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Sample records for nanosecond eleven reference

  1. Nanosecond-level time synchronization of AERA using a beacon reference transmitter and commercial airplanes

    Directory of Open Access Journals (Sweden)

    Huege Tim

    2017-01-01

    Full Text Available Radio detection of cosmic-ray air showers requires time synchronization of detectors on a nanosecond level, especially for advanced reconstruction algorithms based on the wavefront curvature and for interferometric analysis approaches. At the Auger Engineering Radio Array, the distributed, autonomous detector stations are time-synchronized via the Global Positioning System which, however, does not provide sufficient timing accuracy. We thus employ a dedicated beacon reference transmitter to correct for eventby-event clock drifts in our offline data analysis. In an independent cross-check of this “beacon correction” using radio pulses emitted by commercial airplanes, we have shown that the combined timing accuracy of the two methods is better than 2 nanoseconds.

  2. Nanosecond-level time synchronization of AERA using a beacon reference transmitter and commercial airplanes

    Science.gov (United States)

    Huege, Tim

    2017-03-01

    Radio detection of cosmic-ray air showers requires time synchronization of detectors on a nanosecond level, especially for advanced reconstruction algorithms based on the wavefront curvature and for interferometric analysis approaches. At the Auger Engineering Radio Array, the distributed, autonomous detector stations are time-synchronized via the Global Positioning System which, however, does not provide sufficient timing accuracy. We thus employ a dedicated beacon reference transmitter to correct for eventby-event clock drifts in our offline data analysis. In an independent cross-check of this "beacon correction" using radio pulses emitted by commercial airplanes, we have shown that the combined timing accuracy of the two methods is better than 2 nanoseconds.

  3. Definition of the upper reference limit for thyroglobulin antibodies according to the National Academy of Clinical Biochemistry guidelines: comparison of eleven different automated methods.

    Science.gov (United States)

    D'Aurizio, F; Metus, P; Ferrari, A; Caruso, B; Castello, R; Villalta, D; Steffan, A; Gaspardo, K; Pesente, F; Bizzaro, N; Tonutti, E; Valverde, S; Cosma, C; Plebani, M; Tozzoli, R

    2017-12-01

    In the last two decades, thyroglobulin autoantibodies (TgAb) measurement has progressively switched from marker of thyroid autoimmunity to test associated with thyroglobulin (Tg) to verify the presence or absence of TgAb interference in the follow-up of patients with differentiated thyroid cancer. Of note, TgAb measurement is cumbersome: despite standardization against the International Reference Preparation MRC 65/93, several studies demonstrated high inter-method variability and wide variation in limits of detection and in reference intervals. Taking into account the above considerations, the main aim of the present study was the determination of TgAb upper reference limit (URL), according to the National Academy of Clinical Biochemistry guidelines, through the comparison of eleven commercial automated immunoassay platforms. The sera of 120 healthy males, selected from a population survey in the province of Verona, Italy, were tested for TgAb concentration using eleven IMA applied on as many automated analyzers: AIA-2000 (AIA) and AIA-CL2400 (CL2), Tosoh Bioscience; Architect (ARC), Abbott Diagnostics; Advia Centaur XP (CEN) and Immulite 2000 XPi (IMM), Siemens Healthineers; Cobas 6000 (COB), Roche Diagnostics; Kryptor (KRY), Thermo Fisher Scientific BRAHMS, Liaison XL (LIA), Diasorin; Lumipulse G (LUM), Fujirebio; Maglumi 2000 Plus (MAG), Snibe and Phadia 250 (PHA), Phadia AB, Thermo Fisher Scientific. All assays were performed according to manufacturers' instructions in six different laboratories in Friuli-Venezia Giulia and Veneto regions of Italy [Lab 1 (AIA), Lab 2 (CL2), Lab 3 (ARC, COB and LUM), Lab 4 (CEN, IMM, KRY and MAG), Lab 5 (LIA) and Lab 6 (PHA)]. Since TgAb values were not normally distributed, the experimental URL (e-URL) was established at 97.5 percentile according to the non-parametric method. TgAb e-URLs showed a significant inter-method variability. Considering the same method, e-URL was much lower than that suggested by manufacturers (m

  4. Definition of the upper reference limit for thyroglobulin antibodies according to the National Academy of Clinical Biochemistry guidelines: comparison of eleven different automated methods

    OpenAIRE

    D?Aurizio, F.; Metus, P.; Ferrari, A.; Caruso, B.; Castello, R.; Villalta, D.; Steffan, A.; Gaspardo, K.; Pesente, F.; Bizzaro, N.; Tonutti, E.; Valverde, S.; Cosma, C.; Plebani, M.; Tozzoli, R.

    2017-01-01

    Purpose In the last two decades, thyroglobulin autoantibodies (TgAb) measurement has progressively switched from marker of thyroid autoimmunity to test associated with thyroglobulin (Tg) to verify the presence or absence of TgAb interference in the follow-up of patients with differentiated thyroid cancer. Of note, TgAb measurement is cumbersome: despite standardization against the International Reference Preparation MRC 65/93, several studies demonstrated high inter-method variability and wid...

  5. Eleven papers in analysis

    CERN Document Server

    Shabalin, P L; Yakubenko, A A; Pokhilevich, VA; Krein, M G

    1986-01-01

    This collection of eleven papers covers a broad spectrum of topics in analysis, from the study of certain classes of analytic functions to the solvability of singular problems for differential and integral equations to computational schemes for the partial differential equations and singular integral equations.

  6. Nanosecond neutron generator

    International Nuclear Information System (INIS)

    Lobov, S.I.; Pavlovskaya, N.G.; Pukhov, S.P.

    1991-01-01

    High-voltage nanosecond neutron generator for obtaining neutrons in D-T reaction is described. Yield of 6x10 6 neutron/pulse was generated in a sealed gas-filled diode with a target on the cathode by accelerating pulse voltage of approximately 0.5 MV and length at half-height of 0.5 ns and deuterium pressure of 6x10 -2 Torr. Ways of increasing neutron yield and possibilities of creating generators of nanosecond neutron pulses with great service life are considered

  7. Nanosecond fluorescence spectroscopy

    International Nuclear Information System (INIS)

    Leskovar, B.

    1985-03-01

    This article is a summary of a short course lecture given in conjunction with the 1984 Nuclear Science Symposium. Measuring systems for nanosecond fluorescence spectroscopy using single-photon counting techniques are presented. These involve systems based on relaxation-type spark gap light pulser and synchronously pumped mode-locked dye lasers. Furthermore, typical characteristics and optimization of operating conditions of the critical components responsible for the system time resolution are discussed. A short comparison of the most important deconvolution methods for numerical analysis of experimental data is given particularly with respect to the signal-to-noise ratio of the fluorescence signal. 22 refs., 8 figs

  8. Quad nanosecond delay module

    International Nuclear Information System (INIS)

    McDonald, R.J.; Hunter, J.B.; Wozniak, G.J.

    1986-04-01

    Four nanosecond (ns) delay units have been designed to fit in a single-width NIM module. This module is particularly suited for use in conjunction with quad constant fraction timing discriminators (CFTDs) since it has four delay units that can be placed adjacent to the four units of the CFTD. A series of different length cables connected via DIP toggle switches provide delays of 0.60 ns in 4 ns increments. Thus, the CFTD delay can be optimized for pulses of different rise times from approx.10-100 ns. Design work for the PC board and silkscreening of the front panel were done with the MacDraw program on the Apple Mackintosh computer and printed with the Lasewriter printer. 6 refs

  9. 7-Eleven Melejit Lewat Lifestyle

    Directory of Open Access Journals (Sweden)

    Freddy P. Simbolon

    2012-05-01

    Full Text Available The landscape of convenient store businesses or minimarkets now have changed. Location base strategy has not been sufficient any longer now. Psychographic and Demographic approaches tend to share a newly built power. Two main variables that have been managed concern at retail level are the store image and the store atmosphere. While the store image dimensions that can be put into considerations are the items offered, services committed, who and the amount of customers, physical facilities, promotion and convenience, store atmosphere, especially the involvement of affections through built emotions status in store which possibly uncautioned wholly by the customers when doing shopping. Since officially opened, the 7-Eleven had offered unique facilities. Instead of providing instant foods and beverages for 24 hours, the 7-Eleven also provides convenient corners and tables to eat and drink and provides chatting facilities for customers who need it. These make other modern retailers following the concept: opened for 24 hours and providing chatting facilities for young people.

  10. Eleven cases of breast conservation

    International Nuclear Information System (INIS)

    Matsuoka, Toshio; Sekine, Kenshi; Miyagawa, Akira; Sugimoto, Toichi

    1991-01-01

    Eleven patients with T1 and small T2 breast cancer were treated by a combination of quadrantectomy, axillary dissection and radiotherapy. The mean age of the patients was 44.6 years. Mean follow-up period was 7.1 months. Six patients had clinical stage I, and five patients had clinical stage II. Four patients had involvement of axillary content (36.3%) on histological examination. There were eight scirrhous carcinomas and three papillotubular carcinomas. The incidence of local and distant recurrence was none in our group. The multifocality of breast cancer based on pathologic studies had been shown. On the basis of these findings we concluded that the patients undergoing breast conservation should be subjected to postoperative radiotherapy. Psychological morbidity was compared in 10 patients treated by breast conservation and 23 patients treated by mastectomy. There were no statistically significant differences between two groups in the estimation of adjustment disorder, depression, anxiety and stress. The patients in breast conservation group had a significant excess or nervousness and the patients of the mastectomy group had an anger. (author)

  11. A trial of ignition innovation of gasoline engine by nanosecond pulsed low temperature plasma ignition

    International Nuclear Information System (INIS)

    Shiraishi, Taisuke; Urushihara, Tomonori; Gundersen, Martin

    2009-01-01

    Application of nanosecond pulsed low temperature plasma as an ignition technique for automotive gasoline engines, which require a discharge under conditions of high back pressure, has been studied experimentally using a single-cylinder engine. The nanosecond pulsed plasma refers to the transient (non-equilibrated) phase of a plasma before the formation of an arc discharge; it was obtained by applying a high voltage with a nanosecond pulse (FWHM of approximately 80 or 25 ns) between coaxial cylindrical electrodes. It was confirmed that nanosecond pulsed plasma can form a volumetric multi-channel streamer discharge at an energy consumption of 60 mJ cycle -1 under a high back pressure of 1400 kPa. It was found that the initial combustion period was shortened compared with the conventional spark ignition. The initial flame visualization suggested that the nanosecond pulsed plasma ignition results in the formation of a spatially dispersed initial flame kernel at a position of high electric field strength around the central electrode. It was observed that the electric field strength in the air gap between the coaxial cylindrical electrodes was increased further by applying a shorter pulse. It was also clarified that the shorter pulse improved ignitability even further.

  12. A trial of ignition innovation of gasoline engine by nanosecond pulsed low temperature plasma ignition

    Science.gov (United States)

    Shiraishi, Taisuke; Urushihara, Tomonori; Gundersen, Martin

    2009-07-01

    Application of nanosecond pulsed low temperature plasma as an ignition technique for automotive gasoline engines, which require a discharge under conditions of high back pressure, has been studied experimentally using a single-cylinder engine. The nanosecond pulsed plasma refers to the transient (non-equilibrated) phase of a plasma before the formation of an arc discharge; it was obtained by applying a high voltage with a nanosecond pulse (FWHM of approximately 80 or 25 ns) between coaxial cylindrical electrodes. It was confirmed that nanosecond pulsed plasma can form a volumetric multi-channel streamer discharge at an energy consumption of 60 mJ cycle-1 under a high back pressure of 1400 kPa. It was found that the initial combustion period was shortened compared with the conventional spark ignition. The initial flame visualization suggested that the nanosecond pulsed plasma ignition results in the formation of a spatially dispersed initial flame kernel at a position of high electric field strength around the central electrode. It was observed that the electric field strength in the air gap between the coaxial cylindrical electrodes was increased further by applying a shorter pulse. It was also clarified that the shorter pulse improved ignitability even further.

  13. Looking back 2005. Eleven studies evaluated

    International Nuclear Information System (INIS)

    2005-01-01

    Between December 2000 and June 2002 the Netherlands Court of Audit ('Algemene Rekenkamer') carried out a study on the title subject, focusing on the effect of energy saving measures on the energy consumption per product unit in the greenhouse sector in the Netherlands for the period 1994-2000, including the effect of the energy conservation policy for the period 1997-1999. In this retrospective the Court of Audit looks back at the results of eleven studies, among which the fore-mentioned study, in order to assess if and how the ministeries involved followed and implemented the recommendations of the Court of Audit [nl

  14. Rotational Spectroscopy Unveils Eleven Conformers of Adrenaline

    Science.gov (United States)

    Cabezas, C.; Cortijo, V.; Mata, S.; Lopez, J. C.; Alonso, J. L.

    2013-06-01

    Recent improvements in our LA-MB-FTMW instrumentation have allowed the characterization of eleven and eight conformers for the neurotransmitters adrenaline and noradrenaline respectively. The observation of this rich conformational behavior is in accordance with the recent observation of seven conformers for dopamine and in sharp contrast with the conformational reduction proposed for catecholamines. C. Cabezas, I. Peña, J. C. López, J. L. Alonso J. Phys. Chem. Lett. 2013, 4, 486. H. Mitsuda, M. Miyazaki, I. B. Nielsen, P. Carcabal,C. Dedonder, C. Jouvet, S. Ishiuchi, M. Fujii J. Phys. Chem. Lett. 2010, 1, 1130.

  15. Sensory profile of eleven peach cultivars

    Directory of Open Access Journals (Sweden)

    Francine Lorena Cuquel

    2012-03-01

    Full Text Available The goal of this study was to evaluate the sensory profile of eleven peach cultivars grown in an experimental orchard located in the city of Lapa (PR, Brazil in two seasons. The peach cultivars analyzed were Aurora I, Chimarrita, Chiripá, Coral, Eldorado, Granada, Leonense, Maciel, Marli, Premier, and Vanguarda. The sensory analysis was performed by previously trained panelists; 20 of them in the first season and 10 in the second season. The sensory evaluation was performed using Quantitative Descriptive Analysis, in which the following attributes were measured: appearance, aroma, flesh color, flesh firmness, flavor, and juiciness. The results showed preference for sweet, soft, and juicy fruits. Chimarrita, Chiripá, and Coral fruits showed better sensorial performance than the other peach cultivars. It was also verified that the analysis of the attributes aroma, flesh firmness, and flavor is enough for performing the sensory profile of peach fruits for in natura consumption.

  16. STRATEGI PROMOSI BUKU ???CRITICAL ELEVEN??? OLEH AKUN INSTAGRAM IKA NATASSA

    OpenAIRE

    -, AULIANTI SASILIA

    2016-01-01

    2016 AULIANTI SASILIA. Strategi Promosi Buku ???Critical Eleven??? oleh Akun Instagram Ika Natassa (Dibimbing oleh Kahar dan Andi Subhan Amir). Tujuan penelitian ini adalah: (1) Untuk mengetahui motif akun Instagram digunakan sebagai akun aktivitas promosi; (2) Untuk mengetahui strategi promosi buku ???Critical Eleven??? oleh akun Instagram Ika Natassa; (3) Untuk mengetahui faktor yang mempengaruhi aktivitas promosi buku ???Critical Eleven??? menggunakan media Instagram....

  17. Cytotoxicity potentials of eleven Bangladeshi medicinal plants.

    Science.gov (United States)

    Khatun, Amina; Rahman, Mahmudur; Haque, Tania; Rahman, Md Mahfizur; Akter, Mahfuja; Akter, Subarna; Jhumur, Afrin

    2014-01-01

    Various forms of cancer are rising all over the world, requiring newer therapy. The quest of anticancer drugs both from natural and synthetic sources is the demand of time. In this study, fourteen extracts of different parts of eleven Bangladeshi medicinal plants which have been traditionally used for the treatment of different types of carcinoma, tumor, leprosy, and diseases associated with cancer were evaluated for their cytotoxicity for the first time. Extraction was conceded using methanol. Phytochemical groups like reducing sugars, tannins, saponins, steroids, gums, flavonoids, and alkaloids were tested using standard chromogenic reagents. Plants were evaluated for cytotoxicity by brine shrimp lethality bioassay using Artemia salina comparing with standard anticancer drug vincristine sulphate. All the extracts showed potent to moderate cytotoxicity ranging from LC50 2 to 115 µg/mL. The highest toxicity was shown by Hygrophila spinosa seeds (LC50 = 2.93 µg/mL) and the lowest by Litsea glutinosa leaves (LC50 = 114.71 µg/mL) in comparison with standard vincristine sulphate (LC50 = 2.04 µg/mL). Among the plants, the plants traditionally used in different cancer and microbial treatments showed highest cytotoxicity. The results support their ethnomedicinal uses and require advanced investigation to elucidate responsible compounds as well as their mode of action.

  18. Cytotoxicity Potentials of Eleven Bangladeshi Medicinal Plants

    Directory of Open Access Journals (Sweden)

    Amina Khatun

    2014-01-01

    Full Text Available Various forms of cancer are rising all over the world, requiring newer therapy. The quest of anticancer drugs both from natural and synthetic sources is the demand of time. In this study, fourteen extracts of different parts of eleven Bangladeshi medicinal plants which have been traditionally used for the treatment of different types of carcinoma, tumor, leprosy, and diseases associated with cancer were evaluated for their cytotoxicity for the first time. Extraction was conceded using methanol. Phytochemical groups like reducing sugars, tannins, saponins, steroids, gums, flavonoids, and alkaloids were tested using standard chromogenic reagents. Plants were evaluated for cytotoxicity by brine shrimp lethality bioassay using Artemia salina comparing with standard anticancer drug vincristine sulphate. All the extracts showed potent to moderate cytotoxicity ranging from LC50 2 to 115 µg/mL. The highest toxicity was shown by Hygrophila spinosa seeds (LC50=2.93 µg/mL and the lowest by Litsea glutinosa leaves (LC50=114.71 µg/mL in comparison with standard vincristine sulphate (LC50=2.04 µg/mL. Among the plants, the plants traditionally used in different cancer and microbial treatments showed highest cytotoxicity. The results support their ethnomedicinal uses and require advanced investigation to elucidate responsible compounds as well as their mode of action.

  19. Eleven cases of neonatal intracranial hemorrhage

    International Nuclear Information System (INIS)

    Matsuda, Tadashi; Asao, Toyohiko; Shibata, Takeo

    1981-01-01

    Eleven cases of neonatal intracranial hemorrhage were diagnosed and followed up by CT scanning. By CT, hemorrhagic lesions were shown as high density areas in an acute stage and imaged as low density areas after the hemorrhage was absorbed. The time of absorption varies depending upon the site and the severity of hemorrhage. Intraventricular hemorrhage, petechial hemorrhage and subdural hematoma were absorbed rapidly in more than 70% of the exanimed cases, CT scanning 1 - 2 weeks after the onset revealed absorption of hemorrhage. However, the absorption delayed in intracerebral hematoma; CT scan taken after one month showed hemorrhagic lesions remaining in 75% of the cases. In nine cases who survived, following the absorption of the hemorrhagic lesions, cerebral atrophy was observed in 4 cases (44%), ventricular enlargement in 3 cases (33%), and complete recovery in 2 cases (22%). From these results, CT scanning for diagnosis of neonatal intracranial hemorrhage should be done before the hemorrhagic lesion is absorbed (within 7 days of the onset). Follow-up study by CT is important for observing changes and predicting prognosis of intracranial hemorrhage. (Ueda, J.)

  20. One nanosecond pulsed electron gun systems

    International Nuclear Information System (INIS)

    Koontz, R.F.

    1979-02-01

    At SLAC there has been a continuous need for the injection of very short bunches of electrons into the accelerator. Several time-of-flight experiments have used bursts of short pulses during a normal 1.6 micro-second rf acceleration period. Single bunch beam loading experiments made use of a short pulse injection system which included high power transverse beam chopping equipment. Until the equipment described in this paper came on line, the basic grid-controlled gun pulse was limited to a rise time of 7 nanoseconds and a pulse width of 10 nanoseconds. The system described here has a grid-controlled rise time of less than 500 pico-seconds, and a minimum pulse width of less than 1 nanosecond. Pulse burst repetition rate has been demonstrated above 20 MHz during a 1.6 microsecond rf accelerating period. The order-of-magnitude increase in gun grid switching speed comes from a new gun design which minimizes lead inductance and stray capacitance, and also increases gun grid transconductance. These gun improvements coupled with a newly designed fast pulser mounted directly within the gun envelope make possible subnanosecond pulsing of the gun

  1. Gas Discharge Produced by Strong Microwaves of Nanosecond Duration

    International Nuclear Information System (INIS)

    Vikharev, A.L.

    2000-01-01

    The results of the investigation of nanosecond microwave discharge are reviewed. Nanosecond microwave discharge is a new branch of gas discharge physics. The paper lists base types of microwave generators used to produce nanosecond discharge and classifies the discharges relative to their base parameters: the way the discharge gets localized in a limited space, amplitude and frequency of microwave field, gas pressure, duration of microwave pulses. The laboratory experiments performed and the new effects which appear in nanosecond microwave discharge are briefly summarized. Different applications of such a discharge are analyzed on the basis of the experimental modelling. (author)

  2. Hidden twelve-dimensional super Poincare symmetry in eleven dimensions

    International Nuclear Information System (INIS)

    Bars, Itzhak; Deliduman, Cemsinan; Pasqua, Andrea; Zumino, Bruno

    2004-01-01

    First, we review a result in our previous paper, of how a ten-dimensional superparticle, taken off-shell, has a hidden eleven-dimensional super Poincare symmetry. Then, we show that the physical sector is defined by three first-class constraints which preserve the full eleven-dimensional symmetry. Applying the same concepts to the eleven-dimensional superparticle, taken off-shell, we discover a hidden twelve-dimensional super Poincare symmetry that governs the theory

  3. Electric field measurements in a dielectric barrier nanosecond pulse discharge with sub-nanosecond time resolution

    International Nuclear Information System (INIS)

    Goldberg, Benjamin M; Shkurenkov, Ivan; Adamovich, Igor V; Lempert, Walter R; O’Byrne, Sean

    2015-01-01

    The paper presents the results of time-resolved electric field measurements in a nanosecond discharge between two plane electrodes covered by dielectric plates, using picosecond four-wave mixing diagnostics. For absolute calibration, the IR signal was measured in hydrogen at a pressure of 440 Torr, for electrostatic electric field ranging from 0 to 8 kV cm −1 . The calibration curve (i.e. the square root of IR signal intensity versus electric field) was shown to be linear. By measuring the intensities of the pump, Stokes, and IR signal beam for each laser shot during the time sweep across the high-voltage pulse, temporal evolution of the electric field in the nanosecond pulse discharge was determined with sub-nanosecond time resolution. The results are compared to kinetic modeling predictions, showing good agreement, including non-zero electric field offset before the main high voltage pulse, breakdown moment, and reduction of electric field in the plasma after breakdown. The difference between the experimental results and model predictions is likely due to non-1D structure of the discharge. Comparison with the kinetic modeling predictions shows that electric field in the nanosecond pulse discharge is controlled primarily by electron impact excitation and charge accumulation on the dielectric surfaces. (paper)

  4. Nanosecond bipolar pulse generators for bioelectrics.

    Science.gov (United States)

    Xiao, Shu; Zhou, Chunrong; Yang, Enbo; Rajulapati, Sambasiva R

    2018-04-26

    Biological effects caused by a nanosecond pulse, such as cell membrane permeabilization, peripheral nerve excitation and cell blebbing, can be reduced or cancelled by applying another pulse of reversed polarity. Depending on the degree of cancellation, the pulse interval of these two pulses can be as long as dozens of microseconds. The cancellation effect diminishes as the pulse duration increases. To study the cancellation effect and potentially utilize it in electrotherapy, nanosecond bipolar pulse generators must be made available. An overview of the generators is given in this paper. A pulse forming line (PFL) that is matched at one end and shorted at the other end allows a bipolar pulse to be produced, but no delay can be inserted between the phases. Another generator employs a combination of a resistor, an inductor and a capacitor to form an RLC resonant circuit so that a bipolar pulse with a decaying magnitude can be generated. A third generator is a converter, which converts an existing unipolar pulse to a bipolar pulse. This is done by inserting an inductor in a transmission line. The first phase of the bipolar pulse is provided by the unipolar pulse's rising phase. The second phase is formed during the fall time of the unipolar pulse, when the inductor, which was previously charged during the flat part of the unipolar pulse, discharges its current to the load. The fourth type of generator uses multiple MOSFET switches stacked to turn on a pre-charged, bipolar RC network. This approach is the most flexible in that it can generate multiphasic pulses that have different amplitudes, delays, and durations. However, it may not be suitable for producing short nanosecond pulses (<100 ns), whereas the PFL approach and the RLC approach with gas switches are used for this range. Thus, each generator has its own advantages and applicable range. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. PNG-300 a nanosecond pulsed neutron generator

    International Nuclear Information System (INIS)

    Sztaricskai, T.; Vasvary, L.; Petoe, G.C.; Devkin, B.V.

    1985-01-01

    The design and operation of a nanosecond-pulse neutron generator is reported. It was constructed for the measurement of prompt neutron and gamma radiation in experimental studies of fast neutron reactions by time of flight techniques. The acceleration voltage is 300 kV and the total resolution of the generator-neutron spectrometer system is 2 ns. The ion-optical system, the vacuum system and the control of the neutron generator is described in detail. The equipment was used for prompt neutron and gamma radiation induced in construction materials. (R.P.)

  6. Megavolt nanosecond generator with semiconductor current breaker

    CERN Document Server

    Bushlyakov, A I; Rukin, S N; Slovikovskij, B G; Timoshenkov, S P

    2002-01-01

    The heavy-current nanosecond generator with the pulse capacity up to 1.6 GW and output voltage of 0.5-1 MW is described. The generator contains four capacity storages, one induction storage and six solid body commutators: one thyristor, four magnetic commutators and a semiconductor current breaker on the SOS-diodes. The results of studies on the energy change-over efficiency through a semiconductor breaker by various external resistance loads as well as the results of the thermal and frequency tests are presented. It is established that selection of the optimal cooling system provides for the generator continuous mode of operation with the pulse sequence frequency from 300 Hz up to 850 Hz

  7. High-voltage nanosecond pulse shaper

    International Nuclear Information System (INIS)

    Kapishnikov, N.K.; Muratov, V.M.; Shatanov, A.A.

    1987-01-01

    A high-voltage pulse shaper with an output of up to 250 kV, a base duration of ∼ 10 nsec, and a repetition frequency of 50 pulses/sec is described. The described high-voltage nanosecond pulse shaper is designed for one-orbit extraction of an electron beam from a betatron. A diagram of the pulse shaper, which employs a single-stage generator is shown. The shaping element is a low-inductance capacitor bank of series-parallel KVI-3 (2200 pF at 10 kV) or K15-10 (4700 pF at 31.5 kV) disk ceramic capacitors. Four capacitors are connected in parallel and up to 25 are connected in series

  8. Nanosecond Surface Microdischarges in Multilayer Structures

    Science.gov (United States)

    Dubinov, A. E.; Lyubimtseva, V. A.

    2018-05-01

    Multilayer structures in which nanosecond surface microdischarges are generated have been developed, fabricated, and investigated. In these structures, layers are made in the form of thin transparent films, and a plasma discharge channel is formed in thin spacings between the layers. Passage of the discharge channel from one layer into the neighboring layer is implemented via pre-fabricated microholes. Images of microdischarges were obtained which confirmed that their plasma channels are formed according to the route assigned by the holes. The route may follow a fairly complex scheme and have self-intersection points and portions in which the electrons are bound to move in opposition to the electric field. In studying the shape of channels in multilayer strictures, the authors have found a new physical effect which lies in the azimuthal self-orientation of the discharge channel as it passes from one microhole to another.

  9. Texturing of polypropylene (PP) with nanosecond lasers

    Science.gov (United States)

    Riveiro, A.; Soto, R.; del Val, J.; Comesaña, R.; Boutinguiza, M.; Quintero, F.; Lusquiños, F.; Pou, J.

    2016-06-01

    Polypropylene (PP) is a biocompatible and biostable polymer, showing good mechanical properties that has been recently introduced in the biomedical field for bone repairing applications; however, its poor surface properties due to its low surface energy limit their use in biomedical applications. In this work, we have studied the topographical modification of polypropylene (PP) laser textured with Nd:YVO4 nanosecond lasers emitting at λ = 1064 nm, 532 nm, and 355 nm. First, optical response of this material under these laser wavelengths was determined. The application of an absorbing coating was also studied. The influence of the laser processing parameters on the surface modification of PP was investigated by means of statistically designed experiments. Processing maps to tailor the roughness, and wettability, the main parameters affecting cell adhesion characteristics of implants, were also determined. Microhardness measurements were performed to discern the impact of laser treatment on the final mechanical properties of PP.

  10. Nanosecond high-power dense microplasma switch for visible light

    Energy Technology Data Exchange (ETDEWEB)

    Bataller, A., E-mail: bataller@physics.ucla.edu; Koulakis, J.; Pree, S.; Putterman, S. [Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095 (United States)

    2014-12-01

    Spark discharges in high-pressure gas are known to emit a broadband spectrum during the first 10 s of nanoseconds. We present calibrated spectra of high-pressure discharges in xenon and show that the resulting plasma is optically thick. Laser transmission data show that such a body is opaque to visible light, as expected from Kirchoff's law of thermal radiation. Nanosecond framing images of the spark absorbing high-power laser light are presented. The sparks are ideal candidates for nanosecond, high-power laser switches.

  11. [Mechanism of ablation with nanosecond pulsed electric field].

    Science.gov (United States)

    Cen, Chao; Chen, Xin-hua; Zheng, Shu-sen

    2015-11-01

    Nanosecond pulsed electric field ablation has been widely applied in clinical cancer treatment, while its molecular mechanism is still unclear. Researchers have revealed that nanosecond pulsed electric field generates nanopores in plasma membrane, leading to a rapid influx of Ca²⁺; it has specific effect on intracellular organelle membranes, resulting in endoplasmic reticulum injuries and mitochondrial membrane potential changes. In addition, it may also change cellular morphology through damage of cytoskeleton. This article reviews the recent research advances on the molecular mechanism of cell membrane and organelle changes induced by nanosecond pulsed electric field ablation.

  12. Physics of high intensity nanosecond electron source

    International Nuclear Information System (INIS)

    Herrera-Gomez, A.; Spicer, W.E.

    1993-08-01

    A new high-intensity, short-time electron source is now being used at the Stanford Linear Accelerator Center (SLAC). Using a GaAs negative affinity semiconductor in the construction of the cathode, it is possible to fulfill operation requirements such as peak currents of tens of amperes, peak widths of the order of nanoseconds, hundreds of hours of operation stability, and electron spin polarization. The cathode is illuminated with high intensity laser pulses, and photoemitted electrons constitute the yield. Because of the high currents, some nonlinear effects are present. Very noticeable is the so-called Charge Limit (CL) effect, which consists of a limit on the total charge in each pulse-that is, the total bunch charge stops increasing as the light pulse total energy increases. In this paper, we explain the mechanism of the CL and how it is caused by the photovoltaic effect. Our treatment is based on the Three-Step model of photoemission. We relate the CL to the characteristics of the surface and bulk of the semiconductor, such as doping, band bending, surface vacuum level, and density of surface states. We also discuss possible ways to prevent the Char's Level effect

  13. Redox reaction studies by nanosecond pulse radiolysis

    International Nuclear Information System (INIS)

    Moorthy, P.N.

    1979-01-01

    Free radicals are formed as intermediates in many chemical and biochemical reactions. An important type of reaction which they can undergo is a one electron or redox process. The direction and rate of such electron transfer reactions is governed by the relative redox potentials of the participating species. Because of the generally short lived nature of free radicals, evaluation of their redox potentials poses a number of problems. Two techniques are described for the experimental determination of the redox potentials of short lived species generated by either a nanosecond electron pulse or laser flash. In the first method, redox titration of the short lived species with stable molecules of known redox potential is carried out, employing the technique of fast kinetic spectrophotometry. Conversely, by the same method it is also possible to evaluate the one electron redox potentials of stable molecules by redox titration with free radicals of known redox potential produced as above. In the second method, electrochemical reduction or oxidation of the short lived species at an appropriate electrode (generally a mercury drop) is carried out at different fixed potentials, and the redox potential evaluated from the current-potential curves (polarograms). Full description of the experimental set up and theoretical considerations for interpretation of the raw data are given. The relative merits of the two methods and their practical applicability are discussed. (auth.)

  14. Energy coupling to the plasma in repetitive nanosecond pulse discharges

    International Nuclear Information System (INIS)

    Adamovich, Igor V.; Nishihara, Munetake; Choi, Inchul; Uddi, Mruthunjaya; Lempert, Walter R.

    2009-01-01

    A new analytic quasi-one-dimensional model of energy coupling to nanosecond pulse discharge plasmas in plane-to-plane geometry has been developed. The use of a one-dimensional approach is based on images of repetitively pulsed nanosecond discharge plasmas in dry air demonstrating that the plasma remains diffuse and uniform on a nanosecond time scale over a wide range of pressures. The model provides analytic expressions for the time-dependent electric field and electron density in the plasma, electric field in the sheath, sheath boundary location, and coupled pulse energy. The analytic model predictions are in very good agreement with numerical calculations. The model demonstrates that (i) the energy coupled to the plasma during an individual nanosecond discharge pulse is controlled primarily by the capacitance of the dielectric layers and by the breakdown voltage and (ii) the pulse energy coupled to the plasma during a burst of nanosecond pulses decreases as a function of the pulse number in the burst. This occurs primarily because of plasma temperature rise and resultant reduction in breakdown voltage, such that the coupled pulse energy varies approximately proportionally to the number density. Analytic expression for coupled pulse energy scaling has been incorporated into the air plasma chemistry model, validated previously by comparing with atomic oxygen number density measurements in nanosecond pulse discharges. The results of kinetic modeling using the modified air plasma chemistry model are compared with time-resolved temperature measurements in a repetitively pulsed nanosecond discharge in air, by emission spectroscopy, and purely rotational coherent anti-Stokes Raman spectroscopy showing good agreement.

  15. High-Voltage, Multiphasic, Nanosecond Pulses to Modulate Cellular Responses.

    Science.gov (United States)

    Ryan, Hollie A; Hirakawa, Shinji; Yang, Enbo; Zhou, Chunrong; Xiao, Shu

    2018-04-01

    Nanosecond electric pulses are an effective power source in plasma medicine and biological stimulation, in which biophysical responses are governed by peak power and not energy. While uniphasic nanosecond pulse generators are widely available, the recent discovery that biological effects can be uniquely modulated by reversing the polarity of nanosecond duration pulses calls for the development of a multimodal pulse generator. This paper describes a method to generate nanosecond multiphasic pulses for biomedical use, and specifically demonstrates its ability to cancel or enhance cell swelling and blebbing. The generator consists of a series of the fundamental module, which includes a capacitor and a MOSFET switch. A positive or a negative phase pulse module can be produced based on how the switch is connected. Stacking the modules in series can increase the voltage up to 5 kV. Multiple stacks in parallel can create multiphase outputs. As each stack is independently controlled and charged, multiphasic pulses can be created to produce flexible and versatile pulse waveforms. The circuit topology can be used for high-frequency uniphasic or biphasic nanosecond burst pulse production, creating numerous opportunities for the generator in electroporation applications, tissue ablation, wound healing, and nonthermal plasma generation.

  16. Analisis Industri pada Ritel Convenience Store: Kasus 7-Eleven (Sevel

    Directory of Open Access Journals (Sweden)

    Son Wandrial

    2013-05-01

    Full Text Available 7-Eleven, a Japanese retailer is very popular and loved in Jakarta. 7-Eleven or commonly abbreviated to Sevel is now reaping a lot of fans because of the concept of 7-Eleven Indonesia, found only in Indonesia. With the rising middle classes in Indonesia, 7-Eleven becomes a luxurious place for hanging-out but affordable. Consequently, it is attracting the interest of investors to make such a kind of convenience store like Sevel, and it is likely the competition in this sector will be increasingly fierce. PT. Modern’s initial plans are to focus onopening stores in Jakarta, targeting densely-populated commercial and office areas, to offer Indonesian workersa convenient place to shop for lunch, snacks, and emergency items. The company’s goal is to focus on opening stores in Jakarta in its first years of operation. Other major cities, such as Bandung, Semarang, and Surabaya offer for future expansion opportunities. The objective of this article is to describe the competitive condition in convenience store industries using Porter’s Five Forces model. Although the competition is fierce andunfavorable industry condition, Sevel is still leading and dominating the convenience store market in Indonesia.

  17. N = 1 supercurrents of eleven-dimensional supergravity

    Science.gov (United States)

    Becker, Katrin; Becker, Melanie; Butter, Daniel; Linch, William D.

    2018-05-01

    Eleven-dimensional supergravity can be formulated in superspaces locally of the form X × Y where X is 4D N = 1 conformal superspace and Y is an arbitrary 7-manifold admitting a G 2-structure. The eleven-dimensional 3-form and the stable 3-form on Y define the lowest component of a gauge superfield on X × Y that is chiral as a superfield on X. This chiral field is part of a tensor hierarchy giving rise to a superspace Chern-Simons action and its real field strength defines a lifting of the Hitchin functional on Y to the G 2 superspace X × Y . These terms are those of lowest order in a superspace Noether expansion in seven N = 1 conformal gravitino superfields Ψ. In this paper, we compute the O(Ψ) action to all orders in the remaining fields. The eleven-dimensional origin of the resulting non-linear structures is parameterized by the choice of a complex spinor on Y encoding the off-shell 4D N = 1 subalgebra of the eleven-dimensional super-Poincaré algebra.

  18. A CMOS delay locked loop and sub-nanosecond time-to-digital converter chip

    International Nuclear Information System (INIS)

    Santos, D.M.; Dow, S.F.; Levi, M.E.

    1995-12-01

    Many high energy physics and nuclear science applications require sub-nanosecond time resolution measurements over many thousands of detector channels. Phase-locked loops have been employed in the past to obtain accurate time references for these measurements. An alternative solution, based on a delay-locked loop (DLL) is described. This solution allows for a very high level of integration yet still offers resolution in the sub-nanosecond regime. Two variations on this solution are outlined. A novel phase detector, based on the Muller C element, is used to implement a charge pump where the injected charge approaches zero as the loop approaches lock on the leading edge of an input clock reference. This greatly reduces timing jitter. In the second variation the loop locks to both the leading and trailing clock edges. In this second implementation, software coded layout generators are used to automatically layout a highly integrated, multi-channel, time to digital converter (TDC). Complex clock generation can be, achieved by taking symmetric taps off the delay elements. The two circuits, DLL and TDC, were implemented in a CMOS 1.2μm and 0.8μm technology, respectively. Test results show a timing jitter of less than 35 ps for the DLL circuit and better solution for the TDC circuit

  19. Referrals to a regional allergy clinic - an eleven year audit

    Directory of Open Access Journals (Sweden)

    Hewson Paul

    2010-12-01

    Full Text Available Abstract Background Allergy is a serious and apparently increasing public health problem yet relatively little is known about the types of allergy seen in routine tertiary practice, including their spatial distribution, co-occurrence or referral patterns. This study reviewed referrals over an eleven year period to a regional allergy clinic that had a well defined geographical boundary. For those patients confirmed as having an allergy we explored: (i differences over time and by demographics, (ii types of allergy, (iii co-occurrence, and (iv spatial distributions. Methods Data were extracted from consultant letters to GPs, from September 1998 to September 2009, for patients confirmed as having an allergy. Other data included referral statistics and population data by postcode. Simple descriptive analysis was used to describe types of allergy. We calculated 11 year standardised morbidity ratios for postcode districts and checked for spatial clustering. We present maps showing 11 year rates by postcode, and 'difference' maps which try to separate referral effect from possible environmental effect. Results Of 5778 referrals, 961 patients were diagnosed with an allergy. These were referred by a total of 672 different GPs. There were marked differences in referral patterns between GP practices and also individual GPs. The mean age of patients was 35 and there were considerably more females (65% than males. Airborne allergies were the most frequent (623, and there were very high rates of co-occurrence of pollen, house dust mite, and animal hair allergies. Less than half (410 patients had a food allergy, with nuts, fruit, and seafood being the most common allergens. Fifteen percent (142 had both a food and a non-food allergy. Certain food allergies were more likely to co-occur, for example, patients allergic to dairy products were more likely to be allergic to egg. There were age differences by types of allergy; people referred with food allergies were

  20. Energy efficiency in nanoscale synthesis using nanosecond plasmas.

    Science.gov (United States)

    Pai, David Z; Ken Ostrikov, Kostya; Kumar, Shailesh; Lacoste, Deanna A; Levchenko, Igor; Laux, Christophe O

    2013-01-01

    We report a nanoscale synthesis technique using nanosecond-duration plasma discharges. Voltage pulses 12.5 kV in amplitude and 40 ns in duration were applied repetitively at 30 kHz across molybdenum electrodes in open ambient air, generating a nanosecond spark discharge that synthesized well-defined MoO₃ nanoscale architectures (i.e. flakes, dots, walls, porous networks) upon polyamide and copper substrates. No nitrides were formed. The energy cost was as low as 75 eV per atom incorporated into a nanostructure, suggesting a dramatic reduction compared to other techniques using atmospheric pressure plasmas. These findings show that highly efficient synthesis at atmospheric pressure without catalysts or external substrate heating can be achieved in a simple fashion using nanosecond discharges.

  1. Amorphous Terfenol-D films using nanosecond pulsed laser deposition

    International Nuclear Information System (INIS)

    Ma, James; O'Brien, Daniel T.; Kovar, Desiderio

    2009-01-01

    Thin films of Terfenol-D were produced by nanosecond pulsed laser deposition (PLD) at two fluences. Electron dispersive spectroscopy conducted using scanning electron and transmission electron microscopes showed that the film compositions were similar to that of the PLD target. Contrary to previous assertions that suggested that nanosecond PLD results in crystalline films, X-ray diffraction and transmission electron microscopy analysis showed that the films produced at both fluences were amorphous. Splatters present on the film had similar compositions to the overall film and were also amorphous. Magnetic measurements showed that the films had high saturation magnetization and magnetostriction, similar to high quality films produced using other physical vapor deposition methods.

  2. Quantum fluctuations and spontaneous compactification of eleven-dimensional gravity

    International Nuclear Information System (INIS)

    Nguen Van Hieu.

    1985-01-01

    The reduction of the eleven-dimensional pure gravity to the field theory in the four-dimensional Minkowski space-time by means of the spontaneous compactification of the extra dimensions is investigated. The contribution of the quantum fluctuations of the eleven-dimen-- sonal second rank symmetric tensor field to the curvatures of the space-time and the compactified space of the extra dimensions are calculated in the one-loop approximation. It is shown that there exist the values of the cosmological constant for which tachions are absent. As a result, self-consistent quantum field theory is obtained in spontaneous compactified Minkowski space M 4 xS 7 ,is where M 4 is Minkowski space-time, and S 7 is seven-dimensional sphere

  3. Performance of the Fitch generator in a nanosecond electron accelerator

    International Nuclear Information System (INIS)

    Chernyj, V.V.

    1976-01-01

    The operation of the Fitch generator in the nanosecond electron accelerator is discussed. The operating principle of the generator is based on the inversion of the voltage at the storage capacitances. Only one discharger is employed in the discharge circuit of the generator which provides for decreasing the generator impedance to 24 Ohms. The maximum accelerating voltage equals 0.6 MV

  4. High power semiconductor switching in the nanosecond regime

    International Nuclear Information System (INIS)

    Zucker, O.S.; Long, J.R.; Smith, V.L.; Page, D.J.; Roberts, J.S.

    1975-12-01

    Light activated multilayered silicon semiconductor devices have been used to switch at megawatt power levels with nanosecond turnon time. Current rate of rise of 700 kA/μs at 10 kA, with 1 kV across the load have been achieved. Recovery time of 1 millisec has been obtained. Applicability to fusion research needs is discussed

  5. Low charge state heavy ion production with sub-nanosecond laser.

    Science.gov (United States)

    Kanesue, T; Kumaki, M; Ikeda, S; Okamura, M

    2016-02-01

    We have investigated laser ablation plasma of various species using nanosecond and sub-nanosecond lasers for both high and low charge state ion productions. We found that with sub-nanosecond laser, the generated plasma has a long tail which has low charge state ions determined by an electrostatic ion analyzer even under the laser irradiation condition for highly charged ion production. This can be caused by insufficient laser absorption in plasma plume. This property might be suitable for low charge state ion production. We used a nanosecond laser and a sub-nanosecond laser for low charge state ion production to investigate the difference of generated plasma using the Zirconium target.

  6. Low charge state heavy ion production with sub-nanosecond laser

    Energy Technology Data Exchange (ETDEWEB)

    Kanesue, T., E-mail: tkanesue@bnl.gov; Okamura, M. [Collider-Accelerator Department, Brookhaven National Laboratory, Upton, New York 11973 (United States); Kumaki, M. [Research Institute for Science and Engineering, Waseda University, Tokyo 169-8555 (Japan); Nishina Center for Accelerator-Based Science, RIKEN, Saitama 351-0198 (Japan); Ikeda, S. [Nishina Center for Accelerator-Based Science, RIKEN, Saitama 351-0198 (Japan); Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Kanagawa 226-8503 (Japan)

    2016-02-15

    We have investigated laser ablation plasma of various species using nanosecond and sub-nanosecond lasers for both high and low charge state ion productions. We found that with sub-nanosecond laser, the generated plasma has a long tail which has low charge state ions determined by an electrostatic ion analyzer even under the laser irradiation condition for highly charged ion production. This can be caused by insufficient laser absorption in plasma plume. This property might be suitable for low charge state ion production. We used a nanosecond laser and a sub-nanosecond laser for low charge state ion production to investigate the difference of generated plasma using the Zirconium target.

  7. A CMOS delay locked loop and sub-nanosecond time-to-digital converter chip

    International Nuclear Information System (INIS)

    Santos, D.M.; Dow, S.F.; Flasck, J.M.; Levi, M.E.

    1996-01-01

    Phase-locked loops have been employed in the past to obtain sub-nanosecond time resolution in high energy physics and nuclear science applications. An alternative solution based on a delay-locked loop (DLL) is described. This solution allows for a very high level of integration yet still offers resolution in the sub-nanosecond regime. Two variations on this solution are outlined. A novel phase detector, based on the Mueller C-element, is used to implement a charge pump where the injected charge approaches zero as the loop approaches lock on the leading edge of an input clock reference. This greatly reduces timing jitter. In the second variation the loop locks to both the leading and trailing clock edges. In this second implementation, software coded layout generators are used to automatically layout a highly integrated, multichannel, time-to-digital converter (TDC) targeted for one specific frequency. The two circuits, DLL and TDC, are implemented in CMOS 1.2 microm and 0.8 microm technologies, respectively. Test results show a timing jitter of less than 30 ps for the DLL circuit and less than 190 ps integral and differential nonlinearity for the TDC circuit

  8. Research on the impacts of air temperature on the evolution of nanosecond pulse discharge products

    International Nuclear Information System (INIS)

    Yu, Jin-lu; He, Li-ming; Ding, Wei; Zhao, Zi-chen; Zhang, Hua-lei

    2016-01-01

    Highlights: • Most of the O_2 particles become O_2(V1) in high temperature. • The O_3 molecules are produced mainly by decayed O atoms. • NO molecules are obtained by decayed N_2(A3), N(2D) and N(2P) at the first stage, NO molecules are obtained by decayed N atoms at last. - Abstract: Based on nonequilibrium plasma dynamics of air discharge, the kinetic model simulating plasma discharge products induced by nanosecond pulse discharge in air is presented in this work. Then the paper compares the calculation of model with experimental results of references, and verifies the accuracy of the model. The evolution characteristics of nanosecond pulse discharge plasma under different air temperatures are obtained. Because the O, O_3 and NO have close relationship with the combustion, their formation mechanisms are discussed especially. With increasing temperature, there is no significant addition in O atoms and O_3 molecules. It is found that most of the O_2 molecules become O_2(V1) in higher temperature. The decreasing time of the O atoms is in accordance with the increasing time of O_3 molecules. Thus, the O_3 molecules are produced mainly by decayed O atoms. Increased air temperature will not produce more active particles which could assist the combustion. With the increasing temperature, the particle number density of NO increases fast. At last, they have reached an equilibrium value of the same.

  9. Dynamical propagation of nanosecond pulses in Naphthalocyanines and Phthalocyanines

    Energy Technology Data Exchange (ETDEWEB)

    Miao, Quan, E-mail: qmiao2013@yahoo.com [College of Electronics, Communication and Physics, Shandong University of Science and Technology, Qingdao 266590, Shandong (China); Liang, Min; Liu, Qixin [College of Electronics, Communication and Physics, Shandong University of Science and Technology, Qingdao 266590, Shandong (China); College of Electrical Engineering and Automation, Shandong University of Science and Technology, Qingdao 266590, Shandong (China); Wang, Jing-Jing [College of Electronics, Communication and Physics, Shandong University of Science and Technology, Qingdao 266590, Shandong (China); Sun, Erping; Xu, Yan [College of Electronics, Communication and Physics, Shandong University of Science and Technology, Qingdao 266590, Shandong (China); College of Electrical Engineering and Automation, Shandong University of Science and Technology, Qingdao 266590, Shandong (China)

    2016-11-30

    Highlights: • We study the dynamical processes of nanoseconds lasers in Naphthalocyanines and Phthalocyanines. • We provide theoretical evidences of the main mechanism of optical power limiting. • The central metals play more important roles in the dynamical processes. • The main reason is the central metals enhance the spin–orbit coupling. - Abstract: Dynamical propagation and optical limiting of nanosecond pulses in peripherally substituted Naphthalocyanines (Npcs) and Phthalocyanines (Pcs) with central metals gallium and indium were theoretically studied using paraxial field and rate equations. The results demonstrated that both Npcs and Pcs have good optical limiting performances, and Npc with heavier central mental indium shows better optical limiting properities due to the stronger reverse saturable absorption, which is mainly strengthened by the larger one-photo absorption cross section of excited state and the faster intersystem crossing rate.

  10. Nanosecond electric pulses trigger actin responses in plant cells

    International Nuclear Information System (INIS)

    Berghoefer, Thomas; Eing, Christian; Flickinger, Bianca; Hohenberger, Petra; Wegner, Lars H.; Frey, Wolfgang; Nick, Peter

    2009-01-01

    We have analyzed the cellular effects of nanosecond pulsed electrical fields on plant cells using fluorescently tagged marker lines in the tobacco cell line BY-2 and confocal laser scanning microscopy. We observe a disintegration of the cytoskeleton in the cell cortex, followed by contraction of actin filaments towards the nucleus, and disintegration of the nuclear envelope. These responses are accompanied by irreversible permeabilization of the plasma membrane manifest as uptake of Trypan Blue. By pretreatment with the actin-stabilizing drug phalloidin, the detachment of transvacuolar actin from the cell periphery can be suppressed, and this treatment can also suppress the irreversible perforation of the plasma membrane. We discuss these findings in terms of a model, where nanosecond pulsed electric fields trigger actin responses that are key events in the plant-specific form of programmed cell death.

  11. Picosecond absorption relaxation measured with nanosecond laser photoacoustics

    OpenAIRE

    Danielli, Amos; Favazza, Christopher P.; Maslov, Konstantin; Wang, Lihong V.

    2010-01-01

    Picosecond absorption relaxation—central to many disciplines—is typically measured by ultrafast (femtosecond or picosecond) pump-probe techniques, which however are restricted to optically thin and weakly scattering materials or require artificial sample preparation. Here, we developed a reflection-mode relaxation photoacoustic microscope based on a nanosecond laser and measured picosecond absorption relaxation times. The relaxation times of oxygenated and deoxygenated hemoglobin molecules, b...

  12. Synthesis of pure ozone by nanosecond discharge at cryogenic temperatures

    International Nuclear Information System (INIS)

    Amirov, R.H.; Asinovsky, E.I.; Samoilov, I.S.

    1996-01-01

    Synthesis of pure ozone by nanosecond discharge at cryogenic temperatures was experimentally examined. The average ozone concentration in the volume of the discharge tube was less at cryogenic temperatures than at room temperatures. The production of condensed ozone have been determined by measuring the ozone concentration when the walls was heated and ozone evaporated. The energy yield of ozone generation at cryogenic temperatures has been calculated. The maximum value was 200 g/kWh

  13. Characteristics of 2-heptanone decomposition using nanosecond pulsed discharge plasma

    Science.gov (United States)

    Nakase, Yuki; Fukuchi, Yuichi; Wang, Douyan; Namihira, Takao; Akiyama, Hidenori; Kumamoto University Collaboration

    2015-09-01

    Volatile organic compounds (VOC) evaporate at room temperature. VOCs typically consist of toluene, benzene and ethyl acetate, which are used in cosmetics, dry cleaning products and paints. Exposure to elevated levels of VOCs may cause headaches, dizziness and irritation to the eyes, nose, and throat; they may also cause environmental problems such as air pollution, acid rain and photochemical smog. As such, they require prompt removal. Nanosecond pulsed discharge is a kind of non-thermal plasma consisting of a streamer discharge. Several advantages of nanosecond pulsed discharge plasma have been demonstrated by studies of our research group, including low heat loss, highly energetic electron generation, and the production of highly active radicals. These advantages have shown ns pulsed discharge plasma capable of higher energy efficiency for processes, such as air purification, wastewater treatment and ozone generation. In this research, nanosecond pulsed discharge plasma was employed to treat 2-heptanone, which is a volatile organic compound type and presents several harmful effects. Characteristics of treatment dependent on applied voltage, gas flow rate and input energy density were investigated. Furthermore, byproducts generated by treatment were also investigated.

  14. Eleven years that changed the face of particle physics

    CERN Multimedia

    2000-01-01

    Director General Luciano Maiani opens the proceedings at the LEP Celebration. Members of government from around the world gathered at CERN on Monday 9 October to celebrate the achievements of the Large Electron Positron collider (LEP), the Laboratory’s flagship particle accelerator. Over the eleven years of its operational lifetime, LEP has not only added greatly to mankind’s pool of knowledge about the Universe, but has also changed the way that particle physics research is done, and proved to be a valuable training ground for young professionals in many walks of life. The celebration took place in building 180 and the audience of politicians and scientists listened to speeches from:   Prof. Luciano Maiani CERN’s Director-General Prof. Martinus Veltman Nobel Prize Laureat 1999 M. Adolf Ogi President of the Swiss Confederation Switzerland M. Roger-Gérard Schwartzenberg Minister of Research  France Mme Edelgard Bulmahn Minister of Education and R...

  15. On eleven-dimensional supergravity and Chern-Simons theory

    Energy Technology Data Exchange (ETDEWEB)

    Izaurieta, Fernando, E-mail: fizaurie@ucsc.cl [Departamento de Matematica y Fisica Aplicadas, Universidad Catolica de la Santisima Concepcion, Alonso de Ribera 2850, 4090541 Concepcion (Chile); Instituto de Matematicas, Universidad Nacional Autonoma de Mexico, Av. Insurgentes Sur s/n, D.F. (Mexico); Departament de Fisica Teorica, Universitat de Valencia, C/ Dr. Moliner 50, 46100 Burjassot, Valencia (Spain); Rodriguez, Eduardo, E-mail: edurodriguez@ucsc.cl [Departamento de Matematica y Fisica Aplicadas, Universidad Catolica de la Santisima Concepcion, Alonso de Ribera 2850, 4090541 Concepcion (Chile)

    2012-02-11

    We probe in some depth into the structure of eleven-dimensional, osp(32|1)-based Chern-Simons supergravity, as put forward by Troncoso and Zanelli (TZ) in 1997. We find that the TZ Lagrangian may be cast as a polynomial in 1/l, where l is a length, and compute explicitly the first three dominant terms. The term proportional to 1/l{sup 9} turns out to be essentially the Lagrangian of the standard 1978 supergravity theory of Cremmer, Julia and Scherk, thus establishing a previously unknown relation between the two theories. The computation is nontrivial because, when written in a sufficiently explicit way, the TZ Lagrangian has roughly one thousand non-explicitly Lorentz-covariant terms. Specially designed algebraic techniques are used to accomplish the results.

  16. Eleven-dimensional supergravity from filtered subdeformations of the Poincaré superalgebra

    International Nuclear Information System (INIS)

    Figueroa-O’Farrill, José; Santi, Andrea

    2016-01-01

    We summarise recent results concerning the classification of filtered deformations of graded subalgebras of the Poincaré superalgebra in eleven dimensions, highlighting what could be considered a novel Lie-algebraic derivation of eleven-dimensional supergravity. (paper)

  17. The eleven observations of comets between 687 AD and 1114 AD recorded in the Anglo Saxon Chronicle

    Science.gov (United States)

    Mardon, E. G.; Mardon, A. A.; Williams, J.

    1992-12-01

    This research paper is an examination of the eleven cometary references (679AD, 729AD, 892AD, 950AD, 975AD, 995AD, 1066AD, 1097AD, 1106AD, 1110AD and 1114AD) found in the various manuscripts of The Anglo Saxon Chronicle between 678 AD and 1114 AD. The manuscripts contain more than 35 celestial observations. This is an examination of astronomical phenomena and other climatic or natural events, that are described in The Anglo Saxon Chronicle, which is also referred to as The Old English Annals.

  18. Three-channel gated nanosecond integrator

    International Nuclear Information System (INIS)

    Tsirkel', B.I.; Martsinovskij, A.M.

    1981-01-01

    Structure and principle of operation of three-channel gated integrator for investigating the shape of periodical electric and optical signals at high background noise level are described. The integrator consists of an integrating circuit itself for each channel and a circuit of gating pulse formation. If the noise level doesn't exceed the signal, the value of storage capacity can be equal to 22 nF. The value of storage capacity must be increased in the case of a worse signal-to-noise ratio. The gating pulse formation circuit includes a comparator, a sawtooth voltage generator and a reference voltage generator. An integrator flowsheet is given. The time resolution of the system is about 50 ns, time sweep amounts to 5-2000 μs, electric signal sensitivity is about 70 μV. The pulse signal shape recording is performed with manual or automated time sweep at two-coordinate potentiometer. The light signal detection is made on the base of photomultiplier pulse counting rate record by the dynamic capacitor method, sensitivity limit amounts to about 1 pulse/s

  19. Expert Systems in Reference Services.

    Science.gov (United States)

    Roysdon, Christine, Ed.; White, Howard D., Ed.

    1989-01-01

    Eleven articles introduce expert systems applications in library and information science, and present design and implementation issues of system development for reference services. Topics covered include knowledge based systems, prototype development, the use of artificial intelligence to remedy current system inadequacies, and an expert system to…

  20. The second phase of bipolar, nanosecond-range electric pulses determines the electroporation efficiency.

    Science.gov (United States)

    Pakhomov, Andrei G; Grigoryev, Sergey; Semenov, Iurii; Casciola, Maura; Jiang, Chunqi; Xiao, Shu

    2018-03-29

    Bipolar cancellation refers to a phenomenon when applying a second electric pulse reduces ("cancels") cell membrane damage by a preceding electric pulse of the opposite polarity. Bipolar cancellation is a reason why bipolar nanosecond electric pulses (nsEP) cause weaker electroporation than just a single unipolar phase of the same pulse. This study was undertaken to explore the dependence of bipolar cancellation on nsEP parameters, with emphasis on the amplitude ratio of two opposite polarity phases of a bipolar pulse. Individual cells (CHO, U937, or adult mouse ventricular cardiomyocytes (VCM)) were exposed to either uni- or bipolar trapezoidal nsEP, or to nanosecond electric field oscillations (NEFO). The membrane injury was evaluated by time-lapse confocal imaging of the uptake of propidium (Pr) or YO-PRO-1 (YP) dyes and by phosphatidylserine (PS) externalization. Within studied limits, bipolar cancellation showed little or no dependence on the electric field intensity, pulse repetition rate, chosen endpoint, or cell type. However, cancellation could increase for larger pulse numbers and/or for longer pulses. The sole most critical parameter which determines bipolar cancellation was the phase ratio: maximum cancellation was observed with the 2nd phase of about 50% of the first one, whereas a larger 2nd phase could add a damaging effect of its own. "Swapping" the two phases, i.e., delivering the smaller phase before the larger one, reduced or eliminated cancellation. These findings are discussed in the context of hypothetical mechanisms of bipolar cancellation and electroporation by nsEP. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. Dynamic of ozone formation in nanosecond microwave discharges

    International Nuclear Information System (INIS)

    Akhmedzhanov, R.A.; Vikharev, A.L.; Gorbachev, A.M.

    1995-01-01

    Nanosecond gas discharges are efficient sources of chemically active plasma. Studies of the nanosecond microwave discharge are interesting for remote modification of the chemical composition of the atmosphere in term of its purification, for diagnostics of impurities and ozone replenishment in the regions of local open-quotes ozone holesclose quotes. In this connection a study of plasma chemical processes in such a discharge seems appropriate, as well as modeling of ecological consequences of the effect of powerful microwave radiation on the atmosphere. The present paper contains generalized results of studying the process of ozone formation in a pulse-periodic freely localized nanosecond microwave discharge. The experiments were performed in a wide range of parameters: microwave radiation wavelength λ = 0.8 and 3cm, pulse duration τ = 6 and 500ns, pulse power P = 50kW and 20MW, pulse repetition rate F = 1-10 3 Hz. The working gases were air and oxygen under pressure P = 10-100Torr. As a source of the microwave radiation a pulse magnetron was used with a device for pulse compression based on the waveguide resonator, and a relativistic microwave generator. The discharge was produced in the focus of the parabolic mirror and had the form of homogeneous cylinder. The plasma chemical processes were studied in two cases. The discharge was created either in the quartz tube placed along the focal line of the mirror or in the free air. Dynamics of formation of ozone and nitrogen oxides in the discharge was studied by means of absorption spectroscopy in the regime of accumulation of the products of chemical reactions (in a closed volume) and their diffusion spreading

  2. Sub-nanosecond lasers for cosmetics and dermatology

    Science.gov (United States)

    Tarasov, Aleksandr A.; Chu, Hong

    2018-02-01

    We report about the development of two new subnanosecond solid-state laser models for application in dermatology and cosmetics. One model uses subnanosecond Nd: YAG microchip laser as a master oscillator and includes Nd: YAG double- and single-pass amplifiers. At 10 Hz this laser produces more than 600 mJ pulse energy with duration 500 +/- 5 ps. Another model (under development) is gain-switched Ti: Sapphire laser with short cavity. This laser produces 200 mJ, 560 ps pulses at 790 nm and uses standard Q-Switched Nd: YAG laser with nanosecond pulse duration as a pumping sourse.

  3. Picosecond absorption relaxation measured with nanosecond laser photoacoustics.

    Science.gov (United States)

    Danielli, Amos; Favazza, Christopher P; Maslov, Konstantin; Wang, Lihong V

    2010-10-18

    Picosecond absorption relaxation-central to many disciplines-is typically measured by ultrafast (femtosecond or picosecond) pump-probe techniques, which however are restricted to optically thin and weakly scattering materials or require artificial sample preparation. Here, we developed a reflection-mode relaxation photoacoustic microscope based on a nanosecond laser and measured picosecond absorption relaxation times. The relaxation times of oxygenated and deoxygenated hemoglobin molecules, both possessing extremely low fluorescence quantum yields, were measured at 576 nm. The added advantages in dispersion susceptibility, laser-wavelength availability, reflection sensing, and expense foster the study of natural-including strongly scattering and nonfluorescent-materials.

  4. Laser ablation comparison by picosecond pulses train and nanosecond pulse

    Science.gov (United States)

    Lednev, V. N.; Filippov, M. N.; Bunkin, A. F.; Pershin, S. M.

    2015-12-01

    A comparison of laser ablation by a train of picosecond pulses and nanosecond pulses revealed a difference in laser craters, ablation thresholds, plasma sizes and spectral line intensities. Laser ablation with a train of picosecond pulses resulted in improved crater quality while ablated mass decreased up to 30%. A reduction in laser plasma dimensions for picosecond train ablation was observed while the intensity of atomic/ionic lines in the plasma spectra was greater by a factor of 2-4 indicating an improved excitation and atomization in the plasma.

  5. Multiple pulse nanosecond laser induced damage threshold on hybrid mirrors

    Science.gov (United States)

    Vanda, Jan; Muresan, Mihai-George; Bilek, Vojtech; Sebek, Matej; Hanus, Martin; Lucianetti, Antonio; Rostohar, Danijela; Mocek, Tomas; Škoda, Václav

    2017-11-01

    So-called hybrid mirrors, consisting of broadband metallic surface coated with dielectric reflector designed for specific wavelength, becoming more important with progressing development of broadband mid-IR sources realized using parametric down conversion system. Multiple pulse nanosecond laser induced damage on such mirrors was tested by method s-on-1, where s stands for various numbers of pulses. We show difference in damage threshold between common protected silver mirrors and hybrid silver mirrors prepared by PVD technique and their variants prepared by IAD. Keywords: LIDT,

  6. Generation of nanosecond S band microwave pulses based on superradiance

    International Nuclear Information System (INIS)

    Ginzburg, N.S.; Zotova, I.V.; Rozental, R.M.

    2002-01-01

    Modeling carried out demonstrates possibility of generation of gigawatt power level S band microwave pulse with duration of several nanoseconds using superradiation of short electron beam moving along slow-wave periodical structure. A 10 ns / 500 keV / 5 kA accelerator of Kanazawa University can be used in such experiments. It is shown that significant increasing peak power can be obtained by optimization of voltage and current pulses waveforms. Required increasing of electron energy and current by the end of electron pulse can be achieved by using self-acceleration of a short beam passing through a system of passive cavities. (author)

  7. Generation of nanosecond S band microwave pulses based on superradiance

    Energy Technology Data Exchange (ETDEWEB)

    Ginzburg, N.S.; Zotova, I.V.; Rozental, R.M. [Russian Academy of Science, Institute of Applied Physics, Nizhny Novgorod (RU)] [and others

    2002-06-01

    Modeling carried out demonstrates possibility of generation of gigawatt power level S band microwave pulse with duration of several nanoseconds using superradiation of short electron beam moving along slow-wave periodical structure. A 10 ns / 500 keV / 5 kA accelerator of Kanazawa University can be used in such experiments. It is shown that significant increasing peak power can be obtained by optimization of voltage and current pulses waveforms. Required increasing of electron energy and current by the end of electron pulse can be achieved by using self-acceleration of a short beam passing through a system of passive cavities. (author)

  8. Hybrid micromachining using a nanosecond pulsed laser and micro EDM

    International Nuclear Information System (INIS)

    Kim, Sanha; Chung, Do Kwan; Shin, Hong Shik; Chu, Chong Nam; Kim, Bo Hyun

    2010-01-01

    Micro electrical discharge machining (micro EDM) is a well-known precise machining process that achieves micro structures of excellent quality for any conductive material. However, the slow machining speed and high tool wear are main drawbacks of this process. Though the use of deionized water instead of kerosene as a dielectric fluid can reduce the tool wear and increase the machine speed, the material removal rate (MRR) is still low. In contrast, laser ablation using a nanosecond pulsed laser is a fast and non-wear machining process but achieves micro figures of rather low quality. Therefore, the integration of these two processes can overcome the respective disadvantages. This paper reports a hybrid process of a nanosecond pulsed laser and micro EDM for micromachining. A novel hybrid micromachining system that combines the two discrete machining processes is introduced. Then, the feasibility and characteristics of the hybrid machining process are investigated compared to conventional EDM and laser ablation. It is verified experimentally that the machining time can be effectively reduced in both EDM drilling and milling by rapid laser pre-machining prior to micro EDM. Finally, some examples of complicated 3D micro structures fabricated by the hybrid process are shown

  9. A thermal model for nanosecond pulsed laser ablation of aluminum

    Directory of Open Access Journals (Sweden)

    Yu Zhang

    2017-07-01

    Full Text Available In order to simulate the nanosecond pulsed laser ablation of aluminum, a novel model was presented for the target ablation and plume expansion. The simulation of the target ablation was based on one-dimensional heat conduction, taking into account temperature dependent material properties, phase transition, dielectric transition and phase explosion. While the simulation of the plume expansion was based on one-dimensional gas-dynamical equation, taking into account ionization, plume absorption and shielding. By coupling the calculations of the target ablation and plume expansion, the characteristics of the target and plume were obtained. And the calculated results were in good agreement with the experimental data, in terms of ablation threshold and depth within the fluence range of the tested laser. Subsequently, investigations were carried out to analyze the mechanisms of nanosecond pulsed laser ablation. The calculated results showed that the maximum surface temperature remained at about 90% of the critical temperature (0.9Tc due to phase explosion. Moreover, the plume shielding has significant effects on the laser ablation, and the plume shielding proportion increase as the laser fluence increasing. The ambient pressure belows 100 Pa is more suitable for laser ablation, which can obtained larger ablation depth.

  10. Interaction of gold nanoparticles with nanosecond laser pulses: Nanoparticle heating

    International Nuclear Information System (INIS)

    Nedyalkov, N.N.; Imamova, S.E.; Atanasov, P.A.; Toshkova, R.A.; Gardeva, E.G.; Yossifova, L.S.; Alexandrov, M.T.; Obara, M.

    2011-01-01

    Theoretical and experimental results on the heating process of gold nanoparticles irradiated by nanosecond laser pulses are presented. The efficiency of particle heating is demonstrated by in-vitro photothermal therapy of human tumor cells. Gold nanoparticles with diameters of 40 and 100 nm are added as colloid in the cell culture and the samples are irradiated by nanosecond pulses at wavelength of 532 nm delivered by Nd:YAG laser system. The results indicate clear cytotoxic effect of application of nanoparticle as more efficient is the case of using particles with diameter of 100 nm. The theoretical analysis of the heating process of nanoparticle interacting with laser radiation is based on the Mie scattering theory, which is used for calculation of the particle absorption coefficient, and two-dimensional heat diffusion model, which describes the particle and the surrounding medium temperature evolution. Using this model the dependence of the achieved maximal temperature in the particles on the applied laser fluence and time evolution of the particle temperature is obtained.

  11. Interaction of gold nanoparticles with nanosecond laser pulses: Nanoparticle heating

    Science.gov (United States)

    Nedyalkov, N. N.; Imamova, S. E.; Atanasov, P. A.; Toshkova, R. A.; Gardeva, E. G.; Yossifova, L. S.; Alexandrov, M. T.; Obara, M.

    2011-04-01

    Theoretical and experimental results on the heating process of gold nanoparticles irradiated by nanosecond laser pulses are presented. The efficiency of particle heating is demonstrated by in-vitro photothermal therapy of human tumor cells. Gold nanoparticles with diameters of 40 and 100 nm are added as colloid in the cell culture and the samples are irradiated by nanosecond pulses at wavelength of 532 nm delivered by Nd:YAG laser system. The results indicate clear cytotoxic effect of application of nanoparticle as more efficient is the case of using particles with diameter of 100 nm. The theoretical analysis of the heating process of nanoparticle interacting with laser radiation is based on the Mie scattering theory, which is used for calculation of the particle absorption coefficient, and two-dimensional heat diffusion model, which describes the particle and the surrounding medium temperature evolution. Using this model the dependence of the achieved maximal temperature in the particles on the applied laser fluence and time evolution of the particle temperature is obtained.

  12. Nanosecond radar system based on repetitive pulsed relativistic BWO

    International Nuclear Information System (INIS)

    Bunkin, B.V.; Gaponov-Grekhov, A.V.; Eltchaninov, A.S.; Zagulov, F.Ya.; Korovin, S.D.; Mesyats, G.A.; Osipov, M.L.; Otlivantchik, E.A.; Petelin, M.I.; Prokhorov, A.M.

    1993-01-01

    The paper presents the results of studies of a nanosecond radar system based on repetitive pulsed relativistic BWO. A pulsed power repetitive accelerator producing electron beams of electron energy 500-700 keV and current 5 kA in pulses of duraction 10 ns with a repetition rate of 100 pps is described. The results of experiments with a high-voltage gas-filled spark gap and a cold-cathode vacuum diode under the conditions of high repetition rates are given. Also presented are the results of studies of a relativistic BWO operating with a wavelength of 3 cm. It is shown that for a high-current beam electron energy of 500-700 keV, the BWO efficiency can reach 35%, the microwave power being 10 9 W. A superconducting solenoid creating a magnetic field of 30 kOe was used for the formation and transportation of the high-current electron beam. In conclusion, the outcome of tests of a nanosecond radar station based on a pulsed power repetitive accelerator and a relativistic BWO is reported

  13. A note on supersonic flow control with nanosecond plasma actuator

    Science.gov (United States)

    Zheng, J. G.; Cui, Y. D.; Li, J.; Khoo, B. C.

    2018-04-01

    A concept study on supersonic flow control using nanosecond pulsed plasma actuator is conducted by means of numerical simulation. The nanosecond plasma discharge is characterized by the generation of a micro-shock wave in ambient air and a residual heat in the discharge volume arising from the rapid heating of near-surface gas by the quick discharge. The residual heat has been found to be essential for the flow separation control over aerodynamic bodies like airfoil and backward-facing step. In this study, novel experiment is designed to utilize the other flow feature from discharge, i.e., instant shock wave, to control supersonic flow through shock-shock interaction. Both bow shock in front of a blunt body and attached shock anchored at the tip of supersonic projectile are manipulated via the discharged-induced shock wave in an appropriate manner. It is observed that drag on the blunt body is reduced appreciably. Meanwhile, a lateral force on sharp-edged projectile is produced, which can steer the body and give it an effective angle of attack. This opens a promising possibility for extending the applicability of this flow control technique in supersonic flow regime.

  14. Evaluation of material dispersion using a nanosecond optical pulse radiator.

    Science.gov (United States)

    Horiguchi, M; Ohmori, Y; Miya, T

    1979-07-01

    To study the material dispersion effects on graded-index fibers, a method for measuring the material dispersion in optical glass fibers has been developed. Nanosecond pulses in the 0.5-1.7-microm region are generated by a nanosecond optical pulse radiator and grating monochromator. These pulses are injected into a GeO(2)-P(2)0(5)-doped silica graded-index fiber. Relative time delay changes between different wavelengths are used to determine material dispersion, core glass refractive index, material group index, and optimum profile parameter of the graded-index fiber. From the measured data, the optimum profile parameter on the GeO(2)-P(2)O(5)-doped silica graded-index fiber could be estimated to be 1.88 at 1.27 microm of the material dispersion free wavelength region and 1.82 at 1.55 microm of the lowest-loss wavelength region in silica-based optical fiber waveguides.

  15. Current-Voltage Characteristic of Nanosecond - Duration Relativistic Electron Beam

    Science.gov (United States)

    Andreev, Andrey

    2005-10-01

    The pulsed electron-beam accelerator SINUS-6 was used to measure current-voltage characteristic of nanosecond-duration thin annular relativistic electron beam accelerated in vacuum along axis of a smooth uniform metal tube immersed into strong axial magnetic field. Results of these measurements as well as results of computer simulations performed using 3D MAGIC code show that the electron-beam current dependence on the accelerating voltage at the front of the nanosecond-duration pulse is different from the analogical dependence at the flat part of the pulse. In the steady-state (flat) part of the pulse), the measured electron-beam current is close to Fedosov current [1], which is governed by the conservation law of an electron moment flow for any constant voltage. In the non steady-state part (front) of the pulse, the electron-beam current is higher that the appropriate, for a giving voltage, steady-state (Fedosov) current. [1] A. I. Fedosov, E. A. Litvinov, S. Ya. Belomytsev, and S. P. Bugaev, ``Characteristics of electron beam formed in diodes with magnetic insulation,'' Soviet Physics Journal (A translation of Izvestiya VUZ. Fizika), vol. 20, no. 10, October 1977 (April 20, 1978), pp.1367-1368.

  16. Water laws in eleven midwestern states: summary tables

    Energy Technology Data Exchange (ETDEWEB)

    McNeil, T.L.; Torpy, M.F.

    1979-06-01

    Basic information about the water laws of Arkansas, Illinois, Indiana, Iowa, Kansas, Kentucky, Michigan, Minnesota, Missouri, Ohio, and West Virginia is summarized. References to state laws and court decisions that may be useful in assessing the legal availability of water for energy development are provided. (MCW)

  17. A Hidden Twelve-Dimensional SuperPoincare Symmetry In Eleven Dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Bars, Itzhak; Deliduman, Cemsinan; Pasqua, Andrea; Zumino, Bruno

    2003-12-13

    First, we review a result in our previous paper, of how a ten-dimensional superparticle, taken off-shell, has a hidden eleven-dimensional superPoincare symmetry. Then, we show that the physical sector is defined by three first-class constraints which preserve the full eleven-dimensional symmetry. Applying the same concepts to the eleven dimensional superparticle, taken off-shell, we discover a hidden twelve dimensional superPoincare symmetry that governs the theory.

  18. Numerical simulation of nanosecond-pulse electrical discharges

    Science.gov (United States)

    Poggie, J.; Adamovich, I.; Bisek, N.; Nishihara, M.

    2013-02-01

    Recent experiments with a nanosecond-pulse, dielectric barrier discharge at the stagnation point of a Mach 5 cylinder flow have demonstrated the formation of weak shock waves near the electrode edge, which propagate upstream and perturb the bow shock. This is a promising means of flow control, and understanding the detailed physics of the conversion of electrical energy into gas motion will aid in the design of efficient actuators based on the concept. In this work, a simplified configuration with planar symmetry was chosen as a vehicle to develop a physics-based model of nanosecond-pulse discharges, including realistic air kinetics, electron energy transport, and compressible bulk gas flow. A reduced plasma kinetic model (23 species and 50 processes) was developed to capture the dominant species and reactions for energy storage and thermalization in the discharge. The kinetic model included electronically and vibrationally excited species, and several species of ions and ground state neutrals. The governing equations included the Poisson equation for the electric potential, diffusion equations for each neutral species, conservation equations for each charged species, and mass-averaged conservation equations for the bulk gas flow. The results of calculations with this model highlighted the path of energy transfer in the discharge. At breakdown, the input electrical energy was transformed over a time scale on the order of 1 ns into chemical energy of ions, dissociation products, and vibrationally and electronically excited particles. About 30% of this energy was subsequently thermalized over a time scale of 10 µs. Since the thermalization time scale was faster than the acoustic time scale, the heat release led to the formation of weak shock waves originating near the sheath edge, consistent with experimental observations. The computed translational temperature rise (40 K) and nitrogen vibrational temperature rise (370 K) were of the same order of magnitude as

  19. Universal pulse generator with a nanosecond fast responce

    International Nuclear Information System (INIS)

    Basiladze, S.G.; Nguen Kuang Min'.

    1977-01-01

    A pulse generator with nanosecond action is described; it is mainly designed for testing and tuning fast electronic devices operating with pulses in the N/1/M standard. The generator is principally based on integral circuits and has wide functional potentialities: it includes a main-pulse channel, a delayed-pulse channel, and an overall output, which sums up these pulses; in addition to the logic pulse outputs it includes a linear pulse output with an amplitude smoothly regulated in the range from 0.3 to 6.0 V; it can operate in the self-oscillation mode, in the pulse series formation mode, in the starting mode, and in the single-start mode. Two generators are placed in a double-width CAMAC cell. The generation frequency is from 3 Hz to 75 MHz, pulse duration from 8 to 320 ns, and pulse front duration 2 ns

  20. Thermally assisted nanosecond laser generation of ferric nanoparticles

    Science.gov (United States)

    Kurselis, K.; Kozheshkurt, V.; Kiyan, R.; Chichkov, B.; Sajti, L.

    2018-03-01

    A technique to increase nanosecond laser based production of ferric nanoparticles by elevating temperature of the iron target and controlling its surface exposure to oxygen is reported. High power near-infrared laser ablation of the iron target heated up to 600 °C enhances the particle generation efficiency by more than tenfold exceeding 6 μg/J. Temporal and thermal dependencies of the particle generation process indicate correlation of this enhancement with the oxidative processes that take place on the iron surface during the per spot interpulse delay. Nanoparticles, produced using the heat-assisted ablation technique, are examined using scanning electron and transmission electron microscopy confirming the presence of 1-100 nm nanoparticles with an exponential size distribution that contain multiple randomly oriented magnetite nanocrystallites. The described process enables the application of high power lasers and facilitates precise, uniform, and controllable direct deposition of ferric nanoparticle coatings at the industry-relevant rates.

  1. Double nanosecond pulses generation in ytterbium fiber laser

    Energy Technology Data Exchange (ETDEWEB)

    Veiko, V. P.; Samokhvalov, A. A., E-mail: samokhvalov.itmo@gmail.com; Yakovlev, E. B.; Zhitenev, I. Yu.; Kliushin, A. N. [Saint-Petersburg State University of Information Technologies, Mechanics and Optics, Kronverksky Pr. 49, Saint Petersburg (Russian Federation); Lednev, V. N. [Prokhorov General Physics Institute of the Russian Academy of Sciences, Vavilov Str., 38, Moscow (Russian Federation); National University of Science and Technology MISiS, Leninskyave., 4, Moscow (Russian Federation); Pershin, S. M. [Prokhorov General Physics Institute of the Russian Academy of Sciences, Vavilov Str., 38, Moscow (Russian Federation)

    2016-06-15

    Double pulse generation mode for nanosecond ytterbium fiber laser was developed. Two sequential 60-200 ns laser pulses with variable delay between them were generated by acousto-optic modulator opening with continuous diode pumping. A custom radio frequency generator was developed to produce two sequential “opening” radio pulses with a delay of 0.2–1 μs. It was demonstrated that double pulse generation did not decrease the average laser power while providing the control over the laser pulse power profile. Surprisingly, a greater peak power in the double pulse mode was observed for the second laser pulse. Laser crater studies and plasma emission measurements revealed an improved efficiency of laser ablation in the double pulse mode.

  2. Nanosecond-resolved temperature measurements using magnetic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Wenbiao; Zhang, Pu [School of Automation, Huazhong University of Science and Technology, Wuhan 430074 (China); Liu, Wenzhong, E-mail: lwz7410@hust.edu.cn [School of Automation, Huazhong University of Science and Technology, Wuhan 430074 (China); Key Laboratory of Image Processing and Intelligent Control, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2016-05-15

    Instantaneous and noninvasive temperature measurements are important when laser thermotherapy or welding is performed. A noninvasive nanosecond-resolved magnetic nanoparticle (MNP) temperature measurement system is described in which a transient change in temperature causes an instantaneous change in the magnetic susceptibilities of the MNPs. These transient changes in the magnetic susceptibilities are rapidly recorded using a wideband magnetic measurement system with an upper frequency limit of 0.5 GHz. The Langevin function (the thermodynamic model characterizing the MNP magnetization process) is used to obtain the temperature information. Experiments showed that the MNP DC magnetization temperature-measurement system can detect a 14.4 ns laser pulse at least. This method of measuring temperature is likely to be useful for acquiring the internal temperatures of materials irradiated with lasers, as well as in other areas of research.

  3. Removal of Tattoos by Q-Switched Nanosecond Lasers.

    Science.gov (United States)

    Karsai, Syrus

    2017-01-01

    Tattoo removal by Q-switched nanosecond laser devices is generally a safe and effective method, albeit a time-consuming one. Despite the newest developments in laser treatment, it is still not possible to remove every tattoo completely and without complications. Incomplete removal remains one of the most common challenges. As a consequence, particular restraint should be exercised when treating multicoloured tattoos, and patients need to be thoroughly informed about remaining pigment. Other frequent adverse effects include hyper- and hypopigmentation as well as ink darkening; the latter is particularly frequent in permanent make-up. Scarring is also possible, although it is rare when treatment is performed correctly. It is becoming more widespread for laser operators to encounter allergic reactions and even malignant tumours in tattoos, and treating these conditions requires a nuanced approach. © 2017 S. Karger AG, Basel.

  4. Method for integrating a train of fast, nanosecond wide pulses

    International Nuclear Information System (INIS)

    Rose, C.R.

    1987-01-01

    This paper describes a method used to integrate a train of fast, nanosecond wide pulses. The pulses come from current transformers in a RF LINAC beamline. Because they are ac signals and have no dc component, true mathematical integration would yield zero over the pulse train period or an equally erroneous value because of a dc baseline shift. The circuit used to integrate the pulse train first stretches the pulses to 35 ns FWHM. The signals are then fed into a high-speed, precision rectifier which restores a true dc baseline for the following stage - a fast, gated integrator. The rectifier is linear over 55dB in excess of 25 MHz, and the gated integrator is linear over a 60 dB range with input pulse widths as short as 16 ns. The assembled system is linear over 30 dB with a 6 MHz input signal

  5. The Knights’ Eleven Oars: In Praise of Phormio? (Ar. Eq. 546-7)

    DEFF Research Database (Denmark)

    Lech, Marcel Lysgaard

    2009-01-01

    The curious “eleven oars” of the chorus of Knights in Aristophanes’ eponymous play recall the victory of Phormio and his eleven triremes in the gulf of Naupactus in 429 B.C., and echo a lost victory ode performed at the celebration of this victory....

  6. Plasma plume expansion dynamics in nanosecond Nd:YAG laserosteotome

    Science.gov (United States)

    Abbasi, Hamed; Rauter, Georg; Guzman, Raphael; Cattin, Philippe C.; Zam, Azhar

    2018-02-01

    In minimal invasive laser osteotomy precise information about the ablation process can be obtained with LIBS in order to avoid carbonization, or cutting of wrong types of tissue. Therefore, the collecting fiber for LIBS needs to be optimally placed in narrow cavities in the endoscope. To determine this optimal placement, the plasma plume expansion dynamics in ablation of bone tissue by the second harmonic of a nanosecond Nd:YAG laser at 532 nm has been studied. The laserinduced plasma plume was monitored in different time delays, from one nanosecond up to one hundred microseconds. Measurements were performed using high-speed gated illumination imaging. The expansion features were studied using illumination of the overall visible emission by using a gated intensified charged coupled device (ICCD). The camera was capable of having a minimum gate width (Optical FWHM) of 3 ns and the timing resolution (minimum temporal shift of the gate) of 10 ps. The imaging data were used to generate position-time data of the luminous plasma-front. Moreover, the velocity of the plasma plume expansion was studied based on the time-resolved intensity data. By knowing the plasma plume profile over time, the optimum position (axial distance from the laser spot) of the collecting fiber and optimal time delay (to have the best signal to noise ratio) in spatial-resolved and time-resolved laser-induced breakdown spectroscopy (LIBS) can be determined. Additionally, the function of plasma plume expansion could be used to study the shock wave of the plasma plume.

  7. Femtosecond and nanosecond pulsed laser deposition of silicon and germanium

    Energy Technology Data Exchange (ETDEWEB)

    Reenaas, Turid Worren [Department of Physics, Norwegian University of Science and Technology, 7491 Trondheim (Norway); Lee, Yen Sian [Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia); Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Chowdhury, Fatema Rezwana; Gupta, Manisha; Tsui, Ying Yin [Department of Electrical and Computer Engineering, University of Alberta (Canada); Tou, Teck Yong [Faculty of Engineering, Multimedia University, 63100 Cyberjaya, Selangor (Malaysia); Yap, Seong Ling [Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Kok, Soon Yie [Faculty of Engineering, Multimedia University, 63100 Cyberjaya, Selangor (Malaysia); Yap, Seong Shan, E-mail: seongshan@gmail.com [Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2015-11-01

    Highlights: • Ge and Si were deposited by fs and ns laser at room temperature and at vacuum. • Ion of 10{sup 4} ms{sup −1} and 30–200 eV was obtained for ns ablation for Ge and Si. • Highly energetic ions of 10{sup 5} ms{sup −1} with 2–7 KeV were produced in fs laser ablation. • Nanocrystalline Si and Ge were deposited by using fs laser. • Nanoparticles < 10 nm haven been obtained by fs laser. - Abstract: 150 fs Ti:Sapphire laser pulsed laser deposition of Si and Ge were compared to a nanosecond KrF laser (25 ns). The ablation thresholds for ns lasers were about 2.5 J cm{sup −2} for Si and 2.1 J cm{sup −2} for Ge. The values were about 5–10 times lower when fs laser were used. The power densities were 10{sup 8}–10{sup 9} W cm{sup −2} for ns but 10{sup 12} W cm{sup −2} for fs. By using an ion probe, the ions emission at different fluence were measured where the emitting ions achieving the velocity in the range of 7–40 km s{sup −1} and kinetic energy in the range of 30–200 eV for ns laser. The ion produced by fs laser was measured to be highly energetic, 90–200 km s{sup −1}, 2–10 KeV. Two ion peaks were detected above specific laser fluence for both ns and fs laser ablation. Under fs laser ablation, the films were dominated by nano-sized crystalline particles, drastically different from nanosecond pulsed laser deposition where amorphous films were obtained. The ions characteristics and effects of pulse length on the properties of the deposited films were discussed.

  8. Analysis of uranium urinalysis and in vivo measurement results from eleven participating uranium mills

    International Nuclear Information System (INIS)

    Spitz, H.B.; Simpson, J.C.; Aldridge, T.L.

    1984-05-01

    Uranium urinalysis and in vivo examination results obtained from workers at eleven uranium mills between 1978 and 1980 were evaluated. The main purpose was to determine the degree of the mills' compliance with bioassay monitoring recommendations given in the draft NRC Regulatory Guide 8.22 (USNRC 1978). The effect of anticipated changes in the draft regulatory guidance, as expressed to PNL in May 1982, was also studied. Statistical analyses of the data showed that the bioassay results did not reliably meet the limited performance criteria given in the draft regulatory guide. Furthermore, quality control measurements of uranium in urine indicated that detection limits at α = β = 0.05 ranged from 13 μg/l to 29 μg/l, whereas the draft regulatory guidance suggests 5 μg/l as the detection limit. Recommendations for monitoring frequencies given in the draft guide were not followed consistently from mill to mill. The results of these statistical analyses indicate a need to include performance criteria for accuracy, precision, and confidence in revisions of the draft Regulatory Guide 8.22. Revised guidance should also emphasize the need for each mill to continually test the laboratory performing urinalyses by submitting quality control samples (i.e., blank and spiked urine samples as open and blind test) to insure that the performance criteria are being met. Recommendations for a bioassay audit program are also given. 25 references, 15 figures, 17 tables

  9. Studies on laser material processing with nanosecond and sub-nanosecond and picosecond and sub-picosecond pulses

    Science.gov (United States)

    Zhang, Jie; Tao, Sha; Wang, Brian; Zhao, Jay

    2016-03-01

    In this paper, laser ablation of widely used metal (Al, Cu. stainless-steel), semiconductor (Si), transparent material (glass, sapphire), ceramic (Al2O3, AlN) and polymer (PI, PMMA) in industry were systematically studied with pulse width from nanosecond (5-100ns), picosecond (6-10ps) to sub-picosecond (0.8-0.95ps). A critical damage zone (CDZ) of up to 100um with ns laser, efficiency were also investigated. This is to explore how to provide industry users the best laser solution for device micro-fabrication with best price. Our studies of cutting and drilling with ns, ps, and sub-ps lasers indicate that it is feasible to achieve user accepted quality and speed with cost-effective and reliable laser by optimizing processing conditions.

  10. Graphene quantum dot synthesis using nanosecond laser pulses and its comparison to Methylene Blue

    Science.gov (United States)

    Kholikov, Khomidkhodza; Thomas, Zachary; Seyitliyev, Dovletgeldi; Smith, Skylar

    A biocompatible photodynamic therapy agent that generates a high amount of singlet oxygen with high water dispersibility and excellent photostability is desirable. In this work, a graphene based biomaterial which is a promising alternative to a standard photosensitizers was produced. Methylene blue was used as a reference photosensitizer. Bacteria deactivation by methylene blue was shown to be inhibited inside human blood due to protein binding. Graphene quantum dots (GQD) were synthesized by irradiating benzene and nickel oxide mixture using nanosecond laser pulses. High resolution transmission electron microscopy (HR-TEM), scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared (FTIR) spectroscopy, and nuclear magnetic resonance (NMR) were used for characterization of GQDs. Initial results show graphene quantum dots whose size less than 5 nm were successfully obtained. UV-VIS spectra shows absorption peak around 310 nm. The results of these studies can potentially be used to develop therapies for the eradication of pathogens in open wounds, burns, or skin cancers. New therapies for these conditions are particularly needed when antibiotic-resistant infections are present. NIH KBRIN.

  11. Faraday cup with nanosecond response and adjustable impedance for fast electron beam characterization

    International Nuclear Information System (INIS)

    Hu Jing; Rovey, Joshua L.

    2011-01-01

    A movable Faraday cup design with simple structure and adjustable impedance is described in this work. This Faraday cup has external adjustable shunt resistance for self-biased measurement setup and 50 Ω characteristic impedance to match with 50 Ω standard BNC coaxial cable and vacuum feedthroughs for nanosecond-level pulse signal measurements. Adjustable shunt resistance allows self-biased measurements to be quickly acquired to determine the electron energy distribution function. The performance of the Faraday cup is validated by tests of response time and amplitude of output signal. When compared with a reference source, the percent difference of the Faraday cup signal fall time is less than 10% for fall times greater than 10 ns. The percent difference of the Faraday cup signal pulse width is below 6.7% for pulse widths greater than 10 ns. A pseudospark-generated electron beam is used to compare the amplitude of the Faraday cup signal with a calibrated F-70 commercial current transformer. The error of the Faraday cup output amplitude is below 10% for the 4-14 kV tested pseudospark voltages. The main benefit of this Faraday cup is demonstrated by adjusting the external shunt resistance and performing the self-biased method for obtaining the electron energy distribution function. Results from a 4 kV pseudospark discharge indicate a ''double-humped'' energy distribution.

  12. Faraday cup with nanosecond response and adjustable impedance for fast electron beam characterization.

    Science.gov (United States)

    Hu, Jing; Rovey, Joshua L

    2011-07-01

    A movable Faraday cup design with simple structure and adjustable impedance is described in this work. This Faraday cup has external adjustable shunt resistance for self-biased measurement setup and 50 Ω characteristic impedance to match with 50 Ω standard BNC coaxial cable and vacuum feedthroughs for nanosecond-level pulse signal measurements. Adjustable shunt resistance allows self-biased measurements to be quickly acquired to determine the electron energy distribution function. The performance of the Faraday cup is validated by tests of response time and amplitude of output signal. When compared with a reference source, the percent difference of the Faraday cup signal fall time is less than 10% for fall times greater than 10 ns. The percent difference of the Faraday cup signal pulse width is below 6.7% for pulse widths greater than 10 ns. A pseudospark-generated electron beam is used to compare the amplitude of the Faraday cup signal with a calibrated F-70 commercial current transformer. The error of the Faraday cup output amplitude is below 10% for the 4-14 kV tested pseudospark voltages. The main benefit of this Faraday cup is demonstrated by adjusting the external shunt resistance and performing the self-biased method for obtaining the electron energy distribution function. Results from a 4 kV pseudospark discharge indicate a "double-humped" energy distribution.

  13. THE INFLUENCE OF NANOSECOND ELECTROMAGNETIC PULSES TO OBTAIN TIN AND THE PROPERTIES OF ITS ALLOYS

    Directory of Open Access Journals (Sweden)

    V. G. Komkov

    2012-01-01

    Full Text Available Experimentally found that the effect of nanosecond electromagnetic pulses to melt the charge, while the carbon thermal recovery of the tin ore, accelerates the formation of the metallic phase.

  14. Fiber Coupled Pulse Shaper for Sub-Nanosecond Pulse Lidar, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase II effort will develop an all-diode laser and fiber optic based, single frequency, sub-nanosecond pulsed laser source...

  15. Study of the Wavelength Dependence in Laser Ablation of Advanced Ceramics and Glass-Ceramic Materials in the Nanosecond Range.

    Science.gov (United States)

    Sola, Daniel; Peña, Jose I

    2013-11-19

    In this work, geometrical dimensions and ablation yields as a function of the machining method and reference position were studied when advanced ceramics and glass-ceramic materials were machined with pulsed lasers in the nanosecond range. Two laser systems, emitting at 1064 and 532 nm, were used. It was shown that the features obtained depend on whether the substrate is processed by means of pulse bursts or by grooves. In particular, when the samples were processed by grooves, machined depth, removed volume and ablation yields reached their maximum, placing the sample out of focus. It was shown that these characteristics do not depend on the processing conditions, the wavelength or the optical configuration, and that this is intrinsic behavior of the processing method. Furthermore, the existence of a close relation between material hardness and ablation yields was demonstrated.

  16. Nanosecond laser-induced synthesis of nanoparticles with tailorable magneticanisotropy

    International Nuclear Information System (INIS)

    Krishna, H.; Gangopadhyay, A.K.; Strader, J.; Kalyanaraman, R.

    2011-01-01

    Controlling the magnetic orientation of nanoparticles is important for many applications. Recently, it has been shown that single domain ferromagnetic hemispherical Co nanoparticles prepared by nanosecond laser-induced self-organization, show magnetic orientation that was related to the negative sign of the magnetostrictive coefficient λ S [J. Appl. Phys. v103, p073902, 2008]. Here we have extended this work to the Fe 50 Co 50 alloy, which has a positive λ S and Ni, which has a negative λ S . Patterned arrays of ferromagnetic nanoparticles of Fe 50 Co 50 , Ni, (and Co) were synthesized from their ultrathin metal films on SiO 2 substrate by nanosecond laser-induced self-organization. The morphology, nanostructure, and magnetic behavior of the nanoparticle arrays were investigated by a combination of electron microscopy, atomic force microscopy, and magnetic force microscopy techniques. Transmission electron microscopy investigations revealed a granular polycrystalline nanostructure, with the number of grains inside the nanoparticle increasing with their diameter. Magnetic force measurements showed that the magnetization direction of the hemispherical Co and Ni nanoparticles was predominantly out-of-plane while those for the Fe 50 Co 50 alloy was in the plane of the substrate. Finite element analysis was used to estimate the average residual strain in the nanoparticles, following laser processing. The difference in behavior is due to the dominating influence of magnetostrictive energy on the magnetization as a result of residual thermal strain following fast laser processing. Since λ S is negative for polycrystalline Co and Ni, and positive for Fe 50 Co 50 , the tensile residual strain forces the magnetization direction to out-of-plane and in-plane, respectively. This work demonstrates a cost-effective non-epitaxial technique for the synthesis of magnetic nanoparticles with tailored magnetization orientations. - Research Highlights: → Pulsed laser self

  17. Nanosecond electric pulses modulate skeletal muscle calcium dynamics and contraction

    Science.gov (United States)

    Valdez, Chris; Jirjis, Michael B.; Roth, Caleb C.; Barnes, Ronald A.; Ibey, Bennett L.

    2017-02-01

    Irreversible electroporation therapy is utilized to remove cancerous tissues thru the delivery of rapid (250Hz) and high voltage (V) (1,500V/cm) electric pulses across microsecond durations. Clinical research demonstrated that bipolar (BP) high voltage microsecond pulses opposed to monophasic waveforms relieve muscle contraction during electroporation treatment. Our group along with others discovered that nanosecond electric pulses (nsEP) can activate second messenger cascades, induce cytoskeletal rearrangement, and depending on the nsEP duration and frequency, initiate apoptotic pathways. Of high interest across in vivo and in vitro applications, is how nsEP affects muscle physiology, and if nuances exist in comparison to longer duration electroporation applications. To this end, we exposed mature skeletal muscle cells to monopolar (MP) and BP nsEP stimulation across a wide range of electric field amplitudes (1-20 kV/cm). From live confocal microscopy, we simultaneously monitored intracellular calcium dynamics along with nsEP-induced muscle movement on a single cell level. In addition, we also evaluated membrane permeability with Yo-PRO-1 and Propidium Iodide (PI) across various nsEP parameters. The results from our findings suggest that skeletal muscle calcium dynamics, and nsEP-induced contraction exhibit exclusive responses to both MP and BP nsEP exposure. Overall the results suggest in vivo nsEP application may elicit unique physiology and field applications compared to longer pulse duration electroporation.

  18. Trends in nanosecond melanosome microcavitation up to 1540 nm

    Science.gov (United States)

    Schmidt, Morgan S.; Kennedy, Paul K.; Noojin, Gary D.; Vincelette, Rebecca L.; Thomas, Robert J.; Rockwell, Benjamin A.

    2015-09-01

    Thresholds for microcavitation of bovine and porcine melanosomes were previously reported, using single nanosecond (ns) laser pulses in the visible (532 nm) and the near-infrared (NIR) from 1000 to 1319 nm. Here, we report average radiant exposure thresholds for bovine melanosome microcavitation at additional NIR wavelengths up to 1540 nm, which range from ˜0.159 J/cm2 at 800 nm to 4.5 J/cm2 at 1540 nm. Melanosome absorption coefficients were also estimated, and decreased with increasing wavelength. These values were compared to retinal pigment epithelium coefficients, and to water absorption, over the same wavelength range. Corneal total intraocular energy retinal damage threshold values were estimated and compared to the previous (2007) and recently changed (2014) maximum permissible exposure (MPE) safe levels. Results provide additional data that support the recent changes to the MPE levels, as well as the first microcavitation data at 1540 nm, a wavelength for which melanosome microcavitation may be an ns-pulse skin damage mechanism.

  19. Ignition modes of nanosecond discharge with bubbles in distilled water

    International Nuclear Information System (INIS)

    Hamdan, Ahmad; Cha, Min Suk

    2015-01-01

    Here, we present the microscopic physical characteristics of nanosecond discharges with an array of bubbles in distilled water. In particular, applying a single high-voltage pulse, four delayed intensified charge-coupled device cameras successfully visualized four successive images during a single discharge event. We identified three distinctive modes of ignition inside a bubble, depending on the relative location of the bubble with respect to pin-to-hollow needle electrodes when a single bubble was located in an inter-electrode gap of 1 mm: anode-driven ignition, cathode-driven ignition, and co-ignition near both electrodes. Anode- and cathode-driven ignitions evolved into either a complete propagation of the streamer or an incomplete propagation, which were limited in location by proximity to an ignition location, while co-ignitions consistently showed complete propagation. When we increased the gap to 2 mm to accommodate multiple bubbles in the gap, an ignited bubble near the cathode was able to cause the ignition of an upper adjacent bubble. Bubble–bubble interface zones can also be spots of ignition, such that we observed simultaneous co-ignitions in the zones of bubble–bubble interfaces and near electrodes with triple bubbles. We compared the experimental results of discharge propagation with different ignition modes between Ar, He, and N 2 bubbles. In addition, numerical simulations for static electric fields reasonably supported observed ignition behavior such that field intensity was locally enhanced. (paper)

  20. Direct modification of silicon surface by nanosecond laser interference lithography

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Dapeng [JR3CN and CNM (Changchun University of Science and Technology), Changchun 130022 (China); JR3CN and IRAC (University of Bedfordshire), Luton LU1 3JU (United Kingdom); Wang, Zuobin, E-mail: wangz@cust.edu.cn [JR3CN and CNM (Changchun University of Science and Technology), Changchun 130022 (China); JR3CN and IRAC (University of Bedfordshire), Luton LU1 3JU (United Kingdom); Zhang, Ziang [JR3CN and CNM (Changchun University of Science and Technology), Changchun 130022 (China); Yue, Yong [JR3CN and CNM (Changchun University of Science and Technology), Changchun 130022 (China); JR3CN and IRAC (University of Bedfordshire), Luton LU1 3JU (United Kingdom); Li, Dayou [JR3CN and IRAC (University of Bedfordshire), Luton LU1 3JU (United Kingdom); Maple, Carsten [JR3CN and CNM (Changchun University of Science and Technology), Changchun 130022 (China); JR3CN and IRAC (University of Bedfordshire), Luton LU1 3JU (United Kingdom)

    2013-10-01

    Periodic and quasi-periodic structures on silicon surface have numerous significant applications in photoelectronics and surface engineering. A number of technologies have been developed to fabricate the structures in various research fields. In this work, we take the strategy of direct nanosecond laser interference lithography technology, and focus on the silicon material to create different well-defined surface structures based on theoretical analysis of the formation of laser interference patterns. Two, three and four-beam laser interference systems were set up to fabricate the grating, regular triangle and square structures on silicon surfaces, respectively. From the AFM micrographs, the critical features of structures have a dependence on laser fluences. For a relative low laser fluence, grating and dot structures formed with bumps due to the Marangoni Effect. With the increase of laser fluences, melt and evaporation behaviors can be responsible for the laser modification. By properly selecting the process parameters, well-defined grating and dot structures can been achieved. It can be demonstrated that direct laser interference lithography is a facile and efficient technology with the advantage of a single process procedure over macroscale areas for the fabrication of micro and nano structures.

  1. Nanosecond pulsed electric field ablation of hepatocellular carcinoma.

    Science.gov (United States)

    Beebe, Stephen J; Chen, Xinhua; Liu, Jie A; Schoenbach, Karl H

    2011-01-01

    Hepatocellular carcinoma often evades effective therapy and recurrences are frequent. Recently, nanosecond pulsed electric field (nsPEF) ablation using pulse power technology has emerged as a local-regional, non-thermal, and non-drug therapy for skin cancers. In the studies reported here we use nsPEFs to ablate murine, rat and human HCCs in vitro and an ectopic murine Hepa 1-6 HCC in vivo. Using pulses with 60 or 300 ns and electric fields as high as 60 kV/cm, murine Hepa 1-6, rat N1S1 and human HepG2 HCC are readily eliminated with changes in caspase-3 activity. Interestingly caspase activities increase in the mouse and human model and decrease in the rat model as electric field strengths are increased. In vivo, while sham treated control mice survived an average of 15 days after injection and before humane euthanasia, Hepa 1-6 tumors were eliminated for longer than 50 days with 3 treatments using one hundred pulses with 100 ns at 55 kV/cm. Survival was 40% in mice treated with 30 ns pulses at 55 kV/cm. This study demonstrates that nsPEF ablation is not limited to effectively treating skin cancers and provides a rationale for treating orthotopic hepatocellular carcinoma in pre-clinical applications and ultimately in clinical trials.

  2. Absorption and luminescence of crystalline quartz under electron nanosecond irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Gritsenko, B P; Lisitsyn, V M; Stepanchuk, V N [Tomskij Politekhnicheskij Inst. (USSR)

    1981-02-01

    The purpose of the study is continuation of investigations of principal regularities of production and destruction of short-lived defects in quartz and accompanying luminescence under electron pulse irradiation. For investigation purposes samples of crystalline synthetic quartz have been used. The irradiation has been performed at 80-400 K temperatures by means of an electron pulse accelerator with parameters: electron flow pulse duration 10 ns, pulse current density up to 1000 A/cm/sup 2/, electron mean energy 200 keV. Temperature-time characteristics of absorption and luminescence spectrum are studied. It has been found that quartz irradiation by electron pulses of nanosecond duration leads to appearance of short-lived bands of optical absorption at 4.1 and 5.15 eV to which by kinetic parameters correspond luminescence bands at 2.6 and 3.1 eV, respectively. The enumerated absorption bands are induced by quartz irradiation independently of the prehistory and phase state of the sample and are caused obviously by intrinsic radiation defects. Possible models of such defects are suggested.

  3. Acute Disseminated Encephalomyelitis: A Review of Eleven Cases in Childhood in North of Iran

    Directory of Open Access Journals (Sweden)

    Ali Nikkhah

    2016-01-01

    Full Text Available Background: Acute disseminated encephalomyelitis (ADEM is an inflammatory demyelinating disorder. The pathogenesis is unclear, but it is thought to be immune-mediated. The prognosis is favorable, with most children making a full recovery. Objectives: The present report analyzed different clinical presentations, response to treatment and outcome in a series of 11 patients with ADEM who referred to our tertiary center in north of Iran from 2010 to 2014. Materials and Methods: In this retrospective simple descriptive review, eleven cases with ADEM admitted in the neurology ward from 2010 to 2014 were enrolled. The clinical findings and laboratory and imaging results of patients were reviewed. All of these cases were evaluated with neurological examination, serologic tests for bacterial meningitis and viral encephalitis (especially, herpes simplex virus and brain MRI without contrast. After discharge, patients were followed for at least six months (6 to 12 months clinically and radiologically. Results: Of 11 children, 8 were male and 3 female. Their ages ranged between 4 and 10 years. The mean interval between the preceding infection and symptoms of encephalomyelitis was nine days. The most common presenting symptoms were ataxia in 45.4%, fever and headache in 36.4% and altered consciousness in 18.2% of patients. Neurological examination revealed pyramidal motor signs such as brisk deep tendon reflexes (hyperreflexia (81.8%, cranial nerve involvement (18.2%, dysarthria (9.1% and abnormal movements (9.1%. We followed up these patients in long-term for 6 to 12 months. Only in 1 child who received IVIG, mild ataxia had reminded. Conclusions: The prognosis of acute disseminated encephalomyelitis (ADEM is favorable. Early diagnosis and prompt treatment of ADEM would probably reduce morbidity.

  4. Chapter Eleven

    African Journals Online (AJOL)

    User

    not just have much in common with, but also differ from communication. Yet, there is ... Department of English, University of Lagos, Akoka, Yaba, Lagos. 126 ..... According to him, effective communication depends on the choices that we make.

  5. Blind synchronization in asynchronous UWB networks based on the transmit-reference scheme

    NARCIS (Netherlands)

    Djapic, R.; Leus, G.; Veen, A.-J. van der; Trindade, A.

    2006-01-01

    Ultra-wideband (UWB) wireless communication systems are based on the transmission of extremely narrow pulses, with a duration inferior to a nanosecond. The application of transmit reference(TR) to UWB systems allows to side-step channel estimation at the receiver, with a tradeoff of the effective

  6. Blind Synchronization in Asynchronous UWB Networks Based on the Transmit-Reference Scheme

    NARCIS (Netherlands)

    Djapic, R.; Leus, G.; Van Der Veen, A.J.; Trinda, A.

    2006-01-01

    Ultra-wideband (UWB) wireless communication systems are based on the transmission of extremely narrow pulses, with a duration inferior to a nanosecond. The application of transmit reference (TR) to UWB systems allows to side-step channel estimation at the receiver, with a tradeoff of the effective

  7. AN INDUCTION SENSOR FOR MEASURING CURRENTS OF NANOSECOND RANGE

    Directory of Open Access Journals (Sweden)

    S. P. Shalamov

    2016-11-01

    Full Text Available Purpose. A current meter based on the principle of electromagnetic induction is designed to register the current flowing in the rod lightning. The aim of the article is to describe the way of increasing the sensitivity of the converter by means of their serial communication. Methodology. The recorded current is in the nanosecond range. If compared with other methods, meters based on the principle of electromagnetic induction have several advantages, such as simplicity of construction, reliability, low cost, no need in a power source, relatively high sensitivity. Creation of such a meter is necessary, because in some cases there is no possibility to use a shunt. Transient properties of a meter are determined by the number of turns and the constant of integration. Sensitivity is determined by measuring the number of turns, the coil sectional area, the core material and the integration constant. For measuring the magnetic field pulses with a rise time of 5 ns to 50 ns a meter has turns from 5 to 15. The sensitivity of such a meter is low. When the number of turns is increased, the output signal and the front increase. Earlier described dependencies were used to select the main parameters of the converter. It was based on generally accepted and widely known equivalent circuit. The experience of created earlier pulse magnetic field meters was considered both for measuring the magnetic fields, and large pulse current. Originality. Series connection of converters has the property of a long line. The level of the transient response of the meter is calculated. The influence of parasitic parameters on the type of meter transient response is examined. The shown construction was not previously described. Practical value. The results of meter implementation are given. The design peculiarities of the given measuring instruments are shown.

  8. A distributed parameter model of transmission line transformer for high voltage nanosecond pulse generation.

    Science.gov (United States)

    Li, Jiangtao; Zhao, Zheng; Li, Longjie; He, Jiaxin; Li, Chenjie; Wang, Yifeng; Su, Can

    2017-09-01

    A transmission line transformer has potential advantages for nanosecond pulse generation including excellent frequency response and no leakage inductance. The wave propagation process in a secondary mode line is indispensable due to an obvious inside transient electromagnetic transition in this scenario. The equivalent model of the transmission line transformer is crucial for predicting the output waveform and evaluating the effects of magnetic cores on output performance. However, traditional lumped parameter models are not sufficient for nanosecond pulse generation due to the natural neglect of wave propagations in secondary mode lines based on a lumped parameter assumption. In this paper, a distributed parameter model of transmission line transformer was established to investigate wave propagation in the secondary mode line and its influential factors through theoretical analysis and experimental verification. The wave propagation discontinuity in the secondary mode line induced by magnetic cores is emphasized. Characteristics of the magnetic core under a nanosecond pulse were obtained by experiments. Distribution and formation of the secondary mode current were determined for revealing essential wave propagation processes in secondary mode lines. The output waveform and efficiency were found to be affected dramatically by wave propagation discontinuity in secondary mode lines induced by magnetic cores. The proposed distributed parameter model was proved more suitable for nanosecond pulse generation in aspects of secondary mode current, output efficiency, and output waveform. In depth, comprehension of underlying mechanisms and a broader view of the working principle of the transmission line transformer for nanosecond pulse generation can be obtained through this research.

  9. Formation of various types of nanostructures on germanium surface by nanosecond laser pulses

    Science.gov (United States)

    Mikolutskiy, S. I.; Khasaya, R. R.; Khomich, Yu V.; Yamshchikov, V. A.

    2018-03-01

    The paper describes the formation of micro- and nanostructures in different parts of irradiation zone on germanium surface by multiple action of nanosecond pulses of ArF-laser. It proposes a simple method using only one laser beam without any optional devices and masks for surface treatment. Hexa- and pentagonal cells with submicron dimensions along the surface were observed in peripheral zone of irradiation spot by atomic-force microscopy. Nanostructures in the form of bulbs with rounded peaks with lateral sizes of 40-120 nm were obtained in peripheral low-intensity region of the laser spot. Considering experimental data on material processing by nanosecond laser pulses, a classification of five main types of surface reliefs formed by nanosecond laser pulses with energy density near or slightly above ablation threshold was proposed.

  10. Growth references

    NARCIS (Netherlands)

    Buuren, S. van

    2007-01-01

    A growth reference describes the variation of an anthropometric measurement within a group of individuals. A reference is a tool for grouping and analyzing data and provides a common basis for comparing populations.1 A well known type of reference is the age-conditional growth diagram. The

  11. Transmembrane molecular transport during versus after extremely large, nanosecond electric pulses.

    Science.gov (United States)

    Smith, Kyle C; Weaver, James C

    2011-08-19

    Recently there has been intense and growing interest in the non-thermal biological effects of nanosecond electric pulses, particularly apoptosis induction. These effects have been hypothesized to result from the widespread creation of small, lipidic pores in the plasma and organelle membranes of cells (supra-electroporation) and, more specifically, ionic and molecular transport through these pores. Here we show that transport occurs overwhelmingly after pulsing. First, we show that the electrical drift distance for typical charged solutes during nanosecond pulses (up to 100 ns), even those with very large magnitudes (up to 10 MV/m), ranges from only a fraction of the membrane thickness (5 nm) to several membrane thicknesses. This is much smaller than the diameter of a typical cell (∼16 μm), which implies that molecular drift transport during nanosecond pulses is necessarily minimal. This implication is not dependent on assumptions about pore density or the molecular flux through pores. Second, we show that molecular transport resulting from post-pulse diffusion through minimum-size pores is orders of magnitude larger than electrical drift-driven transport during nanosecond pulses. While field-assisted charge entry and the magnitude of flux favor transport during nanosecond pulses, these effects are too small to overcome the orders of magnitude more time available for post-pulse transport. Therefore, the basic conclusion that essentially all transmembrane molecular transport occurs post-pulse holds across the plausible range of relevant parameters. Our analysis shows that a primary direct consequence of nanosecond electric pulses is the creation (or maintenance) of large populations of small pores in cell membranes that govern post-pulse transmembrane transport of small ions and molecules. Copyright © 2011 Elsevier Inc. All rights reserved.

  12. Logistics Management in Retail Industry : A case study of 7-Eleven in Thailand

    OpenAIRE

    Supasansanee, Latika; Kasiphongphaisan, Patthaveekarn

    2009-01-01

    Master’s thesis in International Logistics and Supply Chain Management Title:  Logistics Management in Retail Industry: a case study 7-Eleven in Thailand Author:  Latika Supasansanee and Patthaveekarn Kasiphongphaisan Tutor:     Susanne Hertz and Benedikte Borgström Date:      June 1, 2009 Keywords: 7-Eleven Thailand, Logistics, Retail     Convenience, Distribution Center and Warehouse, IT-Apply in retail store, and Competitive advantage Introduction: In today’s challenging competition ...

  13. Method of the nanosecond microstructure creation of the negative ion beam

    International Nuclear Information System (INIS)

    Novikov-Borodin, A.V.

    2001-01-01

    The method of the nanosecond microstructure creation of the negative ion beam with nanosecond edge times is presented. The method of creation does not destroy the beam compensation by the residual gas,so it available for low-energy beams. Such effects as a beam divergence and,therefore,a bad beam transport are overcome. The two plate travelling wave chopper is used.The special shape of the plate deflecting voltage is needed. The estimations and a comparison with the existing methods of a beam deflection are presented

  14. Microstructured silicon created with a nanosecond neodymium-doped yttrium aluminum garnet laser

    Energy Technology Data Exchange (ETDEWEB)

    Mandeville, W.J. [MITRE Corporation, Colorado Springs, CO (United States); Shaffer, M.K.; Lu, Yalin; O' Keefe, D.; Knize, R.J. [United States Air Force Academy, USAFA, CO (United States)

    2011-08-15

    We produce microstructured silicon using frequency doubled, nanosecond Nd:YAG pulses in SF{sub 6} gas. The micro-penitentes formed are up to 20 {mu}m tall with a sulfur concentration of 0.5% near the surface. The infrared absorption is increased to near unity and extends well below the original bandgap far into the infrared. These data are similar to results reported by others using more complicated and less economical femtosecond titanium sapphire and picosecond and nanosecond excimer lasers. (orig.)

  15. Photoemission in nanosecond and picosecond regimes obtained from macro and micro cathodes

    International Nuclear Information System (INIS)

    Boussoukaya, M.; Bergeret, H.; Chehab, R.; Leblond, B.; Franco, M.

    1987-03-01

    For Lasertron studies at LAL, results obtained from tests on different photocathodes are given below. Using respectively two Nd: YAG lasers (a nanosecond one and a picosecond one) we have determined the level and the intensity of pulsed photoemission and the photoelectric yield in UV, green and infrared lights. We obtained a total current of more than 1 A with nanosecond width from a single W needle, and photoconversion yield of more than 1 was reached in green and UV lights. In classical pulsed photoemission, obtained photoconversion yield from LaB 6 photocathode was of about 10 -3 in higher fields

  16. A Rare Case of Salmonella typhi Meningitis in an Eleven Month Old ...

    African Journals Online (AJOL)

    Non-typhoidal Salmonella are infrequent causes of childhood meningitis. Most reports of Salmonella typhi meningeal infections are confined to neonates. A rare instance of S. typhi in an otherwise healthy eleven month old infant is being reported. Keywords: Salmonella typhi, meningitis, infant.

  17. Vanishing quantum vacuum energy in eleven-dimensional supergravity on the round seven-sphere

    International Nuclear Information System (INIS)

    Inami, T.; Yamagishi, K.

    1984-01-01

    Quantum corrections to the vacuum energy are evaluated at one-loop order in eleven-dimensional supergravity on the round seven-sphere S 7 and are shown to vanish. The cancellation is also shown for all ultraviolet poles at z = 11/2, 10/2,..., corresponding to divergences of eleventh and lower powers of momentum cut-off Λ. (orig.)

  18. Hepneriana Dworakowska (Hemiptera: Cicadellidae: Typhlocybinae: Erythroneurini), first record from China, with descriptions of eleven new species.

    Science.gov (United States)

    Yang, Meixia; Cao, Yanghui; Zhang, Yalin

    2016-11-15

    A redescription of the erythroneurine leafhopper genus Hepneriana Dworakowska and a key to Chinese species of the genus are provided. Eleven new species, Hepneriana applanata, H. bicruris, H. concava, H. euryaedeaga, H. longa, H. menglunensis, H. paragamma, H. prostrata, H. robusta, H. taibaoensis and H. undulata spp. nov. are described and H. joannae (Dworakowska) is newly recorded from China.

  19. An Eleven Year Review of Failed Female Sterilisation in Ile-Ife, Nigeria

    African Journals Online (AJOL)

    An Eleven Year Review of Failed Female Sterilisation in Ile-Ife, Nigeria. ... Teaching Hospitals Complex, Ile-Ife, Nigeria from October 1 1987 to September 30 1998. ... (Tropical Journal of Obstetrics and Gynaecology, 2001, 18(1): 8-11) ...

  20. Symmetries in eleven dimensional supergravity compactified on a parallelized seven sphere

    CERN Document Server

    Englert, F; Spindel, P

    1983-01-01

    We analyse, in eleven-dimensional supergravity compactified on S7, the spontaneous symmetry breaking induced by a spontaneous parallelization of the sphere. The eight supersymmetries are broken at a common scale and the SO(8) gauge group is reduced to Spin (7). Such a large residual symmetry has a simple geometrical significance revealed through use of octonions; this is explained in elementary terms.

  1. (SLC45A2, SLC24A5, MC1R and TYRP1) among eleven

    Indian Academy of Sciences (India)

    2013-04-10

    Apr 10, 2013 ... and TYRP1) among eleven endogamous populations of India ... individuals from different populations (five caste and six tribal) of India, belonging to ... ried out on a 7500 Real-Time PCR System using the fol- lowing cycling ...

  2. On the stability of solutions, compacted to eleven dimensions, with the Euler invariants

    International Nuclear Information System (INIS)

    Fabris, J.C.

    1991-01-01

    The Supergravity Lagrangian at eleven dimensions has been modified by the inclusion of Euler invariants. Compact solutions have been obtained where the space-time is the Minkowski one, preserving, the internal space as a seven-sphere. The stability study of this configuration allows the restriction of the acceptable values for the coupling constants present in this model. (A.C.A.S.)

  3. Natural occurrence, biological activities and synthesis of eight-, nine-, and eleven-membered ring lactones

    Directory of Open Access Journals (Sweden)

    Helena M. C. Ferraz

    2008-01-01

    Full Text Available The natural occurrence, biological activities and synthetic approaches to natural eight-, nine-, and eleven-membered lactones is reviewed. These medium ring lactones are grouped according to ring size, and their syntheses are discussed. The structures of some natural products early identified as medium-ring lactones were revised after total synthesis.

  4. [Reference citation].

    Science.gov (United States)

    Brkić, Silvija

    2013-01-01

    Scientific and professional papers represent the information basis for scientific research and professional work. References important for the paper should be cited within the text, and listed at the end of the paper. This paper deals with different styles of reference citation. Special emphasis was placed on the Vancouver Style for reference citation in biomedical journals established by the International Committee of Medical Journal Editors. It includes original samples for citing various types of articles, both printed and electronic, as well as recommendations related to reference citation in accordance with the methodology and ethics of scientific research and guidelines for preparing manuscripts for publication.

  5. Sodium current inhibition by nanosecond pulsed electric field (nsPEF)--fact or artifact?

    NARCIS (Netherlands)

    Verkerk, Arie O.; van Ginneken, Antoni C. G.; Wilders, Ronald

    2013-01-01

    In two recent publications in Bioelectromagnetics it has been demonstrated that the voltage-gated sodium current (I(Na)) is inhibited in response to a nanosecond pulsed electric field (nsPEF). At the same time, there was an increase in a non-inactivating "leak" current (I(leak)), which was

  6. Low-dielectric layer increases nanosecond electric discharges in distilled water

    KAUST Repository

    Hamdan, Ahmad; Cha, Min

    2016-01-01

    decreasing of the energy consumption are the main goals of today’s research. Here we present an experimental study of nanosecond discharge in distilled water covered by a layer of dielectric material. We demonstrate through this paper that the discharge

  7. Temporal shaping of nanosecond CO2 laser pulses in multiphoton saturable absorbers

    International Nuclear Information System (INIS)

    Haglund, R.F. Jr.

    1981-01-01

    It was shown that substantial temporal distortion of nanosecond 10.6 μm laser pulses occurs in traversing multiphoton saturable absorbers. The risetime and pulse delay effects appear to depend both on fluence and wavelength, and to be qualitatively consistent with predictions of a simple two-level absorption model

  8. Efficient temporal compression of coherent nanosecond pulses in compact SBS generator-amplifier setup

    NARCIS (Netherlands)

    Schiemann, S.; Ubachs, W.M.G.; Hogervorst, W.

    1997-01-01

    A pulse compressor based on stimulated Brillouin scattering (SBS) in liquids is experimentally and theoretically investigated. It allows for the compression of Fourier-transform limited nanosecond pulses of several hundreds of millijoules of energy with both high conversion efficiency and a high

  9. Spin-on nanostructured silicon-silica film displaying room-temperature nanosecond lifetime photoluminescence

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, Y.; Hatton, B.; Miguez, H.; Coombs, N.; Fournier-Bidoz, S.; Ozin, G.A. [Materials Chemistry Research Group, Department of Chemistry, Lash Miller Chemical Laboratories, University of Toronto, 80 St. George Street, Toronto, Ontario, M5S 3H6 (Canada); Grey, J.K.; Beaulac, R.; Reber, C. [Department of Chemistry, University of Montreal, Montreal, Quebec H3C 3J7 (Canada)

    2003-04-17

    A yellow transparent mesoporous silica film has been achieved by the incorporation of silicon nanoclusters into its channels. The resulting nanocomposite - fabricated using a combination of evaporation induced self- assembly and chemical vapor deposition - emits light brightly at visible wavelengths and has nanosecond radiative lifetimes at room temperature when excited by ultraviolet light (see Figure). (Abstract Copyright [2003], Wiley Periodicals, Inc.)

  10. Nanosecond pulsed discharges in N2 and N2/H2O mixtures

    NARCIS (Netherlands)

    Joosten, R.M.; Verreycken, T.; Veldhuizen, van E.M.; Bruggeman, P.J.

    2011-01-01

    Nanosecond pulsed discharges in N2 and N2/H2O at atmospheric pressure between two pin-shaped electrodes are studied. The evolution of the discharge is investigated with time-resolved imaging and optical emission spectroscopy. The discharge consists of three phases, the ignition (mainly molecular

  11. Nano-Second Isomers in Neutron-Rich Ni Region Produced by Deep-Inelastic Collisions

    International Nuclear Information System (INIS)

    Ishii, T.; Asai, M.; Matsuda, M.; Ichikawa, S.; Makishima, A.; Hossain, I.; Kleinheinz, P.; Ogawa, M.

    2001-01-01

    Nuclear structure of the doubly magic 68 Ni and its neighbors has been studied by spectroscopic techniques. Developing a new instrument isomer-scope, we have measured γ rays from nano-second isomers produced in heavy-ion deep-inelastic collisions with great sensitivity. (author)

  12. Integrated circuits with emitter coupling and their application in nanosecond nuclear electronics

    International Nuclear Information System (INIS)

    Basiladze, S.G.

    1976-01-01

    Principal static and dynamic characteristics are considered of integrated circuits with emitter coupling, as well as problems of signal transmission. Diagrams are given of amplifiers, discriminators, time interval drivers, generators, etc. Systems and units of nanosecond electronics employing integrated circuits with emitter coupling are briefly described

  13. Generation of fast-rise time, repetitive, (sub) nanosecond, high-voltage pulses

    NARCIS (Netherlands)

    Huiskamp, T.; Pemen, A.J.M.

    2017-01-01

    In this contribution we present our fast-rise time nanosecond pulse generator, capable of generating up to 50 kV (positive and negative) rectangular pulses at a repetition rate of up to 1 kHz and with a rise time of less than 200 picoseconds. We focus on the general concepts involved in the design

  14. Sub-nanosecond time-of-flight for segmented silicon detectors

    International Nuclear Information System (INIS)

    Souza, R.T. de; Alexander, A.; Brown, K.; Floyd, B.; Gosser, Z.Q.; Hudan, S.; Poehlman, J.; Rudolph, M.J.

    2011-01-01

    Development of a multichannel time-of-flight system for readout of a segmented, ion-passivated, ion-implanted silicon detector is described. This system provides sub-nanosecond resolution (δt∼370ps) even for low energy α particles which deposit E≤7.687MeV in the detector.

  15. Plasma-Enhanced Combustion of Hydrocarbon Fuels and Fuel Blends Using Nanosecond Pulsed Discharges

    Energy Technology Data Exchange (ETDEWEB)

    Cappelli, Mark; Mungal, M Godfrey

    2014-10-28

    This project had as its goals the study of fundamental physical and chemical processes relevant to the sustained premixed and non-premixed jet ignition/combustion of low grade fuels or fuels under adverse flow conditions using non-equilibrium pulsed nanosecond discharges.

  16. A nanosecond high voltage pulse device for accelerator time analytical system

    International Nuclear Information System (INIS)

    Lou Binqiao; Ding Furong; Xue Zhihua; Wang Xuemei; Shen Dingyu

    2002-01-01

    A nanosecond high voltage pulse device has been designed. The pulse rise time is 10 ns. The pulse voltage reached 16000 V. This device has been used to accelerator time analytical system, its resolution time is less than 0.8%

  17. Towards a laser fluence dependent nanostructuring of thin Au films on Si by nanosecond laser irradiation

    International Nuclear Information System (INIS)

    Ruffino, F.; Pugliara, A.; Carria, E.; Romano, L.; Bongiorno, C.; Fisicaro, G.; La Magna, A.; Spinella, C.; Grimaldi, M.G.

    2012-01-01

    Highlights: ► Au nanoclusters are produced by nanosecond laser irradiations of thin Au film on Si. ► The shape, size, and surface density of the Au nanoclusters are tunable by laser fluence. ► The formation dynamic of the Au nanoclusters under nanosecond laser irradiation is analyzed. - Abstract: In this work, we study the nanostructuring effects of nanosecond laser irradiations on 5 nm thick Au film sputter-deposited on Si. After deposition of Au on Si substrate, nanosecond laser irradiations were performed increasing the laser fluence from 750 to 1500 mJ/cm 2 . Several analyses techniques, such as Rutherford backscattering spectrometry, scanning electron microscopy, atomic force microscopy, and transmission electron microscopy were crossed to study the morphological evolution of the Au film as a function of laser fluence. In particular, the formation of Au nanoparticles was observed. The analyses allowed a quantitative evaluation of the evolution of the nanoparticles size, surface density, and shape as a function of the laser fluence. Therefore, a control the structural properties of the Au nanoparticles is reached, for example, for applications in Si nanowires growth or plasmonics.

  18. Enhancing cell proliferation by non-contact nanosecond PEF treatment of cell culture vials

    NARCIS (Netherlands)

    Bree, van J.W.M.; Geysen, J.J.G.; Pemen, A.J.M.

    2012-01-01

    The applicability of nanosecond pulsed electric fields (nsPEF) has been focused on killing of cells by means of direct contact between the nsPEF electrodes and tissue or liquid, such as in melanoma destruction [1] and sterilization of fluids. Here we present a novel, tabletop device that induces

  19. Nanosecond optical limiting response of sandwich-type neodymium dyphthalocyanine in a co-polymer host

    NARCIS (Netherlands)

    Aneeshkumar, B.N.; Gopinath, P.; Thomas, J.; Vallabhan, C.P.G.; Nampoori, V.P.N.; Radhakrishnan, P.

    2004-01-01

    The nanosecond optical limiting characteristics of sandwich-type neodymium diphthalocyanine in a co-polymer matrix of polymethyl methacrylate (PMMA) and methyl-2-cyanoacrylate have been studied for the first time. The measurements were performed using 9 ns laser pulses generated from a

  20. Reference Assessment

    Science.gov (United States)

    Bivens-Tatum, Wayne

    2006-01-01

    This article presents interesting articles that explore several different areas of reference assessment, including practical case studies and theoretical articles that address a range of issues such as librarian behavior, patron satisfaction, virtual reference, or evaluation design. They include: (1) "Evaluating the Quality of a Chat Service"…

  1. Recent references

    International Nuclear Information System (INIS)

    Ramavataram, S.

    1991-01-01

    In support of a continuing program of systematic evaluation of nuclear structure data, the National Nuclear Data Center maintains a complete computer file of references to the nuclear physics literature. Each reference is tagged by a keyword string, which indicates the kinds of data contained in the article. This master file of Nuclear Structure References (NSR) contains complete keyword indexes to literature published since 1969, with partial indexing of older references. Any reader who finds errors in the keyword descriptions is urged to report them to the National Nuclear Data Center so that the master NSR file can be corrected. In 1966, the first collection of Recent References was published as a separate issue of Nuclear Data Sheets. Every four months since 1970, a similar indexed bibliography to new nuclear experiments has been prepared from additions to the NSR file and published. Beginning in 1978, Recent References was cumulated annually, with the third issue completely superseding the two issues previously published during a given year. Due to publication policy changes, cumulation of Recent Reference was discontinued in 1986. The volume and issue number of all the cumulative issues published to date are given. NNDC will continue to respond to individual requests for special bibliographies on nuclear physics topics, in addition to those easily obtained from Recent References. If the required information is available from the keyword string, a reference list can be prepared automatically from the computer files. This service can be provided on request, in exchange for the timely communication of new nuclear physics results (e.g., preprints). A current copy of the NSR file may also be obtained in a standard format on magnetic tape from NNDC. Requests for special searches of the NSR file may also be directed to the National Nuclear Data Center

  2. Evolution of analogical reasoning in children: follow-up from six to eleven years old

    Directory of Open Access Journals (Sweden)

    Luis Fidel Abregú Tueros

    2009-10-01

    Full Text Available The aim of this study is to establish the time and period of development of Analogical Reasoning (AR and evaluate its independence and performance with respect to the age. We performed a longitudinal cohort study of two age groups and six annual follow-up phases from each one (2000-2005, 2001-2006 in six to eleven years-old children in the city of Huanuco (Peru with a sample of 167 children (first stage, and N=121 (sixth stage. The Raven’s progressive matrices test, coloured version, was applied individually without time limits. Results indicate that AR development occurs in a constant and late way from seven to eleven years-old children, and also that there is independence between the ability of AR and the children age. We discuss the importance of knowledge in the relationships between analogies topics, adjusted to the age, as a mediating factor in the development of AR.

  3. [Eleven thesis on the archive of scientific research, for a new patrimonial and scientific policy].

    Science.gov (United States)

    Müller, Bertrand

    2015-12-01

    Abstracting the main content of a recent report on the bad state of the archives of scientific research, this paper puts forward eleven thesis likely to feed, in this time of numeric transition to a new documentary regime and to a new patrimonial policy. The recent numeric conditions impose to set new archival pratices, more proactive, anticipative and prospective. Archives of scientific research must be thought in a double memorial and scientific dimension, and not only as a patrimonial or historical one.

  4. Constitutional hepatic dysfunction (Gilbert's disease), about eleven cases studied in the Hospital Obrero de Lima

    OpenAIRE

    León Navarro, Oswaldo

    2014-01-01

    We report eleven cases of Constitutional Hepatic dysfunction (Gilbert's disease), studied at the Department of Gastroenterology of the Hospital Obrero de Lima. We place this disease in the group of non Chronicles Hemolytic jaundice due to congenital defects in bilirubin metabolism. It is noted, according to the new concepts of bilirubin metabolism, the pathogenic mechanism of this disease is related to deficient activity of glucuronyltransferase, the enzyme responsible for bilirubin conjugati...

  5. Optimizing Federal Fleet Vehicle Acquisitions: An Eleven-Agency FY 2012 Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Singer, M. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Daley, R. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-02-01

    This report focuses on the National Renewable Energy Laboratory's (NREL) fiscal year (FY) 2012 effort that used the NREL Optimal Vehicle Acquisition (NOVA) analysis to identify optimal vehicle acquisition recommendations for eleven diverse federal agencies. Results of the study show that by following a vehicle acquisition plan that maximizes the reduction in greenhouse gas (GHG) emissions, significant progress is also made toward the mandated complementary goals of acquiring alternative fuel vehicles, petroleum use reduction, and alternative fuel use increase.

  6. Pengaruh Komunikasi Pelayanan dan Kepuasan terhadap Loyalitas Pelanggan di 7-Eleven Buaran

    Directory of Open Access Journals (Sweden)

    Jerry Marcellinus Logahan

    2013-11-01

    Full Text Available This research was motivated by low communication in the business retail in terms of service from employees to customers. It influences the decline in customer satisfaction and leads to customer loyalty at a very low level. This study aims to identify and analyze the significance of the influence of customer service (X1 and customer satisfaction (X2 on customer loyalty (Y. Research was conducted in February - May 2013 held at 7-Eleven Buaran Jakarta. Research used quantitative method by using questionnaires filled directly by the visitors of 7-Eleven Buaran with a population of 19.920 people and a sample of 100 people, calculated using the Slovin formula. Validity test, reliability, normality, correlation, regression, hypothesis, and the determination carried out in this study using the data processed using SPSS (Statistical Product and Service Solutions version 16.0. Results indicated that customer service has significant influence by 14.6% on customer loyalty, customer satisfaction has a significant effect of 8.5% on customer loyalty, and customer service and customer satisfaction have significant influence amounted to 15,2%. Thus, this study showed that customer service and customer satisfaction have a significant effect on customer loyalty in 7-eleven Buaran Jakarta.

  7. Prevalence of cheese molars in eleven-year-old Dutch children.

    Science.gov (United States)

    Weerheijm, K L; Groen, H J; Beentjes, V E; Poorterman, J H

    2001-01-01

    In the Netherlands, first permanent molars with idiopathic enamel disturbances (IED) are called cheese molars. Though concern is expressed about their prevalence, adequate figures on the subject are missing. The porous enamel of cheese molars can be very sensitive to cold air and can decay rapidly. The aim of the present study was to investigate the prevalence in eleven-year-old Dutch children of cheese molars (IED). During an epidemiological study performed in four cities in the Netherlands, the first permanent molars and central incisors of eleven-year-old children were examined for hypoplasia, opacities, posteruptive enamel loss, premature extraction, and atypical restorations. The observation of a hypoplasia excluded the possibility of cheese molar. A total of 497 children were examined. Six percent (n = 128) of the molars (n = 1988) showed signs of IED (cheese molars), 10 percent of the children had cheese molars of which 8 percent two or more. Incisors (4 percent) with opacities were found in 3 percent in combination with two or more cheese molars. Among the four cities, no significant differences in occurrence were found. The results of this study showed that in 10 percent of the Dutch children eleven years of age, cheese molars (IED) were found. The cause for the phenomenon called cheese molars appears to be child centered. Further studies on prevalence, causes and prevention are mandatory.

  8. Effectiveness and harmful effects of removal sulphated black crust from granite using Nd:YAG nanosecond pulsed laser

    Energy Technology Data Exchange (ETDEWEB)

    Pozo, S. [Dpto. Ingeniería de los Recursos Naturales y Medio Ambiente, ETSI Minas, University of Vigo, 36310 (Spain); Barreiro, P. [Dpto. Física Aplicada, E.T.S.I. Industriales, University of Vigo, 36310 (Spain); Rivas, T. [Dpto. Ingeniería de los Recursos Naturales y Medio Ambiente, ETSI Minas, University of Vigo, 36310 (Spain); González, P. [Dpto. Física Aplicada, E.T.S.I. Industriales, University of Vigo, 36310 (Spain); Fiorucci, M.P. [Centro de Investigacións Tecnolóxicas (CIT), University of A Coruña, 15403, Ferrol (Spain)

    2014-05-01

    Sulphated black crust is a common form of deterioration affecting stone used in monuments, usually occurs in contaminated atmospheres or urban environments. Its origin and cleaning have been studied extensively, for decades, in the case of carbonate rocks. Recent studies show that this form of alteration also affects granites. Scientific research on laser removal effectiveness of gypsum-rich black crust on granites needs to be scientifically addressed considering the inexistent references. This paper assesses the removal by laser of sulphate-rich black crusts on granite using the different harmonics of a Nd:YAG nanosecond pulsed laser (266 nm, 355 nm, 532 nm and 1064 nm). Effectiveness was evaluated using Scanning Electron Microscopy with Energy Dispersive X-ray Spectrometry (SEM–EDS), X-Ray Diffraction (XRD) and Attenuated Total Reflection-Fourier Infrared Transform Spectroscopy (ATR-FTIR). We also evaluated the effect of the radiation on granite-forming minerals and on the colour of the stone using Scanning Electron Microscopy and spectrophotometry colour measurements respectively. SEM–EDS, XRD and ATR-FTIR analyses show that the higher the wavelength, the more efficient the cleaning, so samples cleaned using 1064 nm pulsed laser recovered its original colour. Nevertheless, the Nd:YAG laser did not completely eliminate the crust, and gypsum crystals remaining on the rock surface are observed, even at the most effective wavelength.

  9. Effectiveness and harmful effects of removal sulphated black crust from granite using Nd:YAG nanosecond pulsed laser

    International Nuclear Information System (INIS)

    Pozo, S.; Barreiro, P.; Rivas, T.; González, P.; Fiorucci, M.P.

    2014-01-01

    Sulphated black crust is a common form of deterioration affecting stone used in monuments, usually occurs in contaminated atmospheres or urban environments. Its origin and cleaning have been studied extensively, for decades, in the case of carbonate rocks. Recent studies show that this form of alteration also affects granites. Scientific research on laser removal effectiveness of gypsum-rich black crust on granites needs to be scientifically addressed considering the inexistent references. This paper assesses the removal by laser of sulphate-rich black crusts on granite using the different harmonics of a Nd:YAG nanosecond pulsed laser (266 nm, 355 nm, 532 nm and 1064 nm). Effectiveness was evaluated using Scanning Electron Microscopy with Energy Dispersive X-ray Spectrometry (SEM–EDS), X-Ray Diffraction (XRD) and Attenuated Total Reflection-Fourier Infrared Transform Spectroscopy (ATR-FTIR). We also evaluated the effect of the radiation on granite-forming minerals and on the colour of the stone using Scanning Electron Microscopy and spectrophotometry colour measurements respectively. SEM–EDS, XRD and ATR-FTIR analyses show that the higher the wavelength, the more efficient the cleaning, so samples cleaned using 1064 nm pulsed laser recovered its original colour. Nevertheless, the Nd:YAG laser did not completely eliminate the crust, and gypsum crystals remaining on the rock surface are observed, even at the most effective wavelength.

  10. Correlates of smoking, quit attempts and attitudes towards total smoking bans at university: findings from eleven faculties in Egypt.

    Science.gov (United States)

    El Ansari, Walid; Labeeb, Shokria; Kotb, Safaa; Yousafzai, Mohammad T; El-Houfey, Amira; Stock, Christiane

    2012-01-01

    Smoking among university students represents a formidable and global public health challenge. We assessed the associations between socio-demographic, health and wellbeing variables as independent variables, with daily smoking, attempts to quit smoking, and agreement with smoking ban as dependent variables. A sample of 3258 undergraduate students from eleven faculties at Assiut University, Assiut, Egypt, completed a general health questionnaire. Overall daily or occasional smoking in last three months prior to the survey was about 9% (8% occasional and 1% daily smokers), and smoking was generally more prevalent among males (male=17%, female=0.6%, P non-smoking policies on university premises, as well as regular up-to-date information on, and the periodic/yearly monitoring of tobacco use by university students employing standardised data collection instruments and reference periods. In addition, it would be valuable to develop campus-based educational/ awareness campaigns designed to counteract tobacco advertisement directed towards young people in Middle East countries. Otherwise, the danger could be that the current relatively low smoking prevalence among university students may escalate in the future.

  11. Electroporation of Mammalian Cells by Nanosecond Electric Field Oscillations and its Inhibition by the Electric Field Reversal

    Science.gov (United States)

    2015-09-08

    Report 3. DATES COVERED (From – To) March 2013 to July 2015 4. TITLE AND SUBTITLE Electroporation of mammalian cells by nanosecond electric field...Prescribed by ANSI Std. Z39.18 1Scientific RepoRts | 5:13818 | DOi: 10.1038/srep13818 www.nature.com/scientificreports Electroporation of mammalian cells...first to demonstrate that mammalian cells can be electroporated by damped sine wave electric stimuli of nanosecond duration. By comparing the

  12. A simple sub-nanosecond ultraviolet light pulse generator with high repetition rate and peak power.

    Science.gov (United States)

    Binh, P H; Trong, V D; Renucci, P; Marie, X

    2013-08-01

    We present a simple ultraviolet sub-nanosecond pulse generator using commercial ultraviolet light-emitting diodes with peak emission wavelengths of 290 nm, 318 nm, 338 nm, and 405 nm. The generator is based on step recovery diode, short-circuited transmission line, and current-shaping circuit. The narrowest pulses achieved have 630 ps full width at half maximum at repetition rate of 80 MHz. Optical pulse power in the range of several hundreds of microwatts depends on the applied bias voltage. The bias voltage dependences of the output optical pulse width and peak power are analysed and discussed. Compared to commercial UV sub-nanosecond generators, the proposed generator can produce much higher pulse repetition rate and peak power.

  13. The effect of polymer type on electric breakdown strength on a nanosecond time scale

    Institute of Scientific and Technical Information of China (English)

    Zhao Liang; Su Jian-Cang; Pan Ya-Feng; Zhang Xi-Bo

    2012-01-01

    Based on the concepts of fast polarization,effective electric field and electron impact ionization criterion,the effect of polymer type on electric breakdown strength (EBD) on a nanosecond time scale is investigated,and a formula that qualitatively characterizes the relation between the electric breakdown strength and the polymer type is derived.According to this formula,it is found that the electric breakdown strength decreases with an increase in the effective relative dielectric constants of the polymers.By calculating the effective relative dielectric constants for different types of polymers,the theoretical relation for the electric breakdown strengths of common polymers is predicted.To verify the prediction,the polymers of PE (polyethylene),PTFE (polytetrafluoroethelene),PMMA (organic glass) and Nylon are tested with a nanosecond-pulse generator.The experimental result shows EBD (PTFE) > EBD (PMMA) > EBD (Nylon) > EBD (PE).This result is consistent with the theoretical prediction.

  14. Supershort avalanche electron beams and x-ray in high-pressure nanosecond discharges

    International Nuclear Information System (INIS)

    Tarasenko, V F; Baksht, E H; Kostyrya, I D; Lomaev, M I; Rybka, D V

    2008-01-01

    The properties of a supershort avalanche electron beam (S AEB) and X-ray radiation produced using a nanosecond volume discharge are examined. An electron beam of the runaway electrons with amplitude of ∼ 50 A has been obtained in air atmospheric pressure. It is reported that S AEB is formed in the angle above 2π sr. Three groups of the runaway electrons are formed in a gas diode under atmospheric air pressure, when nanosecond voltage pulses with amplitude of hundreds of kilovolts are applied. The electron beam has been generated behind a 45 μm thick AlBe foil in SF 6 and Xe under the pressure of 2 arm, and in He under the pressure of about 12 atm. The paper gives the analysis of a generation mechanism of SAEB.

  15. Nanosecond laser pulse stimulation of spiral ganglion neurons and model cells.

    Science.gov (United States)

    Rettenmaier, Alexander; Lenarz, Thomas; Reuter, Günter

    2014-04-01

    Optical stimulation of the inner ear has recently attracted attention, suggesting a higher frequency resolution compared to electrical cochlear implants due to its high spatial stimulation selectivity. Although the feasibility of the effect is shown in multiple in vivo experiments, the stimulation mechanism remains open to discussion. Here we investigate in single-cell measurements the reaction of spiral ganglion neurons and model cells to irradiation with a nanosecond-pulsed laser beam over a broad wavelength range from 420 nm up to 1950 nm using the patch clamp technique. Cell reactions were wavelength- and pulse-energy-dependent but too small to elicit action potentials in the investigated spiral ganglion neurons. As the applied radiant exposure was much higher than the reported threshold for in vivo experiments in the same laser regime, we conclude that in a stimulation paradigm with nanosecond-pulses, direct neuronal stimulation is not the main cause of optical cochlea stimulation.

  16. Radial Distribution of the Nanosecond Dielectric Barrier Discharge Current in Atmospheric-Pressure Air

    Science.gov (United States)

    Malashin, M. V.; Moshkunov, S. I.; Khomich, V. Yu.; Shershunova, E. A.

    2018-01-01

    Experimental results on the radial distribution of the nanosecond dielectric barrier discharge (DBD) current in flat millimeter air gaps under atmospheric pressure and natural humidity of 40-60% at a voltage rise rate at the electrodes of 250 V/ns are presented. The time delay of the appearance of discharge currents was observed to increase from the center to the periphery of the air gap at discharge gap heights above 3 mm, which correlated with the appearance of constricted channels against the background of the volume DBD plasma. Based on the criterion of the avalanche-streamer transition, it is found out that the development of a nanosecond DBD in air gaps of 1-3 mm occurs by the streamer mechanism.

  17. Electrosensitization Increases Antitumor Effectiveness of Nanosecond Pulsed Electric Fields In Vivo

    OpenAIRE

    Muratori, Claudia; Pakhomov, Andrei G.; Heller, Loree; Casciola, Maura; Gianulis, Elena; Grigoryev, Sergey; Xiao, Shu; Pakhomova, O. N.

    2017-01-01

    Nanosecond pulsed electric fields are emerging as a new modality for tissue and tumor ablation. We previously reported that cells exposed to pulsed electric fields develop hypersensitivity to subsequent pulsed electric field applications. This phenomenon, named electrosensitization, is evoked by splitting the pulsed electric field treatment in fractions (split-dose treatments) and causes in vitro a 2- to 3-fold increase in cytotoxicity. The aim of this study was to show the benefit of split-d...

  18. High-voltage nanosecond Marx generator with quasi-rectangular pulses

    International Nuclear Information System (INIS)

    Bulan, V.V.; Grabovskij, E.V.; Gribov, A.N.; Luzhnov, V.G.

    1999-01-01

    The automated high-voltage nanosecond generator, forming single pulses of any polarity on the load of 17 Ohm with polarity voltage from 100 up to 300 kV at the semiheight of 80 ns and the front of 7 ns is described. The generator is assembled on the basis of low-inductive capacitors, which by discharge form the pulse, close by form to rectangular one [ru

  19. Comparative study of femtosecond and nanosecond laser-induced breakdown spectroscopy of depleted uranium

    International Nuclear Information System (INIS)

    Emmert, Luke A.; Chinni, Rosemarie C.; Cremers, David A.; Jones, C. Randy; Rudolph, Wolfgang

    2011-01-01

    We present spectra of depleted uranium metal from laser plasmas generated by nanosecond Nd:YAG (1064 nm) and femtosecond Ti:sapphire (800 nm) laser pulses. The latter pulses produce short-lived and relatively cool plasmas in comparison to the longer pulses, and the spectra of neutral uranium atoms appear immediately after excitation. Evidence for nonequilibrium excitation with femtosecond pulses is found in the dependence of spectral line intensities on the pulse chirp.

  20. Efficient temporal compression of coherent nanosecond pulses in compact SBS generator-amplifier setup

    OpenAIRE

    Schiemann, S.; Ubachs, W.M.G.; Hogervorst, W.

    1997-01-01

    A pulse compressor based on stimulated Brillouin scattering (SBS) in liquids is experimentally and theoretically investigated. It allows for the compression of Fourier-transform limited nanosecond pulses of several hundreds of millijoules of energy with both high conversion efficiency and a high temporal compression factor. The two-cell generator-amplifier arrangement is of a compact design not requiring external attenuation of the generator cell input energy. Pulses from an injection-seeded,...

  1. Low-Cost Facile Fabrication of Flexible Transparent Copper Electrodes by Nanosecond Laser Ablation

    KAUST Repository

    Paeng, Dongwoo

    2015-03-27

    © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Low-cost Cu flexible transparent conducting electrodes (FTCEs) are fabricated by facile nanosecond laser ablation. The fabricated Cu FTCEs show excellent opto-electrical properties (transmittance: 83%, sheet resistance: 17.48 Ω sq-1) with outstanding mechanical durability. Successful demonstration of a touch-screen panel confirms the potential applicability of Cu FTCEs to the flexible optoelectronic devices.

  2. Luminous phase of nanosecond discharge in deionized water: morphology, propagation velocity and optical emission.

    Czech Academy of Sciences Publication Activity Database

    Šimek, Milan; Pongrác, Branislav; Babický, Václav; Člupek, Martin; Lukeš, Petr

    2017-01-01

    Roč. 26, č. 7 (2017), č. článku 07LT01. ISSN 0963-0252 R&D Projects: GA ČR(CZ) GA15-12987S Institutional support: RVO:61389021 Keywords : water * nanosecond discharge * emission spectra * breakdown Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 3.302, year: 2016 http://iopscience.iop.org/article/10.1088/1361-6595/aa758d

  3. Activation of Anti-tumor Immune Response by Ablation of HCC with Nanosecond Pulsed Electric Field.

    Science.gov (United States)

    Xu, Xiaobo; Chen, Yiling; Zhang, Ruiqing; Miao, Xudong; Chen, Xinhua

    2018-03-28

    Locoregional therapy is playing an increasingly important role in the non-surgical management of hepatocellular carcinoma (HCC). The novel technique of non-thermal electric ablation by nanosecond pulsed electric field has been recognized as a potential locoregional methodology for indicated HCC. This manuscript explores the most recent studies to indicate its unique anti-tumor immune response. The possible immune mechanism, termed as nano-pulse stimulation, was also analyzed.

  4. Characterization of Pressure Transients Generated by Nanosecond Electrical Pulse (nsEP) Exposure

    OpenAIRE

    Caleb C. Roth; Ronald A. Barnes Jr.; Bennett L. Ibey; Hope T. Beier; L. Christopher Mimun; Saher M. Maswadi; Mehdi Shadaram; Randolph D. Glickman

    2015-01-01

    The mechanism(s) responsible for the breakdown (nanoporation) of cell plasma membranes after nanosecond pulse (nsEP) exposure remains poorly understood. Current theories focus exclusively on the electrical field, citing electrostriction, water dipole alignment and/or electrodeformation as the primary mechanisms for pore formation. However, the delivery of a high-voltage nsEP to cells by tungsten electrodes creates a multitude of biophysical phenomena, including electrohydraulic cavitation, el...

  5. Interaction Of CO2 Laser Nanosecond Pulse Train With The Metallic Targets In Optical Breakdown Regime

    Science.gov (United States)

    Apollonov, V. V.; Firsov, K. N.; Konov, V. I.; Nikitin, P. I.; Prokhorov, A. M.; Silenok, A. S.; Sorochenko, V. R.

    1986-11-01

    In the present paper the electric field and currents in the air-breakdown plasma, produced by the train of nanosecond pulses of TEA-002 - regenerative amplifier near the un-charged targets are studied. The breakdown thresholds and the efficiency of plasma-target heat transmission are also measured. The results of numerical calculations made for increasing of the pulse train contrast with respect to the background in a regenerative amplifier are advanced.

  6. Explosive Processes on Cathode while Forming Nanosecond Pulsed Discharge of High Pressure

    Directory of Open Access Journals (Sweden)

    A. M. Hashimov

    2012-01-01

    Full Text Available The paper is devoted to research of cathode surfaces with different curvature radius (r = 1–8 mm while forming nanosecond pulsed discharge in dense air. Influence of field and air pressure heterogeneity rate in gas gap on size of micro-craters being formed on working cathode surface after pulsed effect has been shown in the paper. The paper reveals a maximum expansion of separate micro-crater size on cathode surface with small curvature radius.

  7. Femtosecond versus nanosecond laser machining: comparison of induced stresses and structural changes in silicon wafers

    International Nuclear Information System (INIS)

    Amer, M.S.; El-Ashry, M.A.; Dosser, L.R.; Hix, K.E.; Maguire, J.F.; Irwin, Bryan

    2005-01-01

    Laser micromachining has proven to be a very successful tool for precision machining and microfabrication with applications in microelectronics, MEMS, medical device, aerospace, biomedical, and defense applications. Femtosecond (FS) laser micromachining is usually thought to be of minimal heat-affected zone (HAZ) local to the micromachined feature. The assumption of reduced HAZ is attributed to the absence of direct coupling of the laser energy into the thermal modes of the material during irradiation. However, a substantial HAZ is thought to exist when machining with lasers having pulse durations in the nanosecond (NS) regime. In this paper, we compare the results of micromachining a single crystal silicon wafer using a 150-femtosecond and a 30-nanosecond lasers. Induced stress and amorphization of the silicon single crystal were monitored using micro-Raman spectroscopy as a function of the fluence and pulse duration of the incident laser. The onset of average induced stress occurs at lower fluence when machining with the femtosecond pulse laser. Induced stresses were found to maximize at fluence of 44 J cm -2 and 8 J cm -2 for nanosecond and femtosecond pulsed lasers, respectively. In both laser pulse regimes, a maximum induced stress is observed at which point the induced stress begins to decrease as the fluence is increased. The maximum induced stress was comparable at 2.0 GPa and 1.5 GPa for the two lasers. For the nanosecond pulse laser, the induced amorphization reached a plateau of approximately 20% for fluence exceeding 22 J cm -2 . For the femtosecond pulse laser, however, induced amorphization was approximately 17% independent of the laser fluence within the experimental range. These two values can be considered nominally the same within experimental error. For femtosecond laser machining, some effect of the laser polarization on the amount of induced stress and amorphization was also observed

  8. Numerical Simulation of a Nanosecond-Pulse Discharge for High-Speed Flow Control

    Science.gov (United States)

    Poggie, Jonathan; Adamovich, Igor

    2012-10-01

    Numerical calculations were carried out to examine the physics of the operation of a nanosecond-pulse, single dielectric barrier discharge in a configuration with planar symmetry. This simplified configuration was chosen as a vehicle to develop a physics based nanosecond discharge model, including realistic air plasma chemistry and compressible bulk gas flow. First, a reduced plasma kinetic model was developed by carrying out a sensitivity analysis of zero-dimensional plasma computations with an extended chemical kinetic model. Transient, one- dimensional discharge computations were then carried out using the reduced kinetic model, incorporating a drift-diffusion formulation for each species, a self-consistent computation of the electric potential using the Poisson equation, and a mass-averaged gas dynamic formulation for the bulk gas motion. Discharge parameters (temperature, pressure, and input waveform) were selected to be representative of recent experiments on bow shock control with a nanosecond discharge in a Mach 5 cylinder flow. The computational results qualitatively reproduce many of the features observed in the experiments, including the rapid thermalization of the input electrical energy and the consequent formation of a weak shock wave. At breakdown, input electrical energy is rapidly transformed (over roughly 1 ns) into ionization products, dissociation products, and electronically excited particles, with subsequent thermalization over a relatively longer time-scale (roughly 10 μs).

  9. A novel method of calculating the energy deposition curve of nanosecond pulsed surface dielectric barrier discharge

    International Nuclear Information System (INIS)

    He, Kun; Wang, Xinying; Lu, Jiayu; Cui, Quansheng; Pang, Lei; Di, Dongxu; Zhang, Qiaogen

    2015-01-01

    To obtain the energy deposition curve is very important in the fields to which nanosecond pulse dielectric barrier discharges (NPDBDs) are applied. It helps the understanding of the discharge physics and fast gas heating. In this paper, an equivalent circuit model, composed of three capacitances, is introduced and a method of calculating the energy deposition curve is proposed for a nanosecond pulse surface dielectric barrier discharge (NPSDBD) plasma actuator. The capacitance C d and the energy deposition curve E R are determined by mathematically proving that the mapping from C d to E R is bijective and numerically searching one C d that satisfies the requirement for E R to be a monotonically non-decreasing function. It is found that the value of capacitance C d varies with the amplitude of applied pulse voltage due to the change of discharge area and is dependent on the polarity of applied voltage. The bijectiveness of the mapping from C d to E R in nanosecond pulse volumetric dielectric barrier discharge (NPVDBD) is demonstrated and the feasibility of the application of the new method to NPVDBD is validated. This preliminarily shows a high possibility of developing a unified approach to calculate the energy deposition curve in NPDBD. (paper)

  10. Monopole patch antenna for in vivo exposure to nanosecond pulsed electric fields.

    Science.gov (United States)

    Merla, C; Apollonio, F; Paffi, A; Marino, C; Vernier, P T; Liberti, M

    2017-07-01

    To explore the promising therapeutic applications of short nanosecond electric pulses, in vitro and in vivo experiments are highly required. In this paper, an exposure system based on monopole patch antenna is reported to perform in vivo experiments on newborn mice with both monopolar and bipolar nanosecond signals. Analytical design and numerical simulations of the antenna in air were carried out as well as experimental characterizations in term of scattering parameter (S 11 ) and spatial electric field distribution. Numerical dosimetry of the setup with four newborn mice properly placed in proximity of the antenna patch was carried out, exploiting a matching technique to decrease the reflections due to dielectric discontinuities (i.e., from air to mouse tissues). Such technique consists in the use of a matching dielectric box with dielectric permittivity similar to those of the mice. The average computed electric field inside single mice was homogeneous (better than 68 %) with an efficiency higher than 20 V m -1  V -1 for the four exposed mice. These results demonstrate the possibility of a multiple (four) exposure of small animals to short nanosecond pulses (both monopolar and bipolar) in a controlled and efficient way.

  11. Review of supershort avalanche electron beam during nanosecond-pulse discharges in some gases

    Directory of Open Access Journals (Sweden)

    Victor F. Tarasenko

    2017-05-01

    Full Text Available Supershort avalanche electron beam (SAEB plays an important role in nanosecond-pulse discharges. This paper aims at reviewing experiments results on characteritics of SAEB and its spectra in different gases in nanosecond-pulse discharges. All the joint experiments were carried in the Institute of High Current Electronics of the Russian Academy of Sciences and the Institute of Electrical Engineering of the Chinese Academy of Sciences. In these experiments, the generation of a SAEB in SF6 in an inhomogeneous electric field was studied on three generators with pulse rise times of 0.3, 0.5 and ∼2 ns. Firstly, the comparison of SAEB parameters in SF6 with those obtained in other gases (air, nitrogen, argon, and krypton is introduced. Secondly, the SAEB spectra in SF6 and air at pressures of 10 kPa (75 torr, and 0.1 MPa (750 torr are reviewed and discussed. Finally, 1.5-D theoretical simulation of the supershort pulse of the fast electron beam in a coaxial diode filled with SF6 at atmospheric pressure is described. The simulation was carried out in the framework of hybrid model for discharge and runaway electron kinetics. The above research progress can provide better understanding of the investigation into the mechanism of nanosecond-pulse discharges.

  12. The role of nanosecond electric pulse-induced mechanical stress in cellular nanoporation

    Science.gov (United States)

    Roth, Caleb C.

    Background: Exposures of cells to very short (less than 1 microsecond) electric pulses in the megavolt/meter range have been shown to cause a multitude of effects, both physical and molecular in nature. Physically, nanosecond electrical pulse exposure can disrupt the plasma membrane, leading to a phenomenon known as nanoporation. Nanoporation is the production of nanometer sized holes (less than 2 nanometers in diameter) that can persist for up to fifteen minutes, allowing the flow of ions into and out of the cell. Nanoporation can lead to secondary physical effects, such as cellular swelling, shrinking and blebbing. Molecularly, nanosecond electrical pulses have been shown to activate signaling pathways, produce oxidative stress, stimulate hormone secretion and induce both apoptotic and necrotic death. The mechanism by which nanosecond electrical pulses cause molecular changes is unknown; however, it is thought the flow of ions, such as calcium, into the cell via nanopores, could be a major cause. The ability of nanosecond electrical pulses to cause membranes to become permeable and to induce apoptosis makes the technology a desirable modality for cancer research; however, the lack of understanding regarding the mechanisms by which nanosecond electrical pulses cause nanoporation impedes further development of this technology. This dissertation documents the genomic and proteomic responses of cells exposed to nanosecond electrical pulses and describes in detail the biophysical effects of these electrical pulses, including the demonstration for the first time of the generation of acoustic pressure transients capable of disrupting plasma membranes and possibly contributing to nanoporation. Methods: Jurkat, clone E6-1 (human lymphocytic cell line), U937 (human lymphocytic cell line), Chinese hamster ovarian cells and adult primary human dermal fibroblasts exposed to nanosecond electrical pulses were subjected to a variety of molecular assays, including flow cytometry

  13. Nanosecond UV lasers stimulate transient Ca2+ elevations in human hNT astrocytes.

    Science.gov (United States)

    Raos, B J; Graham, E S; Unsworth, C P

    2017-06-01

    Astrocytes respond to various stimuli resulting in intracellular Ca 2+ signals that can propagate through organized functional networks. Recent literature calls for the development of techniques that can stimulate astrocytes in a fast and highly localized manner to emulate more closely the characteristics of astrocytic Ca 2+ signals in vivo. In this article we demonstrate, for the first time, how nanosecond UV lasers are capable of reproducibly stimulating Ca 2+ transients in human hNT astrocytes. We report that laser pulses with a beam energy of 4-29 µJ generate transient increases in cytosolic Ca 2+ . These Ca 2+ transients then propagate to adjacent astrocytes as intercellular Ca 2+ waves. We propose that nanosecond laser stimulation provides a valuable tool for enabling the study of Ca 2+ dynamics in human astrocytes at both a single cell and network level. Compared to previously developed techniques nanosecond laser stimulation has the advantage of not requiring loading of photo-caged or -sensitising agents, is non-contact, enables stimulation with a high spatiotemporal resolution and is comparatively cost effective.

  14. Performance Evaluation of Eleven-Phase Induction Machine with Different PWM Techniques

    Directory of Open Access Journals (Sweden)

    M.I. Masoud

    2015-06-01

    Full Text Available Multiphase induction machines are used extensively in low and medium voltage (MV drives. In MV drives, power switches have a limitation associated with switching frequency. This paper is a comparative study of the eleven-phase induction machine’s performance when used as a prototype and fed sinusoidal pulse-width-modulation (SPWM with a low switching frequency, selective harmonic elimination (SHE, and single pulse modulation (SPM techniques. The comparison depends on voltage/frequency controls for the same phase of voltage applied on the machine terminals for all previous techniques. The comparative study covers torque ripple, stator and harmonic currents, and motor efficiency.

  15. Renewable energy clusters recurring barriers to cluster development in eleven countries

    CERN Document Server

    Jaegersberg, Gudrun

    2017-01-01

    Taking eleven countries in Europe, Canada, South Africa, America, Latin America and Australia, this book discusses recurring barriers to cluster development in the renewable energy sector. The authors look at the real-world dynamics and tensions between stakeholders on the ground, with a particular focus on the relationships between SMEs and other actors. This trans-regional study is unique in its scale and scope, drawing on a decade of field research to show how by learning from the successes and failures of other clusters, costs and risk can be reduced. The book fills a significant gap in the literature for policymakers, managers and economic developers in a key market.

  16. Phonon populations by nanosecond-pulsed Raman scattering in Si

    International Nuclear Information System (INIS)

    Compaan, A.; Lee, M.C.; Trott, G.J.

    1985-01-01

    Since the first time-resolved Raman studies of phonon populations under pulsed-laser-annealing conditions, a number of cw Raman studies have been performed which provide a much improved basis for interpreting the pulsed Raman data. Here we present new pulsed Raman results and interpret them with reference to temperature-dependent resonance effects, high-carrier-density effects, phonon anharmonicity, and laser-induced strain effects. The pulsed Raman data: Stokes to anti-Stokes ratios, shift and shape of the first-order peak, and second-order spectra: indicate the existence of a phase in which the Raman signal disappears followed by a rapidly cooling solid which begins within 300 K of the 1685 K normal melting temperature of Si. We identify a major difficulty in pulsed Raman studies in Si to be the decrease in Raman intensity at high temperatures

  17. Guiding of Long-Distance Electric Discharges by Combined Femtosecond and Nanosecond Pulses Emitted by Hybrid KrF Laser System

    Science.gov (United States)

    2014-01-30

    laser pulse initiated HV discharge with a time delay of tens nanoseconds – evidently it is developing due to an avalanche -like growth of electron...AFRL-AFOSR-UK-TR-2014-0040 Guiding of long-distance electric discharges by combined femtosecond and nanosecond pulses emitted by...and guiding electric discharge , KrF laser, femtosecond pulse , nanosecond pulse , filamentation, plasma channel, lightning control, laser control of

  18. Spectrophotometry of peculiar B and A stars. II. Eleven mercury-manganese stars

    International Nuclear Information System (INIS)

    Adelman, S.J.; Pyper, D.M.

    1979-01-01

    Spectrophotometry of eleven HgMn stars is presented for the optical region. As found in Paper I, the HgMn stars have systematically larger Δiota* and Δa values than the normal main sequence stars due to differences with respect to the mean continuum particularly of the lambda4464 values and the lambda5200 region, respectively. The HgMn stars exhibit a continuous range in the behavior of both the lambda4200 and lambda5200 regions between those stars that have index values larger than the appropriate criterion of presence and present definite evidence for the features to those stars with only a slight possibility of such features. The strengths of the lambda4200 and lambda5200 features appear not to be correlated. In the HgMn stars, both features may be due to differential line blocking. In the energy distribution of all eleven stars, the Balmer jump regions best fit the predictions of slightly hotter solar composition, log g=4.0, fully line blanketed model atmospheres than do the corresponding Paschen continua

  19. Clonal stability of latex yield in eleven clones of Hevea brasiliensis Muell. Arg.

    Directory of Open Access Journals (Sweden)

    K.O. Omokhafe

    2003-01-01

    Full Text Available Eleven Hevea brasiliensis clones were evaluated for clonal stability of latex yield. A randomized complete block design was used with four replicates, two locations, seven years and three periods per year. Stability analysis was based on clone x year and clone x year x location interactions. Five stability parameters viz environmental variance, shukla's stability variance, regression of clonal latex yield on environmental index, variance due to regression and variance due to deviation from regression were applied. There was significant clone x environment effect at the two levels of interaction. Among the eleven clones, C 162 was outstanding for clonal stability and it can serve as donor parent for stability alleles. Three clones (C 76, C 150 and C 154 were also stable. The four stable clones (C 76, C 150, C 154 and C 162 are suitable for broad-spectrum recommendation for latex yield. Five clones (C 83, C 143, C 163, C 202 and RRIM 600 will require environment-specific recommendation because of their unstable phenotype. The stability feature of two clones (C 145 and C 159 was not clear and this will be investigated in subsequent studies.

  20. Ozone and dinitrogen monoxide production in atmospheric pressure air dielectric barrier discharge plasma effluent generated by nanosecond pulse superimposed alternating current voltage

    Science.gov (United States)

    Takashima, Keisuke; Kaneko, Toshiro

    2017-06-01

    The effects of nanosecond pulse superposition to alternating current voltage (NS + AC) on the generation of an air dielectric barrier discharge (DBD) plasma and reactive species are experimentally studied, along with measurements of ozone (O3) and dinitrogen monoxide (N2O) in the exhausted gas through the air DBD plasma (air plasma effluent). The charge-voltage cycle measurement indicates that the role of nanosecond pulse superposition is to induce electrical charge transport and excess charge accumulation on the dielectric surface following the nanosecond pulses. The densities of O3 and N2O in NS + AC DBD are found to be significantly increased in the plasma effluent, compared to the sum of those densities generated in NS DBD and AC DBD operated individually. The production of O3 and N2O is modulated significantly by the phase in which the nanosecond pulse is superimposed. The density increase and modulation effects by the nanosecond pulse are found to correspond with the electrical charge transport and the excess electrical charge accumulation induced by the nanosecond pulse. It is suggested that the electrical charge transport by the nanosecond pulse might result in the enhancement of the nanosecond pulse current, which may lead to more efficient molecular dissociation, and the excess electrical charge accumulation induced by the nanosecond pulse increases the discharge coupling power which would enhance molecular dissociation.

  1. Eleven lectures on the physics of the quark-gluon plasma

    International Nuclear Information System (INIS)

    McLerran, L.

    1984-10-01

    These lectures are intended to be an introduction to the physics of the quark-gluon plasma, and were presented at a workshop on The Physics of the Quark-Gluon Plasma held at Hua-Zhong Normal University in Wuhan, People's Republic of China in September, 1983. The lectures cover perturbation theory of the plasma at high temperature as well as the non-perturbative methods and results of lattice gauge theory computations. Physical models of the confinement-deconfinement phase transition and the modes of chiral symmetry breaking are presented. The possibility that a quark-gluon plasma might be produced in ultra-relativistic nuclear collisions is analyzed. Separate entries were prepared for the data base for the eleven lectures

  2. Comparative Study of Fatty Acids Profile in Eleven Wild Mushrooms of Boletacea and Russulaceae Families.

    Science.gov (United States)

    Dimitrijevic, Marija V; Mitic, Violeta D; Jovanovic, Olga P; Stankov Jovanovic, Vesna P; Nikolic, Jelena S; Petrovic, Goran M; Stojanovic, Gordana S

    2018-01-01

    Eleven species of wild mushrooms which belong to Boletaceae and Russulaceae families were examined by gas chromatography (GC) and gas chromatography-mass spectrometry (GC/MS) analysis for the presence of fatty acids. As far as we know, the fatty acid profiles of B. purpureus and B. rhodoxanthus were described for the first time. Twenty-six fatty acids were determined. Linoleic (19.5 - 72%), oleic (0.11 - 64%), palmitic (5.9 - 22%) and stearic acids (0.81 - 57%) were present in the highest contents. In all samples, unsaturated fatty acids dominate. Agglomerative hierarchical clustering was used to display the correlation between the fatty acids and their relationships with the mushroom species. Based on the fatty acids profile in the samples, the mushrooms can be divided into two families: Boletaceae and Russulaceae families, using cluster analysis. © 2018 Wiley-VHCA AG, Zurich, Switzerland.

  3. Pay For Success And Population Health: Early Results From Eleven Projects Reveal Challenges And Promise.

    Science.gov (United States)

    Lantz, Paula M; Rosenbaum, Sara; Ku, Leighton; Iovan, Samantha

    2016-11-01

    Pay for success (PFS) is a type of social impact investing that uses private capital to finance proven prevention programs that help a government reduce public expenditures or achieve greater value. We conducted an analysis of the first eleven PFS projects in the United States to investigate the potential of PFS as a strategy for financing and disseminating interventions aimed at improving population health and health equity. The PFS approach has significant potential for bringing private-sector resources to interventions regarding social determinants of health. Nonetheless, a number of challenges remain, including structuring PFS initiatives so that optimal prevention benefits can be achieved and ensuring that PFS interventions and evaluation designs are based on rigorous research principles. In addition, increased policy attention regarding key PFS payout issues is needed, including the "wrong pockets" problem and legal barriers to using federal Medicaid funds as an investor payout source. Project HOPE—The People-to-People Health Foundation, Inc.

  4. Teaching Process Simulation in Eleven Easy Lessons Using Excel and Its Tools

    Science.gov (United States)

    Morris, Arthur E.

    The primary market driver for improving process technology is innovation, which requires a skilled and educated workforce. However, many Materials Science and Engineering departments have eliminated extractive metallurgy and chemical thermodynamics from their curricula, yet these topics contain the necessary fundamentals for process innovation. As a result, most MS&E students are ill-prepared for careers in processing. The dearth of process-oriented MS&E curricula has prompted some Universities to develop a "shared" effort to offer distance education between multiple institutions [1]. A target audience for a shared process simulation course would not only benefit students, but also be a basis for an on-line course for practicing engineers faced with new or changing career choices. To fill the gap, the basics of a process simulation course was developed in an abbreviated form as series of eleven articles and Excel workbooks published in Industrial Heating magazine between July 2012 and July 2013.

  5. Possible variations in atmospheric ozone related to the eleven year solar cycle

    International Nuclear Information System (INIS)

    Penner, J.E.; Chang, J.S.

    1978-07-01

    Changes in ozone, temperature, and other minor constituents resulting from eleven year variations in the solar flux between 180 and 340 nm are presented. Results were computed using a one-dimensional time dependent model that allows for all major feedbacks and time delays which may result from changing photolysis rates in the O/sub x/--NO/sub x/--HO/sub x/--ClO/sub x/ system. Since the 1950's the chlorine content of the stratosphere has been increasing. The effect of this increase on ozone variability during the last two solar cycles is analyzed. Expected variations in O 3 and temperature resulting from changes in the uv flux are compared to available measurements

  6. Characterization of potential zones of dust generation at eleven stations in the southern Sahara

    Science.gov (United States)

    Clark, I.; Assamoi, P.; Bertrand, J.; Giorgi, F.

    Synoptic wind data for multi-decadal periods at eleven stations located in the southern Sahara region (Agadez, Atar, Bilma, Dori, Gao, Kayes, Nema, Niamey, Nouadhibou, Ouagadougou and Tessalit) are used to study the monthly dust deflation power over the region. We found that, regardless of the conditions of the soil, the deflation power (or wind efficiency) is not sufficient to generate significant amounts of aerosols south of 15°N. North of this latitude, the deflation power is much larger, with potential zones of either very strong deflation (Nouadhibou and Bilma) or severe deflation (Gao, Tessalit, Nema, Atar, Agadez). Stations in the Sahel region such as Gao, Agadez and Tessalit are characterized by a gradual reinforcement of the deflation power between 1970 and 1984 in correspondence of increasing desertification over the region. During this same period, Bilma, a well know region of dust source, experienced a major reduction in deflation power due to shifts in large scale wind patterns.

  7. Ectodermal Dysplasia: Report and Analysis of Eleven South Indian Patients with Review of Literature

    Directory of Open Access Journals (Sweden)

    Renuka Ammanagi

    2010-01-01

    Full Text Available Ectodermal dysplasia represents a rare syndrome affecting two or more ectodermally derived structures. The condition is thought to occur in approximately 1 in every 100,000 live births. It affects men more frequently and severely, while women being the carriers and heterozygote usually show minor defects. There are more than 150 different variants of ectodermal dysplasia (ED reported in the literature. Most commonly encountered among them is hypohidrotic ED which frequently exhibits the most severe dental anomalies like hypodontia or anodontia along with hypohidrosis and hypotrichosis. Here we make an attempt to collectively report and discuss eleven South Indian patients who reported to our department during the year 1998 to 2004. An added emphasis is laid on family history of consanguineous marriage among the parents of these patients.

  8. Foliar injury responses of eleven plant species to ozone/sulfur dioxide mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Tingey, D T; Reinert, R A; Dunning, J A; Heck, W W

    1973-01-01

    Eleven plant species were exposed to ozone and/or sulfur dioxide to determine if a mixture of the two gases enhanced foliar injury. Tobacco, radish, and alfalfa developed more injury that the additive injury of the single gases. In other species, such as cabbage, broccoli, and tomato, the foliar injury from mixed-gas exposures was additive or less than additive. Leaf injury from the ozone/sulfur dioxide mixture appeared as upper surface flecking, stipple, bifacial necrosis, and lower surface glazing and, in general, appeared similar to injury from oxidant or ozone. The concentrations of ozone and sulfur dioxide that caused plant injury were similar to those found in urban areas. These concentrations may result in yield losses to plants grown under field conditions.

  9. Electrosensitization Increases Antitumor Effectiveness of Nanosecond Pulsed Electric Fields In Vivo.

    Science.gov (United States)

    Muratori, Claudia; Pakhomov, Andrei G; Heller, Loree; Casciola, Maura; Gianulis, Elena; Grigoryev, Sergey; Xiao, Shu; Pakhomova, O N

    2017-01-01

    Nanosecond pulsed electric fields are emerging as a new modality for tissue and tumor ablation. We previously reported that cells exposed to pulsed electric fields develop hypersensitivity to subsequent pulsed electric field applications. This phenomenon, named electrosensitization, is evoked by splitting the pulsed electric field treatment in fractions (split-dose treatments) and causes in vitro a 2- to 3-fold increase in cytotoxicity. The aim of this study was to show the benefit of split-dose treatments for in vivo tumor ablation by nanosecond pulsed electric field. KLN 205 squamous carcinoma cells were embedded in an agarose gel or grown subcutaneously as tumors in mice. Nanosecond pulsed electric field ablations were produced using a 2-needle probe with a 6.5-mm interelectrode distance. In agarose gel, splitting a pulsed electric field dose of 300, 300-ns pulses (20 Hz, 4.4-6.4 kV) in 2 equal fractions increased cell death up to 3-fold compared to single-train treatments. We then compared the antitumor effectiveness of these treatments in vivo. At 24 hours after treatment, sensitizing tumors by a split-dose pulsed electric field exposure (150 + 150, 300-ns pulses, 20 Hz, 6.4 kV) caused a 4- and 2-fold tumor volume reduction as compared to sham and single-train treatments, respectively. Tumor volume reduction that exceeds 75% was 43% for split-dose-treated animals compared to only 12% for single-dose treatments. The difference between the 2 experimental groups remained statistically significant for at least 1 week after the treatment. The results show that electrosensitization occurs in vivo and can be exploited to assist in vivo cancer ablation.

  10. Electrical and optical characteristics of dielectric-barrier discharge driven by high voltage nanosecond generator

    International Nuclear Information System (INIS)

    Ahmadeev, V.V.; Kost'yuchenko, S.V.; Kudryavtsev, N.N.; Kurkin, G.A.; Vasilyak, L.M.

    1998-01-01

    Electrical and optical characteristics of the dielectric-barrier discharge in the pressure range of 10-400 Torr were investigated experimentally, particular attention being paid to the discharge homogeneity and to the energy dissipation in the discharge volume. The discharge was driven by a high-voltage pulse generator producing nanosecond high-voltage pulses with an amplitude of 20-30 kV. Air, nitrogen, and helium were used as working gases. The discharge was found to be homogeneous within a wide range of gas pressure. A power density of up to 250 mW/cm 3 has been achieved. (J.U.)

  11. A 350 KV nanosecond pulse voltage generator with adjustable pulsed-width

    International Nuclear Information System (INIS)

    Wang, X.; Wang, M.; Chen, Y.Q.; Zeng, L.G.; Han, M.

    2002-01-01

    This paper presents a 350 kV nanosecond pulse voltage generator (NPVG). The voltage pulsed-width can be adjusted from 30 to 160 ns. The generator consists of: Marx generator, pulsed forming line (PFL), main switch and matched impedance. The output voltage of Marx generator is over than nU c (n- the stage number of Marx generator, U c -the charging voltage of capacitor). When the pulse forming line is terminated with an impedance that is over than the characteristic impedance of PFL, the higher voltage pulse was provided for the load

  12. Shield gas induced cracks during nanosecond-pulsed laser irradiation of Zr-based metallic glass

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Hu; Noguchi, Jun; Yan, Jiwang [Keio University, Department of Mechanical Engineering, Faculty of Science and Technology, Yokohama (Japan)

    2016-10-15

    Laser processing techniques have been given increasing attentions in the field of metallic glasses (MGs). In this work, effects of two kinds of shield gases, nitrogen and argon, on nanosecond-pulsed laser irradiation of Zr-based MG were comparatively investigated. Results showed that compared to argon gas, nitrogen gas remarkably promoted the formation of cracks during laser irradiation. Furthermore, crack formation in nitrogen gas was enhanced by increasing the peak laser power intensity or decreasing the laser scanning speed. X-ray diffraction and micro-Raman spectroscopy indicated that the reason for enhanced cracks in nitrogen gas was the formation of ZrN. (orig.)

  13. Investigation of the fundamentals of low-energy nanosecond pulse ignition: Final CRADA Report

    Energy Technology Data Exchange (ETDEWEB)

    Wallner, Thomas [Argonne National Lab. (ANL), Argonne, IL (United States); Scarcelli, Riccardo [Argonne National Lab. (ANL), Argonne, IL (United States); Zhang, Anqi [Argonne National Lab. (ANL), Argonne, IL (United States); Sevik, James [Argonne National Lab. (ANL), Argonne, IL (United States); Biruduganti, Munidhar [Argonne National Lab. (ANL), Argonne, IL (United States); Bihari, Bipin [Argonne National Lab. (ANL), Argonne, IL (United States); Matusik, Katarzyna E. [Argonne National Lab. (ANL), Argonne, IL (United States); Duke, Daniel J. [Argonne National Lab. (ANL), Argonne, IL (United States); Powell, Christopher F. [Argonne National Lab. (ANL), Argonne, IL (United States); Kastengren, Alan L. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2017-01-01

    A detailed investigation of the fundamentals of low-energy nanosecond pulse ignition was performed with the objective to overcome the barrier presented by limited knowledge and characterization of nonequilibrium plasma ignition for realistic internal combustion engine applications (be it in the automotive or power generation field) and shed light on the mechanisms which improve the performance of the advanced TPS ignition system compared to conventional state-of-the-art hardware. Three main tasks of the research included experimental evaluation on a single-cylinder automotive gasoline engine, experimental evaluation on a single-cylinder stationary natural gas engine and energy quantification using x-ray diagnostics.

  14. Spatial and temporal evolutions of ozone in a nanosecond pulse corona discharge at atmospheric pressure

    Energy Technology Data Exchange (ETDEWEB)

    Duten, X; Redolfi, M; Aggadi, N; Vega, A; Hassouni, K, E-mail: duten@lspm.cnrs.fr [LSPM-CNRS UPR 3407, Universite Paris Nord, 90 Avenue J.B. Clement, 93430 Villetaneuse (France)

    2011-10-19

    This paper deals with the experimental determination of the spatial and temporal evolutions of the ozone concentration in an atmospheric pressure pulsed plasma, working in the nanosecond regime. We observed that ozone was produced in the localized region of the streamer. The ozone transport requires a characteristic time well above the millisecond. The numerical modelling of the streamer expansion confirms that the hydrodynamic expansion of the filamentary discharge region during the streamer propagation does not lead to a significant transport of atomic oxygen and ozone. It appears therefore that only diffusional transport can take place, which requires a characteristic time of the order of 50 ms.

  15. High voltage nanosecond generator with pulse repetition rate of 1,000 p.p.s.

    Energy Technology Data Exchange (ETDEWEB)

    Gubanov, V P; Korovin, S D; Stepchenko, A S [High Current Electronics Institute, Tomsk (Russian Federation)

    1997-12-31

    A compact high voltage nanosecond generator is described with a pulse repetition rate up to 1000 p.p.s. The generator includes a 30-Ohm coaxial forming line charged by a built-in Tesla transformer with a high coupling coefficient, and a high voltage (N{sub 2}) gas gap switch with gas blowing between the electrodes. The maximum forming line charge voltage is 450 kV, the pulse duration is about 4 ns, and its amplitude for a matched load is up to 200 kV. (author). 3 figs., 9 refs.

  16. Time-domain calculation of sub-nanosecond pulse launched by a proton beam

    International Nuclear Information System (INIS)

    Chan, Kwok-Chi Dominic; Cooper, R.K.

    1990-01-01

    Using the finite-difference time-domain code TBCI, we have numerically calculated the radiation from a sub-nanosecond 800-MeV proton bunch as it is launched into space. The calculation is compared to measurements of the time history of the radiated fields and good agreement is found. A movie showing the development of the radiation pattern will be shown during the presentation at this conference, namely, the First Los Alamos Symposium on Ultra-Wideband Radar. 6 refs., 7 figs

  17. Spatial and temporal evolutions of ozone in a nanosecond pulse corona discharge at atmospheric pressure

    Science.gov (United States)

    Duten, X.; Redolfi, M.; Aggadi, N.; Vega, A.; Hassouni, K.

    2011-10-01

    This paper deals with the experimental determination of the spatial and temporal evolutions of the ozone concentration in an atmospheric pressure pulsed plasma, working in the nanosecond regime. We observed that ozone was produced in the localized region of the streamer. The ozone transport requires a characteristic time well above the millisecond. The numerical modelling of the streamer expansion confirms that the hydrodynamic expansion of the filamentary discharge region during the streamer propagation does not lead to a significant transport of atomic oxygen and ozone. It appears therefore that only diffusional transport can take place, which requires a characteristic time of the order of 50 ms.

  18. Spatial and temporal evolutions of ozone in a nanosecond pulse corona discharge at atmospheric pressure

    International Nuclear Information System (INIS)

    Duten, X; Redolfi, M; Aggadi, N; Vega, A; Hassouni, K

    2011-01-01

    This paper deals with the experimental determination of the spatial and temporal evolutions of the ozone concentration in an atmospheric pressure pulsed plasma, working in the nanosecond regime. We observed that ozone was produced in the localized region of the streamer. The ozone transport requires a characteristic time well above the millisecond. The numerical modelling of the streamer expansion confirms that the hydrodynamic expansion of the filamentary discharge region during the streamer propagation does not lead to a significant transport of atomic oxygen and ozone. It appears therefore that only diffusional transport can take place, which requires a characteristic time of the order of 50 ms.

  19. Fundamental Physics and Engineering of Nanosecond-Pulsed Nonequilibrium Microplasma in Liquid Phase without Bubbles

    Science.gov (United States)

    2013-01-04

    the electrode, the value   coth0  a corresponds to an equipotential surface which coincides with the electrode;  is the ratio of the semiaxes...liquid when filled – see Figure 1. The liquid surface was left open to the air, subject to atmospheric pressure. Nanosecond pulse generators from...temperature T , k is the Boltzmann constant,  is the surface tension coefficient, J is the nucleation rate equal to the density of vapor bubbles of a

  20. Mono-energetic ions emission by nanosecond laser solid target irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Muoio, A., E-mail: Annamaria.Muoio@lns.infn.it [Istituto Nazionale di Fisica Nucleare – Laboratori Nazionali del Sud, Via S. Sofia 62, 95123 Catania (Italy); Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Messina, Viale F.S. D’Alcontres 31, 98166 Messina (Italy); Tudisco, S. [Istituto Nazionale di Fisica Nucleare – Laboratori Nazionali del Sud, Via S. Sofia 62, 95123 Catania (Italy); Altana, C. [Istituto Nazionale di Fisica Nucleare – Laboratori Nazionali del Sud, Via S. Sofia 62, 95123 Catania (Italy); Dipartimento di Fisica e Astronomia, Università degli Studi di Catania, Via S. Sofia 64, 95123 Catania (Italy); Lanzalone, G. [Istituto Nazionale di Fisica Nucleare – Laboratori Nazionali del Sud, Via S. Sofia 62, 95123 Catania (Italy); Università degli Studi di Enna “Kore”, Via delle Olimpiadi, 94100 Enna (Italy); Mascali, D.; Cirrone, G.A.P.; Schillaci, F. [Istituto Nazionale di Fisica Nucleare – Laboratori Nazionali del Sud, Via S. Sofia 62, 95123 Catania (Italy); Trifirò, A. [Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Messina, Viale F.S. D’Alcontres 31, 98166 Messina (Italy); Sezione INFN, Catania (Italy)

    2016-09-01

    An experimental campaign aiming to investigate the acceleration mechanisms through laser–matter interaction in nanosecond domain has been carried out at the LENS (Laser Energy for Nuclear Science) laboratory of INFN-LNS, Catania. Pure Al targets were irradiated by 6 ns laser pulses at different pumping energies, up to 2 J. Advanced diagnostics tools were used to characterize the plasma plume and ion production. We show the preliminary results of this experimental campaign, and especially the ones showing the production of multicharged ions having very narrow energy spreads.

  1. Nanosecond high-voltage generators for supplying the kickers of charged particle accelerators

    International Nuclear Information System (INIS)

    Korchuganov, V.N.; Matveev, Yu.G.; Shvedov, D.A.

    2000-01-01

    The high-voltage nanosecond generators (VNG) of rectangular pulses, developed for supplying the injection and extraction kickers of the accelerator-storage complexes are considered in this work. The pulse hydrogen thyratrons and gas-filled discharges are used as commutators in those generators. If necessary, the VNG pulses fronts may be shortened up to 2-3 ns in the coaxial lines, filled with ferrite rings. The mechanism of the pulse fronts shortening was considered earlier. The basis parameters of the VNG various types are presented [ru

  2. Shield gas induced cracks during nanosecond-pulsed laser irradiation of Zr-based metallic glass

    Science.gov (United States)

    Huang, Hu; Noguchi, Jun; Yan, Jiwang

    2016-10-01

    Laser processing techniques have been given increasing attentions in the field of metallic glasses (MGs). In this work, effects of two kinds of shield gases, nitrogen and argon, on nanosecond-pulsed laser irradiation of Zr-based MG were comparatively investigated. Results showed that compared to argon gas, nitrogen gas remarkably promoted the formation of cracks during laser irradiation. Furthermore, crack formation in nitrogen gas was enhanced by increasing the peak laser power intensity or decreasing the laser scanning speed. X-ray diffraction and micro-Raman spectroscopy indicated that the reason for enhanced cracks in nitrogen gas was the formation of ZrN.

  3. Modeling of plasma chemical processes in the artificial ionized layer in the upper atmosphere by the nanosecond corona discharge

    Science.gov (United States)

    Vikharev, A. L.; Gorbachev, A. M.; Ivanov, O. A.; Kolisko, A. L.; Litvak, A. G.

    1993-08-01

    The plasma chemical processes in the corona discharge formed in air by a series of high voltage pulses of nanosecond duration are investigated experimentally. The experimental conditions (reduced electric field, duration and repetition frequency of the pulses, gas pressure in the chamber) modeled the regime of creation of the artificial ionized layer (AIL) in the upper atmosphere by a nanosecond microwave discharge. It was found that in a nanosecond microwave discharge predominantly generation of ozone occurs, and that the production of nitrogen dioxide is not large. The energy expenditures for the generation of one O 3 molecule were about 15 eV. On the basis of the experimental results the prognosis of the efficiency of ozone generation in AIL was made.

  4. Nanosecond-Timescale Intra-Bunch-Train Feedback for the Linear Collider: Results of the FONT2 Run

    International Nuclear Information System (INIS)

    Barlow, R.; Dufau, M.; Kalinin, A.; Daresbury; Myatt, G.; Perry, C.; Oxford U.; Burrows, P.N.; Hartin, T.; Hussain, S.M.; Molloy, S.; White, G.R.; Queen Mary, U. of London; Adolphsen, C.; Frisch, J.C.; Hendrickson, L.; Jobe, R.K.; Markiewicz, T.; McCormick, D.J.; Nelson, J.; Ross, M.C.; Smith, S.; Smith, T.J.; SLAC

    2005-01-01

    We report on experimental results from the December 2003/January 2004 data run of the Feedback On Nanosecond Timescales (FONT) experiment at the Next Linear Collider Test Accelerator at SLAC. We built a second-generation prototype intra-train beam-based feedback system incorporating beam position monitors, fast analogue signal processors, a feedback circuit, fast-risetime amplifiers and stripline kickers. We applied a novel real-time charge-normalization scheme to account for beam current variations along the train. We used the system to correct the position of the 170-nanosecond-long bunchtrain at NLCTA. We achieved a latency of 53 nanoseconds, representing a significant improvement on FONT1 (2002), and providing a demonstration of intra-train feedback for the Linear Collider

  5. A scheme for recording a fast process at nanosecond scale by using digital holographic interferometry with continuous wave laser

    Science.gov (United States)

    Wang, Jun; Zhao, Jianlin; Di, Jianglei; Jiang, Biqiang

    2015-04-01

    A scheme for recording fast process at nanosecond scale by using digital holographic interferometry with continuous wave (CW) laser is described and demonstrated experimentally, which employs delayed-time fibers and angular multiplexing technique and can realize the variable temporal resolution at nanosecond scale and different measured depths of object field at certain temporal resolution. The actual delay-time is controlled by two delayed-time fibers with different lengths. The object field information in two different states can be simultaneously recorded in a composite hologram. This scheme is also suitable for recording fast process at picosecond scale, by using an electro-optic modulator.

  6. A Novel Nanosecond Pulsed Power Unit for the Formation of ·OH in Water

    Science.gov (United States)

    Li, Shengli; Hu, Sheng; Zhang, Han

    2012-04-01

    A novel nanosecond pulsed power unit was developed for plasma treatment of wastewater, based on the theory of magnetic pulse compression and semiconductor opening switch (SOS). The peak value, rise time and pulse duration of the output voltage were observed to be -51 kV, 60 ns and 120 ns, respectively. The concentrations of ·OH generated by the novel nanosecond pulsed plasma power were determined using the method of high-performance liquid chromatography (HPLC). The results showed that the concentrations of ·OH increased with the increase in peak voltage, and the generation rates of ·OH were 4.1 × 10-10 mol/s, 5.7 × 10-10 mol/s, and 7.7 × 10-10 mol/s at 30 kV, 35 kV, and 40 kV, respectively. The efficiency of OH generation was found to be independent of the input parameters for applied power, with an average value of 3.23×10-12 mol/J obtained.

  7. Development of an electron momentum spectrometer for time-resolved experiments employing nanosecond pulsed electron beam

    Science.gov (United States)

    Tang, Yaguo; Shan, Xu; Liu, Zhaohui; Niu, Shanshan; Wang, Enliang; Chen, Xiangjun

    2018-03-01

    The low count rate of (e, 2e) electron momentum spectroscopy (EMS) has long been a major limitation of its application to the investigation of molecular dynamics. Here we report a new EMS apparatus developed for time-resolved experiments in the nanosecond time scale, in which a double toroidal energy analyzer is utilized to improve the sensitivity of the spectrometer and a nanosecond pulsed electron gun with a repetition rate of 10 kHz is used to obtain an average beam current up to nA. Meanwhile, a picosecond ultraviolet laser with a repetition rate of 5 kHz is introduced to pump the sample target. The time zero is determined by photoionizing the target using a pump laser and monitoring the change of the electron beam current with time delay between the laser pulse and electron pulse, which is influenced by the plasma induced by the photoionization. The performance of the spectrometer is demonstrated by the EMS measurement on argon using a pulsed electron beam, illustrating the potential abilities of the apparatus for investigating the molecular dynamics in excited states when employing the pump-probe scheme.

  8. Nanosecond laser ablation processes in aluminum-doped zinc-oxide for photovoltaic devices

    International Nuclear Information System (INIS)

    Canteli, D.; Fernandez, S.; Molpeceres, C.; Torres, I.; Gandía, J.J.

    2012-01-01

    Highlights: ► A study of the ablation of AZO thin films deposited at different temperature conditions with nanosecond UV laser light for photovoltaic devices has been performed. ► The ablation threshold of AZO thin films was measured and related with the absorption coefficient of the films at the laser wavelength, showing a direct correspondence. ► A change in the material structure in the areas closest to the edges of laser grooves made in samples deposited at temperatures below 100 °C was observed and studied. - Abstract: Aiming to a future use in thin film solar modules, the processing of aluminum doped zinc oxide thin films with good optoelectronic properties with a nanosecond-pulsed ultraviolet laser has been studied. The ablation threshold fluence of the films has been determined and associated with the material properties. The ablation process has been optimized and grooves with good properties for photovoltaic devices have been obtained. The morphology of the ablated surfaces has been observed by confocal microscopy and its structure has been characterized by Raman spectroscopy. The influence of ablation parameters like focus distance, pulse energy and repetition frequency in the groove morphology has been studied with special attention to the thermal effects on the material structure.

  9. Nanosecond laser textured superhydrophobic metallic surfaces and their chemical sensing applications

    Science.gov (United States)

    Ta, Duong V.; Dunn, Andrew; Wasley, Thomas J.; Kay, Robert W.; Stringer, Jonathan; Smith, Patrick J.; Connaughton, Colm; Shephard, Jonathan D.

    2015-12-01

    This work demonstrates superhydrophobic behavior on nanosecond laser patterned copper and brass surfaces. Compared with ultrafast laser systems previously used for such texturing, infrared nanosecond fiber lasers offer a lower cost and more robust system combined with potentially much higher processing rates. The wettability of the textured surfaces develops from hydrophilicity to superhydrophobicity over time when exposed to ambient conditions. The change in the wetting property is attributed to the partial deoxidation of oxides on the surface induced during laser texturing. Textures exhibiting steady state contact angles of up to ∼152° with contact angle hysteresis of around 3-4° have been achieved. Interestingly, the superhydrobobic surfaces have the self-cleaning ability and have potential for chemical sensing applications. The principle of these novel chemical sensors is based on the change in contact angle with the concentration of methanol in a solution. To demonstrate the principle of operation of such a sensor, it is found that the contact angle of methanol solution on the superhydrophobic surfaces exponentially decays with increasing concentration. A significant reduction, of 128°, in contact angle on superhydrophobic brass is observed, which is one order of magnitude greater than that for the untreated surface (12°), when percent composition of methanol reaches to 28%.

  10. Mechanical response of agar gel irradiated with Nd:YAG nanosecond laser pulses

    Science.gov (United States)

    Pérez-Gutiérrez, Francisco G.; Evans, Rodger; Camacho-López, Santiago; Aguilar, Guillermo

    2010-02-01

    Nanosecond long laser pulses are used in medical applications where precise tissue ablation with minimal thermal and mechanical collateral damage is required. When a laser pulse is incident on a material, optical energy will be absorbed by a combination of linear and nonlinear absorption according to both: laser light intensity and material properties. In the case of water or gels, the first results in heat generation and thermoelastic expansion; while the second results in an expanding plasma formation that launches a shock wave and a cavitation/boiling bubble. Plasma formation due to nonlinear absorption of nanosecond laser pulses is originated by a combination of multiphoton ionization and thermionic emission of free electrons, which is enhanced when the material has high linear absorption coefficient. In this work, we present measurements of pressure transients originated when 6 ns laser pulses are incident on agar gels with varying linear absorption coefficient, mechanical properties and irradiation geometry using laser radiant exposures above threshold for bubble formation. The underlying hypothesis is that pressure transients are composed of the superposition of both: shock wave originated by hot expanding plasma resulting from nonlinear absorption of optical energy and, thermoelastic expansion originated by heat generation due to linear absorption of optical energy. The objective of this work is to evaluate the relative contribution of each absorption mechanism to mechanical effects in agar gel. Real time pressure transients are recorded with PVDF piezoelectric sensors and time-resilved imaging from 50 μm to 10 mm away from focal point.

  11. Sub-nanosecond clock synchronization and trigger management in the nuclear physics experiment AGATA

    International Nuclear Information System (INIS)

    Bellato, M; Isocrate, R; Rampazzo, G; Bazzacco, D; Bortolato, D; Triossi, A; Chavas, J; Mengoni, D; Recchia, F

    2013-01-01

    The new-generation spectrometer AGATA, the Advanced GAmma Tracking Array, requires sub-nanosecond clock synchronization among readout and front-end electronics modules that may lie hundred meters apart. We call GTS (Global Trigger and Synchronization System) the infrastructure responsible for precise clock synchronization and for the trigger management of AGATA. It is made of a central trigger processor and nodes, connected in a tree structure by means of optical fibers operated at 2Gb/s. The GTS tree handles the synchronization and the trigger data flow, whereas the trigger processor analyses and eventually validates the trigger primitives centrally. Sub-nanosecond synchronization is achieved by measuring two different types of round-trip times and by automatically correcting for phase-shift differences. For a tree of depth two, the peak-to-peak clock jitter at each leaf is 70 ps; the mean phase difference is 180 ps, while the standard deviation over such phase difference, namely the phase equalization repeatability, is 20 ps. The GTS system has run flawlessly for the two-year long AGATA campaign, held at the INFN Legnaro National Laboratories, Italy, where five triple clusters of the AGATA sub-array were coupled with a variety of ancillary detectors

  12. Sub-nanosecond clock synchronization and trigger management in the nuclear physics experiment AGATA

    Science.gov (United States)

    Bellato, M.; Bortolato, D.; Chavas, J.; Isocrate, R.; Rampazzo, G.; Triossi, A.; Bazzacco, D.; Mengoni, D.; Recchia, F.

    2013-07-01

    The new-generation spectrometer AGATA, the Advanced GAmma Tracking Array, requires sub-nanosecond clock synchronization among readout and front-end electronics modules that may lie hundred meters apart. We call GTS (Global Trigger and Synchronization System) the infrastructure responsible for precise clock synchronization and for the trigger management of AGATA. It is made of a central trigger processor and nodes, connected in a tree structure by means of optical fibers operated at 2Gb/s. The GTS tree handles the synchronization and the trigger data flow, whereas the trigger processor analyses and eventually validates the trigger primitives centrally. Sub-nanosecond synchronization is achieved by measuring two different types of round-trip times and by automatically correcting for phase-shift differences. For a tree of depth two, the peak-to-peak clock jitter at each leaf is 70 ps; the mean phase difference is 180 ps, while the standard deviation over such phase difference, namely the phase equalization repeatability, is 20 ps. The GTS system has run flawlessly for the two-year long AGATA campaign, held at the INFN Legnaro National Laboratories, Italy, where five triple clusters of the AGATA sub-array were coupled with a variety of ancillary detectors.

  13. Damage caused by a nanosecond UV laser on a heated copper surface

    Energy Technology Data Exchange (ETDEWEB)

    Henč-Bartolić, V., E-mail: visnja.henc@fer.hr [University of Zagreb, Faculty of Electrical Engineering and Computing, Unska 3, 10000 Zagreb (Croatia); Bončina, T. [University of Maribor, Faculty of Mechanical Engineering, Smetanova 17, 2000 Maribor (Slovenia); Jakovljević, S., E-mail: suzana.jakovljevic@fsb.hr [University of Zagreb, Faculty of Mechanical Engineering and Naval Architecture, Ivana Lučića 5, 10002 Zagreb (Croatia); Panjan, P. [Jožef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Zupanič, F. [University of Maribor, Faculty of Mechanical Engineering, Smetanova 17, 2000 Maribor (Slovenia)

    2016-08-15

    Highlights: • A Cu-plate was exposed to nanosecond UV laser with max. energy 1.1 J/cm{sup 2}. • Surface topography was studied on the cold and heated copper plate. • At room temperature, a crater formed, the melt was ejected from it. • Capillary waves formed in the vicinity of the crater at 360 °C. - Abstract: This work studied the effect of thin copper plate temperature on its surface morphology after irradiation using a pulsed nanosecond UV laser. The surface characteristics were investigated using scanning electron microscopy, energy dispersive X-ray spectroscopy, focused ion beam and stylus profilometry. When a target was at room temperature, a crater and the radial flow of molten Cu from the crater was observed. When the thin target was warm (about 360 °C ± 20 °C), a crater was smaller, and quasi-semicircular waves with the periodicity of around 3 μm appeared in its vicinity. The origin of the waves is Marangoni effect, causing thermocapillary waves, which in same occasions had a structure of final states of chaos in Rayleigh–Bénard convection.

  14. Nanosecond laser pulses for mimicking thermal effects on nanostructured tungsten-based materials

    Science.gov (United States)

    Besozzi, E.; Maffini, A.; Dellasega, D.; Russo, V.; Facibeni, A.; Pazzaglia, A.; Beghi, M. G.; Passoni, M.

    2018-03-01

    In this work, we exploit nanosecond laser irradiation as a compact solution for investigating the thermomechanical behavior of tungsten materials under extreme thermal loads at the laboratory scale. Heat flux factor thresholds for various thermal effects, such as melting, cracking and recrystallization, are determined under both single and multishot experiments. The use of nanosecond lasers for mimicking thermal effects induced on W by fusion-relevant thermal loads is thus validated by direct comparison of the thresholds obtained in this work and the ones reported in the literature for electron beams and millisecond laser irradiation. Numerical simulations of temperature and thermal stress performed on a 2D thermomechanical code are used to predict the heat flux factor thresholds of the different thermal effects. We also investigate the thermal effect thresholds of various nanostructured W coatings. These coatings are produced by pulsed laser deposition, mimicking W coatings in tokamaks and W redeposited layers. All the coatings show lower damage thresholds with respect to bulk W. In general, thresholds decrease as the porosity degree of the materials increases. We thus propose a model to predict these thresholds for coatings with various morphologies, simply based on their porosity degree, which can be directly estimated by measuring the variation of the coating mass density with respect to that of the bulk.

  15. Nanosecond pulsed laser induced self-organized nano-dots patterns on GaSb surface

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Yutaka, E-mail: yyoshida@cris.hokudai.ac.jp [Center for Advanced Research of Energy and Materials, Faculty of Engineering, Hokkaido University, N8, W13, Kita-ku, Sapporo 060-8628, Hokkaido (Japan); Creative Research Institution Sousei, Hokkaido University, N21, W10, Kita-ku, Sapporo 001-0021, Hokkaido (Japan); Oosawa, Kazuya; Wajima, Jyunya; Watanabe, Seiichi [Center for Advanced Research of Energy and Materials, Faculty of Engineering, Hokkaido University, N8, W13, Kita-ku, Sapporo 060-8628, Hokkaido (Japan); Matsuo, Yasutaka [Research Institute for Electronic Science, Hokkaido University, Sapporo 001-0020, Hokkaido (Japan); Kato, Takahiko [Hitachi Research Laboratory, Hitachi, Ltd., 7-1-1 Omika, Hitachi-shi 319-1292, Ibaraki-ken (Japan); Center for Advanced Research of Energy and Materials, Faculty of Engineering, Hokkaido University, N8, W13, Kita-ku, Sapporo 060-8628, Hokkaido (Japan)

    2014-07-01

    We report a technique for formation of two-dimensional (2D) nanodot (ND) patterns on gaillium antimoide (GaSb) using a nanosecond pulsed laser irradiation with 532 nm wavelength. The patterns have formed because of the interference and the self-organization under energy deposition of the laser irradiation, which induced the growth of NDs on the local area. The NDs are grown and shrunken in the pattern by energy depositions. In the laser irradiation with average laser energy density of 35 mJ cm⁻², large and small NDs are formed on GaSb surface. The large NDs have grown average diameter from 160 to 200 nm with increase of laser pulses, and the small NDs have shrunken average diameter from 75 to 30 nm. The critical dot size is required about 107 nm for growth of the NDs in the patterns. Nanosecond pulsed laser irradiation can control the self-organized ND size on GaSb in air as a function of the laser pulses.

  16. Insight into electronic mechanisms of nanosecond-laser ablation of silicon

    International Nuclear Information System (INIS)

    Marine, Wladimir; Patrone, Lionel; Ozerov, Igor; Bulgakova, Nadezhda M.

    2008-01-01

    We present experimental and theoretical studies of nanosecond ArF excimer laser desorption and ablation of silicon with insight into material removal mechanisms. The experimental studies involve a comprehensive analysis of the laser-induced plume dynamics and measurements of the charge gained by the target during irradiation time. At low laser fluences, well below the melting threshold, high-energy ions with a narrow energy distribution are observed. When the fluence is increased, a thermal component of the plume is formed superimposing on the nonthermal ions, which are still abundant. The origin of these ions is discussed on the basis of two modeling approaches, thermal and electronic, and we analyze the dynamics of silicon target excitation, heating, melting, and ablation. An electronic model is developed that provides insight into the charge-carrier transport in the target. We demonstrate that, contrary to a commonly accepted opinion, a complete thermalization between the electron and lattice subsystems is not reached during the nanosecond-laser pulse action. Moreover, the charging effects can retard the melting process and have an effect on the overall target behavior and laser-induced plume dynamics

  17. Nanosecond laser ablation processes in aluminum-doped zinc-oxide for photovoltaic devices

    Energy Technology Data Exchange (ETDEWEB)

    Canteli, D., E-mail: david.canteli@ciemat.es [Division de Energias Renovables, Energia Solar Fotovoltaica, CIEMAT, Avda. Complutense, 22, 28040 Madrid (Spain); Fernandez, S. [Division de Energias Renovables, Energia Solar Fotovoltaica, CIEMAT, Avda. Complutense, 22, 28040 Madrid (Spain); Molpeceres, C. [Centro Laser, Universidad Politecnica de Madrid, Ctra. de Valencia Km 7.3, 28031 Madrid (Spain); Torres, I.; Gandia, J.J. [Division de Energias Renovables, Energia Solar Fotovoltaica, CIEMAT, Avda. Complutense, 22, 28040 Madrid (Spain)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer A study of the ablation of AZO thin films deposited at different temperature conditions with nanosecond UV laser light for photovoltaic devices has been performed. Black-Right-Pointing-Pointer The ablation threshold of AZO thin films was measured and related with the absorption coefficient of the films at the laser wavelength, showing a direct correspondence. Black-Right-Pointing-Pointer A change in the material structure in the areas closest to the edges of laser grooves made in samples deposited at temperatures below 100 Degree-Sign C was observed and studied. - Abstract: Aiming to a future use in thin film solar modules, the processing of aluminum doped zinc oxide thin films with good optoelectronic properties with a nanosecond-pulsed ultraviolet laser has been studied. The ablation threshold fluence of the films has been determined and associated with the material properties. The ablation process has been optimized and grooves with good properties for photovoltaic devices have been obtained. The morphology of the ablated surfaces has been observed by confocal microscopy and its structure has been characterized by Raman spectroscopy. The influence of ablation parameters like focus distance, pulse energy and repetition frequency in the groove morphology has been studied with special attention to the thermal effects on the material structure.

  18. Nanosecond pulse-width electron diode based on dielectric wall accelerator technology

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Quantang, E-mail: zhaoquantang@impcas.ac.cn [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Zhang, Z.M.; Yuan, P.; Cao, S.C.; Shen, X.K.; Jing, Y. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Yu, C.S. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Li, Z.P.; Liu, M.; Xiao, R.Q. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Zong, Y.; Wang, Y.R. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Zhao, H.W. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

    2013-11-21

    An electron diode using a short section of dielectric wall accelerator (DWA) has been under development at the Institute of Modern Physics (IMP), Chinese Academy of Sciences. Tests have been carried out with spark gap switches triggered by lasers. The stack voltage efficiency of a four-layer of Blumleins reached about 60–70% with gas filled spark gap switching. The generated pulse voltage of peak amplitude of 23 kV and pulse width of 5 ns is used to extract and accelerate an electron beam of 320 mA, measured by a fast current transformer. A nanosecond pulse width electron diode was achieved successfully. Furthermore, the principle of a DWA is well proven and the development details and discussions are presented in this article. -- Highlights: •The key technology of DWA, including switches and pulse forming lines were studied. •The SiC PCSS obtained from Shanghai Institute were tested. •Two layers ZIP lines (new structure) and four layers Blumlein lines were studied with laser triggered spark gap switches. •A nanosecond pulse-width electron diode based on DWA technologies is achieved and studied experimentally. •The principle of DWA is also proved by the diode.

  19. A Novel Nanosecond Pulsed Power Unit for the Formation of ·OH in Water

    International Nuclear Information System (INIS)

    Li Shengli; Hu Sheng; Zhang Han

    2012-01-01

    A novel nanosecond pulsed power unit was developed for plasma treatment of wastewater, based on the theory of magnetic pulse compression and semiconductor opening switch (SOS). The peak value, rise time and pulse duration of the output voltage were observed to be -51 kV, 60 ns and 120 ns, respectively. The concentrations of ·OH generated by the novel nanosecond pulsed plasma power were determined using the method of high-performance liquid chromatography (HPLC). The results showed that the concentrations of ·OH increased with the increase in peak voltage, and the generation rates of ·OH were 4.1 × 10 -10 mol/s, 5.7 × 10 -10 mol/s, and 7.7 × 10 -10 mol/s at 30 kV, 35 kV, and 40 kV, respectively. The efficiency of OH generation was found to be independent of the input parameters for applied power, with an average value of 3.23×10 -12 mol/J obtained. (plasma technology)

  20. Nanosecond laser ablation of target Al in a gaseous medium: explosive boiling

    Science.gov (United States)

    Mazhukin, V. I.; Mazhukin, A. V.; Demin, M. M.; Shapranov, A. V.

    2018-03-01

    An approximate mathematical description of the processes of homogeneous nucleation and homogeneous evaporation (explosive boiling) of a metal target (Al) under the influence of ns laser radiation is proposed in the framework of the hydrodynamic model. Within the continuum approach, a multi-phase, multi-front hydrodynamic model and a computational algorithm are designed to simulate nanosecond laser ablation of the metal targets immersed in gaseous media. The proposed approach is intended for modeling and detailed analysis of the mechanisms of heterogeneous and homogeneous evaporation and their interaction with each other. It is shown that the proposed model and computational algorithm allow modeling of interrelated mechanisms of heterogeneous and homogeneous evaporation of metals, manifested in the form of pulsating explosive boiling. Modeling has shown that explosive evaporation in metals is due to the presence of a near-surface temperature maximum. It has been established that in nanosecond pulsed laser ablation, such exposure regimes can be implemented in which phase explosion is the main mechanism of material removal.

  1. Selective harmonic elimination strategy in eleven level inverter for PV system with unbalanced DC sources

    Science.gov (United States)

    Ghoudelbourk, Sihem.; Dib, D.; Meghni, B.; Zouli, M.

    2017-02-01

    The paper deals with the multilevel converters control strategy for photovoltaic system integrated in distribution grids. The objective of the proposed work is to design multilevel inverters for solar energy applications so as to reduce the Total Harmonic Distortion (THD) and to improve the power quality. The multilevel inverter power structure plays a vital role in every aspect of the power system. It is easier to produce a high-power, high-voltage inverter with the multilevel structure. The topologies of multilevel inverter have several advantages such as high output voltage, lower total harmonic distortion (THD) and reduction of voltage ratings of the power semiconductor switching devices. The proposed control strategy ensures an implementation of selective harmonic elimination (SHE) modulation for eleven levels. SHE is a very important and efficient strategy of eliminating selected harmonics by judicious selection of the firing angles of the inverter. Harmonics elimination technique eliminates the need of the expensive low pass filters in the system. Previous research considered that constant and equal DC sources with invariant behavior; however, this research extends earlier work to include variant DC sources, which are typical of lead-acid batteries when used in system PV. This Study also investigates methods to minimize the total harmonic distortion of the synthesized multilevel waveform and to help balance the battery voltage. The harmonic elimination method was used to eliminate selected lower dominant harmonics resulting from the inverter switching action.

  2. [Eleven Patients with Gastric Cancer Who Received Chemotherapy after Stent Placement for Gastric Outlet Obstruction].

    Science.gov (United States)

    Endo, Shunji; Nakagawa, Tomo; Konishi, Ken; Ikenaga, Masakazu; Ohta, Katsuya; Nakashima, Shinsuke; Matsumoto, Kenichi; Nishikawa, Kazuhiro; Ohmori, Takeshi; Yamada, Terumasa

    2017-01-01

    Endoscopic placement of self-expandable metallic stents is reportedly effective for gastric outlet obstructions due to advanced gastric cancer, and is less invasive than gastrojejunostomy. For patients who have good performance status, we administer chemotherapy after stent placement, although the safety and feasibility of this chemotherapy have not yet been discussed in full. Between 2011 and 2015, 15 patients at our institution underwent endoscopic gastroduodenal stent placement for gastric outlet obstruction due to gastric cancer. Eleven of these patients were administered chemotherapy after stent placement. In our case series, we did not observe any specific adverse event caused by stent placement plus chemotherapy. Adverse events after chemotherapy included anemia of CTCAE Grade 3 in 7 patients. Stent-in-stent placement was needed in 2 patients. Neither stent migration nor perforation was observed. Therefore, chemotherapy after stent placement for gastric outlet obstruction due to gastric cancer was considered safe and feasible. Stent placement is useful not only as palliative care for patients with terminal-stage disease, but also as one of the multimodal therapeutic strategies for gastric cancer.

  3. Osteogenesis imperfecta type V: Genetic and clinical findings in eleven Chinese patients.

    Science.gov (United States)

    Liu, Yi; Wang, Jiawei; Ma, Doudou; Lv, Fang; Xu, Xiaojie; Xia, Weibo; Jiang, Yan; Wang, Ou; Xing, Xiaoping; Zhou, Peiran; Wang, Jianyi; Yu, Wei; Li, Mei

    2016-11-01

    Osteogenesis imperfecta (OI) type V is a rare inherited disease characterized by multiple fractures, intraosseous membrane calcification, and hypercallus formation. We investigate the causative gene, phenotype and also observe the effects of zoledronic acid in Chinese OI type V patients. The clinical phenotype and causative gene mutation was investigated in eleven patients with type V OI. Patients were given a dose of zoledronic acid 5mg intravenously. Fracture incidence and Z-score of bone mineral density (BMD) were evaluated. Serum levels of biomarkers such as cross linked C-telopeptide of type I collagen (β-CTX) and safety parameters were assessed. The c.-14C>T mutation in the 5' untranslated region of IFITM5 was detected in all patients. The phenotype was largely variable, and no significant correlation of genotype and phenotype was found. After one dose of zoledronic acid infusion, fracture incidence significantly dropped from 2fractures/year before treatment to 0fracture/year after treatment (P=0.01). Z score of lumbar spine BMD elevated from -2.6 to -1.3 (P<0.001). Serum β-CTX level decreased by 50% (P<0.05). No serious adverse event was found. No obvious correlation was found between the genotype and phenotype. Zoledronic acid had significantly skeletal protective effects in OI of type V. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Six sigma: program characteristics in eleven companies located in the metropolitan region of Porto Alegre

    Directory of Open Access Journals (Sweden)

    Jaqueline Terezinha Martins Correa Rodrigues

    2012-01-01

    Full Text Available Six Sigma combines managerial factors with statistical tools and is deployed in many enterprises today. Rio Grande do Sul is a Brazilian state that has a great industrialization, especially in the metropolitan area of Porto Alegre. Some of these industries have deployed the Six Sigma program. The aim of this paper is to present characteristics of the Six Sigma program in companies located in this region, through an exploratory study. A literature review subsidized the development of the questionnaire. Eleven companies participated of research in July and August 2008. It used statistical tools and qualitative analysis to analyze the results. Most of the companies that participated is classified as large and uses the DMAIC method to implement Six Sigma. The principal cause of program implementation was process improvement. In only one company the Six Sigma is implemented in all sectors, including administrative areas. Another result is the lack of clearly criteria for defining the career of Belts and the discrepancy of academic formation of these specialists.

  5. 2001 – 2010 Danish Design Reference Year

    DEFF Research Database (Denmark)

    Grunnet Wang, Peter; Scharling, Mikael; Pagh Nielsen, Kristian

    This report presents the Danish Design Reference Year based on observed data from 2001 – 2010. In various sectors - i.e. building and construction, energy, etc. - the climate and weather usually plays a part in a given project. The Danish Design Reference Year dataset is a collection of data series...... for eleven specific parameters, that each represents a typical year in Denmark. The uses of the dataset may vary from simulations to statistical analysis, graphical overviews etc. The Danish land areas have been sectionalized into five to six climatological zones depending on the parameter, each...... characterized by distinct diurnal and yearly variations. The dataset consists of observed data from one station located within and representing each zone. In addition to the complete Danish Design Reference Year dataset, a subset specifically selected to be used for energy performance calculations for obtaining...

  6. High optical label switching add-drop multiplexer nodes with nanoseconds latency for 5G metro/access networks

    NARCIS (Netherlands)

    Calabretta, N.; Miao, W.; De Waardt, H.

    2016-01-01

    We present a novel optical add-drop multiplexer for next-generation metro/access networks by exploiting optical label switching technology. Experimental results of a ring network show nanoseconds add/drop operation including multicasting and power equalization of 50Gb/s data.

  7. System-Level Demonstration of a Dynamically Reconfigured Burst-Mode Link Using a Nanosecond Si-Photonic Switch

    DEFF Research Database (Denmark)

    Forencich, Alex; Kamchevska, Valerija; Dupuis, Nicolas

    2018-01-01

    Using a novel FPGA-based network emulator, microsecond-scale packets with 12.5-20-Gb/s data are generated, routed through a nanosecond Si-photonic switch, and received in a fast-locking burst-mode receiver. Error-free links with <382-ns system-level switching are shown....

  8. Simultaneous high crystallinity and sub-bandgap optical absorptance in hyperdoped black silicon using nanosecond laser annealing

    Energy Technology Data Exchange (ETDEWEB)

    Franta, Benjamin, E-mail: bafranta@gmail.com; Pastor, David; Gandhi, Hemi H.; Aziz, Michael J.; Mazur, Eric [School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138 (United States); Rekemeyer, Paul H.; Gradečak, Silvija [Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2015-12-14

    Hyperdoped black silicon fabricated with femtosecond laser irradiation has attracted interest for applications in infrared photodetectors and intermediate band photovoltaics due to its sub-bandgap optical absorptance and light-trapping surface. However, hyperdoped black silicon typically has an amorphous and polyphasic polycrystalline surface that can interfere with carrier transport, electrical rectification, and intermediate band formation. Past studies have used thermal annealing to obtain high crystallinity in hyperdoped black silicon, but thermal annealing causes a deactivation of the sub-bandgap optical absorptance. In this study, nanosecond laser annealing is used to obtain high crystallinity and remove pressure-induced phases in hyperdoped black silicon while maintaining high sub-bandgap optical absorptance and a light-trapping surface morphology. Furthermore, it is shown that nanosecond laser annealing reactivates the sub-bandgap optical absorptance of hyperdoped black silicon after deactivation by thermal annealing. Thermal annealing and nanosecond laser annealing can be combined in sequence to fabricate hyperdoped black silicon that simultaneously shows high crystallinity, high above-bandgap and sub-bandgap absorptance, and a rectifying electrical homojunction. Such nanosecond laser annealing could potentially be applied to non-equilibrium material systems beyond hyperdoped black silicon.

  9. A comparison between characteristics of atmospheric-pressure plasma jets sustained by nanosecond- and microsecond-pulse generators in helium

    International Nuclear Information System (INIS)

    Zhang, Cheng; Shao, Tao; Wang, Ruixue; Yan, Ping; Zhou, Zhongsheng; Zhou, Yixiao

    2014-01-01

    Power source is an important parameter that can affect the characteristics of atmospheric-pressure plasma jets (APPJs), because it can play a key role on the discharge characteristics and ionization process of APPJs. In this paper, the characteristics of helium APPJs sustained by both nanosecond-pulse and microsecond-pulse generators are compared from the aspects of plume length, discharge current, consumption power, energy, and optical emission spectrum. Experimental results showed that the pulsed APPJ was initiated near the high-voltage electrode with a small curvature radius, and then the stable helium APPJ could be observed when the applied voltage increased. Moreover, the discharge current of the nanosecond-pulse APPJ was larger than that of the microsecond-pulse APPJ. Furthermore, although the nanosecond-pulse generator consumed less energy than the microsecond-pulse generator, longer plume length, larger instantaneous power per pulse and stronger spectral line intensity could be obtained in the nanosecond-pulse excitation case. In addition, some discussion indicated that the rise time of the applied voltage could play a prominent role on the generation of APPJs

  10. X-ray emission from a nanosecond-pulse discharge in an inhomogeneous electric field at atmospheric pressure

    International Nuclear Information System (INIS)

    Zhang Cheng; Shao Tao; Ren Chengyan; Zhang Dongdong; Tarasenko, Victor; Kostyrya, Igor D.; Ma Hao; Yan Ping

    2012-01-01

    This paper describes experimental studies of the dependence of the X-ray intensity on the anode material in nanosecond high-voltage discharges. The discharges were generated by two nanosecond-pulse generators in atmospheric air with a highly inhomogeneous electric field by a tube-plate gap. The output pulse of the first generator (repetitive pulse generator) has a rise time of about 15 ns and a full width at half maximum of 30–40 ns. The output of the second generator (single pulse generator) has a rise time of about 0.3 ns and a full width at half maximum of 1 ns. The electrical characteristics and the X-ray emission of nanosecond-pulse discharge in atmospheric air are studied by the measurement of voltage-current waveforms, discharge images, X-ray count and dose. Our experimental results showed that the anode material rarely affects electrical characteristics, but it can significantly affect the X-ray density. Comparing the density of X-rays, it was shown that the highest x-rays density occurred in the diffuse discharge in repetitive pulse mode, then the spark discharge with a small air gap, and then the corona discharge with a large air gap, in which the X-ray density was the lowest. Therefore, it could be confirmed that the bremsstrahlung at the anode contributes to the X-ray emission from nanosecond-pulse discharges.

  11. Nanosecond laser therapy reverses pathologic and molecular changes in age-related macular degeneration without retinal damage.

    Science.gov (United States)

    Jobling, A I; Guymer, R H; Vessey, K A; Greferath, U; Mills, S A; Brassington, K H; Luu, C D; Aung, K Z; Trogrlic, L; Plunkett, M; Fletcher, E L

    2015-02-01

    Age-related macular degeneration (AMD) is a leading cause of vision loss, characterized by drusen deposits and thickened Bruch's membrane (BM). This study details the capacity of nanosecond laser treatment to reduce drusen and thin BM while maintaining retinal structure. Fifty patients with AMD had a single nanosecond laser treatment session and after 2 yr, change in drusen area was compared with an untreated cohort of patients. The retinal effect of the laser was determined in human and mouse eyes using immunohistochemistry and compared with untreated eyes. In a mouse with thickened BM (ApoEnull), the effect of laser treatment was quantified using electron microscopy and quantitative PCR. In patients with AMD, nanosecond laser treatment reduced drusen load at 2 yr. Retinal structure was not compromised in human and mouse retina after laser treatment, with only a discrete retinal pigment epithelium (RPE) injury, and limited mononuclear cell response observed. BM was thinned in the ApoEnull mouse 3 mo after treatment (ApoEnull treated 683 ± 38 nm, ApoEnull untreated 890 ± 60 nm, C57Bl6J 606 ± 43 nm), with the expression of matrix metalloproteinase-2 and -3 increased (>260%). Nanosecond laser resolved drusen independent of retinal damage and improved BM structure, suggesting this treatment has the potential to reduce AMD progression. © FASEB.

  12. Comparison of two picosecond lasers to a nanosecond laser for treating tattoos: a prospective randomized study on 49 patients.

    Science.gov (United States)

    Lorgeou, A; Perrillat, Y; Gral, N; Lagrange, S; Lacour, J-P; Passeron, T

    2018-02-01

    Q-switched nanosecond lasers demonstrated their efficacy in treating most types of tattoos, but complete disappearance is not always achieved even after performing numerous laser sessions. Picosecond lasers are supposed to be more efficient in clearing tattoos than nanosecond lasers, but prospective comparative data remain limited. To compare on different types of tattoos the efficacy of a nanosecond laser with two types of picosecond lasers. We conducted a prospective randomized study performed from December 2014 to June 2016 on adult patients with all types of tattoos. The tattoos were divided into two halves of equal size. After randomization, half of the tattoo was treated with a picosecond laser and the other half with a nanosecond laser. The evaluation was performed on standardized pictures performed before treatment and 2 months after the last session, by two physicians, not involved in the treatment, blinded on the type of treatments received. The main end point was a clearance above 75% of the tattoos. A total of 49 patients were included. Professional tattoos represented 85.7%, permanent make-up 8.2% and non-professional tattoo 6.1%. The majority were black or blue and 10.2% were polychromatic. No patient was lost during follow-up. A reduction of 75% or more of the colour intensity was obtained for 33% of the tattoos treated with the picosecond lasers compared to 14% with the nanosecond laser (P = 0.008). An improvement superior to 75% was obtained in 34% monochromic black or blue tattoos with the picosecond lasers compared to 9% for the nanosecond laser. Only one of the five polychromic tattoos achieved more than 75% of improvement with the two types of laser. Our results show a statistically significant superiority of the picosecond lasers compared to the nanosecond laser for tattoo clearance. However, they do not show better efficacy for polychromic tattoos and the difference in terms of side-effects was also minimal with a tendency of picosecond

  13. Articulating current service development practices: a qualitative analysis of eleven mental health projects.

    Science.gov (United States)

    Jun, Gyuchan Thomas; Morrison, Cecily; Clarkson, P John

    2014-01-17

    The utilisation of good design practices in the development of complex health services is essential to improving quality. Healthcare organisations, however, are often seriously out of step with modern design thinking and practice. As a starting point to encourage the uptake of good design practices, it is important to understand the context of their intended use. This study aims to do that by articulating current health service development practices. Eleven service development projects carried out in a large mental health service were investigated through in-depth interviews with six operation managers. The critical decision method in conjunction with diagrammatic elicitation was used to capture descriptions of these projects. Stage-gate design models were then formed to visually articulate, classify and characterise different service development practices. Projects were grouped into three categories according to design process patterns: new service introduction and service integration; service improvement; service closure. Three common design stages: problem exploration, idea generation and solution evaluation - were then compared across the design process patterns. Consistent across projects were a top-down, policy-driven approach to exploration, underexploited idea generation and implementation-based evaluation. This study provides insight into where and how good design practices can contribute to the improvement of current service development practices. Specifically, the following suggestions for future service development practices are made: genuine user needs analysis for exploration; divergent thinking and innovative culture for idea generation; and fail-safe evaluation prior to implementation. Better training for managers through partnership working with design experts and researchers could be beneficial.

  14. Morphological and histological characters of penile organization in eleven species of molossid bats.

    Science.gov (United States)

    Comelis, Manuela T; Bueno, Larissa M; Góes, Rejane M; Taboga, S R; Morielle-Versute, Eliana

    2018-04-01

    The penis is the reproductive organ that ensures efficient copulation and success of internal fertilization in all species of mammals, with special challenges for bats, where copulation can occur during flight. Comparative anatomical analyses of different species of bats can contribute to a better understanding of morphological diversity of this organ, concerning organization and function. In this study, we describe the external morphology and histomorphology of the penis and baculum in eleven species of molossid bats. The present study showed that penile organization in these species displayed the basic vascular mammalian pattern and had a similar pattern concerning the presence of the tissues constituting the penis, exhibiting three types of erectile tissue (the corpus cavernosum, accessory cavernous tissue, and corpus spongiosum) around the urethra. However, certain features varied among the species, demonstrating that most species are distinguishable by glans and baculum morphology and glans histological organization. Major variations in glans morphology were genus-specific, and the greatest similarities were shared by Eumops species and N. laticaudatus. The greatest interspecific similarities occurred between M. molossus and M. rufus and between Eumops species. Save for M. molossus and M. rufus, morphology of the baculum was species-specific; and in E. perotis, it did not occur in all specimens, indicating that it is probably under selection. In the histological organization, the most evident differences were number of septa and localization of the corpora cavernosa. In species with a baculum (Molossus, Eumops and Nyctinomops species), the corpora cavernosa predominantly occupied the dorsal region of the penile glans and is associated with the proximal (basal) portion of the baculum. In species that do not have a baculum (Cynomops, Molossops and Neoplatymops species), the corpora cavernosa predominantly occupied the ventro-lateral region of the glans

  15. Comparative meta-analysis of tuberculosis contact investigation interventions in eleven high burden countries.

    Directory of Open Access Journals (Sweden)

    Lucie Blok

    Full Text Available Screening of household contacts of tuberculosis (TB patients is a recommended strategy to improve early case detection. While it has been widely implemented in low prevalence countries, the most optimal protocols for contact investigation in high prevalence, low resource settings is yet to be determined. This study evaluated contact investigation interventions in eleven lower and middle income countries and reviewed the association between context or program-related factors and the yield of cases among contacts.We reviewed data from nineteen first wave TB REACH funded projects piloting innovations to improve case detection. These nineteen had fulfilled the eligibility criteria: contact investigation implementation and complete data reporting. We performed a cross-sectional analysis of the percentage yield and case notifications for each project. Implementation strategies were delineated and the association between independent variables and yield was analyzed by fitting a random effects logistic regression.Overall, the nineteen interventions screened 139,052 household contacts, showing great heterogeneity in the percentage yield of microscopy confirmed cases (SS+, ranging from 0.1% to 6.2%. Compared to the most restrictive testing criteria (at least two weeks of cough the aOR's for lesser (any TB related symptom and least (all contacts restrictive testing criteria were 1.71 (95%CI 0.94-3.13 and 6.90 (95% CI 3.42-13.93 respectively. The aOR for inclusion of SS- and extra-pulmonary TB was 0.31 (95% CI 0.15-0.62 compared to restricting index cases to SS+ TB. Contact investigation contributed between <1% and 14% to all SS+ cases diagnosed in the intervention areas.This study confirms that high numbers of active TB cases can be identified through contact investigation in a variety of contexts. However, design and program implementation factors appear to influence the yield of contact investigation and its concomitant contribution to TB case detection.

  16. Total midgut volvulus in adults with intestinal malrotation. Report of eleven patients.

    Science.gov (United States)

    Kotobi, H; Tan, V; Lefèvre, J; Duramé, F; Audry, G; Parc, Y

    2017-06-01

    Total small-intestinal volvulus with malrotation (TSIVM) classically presents in the neonatal period; it occurs much less frequently in the adult and is often misdiagnosed. Prognosis is directly related to the degree and duration of intestinal ischemia. Our goal is to describe our experience with TSIVM in the adult, to identify any specific findings and to discuss its management. Eleven patients who had undergone surgery for TSIVM at three centers between 1992 and 2012 were included. Surgery was performed as an emergency for five patients and surgery was elective for six. Mean follow-up was 63 months (range: 12-270). Six patients had had previous abdominal surgery. In nine cases, the diagnosis of TSIVM was made preoperatively, mainly by CT scan in eight cases. Seven patients had associated congenital failure of retroperitoneal fixation of the right colon and all of these underwent a Ladd procedure. The mortality rate was zero. Of the five patients who underwent emergency surgery, three required intestinal resections, one of whom developed a short bowel syndrome. The six patients who underwent surgery electively had no surgical complications. TSIVM is a very unusual finding in adult patients. The diagnosis can be made by CT scan with IV and oral contrast, but it often comes to light only at the time of surgery, even though the patients have often had recurrent episodes of abdominal symptomatology that dated back to childhood. The Ladd procedure, consisting of division of Ladd's bands, widening of the mesentery, and incidental appendectomy, remains the standard surgical repair. Digestive surgeons who care for adults should be familiar with this procedure, and it should be performed, as often as possible, with the assistance of a pediatric surgeon. Copyright © 2016. Published by Elsevier Masson SAS.

  17. Worldwide food recall patterns over an eleven month period: A country perspective

    Directory of Open Access Journals (Sweden)

    Petróczi Andrea

    2008-09-01

    Full Text Available Abstract Background Following the World Health Organization Forum in November 2007, the Beijing Declaration recognized the importance of food safety along with the rights of all individuals to a safe and adequate diet. The aim of this study is to retrospectively analyze the patterns in food alert and recall by countries to identify the principal hazard generators and gatekeepers of food safety in the eleven months leading up to the Declaration. Methods The food recall data set was collected by the Laboratory of the Government Chemist (LGC, UK over the period from January to November 2007. Statistics were computed with the focus reporting patterns by the 117 countries. The complexity of the recorded interrelations was depicted as a network constructed from structural properties contained in the data. The analysed network properties included degrees, weighted degrees, modularity and k-core decomposition. Network analyses of the reports, based on 'country making report' (detector and 'country reported on' (transgressor, revealed that the network is organized around a dominant core. Results Ten countries were reported for sixty per cent of all faulty products marketed, with the top 5 countries having received between 100 to 281 reports. Further analysis of the dominant core revealed that out of the top five transgressors three made no reports (in the order China > Turkey > Iran. The top ten detectors account for three quarters of reports with three > 300 (Italy: 406, Germany: 340, United Kingdom: 322. Conclusion Of the 117 countries studied, the vast majority of food reports are made by 10 countries, with EU countries predominating. The majority of the faulty foodstuffs originate in ten countries with four major producers making no reports. This pattern is very distant from that proposed by the Beijing Declaration which urges all countries to take responsibility for the provision of safe and adequate diets for their nationals.

  18. Hydrophobic treatment on polymethylmethacrylate surface by nanosecond-pulse DBDs in CF4 at atmospheric pressure

    International Nuclear Information System (INIS)

    Zhang, Cheng; Zhou, Yang; Shao, Tao; Xie, Qing; Xu, Jiayu; Yang, Wenjin

    2014-01-01

    Highlights: • Increase in hydrophobicity on PMMA is achieved after the DBD treatment in CF 4 , and the water contact angle can increase from 68° to 100° after treatment. • Nanosecond-pulse DBD is used for the surface treatment and the power density is about 114.8 mW/cm 2 . • The effects of applied voltage, CF 4 flow, and time on plasma treatment are investigated. • Plasma treatment causes morphological change, significantly increases the roughness of the surface, and introduces fluorine-containing groups into the polymethylmethacrylate surface. • Hydrophobic behavior of the treated PMMA surface is slightly affected by the aging effect. - Abstract: Nanosecond-pulse dielectric barrier discharge (DBD) can provide non-thermal plasmas with extremely high energy and high density, which can result in a series of complicated physical and chemical reactions in the surface treatment of polymers. Therefore, in this paper, hydrophobic treatment of polymethylmethacrylate (PMMA) surface is conducted by nanosecond-pulse DBD in carbon tetrafluoride (CF 4 ) at atmospheric pressure. Investigations on surface morphology and chemical composition before and after the DBD treatment in CF 4 are conducted with the contact angle measurement, atomic force microscope, Fourier transform infrared spectroscopy, and X-ray photoelectron spectrometer. The effects of the applied voltage, CF 4 flow rate, and treatment time on the hydrophobic modification are studied. Results show that the contact angles of the treated PMMA surface increases with the applied voltage, and it could be greatly affected by the CF 4 flow rate and the treatment time. The water contact angle can increase from 68° to 100° after the treatment. Furthermore, both surface morphology and chemical composition of the PMMA samples are changed. Both the increase of the surface roughness and the occurrence of fluorine-containing functional groups on the PMMA surface treated by DBD in CF 4 lead to the hydrophobicity

  19. Studies of multi-wavelength laser-induced damage on KDP crystals in the nanosecond regime

    International Nuclear Information System (INIS)

    Reyne, Stephane

    2011-01-01

    This thesis interests in the laser-induced damage mechanisms of KDP and DKDP crystals in the nanosecond regime. KDP is a non-linear material particularly used in the frequency converters of the Laser MegaJoule, which is under construction at the CEA-Cesta in France. For this facility, the KDP laser damage resistance is one of the keystones and is still under investigations to fix this problem. This is why this manuscript presents different studies which highlight the two main aspects of the nanosecond laser-induced damage of KDP frequency converters: the precursor defects and the mechanisms to initiate damage. First, we propose a study based on the analysis of several photos obtained by DIC microscopy of damage initiated by different wavelengths. A comparison with a code coupling the energy deposition and hydrodynamic is also done. Then, we interest in the influence of the defects geometry through a study based on the laser polarization effect on the laser damage resistance. By the comparison with a CEA home-made code, this study particularly underlines the possibility to define a new geometry for the precursor defects. This geometry proposed has the shape of an ellipsoid and is supposed to keep the crystal structure properties. Finally, we enlarge on the physical mechanisms initiating laser damage with pump-pump experiments. These tests consist in combining two radiations of different wavelengths which impacting the crystal simultaneously or are delayed one by the other. We then observe the influence of this wavelengths mixing on the KDP laser damage resistance. In particular, a coupling effect between the wavelengths of the mixture may occur as a function of the fluences combination. Finally, the goal of these specific studies is to accumulate new data in order to improve the understanding in the initiation of the laser damage in KDP and DKDP crystals in the nanosecond regime. In the end, these data will allow us to develop predictive models to simulate the laser

  20. Acute myeloblastic leukemia with minimal myeloid differentiation (FAB AML-M0): a study of eleven cases.

    Science.gov (United States)

    Sempere, A; Jarque, I; Guinot, M; Palau, J; García, R; Sanz, G F; Gomis, F; Pérez-Sirvent, M L; Senent, L; Sanz, M A

    1993-12-01

    The main clinical, morphological, cytochemical, immunological features and therapy results of eleven patients diagnosed as acute myeloblastic leukemia M0 (AML-M0) are reported here. There were no clinical characteristics, abnormalities on physical examination or initial laboratory parameters that distinguished these eleven patients. Bone marrow aspirates were hypocellular in four patients. The leukemic cells were undifferentiated by light microscopy and myeloperoxidase (MPO) and/or Sudan Black B (SBB) stains were negative in all cases. Myeloid differentiation antigens were present on the leukemic cells of all eleven patients, whereas B and T cell markers were clearly negative except for CD4 and CD7 antigens. Whatever the treatment employed survival was very short. Eight of the eleven patients were treated and two achieved complete remission (CR) but only one of them is alive in continuous CR. Our results like those previously reported, suggest that AML-M0 patients have a very poor prognosis with standard induction therapies and should perhaps be considered for experimental therapeutic approaches.

  1. Emerging and Disruptive Technologies for Education: An Analysis of Planning, Implementation, and Diffusion in Florida's Eleven State University System Institutions

    Science.gov (United States)

    Bradford, Deborah J.

    2010-01-01

    The purpose of the study was to understand and appreciate the methodologies and procedures used in determining the extent to which an information technology (IT) organization within the eleven member State University Systems (SUS) of Florida planned, implemented, and diffused emerging educational technologies. Key findings found how critical it…

  2. Still Not Adult-Like: Lexical Stress Contrastivity in Word Productions of Eight- to Eleven-Year-Olds

    Science.gov (United States)

    Arciuli, Joanne; Ballard, Kirrie J.

    2017-01-01

    Lexical stress is the contrast between strong and weak syllables within words. Ballard et al. (2012) examined the amount of stress contrastivity across adjacent syllables in word productions of typically developing three- to seven-year-olds and adults. Here, eight- to eleven-year-olds are compared with the adults from Ballard et al. using acoustic…

  3. Wind tunnel experiments on flow separation control of an Unmanned Air Vehicle by nanosecond discharge plasma aerodynamic actuation

    International Nuclear Information System (INIS)

    Chen Kang; Liang Hua

    2016-01-01

    Plasma flow control (PFC) is a new kind of active flow control technology, which can improve the aerodynamic performances of aircrafts remarkably. The flow separation control of an unmanned air vehicle (UAV) by nanosecond discharge plasma aerodynamic actuation (NDPAA) is investigated experimentally in this paper. Experimental results show that the applied voltages for both the nanosecond discharge and the millisecond discharge are nearly the same, but the current for nanosecond discharge (30 A) is much bigger than that for millisecond discharge (0.1 A). The flow field induced by the NDPAA is similar to a shock wave upward, and has a maximal velocity of less than 0.5 m/s. Fast heating effect for nanosecond discharge induces shock waves in the quiescent air. The lasting time of the shock waves is about 80 μs and its spread velocity is nearly 380 m/s. By using the NDPAA, the flow separation on the suction side of the UAV can be totally suppressed and the critical stall angle of attack increases from 20° to 27° with a maximal lift coefficient increment of 11.24%. The flow separation can be suppressed when the discharge voltage is larger than the threshold value, and the optimum operation frequency for the NDPAA is the one which makes the Strouhal number equal one. The NDPAA is more effective than the millisecond discharge plasma aerodynamic actuation (MDPAA) in boundary layer flow control. The main mechanism for nanosecond discharge is shock effect. Shock effect is more effective in flow control than momentum effect in high speed flow control. (paper)

  4. Nanosecond field emitted and photo-field emitted current pulses from ZrC tips

    International Nuclear Information System (INIS)

    Ganter, R.; Bakker, R.J.; Gough, C.; Paraliev, M.; Pedrozzi, M.; Le Pimpec, F.; Rivkin, L.; Wrulich, A.

    2006-01-01

    In order to find electron sources with low thermal emittance, cathodes based on single tip field emitter are investigated. Maximum peak current, measured from single tip in ZrC with a typical apex radius around 1 μm, are presented. Voltage pulses of 2 ns duration and up to 50 kV amplitude lead to field emission current up to 470 mA from one ZrC tip. Combination of high applied electric field with laser illumination gives the possibility to modulate the emission with laser pulses. Nanoseconds current pulses have been emitted with laser pulses at 1064 nm illuminating a ZrC tip under high-DC electric field. The dependence of photo-field emitted current with the applied voltage can be explained by the Schottky effect

  5. Modeling of nanosecond pulsed laser processing of polymers in air and water

    DEFF Research Database (Denmark)

    Marla, Deepak; Zhang, Yang; Hattel, Jesper H.

    2018-01-01

    radiation (λ = 1064 nm) of nanosecond pulse duration. The laser–polymer interaction at such wavelengths is purely photo-thermal in nature and the laser–plasma interaction is assumed to occur mainly by inverse-bremsstrahlung photon absorption. The computational model is based on the finite volume method......Laser ablation of polymers in water is known to generate distinct surface characteristics as compared to that in air. In order to understand the role of ambient media during laser ablation of polymers, this paper aims to develop a physics-based model of the process considering the effect of ambient...... media. Therefore, in the present work, models are developed for laser ablation of polymers in air and water considering all the relevant physical phenomena such as laser–polymer interaction, plasma generation, plasma expansion and plasma shielding. The current work focuses on near-infrared laser...

  6. Comparative study of ornamental granite cleaning using femtosecond and nanosecond pulsed lasers

    Energy Technology Data Exchange (ETDEWEB)

    Rivas, T., E-mail: trivas@uvigo.es [Dpto. Ingeniería de los Recursos Naturales y Medioambiente. E.T.S. Ingeniería de Minas, Universidad de Vigo, 36200 Vigo Spain (Spain); Lopez, A.J.; Ramil, A. [Centro de Investigaciones Tecnológicas. Campus de Esteiro. Universidad de A Coruña 15403 Ferrol Spain (Spain); Pozo, S. [Dpto. Ingeniería de los Recursos Naturales y Medioambiente. E.T.S. Ingeniería de Minas, Universidad de Vigo, 36200 Vigo Spain (Spain); Fiorucci, M.P. [Centro de Investigaciones Tecnológicas. Campus de Esteiro. Universidad de A Coruña 15403 Ferrol Spain (Spain); Silanes, M.E. López de [Dpto. Ingeniería de los Recursos Naturales y Medioambiente. E.I. Forestales. Universidad de Vigo, Campus Pontevedra. 36005 Pontevedra Spain (Spain); García, A.; Aldana, J. R. Vazquez de; Romero, C.; Moreno, P. [Grupo de Investigación en Microprocesado de Materiales con Laser. Facultad de Ciencias, Universidad de Salamanca, 37008 Salamanca Spain (Spain)

    2013-08-01

    Granite has been widely used as a structural and ornamental element in public works and buildings. In damp climates it is almost permanently humid and its exterior surfaces are consequently biologically colonized and blackened We describe a comparative analysis of the performance of two different laser sources in removing biological crusts from granite surfaces: nanosecond Nd:YVO{sub 4} laser (355 nm) and femtosecond Ti:Sapphire laser at its fundamental wavelength (790 nm) and second harmonic (395 nm). The granite surface was analyzed using scanning electron microscopy, attenuated total reflection – Fourier transform infrared spectroscopy and profilometry, in order to assess the degree of cleaning and to characterize possible morphological and chemical changes caused by the laser sources.

  7. Nanosecond field emitted and photo-field emitted current pulses from ZrC tips

    Energy Technology Data Exchange (ETDEWEB)

    Ganter, R. [Paul Scherrer Institut, Villigen, CH 5232 (Switzerland)]. E-mail: romain.ganter@psi.ch; Bakker, R.J. [Paul Scherrer Institut, Villigen, CH 5232 (Switzerland); Gough, C. [Paul Scherrer Institut, Villigen, CH 5232 (Switzerland); Paraliev, M. [Paul Scherrer Institut, Villigen, CH 5232 (Switzerland); Pedrozzi, M. [Paul Scherrer Institut, Villigen, CH 5232 (Switzerland); Le Pimpec, F. [Paul Scherrer Institut, Villigen, CH 5232 (Switzerland); Rivkin, L. [Paul Scherrer Institut, Villigen, CH 5232 (Switzerland); Wrulich, A. [Paul Scherrer Institut, Villigen, CH 5232 (Switzerland)

    2006-09-15

    In order to find electron sources with low thermal emittance, cathodes based on single tip field emitter are investigated. Maximum peak current, measured from single tip in ZrC with a typical apex radius around 1 {mu}m, are presented. Voltage pulses of 2 ns duration and up to 50 kV amplitude lead to field emission current up to 470 mA from one ZrC tip. Combination of high applied electric field with laser illumination gives the possibility to modulate the emission with laser pulses. Nanoseconds current pulses have been emitted with laser pulses at 1064 nm illuminating a ZrC tip under high-DC electric field. The dependence of photo-field emitted current with the applied voltage can be explained by the Schottky effect.

  8. Visualization of nanosecond laser-induced dewetting, ablation and crystallization processes in thin silicon films

    Science.gov (United States)

    Qi, Dongfeng; Zhang, Zifeng; Yu, Xiaohan; Zhang, Yawen

    2018-06-01

    In the present work, nanosecond pulsed laser crystallization, dewetting and ablation of thin amorphous silicon films are investigated by time-resolved imaging. Laser pulses of 532 nm wavelength and 7 ns temporal width are irradiated on silicon film. Below the dewetting threshold, crystallization process happens after 400 ns laser irradiation in the spot central region. With the increasing of laser fluence, it is observed that the dewetting process does not conclude until 300 ns after the laser irradiation, forming droplet-like particles in the spot central region. At higher laser intensities, ablative material removal occurs in the spot center. Cylindrical rims are formed in the peripheral dewetting zone due to solidification of transported matter at about 500 ns following the laser pulse exposure.

  9. Image-rotating cavity designs for improved beam quality in nanosecond optical parametric oscillators

    International Nuclear Information System (INIS)

    Smith, Arlee V.; Bowers, Mark S.

    2001-01-01

    We show by computer simulation that high beam quality can be achieved in high-energy, nanosecond optical parametric oscillators by use of image-rotating resonators. Lateral walk-off between the signal and the idler beams in a nonlinear crystal creates correlations across the beams in the walk off direction, or equivalently, creates a restricted acceptance angle. These correlations can improve the beam quality in the walk-off plane. We show that image rotation or reflection can be used to improve beam quality in both planes. The lateral walk-off can be due to birefringent walk-off in type II mixing or to noncollinear mixing in type I or type II mixing

  10. Nanosecond formation of diamond and lonsdaleite by shock compression of graphite.

    Science.gov (United States)

    Kraus, D; Ravasio, A; Gauthier, M; Gericke, D O; Vorberger, J; Frydrych, S; Helfrich, J; Fletcher, L B; Schaumann, G; Nagler, B; Barbrel, B; Bachmann, B; Gamboa, E J; Göde, S; Granados, E; Gregori, G; Lee, H J; Neumayer, P; Schumaker, W; Döppner, T; Falcone, R W; Glenzer, S H; Roth, M

    2016-03-14

    The shock-induced transition from graphite to diamond has been of great scientific and technological interest since the discovery of microscopic diamonds in remnants of explosively driven graphite. Furthermore, shock synthesis of diamond and lonsdaleite, a speculative hexagonal carbon polymorph with unique hardness, is expected to happen during violent meteor impacts. Here, we show unprecedented in situ X-ray diffraction measurements of diamond formation on nanosecond timescales by shock compression of pyrolytic as well as polycrystalline graphite to pressures from 19 GPa up to 228 GPa. While we observe the transition to diamond starting at 50 GPa for both pyrolytic and polycrystalline graphite, we also record the direct formation of lonsdaleite above 170 GPa for pyrolytic samples only. Our experiment provides new insights into the processes of the shock-induced transition from graphite to diamond and uniquely resolves the dynamics that explain the main natural occurrence of the lonsdaleite crystal structure being close to meteor impact sites.

  11. Nanosecond laser scribing of CIGS thin film solar cell based on ITO bottom contact

    Science.gov (United States)

    Kuk, Seungkuk; Wang, Zhen; Fu, Shi; Zhang, Tao; Yu, Yi Yin; Choi, JaeMyung; Jeong, Jeung-hyun; Hwang, David J.

    2018-03-01

    Cu(In,Ga)Se2 (CIGS) thin films, a promising photovoltaic architecture, have mainly relied on Molybdenum for the bottom contact. However, the opaque nature of Molybdenum (Mo) poses limitations in module level fabrication by laser scribing as a preferred method for interconnect. We examined the P1, P2, and P3 laser scribing processes on CIGS photovoltaic architecture on the indium tin oxide (ITO) bottom contact with a cost-effective nanosecond pulsed laser of 532 nm wavelength. Laser illuminated from the substrate side, enabled by the transparent bottom contact, facilitated selective laser energy deposition onto relevant interfaces towards high-quality scribing. Parametric tuning procedures are described in conjunction with experimental and numerical investigation of relevant mechanisms, and preliminary mini-module fabrication results are also presented.

  12. Comparative study of ornamental granite cleaning using femtosecond and nanosecond pulsed lasers

    International Nuclear Information System (INIS)

    Rivas, T.; Lopez, A.J.; Ramil, A.; Pozo, S.; Fiorucci, M.P.; Silanes, M.E. López de; García, A.; Aldana, J. R. Vazquez de; Romero, C.; Moreno, P.

    2013-01-01

    Granite has been widely used as a structural and ornamental element in public works and buildings. In damp climates it is almost permanently humid and its exterior surfaces are consequently biologically colonized and blackened We describe a comparative analysis of the performance of two different laser sources in removing biological crusts from granite surfaces: nanosecond Nd:YVO 4 laser (355 nm) and femtosecond Ti:Sapphire laser at its fundamental wavelength (790 nm) and second harmonic (395 nm). The granite surface was analyzed using scanning electron microscopy, attenuated total reflection – Fourier transform infrared spectroscopy and profilometry, in order to assess the degree of cleaning and to characterize possible morphological and chemical changes caused by the laser sources.

  13. Nanosecond-timescale spin transfer using individual electrons in a quadruple-quantum-dot device

    Energy Technology Data Exchange (ETDEWEB)

    Baart, T. A.; Jovanovic, N.; Vandersypen, L. M. K. [QuTech and Kavli Institute of Nanoscience, Delft University of Technology, P.O. Box 5046, 2600 GA Delft (Netherlands); Reichl, C.; Wegscheider, W. [Solid State Physics Laboratory, ETH Zürich, 8093 Zürich (Switzerland)

    2016-07-25

    The ability to coherently transport electron-spin states between different sites of gate-defined semiconductor quantum dots is an essential ingredient for a quantum-dot-based quantum computer. Previous shuttles using electrostatic gating were too slow to move an electron within the spin dephasing time across an array. Here, we report a nanosecond-timescale spin transfer of individual electrons across a quadruple-quantum-dot device. Utilizing enhanced relaxation rates at a so-called hot spot, we can upper bound the shuttle time to at most 150 ns. While actual shuttle times are likely shorter, 150 ns is already fast enough to preserve spin coherence in, e.g., silicon based quantum dots. This work therefore realizes an important prerequisite for coherent spin transfer in quantum dot arrays.

  14. High pulse energy sub-nanosecond Tm-doped fiber laser

    Science.gov (United States)

    Cserteg, Andras; Guillemet, Sebastien; Hernandez, Yves; Giannone, Domenico

    2012-02-01

    We report a core pumped thulium-doped fiber amplifier that generates 1.4 μJ pulses at 1980 nm with a repetition rate of 3.6 MHz preserving the original spectral bandwidth of the oscillator. The amplifier chain is seeded by a passively modelocked fiber laser with 5 mW output power and the pulses are stretched to 800 picoseconds. The amplifier is core pumped by a single mode erbium fiber laser. The slope efficiency is 35%. To the best of our knowledge, this is the first demonstration of sub nanosecond pulses with energies higher than 1 μJ coming out of a thulium-doped fiber amplifier.

  15. Plasma-assisted ignition and combustion: nanosecond discharges and development of kinetic mechanisms

    Science.gov (United States)

    Starikovskaia, S. M.

    2014-09-01

    This review covers the results obtained in the period 2006-2014 in the field of plasma-assisted combustion, and in particular the results on ignition and combustion triggered or sustained by pulsed nanosecond discharges in different geometries. Some benefits of pulsed high voltage discharges for kinetic study and for applications are demonstrated. The necessity of and the possibility of building a particular kinetic mechanism of plasma-assisted ignition and combustion are discussed. The most sensitive regions of parameters for plasma-combustion kinetic mechanisms are selected. A map of the pressure and temperature parameters (P-T diagram) is suggested, to unify the available data on ignition delay times, ignition lengths and densities of intermediate species reported by different authors.

  16. Particle-in-cell modeling of the nanosecond field emission driven discharge in pressurized hydrogen

    Science.gov (United States)

    Levko, Dmitry; Yatom, Shurik; Krasik, Yakov E.

    2018-02-01

    The high-voltage field-emission driven nanosecond discharge in pressurized hydrogen is studied using the one-dimensional Particle-in-Cell Monte Carlo collision model. It is obtained that the main part of the field-emitted electrons becomes runaway in the thin cathode sheath. These runaway electrons propagate the entire cathode-anode gap, creating rather dense (˜1012 cm-3) seeding plasma electrons. In addition, these electrons initiate a streamer propagating through this background plasma with a speed ˜30% of the speed of light. Such a high streamer speed allows the self-acceleration mechanism of runaway electrons present between the streamer head and the anode to be realized. As a consequence, the energy of runaway electrons exceeds the cathode-anode gap voltage. In addition, the influence of the field emission switching-off time is analyzed. It is obtained that this time significantly influences the discharge dynamics.

  17. Abnormal polarity effect in nanosecond-pulse breakdown of SF6 and nitrogen

    International Nuclear Information System (INIS)

    Shao, Tao; Tarasenko, Victor F.; Zhang, Cheng; Beloplotov, Dmitry S.; Yang, Wenjin; Lomaev, Mikhail I.; Zhou, Zhongsheng; Sorokin, Dmitry A.; Yan, Ping

    2014-01-01

    The breakdown of gas gaps in an inhomogeneous electric field at subnanosecond and nanosecond voltage pulse rise times are studied, and the famous polarity effect in point-to-plane gaps is investigated. It is shown that at a voltage pulse rise time of ∼0.5 ns, the inversion of polarity effect takes place not only in electronegative gases such as SF 6 , but also occurs in electropositive nitrogen. The inversion of polarity effect is related to a delay of electron emission from the plane cathode on arrival of the ionization wave front anode to the cathode. It is found that with a voltage pulse rise time of ∼0.5 ns, the inversion of polarity effect occurs at SF 6 and SF 6 –N 2 pressures of 0.25 MPa and lower, and with a voltage pulse rise time of 15 ns, at a SF 6 pressure lower than 0.12 MPa.

  18. Temporally resolved imaging on quenching and re-ignition of nanosecond underwater discharge

    Directory of Open Access Journals (Sweden)

    Yong Yang

    2012-12-01

    Full Text Available This paper presents the temporally resolved images of plasma discharge in de-ionized water. The discharge was produced by high voltage pulses with 0.3 ns rise time and 10 ns duration. The temporal resolution of the imaging system was one nanosecond. A unique three-stage process, including a fast ignition at the leading edge of the pulse, quenching at the plateau of the pulse, and self re-ignition at the trailing edge of the pulse, was observed in a single pulse cycle. The maximum measured propagation velocity of the plasma discharge was about 1000 km/s. The possibility of direct ionization in water under high reduced electric field conditions was discussed.

  19. Ionization processes in combined high-voltage nanosecond - laser discharges in inert gas

    Science.gov (United States)

    Starikovskiy, Andrey; Shneider, Mikhail; PU Team

    2016-09-01

    Remote control of plasmas induced by laser radiation in the atmosphere is one of the challenging issues of free space communication, long-distance energy transmission, remote sensing of the atmosphere, and standoff detection of trace gases and bio-threat species. Sequences of laser pulses, as demonstrated by an extensive earlier work, offer an advantageous tool providing access to the control of air-plasma dynamics and optical interactions. The avalanche ionization induced in a pre-ionized region by infrared laser pulses where investigated. Pre-ionization was created by an ionization wave, initiated by high-voltage nanosecond pulse. Then, behind the front of ionization wave extra avalanche ionization was initiated by the focused infrared laser pulse. The experiment was carried out in argon. It is shown that the gas pre-ionization inhibits the laser spark generation under low pressure conditions.

  20. Experimental investigation on the repetitively nanosecond pulsed dielectric barrier discharge with the parallel magnetic field

    Science.gov (United States)

    Liu, Yidi; Yan, Huijie; Guo, Hongfei; Fan, Zhihui; Wang, Yuying; Ren, Chunsheng

    2018-02-01

    The effects of a parallel magnetic field on the unipolar positive nanosecond pulsed dielectric barrier discharge are experimentally investigated through electrical and spectral measurements. The discharge is produced between two parallel-plate electrodes in the ambient air with a parallel magnetic field of 1.4 T. Experimental results show that both the discharge intensity and uniformity are improved in the discharge with the parallel magnetic field. The intensity ratio of the spectrum at 371.1 nm and 380.5 nm, which describes the average electron density, is increased by the parallel magnetic field. Meanwhile, the intensity ratio of the spectrum at 391.4 nm and 337.1 nm, which describes the electron temperature, is also increased. It is speculated that both the average electron density and the electron temperature are increased by the parallel magnetic field. The aforementioned phenomena have been explained by the confinement effect of the parallel magnetic field on the electrons.

  1. Histopathology of normal skin and melanomas after nanosecond pulsed electric field treatment

    Science.gov (United States)

    Chen, Xinhua; Swanson, R. James; Kolb, Juergen F.; Nuccitelli, Richard; Schoenbach, Karl H.

    2011-01-01

    Nanosecond pulsed electric fields (nsPEFs) can affect the intracellular structures of cells in vitro. This study shows the direct effects of nsPEFs on tumor growth, tumor volume, and histological characteristics of normal skin and B16-F10 melanoma in SKH-1 mice. A melanoma model was set up by injecting B16-F10 into female SKH-1 mice. After a 100-pulse treatment with an nsPEF (40-kV/cm field strength; 300-ns duration; 30-ns rise time; 2-Hz repetition rate), tumor growth and histology were studied using transillumination, light microscopy with hematoxylin and eosin stain and transmission electron microscopy. Melanin and iron within the melanoma tumor were also detected with specific stains. After nsPEF treatment, tumor development was inhibited with decreased volumes post-nsPEF treatment compared with control tumors (Pelectric fields surrounding the needle electrodes. PMID:19730404

  2. Environmental temperature affects physiology and survival of nanosecond pulsed electric field-treated cells.

    Science.gov (United States)

    Yin, Shengyong; Miao, Xudong; Zhang, Xueming; Chen, Xinhua; Wen, Hao

    2018-02-01

    Nanosecond pulsed electric field (nsPEF) is a novel non-thermal tumor ablation technique. However, how nsPEF affect cell physiology at different environmental temperature is still kept unknown. But this issue is of critical clinical practice relevance. This work aim to investigate how nsPEF treated cancer cells react to different environmental temperatures (0, 4, 25, and 37°C). Their cell viability, apoptosis, mitochondrial membrane potential, and reactive oxygen species (ROS) were examined. Lower temperature resulted in higher apoptosis rate, decreased mitochondria membrane potential, and increased ROS levels. Sucrose and N-acetylcysteine (NAC) pre-incubation inhibit ROS generation and increase cell survival, protecting nsPEF-treated cells from low temperature-caused cell death. This work provides an experimental basis for hypothermia and fluid transfusion during nsPEF ablation with anesthesia. © 2017 Wiley Periodicals, Inc.

  3. Electric field measurements in a nanosecond pulse discharge by picosecond CARS/4-wave mixing

    Science.gov (United States)

    Goldberg, Ben; Shkurenkov, Ivan; Adamovich, Igor; Lempert, Walter

    2014-10-01

    Time-resolved electric field measurements in hydrogen by picosecond CARS/4-wave mixing are presented. Measurements are carried out in a high voltage nanosecond pulse discharge in hydrogen in plane-to-plane geometry, at pressures of up to several hundred Torr, and with a time resolution of 0.2 ns. Absolute calibration of the diagnostics is done using a sub-breakdown high voltage pulse of 12 kV/cm. A diffuse discharge is obtained by applying a peak high voltage pulse of 40 kV/cm between the electrodes. It is found that breakdown occurs at a lower field, 15--20 kV/cm, after which the field in the plasma is reduced rapidly due to plasma self shielding The experimental results are compared with kinetic modeling calculations, showing good agreement between the measured and the predicted electric field.

  4. Nanosecond laser ablation and deposition of silver, copper, zinc and tin

    DEFF Research Database (Denmark)

    Cazzaniga, Andrea Carlo; Ettlinger, Rebecca Bolt; Canulescu, Stela

    2014-01-01

    Nanosecond pulsed laser deposition of different metals (Ag, Cu, Sn, Zn) has been studied in high vacuum at a laser wavelength of 355 nm and pulse length of 6 ns. The deposition rate is roughly similar for Sn, Cu and Ag, which have comparable cohesive energies, and much higher for the deposition...... of Zn which has a low cohesive energy. The deposition rate for all metals is strongly correlated with the total ablation yield, i.e., the total mass ablated per pulse, reported in the literature except for Sn, for which the deposition rate is low, but the total ablation yield is high. This may...... be explained by the continuous erosion by nanoparticles during deposition of the Sn films which appear to have a much rougher surface than those of the other metals studied in the present work....

  5. One - step nanosecond laser microstructuring, sulfur hyperdoping, and annealing of silicon surfaces in liquid carbondisulfide

    Science.gov (United States)

    Van Luong, Nguyen; Danilov, P. A.; Ionin, A. A.; Khmel'nitskii, P. A.; Kudryashov, S. I.; Mel'nik, N. N.; Saraeva, I. N.; Смirnov, H. A.; Rudenko, A. A.; Zayarny, D. A.

    2017-09-01

    We perform a single-shot IR nanosecond laser processing of commercial silicon wafers in ambient air and under a 2 mm thick carbon disulfide liquid layer. We characterize the surface spots modified in the liquid ambient and the spots ablated under the same conditions in air in terms of its surface topography, chemical composition, band-structure modification, and crystalline structure by means of SEM and EDX microscopy, as well as of FT-IR and Raman spectroscopy. These studies indicate that single-step microstructuring and deep (up to 2-3% on the surface) hyperdoping of the crystalline silicon in its submicron surface layer, preserving via pulsed laser annealing its crystallinity and providing high (103 - 104 cm-1) spectrally at near- and mid-IR absorption coefficients, can be obtained in this novel approach, which is very promising for thin - film silicon photovoltaic devices

  6. Micromachining of glass by the third harmonic of nanosecond Nd:YVO{sub 4} laser

    Energy Technology Data Exchange (ETDEWEB)

    Ramil, A. [Centro de Investigacions Tecnoloxicas, Universidade da Coruna, E-15403 Ferrol (A Coruna) (Spain)], E-mail: aramil@cdf.udc.es; Lamas, J.; Alvarez, J.C.; Lopez, A.J.; Saavedra, E.; Yanez, A. [Centro de Investigacions Tecnoloxicas, Universidade da Coruna, E-15403 Ferrol (A Coruna) (Spain)

    2009-03-01

    The ablation processing of glass was performed by using the third harmonic of nanosecond Nd:YVO{sub 4} laser. The objective of this work was the formation of deep holes with a high aspect ratio in soda lime glass; with this purpose different ways to raster the glass surface with the focused laser beam, i.e., single line, parallel lines and orthogonally crossing lines, have been tried and the effect of different parameters as the number of lines and number of scans in the depth and inclination of the sidewalls of the hole has been analyzed. Moreover, to reduce the time consumption in the laser processing of glass plates the relationship between penetration depths and overlapping factor has been studied and an optimum value of scan speed has been obtained for a particular case.

  7. Surface modification of PET films using dielectric barrier discharge driven by repetitive nanosecond-pulses

    International Nuclear Information System (INIS)

    Shao Tao; Zhang Cheng; Long Kaihua; Wang Jue; Zhang Dongdong; Yan Ping; Zhou Yuanxiang

    2010-01-01

    In this paper, surface treatment of PET films for improving the hydrophilicity using DBD excited by unipolar nanosecond-pulses is presented. Homogeneous and filamentary discharge are obtained under certain experimental conditions and then used to modify the surface of PET films. The properties of PET films before and after treatment are characterized with water contact angle measurement, atomic force microscope and X-ray photoelectron spectroscope. The experimental results show that static water contact angles decrease after DBD plasma treatment and the observed contact angle is changed from 80 degree for the untreated samples to 20 degree after treatment. However, the decrease of contact angles is not continuous and it will reach a saturation state after certain treatment time. The improvement of surface hydrophilicity can be attributed to the enhancement of the surface roughness and introduction of oxygen-containing polar functional groups. In contrast with the filamentary DBD treatment, the homogenous DBD is more effective in PET surface treatment. (authors)

  8. Dynamics of the plume produced by nanosecond ultraviolet laser ablation of metals

    DEFF Research Database (Denmark)

    Christensen, Bo Toftmann; Schou, Jørgen; Lunney, J.G.

    2003-01-01

    The dynamics of the ablation plume of a partially ionized plasma produced by a nanosecond UV laser with different irradiation spot geometries has been explored. We have used an ensemble of quartz crystal microbalances to make the first systematic and quantitative study of how the shape of the plume...... varies as the aspect ratio (b/a) of the elliptical laser spot is varied by about a factor of ten. The flip-over effect can be described by the adiabatic expansion model of Anisimov using a value of the adiabatic constant of about gamma = 1.4. We have also studied the forward peaking of the ablation plume...... for a large number of metals at the same laser fluence. Contrary to earlier reports, we find that the more refractory metals have the broader angular distributions....

  9. Laser ablation of lysozyme with UV, visible and infrared femto- and nanosecond pulses

    DEFF Research Database (Denmark)

    Schou, Jørgen; Canulescu, Stela; Matei, Andreea

    Lysozyme is an interesting molecule for laser ablation of organic materials, because the ablation has been comprehensively studied, it is a medium heavy molecule with a mass of 14305 Da, which can be detected by standard techniques, and because it is used as a bactericidal protein in the food...... industry. Lysozyme molecules do not absorb energy for wavelengths above 310 nm, but nevertheless there is a strong mass loss by ablation for laser irradiation in the visible regime. The total ablation yield of lysozyme at 355 nm and at 2 J/cm2 is about 155 µg/pulse, possibly one of the highest ablation...... the ablation process for different wavelengths and time duration. Measurements for 6-7-ns laser ablation were carried out at DTU on Risø Campus, while measurements with pulses of 300 fs were carried out at the University of Naples in a similar setup. For all wavelengths except at nanosecond laser pulses at 355...

  10. High resolution selective multilayer laser processing by nanosecond laser ablation of metal nanoparticle films

    International Nuclear Information System (INIS)

    Ko, Seung H.; Pan Heng; Hwang, David J.; Chung, Jaewon; Ryu, Sangil; Grigoropoulos, Costas P.; Poulikakos, Dimos

    2007-01-01

    Ablation of gold nanoparticle films on polymer was explored using a nanosecond pulsed laser, with the goal to achieve feature size reduction and functionality not amenable with inkjet printing. The ablation threshold fluence for the unsintered nanoparticle deposit was at least ten times lower than the reported threshold for the bulk film. This could be explained by the combined effects of melting temperature depression, lower conductive heat transfer loss, strong absorption of the incident laser beam, and the relatively weak bonding between nanoparticles. The ablation physics were verified by the nanoparticle sintering characterization, ablation threshold measurement, time resolved ablation plume shadowgraphs, analysis of ablation ejecta, and the measurement and calculation of optical properties. High resolution and clean feature fabrication with small energy and selective multilayer processing are demonstrated

  11. Nanosecond radio bursts from strong plasma turbulence in the Crab pulsar.

    Science.gov (United States)

    Hankins, T H; Kern, J S; Weatherall, J C; Eilek, J A

    2003-03-13

    The Crab pulsar was discovered by the occasional exceptionally bright radio pulses it emits, subsequently dubbed 'giant' pulses. Only two other pulsars are known to emit giant pulses. There is no satisfactory explanation for the occurrence of giant pulses, nor is there a complete theory of the pulsar emission mechanism in general. Competing models for the radio emission mechanism can be distinguished by the temporal structure of their coherent emission. Here we report the discovery of isolated, highly polarized, two-nanosecond subpulses within the giant radio pulses from the Crab pulsar. The plasma structures responsible for these emissions must be smaller than one metre in size, making them by far the smallest objects ever detected and resolved outside the Solar System, and the brightest transient radio sources in the sky. Only one of the current models--the collapse of plasma-turbulent wave packets in the pulsar magnetosphere--can account for the nanopulses we observe.

  12. Nanoparticle mediated ablation of breast cancer cells using a nanosecond pulsed electric field

    Science.gov (United States)

    Burford, Christopher

    In the past, both nanomaterials and various heating modalities have been researched as means for treating cancers. However, many of the current methodologies have the flaws of inconsistent tumor ablation and significant destruction of healthy cells. Based on research performed using constant radiofrequency electric fields and metallic nanoparticles (where cell necrosis is induced by the heating of these nanoparticles) we have developed a modality that simlarly uses functionalized metallic nanoparticles, specific for the T47D breast cancer cell line, and nanosecond pulsed electric fields as the hyperthermic inducer. Using both iron oxide and gold nanoparticles the results of our pilot studies indicated that up to 90% of the cancer cells were ablated given the optimal treatment parameters. These quantities of ablated cells were achieved using a cumulative exposure time 6 orders of magnitude less than most in vitro radiofrequency electric field studies.

  13. Thermodynamics of nanosecond nanobubble formation at laser-excited metal nanoparticles

    International Nuclear Information System (INIS)

    Siems, A; Weber, S A L; Boneberg, J; Plech, A

    2011-01-01

    The nonlinear thermal behavior of laser-heated gold nanoparticles in aqueous suspension is determined by time-resolved optical spectroscopy and x-ray scattering. The nanoparticles can be excited transiently to high lattice temperatures owing to their large absorption cross-section and slow heat dissipation to the surrounding. A consequence is the observation of lattice expansion, changed optical transmission, vapor bubble formation or particle melting. The heat transfer equations are solved for two limiting cases of heat pulses shorter and longer than the characteristic cooling time. The results of pulsed excitation with femtosecond and nanosecond lasers are explained by the theoretical prediction, and the bubble formation is interpreted by a spinodal decomposition at the particle-liquid interface. It is shown that both the laser spectroscopy and x-ray scattering results agree qualitatively and quantitatively, underlining the validity of the comprehensive model.

  14. Applications of nanosecond, kilojoule lasers to the basic physics of waves in plasmas

    International Nuclear Information System (INIS)

    Drake, R.P.

    1992-01-01

    Plasmas can sustain many normal modes of oscillation (waves), including both electromagnetic and electrostatic modes. These waves can interact by a wide variety of linear and nonlinear mechanisms, including mode coupling, mixing, and instabilities. Furthermore, such mechanisms compete, so that a given wave might be absorbed, might mode convert, or might decay by one of several instabilities, depending upon the specific circumstances in which it is produced. Moreover, such waves are important in many applications, including for example laser fusion, x-ray lasers, plasma accelerators, and ionospheric heating. Laser-produced plasmas can provide an effective medium for the studies of such waves and the related mechanisms. New opportunities will be made possible by the advent of comparatively inexpensive nanosecond, kilojoule lasers. One can now contemplate affordable experiments, not limited by programmatic constraints, that could study such the basic physics of the waves in such plasmas with unprecedented precision and in unprecedented detail

  15. Two modes of cell death caused by exposure to nanosecond pulsed electric field.

    Directory of Open Access Journals (Sweden)

    Olga N Pakhomova

    Full Text Available High-amplitude electric pulses of nanosecond duration, also known as nanosecond pulsed electric field (nsPEF, are a novel modality with promising applications for cell stimulation and tissue ablation. However, key mechanisms responsible for the cytotoxicity of nsPEF have not been established. We show that the principal cause of cell death induced by 60- or 300-ns pulses in U937 cells is the loss of the plasma membrane integrity ("nanoelectroporation", leading to water uptake, cell swelling, and eventual membrane rupture. Most of this early necrotic death occurs within 1-2 hr after nsPEF exposure. The uptake of water is driven by the presence of pore-impermeable solutes inside the cell, and can be counterbalanced by the presence of a pore-impermeable solute such as sucrose in the medium. Sucrose blocks swelling and prevents the early necrotic death; however the long-term cell survival (24 and 48 hr does not significantly change. Cells protected with sucrose demonstrate higher incidence of the delayed death (6-24 hr post nsPEF. These cells are more often positive for the uptake of an early apoptotic marker dye YO-PRO-1 while remaining impermeable to propidium iodide. Instead of swelling, these cells often develop apoptotic fragmentation of the cytoplasm. Caspase 3/7 activity increases already in 1 hr after nsPEF and poly-ADP ribose polymerase (PARP cleavage is detected in 2 hr. Staurosporin-treated positive control cells develop these apoptotic signs only in 3 and 4 hr, respectively. We conclude that nsPEF exposure triggers both necrotic and apoptotic pathways. The early necrotic death prevails under standard cell culture conditions, but cells rescued from the necrosis nonetheless die later on by apoptosis. The balance between the two modes of cell death can be controlled by enabling or blocking cell swelling.

  16. Cutting and drilling of carbon fiber reinforced plastics (CFRP) by 70W short pulse nanosecond laser

    Science.gov (United States)

    Jaeschke, Peter; Stolberg, Klaus; Bastick, Stefan; Ziolkowski, Ewa; Roehner, Markus; Suttmann, Oliver; Overmeyer, Ludger

    2014-02-01

    Continuous carbon fibre reinforced plastics (CFRP) are recognized as having a significant lightweight construction potential for a wide variety of industrial applications. However, a today`s barrier for a comprehensive dissemination of CFRP structures is the lack of economic, quick and reliable manufacture processes, e.g. the cutting and drilling steps. In this paper, the capability of using pulsed disk lasers in CFRP machining is discussed. In CFRP processing with NIR lasers, carbon fibers show excellent optical absorption and heat dissipation, contrary to the plastics matrix. Therefore heat dissipation away from the laser focus into the material is driven by heat conduction of the fibres. The matrix is heated indirectly by heat transfer from the fibres. To cut CFRP, it is required to reach the melting temperature for thermoplastic matrix materials or the disintegration temperature for thermoset systems as well as the sublimation temperature of the reinforcing fibers simultaneously. One solution for this problem is to use short pulse nanosecond lasers. We have investigated CFRP cutting and drilling with such a laser (max. 7 mJ @ 10 kHz, 30 ns). This laser offers the opportunity of wide range parameter tuning for systematic process optimization. By applying drilling and cutting operations based on galvanometer scanning techniques in multi-cycle mode, excellent surface and edge characteristics in terms of delamination-free and intact fiber-matrix interface were achieved. The results indicate that nanosecond disk laser machining could consequently be a suitable tool for the automotive and aircraft industry for cutting and drilling steps.

  17. Influence of grid resolution in fluid-model simulation of nanosecond dielectric barrier discharge plasma actuator

    Science.gov (United States)

    Hua, Weizhuo; Fukagata, Koji

    2018-04-01

    Two-dimensional numerical simulation of a surface dielectric barrier discharge (SDBD) plasma actuator, driven by a nanosecond voltage pulse, is conducted. A special focus is laid upon the influence of grid resolution on the computational result. It is found that the computational result is not very sensitive to the streamwise grid spacing, whereas the wall-normal grid spacing has a critical influence. In particular, the computed propagation velocity changes discontinuously around the wall-normal grid spacing about 2 μm due to a qualitative change of discharge structure. The present result suggests that a computational grid finer than that was used in most of previous studies is required to correctly capture the structure and dynamics of streamer: when a positive nanosecond voltage pulse is applied to the upper electrode, a streamer forms in the vicinity of upper electrode and propagates along the dielectric surface with a maximum propagation velocity of 2 × 108 cm/s, and a gap with low electron and ion density (i.e., plasma sheath) exists between the streamer and dielectric surface. Difference between the results obtained using the finer and the coarser grid is discussed in detail in terms of the electron transport at a position near the surface. When the finer grid is used, the low electron density near the surface is caused by the absence of ionization avalanche: in that region, the electrons generated by ionization is compensated by drift-diffusion flux. In contrast, when the coarser grid is used, underestimated drift-diffusion flux cannot compensate the electrons generated by ionization, and it leads to an incorrect increase of electron density.

  18. Plasma surface treatment of Cu by nanosecond-pulse diffuse discharges in atmospheric air

    Science.gov (United States)

    Cheng, ZHANG; Jintao, QIU; Fei, KONG; Xingmin, HOU; Zhi, FANG; Yu, YIN; Tao, SHAO

    2018-01-01

    Nanosecond-pulse diffuse discharges could provide high-density plasma and high-energy electrons at atmospheric pressure. In this paper, the surface treatment of Cu by nanosecond-pulse diffuse discharges is conducted in atmospheric air. Factors influencing the water contact angle (WCA), chemical composition and microhardness, such as the gap spacing and treatment time, are investigated. The results show that after the plasma surface treatment, the WCA considerably decreases from 87° to 42.3°, and the surface energy increases from 20.46 mJ m-2 to 66.28 mJ m-2. Results of energy dispersive x-ray analysis show that the concentration of carbon decreases, but the concentrations of oxygen and nitrogen increase significantly. Moreover, the microhardness increases by approximately 30% after the plasma treatment. The aforementioned changes on the Cu surface indicate the plasma surface treatment enhances the hydrophilicity and microhardness, and it cleans the carbon and achieves oxidization on the Cu surface. Furthermore, by increasing the gap spacing and treatment time, better treatment effects can be obtained. The microhardness in the case of a 2.5 cm gap is higher than that in the case of a 3 cm gap. More oxygen and nitrogen species appear on the Cu surface for the 2.5 cm gap treatment than for the 3 cm gap treatment. The WCA significantly decreases with the treatment time when it is no longer than 90 s, and then it reaches saturation. In addition, more oxygen-containing and nitrogen-containing groups appear after extended plasma treatment time. They contribute to the improvement of the hydrophilicity and oxidation on the Cu surface.

  19. Coffee consumption and risk of hepatocellular carcinoma: a meta-analysis of eleven epidemiological studies

    Directory of Open Access Journals (Sweden)

    Bai K

    2016-07-01

    Full Text Available Kai Bai,* Qiucheng Cai,* Yi Jiang, Lizhi Lv Department of Hepatobiliary Surgery, Fuzong Clinical College, Fujian Medical University, Fuzhou, People’s Republic of China *These authors contributed equally to this work Abstract: Growing evidence has shown that coffee consumption is inversely related with the risk of hepatocellular carcinoma. It is suggested that caffeine maintains strong antioxidative activity. With this property, coffee intake may lead to the inhibition of cell proliferation of liver cancer cells; also, some compounds contained in coffee can reduce the genotoxicity of aflatoxin B1 in vitro and lower the damage caused by some carcinogens. A computerized search was performed in PubMed to identify relevant articles published before August 2015. Eleven relevant studies were included with a total of 2,795 cases and 340,749 control subjects. According to the meta-analysis we performed, the pooled odds ratio (OR from all included studies was 0.49 (95% confidence interval [CI] =0.46–0.52. The subgroup analysis indicated that the pooled ORs for Asian studies and other populations were 0.27 (95% CI =0.23–0.31 and 0.82 (95% CI =0.77–0.87, respectively. The overall pooled OR for high consumption was decreased to 0.21 (95% CI =0.18–0.25 and significance was observed. Among other populations, the pooled OR of subjects with high coffee consumption was 0.65 (95% CI =0.56–0.73 compared to the nondrinker. The corresponding OR of five Asian studies was 0.13 (95% CI =0.09–0.17. The findings from this meta-analysis further confirmed the inverse association between the coffee consumption and hepatocellular carcinoma risk with quantitative evidence. The protective effect can be detected among healthy population and patients with chronic liver diseases, and the consumption can also prevent the development of liver cirrhosis. Keywords: hepatocarcinogenesis, meta-analysis, coffee, antioxidant

  20. Korpusbasert undervisning i fremmedspråkene: La elevens nysgjerrighet sette dagsorden

    Directory of Open Access Journals (Sweden)

    Margrete Dyvik Cardona

    2014-09-01

    Full Text Available Korpus er en type digitale språkressurser (maskinlesbare tekstsamlinger som er mye brukt i moderne lingvistikk som empirisk støtte for studiet av ulike språklige fenomener. Korpus kan med hell brukes i fremmedspråkundervisningen, men er frem til nå ikke i tilstrekkelig grad blitt tatt i bruk i norsk skole og høyere utdanning. I denne artikkelen gir vi en gjennomgang av eksisterende forskningslitteratur på feltet, med hovedvekt på bidrag fra det angloamerikanske språkområdet. Deretter går vi gjennom to korpus som er tilgjengelige for norske brukere, Norwegian-Spanish Parallel Corpus og Oslo Multilingual Corpus. Vi viser hvordan disse korpusene kan brukes i undervisningen av ulike språklige fenomener, fra vokabular til sosiolingvistiske fenomener. På grunnlag av eksisterende forskning på pedagogiske applikasjoner av korpus samt våre egne forslag til undervisningsopplegg er det grunn til å tro at bruk av korpus vil kunne være et verdifullt bidrag til fremmedspråkundervisningen i norske klasserom. Likevel finnes visse utfordringer som hindrer at korpus tas i bruk. Både mangel på tid, gruppestørrelser og teknologiske hindre kan stå i veien. Bruk av korpus i fremtidens klasserom er også nært knyttet til ulike trender, både innenfor teknologi og forskning. For det først blir datateknologi stadig mer tilgjengelig, parallelt med at elevenes og studentenes digitale kompetanse øker. Dette er fenomener som begge skulle tilsi økt bruk av korpus. Videre er det en sterk bevegelse for å åpne opp tilgang til forskningsdata og –ressurser (Open Access og denne bølgen kan også brukes til å åpne opp forskningsressurser, herunder korpus, for læringsformål. Til syvende og sist er spørsmålet om bruk av korpus i klasserommet imidlertid avhengig av en tettere dialog mellom lærere og korpuslingvister, både i lærerutdanningen så vel som gjennom faglig oppdatering underveis i yrkeslivet.

  1. Sensory profile of eleven peach cultivars Perfil sensorial de onze cultivares de pêssegos

    Directory of Open Access Journals (Sweden)

    Francine Lorena Cuquel

    2012-03-01

    Full Text Available The goal of this study was to evaluate the sensory profile of eleven peach cultivars grown in an experimental orchard located in the city of Lapa (PR, Brazil in two seasons. The peach cultivars analyzed were Aurora I, Chimarrita, Chiripá, Coral, Eldorado, Granada, Leonense, Maciel, Marli, Premier, and Vanguarda. The sensory analysis was performed by previously trained panelists; 20 of them in the first season and 10 in the second season. The sensory evaluation was performed using Quantitative Descriptive Analysis, in which the following attributes were measured: appearance, aroma, flesh color, flesh firmness, flavor, and juiciness. The results showed preference for sweet, soft, and juicy fruits. Chimarrita, Chiripá, and Coral fruits showed better sensorial performance than the other peach cultivars. It was also verified that the analysis of the attributes aroma, flesh firmness, and flavor is enough for performing the sensory profile of peach fruits for in natura consumption.Este trabalho teve como objetivo avaliar o perfil sensorial de onze cultivares de pêssego produzidos em duas safras em um pomar experimental implantado na Lapa (PR, Brasil. Os cultivares analisados foram Aurora I, Chimarrita, Chiripá, Coral, Eldorado, Granada, Leonense, Maciel, Marli, Premier e Vanguarda. As análises sensoriais foram realizadas por julgadores previamente treinados, sendo 20 julgadores na primeira safra e 10 na segunda. O método de avaliação empregado foi a Análise Descritiva Quantitativa na qual foram mensurados os atributos aparência, aroma, cor de polpa, firmeza de polpa, sabor e suculência dos frutos. Os resultados obtidos demonstraram a preferência por frutos de sabor adocicado, com polpa macia e suculenta. Os cultivares Chimarrita, Chiripá e Coral obtiveram o melhor desempenho nas análises sensoriais. Foi verificado ainda que os atributos aroma, firmeza de polpa e sabor são considerados suficientes para a avaliação do perfil sensorial de

  2. Kinetics and dynamics of nanosecond streamer discharge in atmospheric-pressure gas bubble suspended in distilled water under saturated vapor pressure conditions

    KAUST Repository

    Sharma, Ashish; Levko, Dmitry; Raja, Laxminarayan L; Cha, Min

    2016-01-01

    We perform computational studies of nanosecond streamer discharges generated in helium bubbles immersed in distilled water under atmospheric pressure conditions. The model takes into account the presence of water vapor in the gas bubble

  3. Trends in the eradication rates of Helicobacter pylori infection for eleven years

    Science.gov (United States)

    Yoon, Jai Hoon; Baik, Gwang Ho; Sohn, Kyoung Min; Kim, Dae Yong; Kim, Yeon Soo; Suk, Ki Tae; Kim, Jin Bong; Kim, Dong Joon; Kim, Jin Bae; Shin, Woon Geon; Kim, Hak Yang; Baik, Il Hyun; Jang, Hyun Joo

    2012-01-01

    : gastric ulcer in 855 (21.5%); duodenal ulcer in 878 (22.1%); gastric and duodenal ulcer in 124 (3.1%), erosive, atrophic gastritis and functional dyspepsia in 2055 (51.8%); and other findings (e.g., MALToma, patients who wanted to receive the therapy even though they had no abnormal endoscopic finding) in 57 (0.5%). The overall eradication rate of the 2 wk standard first-line triple regimen was 86.5%. The annual eradication rates from 2000 to 2010 were 86.7%, 85.4%, 86.5%, 83.3%, 89.9%, 90.5%, 88.4%, 84.5%, 89.1%, 85.8%, and 88.3%, sequentially (P = 0.06). No definite evidence of a significant change in the eradication rate was seen during the past eleven years. The eradication rates of second-line therapy were 88.9%, 82.4%, 85%, 83.9%, 77.3%, 85.7%, 84.4%, 87.3%, 83.3%, 88.9%, and 84% (P = 0.77). The overall eradication rate of 1 wk quadruple second-line therapy was 84.7%. There was no significant difference in the eradication rate according to the H. pylori associated diseases. CONCLUSION: This study showed that there was no trend change in the H. pylori eradication rate over the most recent 11 years in our institution. PMID:23236238

  4. Length-weight relationship of eleven species of marine catfishes from the northern Arabian Sea coast of Pakistan

    Science.gov (United States)

    Farooq, Noureen; Qamar, Nazia; Rashid, Shahnaz; Panhwar, Sher Khan

    2017-09-01

    This study records length-weight relationships (LWRs) for eleven commercially important marine catfish species of the family Ariidae (sea catfishes) and Plotosidae (eel catfishes) from the northern Arabian Sea coast of Pakistan. The specimens were sampled from December 2014 to November 2015, using bottom trawls with various mesh sizes by commercial vessels. The species were Nemapteryx caelatus, Sciades sona, Arius gagora, Batrachocephalus mino, Netuma thalassina, N. bilineata, Osteogeneiosus militaris, Plicofollis dussumieri, P. tenuispinis, Plotosus limbatus, and P. lineatus. Of the eleven species, two species A. gagora and N. bilineata were recorded for the first time and LWRs for four species A. gagora, N. bilineata, S. sona, and B. mino still have no data in the FishBase database. In addition, new maximum length for each of the three species N. bilineata, O. militaris and B. mino was also found.

  5. Reading Very Well for Our Age: Hyperobject Metadata and Global Warming in Emily St. John Mandel’s Station Eleven

    Directory of Open Access Journals (Sweden)

    Martin Paul Eve

    2018-02-01

    Full Text Available In recent years, the practices of symptomatic reading have been called into question by scholars such as Stephen Best, Sharon Marcus, Cathy N. Davidson, David Theo Goldberg, Rita Felski and Bruno Latour. It is claimed that such reading has become either formulaic or politically inefficacious. This article argues, against such thinking, that Emily St. John Mandel’s Arthur C. Clarke award–winning novel 'Station Eleven' (2014 presents several challenges for an age of so-called post-critical reading. Given that this novel is, in some ways, about how the future will ‘read’ our present, I use the metaphor of ‘metadata’ here to think through the series of ruined objects in 'Station Eleven' that project a hyperobject-like extent across two epistemic contexts. I argue that this is a comment on interpretative reading practices and an invitation for politicised symptomatic readings of the novel. Using this approach, I show that 'Station Eleven' is a novel that is deeply concerned with global warming and with colonial nationalist legacies, even while such concerns appear buried—or even absent—within the novel. If one takes the novel’s surface instruction to look for ‘another world just out sight’, these concerns of the early twenty-first century emerge as central to the forking futures of Mandel’s work.

  6. Temporal dependence of the enhancement of material removal in femtosecond-nanosecond dual-pulse laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Scaffidi, Jon; Pearman, William; Carter, J. Chance; Colston, Bill W. Jr.; Angel, S. Michael

    2004-01-01

    Despite the large neutral atomic and ionic emission enhancements that have been noted in collinear and orthogonal dual-pulse laser-induced breakdown spectroscopy, the source or sources of these significant signal and signal-to-noise ratio improvements have yet to be explained. In the research reported herein, the combination of a femtosecond preablative air spark and a nanosecond ablative pulse yields eightfold and tenfold material removal improvement for brass and aluminum, respectively, but neutral atomic emission is enhanced by only a factor of 3-4. Additionally, temporal correlation between enhancement of material removal and of atomic emission is quite poor, suggesting that the atomic-emission enhancements noted in the femtosecond-nanosecond pulse configuration result in large part from some source other than simple improvement in material removal

  7. Study on the characteristics of barrier free surface discharge driven by repetitive nanosecond pulses at atmospheric pressure

    Energy Technology Data Exchange (ETDEWEB)

    Lei, Pang; Qiaogen, Zhang [State Key Laboratory of Electrical Insulation and Power Equipment, Xi' an Jiaotong University, Xi' an 710049 (China); Kun, He [China Electric Power Research Institute, Beijing 100192 (China); Chunliang, Liu [State Key Laboratory for Physical Electronics and Devices, Xi' an Jiaotong University, Xi' an 710049 (China)

    2016-05-15

    Nanosecond pulsed plasma has an enormous potential in many applications. In this paper, the characteristics of barrier free nanosecond pulsed surface discharge are investigated by the use of an actuator with a strip-strip film electrode configuration, including the effect of electrode width and the gap distance on the plasma morphology and electrical characteristics at atmospheric pressure. It was found that it is relative easier to generate a quasi uniform discharge with a thinner electrode width and a smaller gap distance. The underlying physical mechanism was also discussed. Besides that, the influence of airflow on repetitive pulsed surface discharge was examined. By comparing to the discharge produced by two different pulse waveforms in airflows, we found that the discharge driven by a faster pulse behaves more stable. Finally, a model was developed to analyze the interaction of the airflow and the discharge channels.

  8. Effect of initial chirp on near-infrared supercontinuum generation by a nanosecond pulse in a nonlinear fiber amplifier

    International Nuclear Information System (INIS)

    Song Rui; Hou Jing; Wang Ze-Feng; Lu Qi-Sheng; Xiao Rui

    2013-01-01

    Theoretical and experimental research on the effect of initial chirp on near-infrared supercontinuum generation by a nanosecond pulse in a nonlinear fiber amplifier is carried out. The complex Ginzburg—Landau equation is used to simulate the propagation of the pulse in the fiber amplifier and the results show that pulses with negative initial chirp produce the widest supercontinuum and pulses with positive initial chirp produce the narrowest supercontinuum when the central wavelength of the pump lies in the normal dispersion region of the gain fiber. A self-made line width narrowing system is utilized to control the initial chirp of the nanosecond pump pulse and a four-stage master oscillator power amplifier configuration is adopted to produce a high power near-infrared suppercontinuum. The experimental results are in good agreement with simulations which can provide some guidance on further optimization of the system in future work. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  9. Nanosecond Pulsed Discharge in Water without Bubbles: A Fundamental Study of Initiation, Propagation and Plasma Characteristics

    Science.gov (United States)

    Seepersad, Yohan

    The state of plasma is widely known as a gas-phase phenomenon, but plasma in liquids have also received significant attention over the last century. Generating plasma in liquids however is theoretically challenging, and this problem is often overcome via liquid-gas phase transition preceding the actual plasma formation. In this sense, plasma forms in gas bubbles in the liquid. Recent work at the Drexel Plasma Institute has shown that nanosecond pulsed electric fields can initiate plasma in liquids without any initial cavitation phase, at voltages below theoretical direct-ionization thresholds. This unique regime is poorly understood and does not fit into any current descriptive mechanisms. As with all new phenomena, a complete fundamental description is paramount to understanding its usefulness to practical applications. The primary goals of this research were to qualitatively and quantitatively understand the phenomenon of nanosecond pulsed discharge in liquids as a means to characterizing properties that may open up niche application possibilities. Analysis of the plasma was based on experimental results from non-invasive, sub-nanosecond time-resolved optical diagnostics, including direct imaging, transmission imaging (Schlieren and shadow), and optical emission spectroscopy. The physical characteristics of the plasma were studied as a function of variations in the electric field amplitude and polarity, liquid permittivity, and pulse duration. It was found that the plasma size and emission intensity was dependent on the permittivity of the liquid, as well as the voltage polarity, and the structure and dynamics were explained by a 'cold-lightning' mechanism. The under-breakdown dynamics at the liquid-electrode interface were investigated by transmission imaging to provide evidence for a novel mechanism for initiation based on the electrostriction. This mechanism was proposed by collaborators on the project and developed alongside the experimental work in this

  10. Study of spatiotemporal dynamics of a nanosecond atmospheric-pressure dielectric barrier discharge in millimeter-long air gaps

    Energy Technology Data Exchange (ETDEWEB)

    Malashin, M. V.; Moshkunkov, S. I.; Khomich, V. Yu.; Shershunova, E. A., E-mail: eshershunova@gmail.com [Russian Academy of Sciences, Institute for Electrophysics and Electric Power (Russian Federation)

    2017-02-15

    The spatiotemporal dynamics of a nanosecond atmospheric-pressure dielectric barrier discharge in 1- to 3-mm-long air gaps was studied experimentally. By using a segmented electrode, data on the time evolution of the discharge in different regions of the discharge gap were obtained. The uniformity of the discharge over the cross section is estimated by analyzing the spatial distribution of its glow.

  11. Analysis of copper contamination in transformer insulating material with nanosecond- and femtosecond-laser-induced breakdown spectroscopy

    Science.gov (United States)

    Aparna, N.; Vasa, N. J.; Sarathi, R.

    2018-06-01

    This work examines the oil-impregnated pressboard insulation of high-voltage power transformers, for the determination of copper contamination. Nanosecond- and femtosecond-laser-induced breakdown spectroscopy revealed atomic copper lines and molecular copper monoxide bands due to copper sulphide diffusion. X-ray diffraction studies also indicated the presence of CuO emission. Elemental and molecular mapping compared transformer insulating material ageing in different media—air, N2, He and vacuum.

  12. Transitions between corona, glow, and spark regimes of nanosecond repetitively pulsed discharges in air at atmospheric pressure

    OpenAIRE

    Pai , David ,; Lacoste , Deanna ,; Laux , C.

    2010-01-01

    International audience; In atmospheric pressure air preheated from 300 to 1000 K, the nanosecond repetitively pulsed (NRP) method has been used to generate corona, glow, and spark discharges. Experiments have been performed to determine the parameter space (applied voltage, pulse repetition frequency, ambient gas temperature, and interelectrode gap distance) of each discharge regime. In particular, the experimental conditions necessary for the glow regime of NRP discharges have been determine...

  13. Comparative study of the dissociative ionization of 1,1,1-trichloroethane using nanosecond and femtosecond laser pulses

    CSIR Research Space (South Africa)

    Du Plessis, A

    2010-03-01

    Full Text Available , but different fragmentation patterns. A general trend is that when using femtosecond laser pulses for ionization, the parent molecular ion is observed but not for nanosecond laser ionization. There is also a fundamental interest in laser...-molecule interactions at the high intensities available from femtosecond lasers [12,13]. These papers describe the multiphoton ionization mechanisms termed ladder climbing and ladder switching, which explain the presence of parent molecular ion in ultrashort pulse...

  14. Measurements of Electric Field in a Nanosecond Pulse Discharge by 4-WAVE Mixing

    Science.gov (United States)

    Baratte, Edmond; Adamovich, Igor V.; Simeni Simeni, Marien; Frederickson, Kraig

    2017-06-01

    Picosecond four-wave mixing is used to measure temporally and Picosecond four-wave mixing is used to measure temporally and spatially resolved electric field in a nanosecond pulse dielectric discharge sustained in room air and in an atmospheric pressure hydrogen diffusion flame. Measurements of the electric field, and more precisely the reduced electric field (E/N) in the plasma is critical for determination rate coefficients of electron impact processes in the plasma, as well as for quantifying energy partition in the electric discharge among different molecular energy modes. The four-wave mixing measurements are performed using a collinear phase matching geometry, with nitrogen used as the probe species, at temporal resolution of about 2 ns . Absolute calibration is performed by measurement of a known electrostatic electric field. In the present experiments, the discharge is sustained between two stainless steel plate electrodes, each placed in a quartz sleeve, which greatly improves plasma uniformity. Our previous measurements of electric field in a nanosecond pulse dielectric barrier discharge by picosecond 4-wave mixing have been done in air at room temperature, in a discharge sustained between a razor edge high-voltage electrode and a plane grounded electrode (a quartz plate or a layer of distilled water). Electric field measurements in a flame, which is a high-temperature environment, are more challenging because the four-wave mixing signal is proportional to the to square root of the difference betwen the populations of N2 ground vibrational level (v=0) and first excited vibrational level (v=1). At high temperatures, the total number density is reduced, thus reducing absolute vibrational level populations of N2. Also, the signal is reduced further due to a wider distribution of N2 molecules over multiple rotational levels at higher temperatures, while the present four-wave mixing diagnostics is using spectrally narrow output of a ps laser and a high

  15. Studies of nanosecond pulse surface ionization wave discharges over solid and liquid dielectric surfaces

    International Nuclear Information System (INIS)

    Petrishchev, Vitaly; Leonov, Sergey; Adamovich, Igor V

    2014-01-01

    Surface ionization wave discharges generated by high-voltage nanosecond pulses, propagating over a planar quartz surface and over liquid surfaces (distilled water and 1-butanol) have been studied in a rectangular cross section test cell. The discharge was initiated using a custom-made, alternating polarity, high-voltage nanosecond pulse plasma generator, operated at a pulse repetition rate of 100–500 Hz, with a pulse peak voltage and current of 10–15 kV and 7–20 A, respectively, a pulse FWHM of ∼100 ns, and a coupled pulse energy of 2–9 mJ/pulse. Wave speed was measured using a capacitive probe. ICCD camera images demonstrated that the ionization wave propagated predominantly over the quartz wall or over the liquid surface adjacent to the grounded waveguide placed along the bottom wall of the test cell. Under all experimental conditions tested, the surface plasma ‘sheet’ was diffuse and fairly uniform, both for positive and negative polarities. The parameters of ionization wave discharge propagating over distilled water and 1-butanol surfaces were close to those of the discharge over a quartz wall. No perturbation of the liquid surface by the discharge was detected. In most cases, the positive polarity surface ionization wave propagated at a higher speed and over a longer distance compared to the negative polarity wave. For all three sets of experiments (surface ionization wave discharge over quartz, water and 1-butanol), wave speed and travel distance decreased with pressure. Diffuse, highly reproducible surface ionization wave discharge was also observed over the liquid butanol–saturated butanol vapor interface, as well as over the distilled water–saturated water vapor interface, without buffer gas flow. No significant difference was detected between surface ionization discharges sustained using single-polarity (positive or negative), or alternating polarity high-voltage pulses. Plasma emission images yielded preliminary evidence of charge

  16. Large-volume excitation of air, argon, nitrogen and combustible mixtures by thermal jets produced by nanosecond spark discharges

    Science.gov (United States)

    Stepanyan, Sergey; Hayashi, Jun; Salmon, Arthur; Stancu, Gabi D.; Laux, Christophe O.

    2017-04-01

    This work presents experimental observations of strong expanding thermal jets following the application of nanosecond spark discharges. These jets propagate in a toroidal shape perpendicular to the interelectrode axis, with high velocities of up to 30 m s-1 and over distances of the order of a cm. Their propagation length is much larger than the thermal expansion region produced by the conventional millisecond sparks used in car engine ignition, thus greatly improving the volumetric excitation of gas mixtures. The shape and velocity of the jets is found to be fairly insensitive to the shape of the electrodes. In addition, their spatial extent is found to increase with the number of nanosecond sparks and with the discharge voltage, and to decrease slightly with the pressure between 1 and 7 atm at constant applied voltage. Finally, this thermal jet phenomenon is observed in experiments conducted with many types of gas mixtures, including air, nitrogen, argon, and combustible CH4/air mixtures. This makes nanosecond repetitively pulsed discharges particularly attractive for aerodynamic flow control or plasma-assisted combustion because of their ability to excite large volumes of gas, typically about 100 times the volume of the discharge.

  17. Standard Reference Tables -

    Data.gov (United States)

    Department of Transportation — The Standard Reference Tables (SRT) provide consistent reference data for the various applications that support Flight Standards Service (AFS) business processes and...

  18. Electropermeabilization by uni- or bipolar nanosecond electric pulses: The impact of extracellular conductivity.

    Science.gov (United States)

    Gianulis, Elena C; Casciola, Maura; Xiao, Shu; Pakhomova, Olga N; Pakhomov, Andrei G

    2018-02-01

    Cellular effects caused by nanosecond electric pulses (nsEP) can be reduced by an electric field reversal, a phenomenon known as bipolar cancellation. The reason for this cancellation effect remains unknown. We hypothesized that assisted membrane discharge is the mechanism for bipolar cancellation. CHO-K1 cells bathed in high (16.1mS/cm; HCS) or low (1.8mS/cm; LCS) conductivity solutions were exposed to either one unipolar (300-ns) or two opposite polarity (300+300-ns; bipolar) nsEP (4-40kV/cm) with increasing interpulse intervals (0.1-50μs). Time-lapse YO-PRO-1 (YP) uptake revealed enhanced membrane permeabilization in LCS compared to HCS at all tested voltages. The time-dependence of bipolar cancellation was similar in both solutions, using either identical (22kV/cm) or isoeffective nsEP treatments (12 and 32kV/cm for LCS and HCS, respectively). However, cancellation was significantly stronger in LCS when the bipolar nsEP had no, or very short (bipolar cancellation was still present with interpulse intervals as long as 50μs, beyond the time expected for membrane discharge. Our findings do not support assisted membrane discharge as the mechanism for bipolar cancellation. Instead they exemplify the sustained action of nsEP that can be reversed long after the initial stimulus. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Nanosecond X-ray detector based on high resistivity ZnO single crystal semiconductor

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Xiaolong; He, Yongning, E-mail: yongning@mail.xjtu.edu.cn; Peng, Wenbo; Huang, Zhiyong; Qi, Xiaomeng; Pan, Zijian; Zhang, Wenting [School of Electronic and Information Engineering, Xi' an Jiaotong University, Xi' an 710049 (China); Chen, Liang; Liu, Jinliang; Zhang, Zhongbing; Ouyang, Xiaoping [Radiation Detection Research Center, Northwest Institute of Nuclear Technology, Xi' an 710024 (China)

    2016-04-25

    The pulse radiation detectors are sorely needed in the fields of nuclear reaction monitoring, material analysis, astronomy study, spacecraft navigation, and space communication. In this work, we demonstrate a nanosecond X-ray detector based on ZnO single crystal semiconductor, which emerges as a promising compound-semiconductor radiation detection material for its high radiation tolerance and advanced large-size bulk crystal growth technique. The resistivity of the ZnO single crystal is as high as 10{sup 13} Ω cm due to the compensation of the donor defects (V{sub O}) and acceptor defects (V{sub Zn} and O{sub i}) after high temperature annealing in oxygen. The photoconductive X-ray detector was fabricated using the high resistivity ZnO single crystal. The rise time and fall time of the detector to a 10 ps pulse electron beam are 0.8 ns and 3.3 ns, respectively, indicating great potential for ultrafast X-ray detection applications.

  20. PIC simulations of post-pulse field reversal and secondary ionization in nanosecond argon discharges

    Science.gov (United States)

    Kim, H. Y.; Gołkowski, M.; Gołkowski, C.; Stoltz, P.; Cohen, M. B.; Walker, M.

    2018-05-01

    Post-pulse electric field reversal and secondary ionization are investigated with a full kinetic treatment in argon discharges between planar electrodes on nanosecond time scales. The secondary ionization, which occurs at the falling edge of the voltage pulse, is induced by charge separation in the bulk plasma region. This process is driven by a reverse in the electric field from the cathode sheath to the formerly driven anode. Under the influence of the reverse electric field, electrons in the bulk plasma and sheath regions are accelerated toward the cathode. The electron movement manifests itself as a strong electron current generating high electron energies with significant electron dissipated power. Accelerated electrons collide with Ar molecules and an increased ionization rate is achieved even though the driving voltage is no longer applied. With this secondary ionization, in a single pulse (SP), the maximum electron density achieved is 1.5 times higher and takes a shorter time to reach using 1 kV 2 ns pulse as compared to a 1 kV direct current voltage at 1 Torr. A bipolar dual pulse excitation can increase maximum density another 50%–70% above a SP excitation and in half the time of RF sinusoidal excitation of the same period. The first field reversal is most prominent but subsequent field reversals also occur and correspond to electron temperature increases. Targeted pulse designs can be used to condition plasma density as required for fast discharge applications.

  1. Characteristics of a novel nanosecond DBD microplasma reactor for flow applications

    Science.gov (United States)

    Elkholy, A.; Nijdam, S.; van Veldhuizen, E.; Dam, N.; van Oijen, J.; Ebert, U.; de Goey, L. Philip H.

    2018-05-01

    We present a novel microplasma flow reactor using a dielectric barrier discharge (DBD) driven by repetitive nanosecond high-voltage pulses. Our DBD-based geometry can generate a non-thermal plasma discharge at atmospheric pressure and below in a regular pattern of micro-channels. This reactor can work continuously up to about 100 min in air, depending on the pulse repetition rate and operating pressure. We here present the geometry and main characteristics of the reactor. Pulse energies of 1.46 and 1.3 μJ per channel at atmospheric pressure and 50 mbar, respectively, have been determined by time-resolved measurements of current and voltage. Time-resolved optical emission spectroscopy measurements have been performed to calculate the relative species concentrations and temperatures (vibrational and rotational) of the discharge. The effects of the operating pressure and flow velocity on the discharge intensity have been investigated. In addition, the effective reduced electric field strength {(E/N)}eff} has been obtained from the intensity ratio of vibronic emission bands of molecular nitrogen at different operating pressures and different locations. The derived {(E/N)}eff} increases gradually from about 550 to 4600 Td when decreasing the pressure from 1 bar to 100 mbar. Below 100 mbar, further pressure reduction results in a significant increase in {(E/N)}eff} up to about 10000 Td at 50 mbar.

  2. Nanosecond electrical explosion of thin aluminum wire in vacuum: experimental and computational investigations

    International Nuclear Information System (INIS)

    Cochrane, Kyle Robert; Struve, Kenneth William; Rosenthal, Stephen Edgar; McDaniel, Dillon Heirman; Sarkisov, Gennady Sergeevich; Deeney, Christopher

    2004-01-01

    The experimental and computational investigations of nanosecond electrical explosion of thin Al wire in vacuum are presented. We have demonstrated that increasing the current rate leads to increased energy deposited before voltage collapse. Laser shadowgrams of the overheated Al core exhibit axial stratification with a ∼100 (micro)m period. The experimental evidence for synchronization of the wire expansion and light emission with voltage collapse is presented. Two-wavelength interferometry shows an expanding Al core in a low-ionized gas condition with increasing ionization toward the periphery. Hydrocarbons are indicated in optical spectra and their influence on breakdown physics is discussed. The radial velocity of low-density plasma reaches a value of ∼100 km/s. The possibility of an overcritical phase transition due to high pressure is discussed. 1D MHD simulation shows good agreement with experimental data. MHD simulation demonstrates separation of the exploding wire into a high-density cold core and a low-density hot corona as well as fast rejection of the current from the wire core to the corona during voltage collapse. Important features of the dynamics for wire core and corona follow from the MHD simulation and are discussed.

  3. Nanosecond multi-pulse laser milling for certain area removal of metal coating on plastics surface

    Science.gov (United States)

    Zhao, Kai; Jia, Zhenyuan; Ma, Jianwei; Liu, Wei; Wang, Ling

    2014-12-01

    Metal coating with functional pattern on engineering plastics surface plays an important role in industry applications; it can be obtained by adding or removing certain area of metal coating on engineering plastics surface. However, the manufacturing requirements are improved continuously and the plastic substrate presents three-dimensional (3D) structure-many of these parts cannot be fabricated by conventional processing methods, and a new manufacturing method is urgently needed. As the laser-processing technology has many advantages like high machining accuracy and constraints free substrate structure, the machining of the parts is studied through removing certain area of metal coating based on the nanosecond multi-pulse laser milling. To improve the edge quality of the functional pattern, generation mechanism and corresponding avoidance strategy of the processing defects are studied. Additionally, a prediction model for the laser ablation depth is proposed, which can effectively avoid the existence of residual metal coating and reduces the damage of substrate. With the optimal machining parameters, an equiangular spiral pattern on copper-clad polyimide (CCPI) is machined based on the laser milling at last. The experimental results indicate that the edge of the pattern is smooth and consistent, the substrate is flat and without damage. The achievements in this study could be applied in industrial production.

  4. Calcium influx affects intracellular transport and membrane repair following nanosecond pulsed electric field exposure.

    Science.gov (United States)

    Thompson, Gary Lee; Roth, Caleb C; Dalzell, Danielle R; Kuipers, Marjorie; Ibey, Bennett L

    2014-05-01

    The cellular response to subtle membrane damage following exposure to nanosecond pulsed electric fields (nsPEF) is not well understood. Recent work has shown that when cells are exposed to nsPEF, ion permeable nanopores (2  nm) created by longer micro- and millisecond duration pulses. Nanoporation of the plasma membrane by nsPEF has been shown to cause a transient increase in intracellular calcium concentration within milliseconds after exposure. Our research objective is to determine the impact of nsPEF on calcium-dependent structural and repair systems in mammalian cells. Chinese hamster ovary (CHO-K1) cells were exposed in the presence and absence of calcium ions in the outside buffer to either 1 or 20, 600-ns duration electrical pulses at 16.2  kV/cm, and pore size was determined using propidium iodide and calcium green. Membrane organization was observed with morphological changes and increases in FM1-43 fluorescence. Migration of lysosomes, implicated in membrane repair, was followed using confocal microscopy of red fluorescent protein-tagged LAMP1. Microtubule structure was imaged using mEmerald-tubulin. We found that at high 600-ns PEF dosage, calcium-induced membrane restructuring and microtubule depolymerization coincide with interruption of membrane repair via lysosomal exocytosis.

  5. Surface modification induced by UV nanosecond Nd:YVO4 laser structuring on biometals

    Science.gov (United States)

    Fiorucci, M. Paula; López, Ana J.; Ramil, Alberto

    2014-08-01

    Laser surface texturing is a promising tool for improving metallic biomaterials performance in dental and orthopedic bone-replacing applications. Laser ablation modifies the topography of bulk material and might alter surface properties that govern the interactions with the surrounding tissue. This paper presents a preliminary evaluation of surface modifications in two biometals, stainless steel 316L and titanium alloy Ti6Al4V by UV nanosecond Nd:YVO4. Scanning electron microscopy of the surface textured by parallel micro-grooves reveals a thin layer of remelted material along the grooves topography. Furthermore, X-ray diffraction allowed us to appreciate a grain refinement of original crystal structure and consequently induced residual strain. Changes in the surface chemistry were determined by means of X-ray photoelectron spectroscopy; in this sense, generalized surface oxidation was observed and characterization of the oxides and other compounds such hydroxyl groups was reported. In case of titanium alloy, oxide layer mainly composed by TiO2 which is a highly biocompatible compound was identified. Furthermore, laser treatment produces an increase in oxide thickness that could improve the corrosion behavior of the metal. Otherwise, laser treatment led to the formation of secondary phases which might be detrimental to physical and biocompatibility properties of the material.

  6. Comparison of femtosecond and nanosecond laser ablation inductively coupled plasma mass spectrometry for uranium isotopic measurements

    Energy Technology Data Exchange (ETDEWEB)

    Havrilla, George Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); McIntosh, Kathryn Gallagher [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Judge, Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dirmyer, Matthew R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Campbell, Keri [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gonzalez, Jhanis J. [Applied Spectra Inc., Fremont, CA (United States)

    2016-10-20

    Feasibility tests were conducted using femtosecond and nanosecond laser ablation inductively coupled plasma mass spectrometry for rapid uranium isotopic measurements. The samples used in this study consisted of a range of pg quantities of known 235/238 U solutions as dried spot residues of 300 pL drops on silicon substrates. The samples spanned the following enrichments of 235U: 0.5, 1.5, 2, 3, and 15.1%. In this direct comparison using these particular samples both pulse durations demonstrated near equivalent data can be produced on either system with respect to accuracy and precision. There is no question that either LA-ICP-MS method offers the potential for rapid, accurate and precise isotopic measurements of U10Mo materials whether DU, LEU or HEU. The LA-ICP-MS equipment used for this work is commercially available. The program is in the process of validating this work for large samples using center samples strips from Y-12 MP-1 LEU-Mo Casting #1.

  7. XPS and μ-Raman study of nanosecond-laser processing of poly(dimethylsiloxane) (PDMS)

    Energy Technology Data Exchange (ETDEWEB)

    Armyanov, S., E-mail: armyanov@ipc.bas.bg [Rostislaw Kaischew Institute of Physical Chemistry, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Block 11, Sofia 1113 (Bulgaria); Stankova, N.E.; Atanasov, P.A. [Institute of Electronics, Bulgarian Academy of Sciences, 72 Tsarigradsko Shose, Sofia 1784 (Bulgaria); Valova, E.; Kolev, K.; Georgieva, J. [Rostislaw Kaischew Institute of Physical Chemistry, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Block 11, Sofia 1113 (Bulgaria); Steenhaut, O.; Baert, K.; Hubin, A. [Vrije Universiteit Brussels, Faculty of Engineering, Research Group, SURF “Electrochemical and Surface Engineering” (Belgium)

    2015-10-01

    Data about the chemical status of poly(dimethylsiloxane) (PDMS) after nanosecond Q-switched Nd:YAG laser treatment with near infrared, visible and ultraviolet radiation are presented. The μ-Raman spectroscopy analyses reveal as irradiation result a new sharp peak of crystalline silicon. In addition, broad bands appear assigned to D band of amorphous carbon and G band of microcrystalline and polycrystalline graphite. The μ-Raman spectra are variable taken in different inspected points in the trenches formed by laser treatment. The XPS surface survey spectra indicate the constituent elements of PDMS: carbon, oxygen and silicon. The spectra of detail XPS scans illustrate the influence of the laser treatment. The position of Si 2p peaks of the treated samples is close to the value of non-treated except that irradiated by 1064 nm 66 pulses, which is shifted by 0.9 eV. Accordingly, a shift by 0.4 eV is noticed of the O 1s peak, which reflects again a stronger oxidation of silicon. The curve fitting of Si 2p and O 1s peaks after this particular laser treatment shows the degree of conversion of organic to inorganic silicon that takes place during the irradiation.

  8. High efficiency fourth-harmonic generation from nanosecond fiber master oscillator power amplifier

    Science.gov (United States)

    Mu, Xiaodong; Steinvurzel, Paul; Rose, Todd S.; Lotshaw, William T.; Beck, Steven M.; Clemmons, James H.

    2016-03-01

    We demonstrate high power, deep ultraviolet (DUV) conversion to 266 nm through frequency quadrupling of a nanosecond pulse width 1064 nm fiber master oscillator power amplifier (MOPA). The MOPA system uses an Yb-doped double-clad polarization-maintaining large mode area tapered fiber as the final gain stage to generate 0.5-mJ, 10 W, 1.7- ns single mode pulses at a repetition rate of 20 kHz with measured spectral bandwidth of 10.6 GHz (40 pm), and beam qualities of Mx 2=1.07 and My 2=1.03, respectively. Using LBO and BBO crystals for the second-harmonic generation (SHG) and fourth-harmonic generation (FHG), we have achieved 375 μJ (7.5 W) and 92.5 μJ (1.85 W) at wavelengths of 532 nm and 266 nm, respectively. To the best of our knowledge these are the highest narrowband infrared, green and UV pulse energies obtained to date from a fully spliced fiber amplifier. We also demonstrate high efficiency SHG and FHG with walk-off compensated (WOC) crystal pairs and tightly focused pump beam. An SHG efficiency of 75%, FHG efficiency of 47%, and an overall efficiency of 35% from 1064 nm to 266 nm are obtained.

  9. Experimental Investigation of Pulsed Nanosecond Streamer Discharges for CO2 Reforming

    Science.gov (United States)

    Pachuilo, Michael; Levko, Dima; Raja, Laxminarayan; Varghese, Philip

    2016-09-01

    Rapid global industrialization has led to an increase in atmospheric greenhouse gases, specifically carbon dioxide levels. Plasmas present a great potential for efficient reforming of greenhouse gases. There are several plasma discharges which have been reported for reforming process: dielectric barrier discharges (DBD), microwave discharges, and glide-arcs. Microwave discharges have CO2 conversion energy efficiency of up to 40% at atmospheric conditions, while glide-arcs have 43% and DBD 2-10%. In our study, we analyze a single nanosecond pulsed cathode directed streamer discharge in CO2 at atmospheric pressure and temperature. We have conducted time resolved imaging with spectral bandpass filters of a streamer discharge with an applied negative polarity pulse. The image sequences have been correlated to the applied voltage and current pulses. From the spectral filters we can determine where spatially and temporally excited species are formed. In this talk we report on spectroscopic studies of the discharge and estimate plasma properties such as temperature and density of excited species and electrons. Furthermore, we report on the effects of pulse polarity as well as anodic streamer discharges on the CO2 conversion efficiency. Finally, we will focus on the effects of vibrational excitation on carbon dioxide reforming efficiency for streamer discharges. Our experimental results will be compared with an accompanying plasma computational model studies.

  10. Nanosecond Discharge in Bubbled Liquid n-Heptane: Effects of Gas Composition and Water Addition

    KAUST Repository

    Hamdan, Ahmad

    2016-08-30

    Recently, an aqueous discharge reactor was developed to facilitate reformation of liquid fuels by in-liquid plasma. To gain a microscopic understanding of the physical elements behind this aqueous reactor, we investigate nanosecond discharges in liquid n-heptane with single and double gaseous bubbles in the gap between electrodes. We introduce discharge probability (DP) to characterize the stochastic nature of the discharges, and we investigate the dependence of DP on the gap distance, applied voltage, gaseous bubble composition, and the water content in n-heptane/distilled-water emulsified mixtures. Propagation of a streamer through the bubbles indicates no discharges in the liquids. DP is controlled by the properties of the gaseous bubble rather than by the composition of the liquid mixture in the gap with a single bubble; meanwhile, DP is determined by the dielectric permittivity of the liquid mixture in the gap with double bubbles, results that are supported by static electric field simulations. We found that a physical mechanism of increasing DP is caused by an interaction between bubbles and an importance of the dielectric permittivity of a liquid mixture on the local enhancement of field intensity. We also discuss detailed physical characteristics, such as plasma lifetime and electron density within the discharge channel, by estimating from measured emissions with a gated-intensified charge-coupled device and by using spectroscopic images, respectively. © 1973-2012 IEEE.

  11. Aerodynamic performance enhancement of a flying wing using nanosecond pulsed DBD plasma actuator

    Directory of Open Access Journals (Sweden)

    Han Menghu

    2015-04-01

    Full Text Available Experimental investigation of aerodynamic control on a 35° swept flying wing by means of nanosecond dielectric barrier discharge (NS-DBD plasma was carried out at subsonic flow speed of 20–40 m/s, corresponding to Reynolds number of 3.1 × 105–6.2 × 105. In control condition, the plasma actuator was installed symmetrically on the leading edge of the wing. Lift coefficient, drag coefficient, lift-to-drag ratio and pitching moment coefficient were tested with and without control for a range of angles of attack. The tested results indicate that an increase of 14.5% in maximum lift coefficient, a decrease of 34.2% in drag coefficient, an increase of 22.4% in maximum lift-to-drag ratio and an increase of 2° at stall angle of attack could be achieved compared with the baseline case. The effects of pulsed frequency, amplitude and chord Reynolds number were also investigated. And the results revealed that control efficiency demonstrated strong dependence on pulsed frequency. Moreover, the results of pitching moment coefficient indicated that the breakdown of leading edge vortices could be delayed by plasma actuator at low pulsed frequencies.

  12. Comparison of femtosecond and nanosecond laser ablation inductively coupled plasma mass spectrometry for uranium isotopic measurements

    International Nuclear Information System (INIS)

    Havrilla, George Joseph; McIntosh, Kathryn Gallagher; Judge, Elizabeth; Dirmyer, Matthew R.; Campbell, Keri; Gonzalez, Jhanis J.

    2016-01-01

    Feasibility tests were conducted using femtosecond and nanosecond laser ablation inductively coupled plasma mass spectrometry for rapid uranium isotopic measurements. The samples used in this study consisted of a range of pg quantities of known 235/238 U solutions as dried spot residues of 300 pL drops on silicon substrates. The samples spanned the following enrichments of 235 U: 0.5, 1.5, 2, 3, and 15.1%. In this direct comparison using these particular samples both pulse durations demonstrated near equivalent data can be produced on either system with respect to accuracy and precision. There is no question that either LA-ICP-MS method offers the potential for rapid, accurate and precise isotopic measurements of U10Mo materials whether DU, LEU or HEU. The LA-ICP-MS equipment used for this work is commercially available. The program is in the process of validating this work for large samples using center samples strips from Y-12 MP-1 LEU-Mo Casting #1.

  13. Decolorization of methylene blue in aqueous suspensions of gold nanoparticles using parallel nanosecond pulsed laser.

    Science.gov (United States)

    Zong, Yan P; Liu, Xian H; Du, Xi W; Lu, Yi R; Wang, Mei Y; Wang, Guang Y

    2013-01-01

    Using 532 nm parallel nanosecond pulsed laser, the decolorization of methylene blue (MB) in aqueous suspensions of gold nanoparticles (GNPs) was studied. The effects of various experimental parameters, such as irradiation time, laser energy, and initial MB concentration on the decolorization rate were investigated. Experiments using real samples of textile dyeing wastewater were also carried out to examine the effectiveness of the method in more complex samples. From the results, the following conclusions may be drawn: (i) Under the optimum conditions (pH 7.19, 135 mJ laser energy, 4 mg/L MB concentration, and 11.6 mg/L GNP concentration), the rate of MB decolorization could reach 94% in 15 min. The decolorization follows pseudo-first-order kinetics; (ii) The amount of MB decreased rapidly during the decolorization. No intermediates of the decolorization could be detected by high-performance liquid chromatography. These observations indicate that MB was decolorized through a very rapid degradation mechanism; (iii) The rate of MB decolorization increased with the increase in laser energy (at laser energies of 0 to 135 mJ); and, (iv) The efficient decolorization of MB in real samples of textile dyeing wastewater was achieved at a decolorization rate of about 85% in 15 min.

  14. Low-dielectric layer increases nanosecond electric discharges in distilled water

    KAUST Repository

    Hamdan, Ahmad

    2016-10-24

    Electric discharge in liquids is an emerging field of research, and is involved into various environmental applications (water purification, fuel reforming, nanomaterial synthesis, etc.). Increasing the treatment efficiency with simultaneous decreasing of the energy consumption are the main goals of today’s research. Here we present an experimental study of nanosecond discharge in distilled water covered by a layer of dielectric material. We demonstrate through this paper that the discharge efficiency can be improved by changing the interface position regarding the anode tip. The efficiency increase is due to the increase of the discharge probability as well as the plasma volume. The understanding of the experimental results is brought and strengthened by simulating the electric field distribution, using Comsol Multiphysics software. Because the dielectric permittivity (ε) is discontinuous at the interface, the electric field is enhanced by a factor that depends on the relative value of ε of the two liquids. The present result is very promising in future: opportunities for potential applications as well as fundamental studies for discharges in liquid.

  15. Fast switching thyristor applied in nanosecond-pulse high-voltage generator with closed transformer core.

    Science.gov (United States)

    Li, Lee; Bao, Chaobing; Feng, Xibo; Liu, Yunlong; Fochan, Lin

    2013-02-01

    For a compact and reliable nanosecond-pulse high-voltage generator (NPHVG), the specification parameter selection and potential usage of fast controllable state-solid switches have an important bearing on the optimal design. The NPHVG with closed transformer core and fast switching thyristor (FST) was studied in this paper. According to the analysis of T-type circuit, the expressions for the voltages and currents of the primary and secondary windings on the transformer core of NPHVG were deduced, and the theoretical maximum analysis was performed. For NPHVG, the rise-rate of turn-on current (di/dt) across a FST may exceed its transient rating. Both mean and maximum values of di/dt were determined by the leakage inductances of the transformer, and the difference is 1.57 times. The optimum winding ratio is helpful to getting higher voltage output with lower specification FST, especially when the primary and secondary capacitances have been established. The oscillation period analysis can be effectively used to estimate the equivalent leakage inductance. When the core saturation effect was considered, the maximum di/dt estimated from the oscillating period of the primary current is more accurate than one from the oscillating period of the secondary voltage. Although increasing the leakage inductance of NPHVG can decrease di/dt across FST, it may reduce the output peak voltage of the NPHVG.

  16. Nanosecond Neutron Analysis for the search of the lost Leonardo's masterpiece, the Battle of Anghiari

    International Nuclear Information System (INIS)

    Kuznetsov, A.V.; Gorshkov, I.Yu.; Evsenin, A.V.; Osetrov, O.I.; Vakhtin, D.N.; Cosentino, A.; Seracini, M.

    2009-01-01

    Between 1505 and 1506 Leonardo Da Vinci painted his masterpiece, the Battle of Anghiari, in Palazzo Vecchio's Hall of 500 in Florence. The unfinished mural remained visible until 1563, when architect Giorgio Vasari undertook a renovation of the Hall and all traces of the Battle of Anghiari were lost. However, scholarly interpretation and scientific evidence suggest that the mural could be on the eastern wall, hidden behind a brick wall built in 1563 by Vasari. This paper discusses the possibility of using NNA/APT (Nanosecond Neutron Analysis/Associated Particle Technique) to establish the presence of the masterpiece by identifying behind the Vasari's wall chemical elements from the gesso preparation layer of the mural and possibly from its pigments. This paper reports on the experiments run with a simple NNA/APT system and the Monte Carlo simulations that have been carried out in order to outline the experimental setup of an advanced NNA/APT able to detect and locate the tiny amount of gesso and pigments.

  17. Influence of ion transport on discharge propagation of nanosecond dielectric barrier discharge plasma actuator

    Science.gov (United States)

    Hua, Weizhuo; Koji, Fukagata

    2017-11-01

    A numerical study has been conducted to understand the streamer formation and propagation of nanosecond pulsed surface dielectric barrier discharge of positive polarity. First we compared the result of different grid configuration to investigate the influence of x and y direction grid spacing on the streamer propagation. The streamer propagation is sensitive to y grid spacing especially at the dielectric surface. The streamer propagation velocity can reach 0.2 cm/ns when the voltage magnitude is 12 kV. A narrow gap was found between the streamer and dielectric barrier, where the plasma density is several orders of magnitude smaller than the streamer region. Analyses on the ion transport in the gap and streamer regions show the different ion transport mechanisms in the two different region. In the gap region, the diffusion of electron toward the dielectric layer decreases the seed electron in the beginning of voltage pulse, resulting that ionization avalanche does not occur. The streamer region is not significantly affected by the diffusion flux toward the dielectric layer, so that ionization avalanche takes place and leads to dramatic increase of plasma density.

  18. Raising the avermectins production in Streptomyces avermitilis by utilizing nanosecond pulsed electric fields (nsPEFs)

    Science.gov (United States)

    Guo, Jinsong; Ma, Ruonan; Su, Bo; Li, Yinglong; Zhang, Jue; Fang, Jing

    2016-05-01

    Avermectins, a group of anthelmintic and insecticidal agents produced from Streptomyces avermitilis, are widely used in agricultural, veterinary, and medical fields. This study presents the first report on the potential of using nanosecond pulsed electric fields (nsPEFs) to improve avermectin production in S. avermitilis. The results of colony forming units showed that 20 pulses of nsPEFs at 10 kV/cm and 20 kV/cm had a significant effect on proliferation, while 100 pulses of nsPEFs at 30 kV/cm exhibited an obvious effect on inhibition of agents. Ultraviolet spectrophotometry assay revealed that 20 pulses of nsPEFs at 15 kV/cm increased avermectin production by 42% and reduced the time for reaching a plateau in fermentation process from 7 days to 5 days. In addition, the decreased oxidation reduction potential (ORP) and increased temperature of nsPEFs-treated liquid were evidenced to be closely associated with the improved cell growth and fermentation efficiency of avermectins in S. avermitilis. More importantly, the real-time RT-PCR analysis showed that nsPEFs could remarkably enhance the expression of aveR and malE in S. avermitilis during fermentation, which are positive regulator for avermectin biosynthesis. Therefore, the nsPEFs technology presents an alternative strategy to be developed to increase avermectin output in fermentation industry.

  19. Experimental study of plume induced by nanosecond repetitively pulsed spark microdischarges in air at atmospheric pressure

    Science.gov (United States)

    Orriere, Thomas; Benard, Nicolas; Moreau, Eric; Pai, David

    2016-09-01

    Nanosecond repetitively pulsed (NRP) spark discharges have been widely studied due to their high chemical reactivity, low gas temperature, and high ionization efficiency. They are useful in many research areas: nanomaterials synthesis, combustion, and aerodynamic flow control. In all of these fields, particular attention has been devoted to chemical species transport and/or hydrodynamic and thermal effects for applications. The aim of this study is to generate an electro-thermal plume by combining an NRP spark microdischarge in a pin-to-pin configuration with a third DC-biased electrode placed a few centimeters away. First, electrical characterization and optical emission spectroscopy were performed to reveal important plasma processes. Second, particle image velocimetry was combined with schlieren photography to investigate the main characteristics of the generated flow. Heating processes are measured by using the N2(C ->B) (0,2) and (1,3) vibrational bands, and effects due to the confinement of the discharge are described. Moreover, the presence of atomic ions N+ and O+ is discussed. Finally, the electro-thermal plume structure is characterized by a flow velocity around 1.8 m.s-1, and the thermal kernel has a spheroidal shape.

  20. Dynamic features of bubble induced by a nanosecond pulse laser in still and flowing water

    Science.gov (United States)

    Charee, Wisan; Tangwarodomnukun, Viboon

    2018-03-01

    Underwater laser ablation techniques have been developed and employed to synthesis nanoparticles, to texture workpiece surface and to assist the material removal in laser machining process. However, the understanding of laser-material-water interactions, bubble formation and effects of water flow on ablation performance has still been very limited. This paper thus aims at exploring the formation and collapse of bubbles during the laser ablation of silicon in water. The effects of water flow rate on bubble formation and its consequences to the laser disturbance and cut features obtained in silicon were observed by using a high speed camera. A nanosecond pulse laser emitting the laser pulse energy of 0.2-0.5 mJ was employed in the experiment. The results showed that the bubble size was found to increase with the laser pulse energy. The use of high water flow rate can importantly facilitate the ejection of ablated particles from the workpiece surface, hence resulting in less deposition to the work surface and minimizing any disturbance to the laser beam during the ablation in water. Furthermore, a clean micro-groove in silicon wafer can successfully be produced when the process was performed in the high water flow rate condition. The findings of this study could provide an essential guideline for process selection, control and improvement in the laser micro-/submicro-fabrication using the underwater technique.

  1. Inactivation of Ricin Toxin by Nanosecond Pulsed Electric Fields Including Evidences from Cell and Animal Toxicity

    Science.gov (United States)

    Wei, Kai; Li, Wei; Gao, Shan; Ji, Bin; Zang, Yating; Su, Bo; Wang, Kaile; Yao, Maosheng; Zhang, Jue; Wang, Jinglin

    2016-01-01

    Ricin is one of the most toxic and easily produced plant protein toxin extracted from the castor oil plant, and it has been classified as a chemical warfare agent. Here, nanosecond pulsed electric fields (nsPEFs) at 30 kV/cm (pulse durations: 10 ns, 100 ns, and 300 ns) were applied to inactivating ricin up to 4.2 μg/mL. To investigate the efficacy, cells and mice were tested against the ricin treated by the nsPEFs via direct intraperitoneal injection and inhalation exposure. Results showed that nsPEFs treatments can effectively reduce the toxicity of the ricin. Without the nsPEFs treatment, 100% of mice were killed upon the 4 μg ricin injection on the first day, however 40% of the mice survived the ricin treated by the nsPEFs. Compared to injection, inhalation exposure even with higher ricin dose required longer time to observe mice fatality. Pathological observations revealed damages to heart, lung, kidney, and stomach after the ricin exposure, more pronounced for lung and kidney including severe bleeding. Sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE) and circular dichroism (CD) analyses revealed that although the primary structure of ricin was not altered, its secondary structures (beta-sheet and beta-turn) underwent transition upon the nsPEFs treatment. PMID:26728251

  2. Selective susceptibility to nanosecond pulsed electric field (nsPEF) across different human cell types.

    Science.gov (United States)

    Gianulis, Elena C; Labib, Chantelle; Saulis, Gintautas; Novickij, Vitalij; Pakhomova, Olga N; Pakhomov, Andrei G

    2017-05-01

    Tumor ablation by nanosecond pulsed electric fields (nsPEF) is an emerging therapeutic modality. We compared nsPEF cytotoxicity for human cell lines of cancerous (IMR-32, Hep G2, HT-1080, and HPAF-II) and non-cancerous origin (BJ and MRC-5) under strictly controlled and identical conditions. Adherent cells were uniformly treated by 300-ns PEF (0-2000 pulses, 1.8 kV/cm, 50 Hz) on indium tin oxide-covered glass coverslips, using the same media and serum. Cell survival plotted against the number of pulses displayed three distinct regions (initial resistivity, logarithmic survival decline, and residual resistivity) for all tested cell types, but with differences in LD 50 spanning as much as nearly 80-fold. The non-cancerous cells were less sensitive than IMR-32 neuroblastoma cells but more vulnerable than the other cancers tested. The cytotoxic efficiency showed no apparent correlation with cell or nuclear size, cell morphology, metabolism level, or the extent of membrane disruption by nsPEF. Increasing pulse duration to 9 µs (0.75 kV/cm, 5 Hz) produced a different selectivity pattern, suggesting that manipulation of PEF parameters can, at least for certain cancers, overcome their resistance to nsPEF ablation. Identifying mechanisms and cell markers of differential nsPEF susceptibility will critically contribute to the proper choice and outcome of nsPEF ablation therapies.

  3. Transient suppression of gap junctional intercellular communication after exposure to 100-nanosecond pulsed electric fields.

    Science.gov (United States)

    Steuer, Anna; Schmidt, Anke; Labohá, Petra; Babica, Pavel; Kolb, Juergen F

    2016-12-01

    Gap junctional intercellular communication (GJIC) is an important mechanism that is involved and affected in many diseases and injuries. So far, the effect of nanosecond pulsed electric fields (nsPEFs) on the communication between cells was not investigated. An in vitro approach is presented with rat liver epithelial WB-F344 cells grown and exposed in a monolayer. In order to observe sub-lethal effects, cells were exposed to pulsed electric fields with a duration of 100ns and amplitudes between 10 and 20kV/cm. GJIC strongly decreased within 15min after treatment but recovered within 24h. Gene expression of Cx43 was significantly decreased and associated with a reduced total amount of Cx43 protein. In addition, MAP kinases p38 and Erk1/2, involved in Cx43 phosphorylation, were activated and Cx43 became hyperphosphorylated. Immunofluorescent staining of Cx43 displayed the disassembly of gap junctions. Further, a reorganization of the actin cytoskeleton was observed whereas tight junction protein ZO-1 was not significantly affected. All effects were field- and time-dependent and most pronounced within 30 to 60min after treatment. A better understanding of a possible manipulation of GJIC by nsPEFs might eventually offer a possibility to develop and improve treatments. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Disassembly of actin structures by nanosecond pulsed electric field is a downstream effect of cell swelling.

    Science.gov (United States)

    Pakhomov, Andrei G; Xiao, Shu; Pakhomova, Olga N; Semenov, Iurii; Kuipers, Marjorie A; Ibey, Bennett L

    2014-12-01

    Disruption of the actin cytoskeleton structures was reported as one of the characteristic effects of nanosecond-duration pulsed electric field (nsPEF) in both mammalian and plant cells. We utilized CHO cells that expressed the monomeric fluorescent protein (mApple) tagged to actin to test if nsPEF modifies the cell actin directly or as a consequence of cell membrane permeabilization. A train of four 600-ns pulses at 19.2 kV/cm (2 Hz) caused immediate cell membrane poration manifested by YO-PRO-1 dye uptake, gradual cell rounding and swelling. Concurrently, bright actin features were replaced by dimmer and uniform fluorescence of diffuse actin. To block the nsPEF-induced swelling, the bath buffer was isoosmotically supplemented with an electropore-impermeable solute (sucrose). A similar addition of a smaller, electropore-permeable solute (adonitol) served as a control. We demonstrated that sucrose efficiently blocked disassembly of actin features by nsPEF, whereas adonitol did not. Sucrose also attenuated bleaching of mApple-tagged actin in nsPEF-treated cells (as integrated over the cell volume), although did not fully prevent it. We conclude that disintegration of the actin cytoskeleton was a result of cell swelling, which, in turn, was caused by cell permeabilization by nsPEF and transmembrane diffusion of solutes which led to the osmotic imbalance. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Elasticity and tumorigenic characteristics of cells in a monolayer after nanosecond pulsed electric field exposure.

    Science.gov (United States)

    Steuer, A; Wende, K; Babica, P; Kolb, J F

    2017-09-01

    Nanosecond pulsed electric fields (nsPEFs) applied to cells can induce different biological effects depending on pulse duration and field strength. One known process is the induction of apoptosis whereby nsPEFs are currently investigated as a novel cancer therapy. Another and probably related change is the breakdown of the cytoskeleton. We investigated the elasticity of rat liver epithelial cells WB-F344 in a monolayer using atomic force microscopy (AFM) with respect to the potential of cells to undergo malignant transformation or to develop a potential to metastasize. We found that the elastic modulus of the cells decreased significantly within the first 8 min after treatment with 20 pulses of 100 ns and with a field strength of 20 kV/cm but was still higher than the elasticity of their tumorigenic counterpart WB-ras. AFM measurements and immunofluorescent staining showed that the cellular actin cytoskeleton became reorganized within 5 min. However, both a colony formation assay and a cell migration assay revealed no significant changes after nsPEF treatment, implying that cells seem not to adopt malignant characteristics associated with metastasis formation despite the induced transient changes to elasticity and cytoskeleton that can be observed for up to 1 h.

  6. Transient Features in Nanosecond Pulsed Electric Fields Differentially Modulate Mitochondria and Viability

    Science.gov (United States)

    Beebe, Stephen J.; Chen, Yeong-Jer; Sain, Nova M.; Schoenbach, Karl H.; Xiao, Shu

    2012-01-01

    It is hypothesized that high frequency components of nanosecond pulsed electric fields (nsPEFs), determined by transient pulse features, are important for maximizing electric field interactions with intracellular structures. For monopolar square wave pulses, these transient features are determined by the rapid rise and fall of the pulsed electric fields. To determine effects on mitochondria membranes and plasma membranes, N1-S1 hepatocellular carcinoma cells were exposed to single 600 ns pulses with varying electric fields (0–80 kV/cm) and short (15 ns) or long (150 ns) rise and fall times. Plasma membrane effects were evaluated using Fluo-4 to determine calcium influx, the only measurable source of increases in intracellular calcium. Mitochondria membrane effects were evaluated using tetramethylrhodamine ethyl ester (TMRE) to determine mitochondria membrane potentials (ΔΨm). Single pulses with short rise and fall times caused electric field-dependent increases in calcium influx, dissipation of ΔΨm and cell death. Pulses with long rise and fall times exhibited electric field-dependent increases in calcium influx, but diminished effects on dissipation of ΔΨm and viability. Results indicate that high frequency components have significant differential impact on mitochondria membranes, which determines cell death, but lesser variances on plasma membranes, which allows calcium influxes, a primary determinant for dissipation of ΔΨm and cell death. PMID:23284682

  7. Widely-duration-tunable nanosecond pulse Nd:YVO4 laser based on double Pockels cells

    Science.gov (United States)

    He, Li-Jiao; Liu, Ke; Bo, Yong; Wang, Xiao-Jun; Yang, Jing; Liu, Zhao; Zong, Qing-Shuang; Peng, Qin-Jun; Cui, Da-Fu; Xu, Zu-Yan

    2018-05-01

    The development of duration-tunable pulse lasers with constant output power is important for scientific research and materials processing. We present a widely-duration-tunable nanosecond (ns) pulse Nd:YVO4 laser based on double Pockels cells (PCs), i.e. inserting an extra PC into a conventional electro-optic Q-switched cavity dumped laser resonator. Under the absorbed pump power of 24.9 W, the pulse duration is adjustable from 31.9 ns to 5.9 ns by changing the amplitude of the high voltage on the inserted PC from 1100 V to 4400 V at the pulse repetition rate of 10 kHz. The corresponding average output power is almost entirely maintained in the range of 3.5–4.1 W. This represents more than three times increase in pulse duration tunable regime and average power compared to previously reported results for duration-tunable ns lasers. The laser beam quality factor was measured to be M 2  <  1.18.

  8. Study on processing parameters of glass cutting by nanosecond 532 nm fiber laser

    Science.gov (United States)

    Wang, Jin; Gao, Fan; Xiong, Baoxing; Zhang, Xiang; Yuan, Xiao

    2018-03-01

    The processing parameters of soda-lime glass cutting with several nanosecond 532 nm pulsed fiber laser are studied in order to obtain sufficiently large ablation rate and better processing quality. The influences of laser processing parameters on effective cutting speed and cutting quality of 1 2 mm thick soda-lime glass are studied. The experimental results show that larger laser pulse energy will lead to higher effective cutting speed and larger maximum edge collapse of the front side of the glass samples. Compared with that of 1.1 mm thick glass samples, the 2.0 mm thick glass samples is more difficult to cut. With the pulse energy of 51.2 μJ, the maximum edge collapse is more than 200 μm for the 2.0 mm thick glass samples. In order to achieve the high effective cutting speed and good cutting quality at the same time, the dual energy overlapping method is used to obtain the better cutting performance for the 2.0 mm thick glass samples, and the cutting speed of 194 mm/s and the maximum edge collapse of less than 132 μm are realized.

  9. Characterization of Pressure Transients Generated by Nanosecond Electrical Pulse (nsEP) Exposure

    Science.gov (United States)

    Roth, Caleb C.; Barnes Jr., Ronald A.; Ibey, Bennett L.; Beier, Hope T.; Christopher Mimun, L.; Maswadi, Saher M.; Shadaram, Mehdi; Glickman, Randolph D.

    2015-01-01

    The mechanism(s) responsible for the breakdown (nanoporation) of cell plasma membranes after nanosecond pulse (nsEP) exposure remains poorly understood. Current theories focus exclusively on the electrical field, citing electrostriction, water dipole alignment and/or electrodeformation as the primary mechanisms for pore formation. However, the delivery of a high-voltage nsEP to cells by tungsten electrodes creates a multitude of biophysical phenomena, including electrohydraulic cavitation, electrochemical interactions, thermoelastic expansion, and others. To date, very limited research has investigated non-electric phenomena occurring during nsEP exposures and their potential effect on cell nanoporation. Of primary interest is the production of acoustic shock waves during nsEP exposure, as it is known that acoustic shock waves can cause membrane poration (sonoporation). Based on these observations, our group characterized the acoustic pressure transients generated by nsEP and determined if such transients played any role in nanoporation. In this paper, we show that nsEP exposures, equivalent to those used in cellular studies, are capable of generating high-frequency (2.5 MHz), high-intensity (>13 kPa) pressure transients. Using confocal microscopy to measure cell uptake of YO-PRO®-1 (indicator of nanoporation of the plasma membrane) and changing the electrode geometry, we determined that acoustic waves alone are not responsible for poration of the membrane. PMID:26450165

  10. Characterization of Pressure Transients Generated by Nanosecond Electrical Pulse (nsEP) Exposure.

    Science.gov (United States)

    Roth, Caleb C; Barnes, Ronald A; Ibey, Bennett L; Beier, Hope T; Christopher Mimun, L; Maswadi, Saher M; Shadaram, Mehdi; Glickman, Randolph D

    2015-10-09

    The mechanism(s) responsible for the breakdown (nanoporation) of cell plasma membranes after nanosecond pulse (nsEP) exposure remains poorly understood. Current theories focus exclusively on the electrical field, citing electrostriction, water dipole alignment and/or electrodeformation as the primary mechanisms for pore formation. However, the delivery of a high-voltage nsEP to cells by tungsten electrodes creates a multitude of biophysical phenomena, including electrohydraulic cavitation, electrochemical interactions, thermoelastic expansion, and others. To date, very limited research has investigated non-electric phenomena occurring during nsEP exposures and their potential effect on cell nanoporation. Of primary interest is the production of acoustic shock waves during nsEP exposure, as it is known that acoustic shock waves can cause membrane poration (sonoporation). Based on these observations, our group characterized the acoustic pressure transients generated by nsEP and determined if such transients played any role in nanoporation. In this paper, we show that nsEP exposures, equivalent to those used in cellular studies, are capable of generating high-frequency (2.5 MHz), high-intensity (>13 kPa) pressure transients. Using confocal microscopy to measure cell uptake of YO-PRO®-1 (indicator of nanoporation of the plasma membrane) and changing the electrode geometry, we determined that acoustic waves alone are not responsible for poration of the membrane.

  11. Modification of composite por -Si/SnOx power ion beam of nanosecond duration

    International Nuclear Information System (INIS)

    Korusenko, P.M.; Bolotov, V.V.; Knyazev, E.V.; Kovivchak, V.S.; Korepanov, A.A.; Nesov, S.N.; Povoroznyuk, S.N.

    2011-01-01

    The results of XPS (X-ray photoelectron spectroscopy), AES (Auger electron spectroscopy) and SEM (Scanning electron microscopy) investigation of tin oxide nanolayers on the samples of the composite por-Si/SnO x with different porosity of the matrix, formed under the influence of a powerful ion beam of nanosecond duration was presented. It is shown that fast melting and crystallization of the surface leads to the formation of globular structures with a typical size of 200 nm. Established that the tin is included in structure of the nanocomposite in the oxidized state with little inclusion of metallic β-tin. With increasing porosity, phase composition of nanolayers of tin is close to the state corresponding to the higher tin oxide SnO 2 . Also shows that with increasing porosity, the intensity of subvalent 4d lines of tin, which is apparently associated with an increased degree of hybridization of the tin atoms and oxygen atoms. According to the results stratified etching was to evaluate the changes of the elemental structure of the composite and the depth of penetration of tin. (authors)

  12. Experimental investigation of lift enhancement for flying wing aircraft using nanosecond DBD plasma actuators

    Science.gov (United States)

    Yao, Junkai; Zhou, Danjie; He, Haibo; He, Chengjun; Shi, Zhiwei; Du, Hai

    2017-04-01

    The effects of the arrangement position and control parameters of nanosecond dielectric barrier discharge (NS-DBD) plasma actuators on lift enhancement for flying wing aircraft were investigated through wind tunnel experiments at a flow speed of 25 m s-1. The aerodynamic forces and moments were obtained by a six-component balance at angles of attack ranging from -4° to 28°. The lift, drag and pitching moment coefficients were compared for the cases with and without plasma control. The results revealed that the maximum control effect was achieved by placing the actuator at the leading edge of the inner and middle wing, for which the maximum lift coefficient increased by 37.8% and the stall angle of attack was postponed by 8° compared with the plasma-off case. The effects of modulation frequency and discharge voltage were also investigated. The results revealed that the lift enhancement effect of the NS-DBD plasma actuators was strongly influenced by the modulation frequency. Significant control effects were obtained at f = 70 Hz, corresponding to F + ≈ 1. The result for the pitching moment coefficient demonstrated that the plasma actuator can induce the reattachment of the separation flows when it is actuated. However, the results indicated that the discharge voltage had a negligible influence on the lift enhancement effect.

  13. Processing of Dielectric Optical Coatings by Nanosecond and Femtosecond UV Laser Ablation

    International Nuclear Information System (INIS)

    Ihlemann, J.; Bekesi, J.; Klein-Wiele, J.H.; Simon, P.

    2008-01-01

    Micro processing of dielectric optical coatings by UV laser ablation is demonstrated. Excimer laser ablation at deep UV wavelengths (248 nm, 193 nm) is used for the patterning of thin oxide films or layer stacks. The layer removal over extended areas as well as sub-μm-structuring is possible. The ablation of SiO2, Al2O3, HfO2, and Ta2O5 layers and layer systems has been investigated. Due to their optical, chemical, and thermal stability, these inorganic film materials are well suited for optical applications, even if UV-transparency is required. Transparent patterned films of SiO2 are produced by patterning a UV-absorbing precursor SiOx suboxide layer and oxidizing it afterwards to SiO2. In contrast to laser ablation of bulk material, in the case of thin films, the layer-layer or layer-substrate boundaries act as predetermined end points, so that precise depth control and a very smooth surface can be achieved. For large area ablation, nanosecond lasers are well suited; for patterning with submicron resolution, femtosecond excimer lasers are applied. Thus the fabrication of optical elements like dielectric masks, pixelated diffractive elements, and gratings can be accomplished.

  14. Mechanism of nanosecond laser drilling process of 4H-SiC for through substrate vias

    Science.gov (United States)

    Kim, Byunggi; Iida, Ryoichi; Doan, Duc Hong; Fushinobu, Kazuyoshi

    2017-06-01

    Role of optical parameters on nanosecond laser drilling of 4H-SiC was experimentally studied. Using ns pulsed Nd:YAG laser, parametric studies on effects of wavelength (1064 nm or 532 nm), beam profile (Gaussian or Bessel), and ambient condition (air or water) were conducted. The wavelengths which have large optical penetration depth were selected as wavefront has to propagate through materials to generate Bessel beam. The experimental results showed that carbonization of SiC surface accelerates thermal ablation of the materials with fluence under the lattice melting threshold. Especially, pattern of side lobes with small fluence was formed by irradiation of Bessel beam. The pattern disturbed penetration of wavefronts through materials. Implementation of water environment was not effective to suppress carbonization and had slight effect on improvement of drilling quality. For this reason, deep drilling with small entrance was not achieved using Bessel beam. Irradiation of 1064 nm Gaussian beam with large fluence led to formation of critical amount of re-solidified silicon due to the large optical penetration depth. Carbonization and silicon formation had a significant effect on unique fluence dependence of drilling depth. Absorption mechanism was studied as well to discuss effect of wavelength on processing characteristics.

  15. Simulation of transformations of thin metal films heated by nanosecond laser pulses

    Science.gov (United States)

    Balandin, V. Yu.; Niedrig, R.; Bostanjoglo, O.

    1995-01-01

    The ablation of free-standing thin aluminum films by a nanosecond laser pulse was investigated by time-resolved transmission electron microscopy and numerical simulation. It was established that thin film geometry is particularly suited to furnish information on the mechanism of evaporation and the surface tension of the melt. In the case of aluminum the surface tension sigma as function of temperature can be approximated by two linear sections with a coefficient -0.3 x 10(exp -3) N/K m from the melting point 933 K up to 3000 K and -0.02 x 10(exp -3) N/K m above 3000 K, respectively, with sigma(993 K) = 0.9 N/m and sigma(8500 K) = 0. At lower pulse energies the films disintegrated predominantly by thermocapillary flow. Higher pulse energies produced volume evaporation, and a nonmonotonous flow, explained by recoil from evaporating atoms and thermocapillarity. The familiar equations of energy and motion, which presuppose separate and coherent vapor and liquid phases, were not adequate to describe the ablation of the hottest zone. Surface evaporation seemed to be marginal at all laser pulse energies used.

  16. Laser induced fluorescence in nanosecond repetitively pulsed discharges for CO2 conversion

    Science.gov (United States)

    Martini, L. M.; Gatti, N.; Dilecce, G.; Scotoni, M.; Tosi, P.

    2018-01-01

    A CO2 nanosecond repetitively pulsed discharge (NRP) is a harsh environment for laser induced fluorescence (LIF) diagnostics. The difficulties arise from it being a strongly collisional system in which the gas composition, pressure and temperature, have quick and strong variations. The relevant diagnostic problems are described and illustrated through the application of LIF to the measurement of the OH radical in three different discharge configurations, with gas mixtures containing CO2 + H2O. These range from a dielectric barrier NRP with He buffer gas, a less hostile case in which absolute OH density measurement is possible, to an NRP in CO2+H2O, where the full set of drawbacks is at work. In the last case, the OH density measurement is not possible with laser pulses and detector time resolution in the ns time scale. Nevertheless, it is shown that with a proper knowledge of the collisional rate constants involved in the LIF process, a collisional energy transfer-LIF methodology is still applicable to deduce the gas composition from the analysis of LIF spectra.

  17. Nanosecond time-resolved characterization of a pentacene-based room-temperature MASER

    Science.gov (United States)

    Salvadori, Enrico; Breeze, Jonathan D.; Tan, Ke-Jie; Sathian, Juna; Richards, Benjamin; Fung, Mei Wai; Wolfowicz, Gary; Oxborrow, Mark; Alford, Neil McN.; Kay, Christopher W. M.

    2017-01-01

    The performance of a room temperature, zero-field MASER operating at 1.45 GHz has been examined. Nanosecond laser pulses, which are essentially instantaneous on the timescale of the spin dynamics, allow the visible-to-microwave conversion efficiency and temporal response of the MASER to be measured as a function of excitation energy. It is observed that the timing and amplitude of the MASER output pulse are correlated with the laser excitation energy: at higher laser energy, the microwave pulses have larger amplitude and appear after shorter delay than those recorded at lower laser energy. Seeding experiments demonstrate that the output variation may be stabilized by an external source and establish the minimum seeding power required. The dynamics of the MASER emission may be modeled by a pair of first order, non-linear differential equations, derived from the Lotka-Volterra model (Predator-Prey), where by the microwave mode of the resonator is the predator and the spin polarization in the triplet state of pentacene is the prey. Simulations allowed the Einstein coefficient of stimulated emission, the spin-lattice relaxation and the number of triplets contributing to the MASER emission to be estimated. These are essential parameters for the rational improvement of a MASER based on a spin-polarized triplet molecule. PMID:28169331

  18. Nanosecond time-resolved investigations using the in situ of dynamic transmission electron microscope (DTEM)

    International Nuclear Information System (INIS)

    LaGrange, Thomas; Campbell, Geoffrey H.; Reed, B.W.; Taheri, Mitra; Pesavento, J. Bradley; Kim, Judy S.; Browning, Nigel D.

    2008-01-01

    Most biological processes, chemical reactions and materials dynamics occur at rates much faster than can be captured with standard video rate acquisition methods in transmission electron microscopes (TEM). Thus, there is a need to increase the temporal resolution in order to capture and understand salient features of these rapid materials processes. This paper details the development of a high-time resolution dynamic transmission electron microscope (DTEM) that captures dynamics in materials with nanosecond time resolution. The current DTEM performance, having a spatial resolution <10 nm for single-shot imaging using 15 ns electron pulses, will be discussed in the context of experimental investigations in solid state reactions of NiAl reactive multilayer films, the study of martensitic transformations in nanocrystalline Ti and the catalytic growth of Si nanowires. In addition, this paper will address the technical issues involved with high current, electron pulse operation and the near-term improvements to the electron optics, which will greatly improve the signal and spatial resolutions, and to the laser system, which will allow tailored specimen and photocathode drive conditions

  19. Nanosecond time-resolved investigations using the in situ of dynamic transmission electron microscope (DTEM)

    Energy Technology Data Exchange (ETDEWEB)

    LaGrange, Thomas [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550 (United States)], E-mail: lagrange@llnl.gov; Campbell, Geoffrey H.; Reed, B.W.; Taheri, Mitra; Pesavento, J. Bradley [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550 (United States); Kim, Judy S.; Browning, Nigel D. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550 (United States); Department of Chemical Engineering and Materials Science, University of California, One Shields Avenue, Davis, CA 95616 (United States)

    2008-10-15

    Most biological processes, chemical reactions and materials dynamics occur at rates much faster than can be captured with standard video rate acquisition methods in transmission electron microscopes (TEM). Thus, there is a need to increase the temporal resolution in order to capture and understand salient features of these rapid materials processes. This paper details the development of a high-time resolution dynamic transmission electron microscope (DTEM) that captures dynamics in materials with nanosecond time resolution. The current DTEM performance, having a spatial resolution <10 nm for single-shot imaging using 15 ns electron pulses, will be discussed in the context of experimental investigations in solid state reactions of NiAl reactive multilayer films, the study of martensitic transformations in nanocrystalline Ti and the catalytic growth of Si nanowires. In addition, this paper will address the technical issues involved with high current, electron pulse operation and the near-term improvements to the electron optics, which will greatly improve the signal and spatial resolutions, and to the laser system, which will allow tailored specimen and photocathode drive conditions.

  20. Time-resolved dynamics of nanosecond laser-induced phase explosion

    International Nuclear Information System (INIS)

    Porneala, Cristian; Willis, David A

    2009-01-01

    Visualization of Nd : YAG laser ablation of aluminium targets was performed by a shadowgraph apparatus capable of imaging the dynamics of ablation with nanosecond time resolution. Direct observations of vaporization, explosive phase change and shock waves were obtained. The influence of vaporization and phase explosion on shock wave velocity was directly measured. A significant increase in the shock wave velocity was observed at the onset of phase explosion. However, the shock wave behaviour followed the form of a Taylor-Sedov spherical shock below and above the explosive phase change threshold. The jump in the shock wave velocity above phase explosion threshold is attributed to the release of stored enthalpy in the superheated liquid surface. The energy released during phase explosion was estimated by fitting the transient shock wave position to the Taylor scaling rules. Results of temperature calculations indicate that the vapour temperature at the phase explosion threshold is slightly higher than the critical temperature at the early stages of the shock wave formation. The shock wave pressure nearly doubled when transitioning from normal vaporization to phase explosion.

  1. Simulation of Few Bifurcation Phase Diagrams of Belousov-Zhabotinsky Reaction with Eleven Variable Chaotic Model in CSTR

    Directory of Open Access Journals (Sweden)

    B. Swathi

    2009-01-01

    Full Text Available Simulation of the Gyorgyi, Rempe and Field eleven variable chaotic model in CSTR [Continuously Stirred Tank Reactor] is performed with respect to the concentrations of malonic acid and [Ce(III]. These simulation studies show steady state, periodic and non-periodic regions. These studies have been presented as two variable bifurcation phase diagrams. We also have observed the bursting phenomenon under different set of constraints. We have given much importance on computer simulation work but not included the experimental methods in this paper.

  2. Therapeutic Change in Colombian Families Dealing with Violence: Therapists, Clients, and Referring Systems in Conversation

    Science.gov (United States)

    Ripoll-Nunez, Karen; Villar-Guhl, Carlos Felipe; Villar-Concha, Eduardo

    2012-01-01

    There is a gap in the Marriage and Family Therapy literature regarding clients', therapists', and family judges' theories of change in relational therapy for family violence. We conducted in-depth interviews with eleven court-referred families, their therapists, and two family judges in Bogota, Colombia. Interviews focused on their expectations of…

  3. Computer Vision Syndrome in Eleven to Eighteen-Year-Old Students in Qazvin

    Directory of Open Access Journals (Sweden)

    Khalaj

    2015-08-01

    Full Text Available Background Prolonged use of computers can lead to complications such as eye strain, eye and head aches, double and blurred vision, tired eyes, irritation, burning and itching eyes, eye redness, light sensitivity, dry eyes, muscle strains, and other problems. Objectives The aim of the present study was to evaluate visual problems and major symptoms, and their associations among computer users, aged between 11 and 18 years old, residing in the Qazvin city of Iran, during year 2010. Patients and Methods This cross-sectional study was done on 642 secondary to pre university students who had referred to the eye clinic of Buali hospital of Qazvin during year 2013. A questionnaire consisting of demographic information and 26 questions on visual effects of the computer was used to gather information. Participants answered all questions and then underwent complete eye examinations and in some cases cycloplegic refraction. Visual acuity (VA was measured with a logMAR in six meters. Refraction errors were determined using an auto refractometer (Potece and Heine retinoscope. The collected data was then analyzed using the SPSS statistical software. Results The results of this study indicated that 63.86% of the subjects had refractive errors. Refractive errors were significantly different in children of different genders (P < 0.05. The most common complaints associated with the continuous use of computers were eyestrain, eye pain, eye redness, headache, and blurred vision. The most prevalent (81.8% eye-related problem in computer users was eyestrain and the least prevalent was dry eyes (7.84%. In order to reduce computer related problems 54.2% of the participants suggested taking enough rest, 37.9% recommended use of computers only for necessary tasks, while 24.4% and 19.1% suggested the use of monitor shields and proper working distance, respectively. Conclusions Our findings revealed that using computers for prolonged periods of time can lead to eye

  4. The E-pistolary Novel: Print Screens of Media-driven Thoughts in David Llewellyn’s Eleven

    Directory of Open Access Journals (Sweden)

    Oana Celia GHEORGHIU

    2014-12-01

    Full Text Available Contemporary literature seems to have reconciled the idea that everything valuable has already been said and done and, as such, has wilfully inscribed itself in a never-ending cycle of narratives about narratives, in a process of recycling and updating the past, which some love to name postmodernist. What is left at stake is simply the consumerist need to produce an oxymoronic ‘original copy’: to launch that piece of literature unseen and unheard of before on a crowded book market. A recipe for success seems to be the ability to combine the novelty of the architectural design – the formal innovation – with the thematisation of the present. It is precisely what the young Welsh novelist and scriptwriter, David Llewellyn, achieves with his debut novel, Eleven. In an attempt to translate the old into the new, Eleven is constructed following the design of the early modern epistolary novels, yet making use of a contemporary mode of writing: the email. Thematically, it is an exploration of patterns of individual thinking shaped by the media, against the background of an event with global consequences, which is, nevertheless, viewed from afar, without the inherent trauma so visible in American post-9/11 fiction. The present paper aims at analysing the construction of the novel, including the linguistic transformations it employs, and at accounting for the identitaryrevolt that transpires from the e mails exchanged between various character-narrators on an apparently ordinary day: September 11, 2001.

  5. Caries risk assessment/treatment programs in U.S. dental schools: an eleven-year follow-up.

    Science.gov (United States)

    Yorty, Jack S; Walls, Allan Todd; Wearden, Stanley

    2011-01-01

    The purpose of this survey was to identify the number and characteristics of caries risk assessment/treatment (CRA/ Tx) programs in U.S. dental schools in 2009 and compare the results to those of the 1998 survey. A survey of U.S. dental schools was conducted in 2009 using the same eleven-question survey instrument as in 1998. Results were analyzed using stratified random sampling and chi-square tests for six of the questions. Additionally, data from the other questions were directly compared. Two questions showed a statistically significant difference: an increase in programs supervised by one school department and the number of schools using CRA as a graduation requirement. Positive changes are occurring in the development of CRA/Tx programs in U.S. dental schools. A wide variety of approaches to teaching this subject, including use of terminology and treatment philosophies, is evident. The evolution of this subject has been slow and varied over the past eleven years. Changing from a mainly surgical approach model to a medical model is occurring, but a more integrated method is needed to clarify terminology, diagnosis, treatment, and communications with researchers, clinicians, teachers, patients, and third-party payers.

  6. 2002 reference document; Document de reference 2002

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    This 2002 reference document of the group Areva, provides information on the society. Organized in seven chapters, it presents the persons responsible for the reference document and for auditing the financial statements, information pertaining to the transaction, general information on the company and share capital, information on company operation, changes and future prospects, assets, financial position, financial performance, information on company management and executive board and supervisory board, recent developments and future prospects. (A.L.B.)

  7. Remote Sensing of Cloud Top Height from SEVIRI: Analysis of Eleven Current Retrieval Algorithms

    Science.gov (United States)

    Hamann, U.; Walther, A.; Baum, B.; Bennartz, R.; Bugliaro, L.; Derrien, M.; Francis, P. N.; Heidinger, A.; Joro, S.; Kniffka, A.; hide

    2014-01-01

    .90. The average CTHs derived by the SEVIRI algorithms are closer to the CPR measurements than to CALIOP measurements. The biases between SEVIRI and CPR retrievals range from -0.8 kilometers to 0.6 kilometers. The correlation coefficients of CPR and SEVIRI observations vary between 0.82 and 0.89. To discuss the origin of the CTH deviation, we investigate three cloud categories: optically thin and thick single layer as well as multi-layer clouds. For optically thick clouds the correlation coefficients between the SEVIRI and the reference data sets are usually above 0.95. For optically thin single layer clouds the correlation coefficients are still above 0.92. For this cloud category the SEVIRI algorithms yield CTHs that are lower than CALIOP and similar to CPR observations. Most challenging are the multi-layer clouds, where the correlation coefficients are for most algorithms between 0.6 and 0.8. Finally, we evaluate the performance of the SEVIRI retrievals for boundary layer clouds. While the CTH retrieval for this cloud type is relatively accurate, there are still considerable differences between the algorithms. These are related to the uncertainties and limited vertical resolution of the assumed temperature profiles in combination with the presence of temperature inversions, which lead to ambiguities in the CTH retrieval. Alternative approaches for the CTH retrieval of low clouds are discussed.

  8. Nanosecond-level time synchronization of autonomous radio detector stations for extensive air showers

    Science.gov (United States)

    The Pierre Auger Collaboration

    2016-01-01

    To exploit the full potential of radio measurements of cosmic-ray air showers at MHz frequencies, a detector timing synchronization within 1 ns is needed. Large distributed radio detector arrays such as the Auger Engineering Radio Array (AERA) rely on timing via the Global Positioning System (GPS) for the synchronization of individual detector station clocks. Unfortunately, GPS timing is expected to have an accuracy no better than about 5 ns. In practice, in particular in AERA, the GPS clocks exhibit drifts on the order of tens of ns. We developed a technique to correct for the GPS drifts, and an independent method is used to cross-check that indeed we reach a nanosecond-scale timing accuracy by this correction. First, we operate a ``beacon transmitter'' which emits defined sine waves detected by AERA antennas recorded within the physics data. The relative phasing of these sine waves can be used to correct for GPS clock drifts. In addition to this, we observe radio pulses emitted by commercial airplanes, the position of which we determine in real time from Automatic Dependent Surveillance Broadcasts intercepted with a software-defined radio. From the known source location and the measured arrival times of the pulses we determine relative timing offsets between radio detector stations. We demonstrate with a combined analysis that the two methods give a consistent timing calibration with an accuracy of 2 ns or better. Consequently, the beacon method alone can be used in the future to continuously determine and correct for GPS clock drifts in each individual event measured by AERA.

  9. A method for the formation of Pt metal nanoparticle arrays using nanosecond pulsed laser dewetting

    Energy Technology Data Exchange (ETDEWEB)

    Owusu-Ansah, Ebenezer; Horwood, Corie A.; Birss, Viola I.; Shi, Yujun J., E-mail: shiy@ucalgary.ca [Department of Chemistry, University of Calgary, Calgary, Alberta T2N 1N4 (Canada); El-Sayed, Hany A. [Institute for Technical Electrochemistry, Technische Universität München, D-85748 Garching (Germany)

    2015-05-18

    Nanosecond pulsed laser dewetting of Pt thin films, deposited on a dimpled Ta (DT) surface, has been studied here in order to form ordered Pt nanoparticle (NP) arrays. The DT substrate was fabricated via a simple electrochemical anodization process in a highly concentrated H{sub 2}SO{sub 4} and HF solution. Pt thin films (3–5 nm) were sputter coated on DT and then dewetted under vacuum to generate NPs using a 355 nm laser radiation (6–9 ns, 10 Hz). The threshold laser fluence to fully dewet a 3.5 nm thick Pt film was determined to be 300 mJ/cm{sup 2}. Our experiments have shown that shorter irradiation times (≤60 s) produce smaller nanoparticles with more uniform sizes, while longer times (>60 s) give large nanoparticles with wider size distributions. The optimum laser irradiation time of 1 s (10 pulses) has led to the formation of highly ordered Pt nanoparticle arrays with an average nanoparticle size of 26 ± 3 nm with no substrate deformation. At the optimum condition of 1 s and 500 mJ/cm{sup 2}, as many as 85% of the dewetted NPs were found neatly in the well-defined dimples. This work has demonstrated that pulsed laser dewetting of Pt thin films on a pre-patterned dimpled substrate is an efficient and powerful technique to produce highly ordered Pt nanoparticle arrays. This method can thus be used to produce arrays of other high-melting-point metal nanoparticles for a range of applications, including electrocatalysis, functionalized nanomaterials, and analytical purposes.

  10. Nanosecond pulsed laser ablation of Ge investigated by employing photoacoustic deflection technique and SEM analysis

    Energy Technology Data Exchange (ETDEWEB)

    Yaseen, Nazish; Bashir, Shazia; Shabbir, Muhammad Kaif; Jalil, Sohail Abdul; Akram, Mahreen; Hayat, Asma; Mahmood, Khaliq; Haq, Faizan-ul; Ahmad, Riaz; Hussain, Tousif

    2016-06-01

    Nanosecond pulsed laser ablation phenomena of single crystal Ge (100) has been investigated by employing photoacoustic deflection as well as SEM analysis techniques. Nd: YAG laser (1064 nm, 10 ns, 1–10 Hz) at various laser fluences ranging from 0.2 to 11 J cm{sup −2} is employed as pump beam to ablate Ge targets. In order to evaluate in-situe ablation threshold fluence of Ge by photoacoustic deflection technique, Continuous Wave (CW) He–Ne laser (632 nm, power 10 mW) is employed as a probe beam. It travels parallel to the target surface at a distance of 3 mm and after passing through Ge plasma it causes deflection due to density gradient of acoustic waves. The deflected signal is detected by photodiode and is recorded by oscilloscope. The threshold fluence of Ge, the velocity of ablated species and the amplitude of the deflected signal are evaluated. The threshold fluence of Ge comes out to be 0.5 J cm{sup −2} and is comparable with the analytical value. In order to compare the estimated value of threshold with ex-situe measurements, the quantitative analysis of laser irradiated Ge is performed by using SEM analysis. For this purpose Ge is exposed to single and multiple shots of 5, 10, 50 and 100 at various laser fluences ranging from 0.2 to 11 J cm{sup −2}. The threshold fluence for single and multiple shots as well as incubation coefficients are evaluated. It is observed that the value of incubation co-efficient decreases with increasing number of pulses and is therefore responsible for lowering the threshold fluence of Ge. SEM analysis also reveals the growth of various features such as porous structures, non-uniform ripples and blisters on the laser irradiated Ge. It is observed that both the fluence as well as number of laser shots plays a significant role for the growth of these structures.

  11. Nanosecond pulsed laser ablation of Ge investigated by employing photoacoustic deflection technique and SEM analysis

    International Nuclear Information System (INIS)

    Yaseen, Nazish; Bashir, Shazia; Shabbir, Muhammad Kaif; Jalil, Sohail Abdul; Akram, Mahreen; Hayat, Asma; Mahmood, Khaliq; Haq, Faizan-ul; Ahmad, Riaz; Hussain, Tousif

    2016-01-01

    Nanosecond pulsed laser ablation phenomena of single crystal Ge (100) has been investigated by employing photoacoustic deflection as well as SEM analysis techniques. Nd: YAG laser (1064 nm, 10 ns, 1–10 Hz) at various laser fluences ranging from 0.2 to 11 J cm"−"2 is employed as pump beam to ablate Ge targets. In order to evaluate in-situe ablation threshold fluence of Ge by photoacoustic deflection technique, Continuous Wave (CW) He–Ne laser (632 nm, power 10 mW) is employed as a probe beam. It travels parallel to the target surface at a distance of 3 mm and after passing through Ge plasma it causes deflection due to density gradient of acoustic waves. The deflected signal is detected by photodiode and is recorded by oscilloscope. The threshold fluence of Ge, the velocity of ablated species and the amplitude of the deflected signal are evaluated. The threshold fluence of Ge comes out to be 0.5 J cm"−"2 and is comparable with the analytical value. In order to compare the estimated value of threshold with ex-situe measurements, the quantitative analysis of laser irradiated Ge is performed by using SEM analysis. For this purpose Ge is exposed to single and multiple shots of 5, 10, 50 and 100 at various laser fluences ranging from 0.2 to 11 J cm"−"2. The threshold fluence for single and multiple shots as well as incubation coefficients are evaluated. It is observed that the value of incubation co-efficient decreases with increasing number of pulses and is therefore responsible for lowering the threshold fluence of Ge. SEM analysis also reveals the growth of various features such as porous structures, non-uniform ripples and blisters on the laser irradiated Ge. It is observed that both the fluence as well as number of laser shots plays a significant role for the growth of these structures.

  12. Porcine skin damage thresholds for pulsed nanosecond-scale laser exposure at 1064-nm

    Science.gov (United States)

    DeLisi, Michael P.; Peterson, Amanda M.; Noojin, Gary D.; Shingledecker, Aurora D.; Tijerina, Amanda J.; Boretsky, Adam R.; Schmidt, Morgan S.; Kumru, Semih S.; Thomas, Robert J.

    2018-02-01

    Pulsed high-energy lasers operating in the near-infrared (NIR) band are increasingly being used in medical, industrial, and military applications, but there are little available experimental data to characterize their hazardous effects on skin tissue. The current American National Standard for the Safe Use of Lasers (ANSI Z136.1-2014) defines the maximum permissible exposure (MPE) on the skin as either a single-pulse or total exposure time limit. This study determined the minimum visible lesion (MVL) damage thresholds in Yucatan miniature pig skin for the single-pulse case and several multiple-pulse cases over a wide range of pulse repetition frequencies (PRFs) (10, 125, 2,000, and 10,000 Hz) utilizing nanosecond-scale pulses (10 or 60 ns). The thresholds are expressed in terms of the median effective dose (ED50) based on varying individual pulse energy with other laser parameters held constant. The results confirm a decrease in MVL threshold as PRF increases for exposures with a constant number of pulses, while also noting a PRF-dependent change in the threshold as a function of the number of pulses. Furthermore, this study highlights a change in damage mechanism to the skin from melanin-mediated photomechanical events at high irradiance levels and few numbers of pulses to bulk tissue photothermal additivity at lower irradiance levels and greater numbers of pulses. The observed trends exceeded the existing exposure limits by an average factor of 9.1 in the photothermally-damaged cases and 3.6 in the photomechanicallydamaged cases.

  13. Nanosecond repetitively pulsed discharges in air at atmospheric pressure-the spark regime

    International Nuclear Information System (INIS)

    Pai, David Z; Lacoste, Deanna A; Laux, Christophe O

    2010-01-01

    Nanosecond repetitively pulsed (NRP) spark discharges have been studied in atmospheric pressure air preheated to 1000 K. Measurements of spark initiation and stability, plasma dynamics, gas temperature and current-voltage characteristics of the spark regime are presented. Using 10 ns pulses applied repetitively at 30 kHz, we find that 2-400 pulses are required to initiate the spark, depending on the applied voltage. Furthermore, about 30-50 pulses are required for the spark discharge to reach steady state, following initiation. Based on space- and time-resolved optical emission spectroscopy, the spark discharge in steady state is found to ignite homogeneously in the discharge gap, without evidence of an initial streamer. Using measured emission from the N 2 (C-B) 0-0 band, it is found that the gas temperature rises by several thousand Kelvin in the span of about 30 ns following the application of the high-voltage pulse. Current-voltage measurements show that up to 20-40 A of conduction current is generated, which corresponds to an electron number density of up to 10 15 cm -3 towards the end of the high-voltage pulse. The discharge dynamics, gas temperature and electron number density are consistent with a streamer-less spark that develops homogeneously through avalanche ionization in volume. This occurs because the pre-ionization electron number density of about 10 11 cm -3 produced by the high frequency train of pulses is above the critical density for streamer-less discharge development, which is shown to be about 10 8 cm -3 .

  14. Lead extraction by selective operation of a nanosecond-pulsed 355nm laser

    Science.gov (United States)

    Herzog, Amir; Bogdan, Stefan; Glikson, Michael; Ishaaya, Amiel A.; Love, Charles

    2016-03-01

    Lead extraction (LE) is necessary for patients who are suffering from a related infection, or in opening venous occlusions that prevent the insertion of additional lead. In severe cases of fibrous encapsulation of the lead within a vein, laser-based cardiac LE has become one of the foremost methods of removal. In cases where the laser radiation (typically at 308 nm wavelength) interacts with the vein wall rather than with the fibrotic lesion, severe injury and subsequent bleeding may occur. Selective tissue ablation was previously demonstrated by a laser operating in the UV regime; however, it requires the use of sensitizers (e.g.: tetracycline). In this study, we present a preliminary examination of efficacy and safety aspects in the use of a nanosecond-pulsed solid-state laser radiation, at 355 nm wavelength, guided in a catheter consisting of optical fibers, in LE. Specifically, we demonstrate a correlation between the tissue elasticity and the catheter advancement rate, in ex-vivo experiments. Our results indicate a selectivity property for specific parameters of the laser radiation and catheter design. The selectivity is attributed to differences in the mechanical properties of the fibrotic tissue and a normal vein wall, leading to a different photomechanical response of the tissue's extracellular matrix. Furthermore, we performed successful in-vivo animal trials, providing a basic proof of concept for using the suggested scheme in LE. Selective operation using a 355 nm laser may reduce the risk of blood vessel perforation as well as the incidence of major adverse events.

  15. Electric field measurements in a nanosecond pulse discharge in atmospheric air

    International Nuclear Information System (INIS)

    Simeni Simeni, Marien; Frederickson, Kraig; Lempert, Walter R; Adamovich, Igor V; Goldberg, Benjamin M; Zhang, Cheng

    2017-01-01

    The paper presents the results of temporally and spatially resolved electric field measurements in a nanosecond pulse discharge in atmospheric air, sustained between a razor edge high-voltage electrode and a plane grounded electrode covered by a thin dielectric plate. The electric field is measured by picosecond four-wave mixing in a collinear phase-matching geometry, with time resolution of approximately 2 ns, using an absolute calibration provided by measurements of a known electrostatic electric field. The results demonstrate electric field offset on the discharge center plane before the discharge pulse due to surface charge accumulation on the dielectric from the weaker, opposite polarity pre-pulse. During the discharge pulse, the electric field follows the applied voltage until ‘forward’ breakdown occurs, after which the field in the plasma is significantly reduced due to charge separation. When the applied voltage is reduced, the field in the plasma reverses direction and increases again, until the weak ‘reverse’ breakdown occurs, producing a secondary transient reduction in the electric field. After the pulse, the field is gradually reduced on a microsecond time scale, likely due to residual surface charge neutralization by transport of opposite polarity charges from the plasma. Spatially resolved electric field measurements show that the discharge develops as a surface ionization wave. Significant surface charge accumulation on the dielectric surface is detected near the end of the discharge pulse. Spatially resolved measurements of electric field vector components demonstrate that the vertical electric field in the surface ionization wave peaks ahead of the horizontal electric field. Behind the wave, the vertical field remains low, near the detection limit, while the horizontal field is gradually reduced to near the detection limit at the discharge center plane. These results are consistent with time-resolved measurements of electric field

  16. Nanosecond-level time synchronization of autonomous radio detector stations for extensive air showers

    International Nuclear Information System (INIS)

    Aab, A.; Abreu, P.; Aglietta, M.; Ahn, E.J.; Al Samarai, I.; Albuquerque, I.F.M.; Allekotte, I.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Alves Batista, R.; Ambrosio, M.; Aminaei, A.

    2016-01-01

    To exploit the full potential of radio measurements of cosmic-ray air showers at MHz frequencies, a detector timing synchronization within 1 ns is needed. Large distributed radio detector arrays such as the Auger Engineering Radio Array (AERA) rely on timing via the Global Positioning System (GPS) for the synchronization of individual detector station clocks. Unfortunately, GPS timing is expected to have an accuracy no better than about 5 ns. In practice, in particular in AERA, the GPS clocks exhibit drifts on the order of tens of ns. We developed a technique to correct for the GPS drifts, and an independent method is used to cross-check that indeed we reach a nanosecond-scale timing accuracy by this correction. First, we operate a ''beacon transmitter'' which emits defined sine waves detected by AERA antennas recorded within the physics data. The relative phasing of these sine waves can be used to correct for GPS clock drifts. In addition to this, we observe radio pulses emitted by commercial airplanes, the position of which we determine in real time from Automatic Dependent Surveillance Broadcasts intercepted with a software-defined radio. From the known source location and the measured arrival times of the pulses we determine relative timing offsets between radio detector stations. We demonstrate with a combined analysis that the two methods give a consistent timing calibration with an accuracy of 2 ns or better. Consequently, the beacon method alone can be used in the future to continuously determine and correct for GPS clock drifts in each individual event measured by AERA

  17. Nanosecond pulsed laser nanostructuring of Au thin films: Comparison between irradiation at low and atmospheric pressure

    Energy Technology Data Exchange (ETDEWEB)

    Sánchez-Aké, C., E-mail: citlali.sanchez@ccadet.unam.mx [Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, Circuito Exterior S/N, C. U., Delegación Coyoacán, C.P. 04510, México D.F. (Mexico); Canales-Ramos, A. [Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, Circuito Exterior S/N, C. U., Delegación Coyoacán, C.P. 04510, México D.F. (Mexico); García-Fernández, T. [Universidad Autónoma de la Ciudad de México (UACM), Prolongación San Isidro 151, Col. San Lorenzo Tezonco, México D.F., C.P. 09790 (Mexico); Villagrán-Muniz, M. [Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, Circuito Exterior S/N, C. U., Delegación Coyoacán, C.P. 04510, México D.F. (Mexico)

    2017-05-01

    Highlights: • Background pressure plays an important role in NPs formation and its characteristics. • The NPs diameter and their size dispersion are smaller when irradiating in vacuum. • The plasmon resonance shifts ∼15 nm to higher frequencies when irradiating in vacuum. • Film partial ablation cannot be neglected for thickness in the range 40–80 nm. • In situ optical techniques monitor the timescale of the process and ablation dynamics. - Abstract: Au thin films with tens of nm in thickness deposited on glass substrates were irradiated with nanosecond UV (355 nm) laser pulses at atmospheric pressure and in vacuum conditions (∼600 and 10{sup −5} Torr). We studied the effect of the laser fluence (200–400 mJ/cm{sup 2}), thickness of the starting film (∼40–80 nm) and surrounding pressure on the partial ablation/evaporation of the films and the morphology of the produced nanoparticles (NPs). The dynamics of NPs formation was studied by measuring in real time the transmission of the samples upon continuous-wave laser exposure, and by means of probe beam deflection technique. The ejection of material from the film as a result of the irradiation was confirmed by time-resolved shadowgraphy technique. Experiments show that the NPs diameter and their size distribution are smaller when the irradiation is performed in vacuum regardless the laser fluence and thickness of the started film. It is also shown that the plasmon band shifts to higher frequencies with lower background pressure. The optical measurements show that the films melt and ablate during the laser pulse, but the transmission of the irradiated areas continues changing during tens of microseconds due to ejection of material and solidification of the remaining gold. Our results indicate that partial ablation cannot be neglected in nanostructuration by ns-pulsed irradiation of thin films when their thickness is in the studied range.

  18. Nanosecond repetitively pulsed discharges in air at atmospheric pressure—the spark regime

    Science.gov (United States)

    Pai, David Z.; Lacoste, Deanna A.; Laux, Christophe O.

    2010-12-01

    Nanosecond repetitively pulsed (NRP) spark discharges have been studied in atmospheric pressure air preheated to 1000 K. Measurements of spark initiation and stability, plasma dynamics, gas temperature and current-voltage characteristics of the spark regime are presented. Using 10 ns pulses applied repetitively at 30 kHz, we find that 2-400 pulses are required to initiate the spark, depending on the applied voltage. Furthermore, about 30-50 pulses are required for the spark discharge to reach steady state, following initiation. Based on space- and time-resolved optical emission spectroscopy, the spark discharge in steady state is found to ignite homogeneously in the discharge gap, without evidence of an initial streamer. Using measured emission from the N2 (C-B) 0-0 band, it is found that the gas temperature rises by several thousand Kelvin in the span of about 30 ns following the application of the high-voltage pulse. Current-voltage measurements show that up to 20-40 A of conduction current is generated, which corresponds to an electron number density of up to 1015 cm-3 towards the end of the high-voltage pulse. The discharge dynamics, gas temperature and electron number density are consistent with a streamer-less spark that develops homogeneously through avalanche ionization in volume. This occurs because the pre-ionization electron number density of about 1011 cm-3 produced by the high frequency train of pulses is above the critical density for streamer-less discharge development, which is shown to be about 108 cm-3.

  19. Nanosecond repetitively pulsed discharges in air at atmospheric pressure-the spark regime

    Energy Technology Data Exchange (ETDEWEB)

    Pai, David Z; Lacoste, Deanna A; Laux, Christophe O [Laboratoire EM2C, CNRS UPR288, Ecole Centrale Paris, 92295 Chatenay-Malabry (France)

    2010-12-15

    Nanosecond repetitively pulsed (NRP) spark discharges have been studied in atmospheric pressure air preheated to 1000 K. Measurements of spark initiation and stability, plasma dynamics, gas temperature and current-voltage characteristics of the spark regime are presented. Using 10 ns pulses applied repetitively at 30 kHz, we find that 2-400 pulses are required to initiate the spark, depending on the applied voltage. Furthermore, about 30-50 pulses are required for the spark discharge to reach steady state, following initiation. Based on space- and time-resolved optical emission spectroscopy, the spark discharge in steady state is found to ignite homogeneously in the discharge gap, without evidence of an initial streamer. Using measured emission from the N{sub 2} (C-B) 0-0 band, it is found that the gas temperature rises by several thousand Kelvin in the span of about 30 ns following the application of the high-voltage pulse. Current-voltage measurements show that up to 20-40 A of conduction current is generated, which corresponds to an electron number density of up to 10{sup 15} cm{sup -3} towards the end of the high-voltage pulse. The discharge dynamics, gas temperature and electron number density are consistent with a streamer-less spark that develops homogeneously through avalanche ionization in volume. This occurs because the pre-ionization electron number density of about 10{sup 11} cm{sup -3} produced by the high frequency train of pulses is above the critical density for streamer-less discharge development, which is shown to be about 10{sup 8} cm{sup -3}.

  20. Electric field measurements in nanosecond pulse discharges in air over liquid water surface

    Science.gov (United States)

    Simeni Simeni, Marien; Baratte, Edmond; Zhang, Cheng; Frederickson, Kraig; Adamovich, Igor V.

    2018-01-01

    Electric field in nanosecond pulse discharges in ambient air is measured by picosecond four-wave mixing, with absolute calibration by a known electrostatic field. The measurements are done in two geometries, (a) the discharge between two parallel cylinder electrodes placed inside quartz tubes, and (b) the discharge between a razor edge electrode and distilled water surface. In the first case, breakdown field exceeds DC breakdown threshold by approximately a factor of four, 140 ± 10 kV cm-1. In the second case, electric field is measured for both positive and negative pulse polarities, with pulse durations of ˜10 ns and ˜100 ns, respectively. In the short duration, positive polarity pulse, breakdown occurs at 85 kV cm-1, after which the electric field decreases over several ns due to charge separation in the plasma, with no field reversal detected when the applied voltage is reduced. In a long duration, negative polarity pulse, breakdown occurs at a lower electric field, 30 kV cm-1, after which the field decays over several tens of ns and reverses direction when the applied voltage is reduced at the end of the pulse. For both pulse polarities, electric field after the pulse decays on a microsecond time scale, due to residual surface charge neutralization by transport of opposite polarity charges from the plasma. Measurements 1 mm away from the discharge center plane, ˜100 μm from the water surface, show that during the voltage rise, horizontal field component (Ex ) lags in time behind the vertical component (Ey ). After breakdown, Ey is reduced to near zero and reverses direction. Further away from the water surface (≈0.9 mm), Ex is much higher compared to Ey during the entire voltage pulse. The results provide insight into air plasma kinetics and charge transport processes near plasma-liquid interface, over a wide range of time scales.

  1. Permeabilization of the nuclear envelope following nanosecond pulsed electric field exposure

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Gary L., E-mail: gary.l.thompson.3@gmail.com [Oak Ridge Institute for Science & Education, Joint Base San Antonio Fort Sam Houston, TX, 78234 (United States); Roth, Caleb C. [Department of Radiological Sciences, University of Texas Health Science Center at San Antonio, TX, 78234 (United States); Kuipers, Marjorie A. [Radio Frequency Radiation Branch, Bioeffects Division, Human Effectiveness Directorate, 711th Human Performance Wing, Air Force Research Laboratory, Joint Base San Antonio Fort Sam Houston, TX, 78234 (United States); Tolstykh, Gleb P. [General Dynamics IT, Joint Base San Antonio Fort Sam Houston, TX, 78234 (United States); Beier, Hope T. [Optical Radiation Branch, Bioeffects Division, Human Effectiveness Directorate, 711th Human Performance Wing, Air Force Research Laboratory, Joint Base San Antonio Fort Sam Houston, TX, 78234 (United States); Ibey, Bennett L. [Radio Frequency Radiation Branch, Bioeffects Division, Human Effectiveness Directorate, 711th Human Performance Wing, Air Force Research Laboratory, Joint Base San Antonio Fort Sam Houston, TX, 78234 (United States)

    2016-01-29

    Permeabilization of cell membranes occurs upon exposure to a threshold absorbed dose (AD) of nanosecond pulsed electric fields (nsPEF). The ultimate, physiological bioeffect of this exposure depends on the type of cultured cell and environment, indicating that cell-specific pathways and structures are stimulated. Here we investigate 10 and 600 ns duration PEF effects on Chinese hamster ovary (CHO) cell nuclei, where our hypothesis is that pulse disruption of the nuclear envelope membrane leads to observed cell death and decreased viability 24 h post-exposure. To observe short-term responses to nsPEF exposure, CHO cells have been stably transfected with two fluorescently-labeled proteins known to be sequestered for cellular chromosomal function within the nucleus – histone-2b (H2B) and proliferating cell nuclear antigen (PCNA). H2B remains associated with chromatin after nsPEF exposure, whereas PCNA leaks out of nuclei permeabilized by a threshold AD of 10 and 600 ns PEF. A downturn in 24 h viability, measured by MTT assay, is observed at the number of pulses required to induce permeabilization of the nucleus. - Highlights: • The ability of nsPEF to damage nuclear structures within cells is investigated. • Leakage of proliferating nuclear antigen from nuclei is induced by nsPEF. • High doses of nsPEF disrupt cortical lamin and cause chromatin decompaction. • Histone H2B remains attached to chromatin following nsPEF exposure. • DNA does not leak out of nsPEF-permeabilized nuclei.

  2. Laser machining micro-structures on diamond surface with a sub-nanosecond pulsed laser

    Science.gov (United States)

    Wu, Mingtao; Guo, Bing; Zhao, Qingliang

    2018-02-01

    Micro-structure surface on diamond material is widely used in a series of industrial and scientific applications, such as micro-electromechanical systems (MEMS), nanoelectromechanical systems (NEMS), microelectronics, textured or micro-structured diamond machining tools. The efficient machining of micro-structure on diamond surface is urgently demanded in engineering. In this paper, laser machining square micro-structure on diamond surface was studied with a sub-nanosecond pulsed laser. The influences of laser machining parameters, including the laser power, scanning speed, defocusing quantity and scanning pitch, were researched in view of the ablation depth, material removal rate and machined surface topography. Both the ablation depth and material removal rate increased with average laser power. A reduction of the growth rate of the two parameters was induced by the absorption of the laser plasma plume at high laser power. The ablation depth non-linearly decreased with the increasing of the scanning speed while the material removal rate showed an opposite tendency. The increasing of the defocusing quantity induced complex variation of the ablation depth and the material removal rate. The maximum ablation depth and material removal rate were achieved at a defocusing position. The ablation depth and material removal rate oppositely varied about the scanning pitch. A high overlap ratio was meaningful for achieving a smooth micro-structure surface topography. Laser machining with a large defocusing quantity, high laser power and small scanning pitch was helpful for acquiring the desired micro-structure which had a large depth and smooth micro-structure surface topography.

  3. Surface morphological modification of crosslinked hydrophilic co-polymers by nanosecond pulsed laser irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Primo, Gastón A.; Alvarez Igarzabal, Cecilia I. [IMBIV (CONICET), Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Haya de la Torre y Medina Allende, Edificio de Ciencias II, Ciudad Universitaria, Córdoba X5000HUA (Argentina); Pino, Gustavo A.; Ferrero, Juan C. [INFIQC (CONICET), Departamento de Fisicoquímica, Facultad de Ciencias Químicas, and Centro Láser de Ciencias Moleculares, Universidad Nacional de Córdoba, Córdoba X5000IUS (Argentina); Rossa, Maximiliano, E-mail: mrossa@fcq.unc.edu.ar [INFIQC (CONICET), Departamento de Fisicoquímica, Facultad de Ciencias Químicas, and Centro Láser de Ciencias Moleculares, Universidad Nacional de Córdoba, Córdoba X5000IUS (Argentina)

    2016-04-30

    Graphical abstract: - Highlights: • Laser-induced surface modification of crosslinked hydrophilic co-polymers by ns pulses. • Formation of ablation craters observed under most of the single-pulse experimental conditions. • UV laser foaming of dried hydrogel samples resulting from single- and multiple-pulse experiments. • Threshold values of the incident laser fluence reported for the observed surface modifications. • Lower threshold fluences for acrylate-based, compared to acrylamide-based hydrogels. - Abstract: This work reports an investigation of the surface modifications induced by irradiation with nanosecond laser pulses of ultraviolet and visible wavelengths on crosslinked hydrophilic co-polymeric materials, which have been functionalized with 1-vinylimidazole as a co-monomer. A comparison is made between hydrogels differing in the base co-monomer (N,N-dimethylaminoethyl methacrylate and N-[3-(dimethylamino)propyl] methacrylamide) and in hydration state (both swollen and dried states). Formation of craters is the dominant morphological change observed by ablation in the visible at 532 nm, whereas additional, less aggressive surface modifications, chiefly microfoams and roughness, are developed in the ultraviolet at 266 nm. At both irradiation wavelengths, threshold values of the incident laser fluence for the observation of the various surface modifications are determined under single-pulse laser irradiation conditions. It is shown that multiple-pulse irradiation at 266 nm with a limited number of laser shots can be used alternatively for generating a regular microfoam layer at the surface of dried hydrogels based on N,N-dimethylaminoethyl methacrylate. The observations are rationalized on the basis of currently accepted mechanisms for laser-induced polymer surface modification, with a significant contribution of the laser foaming mechanism. Prospective applications of the laser-foamed hydrogel matrices in biomolecule immobilization are suggested.

  4. Molecular signatures in femtosecond laser-induced organic plasmas: comparison with nanosecond laser ablation.

    Science.gov (United States)

    Serrano, Jorge; Moros, Javier; Laserna, J Javier

    2016-01-28

    During the last few years, laser-induced breakdown spectroscopy (LIBS) has evolved significantly in the molecular sensing area through the optical monitoring of emissions from organic plasmas. Large efforts have been made to study the formation pathways of diatomic radicals as well as their connections with the bonding framework of molecular solids. Together with the structural and chemical-physical properties of molecules, laser ablation parameters seem to be closely tied to the observed spectral signatures. This research focuses on evaluating the impact of laser pulse duration on the production of diatomic species that populate plasmas of organic materials. Differences in relative intensities of spectral signatures from the plasmas of several organic molecules induced in femtosecond (fs) and nanosecond (ns) ablation regimes have been studied. Beyond the abundance and origin of diatomic radicals that seed the plasma, findings reveal the crucial role of the ablation regime in the breakage pattern of the molecule. The laser pulse duration dictates the fragments and atoms resulting from the vaporized molecules, promoting some formation routes at the expense of other paths. The larger amount of fragments formed by fs pulses advocates a direct release of native bonds and a subsequent seeding of the plasma with diatomic species. In contrast, in the ns ablation regime, the atomic recombinations and single displacement processes dominate the contribution to diatomic radicals, as long as atomization of molecules prevails over their progressive decomposition. Consequently, fs-LIBS better reflects correlations between strengths of emissions from diatomic species and molecular structure as compared to ns-LIBS. These new results entail a further step towards the specificity in the analysis of molecular solids by fs-LIBS.

  5. Novel X-ray imaging diagnostics of high energy nanosecond pulse accelerators

    International Nuclear Information System (INIS)

    Smith, Graham W.; Gallegos, Roque Rosauro; Hohlfelder, Robert James; Beutler, David Eric; Dudley, John; Seymour, Calvin L.G.; Bell, John D.

    2004-01-01

    Pioneering x-ray imaging has been undertaken on a number of AWE's and Sandia National Laboratories radiation effects x-ray simulators. These simulators typically yield a single very short (<50ns) pulse of high-energy (MeV endpoint energy bremsstrahlung) x-ray radiation with doses in the kilorad (krad(Si)) region. X-ray source targets vary in size from 2 to 25cm diameter, dependent upon the particular simulator. Electronic imaging of the source x-ray emission under dynamic conditions yields valuable information upon how the simulator is performing. The resultant images are of interest to the simulator designer who may configure new x-ray source converter targets and diode designs. The images can provide quantitative information about machine performance during radiation effects testing of components under active conditions. The effects testing program is a valuable interface for validation of high performance computer codes and models for the radiation effects community. A novel high-energy x-ray imaging spectrometer is described whereby the spectral energy (0.1 to 2.5MeV) profile may be discerned from the digitally recorded and viewable images via a pinhole/scintillator/CCD imaging system and knowledge of the filtration parameters. Unique images, analysis and a preliminary evaluation of the capability of the spectrometer are presented. Further, a novel time resolved imaging system is described that captures a sequence of high spatial resolution temporal images, with zero interframe time, in the nanosecond timeframe, of our source x-rays.

  6. 100J-level nanosecond pulsed Yb:YAG cryo-cooled DPSSL amplifier

    Science.gov (United States)

    Smith, J. M.; Butcher, T. J.; Mason, P. D.; Ertel, K.; Phillips, P. J.; Banerjee, S.; De Vido, M.; Chekhlov, O.; Divoky, M.; Pilar, J.; Shaikh, W.; Hooker, C.; Lucianetti, A.; Hernandez Gomez, C.; Mocek, T.; Edwards, C.; Collier, J. L.

    2018-02-01

    We report on the successful demonstration of the world's first kW average power, 100 Joule-class, high-energy, nanosecond pulsed diode-pumped solid-state laser (DPSSL), DiPOLE100. Results from the first long-term test for amplification will be presented; the system was operated for 1 hour with 10 ns duration pulses at 10 Hz pulse repetition rate and an average output energy of 105 J and RMS energy stability of approximately 1%. The laser system is based on scalable cryogenic gas-cooled multi-slab ceramic Yb:YAG amplifier technology. The DiPOLE100 system comprises three major sub-systems, a spatially and temporally shaped front end, a 10 J cryo-amplifier and a 100 J cryo-amplifier. The 10 J cryo-amplifier contain four Yb:YAG ceramic gain media slabs, which are diode pumped from both sides, while a multi-pass architecture configured for seven passes enables 10 J of energy to be extracted at 10 Hz. This seeds the 100 J cryo-amplifier, which contains six Yb:YAG ceramic gain media slabs with the multi-pass configured for four passes. Our future development plans for this architecture will be introduced including closed-loop pulse shaping, increased energy, higher repetition rates and picosecond operation. This laser architecture unlocks the potential for practical applications including new sources for industrial materials processing and high intensity laser matter studies as envisioned for ELI [1], HiLASE [2], and the European XFEL [3]. Alternatively, it can be used as a pump source for higher repetition rate PW-class amplifiers, which can themselves generate high-brightness secondary radiation and ion sources leading to new remote imaging and medical applications.

  7. Plasma surface treatment to improve surface charge accumulation and dissipation of epoxy resin exposed to DC and nanosecond-pulse voltages

    Science.gov (United States)

    Zhang, Cheng; Lin, Haofan; Zhang, Shuai; Xie, Qin; Ren, Chengyan; Shao, Tao

    2017-10-01

    In this paper, deposition by non-thermal plasma is used as a surface modification technique to change the surface characteristics of epoxy resin exposed to DC and nanosecond-pulse voltages. The corresponding surface characteristics in both cases of DC and nanosecond-pulse voltages before and after the modification are compared and investigated. The measurement of the surface potential provides the surface charge distribution, which is used to show the accumulation and dissipation process of the surface charges. Morphology observations, chemical composition and electrical parameters measurements are used to evaluate the treatment effects. The experimental results show that, before the plasma treatment, the accumulated surface charges in the case of the DC voltage are more than that in the case of the nanosecond-pulse voltage. Moreover, the decay rate of the surface charges for the DC voltage is higher than that for the nanosecond-pulse voltage. However, the decay rate is no more than 41% after 1800 s for both types of voltages. After the plasma treatment, the maximum surface potentials decrease to 57.33% and 32.57% of their values before treatment for the DC and nanosecond-pulse voltages, respectively, indicating a decrease in the accumulated surface charges. The decay rate exceeds 90% for both types of voltages. These changes are mainly attributed to a change in the surface nanostructure, an increase in conductivity, and a decrease in the depth of energy level.

  8. Plasma surface treatment to improve surface charge accumulation and dissipation of epoxy resin exposed to DC and nanosecond-pulse voltages

    International Nuclear Information System (INIS)

    Zhang, Cheng; Lin, Haofan; Zhang, Shuai; Ren, Chengyan; Shao, Tao; Xie, Qin

    2017-01-01

    In this paper, deposition by non-thermal plasma is used as a surface modification technique to change the surface characteristics of epoxy resin exposed to DC and nanosecond-pulse voltages. The corresponding surface characteristics in both cases of DC and nanosecond-pulse voltages before and after the modification are compared and investigated. The measurement of the surface potential provides the surface charge distribution, which is used to show the accumulation and dissipation process of the surface charges. Morphology observations, chemical composition and electrical parameters measurements are used to evaluate the treatment effects. The experimental results show that, before the plasma treatment, the accumulated surface charges in the case of the DC voltage are more than that in the case of the nanosecond-pulse voltage. Moreover, the decay rate of the surface charges for the DC voltage is higher than that for the nanosecond-pulse voltage. However, the decay rate is no more than 41% after 1800 s for both types of voltages. After the plasma treatment, the maximum surface potentials decrease to 57.33% and 32.57% of their values before treatment for the DC and nanosecond-pulse voltages, respectively, indicating a decrease in the accumulated surface charges. The decay rate exceeds 90% for both types of voltages. These changes are mainly attributed to a change in the surface nanostructure, an increase in conductivity, and a decrease in the depth of energy level. (paper)

  9. Benthic sediment data from eleven stations in the Mobile-Tensaw River Delta, Alabama on 17 June 1981 (NODC Accession 0118497)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic sediment samples were collected from eleven stations in the Mobile-Tensaw River Delta on 17 June 1981. Samples were analyzed for particle size distribution...

  10. Experimental study of mechanical response of artificial tissue models irradiated with Nd:YAG nanosecond laser pulses

    Science.gov (United States)

    Pérez-Gutiérrez, Francisco G.; Camacho-López, Santiago; Aguilar, Guillermo

    2011-07-01

    Nanosecond long laser pulses are used in medical applications where precise tissue ablation with minimal thermal and mechanical collateral damage is required. When a laser pulse is incident on a material, optical energy will be absorbed by a combination of linear and nonlinear absorption according to both: laser light irradiance and material properties. In the case of water or gels, the first results in heat generation and thermoelastic expansion; while the second results in an expanding plasma formation that launches a shock wave and a cavitation/boiling bubble. Plasma formation due to nonlinear absorption of nanosecond laser pulses is originated by a combination of multiphoton ionization and thermionic emission of free electrons, which is enhanced when the material has high linear absorption coefficient. In this work, we present three experimental approaches to study pressure transients originated when 6 ns laser pulses are incident on agar gels and water with varying linear absorption coefficient, using laser radiant exposures above and below threshold for bubble formation: (a) PVDF sensors, (b) Time-resolved shadowgraphy and (c) Time-resolved interferometry. The underlying hypothesis is that pressure transients are composed of the superposition of both: shock wave originated by hot expanding plasma resulting from nonlinear absorption of optical energy and, thermoelastic expansion originated by heat generation due to linear absorption of optical energy. The objective of this study is to carry out a comprehensive experimental analysis of the mechanical effects that result when tissue models are irradiated with nanosecond laser pulses to elucidate the relative contribution of linear and nonlinear absorption to bubble formation. Furthermore, we investigate cavitation bubble formation with temperature increments as low as 3 °C.

  11. Micro-processing of NiMnGa shape memory alloy by using a nanosecond fiber laser

    Science.gov (United States)

    Biffi, C. A.; Tuissi, A.

    2016-04-01

    The interest on Ferromagnetic Shape Memory Alloys (FSMAs), such as NiMnGa, is growing up, thanks to their functional properties to be employed in a new class of micro-devices. The most evident critical issue, limiting the use of these systems in the production of industrial devices, is the brittleness of the bulk material; its workability by using convectional processing methods is very limited. Thus, alternative processing methods, including laser processing, are encouraged for the manufacture of FSMAs based new devices. In this work, the effect of the nanosecond laser microprocessing on Ni45Mn33Ga22 [at%] has been studied. Linear grooves were realized by a nanosecond 30 W fiber laser; the machined surfaces were analyzed with scanning electron microscopy, coupled with energetic dispersion spectroscopy for the composition analysis. The morphology of the grooves was affected by the laser scanning velocity and the number of laser pulses while the measured material removal rate appeared to be influenced mainly by the number of laser pulses. Compositional modification, associated to the loss of Ga content, was detected only for the lower scanning velocity, because of the high fluence. On the contrary, by increasing the velocity up to 1000 mm/s no Ga loss can be seen, making possible the laser processing of this functional alloy without its chemical modification. The use of short pulses allowed also to reduce the amount of recast material and the compositional change with respect to long pulses. Finally, the calorimetric analysis indicated that laser nanosecond microprocessing could affect the functional properties of this alloy: a larger decrease of the characteristic temperatures of the martensitic transformation was observed in correspondence of the low scanning velocity.

  12. VBE reference framework

    NARCIS (Netherlands)

    Afsarmanesh, H.; Camarinha-Matos, L.M.; Ermilova, E.; Camarinha-Matos, L.M.; Afsarmanesh, H.; Ollus, M.

    2008-01-01

    Defining a comprehensive and generic "reference framework" for Virtual organizations Breeding Environments (VBEs), addressing all their features and characteristics, is challenging. While the definition and modeling of VBEs has become more formalized during the last five years, "reference models"

  13. CMS Statistics Reference Booklet

    Data.gov (United States)

    U.S. Department of Health & Human Services — The annual CMS Statistics reference booklet provides a quick reference for summary information about health expenditures and the Medicare and Medicaid health...

  14. Design and implementation of a nanosecond time-stamping readout system-on-chip for photo-detectors

    International Nuclear Information System (INIS)

    Anvar, Shebli; Château, Frédéric; Le Provost, Hervé; Louis, Frédéric; Manolopoulos, Konstantinos; Moudden, Yassir; Vallage, Bertrand; Zonca, Eric

    2014-01-01

    A readout system suitable for a large number of synchronized photo-detection units has been designed. Each unit embeds a specifically designed fully integrated communicating system based on Xilinx FPGA SoC technology. It runs the VxWorks real-time OS and a custom data acquisition software designed within the Ice middleware framework, resulting in a highly flexible, controllable and scalable distributed application. Clock distribution and delay calibration over customized fixed latency gigabit Ethernet links enable synchronous time-stamping of events with nanosecond precision. The implementation of this readout system on several data-collecting units as well as its performances are described

  15. Effect of nanosecond UV laser irradiation on luminescence and absorption in silver- and copper-containing phosphate glasses

    Science.gov (United States)

    Murashov, A. A.; Sidorov, A. I.; Stoliarchuk, M. V.

    2018-03-01

    Experimental evidence is presented that nanosecond UV laser irradiation of silver- and copper-containing barium phosphate glasses leads to luminescence quenching in the visible range. Subsequent heat treatment induces an absorption in the range 350–500 nm. These effects are due to the ionisation and fragmentation of subnanometre molecular clusters by laser radiation and subsequent (heat treatment-induced) formation of nanoparticles possessing plasmon resonance. Our numerical modelling results demonstrate the feasibility of producing stable AgnCum hybrid molecular clusters in glass. Local modification of the optical properties of glass by laser light can be used for optical information recording.

  16. On nuclear DD synthesis at the initial stage of nanosecond vacuum discharge with deuterium-loaded Pd anode

    Science.gov (United States)

    Kurilenkov, Yu K.; Gus'kov, S. Yu; Karpukhin, V. T.; Oginov, A. V.; Samoylov, I. S.

    2018-01-01

    Earlier, there was demonstrated generation of DD neutrons in an interelectrode medium of a low-energy (˜ 1 J) nanosecond vacuum discharge with a hollow cathode and a deuterium-loaded Pd anode. There was revealed essential role of formation of a virtual cathode and a potential well corresponding thereto in the processes of collisional DD synthesis in the interelectrode space. In this work, we have obtained as a result of an experiment and discussed the neutron yield at the very initial stage of the discharge, when the beam of auto-electrons just starts to irradiate the non-ideal surface of the deuterium-loaded Pd anode.

  17. Sub-nanosecond cinematography in laser fusion research: current techniques and applications at the Lawrence Livermore National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, L.W.

    1985-01-10

    Progress in laser fusion research has increased the need for detail and precision in the diagnosis of experiments. This has spawned the development and use of sophisticated sub-nanosecond resolution diagnostic systems. These systems typically use ultrafast x-ray or optical streak cameras in combination with spatially imaging or spectrally dispersing elements. These instruments provide high resolution data essential for understanding the processes occurring in the interaction of high intensity laser light with targets. Several of these types of instruments and their capabilities will be discussed. The utilization of these kinds of diagnostics systems on the nearly completed 100 kJ Nova laser facility will be described.

  18. Outlook for the use of microsecond plasma opening switches to generate high-power nanosecond current pulses

    International Nuclear Information System (INIS)

    Dolgachev, G.I.; Maslennikov, D.D.; Ushakov, A.G.

    2006-01-01

    Paper deals with a phenomenon of current breaking in a conducting plasma volume of plasma opening switchers with a nanosecond time of energy initiation and their application in high-power generators. One determined the conditions to ensure megavolt voltages under the erosion mode making use of external applied magnetic field to ensure magnetic insulation of gap of plasma opening switchers. One studied the peculiar features of application of plasma opening switchers under 5-6 MV voltages to ensure X-ray and gamma-radiation pulses [ru

  19. Nanosecond and femtosecond mass spectroscopic analysis of a molecular beam produced by the spray-jet technique

    International Nuclear Information System (INIS)

    Yamada, Toshiki; Shinohara, Hidenori; Kamikado, Toshiya; Okuno, Yoshishige; Suzuki, Hitoshi; Mashiko, Shinro; Yokoyama, Shiyoshi

    2008-01-01

    The spray-jet molecular beam apparatus enabled us to produce a molecular beam of non-volatile molecules under high vacuum from a sprayed mist of sample solutions. The apparatus has been used in spectroscopic studies and as a means of molecular beam deposition. We analyzed the molecular beam, consisting of non-volatile, solvent, and carrier-gas molecules, by using femtosecond- and nanosecond- laser mass spectroscopy. The information thus obtained provided insight into the molecular beam produced by the spray-jet technique

  20. Changing quantum reference frames

    OpenAIRE

    Palmer, Matthew C.; Girelli, Florian; Bartlett, Stephen D.

    2013-01-01

    We consider the process of changing reference frames in the case where the reference frames are quantum systems. We find that, as part of this process, decoherence is necessarily induced on any quantum system described relative to these frames. We explore this process with examples involving reference frames for phase and orientation. Quantifying the effect of changing quantum reference frames serves as a first step in developing a relativity principle for theories in which all objects includ...

  1. Study of the pulsation of an ion accelerator giving 20 nano-second pulses; Etude de la pulsation d'un accelerateur d'ions fournissant des impulsions d'une duree de 20 nano-secondes

    Energy Technology Data Exchange (ETDEWEB)

    Cosnac, B de [Commissariat a l' Energie Atomique, Fontenay aux Roses (France). Centre d' Etudes Nucleaires

    1965-03-01

    In order to measure fast neutron spectra by the time-of-flight method, we have studied a pulsed ion-source which has been placed on the 600 kV electrostatic accelerator at Fontenay-aux-Roses. We examine successively: the ion-source itself, its extraction device, the focussing equipment and the pulsation system constituted by a slit which is swept by the beam. Using this ion-source it is possible to obtain a direct current of deutons of over 800 {mu}A, and clouds having a duration which can be adjusted to between 15 and 40 nano-seconds. (author) [French] Pour mesurer des spectres de neutrons rapides par la methode de temps de vol, nous avons etudie une source d'ions pulsee qui a ete placee sur l'accelerateur electrostatique de 600 kV de Fontenay-aux-Roses. Nous examinons successivement: la source d'ions elle-meme, son dispositif d'extraction, l'optique de focalisation et le systeme de pulsation constituee par le balayage du faisceau devant une fente. La source d'ions permet d'obtenir un courant continu de deutons superieur a 800 {mu}A et des bouffees d'une duree reglable comprise entre 15 et 40 nanosecondes. (auteur)

  2. Amphibian and reptile communities in eleven Sites of Community Importance (SCI: relations between SCI area, heterogeneity and richness

    Directory of Open Access Journals (Sweden)

    Luca Canova

    2007-11-01

    Full Text Available Seven species of amphibians and reptiles were observed in eleven Sites of Community Importance (SCI of the Lodi Province (NW Italy. Distribution and relative abundance of amphibians appeared more variable than reptiles. Some species of conservation concern as R. latastei were influenced by habitat physiognomy, i.e. the surface of wooded areas are important in predict presence and relative abundance of this species. SCI with wider surfaces and higher habitat heterogeneity included higher number of species. Species richness, here considered as a raw index of biodiversity value and community quality, was significantly related to SCI area and habitat heterogeneity; since this significant positive relation is confirmed both for amphibians and reptiles we suggest that, in planning of natural areas, priority must be retained for biotopes able to host the higher number of species.

  3. Measurement equivalence of the CES-D 8 depression-scale among the ageing population in eleven European countries.

    Science.gov (United States)

    Missinne, Sarah; Vandeviver, Christophe; Van de Velde, Sarah; Bracke, Piet

    2014-07-01

    Depression is one of the most prevalent mental disorders in later life. However, despite considerable research attention, great confusion remains regarding the association between ageing and depression. There is doubt as to whether a depression scale performs identically for different age groups and countries. Although measurement equivalence is a crucial prerequisite for valid comparisons across age groups and countries, it has not been established for the eight-item version of the Centre for Epidemiological Studies Depression Scale (CES-D8). Using multi-group confirmatory factor analysis, we assess configural, metric, and scalar measurement equivalence across two age groups (50-64 years of age and 65 or older) in eleven European countries, employing data from the Survey of Health, Ageing, and Retirement (SHARE). Results indicate that the construct of depression is comparable across age and country groups, allowing the substantive interpretation of correlates and mean levels of depressive symptoms. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. IAEA biological reference materials

    International Nuclear Information System (INIS)

    Parr, R.M.; Schelenz, R.; Ballestra, S.

    1988-01-01

    The Analytical Quality Control Services programme of the IAEA encompasses a wide variety of intercomparisons and reference materials. This paper reviews only those aspects of the subject having to do with biological reference materials. The 1988 programme foresees 13 new intercomparison exercises, one for major, minor and trace elements, five for radionuclides, and seven for stable isotopes. Twenty-two natural matrix biological reference materials are available: twelve for major, minor and trace elements, six for radionuclides, and four for chlorinated hydrocarbons. Seven new intercomparisons and reference materials are in preparation or under active consideration. Guidelines on the correct use of reference materials are being prepared for publication in 1989 in consultation with other major international producers and users of biological reference materials. The IAEA database on available reference materials is being updated and expanded in scope, and a new publication is planned for 1989. (orig.)

  5. Uniform and non-uniform modes of nanosecond-pulsed dielectric barrier discharge in atmospheric air: fast imaging and spectroscopic measurements of electric field.

    Science.gov (United States)

    Liu, Chong; Dobrynin, Danil; Fridman, Alexander

    2014-06-25

    In this study, we report experimental results on fast ICCD imaging of development of nanosecond-pulsed dielectric barrier discharge (DBD) in atmospheric air and spectroscopic measurements of electric field in the discharge. Uniformity of the discharge images obtained with nanosecond exposure times were analyzed using chi-square test. The results indicate that DBD uniformity strongly depends on applied (global) electric field in the discharge gap, and is a threshold phenomenon. We show that in the case of strong overvoltage on the discharge gap (provided by fast rise times), there is transition from filamentary to uniform DBD mode which correlates to the corresponding decrease of maximum local electric field in the discharge.

  6. Enhanced mass removal due to phase explosion during high irradiance nanosecond laser ablation of silicon

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Jong Hyun [Univ. of California, Berkeley, CA (United States)

    2000-05-01

    mechanism for high irradiance laser ablation. Laser processing parameters were also investigated for nanosecond laser ablation of silicon. Longer incident wavelengths and larger laser beam sizes were associated with higher values of a threshold irradiance.

  7. Investigations into localized re-treatment of the retina with a 3-nanosecond laser.

    Science.gov (United States)

    Chidlow, Glyn; Plunkett, Malcolm; Casson, Robert J; Wood, John P M

    2016-08-01

    Subvisual retinal lasers necessarily cause clinically invisible lesions, hence, they could intentionally or inadvertently be targeted at precisely the same or an overlapping location during repeat laser treatment. Herein, we investigated the structural integrity and cellular responses of localized re-treatment using a nanosecond laser (2RT) currently in trials for early age-related macular degeneration. Rats were randomly assigned to one of five groups: sham, subvisual 2RT, subvisual 2RT re-treatment, visual effect 2RT, visual effect 2RT re-treatment. Re-treatment groups were lasered on days 0 and 21; single laser groups were only lasered on day 21. All rats were euthanized at day 28 and eyes were then dissected and processed for immunohistochemistry. For re-treatment, the laser was targeted at precisely the same locations on both delivery occasions. Analytical endpoints included monitoring of retinal vascular integrity overlying lesions, investigation into any potential choroidal neovascularization, assessment of the RPE, quantification of collateral injury to photoreceptors or other neuronal classes, and delineation of glial reactivity. Repeat laser administration to rats caused ostensibly identical retinal-RPE-choroid responses to those obtained in age-matched rats that received only a single application. Specifically, 7 days after treatment, RPE cells were re-populating lesion sites. No obvious consistent differences were evident between the single and repeat laser groups. Moreover, repeat laser caused no (measurable) additive injury to photoreceptors or other retinal neuronal classes from single laser treatment. In re-lasered animals, there was no increase in microglial activity overlying and adjacent to lesion sites relative to single lasered rats. Finally, there was no evidence of choroidal neovascularization after repeat laser treatment. The overall results provide a measure of confidence that re-treatment of patients with 2RT should not provide any

  8. Balanced cross-rate model for saturated molecular fluorescence in flames using a nanosecond pulse length laser

    International Nuclear Information System (INIS)

    Lucht, R.P.; Sweeney, D.W.; Laurendeau, N.M.

    1980-01-01

    The balanced cross-rate model is proposed to analyze laser-induced molecular fluorescence signals when the laser pulse length is of the order of nanoseconds. Nanosecond pulse length lasers. specifically Q-switched Nd:YAG-pumped dye lasers, are attractive for saturated molecular fluorescence spectroscopy because of their high peak power and because of their short pulse length minimizes the risk of laser-induced chemistry. In the balanced cross-rate model, single upper and lower rotational levels are assumed to be directly coupled by the laser radiation. Because the laser-induced processes which couple these levels are so fast at saturation intensities, a steady state is established between the two levels within picoseconds. Provided that the total population of the two laser-coupled rotational levels is constant during the laser pulse, the total molecular population can be calculated from the observed upper rotational level population using a two-level saturation model and Boltzmann statistics. Numerical simulation of the laser excitation dynamics of OH in an atmospheric pressure H 2 /O 2 /N 2 flame indicates that the balanced cross-rate model will give accurate results provided that the rotational relaxation rates in the upper and lower sets of rotational levels are approximately equal

  9. Differences in Nanosecond Laser Ablation and Deposition of Tungsten, Boron, and WB2/B Composite due to Optical Properties

    Directory of Open Access Journals (Sweden)

    Tomasz Moscicki

    2016-01-01

    Full Text Available The first attempt to the deposition of WB3 films using nanosecond Nd:YAG laser demonstrated that deposited coatings are superhard. However, they have very high roughness. The deposited films consisted mainly of droplets. Therefore, in the present work, the explanation of this phenomenon is conducted. The interaction of Nd:YAG nanosecond laser pulse with tungsten, boron, and WB2/B target during ablation is investigated. The studies show the fundamental differences in ablation of those materials. The ablation of tungsten is thermal and occurs due to only evaporation. In the same conditions, during ablation of boron, the phase explosion and/or fragmentation due to recoil pressure is observed. The deposited films have a significant contribution of big debris with irregular shape. In the case of WB2/B composite, ablation is significantly different. The ablation seems to be the detonation in the liquid phase. The deposition mechanism is related mainly to the mechanical transport of the target material in the form of droplets, while the gaseous phase plays marginal role. The main origin of differences is optical properties of studied materials. A method estimating phase explosion occurrence based on material data such as critical temperature, thermal diffusivity, and optical properties is shown. Moreover, the effect of laser wavelength on the ablation process and the quality of the deposited films is discussed.

  10. Control of Reactive Species Generated by Low-frequency Biased Nanosecond Pulse Discharge in Atmospheric Pressure Plasma Effluent

    Science.gov (United States)

    Takashima, Keisuke; Kaneko, Toshiro

    2016-09-01

    The control of hydroxyl radical and the other gas phase species generation in the ejected gas through air plasma (air plasma effluent) has been experimentally studied, which is a key to extend the range of plasma treatment. Nanosecond pulse discharge is known to produce high reduced electric field (E/N) discharge that leads to efficient generation of the reactive species than conventional low frequency discharge, while the charge-voltage cycle in the low frequency discharge is known to be well-controlled. In this study, the nanosecond pulse discharge biased with AC low frequency high voltage is used to take advantages of these discharges, which allows us to modulate the reactive species composition in the air plasma effluent. The utilization of the gas-liquid interface and the liquid phase chemical reactions between the modulated long-lived reactive species delivered from the air plasma effluent could realize efficient liquid phase chemical reactions leading to short-lived reactive species production far from the air plasma, which is crucial for some plasma agricultural applications.

  11. Pixel readout ASIC for an APD based 2D X-ray hybrid pixel detector with sub-nanosecond resolution

    Energy Technology Data Exchange (ETDEWEB)

    Thil, Ch., E-mail: christophe.thil@ziti.uni-heidelberg.d [Heidelberg University, Institute of Computer Engineering, B6, 26, 68161 Mannheim (Germany); Baron, A.Q.R. [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Fajardo, P. [ESRF, Polygone Scientifique Louis Neel, 6, rue Jules Horowitz, 38000 Grenoble (France); Fischer, P. [Heidelberg University, Institute of Computer Engineering, B6, 26, 68161 Mannheim (Germany); Graafsma, H. [DESY, Notkestrasse 85, 22607 Hamburg (Germany); Rueffer, R. [ESRF, Polygone Scientifique Louis Neel, 6, rue Jules Horowitz, 38000 Grenoble (France)

    2011-02-01

    The fast response and the short recovery time of avalanche photodiodes (APDs) in linear mode make those devices ideal for direct X-ray detection in applications requiring high time resolution or counting rate. In order to provide position sensitivity, the XNAP project aims at creating a hybrid pixel detector with nanosecond time resolution based on a monolithic APD sensor array with 32 x32 pixels covering about 1 cm{sup 2} active area. The readout is implemented in a pixelated front-end ASIC suited for the readout of such arrays, matched to pixels of 280{mu}mx280{mu}m size. Every single channel features a fast transimpedance amplifier, a discriminator with locally adjustable threshold and two counters with high dynamic range and counting speed able to accumulate X-ray hits with no readout dead time. Additionally, the detector can be operated in list mode by time-stamping every single event with sub-nanosecond resolution. In a first phase of the project, a 4x4 pixel test module is built to validate the conceptual design of the detector. The XNAP project is briefly presented and the performance of the readout ASIC is discussed.

  12. Pixel readout ASIC for an APD based 2D X-ray hybrid pixel detector with sub-nanosecond resolution

    International Nuclear Information System (INIS)

    Thil, Ch.; Baron, A.Q.R.; Fajardo, P.; Fischer, P.; Graafsma, H.; Rueffer, R.

    2011-01-01

    The fast response and the short recovery time of avalanche photodiodes (APDs) in linear mode make those devices ideal for direct X-ray detection in applications requiring high time resolution or counting rate. In order to provide position sensitivity, the XNAP project aims at creating a hybrid pixel detector with nanosecond time resolution based on a monolithic APD sensor array with 32 x32 pixels covering about 1 cm 2 active area. The readout is implemented in a pixelated front-end ASIC suited for the readout of such arrays, matched to pixels of 280μmx280μm size. Every single channel features a fast transimpedance amplifier, a discriminator with locally adjustable threshold and two counters with high dynamic range and counting speed able to accumulate X-ray hits with no readout dead time. Additionally, the detector can be operated in list mode by time-stamping every single event with sub-nanosecond resolution. In a first phase of the project, a 4x4 pixel test module is built to validate the conceptual design of the detector. The XNAP project is briefly presented and the performance of the readout ASIC is discussed.

  13. Combination of microsecond and nanosecond pulsed electric field treatments for inactivation of Escherichia coli in water samples.

    Science.gov (United States)

    Žgalin, Maj Kobe; Hodžić, Duša; Reberšek, Matej; Kandušer, Maša

    2012-10-01

    Inactivation of microorganisms with pulsed electric fields is one of the nonthermal methods most commonly used in biotechnological applications such as liquid food pasteurization and water treatment. In this study, the effects of microsecond and nanosecond pulses on inactivation of Escherichia coli in distilled water were investigated. Bacterial colonies were counted on agar plates, and the count was expressed as colony-forming units per milliliter of bacterial suspension. Inactivation of bacterial cells was shown as the reduction of colony-forming units per milliliter of treated samples compared to untreated control. According to our results, when using microsecond pulses the level of inactivation increases with application of more intense electric field strengths and with number of pulses delivered. Almost 2-log reductions in bacterial counts were achieved at a field strength of 30 kV/cm with eight pulses and a 4.5-log reduction was observed at the same field strength using 48 pulses. Extending the duration of microsecond pulses from 100 to 250 μs showed no improvement in inactivation. Nanosecond pulses alone did not have any detectable effect on inactivation of E. coli regardless of the treatment time, but a significant 3-log reduction was achieved in combination with microsecond pulses.

  14. Electric field measurements in a near atmospheric pressure nanosecond pulse discharge with picosecond electric field induced second harmonic generation

    Science.gov (United States)

    Goldberg, Benjamin M.; Chng, Tat Loon; Dogariu, Arthur; Miles, Richard B.

    2018-02-01

    We present an optical electric field measurement method for use in high pressure plasma discharges. The method is based upon the field induced second harmonic generation technique and can be used for localized electric field measurements with sub-nanosecond resolution in any gaseous species. When an external electric field is present, a dipole is induced in the typically centrosymmetric medium, allowing for second harmonic generation with signal intensities which scale by the square of the electric field. Calibrations have been carried out in 100 Torr room air, and a minimum sensitivity of 450 V/cm is demonstrated. Measurements were performed with nanosecond or faster temporal resolution in a 100 Torr room air environment both with and without a plasma present. It was shown that with no plasma present, the field follows the applied voltage to gap ratio, as measured using the back current shunt method. When the electric field is strong enough to exceed the breakdown threshold, the measured field was shown to exceed the anticipated voltage to gap ratio which is taken as an indication of the ionization wave front as it sweeps through the plasma volume.

  15. Few-nanosecond pulse switching with low write error for in-plane nanomagnets using the spin-Hall effect

    Science.gov (United States)

    Aradhya, Sriharsha; Rowlands, Graham; Shi, Shengjie; Oh, Junseok; Ralph, D. C.; Buhrman, Robert

    Magnetic random access memory (MRAM) using spin transfer torques (STT) holds great promise for replacing existing best-in-class memory technologies in several application domains. Research on conventional two-terminal STT-MRAM thus far has revealed the existence of limitations that constrain switching reliability and speed for both in-plane and perpendicularly magnetized devices. Recently, spin torque arising from the giant spin-Hall effect in Ta, W and Pt has been shown to be an efficient mechanism to switch magnetic bits in a three-terminal geometry. Here we report highly reliable, nanosecond timescale pulse switching of three-terminal devices with in-plane magnetized magnetic tunnel junctions. We obtain write error rates (WER) down to ~10-5 using pulses as short as 2 ns, in contrast to conventional in-plane STT-MRAM devices where write speeds were limited to a few tens of nanoseconds for comparable WER. Utilizing micro-magnetic simulations, we discuss the differences from conventional MRAM that allow for this unanticipated and significant performance improvement. Finally, we highlight the path towards practical application enabled by the ability to separately optimize the read and write pathways in three-terminal devices.

  16. Nanosecond barrier discharge in a krypton/helium mixture containing mercury dibromide: Optical emission and plasma parameters

    Science.gov (United States)

    Malinina, A. A.; Starikovskaya, S. M.; Malinin, A. N.

    2015-01-01

    Spectral and electrical characteristics of atmospheric-pressure nanosecond barrier discharge plasma in a HgBr2/Kr/He mixture have been investigated. The discharge was initiated by positive 10-kV voltage pulses with a rise time of 4 ns and a half-amplitude duration of 28 ns. Emission from exciplex HgBr ( B 2Σ{1/2/+} - X 2Σ{1/2/+}) and KrBr ( B 2Σ{1/2/+} - X 2Σ{1/2/+}, C3/2-AΠ1/2, D1/2-AΠ1/2) molecules have been studied. From the time evolution of the B-X transition spectra of the HgBr molecule (502 nm) and KrBr molecule (207 nm), a mechanism of the formation of the exciplex molecules in the nanosecond discharge has been deduced. The distributions of the energies and rates of the processes responsible for emission from HgBr and KrBr molecules have been analyzed by numerically solving the Boltzmann equation for the electron distribution function. Experiments have confirmed the possibility of optimizing the voltage supply pulse for maximizing the efficiency of simultaneous emission in the UV and visible (green) spectral ranges from atmospheric-pressure discharge in the HgBr2/Kr/He mixture.

  17. The effects of gaseous bubble composition and gap distance on the characteristics of nanosecond discharges in distilled water

    KAUST Repository

    Hamdan, Ahmad

    2016-05-17

    Electric discharge in liquids with bubbles can reduce the energy consumption, which increases treatment efficiency. We present an experimental study of nanosecond discharges in distilled water bubbled with the monoatomic gas argon and with the polyatomic gases methane, carbon dioxide, and propane. We monitor the time evolution of the voltage and current waveforms, and calculate the injected charges to characterize the discharge. We establish a relationship between the injected charges and the shape of the plasma by time-resolved imaging to find that increasing the size of the gap reduces the injected charges. Moreover, we determine the plasma characteristics, including electron density, excitation temperatures (for atoms and ions), and rotational temperature of the OH and C2 radicals found in the plasma. Our space- and time-averaged measurements allow us to propose a spatial distribution of the plasma that is helpful for understanding the plasma dynamics necessary to develop and optimize applications based on nanosecond discharges in bubbled liquids. © 2016 IOP Publishing Ltd.

  18. Nine-Elevenism

    Directory of Open Access Journals (Sweden)

    Juanjo Bermúdez de Castro

    2011-09-01

    Full Text Available The literary text is a time-and-place-bound verbal construction that is always in one way or another political. Because it is inevitably involved with one or more discourses or an ideology it cannot help being a vehicle for power. As a consequence, and just like any other text, literature does not simply reflect relations of power, but actively participates in the consolidation and/or construction of discourses and ideologies, just as functions as an instrument in the construction of identiti...

  19. Indoor air: Reference bibliography

    International Nuclear Information System (INIS)

    Campbell, D.; Staves, D.; McDonald, S.

    1989-07-01

    The U. S. Environmental Protection Agency initially established the indoor air Reference Bibliography in 1987 as an appendix to the Indoor Air Quality Implementation Plan. The document was submitted to Congress as required under Title IV--Radon Gas and Indoor Air Quality Research of the Superfund Amendments and Reauthorization Act of 1986. The Reference Bibliography is an extensive bibliography of reference materials on indoor air pollution. The Bibliography contains over 4500 citations and continues to increase as new articles appear

  20. Android quick APIs reference

    CERN Document Server

    Cinar, Onur

    2015-01-01

    The Android Quick APIs Reference is a condensed code and APIs reference for the new Google Android 5.0 SDK. It presents the essential Android APIs in a well-organized format that can be used as a handy reference. You won't find any technical jargon, bloated samples, drawn out history lessons, or witty stories in this book. What you will find is a software development kit and APIs reference that is concise, to the point and highly accessible. The book is packed with useful information and is a must-have for any mobile or Android app developer or programmer. In the Android Quick APIs Refe

  1. 2001 - 2010 Danish design reference year. Reference climate dataset for technical dimensioning in building, construction and other sectors

    Energy Technology Data Exchange (ETDEWEB)

    Grunnet Wang, P.; Scharling, M.; Pagh Nielsen, K.; Kern-Hansen, C. [Danish Meteorological Institute (DMI), Copenhagen (Denmark); Wittchen, K.B. [Aalborg Univ., Danish Building Research Institute (SBi), Copenhagen (Denmark)

    2013-09-15

    This report presents the Danish Design Reference Year based on observed data from 2001 - 2010. In various sectors - i.e. building and construction, energy, etc. - the climate and weather usually plays a part in a given project. The Danish Design Reference Year dataset is a collection of data series for eleven specific parameters, that each represents a typical year in Denmark. The uses of the dataset may vary from simulations to statistical analysis, graphical overviews etc. The Danish land areas have been sectionalised into five to six climatological zones depending on the parameter, each characterized by distinct diurnal and yearly variations. The dataset consists of observed data from one station located within and representing each zone. In addition to the complete Danish Design Reference Year dataset, a subset specifically selected to be used for energy performance calculations for obtaining a building permit is included. (Author)

  2. Marketing Reference Services.

    Science.gov (United States)

    Norman, O. Gene

    1995-01-01

    Relates the marketing concept to library reference services. Highlights include a review of the literature and an overview of marketing, including research, the marketing mix, strategic plan, marketing plan, and marketing audit. Marketing principles are applied to reference services through the marketing mix elements of product, price, place, and…

  3. Reference class forecasting

    DEFF Research Database (Denmark)

    Flyvbjerg, Bent

    optimisme og misinformation. RCF bygger på teorier, som vandt Daniel Kahneman Nobelprisen i økonomi i 2002. RCF estimerer budgettet for et givet projekt på grundlag af de faktiske udfald for budgetterne i en reference-klasse af projekter. RCF udføres i tre trin: 1. Identifikation af en relevant reference...

  4. Study of nanosecond discharges in H2-air mixtures at atmospheric pressure for plasma assisted combustion applications

    Science.gov (United States)

    Kobayashi, Sumire; Bonaventura, Zdeněk; Tholin, Fabien; Popov, Nikolay A.; Bourdon, Anne

    2017-07-01

    This paper presents 2D simulations of nanosecond discharges between two point electrodes for four different H2-air mixtures defined by their equivalence ratios ϕ (i.e. φ =0, air, φ =0.3, lean mixture, φ =1, stoichiometric mixture and φ =1.5, rich mixture) at atmospheric pressure and at an initial temperature of 1000 K. In a first step, we have shown that the mixture composition has only a very small influence on the discharge dynamics and structure during the streamer phase and up to the formation of the plasma channel between the two point electrodes in H2-air mixtures with φ \\in [0,1.5]. However, as the plasma channel is formed slightly earlier as the equivalence ratio increases, for a given voltage pulse, the duration of the nanosecond spark phase increases as the equivalence ratio increases. As expected, we have shown that excited states of N2 (and in particular N2(A)) and radicals (and in particular O(D), O(P), H and OH) are very efficiently produced during the voltage pulse after the start of the spark phase. After the voltage pulse, and up to 100 ns, the densities of excited states of N2 and of O(D) decrease. Conversely, most of the O(P), H and OH radicals are produced after the voltage pulse due to the dissociative quenching of electronically excited N2. As for radicals, the gas temperature starts increasing after the start of the spark phase. For all studied mixtures, the density of O(P) atoms and the gas temperature reach their maxima after the end of the voltage pulse and the densities of O(P), H and OH radicals and the maximal gas temperature increase as the equivalence ratio increases. We have shown that the production of radicals is the highest on the discharge axis and the distribution of species after the voltage pulse and up to 100 ns has a larger diameter between the electrodes than close to both electrode tips. As for species, the temperature distribution presents two hot spots close to the point electrode tips. The non

  5. Hydrophobic treatment on polymethylmethacrylate surface by nanosecond-pulse DBDs in CF{sub 4} at atmospheric pressure

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Cheng [Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Key Laboratory of Power Electronics and Electric Drive, Chinese Academy of Sciences, Beijing 100190 (China); Zhou, Yang [Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Shao, Tao, E-mail: st@mail.iee.ac.cn [Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Key Laboratory of Power Electronics and Electric Drive, Chinese Academy of Sciences, Beijing 100190 (China); Xie, Qing [State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Baoding 071003 (China); Xu, Jiayu [Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Yang, Wenjin [Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Key Laboratory of Power Electronics and Electric Drive, Chinese Academy of Sciences, Beijing 100190 (China)

    2014-08-30

    Highlights: • Increase in hydrophobicity on PMMA is achieved after the DBD treatment in CF{sub 4}, and the water contact angle can increase from 68° to 100° after treatment. • Nanosecond-pulse DBD is used for the surface treatment and the power density is about 114.8 mW/cm{sup 2}. • The effects of applied voltage, CF{sub 4} flow, and time on plasma treatment are investigated. • Plasma treatment causes morphological change, significantly increases the roughness of the surface, and introduces fluorine-containing groups into the polymethylmethacrylate surface. • Hydrophobic behavior of the treated PMMA surface is slightly affected by the aging effect. - Abstract: Nanosecond-pulse dielectric barrier discharge (DBD) can provide non-thermal plasmas with extremely high energy and high density, which can result in a series of complicated physical and chemical reactions in the surface treatment of polymers. Therefore, in this paper, hydrophobic treatment of polymethylmethacrylate (PMMA) surface is conducted by nanosecond-pulse DBD in carbon tetrafluoride (CF{sub 4}) at atmospheric pressure. Investigations on surface morphology and chemical composition before and after the DBD treatment in CF{sub 4} are conducted with the contact angle measurement, atomic force microscope, Fourier transform infrared spectroscopy, and X-ray photoelectron spectrometer. The effects of the applied voltage, CF{sub 4} flow rate, and treatment time on the hydrophobic modification are studied. Results show that the contact angles of the treated PMMA surface increases with the applied voltage, and it could be greatly affected by the CF{sub 4} flow rate and the treatment time. The water contact angle can increase from 68° to 100° after the treatment. Furthermore, both surface morphology and chemical composition of the PMMA samples are changed. Both the increase of the surface roughness and the occurrence of fluorine-containing functional groups on the PMMA surface treated by DBD in CF

  6. Analysis of self-fertilization and meiotic behavior of eleven Brazilian triticale cultivars at two sowing dates

    Directory of Open Access Journals (Sweden)

    Divanilde Guerra

    2011-01-01

    Full Text Available Eleven Brazilian hexaploid triticale cultivars (2n = 6x = 42, from three breeding programs, were evaluated for theirability of self-fertilization in 2006 and for meiotic behavior, meiotic index and pollen viability at two sowing dates in 2007. Highpotential of self-fertilization was observed, with values up to 89.52 %. Many irregularities were found in the meiotic analysis, suchas the presence of univalents, laggard chromosomes and micronuclei in tetrads, which compromised both meiotic behavior andmeiotic index. At the first sowing date, more suitable for normal plant development, overall mean values of 52.68 % for normal cellsand 64.95 % for meiotic index were observed. At the second sowing date, less appropriate for the crop, overall means of 52.23 %for normal cells and 58.24 % for meiotic index were obtained. Despite all the irregularities, considerable pollen viability wasobserved, reaching overall means of 92.08 % and 91.07 % for the first and second sowing dates, respectively.

  7. Health care usage among immigrants and native-born elderly populations in eleven European countries: results from SHARE

    Science.gov (United States)

    Guillén, Montserrat; Crimmins, Eileen M.

    2013-01-01

    Differences in health care utilization of immigrants 50 years of age and older relative to the native-born populations in eleven European countries are investigated. Negative binomial and zero-inflated Poisson regression are used to examine differences between immigrants and native-borns in number of doctor visits, visits to general practitioners, and hospital stays using the 2004 Survey of Health, Ageing, and Retirement in Europe database. In the pooled European sample and in some individual countries, older immigrants use from 13 to 20% more health services than native-borns after demographic characteristics are controlled. After controlling for the need for health care, differences between immigrants and native-borns in the use of physicians, but not hospitals, are reduced by about half. These are not changed much with the incorporation of indicators of socioeconomic status and extra insurance coverage. Higher country-level relative expenditures on health, paying physicians a fee-for-service, and physician density are associated with higher usage of physician services among immigrants. PMID:21660564

  8. Failure analysis of eleven Gates Glidden drills that fractured intraorally during post space preparation. A retrieval analysis study.

    Science.gov (United States)

    Al Jabbari, Youssef S; Fournelle, Raymond; Al Taweel, Sara M; Zinelis, Spiros

    2017-07-19

    The purpose of this study was to determine the failure mechanism of clinically failed Gates Glidden (GG) drills. Eleven retrieved GG drills (sizes #1 to #3) which fractured during root canal preparation were collected and the fracture location was recorded based on macroscopic observation. All fracture surfaces were investigated by a SEM. Then the fractured parts were embedded in acrylic resin and after metallographic preparation, the microstructure and elemental composition was evaluated by SEM and EDS. The Vickers hardness (HV) of all specimens was also determined. Macroscopic examination and SEM analysis showed that the drills failed near the hand piece end by torsional fatigue with fatigue cracks initiating at several locations around the circumference and propagating toward the center. Final fracture followed by a tensile overloading at the central region of cross section. Microstructural analysis, hardness measurements and EDS show that the drills are made of a martensitic stainless steel like AISI 440C. Based on the findings of this study, clinicians should expect fatigue fracture of GG drills that have small size during root canal preparation. Selection of a more fatigue resistant stainless steel alloy and enhancing the instrument design might reduce the incidence of quasi-cleavage fracture on GG drills.

  9. Evaluation of Eleven Macro and Micro Elements Present in Various Hybrids of Millet (Pennisetum glaucum, or P. Americanum

    Directory of Open Access Journals (Sweden)

    Ghulam Qadir Shar

    2012-06-01

    Full Text Available Maize and Millet Research Institute (MMRI situated in Yousuf wala, District Sahiwal, Punjab, Pakistan was selected to grow nine different hybrids/cultivars of millet for study to comprehend the variable concentration of macro, micro and trace and toxic elements in their grains. Wet digestion method was used for the preparation of samples and flame atomic absorption spectrophotometer for analysis of eleven major and minor elements. High values of macro-elements i.e. sodium and potassium was found in ICMP-451 and magnesium in ICMP-53506. The high value of essential micro-elements i.e.zinc (50mg/kg, manganese (8mg/kg, and copper (8mg/kg was calculated in ICMP-53506, Bullo-94-1, and ICMP-83720 respectively. In case of trace and toxic micro-elements, high concentration of nickel, cobalt, chromium and cadmium was found in O.B.V, Bullo-7704, ICMP-83401, and ICMP-83720 in the edible part of millet plants (grains cultivars respectively.

  10. Evaluation of eleven macro and micro elements present in various hybrids of millet (pennisetum glucum, or P. americanum)

    International Nuclear Information System (INIS)

    Shar, G.Q.; Shar, L.A.

    2012-01-01

    Maize and Millet Research Institute (MMRI) situated in Yousuf wala, District Sahiwal, Punjab, Pakistan was selected to grow nine different hybrids/cultivars of millet for study to comprehend the variable concentration of macro, micro and trace and toxic elements in their grains. Wet digestion method was used for the preparation of samples and flame atomic absorption spectrophotometer for analysis of eleven major and minor elements. High values of macro-elements i.e. sodium and potassium was found in ICMP-45 I and magnesium in ICMP-53506. The high value of essential micro-elements i.e. zinc (50 mg/kg), manganese (8 mg/kg), and copper (8mg/kg) was calculated in ICMP-53506, Bullo-94-1, and ICMP-83120 respectively. In case of trace and toxic micro-elements, high concentration of nickel, cobalt, chromium and cadmium was found in O.B.V, Bullo-1104, ICMP-83401, and ICMP-83120 in the edible part of millet plants (grains) cultivars respectively. (author)

  11. Isolation and Characterization of Eleven Polymorphic Microsatellite Loci for the Valuable Medicinal Plant Dendrobium huoshanense and Cross-Species Amplification

    Science.gov (United States)

    Wang, Hui; Chen, Nai-Fu; Zheng, Ji-Yang; Wang, Wen-Cai; Pei, Yun-Yun; Zhu, Guo-Ping

    2012-01-01

    Dendrobium huoshanense (Orchidaceae) is a perennial herb and a widely used medicinal plant in Traditional Chinese medicine (TCM) endemic to Huoshan County town in Anhui province in Southeast China. A microsatellite-enriched genomic DNA library of D. huoshanense was developed and screened to identify marker loci. Eleven polymorphic loci were isolated and analyzed by screening 25 individuals collected from a natural population. The number of alleles per locus ranged from 2 to 5. The observed and expected heterozygosities ranged from 0.227 to 0.818 and from 0.317 to 0.757, respectively. Two loci showed significant deviations from Hardy-Weinberg equilibrium and four of the pairwise comparisons of loci revealed linkage disequilibrium (p < 0.05). These microsatellite loci were cross-amplified for five congeneric species and seven loci can be amplified in all species. These simple sequence repeats (SSR) markers are useful in genetic studies of D. huoshanense and other related species and in conservation decision-making. PMID:23222682

  12. Eliminating traditional reference services in an academic health sciences library: a case study

    Science.gov (United States)

    Schulte, Stephanie J

    2011-01-01

    Question: How were traditional librarian reference desk services successfully eliminated at one health sciences library? Setting: The analysis was done at an academic health sciences library at a major research university. Method: A gap analysis was performed, evaluating changes in the first eleven months through analysis of reference transaction and instructional session data. Main Results: Substantial increases were seen in the overall number of specialized reference transactions and those conducted by librarians lasting more than thirty minutes. The number of reference transactions overall increased after implementing the new model. Several new small-scale instructional initiatives began, though perhaps not directly related to the new model. Conclusion: Traditional reference desk services were eliminated at one academic health sciences library without negative impact on reference and instructional statistics. Eliminating ties to the confines of the physical library due to staffing reference desk hours removed one significant barrier to a more proactive liaison program. PMID:22022221

  13. Uranium reference materials

    International Nuclear Information System (INIS)

    Donivan, S.; Chessmore, R.

    1987-07-01

    The Technical Measurements Center has prepared uranium mill tailings reference materials for use by remedial action contractors and cognizant federal and state agencies. Four materials were prepared with varying concentrations of radionuclides, using three tailings materials and a river-bottom soil diluent. All materials were ground, dried, and blended thoroughly to ensure homogeneity. The analyses on which the recommended values for nuclides in the reference materials are based were performed, using independent methods, by the UNC Geotech (UNC) Chemistry Laboratory, Grand Junction, Colorado, and by C.W. Sill (Sill), Idaho National Engineering Laboratory, Idaho Falls, Idaho. Several statistical tests were performed on the analytical data to characterize the reference materials. Results of these tests reveal that the four reference materials are homogeneous and that no large systematic bias exists between the analytical methods used by Sill and those used by TMC. The average values for radionuclides of the two data sets, representing an unbiased estimate, were used as the recommended values for concentrations of nuclides in the reference materials. The recommended concentrations of radionuclides in the four reference materials are provided. Use of these reference materials will aid in providing uniform standardization among measurements made by remedial action contractors. 11 refs., 9 tabs

  14. STL pocket reference

    CERN Document Server

    Lischner, Ray

    2003-01-01

    The STL Pocket Reference describes the functions, classes, and templates in that part of the C++ standard library often referred to as the Standard Template Library (STL). The STL encompasses containers, iterators, algorithms, and function objects, which collectively represent one of the most important and widely used subsets of standard library functionality. The C++ standard library, even the subset known as the STL, is vast. It's next to impossible to work with the STL without some sort of reference at your side to remind you of template parameters, function invocations, return types--ind

  15. Handbook of reference electrodes

    CERN Document Server

    Inzelt, György; Scholz, Fritz

    2013-01-01

    Reference Electrodes are a crucial part of any electrochemical system, yet an up-to-date and comprehensive handbook is long overdue. Here, an experienced team of electrochemists provides an in-depth source of information and data for the proper choice and construction of reference electrodes. This includes all kinds of applications such as aqueous and non-aqueous solutions, ionic liquids, glass melts, solid electrolyte systems, and membrane electrodes. Advanced technologies such as miniaturized, conducting-polymer-based, screen-printed or disposable reference electrodes are also covered. Essen

  16. Regular Expression Pocket Reference

    CERN Document Server

    Stubblebine, Tony

    2007-01-01

    This handy little book offers programmers a complete overview of the syntax and semantics of regular expressions that are at the heart of every text-processing application. Ideal as a quick reference, Regular Expression Pocket Reference covers the regular expression APIs for Perl 5.8, Ruby (including some upcoming 1.9 features), Java, PHP, .NET and C#, Python, vi, JavaScript, and the PCRE regular expression libraries. This concise and easy-to-use reference puts a very powerful tool for manipulating text and data right at your fingertips. Composed of a mixture of symbols and text, regular exp

  17. Neptunium: a bibliographic reference

    International Nuclear Information System (INIS)

    Mosley, R.E.

    1979-06-01

    A comprehensive bibliograhy of the literature on the element neptunium published prior to January 1976 is presented. A short abstract is given for each listed reference, with a few exceptions. The references are divided into sections categorized as General, Man-Made Sources (Reactors), Man-Made Sources (Fuel Reprocessing), Chemistry (Solubility), Chemistry (Compounds), Chemistry (Isotopes), Analyses (Instrumental), Analyses (Chemical), Chemical (Animal), Biological (Effects), Biological (Animal-Metabolism-Retention), Biological (Air Movement), Biological (Human Inhalation), Measurement, and Dosimetry. The bibliography contains author and keyword indexes and was compiled to serve as a quick reference source for neptunium-related work. 184 citations

  18. CSS Pocket Reference

    CERN Document Server

    Meyer, Eric

    2011-01-01

    When you're working with CSS and need a quick answer, CSS Pocket Reference delivers. This handy, concise book provides all of the essential information you need to implement CSS on the fly. Ideal for intermediate to advanced web designers and developers, the 4th edition is revised and updated for CSS3, the latest version of the Cascading Style Sheet specification. Along with a complete alphabetical reference to CSS3 selectors and properties, you'll also find a short introduction to the key concepts of CSS. Based on Cascading Style Sheets: The Definitive Guide, this reference is an easy-to-us

  19. Biomedical Engineering Desk Reference

    CERN Document Server

    Ratner, Buddy D; Schoen, Frederick J; Lemons, Jack E; Dyro, Joseph; Martinsen, Orjan G; Kyle, Richard; Preim, Bernhard; Bartz, Dirk; Grimnes, Sverre; Vallero, Daniel; Semmlow, John; Murray, W Bosseau; Perez, Reinaldo; Bankman, Isaac; Dunn, Stanley; Ikada, Yoshito; Moghe, Prabhas V; Constantinides, Alkis

    2009-01-01

    A one-stop Desk Reference, for Biomedical Engineers involved in the ever expanding and very fast moving area; this is a book that will not gather dust on the shelf. It brings together the essential professional reference content from leading international contributors in the biomedical engineering field. Material covers a broad range of topics including: Biomechanics and Biomaterials; Tissue Engineering; and Biosignal Processing* A hard-working desk reference providing all the essential material needed by biomedical and clinical engineers on a day-to-day basis * Fundamentals, key techniques,

  20. LINQ Pocket Reference

    CERN Document Server

    Albahari, Joseph

    2008-01-01

    Ready to take advantage of LINQ with C# 3.0? This guide has the detail you need to grasp Microsoft's new querying technology, and concise explanations to help you learn it quickly. And once you begin to apply LINQ, the book serves as an on-the-job reference when you need immediate reminders. All the examples in the LINQ Pocket Reference are preloaded into LINQPad, the highly praised utility that lets you work with LINQ interactively. Created by the authors and free to download, LINQPad will not only help you learn LINQ, it will have you thinking in LINQ. This reference explains: LINQ's ke

  1. R quick syntax reference

    CERN Document Server

    Tollefson, Margot

    2014-01-01

    The R Quick Syntax Reference is a handy reference book detailing the intricacies of the R language. Not only is R a free, open-source tool, R is powerful, flexible, and has state of the art statistical techniques available. With the many details which must be correct when using any language, however, the R Quick Syntax Reference makes using R easier.Starting with the basic structure of R, the book takes you on a journey through the terminology used in R and the syntax required to make R work. You will find looking up the correct form for an expression quick and easy. With a copy of the R Quick

  2. Nanosecond laser ablated copper superhydrophobic surface with tunable ultrahigh adhesion and its renewability with low temperature annealing

    Science.gov (United States)

    He, An; Liu, Wenwen; Xue, Wei; Yang, Huan; Cao, Yu

    2018-03-01

    Recently, metallic superhydrophobic surfaces with ultrahigh adhesion have got plentiful attention on account of their significance in scientific researches and industrial applications like droplet transport, drug delivery and novel microfluidic devices. However, the long lead time and transience hindered its in-depth development and industrial application. In this work, nanosecond laser ablation was carried out to construct grid of micro-grooves on copper surface, whereafter, by applying fast ethanol assisted low-temperature annealing, we obtained surface with superhydrophobicity and ultrahigh adhesion within hours. And the ultrahigh adhesion force was found tunable by varying the groove spacing. Using ultrasonic cleaning as the simulation of natural wear and tear in service, the renewability of superhydrophobicity was also investigated, and the result shows that the contact angle can rehabilitate promptly by the processing of ethanol assisted low-temperature annealing, which gives a promising fast and cheap circuitous strategy to realize the long wish durable metallic superhydrophobic surfaces in practical applications.

  3. Long-lived nanosecond spin coherence in high-mobility 2DEGs confined in double and triple quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Ullah, S.; Gusev, G. M.; Hernandez, F. G. G., E-mail: felixggh@if.usp.br [Instituto de Física, Universidade de São Paulo, Caixa Postal 66318, CEP 05315-970 São Paulo, SP (Brazil); Bakarov, A. K. [Institute of Semiconductor Physics and Novosibirsk State University, Novosibirsk 630090 (Russian Federation)

    2016-06-07

    We investigated the spin coherence of high-mobility two-dimensional electron gases confined in multilayer GaAs quantum wells. The dynamics of the spin polarization was optically studied using pump-probe techniques: time-resolved Kerr rotation and resonant spin amplification. For double and triple quantum wells doped beyond the metal-to-insulator transition, the spin-orbit interaction was tailored by the sample parameters of structural symmetry (Rashba constant), width, and electron density (Dresselhaus linear and cubic constants) which allow us to attain long dephasing times in the nanoseconds range. The determination of the scales, namely, transport scattering time, single-electron scattering time, electron-electron scattering time, and spin polarization decay time further supports the possibility of using n-doped multilayer systems for developing spintronic devices.

  4. Numerical simulation of nanosecond pulsed DBD in lean methane–air mixture for typical conditions in internal engines

    International Nuclear Information System (INIS)

    Takana, Hidemasa; Nishiyama, Hideya

    2014-01-01

    Detailed two-dimensional numerical simulations of a high energy loading nanosecond dc pulse DBD in a lean methane–air mixture were conducted for plasma-assisted combustion by integrating individual models of plasma chemistry, photoionization and energy loading. The DBD streamer propagation process with radical productions was clarified at 10 atm and 600 K as under the condition of actual internal engines at ignition. Energy is loaded to the streamer first by the formation of plasma channel and then ceased due to the self-shielding effect. Because of the inversed electric field in a discharge space during decrease in applied voltage, energy is loaded to the discharge again. It was found that higher energy is loaded to the DBD streamer for larger dielectric constant even at lower applied voltage, and higher number density of oxygen radical is produced at almost the same radical production efficiency. (paper)

  5. Study of photo-activated electron transfer reactions in the first excited singlet state by picosecond and nanosecond laser spectroscopy

    International Nuclear Information System (INIS)

    Doizi, Denis

    1983-01-01

    Picosecond laser spectroscopy has been used to study two photo-activated electron transfer reactions: - a bimolecular electron transfer reaction between a sensitizer, DODCI, and an electron acceptor, methylviologen. The two radical ions created with an electron transfer efficiency γ ≅ 0.07 have been identified in picosecond and nanosecond laser absorption spectroscopy by adding selective solutes such as para-benzoquinone (an electron acceptor) or L(+) ascorbic acid (an electron donor). - an intramolecular electron transfer reaction in a triad molecule consisting of a tetra-aryl-porphyrin covalently linked to both a carotenoid and a quinone. The photoinduced charge separation occurs within 30 ps and leads, with a yield of 25 pc, to the formation of a zwitterion whose half-life is 2.5 μs. The experimental results obtained in these two studies show an effective decrease in the recombination rate of the two radical ions created in the encounter pair. (author) [fr

  6. Time-resolved analysis of thickness-dependent dewetting and ablation of silver films upon nanosecond laser irradiation

    International Nuclear Information System (INIS)

    Qi, Dongfeng; Paeng, Dongwoo; Yeo, Junyeob; Kim, Eunpa; Wang, Letian; Grigoropoulos, Costas P.; Chen, Songyan

    2016-01-01

    Nanosecond pulsed laser dewetting and ablation of thin silver films is investigated by time-resolved imaging. Laser pulses of 532 nm wavelength and 5 ns temporal width are irradiated on silver films of different thicknesses (50 nm, 80 nm, and 350 nm). Below the ablation threshold, it is observed that the dewetting process does not conclude until 630 ns after the laser irradiation for all samples, forming droplet-like particles in the spot central region. At higher laser intensities, ablative material removal occurs in the spot center. Cylindrical rims are formed in the peripheral dewetting zone due to the solidification of transported matter at about 700 ns following the laser pulse exposure. In addition to these features, droplet fingers are superposed upon irradiation of 350-nm thick silver films with higher intensity.

  7. Time-resolved analysis of thickness-dependent dewetting and ablation of silver films upon nanosecond laser irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Dongfeng [Laser Thermal Laboratory, Department of Mechanical Engineering, University of California, Berkeley, California 94720-1740 (United States); Semiconductor Photonics Research Center, Department of Physics, Xiamen University, Xiamen 361005 (China); Paeng, Dongwoo; Yeo, Junyeob; Kim, Eunpa; Wang, Letian; Grigoropoulos, Costas P., E-mail: cgrigoro@berkeley.edu [Laser Thermal Laboratory, Department of Mechanical Engineering, University of California, Berkeley, California 94720-1740 (United States); Chen, Songyan [Semiconductor Photonics Research Center, Department of Physics, Xiamen University, Xiamen 361005 (China)

    2016-05-23

    Nanosecond pulsed laser dewetting and ablation of thin silver films is investigated by time-resolved imaging. Laser pulses of 532 nm wavelength and 5 ns temporal width are irradiated on silver films of different thicknesses (50 nm, 80 nm, and 350 nm). Below the ablation threshold, it is observed that the dewetting process does not conclude until 630 ns after the laser irradiation for all samples, forming droplet-like particles in the spot central region. At higher laser intensities, ablative material removal occurs in the spot center. Cylindrical rims are formed in the peripheral dewetting zone due to the solidification of transported matter at about 700 ns following the laser pulse exposure. In addition to these features, droplet fingers are superposed upon irradiation of 350-nm thick silver films with higher intensity.

  8. Nanosecond-pulsed Q-switched Nd:YAG laser at 1064 nm with a gold nanotriangle saturable absorber

    Science.gov (United States)

    Chen, Xiaohan; Li, Ping; Dun, Yangyang; Song, Teng; Ma, Baomin

    2018-06-01

    Gold nanotriangles (GNTs) were successfully employed as a saturable absorber (SA) to achieve passively Q-switched lasers for the first time. The performance of the Q-switched Nd:YAG laser at 1064 nm has been systematically investigated. The corresponding shortest pulsewidth, the threshold pump power and the maximum Q-switched average output power were 275.5 ns, 1.37 W, and 171 mW, respectively. To our knowledge, this is the shortest pulsewidth and the lowest threshold in a passively Q-switched laser at approximately 1.1 µm based on a gold nanoparticle SA (GNPs-SA). Our experimental results proved that the GNTs-SA can be used as a promising saturable absorber for nanosecond-pulsed lasers.

  9. Study of emission of a volume nanosecond discharge plasma in xenon, krypton and argon at high pressures

    International Nuclear Information System (INIS)

    Baksht, E Kh; Lomaev, Mikhail I; Rybka, D V; Tarasenko, Viktor F

    2006-01-01

    The emission properties of a volume nanosecond discharge plasma produced in xenon, krypton and argon at high pressures in a discharge gap with a cathode having a small radius of curvature are studied. Spectra in the range 120-850 nm and amplitude-time characteristics of xenon emission at different regimes and excitation techniques are recorded and analysed. It is shown that upon excitation of the volume discharge initiated by a beam of avalanche electrons, at least 90% of the energy in the spectral range 120-850 nm is emitted by xenon dimers. For xenon at a pressure of 1.2 atm, ∼45 mJ of the spontaneous emission energy was obtained in the full solid angle in a pulse with the full width at half-maximum ∼130 ns. (laser applications and other topics in quantum electronics)

  10. The formation of diffuse discharge by short-front nanosecond voltage pulses and the modification of dielectrics in this discharge

    Science.gov (United States)

    Orlovskii, V. M.; Panarin, V. A.; Shulepov, M. A.

    2014-07-01

    The dynamics of diffuse discharge formation under the action of nanosecond voltage pulses with short fronts (below 1 ns) in the absence of a source of additional preionization and the influence of a dielectric film on this process have been studied. It is established that the diffuse discharge is induced by the avalanche multiplication of charge initiated by high-energy electrons and then maintained due to secondary breakdowns propagating via ionized gas channels. If a dielectric film (polyethylene, Lavsan, etc.) is placed on the anode, then multiply repeated discharge will lead to surface and bulk modification of the film material. Discharge-treated polyethylene film exhibits a change in the optical absorption spectrum in the near-IR range.

  11. Rapid formation of electric field profiles in repetitively pulsed high-voltage high-pressure nanosecond discharges

    International Nuclear Information System (INIS)

    Ito, Tsuyohito; Kobayashi, Kazunobu; Hamaguchi, Satoshi; Czarnetzki, Uwe

    2010-01-01

    Rapid formation of electric field profiles has been observed directly for the first time in nanosecond narrow-gap parallel-plate discharges at near-atmospheric pressure. The plasmas examined here are of hydrogen, and the field measurement is based on coherent Raman scattering (CRS) by hydrogen molecules. Combined with the observation of spatio-temporal light emission profiles by a high speed camera, it has been found that the rapid formation of a high-voltage thin cathode sheath is accompanied by fast propagation of an ionization front from a region near the anode. Unlike well-known parallel-plate discharges at low pressure, the discharge formation process at high pressure is almost entirely driven by electron dynamics as ions and neutral species are nearly immobile during the rapid process. (fast track communication)

  12. Generator of pulses with the nanosecond duration and accurate amplitude using the digital control in the CAMAC standard

    International Nuclear Information System (INIS)

    Basiladze, S.G.; Nguen Kuang Min'

    1980-01-01

    A generator of square-wave fine-amplitude nanosecond pulses is described. The generator is primarily intended for checking the performances of fast electronics analog-to-digital units with the help of a computer. In addition to digital control the pulse amplitude can be controlled manually or by the external voltage. Basic circuits of main generator assemblies: a triggering circuit, transistor key and digital-to-analog converter are given. Output pulses produced by the generator have the following parameters: the amplitude from - 0.15 to - 10 V (smooth or gradual, with a minimum step of 5 mV), the rising and decay pulse times approximately 2 ns, the maximum repetition frequency 10 kHz, the control linearity at a pulse duration of more than 50 ns 0.15%. A double-width CAMAC cell accomodates two generators

  13. Production of atmospheric pressure diffuse nanosecond pulsed dielectric barrier discharge using the array needles-plate electrode in air

    International Nuclear Information System (INIS)

    Yang Dezheng; Wang Wenchun; Jia Li; Nie Dongxia; Shi Hengchao

    2011-01-01

    In this paper, a bidirectional high pulse voltage with 20 ns rising time is employed to generate an atmospheric pressure diffuse dielectric barrier discharge using the array needles-plate electrode configuration. Both double needle and multiple needle electrode configurations nanosecond pulsed dielectric barrier discharges are investigated. It is found that a diffuse discharge plasma with low gas temperature can be obtained, and the plasma volume increases with the increase of the pulse peak voltage, but remains almost constant with the increase of the pulse repetition rate. In addition to showing the potential application on a topographically nonuniform surface treatment of the discharge, the multiple needle-plate electrode configuration with different needle-plate electrode gaps are also employed to generate diffuse discharge plasma.

  14. Study on the effect of beam propagation through atmospheric turbulence on standoff nanosecond laser induced breakdown spectroscopy measurements.

    Science.gov (United States)

    Laserna, J J; Reyes, R Fernández; González, R; Tobaria, L; Lucena, P

    2009-06-08

    We report on an experimental study of the effect of atmospheric turbulence on laser induced breakdown spectroscopy (LIBS) measurements. The characteristics of the atmosphere dictate specific performance constraints to this technology. Unlike classical laboratory LIBS systems where the distance to the sample is well known and characterized, LIBS systems working at several tens of meters to the target have specific atmospheric propagation conditions that cause the quality of the LIBS signals to be affected to a significant extent. Using a new LIBS based sensor system fitted with a nanosecond laser emitting at 1064 nm, propagation effects at distances of up to 120 m were investigated. The effects observed include wander and scintillation in the outgoing laser beam and in the return atomic emission signal. Plasmas were formed on aluminium targets. Average signal levels and signal fluctuations are measured so the effect of atmospheric turbulence on LIBS measurements is quantified.

  15. Topological structures of vortex flow on a flying wing aircraft, controlled by a nanosecond pulse discharge plasma actuator

    Science.gov (United States)

    Du, Hai; Shi, Zhiwei; Cheng, Keming; Wei, Dechen; Li, Zheng; Zhou, Danjie; He, Haibo; Yao, Junkai; He, Chengjun

    2016-06-01

    Vortex control is a thriving research area, particularly in relation to flying wing or delta wing aircraft. This paper presents the topological structures of vortex flow on a flying wing aircraft controlled by a nanosecond plasma dielectric barrier discharge actuator. Experiments, including oil flow visualization and two-dimensional particle image velocimetry (PIV), were conducted in a wind tunnel with a Reynolds number of 0.5 × 106. Both oil and PIV results show that the vortex can be controlled. Oil topological structures on the aircraft surface coincide with spatial PIV flow structures. Both indicate vortex convergence and enhancement when the plasma discharge is switched on, leading to a reduced region of separated flow.

  16. Unit for the nanosecond, laser, pulse photolysis in the ultraviolet region for a combination of photochemical studies

    Energy Technology Data Exchange (ETDEWEB)

    Pikel' ni, V F; Kolosov, V A; Kiryukhin, Yu I; Kondrat' ev, V A; Borovkova, V A; Tarasov, E N

    1976-06-01

    A description is given of a nanosecond laser unit for pulse photolysis in the ultraviolet region, by means of which it is possible to investigate the kinetics of the death of interstitial particles, their optical absorption and luminescence spectra, and also the photoconductivity induced by the laser radiation, at a time resolution of about 15 ns. As a source of powerful, stable uv-radiation, use is made of the fourth harmonic (266 nm) of radiation from an aluminum-yttrium garnet containing neodymium. The radiation power of the fourth harmonic attained 2 MW. The time of bringing the unit into the operating mode is considerably shortened because of the possibility of operating in a frequency mode. Absorption spectra of carbazole in hexane were obtained at 20/sup 0/C. (SJR)

  17. Optimal primitive reference frames

    International Nuclear Information System (INIS)

    Jennings, David

    2011-01-01

    We consider the smallest possible directional reference frames allowed and determine the best one can ever do in preserving quantum information in various scenarios. We find that for the preservation of a single spin state, two orthogonal spins are optimal primitive reference frames; and in a product state, they do approximately 22% as well as an infinite-sized classical frame. By adding a small amount of entanglement to the reference frame, this can be raised to 2(2/3) 5 =26%. Under the different criterion of entanglement preservation, a very similar optimal reference frame is found; however, this time it is for spins aligned at an optimal angle of 87 deg. In this case 24% of the negativity is preserved. The classical limit is considered numerically, and indicates under the criterion of entanglement preservation, that 90 deg. is selected out nonmonotonically, with a peak optimal angle of 96.5 deg. for L=3 spins.

  18. Reference Climatological Stations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Reference Climatological Stations (RCS) network represents the first effort by NOAA to create and maintain a nationwide network of stations located only in areas...

  19. Toxicity Reference Database

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Toxicity Reference Database (ToxRefDB) contains approximately 30 years and $2 billion worth of animal studies. ToxRefDB allows scientists and the interested...

  20. Python essential reference

    CERN Document Server

    Beazley, David M

    2009-01-01

    Python Essential Reference is the definitive reference guide to the Python programming language — the one authoritative handbook that reliably untangles and explains both the core Python language and the most essential parts of the Python library. Designed for the professional programmer, the book is concise, to the point, and highly accessible. It also includes detailed information on the Python library and many advanced subjects that is not available in either the official Python documentation or any other single reference source. Thoroughly updated to reflect the significant new programming language features and library modules that have been introduced in Python 2.6 and Python 3, the fourth edition of Python Essential Reference is the definitive guide for programmers who need to modernize existing Python code or who are planning an eventual migration to Python 3. Programmers starting a new Python project will find detailed coverage of contemporary Python programming idioms.

  1. Collaborative networks: Reference modeling

    NARCIS (Netherlands)

    Camarinha-Matos, L.M.; Afsarmanesh, H.

    2008-01-01

    Collaborative Networks: Reference Modeling works to establish a theoretical foundation for Collaborative Networks. Particular emphasis is put on modeling multiple facets of collaborative networks and establishing a comprehensive modeling framework that captures and structures diverse perspectives of

  2. Ozone Standard Reference Photometer

    Data.gov (United States)

    Federal Laboratory Consortium — The Standard Reference Photometer (SRP) Program began in the early 1980s as collaboration between NIST and the U.S. Environmental Protection Agency (EPA) to design,...

  3. Enterprise Reference Library

    Science.gov (United States)

    Bickham, Grandin; Saile, Lynn; Havelka, Jacque; Fitts, Mary

    2011-01-01

    Introduction: Johnson Space Center (JSC) offers two extensive libraries that contain journals, research literature and electronic resources. Searching capabilities are available to those individuals residing onsite or through a librarian s search. Many individuals have rich collections of references, but no mechanisms to share reference libraries across researchers, projects, or directorates exist. Likewise, information regarding which references are provided to which individuals is not available, resulting in duplicate requests, redundant labor costs and associated copying fees. In addition, this tends to limit collaboration between colleagues and promotes the establishment of individual, unshared silos of information The Integrated Medical Model (IMM) team has utilized a centralized reference management tool during the development, test, and operational phases of this project. The Enterprise Reference Library project expands the capabilities developed for IMM to address the above issues and enhance collaboration across JSC. Method: After significant market analysis for a multi-user reference management tool, no available commercial tool was found to meet this need, so a software program was built around a commercial tool, Reference Manager 12 by The Thomson Corporation. A use case approach guided the requirements development phase. The premise of the design is that individuals use their own reference management software and export to SharePoint when their library is incorporated into the Enterprise Reference Library. This results in a searchable user-specific library application. An accompanying share folder will warehouse the electronic full-text articles, which allows the global user community to access full -text articles. Discussion: An enterprise reference library solution can provide a multidisciplinary collection of full text articles. This approach improves efficiency in obtaining and storing reference material while greatly reducing labor, purchasing and

  4. Nanosecond laser texturing of uniformly and non-uniformly wettable micro structured metal surfaces for enhanced boiling heat transfer

    Energy Technology Data Exchange (ETDEWEB)

    Zupančič, Matevž, E-mail: matevz.zupancic@fs.uni-lj.si; Može, Matic; Gregorčič, Peter; Golobič, Iztok

    2017-03-31

    Highlights: • Surfaces with periodically changed wettability were produced by a ns marking laser. • Heat transfer was investigated on uniformly and non-uniformly wettable surfaces. • Microporous surfaces with non-uniform wettability enhance boiling heat transfer. • The most bubble nucleations were observed in the vicinity of the microcavities. • Results agree with the predictions of the nucleation criteria. - Abstract: Microstructured uniformly and non-uniformly wettable surfaces were created on 25-μm-thin stainless steel foils by laser texturing using a marking nanosecond Nd:YAG laser (λ = 1064 nm) and utilizing various laser fluences and scan line separations. High-speed photography and high-speed IR thermography were used to investigate nucleate boiling heat transfer on the microstructured surfaces. The most pronounced results were obtained on a surface with non-uniform microstructure and non-uniform wettability. The obtained results show up to a 110% higher heat transfer coefficients and 20–40 times higher nucleation site densities compared to the untextured surface. We show that the number of active nucleation sites is significantly increased in the vicinity of microcavities that appeared in areas with the smallest (10 μm) scan line separation. Furthermore, this confirms the predictions of nucleation criteria and proves that straightforward, cost-effective nanosecond laser texturing allows the production of cavities with diameters of up to a few micrometers and surfaces with non-uniform wettability. Additionally, this opens up important possibilities for a more deterministic control over the complex boiling process.

  5. Decomposition of methane to hydrogen using nanosecond pulsed plasma reactor with different active volumes, voltages and frequencies

    International Nuclear Information System (INIS)

    Khalifeh, Omid; Mosallanejad, Amin; Taghvaei, Hamed; Rahimpour, Mohammad Reza; Shariati, Alireza

    2016-01-01

    Highlights: • CH 4 conversion into H 2 is investigated in a nanosecond pulsed DBD reactor. • The absence of CO and CO 2 in the product gas is highly favorable. • Effects of external electrode length, applied voltage and frequency are examined. • The maximum efficiency of 7.23% is achieved at the electrode length of 15 cm. • The maximum CH 4 conversion of 87.2% is obtained at discharge power 268.92 W. - Abstract: In this paper, the methane conversion into hydrogen is investigated experimentally in a nanosecond pulsed DBD reactor. In order to achieve pure hydrogen production with minimum power consumption, effects of some operating parameters including external electrode length, applied voltage and pulse repetition frequency have been evaluated. Results show that although higher CH 4 conversion and H 2 concentration can be obtained at longer electrode lengths, higher applied voltages and pulse repetition frequencies, these parameters should be optimized for efficient hydrogen production. Actually, the maximum CH 4 conversion of 87.2% and maximum hydrogen percentage of 80% are obtained at the external electrode length, discharge power, voltage and frequency of 15 cm, 268.92 W, 12 kV and 10 kHz, respectively. However, the maximum efficiency of 7.23% is achieved at the external electrode length of 15 cm, applied voltage of 6 kV, pulse repetition frequency of 0.9 kHz and discharge power of 4 W. Furthermore, at this condition, due to low temperature of discharge zone very little amount of solid carbon was observed on the inner electrode surface of the reactor.

  6. Numerical investigation of energy transfer for fast gas heating in an atmospheric nanosecond-pulsed DBD under different negative slopes

    International Nuclear Information System (INIS)

    Zhu, Yifei; Wu, Yun; Cui, Wei; Li, Yinghong; Jia, Min

    2013-01-01

    A validated one-dimensional air plasma kinetics model (13 species and 37 processes) for a nanosecond discharge under atmospheric pressure was developed to reveal the energy transfer mechanism for fast gas heating of a plane-to-plane dielectric barrier discharge (DBD). Calculations for voltage profiles with three different negative slopes were performed. Results have shown that 72% of the total heating energy goes to quench heating, which results in a temperature rise across the gap, the remaining 28% goes to ion collisions, thus heating the cathode sheath in a higher power density. The relationships between ion collision heating, quench heating and reduced electric field are given as two functions, which indicates that 10 13  W m −3 is the peak magnitude of power density produced by ion collisions in the nanosecond-pulsed DBD under atmospheric pressure, and a further increase in E/N does not increase the higher quench heating power. The steepness of the negative slope mainly affects the energy transfer efficiency, and the percentage of two heating sources in the total heating power. A short pulse will couple positive and negative slopes and provide a higher transient total heating power but lower energy transfer efficiency. By uncoupling the positive slope, steady stage and negative slope, the energy transfer efficiency under a certain voltage amplitude (20 kV in this paper) is found to have a maximum value of 68.5%. Two wave crests of temperature rise near the cathode sheath are observed, one is caused by a positive slope and the other by a negative slope. (paper)

  7. Comparability of reference values

    International Nuclear Information System (INIS)

    Rossbach, M.; Stoeppler, M.

    1993-01-01

    Harmonization of certified values in Reference Materials (RMs) can be carried out by applying nuclear analytical techniques to RMs of various matrix types and concentration levels. Although RMs generally should not be used as primary standards the cross evaluation of concentrations in RMs leads to better compatibility of reference values and thus to a greater agreement between analytical results from different laboratories using these RMs for instrument calibration and quality assurance. (orig.)

  8. Electronics engineer's reference book

    CERN Document Server

    Turner, L W

    1976-01-01

    Electronics Engineer's Reference Book, 4th Edition is a reference book for electronic engineers that reviews the knowledge and techniques in electronics engineering and covers topics ranging from basics to materials and components, devices, circuits, measurements, and applications. This edition is comprised of 27 chapters; the first of which presents general information on electronics engineering, including terminology, mathematical equations, mathematical signs and symbols, and Greek alphabet and symbols. Attention then turns to the history of electronics; electromagnetic and nuclear radiatio

  9. 2002 reference document

    International Nuclear Information System (INIS)

    2002-01-01

    This 2002 reference document of the group Areva, provides information on the society. Organized in seven chapters, it presents the persons responsible for the reference document and for auditing the financial statements, information pertaining to the transaction, general information on the company and share capital, information on company operation, changes and future prospects, assets, financial position, financial performance, information on company management and executive board and supervisory board, recent developments and future prospects. (A.L.B.)

  10. The distribution of fruit and seed toxicity during development for eleven neotropical trees and vines in Central Panama.

    Science.gov (United States)

    Beckman, Noelle G

    2013-01-01

    Secondary compounds in fruit mediate interactions with natural enemies and seed dispersers, influencing plant survival and species distributions. The functions of secondary metabolites in plant defenses have been well-studied in green tissues, but not in reproductive structures of plants. In this study, the distribution of toxicity within plants was quantified and its influence on seed survival was determined in Central Panama. To investigate patterns of allocation to chemical defenses and shifts in allocation with fruit development, I quantified variation in toxicity between immature and mature fruit and between the seed and pericarp for eleven species. Toxicity of seed and pericarp was compared to leaf toxicity for five species. Toxicity was measured as reduced hyphal growth of two fungal pathogens, Phoma sp. and Fusarium sp., and reduced survivorship of brine shrimp, Artemia franciscana, across a range of concentrations of crude extract. I used these measures of potential toxicity against generalist natural enemies to examine the effect of fruit toxicity on reductions of fruit development and seed survival by vertebrates, invertebrates, and pathogens measured for seven species in a natural enemy removal experiment. The seed or pericarp of all vertebrate- and wind-dispersed species reduced Artemia survivorship and hyphal growth of Fusarium during the immature and mature stages. Only mature fruit of two vertebrate-dispersed species reduced hyphal growth of Phoma. Predispersal seed survival increased with toxicity of immature fruit to Artemia during germination and decreased with toxicity to fungi during fruit development. This study suggests that fruit toxicity against generalist natural enemies may be common in Central Panama. These results support the hypothesis that secondary metabolites in fruit have adaptive value and are important in the evolution of fruit-frugivore interactions.

  11. Otolith Length-Fish Length Relationships of Eleven US Arctic Fish Species and Their Application to Ice Seal Diet Studies

    Science.gov (United States)

    Walker, K. L.; Norcross, B.

    2016-02-01

    The Arctic ecosystem has moved into the spotlight of scientific research in recent years due to increased climate change and oil and gas exploration. Arctic fishes and Arctic marine mammals represent key parts of this ecosystem, with fish being a common part of ice seal diets in the Arctic. Determining sizes of fish consumed by ice seals is difficult because otoliths are often the only part left of the fish after digestion. Otolith length is known to be positively related to fish length. By developing species-specific otolith-body morphometric relationships for Arctic marine fishes, fish length can be determined for fish prey found in seal stomachs. Fish were collected during ice free months in the Beaufort and Chukchi seas 2009 - 2014, and the most prevalent species captured were chosen for analysis. Otoliths from eleven fish species from seven families were measured. All species had strong linear relationships between otolith length and fish total length. Nine species had coefficient of determination values over 0.75, indicating that most of the variability in the otolith to fish length relationship was explained by the linear regression. These relationships will be applied to otoliths found in stomachs of three species of ice seals (spotted Phoca largha, ringed Pusa hispida, and bearded Erignathus barbatus) and used to estimate fish total length at time of consumption. Fish lengths can in turn be used to calculate fish weight, enabling further investigation into ice seal energetic demands. This application will aid in understanding how ice seals interact with fish communities in the US Arctic and directly contribute to diet comparisons among and within ice seal species. A better understanding of predator-prey interactions in the US Arctic will aid in predicting how ice seal and fish species will adapt to a changing Arctic.

  12. The distribution of fruit and seed toxicity during development for eleven neotropical trees and vines in Central Panama.

    Directory of Open Access Journals (Sweden)

    Noelle G Beckman

    Full Text Available Secondary compounds in fruit mediate interactions with natural enemies and seed dispersers, influencing plant survival and species distributions. The functions of secondary metabolites in plant defenses have been well-studied in green tissues, but not in reproductive structures of plants. In this study, the distribution of toxicity within plants was quantified and its influence on seed survival was determined in Central Panama. To investigate patterns of allocation to chemical defenses and shifts in allocation with fruit development, I quantified variation in toxicity between immature and mature fruit and between the seed and pericarp for eleven species. Toxicity of seed and pericarp was compared to leaf toxicity for five species. Toxicity was measured as reduced hyphal growth of two fungal pathogens, Phoma sp. and Fusarium sp., and reduced survivorship of brine shrimp, Artemia franciscana, across a range of concentrations of crude extract. I used these measures of potential toxicity against generalist natural enemies to examine the effect of fruit toxicity on reductions of fruit development and seed survival by vertebrates, invertebrates, and pathogens measured for seven species in a natural enemy removal experiment. The seed or pericarp of all vertebrate- and wind-dispersed species reduced Artemia survivorship and hyphal growth of Fusarium during the immature and mature stages. Only mature fruit of two vertebrate-dispersed species reduced hyphal growth of Phoma. Predispersal seed survival increased with toxicity of immature fruit to Artemia during germination and decreased with toxicity to fungi during fruit development. This study suggests that fruit toxicity against generalist natural enemies may be common in Central Panama. These results support the hypothesis that secondary metabolites in fruit have adaptive value and are important in the evolution of fruit-frugivore interactions.

  13. Reference Japanese man

    International Nuclear Information System (INIS)

    Tanaka, Giichiro

    1985-01-01

    To make real and accurate dose assessment method so far, it is necessitated to provide ''Reference Japanese Man'' based on anotomical, physiological and biochemical data of Japanese people instead of the Reference Man presented in ICRP Publications 23 and 30. This review describes present status of researched for the purpose of establishing of Reference Japanese Man. The Reference Japanese Man is defined as a male or female adult who lives in Japan with a Japanese life-style and food custom. His stature and body weight, and the other data was decided as mean values of male or female people of Japan. As for food custom, Japanese people take significantly smaller amount of meat and milk products than Western people, while larger intake amount of cereals and marine products such as fish or seaweeds. Weight of organs is a principal factor for internal dose assessment and mean values for living Japanese adult has been investigated and the value employable for dose assessment for organs and tissues are shown. To employ these values of Reference Japanese Man, it should be taken into account of age. Metabolic parameters should also be considered. Iodine metabolism in Japanese is quite different from that of Western people. The above-mentioned data are now tentatively employing in modification of table of MIRD method and others. (Takagi, S.)

  14. Reference costs of electricity

    International Nuclear Information System (INIS)

    Terraz, N.

    1997-01-01

    The calculation of electric power production reference costs is used in France, even in the present case of over-capacity, for comparing the relative interest of the various means of power generation (nuclear plants, coal plants, hydroelectricity, gas combined cycles, etc.) and as an aid for future investment decisions. Reference costs show a sharp decrease between 1993 and 1997 due to advancements in nuclear plant operating ability and fossil fuel price decrease. Actuarial rates, plant service life, fuel costs and exchange rates are important parameters. The various costs from the research stage to the waste processing stages are discussed and the reference costs of the various power generation systems are presented and compared together with their competitiveness; the future of wind energy and cogeneration and the prospective of the renewal of nuclear plants at the 2010 horizon are also addressed

  15. Setting reference targets

    International Nuclear Information System (INIS)

    Ruland, R.E.

    1997-04-01

    Reference Targets are used to represent virtual quantities like the magnetic axis of a magnet or the definition of a coordinate system. To explain the function of reference targets in the sequence of the alignment process, this paper will first briefly discuss the geometry of the trajectory design space and of the surveying space, then continue with an overview of a typical alignment process. This is followed by a discussion on magnet fiducialization. While the magnetic measurement methods to determine the magnetic centerline are only listed (they will be discussed in detail in a subsequent talk), emphasis is given to the optical/mechanical methods and to the task of transferring the centerline position to reference targets

  16. Electrical engineer's reference book

    CERN Document Server

    Jones, G R

    2013-01-01

    A long established reference book: radical revision for the fifteenth edition includes complete rearrangement to take in chapters on new topics and regroup the subjects covered for easy access to information.The Electrical Engineer's Reference Book, first published in 1945, maintains its original aims: to reflect the state of the art in electrical science and technology and cater for the needs of practising engineers. Most chapters have been revised and many augmented so as to deal properly with both fundamental developments and new technology and applications that have come to the fore since

  17. Python pocket reference

    CERN Document Server

    Lutz, Mark

    2010-01-01

    This is the book to reach for when you're coding on the fly and need an answer now. It's an easy-to-use reference to the core language, with descriptions of commonly used modules and toolkits, and a guide to recent changes, new features, and upgraded built-ins -- all updated to cover Python 3.X as well as version 2.6. You'll also quickly find exactly what you need with the handy index. Written by Mark Lutz -- widely recognized as the world's leading Python trainer -- Python Pocket Reference, Fourth Edition, is the perfect companion to O'Reilly's classic Python tutorials, also written by Mark

  18. The Reference Return Ratio

    DEFF Research Database (Denmark)

    Nicolaisen, Jeppe; Faber Frandsen, Tove

    2008-01-01

    The paper introduces a new journal impact measure called The Reference Return Ratio (3R). Unlike the traditional Journal Impact Factor (JIF), which is based on calculations of publications and citations, the new measure is based on calculations of bibliographic investments (references) and returns...... (citations). A comparative study of the two measures shows a strong relationship between the 3R and the JIF. Yet, the 3R appears to correct for citation habits, citation dynamics, and composition of document types - problems that typically are raised against the JIF. In addition, contrary to traditional...

  19. Perl Pocket Reference

    CERN Document Server

    Vromans, Johan

    2011-01-01

    If you have a Perl programming question, you'll find the answer quickly in this handy, easy-to-use quick reference. The Perl Pocket Reference condenses and organizes stacks of documentation down to the most essential facts, so you can find what you need in a heartbeat. Updated for Perl 5.14, the 5th edition provides a summary of Perl syntax rules and a complete list of operators, built-in functions, and other features. It's the perfect companion to O'Reilly's authoritative and in-depth Perl programming books, including Learning Perl, Programming Perl, and the Perl Cookbook..

  20. HTML & XHTML Pocket Reference

    CERN Document Server

    Robbins, Jennifer

    2010-01-01

    After years of using spacer GIFs, layers of nested tables, and other improvised solutions for building your web sites, getting used to the more stringent standards-compliant design can be intimidating. HTML and XHTML Pocket Reference is the perfect little book when you need answers immediately. Jennifer Niederst-Robbins, author Web Design in a Nutshell, has revised and updated the fourth edition of this pocket guide by taking the top 20% of vital reference information from her Nutshell book, augmenting it judiciously, cross-referencing everything, and organizing it according to the most com

  1. CSS Pocket Reference

    CERN Document Server

    Meyer, Eric A

    2007-01-01

    They say that good things come in small packages, and it's certainly true for this edition of CSS Pocket Reference. Completely revised and updated to reflect the latest Cascading Style Sheet specifications in CSS 2.1, this indispensable little book covers the most essential information that web designers and developers need to implement CSS effectively across all browsers. Inside, you'll find: A short introduction to the key concepts of CSS A complete alphabetical reference to all CSS 2.1 selectors and properties A chart displaying detailed information about CSS support for every style ele

  2. JDBC Pocket Reference

    CERN Document Server

    Bales, Donald

    2003-01-01

    JDBC--the Java Database Connectivity specification--is a complex set of application programming interfaces (APIs) that developers need to understand if they want their Java applications to work with databases. JDBC is so complex that even the most experienced developers need to refresh their memories from time to time on specific methods and details. But, practically speaking, who wants to stop and thumb through a weighty tutorial volume each time a question arises? The answer is the JDBC Pocket Reference, a data-packed quick reference that is both a time-saver and a lifesaver. The JDBC P

  3. Reference values for electrooculography

    International Nuclear Information System (INIS)

    Barrientos Castanno, Alberto; Herrera Mora, Maritza; Garcia Baez, Obel

    2012-01-01

    Obtain electrooculographic reference values based on the patterns set by the Standardization Committee of the International Society for Clinical Electrophysiology of Vision (ISCEV). the lowest amplitude values of the potential ranged between 388 and 882 μv in the dark phase. The light peak was obtained between 9 and 10 minutes, and during this phase the potential reached an amplitude ranging between 808 and 1 963 μv. This amplitude variability may be related to the fact that the test was conducted without pupillary mydriasis. The reference value obtained for Arden index was 1,55 to 2,87

  4. NASCAP programmer's reference manual

    Science.gov (United States)

    Mandell, M. J.; Stannard, P. R.; Katz, I.

    1993-05-01

    The NASA Charging Analyzer Program (NASCAP) is a computer program designed to model the electrostatic charging of complicated three-dimensional objects, both in a test tank and at geosynchronous altitudes. This document is a programmer's reference manual and user's guide. It is designed as a reference to experienced users of the code, as well as an introduction to its use for beginners. All of the many capabilities of NASCAP are covered in detail, together with examples of their use. These include the definition of objects, plasma environments, potential calculations, particle emission and detection simulations, and charging analysis.

  5. Symptoms and health complaints and their association with perceived stress at university: survey of students at eleven faculties in Egypt.

    Science.gov (United States)

    El Ansari, Walid; Oskrochi, Reza; Labeeb, Shokria; Stock, Christiane

    2014-06-01

    This study examined the relationships between perceived stress and a range of self reported symptoms and health complaints in a representative sample of students at one university in Egypt. The data (3,271 students) was collected during the academic year 2009-2010 at eleven faculties at the university of Assiut city, Egypt. A self-administered questionnaire measured health complaints (22 symptoms) and Cohen's Perceived Stress Scale. Socio-demographic and lifestyle data were also collected. Factor analysis generated four groups of health complaints: psychological, circulatory/breathing, gastrointestinal, and pains/aches, and the internal consistency of each group of symptoms was computed using reliability analyses (Cronbach's alpha). Perceived stress was categorized into four levels based on quartiles. Multiple binomial or multinomial logistic regression analyses analysed the relationship between each of the four groups of symptoms and other students' general characteristics adjusted for the effect of all other groups of symptoms. The symptoms most often reported as having occurred sometimes/very often in the last 12 months were fatigue (85.3%), difficulties to concentrate (78.1%), headache (77.9%), and mood swings (74.5%), while nervousness/anxiety (63.2%) and sleep disorder (63.7%) affected many students. Multinominal logistic regression revealed a clear association and a linear trend between increasing level of stress and a higher frequency of psychological symptoms that remained significant after adjustment for other groups of symptoms. There were no associations between perceived stress and circulatory/breathing symptoms, gastrointestinal symptoms, or for pains/aches. Poor health was consistently associated with higher frequency of symptoms across all symptom groups except for gastrointestinal symptoms. Higher health awareness was associated with lower frequency of psychological and circulatory/breathing symptoms but not for the other two symptom groups. Better

  6. Characterization of eleven monosomic alien addition lines added from Gossypium anomalum to Gossypium hirsutum using improved GISH and SSR markers.

    Science.gov (United States)

    Wang, Xiaoxiao; Wang, Yingying; Wang, Chen; Chen, Yu; Chen, Yu; Feng, Shouli; Zhao, Ting; Zhou, Baoliang

    2016-10-07

    Gossypium anomalum (BB genome) possesses the desirable characteristics of drought tolerance, resistance to diseases and insect pests, and the potential for high quality fibers. However, it is difficult to transfer the genes associated with these desirable traits into cultivated cotton (G. hirsutum, AADD genome). Monosomic alien addition lines (MAALs) can be used as a bridge to transfer desired genes from wild species into G. hirsutum. In cotton, however, the high number and smaller size of the chromosomes has resulted in difficulties in discriminating chromosomes from wild species in cultivated cotton background, the development of cotton MAALs has lagged far behind many other crops. To date, no set of G. hirsutum-G. anomalum MAALs was reported. Here the amphiploid (AADDBB genome) derived from G. hirsutum × G. anomalum was used to generate a set of G. hirsutum-G. anomalum MAALs through a combination of consecutive backcrossing, genomic in situ hybridization (GISH), morphological survey and microsatellite marker identification. We improved the GISH technique used in our previous research by using a mixture of two probes from G. anomalum and G. herbaceum (AA genome). The results indicate that a ratio of 4:3 (G. anomalum : G. herbaceum) is the most suitable for discrimination of chromosomes from G. anomalum and the At-subgenome of G. hirsutum. Using this improved GISH technique, 108 MAAL individuals were isolated. Next, 170 G. hirsutum- and G. anomalum-specific codominant markers were obtained and employed for characterization of these MAAL individuals. Finally, eleven out of 13 MAALs were identified. Unfortunately, we were unable to isolate Chrs. 1B a and 5B a due to their very low incidences in backcrossing generation, as these remained in a condition of multiple additions. The characterized lines can be employed as bridges for the transfer of desired genes from G. anomalum into G. hirsutum, as well as for gene assignment, isolation of chromosome

  7. Association between Maternal Depression Symptoms across the First Eleven Years of Their Child's Life and Subsequent Offspring Suicidal Ideation.

    Directory of Open Access Journals (Sweden)

    Gemma Hammerton

    Full Text Available Depression is common, especially in women of child-bearing age; prevalence estimates for this group range from 8% to 12%, and there is robust evidence that maternal depression is associated with mental health problems in offspring. Suicidal behaviour is a growing concern amongst young people and those exposed to maternal depression are likely to be especially at high risk. The aim of this study was to utilise a large, prospective population cohort to examine the relationship between depression symptom trajectories in mothers over the first eleven years of their child's life and subsequent adolescent suicidal ideation. An additional aim was to test if associations were explained by maternal suicide attempt and offspring depressive disorder. Data were utilised from a population-based birth cohort: the Avon Longitudinal Study of Parents and Children. Maternal depression symptoms were assessed repeatedly from pregnancy to child age 11 years. Offspring suicidal ideation was assessed at age 16 years. Using multiple imputation, data for 10,559 families were analysed. Using latent class growth analysis, five distinct classes of maternal depression symptoms were identified (minimal, mild, increasing, sub-threshold, chronic-severe. The prevalence of past-year suicidal ideation at age 16 years was 15% (95% CI: 14-17%. Compared to offspring of mothers with minimal symptoms, the greatest risk of suicidal ideation was found for offspring of mothers with chronic-severe symptoms [OR 3.04 (95% CI 2.19, 4.21], with evidence for smaller increases in risk of suicidal ideation in offspring of mothers with sub-threshold, increasing and mild symptoms. These associations were not fully accounted for by maternal suicide attempt or offspring depression diagnosis. Twenty-six percent of non-depressed offspring of mothers with chronic-severe depression symptoms reported suicidal ideation. Risk for suicidal ideation should be considered in young people whose mothers have a

  8. Association between Maternal Depression Symptoms across the First Eleven Years of Their Child's Life and Subsequent Offspring Suicidal Ideation.

    Science.gov (United States)

    Hammerton, Gemma; Mahedy, Liam; Mars, Becky; Harold, Gordon T; Thapar, Anita; Zammit, Stanley; Collishaw, Stephan

    2015-01-01

    Depression is common, especially in women of child-bearing age; prevalence estimates for this group range from 8% to 12%, and there is robust evidence that maternal depression is associated with mental health problems in offspring. Suicidal behaviour is a growing concern amongst young people and those exposed to maternal depression are likely to be especially at high risk. The aim of this study was to utilise a large, prospective population cohort to examine the relationship between depression symptom trajectories in mothers over the first eleven years of their child's life and subsequent adolescent suicidal ideation. An additional aim was to test if associations were explained by maternal suicide attempt and offspring depressive disorder. Data were utilised from a population-based birth cohort: the Avon Longitudinal Study of Parents and Children. Maternal depression symptoms were assessed repeatedly from pregnancy to child age 11 years. Offspring suicidal ideation was assessed at age 16 years. Using multiple imputation, data for 10,559 families were analysed. Using latent class growth analysis, five distinct classes of maternal depression symptoms were identified (minimal, mild, increasing, sub-threshold, chronic-severe). The prevalence of past-year suicidal ideation at age 16 years was 15% (95% CI: 14-17%). Compared to offspring of mothers with minimal symptoms, the greatest risk of suicidal ideation was found for offspring of mothers with chronic-severe symptoms [OR 3.04 (95% CI 2.19, 4.21)], with evidence for smaller increases in risk of suicidal ideation in offspring of mothers with sub-threshold, increasing and mild symptoms. These associations were not fully accounted for by maternal suicide attempt or offspring depression diagnosis. Twenty-six percent of non-depressed offspring of mothers with chronic-severe depression symptoms reported suicidal ideation. Risk for suicidal ideation should be considered in young people whose mothers have a history of

  9. Book Catalogs; Selected References.

    Science.gov (United States)

    Brandhorst, Wesley T.

    The 116 citations on book catalogs are divided into the following two main sections: (1) Selected References, in alphabetic sequence by personal or institutional author and (2) Anonymous Entries, in alphabetic sequence by title. One hundred and seven of the citations cover the years 1960 through March 1969. There are five scattered citations in…

  10. ROOT Reference Documentation

    CERN Document Server

    Fuakye, Eric Gyabeng

    2017-01-01

    A ROOT Reference Documentation has been implemented to generate all the lists of libraries needed for each ROOT class. Doxygen has no option to generate or add the lists of libraries for each ROOT class. Therefore shell scripting and a basic C++ program was employed to import the lists of libraries needed by each ROOT class.

  11. Hospitality Services Reference Book.

    Science.gov (United States)

    Texas Tech Univ., Lubbock. Home Economics Curriculum Center.

    This reference book provides information needed by employees in hospitality services occupations. It includes 29 chapters that cover the following topics: the hospitality services industry; professional ethics; organization and management structures; safety practices and emergency procedures; technology; property maintenance and repair; purchasing…

  12. Quantum frames of reference

    International Nuclear Information System (INIS)

    Kaufherr, T.

    1981-01-01

    The idea that only relative variables have physical meaning came to be known as Mach's principle. Carrying over this idea to quantum theory, has led to the consideration of finite mass, macroscopic reference frames, relative to which all physical quantities are measured. During the process of measurement, a finite mass observer receives a kickback, and this reaction of the measuring device is not negligible in quantum theory because of the quantization of the action. Hence, the observer himself has to be included in the system that is being considered. Using this as the starting point, a number of thought experiments involving finite mass observers is discussed which have quantum uncertainties in their time or in their position. These thought experiments serve to elucidate in a qualitative way some of the difficulties involved, as well as pointing out a direction to take in seeking solutions to them. When the discussion is extended to include more than one observer, the question of the covariance of the theory immediately arises. Because none of the frames of reference should be preferred, the theory should be covariant. This demand expresses an equivalence principle which here is extended to include reference frames which are in quantum uncertainties relative to each other. Formulating the problem in terms of canonical variables, the ensueing free Hamiltonian contains vector and scalar potentials which represent the kick that the reference frame receives during measurement. These are essentially gravitational type potentials, resulting, as it were, from the extension of the equivalence principle into the quantum domain

  13. Pollen reference collection digitization

    NARCIS (Netherlands)

    Ercan, F.E.Z.; Donders, T.H.; Bijl, P.K.; Wagner, F.

    2016-01-01

    The extensive Utrecht University pollen reference collection holds thousands of pollen samples of many species and genera from all over the world and has been a basis for the widely-used North West European Pollen Flora. These samples are fixed on glass slides for microscopy use, but the aging

  14. Virtual Reference Services.

    Science.gov (United States)

    Brewer, Sally

    2003-01-01

    As the need to access information increases, school librarians must create virtual libraries. Linked to reliable reference resources, the virtual library extends the physical collection and library hours and lets students learn to use Web-based resources in a protected learning environment. The growing number of virtual schools increases the need…

  15. Reference-Dependent Sympathy

    Science.gov (United States)

    Small, Deborah A.

    2010-01-01

    Natural disasters and other traumatic events often draw a greater charitable response than do ongoing misfortunes, even those that may cause even more widespread misery, such as famine or malaria. Why is the response disproportionate to need? The notion of reference dependence critical to Prospect Theory (Kahneman & Tversky, 1979) maintains that…

  16. Genetics Home Reference

    Science.gov (United States)

    ... Page Search Home Health Conditions Genes Chromosomes & mtDNA Resources Help Me Understand Genetics Share: Email Facebook Twitter Genetics Home Reference provides consumer-friendly information about the effects of genetic variation on human health. Health Conditions More than 1,200 health ...

  17. Python library reference

    NARCIS (Netherlands)

    G. van Rossum (Guido)

    1995-01-01

    textabstractPython is an extensible, interpreted, object-oriented programming language. It supports a wide range of applications, from simple text processing scripts to interactive WWW browsers. While the Python Reference Manual describes the exact syntax and semantics of the language, it does not

  18. Uniform and non-uniform modes of nanosecond-pulsed dielectric barrier discharge in atmospheric air: fast imaging and spectroscopic measurements of electric fields

    International Nuclear Information System (INIS)

    Liu, Chong; Dobrynin, Danil; Fridman, Alexander

    2014-01-01

    In this study, we report experimental results on fast intensified charge-coupled device (ICCD) imaging of the development of nanosecond-pulsed dielectric barrier discharge (DBD) in atmospheric air and spectroscopic measurements of the electric field in the discharge. The uniformity of the discharge images obtained with nanosecond exposure times was analysed using chi-square test. The results indicate that DBD uniformity strongly depends on the applied (global) electric field in the discharge gap, which is a threshold phenomenon. We show that in the case of strong overvoltage on the discharge gap (provided by fast rise times), there is a transition from filamentary to uniform DBD mode that correlates to the corresponding decrease of the maximum local electric field in the discharge. (fast track communication)

  19. Uniform and non-uniform modes of nanosecond-pulsed dielectric barrier discharge in atmospheric air: fast imaging and spectroscopic measurements of electric field

    Science.gov (United States)

    Liu, Chong; Dobrynin, Danil; Fridman, Alexander

    2014-01-01

    In this study, we report experimental results on fast ICCD imaging of development of nanosecond-pulsed dielectric barrier discharge (DBD) in atmospheric air and spectroscopic measurements of electric field in the discharge. Uniformity of the discharge images obtained with nanosecond exposure times were analyzed using chi-square test. The results indicate that DBD uniformity strongly depends on applied (global) electric field in the discharge gap, and is a threshold phenomenon. We show that in the case of strong overvoltage on the discharge gap (provided by fast rise times), there is transition from filamentary to uniform DBD mode which correlates to the corresponding decrease of maximum local electric field in the discharge. PMID:25071294

  20. Cross-scale intercomparison of climate change impacts simulated by regional and global hydrological models in eleven large river basins

    Energy Technology Data Exchange (ETDEWEB)

    Hattermann, F. F.; Krysanova, V.; Gosling, S. N.; Dankers, R.; Daggupati, P.; Donnelly, C.; Flörke, M.; Huang, S.; Motovilov, Y.; Buda, S.; Yang, T.; Müller, C.; Leng, G.; Tang, Q.; Portmann, F. T.; Hagemann, S.; Gerten, D.; Wada, Y.; Masaki, Y.; Alemayehu, T.; Satoh, Y.; Samaniego, L.

    2017-01-04

    Ideally, the results from models operating at different scales should agree in trend direction and magnitude of impacts under climate change. However, this implies that the sensitivity of impact models designed for either scale to climate variability and change is comparable. In this study, we compare hydrological changes simulated by 9 global and 9 regional hydrological models (HM) for 11 large river basins in all continents under reference and scenario conditions. The foci are on model validation runs, sensitivity of annual discharge to climate variability in the reference period, and sensitivity of the long-term average monthly seasonal dynamics to climate change. One major result is that the global models, mostly not calibrated against observations, often show a considerable bias in mean monthly discharge, whereas regional models show a much better reproduction of reference conditions. However, the sensitivity of two HM ensembles to climate variability is in general similar. The simulated climate change impacts in terms of long-term average monthly dynamics evaluated for HM ensemble medians and spreads show that the medians are to a certain extent comparable in some cases with distinct differences in others, and the spreads related to global models are mostly notably larger. Summarizing, this implies that global HMs are useful tools when looking at large-scale impacts of climate change and variability, but whenever impacts for a specific river basin or region are of interest, e.g. for complex water management applications, the regional-scale models validated against observed discharge should be used.

  1. Measurements and kinetic modeling of atomic species in fuel-oxidizer mixtures excited by a repetitive nanosecond pulse discharge

    Science.gov (United States)

    Winters, C.; Eckert, Z.; Yin, Z.; Frederickson, K.; Adamovich, I. V.

    2018-01-01

    This work presents the results of number density measurements of metastable Ar atoms and ground state H atoms in diluted mixtures of H2 and O2 with Ar, as well as ground state O atoms in diluted H2-O2-Ar, CH4-O2-Ar, C3H8-O2-Ar, and C2H4-O2-Ar mixtures excited by a repetitive nanosecond pulse discharge. The measurements have been made in a nanosecond pulse, double dielectric barrier discharge plasma sustained in a flow reactor between two plane electrodes encapsulated within dielectric material, at an initial temperature of 500 K and pressures ranging from 300 Torr to 700 Torr. Metastable Ar atom number density distribution in the afterglow is measured by tunable diode laser absorption spectroscopy, and used to characterize plasma uniformity. Temperature rise in the reacting flow is measured by Rayleigh scattering. H atom and O atom number densities are measured by two-photon absorption laser induced fluorescence. The results are compared with kinetic model predictions, showing good agreement, with the exception of extremely lean mixtures. O atoms and H atoms in the plasma are produced mainly during quenching of electronically excited Ar atoms generated by electron impact. In H2-Ar and O2-Ar mixtures, the atoms decay by three-body recombination. In H2-O2-Ar, CH4-O2-Ar, and C3H8-O2-Ar mixtures, O atoms decay in a reaction with OH, generated during H atom reaction with HO2, with the latter produced by three-body H atom recombination with O2. The net process of O atom decay is O  +  H  →  OH, such that the decay rate is controlled by the amount of H atoms produced in the discharge. In extra lean mixtures of propane and ethylene with O2-Ar the model underpredicts the O atom decay rate. At these conditions, when fuel is completely oxidized by the end of the discharge burst, the net process of O atom decay, O  +  O  →  O2, becomes nearly independent of H atom number density. Lack of agreement with the data at these conditions is

  2. Hybrid Ti:Sapphire / KrF laser facility GARPUN for combined subpicosecond/nanosecond laser-matter interaction studies

    International Nuclear Information System (INIS)

    Zvorykin, V.D.; Ionin, A.A.; Konyashcenko, A.V.; Levchenko, A.O.; Krokhin, O.N.; Mesyats, G.A.; Molchanov, A.G.; Rorulev, M.A.

    2006-01-01

    Complete test of publication follows. Hybrid laser facility consisting of Ti:Sapphire front end, 3ω converter, and e-beam-pumped large-aperture KrF amplifiers is under construction to generate combined sub-picosecond/nanosecond pulses in UV spectral range at 248-nm wavelength. This is a part of the Petawatt excimer laser project started at P.N. Lebedev Physical Institute. In comparison with commonly used solid-state chirped-pulse amplifiers (CPA), KrF amplifiers have following advantages: (i) low-density gaseous matter with three orders of magnitude lower non-linear refraction index has a small value of B-integral and negligible pulse distortion; (ii) short radiation lifetime τ r = 6 ns of the upper laser level of KrF(B-X) transition (with accounting for collisions τ c ∼ 2 ns), that means the population inversion is recovered each 2 ns during the pumping time, which is typically τ p ≥ 100 ns for technical reasons. Thus, it might be possible eliminating of very costly large-aperture compressor gratings and to amplify both short τ sh c and long τ long ≥ τ c pulses in the same amplifiers, as a short pulse does not affect the gain during the most of pumping. This gives a unique opportunity for realization of fast-ignition scheme in Inertial Confinement Fusion using large-scale KrF drivers. The Ti:Sapphire front end 'Start 248M' currently operates with the following parameters: rep rate 10 Hz, pulse energy and duration at fundamental wavelength (744 nm) > 8 mJ and 0.5 mJ and 0.4 mJ, 740 nm) and multi-pass amplifier (10 Hz, > 15 mJ, 740 nm), both pumped by 2ω pulsed Lotis LS-2134 Nd:YAG laser (10 Hz, 10 ns, 532 nm) with distributed energies of 5 and 70 mJ, two-gratings compressor, and 3ω converter with two BBO crystals and total efficiency 8%. EMG 150MSC Lambda Physik KrF laser is used afterwards to generate ns pulses and to amplify fs pulses in its two separate discharge chambers. Two e-beam pumped KrF amplifiers Berdysh and GARPUN with active volumes 10

  3. ``Frames of Reference'' revisited

    Science.gov (United States)

    Steyn-Ross, Alistair; Ivey, Donald G.

    1992-12-01

    The PSSC teaching film, ``Frames of Reference,'' was made in 1960, and was one of the first audio-visual attempts at showing how your physical ``point of view,'' or frame of reference, necessarily alters both your perceptions and your observations of motion. The gentle humor and original demonstrations made a lasting impact on many audiences, and with its recent re-release as part of the AAPT Cinema Classics videodisc it is timely that we should review both the message and the methods of the film. An annotated script and photographs from the film are presented, followed by extension material on rotating frames which teachers may find appropriate for use in their classrooms: constructions, demonstrations, an example, and theory.

  4. Program reference schedule baseline

    International Nuclear Information System (INIS)

    1986-07-01

    This Program Reference Schedule Baseline (PRSB) provides the baseline Program-level milestones and associated schedules for the Civilian Radioactive Waste Management Program. It integrates all Program-level schedule-related activities. This schedule baseline will be used by the Director, Office of Civilian Radioactive Waste Management (OCRWM), and his staff to monitor compliance with Program objectives. Chapter 1 includes brief discussions concerning the relationship of the PRSB to the Program Reference Cost Baseline (PRCB), the Mission Plan, the Project Decision Schedule, the Total System Life Cycle Cost report, the Program Management Information System report, the Program Milestone Review, annual budget preparation, and system element plans. Chapter 2 includes the identification of all Level 0, or Program-level, milestones, while Chapter 3 presents and discusses the critical path schedules that correspond to those Level 0 milestones

  5. OSH technical reference manual

    Energy Technology Data Exchange (ETDEWEB)

    1993-11-01

    In an evaluation of the Department of Energy (DOE) Occupational Safety and Health programs for government-owned contractor-operated (GOCO) activities, the Department of Labor`s Occupational Safety and Health Administration (OSHA) recommended a technical information exchange program. The intent was to share written safety and health programs, plans, training manuals, and materials within the entire DOE community. The OSH Technical Reference (OTR) helps support the secretary`s response to the OSHA finding by providing a one-stop resource and referral for technical information that relates to safe operations and practice. It also serves as a technical information exchange tool to reference DOE-wide materials pertinent to specific safety topics and, with some modification, as a training aid. The OTR bridges the gap between general safety documents and very specific requirements documents. It is tailored to the DOE community and incorporates DOE field experience.

  6. Modelling of heating and photoexcitation of single-crystal silicon under multipulse irradiation by a nanosecond laser at 1.06 μm

    Science.gov (United States)

    Polyakov, D. S.; Yakovlev, E. B.

    2018-03-01

    We report a theoretical study of heating and photoexcitation of single-crystal silicon by nanosecond laser radiation at a wavelength of 1.06 μm. The proposed physicomathematical model of heating takes into account the complex nonlinear dynamics of the interband absorption coefficient of silicon and the contribution of the radial heat removal to the cooling of silicon between pulses under multipulse irradiation, which allows one to obtain a satisfactory agreement between theoretical predictions of silicon melting thresholds at different nanosecond pulse durations and experimental data (both under single-pulse and multipulse irradiation). It is found that under irradiation by nanosecond pulses at a wavelength of 1.06 μm, the dynamic Burshtein–Moss effect can play an important role in processes of photoexcitation and heating. It is shown that with the regimes typical for laser multipulse microprocessing of silicon (the laser spot diameter is less than 100 μm, and the repetition rate of pulses is about 100 kHz), the radial heat removal cannot be neglected in the analysis of heat accumulation processes.

  7. Nanosecond (ns) laser transfer of silver nanoparticles from silver-exchanged soda-lime glass to transparent soda-lime glass and shock waves formation

    International Nuclear Information System (INIS)

    Sow, Mohamed Chérif; Blondeau, Jean-Philippe; Sagot, Nadine; Ollier, Nadège; Tite, Teddy

    2015-01-01

    Highlights: • Silver nanoparticles growth by nanosecond laser irradiation of silver exchanged soda-lime glasses. • Silver nanoparticles transfer. • Nanosecond laser induced shock waves formation on glass. - Abstract: In this contribution, we showed for the first time in our knowledge a single-step process for silver clusters and nanoparticles growth and transfer from silver-exchanged soda-lime glass to un-exchanged soda-lime glass (transparent glass in visible and NIR domain) by nanosecond (ns) laser irradiation. The transferred silver nanoparticles in transparent glass are strongly linked to the glass surface. In addition, we point out the formation of shock waves, with selective silver clustering on the top wave. This technique provides an alternative and simple way to obtain metallic nanoparticles in different media which can be traversed by laser wavelength used. Moreover, this experiment is made at room temperature and air environment. It is worth noting that our technique requires a glass previously doped with the corresponding silver ions

  8. New approach to the dosimetry of ionizing radiations by fluorescence measurement, according to the single photon counting technique, correlated in time at the nanosecond scale

    International Nuclear Information System (INIS)

    Sohier, Till

    2011-01-01

    This research thesis reports the first fundamental study of the dosimetry of charged and gamma radiations by measurement of fluorescence resolved in time at a nanosecond scale, in organic matter. This method allows an in-depth and real-time analysis of the deposited dose, while taking ionisation as well as excitation processes into account. The author describes mechanisms of interaction and deposition of energy on dense matter, reports the detailed study of the ion-matter interaction, and the interaction of secondary electrons produced within traces. He addresses mechanisms of energy relaxation, and more particularly the study or organic scintillators. Then, he presents the adopted experimental approach: experimental observation with a statistic reconstitution of the curve representing the intensity of the emitted fluorescence in time and with a nanosecond resolution by using a scintillating sensor for time correlated single photon counting (TCSPC). The next part reports the development of an experimental multi-modal platform for dosimetry by TCSPC aimed at the measurement of fluorescence decays under pulsed excitation (nanosecond pulsed ion beams) and continuous flow excitation (non pulsed beams and radioactive sources). Experimental results are then presented for fluorescence measurements, and compared with measurements obtained by using an ionization chamber under the same irradiation conditions: dose deposited by hellions and carbon ions within polyvinyl toluene and polyethylene terephthalate, use of scintillating optic fibers under gamma irradiation of Caesium 137 and Cobalt 60. A new experimental approach is finally presented to perform dosimetry measurements while experimentally ignoring luminescence produced by Cerenkov effect [fr

  9. Multiply ionization of diethyl ether clusters by 532 nm nanosecond laser: The influence of laser intensity and the electron energy distribution

    International Nuclear Information System (INIS)

    Zhang Nazhen; Wang Weiguo; Zhao Wuduo; Han Fenglei; Li Haiyang

    2010-01-01

    Graphical abstract: The formation mechanism for multiply charged ions (C q+ and O q+ (q = 2-4)) were investigated experimentally and theoretically using a dual polarity time-of-flight mass spectrometer when diethyl ether clusters interacted with nanosecond laser pulse. - Abstract: The formation mechanism for multiply charged ions (C q+ and O q+ (q = 2-4)) were investigated using a dual polarity time-of-flight mass spectrometer when diethyl ether clusters interacted with nanosecond laser pulse. The signal intensity of multiply charged ions and electron energy was measured experimentally. It was shown that the intensity of multiply charged ions increased about 50 times when laser intensity increased from 7.6 x 10 9 to 7.0 x 10 10 W/cm 2 , then saturated as laser intensity increased further. It is interesting that the evolution of the mean value of electron energy was same to that of multiply charged ions. The theoretical calculation showed the ionization potential of atomic ions could be significantly decreased due to the effect of Coulomb screening especially at low laser intensity. It indicated that the electron ionization combined with Coulomb screening effect could explain the production of multiply charged ions in nanosecond laser field.

  10. Comparison of treatment with an Alexandrite picosecond laser and Nd:YAG nanosecond laser for removing blue-black Chinese eyeliner tattoos.

    Science.gov (United States)

    Zhang, Mengli; Huang, Yuqing; Lin, Tong; Wu, Qiuju

    2018-02-28

    To retrospectively evaluate the efficacy of an Alexandrite picosecond laser versus Nd:YAG nanosecond laser for removing blue-black eyeliner tattoos which have existed more than 10 years. A total of 40 patients were treated with an Alexandrite picosecond laser in our department from August 2015 to July 2017, with a fluence of 1.96-6.37J/cm 2 , spot size of 2.0-3.6 mm, and pulse width of 750 ps. Another 32 patients were treated with an Nd:YAG nanosecond laser, with a fluence of 2.80-7.00 J/cm 2 , spot size of 3 mm, and pulse width of 5-20 ns. All analysed patients completed at least one treatment and follow-up. The median number of treatment for all the patients was 1 (range, 1-4). After a single session, no difference was found between the two lasers for the eyeliner removal (p > 0.05). For the people who achieved an excellent response of tattoo clearance, there was still no difference between the two groups (p > 0.05). Transient side effects were observed in two groups, but neither group had significant adverse reactions. To treat blue-black Chinese eyeliner tattoos over 10 years, Alexandrite picosecond laser does not provide better clearance than the Nd:YAG nanosecond laser.

  11. Electrical engineer's reference book

    CERN Document Server

    Laughton, M A

    1985-01-01

    Electrical Engineer's Reference Book, Fourteenth Edition focuses on electrical engineering. The book first discusses units, mathematics, and physical quantities, including the international unit system, physical properties, and electricity. The text also looks at network and control systems analysis. The book examines materials used in electrical engineering. Topics include conducting materials, superconductors, silicon, insulating materials, electrical steels, and soft irons and relay steels. The text underscores electrical metrology and instrumentation, steam-generating plants, turbines

  12. Reference Sources in Chemistry

    OpenAIRE

    Sthapit, Dilip Man

    1995-01-01

    Information plays an important role in the development of every field. Therefore a brief knowledge regarding information sources is necessary to function in any field. There are many information sources about scientific and technical subjects. In this context there are many reference sources in Chemistry too. Chemistry is one important part of the science which deals with the study of the composition of substances and the chemical changes that they undergo. The purpose of this report is...

  13. Radioactive certified reference materials

    International Nuclear Information System (INIS)

    Watanabe, Kazuo

    2010-01-01

    Outline of radioactive certified reference materials (CRM) for the analysis of nuclear materials and radioactive nuclides were described. The nuclear fuel CRMs are supplied by the three institutes: NBL in the US, CETAMA in France and IRMM in Belgium. For the RI CRMs, the Japan Radioisotope Association is engaged in activities concerning supply. The natural-matrix CRMs for the analysis of trace levels of radio-nuclides are prepared and supplied by NIST in the US and the IAEA. (author)

  14. Reference Japanese man

    International Nuclear Information System (INIS)

    Tanaka, G.-I.; Kawamura, H.; Nakahara, Y.

    1979-01-01

    The weight of organs from autopsy cases of normal Japanese adults, children, and infants is presented for the purpose of approaching a Reference Japanese Man. The skeletal content and the daily intake of alkaline earth elements are given. A lower rate of transfer (K 2 ) to the thyroid gland of ingested radioiodine, as well as a remarkably shorter biological half-life than the data adopted by ICRP, is also proved as a result of this study. (author)

  15. Incidence of paediatric fatal and non-fatal low speed vehicle run over events in Queensland, Australia: eleven year analysis

    Science.gov (United States)

    2014-01-01

    Background The purpose of this study was to estimate the incidence of fatal and non-fatal Low Speed Vehicle Run Over (LSVRO) events among children aged 0–15 years in Queensland, Australia, at a population level. Methods Fatal and non-fatal LSVRO events that occurred in children resident in Queensland over eleven calendar years (1999-2009) were identified using ICD codes, text description, word searches and medical notes clarification, obtained from five health related data bases across the continuum of care (pre-hospital to fatality). Data were manually linked. Population data provided by the Australian Bureau of Statistics were used to calculate crude incidence rates for fatal and non-fatal LSVRO events. Results There were 1611 LSVROs between 1999–2009 (IR = 16.87/100,000/annum). Incidence of non-fatal events (IR = 16.60/100,000/annum) was 61.5 times higher than fatal events (IR = 0.27/100,000/annum). LSVRO events were more common in boys (IR = 20.97/100,000/annum) than girls (IR = 12.55/100,000/annum), and among younger children aged 0–4 years (IR = 21.45/100000/annum; 39% or all events) than older children (5–9 years: IR = 16.47/100,000/annum; 10–15 years IR = 13.59/100,000/annum). A total of 896 (56.8%) children were admitted to hospital for 24 hours of more following an LSVRO event (IR = 9.38/100,000/annum). Total LSVROs increased from 1999 (IR = 14.79/100,000) to 2009 (IR = 18.56/100,000), but not significantly. Over the 11 year period, there was a slight (non –significant) increase in fatalities (IR = 0.37-0.42/100,000/annum); a significant decrease in admissions (IR = 12.39–5.36/100,000/annum), and significant increase in non-admissions (IR = 2.02-12.77/100,000/annum). Trends over time differed by age, gender and severity. Conclusion This is the most comprehensive, population-based epidemiological study on fatal and non-fatal LSVRO events to date. Results from this study indicate

  16. Reference handbook: Level detectors

    International Nuclear Information System (INIS)

    1990-01-01

    The purpose of this handbook is to provide Rocky Flats personnel with the information necessary to understand level measurement and detection. Upon completion of this handbook you should be able to do the following: List three reasons for measuring level. Describe the basic operating principles of the sight glass. Demonstrate proper techniques for reading a sight glass. Describe the basic operating principles of a float level detector. Describe the basic operating principles of a bubbler level indicating system. Explain the differences between a wet and dry reference leg indicating system, and describe how each functions. This handbook is designed for use by experienced Rocky Flats operators to reinforce and improve their current knowledge level, and by entry-level operators to ensure that they possess a minimum level of fundamental knowledge. Level Detectors is applicable to many job classifications and can be used as a reference for classroom work or for self-study. Although this reference handbook is by no means all-encompassing, you will gain enough information about this subject area to assist you in contributing to the safe operation of Rocky Flats Plant

  17. Electroacoustical reference data

    CERN Document Server

    Eargle, John M

    2002-01-01

    The need for a general collection of electroacoustical reference and design data in graphical form has been felt by acousticians and engineers for some time. This type of data can otherwise only be found in a collection of handbooks. Therefore, it is the author's intention that this book serve as a single source for many electroacoustical reference and system design requirements. In form, the volume closely resembles Frank Massa's Acoustic Design Charts, a handy book dating from 1942 that has long been out of print. The basic format of Massa's book has been followed here: For each entry, graphical data are presented on the right page, while text, examples, and refer­ ences appear on the left page. In this manner, the user can solve a given problem without thumbing from one page to the next. All graphs and charts have been scaled for ease in data entry and reading. The book is divided into the following sections: A. General Acoustical Relationships. This section covers the behavior of sound transmis­ sion in...

  18. "Vi har musikk i skolen for å bli bedre til å synge!" Elevens egen stemme om sangaktiviteten i skolens musikkopplæring

    Directory of Open Access Journals (Sweden)

    Odd Magne Bøe

    2010-12-01

    Full Text Available Artikkelen fokuserer på elevenes egne opplevelser omkring sangaktiviteter i skolens musikkopplæring. Sang i skolen drøftes i lys av de rammene vi finner i ”Læreplanverket for Kunnskapsløftet” (LK06. Et sentralt spørsmål vil være om elever i ulike aldre forteller om endring av musikkaktiviteter i takt med et utvidet register i faget. Jeg vil i tillegg diskutere i hvilken grad elevens stemme vil kunne bringe fram ny viten om musikkfaget. Artikkelen er tredelt. Først beskrives målet med studien og begrunnelser for valg av metode. Deretter presenteres resultater fra empirien basert på kvalitative data fra elevintervjuer. I den tredje delen tar drøftingen utgangspunkt i de funn jeg gjorde i min studie.

  19. Determination of the food consumption in eleven regions of the european community with a view to studying the radioactive contamination level: Methods used. Results of family enquiries

    International Nuclear Information System (INIS)

    Cresta, M.; Lacourly, G.

    1966-01-01

    In the present report are given the results obtained from food surveys carried out during the period 1963-1965 and involving 9000 families living in eleven regions spread out over the six European Community countries. A partial analysis of the results obtained covers a reduced sample of 3725 families; it makes it possible to fix the composition of the mean individual, monthly and annual food consumptions for each of the eleven regions. Details of the organisation of the survey, of the data processing methods and of the method of presenting the results are given in the first part of the report. the second part presents, in numerical table form, the consumption of various foodstuffs and the feeding principles for each region covered by the survey. Tables summarizing the data make it possible to compare the mean individual consumptions in the various regions studied. (author) [fr

  20. Age group athletes in inline skating: decrease in overall and increase in master athlete participation in the longest inline skating race in Europe - the Inline One-Eleven.

    Science.gov (United States)

    Teutsch, Uwe; Knechtle, Beat; Rüst, Christoph Alexander; Rosemann, Thomas; Lepers, Romuald

    2013-01-01

    Participation and performance trends in age group athletes have been investigated in endurance and ultraendurance races in swimming, cycling, running, and triathlon, but not in long-distance inline skating. The aim of this study was to investigate trends in participation, age, and performance in the longest inline race in Europe, the Inline One-Eleven over 111 km, held between 1998 and 2009. The total number, age distribution, age at the time of the competition, and race times of male and female finishers at the Inline One-Eleven were analyzed. Overall participation increased until 2003 but decreased thereafter. During the 12-year period, the relative participation in skaters younger than 40 years old decreased while relative participation increased for skaters older than 40 years. The mean top ten skating time was 199 ± 9 minutes (range: 189-220 minutes) for men and 234 ± 17 minutes (range: 211-271 minutes) for women, respectively. The gender difference in performance remained stable at 17% ± 5% across years. To summarize, although the participation of master long-distance inline skaters increased, the overall participation decreased across years in the Inline One-Eleven. The race times of the best female and male skaters stabilized across years with a gender difference in performance of 17% ± 5%. Further studies should focus on the participation in the international World Inline Cup races.