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Journal articles on the topic 'Long spark'

Author: Grafiati

Published: 30 May 2022

Last updated: 31 May 2022

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1

Zhou, J., G. Brum, A. González, B. S. Launikonis, M. D. Stern, and E. Ríos. "Ca2+ Sparks and Embers of Mammalian Muscle. Properties of the Sources." Journal of General Physiology 122, no. 1 (June 30, 2003): 95–114. http://dx.doi.org/10.1085/jgp.200308796.

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Ca2+ sparks of membrane-permeabilized rat muscle cells were analyzed to derive properties of their sources. Most events identified in longitudinal confocal line scans looked like sparks, but 23% (1,000 out of 4,300) were followed by long-lasting embers. Some were preceded by embers, and 48 were “lone embers.” Average spatial width was ∼2 μm in the rat and 1.5 μm in frog events in analogous solutions. Amplitudes were 33% smaller and rise times 50% greater in the rat. Differences were highly significant. The greater spatial width was not a consequence of greater open time of the rat source, and was greatest at the shortest rise times, suggesting a wider Ca2+ source. In the rat, but not the frog, spark width was greater in scans transversal to the fiber axis. These features suggested that rat spark sources were elongated transversally. Ca2+ release was calculated in averages of sparks with long embers. Release current during the averaged ember started at 3 or 7 pA (depending on assumptions), whereas in lone embers it was 0.7 or 1.3 pA, which suggests that embers that trail sparks start with five open channels. Analysis of a spark with leading ember yielded a current ratio ranging from 37 to 160 in spark and ember, as if 37–160 channels opened in the spark. In simulations, 25–60 pA of Ca2+ current exiting a point source was required to reproduce frog sparks. 130 pA, exiting a cylindric source of 3 μm, qualitatively reproduced rat sparks. In conclusion, sparks of rat muscle require a greater current than frog sparks, exiting a source elongated transversally to the fiber axis, constituted by 35–260 channels. Not infrequently, a few of those remain open and produce the trailing ember.

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2

Satoh, H., L. A. Blatter, and D. M. Bers. "Effects of [Ca2+]i, SR Ca2+ load, and rest on Ca2+ spark frequency in ventricular myocytes." American Journal of Physiology-Heart and Circulatory Physiology 272, no. 2 (February 1, 1997): H657—H668. http://dx.doi.org/10.1152/ajpheart.1997.272.2.h657.

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In heart, spontaneous local increases in cytosolic Ca2+ concentration ([Ca2+]i) called "Ca2+ sparks" may be fundamental events underlying both excitation-contraction coupling and resting Ca2+ leak from the sarcoplasmic reticulum (SR). In this study, resting Ca2+ sparks were analyzed in rabbit and rat ventricular myocytes with laser scanning confocal microscopy and the fluorescent Ca2+ indicator fluo 3. During the first 20 s of rest after regular electrical stimulation, both the frequency of Ca2+ sparks and SR Ca2+ content gradually decreased in rabbit. When rabbit SR Ca2+ content was decreased by reduction of stimulation rate. the initial resting spark frequency was also decreased, even though resting [Ca2+]i was unchanged. The rest-dependent decrease in spark frequency in rabbit cells was prevented by inhibition of Na+/Ca2+ exchange (which also prevents SR Ca2+ depletion during rest). These results suggest that elevation of SR Ca2+ content can increase Ca2+ spark frequency. In contrast to rabbit cells, 20 s of rest produced a gradual increase in spark frequency in rat cells, although SR Ca2+ content was constant and Ca2+ influx was completely prevented. This indicates that there is a time-dependent increase in spark probability during rest that is independent of [Ca2+]i or SR Ca2+. This effect was also apparent in rabbit cells when SR Ca2+ depletion was prevented by blocking Na+/Ca2+ exchange. Stimulation of Ca2+ extrusion via Na+/Ca2+ exchange in the rat (by Ca2+-free superfusion, which slowly depletes SR Ca2+ content) converted the normal rest-dependent increase in spark frequency to a decrease. The amplitude of individual Ca2+ sparks increased with increasing SR Ca2+ content. In the Ca2+-overloaded state, fusion of sparks or long-lasting localized increases of [Ca2+]i were observed with increased spark frequency. We conclude that the resting frequency of Ca2+ sparks can be independently affected by changes in SR Ca2+ content, [Ca2+]i, or rest period. The latter may reflect recovery of the SR Ca2+ release channels from inactivation or adaptation.

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3

Zhao, Zheng, Chenjie Li, Xinlei Zheng, Anbang Sun, and Jiangtao Li. "Periodical discharge regime transitions under long-term repetitive nanosecond pulses." Plasma Sources Science and Technology 31, no. 4 (April 1, 2022): 045005. http://dx.doi.org/10.1088/1361-6595/ac6050.

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Abstract Intuitively, the nanosecond repetitively pulsed (NRP) corona and spark regimes are sustained successively after onsets due to the high background electron density and/or the surplus heat. In this paper, the NRP discharge unexpectedly swings among different regimes (corona → glow → spark → corona → …) in one pulse train, which is characterized by the periodical spark quench and reestablishment. We have investigated discharge regime instabilities by applying long-term repetitive high-voltage nanosecond pulses of ∼15 ns duration to needle–needle and needle–plane gaps in atmospheric-pressure N2 and N2–O2 mixtures. Pulse-sequence resolved electrical and optical diagnostics have been implemented to capture transition processes. The initial corona gradually grows into glow and then spark ‘pulse-by-pulse’, however, the spark regime was interrupted after a certain number of voltage pulses until the next reestablishment. Narrow pulse width impedes the discharge instability growth within one pulse, and a certain number of voltage pulses are required for the discharge regime transition. The addition of O2 dramatically boosts the duration length of spark regime. A lower output impedance of the power supply induces a higher deposited energy into a spark, however, not necessarily leads to a longer spark regime duration, although both the energy storage and the average electric field strength are approximate. Polarity effects, conventionally diminished in pulse-periodic discharges, are still evident during the discharge regime transition. The periodical discharge regime transition is qualitatively explained based on the plasma–source coupling and the evolution trajectory along the power transfer curve. Feedback mechanisms and residual-conductivity related screening effect in NRP spark discharges are analyzed based on a simplified 0D simulation. The periodical feature is probably caused by the insufficient average deposited energy per unit distance per one pulse cycle. In-depth understandings of ‘non-binary’ regimes (neither corona nor spark) and memory effect mechanisms of NRP discharges could be reached.

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4

Shelobolin, A. V. "Long laser spark and electric gas breakdown." Plasma Physics Reports 26, no. 4 (April 2000): 320–27. http://dx.doi.org/10.1134/1.952856.

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5

Brookes, Ken. "Long life demands spark probe into tool performance." Metal Powder Report 62, no. 1 (January 2007): 24–29. http://dx.doi.org/10.1016/s0026-0657(07)70022-x.

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6

Danilov, O. B., and S. A. Tul'ski. "An electrical discharge initiated by a long laser spark." Journal of Optical Technology 66, no. 3 (March 1, 1999): 187. http://dx.doi.org/10.1364/jot.66.000187.

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7

Savel'eva, V. P. "Optical shaping systems for generating a long laser spark." Journal of Optical Technology 66, no. 3 (March 1, 1999): 215. http://dx.doi.org/10.1364/jot.66.000215.

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8

Hopland, Arnt O. "Long-run relationship between investment and maintenance in local governments." Facilities 34, no. 11/12 (August 1, 2016): 703–22. http://dx.doi.org/10.1108/f-02-2015-0006.

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Purpose The purpose of the paper is to analyze the relationship between maintenance of existent and investment in new infrastructure in Norwegian local governments. Design/methodology/approach A reduced form vector autoregressive system is estimated using a 29-year-long panel data set for the Norwegian local governments. Findings The data reveal that increased investment in new infrastructure sparks little, if any, increase in maintenance. The results also indicate that increased maintenance expenditures spark new investments. Because more investments mean more infrastructure and adequate maintenance should give that investments are not caused by maintenance, the results suggest that the local governments have not optimized their maintenance scheduling in this period. Originality/value Even though maintenance and investment are large expenditures that both serve as inputs to the stock of infrastructure, little is known about the relationship between the two. The findings in this paper suggests that Norwegian local governments have not planned their maintenance and investments well in the past, and this can be part of the explanation as to why local public infrastructure in Norway is presently in poor condition.

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9

Bogatov, Nikolay, Vladimir Syssoev, Marat Bulatov, and Dmitry Sukharevsky. "Microwave diagnostics of the streamer zone of a long spark." ITM Web of Conferences 30 (2019): 11007. http://dx.doi.org/10.1051/itmconf/20193011007.

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Microwave diagnostics was first applied to the study of long spark and some new parameters of this discharge not available by the traditional experimental methods in this field were measured. The conditions of applicability of the method of measuring the high-frequency conductivity of the streamer zone by absorption of probing microwave radiation were theoretically analyzed.

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10

Bazelyan, E. M., and N. A. Popov. "Stepwise Development of a Positive Long Spark in the Air." Plasma Physics Reports 46, no. 3 (March 2020): 293–305. http://dx.doi.org/10.1134/s1063780x20030022.

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11

Piskarev, I. M. "Spark plasma radiation-induced formation of long-lived active species." High Energy Chemistry 50, no. 5 (September 2016): 424–25. http://dx.doi.org/10.1134/s001814391605012x.

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12

Medvedev, M. A., E. V. Parkevich, A. V. Oginov, S. M. Zakharov, and I. S. Baidin. "Internal Microstructure of Current Channel of the Long Spark Discharge." Bulletin of the Lebedev Physics Institute 48, no. 12 (December 2021): 373–77. http://dx.doi.org/10.3103/s1068335621120034.

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13

Hadley, Scott R., Quintin Blood, Monica Rubalcava, Edith Waskel, Britney Lumbard, Petersen Le, Lawrence D. Longo, John N. Buchholz, and Sean M. Wilson. "Maternal high-altitude hypoxia and suppression of ryanodine receptor-mediated Ca2+ sparks in fetal sheep pulmonary arterial myocytes." American Journal of Physiology-Lung Cellular and Molecular Physiology 303, no. 9 (November 1, 2012): L799—L813. http://dx.doi.org/10.1152/ajplung.00009.2012.

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Ca2+ sparks are fundamental Ca2+ signaling events arising from ryanodine receptor (RyR) activation, events that relate to contractile and dilatory events in the pulmonary vasculature. Recent studies demonstrate that long-term hypoxia (LTH) can affect pulmonary arterial reactivity in fetal, newborn, and adult animals. Because RyRs are important to pulmonary vascular reactivity and reactivity changes with ontogeny and LTH we tested the hypothesis that RyR-generated Ca2+ signals are more active before birth and that LTH suppresses these responses. We examined these hypotheses by performing confocal imaging of myocytes in living arteries and by performing wire myography studies. Pulmonary arteries (PA) were isolated from fetal, newborn, or adult sheep that lived at low altitude or from those that were acclimatized to 3,801 m for > 100 days. Confocal imaging demonstrated preservation of the distance between the sarcoplasmic reticulum, nucleus, and plasma membrane in PA myocytes. Maturation increased global Ca2+ waves and Ca2+ spark activity, with sparks becoming larger, wider, and slower. LTH preferentially depressed Ca2+ spark activity in immature pulmonary arterial myocytes, and these sparks were smaller, wider, and slower. LTH also suppressed caffeine-elicited contraction in fetal PA but augmented contraction in the newborn and adult. The influence of both ontogeny and LTH on RyR-dependent cell excitability shed new light on the therapeutic potential of these channels for the treatment of pulmonary vascular disease in newborns as well as adults.

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14

Cheng, Chen, Hengxin He, Bin Luo, Lipeng Liu, Weijiang Chen, Kai Bian, Nianwen Xiang, and Jinyang Hu. "Temperature measurements of long sparks in air using time-resolved moiré deflectometry." Journal of Physics D: Applied Physics 55, no. 26 (April 4, 2022): 265201. http://dx.doi.org/10.1088/1361-6463/ac5bcb.

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Abstract This paper presents an original investigation into time-resolved moiré deflectometry (MD) for gas temperature measurements of long sparks in air. In order to perform a rigorous comparative investigation with the widely used quantitative schlieren (QS) method, we set up an orthogonal optical measurement system. The impacts of spatial resolution and exposure time on the measurement accuracy are investigated by comparing the measured radial distribution of the gas temperature and its time evolution during the same spark discharge event. It is found that the time-resolved MD with an exposure time of 1.0 μs can accurately measure the gas temperature evolution during the isobaric heating and relaxation process of long sparks. The measured results of the expansion rate of cross-section π ⋅ R g 2 and average temperature T g confirms that the energy loss is dominated by thermal conduction during the isobaric heating and relaxation process after the extinction of discharge current. The MD can achieve a finer spatial resolution than the QS method, which is beneficial to the reconstruction of steep radial temperature distribution and the suppression of measured temperature fluctuation. Moreover, the MD can obtain a sub-microsecond exposure time by increasing the power of continuous-wave laser source, which shows its potential to capture the rapid changes in gas temperature during the fast-heating process.

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15

Huang, Shengfang, Zhibo Zhang, Huimin Song, Yun Wu, and Yinghong Li. "A Novel Way to Enhance the Spark Plasma-Assisted Ignition for an Aero-Engine Under Low Pressure." Applied Sciences 8, no. 9 (September 1, 2018): 1533. http://dx.doi.org/10.3390/app8091533.

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Finding a new ignition strategy for ignition enhancement in a lean-burn combustor has always been the biggest challenge for high-altitude, long-endurance unmanned aerial vehicles (UAVs). It is of great importance for the development of high-altitude, long-endurance aircraft to improve the secondary ignition ability of the aero-engine at high altitude where the ignition capability of the aero-engine igniter rapidly declines. An innovative ignition mode is therefore urgently needed. A novel plasma-assisted ignition method based on a multichannel discharge jet-enhanced spark (MDJS) was proposed in this study. Compared to the conventional spark igniter (SI), the arc discharge energy of the MDJS was increased by 13.6% at 0.12 bar and by 14.7% at 0.26 bar. Furthermore, the spark plasma penetration depth of the MDJS was increased by 49% and 103% at 0.12 bar and 0.26 bar, respectively. The CH* radicals showed that the MDJS obtained a larger initial spark kernel and reached a higher spark plasma penetration depth, which helped accelerate the burning velocity. Ignition tests in a model swirl combustor showed that the lean ignition limit was extended 24% from 0.034 to 0.026 at 25 m/s with 20 °C kerosene and 17% from 0.075 to 0.062 at 12 m/s with −30 °C kerosene maximally. The MDJS was a unique plasma-assisted ignition method, activated by the custom ignition power supply instead of a special power supply with an extra gas source. The objective of this study was to provide a novel multichannel discharge jet-enhanced spark ignition strategy which would help to increase the arc discharge energy, the spark plasma penetration depth and the activated area without changing the power supply system and to improve the safety and performance of aero-engines.

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16

Wuerker, R. F., J. Chen, W. Beam, and E. Nichols. "Pulsed energy storage antennas for ionospheric modification." Annales Geophysicae 23, no. 1 (January 31, 2005): 101–7. http://dx.doi.org/10.5194/angeo-23-101-2005.

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Abstract. Interesting, "new", very high peak-power pulsed radio frequency (RF) antennas have been assembled at the HIPAS Observatory (Alaska, USA) and also at the University of California at Los Angeles (UCLA, USA); namely, a pair of quarter wavelength (λ/4) long cylindrical conductors separated by a high voltage spark gap. Such a combination can radiate multi-megawatt RF pulses whenever the spark gap fires. The antenna at HIPAS is 53m long (λ/2) with a central pressurized SF6 spark gap. It is mounted 5 meters (λ/21) above a ground plane. It radiates at 2.85MHz. The two antenna halves are charged to ± high voltages by a Tesla coil. Spark gap voltages of 0.4 MV (at the instant of spark gap closure) give peak RF currents of ~1200A which correspond to ~14 MW peak total radiated power, or ~56 MW of Effective Radiated Power (ERP). The RF pulse train is initially square, decaying exponentially in time with Qs of ~50. Two similar but smaller 80-MHz antennas were assembled at UCLA to demonstrate their synchronization with a pulsed laser which fired the spark gaps in the two antennas simultanoeously. These experiments show that one can anticipate a pulsed array of laser synchronized antennas having a coherent Effective Radiated Power (ERP)>10GW. One can even reconsider a pulse array radiating at 1.43MHz which corresponds to the electron gyrofrequency in the Earth's magnetic field at ~200km altitude. These "new" pulsed high power antennas are hauntingly similar to the ones used originally by Hertz (1857-1894) during his (1886-1889) seminal verifications of Maxwell's (1864) theory of electrodynamics.

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17

Zakuskin, Aleksandr S., Andrey M. Popov, and Timur A. Labutin. "Emission spectroscopy of long cylindrical laser spark with additional coaxial excitation." Spectrochimica Acta Part B: Atomic Spectroscopy 157 (July 2019): 22–26. http://dx.doi.org/10.1016/j.sab.2019.05.007.

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18

Winands, G. J. J., Z. Liu, A. J. M. Pemen, E. J. M. van Heesch, and K. Yan. "Long lifetime, triggered, spark-gap switch for repetitive pulsed power applications." Review of Scientific Instruments 76, no. 8 (August 2005): 085107. http://dx.doi.org/10.1063/1.2008047.

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19

Lee, Kern, Kyoung-Jae Chung, Y. S. Hwang, and C. Y. Kim. "Underwater spark discharge with long transmission line for cleaning horizontal wells." Journal of Applied Physics 121, no. 24 (June 28, 2017): 243302. http://dx.doi.org/10.1063/1.4986634.

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20

Borisov, M. F., V. M. Gromovenko, M. F. Danilov, and V. A. Lapshin. "Interaction of a long laser spark with an atmospheric electric field." Journal of Optical Technology 66, no. 3 (March 1, 1999): 210. http://dx.doi.org/10.1364/jot.66.000210.

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21

Nakamura, Taizo, Eiichi Takahashi, Makihito Nishioka, and Tokuyuki Teraji. "Long gap spark discharge ignition using a boron-doped diamond electrode." Journal of Physics D: Applied Physics 54, no. 40 (July 28, 2021): 405204. http://dx.doi.org/10.1088/1361-6463/ac12f5.

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22

Wachowicz, Joanna. "Spark Plasma Sintering – new technology for obtaining tool materials." Annals of WULS, Forestry and Wood Technology 109 (March 31, 2020): 64–69. http://dx.doi.org/10.5604/01.3001.0014.3262.

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Spark Plasma Sintering – new technology for obtaining tool materials. Cemented carbides are a valued tool material used for tools to process, among others, wood-based materials. They are traditionally obtained using high temperatures and long periods. New electric current activated sintering methods make it possible to obtain sinters with good mechanical properties in a short time and low temperature. This paper presents a comparative analysis of conventional and advanced SPS (Spark Plasma Sintering) technology of obtaining cemented carbides.

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23

Rohlena, Karel, and Martin Mašek. "Ambient fields generated by a laser spark." Nukleonika 61, no. 2 (June 1, 2016): 119–24. http://dx.doi.org/10.1515/nuka-2016-0021.

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Abstract The electric and magnetic fields surrounding a laser spark formed after an optical breakdown due to a focused nanosecond laser beam in a gaseous environment are examined in order to assess their possible influence on the processes going on in the gas medium, mainly chemical reactions triggered by the spark plasma radiation. The magnetic field is generated by the standard mechanism of crossed electron density and temperature gradients, the electric field is supposed to be produced by the plasma polarization due to its radial expansion across the self-generated magnetic field. A simple model of spark plasma formation near the tip of the focal cone is assumed, with a delayed breakdown, which allows the focused laser light to sweep the whole volume of the forming spark right down to the focal caustic and thus to form a centimeter long plasma cone. In this conical geometry, the value of plasma electric dipole moment is evaluated as a measurable quantity as well as approximate values of the electric and magnetic field near the focal caustic, where they both tend to grow in magnitude.

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24

Liu, Kun, Jan Boehm, and Christian Alis. "CHANGE DETECTION OF MOBILE LIDAR DATA USING CLOUD COMPUTING." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B3 (June 9, 2016): 309–13. http://dx.doi.org/10.5194/isprsarchives-xli-b3-309-2016.

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Change detection has long been a challenging problem although a lot of research has been conducted in different fields such as remote sensing and photogrammetry, computer vision, and robotics. In this paper, we blend voxel grid and Apache Spark together to propose an efficient method to address the problem in the context of big data. Voxel grid is a regular geometry representation consisting of the voxels with the same size, which fairly suites parallel computation. Apache Spark is a popular distributed parallel computing platform which allows fault tolerance and memory cache. These features can significantly enhance the performance of Apache Spark and results in an efficient and robust implementation. In our experiments, both synthetic and real point cloud data are employed to demonstrate the quality of our method.

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25

Liu, Kun, Jan Boehm, and Christian Alis. "CHANGE DETECTION OF MOBILE LIDAR DATA USING CLOUD COMPUTING." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B3 (June 9, 2016): 309–13. http://dx.doi.org/10.5194/isprs-archives-xli-b3-309-2016.

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Change detection has long been a challenging problem although a lot of research has been conducted in different fields such as remote sensing and photogrammetry, computer vision, and robotics. In this paper, we blend voxel grid and Apache Spark together to propose an efficient method to address the problem in the context of big data. Voxel grid is a regular geometry representation consisting of the voxels with the same size, which fairly suites parallel computation. Apache Spark is a popular distributed parallel computing platform which allows fault tolerance and memory cache. These features can significantly enhance the performance of Apache Spark and results in an efficient and robust implementation. In our experiments, both synthetic and real point cloud data are employed to demonstrate the quality of our method.

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26

Bennett, John. "Additives for Spark Ignition and Compression Ignition engine fuels." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 232, no. 1 (October 23, 2017): 148–58. http://dx.doi.org/10.1177/0954407017732265.

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Fuel additives for automotive applications have been in use for almost as long as the automobile has existed. They provide significant benefits, both in making fuels fit for purpose and to deliver protection and performance benefits. Performance benefits can range from protection against degradation, through recovery of lost performance, all the way to enhanced engine function. This has become particularly important with the tension between increasingly stringent long emissions requirements, the encouragement of renewable biofuel content and the drive to improved engine efficiency and reduce fuel consumption. The paper discusses where performance fuel additives provide their benefits and how they are evolving to work with latest generations of fuel and engines, and provides an overview of the current and upcoming industry engine tests for fuels and their additives.

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27

Cirigliano, Daniele, Aaron M. Frisch, Feng Liu, and William A. Sirignano. "Diesel, Spark-Ignition, and Turboprop Engines for Long-Duration Unmanned Air Flights." Journal of Propulsion and Power 34, no. 4 (July 2018): 878–92. http://dx.doi.org/10.2514/1.b36547.

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28

Bondiou, A., and I. Gallimberti. "Theoretical modelling of the development of the positive spark in long gaps." Journal of Physics D: Applied Physics 27, no. 6 (June 14, 1994): 1252–66. http://dx.doi.org/10.1088/0022-3727/27/6/024.

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29

Larigaldie, S., A. Roussaud, and B. Jecko. "Mechanisms of high‐current pulses in lightning and long‐spark stepped leaders." Journal of Applied Physics 72, no. 5 (September 1992): 1729–39. http://dx.doi.org/10.1063/1.351696.

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30

Borisov, M. F., V. M. Gromovenko, V. A. Lapshin, Yu A. Rezunkov, V. P. Savel'eva, and V. V. Stepanov. "Long laser spark for controlling the trajectory of an atmospheric electric discharge." Journal of Optical Technology 66, no. 3 (March 1, 1999): 203. http://dx.doi.org/10.1364/jot.66.000203.

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31

Arevalo, Liliana, Vernon Cooray, Dong Wu, and Bjorn Jacobson. "A new static calculation of the streamer region for long spark gaps." Journal of Electrostatics 70, no. 1 (February 2012): 15–19. http://dx.doi.org/10.1016/j.elstat.2011.07.013.

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32

George Done, Bogdan, and Ion Copae. "Performances of a Research CFR Octane Rating Unit Engine and Dacia Single Cylinder SI Engine Ignited by a LASER System." E3S Web of Conferences 112 (2019): 01009. http://dx.doi.org/10.1051/e3sconf/201911201009.

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At this time, the severe legislation regarding the level limits of the waste and exhaust gases released by thermal engines and also the necessity of engines efficiency improvement boost the engine research domain to bring in front the use of new technologies that can be used to control the in-cylinder combustion process. Now, the new technologies is represented by LASER spark plug systems which can be successfully used at petrol engines. LASER spark plug technology can have many advantages for engine operation control, an ignition system that could provide improved combustion is the one using plasma generation and a Q-switched LASER that results in pulses with high MW power. The LASER spark plug device used in the current research was a LASER medium Nd:YAG/Cr4+:YAG ceramic structure made up of a 8.0-mm long, 1.0-at.% Nd:YAG ceramic, optically-bonded to a Cr4+:YAG c. It was developed and constructed similar to classical spark plug and could be assembled on a CFR Octane Rating Unit Engine as well as on a Dacia Single Cylinder SI Engine which led to several results among which: influences on in-cylinder pressure, combustion and pollutant emissions.

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33

Liu, Peng, Shuai Ye, Can Wang, and Zongwei Zhu. "Spark-Based Parallel Genetic Algorithm for Simulating a Solution of Optimal Deployment of an Underwater Sensor Network." Sensors 19, no. 12 (June 17, 2019): 2717. http://dx.doi.org/10.3390/s19122717.

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Underwater sensor networks have wide application prospects, but the large-scale sensing node deployment is severely hindered by problems like energy constraints, long delays, local disconnections, and heavy energy consumption. These problems can be solved effectively by optimizing sensing node deployment with a genetic algorithm. However, the genetic algorithm (GA) needs many iterations in solving the best location of underwater sensor deployment, which results in long running time delays and limited practical application when dealing with large-scale data. The classical parallel framework Hadoop can improve the GA running efficiency to some extent while the state-of-the-art parallel framework Spark can release much more parallel potential of GA by realizing parallel crossover, mutation, and other operations on each computing node. Giving full allowance for the working environment of the underwater sensor network and the characteristics of sensors, this paper proposes a Spark-based parallel GA to calculate the extremum of the Shubert multi-peak function, through which the optimal deployment of the underwater sensor network can be obtained. Experimental results show that while faced with a large-scale underwater sensor network, compared with single node and Hadoop framework, the Spark-based implementation not only significantly reduces the running time but also effectively avoids the problem of premature convergence because of its powerful randomness.

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34

Marples, David R. "Catastrophe and Denial in Belarus." Current History 119, no. 819 (September 21, 2020): 282–84. http://dx.doi.org/10.1525/curh.2020.119.819.282.

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The long-ruling president has manipulated World War II history and downplayed the lasting effects of the Chernobyl nuclear disaster. His similarly dismissive approach to the pandemic provided a spark for an unprecedented election challenge and popular resistance.

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35

Castillo, Luis, Gabriella Cortellessa, and Neil Yorke-Smith. "The 2008 Scheduling and Planning Applications Workshop (SPARK'08)." AI Magazine 30, no. 1 (January 18, 2009): 119. http://dx.doi.org/10.1609/aimag.v30i1.2215.

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SPARK'08 was the first edition of a workshop series designed to provide a stable, long-term forum where researchers could discuss the applications of planning and scheduling techniques to real problems. Animated discussion characterized the workshop, which was collocated with Eighteenth International Conference on Automated Planning and Scheduling (ICAPS-08) held in Sydney, Australia in September 2008.

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Shen, Christine P., Monica Romero, Alexander Brunelle, Craig Wolfe, Abigail Dobyns, Michael Francis, Mark S. Taylor, et al. "Long-term high-altitude hypoxia influences pulmonary arterial L-type calcium channel-mediated Ca2+ signals and contraction in fetal and adult sheep." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 314, no. 3 (March 1, 2018): R433—R446. http://dx.doi.org/10.1152/ajpregu.00154.2017.

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Long-term hypoxia (LTH) has a profound effect on pulmonary arterial vasoconstriction in the fetus and adult. Dysregulation in Ca2+ signaling is important during the development of LTH-induced pulmonary hypertension. In the present study, we tested the hypothesis that L-type Ca2+ channels (CaL), which are voltage dependent and found in smooth, skeletal, and cardiac muscle, are important in the adaptation of pulmonary arterial contractions in postnatal maturation and in response to LTH. Pulmonary arteries were isolated from fetal or adult sheep maintained at low or high altitude (3,801 m) for >100 days. The effects were measured using an L-type Ca2+ channel opener FPL 64176 (FPL) in the presence or absence of an inhibitor, Nifedipine (NIF) on arterial contractions, intracellular Ca2+ oscillations, and ryanodine receptor-driven Ca2+ sparks. FPL induced pulmonary arterial contractions in all groups were sensitive to NIF. However, when compared with 125 mM K+, FPL contractions were greater in fetuses than in adults. FPL reduced Ca2+ oscillations in myocytes of adult but not fetal arteries, independently of altitude. The FPL effects on Ca2+ oscillations were reversed by NIF in myocytes of hypoxic but not normoxic adults. FPL failed to enhance Ca2+ spark frequency and had little impact on spatiotemporal firing characteristics. These data suggest that CaL-dependent contractions are largely uncoupled from intracellular Ca2+ oscillations and the development of Ca2+ sparks. This raises questions regarding the coupling of pulmonary arterial contractility to membrane depolarization, attendant CaL facilitation, and the related associations with the activation of Ca2+ oscillations and Ca2+ sparks.

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Popov, Andrey M., Timur F. Akhmetzhanov, Timur A. Labutin, Sergey M. Zaytsev, Nikita B. Zorov, and Nikolay V. Chekalin. "Experimental measurements of Stark widths for Mn I lines in long laser spark." Spectrochimica Acta Part B: Atomic Spectroscopy 125 (November 2016): 43–51. http://dx.doi.org/10.1016/j.sab.2016.09.014.

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38

McKenzie, Thomas L., James F. Sallis, Bohdan Kolody, and F. Nell Faucette. "Long-Term Effects of a Physical Education Curriculum and Staff Development Program: SPARK." Research Quarterly for Exercise and Sport 68, no. 4 (December 1997): 280–91. http://dx.doi.org/10.1080/02701367.1997.10608009.

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39

Baby, T., T. Ramachandran, P. Radhakrishnan, V. P. N. Nampoori, and C. P. G. Vallabhan. "A low-inductance, long-life, triggered spark gap switch for Blumlein-driven lasers." Measurement Science and Technology 2, no. 9 (September 1, 1991): 873–75. http://dx.doi.org/10.1088/0957-0233/2/9/008.

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40

Forestier, B., A. Houard, I. Revel, M. Durand, Y. B. André, B. Prade, A. Jarnac, et al. "Triggering, guiding and deviation of long air spark discharges with femtosecond laser filament." AIP Advances 2, no. 1 (March 2012): 012151. http://dx.doi.org/10.1063/1.3690961.

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Rodolfa, Kit T., and David A. Cremers. "Capabilities of Surface Composition Analysis Using a Long Laser-Induced Breakdown Spectroscopy Spark." Applied Spectroscopy 58, no. 4 (April 2004): 367–75. http://dx.doi.org/10.1366/000370204773580185.

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Wu, Jia-Wei, Ruo-Yu Han, Wei-Dong Ding, Hai-Bin Zhou, Yun-Fei Liu, Qiao-Jue Liu, Yan Jing, and Ai-Ci Qiu. "Electrode Erosion Characteristics of Repetitive Long-Life Gas Spark Switch Under Airtight Conditions." IEEE Transactions on Plasma Science 43, no. 10 (October 2015): 3425–33. http://dx.doi.org/10.1109/tps.2015.2428934.

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43

Denisov, Vyacheslav A., Aleksandr Yu Kostyukov, and Roman N. Zadorozhniy. "Restoration of cylinder liners for automotive tractors engines in modern conditions." Tekhnicheskiy servis mashin, no. 2 (June 10, 2020): 122–33. http://dx.doi.org/10.22314/2618-8287-2020-58-1-122-133.

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One of the most promising technologies for restoring machine parts and cylinder liners is electric spark treatment as the most versatile technology that provides high-quality restoration of worn parts with wear up to 0.5 mm. (Research purpose) The research purpose is in developing a technology for restoring various cylinder liners by means of electric spark processing, selecting optimal modes and electrode materials that allow improving the quality of repair and increasing the post-repair life of the sleeve. (Materials and methods) It was taken into account when conducting research aimed at restoring the geometric parameters of the sleeve, that the coating must have sufficient adhesion strength to the surface of the sleeve under mechanical, thermal loads and long-term operation. Laboratory studies of the adhesion strength of electric spark coatings on the separation (adhesive) and on the cut, as well as tribotechnical studies of interfaces were conducted. Authors have found by analyzing the results of operational tests of restored and new cylinder liners the prospects for using electric spark treatment of worn parts, including diesel engine liners. (Results and discussion) It was shown by laboratory studies of the adhesion strength of electric spark coatings with a 0.2 mm thick BrMKc 3-1 electrode to the working surface of cylinder liners that their separation strength (adhesive) was 20-40 megapascals, and the shear strength (cohesive) was 50-80 megapascals. It was found that this provides the required functional strength of coatings with maximum operational load. The article presents the results of comprehensive research in graphs and tables. (Conclusions) The research conducted in the CCP "Nano-Center" of the FSAC VIM and operational tests in the 2nd bus fleet of Moscow confirmed the principal possibility of effectively restoring cast iron liners (blocks) using the technology of electric spark processing.

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Robert, Anthony, Karine Truffin, Nicolas Iafrate, Stephane Jay, Olivier Colin, and Christian Angelberger. "Large-eddy simulation analysis of knock in a direct injection spark ignition engine." International Journal of Engine Research 20, no. 7 (December 2, 2018): 765–76. http://dx.doi.org/10.1177/1468087418796323.

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Downsized spark ignition engines running under high loads have become more and more attractive for car manufacturers because of their increased thermal efficiency and lower CO2 emissions. However, the occurrence of abnormal combustions promoted by the thermodynamic conditions encountered in such engines limits their practical operating range, especially in high efficiency and low fuel consumption regions. One of the main abnormal combustion is knock, which corresponds to an auto-ignition of end gases during the flame propagation initiated by the spark plug. Knock generates pressure waves which can have long-term damages on the engine, that is why the aim for car manufacturers is to better understand and predict knock appearance. However, an experimental study of such recurrent but non-cyclic phenomena is very complex, and these difficulties motivate the use of computational fluid dynamics for better understanding them. In the present article, large-eddy simulation (LES) is used as it is able to represent the instantaneous engine behavior and thus to quantitatively capture cyclic variability and knock. The proposed study focuses on the large-eddy simulation analysis of knock for a direct injection spark ignition engine. A spark timing sweep available in the experimental database is simulated, and 15 LES cycles were performed for each spark timing. Wall temperatures, which are a first-order parameter for knock prediction, are obtained using a conjugate heat transfer study. Present work points out that LES is able to describe the in-cylinder pressure envelope whatever the spark timing, even if the sample of LES cycles is limited compared to the 500 cycles recorded in the engine test bench. The influence of direct injection and equivalence ratio stratifications on combustion is also (MAPO) analyzed. Finally, focusing on knock, a Maximum Amplitude Pressure Oscillation analysis (MAPO) is conducted for both experimental and numerical pressure traces pointing out that LES well reproduces experimental knock tendencies.

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Khan, Muhammad Ashfaq, Md Rezaul Karim, and Yangwoo Kim. "A Two-Stage Big Data Analytics Framework with Real World Applications Using Spark Machine Learning and Long Short-Term Memory Network." Symmetry 10, no. 10 (October 11, 2018): 485. http://dx.doi.org/10.3390/sym10100485.

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Every day we experience unprecedented data growth from numerous sources, which contribute to big data in terms of volume, velocity, and variability. These datasets again impose great challenges to analytics framework and computational resources, making the overall analysis difficult for extracting meaningful information in a timely manner. Thus, to harness these kinds of challenges, developing an efficient big data analytics framework is an important research topic. Consequently, to address these challenges by exploiting non-linear relationships from very large and high-dimensional datasets, machine learning (ML) and deep learning (DL) algorithms are being used in analytics frameworks. Apache Spark has been in use as the fastest big data processing arsenal, which helps to solve iterative ML tasks, using distributed ML library called Spark MLlib. Considering real-world research problems, DL architectures such as Long Short-Term Memory (LSTM) is an effective approach to overcoming practical issues such as reduced accuracy, long-term sequence dependency, and vanishing and exploding gradient in conventional deep architectures. In this paper, we propose an efficient analytics framework, which is technically a progressive machine learning technique merged with Spark-based linear models, Multilayer Perceptron (MLP) and LSTM, using a two-stage cascade structure in order to enhance the predictive accuracy. Our proposed architecture enables us to organize big data analytics in a scalable and efficient way. To show the effectiveness of our framework, we applied the cascading structure to two different real-life datasets to solve a multiclass and a binary classification problem, respectively. Experimental results show that our analytical framework outperforms state-of-the-art approaches with a high-level of classification accuracy.

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Zuo, Yilu. "A Single Spark Can Start a Prairie Fire." ICL Journal 11, no. 1 (May 1, 2017): 43–97. http://dx.doi.org/10.1515/icl-2017-0002.

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Abstract This article examines the human flesh search (Ren Rou Sou Suo), which may be the most salient and controversial phenomenon in the Chinese cyberspace. Unlike the conventional view that treats the human flesh search as illegal or trivial, this article argues that: first, the human flesh search may indeed have some ‘bad’ aspects (eg libel and privacy infringement), but the laws we have so far are sufficient in regulating these ‘bad’ aspects without scapegoating the entire human flesh search; second, and more importantly, every human flesh search is an online free speech mass movement. It gives millions of ordinary Chinese citizens a chance to express themselves in various forms and on wide-ranging topics, and allows them to create a new and more democratic culture. For the first time, activating the long dormant Article 47 of the Chinese Constitution and creating a culture ‘of the people, by the people, for the people’ may become possible in China.

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Suroso, Indreswari, and Hendriana Helda Pratama. "Analysis Mapping of Long Dry With Drone Type Dji Spark in Hargowilis, Kokap, Kulonprogo." Journal of Applied Geospatial Information 4, no. 1 (February 3, 2020): 259–64. http://dx.doi.org/10.30871/jagi.v4i1.1858.

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This research was conducted in the village of Hargowilis, Kokap District, Kulon Progo Regency with a temperature of 31oC, with a wind speed of 13 km/h, 55% air humidity, and a height of 35 m from the ground surface. This research was carried out on November 8, 2019 with hot weather conditions and wind speeds of around 13 km/hour. The purpose of this study is to map the drought area in Mount Menoreh Hargowilis Village, Kokap, Kulon Progo. The method used in this study are preparation for making a drone, survey of area Menoreh hills in Hargowilis, Kokap, Kulon Progo planning testing at certain altitude in the air; calibration drone; taking aerial photograph in area long dry and then analysis of data then mapping the area in Hargowilis, Kokap, Kulon Progo. Calibration drone DJI Spark is the way to calibrate the drone is automatically. When the drone is turned on it automatically calibrates the accelerometer; gyrometer; and GPS Drones use rotors for propulsion and control. Rotating rotors push air down, to be able to fly forward, it requires a push from the rotor. When the rotor presses air, air pushes the rotor. Lift force to control the force up and down. The faster the rotor rotates, the greater the lift. Multicopter has the advantage of being stable against wind speed. The battery capacity of drone is 2200 mAH with camera DJI Spark. Drone time used in this study ranges from 15 minutes at a speed of 30 mph. Aerial photo results show that the Hargowilis area, Kokap, Kulon Progo Regency experienced a drought so that the Menoreh Hills became a deforested forest. Keywords: Drone, Long Dry, Mapping, Photography, Kokap

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Goelian, N., P. Lalande, A. Bondiou-Clergerie, G. L. Bacchiega, A. Gazzani, and I. Gallimberti. "A simplified model for the simulation of positive-spark development in long air gaps." Journal of Physics D: Applied Physics 30, no. 17 (September 7, 1997): 2441–52. http://dx.doi.org/10.1088/0022-3727/30/17/010.

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49

Frey, W., M. Sack, R. Wuestner, and G. Mueller. "Gas-Insulated Self-Breakdown Spark Gaps: Aspects on Low-Scattering and Long-Lifetime Switching." Acta Physica Polonica A 115, no. 6 (June 2009): 1016–18. http://dx.doi.org/10.12693/aphyspola.115.1016.

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50

Guthrie, John T., Laurel W. Hoa, Allan Wigfield, Stephen M. Tonks, and Kathleen C. Perencevich. "From spark to fire: Can situational reading interest lead to long‐term reading motivation?" Reading Research and Instruction 45, no. 2 (December 2005): 91–117. http://dx.doi.org/10.1080/19388070609558444.

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