, Z M; Weber, A; Wittgenstein, F; Wu, S X; Wynhoff, S; Xu, J; Xu, Z Z; Yang, B Z; Yang, C G; Yao, X Y; Ye, J B; Yeh, S C; You, J M; Zalite, A; Zalite, Yu; Zemp, P; Zeng, Y; Zhang, Z; Zhang, Z P; Zhou, B; Zhou, Y; Zhu, G Y; Zhu, R Y; Zichichi, Antonino

    1996-01-01

    The lifetime of the tau lepton is measured using data collected in 1994 by the L3 detector at LEP. The precise track position information of the Silicon Microvertex Detector is exploited. The tau lepton lifetime is determined from the signed impact parameter distribution for 30 322 tau decays into one charged particle and from the decay length distribution for 3891 tau decays into three charged particles. Combining the two methods we obtain $\\tau_{\\tau}$ = 290.1 $\\pm$ 4.0 fs.

  13. Single photon counting fluorescence lifetime detection of pericellular oxygen concentrations.

    Science.gov (United States)

    Hosny, Neveen A; Lee, David A; Knight, Martin M

    2012-01-01

    Fluorescence lifetime imaging microscopy offers a non-invasive method for quantifying local oxygen concentrations. However, existing methods are either invasive, require custom-made systems, or show limited spatial resolution. Therefore, these methods are unsuitable for investigation of pericellular oxygen concentrations. This study describes an adaptation of commercially available equipment which has been optimized for quantitative extracellular oxygen detection with high lifetime accuracy and spatial resolution while avoiding systematic photon pile-up. The oxygen sensitive fluorescent dye, tris(2,2'-bipyridyl)ruthenium(II) chloride hexahydrate [Ru(bipy)(3)](2+), was excited using a two-photon excitation laser. Lifetime was measured using a Becker & Hickl time-correlated single photon counting, which will be referred to as a TCSPC card. [Ru(bipy)(3)](2+) characterization studies quantified the influences of temperature, pH, cellular culture media and oxygen on the fluorescence lifetime measurements. This provided a precisely calibrated and accurate system for quantification of pericellular oxygen concentration based on measured lifetimes. Using this technique, quantification of oxygen concentrations around isolated viable chondrocytes, seeded in three-dimensional agarose gel, revealed a subpopulation of cells that exhibited significant spatial oxygen gradients such that oxygen concentration reduced with increasing proximity to the cell. This technique provides a powerful tool for quantifying spatial oxygen gradients within three-dimensional cellular models.

  14. Analyzing the factors affecting network lifetime cluster-based wireless sensor network

    International Nuclear Information System (INIS)

    Malik, A.S.; Qureshi, A.

    2010-01-01

    Cluster-based wireless sensor networks enable the efficient utilization of the limited energy resources of the deployed sensor nodes and hence prolong the node as well as network lifetime. Low Energy Adaptive Clustering Hierarchy (Leach) is one of the most promising clustering protocol proposed for wireless sensor networks. This paper provides the energy utilization and lifetime analysis for cluster-based wireless sensor networks based upon LEACH protocol. Simulation results identify some important factors that induce unbalanced energy utilization between the sensor nodes and hence affect the network lifetime in these types of networks. These results highlight the need for a standardized, adaptive and distributed clustering technique that can increase the network lifetime by further balancing the energy utilization among sensor nodes. (author)

  15. Irradiation creep lifetime analysis on first wall structure materials for CFETR

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Bing; Peng, Lei, E-mail: penglei@ustc.edu.cn; Zhang, Xiansheng; Shi, Jingyi; Zhan, Jie

    2017-05-15

    Fusion reactor first wall services on the conditions of high surface heat flux and intense neutron irradiation. For China Fusion Engineering Test Reactor (CFETR) with high duty time factor, it is important to analyze the irradiation effect on the creep lifetime of the main candidate structure materials for first wall, i.e. ferritic/martensitic steel, austenite steel and oxide dispersion strengthened steel. The allowable irradiation creep lifetime was evaluated with Larson-Miller Parameter (LMP) model and finite element method. The results show that the allowable irradiation creep lifetime decreases with increasing of surface heat flux, first wall thickness and inlet coolant temperature. For the current CFETR conceptual design, the lifetime is not limited by thermal creep or irradiation creep, which indicated the room for design parameters optimization.

  16. Histidine-lysine peptides as carriers of nucleic acids.

    Science.gov (United States)

    Leng, Qixin; Goldgeier, Lisa; Zhu, Jingsong; Cambell, Patricia; Ambulos, Nicholas; Mixson, A James

    2007-03-01

    With their biodegradability and diversity of permutations, peptides have significant potential as carriers of nucleic acids. This review will focus on the sequence and branching patterns of peptide carriers composed primarily of histidines and lysines. While lysines within peptides are important for binding to the negatively charged phosphates, histidines are critical for endosomal lysis enabling nucleic acids to reach the cytosol. Histidine-lysine (HK) polymers by either covalent or ionic bonds with liposomes augment transfection compared to liposome carriers alone. More recently, we have examined peptides as sole carriers of nucleic acids because of their intrinsic advantages compared to the bipartite HK/liposome carriers. With a protocol change and addition of a histidine-rich tail, HK peptides as sole carriers were more effective than liposomes alone in several cell lines. While four-branched polymers with a primary repeating sequence pattern of -HHK- were more effective as carriers of plasmids, eight-branched polymers with a sequence pattern of -HHHK- were more effective as carriers of siRNA. Compared to polyethylenimine, HK carriers of siRNA and plasmids had reduced toxicity. When injected intravenously, HK polymers in complex with plasmids encoding antiangiogenic proteins significantly decreased tumor growth. Furthermore, modification of HK polymers with polyethylene glycol and vascular-specific ligands increased specificity of the polyplex to the tumor by more than 40-fold. Together with further development and insight on the structure of HK polyplexes, HK peptides may prove to be useful as carriers of different forms of nucleic acids both in vitro and in vivo.

  17. Comparison of age at natural menopause in BRCA1/2 mutation carriers with a non-clinic-based sample of women in northern California.

    Science.gov (United States)

    Lin, Wayne T; Beattie, Mary; Chen, Lee-May; Oktay, Kutluk; Crawford, Sybil L; Gold, Ellen B; Cedars, Marcelle; Rosen, Mitchell

    2013-05-01

    Germline mutations in BRCA1 and BRCA2 (BRCA1/2) are related to an increased lifetime risk of developing breast and ovarian cancer. Although risk-reducing salpingo-oophorectomy reduces the risk of both cancers, loss of fertility is a major concern. A recent study suggested an association between BRCA1 mutation and occult primary ovarian insufficiency. The objective of the current study was to determine whether BRCA1/2 mutation carriers have an earlier onset of natural menopause compared with unaffected women. White carriers of the BRCA1/2 gene (n = 382) were identified within the Breast Cancer Risk Program Registry at the University of California at San Francisco and compared with non-clinic-based white women in northern California (n = 765). The 2 groups were compared with regard to median age at the time of natural menopause before and after adjustment for known risk factors, and the role of smoking within each group was examined using the Kaplan-Meier approach for unadjusted analyses and Cox proportional hazards regression analyses for adjusted analyses. The median age at the time of natural menopause in the BRCA1/2 carriers was significantly younger than among the unaffected sample (50 years vs 53 years; P < .001). The unadjusted hazard ratio for natural menopause when comparing BRCA1/2 carriers with unaffected women was 4.06 (95% confidence interval, 3.03-5.45) and was 3.98 (95% confidence interval, 2.87-5.53) after adjusting for smoking, parity, and oral contraceptive use. For BRCA1/2 carriers who were current heavy smokers (smoking ≥ 20 cigarettes/day), the median age at natural menopause was 46 years versus 49 years for nonsmokers (P = .027). The BRCA1/2 mutation was associated with a significantly earlier age at natural menopause, and heavy smoking compounded this risk. Because the relationship between menopause and the end of natural fertility is considered to be fixed, these findings suggest the risk of earlier infertility among BRCA1/2 carriers

  18. Studies of Lifetimes in an Ion Storage Ring Using Laser Technique

    International Nuclear Information System (INIS)

    Rostohar, Danijela; Derkatch, Anna; Hartman, Henrik; Norlin, Lars-Olov; Royen, Peder; Schef, Peter; Mannervik, Sven

    2003-01-01

    The laser-probing method for lifetime measurements of metastable levels, performed by applying the Fast Ion Beam Laser (FIBLAS) method to ions stored in a storage ring, has been developed by the Stockholm group. Recently, we have applied this method to lifetime measurements of close lying metastable levels. In this paper we discuss experimental studies of ions with complex structure and present the first experimentally obtained lifetimes of selected metastable levels in complex systems as Fe + , Eu + and La + .

  19. Practices of prolongation of the I and C equipment lifetime

    International Nuclear Information System (INIS)

    Samoylov, O.B.; Pronin, V.S.; Savelov, I.D.; Bogomazov, V.A.; Drumov, V.V.; Chudin, A.G.

    2000-01-01

    The lifetime of nuclear power plants (NPP) always exceeds the operational time of Instrumentation and Control (I and C) systems. Ageing of I and C equipment in NPPs have many aspects. Research of these aspects is being performed in OKB Mechanical Engineering. Under condition of fast development of I and C systems and applying more stringent safety requirements, modernization of the equipment irrespective of its operational condition is getting important. However, an equipment of I and C systems operated in Russia was designed and manufactured applying highest requirements for a reliability of their work during its whole operational time. Therefore, in many cases it is not necessary to replace them in spite of expiration of their specified lifetime. During operation this equipment is maintained in a proper operation condition by a special service procedures stipulated by its development. When the equipment lifetime approaches to its end, lifetime extension for the certain period should be considered. (author)

  20. Positron Lifetimes in Pure and Doped Ice and in Water

    DEFF Research Database (Denmark)

    Eldrup, Morten Mostgaard; Mogensen, O.; Trumpy, Georg

    1972-01-01

    for the other components show a complex behavior. The spectra for mono- and polycrystalline light ice and for polycrystalline heavy ice are identical. For water long lifetime components attributed to ortho-Ps are 1.86 nsec, 27% for H2O and 2.01 nsec, 22% for D2O. Theoretical explanations are suggested. Fast......Positron lifetime spectra were measured in mono- and polycrystalline light ice, polycrystalline heavy ice, doped light ice, as well as in light and heavy water. All spectra were resolved into three components. At temperatures between −196° and −100°C the lifetimes and relative intensities...... of the spectra are found by heating above approximately −120°C. Measurements on a number of fast frozen aqueous solutions of acids, bases, and salts are reported, none of them showing as strong influence on the ortho-Ps lifetime as HF. ©1972 The American Institute of Physics...