WorldWideScience

Sample records for repetition rate marx

  1. High-repetition-rate short-pulse gas discharge.

    Science.gov (United States)

    Tulip, J; Seguin, H; Mace, P N

    1979-09-01

    A high-average-power short-pulse gas discharge is described. This consists of a volume-preionized transverse discharge of the type used in gas lasers driven by a Blumlein energy storage circuit. The Blumlein circuit is fabricated from coaxial cable, is pulse-charged from a high-repetition-rate Marx-bank generator, and is switched by a high-repetition-rate segmented rail gap. The operation of this discharge under conditions typical of rare-gas halide lasers is described. A maximum of 900 pps was obtained, giving a power flow into the discharge of 30 kW.

  2. A Descriptive and Analytic Look at Marxs Own Explanations for the Falling Rate of Profit

    OpenAIRE

    Howard Petith

    2001-01-01

    Abstract: Marxs conclusions about the falling rate of profit have been analysed exhaustively. Usually this has been done by building models which broadly conform to Marxs views and then showing that his conclusions are either correct or, more frequently, that they can not be sustained. By contrast, this paper examines, both descriptively and analytically, Marxs arguments from the Hodgskin section of Theories of Surplus Value, the General Law section of the recently published Volume 33 of the ...

  3. A Descriptive and Analytic Look at Marx's Own Explanations for the Falling Rate of Profit

    OpenAIRE

    Petith, Howard

    2001-01-01

    Marx's conclusions about the falling rate of profit have been analysed exhaustively. Usually this has been done by building models which broadly conform to Marx's views and then showing that his conclusions are either correct or, more frequently, that they can not be sustained. By contrast, this paper examines, both descriptively and analytically, Marx's arguments from the Hodgskin section of Theories of Surplus Value, the General Law section of the recently published Volume 33 of the Collect...

  4. A Descriptive and Analytic Look at Marxs Own Explanations for the Falling Rate of Profit (Long Version)

    OpenAIRE

    Petith, Howard

    2001-01-01

    Abstract: Marxs conclusions about the falling rate of profit have been analysed exhaustively. Usually this has been done by building models which broadly conform to Marxs views and then showing that his conclusions are either correct or, more frequently, that they can not be sustained. By contrast, this paper examines, both descriptively and analytically, Marxs arguments from the Hodgskin section of Theories of Surplus Value, the General Law section of the recently published Volume 33 of the ...

  5. Conducted noise analysis and protection of 45 kJ/s, ±50 kV capacitor charging power supply when interfaced with repetitive Marx based pulse power system

    Science.gov (United States)

    Naresh, P.; Patel, Ankur; Sharma, Archana

    2015-09-01

    Pulse power systems with highly dynamic loads like klystron, backward wave oscillator (BWO), and magnetron generate highly dynamic noise. This noise leads to frequent failure of controlled switches in the inverter stage of charging power supply. Designing a reliable and compatible power supply for pulse power applications is always a tricky job when charging rate is in multiples of 10 kJ/s. A ±50 kV and 45 kJ/s capacitor charging power supply based on 4th order LCLC resonant topology has been developed for a 10 Hz repetitive Marx based system. Conditions for load independent constant current and zero current switching (ZCS) are derived mathematically. Noise generated at load end due to dynamic load is tackled effectively and reduction in magnitude noise voltage is achieved by providing shielding between primary and secondary of high voltage high frequency transformer and with LCLC low pass filter. Shielding scales down the ratio between coupling capacitance (Cc) and the collector-emitter capacitance of insulated gate bi-polar transistor switch, which in turn reduces the common mode noise voltage magnitude. The proposed 4th order LCLC resonant network acts as a low pass filter for differential mode noise in the reverse direction (from load to source). Power supply has been tested repeatedly with 5 Hz repetition rate with repetitive Marx based system connected with BWO load working fine without failure of single switch in the inverter stage.

  6. Impedance matching for repetitive high voltage all-solid-state Marx generator and excimer DBD UV sources

    Science.gov (United States)

    Wang, Yonggang; Tong, Liqing; Liu, Kefu

    2017-06-01

    The purpose of impedance matching for a Marx generator and DBD lamp is to limit the output current of the Marx generator, provide a large discharge current at ignition, and obtain fast voltage rising/falling edges and large overshoot. In this paper, different impedance matching circuits (series inductor, parallel capacitor, and series inductor combined with parallel capacitor) are analyzed. It demonstrates that a series inductor could limit the Marx current. However, the discharge current is also limited. A parallel capacitor could provide a large discharge current, but the Marx current is also enlarged. A series inductor combined with a parallel capacitor takes full advantage of the inductor and capacitor, and avoids their shortcomings. Therefore, it is a good solution. Experimental results match the theoretical analysis well and show that both the series inductor and parallel capacitor improve the performance of the system. However, the series inductor combined with the parallel capacitor has the best performance. Compared with driving the DBD lamp with a Marx generator directly, an increase of 97.3% in radiant power and an increase of 59.3% in system efficiency are achieved using this matching circuit.

  7. Karl Marx

    Directory of Open Access Journals (Sweden)

    Rosa Luxemburg

    2018-05-01

    Full Text Available Marx died on March 14, 1883. Exactly twenty years later, on March 14, 1903, Rosa Luxemburg’s reflections on Karl Marx were published in German in Vorwärts, the newspaper of the Social Democratic Party of Germany. tripleC publishes an English translation of Luxemburg’s essay on the occasion of Marx’s bicentenary. Christian Fuchs’ postface “Karl Marx and Rosa Luxemburg” asks the question of how we can make sense of Rosa Luxemburg’s reading of Marx in 2018. Source of the German original: Luxemburg, Rosa. 1903. Karl Marx. Vorwärts 62: 1-2.

  8. High repetition rate intense ion beam source

    International Nuclear Information System (INIS)

    Hammer, D.A.; Glidden, S.C.; Noonan, B.

    1992-01-01

    This final report describes a ≤ 150kV, 40kA, 100ns high repetition rate pulsed power system and intense ion beam source which is now in operation at Cornell University. Operation of the Magnetically-controlled Anode Plasma (MAP) ion diode at > 100Hz (burst mode for up to 10 pulse bursts) provides an initial look at repetition rate limitations of both the ion diode and beam diagnostics. The pulsed power systems are capable of ≥ 1kHz operation (up to 10 pulse bursts), but ion diode operation was limited to ∼100Hz because of diagnostic limitations. By varying MAP diode operating parameters, ion beams can be extracted at a few 10s of keV or at up to 150keV, the corresponding accelerating gap impedance ranging from about 1Ω to about 10Ω. The ability to make hundreds of test pulses per day at an average repetition rate of about 2 pulses per minute permits statistical analysis of diode operation as a function of various parameters. Most diode components have now survived more than 10 4 pulses, and the design and construction of the various pulsed power components of the MAP diode which have enabled us to reach this point are discussed. A high speed data acquisition system and companion analysis software capable of acquiring pulse data at 1ms intervals (in bursts of up to 10 pulses) and processing it in ≤ min is described

  9. Karl Marx

    OpenAIRE

    Rosa Luxemburg

    2018-01-01

    Marx died on March 14, 1883. Exactly twenty years later, on March 14, 1903, Rosa Luxemburg’s reflections on Karl Marx were published in German in Vorwärts, the newspaper of the Social Democratic Party of Germany. tripleC publishes an English translation of Luxemburg’s essay on the occasion of Marx’s bicentenary. Christian Fuchs’ postface “Karl Marx and Rosa Luxemburg” asks the question of how we can make sense of Rosa Luxemburg’s reading of Marx in 2018. Source of the German original: Luxembu...

  10. The ILC P2 Marx and Application of the Marx Topology to Future Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Kemp, M.A.; Benwell, A.; Burkhart, C.; Hugyik, J.; Larsen, R.; Macken, K.; MacNair, D.; Nguyen, M.; Olsen, J.; /SLAC

    2011-08-19

    The SLAC P2 Marx is under development as the linac klystron modulator for the ILC. This modulator builds upon the success of the P1 Marx, which is currently undergoing lifetime evaluation. While the SLAC P2 Marx's (henceforth, 'P2 Marx') target application is the ILC, characteristics of the Marx topology make it equally well-suited for operation at different parameter ranges; for example, increased pulse repetition frequency, increased output current, longer pulse width, etc. Marx parameters such as the number of cells, cell capacitance, and component selection can be optimized for the application. This paper provides an overview of the P2 Marx development. In addition, the scalability of the Marx topology to other long-pulse parameter ranges is discussed.

  11. Photocathodes for High Repetition Rate Light Sources

    Energy Technology Data Exchange (ETDEWEB)

    Ben-Zvi, Ilan [Stony Brook Univ., NY (United States). Dept. of Physics and Astronomy. Center for Accelerator Science and Education

    2014-04-20

    This proposal brought together teams at Brookhaven National Laboratory (BNL), Lawrence Berkeley National Laboratory (LBNL) and Stony Brook University (SBU) to study photocathodes for high repetition rate light sources such as Free Electron Lasers (FEL) and Energy Recovery Linacs (ERL). Below details the Principal Investigators and contact information. Each PI submits separately for a budget through his corresponding institute. The work done under this grant comprises a comprehensive program on critical aspects of the production of the electron beams needed for future user facilities. Our program pioneered in situ and in operando diagnostics for alkali antimonide growth. The focus is on development of photocathodes for high repetition rate Free Electron Lasers (FELs) and Energy Recovery Linacs (ERLs), including testing SRF photoguns, both normal-­conducting and superconducting. Teams from BNL, LBNL and Stony Brook University (SBU) led this research, and coordinated their work over a range of topics. The work leveraged a robust infrastructure of existing facilities and the support was used for carrying out the research at these facilities. The program concentrated in three areas: a) Physics and chemistry of alkali-­antimonide cathodes (BNL – LBNL) b) Development and testing of a diamond amplifier for photocathodes (SBU -­ BNL) c) Tests of both cathodes in superconducting RF photoguns (SBU) and copper RF photoguns (LBNL) Our work made extensive use of synchrotron radiation materials science techniques, such as powder-­ and single-­crystal diffraction, x-­ray fluorescence, EXAFS and variable energy XPS. BNL and LBNL have many complementary facilities at the two light sources associated with these laboratories (NSLS and ALS, respectively); use of these will be a major thrust of our program and bring our understanding of these complex materials to a new level. In addition, CHESS at Cornell will be used to continue seamlessly throughout the NSLS dark period and

  12. Repeating Marx

    DEFF Research Database (Denmark)

    Fuchs, Christian; Monticelli, Lara

    2018-01-01

    This introduction sets out the context of the special issue “Karl Marx @ 200: Debating Capitalism & Perspectives for the Future of Radical Theory”, which was published on the occasion of Marx’s bicentenary on 5 May 2018. First, we give a brief overview of contemporary capitalism’s development...... and its crises. Second, we argue that it is important to repeat Marx today. Third, we reflect on lessons learned from 200 years of struggles for alternatives to capitalism. Fourth, we give an overview of the contributions in this special issue. Taken together, the contributions in this special issue show...... that Marx’s theory and politics remain key inspirations for understanding exploitation and domination in 21st-century society and for struggles that aim to overcome these phenomena and establishing a just and fair society. We need to repeat Marx today....

  13. Properties of water surface discharge at different pulse repetition rates

    International Nuclear Information System (INIS)

    Ruma,; Yoshihara, K.; Hosseini, S. H. R.; Sakugawa, T.; Akiyama, H.; Akiyama, M.; Lukeš, P.

    2014-01-01

    The properties of water surface discharge plasma for variety of pulse repetition rates are investigated. A magnetic pulse compression (MPC) pulsed power modulator able to deliver pulse repetition rates up to 1000 Hz, with 0.5 J per pulse energy output at 25 kV, was used as the pulsed power source. Positive pulse with a point-to-plane electrode configuration was used for the experiments. The concentration and production yield of hydrogen peroxide (H 2 O 2 ) were quantitatively measured and orange II organic dye was treated, to evaluate the chemical properties of the discharge reactor. Experimental results show that the physical and chemical properties of water surface discharge are not influenced by pulse repetition rate, very different from those observed for under water discharge. The production yield of H 2 O 2 and degradation rate per pulse of the dye did not significantly vary at different pulse repetition rates under a constant discharge mode on water surface. In addition, the solution temperature, pH, and conductivity for both water surface and underwater discharge reactors were measured to compare their plasma properties for different pulse repetition rates. The results confirm that surface discharge can be employed at high pulse repetition rates as a reliable and advantageous method for industrial and environmental decontamination applications.

  14. Temporal dynamics of high repetition rate pulsed single longitudinal ...

    Indian Academy of Sciences (India)

    ing (GIG) cavity, single-mode dye laser pumped by high repetition rate ... in a high loss cavity, a detailed theoretical study and optimization of cavity ..... rate for high conversion efficiency and longer pulse width of the single-mode dye laser.

  15. Iodine laser of high efficiency and fast repetition rate

    Energy Technology Data Exchange (ETDEWEB)

    Hohla, K; Witte, K J

    1976-07-01

    The scaling laws of an iodine laser of high efficiency and fast repetition rate are reported. The laser is pumped with a new kind of low pressure Hg-UV-lamps which convert 32% of the electrical input in UV-light in the absorption band of the iodine laser and which can be fired up to 100 Hz. Details of a 10 kJ/1 nsec system as dimensions, energy density, repetition rate, flow velocity, gas composition and gas pressure and the overall efficiency are given which is expected to be about 2%.

  16. High repetition rate burst-mode spark gap

    International Nuclear Information System (INIS)

    Faltens, A.; Reginato, L.; Hester, R.; Chesterman, A.; Cook, E.; Yokota, T.; Dexter, W.

    1978-01-01

    Results are presented on the design and testing of a pressurized gas blown spark gap switch capable of high repetition rates in a burst mode of operation. The switch parameters which have been achieved are as follows: 220-kV, 42-kA, a five pulse burst at 1-kHz, 12-ns risetime, 2-ns jitter at a pulse width of 50-ns

  17. High repetition rate ultrashort laser cuts a path through fog

    Science.gov (United States)

    de la Cruz, Lorena; Schubert, Elise; Mongin, Denis; Klingebiel, Sandro; Schultze, Marcel; Metzger, Thomas; Michel, Knut; Kasparian, Jérôme; Wolf, Jean-Pierre

    2016-12-01

    We experimentally demonstrate that the transmission of a 1030 nm, 1.3 ps laser beam of 100 mJ energy through fog increases when its repetition rate increases to the kHz range. Due to the efficient energy deposition by the laser filaments in the air, a shockwave ejects the fog droplets from a substantial volume of the beam, at a moderate energy cost. This process opens prospects for applications requiring the transmission of laser beams through fogs and clouds.

  18. High-repetition-rate hydrogen chamber: Preliminary studies

    International Nuclear Information System (INIS)

    1967-01-01

    This report is a conclusion to the tests realised with an experimental bubbles chamber in view to study the possibilities to increase the repetition rate. The more important parameters (the evolution of the bubbles, the expansion system) are considered in a theoretical way. Then the hardware is described. To end, experimental results are compared with the first evaluations. The calculations and the experimentation are against an oscillation system for the expansion. A system with a locking is to he considered. (authors) [fr

  19. MARX EMBRYOLOGY OF SOCIETY

    NARCIS (Netherlands)

    WOUTERS, A

    This article presents a new interpretation of Marx's dialectical method. Marx conceived dialectics as a method for constructing a model of society. The way this model is developed is analogous to the way organisms develop according to the German embryologist Karl Ernst von Baer, and, indeed, Marx's

  20. Closed cycle high-repetition-rate pulsed HF laser

    Science.gov (United States)

    Harris, Michael R.; Morris, A. V.; Gorton, Eric K.

    1997-04-01

    The design and performance of a closed cycle high repetition rate HF laser is described. A short pulse, glow discharge is formed in a 10 SF6:1 H2 gas mixture at a total pressure of approximately 110 torr within a 15 by 0.5 by 0.5 cm3 volume. Transverse, recirculated gas flow adequate to enable repetitive operation up to 3 kHz is imposed by a centrifugal fan. The fan also forces the gas through a scrubber cell to eliminate ground state HF from the gas stream. An automated gas make-up system replenishes spent gas removed by the scrubber. Typical mean laser output powers up to 3 W can be maintained for extended periods of operation.

  1. Influence of Music Style and Rate on Repetitive Finger Tapping.

    Science.gov (United States)

    Stegemöller, Elizabeth L; Tatz, Joshua R; Warnecke, Alison; Hibbing, Paul; Bates, Brandon; Zaman, Andrew

    2018-03-09

    Auditory cues, including music, are commonly used in the treatment of persons with Parkinson's disease. Yet, how music style and movement rate modulate movement performance in persons with Parkinson's disease have been neglected and remain limited in healthy young populations. The purpose of this study was to determine how music style and movement rate influence movement performance in healthy young adults. Healthy participants were asked to perform repetitive finger movements at two pacing rates (70 and 140 beats per minute) for the following conditions: (a) a tone only, (b) activating music, and (c) relaxing music. Electromyography, movement kinematics, and variability were collected. Results revealed that the provision of music, regardless of style, reduced amplitude variability at both pacing rates. Intermovement interval was longer, and acceleration variability was reduced during both music conditions at the lower pacing rate only. These results may prove beneficial for designing therapeutic interventions for persons with Parkinson's disease.

  2. Environmentally stable picosecond Yb fiber laser with low repetition rate

    Science.gov (United States)

    Baumgartl, M.; Abreu-Afonso, J.; Díez, A.; Rothhardt, M.; Limpert, J.; Tünnermann, A.

    2013-04-01

    A SESAM-mode-locked, all-polarization-maintaining Ytterbium fiber laser producing picosecond pulses with narrow spectral bandwidth is presented. A simple linear all-fiber cavity without dispersion compensation is realized using a uniform fiber Bragg grating (FBG). Different cavity lengths are investigated and repetition rates down to 0.7 MHz are obtained. Bandwidth and pulse duration of the output pulses are mainly determined by the choice of FBG. Pulses between 30 and 200 ps are generated employing different FBGs with bandwidths between 17 and 96 pm. The experimental results are in good agreement with numerical simulations. The laser holds great potential for simple amplification setups without pulse picking.

  3. Marxismen efter Marx

    DEFF Research Database (Denmark)

    Karl Marx har fået momentum oven på finanskrisen som kritiker af kapitalismen. Men i Marx og i den marxistiske tradition findes en en teoretisk dybde og analysekraft, der rækker langt ud over den nuværende krise. Karl Marx har både som medspiller og modspiller været inspirationskilde for en lang ...

  4. Engineering high reliability, low-jitter Marx generators

    International Nuclear Information System (INIS)

    Schneider, L.X.; Lockwood, G.J.

    1985-01-01

    Multimodule pulsed power accelerators typically require high module reliability and nanosecond regime simultaneity between modules. Energy storage using bipolar Marx generators can meet these requirements. Experience gained from computer simulations and the development of the DEMON II Marx generator has led to a fundamental understanding of the operation of these multistage devices. As a result of this research, significant improvements in erection time jitter and reliability have been realized in multistage, bipolar Marx generators. Erection time jitter has been measured as low as 2.5 nanoseconds for the 3.2MV, 16-stage PBFA I Marx and 3.5 nanoseconds for the 6.0MV, 30-stage PBFA II (DEMON II) Marx, while maintaining exceptionally low prefire rates. Performance data are presented from the DEMON II Marx research program, as well as discussions on the use of computer simulations in designing low-jitter Marx generators

  5. High repetition rate driver circuit for modulation of injection lasers

    International Nuclear Information System (INIS)

    Dornan, B.R.; Goel, J.; Wolkstein, H.J.

    1981-01-01

    An injection laser modulator comprises a self-biased field effect transistor (FET) and an injection laser to provide a quiescent state during which lasing of the injection laser occurs in response to a high repetition rate signal of pulse coded modulation (pcm). The modulator is d.c. coupled to an input pulse source of pcm rendering it compatible with an input pulse referenced to ground and not being subject to voltage level shifting of the input pulse. The modulator circuit in its preferred and alternate embodiments provides various arrangements for high impedance input and low impedance output matching. In addition, means are provided for adjusting the bias of the FET as well as the bias of the injection laser

  6. A high repetition rate XUV seeding source for FLASH2

    International Nuclear Information System (INIS)

    Willner, Arik

    2012-05-01

    Improved performance of free-electron laser (FEL) light sources in terms of timing stability, pulse shape and spectral properties of the amplified FEL pulses is of interest in material science, the fields of ultrafast dynamics, biology, chemistry and even special branches in industry. A promising scheme for such an improvement is direct seeding with high harmonic generation (HHG) in a noble gas target. A free-electron laser seeded by an external extreme ultraviolet (XUV) source is planned for FLASH2 at DESY in Hamburg. The requirements for the XUV/soft X-ray source can be summarized as follows: A repetition rate of at least 100 kHz in a 10 Hz burst is needed at variable wavelengths from 10 to 40 nm and pulse energies of several nJ within a single laser harmonic. This application requires a laser amplifier system with exceptional parameters, mJ-level pulse energy, 10-15 fs pulse duration at 100 kHz (1 MHz) burst repetition rate. A new optical parametric chirped-pulse amplification (OPCPA) system is under development in order to meet these requirements, and very promising results have been achieved in the last three years. In parallel to this development, a new HHG concept is necessary to sustain high average power of the driving laser system and to generate harmonics with high conversion efficiencies. Currently, the highest conversion efficiency with HHG has been demonstrated using gas-filled capillary targets. For our application, only a free-jet target can be used for HHG, in order to overcome damage threshold limitations of HHG target optics at a high repetition rate. A novel dual-gas multijet gas target has been developed and first experiments show remarkable control of the degree of phase matching forming the basis for improved control of the harmonic photon flux and the XUV pulse characteristics. The basic idea behind the dual-gas concept is the insertion of matching zones in between multiple HHG sources. These matching sections are filled with hydrogen which

  7. A high repetition rate XUV seeding source for FLASH2

    Energy Technology Data Exchange (ETDEWEB)

    Willner, Arik

    2012-05-15

    Improved performance of free-electron laser (FEL) light sources in terms of timing stability, pulse shape and spectral properties of the amplified FEL pulses is of interest in material science, the fields of ultrafast dynamics, biology, chemistry and even special branches in industry. A promising scheme for such an improvement is direct seeding with high harmonic generation (HHG) in a noble gas target. A free-electron laser seeded by an external extreme ultraviolet (XUV) source is planned for FLASH2 at DESY in Hamburg. The requirements for the XUV/soft X-ray source can be summarized as follows: A repetition rate of at least 100 kHz in a 10 Hz burst is needed at variable wavelengths from 10 to 40 nm and pulse energies of several nJ within a single laser harmonic. This application requires a laser amplifier system with exceptional parameters, mJ-level pulse energy, 10-15 fs pulse duration at 100 kHz (1 MHz) burst repetition rate. A new optical parametric chirped-pulse amplification (OPCPA) system is under development in order to meet these requirements, and very promising results have been achieved in the last three years. In parallel to this development, a new HHG concept is necessary to sustain high average power of the driving laser system and to generate harmonics with high conversion efficiencies. Currently, the highest conversion efficiency with HHG has been demonstrated using gas-filled capillary targets. For our application, only a free-jet target can be used for HHG, in order to overcome damage threshold limitations of HHG target optics at a high repetition rate. A novel dual-gas multijet gas target has been developed and first experiments show remarkable control of the degree of phase matching forming the basis for improved control of the harmonic photon flux and the XUV pulse characteristics. The basic idea behind the dual-gas concept is the insertion of matching zones in between multiple HHG sources. These matching sections are filled with hydrogen which

  8. Repetition rates in heavy ion beam driven fusion reactors

    Science.gov (United States)

    Peterson, Robert R.

    1986-01-01

    The limits on the cavity gas density required for beam propagation and condensation times for material vaporized by target explosions can determine the maximum repetition rate of Heavy Ion Beam (HIB) driven fusion reactors. If the ions are ballistically focused onto the target, the cavity gas must have a density below roughly 10-4 torr (3×1012 cm-3) at the time of propagation; other propagation schemes may allow densities as high as 1 torr or more. In some reactor designs, several kilograms of material may be vaporized off of the target chamber walls by the target generated x-rays, raising the average density in the cavity to 100 tor or more. A one-dimensional combined radiation hydrodynamics and vaporization and condensation computer code has been used to simulate the behavior of the vaporized material in the target chambers of HIB fusion reactors.

  9. Repetition rates in heavy ion beam driven fusion reactors

    International Nuclear Information System (INIS)

    Peterson, R.R.

    1986-01-01

    The limits on the cavity gas density required for beam propagation and condensation times for material vaporized by target explosions can determine the maximum repetition rate of Heavy Ion Beam (HIB) driven fusion reactors. If the ions are ballistically focused onto the target, the cavity gas must have a density below roughly 10 -4 torr (3 x 10 12 cm -3 ) at the time of propagation; other propagation schemes may allow densities as high as 1 torr or more. In some reactor designs, several kilograms of material may be vaporized off of the target chamber walls by the target generated x-rays, raising the average density in the cavity to 100 tor or more. A one-dimensional combined radiation hydrodynamics and vaporization and condensation computer code has been used to simulate the behavior of the vaporized material in the target chambers of HIB fusion reactors

  10. Marx on Money

    NARCIS (Netherlands)

    Visser, H.

    1977-01-01

    Marx's contributions to monetary theory have generally been somewhat neglected and, if they were paid any attention at all, they have been rather severely criticized, even by Marxist economists. It should be emphasized, however, that they are central to Marx's view of the functioning of commodity

  11. Nanosecond pulsed power generator for a voltage amplitude up to 300 kV and a repetition rate up to 16 Hz for fine disintegration of quartz

    Energy Technology Data Exchange (ETDEWEB)

    Krastelev, E. G., E-mail: ekrastelev@yandex.ru; Sedin, A. A.; Tugushev, V. I. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

    2015-12-15

    A generator of high-power high-voltage nanosecond pulses is intended for electrical discharge disintegration of mineral quartz and other nonconducting minerals. It includes a 320 kV Marx pulsed voltage generator, a high-voltage glycerin-insulated coaxial peaking capacitor, and an output gas spark switch followed by a load, an electric discharge disintegration chamber. The main parameters of the generator are as follows: a voltage pulse amplitude of up to 300 kV, an output impedance of ≈10 Ω, a discharge current amplitude of up to 25 kA for a half-period of 80–90 ns, and a pulse repetition rate of up to 16 Hz.

  12. Nanosecond pulsed power generator for a voltage amplitude up to 300 kV and a repetition rate up to 16 Hz for fine disintegration of quartz

    International Nuclear Information System (INIS)

    Krastelev, E. G.; Sedin, A. A.; Tugushev, V. I.

    2015-01-01

    A generator of high-power high-voltage nanosecond pulses is intended for electrical discharge disintegration of mineral quartz and other nonconducting minerals. It includes a 320 kV Marx pulsed voltage generator, a high-voltage glycerin-insulated coaxial peaking capacitor, and an output gas spark switch followed by a load, an electric discharge disintegration chamber. The main parameters of the generator are as follows: a voltage pulse amplitude of up to 300 kV, an output impedance of ≈10 Ω, a discharge current amplitude of up to 25 kA for a half-period of 80–90 ns, and a pulse repetition rate of up to 16 Hz

  13. Pulse repetition rate multiplication by Talbot effect in a coaxial fiber

    Science.gov (United States)

    Dhingra, Nikhil; Saxena, Geetika Jain; Anand, Jyoti; Sharma, Enakshi K.

    2018-03-01

    We use a coaxial fiber, which is a cylindrical coupled waveguide structure consisting of two concentric cores, the inner rod and an outer ring core as a first order dispersive media to achieve temporal Talbot effect for pulse repetition rate multiplication (PRRM) in high bit rate optical fiber communication. It is observed that for an input Gaussian pulse train with pulse width, 2τ0=1ps at a repetition rate of 40 Gbps (repetition period, T=25ps), an output repetition rate of 640 Gbps can be achieved without significant distortion at a length of 40.92 m.

  14. Pulsed Corona Discharge Generated By Marx Generator

    Science.gov (United States)

    Sretenovic, G. B.; Obradovic, B. M.; Kovacevic, V. V.; Kuraica, M. M.; Puric J.

    2010-07-01

    The pulsed plasma has a significant role in new environmental protection technologies. As a part of a pulsed corona system for pollution control applications, Marx type repetitive pulse generator was constructed and tested in arrangement with wire-plate corona reactor. We performed electrical measurements, and obtained voltage and current signals, and also power and energy delivered per pulse. Ozone formation by streamer plasma in air was chosen to monitor chemical activity of the pulsed corona discharge.

  15. A note on Marx

    OpenAIRE

    Olesen, Finn; Jensen, Frank

    2001-01-01

    Throughout all his life Karl Marx wrote angrily about capitalism. By use of a dialectic approach he was convinced that the working class had to unite and make a social revolution and thereby free them selves from exploitation. Marx himself was in many ways a dialectic person as we try to show in the note. So in some sense he became one with his scientific methodology.

  16. Lifetime Tests on a High Ohms/Square Metalized High Crystalline Polypropylene Film Capacitor with Application to a Marx Modulator

    International Nuclear Information System (INIS)

    Kemp, Mark A.; Burkhart, Craig; Tang, Tao

    2010-01-01

    This paper presents accelerated lifetime tests on a polypropylene film capacitor. Experimental parameters (20% droop, 5 Hz repetition rate) simulate anticipated operating conditions encountered in the SLAC P2 Marx. Elevated film electric field stress is utilized as the acceleration parameter. Results indicate that, for the particular film of interest, a film stress of ∼290 V/μm corresponds to a 10 5 hour lifetime. In addition, the voltage scaling exponent for this film is 13.1.

  17. Heavy-duty high-repetition-rate generators

    NARCIS (Netherlands)

    Heesch, van E.J.M.; Yan, K.; Pemen, A.J.M.

    2002-01-01

    We present our results on high-power repetitive pulse sources for continuous operation. Two 1-10-kW systems using advanced spark gap technology and a transmission line transformer have been tested for several hundred hours at a 60-MW pulse level. High reliability and above 90% overall efficiency are

  18. Generation of µW level plateau harmonics at high repetition rate.

    Science.gov (United States)

    Hädrich, S; Krebs, M; Rothhardt, J; Carstens, H; Demmler, S; Limpert, J; Tünnermann, A

    2011-09-26

    The process of high harmonic generation allows for coherent transfer of infrared laser light to the extreme ultraviolet spectral range opening a variety of applications. The low conversion efficiency of this process calls for optimization or higher repetition rate intense ultrashort pulse lasers. Here we present state-of-the-art fiber laser systems for the generation of high harmonics up to 1 MHz repetition rate. We perform measurements of the average power with a calibrated spectrometer and achieved µW harmonics between 45 nm and 61 nm (H23-H17) at a repetition rate of 50 kHz. Additionally, we show the potential for few-cycle pulses at high average power and repetition rate that may enable water-window harmonics at unprecedented repetition rate. © 2011 Optical Society of America

  19. Contributions to a Marxist Critical Pedagogy: Revisiting Marx's Humanism

    Science.gov (United States)

    Malott, Curry

    2014-01-01

    In this essay Malott makes a case for a Marxist-informed critical pedagogy situating Marx's approach to Hegelian dialectics at the center. After reviewing Marx's critique of Hegel in his 1844 manuscripts, Malott outlines Marx's shifting conception of the falling rate of profit reflecting his developing understanding of what the…

  20. Karl Marx 1864

    DEFF Research Database (Denmark)

    Czeskleba-Dupont, Rolf

    2015-01-01

    (Inaugural-)adressen til den 1.Internationale Arbejderassociation som Marx formulerede efter dennes grundlæggelse i september 1864 undersøges i en kritisk diskursanalyse der omfatter det engelske (!) original, efterfølgende tyske oversættelser samt den danske oversættelse fra 1971 (MEUS). Marx......' egne tekster sammenlignes med hinanden og med andres oversættelser. Marx' mindre kendte, tyske version som 'Manifest an die arbeitende Klasse Europas' præciserer hans karakteristika for hvad han kalder 'Arbejderklassens politiske økonomi'. Det sker på en måde, der ikke er identisk med den...... engelsksprogede eller for den sags skyld den danske version. På denne måde findes der en mere 'profetisk' version side om side med en version, der fremhæver en tilgang svarende til forsigtigheds-princippet. Udover politisk økonomi anvendte Marx det også på udenrigspolitikken. I dag rammer det den miljøpolitiske...

  1. Karl Marx' glemte arvtager

    DEFF Research Database (Denmark)

    Jakobsen, Uffe

    1988-01-01

    For 50 år siden hyldede avisen 'Social-Demokraten' Karl Kautsky (1854-1938) som "den største Tænker inden for den socialdemokratiske Arbejderbevægelse". I perioden fra Friedrich Engels' død i 1895 til 1. Verdenskrigs udbrud i 1914 blev Karl Kautsky alment anset som Karl Marx's arvtager inden...

  2. Keynes, Hobson, Marx

    Directory of Open Access Journals (Sweden)

    Robert Slidelsky

    2013-03-01

    Full Text Available The work compares the relative strenghts, in understanding the current crisis, of the Keynesian tradition with those of two non-Keynesian traditions: those which emphasise income inequality and those which emphasise power. In other words, Hobson and Marx. Text of a speech given at the Post-Keynesian conference ‘Reclaiming the Keynesian Revolution’ in Kansas City.

  3. Reduction of the beam pulse repetition rate of the Hamburg Isochronous Cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Krause, H; Langkau, R; Schirm, N [Hamburg Univ. (F.R. Germany). 1. Inst. fuer Experimentalphysik

    1976-04-01

    A system for the reduction of the beam pulse repetition rate of the energy-variable Hamburg Isochronous Cyclotron comprising beam pulse supression in the cyclotron center and in the external beam is described.

  4. On the mechanisms governing the repetition rate of mode-locked semiconductor lasers

    DEFF Research Database (Denmark)

    Mulet, Josep; Mørk, Jesper

    2004-01-01

    We investigate the mechanisms influencing the synchronization locking range of mode-locked lasers. We find that changes in repetition rates can be accomodated through a joint interplay of dispersion and pulse shaping effects....

  5. A copper bromide vapour laser with a high pulse repetition rate

    International Nuclear Information System (INIS)

    Shiyanov, D V; Evtushenko, Gennadii S; Sukhanov, V B; Fedorov, V F

    2002-01-01

    The results of an experimental study of a copper bromide vapour laser with a discharge-channel diameter above 2.5 cm and a high pump-pulse repetition rate are presented. A TGU1-1000/25 high-power tacitron used as a switch made it possible to obtain for the first time a fairly high output radiation power for pump-pulse repetition rates exceeding 200 kHz. At a maximum pump-pulse repetition rate of 250 kHz achieved in a laser tube 2.6 cm in diameter and 76 cm long, the output power was 1.5 W. The output powers of 3 and 10.5 W were reached for pump-pulse repetition rates of 200 and 100 kHz, respectively. These characteristics were obtained without circulating a buffer gas and (or) low-concentration active impurities through the active volume. (active media. lasers)

  6. Femtosecond Ti:sapphire cryogenic amplifier with high gain and MHz repetition rate

    DEFF Research Database (Denmark)

    Dantan, Aurelien Romain; Laurat, Julien; Ourjoumtsev, Alexei

    2007-01-01

    We demonstrate high gain amplification of 160-femtosecond pulses in a compact double-pass cryogenic Ti:sapphire amplifier. The setup involves a negative GVD mirrors recompression stage, and operates with a repetition rate between 0.2 and 4 MHz with a continuous pump laser. Amplification factors a...... as high as 17 and 320 nJ Fourier-limited pulses are obtained at a 800 kHz repetition rate....

  7. Scaling of black silicon processing time by high repetition rate femtosecond lasers

    Directory of Open Access Journals (Sweden)

    Nava Giorgio

    2013-11-01

    Full Text Available Surface texturing of silicon substrates is performed by femtosecond laser irradiation at high repetition rates. Various fabrication parameters are optimized in order to achieve very high absorptance in the visible region from the micro-structured silicon wafer as compared to the unstructured one. A 70-fold reduction of the processing time is demonstrated by increasing the laser repetition rate from 1 kHz to 200 kHz. Further scaling up to 1 MHz can be foreseen.

  8. Foucault reads Marx. Marx reads Foucault.

    Directory of Open Access Journals (Sweden)

    Michal Kozłowski

    2011-01-01

    Full Text Available Important element which funds the base of Foucaultian social science is his thesis on the locality of power, on its material and corporeal characteristics. We are discussing here his very relationship with capitalism, and, indirectly, with Marx himself. Foucault claims, that power has no center and it is not commanded from any kind of headquarter. That has enormous epistemic, as well as political consequences. Foucault stays suspicious to systemic thinking, if we consider system following Hegel, that is, both a point of departure and a point of arrival of research. His controversy with Marxism has many levels, but one of the most important refers to the issue of power: system of power does not have its center, which according to Marxists lays in the political economy, and it has no dualistic character, that is structure and superstructure.

  9. High-repetition-rate hydrogen chamber: Preliminary studies; Chambre a hydrogene a haut taux de repetition: Etudes preliminaires

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1967-01-01

    This report is a conclusion to the tests realised with an experimental bubbles chamber in view to study the possibilities to increase the repetition rate. The more important parameters (the evolution of the bubbles, the expansion system) are considered in a theoretical way. Then the hardware is described. To end, experimental results are compared with the first evaluations. The calculations and the experimentation are against an oscillation system for the expansion. A system with a locking is to he considered. (authors) [French] Ce rapport est une conclusion aux essais realises avec une chambre a bulles experimentale en vue d'etudier les possibilites d'accroitre les taux de repetition. Les parametres les plus importants (evolution des bulles, mecanique de la detente) sont etudies par voie theorique. Puis l'appareillage est decrit. Enfin, les resultats experimentaux sont compares aux evaluations donnees au debut. Ces calculs et cette experimentation ne sont pas en faveur d'un systeme oscillant pour la detente et il faut envisager un systeme avec verrouillage. (auteurs)

  10. O "Outubro" de Marx

    Directory of Open Access Journals (Sweden)

    João Antonio de Paula

    2009-06-01

    Full Text Available This article examines a decisive moment in the critique of political economy developed by Marx,  which is the somewhat abrupt choice of theconcept of merchandise as a starting point for the book Contribution to a Critique of Political Economy, of 1859. It is known that up until a few months before he delivered his text to the publisher, Marx thought about beginning his book with a chapter on value, similar to what Ricardo had done in his Principles. The theoretical and methodological implications of this choice are well known today. This text seeks to situate the circumstances and meanings of the concept of merchandise in Marx’s work.

  11. Marx, Engels and Ecology

    Directory of Open Access Journals (Sweden)

    Michael Löwy

    2017-11-01

    Full Text Available This is a brief survey of Marx and Engels’ views on ecology, from the viewpoint of their relevance for 21th Century ecosocialism. While there are some serious limitations in the way both consider the “development of productive forces”, there are powerfull insights in their discussion of the destructive consequences of capitalist expansion for the environment - an expansion that generates a disastrous metabolic rift in the exchanges between human societies and nature. Some ecological Marxists distinguish between “first stage ecosocialists” - who believe that Marx analyses on ecological issues are too incomplete and dated to be of real relevance today - and “second stage ecosocialists” that emphasize the contemporary methodological significance of Marx’s ecological critique of capitalism. This paper tries to argue for a third position (which probably could be accepted by several people of the two groups above: Marx and Engels discussion on ecological issues is incomplete and dated, but inspite these shortcomings, it has real relevance and methodological significance today.

  12. Marx and Feminism

    Directory of Open Access Journals (Sweden)

    Silvia Federici

    2018-05-01

    Full Text Available This contribution focuses on aspects of feminism and gender in Marx’s theory. Marx’s methodology has given us the tools and the categories enabling us to think together gender and class, feminism and anti-capitalism. However, his contribution is an indirect one because Marx never developed a theory of gender. It is important to include the role of reproductive labour, slave labour, migrant labour, labour in the Global South and the unemployed in the critical analysis of capitalism and its division of labour. Reproductive labour is the largest activity on this planet and a major ground of divisions within the working class. A different Marx was discovered in the 1970s by feminists who turned to his work searching for a theory capable of explaining the roots of women’s oppression from a class viewpoint. The result has been a theoretical revolution that has changed both Marxism and Feminism. What was redefined by the realisation of the centrality of women’s unpaid labour in the home to the production of the work-force was not domestic work alone but the nature of capitalism itself and the struggle against it. This meant to turn Marx upside down to make his work important for feminism.

  13. Effect of Bench Press Load Knowledge on Repetitions, Rating of Perceived Exertion, and Attentional Focus.

    Science.gov (United States)

    Beaudoin, Christina M; Cox, Zachary; Dundore, Tyler; Thomas, Tayler; Kim, Johnathon; Pillivant, Daniel

    2018-02-01

    Beaudoin, CM, Cox, Z, Dundore, T, Thomas, T, Kim, J, and Pillivant, D. Effect of bench press load knowledge on repetitions, rating of perceived exertion, and attentional focus. J Strength Cond Res 32(2): 514-519, 2018-Few studies have examined the role of the teleoanticipation during resistance training. The purpose of this study was to examine the effect of bench press (BP) load knowledge on repetitions completed, ratings of perceived exertion (RPEs), and attentional focus (% associative). Thirty-six recreationally active resistance-trained men (n = 25) and women (n = 11) participated in this study (age = 20.97 ± 1.87 years; ht = 174.12 ± 9.41 cm; and mass = 80.14 ± 14.03 kg). All subjects completed 3 testing sessions: (a) 1 repetition maximum (1RM) BP determination; (b) submaximal BP repetitions to fatigue known load (KL); and (c) submaximal BP repetitions to fatigue unknown load (UL). Known load and UL sessions were randomized and counterbalanced and both completed at 70% 1RM. An estimated weight ratio was computed using the subject's estimate of the UL weight relative to the KL weight. An independent samples t-test revealed no significant testing order difference for the estimated weight ratio. Two-way repeated-measures analysis of variances revealed no significant differences in the number of repetitions (p = 0.63), RPE (p = 0.18), or attentional focus (% associative) (p = 0.93) between the KL and UL conditions. Pearson correlations found a moderate positive association between KL repetitions completed and % associative focus when the UL was completed before the KL. Load knowledge did not influence the number of repetitions, RPE, or attentional focus while completing the BP. Further research examining the use of pacing strategies, RPE, and attentional focus during KL and UL conditions are warranted.

  14. Patterning crystalline indium tin oxide by high repetition rate femtosecond laser-induced crystallization

    International Nuclear Information System (INIS)

    Cheng, Chung-Wei; Lin, Cen-Ying; Shen, Wei-Chih; Lee, Yi-Ju; Chen, Jenq-Shyong

    2010-01-01

    A method is proposed for patterning crystalline indium tin oxide (c-ITO) patterns on amorphous ITO (a-ITO) thin films by femtosecond laser irradiation at 80 MHz repetition rate followed by chemical etching. In the proposed approach, the a-ITO film is transformed into a c-ITO film over a predetermined area via the heat accumulation energy supplied by the high repetition rate laser beam, and the unirradiated a-ITO film is then removed using an acidic etchant solution. The fabricated c-ITO patterns are observed using scanning electron microscopy and cross-sectional transmission electron microscopy. The crystalline, optical, electrical properties were measured by X-ray diffraction, spectrophotometer, and four point probe station, respectively. The experimental results show that a high repetition rate reduces thermal shock and yields a corresponding improvement in the surface properties of the c-ITO patterns.

  15. A high-repetition rate LWFA for studies of laser propagation and electron generation

    Science.gov (United States)

    He, Zhaohan; Easter, James; Hou, Bixue; Krushelnick, Karl; Nees, John; Thomas, Alec

    2010-11-01

    Advances in ultrafast optics today have enabled laser systems to deliver ever shorter and more intense pulses. When focused, such laser pulses can easily exceed relativistic intensities where the wakefield created by the strong laser electric field can be used to accelerate electrons. Laser wakefield acceleration of electrons holds promise for future compact electron accelerators or drivers of other radiation sources in many scientific, medical and engineering applications. We present experimental studies of laser wakefield acceleration using the λ-cubed laser at the University of Michigan -- a table-top high-power laser system operating at 500 Hz repetition rate. The high repetition rate allows statistical studies of laser propagation and electron acceleration which are not accessible with typical sub-0.1 Hz repetition rate systems. In addition, we compare the experiments with particle-in-cell simulations using the code OSIRIS.

  16. Design of a low emittance and high repetition rate S-band photoinjector

    Science.gov (United States)

    Han, Jang-Hui

    2014-09-01

    As an electron beam injector of X-ray free-electron lasers (FELs), photoinjectors have been developed for the past few decades. Such an injector starting with a photocathode RF gun provides high brightness beams and therefore it is being adopted as an injector of X-ray FELs. In this paper we show how to improve photoinjector performance in terms of emittance and repetition rates by means of injector components optimization, especially with the gun. Transverse emittance at the end of an injector is reduced by optimizing the gun design, gun solenoid position, and accelerating section position. The repetition rate of an injector mainly depends on the gun. It is discussed that a repetition rate of 1 kHz at a normal-conducting S-band photoinjector is feasible by adopting a coaxial RF coupler and improving cooling-water channels surrounding the gun.

  17. Reference Values for the Marx Activity Rating Scale in a Young Athletic Population: History of Knee Ligament Injury Is Associated With Higher Scores.

    Science.gov (United States)

    Cameron, Kenneth L; Peck, Karen Y; Thompson, Brandon S; Svoboda, Steven J; Owens, Brett D; Marshall, Stephen W

    2015-01-01

    Activity-related patient-reported outcome measures are an important component of assessment after knee ligament injury in young and physically active patients; however, normative data for most activity scales are limited. To present reference values by sex for the Marx Activity Rating Scale (MARS) within a young and physically active population while accounting for knee ligament injury history and sex. Cross-sectional study. Level 2. All incoming freshman entering a US Service Academy in June of 2011 were recruited to participate in this study. MARS was administered to 1169 incoming freshmen (203 women) who consented to participate within the first week of matriculation. All subjects were deemed healthy and medically fit for military service on admission. Subjects also completed a baseline questionnaire that asked for basic demographic information and injury history. We calculated means with standard deviations, medians with interquartile ranges, and percentiles for ordinal and continuous variables, and frequencies and proportions for dichotomous variables. We also compared median scores by sex and history of knee ligament injury using the Kruskal-Wallis test. MARS was the primary outcome of interest. The median MARS score was significantly higher for men when compared with women (χ(2) = 13.22, df = 1, P MARS scores between men and women (χ(2) = 0.47, df = 1, P = 0.493) who reported a history of injury. Overall, median MARS scores were significantly higher among those who reported a history of knee ligament injury when compared with those who did not (χ(2) = 9.06, df = 1, P = 0.003). Assessing activity as a patient-reported outcome after knee ligament injury is important, and reference values for these instruments need to account for the influence of prior injury and sex. © 2015 The Author(s).

  18. Progress of compact Marx generators high power microwave source

    International Nuclear Information System (INIS)

    Liu Jinliang; Fan Xuliang; Bai Guoqiang; Cheng Xinbing

    2012-01-01

    The compact Marx generators, which can operate at a certain repetition frequency with small size, light weight, and high energy efficiency, are widely used in narrowband, wideband and ultra-wideband high power microwave (HPM) sources. This type of HPM source based on compact Marx generators is a worldwide research focus in recent years, and is important trend of development. The developments of this type of HPM source are described systemically in this paper. The output parameters and structural characteristics are reviewed, and the trends of development are discussed. This work provides reference and evidence for us to master the status of the HPM source based on compact Marx generators correctly and to explore its technical routes scientifically. (authors)

  19. Advances in high repetition rate, ultra-short, gigawatt laser systems for time-resolved spectroscopy

    International Nuclear Information System (INIS)

    DiMauro, L.F.

    1991-01-01

    The objective of this article is to emphasize the current advances in the development of high-repetition rate amplifier pumps. Although this review highlights amplifier pump development, any recent data from achieved outputs via the tunable amplifier section is also discussed. The first section describes desirable parameters attributable to the pump amplifier while the rest of the article deals with specific examples for various options. The pump amplifiers can be characterized into two distinct classes; those achieving operation in the hundred hertz regime and those performing at repetition rates ≥1kHz. 23 refs., 4 figs

  20. High-power pre-chirp managed amplification of femtosecond pulses at high repetition rates

    International Nuclear Information System (INIS)

    Liu, Yang; Li, Wenxue; Zhao, Jian; Bai, Dongbi; Luo, Daping; Zeng, Heping

    2015-01-01

    Femtosecond pulses at 250 MHz repetition rate from a mode-locked fiber laser are amplified to high power in a pre-chirp managed amplifier. The experimental strategy offers a potential towards high-power ultrashort laser pulses at high repetition rates. By investigating the laser pulse evolution in the amplification processes, we show that self-similar evolution, finite gain bandwidth and mode instabilities determine pulse characteristics in different regimes. Further average power scaling is limited by the mode instabilities. Nevertheless, this laser system enables us to achieve sub-50 fs pulses with an average power of 93 W. (letter)

  1. Comparison on different repetition rate locking methods in Er-doped fiber laser

    Science.gov (United States)

    Yang, Kangwen; Zhao, Peng; Luo, Jiang; Huang, Kun; Hao, Qiang; Zeng, Heping

    2018-05-01

    We demonstrate a systematic comparative research on the all-optical, mechanical and opto-mechanical repetition rate control methods in an Er-doped fiber laser. A piece of Yb-doped fiber, a piezoelectric transducer and an electronic polarization controller are simultaneously added in the laser cavity as different cavity length modulators. By measuring the cavity length tuning ranges, the output power fluctuations, the temporal and frequency repetition rate stability, we show that all-optical method introduces the minimal disturbances under current experimental condition.

  2. High-q microring resonator with narrow free spectral range for pulse repetition rate multiplication

    DEFF Research Database (Denmark)

    Pu, Minhao; Ji, Hua; Frandsen, Lars Hagedorn

    2009-01-01

    We demonstrate a silicon-on-insulator microring resonator with a free-spectral-range of 0.32 nm, an extinction ratio of 27 dB, and a quality factor of ~140900 at 1550 nm that is used for pulse repetition-rate multiplication from 10 to 40 GHz.......We demonstrate a silicon-on-insulator microring resonator with a free-spectral-range of 0.32 nm, an extinction ratio of 27 dB, and a quality factor of ~140900 at 1550 nm that is used for pulse repetition-rate multiplication from 10 to 40 GHz....

  3. Solid state pump lasers with high power and high repetition rate

    International Nuclear Information System (INIS)

    Oba, Masaki; Kato, Masaaki; Arisawa, Takashi

    1995-01-01

    We built a laser diode pumped solid state green laser (LDPSSGL) rated at high repetition rate. Two laser heads are placed in one cavity with a rotator in between to design to avoid thermal lensing and thermal birefringence effect. Although average green laser power higher than 10 W was obtained at 1 kHz repetition rate with pulse width of 20-30 nsec, the beam quality was so much deteriorated that energy efficiency was as low as 2 %. Learning from this experience that high power oscillator causes a lot of thermal distortion not only in the laser rod but also in the Q-switch device, we proceeded to built a oscillator/amplifier system. A low power oscillator has a slab type crystal in the cavity. As a result spatial distribution of laser power was extremely improved. As we expect that the high repetition rate solid state laser should be CW operated Q-switch type laser from the view point of lifetime of diode lasers, a conventional arc lamp pumped CW Q-switch green YAG laser of which the repetition rate is changeable from 1 kHz to 5 kHz and the pulse width is 250-570 nsec was also tested to obtain pumping characteristics of a dye laser as a function of power, pulse width etc., and dye laser pulse width of 100-130 nsec were obtained. (author)

  4. Retornos del marx rechazado

    Directory of Open Access Journals (Sweden)

    Hernán Alvarado Ugarte

    2010-03-01

    Full Text Available Karl Marx (1818-1883 es el teórico que mejor ha explicado cómo funciona y por que no funciona el capitalismo. Sin embargo, la lectura de su obra cumbre, El Capital, no es una tarea fácil. En este texto se reflexiona acerca de los factores que dificultan al lector esta tarea, así como la importancia de recuperar una obra que analiza los orígenes y que propone la lucha contra la injusticia social inherente al capitalismo. Abstract Karl Marx (1818-1883 is the theoretician who has better explained how and why the Capitalism does not work. Nevertheless, the reading of its work summit, The Capital, is not an easy task. In this text the author reflects about the factors that make difficult this task to the reader as well as the importance of recovering a work that analyzes the origins and proposes to fight against the social injustice inherent to capitalism.

  5. Generation of plasma X-ray sources via high repetition rate femtosecond laser pulses

    Science.gov (United States)

    Baguckis, Artūras; Plukis, Artūras; Reklaitis, Jonas; Remeikis, Vidmantas; Giniūnas, Linas; Vengris, Mikas

    2017-12-01

    In this study, we present the development and characterization of Cu plasma X-ray source driven by 20 W average power high repetition rate femtosecond laser in ambient atmosphere environment. The peak Cu- Kα photon flux of 2.3 × 109 photons/s into full solid angle is demonstrated (with a process conversion efficiency of 10-7), using pulses with peak intensity of 4.65 × 1014 W/cm2. Such Cu- Kα flux is significantly larger than others found in comparable experiments, performed in air environment. The effects of resonance plasma absorption process, when optimized, are shown to increase measured flux by the factor of 2-3. The relationship between X-ray photon flux and plasma-driving pulse repetition rate is quasi-linear, suggesting that fluxes could further be increased to 1010 photons/s using even higher average powers of driving radiation. These results suggest that to fully utilize the potential of high repetition rate laser sources, novel target material delivery systems (for example, jet-based ones) are required. On the other hand, this study demonstrates that high energy lasers currently used for plasma X-ray sources can be conveniently and efficiently replaced by high average power and repetition rate laser radiation, as a way to increase the brightness of the generated X-rays.

  6. High repetition rate, high energy, actively Q-switched all-in-fiber laser

    Science.gov (United States)

    Lecourt, J. B.; Bertrand, A.; Guillemet, S.; Hernandez, Y.; Giannone, D.

    2010-05-01

    We report an actively Q-switched Ytterbium-doped all-in-fibre laser delivering 10ns pulses with high repetition rate (from 100kHz to 1MHz). The laser operation has been validated at three different wavelengths (1040, 1050 and 1064nm). The laser can deliver up to 20Watts average power with an high beam quality (M2 = 1).

  7. Electrode patterning of ITO thin films by high repetition rate fiber laser

    Energy Technology Data Exchange (ETDEWEB)

    Lin, H.K., E-mail: HKLin@mail.npust.edu.tw; Hsu, W.C.

    2014-07-01

    Indium tin oxide (ITO) thin films are deposited on glass substrates using a radio frequency magnetron sputtering system. As-deposited ITO thin film was 100 nm in thickness and a transmittance of ITO film on glass substrate was 79% at 550 nm. Conductive electrodes are then patterned on the ITO films using a high repetition rate fiber laser system followed by a wet chemical etching process. The electrical, optical and structural properties of the patterned samples are evaluated by means of a four-point probe technique, spectrophotometer, X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The results show that the samples annealed with a pulse repetition rate of 150 kHz or 400 kHz have a low sheet resistivity of 21 Ω/□ and a high optical transmittance of 90%. In addition, it is shown that a higher pulse repetition rate reduces both the residual stress and the surface roughness of the patterned specimens. Therefore, the present results suggest that a pulse repetition rate of 400 kHz represents the optimal processing condition for the patterning of crack-free ITO-coated glass substrates with good electrical and optical properties.

  8. Operation and Thermal Modeling of the ISIS H– Source from 50 to 2 Hz Repetition Rates

    CERN Document Server

    Pereira, H; Lettry, J

    2013-01-01

    CERN’s Linac4 accelerator H− ion source, currently under construction, will operate at a 2 Hz repetition rate, with pulse length of 0.5 ms and a beam current of 80 mA. Its reliability must exceed 99 % with a mandatory 3 month uninterrupted operation period. A Penning ion source is successfully operated at ISIS; at 50 Hz repetition rate it reliably provides 55 mA H− pulses of 0.25 ms duration over 1 month. The discharge plasma ignition is very sensitive to the temperatures of the discharge region, especially of its cathode. The investigation by modeling and measurement of operation parameters suitable for arc ignition and H− production at 2 Hz is of paramount importance and must be understood prior to the implementation of discharge ion sources in the Linac4 accelerator. In its original configuration, the ISIS H− source delivers beam only if the repetition rate is above 12.5 Hz, this paper describes the implementation of a temperature control of the discharge region aiming at lower repetition rate op...

  9. A fast 30 kV 5 kHz repetition rate resonant capacitor charger

    NARCIS (Netherlands)

    Beckers, F.J.C.M.; Huiskamp, T.; van Heesch, E.J.M.; Pemen, A.J.M.

    2016-01-01

    A novel circuit topology of a fast 30 kV resonant capacitor charger is presented in this paper. The charger is designed for high repetition rate spark gap based pulsed power modulators. A spark gap can fire spontaneously (pre-firing) during charging of a capacitor bank due to poor dielectric

  10. Electrode patterning of ITO thin films by high repetition rate fiber laser

    International Nuclear Information System (INIS)

    Lin, H.K.; Hsu, W.C.

    2014-01-01

    Indium tin oxide (ITO) thin films are deposited on glass substrates using a radio frequency magnetron sputtering system. As-deposited ITO thin film was 100 nm in thickness and a transmittance of ITO film on glass substrate was 79% at 550 nm. Conductive electrodes are then patterned on the ITO films using a high repetition rate fiber laser system followed by a wet chemical etching process. The electrical, optical and structural properties of the patterned samples are evaluated by means of a four-point probe technique, spectrophotometer, X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The results show that the samples annealed with a pulse repetition rate of 150 kHz or 400 kHz have a low sheet resistivity of 21 Ω/□ and a high optical transmittance of 90%. In addition, it is shown that a higher pulse repetition rate reduces both the residual stress and the surface roughness of the patterned specimens. Therefore, the present results suggest that a pulse repetition rate of 400 kHz represents the optimal processing condition for the patterning of crack-free ITO-coated glass substrates with good electrical and optical properties.

  11. Probing background ionization: positive streamers with varying pulse repetition rate and with a radioactive admixture

    International Nuclear Information System (INIS)

    Nijdam, S; Van Veldhuizen, E M; Ebert, U; Wormeester, G

    2011-01-01

    Positive streamers need a source of free electrons ahead of them to propagate. A streamer can supply these electrons by itself through photo-ionization, or the electrons can be present due to external background ionization. Here we investigate the effects of background ionization on streamer propagation and morphology by changing the gas composition and the repetition rate of the voltage pulses, and by adding a small amount of radioactive 85 Kr. We find that the general morphology of a positive streamer discharge in high-purity nitrogen depends on background ionization: at lower background ionization levels the streamers branch more and have a more feather-like appearance. This is observed both when varying the repetition rate and when adding 85 Kr, though side branches are longer with the radioactive admixture. But velocities and minimal diameters of streamers are virtually independent of the background ionization level. In air, the inception cloud breaks up into streamers at a smaller radius when the repetition rate and therefore the background ionization level is higher. When measuring the effects of the pulse repetition rate and of the radioactive admixture on the discharge morphology, we found that our estimates of background ionization levels are consistent with these observations; this gives confidence in the estimates. Streamer channels generally do not follow the paths of previous discharge channels for repetition rates of up to 10 Hz. We estimate the effect of recombination and diffusion of ions and free electrons from the previous discharge and conclude that the old trail has largely disappeared at the moment of the next voltage pulse; therefore the next streamers indeed cannot follow the old trail.

  12. Retorno a Marx

    Directory of Open Access Journals (Sweden)

    Roy Alfaro Vargas

    2016-01-01

    Full Text Available Henri Lefèbvre analiza aquí la etiqueta de materialismo dialéctico, en relación con los imperativos derivados del pensamiento de Marx. Es decir, Lefèbvre cuestiona la noción de materialismo dialéctico como un resabio de la vieja discusión entre materialismo e idealismo, con el fin de superar tal división a través de la noción de praxis. Lefèbvre define, entonces, el marxismo y el pensamiento dialéctico como la superación (Aufhebung de la filosofía, en cuanto proceso de realización de ella misma, el cual se fundamenta en la negatividad de la relación entre sujeto y objeto.

  13. Effects of picosecond laser repetition rate on ablation of Cr12MoV cold work mold steel

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Baoye; Deng, Leimin; Liu, Peng; Zhang, Fei; Duan, Jun, E-mail: duans@hust.edu.cn; Zeng, Xiaoyan

    2017-07-01

    In this paper, the effects of pulse repetition rate on ablation efficiency and quality of Cr12MoV cold work mold steel have been studied using a picosecond (ps) pulse Nd:YVO{sub 4} laser system at λ= 1064 nm. The experimental results of area ablation on target surface reveal that laser repetition rate plays a significant role in controlling ablation efficiency and quality. Increasing the laser repetition rate, while keeping a constant mean power improves the ablation efficiency and quality. For each laser mean power, there is an optimal repetition rate to achieve a higher laser ablation efficiency with low surface roughness. A high ablation efficiency of 42.29, 44.11 and 47.52 μm{sup 3}/mJ, with surface roughness of 0.476, 0.463 and 0.706 μm could be achieved at laser repetition rate of 10 MHz, for laser mean power of 15, 17 and 19 W, respectively. Scanning electron microcopy images revels that the surface morphology evolves from rough with numerous craters, to flat without pores when we increased the laser repetition rate. The effects of laser repetition rate on the heat accumulation, plasma shield and ablation threshold were analyzed by numerical simulation, spectral analysis and multi-laser shot, respectively. The synergetic effects of laser repetition rate on laser ablation rate and machining quality were analyzed and discussed systemically in this paper.

  14. Effects of high repetition rate and beam size on hard tissue damage due to subpicosecond laser pulses

    International Nuclear Information System (INIS)

    Kim, Beop-Min; Feit, Michael D.; Rubenchik, Alexander M.; Joslin, Elizabeth J.; Eichler, Juergen; Stoller, Patrick C.; Da Silva, Luiz B.

    2000-01-01

    We report the effects of the repetition rate and the beam size on the threshold for ultrashort laser pulse induced damage in dentin. The observed results are explained as cumulative thermal effects. Our model is consistent with the experimental results and explains the dependence of the threshold on repetition rate, beam size, and exposure time. (c) 2000 American Institute of Physics

  15. Design and Development of High-Repetition-Rate Satellite Laser Ranging System

    Science.gov (United States)

    Choi, Eun-Jung; Bang, Seong-Cheol; Sung, Ki-Pyoung; Lim, Hyung-Chul; Jung, Chan-Gyu; Kim, In-Yeung; Choi, Jae-Seung

    2015-09-01

    The Accurate Ranging System for Geodetic Observation ? Mobile (ARGO-M) was successfully developed as the first Korean mobile Satellite Laser Ranging (SLR) system in 2012, and has joined in the International Laser Ranging Service (ILRS) tracking network, DAEdeoK (DAEK) station. The DAEK SLR station was approved as a validated station in April 2014, through the ILRS station ¡°data validation¡± process. The ARGO-M system is designed to enable 2 kHz laser ranging with millimeter-level precision for geodetic, remote sensing, navigation, and experimental satellites equipped with Laser Retroreflector Arrays (LRAs). In this paper, we present the design and development of a next generation high-repetition-rate SLR system for ARGO-M. The laser ranging rate up to 10 kHz is becoming an important issue in the SLR community to improve ranging precision. To implement high-repetition-rate SLR system, the High-repetition-rate SLR operation system (HSLR-10) was designed and developed using ARGO-M Range Gate Generator (A-RGG), so as to enable laser ranging from 50 Hz to 10 kHz. HSLR-10 includes both hardware controlling software and data post-processing software. This paper shows the design and development of key technologies of high-repetition-rate SLR system. The developed system was tested successfully at DAEK station and then moved to Sejong station, a new Korean SLR station, on July 1, 2015. HSLR-10 will begin normal operations at Sejong station in the near future.

  16. 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.

  17. An optical parametric chirped-pulse amplifier for seeding high repetition rate free-electron lasers

    International Nuclear Information System (INIS)

    Höppner, H; Hage, A; Tanikawa, T; Schulz, M; Faatz, B; Riedel, R; Prandolini, M J; Teubner, U; Tavella, F

    2015-01-01

    High repetition rate free-electron lasers (FEL), producing highly intense extreme ultraviolet and x-ray pulses, require new high power tunable femtosecond lasers for FEL seeding and FEL pump-probe experiments. A tunable, 112 W (burst mode) optical parametric chirped-pulse amplifier (OPCPA) is demonstrated with center frequencies ranging from 720–900 nm, pulse energies up to 1.12 mJ and a pulse duration of 30 fs at a repetition rate of 100 kHz. Since the power scalability of this OPCPA is limited by the OPCPA-pump amplifier, we also demonstrate a 6.7–13.7 kW (burst mode) thin-disk OPCPA-pump amplifier, increasing the possible OPCPA output power to many hundreds of watts. Furthermore, third and fourth harmonic generation experiments are performed and the results are used to simulate a seeded FEL with high-gain harmonic generation. (paper)

  18. Studies of a Linac Driver for a High Repetition Rate X-Ray FEL

    International Nuclear Information System (INIS)

    Venturini, M.; Corlett, J.; Doolittle, L.; Filippetto, D.; Papadopoulos, C.; Penn, G.; Prosnitz, D.; Qiang, J.; Reinsch, M.; Ryne, R.; Sannibale, F.; Staples, J.; Wells, R.; Wurtele, J.; Zolotorev, M.; Zholents, A.

    2011-01-01

    We report on on-going studies of a superconducting CW linac driver intended to support a high repetition rate FEL operating in the soft x-rays spectrum. We present a pointdesign for a 1.8 GeV machine tuned for 300 pC bunches and delivering low-emittance, low-energy spread beams as needed for the SASE and seeded beamlines.

  19. Impact of visual repetition rate on intrinsic properties of low frequency fluctuations in the visual network.

    Directory of Open Access Journals (Sweden)

    Yi-Chia Li

    Full Text Available BACKGROUND: Visual processing network is one of the functional networks which have been reliably identified to consistently exist in human resting brains. In our work, we focused on this network and investigated the intrinsic properties of low frequency (0.01-0.08 Hz fluctuations (LFFs during changes of visual stimuli. There were two main questions to be discussed in this study: intrinsic properties of LFFs regarding (1 interactions between visual stimuli and resting-state; (2 impact of repetition rate of visual stimuli. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed scanning sessions that contained rest and visual stimuli in various repetition rates with a novel method. The method included three numerical approaches involving ICA (Independent Component Analyses, fALFF (fractional Amplitude of Low Frequency Fluctuation, and Coherence, to respectively investigate the modulations of visual network pattern, low frequency fluctuation power, and interregional functional connectivity during changes of visual stimuli. We discovered when resting-state was replaced by visual stimuli, more areas were involved in visual processing, and both stronger low frequency fluctuations and higher interregional functional connectivity occurred in visual network. With changes of visual repetition rate, the number of areas which were involved in visual processing, low frequency fluctuation power, and interregional functional connectivity in this network were also modulated. CONCLUSIONS/SIGNIFICANCE: To combine the results of prior literatures and our discoveries, intrinsic properties of LFFs in visual network are altered not only by modulations of endogenous factors (eye-open or eye-closed condition; alcohol administration and disordered behaviors (early blind, but also exogenous sensory stimuli (visual stimuli with various repetition rates. It demonstrates that the intrinsic properties of LFFs are valuable to represent physiological states of human brains.

  20. Meaningful Words and Non-Words Repetitive Articulatory Rate (Oral Diadochokinesis) in Persian Speaking Children.

    Science.gov (United States)

    Zamani, Peyman; Rezai, Hossein; Garmatani, Neda Tahmasebi

    2017-08-01

    Repetitive articulatory rate or Oral Diadochokinesis (oral-DDK) shows a guideline for appraisal and diagnosis of subjects with oral-motor disorder. Traditionally, meaningless words repetition has been utilized in this task and preschool children have challenges with them. Therefore, we aimed to determine some meaningful words in order to test oral-DDK in Persian speaking preschool children. Participants were 142 normally developing children, (age range 4-6 years), who were asked to produce /motæka, golabi/ as two meaningful Persian words and /pa-ta-ka/ as non-word in conventional oral-DDK task. We compared the time taken for 10-times fast repetitions of two meaningful Persian words and the tri-syllabic nonsense word /pa-ta-ka/. Praat software was used to calculate the average time that subjects took to produce the target items. In 4-5 year old children, [Formula: see text] of time taken for 10-times repetitions of /pa-ta-ka, motæka, golabi/ were [Formula: see text], and [Formula: see text] seconds respectively, and in 5-6 year old children were [Formula: see text], and [Formula: see text] seconds respectively. Findings showed that the main effect of type of words on oral diadochokinesis was significant ([Formula: see text]). Children repeated meaningful words /motæka, golabi/ faster than the non-word /pa-ta-ka/. Sex and age factors had no effect on time taken for repetition of oral-DDK test. It is suggested that Speech Therapists can use meaningful words to facilitate oral-DDK test for children.

  1. Research on the optoacoustic communication system for speech transmission by variable laser-pulse repetition rates

    Science.gov (United States)

    Jiang, Hongyan; Qiu, Hongbing; He, Ning; Liao, Xin

    2018-06-01

    For the optoacoustic communication from in-air platforms to submerged apparatus, a method based on speech recognition and variable laser-pulse repetition rates is proposed, which realizes character encoding and transmission for speech. Firstly, the theories and spectrum characteristics of the laser-generated underwater sound are analyzed; and moreover character conversion and encoding for speech as well as the pattern of codes for laser modulation is studied; lastly experiments to verify the system design are carried out. Results show that the optoacoustic system, where laser modulation is controlled by speech-to-character baseband codes, is beneficial to improve flexibility in receiving location for underwater targets as well as real-time performance in information transmission. In the overwater transmitter, a pulse laser is controlled to radiate by speech signals with several repetition rates randomly selected in the range of one to fifty Hz, and then in the underwater receiver laser pulse repetition rate and data can be acquired by the preamble and information codes of the corresponding laser-generated sound. When the energy of the laser pulse is appropriate, real-time transmission for speaker-independent speech can be realized in that way, which solves the problem of underwater bandwidth resource and provides a technical approach for the air-sea communication.

  2. Novel fast-neutron activation counter for high repetition rate measurements

    International Nuclear Information System (INIS)

    Mahmood, S.; Springham, S. V.; Zhang, T.; Rawat, R. S.; Tan, T. L.; Krishnan, M.; Beg, F. N.; Lee, S.; Schmidt, H.; Lee, P.

    2006-01-01

    A fast-neutron beryllium activation counter has been constructed for neutron measurements on a high repetition rate deuterium plasma focus. Beryllium activation is especially suitable for measurements of DD neutron yields. The cross section for the relevant reaction, 9 Be(n,α) 6 He, results in a maximum sensitivity at the characteristic energy of the DD neutrons (∼2.5 MeV) and practically no sensitivity to neutrons with energies 6 He enabled the shot-to-shot neutron yield from the plasma focus to be measured for repetition rates from 0.2 to 3 Hz (and for a range of deuterium gas pressures). With careful analysis, the shot-to-shot yield can be measured up to a maximum repetition rate of 3 Hz, beyond which the pileup of counts from the previous shots reduces the accuracy of the measurements to an unacceptable level. This new beryllium activation counter has been cross-checked against an indium activation counter to obtain absolute neutron yields. At a charging voltage of 12.5 kV (bank energy of 2.2 kJ), the average neutron yield was found to be (7.9±0.7)x10 7 per shot (standard deviation of 4x10 7 ). It was found that activation of the plasma focus construction materials (especially aluminum) must be taken into account

  3. High repetition rate laser-driven MeV ion acceleration at variable background pressures

    Science.gov (United States)

    Snyder, Joseph; Ngirmang, Gregory; Orban, Chris; Feister, Scott; Morrison, John; Frische, Kyle; Chowdhury, Enam; Roquemore, W. M.

    2017-10-01

    Ultra-intense laser-plasma interactions (LPI) can produce highly energetic photons, electrons, and ions with numerous potential real-world applications. Many of these applications will require repeatable, high repetition targets that are suitable for LPI experiments. Liquid targets can meet many of these needs, but they typically require higher chamber pressure than is used for many low repetition rate experiments. The effect of background pressure on the LPI has not been thoroughly studied. With this in mind, the Extreme Light group at the Air Force Research Lab has carried out MeV ion and electron acceleration experiments at kHz repetition rate with background pressures ranging from 30 mTorr to >1 Torr using a submicron ethylene glycol liquid sheet target. We present these results and provide two-dimensional particle-in-cell simulation results that offer insight on the thresholds for the efficient acceleration of electrons and ions. This research is supported by the Air Force Office of Scientific Research under LRIR Project 17RQCOR504 under the management of Dr. Riq Parra and Dr. Jean-Luc Cambier. Support was also provided by the DOD HPCMP Internship Program.

  4. Optimization of graffiti removal on natural stone by means of high repetition rate UV laser

    International Nuclear Information System (INIS)

    Fiorucci, M.P.; López, A.J.; Ramil, A.; Pozo, S.; Rivas, T.

    2013-01-01

    The use of laser for graffiti removal is a promising alternative to conventional cleaning methods, though irradiation parameters must be carefully selected in order to achieve the effective cleaning without damaging the substrate, especially when referring to natural stone. From a practical point of view, once a safe working window is selected, it is necessary to determine the irradiation conditions to remove large paint areas, with minimal time consumption. The aim of this paper is to present a systematic procedure to select the optimum parameters for graffiti removal by means of the 3rd harmonic of a high repetition rate nanosecond Nd:YVO 4 laser. Ablation thresholds of four spray paint colors were determined and the effect of pulse repetition frequency, beam diameter and line scan separation was analyzed, obtaining a set of values which optimize the ablation process.

  5. Optimization of graffiti removal on natural stone by means of high repetition rate UV laser

    Energy Technology Data Exchange (ETDEWEB)

    Fiorucci, M.P., E-mail: m.p.fiorucci@udc.es [Centro de Investigacións Tecnolóxicas, Universidade da Coruña, 15403 Ferrol (Spain); Dpto. Enxeñaría dos Recursos Naturais e Medio Ambiente, E.T.S.E. Minas, Universidade de Vigo, 36200 Vigo (Spain); López, A.J., E-mail: ana.xesus.lopez@udc.es [Centro de Investigacións Tecnolóxicas, Universidade da Coruña, 15403 Ferrol (Spain); Ramil, A., E-mail: alberto.ramil@udc.es [Centro de Investigacións Tecnolóxicas, Universidade da Coruña, 15403 Ferrol (Spain); Pozo, S., E-mail: ipozo@uvigo.es [Dpto. Enxeñaría dos Recursos Naturais e Medio Ambiente, E.T.S.E. Minas, Universidade de Vigo, 36200 Vigo (Spain); Rivas, T., E-mail: trivas@uvigo.es [Dpto. Enxeñaría dos Recursos Naturais e Medio Ambiente, E.T.S.E. Minas, Universidade de Vigo, 36200 Vigo (Spain)

    2013-08-01

    The use of laser for graffiti removal is a promising alternative to conventional cleaning methods, though irradiation parameters must be carefully selected in order to achieve the effective cleaning without damaging the substrate, especially when referring to natural stone. From a practical point of view, once a safe working window is selected, it is necessary to determine the irradiation conditions to remove large paint areas, with minimal time consumption. The aim of this paper is to present a systematic procedure to select the optimum parameters for graffiti removal by means of the 3rd harmonic of a high repetition rate nanosecond Nd:YVO{sub 4} laser. Ablation thresholds of four spray paint colors were determined and the effect of pulse repetition frequency, beam diameter and line scan separation was analyzed, obtaining a set of values which optimize the ablation process.

  6. Characterization of a high repetition-rate laser-driven short-pulsed neutron source

    Science.gov (United States)

    Hah, J.; Nees, J. A.; Hammig, M. D.; Krushelnick, K.; Thomas, A. G. R.

    2018-05-01

    We demonstrate a repetitive, high flux, short-pulsed laser-driven neutron source using a heavy-water jet target. We measure neutron generation at 1/2 kHz repetition rate using several-mJ pulse energies, yielding a time-averaged neutron flux of 2 × 105 neutrons s‑1 (into 4π steradians). Deuteron spectra are also measured in order to understand source characteristics. Analyses of time-of-flight neutron spectra indicate that two separate populations of neutrons, ‘prompt’ and ‘delayed’, are generated at different locations. Gamma-ray emission from neutron capture 1H(n,γ) is also measured to confirm the neutron flux.

  7. High speed surface cleaning by a high repetition rated TEA-CO2 laser

    International Nuclear Information System (INIS)

    Tsunemi, Akira; Hirai, Ryo; Hagiwara, Kouji; Nagasaka, Keigo; Tashiro, Hideo

    1994-01-01

    We demonstrated the feasibility of high speed cleaning of solid surfaces by the laser ablation technique using a TEA-CO 2 laser. The laser pulses with the repetition rate of 1 kHz were applied to paint, rust, moss and dirt attached on the surfaces. The attachments were effectively removed without the damage of bulk surfaces by the irradiation of line-focused sequential pulses with an energy of 300 mJ/pulse. A cleaning rate reached to 17 m 2 /hour for the case of paint removal from iron surfaces. (author)

  8. Ultraviolet excimer laser ablation: the effect of wavelength and repetition rate on in vivo guinea pig skin

    Energy Technology Data Exchange (ETDEWEB)

    Morelli, J.; Kibbi, A.G.; Farinelli, W.; Boll, J.; Tan, O.T.

    1987-06-01

    Multiple dermatologic conditions that are currently treated with traditional cold-knife surgery are amenable to laser therapy. The ideal surgical treatment would be precise and total removal of abnormal tissue with maximal sparing of remaining structures. The ultraviolet (UV) excimer laser is capable of such precise tissue removal due to the penetration depth of 193 nm and 248 nm irradiation of 1 micron per pulse. This type of ablative tissue removal requires a high repetition rate for efficient lesional destruction. Excimer laser radiation at 193 nm is capable of high repetition rates, which are necessary while 248 nm radiation causes increasing nonspecific thermal injury as the laser repetition rate is increased.

  9. Very high repetition-rate electro-optical cavity-dumped Nd: YVO4 laser with optics and dynamics stabilities

    Science.gov (United States)

    Liu, Xuesong; Shi, Zhaohui; Huang, Yutao; Fan, Zhongwei; Yu, Jin; Zhang, Jing; Hou, Liqun

    2015-02-01

    In this paper, a very high repetition-rate, short-pulse, electro-optical cavity-dumped Nd: YVO4 laser is experimentally and theoretically investigated. The laser performance is optimized from two aspects. Firstly, the laser resonator is designed for a good thermal stability under large pump power fluctuation through optics methods. Secondly, dynamics simulation as well as experiments verifies that cavity dumping at very high repetition rate has better stability than medium/high repetition rate. At 30 W, 880 nm pump power, up to 500 kHz, constant 5 ns, stable 1064 nm fundamental-mode laser pulses can be obtained with 10 W average output power.

  10. High energy high repetition-rate thin-disk amplifier for OPCPA pumping

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, Michael

    2013-08-15

    The development of a pump laser system for a high power and high repetition rate optical parametric chirped-pulse amplification (OPCPA) is presented in this thesis. The OPCPA system requires pump pulse energies in the range of tens of millijoules at high repetition rates with sub-picosecond pulse durations. This can be achieved to some extend with Innoslab amplifier technology. However, scaling to higher pulse energies at high repetition rates may be problematic. With the thin-disk amplifier presented in this thesis, output energies of 140 mJ at 100 kHz repetition rate could be achieved in burst-mode operation, which is a world record for this type of laser amplifier. Due to its material and spectral properties, ytterbium doped YAG (Yb:YAG) is used as a gain medium for the high power amplifier stages. The low quantum defect and the comparatively large emission bandwidth makes this material the choice for high power operation and sub-picosecond compressed pulse durations. The output beam profile as well as the shape of the output bursts is ideal to pump an OPCPA system. An OPCPA output energy in the millijoule range with repetition rates of 100 kHz to 1 MHz is needed to generate seed pulses for the FEL and for the application as pump-probe laser at the FEL facility. Since the development of this laser system needs to meet requirements set by the Free-Electron Laser in Hamburg (FLASH), the amplifier is conceived for burst-mode operation. The main requirement is a high intra-burst pulse repetition rate of more than 100 kHz and a uniform pulse train (burst) with equal properties for every pulse. The burst-mode is an operation mode where the laser never reaches a lasing equilibrium, which means that the behavior of the amplifier is similar to a switch-on of the laser system for every burst. This makes the development of the amplifier system difficult. Therefore, an analytical model has been developed to study the amplification process during the burst. This includes the

  11. High energy high repetition-rate thin-disk amplifier for OPCPA pumping

    International Nuclear Information System (INIS)

    Schulz, Michael

    2013-08-01

    The development of a pump laser system for a high power and high repetition rate optical parametric chirped-pulse amplification (OPCPA) is presented in this thesis. The OPCPA system requires pump pulse energies in the range of tens of millijoules at high repetition rates with sub-picosecond pulse durations. This can be achieved to some extend with Innoslab amplifier technology. However, scaling to higher pulse energies at high repetition rates may be problematic. With the thin-disk amplifier presented in this thesis, output energies of 140 mJ at 100 kHz repetition rate could be achieved in burst-mode operation, which is a world record for this type of laser amplifier. Due to its material and spectral properties, ytterbium doped YAG (Yb:YAG) is used as a gain medium for the high power amplifier stages. The low quantum defect and the comparatively large emission bandwidth makes this material the choice for high power operation and sub-picosecond compressed pulse durations. The output beam profile as well as the shape of the output bursts is ideal to pump an OPCPA system. An OPCPA output energy in the millijoule range with repetition rates of 100 kHz to 1 MHz is needed to generate seed pulses for the FEL and for the application as pump-probe laser at the FEL facility. Since the development of this laser system needs to meet requirements set by the Free-Electron Laser in Hamburg (FLASH), the amplifier is conceived for burst-mode operation. The main requirement is a high intra-burst pulse repetition rate of more than 100 kHz and a uniform pulse train (burst) with equal properties for every pulse. The burst-mode is an operation mode where the laser never reaches a lasing equilibrium, which means that the behavior of the amplifier is similar to a switch-on of the laser system for every burst. This makes the development of the amplifier system difficult. Therefore, an analytical model has been developed to study the amplification process during the burst. This includes the

  12. A mode-locked external-cavity quantum-dot laser with a variable repetition rate

    International Nuclear Information System (INIS)

    Wu Jian; Jin Peng; Li Xin-Kun; Wei Heng; Wu Yan-Hua; Wang Fei-Fei; Chen Hong-Mei; Wu Ju; Wang Zhan-Guo

    2013-01-01

    A mode-locked external-cavity laser emitting at 1.17-μm wavelength using an InAs/GaAs quantum-dot gain medium and a discrete semiconductor saturable absorber mirror is demonstrated. By changing the external-cavity length, repetition rates of 854, 912, and 969 MHz are achieved respectively. The narrowest −3-dB radio-frequency linewidth obtained is 38 kHz, indicating that the laser is under stable mode-locking operation. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  13. Development of a cryogenic hydrogen microjet for high-intensity, high-repetition rate experiments

    Science.gov (United States)

    Kim, J. B.; Göde, S.; Glenzer, S. H.

    2016-11-01

    The advent of high-intensity, high-repetition-rate lasers has led to the need for replenishing targets of interest for high energy density sciences. We describe the design and characterization of a cryogenic microjet source, which can deliver a continuous stream of liquid hydrogen with a diameter of a few microns. The jet has been imaged at 1 μm resolution by shadowgraphy with a short pulse laser. The pointing stability has been measured at well below a mrad, for a stable free-standing filament of solid-density hydrogen.

  14. 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.

  15. Power scaling of supercontinuum seeded megahertz-repetition rate optical parametric chirped pulse amplifiers.

    Science.gov (United States)

    Riedel, R; Stephanides, A; Prandolini, M J; Gronloh, B; Jungbluth, B; Mans, T; Tavella, F

    2014-03-15

    Optical parametric chirped-pulse amplifiers with high average power are possible with novel high-power Yb:YAG amplifiers with kW-level output powers. We demonstrate a compact wavelength-tunable sub-30-fs amplifier with 11.4 W average power with 20.7% pump-to-signal conversion efficiency. For parametric amplification, a beta-barium borate crystal is pumped by a 140 W, 1 ps Yb:YAG InnoSlab amplifier at 3.25 MHz repetition rate. The broadband seed is generated via supercontinuum generation in a YAG crystal.

  16. Observation of Repetition-Rate Dependent Emission From an Un-Gated Thermionic Cathode Rf Gun

    Energy Technology Data Exchange (ETDEWEB)

    Edelen, J. P.; Sun, Y.; Harris, J.R.; Lewellen, J.W.

    2017-06-02

    Recent work at Fermilab in collaboration with the Advanced Photon Source and members of other national labs, designed an experiment to study the relationship between the RF repetition rate and the average current per RF pulse. While existing models anticipate a direct relationship between these two parameters we observed an inverse relationship. We believe this is a result of damage to the barium coating on the cathode surface caused by a change in back-bombardment power that is unaccounted for in the existing theories. These observations shed new light on the challenges and fundamental limitations associated with scaling an ungated thermionic cathode RF gun to high average current.

  17. HIGH REPETITION RATE MICROCHIP ER3+,YB3+:YAL3(BO34 DIODE-PUMPED LASER

    Directory of Open Access Journals (Sweden)

    K. N. Gorbachenya

    2012-01-01

    Full Text Available Diode-pumped passively Q-switched microchip Er,Yb:YAl3(BO34 laser for range-finding has been demonstrated. By using a Co2+:MgAl2O4 as a saturable absorber TEM00–mode Q-switched average output power of 315 mW was demonstrated at 1522 nm with pulse duration of 5 ns and pulse energy of 5,25 μJ at a repetition rate of 60 kHz.

  18. Development of ultra high speed photographic system using high repetition rate visible laser

    International Nuclear Information System (INIS)

    Lee, Jong Min; Cha, Byung Hun; Kim, Sung Ho; Kim, Jung Bog; Lim, Chang Hwan; Cha, Hyung Ki; Song, Kyu Seok; Lee, Byung Deok; Rhi, Jong Hoon; Baik, Dae Hyun; Han, Jae Min; Rho, Si Pyo; Lee, Byung Cheol; Jeong, Do Yung; Choi, An Seong; Jeong, Chan Ik; Park, Dae Ung; Jeong, Sung Min; Lee, Sang Kil; Kim, Heon Jun; Jang, Rae gak; Jo, Do Hun; Park, Min Young

    1992-12-01

    The goal of this project is to develop and commercialize a high speed photographic system equipped with a high repetition rate visible laser. The developed system provides the characteristics of high time resolution and large number of frames. The system consists of 10 W air cooled CVL or a 30 W water cooled CVL, a rotating drum-type high speed camera with the framing rate of 35,000 fps, and a automatic control device. The system has the performance of 10 nsec time resolution, 35,000 fps framing rate, and 250 picture frames. The high speed photographic systems are widely applied to the fields such as high-efficient engine development, high-speed vibration analysis, shock wave propagation study, flow visualization analysis, weapon development, etc. (Author)

  19. Elemental redistribution behavior in tellurite glass induced by high repetition rate femtosecond laser irradiation

    International Nuclear Information System (INIS)

    Teng, Yu; Zhou, Jiajia; Khisro, Said Nasir; Zhou, Shifeng; Qiu, Jianrong

    2014-01-01

    Highlights: • Abnormal elements redistribution behavior was observed in tellurite glass. • The refractive index and Raman intensity distribution changed significantly. • The relative glass composition remained unchanged while the glass density changed. • First time report on the abnormal element redistribution behavior in glass. • The glass network structure determines the elemental redistribution behavior. - Abstract: The success in the fabrication of micro-structures in glassy materials using femtosecond laser irradiation has proved its potential applications in the construction of three-dimensional micro-optical components or devices. In this paper, we report the elemental redistribution behavior in tellurite glass after the irradiation of high repetition rate femtosecond laser pulses. The relative glass composition remained unchanged while the glass density changed significantly, which is quite different from previously reported results about the high repetition rate femtosecond laser induced elemental redistribution in silicate glasses. The involved mechanism is discussed with the conclusion that the glass network structure plays the key role to determine the elemental redistribution. This observation not only helps to understand the interaction process of femtosecond laser with glassy materials, but also has potential applications in the fabrication of micro-optical devices

  20. Repetition rate multiplication of frequency comb using all-pass fiber resonator

    International Nuclear Information System (INIS)

    Yang, Lijun; Yang, Honglei; Zhang, Hongyuan; Wei, Haoyun; Li, Yan

    2016-01-01

    We propose a stable method for repetition rate multiplication of a 250-MHz Er-fiber frequency comb by a phase-locked all-pass fiber ring resonator, whose phase-locking configuration is simple. The optical path length of the fiber ring resonator is automatically controlled to be accurately an odd multiple of half of the original cavity length using an electronical phase-locking unit with an optical delay line. As for shorter cavity length of the comb, high-order odd multiple is preferable. Because the power loss depends only on the net-attenuation of the fiber ring resonator, the energetic efficiency of the proposed method is high. The input and output optical spectrums show that the spectral width of the frequency comb is clearly preserved. Besides, experimental results show less pulse intensity fluctuation and 35 dB suppression ratio of side-modes while providing a good long-term and short-term frequency stability. Higher-order repetition rate multiplication to several GHz can be obtained by using several fiber ring resonators in cascade configuration.

  1. Repetition rate multiplication of frequency comb using all-pass fiber resonator

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Lijun; Yang, Honglei; Zhang, Hongyuan; Wei, Haoyun; Li, Yan, E-mail: liyan@mail.tsinghua.edu.cn [State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instruments, Tsinghua University, Beijing 100084 (China)

    2016-09-15

    We propose a stable method for repetition rate multiplication of a 250-MHz Er-fiber frequency comb by a phase-locked all-pass fiber ring resonator, whose phase-locking configuration is simple. The optical path length of the fiber ring resonator is automatically controlled to be accurately an odd multiple of half of the original cavity length using an electronical phase-locking unit with an optical delay line. As for shorter cavity length of the comb, high-order odd multiple is preferable. Because the power loss depends only on the net-attenuation of the fiber ring resonator, the energetic efficiency of the proposed method is high. The input and output optical spectrums show that the spectral width of the frequency comb is clearly preserved. Besides, experimental results show less pulse intensity fluctuation and 35 dB suppression ratio of side-modes while providing a good long-term and short-term frequency stability. Higher-order repetition rate multiplication to several GHz can be obtained by using several fiber ring resonators in cascade configuration.

  2. A 7.8 kV nanosecond pulse generator with a 500 Hz repetition rate

    Science.gov (United States)

    Lin, M.; Liao, H.; Liu, M.; Zhu, G.; Yang, Z.; Shi, P.; Lu, Q.; Sun, X.

    2018-04-01

    Pseudospark switches are widely used in pulsed power applications. In this paper, we present the design and performance of a 500 Hz repetition rate high-voltage pulse generator to drive TDI-series pseudospark switches. A high-voltage pulse is produced by discharging an 8 μF capacitor through a primary windings of a setup isolation transformer using a single metal-oxide-semiconductor field-effect transistor (MOSFET) as a control switch. In addition, a self-break spark gap is used to steepen the pulse front. The pulse generator can deliver a high-voltage pulse with a peak trigger voltage of 7.8 kV, a peak trigger current of 63 A, a full width at half maximum (FWHM) of ~30 ns, and a rise time of 5 ns to the trigger pin of the pseudospark switch. During burst mode operation, the generator achieved up to a 500 Hz repetition rate. Meanwhile, we also provide an AC heater power circuit for heating a H2 reservoir. This pulse generator can be used in circuits with TDI-series pseudospark switches with either a grounded cathode or with a cathode electrically floating operation. The details of the circuits and their implementation are described in the paper.

  3. Diffusively cooled thin-sheath high-repetition-rate TEA and TEMA lasers

    Science.gov (United States)

    Yatsiv, Shaul; Gabay, Amnon; Sintov, Yoav

    1993-05-01

    Transverse electric atmospheric (TEA), or multi atmospheric (TEMA) lasers deliver intense short laser pulses of considerable energies. Recurrent high repetition rate pulse trains afford substantial average power levels. In a high rep-rate operation the gas flows across the cavity and is externally cooled to maintain a reasonably low temperature. The gas flow gear and heat exchanger are bulky and costly. In this work we present a repetitively pulsed TEA or TEMA laser that combines energy and peak power features in an individual pulse with the substantial average power levels of a pulse train in a thin layer of gas. Excess heat is disposed of, by conduction through the gas, to cooled enclosing walls. The gas does not flow. The method applies to vibrational transition molecular lasers in the infrared, where elevated temperatures are deleterious to the laser operation. The gist of the method draws on the law that heat conductivity in gases does not depend on their pressure. The fact lends unique operational flexibility and compactness, desirable for industrial and research purposes.

  4. Diagnostic for a high-repetition rate electron photo-gun and first measurements

    Science.gov (United States)

    Filippetto, D.; Doolittle, L.; Huang, G.; Norum, E.; Portmann, G.; Qian, H.; Sannibale, F.

    2015-05-01

    The APEX electron source at LBNL combines the high-repetition-rate with the high beam brightness typical of photoguns, delivering low emittance electron pulses at MHz frequency. Proving the high beam quality of the beam is an essential step for the success of the experiment, opening the doors of the high average power to brightness-hungry applications as X-Ray FELs, MHz ultrafast electron diffraction etc.. As first step, a complete characterization of the beam parameters is foreseen at the Gun beam energy of 750 keV. Diagnostics for low and high current measurements have been installed and tested, and measurements of cathode lifetime and thermal emittance in a RF environment with mA current performed. The recent installation of a double slit system, a deflecting cavity and a high precision spectrometer, allow the exploration of the full 6D phase space. Here we discuss the present layout of the machine and future upgrades, showing the latest results at low and high repetition rate, together with the tools and techniques used.

  5. MHz repetition rate solid-state driver for high current induction accelerators

    International Nuclear Information System (INIS)

    Brooksby, C; Caporaso, G; Goerz, D; Hanks, R; Hickman, B; Kirbie, H; Lee, B; Saethre, R.

    1999-01-01

    A research team from the Lawrence Livermore National Laboratory and Bechtel Nevada Corporation is developing an all solid-state power source for high current induction accelerators. The original power system design, developed for heavy-ion fusion accelerators, is based on the simple idea of using an array of field effect transistors to switch energy from a pre-charged capacitor bank to an induction accelerator cell. Recently, that idea has been expanded to accommodate the greater power needs of a new class of high-current electron accelerators for advanced radiography. For this purpose, we developed a 3-stage induction adder that uses over 4,000 field effect transistors to switch peak voltages of 45 kV at currents up to 4.8 kA with pulse repetition rates of up to 2 MHz. This radically advanced power system can generate a burst of five or more pulses that vary from 200 ns to 2 ampersand micro;s at a duty cycle of up to 25%. Our new source is precise, robust, flexible, and exceeds all previous drivers for induction machines by a factor of 400 in repetition rate and a factor of 1000 in duty cycle

  6. Karl Marx 1864 og forsigtighedsprincippet

    DEFF Research Database (Denmark)

    Czeskleba-Dupont, Rolf

    2015-01-01

    Artiklen analyserer divergerende versioner af den tekst, som Karl Marx efter dannelsen af den 1.Internationale Arbejderassociation i London september 1864 har oversat fra sit engelske original (Inaugural Address...), der udkom i november, til en tysk version med overskriften 'Manifest an die...

  7. Karl Marx and the Environment

    Science.gov (United States)

    Shifferd, K. D.

    1972-01-01

    Implications from Karl Marx's concept of nature are explored. Serving as a frame of reference for the fight against pollution, the Marxian philosophy provides a kind of systems analysis of the origins and dynamics of pollution at the level of society and a set of conceptual tools and attitudes for unmasking the claims of industry. (BL)

  8. Fluorescence fluctuation of Rhodamine 6G dye for high repetition rate laser excitation

    International Nuclear Information System (INIS)

    Singh, Nageshwar; Patel, Hemant K.; Dixit, S.K.; Vora, H.S.

    2013-01-01

    In this paper, fluorescence from Rhodamine 6G dye for stationary and flowing liquid medium, excited by copper vapor laser, operating at 6 kHz pulse repetition frequency, was investigated. Large fluctuations in spectral width (about 5 nm) and spectral intensity in the fluorescence from stationary dye solution were observed, while fluctuations in the spectral width diminish in a flowing dye medium. However, this increases spectral intensity and slightly red shifts the fluorescence peak emission wavelength. Theoretical analysis was carried out to explain the observed results by incorporating the temperature induced refractive index, beam deflection and spectral variation in stationary dye solution. Numerical analysis of thermal load and contour of temperature in the optical pumped region inside the dye cell in stationary, 0.2 and 1.5 m/s flow velocity was also investigated to support our analysis. - Highlights: ► High repetition rate excitation generates inhomogeneity in the gain medium. ► Fluorescence of Rhodamine 6G in stationary and flowing medium was carried out. ► Fluorescence fluctuations lessen in flowing medium in contrast to stationary medium. ► Our theoretical and numerical analysis enlightens the experimented outcome trend.

  9. New results on spin determination of nanosatellite BLITS from High Repetition Rate SLR data

    Science.gov (United States)

    Kucharski, D.; Kirchner, G.; Lim, H.-C.; Koidl, F.

    2013-03-01

    The nanosatellite BLITS (Ball Lens In The Space) demonstrates a successful design of the new spherical lens type satellite for Satellite Laser Ranging (SLR). The spin parameters of the satellite were calculated from more than 1000 days of SLR data collected from 6 High Repetition Rate (HRR) systems: Beijing, Changchun, Graz, Herstmonceux, Potsdam, Shanghai.Analysis of the 892 passes (September 26, 2009-June 18, 2012) shows precession of the spin axis around orientation of the along track vector calculated at the launch epoch of the satellite RA = 9h16m39s, Dec = 43.1°. The spin period of BLITS remains stable with the mean value Tmean = 5.613 s, RMS = 11 ms. The incident angle between the spin axis and the symmetry axis of the body changes within 60° range.

  10. Heat accumulation during high repetition rate ultrafast laser interaction: Waveguide writing in borosilicate glass

    International Nuclear Information System (INIS)

    Zhang, Haibin; Eaton, Shane M; Li, Jianzhao; Herman, Peter R

    2007-01-01

    During high repetition rate (>200 kHz) ultrafast laser waveguide writing, visible heat modified zones surrounding the formed waveguide occur as a result of heat accumulation. The radii of the heat-modified zones increase with the laser net fluence, and were found to correlate with the formation of low-loss and cylindrically symmetric optical waveguides. A numerical thermal model based on the finite difference method is applied here to account for cumulative heating and diffusion effects. The model successfully shows that heat propagation and accumulation accurately predict the radius of the 'heat modified' zones observed in borosilicate glass waveguides formed across a wide range of laser exposure conditions. Such modelling promises better control of thermal effects for optimizing the fabrication and performance of three-dimensional optical devices in transparent materials

  11. High-power 355 nm ultraviolet lasers operating at ultrahigh repetition rate

    International Nuclear Information System (INIS)

    Chen, H; Liu, Q; Yan, P; Gong, M

    2013-01-01

    In this letter, we demonstrate a novel 355 nm ultraviolet (UV) laser operating at ultrahigh repetition rate from 300 kHz to 1 MHz. The hybrid fiber-MOPA–bulk amplifiers based IR source exhibits a high average power of 105 W with near-diffraction-limited beam quality, narrow linewidth and high polarization extinction ratio. Two-cascaded LBO crystals are employed for high efficiency frequency tripling, and a maximum 43.7 W of average UV power is achieved at 400 kHz, corresponding to a conversion efficiency as high as 41.6%. The pulse duration of the UV pulse can be tuned from 5 to 10 ns with good pulse peak stability (better than 2.2% (RMS)). (letter)

  12. High repetition rate tunable femtosecond pulses and broadband amplification from fiber laser pumped parametric amplifier.

    Science.gov (United States)

    Andersen, T V; Schmidt, O; Bruchmann, C; Limpert, J; Aguergaray, C; Cormier, E; Tünnermann, A

    2006-05-29

    We report on the generation of high energy femtosecond pulses at 1 MHz repetition rate from a fiber laser pumped optical parametric amplifier (OPA). Nonlinear bandwidth enhancement in fibers provides the intrinsically synchronized signal for the parametric amplifier. We demonstrate large tunability extending from 700 nm to 1500 nm of femtosecond pulses with pulse energies as high as 1.2 muJ when the OPA is seeded by a supercontinuum generated in a photonic crystal fiber. Broadband amplification over more than 85 nm is achieved at a fixed wavelength. Subsequent compression in a prism sequence resulted in 46 fs pulses. With an average power of 0.5 W these pulses have a peak-power above 10 MW. In particular, the average power and pulse energy scalability of both involved concepts, the fiber laser and the parametric amplifier, will enable easy up-scaling to higher powers.

  13. 200 ps FWHM and 100 MHz repetition rate ultrafast gated camera for optical medical functional imaging

    Science.gov (United States)

    Uhring, Wilfried; Poulet, Patrick; Hanselmann, Walter; Glazenborg, René; Zint, Virginie; Nouizi, Farouk; Dubois, Benoit; Hirschi, Werner

    2012-04-01

    The paper describes the realization of a complete optical imaging device to clinical applications like brain functional imaging by time-resolved, spectroscopic diffuse optical tomography. The entire instrument is assembled in a unique setup that includes a light source, an ultrafast time-gated intensified camera and all the electronic control units. The light source is composed of four near infrared laser diodes driven by a nanosecond electrical pulse generator working in a sequential mode at a repetition rate of 100 MHz. The resulting light pulses, at four wavelengths, are less than 80 ps FWHM. They are injected in a four-furcated optical fiber ended with a frontal light distributor to obtain a uniform illumination spot directed towards the head of the patient. Photons back-scattered by the subject are detected by the intensified CCD camera; there are resolved according to their time of flight inside the head. The very core of the intensified camera system is the image intensifier tube and its associated electrical pulse generator. The ultrafast generator produces 50 V pulses, at a repetition rate of 100 MHz and a width corresponding to the 200 ps requested gate. The photocathode and the Micro-Channel-Plate of the intensifier have been specially designed to enhance the electromagnetic wave propagation and reduce the power loss and heat that are prejudicial to the quality of the image. The whole instrumentation system is controlled by an FPGA based module. The timing of the light pulses and the photocathode gating is precisely adjustable with a step of 9 ps. All the acquisition parameters are configurable via software through an USB plug and the image data are transferred to a PC via an Ethernet link. The compactness of the device makes it a perfect device for bedside clinical applications.

  14. Design of a high repetition rate S-band photocathode gun

    International Nuclear Information System (INIS)

    Han Janghui; Cox, Matthew; Huang, Houcheng; Pande, Shivaji

    2011-01-01

    Photocathode RF guns have been developed in many laboratories for generating high quality electron beams for free-electron lasers based on linear accelerators. Such guns can generate electron beams with an exceptionally high peak current as well as a small transverse emittance. Their applications have been recently expanded for ultrafast electron diffraction, coherent terahertz radiation, and X-ray or γ-ray radiation by Compton scattering. In this paper, we design an S-band normal-conducting gun with capabilities of high quality beam generation and high repetition rate operation. The RF design and thermal analysis of the gun cavity and coupler are introduced. Optimal position of the gun focusing solenoid for low emittance beam generation is found by performing particle tracking simulations. Then, the gun system is designed to be able to afford the optimal solenoid position. The cooling-water channel surrounding the gun cavity and coupler is designed and analyzed numerically. The pressure in the gun is simulated with a vacuum model containing the detailed inner structure of the gun. An injector for a free-electron laser application is designed by using this gun and the beam dynamics simulation is shown. A cold test with a prototype gun for confirmation of the RF design is reported. - Highlights: → We design an S-band gun for low emittance beam generation and high repetition rate operation. → The RF design and thermal analysis of the gun cavity and coupler are studied. → An FEL injector is designed by using this gun and the beam dynamics simulation is shown. → A cold test with a prototype gun for confirmation of the RF design is reported.

  15. Marx, Production, Society and Archaeology

    Directory of Open Access Journals (Sweden)

    Lull, Vicente

    2005-06-01

    Full Text Available Social life is produced. Social life takes place before the fact of thinking about it. Drawing upon elements coming from utopian Socialism. British economy and, especially, Hegel’s philosophy, Marx proposed a set of dialectic categories addressed to thinking and to explaining how social life is produced, including in these dynamics the production of ourselves. In this paper, the guidelines of Marx’ thoughts are shown starting from the reading and analysis of his own texts. Also, the pertinence of the relationship between Marx and the research of society is argued through the material objects which make any society real: the archaeological research.

    La vida social se produce. La vida social es anterior al hecho de pensarla. Basándose en elementos procedentes del socialismo utópico, la economía británica y, sobre todo, la filosofía de Hegel, Marx propuso categorías dialécticas para pensar y explicar cómo se produce la vida social, y nosotros en ella. En este artículo se exponen las líneas básicas del pensamiento de Marx a partir de una lectura y análisis de sus propios textos, y se argumenta la pertinencia de la relación entre dicho pensamiento y la investigación de la sociedad a partir de los objetos materiales que la hicieron posible: la investigación arqueológica.

  16. Value and money in Marx

    Directory of Open Access Journals (Sweden)

    Fahd Boundi Chraki

    2018-04-01

    Full Text Available The aim of this paper is to examine the link between Marx's monetary theory and its explanation of value, production and circulation. For this, it presents the basic theoretical elements that allow a critique of the quantitative theory, the Chartalist conception of the genesis of money and the post-Keynesian theory of endogenous money. Then, from a Marxist perspective, it analyzes the controversial relationship between the monetization of public debt and the increase in the general level of prices.

  17. Pulsed laser deposition of SrRuO3 thin-films: The role of the pulse repetition rate

    Directory of Open Access Journals (Sweden)

    H. Schraknepper

    2016-12-01

    Full Text Available SrRuO3 thin-films were deposited with different pulse repetition rates, fdep, epitaxially on vicinal SrTiO3 substrates by means of pulsed laser deposition. The measurement of several physical properties (e.g., composition by means of X-ray photoelectron spectroscopy, the out-of-plane lattice parameter, the electric conductivity, and the Curie temperature consistently reveals that an increase in laser repetition rate results in an increase in ruthenium deficiency in the films. By the same token, it is shown that when using low repetition rates, approaching a nearly stoichiometric cation ratio in SrRuO3 becomes feasible. Based on these results, we propose a mechanism to explain the widely observed Ru deficiency of SrRuO3 thin-films. Our findings demand these theoretical considerations to be based on kinetic rather than widely employed thermodynamic arguments.

  18. [Medical history impressions of Karl Marx 1983].

    Science.gov (United States)

    Kaiser, W

    1983-12-15

    Excerpts of his London era first published on the occasion of the Karl Marx testimonials of 1983 gave rise to extend the memory of the fundamental achievements of Karl Marx to medico-historical aspects. In this case Karl Marx paid special attention to the working and living conditions of the working class and an analysis of his adequate statements and records shows multifarious details which give a research basis also for the history of medicine. Marx and Engels had friendly contacts with several physicians who shared the opinions of the two classics: their way of life is shown in the most important points.

  19. Efficient high-peak-power and high-repetition-rate eye-safe laser using an intracavity KTP OPO

    International Nuclear Information System (INIS)

    Guo, J; Jiao, Z X; Wang, B; He, G Y

    2015-01-01

    An efficient high-peak-power and high-repetition-rate intracavity KTP optical parametric oscillator pumped by a Q-switched Nd:YVO 4 laser is demonstrated. We achieved 1.5 W output power of 1.5 μm at 10 kHz repetition rate with the pulse duration of 6 ns. The maximum peak power of 25 kW and the maximum pulse energy of 150 μJ have been obtained. The maximum conversion efficiency of 9.5% is achieved with respect to a laser diode power of 10.5 W. (paper)

  20. Compact and high repetition rate Kerr-lens mode-locked 532 nm Nd:YVO4 laser

    International Nuclear Information System (INIS)

    Li, Zuohan; Peng, Jiying; Yuan, Ruixia; Yao, Jianquan; Zheng, Yi; Wang, Tongtong

    2015-01-01

    A compact and feasible CW Kerr-lens-induced mode-locked 532 nm Nd:YVO 4 laser system was experimentally demonstrated for the first time with theoretical analysis. Kerr-lens mode locking with intracavity second harmonic generation provides a promising method to generate a high-repetition-rate picosecond green laser. With an incident pump power of 6 W, the average output power of mode locking was 258 mW at a high repetition rate of 1.1 GHz. (paper)

  1. Development of a Watt-level gamma-ray source based on high-repetition-rate inverse Compton scattering

    Energy Technology Data Exchange (ETDEWEB)

    Mihalcea, D.; Murokh, A.; Piot, P.; Ruan, J.

    2017-07-01

    A high-brilliance (~1022 photon s-1 mm-2 mrad-2 /0.1%) gamma-ray source experiment is currently being planned at Fermilab (Eγ≃1.1 MeV). The source implements a high-repetition-rate inverse Compton scattering by colliding electron bunches formed in a ~300-MeV superconducting linac with a high-intensity laser pulse. This paper describes the design rationale along with some of technical challenges associated to producing high-repetition-rate collision. The expected performances of the gamma-ray source are also presented.

  2. Improved repetition rate mixed isotope CO{sub 2} TEA laser

    Energy Technology Data Exchange (ETDEWEB)

    Cohn, D. B., E-mail: dbctechnology@earthlink.net [DBC Technology Corp., 4221 Mesa St, Torrance, California 90505 (United States)

    2014-09-15

    A compact CO{sub 2} TEA laser has been developed for remote chemical detection that operates at a repetition rate of 250 Hz. It emits 700 mJ/pulse at 10.6 μm in a multimode beam with the {sup 12}C{sup 16}O{sub 2} isotope. With mixed {sup 12}C{sup 16}O{sub 2} plus {sup 13}C{sup 16}O{sub 2} isotopes it emits multiple lines in both isotope manifolds to improve detection of a broad range of chemicals. In particular, output pulse energies are 110 mJ/pulse at 9.77 μm, 250 mJ/pulse at 10 μm, and 550 mJ/pulse at 11.15 μm, useful for detection of the chemical agents Sarin, Tabun, and VX. Related work shows capability for long term sealed operation with a catalyst and an agile tuner at a wavelength shift rate of 200 Hz.

  3. Solid-state pulse modulator using Marx generator for a medical linac electron-gun

    Science.gov (United States)

    Lim, Heuijin; Hyeok Jeong, Dong; Lee, Manwoo; Lee, Mujin; Yi, Jungyu; Yang, Kwangmo; Ro, Sung Chae

    2016-04-01

    A medical linac is used for the cancer treatment and consists of an accelerating column, waveguide components, a magnetron, an electron-gun, a pulse modulator, and an irradiation system. The pulse modulator based on hydrogen thyratron-switched pulse-forming network is commonly used in linac. As the improvement of the high power semiconductors in switching speed, voltage rating, and current rating, an insulated gate bipolar transistor has become the more popular device used for pulsed power systems. We propose a solid-state pulse modulator to generator high voltage by multi-stacked storage-switch stages based on the Marx generator. The advantage of our modulator comes from the use of two semiconductors to control charging and discharging of the storage capacitor at each stage and it allows to generate the pulse with various amplitudes, widths, and shapes. In addition, a gate driver for two semiconductors is designed to reduce the control channels and to protect the circuits. It is developed for providing the pulsed power to a medical linac electron-gun that requires 25 kV and 1 A as the first application. In order to improve the power efficiency and achieve the compactness modulator, a capacitor charging power supply, a Marx pulse generator, and an electron-gun heater isolated transformer are constructed and integrated. This technology is also being developed to extend the high power pulsed system with > 1 MW and also other applications such as a plasma immersed ion implantation and a micro pulse electrostatic precipitator which especially require variable pulse shape and high repetition rate > 1 kHz. The paper describes the design features and the construction of this solid-state pulse modulator. Also shown are the performance results into the linac electron-gun.

  4. Solid-state pulse modulator using Marx generator for a medical linac electron-gun

    International Nuclear Information System (INIS)

    Lim, Heuijin; Jeong, Dong Hyeok; Lee, Manwoo; Lee, Mujin; Yi, Jungyu; Yang, Kwangmo; Ro, Sung Chae

    2016-01-01

    A medical linac is used for the cancer treatment and consists of an accelerating column, waveguide components, a magnetron, an electron-gun, a pulse modulator, and an irradiation system. The pulse modulator based on hydrogen thyratron-switched pulse-forming network is commonly used in linac. As the improvement of the high power semiconductors in switching speed, voltage rating, and current rating, an insulated gate bipolar transistor has become the more popular device used for pulsed power systems. We propose a solid-state pulse modulator to generator high voltage by multi-stacked storage-switch stages based on the Marx generator. The advantage of our modulator comes from the use of two semiconductors to control charging and discharging of the storage capacitor at each stage and it allows to generate the pulse with various amplitudes, widths, and shapes. In addition, a gate driver for two semiconductors is designed to reduce the control channels and to protect the circuits. It is developed for providing the pulsed power to a medical linac electron-gun that requires 25 kV and 1 A as the first application. In order to improve the power efficiency and achieve the compactness modulator, a capacitor charging power supply, a Marx pulse generator, and an electron-gun heater isolated transformer are constructed and integrated. This technology is also being developed to extend the high power pulsed system with > 1 MW and also other applications such as a plasma immersed ion implantation and a micro pulse electrostatic precipitator which especially require variable pulse shape and high repetition rate > 1 kHz. The paper describes the design features and the construction of this solid-state pulse modulator. Also shown are the performance results into the linac electron-gun

  5. High-repetition-rate laser-proton acceleration from a condensed hydrogen jet

    Energy Technology Data Exchange (ETDEWEB)

    Obst, Lieselotte; Zeil, Karl; Metzkes, Josefine; Schlenvoigt, Hans-Peter; Rehwald, Martin; Sommer, Philipp; Brack, Florian; Schramm, Ulrich [Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden (Germany); Goede, Sebastian; Gauthier, Maxence; Roedel, Christian; MacDonald, Michael; Schumaker, William; Glenzer, Siegfried [SLAC National Accelerator Laboratory, Stanford (United States)

    2016-07-01

    Applications of laser-accelerated protons demand a stable source of energetic particles at high repetition rates. We present the results of our experimental campaign in cooperation with MEC/SLAC at the 10Hz Ti:Sa laser Draco of Helmholtz-Zentrum Dresden-Rossendorf (HZDR), employing a pure condensed hydrogen jet as a renewable target. Draco delivers pulses of 30 fs and 5 J at 800 nm, focused to a 3 μm spot by an F/2.5 off-axis parabolic mirror. The jet's nominal electron density is approximately 30 times the critical density and its thickness is 2 μm, 5 μm or 10 μm, depending on the applied aperture on the source. Ion diagnostics reveal mono-species proton acceleration in a solid angle of at least +/-45 with respect to the incoming laser beam, with maximum energies of around 5 MeV. The expanding jet could be monitored on-shot with a temporally synchronized probe beam perpendicular to the pump laser axis. Recorded probe images resemble those of z-pinch experiments with metal wires and indicate an m=0 instability in the plasma.

  6. Direct writing of sub-wavelength ripples on silicon using femtosecond laser at high repetition rate

    International Nuclear Information System (INIS)

    Xie, Changxin; Li, Xiaohong; Liu, Kaijun; Zhu, Min; Qiu, Rong; Zhou, Qiang

    2016-01-01

    Graphical abstract: - Highlights: • The NSRs and DSRs are obtained on silicon surface. • With increasing direct writing speed, the NSRs suddenly changes and becomes the DSRs. • We develop a Sipe–Drude interference theory by considering the thermal excitation. - Abstract: The near sub-wavelength and deep sub-wavelength ripples on monocrystalline silicon were formed in air by using linearly polarized and high repetition rate femtosecond laser pulses (f = 76 MHz, λ = 800 nm, τ = 50 fs). The effects of laser pulse energy, direct writing speed and laser polarization on silicon surface morphology are studied. When the laser pulse energy is 2 nJ/pulse and the direct writing speed varies from 10 to 25 mm/s, the near sub-wavelength ripples (NSRs) with orientation perpendicular to the laser polarization are generated. While the direct writing speed reaches 30 mm/s, the direction of the obtained deep sub-wavelength ripples (DSRs) suddenly changes and becomes parallel to the laser polarization, rarely reported so far for femtosecond laser irradiation of silicon. Meanwhile, we extend the Sipe–Drude interference theory by considering the thermal excitation, and numerically calculate the efficacy factor for silicon irradiated by femtosecond laser pulses. The revised Sipe–Drude interference theoretical results show good agreement with the periods and orientations of sub-wavelength ripples.

  7. A HIGH REPETITION RATE VUV-SOFT X-RAY FEL CONCEPT

    International Nuclear Information System (INIS)

    Corlett, J.; Byrd, J.; Fawley, W.M.; Gullans, M.; Li, D.; Lidia, S.M.; Padmore, H.; Penn, G.; Pogorelov, I.; Qiang, J.; Robin, D.; Sannibale, F.; Staples, J.W.; Steier, C.; Venturini, M.; Virostek, S.; Wan, W.; Wells, R.; Wilcox, R.; Wurtele, J.; Zholents, A.

    2007-01-01

    We report on design studies for a seeded FEL light source that is responsive to the scientific needs of the future. The FEL process increases radiation flux by several orders of magnitude above existing incoherent sources, and offers the additional enhancements attainable by optical manipulations of the electron beam: control of the temporal duration and bandwidth of the coherent output, reduced gain length in the FEL, utilization of harmonics to attain shorter wavelengths, and precise synchronization of the x-ray pulse with seed laser systems. We describe an FEL facility concept based on a high repetition rate RF photocathode gun, that would allow simultaneous operation of multiple independent FEL's, each producing high average brightness, tunable over the VUV-soft x-ray range, and each with individual performance characteristics determined by the configuration of the FEL. SASE, enhanced-SASE (ESASE), seeded, harmonic generation, and other configurations making use of optical manipulations of the electron beam may be employed, providing a wide range of photon beam properties to meet varied user demands

  8. The effect of the pulse repetition rate on the fast ionization wave discharge

    Science.gov (United States)

    Huang, Bang-Dou; Carbone, Emile; Takashima, Keisuke; Zhu, Xi-Ming; Czarnetzki, Uwe; Pu, Yi-Kang

    2018-06-01

    The effect of the pulse repetition rate (PRR) on the generation of high energy electrons in a fast ionization wave (FIW) discharge is investigated by both experiment and modelling. The FIW discharge is driven by nanosecond high voltage pulses and is generated in helium with a pressure of 30 mbar. The axial electric field (E z ), as the driven force of high energy electron generation, is strongly influenced by PRR. Both the measurement and the model show that, during the breakdown, the peak value of E z decreases with the PRR, while after the breakdown, the value of E z increases with the PRR. The electron energy distribution function (EEDF) is calculated with a model similar to Boeuf and Pitchford (1995 Phys. Rev. E 51 1376). It is found that, with a low value of PRR, the EEDF during the breakdown is strongly non-Maxwellian with an elevated high energy tail, while the EEDF after the breakdown is also non-Maxwellian but with a much depleted population of high energy electrons. However, with a high value of PRR, the EEDF is Maxwellian-like without much temporal variation both during and after the breakdown. With the calculated EEDF, the temporal evolution of the population of helium excited species given by the model is in good agreement with the measured optical emission, which also depends critically on the shape of the EEDF.

  9. A high repetition rate transverse beam profile diagnostic for laser-plasma proton sources

    Science.gov (United States)

    Dover, Nicholas; Nishiuchi, Mamiko; Sakaki, Hironao; Kando, Masaki; Nishitani, Keita

    2016-10-01

    The recently upgraded J-KAREN-P laser can provide PW peak power and intensities approaching 1022 Wcm-2 at 0.1 Hz. Scaling of sheath acceleration to such high intensities predicts generation of protons to near 100 MeV, but changes in electron heating mechanisms may affect the emitted proton beam properties, such as divergence and pointing. High repetition rate simultaneous measurement of the transverse proton distribution and energy spectrum are therefore key to understanding and optimising the source. Recently plastic scintillators have been used to measure online proton beam transverse profiles, removing the need for time consuming post-processing. We are therefore developing a scintillator based transverse proton beam profile diagnostic for use in ion acceleration experiments using the J-KAREN-P laser. Differential filtering provides a coarse energy spectrum measurement, and time-gating allows differentiation of protons from other radiation. We will discuss the design and implementation of the diagnostic, as well as proof-of-principle results from initial experiments on the J-KAREN-P system demonstrating the measurement of sheath accelerated proton beams up to 20 MeV.

  10. Direct electron acceleration in plasma waveguides for compact high-repetition-rate x-ray sources

    International Nuclear Information System (INIS)

    Lin, M-W; Jovanovic, I

    2014-01-01

    Numerous applications in fundamental and applied research, security, and industry require robust, compact sources of x-rays, with a particular recent interest in monochromatic, spatially coherent, and ultrafast x-ray pulses in well-collimated beams. Such x-ray sources usually require production of high-quality electron beams from compact accelerators. Guiding a radially polarized laser pulse in a plasma waveguide has been proposed for realizing direct laser acceleration (DLA), where the electrons are accelerated by the axial electric field of a co-propagating laser pulse (Serafim et al 2000 IEEE Trans. Plasma Sci. 28 1190). A moderate laser peak power is required for DLA when compared to laser wakefield acceleration, thus offering the prospect for high repetition rate operation. By using a density-modulated plasma waveguide for DLA, the acceleration distance can be extended with pulse guiding, while the density-modulation with proper axial structure can realize the quasi-phase matching between the laser pulses and electrons for a net gain accumulation (York et al 2008 Phys. Rev. Lett. 100 195001; York et al 2008 J. Opt. Soc. Am. B 25 B137; Palastro et al 2008 Phys. Rev. E 77 036405). We describe the development and application of a test particle model and particle-in-cell model for DLA. Experimental setups designed for fabrication of optically tailored plasma waveguides via the ignitor-heater scheme, and for generation and characterization of radially polarized short pulses used to drive DLA, are presented. (paper)

  11. Choppers to optimise the repetition rate multiplication technique on a direct geometry neutron chopper spectrometer

    International Nuclear Information System (INIS)

    Vickery, A.; Deen, P. P.

    2014-01-01

    In recent years the use of repetition rate multiplication (RRM) on direct geometry neutron spectrometers has been established and is the common mode of operation on a growing number of instruments. However, the chopper configurations are not ideally optimised for RRM with a resultant 100 fold flux difference across a broad wavelength band. This paper presents chopper configurations that will produce a relative constant (RC) energy resolution and a relative variable (RV) energy resolution for optimised use of RRM. The RC configuration provides an almost uniform ΔE/E for all incident wavelengths and enables an efficient use of time as the entire dynamic range is probed with equivalent statistics, ideal for single shot measurements of transient phenomena. The RV energy configuration provides an almost uniform opening time at the sample for all incident wavelengths with three orders of magnitude in time resolution probed for a single European Spallation Source (ESS) period, which is ideal to probe complex relaxational behaviour. These two chopper configurations have been simulated for the Versatile Optimal Resolution direct geometry spectrometer, VOR, that will be built at ESS

  12. Practical aspects on a Marx generator construction

    International Nuclear Information System (INIS)

    Diniz, R.; Sudano, J.P.

    1991-01-01

    The practical aspects of Marx generator construction has been studied. The problems and the ways to solve them are related, once the tests with the Marx generator will continue until the specification with the 16 capacitors. (L.C.J.A.). 7 refs, 6 figs

  13. Marx voor de 21e eeuw

    NARCIS (Netherlands)

    van der Linden, M.M.; van der Velden, S.

    2008-01-01

    Karl Marx werd 190 jaar geleden geboren en is 125 jaar dood. Zo'n man uit de voorvorige eeuw heeft die ons eigenlijk nog wel iets te zeggen? Zijn zijn denkbeelden niet totaal verouderd? Ik denk persoonlijk dat het antwoord krachtig NEE moet luiden. Marx is niet verouderd, integendeel.

  14. Vibrational sum-frequency generation spectroscopy of lipid bilayers at repetition rates up to 100 kHz

    Science.gov (United States)

    Yesudas, Freeda; Mero, Mark; Kneipp, Janina; Heiner, Zsuzsanna

    2018-03-01

    Broadband vibrational sum-frequency generation (BB-VSFG) spectroscopy has become a well-established surface analytical tool capable of identifying the orientation and structure of molecular layers. A straightforward way to boost the sensitivity of the technique could be to increase the laser repetition rate beyond that of standard BB-VSFG spectrometers, which rely on Ti:sapphire lasers operating at repetition rates of 1-5 kHz. Nevertheless, possible thermally induced artifacts in the vibrational spectra due to higher laser average powers are unexplored. Here, we discuss laser power induced temperature accumulation effects that distort the BB-VSFG spectra of 1,2-diacyl-sn-glycero-3-phosphocholine at an interface between two transparent phases at repetition rates of 5, 10, 50, and 100 kHz at constant pulse energy. No heat-induced distortions were found in the spectra, suggesting that the increase in the laser repetition rate provides a feasible route to an improved signal-to-noise ratio or shorter data acquisition times in BB-VSFG spectroscopy for thin films on transparent substrates. The results have implications for future BB-VSFG spectrometers pushing the detection limit for molecular layers with low surface coverage.

  15. Marx et Engels, quelle politique? - Marx and Engels, which politics?

    Directory of Open Access Journals (Sweden)

    Michel Kail

    2012-10-01

    Full Text Available Under the cover of the crisis, the European media and intellectual milieu shows a renewed interest for Marx and Engels’ analyses. In order to integrate them in the omnipresent economic liberal thinking, these analyses need to be submitted to a process “economization”. There is an undeniable tendency toward “economization and “naturalization” in the works of Marx and Engels which helps to legitimize their critical project. But this “naturalization” process also leads to the confusion of reality with necessity and to the overlapping of the concept of the “ought” on the concept of “being”, while critical thinking actually distinguishes these two levels and questions their articulation. In the Manifesto of the Communist Party, the proletariat bears a project of emancipation since it expresses an inner contradiction of the capitalistic system. The proletariat is therefore stimulated by a determination which is outside the capitalistic system. This kind of conception does not leave any room for politics and in order to avoid this, one should not consider determinism as a principle of explanation but rather as an imperative of domination. The being of the proletariat is not determined, “essential”, but rather “relational” within a relationship of domination. It is not the essential being of the proletariat to spur struggle against capitalism but rather the struggle of the proletarians which historically qualifies being proletarian.

  16. Design study of a low-emittance high-repetition rate thermionic rf gun

    Directory of Open Access Journals (Sweden)

    A. Opanasenko

    2017-05-01

    Full Text Available We propose a novel gridless continuous-wave radiofrequency (rf thermionic gun capable of generating nC ns electron bunches with a rms normalized slice emittance close to the thermal level of 0.3 mm mrad. In order to gate the electron emission, an externally heated thermionic cathode is installed into a stripline-loop conductor. Two high-voltage pulses propagating towards each other in the stripline-loop overlap in the cathode region and create a quasielectrostatic field gating the electron emission. The repetition rate of pulses is variable and can reach up to one MHz with modern solid-state pulsers. The stripline attached to a rf gun cavity wall has with the wall a common aperture that allows the electrons to be injected into the rf cavity for further acceleration. Thanks to this innovative gridless design, simulations suggest that the bunch emittance is approximately at the thermal level after the bunch injection into the cavity provided that the geometry of the cathode and aperture are properly designed. Specifically, a concave cathode is adopted to imprint an Ƨ-shaped distribution onto the beam transverse phase-space to compensate for an S-shaped beam distribution created by the spherical aberration of the aperture-cavity region. In order to compensate for the energy spread caused by rf fields of the rf gun cavity, a 3rd harmonic cavity is used. A detailed study of the electrodynamics of the stripline and rf gun cavity as well as the beam optics and bunch dynamics are presented.

  17. Et kritisk blik på Marx og poesien

    DEFF Research Database (Denmark)

    Bredsdorff, Nils

    2005-01-01

    En undersøglse af Karl Marx' historiefilosofi, delvis med afsæt i et af Marx brugt digt af Goethe.......En undersøglse af Karl Marx' historiefilosofi, delvis med afsæt i et af Marx brugt digt af Goethe....

  18. Upper arm elevation and repetitive shoulder movements: a general population job exposure matrix based on expert ratings and technical measurements.

    Science.gov (United States)

    Dalbøge, Annett; Hansson, Gert-Åke; Frost, Poul; Andersen, Johan Hviid; Heilskov-Hansen, Thomas; Svendsen, Susanne Wulff

    2016-08-01

    We recently constructed a general population job exposure matrix (JEM), The Shoulder JEM, based on expert ratings. The overall aim of this study was to convert expert-rated job exposures for upper arm elevation and repetitive shoulder movements to measurement scales. The Shoulder JEM covers all Danish occupational titles, divided into 172 job groups. For 36 of these job groups, we obtained technical measurements (inclinometry) of upper arm elevation and repetitive shoulder movements. To validate the expert-rated job exposures against the measured job exposures, we used Spearman rank correlations and the explained variance[Formula: see text] according to linear regression analyses (36 job groups). We used the linear regression equations to convert the expert-rated job exposures for all 172 job groups into predicted measured job exposures. Bland-Altman analyses were used to assess the agreement between the predicted and measured job exposures. The Spearman rank correlations were 0.63 for upper arm elevation and 0.64 for repetitive shoulder movements. The expert-rated job exposures explained 64% and 41% of the variance of the measured job exposures, respectively. The corresponding calibration equations were y=0.5%time+0.16×expert rating and y=27°/s+0.47×expert rating. The mean differences between predicted and measured job exposures were zero due to calibration; the 95% limits of agreement were ±2.9% time for upper arm elevation >90° and ±33°/s for repetitive shoulder movements. The updated Shoulder JEM can be used to present exposure-response relationships on measurement scales. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  19. A hybrid pulse combining topology utilizing the combination of modularized avalanche transistor Marx circuits, direct pulse adding, and transmission line transformer.

    Science.gov (United States)

    Li, Jiangtao; Zhao, Zheng; Sun, Yi; Liu, Yuhao; Ren, Ziyuan; He, Jiaxin; Cao, Hui; Zheng, Minjun

    2017-03-01

    Numerous applications driven by pulsed voltage require pulses to be with high amplitude, high repetitive frequency, and narrow width, which could be satisfied by utilizing avalanche transistors. The output improvement is severely limited by power capacities of transistors. Pulse combining is an effective approach to increase the output amplitude while still adopting conventional pulse generating modules. However, there are drawbacks in traditional topologies including the saturation tendency of combining efficiency and waveform oscillation. In this paper, a hybrid pulse combining topology was adopted utilizing the combination of modularized avalanche transistor Marx circuits, direct pulse adding, and transmission line transformer. The factors affecting the combining efficiency were determined including the output time synchronization of Marx circuits, and the quantity and position of magnetic cores. The numbers of the parallel modules and the stages were determined by the output characteristics of each combining method. Experimental results illustrated the ability of generating pulses with 2-14 kV amplitude, 7-11 ns width, and a maximum 10 kHz repetitive rate on a matched 50-300 Ω resistive load. The hybrid topology would be a convinced pulse combining method for similar nanosecond pulse generators based on the solid-state switches.

  20. Repetition rate stabilization of an erbium-doped all-fiber laser via opto-mechanical control of the intracavity group velocity

    International Nuclear Information System (INIS)

    Shen, Xuling; He, Boqu; Zhao, Jian; Liu, Yang; Bai, Dongbi; Wang, Chao; Liu, Geping; Luo, Daping; Liu, Fengjiang; Li, Wenxue; Zeng, Heping; Yang, Kangwen; Hao, Qiang

    2015-01-01

    We present a method for stabilizing the repetition rate of an erbium-doped all-fiber laser by inserting an electronic polarization controller (EPC) in the fiber laser cavity. The device exhibited good integration, low cost, and convenient operation. Such a repetition rate stabilization may facilitate an all-fiber laser comb system with high integration. The repetition rate was phase-locked to a Rb reference more than 72 h with a low feedback voltage applied to one channel of the EPC. The repetition rate was 74.6 MHz. The standard deviation and the repetition rate linewidth were 1.4 and 1.7 mHz, respectively

  1. Tunable dispersion compensator based on uniform fiber Bragg grating and its application to tunable pulse repetition-rate multiplication.

    Science.gov (United States)

    Han, Young-Geun; Lee, Sang

    2005-11-14

    A new technique to control the chromatic dispersion of a uniform fiber Bragg grating based on the symmetrical bending is proposed and experimentally demonstrated. The specially designed two translation stages with gears and a sawtooth wheel can simultaneously induce the tension and compression strain corresponding to the bending direction. The tension and compression strain can effectively control the chirp ratio along the fiber grating attached on a flexible cantilever beam and consequently the dispersion value without the center wavelength shift. We successfully achieve the wide tuning range of chromatic dispersion without the center wavelength shift, which is less than 0.02 nm. We also reduce the group delay ripple as low as ~+/-5 ps. And we also demonstrate the application of the proposed tunable dispersion compensation technique to the tunable pulse repetition-rate multiplication and obtain high-quality pulses at repetition rates of 20 ~ 40 GHz.

  2. Ultrafast, high repetition rate, ultraviolet, fiber-laser-based source: application towards Yb+ fast quantum-logic.

    Science.gov (United States)

    Hussain, Mahmood Irtiza; Petrasiunas, Matthew Joseph; Bentley, Christopher D B; Taylor, Richard L; Carvalho, André R R; Hope, Joseph J; Streed, Erik W; Lobino, Mirko; Kielpinski, David

    2016-07-25

    Trapped ions are one of the most promising approaches for the realization of a universal quantum computer. Faster quantum logic gates could dramatically improve the performance of trapped-ion quantum computers, and require the development of suitable high repetition rate pulsed lasers. Here we report on a robust frequency upconverted fiber laser based source, able to deliver 2.5 ps ultraviolet (UV) pulses at a stabilized repetition rate of 300.00000 MHz with an average power of 190 mW. The laser wavelength is resonant with the strong transition in Ytterbium (Yb+) at 369.53 nm and its repetition rate can be scaled up using high harmonic mode locking. We show that our source can produce arbitrary pulse patterns using a programmable pulse pattern generator and fast modulating components. Finally, simulations demonstrate that our laser is capable of performing resonant, temperature-insensitive, two-qubit quantum logic gates on trapped Yb+ ions faster than the trap period and with fidelity above 99%.

  3. Optimization and phase matching of fiber-laser-driven high-order harmonic generation at high repetition rate.

    Science.gov (United States)

    Cabasse, Amélie; Machinet, Guillaume; Dubrouil, Antoine; Cormier, Eric; Constant, Eric

    2012-11-15

    High-repetition-rate sources are very attractive for high-order harmonic generation (HHG). However, due to their pulse characteristics (low energy, long duration), those systems require a tight focusing geometry to achieve the necessary intensity to generate harmonics. In this Letter, we investigate theoretically and experimentally the optimization of HHG in this geometry, to maximize the extreme UV (XUV) photon flux and improve the conversion efficiency. We analyze the influence of atomic gas media (Ar, Kr, or Xe), gas pressure, and interaction geometries (a gas jet and a finite and a semi-infinite gas cell). Numerical simulations allow us to define optimal conditions for HHG in this tight focusing regime and to observe the signature of on-axis phase matching. These conditions are implemented experimentally using a high-repetition-rate Yb-doped fiber laser system. We achieve optimization of emission with a recorded XUV photon flux of 4.5×10(12) photons/s generated in Xe at 100 kHz repetition rate.

  4. Optically stabilized Erbium fiber frequency comb with hybrid mode-locking and a broad tunable range of repetition rate.

    Science.gov (United States)

    Yang, Honglei; Wu, Xuejian; Zhang, Hongyuan; Zhao, Shijie; Yang, Lijun; Wei, Haoyun; Li, Yan

    2016-12-01

    We present an optically stabilized Erbium fiber frequency comb with a broad repetition rate tuning range based on a hybrid mode-locked oscillator. We lock two comb modes to narrow-linewidth reference lasers in turn to investigate the best performance of control loops. The control bandwidth of fast and slow piezoelectric transducers reaches 70 kHz, while that of pump current modulation with phase-lead compensation is extended to 32 kHz, exceeding laser intrinsic response. Eventually, simultaneous lock of both loops is realized to totally phase-stabilize the comb, which will facilitate precision dual-comb spectroscopy, laser ranging, and timing distribution. In addition, a 1.8-MHz span of the repetition rate is achieved by an automatic optical delay line that is helpful in manufacturing a secondary comb with a similar repetition rate. The oscillator is housed in a homemade temperature-controlled box with an accuracy of ±0.02  K, which not only keeps high signal-to-noise ratio of the beat notes with reference lasers, but also guarantees self-starting at the same mode-locking every time.

  5. Development of a high repetition rate laser-plasma accelerator for ultra-fast electron diffraction experiments

    International Nuclear Information System (INIS)

    Beaurepaire, B.

    2009-01-01

    Electronic microscopy and electron diffraction allowed the understanding of the organization of atoms in matter. Using a temporally short source, one can measure atomic displacements or modifications of the electronic distribution in matter. To date, the best temporal resolution for time resolved diffraction experiments is of the order of a hundred femto-seconds (fs). Laser accelerators are good candidates to reach the femtosecond temporal resolution in electron diffraction experiments. Such accelerators used to work at a low repetition rate, so that it was necessary to develop a new one operating at a high repetition rate in order to accumulate a large amount of data. In this thesis, a laser-plasma accelerator operating at the kHz repetition rate was developed and built. This source generates electron bunches at 100 keV from 3 mJ and 25 fs laser pulses. The physics of the acceleration has been studied, and the effect of the laser wavefront on the electron transverse distribution has been demonstrated. (author)

  6. A Simulation of the Effects of Varying Repetition Rate and Pulse Width of Nanosecond Discharges on Premixed Lean Methane-Air Combustion

    Directory of Open Access Journals (Sweden)

    Moon Soo Bak

    2012-01-01

    Full Text Available Two-dimensional kinetic simulation has been carried out to investigate the effects of repetition rate and pulse width of nanosecond repetitively pulsed discharges on stabilizing premixed lean methane-air combustion. The repetition rate and pulse width are varied from 10 kHz to 50 kHz and from 9 ns to 2 ns while the total power is kept constant. The lower repetition rates provide larger amounts of radicals such as O, H, and OH. However, the effect on stabilization is found to be the same for all of the tested repetition rates. The shorter pulse width is found to favor the production of species in higher electronic states, but the varying effects on stabilization are also found to be small. Our results indicate that the total deposited power is the critical element that determines the extent of stabilization over this range of discharge properties studied.

  7. Ud med Freud, Marx og Lacan

    DEFF Research Database (Denmark)

    Clasen, Mathias

    2009-01-01

    Det er på høje tid, at humanister løsriver sig fra deres forældede teorier. Freud, Marx og Lacan skal erstattes med evolutionspsykologi, biologi og kognitionsvidenskab.......Det er på høje tid, at humanister løsriver sig fra deres forældede teorier. Freud, Marx og Lacan skal erstattes med evolutionspsykologi, biologi og kognitionsvidenskab....

  8. Marx versus Walras on Labour Exchange

    OpenAIRE

    Motohiro, Okada; Faculty of Economics, Konan University

    2011-01-01

    This paper compares Leon Walras's and Marx's thoughts on labour exchange, thereby illuminating the latter's perspective that can lead to a forceful counterargument to the neoclassical principle of labour exchange, for which the former affords a foundation. Both Walras and Marx distinguish between labour ability as a factor of production and labour as its service, but exhibit a striking contrast in their explanations of the distinction. Walras's distinction between 'personal faculties' and lab...

  9. Humanismo de Marx e industrialismo de Gramsci

    Directory of Open Access Journals (Sweden)

    Mario Alighiero Manacorda

    2017-05-01

    Full Text Available In this conference, which took place at UFSCar, Brazil, in 1987, Manacorda refutes the contemporary tendency to dissociate Gramsci from Marx. He emphasizes the deep connections between structures and superstructures and reverses the most common understanding of the economistic aspect of structures in Marx and the humanistic aspect of superstructures in Gramsci. So, he stresses the humanistic aspect in Marx and the “industrialistic” one in Gramsci for the purpose to show the unity between being and conscience in the thought of both authors. Nesta conferência, proferida em 1987 no PPGE/UFSCar, Brasil, Manacorda refuta a tendência contemporânea de dissociar Gramsci de Marx. Realçando as ligações profundas entre estruturas e superestruturas e invertendo o entendimento mais comum que lê em Marx, sobretudo, o aspecto economicista das estruturas, e em Gramsci, sobretudo, o aspecto humanístico das superestruturas, Manacorda afirma em Marx o aspecto humanístico e em Gramsci o aspecto “industrialístico” para mostrar a unidade entre ser e consciência no pensamento de ambos.

  10. What if Marx and Veblen met…

    Directory of Open Access Journals (Sweden)

    Takay Bahar Araz

    2014-01-01

    Full Text Available The aim of this study is to analyse both the differences and the similarities between Marx and Veblen regarding historical specificity, evolution, and alienation. Starting with their discussions on these subjects, this article builds on the analyses of capitalism. The goal of this study is not to collapse Marx and Veblen into one another but rather to understand capitalism by presenting the complementary relationship of the two economists’ analyses and to introduce an appropriate analytical framework for understanding capitalism. This study consists of three parts. The first part examines how Veblen regarded Marx’s analysis, and how Marx especially viewed Darwin’s theory of evolution. Marx’s approach to evolution and Veblen’s criticism of Marx on this topic will constitute the general framework of this part. The second part of the study evaluates the level of agreement or disagreement between Veblen and Marx on the idea of historicism from the perspective of dialectical materialism. The last part analyses Marx and Veblen’s different ideas of the concept of alienation. The two economists’ views on the capitalist system will be determined based on these three concepts, introducing the similarities between them as well as the differences.

  11. The effect of laser repetition rate on the LASiS synthesis of biocompatible silver nanoparticles in aqueous starch solution

    Directory of Open Access Journals (Sweden)

    Zamiri R

    2013-01-01

    Full Text Available Reza Zamiri,1 Azmi Zakaria,1,* Hossein Abbastabar Ahangar,2 Majid Darroudi,3 Golnoosh Zamiri,1 Zahid Rizwan,1 Gregor PC Drummen4,* 1Department of Physics, Faculty of Science, Universiti Putra Malaysia, Serdang, Selangor, Malaysia; 2Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, Selangor Darul Ehsan, Malaysia; 3Advanced Materials and Nanotechnology Laboratory, Institute of Advanced Technology (ITMA, Universiti Putra Malaysia, Serdang, Selangor, Malaysia; 4Bionanoscience and Bio-Imaging Program, Cellular Stress and Ageing Program, Bio&Nano-Solutions, Düsseldorf, Germany*These authors contributed to this work equallyAbstract: Laser ablation-based nanoparticle synthesis in solution is rapidly becoming popular, particularly for potential biomedical and life science applications. This method promises one pot synthesis and concomitant bio-functionalization, is devoid of toxic chemicals, does not require complicated apparatus, can be combined with natural stabilizers, is directly biocompatible, and has high particle size uniformity. Size control and reduction is generally determined by the laser settings; that the size and size distribution scales with laser fluence is well described. Conversely, the effect of the laser repetition rate on the final nanoparticle product in laser ablation is less well-documented, especially in the presence of stabilizers. Here, the influence of the laser repetition rate during laser ablation synthesis of silver nanoparticles in the presence of starch as a stabilizer was investigated. The increment of the repetition rate does not negatively influence the ablation efficiency, but rather shows increased productivity, causes a red-shift in the plasmon resonance peak of the silver–starch nanoparticles, an increase in mean particle size and size distribution, and a distinct lack of agglomerate formation. Optimal results were achieved at 10 Hz repetition rate, with a mean particle size of ~10 nm and a

  12. Laser-diode pumped self-mode-locked praseodymium visible lasers with multi-gigahertz repetition rate.

    Science.gov (United States)

    Zhang, Yuxia; Yu, Haohai; Zhang, Huaijin; Di Lieto, Alberto; Tonelli, Mauro; Wang, Jiyang

    2016-06-15

    We demonstrate efficient laser-diode pumped multi-gigahertz (GHz) self-mode-locked praseodymium (Pr3+) visible lasers with broadband spectra from green to deep red for the first time to our knowledge. With a Pr3+-doped GdLiF4 crystal, stable self-mode-locked visible pulsed lasers at the wavelengths of 522 nm, 607 nm, 639 nm, and 720 nm have been obtained with the repetition rates of 2.8 GHz, 3.1 GHz, 3.1 GHz, and 3.0 GHz, respectively. The maximum output power was 612 mW with the slope efficiency of 46.9% at 639 nm. The mode-locking mechanism was theoretically analyzed. The stable second-harmonic mode-locking with doubled repetition frequency was also realized based on the Fabry-Perot effect formed in the laser cavity. In addition, we find that the polarization directions were turned with lasing wavelengths. This work may provide a new way for generating efficient ultrafast pulses with high- and changeable-repetition rates in the visible range.

  13. Oral-diadochokinetic rates for Hebrew-speaking school-age children: real words vs. non-words repetition.

    Science.gov (United States)

    Icht, Michal; Ben-David, Boaz M

    2015-02-01

    Oral-diadochokinesis (DDK) tasks are a common tool for evaluating speech disorders. Usually, these tasks involve repetitions of non-words. It has been suggested that repeating real words can be more suitable for preschool children. But, the impact of using real words with elementary school children has not been studied yet. This study evaluated oral-DDK rates for Hebrew-speaking elementary school children using non-words and real words. The participants were 60 children, 9-11 years old, with normal speech and language development, who were asked to repeat "pataka" (non-word) and "bodeket" (Hebrew real word). Data replicate the advantage generally found for real word repetition with preschoolers. Children produced real words faster than non-words for all age groups, and repetition rates were higher for the older children. The findings suggest that adding real words to the standard oral-DDK task with elementary school children may provide a more comprehensive picture of oro-motor function.

  14. Investigation on repetition rate and pulse duration influences on ablation efficiency of metals using a high average power Yb-doped ultrafast laser

    Directory of Open Access Journals (Sweden)

    Lopez J.

    2013-11-01

    Full Text Available Ultrafast lasers provide an outstanding processing quality but their main drawback is the low removal rate per pulse compared to longer pulses. This limitation could be overcome by increasing both average power and repetition rate. In this paper, we report on the influence of high repetition rate and pulse duration on both ablation efficiency and processing quality on metals. All trials have been performed with a single tunable ultrafast laser (350 fs to 10ps.

  15. Lo Transindividual: de Simondon a Marx

    Directory of Open Access Journals (Sweden)

    Daniel Alvaro

    Full Text Available RESUMEN: El presente artículo trata de lo transindividual, un concepto fundamental en la teoría de la individuación elaborada por Gilbert Simondon (1924-1989, y de su vinculación con ciertas proposiciones de Karl Marx que tratan del individuo y la sociedad. Entre ambos autores existe una relación directa, evidenciada en cada uno de los textos donde Simondon hace mención a Marx y al marxismo en general. Pero también existe una relación indirecta, para nada evidente, que surge menos de lo que Simondon dice acerca de Marx que de lo que ciertos pensadores contemporáneos dicen sobre uno y otro. Aquí intento dar cuenta de ambos tipos de relaciones. Asimismo, me propongo introducir y comentar algunos pasajes de Marx que compiten en radicalidad y audacia con los que escribiera Simondon un siglo más tarde, y en los cuales quiero apoyar mi hipótesis de lectura, a saber, que Marx es un pensador de lo transindividual avant la lettre.

  16. Actual laser removal of black soiling crust from siliceous sandstone by high pulse repetition rate equipment: effects on surface morphology

    Directory of Open Access Journals (Sweden)

    Iglesias-Campos, M. A.

    2016-03-01

    Full Text Available This research project studies the role of pulse repetition rate in laser removal of black soiling crust from siliceous sandstone, and specifically, how laser fluence correlates with high pulse repetition rates in cleaning practice. The aim is to define practical cleaning processes and determine simple techniques for evaluation based on end-users’ perspective (restorers. Spot and surface tests were made using a Q-switched Nd:YAG laser system with a wide range of pulse repetition rates (5–200 Hz, systematically analysed and compared by macrophotography, portable microscope, stereomicroscope with 3D visualizing and area roughness measurements, SEM imaging and spectrophotometry. The results allow the conclusion that for operation under high pulse repetition rates the average of total energy applied per spot on a treated surface should be attendant upon fluence values in order to provide a systematic and accurate description of an actual laser cleaning intervention.En este trabajo se estudia el papel de la frecuencia de repetición en la limpieza láser de costras de contaminación sobre una arenisca silícea, y concretamente, como se relaciona fluencia y frecuencias elevadas en una limpieza real. Se pretende definir un procedimiento práctico de limpieza y determinar técnicas sencillas de evaluación desde el punto de vista de los usuarios finales (restauradores. Para el estudio se realizaron diferentes ensayos en spot y en superficie mediante un equipo Q-switched Nd:YAG con un amplio rango de frecuencias (5–200 Hz, que se analizaron y compararon sistemáticamente mediante macrofotografía, microscopio portátil, estereomicroscopio con visualización 3D y mediciones de rugosidad en área, imágenes SEM y espectrofotometría. Los resultados permiten proponer que, al trabajar con altas frecuencias, la media de la energía total depositada por spot en la superficie debería acompañar los valores de fluencia para describir y comprender mejor una

  17. Electron diffraction using ultrafast electron bunches from a laser-wakefield accelerator at kHz repetition rate

    Science.gov (United States)

    He, Z.-H.; Thomas, A. G. R.; Beaurepaire, B.; Nees, J. A.; Hou, B.; Malka, V.; Krushelnick, K.; Faure, J.

    2013-02-01

    We show that electron bunches in the 50-100 keV range can be produced from a laser wakefield accelerator using 10 mJ, 35 fs laser pulses operating at 0.5 kHz. It is shown that using a solenoid magnetic lens, the electron bunch distribution can be shaped. The resulting transverse and longitudinal coherence is suitable for producing diffraction images from a polycrystalline 10 nm aluminum foil. The high repetition rate, the stability of the electron source, and the fact that its uncorrelated bunch duration is below 100 fs make this approach promising for the development of sub-100 fs ultrafast electron diffraction experiments.

  18. Electron diffraction using ultrafast electron bunches from a laser-wakefield accelerator at kHz repetition rate

    Energy Technology Data Exchange (ETDEWEB)

    He, Z.-H.; Thomas, A. G. R.; Nees, J. A.; Hou, B.; Krushelnick, K. [Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48106-2099 (United States); Beaurepaire, B.; Malka, V.; Faure, J. [Laboratoire d' Optique Appliquee, ENSTA-CNRS-Ecole Polytechnique, UMR 7639, 91761 Palaiseau (France)

    2013-02-11

    We show that electron bunches in the 50-100 keV range can be produced from a laser wakefield accelerator using 10 mJ, 35 fs laser pulses operating at 0.5 kHz. It is shown that using a solenoid magnetic lens, the electron bunch distribution can be shaped. The resulting transverse and longitudinal coherence is suitable for producing diffraction images from a polycrystalline 10 nm aluminum foil. The high repetition rate, the stability of the electron source, and the fact that its uncorrelated bunch duration is below 100 fs make this approach promising for the development of sub-100 fs ultrafast electron diffraction experiments.

  19. Impedance-matched Marx generators

    Directory of Open Access Journals (Sweden)

    W. A. Stygar

    2017-04-01

    Full Text Available We have conceived a new class of prime-power sources for pulsed-power accelerators: impedance-matched Marx generators (IMGs. The fundamental building block of an IMG is a brick, which consists of two capacitors connected electrically in series with a single switch. An IMG comprises a single stage or several stages distributed axially and connected in series. Each stage is powered by a single brick or several bricks distributed azimuthally within the stage and connected in parallel. The stages of a multistage IMG drive an impedance-matched coaxial transmission line with a conical center conductor. When the stages are triggered sequentially to launch a coherent traveling wave along the coaxial line, the IMG achieves electromagnetic-power amplification by triggered emission of radiation. Hence a multistage IMG is a pulsed-power analogue of a laser. To illustrate the IMG approach to prime power, we have developed conceptual designs of two ten-stage IMGs with LC time constants on the order of 100 ns. One design includes 20 bricks per stage, and delivers a peak electrical power of 1.05 TW to a matched-impedance 1.22-Ω load. The design generates 113 kV per stage and has a maximum energy efficiency of 89%. The other design includes a single brick per stage, delivers 68 GW to a matched-impedance 19-Ω load, generates 113 kV per stage, and has a maximum energy efficiency of 90%. For a given electrical-power-output time history, an IMG is less expensive and slightly more efficient than a linear transformer driver, since an IMG does not use ferromagnetic cores.

  20. Impedance-matched Marx generators

    Science.gov (United States)

    Stygar, W. A.; LeChien, K. R.; Mazarakis, M. G.; Savage, M. E.; Stoltzfus, B. S.; Austin, K. N.; Breden, E. W.; Cuneo, M. E.; Hutsel, B. T.; Lewis, S. A.; McKee, G. R.; Moore, J. K.; Mulville, T. D.; Muron, D. J.; Reisman, D. B.; Sceiford, M. E.; Wisher, M. L.

    2017-04-01

    We have conceived a new class of prime-power sources for pulsed-power accelerators: impedance-matched Marx generators (IMGs). The fundamental building block of an IMG is a brick, which consists of two capacitors connected electrically in series with a single switch. An IMG comprises a single stage or several stages distributed axially and connected in series. Each stage is powered by a single brick or several bricks distributed azimuthally within the stage and connected in parallel. The stages of a multistage IMG drive an impedance-matched coaxial transmission line with a conical center conductor. When the stages are triggered sequentially to launch a coherent traveling wave along the coaxial line, the IMG achieves electromagnetic-power amplification by triggered emission of radiation. Hence a multistage IMG is a pulsed-power analogue of a laser. To illustrate the IMG approach to prime power, we have developed conceptual designs of two ten-stage IMGs with L C time constants on the order of 100 ns. One design includes 20 bricks per stage, and delivers a peak electrical power of 1.05 TW to a matched-impedance 1.22 -Ω load. The design generates 113 kV per stage and has a maximum energy efficiency of 89%. The other design includes a single brick per stage, delivers 68 GW to a matched-impedance 19 -Ω load, generates 113 kV per stage, and has a maximum energy efficiency of 90%. For a given electrical-power-output time history, an IMG is less expensive and slightly more efficient than a linear transformer driver, since an IMG does not use ferromagnetic cores.

  1. The Debates in Marx's Scholarship on Dimensions of Human nature ...

    African Journals Online (AJOL)

    Debates in Marx scholarship revolve around whether Karl Marx recognizes the individual and social dimensions of human nature and which of the two he prefers. This paper considers the debates in two ways. The first relates to Marx scholarship in favour of the individual dimension of human nature. The second concerns ...

  2. "Our Table Factory, Inc.": Learning Marx through Role Play

    Science.gov (United States)

    Maghbouleh, Neda; Childress, Clayton; Alamo-Pastrana, Carlos

    2015-01-01

    Marx's critique of capitalism remains foundational to the university social science curriculum yet little is known about how instructors teach Marx. In post-industrial, service-oriented economies, students are also increasingly disconnected from the conditions of industrial capitalism that animate Marx's analysis. Inspired by the discussion of how…

  3. Value in Capitalist Society : Rethinking Marx's Criticism of Capitalism

    NARCIS (Netherlands)

    Cobben, Paul

    2015-01-01

    Marx's analysis of the commodity results in his conception of Capital as substance in the form of alienation. While Hegel claims that substance can be understood as the realization of freedom, Marx shows this freedom to be alienated labor: abstract labor, which Marx identifies as the capitalist

  4. Marx and Education. Routledge Key Ideas in Education

    Science.gov (United States)

    Anyon, Jean

    2011-01-01

    There was only one Karl Marx, but there have been a multitude of Marxisms. This concise, introductory book by internationally renowned scholar Jean Anyon centers on the ideas of Marx that have been used in education studies as a guide to theory, analysis, research, and practice. "Marx and Education" begins with a brief overview of basic Marxist…

  5. Periodic structures on germanium induced by high repetition rate femtosecond laser

    Science.gov (United States)

    Lin, Xiaoming; Li, Xiaohong; Zhang, Yanbin; Xie, Changxin; Liu, Kaijun; Zhou, Qiang

    2018-05-01

    Laser-induced periodic surface structures (LIPSS) are studied on germanium surface in air by the femtosecond pulsed laser with repetition frequency of 76 MHz and wavelength λ of 800 nm. Three types of LIPSS were found and they are low-spatial-frequency LIPSS (LSFL), high-spatial-frequency LIPSS (HSFL), and LSFL superimposed with HSFL. The period ΛLSFL of LSFL shrinks quickly from approximately 650 nm to 400 nm (∼λ/2) when lowering the scanning speed. Comparatively, the period ΛHSFL of HSFL keeps almost constant between 90 and 100 nm (∼λ/8) when the scanning speed and the laser pulse energy vary. LSFL and HSFL coexist when the laser pulse energy is around 3.3 nJ/pulse and the scanning speed ranges between 3 and 8 mm/s. The surface plasmon polariton waves make a contribution to the formation of LIPSS and the fourth harmonic generation (FHG) might be involved in the formation of HSFL.

  6. Tropical cyclone turbulent mixing as observed by autonomous oceanic profilers with the high repetition rate

    International Nuclear Information System (INIS)

    Baranowski, D B; Malinowski, S P; Flatau, P J

    2011-01-01

    Changes in the ocean mixed layer caused by passage of two consecutive typhoons in the Western Pacific are presented. Ocean profiles were measured by a unique Argo float sampling the upper ocean in high repetition cycle with a period of about one day. It is shown that the typhoon passage coincides with cooling of the mixed layer and variations of its salinity. Independent data from satellite measurements of surface winds were used to set-up an and idealized numerical simulation of mixed layer evolution. Results, compared to Argo profiles, confirm known effect that cooling is a result of increased entrainment from the thermocline due to enhancement of turbulence in the upper ocean by the wind stress. Observed pattern of salinity changes in the mixed layer suggest important role of typhoon precipitation. Fast changes of the mixed layer in course of typhoon passage show that fast profiling (at least once a day) is crucial to study response of the upper ocean to tropical cyclone.

  7. Bright high-repetition-rate source of narrowband extreme-ultraviolet harmonics beyond 22 eV

    Energy Technology Data Exchange (ETDEWEB)

    Wang, He [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division; Xu, Yiming [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division; Ulonska, Stefan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division; Robinson, Joseph S. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division; Ranitovic, Predrag [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division; Kaindl, Robert A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division

    2015-06-11

    Novel table-top sources of extreme-ultraviolet light based on high-harmonic generation yield unique insight into the fundamental properties of molecules, nanomaterials or correlated solids, and enable advanced applications in imaging or metrology. Extending high-harmonic generation to high repetition rates portends great experimental benefits, yet efficient extreme-ultraviolet conversion of correspondingly weak driving pulses is challenging. In this article, we demonstrate a highly-efficient source of femtosecond extreme-ultraviolet pulses at 50-kHz repetition rate, utilizing the ultraviolet second-harmonic focused tightly into Kr gas. In this cascaded scheme, a photon flux beyond ≈3 × 1013 s-1 is generated at 22.3 eV, with 5 × 10-5 conversion efficiency that surpasses similar harmonics directly driven by the fundamental by two orders-of-magnitude. The enhancement arises from both wavelength scaling of the atomic dipole and improved spatio-temporal phase matching, confirmed by simulations. Finally, spectral isolation of a single 72-meV-wide harmonic renders this bright, 50-kHz extreme-ultraviolet source a powerful tool for ultrafast photoemission, nanoscale imaging and other applications.

  8. Labour in Capitalist Society : Marx's View

    OpenAIRE

    Tsuto, Masahiro

    2007-01-01

    Marx's view on labour is many-sided. I will argue the multiple character of labour in five aspects, based on his 1857-58 note. We can grasp his view in following five phases. Namely, (1) material metabolism between man and Nature, (2) abstract human labour, (3) labour and free time, (4) active and creative labour, and (5) painful labour. In general, Marx's statements on (3), (4) and (5) phases of labour are less in his "Capital" than in his 1857-58 note. This is the reason why we often deal w...

  9. Design of the individual Marx modules for the Atlas machine 36 megajoule, 25 megampere capacitor bank

    International Nuclear Information System (INIS)

    Reass, W.A.; Bowman, D.W.; Gribble, R.F.; Griego, J.R.; Thompson, C.; Parsons, W.M.

    1995-01-01

    This paper presents the preliminary electrical and mechanical design of the Atlas machine's 1.8 megajoule, 600 kV Marx modules. The modules are implemented with plastic cased capacitors similar to those developed for the Defense Nuclear Agency (DNA) ACE II and ACE IV machines. The double ended electrode capacitor style has been dubbed ''FASTCAP.'' Electrodes are provided for mounting rail-gaps on one side and flat plate transmission line damping resistors on the other. This provides for an extremely low circuit inductance. A series array of ten capacitors, each rated at 60 kV, 33.5 uF, and 60 kJ, with their five triggered rail-gaps, form a Marx submodule. Three Marx submodules are nested into a large G-10 fiberglass rack to form a complete Marx module. The module support rack has individual capacitor shelves that ease assembly and replacement. The Marx's design also facilitates construction, testing and verification of a modules performance prior to installation. Modules will be repaired or maintained in a separate test bay without affecting machine operation schedules. Railgap maintenance will become part of a regularly-scheduled preventative maintenance program as spare modules are installed and removed from the machine

  10. Research of narrow pulse width, high repetition rate, high output power fiber lasers for deep space exploration

    Science.gov (United States)

    Tang, Yan-feng; Li, Hong-zuo; Wang, Yan; Hao, Zi-qiang; Xiao, Dong-Ya

    2013-08-01

    As human beings expand the research in unknown areas constantly, the deep space exploration has become a hot research topic all over the world. According to the long distance and large amount of information transmission characteristics of deep space exploration, the space laser communication is the preferred mode because it has the advantages of concentrated energy, good security, and large information capacity and interference immunity. In a variety of laser source, fibre-optical pulse laser has become an important communication source in deep space laser communication system because of its small size, light weight and large power. For fiber lasers, to solve the contradiction between the high repetition rate and the peak value power is an important scientific problem. General Q technology is difficult to obtain a shorter pulse widths, This paper presents a DFB semiconductor laser integrated with Electro-absorption modulator to realize the narrow pulse width, high repetition rate of the seed source, and then using a two-cascaded high gain fiber amplifier as amplification mean, to realize the fibre-optical pulse laser with pulse width 3ns, pulse frequency 200kHz and peak power 1kW. According to the space laser atmospheric transmission window, the wavelength selects for 1.06um. It is adopted that full fibre technology to make seed source and amplification, pumping source and amplification of free-space coupled into fiber-coupled way. It can overcome that fibre lasers are vulnerable to changes in external conditions such as vibration, temperature drift and other factors affect, improving long-term stability. The fiber lasers can be modulated by PPM mode, to realize high rate modulation, because of its peak power, high transmission rate, narrow pulse width, high frequency stability, all technical indexes meet the requirements of the exploration of deep space communication technology.

  11. Some Educational Implications of Karl Marx's Communism

    Science.gov (United States)

    Hellerich, Gert

    1970-01-01

    According to the expressed ideas of Karl Marx, education should be viewed as a means to develop a person's whole potential and to make him a better human being. It is his contention that in a capitalist society, the educational process causes misery and exists solely to further entrench the power of the rich. (CK)

  12. Karl Marx: "A Swarthy Fellow from Trier."

    Science.gov (United States)

    Machalek, Richard

    1983-01-01

    Discussed are Marx's roles as a student, a journalist-scholar, a revolutionary, and a family member. Revealed is a political and intellectual figure of enormous stature and complexity, but a person typically human in passions and commitments, strengths, and shortcomings. (RM)

  13. Application of a high-repetition-rate laser diagnostic system for single-cycle-resolved imaging in internal combustion engines.

    Science.gov (United States)

    Hult, Johan; Richter, Mattias; Nygren, Jenny; Aldén, Marcus; Hultqvist, Anders; Christensen, Magnus; Johansson, Bengt

    2002-08-20

    High-repetition-rate laser-induced fluorescence measurements of fuel and OH concentrations in internal combustion engines are demonstrated. Series of as many as eight fluorescence images, with a temporal resolution ranging from 10 micros to 1 ms, are acquired within one engine cycle. A multiple-laser system in combination with a multiple-CCD camera is used for cycle-resolved imaging in spark-ignition, direct-injection stratified-charge, and homogeneous-charge compression-ignition engines. The recorded data reveal unique information on cycle-to-cycle variations in fuel transport and combustion. Moreover, the imaging system in combination with a scanning mirror is used to perform instantaneous three-dimensional fuel-concentration measurements.

  14. Time-gated single-photon detection module with 110 ps transition time and up to 80 MHz repetition rate

    Energy Technology Data Exchange (ETDEWEB)

    Buttafava, Mauro, E-mail: mauro.buttafava@polimi.it; Boso, Gianluca; Ruggeri, Alessandro; Tosi, Alberto [Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria, Piazza Leonardo Da Vinci 32, 20133 Milano (Italy); Dalla Mora, Alberto [Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo Da Vinci 32, 20133 Milano (Italy)

    2014-08-15

    We present the design and characterization of a complete single-photon counting module capable of time-gating a silicon single-photon avalanche diode with ON and OFF transition times down to 110 ps, at repetition rates up to 80 MHz. Thanks to this sharp temporal filtering of incoming photons, it is possible to reject undesired strong light pulses preceding (or following) the signal of interest, allowing to increase the dynamic range of optical acquisitions up to 7 decades. A complete experimental characterization of the module highlights its very flat temporal response, with a time resolution of the order of 30 ps. The instrument is fully user-configurable via a PC interface and can be easily integrated in any optical setup, thanks to its small and compact form factor.

  15. Time-gated single-photon detection module with 110 ps transition time and up to 80 MHz repetition rate

    International Nuclear Information System (INIS)

    Buttafava, Mauro; Boso, Gianluca; Ruggeri, Alessandro; Tosi, Alberto; Dalla Mora, Alberto

    2014-01-01

    We present the design and characterization of a complete single-photon counting module capable of time-gating a silicon single-photon avalanche diode with ON and OFF transition times down to 110 ps, at repetition rates up to 80 MHz. Thanks to this sharp temporal filtering of incoming photons, it is possible to reject undesired strong light pulses preceding (or following) the signal of interest, allowing to increase the dynamic range of optical acquisitions up to 7 decades. A complete experimental characterization of the module highlights its very flat temporal response, with a time resolution of the order of 30 ps. The instrument is fully user-configurable via a PC interface and can be easily integrated in any optical setup, thanks to its small and compact form factor

  16. Generation of tunable, high repetition rate frequency combs with equalized spectra using carrier injection based silicon modulators

    Science.gov (United States)

    Nagarjun, K. P.; Selvaraja, Shankar Kumar; Supradeepa, V. R.

    2016-03-01

    High repetition-rate frequency combs with tunable repetition rate and carrier frequency are extensively used in areas like Optical communications, Microwave Photonics and Metrology. A common technique for their generation is strong phase modulation of a CW-laser. This is commonly implemented using Lithium-Niobate based modulators. With phase modulation alone, the combs have poor spectral flatness and significant number of missing lines. To overcome this, a complex cascade of multiple intensity and phase modulators are used. A comb generator on Silicon based on these principles is desirable to enable on-chip integration with other functionalities while reducing power consumption and footprint. In this work, we analyse frequency comb generation in carrier injection based Silicon modulators. We observe an interesting effect in these comb generators. Enhanced absorption accompanying carrier injection, an undesirable effect in data modulators, shapes the amplitude here to enable high quality combs from a single modulator. Thus, along with reduced power consumption to generate a specific number of lines, the complexity has also been significantly reduced. We use a drift-diffusion solver and mode solver (Silvaco TCAD) along with Soref-Bennett relations to calculate the variations in refractive indices and absorption of an optimized Silicon PIN - waveguide modulator driven by an unbiased high frequency (10 Ghz) voltage signal. Our simulations demonstrate that with a device length of 1 cm, a driving voltage of 2V and minor shaping with a passive ring-resonator filter, we obtain 37 lines with a flatness better than 5-dB across the band and power consumption an order of magnitude smaller than Lithium-Niobate modulators.

  17. Evaluation of 25-gauge Quincke and 24 — gauge Gertie Marx ...

    African Journals Online (AJOL)

    Objective: To compare the insertion characteristics and rate of complications between 25-gauge Quincke and 24-gauge Gertie Marx needles. Design: Prospective, randomized. Setting: University of Benin Teaching Hospital; a university-affiliated tertiary centre. Subjects: Parturients (ASA 1 and 2) scheduled for elective ...

  18. High-energy, high-repetition-rate picosecond pulses from a quasi-CW diode-pumped Nd:YAG system.

    Science.gov (United States)

    Noom, Daniel W E; Witte, Stefan; Morgenweg, Jonas; Altmann, Robert K; Eikema, Kjeld S E

    2013-08-15

    We report on a high-power quasi-CW pumped Nd:YAG laser system, producing 130 mJ, 64 ps pulses at 1064 nm wavelength with a repetition rate of 300 Hz. Pulses from a Nd:YVO(4) oscillator are first amplified by a regenerative amplifier to the millijoule level and then further amplified in quasi-CW diode-pumped Nd:YAG modules. Pulsed diode pumping enables a high gain at repetition rates of several hundred hertz, while keeping thermal effects manageable. Birefringence compensation and multiple thermal-lensing-compensated relay-imaging stages are used to maintain a top-hat beam profile. After frequency doubling, 75 mJ pulses are obtained at 532 nm. The intensity stability is better than 1.1%, which makes this laser an attractive pump source for a high-repetition-rate optical parametric amplification system.

  19. Experimental investigation of different regimes of mode-locking in a high repetition rate passively mode-locked semiconductor quantum-dot laser.

    Science.gov (United States)

    Kéfélian, Fabien; O'Donoghue, Shane; Todaro, Maria Teresa; McInerney, John; Huyet, Guillaume

    2009-04-13

    We report experimental investigations on a two-section 16-GHz repetition rate InAs/GaAs quantum dot passively mode-locked laser. Near the threshold current, pseudo-periodic Q-switching with complex dynamics is exhibited. Mode-locking operation regimes characterized by different repetition rates and timing jitter levels are encountered up to twice the threshold current. Evolution of the RF spectrum and optical spectrum with current is compared. The different mode-locked regimes are shown to be associated with different spectral and temporal shapes, ranging from 1.3 to 6 ps. This point is discussed by introducing the existence of two different supermodes. Repetition rate evolution and timing jitter increase is attributed to the coupling between the dominant and the secondary supermodes.

  20. Development of high repetition rate nitric oxide planar laser induced fluorescence imaging

    Science.gov (United States)

    Jiang, Naibo

    This thesis has documented the development of a MHz repitition rate pulse burst laser system. Second harmonic and third harmonic efficiencies are improved by adding a Phase Conjugate Mirror to the system. Some high energy fundamental, second harmonic, and third harmonic burst sequences consisting of 1--12 pulses separated in time by between 4 and 12 microseconds are now routinely obtained. The reported burst envelopes are quite uniform. We have also demonstrated the ability to generate ultra-high frequency sequences of broadly wavelength tunable, high intensity laser pulses using a home built injection seeded Optical Parametric Oscillator (OPO), pumped by the second and third harmonic output of the pulse burst laser. Typical OPO output burst sequences consist of 6--10 pulses, separated in time by between 6 and 10 microseconds. With third harmonic pumping of the OPO system, we studied four conditions, two-crystal Singly Resonant OPO (SRO) cavity, three-crystal OPO cavity, single pass two-crystal Doubly Resonant OPO (DRO) cavity and double pass two-crystal OPO cavity. The double pass two-crystal OPO cavity gives the best operation in burst mode. For single pass OPO, the average total OPO conversion efficiency is approximately 25%. For double pass OPO, the average total OPO conversion efficiency is approximately 35%. As a preliminary work, we studied 532nm pumping of a single crystal OPO cavity. With single pulse pumping, the conversion efficiency can reach 30%. For both 355nm and 532nm pumping OPO, we have demonstrated injection seeding. The OPO output light linewidth is significantly narrowed. Some preliminary etalon traces are also reported. By mixing the OPO signal output at 622nm with residual third harmonic at 355nm, we obtained 226nm burst sequences with average pulse energy of ˜0.2 mJ. Injection seeding of the OPO increases the energy achieved by a factor of ˜2. 226nm burst sequences with reasonably uniform burst envelopes are reported. Using the system we

  1. A soft X-ray source based on a low divergence, high repetition rate ultraviolet laser

    Science.gov (United States)

    Crawford, E. A.; Hoffman, A. L.; Milroy, R. D.; Quimby, D. C.; Albrecht, G. F.

    The CORK code is utilized to evaluate the applicability of low divergence ultraviolet lasers for efficient production of soft X-rays. The use of the axial hydrodynamic code wih one ozone radial expansion to estimate radial motion and laser energy is examined. The calculation of ionization levels of the plasma and radiation rates by employing the atomic physics and radiation model included in the CORK code is described. Computations using the hydrodynamic code to determine the effect of laser intensity, spot size, and wavelength on plasma electron temperature are provided. The X-ray conversion efficiencies of the lasers are analyzed. It is observed that for a 1 GW laser power the X-ray conversion efficiency is a function of spot size, only weakly dependent on pulse length for time scales exceeding 100 psec, and better conversion efficiencies are obtained at shorter wavelengths. It is concluded that these small lasers focused to 30 micron spot sizes and 10 to the 14th W/sq cm intensities are useful sources of 1-2 keV radiation.

  2. High power RF oscillator with Marx generators

    International Nuclear Information System (INIS)

    Murase, Hiroshi; Hayashi, Izumi

    1980-01-01

    A method to maintain RF oscillation by using many Marx generators was proposed and studied experimentally. Many charging circuits were connected to an oscillator circuit, and successive pulsed charging was made. This successive charging amplified and maintained the RF oscillation. The use of vacuum gaps and high power silicon diodes improved the characteristics of RF current cut-off of the circuit. The efficiency of the pulsed charging from Marx generators to a condenser was theoretically investigated. The theoretical result showed the maximum efficiency of 0.98. The practical efficiency obtained by using a proposed circuit with a high power oscillator was in the range 0.50 to 0.56. The obtained effective output power of the RF pulses was 11 MW. The maximum holding time of the RF pulses was about 21 microsecond. (Kato, T.)

  3. High-average-power 2 μm few-cycle optical parametric chirped pulse amplifier at 100 kHz repetition rate.

    Science.gov (United States)

    Shamir, Yariv; Rothhardt, Jan; Hädrich, Steffen; Demmler, Stefan; Tschernajew, Maxim; Limpert, Jens; Tünnermann, Andreas

    2015-12-01

    Sources of long wavelengths few-cycle high repetition rate pulses are becoming increasingly important for a plethora of applications, e.g., in high-field physics. Here, we report on the realization of a tunable optical parametric chirped pulse amplifier at 100 kHz repetition rate. At a central wavelength of 2 μm, the system delivered 33 fs pulses and a 6 W average power corresponding to 60 μJ pulse energy with gigawatt-level peak powers. Idler absorption and its crystal heating is experimentally investigated for a BBO. Strategies for further power scaling to several tens of watts of average power are discussed.

  4. 2 ~ 5 times tunable repetition-rate multiplication of a 10 GHz pulse source using a linearly tunable, chirped fiber Bragg grating.

    Science.gov (United States)

    Lee, Ju Han; Chang, You; Han, Young-Geun; Kim, Sang; Lee, Sang

    2004-08-23

    We experimentally demonstrate a simple scheme for the tunable pulse repetition-rate multiplication based on the fractional Talbot effect in a linearly tunable, chirped fiber Bragg grating (FBG). The key component in this scheme is our linearly tunable, chirped FBG with no center wavelength shift, which was fabricated with the S-bending method using a uniform FBG. By simply tuning the group velocity dispersion of the chirped FBG, we readily multiply an original 8.5 ps, 10 GHz soliton pulse train by a factor of 2 ~ 5 to obtain high quality pulses at repetition-rates of 20 ~ 50 GHz without significantly changing the system configuration.

  5. Optically isolated, 2 kHz repetition rate, 4 kV solid-state pulse trigger generator.

    Science.gov (United States)

    Barnett, D H; Parson, J M; Lynn, C F; Kelly, P M; Taylor, M; Calico, S; Scott, M C; Dickens, J C; Neuber, A A; Mankowski, J J

    2015-03-01

    This paper presents the design and operation characteristics of a solid-state high voltage pulse generator. Its primary utilization is aimed at triggering a gaseous spark gap with high repeatability. Specifically, the trigger generator is designed to achieve a risetime on the order of 0.1 kV/ns to trigger the first stage, trigatron spark gap of a 10-stage, 500 kV Marx generator. The major design components are comprised of a 60 W constant current DC-DC converter for high voltage charging, a single 4 kV thyristor, a step-up pulse transformer, and magnetic switch for pulse steepening. A risetime of <30 ns and pulse magnitude of 4 kV is achieved matching the simulated performance of the design.

  6. Karl Marx dan Konsep Perjuangan Kelas Sosial

    Directory of Open Access Journals (Sweden)

    Indriaty Ismail

    2012-06-01

    Full Text Available ¬¬This article explores the history of the renowned world economic and political reformist, Karl Marx with a special focus on the social class concept. It also discusses to what extent that the Marx’s concept of social class struggle is capable to provide a way out to the proletariats, to free themselves from the chains of cruelty, violence and alienation in the capitalist system. Our main focal point is to scrutinize the relationship between the concepts of social class struggle and the need for a social revolution as a catalyst for the formation of a classless society. Along the way, we studied and analyzed the documents produced on the primary sources covering major works of Marx and the secondary sources consisting reviews of the Marx’s class concept. As a result, we found out that Marx’s concept of class fight is competent to represent the oppressed group to battle for their freedom rights. The Proletariat dictatorship attitude was used as their main shield to face the threat of the capitalist class. Marx’s ultimate success is realized through a burst of ideas and beliefs that supports the ideas of egalitarian Communism although many contradictions arise between the ideas of Marx and the 20th centuries Communism when they are translated into practice.

  7. Changes in patellofemoral pain resulting from repetitive impact landings are associated with the magnitude and rate of patellofemoral joint loading.

    Science.gov (United States)

    Atkins, Lee T; James, C Roger; Yang, Hyung Suk; Sizer, Phillip S; Brismée, Jean-Michel; Sawyer, Steven F; Powers, Christopher M

    2018-03-01

    Although a relationship between elevated patellofemoral forces and pain has been proposed, it is unknown which joint loading variable (magnitude, rate) is best associated with pain changes. The purpose of this study was to examine associations among patellofemoral joint loading variables and changes in patellofemoral pain across repeated single limb landings. Thirty-one females (age: 23.5(2.8) year; height: 166.8(5.8) cm; mass: 59.6(8.1) kg) with PFP performed 5 landing trials from 0.25 m. The dependent variable was rate of change in pain obtained from self-reported pain scores following each trial. Independent variables included 5-trial averages of peak, time-integral, and average and maximum development rates of the patellofemoral joint reaction force obtained using a previously described model. Pearson correlation coefficients were calculated to evaluate individual associations between rate of change in pain and each independent variable (α = 0.05). Stepwise linear multiple regression (α enter  = 0.05; α exit  = 0.10) was used to identify the best predictor of rate of change in pain. Subjects reported an average increase of 0.38 pain points with each landing trial. Although, rate of change in pain was positively correlated with peak force (r = 0.44, p = 0.01), and average (r = 0.41, p = 0.02) and maximum force development rates (r = 0.39, p = 0.03), only the peak force entered the predictive model explaining 19% of variance in rate of change in pain (r 2  = 0.19, p = 0.01). Peak patellofemoral joint reaction force was the best predictor of the rate of change in pain following repetitive singe limb landings. The current study supports the theory that patellofemoral joint loading contributes to changes in patellofemoral pain. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. HANNA ARENDT VERSUS MARX: UMA DEFESA DE MARX FRENTE À CRÍTICA ARENDTIANA

    Directory of Open Access Journals (Sweden)

    Júlia Sebba Ramalho

    2009-03-01

    Full Text Available O presente trabalho trata das críticas de Hanna Arendt a Karl Marx especificamentena obra de Arendt A condição humana. No capítulo III desta obra Arendt versa sobre a atividadedo trabalho que, segundo ela, emergiu na Era Moderna como o principal foco das preocupaçõeshumanas. Para a autora a expressão teórica mais elaborada da emergência do animal laborans éa obra de Marx. Desse modo, toda a discussão do capítulo III de A condição humana gira emtorno das críticas de Arendt a Marx. No presente artigo trataremos de elucidar os aspectoscentrais desta crítica e de mostrar os equívocos de Arendt em sua leitura da obra marxiana.

  9. Test-Retest Reliability of Rating of Perceived Exertion and Agreement With 1-Repetition Maximum in Adults.

    Science.gov (United States)

    Bove, Allyn M; Lynch, Andrew D; DePaul, Samantha M; Terhorst, Lauren; Irrgang, James J; Fitzgerald, G Kelley

    2016-09-01

    Study Design Clinical measurement. Background It has been suggested that rating of perceived exertion (RPE) may be a useful alternative to 1-repetition maximum (1RM) to determine proper resistance exercise dosage. However, the test-retest reliability of RPE for resistance exercise has not been determined. Additionally, prior research regarding the relationship between 1RM and RPE is conflicting. Objectives The purpose of this study was to (1) determine test-retest reliability of RPE related to resistance exercise and (2) assess agreement between percentages of 1RM and RPE during quadriceps resistance exercise. Methods A sample of participants with and without knee pathology completed a series of knee extension exercises and rated the perceived difficulty of each exercise on a 0-to-10 RPE scale, then repeated the procedure 1 to 2 weeks later for test-retest reliability. To determine agreement between RPE and 1RM, participants completed knee extension exercises at various percentages of their 1RM (10% to 130% of predicted 1RM) and rated the perceived difficulty of each exercise on a 0-to-10 RPE scale. Percent agreement was calculated between the 1RM and RPE at each resistance interval. Results The intraclass correlation coefficient indicated excellent test-retest reliability of RPE for quadriceps resistance exercises (intraclass correlation coefficient = 0.895; 95% confidence interval: 0.866, 0.918). Overall percent agreement between RPE and 1RM was 60%, but agreement was poor within the ranges that would typically be used for training (50% 1RM for muscle endurance, 70% 1RM and greater for strength). Conclusion Test-retest reliability of perceived exertion during quadriceps resistance exercise was excellent. However, agreement between the RPE and 1RM was poor, especially in common training zones for knee extensor strengthening. J Orthop Sports Phys Ther 2016;46(9):768-774. Epub 5 Aug 2016. doi:10.2519/jospt.2016.6498.

  10. Measurement of acoustic velocity components in a turbulent flow using LDV and high-repetition rate PIV

    Science.gov (United States)

    Léon, Olivier; Piot, Estelle; Sebbane, Delphine; Simon, Frank

    2017-06-01

    The present study provides theoretical details and experimental validation results to the approach proposed by Minotti et al. (Aerosp Sci Technol 12(5):398-407, 2008) for measuring amplitudes and phases of acoustic velocity components (AVC) that are waveform parameters of each component of velocity induced by an acoustic wave, in fully turbulent duct flows carrying multi-tone acoustic waves. Theoretical results support that the turbulence rejection method proposed, based on the estimation of cross power spectra between velocity measurements and a reference signal such as a wall pressure measurement, provides asymptotically efficient estimators with respect to the number of samples. Furthermore, it is shown that the estimator uncertainties can be simply estimated, accounting for the characteristics of the measured flow turbulence spectra. Two laser-based measurement campaigns were conducted in order to validate the acoustic velocity estimation approach and the uncertainty estimates derived. While in previous studies estimates were obtained using laser Doppler velocimetry (LDV), it is demonstrated that high-repetition rate particle image velocimetry (PIV) can also be successfully employed. The two measurement techniques provide very similar acoustic velocity amplitude and phase estimates for the cases investigated, that are of practical interest for acoustic liner studies. In a broader sense, this approach may be beneficial for non-intrusive sound emission studies in wind tunnel testings.

  11. Determination of trace amounts of plutonium in environmental samples by RIMS using a high repetition rate solid state laser system

    International Nuclear Information System (INIS)

    Gruening, C.; Kratz, J.V.; Trautmann, N.; Waldek, A.; Huber, G.; Passler, G.; Wendt, K.

    2001-01-01

    A reliable and easy to handle high repetition rate solid state laser system has been set up for routine applications of Resonance Ionization Mass Spectrometry (RIMS). It consists of three Titanium-Sapphire (Ti:Sa) lasers pumped by one Nd:YAG laser, providing up to 3 W of tunable laser light each in a wavelength range from 725 nm to 895 nm. The isotope shifts for 238 Pu to 244 Pu have been measured in an efficient ionization scheme with λ 1 =420.76 nm, λ 2 =847.28 nm and λ 3 =767.53 nm. An overall detection efficiency of the RIMS apparatus of ε=1x10 -5 is routinely reached, resulting in a detection limit of 2x10 6 atoms (0.8 fg) of plutonium. The isotopic compositions of synthetic samples and the NIST standard reference material SRM996 were measured. The content of 238 Pu to 242 Pu has been determined in dust samples from the surroundings of a nuclear power plant and 244 Pu was determined in urine samples for the National Radiation Protection Board (NRPB), U.K. Routine operation of plutonium ultratrace detection could thus be established

  12. Thin liquid sheet target capabilities for ultra-intense laser acceleration of ions at a kHz repetition rate

    Science.gov (United States)

    Klim, Adam; Morrison, J.; Orban, C.; Chowdhury, E.; Frische, K.; Feister, S.; Roquemore, M.

    2017-10-01

    The success of laser-accelerated ion experiments depends crucially on a number of factors including how thin the targets can be created. We present experimental results demonstrating extremely thin (under 200 nm) glycol sheet targets that can be used for ultra-intense laser-accelerated ion experiments conducted at the Air Force Research Laboratory at Wright-Patterson Air Force Base. Importantly, these experiments operate at a kHz repetition rate and the recovery time of the liquid targets is fast enough to allow the laser to interact with a refreshed, thin target on every shot. These thin targets can be used to produce energetic electrons, light ions, and neutrons as well as x-rays, we present results from liquid glycol targets which are useful for proton acceleration experiments via the mechanism of Target Normal Sheath Acceleration (TNSA). In future work, we will create thin sheets from deuterated water in order to perform laser-accelerated deuteron experiments. This research was sponsored by the Quantum and Non-Equilibrium Processes Division of the AFOSR, under the management of Dr. Enrique Parra, and support from the DOD HPCMP Internship Program.

  13. 500 MW peak power degenerated optical parametric amplifier delivering 52 fs pulses at 97 kHz repetition rate.

    Science.gov (United States)

    Rothhardt, J; Hädrich, S; Röser, F; Limpert, J; Tünnermann, A

    2008-06-09

    We present a high peak power degenerated parametric amplifier operating at 1030 nm and 97 kHz repetition rate. Pulses of a state-of-the art fiber chirped-pulse amplification (FCPA) system with 840 fs pulse duration and 410 microJ pulse energy are used as pump and seed source for a two stage optical parametric amplifier. Additional spectral broadening of the seed signal in a photonic crystal fiber creates enough bandwidth for ultrashort pulse generation. Subsequent amplification of the broadband seed signal in two 1 mm BBO crystals results in 41 microJ output pulse energy. Compression in a SF 11 prism compressor yields 37 microJ pulses as short as 52 fs. Thus, pulse shortening of more than one order of magnitude is achieved. Further scaling in terms of average power and pulse energy seems possible and will be discussed, since both concepts involved, the fiber laser and the parametric amplifier have the reputation to be immune against thermo-optical effects.

  14. Accumulation effects in modulation spectroscopy with high-repetition-rate pulses: Recursive solution of optical Bloch equations

    Science.gov (United States)

    Osipov, Vladimir Al.; Pullerits, Tõnu

    2017-10-01

    Application of the phase-modulated pulsed light for advance spectroscopic measurements is the area of growing interest. The phase modulation of the light causes modulation of the signal. Separation of the spectral components of the modulations allows to distinguish the contributions of various interaction pathways. The lasers with high repetition rate used in such experiments can lead to appearance of the accumulation effects, which become especially pronounced in systems with long-living excited states. Recently it was shown that such accumulation effects can be used to evaluate parameters of the dynamical processes in the material. In this work we demonstrate that the accumulation effects are also important in the quantum characteristics measurements provided by modulation spectroscopy. In particular, we consider a model of quantum two-level system driven by a train of phase-modulated light pulses, organized in analogy with the two-dimensional spectroscopy experiments. We evaluate the harmonics' amplitudes in the fluorescent signal and calculate corrections appearing from the accumulation effects. We show that the corrections can be significant and have to be taken into account at analysis of experimental data.

  15. Efficacy Of The Repetitions In Reserve-Based Rating Of Perceived Exertion For The Bench Press In Experienced And Novice Benchers.

    Science.gov (United States)

    Ormsbee, Michael J; Carzoli, Joseph P; Klemp, Alex; Allman, Brittany R; Zourdos, Michael C; Kim, Jeong-Su; Panton, Lynn B

    2017-03-13

    Autoregulation (AR) is the practice of adjusting training variables in response to athlete feedback. One component of AR postulated to enhance resistance training adaptations involves implementing a resistance training-specific rating of perceived exertion (RPE) scale measuring repetitions in reserve (RIR). The purpose of this study was to examine the efficacy of this method using the bench press exercise. Twenty-seven college-aged men were assigned to one of two groups based upon training age: experience benchers (EB) (n=14, training age: 4.7±2.0 yrs) and novice benchers (NB) (n=13, training age: 1.1±0.6 yrs). Subjects performed one-repetition maximum (1RM) followed by single-repetition sets with loads corresponding to 60, 75, and 90% of 1RM and an 8-repetition set at 70% 1RM. Subjects reported a corresponding RPE, based on RIR, for every set. Average velocity was recorded for each single-repetition set along with the first and last repetitions of the 8-repetition set at 70% 1RM. Average velocity at 100% of 1RM in EB was slower (0.14±0.04 m[BULLET OPERATOR]s) compared to NB (0.20±0.05 m[BULLET OPERATOR]s) (pvelocity or RPE at any other intensity. Both EB (r=0.85, pvelocity and RPE at all intensities. Our findings suggest that the RIR-based RPE scale may be an efficacious approach for AR of bench press training load and volume in college-aged men.

  16. Phase-stable, multi-µJ femtosecond pulses from a repetition-rate tunable Ti:Sa-oscillator-seeded Yb-fiber amplifier

    Science.gov (United States)

    Saule, T.; Holzberger, S.; De Vries, O.; Plötner, M.; Limpert, J.; Tünnermann, A.; Pupeza, I.

    2017-01-01

    We present a high-power, MHz-repetition-rate, phase-stable femtosecond laser system based on a phase-stabilized Ti:Sa oscillator and a multi-stage Yb-fiber chirped-pulse power amplifier. A 10-nm band around 1030 nm is split from the 7-fs oscillator output and serves as the seed for subsequent amplification by 54 dB to 80 W of average power. The µJ-level output is spectrally broadened in a solid-core fiber and compressed to 30 fs with chirped mirrors. A pulse picker prior to power amplification allows for decreasing the repetition rate from 74 MHz by a factor of up to 4 without affecting the pulse parameters. To compensate for phase jitter added by the amplifier to the feed-forward phase-stabilized seeding pulses, a self-referencing feed-back loop is implemented at the system output. An integrated out-of-loop phase noise of less than 100 mrad was measured in the band from 0.4 Hz to 400 kHz, which to the best of our knowledge corresponds to the highest phase stability ever demonstrated for high-power, multi-MHz-repetition-rate ultrafast lasers. This system will enable experiments in attosecond physics at unprecedented repetition rates, it offers ideal prerequisites for the generation and field-resolved electro-optical sampling of high-power, broadband infrared pulses, and it is suitable for phase-stable white light generation.

  17. Low-timing-jitter, stretched-pulse passively mode-locked fiber laser with tunable repetition rate and high operation stability

    International Nuclear Information System (INIS)

    Liu, Yuanshan; Zhang, Jian-Guo; Chen, Guofu; Zhao, Wei; Bai, Jing

    2010-01-01

    We design a low-timing-jitter, repetition-rate-tunable, stretched-pulse passively mode-locked fiber laser by using a nonlinear amplifying loop mirror (NALM), a semiconductor saturable absorber mirror (SESAM), and a tunable optical delay line in the laser configuration. Low-timing-jitter optical pulses are stably produced when a SESAM and a 0.16 m dispersion compensation fiber are employed in the laser cavity. By inserting a tunable optical delay line between NALM and SESAM, the variable repetition-rate operation of a self-starting, passively mode-locked fiber laser is successfully demonstrated over a range from 49.65 to 50.47 MHz. The experimental results show that the newly designed fiber laser can maintain the mode locking at the pumping power of 160 mW to stably generate periodic optical pulses with width less than 170 fs and timing jitter lower than 75 fs in the 1.55 µm wavelength region, when the fundamental repetition rate of the laser is continuously tuned between 49.65 and 50.47 MHz. Moreover, this fiber laser has a feature of turn-key operation with high repeatability of its fundamental repetition rate in practice

  18. Performance of a high repetition pulse rate laser system for in-gas-jet laser ionization studies with the Leuven laser ion source LISOL

    International Nuclear Information System (INIS)

    Ferrer, R.; Sonnenschein, V.T.; Bastin, B.; Franchoo, S.; Huyse, M.; Kudryavtsev, Yu.; Kron, T.; Lecesne, N.; Moore, I.D.; Osmond, B.; Pauwels, D.; Radulov, D.; Raeder, S.; Rens, L.

    2012-01-01

    The laser ionization efficiency of the Leuven gas cell-based laser ion source was investigated under on- and off-line conditions using two distinctly different laser setups: a low-repetition rate dye laser system and a high-repetition rate Ti:sapphire laser system. A systematic study of the ion signal dependence on repetition rate and laser pulse energy was performed in off-line tests using stable cobalt and copper isotopes. These studies also included in-gas-jet laser spectroscopy measurements on the hyperfine structure of 63 Cu. A final run under on-line conditions in which the radioactive isotope 59 Cu (T 1/2 = 81.5 s) was produced, showed a comparable yield of the two laser systems for in-gas-cell ionization. However, a significantly improved time overlap by using the high-repetition rate laser system for in-gas-jet ionization was demonstrated by an increase of the overall duty cycle, and at the same time, pointed to the need for a better shaped atomic jet to reach higher ionization efficiencies.

  19. Narrow Q-switching pulse width and low mode-locking repetition rate Q-switched mode locking with a new coupled laser cavity

    International Nuclear Information System (INIS)

    Peng, J Y; Zheng, Y; Shen, J P; Shi, Y X

    2013-01-01

    An original diode-pumped Q-switched and mode-locked solid state Nd:GdVO 4 laser is demonstrated. The laser operates with double saturable absorbers and a new coupled laser cavity. The Q-switching envelope width is compressed to be about 15 ns and the mode-locking repetition rate is as low as 90 MHz. (paper)

  20. Improving the ablation efficiency of excimer laser systems with higher repetition rates through enhanced debris removal and optimized spot pattern.

    Science.gov (United States)

    Arba-Mosquera, Samuel; Klinner, Thomas

    2014-03-01

    To evaluate the reasons for the required increased radiant exposure for higher-repetition-rate excimer lasers and determine experimentally possible compensations to achieve equivalent ablation profiles maintaining the same single-pulse energies and radiant exposures for laser repetition rates ranging from 430 to 1000 Hz. Schwind eye-tech-solutions GmbH and Co. KG, Kleinostheim, Germany. Experimental study. Poly(methyl methacrylate) (PMMA) plates were photoablated. The pulse laser energy was maintained during all experiments; the effects of the flow of the debris removal, the shot pattern for the correction, and precooling the PMMA plates were evaluated in terms of achieved ablation versus repetition rate. The mean ablation performance ranged from 88% to 100%; the variability between the profile measurements ranged from 1.4% to 6.2%. Increasing the laser repetition rate from 430 Hz to 1000 Hz reduced the mean ablation performance from 98% to 91% and worsened the variability from 1.9% to 4.3%. Increasing the flow of the debris removal, precooling the PMMA plates to -18°C, and adapting the shot pattern for the thermal response of PMMA to excimer ablation helped stabilize the variability. Only adapting the shot pattern for the thermal response of PMMA to excimer ablation helped stabilize the mean ablation performance. The ablation performance of higher-repetition-rate excimer lasers on PMMA improved with improvements in the debris removal systems and shot pattern. More powerful debris removal systems and smart shot patterns in terms of thermal response improved the performance of these excimer lasers. Copyright © 2014 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  1. Karl Marx as a Social Scientist and Utopian Dreamer.

    Science.gov (United States)

    Stevenson, James A.

    The central paradox of Karl Marx's work is his belief that the vision of mankind leaving inequality and scarcity behind is attainable. The idea that human alienation, inequality, and need could be rendered obsolete by a future communist society of abundance is a significant failing in Marx's thought. It is at the same time the critical element in…

  2. Design of a Marx-Topology Modulator for FNAL Linac

    Energy Technology Data Exchange (ETDEWEB)

    Butler, T. A. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Garcia, F. G. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Kufer, M. R. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Pfeffer, H. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Wolff, D. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2015-04-28

    The Fermilab Proton Improvement Plan (PIP) was formed in late 2011 to address important and necessary upgrades to the Proton Source machines (Injector line, Linac and Booster). The goal is to increase the proton flux by doubling the Booster beam cycle rate while maintaining the same intensity per cycle, the same uptime, and the same residual activation in the enclosure. For the Linac, the main focus within PIP is to address reliability. One of the main tasks is to replace the present hard-tube modulator used on the 200 MHz RF system. Plans to replace this high power system with a Marx-topology modulator, capable of providing the required waveform shaping to stabilize the accelerating gradient and compensate for beam loading, will be presented, along with development data from the prototype unit.

  3. Over-voltage trigger device for Marx generators

    International Nuclear Information System (INIS)

    Sack, M.; Staengle, R.; Mueller, G.

    2011-01-01

    For treatment of plant tissue with pulsed electric fields in large scale, synchronized operation of several Marx generators is required in order to minimize the low-field regions inside the electroporation reactor and to overcome the current limitations of a single pulse circuit. Hence, the Marx generators must be triggered. If long-term operation without service is to be achieved, these generators are triggered by over-volting the first spark gap without the use of an additional electrode for ignition, which would cause increased wear. A trigger device for over-volting the first spark gap of a Marx generator has been designed. It has been tailored to replace the charging coils between the 1st and the 2nd stage of an already existing Marx generator. In order to overcome the requirements for insulation to ground potential, the trigger device is powered by the charging current of the Marx generator. This paper describes some design issues.

  4. LASERS: Parameters of a trigatron-driven low-pulse-repetition-rate TEA CO2 laser preionised by a surface corona discharge

    Science.gov (United States)

    Aram, M.; Behjat, A.; Shabanzadeh, M.; Mansori, F.

    2007-01-01

    The design of a TEA CO2 laser with UV preionisation by a surface corona discharge is described and the dependences of its average output energy on the gas-flow rate, discharge voltage and pulse repetition rate are presented. The scheme of the electric circuit and the geometry of the pre-ionisation system are considered. The electric circuit is designed to produce only impulse voltage difference between the laser electrodes. The triggering system of the trigatron is used to prevent the appearance of the arc. The dependences of the current, voltage and average output energy on the gas-mixture composition and applied voltages at a low pulse repetition rate are presented. The central output wavelength of the laser was measured with an IR spectrometer. Lasing at two adjacent vibrational-rotational transitions of the CO2 molecule was observed, which demonstrates the possibility of simultaneous lasing at several lines.

  5. Parameters of a trigatron-driven low-pulse-repetition-rate TEA CO2 laser preionised by a surface corona discharge

    International Nuclear Information System (INIS)

    Aram, M; Shabanzadeh, M; Mansori, F; Behjat, A

    2007-01-01

    The design of a TEA CO 2 laser with UV preionisation by a surface corona discharge is described and the dependences of its average output energy on the gas-flow rate, discharge voltage and pulse repetition rate are presented. The scheme of the electric circuit and the geometry of the pre-ionisation system are considered. The electric circuit is designed to produce only impulse voltage difference between the laser electrodes. The triggering system of the trigatron is used to prevent the appearance of the arc. The dependences of the current, voltage and average output energy on the gas-mixture composition and applied voltages at a low pulse repetition rate are presented. The central output wavelength of the laser was measured with an IR spectrometer. Lasing at two adjacent vibrational-rotational transitions of the CO 2 molecule was observed, which demonstrates the possibility of simultaneous lasing at several lines. (lasers)

  6. Burle Marx e os jardins do Recife

    Directory of Open Access Journals (Sweden)

    Ana Rita Sá Carneiro

    2014-05-01

    Full Text Available Passados cinquenta anos de seu desempenho no governo de Pernambuco, Burle Marx declara que alcançou a “consciência concreta” no momento em que criou os jardins públicos do Recife. Seu olhar erudito, de músico e pintor, observando as paisagens ribeirinhas, de matas e do Sertão, ávido em conhecer os hábitos e a arte populares, decidiu que a planta seria seu objeto de composição no desenho, na pintura e no jardim. Portanto, é o diálogo entre jardim e paisagem que se estabelece no exercício do paisagismo como arte nas praças do Recife. O propósito em conservar esses jardins históricos como monumento vivo prioriza a educação patrimonial que começa com a capacitação de jardineiros já praticada por Burle Marx nos anos 30 ao realizar os desenhos de cada jardim em perspectiva para orientar os que iriam executá-los.

  7. Gigahertz repetition rate, sub-femtosecond timing jitter optical pulse train directly generated from a mode-locked Yb:KYW laser.

    Science.gov (United States)

    Yang, Heewon; Kim, Hyoji; Shin, Junho; Kim, Chur; Choi, Sun Young; Kim, Guang-Hoon; Rotermund, Fabian; Kim, Jungwon

    2014-01-01

    We show that a 1.13 GHz repetition rate optical pulse train with 0.70 fs high-frequency timing jitter (integration bandwidth of 17.5 kHz-10 MHz, where the measurement instrument-limited noise floor contributes 0.41 fs in 10 MHz bandwidth) can be directly generated from a free-running, single-mode diode-pumped Yb:KYW laser mode-locked by single-wall carbon nanotube-coated mirrors. To our knowledge, this is the lowest-timing-jitter optical pulse train with gigahertz repetition rate ever measured. If this pulse train is used for direct sampling of 565 MHz signals (Nyquist frequency of the pulse train), the jitter level demonstrated would correspond to the projected effective-number-of-bit of 17.8, which is much higher than the thermal noise limit of 50 Ω load resistance (~14 bits).

  8. Generation of nanosecond laser pulses at a 2.2-MHz repetition rate by a cw diode-pumped passively Q-switched Nd3+:YVO4 laser

    International Nuclear Information System (INIS)

    Nghia, Nguyen T; Hao, Nguyen V; Orlovich, Valentin A; Hung, Nguyen D

    2011-01-01

    We report a new configuration of a high-repetition rate nanosecond laser based on a semiconductor saturable absorber mirror (SESAM). The SESAM is conventional technical solution for passive mode-locking at 1064 nm and simultaneously used as a highly reflecting mirror and a saturable absorber in a high-Q and short cavity of a cw diode-end-pumped a-cut Nd 3+ :YVO 4 laser. Two laser beams are coupled out from the cavity using an intracavity low-reflection thin splitter. The laser characteristics are investigated as functions of pump and resonator parameters. Using a 1.8-W cw pump laser diode at 808 nm, the passively Q-switched SESAMbased laser generates 22-ns pulses with an average power of 275 mW at a pulse repetition rate of 2250 kHz.

  9. Low-threshold, nanosecond, high-repetition-rate vortex pulses with controllable helicity generated in Cr,Nd:YAG self-Q-switched microchip laser

    Science.gov (United States)

    He, Hong-Sen; Chen, Zhen; Li, Hong-Bin; Dong, Jun

    2018-05-01

    A high repetition rate, nanosecond, pulsed optical vortex beam has been generated in a Cr,Nd:YAG self-Q-switched microchip laser pumped by the annular-beam formed with a hollow focus lens. The lasing threshold for vortex pulses is 0.9 W. A pulse width of 6.5 ns and a repetition rate of over 330 kHz have been achieved. The average output power of 1 W and the slope efficiency of 46.6% have been obtained. The helicity of the optical vortices has been controlled by adjusting the tilted angle between Cr,Nd:YAG crystal and output coupler. The work provides a new method for developing pulsed optical vortices for potential applications on quantum communication and optical trapping.

  10. Testing of super conducting low-beta 704 Mhz cavities at 50 Hz pulse repetition rate in view of SPL- first results

    CERN Document Server

    Höfle, W; Lollierou, J; Valuch, D; Chel, S; Devanz, G; Desmons, M; Piquet, O; Paparella, R; Pierini, P

    2010-01-01

    In the framework of the preparatory phase for the luminosity upgrade of the LHC (SLHC-PP ) it is foreseen to characterize two superconducting RF cavities and demonstrate compliance of the required SPL field stability in amplitude and phase using a prototype LLRF system. We report on the preparation for testing of two superconducting low-beta cavities at 50 Hz pulse repetition rate including the setting-up of the low level RF control system to evaluate the performance of the piezo-tuning system and cavity field stability in amplitude and phase. Results from tests with 50 Hz pulse repetition rate are presented. Simulations of the RF system will be used to predict the necessary specifications for power and bandwidth to control the cavity field and derive specifications for the RF system and its control. Exemplary results of the simulation are presented.

  11. 300-MHz-repetition-rate, all-fiber, femtosecond laser mode-locked by planar lightwave circuit-based saturable absorber.

    Science.gov (United States)

    Kim, Chur; Kim, Dohyun; Cheong, YeonJoon; Kwon, Dohyeon; Choi, Sun Young; Jeong, Hwanseong; Cha, Sang Jun; Lee, Jeong-Woo; Yeom, Dong-Il; Rotermund, Fabian; Kim, Jungwon

    2015-10-05

    We show the implementation of fiber-pigtailed, evanescent-field-interacting, single-walled carbon nanotube (CNT)-based saturable absorbers (SAs) using standard planar lightwave circuit (PLC) fabrication processes. The implemented PLC-CNT-SA device is employed to realize self-starting, high-repetition-rate, all-fiber ring oscillators at telecommunication wavelength. We demonstrate all-fiber Er ring lasers operating at 303-MHz (soliton regime) and 274-MHz (stretched-pulse regime) repetition-rates. The 303-MHz (274-MHz) laser centered at 1555 nm (1550 nm) provides 7.5 nm (19 nm) spectral bandwidth. After extra-cavity amplilfication, the amplified pulse train of the 303-MHz (274-MHz) laser delivers 209 fs (178 fs) pulses. To our knowledge, this corresponds to the highest repetition-rates achieved for femtosecond lasers employing evanescent-field-interacting SAs. The demonstrated SA fabrication method, which is based on well-established PLC processes, also shows a potential way for mass-producible and lower-cost waveguide-type SA devices suitable for all-fiber and waveguide lasers.

  12. Influence of the laser pulse repetition rate and scanning speed on the morphology of Ag nanostructures fabricated by pulsed laser ablation of solid target in water

    Science.gov (United States)

    Nikolov, A. S.; Balchev, I. I.; Nedyalkov, N. N.; Kostadinov, I. K.; Karashanova, D. B.; Atanasova, G. B.

    2017-11-01

    Nanostructures of noble metal were produced by pulsed laser ablation in liquid. A solid Ag target was immersed in double distilled water and a CuBr laser in a master oscillator—power amplifier configuration oscillating at 511 nm and emitting pulses with duration of 30 ns at a repetition rate of up to 20 kHz was employed to produce different colloids. The impact was studied of the laser pulse repetition rate and the beam scanning speed on the morphology of the nanostructures formed. Further, the optical extinction spectra of the colloids in the UV/VIS range were measured and used to make an indirect assessment of the changes in the shape and size distribution of the nanostructures. The transmission values in the near UV range were used to estimate the efficiency of the ablation process under the different experimental conditions implemented. A visualization of the nanostructures was made possible by transmission electron microscopy (TEM). The structure and phase composition of the nanoparticles were studied by high-resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED), while the alteration of the target surface caused by the impact of the high-repetition-rate laser illumination was investigated by X-ray photoelectron spectroscopy (XPS). The optimal conditions were determined yielding the highest efficiency in terms of amount of ablated material.

  13. Highly efficient, versatile, self-Q-switched, high-repetition-rate microchip laser generating Ince–Gaussian modes for optical trapping

    Energy Technology Data Exchange (ETDEWEB)

    Jun Dong; Yu He; Xiao Zhou; Shengchuang Bai [Department of Electronics Engineering, School of Information Science and Engineering, Xiamen, 361005 (China)

    2016-03-31

    Lasers operating in the Ince-Gaussian (IG) mode have potential applications for optical manipulation of microparticles and formation of optical vortices, as well as for optical trapping and optical tweezers. Versatile, self-Q-switched, high-peak-power, high-repetition-rate Cr, Nd:YAG microchip lasers operating in the IG mode are implemented under tilted, tightly focused laser-diode pumping. An average output power of over 2 W is obtained at an absorbed pump power of 6.4 W. The highest optical-to-optical efficiency of 33.2% is achieved at an absorbed pump power of 3.9 W. Laser pulses with a pulse energy of 7.5 μJ, pulse width of 3.5 ns and peak power of over 2 kW are obtained. A repetition rate up to 335 kHz is reached at an absorbed pump power of 5.8 W. Highly efficient, versatile, IG-mode lasers with a high repetition rate and a high peak power ensure a better flexibility in particle manipulation and optical trapping. (control of laser radiation parameters)

  14. Antares prototype 300-kJ, 250-kA Marx generator. Final report

    International Nuclear Information System (INIS)

    Riepe, K.B.; Barrone, L.L.; Bickford, K.J.; Livermore, G.H.

    1981-01-01

    A high-energy, low-inductance, low prefire rate, low trigger jitter, high-voltage, pulsed-power supply was needed to drive the gas discharge in the Antares laser power amplifier. This report describes the design and testing of a Marx generator that meets these requirements, the development and testing of a high-capacity spark gap, and the selection of suitable capacitors and resistors

  15. Gyromagnetic nonlinear transmission line generator of high voltage pulses modulated at 4 GHz frequency with 1000 Hz pulse repetition rate

    International Nuclear Information System (INIS)

    Ulmasculov, M R; Sharypov, K A; Shunailov, S A; Shpak, V G; Yalandin, M I; Pedos, M S; Rukin, S N

    2017-01-01

    Results of testing of a generator based on a solid-state drive and the parallel gyromagnetic nonlinear transmission lines with external bias are presented. Stable rf-modulated high-voltage nanosecond pulses were shaped in each of the four channels in 1 s packets with 1000 Hz repetition frequencies. Pulse amplitude reaches -175 kV, at a modulation depth of rf-oscillations to 50 % and the effective frequency ∼4 GHz. (paper)

  16. El Marx de Dussel: Notas acerca de la recepción dusseliana de la obra teórica de Karl Marx The Marx of Dussel: Notes on dusselian receipt of the theoretical work of Karl Marx

    Directory of Open Access Journals (Sweden)

    Flavio Hernán Teruel

    2010-06-01

    Full Text Available A partir de su exilio en México, a mediados de la década del setenta del siglo pasado, Enrique Dussel se entrega a la tarea de "leer seria y directamente" la obra teórica de Karl Marx producida entre los años 1857 y 1882. Al cabo de diez semestres de arduo trabajo, el resultado es una interpretación novedosa de las cuatro redacciones de El Capital. En efecto, ante los ojos de Dussel la obra maestra de Karl Marx se revela no solo como un tratado de economía sino antes bien como uno de antropología y ética. Marx, afirma Dussel, "deconstruye la economía capitalista críticamente y la reconstruye antropológica y éticamente". Asimismo, Dussel descubre que la producción teórica de Marx quedó inconclusa y, sobre todo, abierta a futuros desarrollos. Para el filósofo mendocino es necesario, en nuestro tiempo, no solo reinterpretar la totalidad de la obra de Marx sino también continuar su labor teórica, en especial desde América Latina, para el estudio del capitalismo periférico latinoamericano. Nuestro interés es indicar aquellos elementos que constituyen lo novedoso en la interpretación dusseliana de la obra teórica de Marx.From his exile in Mexico in the mid seventies of last century, Enrique Dussel is given the task of "reading seriously and directly" the theoretical work of Karl Marx produced between 1857 and 1882. After ten semesters of hard work, the result is a novel interpretation of the four drafts of The Capital. Indeed, in the eyes of Dussel, the masterpiece of Karl Marx is revealed not only as an economic treatise but rather as an anthropology and ethics. Marx "capitalist economy critically deconstructs and reconstructs anthropological and ethically". Moreover, Dussel finds that the theoretical yield of Marx was inconclusive and, above all, open to future developments. For the philosopher is needed in our time, not only reinterpret the whole work of Marx but also to continue his theoretical work, especially from Latin

  17. Assembly and handling apparatus for the EBFA Marx generator

    International Nuclear Information System (INIS)

    Staller, G.E.; Hiett, G.E.; Hamilton, I.D.; Aker, M.F.; Daniels, G.A.

    1979-05-01

    Marx generators, a major slow-pulsed power component in Sandia Laboratories' Electron Beam Fusion Accelerator (EBFA), were assembled at a remote facility modified to utilize an assembly-line technique. Due to the size and weight of the various components, as well as the final Marx generator assembly, special handling apparatus was designed. Time and manpower constraints required that this assembly be done in parallel with the construction of the Electron Beam Fusion Facility (EBFF). The completed Marx generators were temporarily stored and then moved from the assembly building to the EBFF using special transportation racks designed specifically for this purpose

  18. [Karl Marx and the Malthusian theory of population].

    Science.gov (United States)

    Jaggi, S

    1985-06-01

    An analysis of the works of Karl Marx is presented in order to demonstrate the importance of the population factor. The author contends that population growth is a critical factor in Marx's theory of the progressive impoverishment of the working class. However, because of his reluctance to acknowledge the value of the Malthusian contribution, Marx focused his analysis of the labor force under capitalism on the demand for workers and neglected the supply side, which is determined by the growth of population. The author concludes that Marxist theory would have benefited from greater consideration of Malthusian theory.

  19. Marx, o cínico?

    Directory of Open Access Journals (Sweden)

    Reginaldo Carmello Corrêa de Moraes

    1983-01-01

    Full Text Available Este artigo foi escrito em agosto/83, para conferência-debate na Jornada de Filosofia da UNESP (Campus de Marília, setembro de 1983. Partindo de aproximações Marx/Hegel sobre o tema da "fatalidade histórica", passamos a discutir a reprodução da força de trabalho como parte do capital, entendido este último, por sua vez, como relação social. Este exame é feito na esteira de algumas passagens de O Capital e dos Grundrisse. A seguir, procedemos à leitura de alguns fatos contemporâneos à luz dessa "anatomia cínica".

  20. THE ISSUE OF EDUCATION IN MARX: SOME NOTES

    Directory of Open Access Journals (Sweden)

    João Carlos da Silva

    2011-02-01

    Full Text Available : Article as a result of readability and reflections carried out in the study group on the works of Marx and Engels, within the group of search HISTEDOPR - GT, Cascavel, PR. The question educational not received a specific treatment in the work of Marx, even if many seek in their formulations, theoreticalmethodological principles for the process of teaching-learning. Its educational thinking must be observed in the whole production marxist. This text to understand, in the light of historical change, the question educational, based on some of his writings. Their conception of education is immersed in horizon of socioeconomic relations, central object of discussion. We will see that education, in Marx, presents a politicalideological perspective, even before the determinant economic. Understand the analysis of Marx about the educative phenomenon does without to observe its way to understand the society.

  1. Marx, Althusser a problém metody

    Czech Academy of Sciences Publication Activity Database

    Kužel, Petr

    2015-01-01

    Roč. 63, č. 3 (2015), s. 379-396 ISSN 0015-1831 Institutional support: RVO:67985955 Keywords : Karl Marx * Louis Althusser * epistemological rupture * epistemological obstacles * over-determination * structural causality * ideology Subject RIV: AA - Philosophy ; Religion

  2. High voltage wide range marx generator design and construction

    International Nuclear Information System (INIS)

    Thompson, J.E.

    1976-01-01

    A wide range, long pulse, Marx generator has been designed and constructed for the purpose of exciting a thermionic electron gun utilized for quasi-cw gas laser medium ionization. The Marx generator has been specifically designed to operate over a voltage range variable from 100 kV to 200 kV into a resistive load of between 83 kΩ and open circuit. This wide operating range, both in voltage and load impedance, was obtained using interstage coupling capacitors to assure overvoltage and subsequent breakdown of the three element spark gap switches used. This paper will discuss the motivation and specific application for the Marx generator and will present the relevant design procedure with particular emphasis on the interstage coupling and triggering techniques employed. Experimental data regarding the measured Marx generator performance will also be presented

  3. Modernity or Capitalism? Technology in Heidegger and Marx

    OpenAIRE

    Duncan, Cameron

    2013-01-01

    Modernity or Capitalism? explores a parallelism that can be found in the work of Martin Heidegger and Karl Marx. The two share a similar ontology of labour that forms the basis of their distinct understandings of the technological world. I first outline the respective critiques of technology by Heidegger and Marx, then argue that the global system comprises both modern techno-scientific representation and capitalism. Everything must fall within the system’s self-enclosed logic. Abstraction, t...

  4. Johann Baptist von Schweitzer: the queer Marx loved to hate.

    Science.gov (United States)

    Kennedy, H

    1995-01-01

    Despite his conviction on a morals charge involving a boy, the early German Social Democrat Johann Baptist von Schweitzer went on to have a successful political career. His life furnishes the context to present remarks by his political opponents Marx and Engels, which reveal their deep-seated homophobia. It is pointed out that this has been glossed over by the translations of the recently published Marx/Engels Collected Works. Some remarks on boy-love and anarchism are appended.

  5. Karl Marx: um balanço biográfico = Karl Marx: an overview of his biographies = Karl Marx: un panorama de sus biografias

    Directory of Open Access Journals (Sweden)

    Segrillo, Angelo

    2017-01-01

    Full Text Available Muitos balanços bibliográficos/teóricos foram feitos sobre o pensamento e obras de Marx, entretanto, nunca foi realizado um balanço biográfico sobre o pensador alemão, no sentido de um balanço das biografias que foram escritas sobre sua vida, independentemente de sua obra teórica. É este balanço inédito que é oferecido aqui. Serão examinadas as principais biografias de Marx, desde a primeira (surgida dois anos após sua morte até as lançadas no século XXI. Procurar-se-á mostrar a evolução na qualidade deste tipo de trabalho, tanto no aspecto metodológico-formal como no aspecto de novas facetas factuais da vida de Marx sendo descobertas ao longo do tempo

  6. Transient thermal stress wave and vibrational analyses of a thin diamond crystal for X-ray free-electron lasers under high-repetition-rate operation.

    Science.gov (United States)

    Yang, Bo; Wang, Songwei; Wu, Juhao

    2018-01-01

    High-brightness X-ray free-electron lasers (FELs) are perceived as fourth-generation light sources providing unprecedented capabilities for frontier scientific researches in many fields. Thin crystals are important to generate coherent seeds in the self-seeding configuration, provide precise spectral measurements, and split X-ray FEL pulses, etc. In all of these applications a high-intensity X-ray FEL pulse impinges on the thin crystal and deposits a certain amount of heat load, potentially impairing the performance. In the present paper, transient thermal stress wave and vibrational analyses as well as transient thermal analysis are carried out to address the thermomechanical issues for thin diamond crystals, especially under high-repetition-rate operation of an X-ray FEL. The material properties at elevated temperatures are considered. It is shown that, for a typical FEL pulse depositing tens of microjoules energy over a spot of tens of micrometers in radius, the stress wave emission is completed on the tens of nanoseconds scale. The amount of kinetic energy converted from a FEL pulse can reach up to ∼10 nJ depending on the layer thickness. Natural frequencies of a diamond plate are also computed. The potential vibrational amplitude is estimated as a function of frequency. Due to the decreasing heat conductivity with increasing temperature, a runaway temperature rise is predicted for high repetition rates where the temperature rises abruptly after ratcheting up to a point of trivial heat damping rate relative to heat deposition rate.

  7. Marx, Keynes y la posibilidad de crisis Marx, Keynes and the Possibility of crisis

    Directory of Open Access Journals (Sweden)

    Kenway Peter

    1992-12-01

    Full Text Available En este artículo Peter Kenway plantea que las teorías desarrolladas por Marx y Keynes para explicar el funcionamiento de la economía capitalista son complementarias. Debido a la existencia del dinero, en Marx la crisis económica es siempre una posibilidad que puede ocurrir cuando una ruptura en el circuito del capi tal separa el acto de compra del de venta. Esta posibilidad emerge de la anarquía de la producción capitalista, su característica fundamental, y plantea interrogantes sobre el nivel de
    demanda requerido para realizarla. La teoría de la demanda efectiva en Keynes sostiene que la crisis ocurre cuando los flujos y escapes de inversión no proveen la demanda
    agregada suficiente para realizar el producto. Según el autor la característica común a ambos enfoques es así el
    intento por construir una teoría monetaria de la producción capitalista, en la que la teoría de la posibilidad complementa la de la demanda efectiva en la explicación de porqué el dinero desempeña un papel operativo en el proceso de producción. A su vez, la teoría de la demanda efectiva complementa a la teoría de la posibilidad para explicar el nivel de demanda que se requiere para la realización del producto entre los diferentes departamentos de la
    economía. Así, en el análisis de Kenway, Marx y Keynes comparten un mismo terreno en cuanto a la teoría de la posibilidad de crisis. La teoría de la realidad sería campo para otro análisis.In this article Peter Kenway states that the theories developed by Marx and Keynes to explain the operation of the capitalistic economy complement each other. Due to the existence of money, in Marx the economic crisis is always a possibili ty that may occur when a rupture in the capi tal circuit separates the act of purchasing from the act of selling. This possibility
    arises from the anarchy of capitalistic production, its basic
    characteristic, and raises questions on the demand level

  8. Money, interest, and capital accumulation in Karl Marx's economics: A monetary interpretation

    OpenAIRE

    Hein, Eckhard

    2002-01-01

    Starting from Schumpeter.s important distinction between .real analysis. and .monetary analysis., in this paper it is shown that major elements of Marx.s economic theory fall in the camp of monetary analysis and the implications for Marx.s theory of capital accumulation are derived. First, Marx.s theory of labour value has to be considered a .monetary theory of value. because .abstract labour. as the social substance of value cannot be measured without a social standard of value. Money as a s...

  9. The Multidisk Diode-Pumped High Power Yb:YAG Laser Amplifier of High-Intensity Laser System with 1 kHz Repetition Rate

    Science.gov (United States)

    Kuptsov, G. V.; Petrov, V. V.; Petrov, V. A.; Laptev, A. V.; Kirpichnikov, A. V.; Pestryakov, E. V.

    2018-04-01

    The source of instabilities in the multidisk diode-pumped high power Yb:YAG laser amplifier with cryogenic closed-loop cooling in the laser amplification channel of the high-intensity laser system with 1 kHz repetition rate was determined. Dissected copper mounts were designed and used to suppress instabilities and to achieve repeatability of the system. The equilibrium temperature dependency of the active elements on average power was measured. The seed laser for the multidisk amplifier was numerically simulated and designed to allow one to increase pulses output energy after the amplifier up to 500 mJ.

  10. Repetitive Stress Injuries

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Repetitive Stress Injuries KidsHealth / For Teens / Repetitive Stress Injuries What's ... t had any problems since. What Are Repetitive Stress Injuries? Repetitive stress injuries (RSIs) are injuries that ...

  11. Les limites du capitalisme selon Joseph Schumpeter et Karl Marx The limits of capitalism by Joseph Schumpeter and Karl Marx

    Directory of Open Access Journals (Sweden)

    Omer Moussaly

    2012-11-01

    Full Text Available À jongler avec les mérites et les ratés de la théorie de Marx et de ses adeptes, Schumpeter semble vouloir s’imposer en tant qu’arbitre unique et impartial du marxisme. Bien qu’il reconnaisse plusieurs mérites à la conception économique de Marx, Schumpeter soulève de multiples limites à l’analyse des marxistes orthodoxes qui ne font que corroborer sa prise de position critique du marxisme. Une lecture des critiques et des réponses que Schumpeter a adressées au marxisme permet de révéler les points communs et les divergences entre les deux auteurs. Chez Schumpeter comme chez Marx, le capitalisme est un mode passager de la production sociale. Schumpeter se fixe comme objectif de combler la lacune des marxistes qui n’ont pas su identifier les vraies raisons du dépérissement du capitalisme. Il lui fallait relever le défi de critiquer certains adeptes de Marx sans pour autant s’en prendre trop au fondateur du marxisme auquel il vouait une admiration sincère.Juggling with the merits and flaws of Marx and his followers, Schumpeter seems to be acting as an impartial judge, especially since he eliminates the extreme arguments of both the Marxists and their opponents. His technique seeks to make his position unassailable from either side of the debate. Although he recognizes several merits to the economic conceptions of Marx, Schumpeter points out several limits of orthodox Marxists which only confirm his critical position towards Marxism. A careful reading of Schumpeter’s commentary on Marxism reveals many points in common between himself and Marx. For Schumpeter as for Marx, capitalism is a transitory and historically limited social mode of production. Unlike most Marxists, who merely repeated ideological slogans from the works of Marx, Schumpeter believed he had discovered the true reasons behind capitalism’s demise. With his critique of Marxism, Schumpeter did not wish to diminish the merit of its founder, but rather

  12. On the Optimality of Repetition Coding among Rate-1 DC-offset STBCs for MIMO Optical Wireless Communications

    KAUST Repository

    Sapenov, Yerzhan

    2017-07-06

    In this paper, an optical wireless multiple-input multiple-output communication system employing intensity-modulation direct-detection is considered. The performance of direct current offset space-time block codes (DC-STBC) is studied in terms of pairwise error probability (PEP). It is shown that among the class of DC-STBCs, the worst case PEP corresponding to the minimum distance between two codewords is minimized by repetition coding (RC), under both electrical and optical individual power constraints. It follows that among all DC-STBCs, RC is optimal in terms of worst-case PEP for static channels and also for varying channels under any turbulence statistics. This result agrees with previously published numerical results showing the superiority of RC in such systems. It also agrees with previously published analytic results on this topic under log-normal turbulence and further extends it to arbitrary turbulence statistics. This shows the redundancy of the time-dimension of the DC-STBC in this system. This result is further extended to sum power constraints with static and turbulent channels, where it is also shown that the time dimension is redundant, and the optimal DC-STBC has a spatial beamforming structure. Numerical results are provided to demonstrate the difference in performance for systems with different numbers of receiving apertures and different throughput.

  13. Human sensory-evoked responses differ coincident with either "fusion-memory" or "flash-memory", as shown by stimulus repetition-rate effects

    Directory of Open Access Journals (Sweden)

    Baird Bill

    2006-02-01

    Full Text Available Abstract Background: A new method has been used to obtain human sensory evoked-responses whose time-domain waveforms have been undetectable by previous methods. These newly discovered evoked-responses have durations that exceed the time between the stimuli in a continuous stream, thus causing an overlap which, up to now, has prevented their detection. We have named them "A-waves", and added a prefix to show the sensory system from which the responses were obtained (visA-waves, audA-waves, somA-waves. Results: When A-waves were studied as a function of stimulus repetition-rate, it was found that there were systematic differences in waveshape at repetition-rates above and below the psychophysical region in which the sensation of individual stimuli fuse into a continuity. The fusion phenomena is sometimes measured by a "Critical Fusion Frequency", but for this research we can only identify a frequency-region [which we call the STZ (Sensation-Transition Zone]. Thus, the A-waves above the STZ differed from those below the STZ, as did the sensations. Study of the psychophysical differences in auditory and visual stimuli, as shown in this paper, suggest that different stimulus features are detected, and remembered, at stimulation rates above and below STZ. Conclusion: The results motivate us to speculate that: 1 Stimulus repetition-rates above the STZ generate waveforms which underlie "fusion-memory" whereas rates below the STZ show neuronal processing in which "flash-memory" occurs. 2 These two memories differ in both duration and mechanism, though they may occur in the same cell groups. 3 The differences in neuronal processing may be related to "figure" and "ground" differentiation. We conclude that A-waves provide a novel measure of neural processes that can be detected on the human scalp, and speculate that they may extend clinical applications of evoked response recordings. If A-waves also occur in animals, it is likely that A-waves will provide

  14. Human sensory-evoked responses differ coincident with either "fusion-memory" or "flash-memory", as shown by stimulus repetition-rate effects

    Science.gov (United States)

    Jewett, Don L; Hart, Toryalai; Larson-Prior, Linda J; Baird, Bill; Olson, Marram; Trumpis, Michael; Makayed, Katherine; Bavafa, Payam

    2006-01-01

    Background: A new method has been used to obtain human sensory evoked-responses whose time-domain waveforms have been undetectable by previous methods. These newly discovered evoked-responses have durations that exceed the time between the stimuli in a continuous stream, thus causing an overlap which, up to now, has prevented their detection. We have named them "A-waves", and added a prefix to show the sensory system from which the responses were obtained (visA-waves, audA-waves, somA-waves). Results: When A-waves were studied as a function of stimulus repetition-rate, it was found that there were systematic differences in waveshape at repetition-rates above and below the psychophysical region in which the sensation of individual stimuli fuse into a continuity. The fusion phenomena is sometimes measured by a "Critical Fusion Frequency", but for this research we can only identify a frequency-region [which we call the STZ (Sensation-Transition Zone)]. Thus, the A-waves above the STZ differed from those below the STZ, as did the sensations. Study of the psychophysical differences in auditory and visual stimuli, as shown in this paper, suggest that different stimulus features are detected, and remembered, at stimulation rates above and below STZ. Conclusion: The results motivate us to speculate that: 1) Stimulus repetition-rates above the STZ generate waveforms which underlie "fusion-memory" whereas rates below the STZ show neuronal processing in which "flash-memory" occurs. 2) These two memories differ in both duration and mechanism, though they may occur in the same cell groups. 3) The differences in neuronal processing may be related to "figure" and "ground" differentiation. We conclude that A-waves provide a novel measure of neural processes that can be detected on the human scalp, and speculate that they may extend clinical applications of evoked response recordings. If A-waves also occur in animals, it is likely that A-waves will provide new methods for

  15. Development of MOS-FET based Marx generator with self-proved gate power

    International Nuclear Information System (INIS)

    Tokuchi, A.; Jiang, W.; Takayama, K.; Arai, T.; Kawakubo, T.; Adachi, T.

    2012-01-01

    New MOS-FET based Marx generator is described. An electric gate power for the MOS-FET is provided from the Marx main circuit itself. Four-stage Marx generator generates -12kV of the output voltage. The Marx Generator is successfully used to drive an Einzel lens chopper to generate a short pulsed ion beam for a KEK digital accelerator. (author)

  16. Marx, Mensch und die übrige Natur

    DEFF Research Database (Denmark)

    Tjaden, Karl Hermann; Czeskleba-Dupont, Rolf

    2009-01-01

    Grundet den kapitalistiske økonomis katastrofiske effekter såvel som forandringer i de materielle og energetiske ressourcestrømme må de globale økologiske relationer mellem menneskene og deres naturmæssige (medleve-)omverden revurderes. Marx' arbejdsbegreb gør den konstitutive relation mellem...... profitorienteret vareproduktion og deraf følgende forstyrrelser i materie- og energistrømme begribelig. Det relaterer sig imidlertid kun delvist til effekterne af en økonomi der er produktionsfikseret og til interaktionerne mellem menneskene og deres (medleve-)omverdener. Udover Marx skulle reproduktion begribes...... ud fra konceptet af et 'humant-naturalt substrat for produktionen' med dets kategori af naturpotentialer. Tilgange til den teknisk-organisatoriske omstrukturering af den samfundsmæssige reproduktionsmåde bliver udviklet ud fra Marx-Engels' kriterium af en afvejning mellem hhv. arbejdsudgifter og...

  17. Karl Marx e a Revolução Russa

    Directory of Open Access Journals (Sweden)

    Angelo Segrillo

    Full Text Available Resumo O artigo analisa a visão de Karl Marx sobre a possibilidade de ocorrência da revolução na Rússia. Inicialmente concentrando suas esperanças nos países da Europa Ocidental, onde o capitalismo estava mais desenvolvido, com o fracasso das revoluções de 1948 e da Comuna de Paris, Marx se volta para as possibilidades de revolução a partir do Leste, da Rússia, até ali considerada o bastião da reação. Suas ideias são expostas em correspondência com os próprios revolucionários russos. Essa trajetória intelectual de Marx é descrita a partir de seus próprios escritos.

  18. Problematizing the "Taken for Granted" in Educational Issues: Karl Marx, Antonio Gramsci, and Michel Foucault.

    Science.gov (United States)

    Qi, Jie

    This paper explores how educators would raise different questions about educational issues by using Karl Marx's framework, Antonio Gramsci's conception, and Michel Foucault's notions, respectively. First, the paper compares the historical perspectives of Marx and Foucault. Marx concludes that history is a progressive linear production and that…

  19. Kapitalismus versus Marktwirtschaft. Karl Marx und Fernand Braudel

    OpenAIRE

    Faber, Malte; Petersen, Thomas

    2018-01-01

    Since the beginning of the finance crisis, the notion of capitalism and the adjective capitalistic are more and more employed in public discourse without making an attempt to define it. In contrast, the concept of market economy is less used. We try in this paper to differentiate both concepts by going back to the approaches by Karl Marx (1818-1883) and Fernand Braudel (1902-1985). Marx does not use the term capitalism but only capitalistic production, while Braudel argues on the basis of a w...

  20. MARX AND WEBER - POSSIBLE AFFINITIES IN LEGAL SOCIOLOGY

    Directory of Open Access Journals (Sweden)

    Daniel Nunes Pereira

    2015-12-01

    Full Text Available This paper aims to draw parallels between the works of Max Weber and Karl Marx, demontrating their acquiescences and objections on Law and State. This study assumes that both authors are, each in their measures, critics of capitalism and the society that forms around its Mode of production. For such, this paper attempts to analyze the similarities, disagreements and parallel discussions between Marx and Weber regarding to outline what would be a so called possible "Weberian Marxism", and how it epistemologically occurs on Legal Sociology.

  1. Træk af en ung Karl Marx

    DEFF Research Database (Denmark)

    Ziegler, Magnus Møller

    2018-01-01

    Det kritiske program, som var Karl Marx' bidrag til både tænkningen og den revolutionære bevægelse, tog sit udgangspunkt i det filosofiske miljø, der dominerede i Tyskland i 1840'erne.......Det kritiske program, som var Karl Marx' bidrag til både tænkningen og den revolutionære bevægelse, tog sit udgangspunkt i det filosofiske miljø, der dominerede i Tyskland i 1840'erne....

  2. The MARX Modulator Development Program for the International Linear Collider

    International Nuclear Information System (INIS)

    Leyh, G.E.

    2006-01-01

    The International Linear Collider (ILC) Marx Modulator Development Program at SLAC is working towards developing a full-scale ILC Marx ''Reference Design'' modulator prototype, with the goal of significantly reducing the size and cost of the ILC modulator while improving overall modulator efficiency and availability. The ILC Reference Design prototype will provide a proof-of-concept model to industry in advance of Phase II SBIR funding, and also allow operation of the new 10MW L-Band Klystron prototypes immediately upon their arrival at SLAC

  3. Effect of pulse repetition rate and number of pulses in the analysis of polypropylene and high density polyethylene by nanosecond infrared laser induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Leme, Flavio O. [Laboratorio de Quimica Analitica ' Henrique Bergamin Filho' , Centro de Energia Nuclear na Agricultura, Universidade de Sao Paulo, Av. Centenario 303, 13416-000 Piracicaba, SP (Brazil); Godoi, Quienly [Laboratorio de Quimica Analitica ' Henrique Bergamin Filho' , Centro de Energia Nuclear na Agricultura, Universidade de Sao Paulo, Av. Centenario 303, 13416-000 Piracicaba, SP (Brazil); Departamento de Quimica, Universidade Federal de Sao Carlos, Rod. Washington Luis, km 235, 13565-905 Sao Carlos, SP (Brazil); Kiyataka, Paulo H.M. [Centro de Tecnologia de Embalagens, Instituto de Tecnologia de Alimentos, Av. Brasil 2880, 13070-178 Campinas, SP (Brazil); Santos, Dario [Departamento de Ciencias Exatas e da Terra, Universidade Federal de Sao Paulo, Rua Prof. Artur Riedel 275, 09972-270 Diadema, SP (Brazil); Agnelli, Jose A.M. [Departamento de Engenharia de Materiais, Universidade Federal de Sao Carlos, Rod. Washington Luis, km 235, 13565-905 Sao Carlos, SP (Brazil); and others

    2012-02-01

    Pulse repetition rates and the number of laser pulses are among the most important parameters that do affect the analysis of solid materials by laser induced breakdown spectroscopy, and the knowledge of their effects is of fundamental importance for suggesting analytical strategies when dealing with laser ablation processes of polymers. In this contribution, the influence of these parameters in the ablated mass and in the features of craters was evaluated in polypropylene and high density polyethylene plates containing pigment-based PbCrO{sub 4}. Surface characterization and craters profile were carried out by perfilometry and scanning electron microscopy. Area, volume and profile of craters were obtained using Taylor Map software. A laser induced breakdown spectroscopy system consisted of a Q-Switched Nd:YAG laser (1064 nm, 5 ns) and an Echelle spectrometer equipped with ICCD detector were used. The evaluated operating conditions consisted of 10, 25 and 50 laser pulses at 1, 5 and 10 Hz, 250 mJ/pulse (85 J cm{sup -2}), 2 {mu}s delay time and 6 {mu}s integration time gate. Differences in the topographical features among craters of both polymers were observed. The decrease in the repetition rate resulted in irregular craters and formation of edges, especially in polypropylene sample. The differences in the topographical features and ablated masses were attributed to the influence of the degree of crystallinity, crystalline melting temperature and glass transition temperature in the ablation process of the high density polyethylene and polypropylene. It was also observed that the intensities of chromium and lead emission signals obtained at 10 Hz were two times higher than at 5 Hz by keeping the number of laser pulses constant.

  4. Experimental study of the inverse diffusion flame using high repetition rate OH/acetone PLIF and PIV

    KAUST Repository

    Elbaz, Ayman M.; Roberts, William L.

    2015-01-01

    Most previous work on inverse diffusion flames (IDFs) has focused on laminar IDF emissions and the soot formation characteristics. Here, we investigate the characteristics and structure of methane IDFs using high speed planar laser-induced fluorescence (PLIF) images of OH, particle image velocimetry (PIV), and acetone PLIF imaging for non-reacting cases. First, the flame appearance was investigated with fixed methane loading (mass flux) but with varying airflow rates, yielding a central air jet Reynolds number (Re) of 1,000 to 6,000 (when blow-off occurs). Next, it was investigated a fixed central air jet Re of 4500, but with varied methane mass flux such that the global equivalence ratio spanned 0.5 to 4. It was observed that at Re smaller than 2000, the inner air jet promotes the establishment of an inverse diffusion flame surrounded by a normal diffusion flame. However, when the Re was increased to 2500, two distinct zones became apparent in the flame, a lower entrainment zone and an upper mixing and combustion zone. 10 kHz OH-PLIF images, and 2D PIV allow the identification of the fate and spatial flame structure. Many flame features were identified and further analyzed using simple but effective image processing methods, where three types of structure in all the flames investigated here: flame holes or breaks; closures; and growing kernels. Insights about the rate of evolution of these features, the dynamics of local extinction, and the sequence of events that lead to re-ignition are reported here. In the lower entrainment zone, the occurrence of the flame break events is counterbalanced by closure events, and the edge propagation appears to control the rate at which the flame holes and closures propagate. The rate of propagation of holes was found to be statistically faster than the rate of closure. As the flames approach blow-off, flame kernels become the main mechanism for flame re-ignition further downstream. The simultaneous OH-PLIF/Stereo PIV

  5. Experimental study of the inverse diffusion flame using high repetition rate OH/acetone PLIF and PIV

    KAUST Repository

    Elbaz, Ayman M.

    2015-10-29

    Most previous work on inverse diffusion flames (IDFs) has focused on laminar IDF emissions and the soot formation characteristics. Here, we investigate the characteristics and structure of methane IDFs using high speed planar laser-induced fluorescence (PLIF) images of OH, particle image velocimetry (PIV), and acetone PLIF imaging for non-reacting cases. First, the flame appearance was investigated with fixed methane loading (mass flux) but with varying airflow rates, yielding a central air jet Reynolds number (Re) of 1,000 to 6,000 (when blow-off occurs). Next, it was investigated a fixed central air jet Re of 4500, but with varied methane mass flux such that the global equivalence ratio spanned 0.5 to 4. It was observed that at Re smaller than 2000, the inner air jet promotes the establishment of an inverse diffusion flame surrounded by a normal diffusion flame. However, when the Re was increased to 2500, two distinct zones became apparent in the flame, a lower entrainment zone and an upper mixing and combustion zone. 10 kHz OH-PLIF images, and 2D PIV allow the identification of the fate and spatial flame structure. Many flame features were identified and further analyzed using simple but effective image processing methods, where three types of structure in all the flames investigated here: flame holes or breaks; closures; and growing kernels. Insights about the rate of evolution of these features, the dynamics of local extinction, and the sequence of events that lead to re-ignition are reported here. In the lower entrainment zone, the occurrence of the flame break events is counterbalanced by closure events, and the edge propagation appears to control the rate at which the flame holes and closures propagate. The rate of propagation of holes was found to be statistically faster than the rate of closure. As the flames approach blow-off, flame kernels become the main mechanism for flame re-ignition further downstream. The simultaneous OH-PLIF/Stereo PIV

  6. Use of a high repetition rate neutron generator for in vivo body composition measurements via neutron inelastic scattering

    International Nuclear Information System (INIS)

    Kehayias, J.J.; Ellis, K.J.; Cohn, S.H.; Weinlein, J.H.

    1986-01-01

    A small D-T neutron generator with a high pulse rate is used for the in vivo measurement of body carbon, oxygen and hydrogen. The core of the neutron generator is a 13 cm-long Zetatron tube pulsed at a rate of 10 kHz delivering 10 3 to 10 4 neutrons per pulse. A target-current feedback system regulates the source of the accelerator to assure constant neutron output. Carbon is measured by detecting the 4.44 MeV γ-rays from inelastic scattering. The short half-life of the 4.44 MeV state of carbon requires detection of the γ-rays during the 10 μs neutron pulse. Generators with low pulsing rate were found inappropriate for carbon measurements because of their low duty-cycle (high neutron output during the pulse). In vivo measurements were performed with normal volunteers using a scanning bed facility for a dose less than 25 mrem. This technique offers medical as well as general bulk analysis applications. 8 refs., 5 figs

  7. Plato, Freud and Marx on Human Nature: A Comparative Analysis ...

    African Journals Online (AJOL)

    This paper examines the conceptions of human nature by Plato, Sigmund Freud and Karl Marx, with a view to revealing and explaining the convergence and divergence between these conceptions. It shows that agreement or disagreement on the distinguishing characteristics of human individuals can be situated on ...

  8. Marx and Education: Working with the Revolutionary Educator

    Science.gov (United States)

    Banfield, Grant

    2015-01-01

    This paper positions education as productive work, i.e. radical labour. It argues that education is a deliberate and conscious process directed to the building of human capacities to labour for socialist transformation. In drawing on the intellectual resources left by Marx the objective of education is the production of the "revolutionary…

  9. Developmental Stages in School Computer Use: Neither Marx Nor Piaget.

    Science.gov (United States)

    Lengel, James G.

    Karl Marx's theory of stages can be applied to computer use in the schools. The first stage, the P Stage, comprises the entry of the computer into the school. Computer use at this stage is personal and tends to center around one personality. Social studies teachers are seldom among this select few. The second stage of computer use, the D Stage, is…

  10. The nature and consequence of Karl Marx's skin disease.

    Science.gov (United States)

    Shuster, S

    2008-01-01

    From an analysis of the original correspondence, it has been possible to establish that Karl Marx's incapacitating skin disease was hidradenitis suppurativa, not 'boils' as was universally assumed at the time and since; the psychological effect of this illness on the man and his work appears to have been considerable.

  11. Kant or Marx? Philosophy and the Origins of Social Science.

    Science.gov (United States)

    Scaff, Lawrence A.

    The origins of social science as a discipline are analyzed in terms of the German scientific community before 1920, which tended to define itself according to the theories of Karl Marx or Immanuel Kant. Following a brief introduction about the nature of social science debates in intellectual Germany, section 2 of the paper considers whether the…

  12. Estimation of the dust production rate from the tungsten armour after repetitive ELM-like heat loads

    Science.gov (United States)

    Pestchanyi, S.; Garkusha, I.; Makhlaj, V.; Landman, I.

    2011-12-01

    Experimental simulations for the erosion rate of tungsten targets under ITER edge-localized mode (ELM)-like surface heat loads of 0.75 MJ m-2 causing surface melting and of 0.45 MJ m-2 without melting have been performed in the QSPA-Kh50 plasma accelerator. Analytical considerations allow us to conclude that for both energy deposition values the erosion mechanism is solid dust ejection during surface cracking under the action of thermo-stress. Tungsten influx into the ITER containment of NW~5×1018 W per medium size ELM of 0.75 MJ m-2 and 0.25 ms time duration has been estimated. The radiation cooling power of Prad=150-300 MW due to such influx of tungsten is intolerable: it should cool the ITER core to 1 keV within a few seconds.

  13. Estimation of the dust production rate from the tungsten armour after repetitive ELM-like heat loads

    International Nuclear Information System (INIS)

    Pestchanyi, S; Landman, I; Garkusha, I; Makhlaj, V

    2011-01-01

    Experimental simulations for the erosion rate of tungsten targets under ITER edge-localized mode (ELM)-like surface heat loads of 0.75 MJ m - 2 causing surface melting and of 0.45 MJ m - 2 without melting have been performed in the QSPA-Kh50 plasma accelerator. Analytical considerations allow us to conclude that for both energy deposition values the erosion mechanism is solid dust ejection during surface cracking under the action of thermo-stress. Tungsten influx into the ITER containment of N W ∼5×10 18 W per medium size ELM of 0.75 MJ m - 2 and 0.25 ms time duration has been estimated. The radiation cooling power of P rad =150-300 MW due to such influx of tungsten is intolerable: it should cool the ITER core to 1 keV within a few seconds.

  14. Study of X-ray source based on a small marx generator

    International Nuclear Information System (INIS)

    Jia Wei; Li Junna; Chen Weiqing; Tang Junping; He Xiaoping

    2014-01-01

    A 600 kV Marx generator accompanied with a water compression line, an output switch and a diode component is designed to generate the X ray with low energy level and low dose rate. The diode parameters are follows: gap space of anode and cathode is 3∼5 mm; cathode with ring structure is a graphite electrode which diameter is 40 mm; the anode is a tantalum target with a thickness of l.5 mm and a diameter of 200 mm. The study results show that: when the output voltage of Marx generator reaches to 550 kV, the voltage drop of the diode is 196 kV. And a low energy level, small dose rate X ray can be obtained in front of the anode. The X ray at the distance of 30 mm before the anode surface has a half width of 20 ns. The total energy dose of the X ray on the center of anode surface is 8 rad and dose rate is 4 × lO"8 rad/s, which have been measured by the method of thermoluminescence dosimetry. (authors)

  15. Shock-tube study of the decomposition of tetramethylsilane using gas chromatography and high-repetition-rate time-of-flight mass spectrometry.

    Science.gov (United States)

    Sela, P; Peukert, S; Herzler, J; Fikri, M; Schulz, C

    2018-04-25

    The decomposition of tetramethylsilane was studied in shock-tube experiments in a temperature range of 1270-1580 K and pressures ranging from 1.5 to 2.3 bar behind reflected shock waves combining gas chromatography/mass spectrometry (GC/MS) and high-repetition-rate time-of-flight mass spectrometry (HRR-TOF-MS). The main observed products were methane (CH4), ethylene (C2H4), ethane (C2H6), and acetylene (C2H2). In addition, the formation of a solid deposit was observed, which was identified to consist of silicon- and carbon-containing nanoparticles. A kinetics sub-mechanism with 13 silicon species and 20 silicon-containing reactions was developed. It was combined with the USC_MechII mechanism for hydrocarbons, which was able to simulate the experimental observations. The main decomposition channel of TMS is the Si-C bond scission forming methyl (CH3) and trimethylsilyl radicals (Si(CH3)3). The rate constant for TMS decomposition is represented by the Arrhenius expression ktotal[TMS → products] = 5.9 × 1012 exp(-267 kJ mol-1/RT) s-1.

  16. Emotional response to musical repetition.

    Science.gov (United States)

    Livingstone, Steven R; Palmer, Caroline; Schubert, Emery

    2012-06-01

    Two experiments examined the effects of repetition on listeners' emotional response to music. Listeners heard recordings of orchestral music that contained a large section repeated twice. The music had a symmetric phrase structure (same-length phrases) in Experiment 1 and an asymmetric phrase structure (different-length phrases) in Experiment 2, hypothesized to alter the predictability of sensitivity to musical repetition. Continuous measures of arousal and valence were compared across music that contained identical repetition, variation (related), or contrasting (unrelated) structure. Listeners' emotional arousal ratings differed most for contrasting music, moderately for variations, and least for repeating musical segments. A computational model for the detection of repeated musical segments was applied to the listeners' emotional responses. The model detected the locations of phrase boundaries from the emotional responses better than from performed tempo or physical intensity in both experiments. These findings indicate the importance of repetition in listeners' emotional response to music and in the perceptual segmentation of musical structure.

  17. Repetition and the Concept of Repetition

    Directory of Open Access Journals (Sweden)

    Arne Grøn

    2013-11-01

    Full Text Available This paper offers a description of the meaning of the category of repetition. Firstly, it is pointed out that Constantin uses repetition as a concept that means the creation of epochs; the passing from Greece to Modernity is accomplished distinguishing between recollection, a concept that looks back to the past, and repetition, a concept that looks forward to future. Secondly, it is showed that the category of repetition, as a religious category, relates with what Climacus calls “ethic despair” and with what Vigilius calls “second ethics”; it is through repetition that it can be understood that sin finds its place in ethics and these shows the tension between it and dogmatics. And thirdly, it is showed that the descovery of the new category of repetition is a rediscovery of what Kierkegaard calls category of spirit; repetition has for its object the individuality, and coming to be oneself is what Kierkegaard undertands as liberty. At the end of the paper it is questioned if the category of repetition is inconsistent with the book Repetition.

  18. Versatile high-repetition-rate phase-locked chopper system for fast timing experiments in the vacuum ultraviolet and x-ray spectral region

    Energy Technology Data Exchange (ETDEWEB)

    Plogmaker, Stefan; Johansson, Erik M. J.; Rensmo, Haakan; Feifel, Raimund; Siegbahn, Hans [Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala (Sweden); Linusson, Per [Department of Physics, Stockholm University, AlbaNova University Center, SE-106 91 Stockholm (Sweden); Eland, John H. D. [Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala (Sweden); Department of Chemistry, Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford OX1 3QZ (United Kingdom); Baker, Neville [Department of Chemistry, Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford OX1 3QZ (United Kingdom)

    2012-01-15

    A novel light chopper system for fast timing experiments in the vacuum-ultraviolet (VUV) and x-ray spectral region has been developed. It can be phase-locked and synchronized with a synchrotron radiation storage ring, accommodating repetition rates in the range of {approx}8 to {approx}120 kHz by choosing different sets of apertures and subharmonics of the ring frequency (MHz range). Also the opening time of the system can be varied from some nanoseconds to several microseconds to meet the needs of a broad range of applications. Adjusting these parameters, the device can be used either for the generation of single light pulses or pulse packages from a microwave driven, continuous He gas discharge lamp or from storage rings which are otherwise often considered as quasi-continuous light sources. This chopper can be utilized for many different kinds of experiments enabling, for example, unambiguous time-of-flight (TOF) multi-electron coincidence studies of atoms and molecules excited by a single light pulse as well as time-resolved visible laser pump x-ray probe electron spectroscopy of condensed matter in the valence and core level region.

  19. Tunable, high-repetition-rate, dual-signal-wavelength femtosecond optical parametric oscillator based on BiB3O6

    Science.gov (United States)

    Meng, Xianghao; Wang, Zhaohua; Tian, Wenlong; Fang, Shaobo; Wei, Zhiyi

    2018-01-01

    We have demonstrated a high-repetition-rate tunable femtosecond dual-signal-wavelength optical parametric oscillator (OPO) based on BiB3O6 (BiBO) crystal, synchronously pumped by a frequency-doubled mode-locked Yb:KGW laser. The cavity is simple since no dispersion compensators are used in the cavity. The wavelength range of dual-signal is widely tunable from 710 to 1000 nm. Tuning is accomplished by rotating phase-matching angle of BiBO, and optimizing cavity length and output coupler. Using a 3.75 W pump laser, the maximum average dual-signal output power is 760 mW at 707 and 750 nm, leading to a conversion efficiency of 20.3% not taking into account the idler power. Our experimental results show a non-critical phase-matching configuration pumped by a high peak power laser source. The operation of the dual-signal benefits from the balance of phase matching and group velocity mismatching between the two signals.

  20. High power all-solid-state fourth harmonic generation of 266 nm at the pulse repetition rate of 100 kHz

    International Nuclear Information System (INIS)

    Liu, Q; Yan, X P; Fu, X; Gong, M; Wang, D S

    2009-01-01

    14.8 W UV laser at 266 nm was reported with the extra cavity frequency quartered configuration. The fundamental frequency IR source is a high-power high-beam-quality acoustic-optic Q-switched Nd:YVO 4 master-oscillator-power-amplifier laser. The type-I phase-matched LBO and type-I phase-matched BBO crystals were used as the extra-cavity frequency doubled and quartered crystal respectively. 14.8 W UV laser of 266 nm was obtained at the pulse repetition rate of 100 kHz with the conversion efficiency of 18.3% from green to UV, and the pulse duration of the UV laser was 10 ns corresponding to the pulse peak power of 14.8 kW. At 150 kHz, 11.5 W power output was obtained. The highest peak power of 21 kW was also achieved at 80 kHz with the average output power of 14.5 W

  1. Marx and Freud in Erich Fromm reading: some notes

    Directory of Open Access Journals (Sweden)

    Henrique Bisetto

    2015-06-01

    Full Text Available The theoretical apparatus used by Erich Fromm on his analysis of contemporary society is based on two main sources: Marx and Freud. The approach of these different chains of thought also happened with the critical theorists of the Institute for Social Research at the University of Frankfurt, as Max Horkheimer, Theodor Adorno and Herbert Marcuse. Erich Fromm was member of the Institute, where he contributed decisively to the convergence of psychoanalysis and Marxism in the early years of this institution. Afterwards, he breaks his ties with the Institute and develops an original analysis of contemporary society, with the main theoretical framework being a singular way of reading the works of Marx and Freud.

  2. Marx As Journalist: Revisiting The Free Speech Debate

    Directory of Open Access Journals (Sweden)

    Padmaja Shaw

    2012-05-01

    Full Text Available Marx was a practicing journalist for most of his adult life. He was editor, columnist and special correspondent at different times and his journalistic work provided significant inputs for his later theoretical work. Marx, through his engagement with the political revolutions of 19th century Europe, developed one of the finest arguments in defence of free speech and the need for expanding bourgeois democratic freedoms in the process of transition to socialism. This paper describes the role of the Marxist parties and intellectuals in India in using and expanding the democratic freedoms available in India. The paper concludes that there is a gap between the Marx’s ideological position on free speech and the praxis of Marxist parties. In contemporary India, there is urgent need to protect free speech, fight censorship and strengthen independent constitutional authorities that are governed by democratic principles.

  3. Tiempo, trabajo y capital en Marx y Bourdieu: un metacomentario

    Directory of Open Access Journals (Sweden)

    George I. García Quesada

    2010-03-01

    Full Text Available In this paper we deal with the conceptualization regarding time, labour and capital in the theory of the French sociologist Pierre Boudieu (1930-2002. We demonstrate that his theoretical developments in respect to these categories are compatible with the theoretical matriz founded by Karl Marx, as specific forms accumulative of praxis. Thus, Bourdieu’s pretended pluralism can be intrepreted from the perspective of a socio-historical dialectical totality.

  4. Final Design of the SLAC P2 Marx Klystron Modulator

    Energy Technology Data Exchange (ETDEWEB)

    Kemp, M.A.; Benwell, A.; Burkhart, C.; Larsen, R.; MacNair, D.; Nguyen, M.; Olsen, J.; /SLAC

    2011-11-08

    The SLAC P2 Marx has been under development for two years, and follows on the P1 Marx as an alternative to the baseline klystron modulator for the International Linear Collider. The P2 Marx utilizes a redundant architecture, air-insulation, a control system with abundant diagnostic access, and a novel nested droop correction scheme. This paper is an overview of the design of this modulator. There are several points of emphasis for the P2 Marx design. First, the modulator must be compatible with the ILC two-tunnel design. In this scheme, the modulator and klystron are located within a service tunnel with limited access and available footprint for a modulator. Access to the modulator is only practical from one side. Second, the modulator must have high availability. Robust components are not sufficient alone to achieve availability much higher than 99%. Therefore, redundant architectures are necessary. Third, the modulator must be relatively low cost. Because of the large number of stations in the ILC, the investment needed for the modulator components is significant. High-volume construction techniques which take advantage of an economy of scale must be utilized. Fourth, the modulator must be simple and efficient to maintain. If a modulator does become inoperable, the MTTR must be small. Fifth, even though the present application for the modulator is for the ILC, future accelerators can also take advantage of this development effort. The hardware, software, and concepts developed in this project should be designed such that further development time necessary for other applications is minimal.

  5. Architecture and Art Regulations for Karl Marx Street

    Directory of Open Access Journals (Sweden)

    Alla Mironenko

    2015-08-01

    Full Text Available The architecture and art regulations for Karl Marx Street and adjoining territories have been worked out for the Committee for town planning of the Irkutsk city administration. Basic provisions: facades of buildings and structures, outdoor advertising and information facilities, artistic illumination of buildings, elements of land improvements. The main principle is to preserve historical appearance and to create a contemporary and comfortable environment.

  6. Karl Marx and the Study of Media and Culture Today

    Directory of Open Access Journals (Sweden)

    Christian Fuchs

    2014-02-01

    Full Text Available The task of this paper discusses the role of Marx in analysing media, communica-tion and culture today. An analysis of three contemporary Cultural Studies works – Lawrence Grossberg’s monograph Cultural Studies in the Future Tense, John Hartley’s monograph Digital Futures for Cultural and Media Studies and Paul Smith’s edited volume The Renewal of Cultural Studies – shows that there is an agreement that the economy needs to be taken more into account by Cultural Studies, but disagreement on which approach should be taken and what the role of Karl Marx’s works shall be. The paper argues that Marx’s labour theory of value is especially important for critically analysing the media, culture and communica-tion. Labour is still a blind spot of the study of culture and the media, although this situation is slowly improving. It is maintained that the turn away from Marx in Cultural and Media Studies was a profound mistake that should be reverted. Only an engagement with Marx can make Cultural and Media Studies topical, politically relevant, practical and critical, in the current times of global crisis and resurgent critique.

  7. Marx is Back, But Which One? On Knowledge Labour and Media Practice

    OpenAIRE

    Vincent Mosco

    2012-01-01

    The global economic crisis has led to a resurgence of interest in the work of Karl Marx. This paper acknowledges this interest, but asks on which of the many shades of Marx, communication scholars should be focusing their research attention. The most general answer is all of Marx, from the early work on consciousness, ideology and culture, which has informed critical cultural studies through to the later work on the structure and dynamics of capitalism that provides bedrock for the political ...

  8. Money, interest and capital accumulation in Karl Marx's economies: a monetary interpretation

    OpenAIRE

    Hein, Eckhard

    2002-01-01

    "Starting from Schumpeter's important distinction between 'real analysis' and 'monetary analysis', in this paper it is shown that major elements of Marx's economic theory fall in the camp of monetary analysis and the implications for Marx's theory of capital accumulation are derived. First, Marx's theory of labour value has to be considered a 'monetary theory of value' because 'abstract labour' as the social substance of value cannot be measured without a social standard of val...

  9. Marx and the Kabbalah: Aaron Shemuel Lieberman's Materialist Interpretation of Jewish History.

    Science.gov (United States)

    Stern, Eliyahu

    2018-01-01

    This essay addresses the reception of Karl Marx's writings among Russian Jewish revolutionaries in the 1870s. It explores the way Aaron Shemuel Lieberman (1843-1880), known as "the father of Jewish socialism," interpreted Marx through a kabbalistic prism. It argues that Jews were attracted to Marx in part because of the overlaps between historical materialism and certain strands of the kabbalistic tradition. It also sheds light on the early reception of Marx and the way his theory of revolution was reinterpreted to reflect the unique socio-economic conditions of the Russian Empire.

  10. Development of highly repetitive pulse power system using amorphous metallic cores

    Energy Technology Data Exchange (ETDEWEB)

    Masugata, K; Yatsui, K [Nagaoka Univ. of Technology (Japan). Dept. of Electrical Engineering

    1997-12-31

    A new type of pulse power system has been developed to obtain an efficient highly repetitive pulse-power generation. The system is constructed of a double pulse circuit (1st stage), step-up transformer and Blumlein pulse forming line (BL) and can generate high power pulse of 600 kV, 24 kA, 60 ns. In the system, discharge gap switches are replaced by magnetic switches. In addition, instead of Marx generator, a step-up transformer is utilized to generate high voltage pulse. The system is tested under the double pulse mode where two 1st stage capacitors are connected in parallel and switched with a interval of T{sub d}. The minimum value of T{sub d} is limited by the recovery of 1st stage gap switches and at T{sub d} {>=} 500 {mu}s (equivalent rep-rate of 2 kHz), the system is operated with good reproducibility. To enhance the recovery, magnetic switch is utilized, which enables operation at T{sub d} {>=} 30 {mu}s (equivalent rep-rate of 33 kHz). (author). 7 figs., 7 refs.

  11. Short-time X-ray diffraction with an efficient-optimized, high repetition-rate laser-plasma X-ray-source

    International Nuclear Information System (INIS)

    Kaehle, Stephan

    2009-01-01

    This thesis deals with the production and application of ultrashort X-ray pulses. In the beginning different possibilities for the production of X-ray pulses with pulse durations of below one picosecond are presented, whereby the main topic lies on the so called laser-plasma X-ray sources with high repetition rate. In this case ultrashort laser pulses are focused on a metal, so that in the focus intensities of above 10 16 W/cm 2 dominate. In the ideal case in such way ultrafast electrons are produced, which are responsible for line radiation. In these experiments titanium K α radiation is produced, thes photons possess an energy of 4.51 keV. For the efficient production of line radiation here the Ti:Sa laser is optimized in view of the laser energy and the pulse shape and the influence of the different parameters on the K α production systematically studied. The influences of laser intensity, system-conditioned pre-pulses and of phase modulation are checked. It turns out that beside the increasement of the K α radiation by a suited laser intensity a reduction of the X-ray background radiation is of deciding importance for the obtaining of clear diffraction images. This background radiation is mainly composed of bremsstrahlung. It can be suppressed by the avoidance of intrinsic pre-pulses and by means of 2nd-order phase modulation. By means of optical excitation and X-ray exploration experiments the production of acoustic waves after ultrashort optical excitation in a 150 nm thick Ge(111) film on Si(111) is studied. These acoustic waves are driven by thermal (in this time scale time-independent) and electronic (time dependent) pressure amounts. As essential results it turns out that the relative amount of the electronic pressure increases with decreasing excitation density [de

  12. Ultra-high-resolution inelastic X-ray scattering at high-repetition-rate self-seeded X-ray free-electron lasers

    Energy Technology Data Exchange (ETDEWEB)

    Chubar, Oleg [Brookhaven National Laboratory, Upton, NY 11973 (United States); Geloni, Gianluca [European X-ray Free-Electron Laser, Albert-Einstein-Ring 19, 22761 Hamburg (Germany); Kocharyan, Vitali [Deutsches Elektronen-Synchrotron, 22761 Hamburg (Germany); Madsen, Anders [European X-ray Free-Electron Laser, Albert-Einstein-Ring 19, 22761 Hamburg (Germany); Saldin, Evgeni; Serkez, Svitozar [Deutsches Elektronen-Synchrotron, 22761 Hamburg (Germany); Shvyd’ko, Yuri, E-mail: shvydko@aps.anl.gov [Argonne National Laboratory, Argonne, IL 60439 (United States); Sutter, John [Diamond Light Source Ltd, Didcot OX11 0DE (United Kingdom)

    2016-02-12

    This article explores novel opportunities for ultra-high-resolution inelastic X-ray scattering (IXS) at high-repetition-rate self-seeded XFELs. These next-generation light sources are promising a more than three orders of magnitude increase in average spectral flux compared with what is possible with storage-ring-based radiation sources. In combination with the advanced IXS spectrometer described here, this may become a real game-changer for ultra-high-resolution X-ray spectroscopies, and hence for the studies of dynamics in condensed matter systems. Inelastic X-ray scattering (IXS) is an important tool for studies of equilibrium dynamics in condensed matter. A new spectrometer recently proposed for ultra-high-resolution IXS (UHRIX) has achieved 0.6 meV and 0.25 nm{sup −1} spectral and momentum-transfer resolutions, respectively. However, further improvements down to 0.1 meV and 0.02 nm{sup −1} are required to close the gap in energy–momentum space between high- and low-frequency probes. It is shown that this goal can be achieved by further optimizing the X-ray optics and by increasing the spectral flux of the incident X-ray pulses. UHRIX performs best at energies from 5 to 10 keV, where a combination of self-seeding and undulator tapering at the SASE-2 beamline of the European XFEL promises up to a 100-fold increase in average spectral flux compared with nominal SASE pulses at saturation, or three orders of magnitude more than what is possible with storage-ring-based radiation sources. Wave-optics calculations show that about 7 × 10{sup 12} photons s{sup −1} in a 90 µeV bandwidth can be achieved on the sample. This will provide unique new possibilities for dynamics studies by IXS.

  13. Marx and Dahrendorf on Income Inequality, Class Consciousness and Class Conflict: An Empirical Test.

    Science.gov (United States)

    Robinson, Robert V.; Kelley, Jonathan

    The issue addressed by this paper is the lack of empirical research on the class theories of Karl Marx and Ralf Dahrendorf. In order to bridge this gap, data are analyzed on the theoretical and statistical implications of Marx's theory (which focuses on ownership of the means of production) and Dahrendorf's theory (which focuses on authority in…

  14. Karl Marx:"Er waart een spook door Europa" door Bart Tromp

    NARCIS (Netherlands)

    ir.ing Ruud Thelosen

    2011-01-01

    In dit in 2006 verschenen boekje van prof. Sociologie Bart Tromp, die zelf in 2007 overleed, worden niet alleen belangrijke stukken van de hand van Karl Marx zelf weergegeven, maar ook een grondige biografie en een inleiding om het belang van Marx ook voor de actualiteit te benadrukken.

  15. Uma atualidade in extremis: Foucault entre Marx e o neoliberalismo

    Directory of Open Access Journals (Sweden)

    Nilton Ken Ota

    2017-12-01

    Full Text Available A participação de Foucault no GIP marcou o momento de constituição de sua teoria estratégica das lutas no contexto de uma interlocução com militantes marxistas. O enfraquecimento dessa interlocução foi acompanhado pelo início das pesquisas genealógicas e por uma reformulação conceitual que dispersou o problema da racionalidade estratégica em benefício da construção de uma discursividade propriamente teórica. As controvérsias atuais ao redor dos sentidos do legado foucaultiano, cujo movimento pendular tem variado entre Marx e o neoliberalismo, revelam os efeitos de uma trajetória intelectual que se dividiu entre a reflexão crítica do combate concreto e a elaboração conceitual de um experimentalismo radical. Este artigo pretende reconstruir os principais pontos e conformações teóricas dessa trajetória. The participation of Foucault in GIP marked the moment of creation of strategic theory about the struggles in the context of a dialogue with Marxist militants. The weakening of that dialogue was accompanied by the start of genealogical research and, consequently, a conceptual reformulation which, among other changes, dispersed the problem of strategic rationality for the construction of a properly theoretical discursiveness. The current controversy surrounding the way the Foucault's legacy, whose pendulum has varied between Marx and neo-liberalism, reveal the effects of an intellectual journey that was divided between the critical reflection of the actual combat and the conceptual formulation of a radical experimentalism. The article An Actuality in extremis: Foucault Between Marx and Neoliberalism aims to reconstruct the main points and theoretical conformations that trajectory.Keywords: Marxism, strategy, neoliberalism, engagement, intellectuals

  16. Marx Generator Charged via Biperiodic Resonant Cascaded Transformers

    Science.gov (United States)

    Potter, Rudolf H.

    In this work, a novel method for charging solid state Marx generators is described for the first time. We first review the utility of modulators for powering high power microwave devices. The principal of operation of the Marx generator is then described starting with the classic topology and leading to solid state topologies. The concept of a generalized Marx generator is introduced and several methods of charging are discussed. A resonant cascaded transformers topology emerges from this discussion. Resonant modes are discussed and the topology is refined to take advantage of the pi/2 mode leading to the circuit that is the focus of this work. We begin our analysis of this circuit by considering the corresponding infinite biperiodic system and derive the characteristic dispersion relation. Motivation for closing the stopband is discussed and benefits of the pi/2 mode are noted. We proceed next to derive the matrix equation for the corresponding lossless system of coupled oscillators. To test and verify the analytic work, a five cell benchtop prototype of the charging system is built and its resonant modes are determined empirically. Capacitors in odd numbered resonators are each connected to the input of a voltage doubler circuit and high voltage dc is generated. A MOSFET is added to the output of each doubler circuit and pulsed output is demonstrated. A SPICE simulation of the physical circuit is created. The mode frequencies from the simulation are in good agreement with those measured and calculated. A practical high-power design is considered for the E2V/Teledyne MG7095 magnetron and simulated in SPICE.

  17. Karl Marx and the Study of Media and Culture Today

    OpenAIRE

    Christian Fuchs

    2014-01-01

    The task of this paper discusses the role of Marx in analysing media, communica-tion and culture today. An analysis of three contemporary Cultural Studies works – Lawrence Grossberg’s monograph Cultural Studies in the Future Tense, John Hartley’s monograph Digital Futures for Cultural and Media Studies and Paul Smith’s edited volume The Renewal of Cultural Studies – shows that there is an agreement that the economy needs to be taken more into account by Cultural Studies, but disagreement on w...

  18. Grade Repetition in Queensland State Prep Classes

    Science.gov (United States)

    Anderson, Robyn

    2012-01-01

    The current study considers grade repetition rates in the early years of schooling in Queensland state schools with specific focus on the pre-schooling year, Prep. In particular, it provides empirical evidence of grade repetition in Queensland state schools along with groups of students who are more often repeated. At the same time, much of the…

  19. Multi-Channel Data Recording of Marx switch closures

    International Nuclear Information System (INIS)

    Lockwood, G.J.; Ruggles, L.E.; Ziska, G.R.

    1984-01-01

    The authors have measured the optical signals associated with switch closure on the Demon marx at Sandia National Laboratories. Using the High Speed Multi-Channel Data Recorder(HSMCDR), they have recorded the time histories of the optical signals from the thirty switches in the marx generator. All thirty switches were fiber connected to the HSMCDR. The HSMCDR consists of a high speed streak camera, and a microcomputer-based video digitizing system. Since the thirty signals are recorded on a single streak, the time sequence can be determined with great accuracy. The appearance of a given signal can be determined to within two samples of the 256 samples that make up the time streak. The authors have found that the light intensity and time history of any given switch varied over a large range from shot to shot. Thus, the ability to record the entire optical signal as a function of time for each switch on every shot is necessary if accurate timing results are required

  20. Roles of repetitive sequences

    Energy Technology Data Exchange (ETDEWEB)

    Bell, G.I.

    1991-12-31

    The DNA of higher eukaryotes contains many repetitive sequences. The study of repetitive sequences is important, not only because many have important biological function, but also because they provide information on genome organization, evolution and dynamics. In this paper, I will first discuss some generic effects that repetitive sequences will have upon genome dynamics and evolution. In particular, it will be shown that repetitive sequences foster recombination among, and turnover of, the elements of a genome. I will then consider some examples of repetitive sequences, notably minisatellite sequences and telomere sequences as examples of tandem repeats, without and with respectively known function, and Alu sequences as an example of interspersed repeats. Some other examples will also be considered in less detail.

  1. ESSÊNCIA E VERDADE: DUAS CATEGORIAS DO MÉTODO EM MARX

    Directory of Open Access Journals (Sweden)

    Ranieri Carli

    2011-05-01

    Full Text Available O presente artigo pretende estudar alguns dos aspectos do método de Marx,especialmente o tratamento dado a duas categorias: essência e verdade. Herdeiro datradição racionalista, Marx mantém em seu aparato categorial tanto a essência quanto averdade, ambas entrelaçadas uma à outra. Na mesma medida, será nosso intento atentarpara a peculiaridade do tratamento legado por Marx a essas duas categorias, tendo emconta as especificidades do materialismo de sua concepção teórica.

  2. Review of Eagleton’s Why Marx Was Right

    Directory of Open Access Journals (Sweden)

    Morgan A. Brown

    2011-04-01

    Full Text Available This article is a critical review of Terry Eagleton’s latest publication, Why Marx Was Right (2011. Eagleton, one of the more celebrated Marxist literary critics in academia, presents his readers with a manifesto of Marxian individualism for the budding theoreticians of market socialism. This book represents Eagleton’s latest sally from the cloisters of stuffy English departments into the realms of economic theory. I cover many of the book’s most important talking points, debate his primary theses with ample counterpoints, and probe Eagleton’s vision of the socialist future from an Austrian angle to see where the author succeeds and falls short of his mark.

  3. [Darwin versus Marx? Reflections on a book by Giovanni Jervis].

    Science.gov (United States)

    Cavallaro, Luigi

    2012-01-01

    Giovanni Jervis'2002 book Individualismo e cooperazione. Psicologia della politica [Individualism and Cooperation: Psychology of Politics] is the outcome of a critical reflection begun by the author at the end of the 1970s in order to explore the manifestations and the problems of cooperation between individuals, and to identify some "universal" psychological factors that could define the role of psychology within politics and constitute an "objective foundation" of any human culture. Although Jervis was, so to speak,favoring Darwin against Marx, it is argued that,from his overall reasoning, several of his arguments actually are in favor of the inevitable "historicity" of individuals, due to the social conditioning they are subjected since birth: too often certain "universalistic" approaches transmit, together with scientific advances (or even without them), well identifiable ideological motives linked to precise and well defined historical and economic interests?

  4. Karl Marx & Communication @ 200: Towards a Marxian Theory of Communication

    Directory of Open Access Journals (Sweden)

    Christian Fuchs

    2018-05-01

    Full Text Available This contribution takes Marx’s bicentenary as occasion for reflecting on foundations of a Marxian theory of communication. It aims to show that Marx provides a consistent account as foundation for a critical, dialectical theory of communication. The article first discusses the relationship of communication and materialism in order to ground a communicative materialism that avoids the dualist assumption that communication is a superstructure erected on a material base. Second, the paper provides an overview of how Marx’s approach helps us to understand the role of the means of communication and communicative labour in capitalism. Third, it conceives of ideology as a form of fetishised communication and fetishism as ideological communication. Given that communicative capitalism is a significant dimension of contemporary society, it is about time to develop a Marxian theory of communication.

  5. Marx y los signos de una época

    Directory of Open Access Journals (Sweden)

    Juan Ignacio Garrido

    2016-01-01

    Full Text Available Se muestra cómo K. Marx establece en el marxismo y en la filosofía política en general una ambivalencia constitutiva entre la crítica y la imaginación política, pues desarrolla un realismo político que derrumba los artificios del idealismo al denunciar los intereses dominantes que lo sostienen, y que constituye una nueva figura del presente. En El Capital y en los Grundrisse lleva a cabo un desmontaje de las apariencias del mundo de las mercancías, y al mismo tiempo indica cómo los montajes colectivos constituyen la manera en que la realidad y la praxis proletaria no pueden dejar de aparecer.

  6. Suicide and society: a comparative study of Durkheim and Marx

    OpenAIRE

    Rodrigues, Marta M. Assumpção

    2009-01-01

    Este artigo trata do suicídio de uma perspectiva sociológica e comparativa. Salienta as diferenças e similitudes das obras O suicídio. Estudo sociológico, de Émile Durkheim, e Peuchet: sobre o suicídio, de Karl Marx, para mostrar que, apesar de cada um desses autores assumirem uma posição filosófica própria, o resultado de seus trabalhos é mais complementar do que antagônico: ambos buscam delimitar o campo da Sociologia como disciplina científica. El presente artículo trata del suicidio de...

  7. Tiempo y capital financiero en El Capital de Marx

    Directory of Open Access Journals (Sweden)

    Boris Salazar

    2018-06-01

    Full Text Available Este artículo sugiere que la metamorfosis de las deudas en derivados y títulos financieros, y de estos en deudas, genera redes de activos y obligaciones, que inducen la emergencia de distintos tiempos del capital, articulados en un sistema complejo, cuya dinámica hace posible sincronizarlos en forma de crisis de carácter global. La crisis se trata como un cambio de estado en un sistema complejo, precipitada por la conectividad generada por el apalancamiento creciente. Es un desarrollo de las teorías de la crisis y de la socialización de la deuda planteadas por Marx en El Capital.

  8. Repetition and Translation Shifts

    Directory of Open Access Journals (Sweden)

    Simon Zupan

    2006-06-01

    Full Text Available Repetition manifests itself in different ways and at different levels of the text. The first basic type of repetition involves complete recurrences; in which a particular textual feature repeats in its entirety. The second type involves partial recurrences; in which the second repetition of the same textual feature includes certain modifications to the first occurrence. In the article; repetitive patterns in Edgar Allan Poe’s short story “The Fall of the House of Usher” and its Slovene translation; “Konec Usherjeve hiše”; are compared. The author examines different kinds of repetitive patterns. Repetitions are compared at both the micro- and macrostructural levels. As detailed analyses have shown; considerable microstructural translation shifts occur in certain types of repetitive patterns. Since these are not only occasional; sporadic phenomena; but are of a relatively high frequency; they reduce the translated text’s potential for achieving some of the gothic effects. The macrostructural textual property particularly affected by these shifts is the narrator’s experience as described by the narrative; which suffers a reduction in intensity.

  9. Ještě mladší Marx, antipolitik a antiobčan

    Czech Academy of Sciences Publication Activity Database

    Feinberg, Joseph Grim

    2015-01-01

    Roč. 63, č. 3 (2015), s. 357-377 ISSN 0015-1831 Institutional support: RVO:67985955 Keywords : young Marx * anti-politics * civil society * theory of the proletariat Subject RIV: AA - Philosophy ; Religion

  10. Marx a rozpory společnosti vědění

    Czech Academy of Sciences Publication Activity Database

    Hauser, Michael

    2015-01-01

    Roč. 63, č. 3 (2015), s. 431-447 ISSN 0015-1831 Institutional support: RVO:67985955 Keywords : society of knowledge * capital * free time * Radovan Richta * Karl Marx Subject RIV: AA - Philosophy ; Religion

  11. Study in Arthur's thesis about Marx's Being influenced by Hegel's Master-Servant in Labor

    Directory of Open Access Journals (Sweden)

    Mojtaba Seifi

    2014-06-01

    Full Text Available o one is denying that Hegel had a strong influence on Marx, especially influenced by the Master-Servitude of Phenomenology of Spirit. For people like Arthur, however, it is not more than a Myth. Sartre and Hyppolite who influenced by Kojeve are the creators of this famous theory, but, they have claimed this without any evidences. Based on Marcuse’s citation of Marx's Economic and Philosophical Manuscripts of 1844, Arthur begins to criticize the theory. His argument is that Marx never refers to this section of Phenomenology of Spirit. Here, I argue that Marx used the keywords of this section in his other writings such as; Gauderies and Capital. Furthermore, it can be said that the meaning of very influence is not clear enough.

  12. The young Marx on constituent power and “true democracy.”

    DEFF Research Database (Denmark)

    Flohr, Mikkel

    Marx and Marxism is commonly charged with having neglected politics and the development of a theory of politics. However, this presumption ignores Marx’s unfinished and unpublished 1843 Critique of Hegel’s Doctrine of State, where he engaged political theory at length – an engagement, which...... propelled him towards his subsequent critique of political economy. It is the aim of the proposed paper to reconstruct and reinterpret his argument focusing in particular on his conceptualization of constituent power and “true democracy.” In the 1843 Critique Marx argues that democracy is the foundation...... the conflicts of civil society. Marx therefore concludes that all these political forms are democracies in contradiction with themselves. Marx proceeds to suggest that it is possible to overcome these contradictions and develop an adequate political form of democracy, which he describes as “true democracy...

  13. Laser stand for irradiation of targets by laser pulses from the Iskra-5 facility at a repetition rate of 100 MHz

    International Nuclear Information System (INIS)

    Annenkov, V I; Garanin, Sergey G; Eroshenko, V A; Zhidkov, N V; Zubkov, A V; Kalipanov, S V; Kalmykov, N A; Kovalenko, V P; Krotov, V A; Lapin, S G; Martynenko, S P; Pankratov, V I; Faizullin, V S; Khrustalev, V A; Khudikov, N M; Chebotar, V S

    2009-01-01

    A train of a few tens of high-power subnanosecond laser pulses with a repetition period of 10 ns is generated in the Iskra-5 facility. The laser pulse train has an energy of up to 300 J and contains up to 40 pulses (by the 0.15 intensity level), the single pulse duration in the train being ∼0.5 ns. The results of experiments on conversion of a train of laser pulses to a train of X-ray pulses are presented. Upon irradiation of a tungsten target, a train of X-ray pulses is generated with the shape of an envelope in the spectral band from 0.18 to 0.28 keV similar to that of the envelope of the laser pulse train. The duration of a single X-ray pulse in the train is equal to that of a single laser pulse. (lasers)

  14. Repeating Marx: Introduction to the Special Issue “Karl Marx @ 200: Debating Capitalism & Perspectives for the Future of Radical Theory”

    Directory of Open Access Journals (Sweden)

    Christian Fuchs

    2018-05-01

    Full Text Available This introduction sets out the context of the special issue “Karl Marx @ 200: Debating Capitalism & Perspectives for the Future of Radical Theory”, which was published on the occasion of Marx’s bicentenary on 5 May 2018. First, we give a brief overview of contemporary capitalism’s development and its crises. Second, we argue that it is important to repeat Marx today. Third, we reflect on lessons learned from 200 years of struggles for alternatives to capitalism. Fourth, we give an overview of the contributions in this special issue. Taken together, the contributions in this special issue show that Marx’s theory and politics remain key inspirations for understanding exploitation and domination in 21st-century society and for struggles that aim to overcome these phenomena and establishing a just and fair society. We need to repeat Marx today.

  15. Marx y Keynes: sobre crédito, tasa de interés y crisis

    Directory of Open Access Journals (Sweden)

    Sánchez Torres Fabio

    1985-12-01

    Full Text Available

    Este ensayo tiene por objeto presentar la visión de Marx y Keynes del crédito y la tasa de interés en relación a las condiciones de acumulación, teniendo éstas condiciones su expresión, de acuerdo con las concepción de Marx, en el comportamiento de la tasa de ganancia.

  16. Repetitive Questioning Exasperates Caregivers

    Directory of Open Access Journals (Sweden)

    R. C. Hamdy MD

    2018-01-01

    Full Text Available Repetitive questioning is due to an impaired episodic memory and is a frequent, often presenting, problem in patients with Alzheimer’s disease (amnestic type. It is due to the patients’ difficulties learning new information, retaining it, and recalling it, and is often aggravated by a poor attention span and easy distractibility. A number of factors may trigger and maintain repetitive questioning. Caregivers should try to identify and address these triggers. In the case discussion presented, it is due to the patient’s concerns about her and her family’s safety triggered by watching a particularly violent movie aired on TV. What went wrong in the patient/caregiver interaction and how it could have been avoided or averted are explored. Also reviewed are the impact of repetitive questioning, the challenges it raises for caregivers, and some effective intervention strategies that may be useful to diffuse the angst that caregivers experience with repetitive questioning.

  17. Marx is Back, But Which One? On Knowledge Labour and Media Practice

    Directory of Open Access Journals (Sweden)

    Vincent Mosco

    2012-05-01

    Full Text Available The global economic crisis has led to a resurgence of interest in the work of Karl Marx. This paper acknowledges this interest, but asks on which of the many shades of Marx, communication scholars should be focusing their research attention. The most general answer is all of Marx, from the early work on consciousness, ideology and culture, which has informed critical cultural studies through to the later work on the structure and dynamics of capitalism that provides bedrock for the political economy of communication. But there is particular need for communication scholars to pay more attention to work that does not fit so neatly in either of these foci, namely, Marx of the Grundrisse and Marx, the professional journalist. Communication scholars need to do so because we have paid insufficient attention to labour in the communication, cultural and knowledge industries. The Marx of these two streams of work provides important guidance for what I have called the labouring of communication as well as for addressing general problems in communication theory.

  18. Repeating Marx: Introduction to the Special Issue “Karl Marx @ 200: Debating Capitalism & Perspectives for the Future of Radical Theory”

    OpenAIRE

    Christian Fuchs; Lara Monticelli

    2018-01-01

    This introduction sets out the context of the special issue “Karl Marx @ 200: Debating Capitalism & Perspectives for the Future of Radical Theory”, which was published on the occasion of Marx’s bicentenary on 5 May 2018. First, we give a brief overview of contemporary capitalism’s development and its crises. Second, we argue that it is important to repeat Marx today. Third, we reflect on lessons learned from 200 years of struggles for alternatives to capitalism. Fourth, we give an overview of...

  19. Repetition code of 15 qubits

    Science.gov (United States)

    Wootton, James R.; Loss, Daniel

    2018-05-01

    The repetition code is an important primitive for the techniques of quantum error correction. Here we implement repetition codes of at most 15 qubits on the 16 qubit ibmqx3 device. Each experiment is run for a single round of syndrome measurements, achieved using the standard quantum technique of using ancilla qubits and controlled operations. The size of the final syndrome is small enough to allow for lookup table decoding using experimentally obtained data. The results show strong evidence that the logical error rate decays exponentially with code distance, as is expected and required for the development of fault-tolerant quantum computers. The results also give insight into the nature of noise in the device.

  20. Reflections on Sven-Eric Liedman’s Marx-Biography “A World to Win: The Life and Works of Karl Marx”

    OpenAIRE

    Christian Fuchs

    2018-01-01

    The English translation of Sven-Eric Liedman’s Marx-biography A World to Win: The Life and Works of Karl Marx was published two weeks before Marx’s bicentenary. This article presents reflections on Liedman’s book and asks how one should best write biographically about Marx. The paper compares Liedman’s biography to the Marx-biographies written by Jonathan Sperber (Karl Marx: A Nineteenth-Century Life) and Gareth Stedman-Jones (Karl Marx: Greatness and Illusion). A biography is a way of repeat...

  1. All-fiber interferometer-based repetition-rate stabilization of mode-locked lasers to 10-14-level frequency instability and 1-fs-level jitter over 1  s.

    Science.gov (United States)

    Kwon, Dohyeon; Kim, Jungwon

    2017-12-15

    We report on all-fiber Michelson interferometer-based repetition-rate stabilization of femtosecond mode-locked lasers down to 1.3×10 -14 frequency instability and 1.4 fs integrated jitter in a 1 s time scale. The use of a compactly packaged 10 km long single-mode fiber (SMF)-28 fiber link as a timing reference allows the scaling of phase noise at a 10 GHz carrier down to -80  dBc/Hz at 1 Hz Fourier frequency. We also tested a 500 m long low-thermal-sensitivity fiber as a reference and found that, compared to standard SMF-28 fiber, it can mitigate the phase noise divergence by ∼10  dB/dec in the 0.1-1 Hz Fourier frequency range. These results suggest that the use of a longer low-thermal-sensitivity fiber may achieve sub-femtosecond integrated timing jitter with sub-10 -14 -level frequency instability in repetition rate by a simple and robust all-fiber-photonic method.

  2. Efficacy of single versus three sessions of high rate repetitive transcranial magnetic stimulation in chronic migraine and tension-type headache.

    Science.gov (United States)

    Kalita, Jayantee; Laskar, Sanghamitra; Bhoi, Sanjeev Kumar; Misra, Usha Kant

    2016-11-01

    We report the efficacy of three versus single session of 10 Hz repetitive transcranial magnetic stimulation (rTMS) in chronic migraine (CM) and chronic tension-type headache (CTTH). Ninety-eight patients with CM or CTTH were included and their headache frequency, severity, functional disability and number of abortive medications were noted. Fifty-two patients were randomly assigned to group I (three true sessions) and 46 to group II (one true and two sham rTMS sessions) treatment. 10 Hz rTMS comprising 600 pulses was delivered in 412.4 s on the left frontal cortex. Outcomes were noted at 1, 2 and 3 months. The primary outcome was 50 % reduction in headache frequency, and secondary outcomes were improvement in severity, functional disability, abortive drugs and side effects. The baseline headache characteristics were similar between the two groups. Follow up at different time points revealed significant improvement in headache frequency, severity, functional disability and number of abortive drugs compared to baseline in both group I and group II patients, although these parameters were not different between the two groups. In group I, 31 (79.4 %) had reduction of headache frequency and 29 (74.4 %) converted to episodic headache. In group II, these were 24 (64.8 %) and 22 (59.2 %), respectively. In chronic migraine, the severity of headache at 2 months reduced in group I compared to group II (62.5 vs 35.3 %; P = 0.01). Both single and three sessions of 10 Hz rTMS were found to be equally effective in CM and CTTH, and resulted in conversion of chronic to episodic headache in 67.1 % patients.

  3. Eroticizing Marx, Revolutionizing Freud: Marcuse’s Psychoanalytic Turn

    Directory of Open Access Journals (Sweden)

    Jeffry V. Ocay

    2009-06-01

    Full Text Available The conclusion arrived at in the article titled “Heidegger, Hegel, Marx: Marcuse and the Theory of Historicity,” which appeared in a previous issue of this journal, accounts for Herbert Marcuse’s view of the possibility of the individual to become disposed to radical action. Marcuse thus wants to suggest that there is still hope for the Enlightenment’s project of “emancipation,” and that there is still a revolutionary subject who can carry out this political struggle for liberation. The progression of consciousness which results in a historically conscious individual exemplified by the “consciousslave” in Hegel’s discussion of master-slave relation provided Marcuse the basis of his claim that the individual can be an active and dynamic political subject. Yet the slave who realizes via the notion of labor that it is himself and not the master who is truly free is, after all, still a slave. This means that individuals still need to fight for their freedom.

  4. Of Marx and Makers: an Historical Perspective on Generative Justice

    Directory of Open Access Journals (Sweden)

    Ron Eglash

    2016-06-01

    Full Text Available In Marxist frameworks “distributive justice” depends on extracting value through a centralized state. Many new social movements—peer to peer economy, maker activism, community agriculture, queer ecology, etc.—take the opposite approach, keeping value in its unalienated form and allowing it to freely circulate from the bottom up. Unlike Marxism, there is no general theory for bottom-up, unalienated value circulation. This paper examines the concept of “generative justice” through an historical contrast between Marx’s writings and the indigenous cultures that he drew upon. Marx erroneously concluded that while indigenous cultures had unalienated forms of production, only centralized value extraction could allow the productivity needed for a high quality of life. To the contrary, indigenous cultures now provide a robust model for the “gift economy” that underpins open source technological production, agroecology, and restorative approaches to civil rights. Expanding Marx’s concept of unalienated labor value to include unalienated ecological (nonhuman value, as well as the domain of freedom in speech, sexual orientation, spirituality and other forms of “expressive” value, we arrive at an historically informed perspective for generative justice. 

  5. Novel porcine repetitive elements

    Directory of Open Access Journals (Sweden)

    Nonneman Dan J

    2006-12-01

    Full Text Available Abstract Background Repetitive elements comprise ~45% of mammalian genomes and are increasingly known to impact genomic function by contributing to the genomic architecture, by direct regulation of gene expression and by affecting genomic size, diversity and evolution. The ubiquity and increasingly understood importance of repetitive elements contribute to the need to identify and annotate them. We set out to identify previously uncharacterized repetitive DNA in the porcine genome. Once found, we characterized the prevalence of these repeats in other mammals. Results We discovered 27 repetitive elements in 220 BACs covering 1% of the porcine genome (Comparative Vertebrate Sequencing Initiative; CVSI. These repeats varied in length from 55 to 1059 nucleotides. To estimate copy numbers, we went to an independent source of data, the BAC-end sequences (Wellcome Trust Sanger Institute, covering approximately 15% of the porcine genome. Copy numbers in BAC-ends were less than one hundred for 6 repeat elements, between 100 and 1000 for 16 and between 1,000 and 10,000 for 5. Several of the repeat elements were found in the bovine genome and we have identified two with orthologous sites, indicating that these elements were present in their common ancestor. None of the repeat elements were found in primate, rodent or dog genomes. We were unable to identify any of the replication machinery common to active transposable elements in these newly identified repeats. Conclusion The presence of both orthologous and non-orthologous sites indicates that some sites existed prior to speciation and some were generated later. The identification of low to moderate copy number repetitive DNA that is specific to artiodactyls will be critical in the assembly of livestock genomes and studies of comparative genomics.

  6. Marx, Materialism and the Brain: Determination in the Last Instance?

    Directory of Open Access Journals (Sweden)

    Joss Hands

    2018-05-01

    Full Text Available It is well acknowledged that there is not one but many Marxes, and one area where this has been most evident is in the question of technological and economic determinism. This article traces some key moments in this debate and attempts to locate their most recent iteration in disagreements over the place of the human brain in both historical agency and value creation in so called ‘cognitive’ or ‘post-Fordist’ capitalism. Of significant interest in the current configuration – or rather composition – of capital is the place of the digitisation of the labour process and its relation to, and integration with, human cognition and volition. Arguments over the attention economy and the power of post-Fordist capitalism to distract and direct is a significant variation of the question of ideology and the latest variation of the base/superstructure debate. This article will unpack the aforesaid issues to offer an articulated perspective in order to make the argument that taking a balanced view of determination will allow us to acknowledge that – drawing on the argument of determination in the last instance – we can hold both of these ‘Marxes’ to be simultaneously valid. Here, a revisiting of Marx’s concept of General Intellect will be undertaken, wherein the productive capacity of living labour is employed in both active agency and the capture of value, in which the plasticity of the living brain becomes the pivot point for both exploitation by, and resistance to, capital.

  7. Validity of the economic thoughts of Keynes and Marx for the 21st century

    Directory of Open Access Journals (Sweden)

    Dragoljub Stojanov

    2007-05-01

    Full Text Available This paper examines the validity of economic thoughts of Karl Marx and John Maynard Keynes for the present time. The paper compares Marx and Keynes, and aims to show that the difference in treatment of the major economic issues between them is not as significant as one may expect. Marx and Keynes held some ideas in common with neo-classical economists especially in the sphere of microeconomics, and they differ from neo-classical economists significantly in their approach to both: macroeconomic issues and their consequences for a society as a whole. They predicted wars in the future, and were speaking about a new, and global world! That is why those giants of economic thought deserve to be re-approached and reexamined, especially as the events of our age remind us of no small extent of the times when they had written

  8. Design and development of high voltage MARX modulator technology for long pulse application

    International Nuclear Information System (INIS)

    Acharya, Mahesh; Shrivastava, Purushottam

    2013-01-01

    High power pulse modulators are used for powering the RF amplifier like klystrons. This paper describes the development of a 10 kV, 10 A, 1 ms Marx modulator for technology demonstration. The modulator is developed using four no. of main modules each of 2.5 kV. To reduce the over sizing factor of capacitors, the allowed drop of main Marx cell is 9%. A droop compensation circuit has been developed to reduce the output pulse voltage droop from 9% to within ±1%. Droop compensation consists of 10 numbers of corrector modules each of 200 V. A microcontroller based trigger circuit was used for simultaneous triggering of main modules and for staggered triggering of corrector modules. A 25 kV, 10 A, 1 ms Marx modulator is being developed. The advantages of this scheme are oil free design, low DC voltage, adjustable pulse width, adjustable rise time/fall time and modular design etc. (author)

  9. The Transcendental Character of Money: An Exposition of Marx's Argument in the Grundrisse

    Directory of Open Access Journals (Sweden)

    John Frederick Humphrey

    2010-03-01

    Full Text Available An exposition of Karl Marx’s argument in the Grundrisse for the logical development of money, this essay is divided into three parts. Since Marx is concerned to distinguish himself and his method from that of the seventeenth century political economists, I begin my paper with a brief reflection on “the scientifically correct method” or the “theoretical method” (Grundrisse 101 and 102. The second part of this paper considers how Marx justifies beginning his reflection with the concept of production in general. To understand the importance that Marx attributes to production, one must also appreciate the way in which distribution, exchange, and consumption belong to the sphere of production. In the remaining pages of this section of my paper, then, I attempt to reconstruct Marx’s argument for the way in which these concepts (distribution, exchange, and consumption are to be understood in relation to the sphere of production.

  10. Komunisme Sebuah Utopia dalam Era Globalisasi: Tinjauan Historis terhadap Pemikiran Karl Marx

    Directory of Open Access Journals (Sweden)

    Nasrullah Nazsir

    2001-12-01

    Full Text Available Kehancuran negara-negara berhaluan komunis pasca Perang Dingin menyebabkan keabsahan ideologi komunis yang digagas Marx dipertanyakan kembali. Kendati demikian, hancurnya pemerintahan negara-negara komunis tersebut tidak berarti matinya komunisme. Banyak pemikiran baru muncul mereinterpretasi gagasan Marx berlandaskan pada kritik dan otokritik yang dilakukan sejumlah Marxis, mulai dari Friedrich Engels yang hidup sezaman dengan Marx, hingga Marxis-Marxis sesudahnya seperti Herbert Marcuse, Roger Garaudy, Jurgen Habermas dan T.W. Adorno. Disimpulkan, Marxisme sebagai sebuah gerakan pemikiran tidak akan pernah mati, karena akan selalu diinterpretasi untuk menjawab tantangan zaman dewasa ini, yang masih ditandai oleh saratnya permasalahan manusia, alienasi, ketimpangan, ketidakadilan, dan berbagai penyakit masyarakat lainnya. Dalam konteks masa kini, paham Marxis bertransformasi menjadi multimuka Marxisme yang menawarkan gagasan-gagasan segar, sekaligus kontroversial seperti Gerakan New Left dan usulan kerjasama antara kaum agamis dan komunis dalam Teologi Pembebasan Amerika Latin.

  11. O jovem Marx e a realização da filosofia

    Directory of Open Access Journals (Sweden)

    Ricardo Rojas Fabres

    2015-07-01

    Full Text Available O artigo acompanha o percurso filosófico do jovem Marx, que vai do hegelianismo de esquerda ao materialismo histórico e é profundamente influenciado por Feuerbach. Pretende-se demonstrar que o projeto marxiano está, em grande parte, vinculado à realização dos princípios filosóficos da tradição teórica que o antecedeu, em especial as ideias de Aristóteles e Kant. Ao fim, o trabalho reconstrói a gênese ontológica da revolução social em Marx, interpretando-a, nos termos do próprio autor, como um “imperativo categórico” (MARX, 2010a.

  12. Repetitive Questioning II

    Directory of Open Access Journals (Sweden)

    R. C. Hamdy MD

    2018-02-01

    Full Text Available Repetitive questioning is a major problem for caregivers, particularly taxing if they are unable to recognize and understand the reasons why their loved one keeps asking the same question over and over again. Caregivers may be tempted to believe that the patient does not even try to remember the answer given or is just getting obnoxious. This is incorrect. Repetitive questioning is due to the underlying disease: The patient’s short term memory is impaired and he is unable to register, encode, retain and retrieve the answer. If he is concerned about a particular topic, he will keep asking the same question over and over again. To the patient each time she asks the question, it is as if she asked it for the first time. Just answering repetitive questioning by providing repeatedly the same answer is not sufficient. Caregivers should try to identify the underlying cause for this repetitive questioning. In an earlier case study, the patient was concerned about her and her family’s safety and kept asking whether the doors are locked. In this present case study, the patient does not know how to handle the awkward situation he finds himself in. He just does not know what to do. He is not able to adjust to the new unexpected situation. So he repeatedly wants to reassure himself that he is not intruding by asking the same question over and over again. We discuss how the patient’s son-in-law could have avoided this situation and averted the catastrophic ending.

  13. Karl Marx and the employment contract: from natural abstraction to formal subsumption

    OpenAIRE

    Ernesto Screpanti

    2008-01-01

    Marx develops two alternative theories of the employment contract: one treats it as an agreement of commodity exchange, and one as a relational arrangement. In the former theory Marx introduces the notion of 'labour power' as a physical stock of labour capacity. Then he argues that the worker, in exchange for a wage, sells a flow of labour whose use-value consists in the capacity to produce value. He calls this flow "abstract labour" and regards it as a "natural" abstraction, i.e. as an objec...

  14. O caráter metafísico da mercadoria em Marx

    Directory of Open Access Journals (Sweden)

    José João Neves Barbosa Vicente

    2013-02-01

    Full Text Available A mercadoria é um conceito fundamental na teoria de Marx, mas ela não é algo objetivo, não subsiste por si mesma, ninguém pode tocá-la com o dedo. Isso ocorre porque ela é concebida por Marx dentro dos moldes da metafísica tradicional. Assim, o objetivo deste texto é apresentar uma contribuição preliminar para uma leitura filosófica de O Capital a partir da análise desse conceito, como aparece no início do livro primeiro.

  15. Inter fraction variations in rectum and bladder volumes and dose distributions during high dose rate brachytherapy treatment of the uterine cervix investigated by repetitive CT-examinations

    International Nuclear Information System (INIS)

    Hellebust, Taran Paulsen; Dale, Einar; Skjoensberg, Ane; Olsen, Dag Rune

    2001-01-01

    Purpose: To evaluate variation of dose to organs at risk for patients receiving fractionated high dose rate gynaecological brachytherapy by using CT-based 3D treatment planning and dose-volume histograms (DVH). Materials and methods: Fourteen patients with cancer of the uterine cervix underwent three to six CT examinations (mean 4.9) during their course of high-dose-rate brachytherapy using radiographically compatible applicators. The rectal and bladder walls were delineated and DVHs were calculated. Results: Inter fraction variation of the bladder volume (CV mean =44.1%) was significantly larger than the inter fraction variation of the mean dose (CV mean =19.9%, P=0.005) and the maximum dose (CV mean =17.5%, P=0.003) of the bladder wall. The same trend was seen for rectum, although the figures were not significantly different. Performing CT examinations at four of seven brachytherapy fractions reduced the uncertainty to 4 and 7% for the bladder and rectal doses, respectively. A linear regression analysis showed a significant, negative relationship between time after treatment start and the whole bladder volume (P=0.018), whereas no correlation was found for the rectum. For both rectum and bladder a linear regression analysis revealed a significant, negative relationship between the whole volume and median dose (P<0.05). Conclusion: Preferably a CT examination should be provided at every fraction. However, this is logistically unfeasible in most institutions. To obtain reliable DVHs the patients will in the future undergo 3-4 CT examinations during the course of brachytherapy at our institution. Since this study showed an association between large bladder volumes and dose reductions, the patients will be treated with a standardized bladder volume

  16. Emancipação política, direito de resistência e direitos humanos em Robespierre e Marx

    Directory of Open Access Journals (Sweden)

    Pogrebinschi Thamy

    2003-01-01

    Full Text Available The article analyzes Marx's critique of the theme of human rights, based on his writings concerning the 1789 Declaration of the Rights of Man and the Citizen. Marx and Robespierre are confronted within the context of this analysis. After demonstrating the identity between the two concepts of freedom expounded by Robespierre and Marx and between the concept of resistance to oppression in Robespierre and that of political emancipation in Marx, the article concludes by contending the impossibility and inadequacy of recourse to Marx in the contemporary defense of human rights and their universalization.

  17. Multi-purpose two- and three-dimensional momentum imaging of charged particles for attosecond experiments at 1 kHz repetition rate

    Energy Technology Data Exchange (ETDEWEB)

    Månsson, Erik P., E-mail: erik.mansson@sljus.lu.se; Sorensen, Stacey L.; Gisselbrecht, Mathieu [Division of Synchrotron Radiation Research, Lund University, Box 118, 221 00 Lund (Sweden); Arnold, Cord L.; Kroon, David; Guénot, Diego; Fordell, Thomas; Johnsson, Per; L’Huillier, Anne [Division of Atomic Physics, Lund University, Box 118, 221 00 Lund (Sweden); Lépine, Franck [Institut Lumière Matière, UMR5306, Université Lyon 1-CNRS, 10 rue Ada Byron, 69622 Villeurbanne cedex (France)

    2014-12-15

    We report on the versatile design and operation of a two-sided spectrometer for the imaging of charged-particle momenta in two dimensions (2D) and three dimensions (3D). The benefits of 3D detection are to discern particles of different mass and to study correlations between fragments from multi-ionization processes, while 2D detectors are more efficient for single-ionization applications. Combining these detector types in one instrument allows us to detect positive and negative particles simultaneously and to reduce acquisition times by using the 2D detector at a higher ionization rate when the third dimension is not required. The combined access to electronic and nuclear dynamics available when both sides are used together is important for studying photoreactions in samples of increasing complexity. The possibilities and limitations of 3D momentum imaging of electrons or ions in the same spectrometer geometry are investigated analytically and three different modes of operation demonstrated experimentally, with infrared or extreme ultraviolet light and an atomic/molecular beam.

  18. Repetition or Reconfiguration

    DEFF Research Database (Denmark)

    Andersen, Kristina Vaarst

    , the cognitive quality of knowledge held by individual professionals is the key microfoundation for project level performance. This paper empirically tests effects of project participants with and without knowledge diversity for project level performance for projects aiming for varying degrees of repetition...... and reconfiguration. The results indicate that project performance benefits form contributions from individuals holding diverse knowledge only when projects aim for high differentiation levels. This positive association is not just moderated, it may even be reversed in the case of professionals participating in low...

  19. MIMICRY, DIFFERENCE AND REPETITION

    Directory of Open Access Journals (Sweden)

    Marcelo Mendes de Souza

    2008-07-01

    Full Text Available This article addresses Homi K. Bhabha’s concept of mimicry in a broader context, other than that of cultural studies and post-colonial studies, bringing together other concepts, such as that of Gilles Deleuze in Difference and repetition, among other texts, and other names, such as Silviano Santiago, Jorge Luís Borges, Franz Kafka and Giorgio Agamben. As a partial conclusion, the article intends to oppose Bhabha’s freudian-marxist view to Five propositions on Psychoanalysis (1973, Gilles Deleuze’s text about Psychoanalysis published right after his book The Anti-Oedipus.

  20. Reflections on Sven-Eric Liedman’s Marx-Biography “A World to Win: The Life and Works of Karl Marx”

    Directory of Open Access Journals (Sweden)

    Christian Fuchs

    2018-05-01

    Full Text Available The English translation of Sven-Eric Liedman’s Marx-biography A World to Win: The Life and Works of Karl Marx was published two weeks before Marx’s bicentenary. This article presents reflections on Liedman’s book and asks how one should best write biographically about Marx. The paper compares Liedman’s biography to the Marx-biographies written by Jonathan Sperber (Karl Marx: A Nineteenth-Century Life and Gareth Stedman-Jones (Karl Marx: Greatness and Illusion. A biography is a way of repeating a person’s life, works and age in a process of reconstruction and retelling. The question that arises is how to write a biography as a dialectical text. Sven-Eric Liedman: A World to Win: The Life and Works of Karl Marx. London: Verso, London, 2018. 768 pages., £35.00 hbk. ISBN 9781786635044

  1. Universal data compression and repetition times

    NARCIS (Netherlands)

    Willems, Frans M J

    1989-01-01

    A new universal data compression algorithm is described. This algorithm encodes L source symbols at a time. For the class of binary stationary sources, its rate does not exceed [formula omitted] [formula omitted] bits per source symbol. In our analysis, a property of repetition times turns out to be

  2. Althusser, Marx a neempiristická teorie dějin

    Czech Academy of Sciences Publication Activity Database

    Kužel, Petr

    2013-01-01

    Roč. 10, č. 2 (2013), s. 191-208 ISSN 1214-7249 Institutional support: RVO:67985955 Keywords : empiricism * historical epistemology * Louis Althusser * Karl Marx Subject RIV: AA - Philosophy ; Religion http://www.dejinyteoriekritika.cz/Modules/ViewDocument.aspx?Did=410

  3. Marx @ 200: Debating Capitalism & Perspectives for the Future of Radical Theory (combined PDF of all articles

    Directory of Open Access Journals (Sweden)

    Christian Fuchs

    2018-05-01

    Full Text Available Combined pdf of all articles published in the special issue "Marx @ 200: Debating Capitalism & Perspectives for the Future of Radical Theory", edited by Christian Fuchs and Lara Monticelli, tripleC: Communication, Capitalism & Critique 16 (2, 2018, pp. 406-741.

  4. Merleau-Ponty entre Machiavel et Marx: vers une nouvelle analogie du corps politique

    Czech Academy of Sciences Publication Activity Database

    Gléonec, Anne

    2015-01-01

    Roč. 4, č. 1 (2015), s. 70-96 ISSN 2226-5260 Institutional support: RVO:67985955 Keywords : Merleau-Ponty * flesh * life * politics * passivity * Marx * Machiavelli Subject RIV: AA - Philosophy ; Religion http://horizon.spb.ru/index.php?option=com_content&view=article&id=460&Itemid=152&lang=ru

  5. The Educator Needs to Be Educated: Reflections on the Political Pedagogy of Marx, Lenin and Habermas

    Science.gov (United States)

    Welton, Michael R.

    2014-01-01

    This essay examines one of the most intractable pedagogical problems of the Marxian revolutionary tradition: who will educate the educator and how ought the learning process to proceed. The solutions of Marx, Lenin and Habermas are critically examined towards the clarification of the emancipatory learning process. This learning process has three…

  6. Marx and Foucault: Subjectivity, Employability and the Crisis of Youth Unemployment in the Great Global Recession

    Science.gov (United States)

    Peters, Michael A.; Besley, Tina

    2013-01-01

    This article explores the different approaches taken to the concepts of work or labour by Marx and Foucault, examining in particular the question of subjectivity in relation to youth unemployment and the current crisis of youth unemployment as part of the aftermath of the global recession of 2008.

  7. Reconsidering Marx in Post-Marxist Times: A Requiem for Postmodernism?

    Science.gov (United States)

    McLaren, Peter; Farahmandpur, Ramin

    2000-01-01

    Marx's description of capitalism as a dark force that has become uncontrollable is very apt today, despite the fact that postmodernists have relegated Marxism to the status of failed aspirations. Discusses postmodernism, the postmodern promise, postmodern politics, the new social movements, hybridity and postmodern multiculturalism, postmodern…

  8. [Results of school inspections in the county of Karl-Marx-Stadt (author's transl)].

    Science.gov (United States)

    Arnold, J

    1978-10-01

    Within the Health Protection in Childhood and Adolescence Research Project a hygienic inspection questionnaire was designed for schools. To test this questionnaire, 248 schools in 11 districts of the county of Karl-Marx-Stadt were inspected. From the ascertainments made, several instances are cited to point out the priorities of school hygiene.

  9. Pop Culture in the Classroom: "American Idol," Karl Marx, and Alexis de Tocqueville

    Science.gov (United States)

    Centellas, Miguel

    2010-01-01

    This article discusses the use of pop culture in the classroom as a means to teach foundational political science authors and concepts. I focus on my experience using "American Idol" as a point of reference to discuss Marx and Engel's "The Communist Manifesto" and Tocqueville's "Democracy in America" in undergraduate comparative politics courses.…

  10. Karl Marx in One Lesson (1818-1883). Series on Public Issues No. 6.

    Science.gov (United States)

    Pejovich, Steve

    This booklet, one of a series intended to apply economic principles to major social and political issues of the day, starts from the premise that Marxism is a threat to our way of life and offers a critique of fundamental components of the social movement Marx created. The first of six subsections focuses on sources of influence on Karl Marx…

  11. Karl Marx and Group Therapy: An Old Warning about a New Phenomenon.

    Science.gov (United States)

    Cooper, Terry D.

    1984-01-01

    Uses Marx's classic critique of religion to explore the social function of therapy groups. Investigates the manner in which groups conserve the status quo and argues that the Marxist critique can help promote a more realistic social awareness and a more effective perception of groups. (Author/JAC)

  12. From Commodity Production to Sign Production: A Triple Triangle Model for Marx's Semiotics and Peirce's Economics.

    Science.gov (United States)

    Kim, Joohoan

    Using the viewpoint of semiotics, this paper "re-reads" Karl Marx's labor theory of value and suggests a "triple triangle" model for commodity production and shows how this model could be a model for semiosis in general. The paper argues that there are three advantages to considering homogeneity of the sign production and the…

  13. Marx e as “robinsonadas” da Economia Política

    Directory of Open Access Journals (Sweden)

    André Guimarães Augusto

    2016-08-01

    Full Text Available Neste artigo é resgatada a crítica de Marx às “robinsonadas” da Economia Política. Com isso, Marx observa que a Economia Política toma como ponto de partida o indivíduo isolado e sem determinações sociais, o indivíduo tal como é supostamente posto pela natureza representado na imagem de Robinson Crusoé em sua ilha. Seguindo o método da crítica ontológica de Marx, as “robinsonadas” da Economia Política são apreendidas como uma representação teórica ilusória de condições realmente existentes na sociedade capitalista. Na primeira parte do artigo, será resgatada a “robinsonada” da Economia Política, procurando-se sintetizar sua concepção de homem e de sociedade. Será indicada também a perenidade dessa concepção no pensamento econômico, em seus traços gerais. Na terceira parte do artigo, é indicada a crítica ontológica de Marx às “robinsonadas” apontando sua origem nas condições reais da reprodução material na sociedade capitalista. Finalmente é resgatado o tema do indivíduo em Marx, indicando que a crítica de Marx às “robinsonadas” não implica que Marx não dê importância ou desconheça o indivíduo teórica e eticamente.

  14. High Repetition Rate Thermometry System And Method

    KAUST Repository

    Chrystie, Robin

    2015-05-14

    A system and method for rapid thermometry using intrapulse spectroscopy can include a laser for propagating pulses of electromagnetic radiation to a region. Each of the pulses can be chirped. The pulses from the region can be detected. An intrapulse absorbance spectrum can be determined from the pulses. An instantaneous temperature of the region based on the intrapulse absorbance spectrum can be determined.

  15. High Repetition Rate Thermometry System And Method

    KAUST Repository

    Chrystie, Robin; Farooq, Aamir

    2015-01-01

    A system and method for rapid thermometry using intrapulse spectroscopy can include a laser for propagating pulses of electromagnetic radiation to a region. Each of the pulses can be chirped. The pulses from the region can be detected. An intrapulse absorbance spectrum can be determined from the pulses. An instantaneous temperature of the region based on the intrapulse absorbance spectrum can be determined.

  16. Active power filter for harmonic compensation using a digital dual-mode-structure repetitive control approach

    DEFF Research Database (Denmark)

    Zou, Zhixiang; Wang, Zheng; Cheng, Ming

    2012-01-01

    This paper presents an digital dual-mode-structure repetitive control approach for the single-phase shunt active power filter (APF), which aims to enhance the tracking ability and eliminate arbitrary order harmonic. The proposed repetitive control scheme blends the characteristics of both odd......-harmonic repetitive control and even-harmonic repetitive control. Moreover, the convergence rate is faster than conventional repetitive controller. Additionally, the parameters have been designed and optimized for the dual-mode structure repetitive control to improve the performance of APF system. Experimental...

  17. Vacuum-spark metal ion source based on a modified Marx generator

    International Nuclear Information System (INIS)

    Anders, A.; Brown, I.G.; MacGill, R.A.; Dickinson, M.R.

    1996-04-01

    The plasma generating parts of ion sources including their power supplies are usually floated to high potential (ion extraction voltage), thus requiring great insulation efforts and high costs for high-energy ion beams. A new concept for pulsed ion sources is presented in which a single power supply is used to simultaneously produce the plasma and high extractor voltage via a modified Marx generator. Proof-of-principle experiments have been performed with high-current spark discharges in vacuum where multiply charged ions are produced with this Marx-generator based ion source (Magis). Using Magis, it has been demonstrated that pulsed ion beams of very high energies can be obtained with relatively low voltage. For copper, ion of charge states up to 7+ have been found whose energy was 112 keV for a charging voltage of only 10 kV

  18. Study on the construction and its operating characteristics of Marx high voltage pulse generator

    International Nuclear Information System (INIS)

    Chung, W.K.; Yook, C.C.

    1984-01-01

    This study is to investigate the operating characteristics of a Marx high voltage pulse generator, which is designed and fabricated for the purpose of constructing a linear theta-pinch plasma generating facility. The Marx generator consists of a 2 kJ capacitor bank of maximum output voltage of 200kV, a set of main spark switch, a triggring system, and high voltage charging power supply. The experimental results show that the operating characteristics of the generator can be controlled through varying nitrogen pressure as a filling gas. The output pulse of the generator is achieved close to the estimated voltage with the rise time of 3*m seconds. The stability of the generator is also very satisfactory within operating range of main spark switch. (Author)

  19. La pensée de Schumpeter face à celles de Marx et de Walras

    Directory of Open Access Journals (Sweden)

    Henri Denis

    2012-11-01

    Full Text Available L’une des moindres originalités de l’œuvre de Joseph Schumpeter n’est pas de comporter des jugements extrêmement favorables sur des auteurs aussi opposés que Marx et Walras. Dans Capitalisme, socialisme et démocratie, Schumpeter écrit : « La vision de Marx était juste. Nous pouvons donc nous y rallier en associant la transformation sociale spécifique qui se poursuit sous nos yeux avec l’évolution économique qui en est le moteur initial. » (Schumpeter, 1942, 268Mais Schumpeter n’est pas moins...

  20. Marx e a crítica à forma salário

    Directory of Open Access Journals (Sweden)

    Carlos Prado

    2011-09-01

    Full Text Available

    O objetivo desse artigo é descrever, a partir da leitura de “O Capital”, a crítica de Marx a forma salário. Tal categoria é fundamental para encobrir e mistificar as relações entre capital e trabalho. A partir de uma feroz crítica a Economia Política, Marx afirma que fetiche da forma salário cumpre a função de ocultar a apropriação da mais-valia pelo capitalista. Por conseguinte, trata-se de uma forma fundamental para a manutenção das relações capitalistas de produção.

  1. Soft switching circuit to improve efficiency of all solid-state Marx modulator for DBDs

    Science.gov (United States)

    Liqing, TONG; Kefu, LIU; Yonggang, WANG

    2018-02-01

    For an all solid-state Marx modulator applied in dielectric barrier discharges (DBDs), hard switching results in a very low efficiency. In this paper, a series resonant soft switching circuit, which series an inductance with DBD capacitor, is proposed to reduce the power loss. The power loss of the all circuit status with hard switching was analyzed, and the maximum power loss occurred during discharging at the rising and falling edges. The power loss of the series resonant soft switching circuit was also presented. A comparative analysis of the two circuits determined that the soft switching circuit greatly reduced power loss. The experimental results also demonstrated that the soft switching circuit improved the power transmission efficiency of an all solid-state Marx modulator for DBDs by up to 3 times.

  2. [Development of child neuropsychiatry at the Karl Marx University of Leipzig].

    Science.gov (United States)

    Gebelt, H

    1978-05-01

    The development of pedoneuropsychiatry at the University of Leipzig is marked by the opening in 1926 of the first "Department of Pedopsychiatric Observation", the establishment of the Clinic of Pedoneuropsychiatry as an independent unit of the Department of Medicine, Karl Marx University, and the setting up in 1976 of a Chair of Pedoneuropsychiatry. Paul Schröder's and R. A. Pfeifer's services to their university are particularly appreciated.

  3. Karl Marx, Civil Society And Political Community in the Context Of The Jewish Problem

    Directory of Open Access Journals (Sweden)

    Yunus ENTERİLİ

    2017-04-01

    Full Text Available Today, debates and discourses developed over the concepts of civil society and political society are usually made through religious discourses or religious identities, and the individual emerges as a problem of emancipation. In his “Jewish Question”, which Marx wrote during his youthful period with Bauer’s thoughts, it is thought that the religious identities and rhetoric accompanied the present debate about the emergence of the emancipation of individuals in social and political contexts. It is thought that this problem, which emerged as the problem of individual liberation or citizenship, and which is regarded as a Jewish problem and emerged in different forms in different geographies, is the result of the fact that the religious identities can not be torn from the religious part of the world. Another reason for the lack of emancipation of the individual is the understanding of colonialism that is at the core of the capitalist system. In today’s society, it wants to keep up with the existence of religions or to keep up with the capitalist system and wants to influence the capitalist system with state policies by making itself active in the political arena. Judaism and Christianity in this context religion, the effects of the formation of capitalist society, will be discussed from the rhetoric of Marx and Bauer. The issue of the citizenship identity of the individual in this study will be addressed through the relationship between civil society and political society. There will also be mentioned here some other thinkers (Hegel, Feuerbach etc. that affect Marx’s ideas about civil society and political society, besides Marx and Bauer. Civil society, citizenship, liberation of religion, political emancipation, the effects of emancipation of individuals such as the state will be handled through the Jewish example. Prior to this assessment, a better understanding of the subject will be addressed to the civil society and state relationship

  4. Bringing the economy back in: Hannah Arendt, Karl Marx, and the politics of capitalism

    OpenAIRE

    İnce, Onur Ulaş

    2016-01-01

    This article engages with the question of how to construct modern economic relations as an object of political theorizing by placing Hannah Arendt's and Karl Marx's writings in critical conversation. I contend that the political aspect of capitalism comes into sharpest relief less in relations of economic exploitation than in moments of expropriation that produce and reproduce the conditions of capitalist accumulation. To develop a theoretical handle on expropriation and thereby on the politi...

  5. A compact bipolar pulse-forming network-Marx generator based on pulse transformers.

    Science.gov (United States)

    Zhang, Huibo; Yang, Jianhua; Lin, Jiajin; Yang, Xiao

    2013-11-01

    A compact bipolar pulse-forming network (PFN)-Marx generator based on pulse transformers is presented in this paper. The high-voltage generator consisted of two sets of pulse transformers, 6 stages of PFNs with ceramic capacitors, a switch unit, and a matched load. The design is characterized by the bipolar pulse charging scheme and the compact structure of the PFN-Marx. The scheme of bipolar charging by pulse transformers increased the withstand voltage of the ceramic capacitors in the PFNs and decreased the number of the gas gap switches. The compact structure of the PFN-Marx was aimed at reducing the parasitic inductance in the generator. When the charging voltage on the PFNs was 35 kV, the matched resistive load of 48 Ω could deliver a high-voltage pulse with an amplitude of 100 kV. The full width at half maximum of the load pulse was 173 ns, and its rise time was less than 15 ns.

  6. Karl Marx and Liberation Theology: Dialectical Materialism and Christian Spirituality in, against, and beyond Contemporary Capitalism

    Directory of Open Access Journals (Sweden)

    Peter McLaren

    2018-05-01

    Full Text Available This paper explores convergences and discrepancies between liberation theology and the works of Karl Marx through the dialogue between one of the key contemporary proponents of liberation theology, Peter McLaren, and the agnostic scholar in critical pedagogy, Petar Jandrić. The paper briefly outlines liberation theology and its main convergences with the works of Karl Marx. Exposing striking similarities between the two traditions in denouncing the false God of money, it explores differences in their views towards individualism and collectivism. It rejects shallow rhetorical homologies between Marx and the Bible often found in liberation theology, and suggests a change of focus from seeking a formal or Cartesian logical consistency between Marxism and Christianity to exploring their dialectical consistency. Looking at Marxist and Christian approaches to morality, it outlines close links between historical materialism and questions of value. It concludes that the shared eschaton of Marxism and the Christianity gives meaning to human history and an opportunity to change it.

  7. Marx e Marcuse: Acerca da Alienação do Homem e seu Trabalho

    Directory of Open Access Journals (Sweden)

    Fabio Goulart

    2017-02-01

    Full Text Available Este artigo tem como objetivo apresentar e analisar o conceito de alienação nos manuscritos do jovem Marx e a respectiva análise feita por Herbert Marcuse acerca de tal conceito. O primeiro passo é apresentar a distinção e similitude entre os termos alemães Entäusserung e Entfremdung que dão origem a tal conceito. Depois vemos como na análise de Marx seria evidente que na lógica capitalista o trabalhador e seu trabalho estão rebaixados à miserável posição de mercadoria barata e substituível onde o fruto de seu trabalho torna-se cada vez mais distante. Nesta relação o trabalho se torna uma potência sobre o ser humano, fato este que seria a origem de diversos problemas sociais e formas de violência. Depois apresentamos a análise feita por Marcuse acerca dos respectivos texto de Marx, onde veremos os motivos porque ele acreditava que alienação e trabalho seriam conceitos ligados a essência humana e consequentemente muito além da economia.

  8. ¿Hay una teoría normativa de la justicia en Marx?

    Directory of Open Access Journals (Sweden)

    Felipe Curcó Cobos

    2016-12-01

    Full Text Available La obra de Marx ha suscitado una  añeja polémica entre sus estudiosos. Algunos han mantenido que el lenguaje desarrollado en ella es estrictamente explicativo. Dicho lenguaje expresaría ante todo un saber científico expurgado de todo contenido moral (sobre la estructura del capital, las fuerzas que causan la dinámica social y las leyes que la rigen. En el otro extremo, en cambio, otros han argüido que en Marx hallamos más bien un lenguaje ético orientado a denunciar los crímenes y miserias de una determinada formación social con el fin de oponerle otra. En este artículo defiendo la idea de que en la obra de Marx hay elementos tanto para afirmar una cosa como la otra. Sin embargo, argumento que la actualidad del pensamiento marxista  reside esencialmente en los elementos éticos y normativos que configuran la dimensión moral de su planteamiento.

  9. A ideologia de Marx e o discurso de Foucault: convergências e distanciamentos Marx's ideology and Foucault's discourse: convergence and distanciation

    Directory of Open Access Journals (Sweden)

    Sérgio Bacchi Machado

    2010-04-01

    Full Text Available Efetua-se um mapeamento dos conceitos de ideologia e discurso nas obras de Marx e Foucault, respectivamente. Procede-se também a uma recapitulação da análise marxiana da inversão das leis de apropriação como substrato da destruição de uma forma ideológica específica; assim como se retoma, na obra foucaultiana, a arqueologia da relação médico-paciente como exemplo de configuração de um determinado campo discursivo. Por fim, indica-se um distanciamento e uma convergência entre os conceitos em questão.This paper identifies the concepts of ideology and discourse in the works of Marx and Foucault, respectively. It summarizes the Marxist analysis of the reversal of the laws of property as a consequence of the destruction of a specific ideology; and presents the archeology of the doctor-patient relationship, from the work of Foucault, as an example of the configuration of a particular discursive field. To conclude, the paper points to a distanciation and a convergence between the concepts in question.

  10. Priming With 1-Hz Repetitive Transcranial Magnetic Stimulation Over Contralesional Leg Motor Cortex Does Not Increase the Rate of Regaining Ambulation Within 3 Months of Stroke: A Randomized Controlled Trial.

    Science.gov (United States)

    Huang, Ying-Zu; Lin, Li-Fong; Chang, Kwang-Hwa; Hu, Chaur-Jong; Liou, Tsan-Hon; Lin, Yen-Nung

    2018-05-01

    The potential benefits of repetitive transcranial magnetic stimulation (rTMS), applied either alone or as a combination treatment, on recovery of lower limbs after stroke have been insufficiently studied. The aim of the study was to evaluate the effect of priming with 1-Hz repetitive transcranial magnetic stimulation over contralesional leg motor area with a double-cone coil before physical therapy on regaining ambulation. Thirty-eight subacute stroke patients with significant leg disabilities were randomly assigned into the experimental group or control group to receive a 15-min real or sham 1-Hz repetitive transcranial magnetic stimulation, respectively, over the contralesional motor cortex representing the quadriceps muscle followed by 45-min physical therapy for 15 sessions for 3 wks. Functional measures, motor evoked potentials, and quality of life were assessed. There was no significant difference between experimental group and control group regarding the recovery in ambulation, balance, motor functions, and activity of daily living. No significant difference was found in other functional measures and the quality of life. Only the control group displayed significantly increased cortical excitability of the contralesional hemisphere after the intervention. The present study found that insufficient evidence that contralesional priming with 1-Hz repetitive transcranial magnetic stimulation improves ambulatory and other motor functions among patients with a severe leg dysfunction in subacute stroke.

  11. Progress in developing repetitive pulse systems utilizing inductive energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Honig, E.M.

    1983-01-01

    High-power, fast-recovery vacuum switches were used in a new repetitive counterpulse and transfer circuit to deliver a 5-kHz pulse train with a peak power of 75 MW (at 8.6 kA) to a 1-..cap omega.. load, resulting in the first demonstration of fully controlled, high-power, high-repetition-rate operation of an inductive energy-storage and transfer system with nondestructive switches. New circuits, analytical and experimental results, and feasibility of 100-kV repetitive pulse generation are discussed. A new switching concept for railgun loads is presented.

  12. High power, repetitive stacked Blumlein pulse generators

    Energy Technology Data Exchange (ETDEWEB)

    Davanloo, F; Borovina, D L; Korioth, J L; Krause, R K; Collins, C B [Univ. of Texas at Dallas, Richardson, TX (United States). Center for Quantum Electronics; Agee, F J [US Air Force Phillips Lab., Kirtland AFB, NM (United States); Kingsley, L E [US Army CECOM, Ft. Monmouth, NJ (United States)

    1997-12-31

    The repetitive stacked Blumlein pulse power generators developed at the University of Texas at Dallas consist of several triaxial Blumleins stacked in series at one end. The lines are charged in parallel and synchronously commuted with a single switch at the other end. In this way, relatively low charging voltages are multiplied to give a high discharge voltage across an arbitrary load. Extensive characterization of these novel pulsers have been performed over the past few years. Results indicate that they are capable of producing high power waveforms with rise times and repetition rates in the range of 0.5-50 ns and 1-300 Hz, respectively, using a conventional thyratron, spark gap, or photoconductive switch. The progress in the development and use of stacked Blumlein pulse generators is reviewed. The technology and the characteristics of these novel pulsers driving flash x-ray diodes are discussed. (author). 4 figs., 5 refs.

  13. Каrl Marx: The Cultural Memory of the Macedonian People and the Peoples of the Eastern Bloc – Reception and Percertion

    Directory of Open Access Journals (Sweden)

    Boban Karapejovski

    2014-12-01

    Full Text Available The severe economic crisis raised the question: Was Marx right? Or, as Terry Eagleton writes: WHY Marx was right. A reactualization of his ideas, his philosophy or his diagnosis and cures, as well as his economic and social studies, has recently become attractive once again. The acceptance and reactualization of Marx these days, especially in the Western countries, could bring us/open alternative ways of practicing politics, policy making and activism (take, for example, the “Occupy Wall Street” movement; or non-acceptance of Marx and a further global crisis could lead to a rebirth of the extreme right. Are Marx's ideas a philosophy, a view of the world or a practical "know-how"? "Marx was right about self-destruction of capitalism", says Nouriel Roubini. Does he inspire and will be inspiring new tendencies and ways of (more or less global activism and are his ideas a phenomenon that will redefine global politics and society? Are Marx's ideas truly part of cultural memory in the so called Eastern block or were they perverted by the past system(s, which was/were using this philosophy for re-creation of its own bourgeoisie. What is today’s /nowadays reception and perception of Marx in these countries and how do people react to the possibility of their memory becoming their present tomorrow!?

  14. Repetition and lag effects in movement recognition.

    Science.gov (United States)

    Hall, C R; Buckolz, E

    1982-03-01

    Whether repetition and lag improve the recognition of movement patterns was investigated. Recognition memory was tested for one repetition, two-repetitions massed, and two-repetitions distributed with movement patterns at lags of 3, 5, 7, and 13. Recognition performance was examined both immediately afterwards and following a 48 hour delay. Both repetition and lag effects failed to be demonstrated, providing some support for the claim that memory is unaffected by repetition at a constant level of processing (Craik & Lockhart, 1972). There was, as expected, a significant decrease in recognition memory following the retention interval, but this appeared unrelated to repetition or lag.

  15. Readers and academic reading of Karl Marx (São Paulo, 1958-1964

    Directory of Open Access Journals (Sweden)

    Lidiane Soares Rodrigues

    2016-05-01

    Full Text Available Ideas, books and concepts of Karl Marx and various Marxist authors was incorporated into scientific and cultural institutions. It is one of the political sphere importation into the academic implying sense of speed in relation to its origins and gave to Marxism, through the practices of the agents of this transfer, support for their preservation, dissemination and transformation. Concurrently, there is the incorporation of these lines to the required reading of the humanities and the repertoire of cultivated layers. Examination of appropriations that academic and cultured elites made of Marx, situate them (such work and such elites, institutionally. This is what this article does. Arguing that the legitimacy of the uses of a tradition result not only of their intrinsic value, but the work oriented agents interested in it, is elected an exemplary experience for research. This article looks at two university groups initially focused on the study of Karl Marx's work, made in the late 1950. It begins by proposing a collective biography, the reading program and the various uses they made of them. To refine the analysis and proof the advocated method selects for vertical take, within a group (the first one and a discipline (sociology, two contrasting trajectories (Fernando Henrique Cardoso and Octavio Ianni and various forms Marxism (theoretical and empirical / dominant and dominated. Finally, it discusses the profits propitiated to have operated with three concepts of cultural sociology: habitus, « field » and « patterns of intention » – taken from the works of Pierre Bourdieu and Michael Baxandall.

  16. The Materialism of Georges Bataille. A Reading from the Perspective of Nietzsche and Marx

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    Vicente Montenegro Bralic

    2015-12-01

    Full Text Available Georges Bataille’s notion of materialism can be seen as a critique of metaphysical or idealist conceptions of materialism. On the basis of the reconstruction of Bataille’s statements in his different early writings, the paper provides an interpretation of Bataille’s “base materialism” based on his peculiar reading of Nietzsche and Marx. The attempt to make compatible elements from both philosophies leads to a critical discussion with the authors, which, in turn, can be read as a forerunner of the deconstruction of materialism carried out by Jacques Derrida.

  17. MARX AND ENGELS: THE IMPORTANCE OF READING THE CLASSICS IN THE EDUCATOR’S FORMATION

    Directory of Open Access Journals (Sweden)

    Dalva Helena de Medeiros

    2011-02-01

    Full Text Available The current work intends to discuss the importance of reading the classics in the educator’s formation. Among the classics, Karl Marx (1818-1883 and Friedrich Engels (1820-1895 are regarded as the creators of the historical-dialectical materialism, which is a new way to comprehend society and consequently education. These authors highlighted the necessity to understand social relationships to discuss education and, to do so, they used a few paramount categories like: totality, historicity and praxis. Thus the aim of this paper is not to exhaust the proposed theme, but rather, raise and instigate a debate over the subject.

  18. Short-time X-ray diffraction with an efficient-optimized, high repetition-rate laser-plasma X-ray-source; Kurzzeit-Roentgenbeugung mit Hilfe einer Effizienz-optimierten, hochrepetierenden Laser-Plasma-Roentgenquelle

    Energy Technology Data Exchange (ETDEWEB)

    Kaehle, Stephan

    2009-04-23

    This thesis deals with the production and application of ultrashort X-ray pulses. In the beginning different possibilities for the production of X-ray pulses with pulse durations of below one picosecond are presented, whereby the main topic lies on the so called laser-plasma X-ray sources with high repetition rate. In this case ultrashort laser pulses are focused on a metal, so that in the focus intensities of above 10{sup 16} W/cm{sup 2} dominate. In the ideal case in such way ultrafast electrons are produced, which are responsible for line radiation. In these experiments titanium K{sub {alpha}} radiation is produced, thes photons possess an energy of 4.51 keV. For the efficient production of line radiation here the Ti:Sa laser is optimized in view of the laser energy and the pulse shape and the influence of the different parameters on the K{sub {alpha}} production systematically studied. The influences of laser intensity, system-conditioned pre-pulses and of phase modulation are checked. It turns out that beside the increasement of the K{sub {alpha}} radiation by a suited laser intensity a reduction of the X-ray background radiation is of deciding importance for the obtaining of clear diffraction images. This background radiation is mainly composed of bremsstrahlung. It can be suppressed by the avoidance of intrinsic pre-pulses and by means of 2nd-order phase modulation. By means of optical excitation and X-ray exploration experiments the production of acoustic waves after ultrashort optical excitation in a 150 nm thick Ge(111) film on Si(111) is studied. These acoustic waves are driven by thermal (in this time scale time-independent) and electronic (time dependent) pressure amounts. As essential results it turns out that the relative amount of the electronic pressure increases with decreasing excitation density. [German] Diese Arbeit befasst sich mit der Erzeugung und Anwendung ultrakurzer Roentgenimpulse. Zu Beginn werden verschiedene Moeglichkeiten zur

  19. Global Repetition Influences Contextual Cueing

    Science.gov (United States)

    Zang, Xuelian; Zinchenko, Artyom; Jia, Lina; Li, Hong

    2018-01-01

    Our visual system has a striking ability to improve visual search based on the learning of repeated ambient regularities, an effect named contextual cueing. Whereas most of the previous studies investigated contextual cueing effect with the same number of repeated and non-repeated search displays per block, the current study focused on whether a global repetition frequency formed by different presentation ratios between the repeated and non-repeated configurations influence contextual cueing effect. Specifically, the number of repeated and non-repeated displays presented in each block was manipulated: 12:12, 20:4, 4:20, and 4:4 in Experiments 1–4, respectively. The results revealed a significant contextual cueing effect when the global repetition frequency is high (≥1:1 ratio) in Experiments 1, 2, and 4, given that processing of repeated displays was expedited relative to non-repeated displays. Nevertheless, the contextual cueing effect reduced to a non-significant level when the repetition frequency reduced to 4:20 in Experiment 3. These results suggested that the presentation frequency of repeated relative to the non-repeated displays could influence the strength of contextual cueing. In other words, global repetition statistics could be a crucial factor to mediate contextual cueing effect. PMID:29636716

  20. Repetitive elements in parasitic protozoa

    Directory of Open Access Journals (Sweden)

    Clayton Christine

    2010-05-01

    Full Text Available Abstract A recent paper published in BMC Genomics suggests that retrotransposition may be active in the human gut parasite Entamoeba histolytica. This adds to our knowledge of the various types of repetitive elements in parasitic protists and the potential influence of such elements on pathogenicity. See research article http://www.biomedcentral.com/1471-2164/11/321

  1. A novel compact low impedance Marx generator with quasi-rectangular pulse output

    Science.gov (United States)

    Liu, Hongwei; Jiang, Ping; Yuan, Jianqiang; Wang, Lingyun; Ma, Xun; Xie, Weiping

    2018-04-01

    In this paper, a novel low impedance compact Marx generator with near-square pulse output based on the Fourier theory is developed. Compared with the traditional Marx generator, capacitors with different capacity have been used. It can generate a high-voltage quasi-rectangular pulse with a width of 100 ns at low impedance load, and it also has high energy density and power density. The generator consists of 16 modules. Each module comprises an integrative single-ended plastic case capacitor with a nominal value of 54 nF, four ceramic capacitors with a nominal value of 1.5 nF, a gas switch, a charging inductor, a grounding inductor, and insulators which provide mechanical support for all elements. In the module, different discharge periods from different capacitors add to the main circuit to form a quasi-rectangular pulse. The design process of the generator is analyzed, and the test results are provided here. The generator achieved pulse output with a rise time of 32 ns, pulse width of 120 ns, flat-topped width (95%-95%) of 50 ns, voltage of 550 kV, and power of 20 GW.

  2. Aportes para uma compreensão das Relações Internacionais em Marx

    Directory of Open Access Journals (Sweden)

    Regiany Melo

    2017-02-01

    Full Text Available Na obra Contribuição à crítica da economia política, Marx inicia um projeto de análise da anatomia da sociedade civil (aprofundada, posteriormente, em O Capital que, para ele, manifesta-se na história a partir da expansão do sistema econômico associado intrinsecamente ao desenvolvimento do Estado moderno. Seu objetivo é compreender o desenvolvimento social e histórico do capital através do exame da mercadoria, por intermédio de sua teoria do valor e de sua teoria monetária. Desse modo, podemos observar, através da formulação de suas teorias, como ocorre o intercâmbio das mercadorias entre mercados consumidores (economia, e consequentemente, entre os Estados burgueses (política. Assim, a partir da dimensão da economia política, podemos vislumbrar alguns aportes para uma compreensão das Relações Internacionais em Marx no nível das relações entre os Mercados Mundiais.

  3. Gramsci between Machiavelli and Marx: from negative determination of human to ontonegative determination of politics Gramsci entre Maquiavel e Marx: da negatividade do homem a ontonegatividade da política

    Directory of Open Access Journals (Sweden)

    Claudinei Cássio Rezende

    2008-12-01

    Full Text Available In one of his central categories, Gramsci establishes a connection between the Machiavellian and Marxian political conceptions, in a manner that each one writes to the revolutionary class of their time. Nevertheless, a more rigorous critic at Marx’s propositions unveils to us that the proletarian class isn’t just the progressist class of his time, in the same manner that the bourgeois was in the Iluminism, like Gramsci thinks, but it is, actually, the universal sphere and the only one qualifi ed to accomplish a human emancipation. Consequently, the connection between Machiavelli and Marx does not exist, once Marx conceives the ontological work as the central attribute of humanization, and conceives the politics as temporary; while Machiavelli conceives the politics as the founder act of all sociability. Keywords: Machiavelli. Marx. Gramsci. Ontonegative determination of politics. Human emancipation. Em uma de suas categorias centrais, Gramsci estabelece uma identidade direta entre as politicidades maquiaveliana e marxiana, de sorte que cada um escreve para a classe da vanguarda política de sua época. No entanto, uma crítica mais rigorosa aos escritos marxianos nos revela que o proletariado não é somente a classe progressista de sua época, da maneira que a burguesia fora no iluminismo, como quer Gramsci, mas é, em verdade, a esfera universal e a única capaz de levar a cabo uma emancipação humana total. Doravante, a identidade entre Marx e Maquiavel inexiste na medida em que o primeiro, de magnitude filosófica distinta, concebe o trabalho ontologicamente como atributo central da humanização, apreendendo a política como uma figura transitória superável, enquanto o segundo concebe a política como o ato fundador de toda sociabilidade. Palavras-chave: Maquiavel. Marx. Gramsci. Ontonegatividade da política. Emancipação humana.

  4. [Development, problems and results of specialty-specific genetic counseling at the Neurology Clinic of the Karl Marx University].

    Science.gov (United States)

    Bachmann, H

    1987-11-01

    Genetic counselling for inherited neurological diseases has been established at the Clinic for Neurology of Karl Marx University. Comprehensive experiences have been got with the specific and sometimes markedly different problems and aims of counselling in Wilsons disease, X-linked recessive muscular dystrophies, myotonic dystrophy and other neuromuscular disorders, Huntingtons chorea and hereditary ataxias.

  5. [From Paul Flechsig to the Paul Flechsig Institute for Brain Research. Development of brain research at the Karl Marx University].

    Science.gov (United States)

    Leibnitz, L; Werner, L; Schober, W; Brauer, K

    1977-04-01

    A review is given on the development of the brain research institute of the Karl-Marx-University of Leipzig during the directorates of Paul Flechsig (1883-1920), Richard Arwed Pfeifer (1925-1957), and Wolfgang Wünscher (1957-1971).

  6. [Territorial differences in the occurrence of caries in Karl Marx Stadt children and adolescent after 12 years of water fluoridation].

    Science.gov (United States)

    Künzel, W

    1976-01-01

    Cariostatistical comparisons made since the start of drinking-water fluoridation in Karl-Marx-Stadt suggested territorial differences in the prevalence of dental decay. In the present paper an attempt is made to analyse the problems involved, with due consideration being given to both demographic and ecological factors.

  7. Dai Kanak a Marx e ritorno: antropologia della persona e transindividuale - From the Kanak to Marx and back: a transindividual anthropology of the person

    Directory of Open Access Journals (Sweden)

    Carlo Capello

    2013-06-01

    Full Text Available The aim of this article is to show the deep affinity between non-western ideas of the person and antiindividualistic philosophical ideas through a re-reading of some central texts about the anthropology of the person. African concepts of the person, as described by Fortes, Augé and Riesman, have indeed a remarkable consonance with the intersubjective philosophy of Charles Taylor and Axel Honneth. Even more, a significant affinity can be detected between the Melanesian ideas of the person – what Marilyn Strathern called “dividual” – and the notion of transindividual emerging from an anthropological reading of Marx. The common emphasis on social relations as constitutive of the human is the ground permitting the encounter between these two conceptions. The author of this article suggests that the anthropology of the person offers a precious archive of alternative visions of the human reality, which, in dialogue with the idea of transindividuality, could promote the reprise of a Marxist anthropology engaged in the critique of the hegemonic individualism.

  8. Computer-Related Repetitive Stress Injuries

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Computer-Related Repetitive Stress Injuries KidsHealth / For Parents / Computer-Related Repetitive Stress Injuries What's in this article? ...

  9. Thinking the ‘Culture Wars’ and the Present Political Crisis with the Young Marx (and Friends

    Directory of Open Access Journals (Sweden)

    Ben Whitham

    2018-05-01

    Full Text Available We stand at a key juncture: a Western political crisis arose in 2016-17 to match the deep economic crisis of the preceding decade. Events and new social movements of recent years seem to hail the collapse of the project of liberal democracy, though it is hard to see what will replace it. Among the conceptual and analytic tools bequeathed by Marx are those necessary to better understand and anticipate the direction of this key historical moment – from Donald Trump, Brexit and the so-called ‘culture wars’ to the horizon of liberal democracy itself. In this reflection, I suggest some ways in which Marx’s early thoughts on the liberal state and civil society can and should help us to better understand and explain our present predicament. To say that the Young Marx can help us today with what he called ‘the ruthless critique of everything existing’ is not to say that he can do so alone. It is precisely the issues overlooked or ‘fudged’ by Marx and Marxism – gender, sexuality, and race/racism for example – that now sit at the centre of our ‘culture wars’, alongside but never reducible to the contradictions and crises of capitalism. I conclude that it is only with the help of other writers of the 20th and 21st centuries, from Antonio Gramsci to Frantz Fanon and bell hooks, that we can usefully mobilise the Young Marx today, to critique the world as we find it and especially – the very ‘point’ of theory according to Marx – to change it.

  10. Zippo Marx

    Directory of Open Access Journals (Sweden)

    Robin Aaron Bright

    2017-09-01

    Full Text Available Goddesses, like Norse Hel, signify love for women, and between women, because `woman`s seed` is the `seed` of Eve represented by Jesus, who was tortured to death by the Romans as a `dissident` Jewish rabbi nailed to a cross of wood on the hill of Calvary outside the city of Jerusalem in occupied Palestine and left there until he died. Jesus` Resurrection and Ascension to heaven thereafter prefigured that of `woman`s seed`, which is why his mother, the Virgin Mary, approaches to the role of goddess in Christianity, because women who`re loved appear to be worshipped as goddesses by those who don`t love women. So God specifically punishes Eve and Adam for accepting that they`ll be `as gods`, because Eve is Adam`s `goddess`, who he`s to love in order to be redeemed through `woman`s seed`, and the birth of human brainpower to liberate the species from host womb slavery in parasitism, which wants ephemerality for humans in order to keep them as slaves without labor saving technologies conferring freedom.

  11. Karl Marx, un periodista en la Era del Capital. Apuntes para una investigación

    Directory of Open Access Journals (Sweden)

    Espinoza Pino, Mario

    2014-06-01

    Full Text Available The aim of this article is to criticize the traditional representation of Karl Marx’s journalistic works, usually forgotten by a misleading canon that assumes his articles only as a minor work. One of the problems of this traditional conception is that it dissociates his theoretical and economic contributions from the historical development of the author’s thought (and also from its material roots. We will try to point the importance of Karl Marx’s mature journalism in two areas: in the construction of the central concepts of his critic against the capitalist mode of production (surplus value, a multilineal historical perspective, a global description of the world market, etc. and in the production of political cartographies to intervene in the class conflict. This article poses several hypothesis and tentative affirmations about Karl Marx’s journalism that may serve as a point of departure for a critical research.El objetivo de este artículo es criticar la representación tradicional del trabajo periodístico de Karl Marx, habitualmente olvidado por un canon engañoso que sólo asume sus artículos al precio de convertirlos en una obra menor. Uno de los problemas de esta concepción tradicional es que disocia sus contribuciones teóricas y económicas del desarrollo histórico del pensamiento del autor (y también de sus raíces materiales. Intentaremos señalar la importancia del periodismo maduro de Karl Marx en dos áreas: en la construcción de los conceptos centrales de su crítica contra el capitalismo (plusvalor, un enfoque histórico multilineal, una descripción global del mercado mundial, etc. y en la producción de cartografías políticas para intervenir en el conflicto de clases. Este artículo plantea varias hipótesis y afirmaciones tentativas sobre el periodismo de Karl Marx que pueden servir como punto de partida de una investigación crítica.

  12. Repetitive learning control of continuous chaotic systems

    International Nuclear Information System (INIS)

    Chen Maoyin; Shang Yun; Zhou Donghua

    2004-01-01

    Combining a shift method and the repetitive learning strategy, a repetitive learning controller is proposed to stabilize unstable periodic orbits (UPOs) within chaotic attractors in the sense of least mean square. If nonlinear parts in chaotic systems satisfy Lipschitz condition, the proposed controller can be simplified into a simple proportional repetitive learning controller

  13. 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

  14. Influência de Marx nas músicas de John Lennon

    Directory of Open Access Journals (Sweden)

    Roseli Coutinho dos Santos Nunes

    2014-11-01

    Full Text Available Apresenta a influência do filósofo Karl Marx nas músicas abertamente políticas Revolution (1968, Working Class Hero (1970 e Power to the People (1971, cuja principal força criativa na composição e gravação foi John Lennon, o beatle mais envolvido com a teoria marxista. Apresenta a influência do modo de pensar marxista nos muitos trabalhos dos Beatles: mudar o modo que as pessoas pensam acerca do mundo para criar um mundo melhor e mais justo e, nas últimas obras, atrair a atenção para a desigualdade entre as classes sociais.

  15. Gas spark switches with increased operating life for Marx generator of lightning test complex

    Energy Technology Data Exchange (ETDEWEB)

    Bykov, Yu. A.; Krastelev, E. G., E-mail: ekrastelev@yandex.ru [Russian Academy of Sciences, Joint Institute for High Temperature (Russian Federation)

    2016-12-15

    A new design of gas spark switches with an increased operating life and stable dynamic characteristics for the Marx generator of the lightning test complex has been developed. The switches are characterized by the following parameters in the mode of operation: voltage up to 80 kV, discharge current up to 50 kA, flowing charge up to 3.5 C/pulse. An increased operating life is achieved by using torus-shaped electrodes with increased working surface area and a trigger electrode in the form of a thick disk with a hole located between them. Low breakdown delay time and high stability of breakdown voltage under dynamic conditions are provided by gas preionization in the spark gap using UV radiation of an additional corona discharge in the axial region.

  16. An university-scale pulsed-power system using a bipolar Marx generator

    Science.gov (United States)

    Chang, Po-Yu; Yang, Sheng-Hua; Huang, Mei-Feng; Isaps, Natl Cheng Kung Univ Team

    2017-10-01

    A bipolar Marx generator is being built for x-ray sources or laboratory astrophysics and space research for university-scale laboratory. The system consists of ten stages. In each stage, two 1 μF capacitors connected in series are charged to +/- 30 kV storing 9 kJ of total energy. It delivers a current of 200 kA to the load with a 200 ns rise time during the discharge. It will be used for following three purposes: (1) gas-puff z pinches generating soft x-ray for bio-medical research in the future; (2) generating plasma jets to study interactions between plasma flows and unmagnetized/magnetized obstacles analogous to the interactions between solar winds and planetary magnetic fields or unmagnetized planets; and (3) studying the pinch in a dense plasma focus device. The results of current measurements and circuit characteristics are shown.

  17. Bacteriological findings in patients with bone marrow transplantation (Karl Marx University Leipzig, 1985-1987).

    Science.gov (United States)

    Wonitzki, C; Hoffmann, F A

    1989-01-01

    The results of the bacteriological surveillance cultures for 26 patients with bone marrow transplantation (Karl Marx University Leipzig, G.D.R., 1985-1987) are presented. 5.9% of all surveillance cultures contained facultatively pathogenic germs (with Pseudomonas aeruginosa as the most frequent representative, which was the reason of a sepsis in two patients). Coagulasenegative Staphylococci and other germs with an obscure pathogenicity were isolated upon a large scale, especially from the mucous membrane regions. There are hints, that above all special strains of coagulasenegative Staphylococci "colonize" the patient's body (also for longer periods) and turn into the blood too. During the total decontamination intestinal anaerobic flora is absent. After closing of total decontamination Clostridium perfringens is the first detectable anaerobic species. During the selective decontamination systemic applications of antibiotics are able to obliterate anaerobic findings for certain periods. Recommendations for an effective arrangement of the surveillance cultures of bone marrow transplantation patients are given.

  18. El Estado de naturaleza. La comunidad primitiva y el pensamiento de Marx

    OpenAIRE

    Francisco Castilla Urbano

    2001-01-01

    Marx llevó a cabo un tratamiento del estado originario de la humanidad que continúa la tradición ilustrada y utópica, pero con un cambio en los contenidos asignados al mismo; de su análisis desaparece la concepción del hombre como ser aislado, la escasa atención a la producción material y la visión empobrecedora que la economía política tenía del ser humano. El resultado es una antropología filosófica en la que la denuncia de la enajenación del trabajo y la explotac...

  19. El materialismo de Georges Bataille. Una lectura desde Nietzsche y Marx

    Directory of Open Access Journals (Sweden)

    Vicente Montenegro Bralic

    2015-01-01

    Full Text Available La noción de materialismo de Georges Bataille se erige como una crítica a las concepciones metafísicas o idealistas del materialismo A partir de una reconstrucción de lo que Bataille expone en distintos lugares de sus escritos de juventud, se propone una interpretación del “bajo materialismo” de Bataille desde su particular lectura de Nietzsche y Marx, que, al intentar hacer compatibles elementos de una y otra filosofía, desemboca en una discusión crítica con ambos autores. Esta discusión que, a su vez, puede ser leída como antecedente de una deconstrucción del materialismo como la que lleva a cabo Jacques Derrida.

  20. UMA ONTOLOGIA REPRESENTANDO AS SOLUÇÕES DE PROJETO DE ROBERTO BURLE MARX

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo Verzola Vaz

    2012-02-01

    Full Text Available O objetivo deste artigo é propor uma base de dados com soluções de projeto paisagístico que colabore para que estudantes aprendam conceitos básicos de projeto e os ajude a aplicar este novo conhecimento utilizando como referência soluções desenvolvidas por arquitetos experientes. O sistema é baseado em uma ontologia que contém conceitos e instâncias de projeto. A informação necessária para a compreensão do conceito é representada por meio de regras esquemáticas de uma gramática da forma e cada um destes conceitos é relacionado com uma ou mais instâncias de projeto. A primeira etapa para o desenvolvimento deste sistema envolveu a elaboração de uma taxonomia para a ontologia. Esta taxonomia se baseia na estrutura da linguagem de padrões de Christopher Alexander e na estrutura hierárquica de diferentes livros e manuais de arquitetura paisagística. Um protótipo do sistema foi desenvolvido, com exemplos de boa conduta de projeto extraídos do trabalho do paisagista brasileiro Roberto Burle Marx. A partir dele foram realizados uma série de testes com a intenção de comprovar a eficácia do sistema. Palavras-chave. Ontologia, Roberto Burle Marx, arquitetura paisagística, linguagem de padrões, gramática da forma.

  1. Haben repetitive DNA-Sequenzen biologische Funktionen?

    Science.gov (United States)

    John, Maliyakal E.; Knöchel, Walter

    1983-05-01

    By DNA reassociation kinetics it is known that the eucaryotic genome consists of non-repetitive DNA, middle-repetitive DNA and highly repetitive DNA. Whereas the majority of protein-coding genes is located on non-repetitive DNA, repetitive DNA forms a constitutive part of eucaryotic DNA and its amount in most cases equals or even substantially exceeds that of non-repetitive DNA. During the past years a large body of data on repetitive DNA has accumulated and these have prompted speculations ranging from specific roles in the regulation of gene expression to that of a selfish entity with inconsequential functions. The following article summarizes recent findings on structural, transcriptional and evolutionary aspects and, although by no means being proven, some possible biological functions are discussed.

  2. Repetitively pulsed material testing facility

    International Nuclear Information System (INIS)

    Zucker, O.; Bostick, W.; Gullickson, R; Long, J.; Luce, J.; Sahlin, H.

    1975-01-01

    A continuously operated, 1 pps, dense-plasma-focus device capable of delivering a minimum of 10 15 neutrons per pulse for material testing purposes is described. Moderate scaling from existing results is sufficient to provide 2 x 10 13 n/cm 2 .s to a suitable target. The average power consumption, which has become a major issue as a result of the energy crisis, is analyzed with respect to other plasma devices and is shown to be highly favorable. A novel approach to the capacitor bank and switch design allowing repetitive operation is discussed. (U.S.)

  3. Repetitively pulsed material testing facility

    International Nuclear Information System (INIS)

    Zucker, O.; Bostick, W.; Gullickson, R.; Long, J.; Luce, J.; Sahlin, H.

    1975-01-01

    A continuously operated, 1 pps, dense-plasma-focus device capable of delivering a minimum of 10 15 neutrons per pulse for material testing purposes is described. Moderate scaling from existing results is sufficient to provide 2 x 10 13 n/cm 2 . s to a suitable target. The average power consumption, which has become a major issue as a result of the energy crisis, is analyzed with respect to other plasma devices and is shown to be highly favorable. A novel approach to the capacitor bank and switch design allowing repetitive operation is discussed

  4. Exact Repetition as Input Enhancement in Second Language Acquisition.

    Science.gov (United States)

    Jensen, Eva Dam; Vinther, Thora

    2003-01-01

    Reports on two studies on input enhancement used to support learners' selection of focus of attention in Spanish second language listening material. Input consisted of video recordings of dialogues between native speakers. Exact repetition and speech rate reduction were examined for effect on comprehension, acquisition of decoding strategies, and…

  5. Repetitive trauma and nerve compression.

    Science.gov (United States)

    Carragee, E J; Hentz, V R

    1988-01-01

    Repetitive movement of the upper extremity, whether recreational or occupational, may result in various neuropathies, the prototype of which is the median nerve neuropathic in the carpal canal. The pathophysiology of this process is incompletely understood but likely involves both mechanical and ischemic features. Experimentally increased pressures within the carpal canal produced reproducible progressive neuropathy. Changes in vibratory (threshold-type) sensibility appears to be more sensitive than two-point (innervation density-type) sensibility. The specific occupational etiologies of carpal neuropathy are obscured by methodologic and sociological difficulties, but clearly some occupations have high incidences of CTS. History and physical examination are usually sufficient for the diagnosis, but diagnostic assistance when required is available through electrophysiological testing, CT scanning, and possibly MRI. Each of these tests has limitations in both sensitivity and specificity. Treatment by usual conservative means should be combined with rest from possible provocative activities. Surgical release of the carpal canal is helpful in patients failing conservative therapy. Occupational modifications are important in both treatment and prevention of median neuropathy due to repetitive trauma.

  6. A questão da paisagem no Brasil através de Roberto Burle Marx

    Directory of Open Access Journals (Sweden)

    Alexandra Maria Aguiar Leister

    2016-12-01

    Full Text Available Burle Marx believed that the landscape´s aesthetic dimension was an essential concept for human life. In Brasil, Burle Marx’s landscapes enrich our thoughts on landscape architecture, often borrowed from international authors. In this context, this article, based on the theoretical framework of philosophy and geography, leads to a reflection on landscape based on the works of the Brazilian master of landscapes, Roberto Burle Marx. His professional career is a unique contribution to deepening the issue of landscape. As a dyad, his theoretical concepts of nature were transformed into livable landscapes. In this ethereal process, the master built places worthy of awakening the senses. This article reflects on his theoretical concepts of landscape, the way he transformed them into landscape architecture projects and his thoughts about the future of the Brazilian landscape.

  7. [Management of functional sterility using clomiphene and cyclophenyl at the Karl-Marx-Stadt District Hospital Gynecologic Clinic].

    Science.gov (United States)

    Neubert, S; Melzer, H

    1977-01-01

    We report on 39 barren patients suffering from anovulatory cycle disturbances or corpus luteum inadequacies. Them were given treatment in the Gynecological Hospital of Karl-Marx-Stadt County at Karl-Marx-Stadt in the past few years and were administered Clomiphendihydrogencitrate or Cyclophenyl to provoke ovulation. Before and during therapy, the total of estrogenes and pregnanediol were determined in the 24h-urine every two days. The clinical data and the results of the hormone investigations were analysed, and an attempt was made to derive a forecast from the estrogene and pregnanediol secretion so as to be able to form an opinion on the positive or negative result of the treatment.

  8. [Experiences and results in hypertension screening in women between 20 and 65 years of age in Karl-Marx-City].

    Science.gov (United States)

    Voigt, G; Börker, G; Edelmann, S; Hartung, A; Hartung, G; Heyne, S; Töpfer, V

    1980-11-15

    From 1975 to 1979 in the district of the City of Karl-Marx-Stadt 91,130 females at the age between 20 and 65 years were summoned to a gynaecologico-cardiological mass examination which was supported by computer. 56,460 females underwent the examination. According to the WHO-criteria two measurements of blood pressure were carried out, when increased blood pressure was present a third one and a fourth one by an examination group. A diagnostic standard programme was used. In the second measurement of blood pressure we established 19.8% of patients with hypertension and 28.6% patients with borderline values. 52.8% of the hypertensions were known. Of 10,685 females with known or established hypertension 10.1% underwent an optimum therapy. On the basis of these results a programme for the fight against hypertension was developed for the county Karl-Marx-Stadt.

  9. Emprego e trabalho no início do século XXI: revisitando Keynes e Marx

    Directory of Open Access Journals (Sweden)

    Benedito Rodrigues de Moraes Neto

    Full Text Available A natureza do trabalho nas economias avançadas apresentou significativa mudança recente. O progresso tecnológico ocasionou redução do trabalho sem conteúdo e ampliação daquele de maior qualificação ou escolaridade, fenômeno para cuja discussão se busca auxílio de Keynes e Marx. No caso de Keynes, destaca-se sua antevisão de que o progresso tecnológico geraria imensa redução do tempo de trabalho e ampliação do tempo de lazer. Considerando que isso não ocorreu, a falha pode ter acontecido por trabalhar com oposição entre trabalho sem conteúdo e lazer, não possibilitando capturar as mudanças históricas no trabalho e na relação dos homens com ele. A visão de Marx é completamente diferente, pois sua oposição se dá entre trabalho desprovido de conteúdo e "trabalho atividade", esse último impregnado de conteúdo e fundamental para o desenvolvimento das individualidades. A realidade atual tem, portanto, uma maior "colagem" com Marx e apresenta grandes desafios para o capitalismo e sua crítica.

  10. Desenvolvendo a solidariedade no caminho da transição: um ensaio sobre a teoria do socialismo a partir de Marx Developing the solidarity in the path to transition: an essay on the socialism theory based on Marx

    Directory of Open Access Journals (Sweden)

    Jonas de Oliveira Bertucci

    2010-04-01

    Full Text Available Segundo verifica-se nos trabalhos de K. Marx com vista a uma teoria da transição, o socialismo seria uma etapa intermediária para um sistema superior - o comunismo - tornado possível somente após o pleno desenvolvimento das forças produtivas, "missão histórica" do capitalismo. Essa tese se mostrou bastante controversa, posto que a história vem demonstrando que a expansão do capitalismo, nos últimos dois séculos, não foi limitada pelo avanço da técnica a ponto de iniciar um processo de transição fruto de uma intensa reação revolucionária. Neste contexto, a proposta do presente trabalho é discutir alguns aspectos do pensamento de Marx, a atualidade de sua teoria da transição e o processo de crise da reprodução das relações de produção capitalistas na modernidade. Ao final, são discutidas propostas mais recentes que sugerem formas de organização produtiva alternativas a partir das práticas de autogestão, com o título de economia solidária.According to the main ideas that one may extract from Marx's works on a transition theory, the socialism would be an intermediate stage for a superior system - the communism - made possible only after the complete development of the productive forces, capitalism's "historical mission". This thesis represents one of Marx's biggest controversies and history has demonstrated that the reproduction and the expansion of the capitalism have not been limited by the advance of the technique - and that neither a transition process would emerge from a sudden revolutionary reaction. In this work, we put on discussion some aspects of Marx's thought, his transition theory and the current process of crisis of the reproduction of the capitalist relations of production. In the conclusions, a series of experiences of self-management with the heading of solidarity economics are discussed.

  11. Processo de trabalho e eficiência produtiva: Smith, Marx, Taylor e Lênin

    Directory of Open Access Journals (Sweden)

    Benedito Rodrigues de Moraes Neto

    2009-09-01

    Full Text Available A partir de reflexão sobre uma hipotética transição do capitalismo em sua natureza manufatureira ao socialismo, procura-se deixar marcada a razão pela qual, seguindo a proposta de Marx, essa transição exige que a produção se realize sob a égide da maquinaria. Consegue-se, como parte dessa reflexão, identificar, para o caso da manufatura, um trade-off entre eficiência produtiva e humanização das atividades de trabalho. Procura-se esclarecer que, dada a natureza do taylorismo-fordismo como "reinvenção da manufatura", o exercício de início especulativo passa a ter sentido histórico. Busca-se argumentar que a ampla assimilação do taylorismo-fordismo pela experiência de implantação do socialismo na União Soviética a aprisionou ao mencionado trade-off , fazendo com que a primeira experiência de superação do capitalismo se impregnasse perversamente da mediocridade imanente ao taylorismo-fordismo. Finalmente, são feitos rápidos comentários acerca dos desdobramentos da recente automação de base microeletrônica sobre a natureza de um projeto socialista.From an analysis of a hypothetical transition from manufacture capitalism to socialism, we intend to stress the reason why, according to Marx´s proposition, it is demanded that this transition takes place under machinery´s domain. In the case of manufacture it is possible to identify a trade-off between the productive efficiency and the humanization of the labor activities. We then intend to clarify that the initially hypothetical speculation acquires a historic sense in as much as taylorism-fordism´s nature can be understood as a "reinvention of the manufacturing system". We shall then argue that the wide assimilation of taylorism-fordism in the Soviet Union´s experience of socialism implementation imprisoned it within the mentioned trade-off, which caused the first experience of capitalism´s surmount to be perversely impregnated with the immanent mediocrity of

  12. Repetitively pulsed power for meat pasteurization

    International Nuclear Information System (INIS)

    Patterson, E.L.; Kaye, R.J.; Neau, E.L.

    1994-01-01

    Electronic pasteurization of meat offers the potential for drastically reducing the incidence of food poisoning caused by biological pathogens accidentally introduced into meat products. Previous work has shown that γ-rays are an effective method of destroying E. coli 0157:H7, Salmonella, C. jejuni, L. monocytogenes, Listeria, and S. aureus bacteria types. The concern with the use of γ-rays is that radioactive material must be used in the pasteurization process that can lead to some market resistance and activist pressure on the meat industry. The use of accelerator generated high average power electron beams, at energies less than 10 MeV, or X-rays, with energies below 5 MeV, have been approved by the FDA for use in pasteurizing foods. Accelerator produced electronic pasteurization has the advantage that no radioactive material inventory is required. Electronic pasteurization has the additional benefit that it removes bacterial pathogens on the meat surface as well as within the volume of the meat product. High average power, repetitively-pulsed, broad-area electron beam sources being developed in the RHEPP program are suitable for large scale meat treatment in packing plant environments. RHEPP-II, which operates at 2.5 MeV and 25 kA at pulse repetition frequencies up to 120 Hz has adequate electron energy to penetrate hamburger patties which comprise about half of the beef consumption in the United States. Ground beef also has the highest potential for contamination since considerable processing is required in its production. A meat pasteurization facility using this size of accelerator source should be capable of treating 10 6 pounds of hamburger patties per hour to a dose of up to 3 kGy (300 kilorads). The RHEPP modular accelerator technology can easily be modified for other production rates and types of products

  13. Interaction of Repetitively Pulsed High Energy Laser Radiation With Matter

    Science.gov (United States)

    Hugenschmidt, Manfred

    1986-10-01

    The paper is concerned with laser target interaction processes involving new methods of improving the overall energy balance. As expected theoretically, this can be achieved with high repetition rate pulsed lasers even for initially highly reflecting materials, such as metals. Experiments were performed by using a pulsed CO2 laser at mean powers up to 2 kW and repetition rates up to 100 Hz. The rates of temperature rise of aluminium for example were thereby increased by lore than a factor of 3 as compared to cw-radiation of comparable power density. Similar improvements were found for the overall absorptivities that were increased by this method by more than an order of magnitude.

  14. Performance of PROMIS Physical Function Compared with KOOS, SF-36, Eq5d And Marx Activity Scale in Patients Who Undergo ACL Reconstruction

    Science.gov (United States)

    Scott, Elizabeth; Glass, Natalie; Wolf, Brian R.; Hettrich, Carolyn M.; Bollier, Matthew

    2018-01-01

    Objectives: Anterior cruciate ligament reconstruction is a commonly performed orthopaedic procedure. PROMIS (Patient-Reported Outcome Measurement Information System) was developed by the National Institutes of Health in an effort to advance patient-reported outcome (PRO) instruments by developing question banks for major health domains. Our goal was to compare the responsiveness and construct validity of the PROMIS physical function (PF) computer adaptive test (CAT) with current PRO instruments utilized in patients who undergo anterior cruciate ligament reconstruction. Methods: A total of 174 patients ages 14-53 scheduled to undergo anterior cruciate ligament reconstruction were asked to complete PROMIS PF-CAT, Short Form-36 Health Survey (SF36-PF and -GH), Marx activity rating scale (Marx), Knee Injury and Osteoarthritis Score (KOOS-ADL, -Sport, -QOL), and the EuroQol five dimensions questionnaire (EQ5D) at their preoperative visit. These surveys were repeated at six weeks and six months after surgery. Correlations between PRO instruments was defined as excellent (>0.7), excellent-good (0.61-0.7), good (0.4-0.6), and poor (0.2-0.3) using Spearman Correlation Coefficients. The effect size (Cohen d) and standardized response mean (SRM) were used to describe the responsiveness of each PRO at the 6 week and 6 month follow-up visits and were defined as small (0.2), medium (0.5) and large (0.8). Ceiling and floor effects were defined as present if ≥15% of participants scored the highest or lowest score on a PRO, respectively. Subgroup analyses were performed comparing change in PRO scores at follow-up between participants with and without additional arthroscopic procedures (meniscal debridement and/or repair, microfracture, or OATS vs ACL reconstruction only) using linear mixed models. Results: There were excellent and excellent-good correlations between the PROMIS PF-CAT and physical function PROs including the SF36-PF (r=0.75-0.80, p0.05) to poor correlation with

  15. A Nonword Repetition Task for Speakers with Misarticulations: The Syllable Repetition Task (SRT)

    Science.gov (United States)

    Shriberg, Lawrence D.; Lohmeier, Heather L.; Campbell, Thomas F.; Dollaghan, Christine A.; Green, Jordan R.; Moore, Christopher A.

    2009-01-01

    Purpose: Conceptual and methodological confounds occur when non(sense) word repetition tasks are administered to speakers who do not have the target speech sounds in their phonetic inventories or who habitually misarticulate targeted speech sounds. In this article, the authors (a) describe a nonword repetition task, the Syllable Repetition Task…

  16. Algumas questões sobre educação e ensino em Marx e Engels

    Directory of Open Access Journals (Sweden)

    José Claudinei Lombardi

    2012-08-01

    Full Text Available Este texto delineia alguns apontamentos sobre a educação e ensino em Marx e Engels, tendo como central a categoria Modo de Produção. para a análise e compreensão da educação (e nela todo o aparato escolar. A educação, como um aspecto ou dimensão da vida social, surge e se desenvolve no interior de um modo de produção determinado, nos movimentos contraditórios que emergem do processo das lutas entre classes e frações de classe. Neste sentido, a escola moderna surge decorrente das lutas de classes, assumindo os contornos dos embates políticos passaram a se contrapor – o burguês e o proletário. Em oposição à unilateralidade da educação moderna burguesa apresenta fundamentos da proposta pedagógica comunista, na defesa da combinação entre trabalho produtivo e educação. Entre os debates, propostas e práticas pedagógicas marxistas no Brasil defendo que a principal sistematização e difusão ocorre através da pedagogia histórico-crítica criada por Dermeval Saviani, principal elaborador e referência dessa concepção.

  17. Jocasta’s kinsfolk: Marx, Freud and Oedipus among contemporary antiphilosophers

    Directory of Open Access Journals (Sweden)

    Mikulić Borislav

    2007-01-01

    Full Text Available The text deals with the recently renewed issue of ′antiphilosophy′ in the self-understanding of some prominent contemporary continental philosophers but not only them, such as Alain Badiou and Slavoj Žižek, both referring to the psychoanalyst and theoretician of discourse Jacques Lacan. Starting with a metaphorical analysis of the verdict made by Marx of ′merely interpretive′ character of philosophy in relation to ′the study of real world′ and with his comparison of philosophy with ′masturbation′, the text addresses new appeals to ′antiphilosophy′ as samples of a token or rather, as cases of a syndrome connected with Jocasta’s rationalization of Oedipus’ curse. It was her discourse based on general rules of rationality with which she unconsciously attempted to avoid the confrontation with the truth of an event (incestuous marriage which had already occurred. In the text, presuppositions and consequences of such an analogy between ancient and contemporary philosophical material are discussed in order to show-on the basis of arguing that the unconscious is located within (and not beyond rational processes that subjects undertake in order to respond to rational needs (viz. impulses of the Ego-that contemporary discussion about ′antiphilosophy′ by left-wing philosophers bears unacknowledged tendencies to unconsciously reduce Marx’ algorithm of ′realization of philosophy′ to the Hegelian negation of the negation and to integrate it into the discourse of academic philosophy.

  18. Creative Industries, Value Theory and Michael Heinrich’s New Reading of Marx

    Directory of Open Access Journals (Sweden)

    Frederick H. Pitts

    2015-06-01

    Full Text Available This article utilises the new reading of Marx found in the work of Michael Heinrich to analyse the creative industries. It considers the role played in the production of value by the labour that takes place in the sphere of circulation. The specific focus is on creative industries such as graphic design, advertising and branding. It applies Heinrich's conceptualisation of 'social validation' to these sectors. This suggests that valorisation depends upon goods and services attaining commodity status by selling for money. Value is subject to this validation. The capitalist use of advertising, graphic design and branding guarantees the possibility of this validation. Using Heinrich, it reevaluates claims made about the creative industries and cognate fields in three main respects. First, it exposes as inadequate certain Marxist understandings of productive and unproductive labour and the place of circulation activities within this distinction. Second, it refutes autonomist Marxist claims as to the immeasurability of immaterial labour and the redundancy of the law of value. Third, it suggests that creative industries possess a significant role in a capitalist economy blighted by a necessity towards the overproduction of commodities.

  19. Tom McCarthy, Karl Marx, and the Money on the Books

    Directory of Open Access Journals (Sweden)

    Nicholas Huber

    2017-11-01

    Full Text Available By way of contrast to recent work on the problematic of representation of capital and its prioritized aesthetic mode, visuality, this article addresses the problematic of mediation in financialized capitalism through an attention to the relationship between writing and contemporary money forms. To elaborate this problematic, mediation is deployed methodologically as well: selections from two bodies of work concerned with capitalist monetary phenomena—those of Karl Marx and the novelist Tom McCarthy—are analyzed in parallel. McCarthy’s 'oeuvre' is presented as preoccupied with monetary-inscriptive techniques and pockmarked by Marxian concepts and concerns. It is argued that 'Remainder', specifically, can be read as theorizing the relationship between money and writing under early 21st-century regimes of finance capital through its elaboration of retail loyalty accounts and the multivalent concept of ‘remainder’ or ‘surplus’. The article reads this theorization against neglected sections of Marx’s second volume of 'Capital' in which money is enigmatically treated from the perspective of bookkeeping.

  20. High energy, low inductance, high current fiberglass energy storage capacitor for the Atlas Machine Marx modules

    CERN Document Server

    Cooper, R A; Ennis, J B; Cochrane, J C; Reass, W A; Parsons, W M

    1999-01-01

    The Los Alamos National Laboratory's Atlas Marx design team envisioned a double ended plastic case 60 kV, 15 nH, 650 kA, energy storage capacitor. A design specification was established and submitted to various vendors. Maxwell Energy Products drew from its development of large fiberglass case, high voltage, low inductance "FASTCAP" capacitors manufactured for Maxwell Technologies' ACE II, ACE III and ACE IV machines. This paper discusses the LANL specification and Maxwell Energy Products' successful design, Model No. 39232, 34.1 mu F, 60 kV, 13*29*27", the only capacitor qualified by LANL for the 23 Mega Joule Atlas application. Maxwell's past experience in this type of capacitor is covered. The performance data is reviewed and the life test data compared to the original calculated design life. Challenges included Maxwell's "keep it simple " design goal which was maintained to minimize the effort required to create and manufacture a nearly 600 pound capacitor. (1 refs).

  1. From Marx to Marcos - Search of the Subject and the Strategy of Revolution

    Directory of Open Access Journals (Sweden)

    Ilya L. Morozov

    2017-12-01

    Full Text Available The article discusses the evolution of theories of social revolution from the mid-nineteenth to the late twentieth centuries. The author analyzes the basic concepts of theorists and practitioners of the armed revolutionary struggle – from the founder of the classical Communist theory of Karl Marx to the Mexican guerrilla leader Subcomandante Marcos. The author focuses on the analysis of changes in the understanding of the subject (“driving forces” of the left political revolution, as well as the strategy of armed revolutionary struggle. The author comes to the conclusion about the historical evolution of the subject of the revolutionary struggle from major sustainable macro-groups (“classes”, targeted at the armed struggle, to self-born (by the network principle unstructured protest groups, situational leaders, mild forms of the revolutionary struggle, which minimize the armed violence, though do not eliminate it completely. The author substantiates the conclusion about the absence in the modern protest movement of social forces, able to become the subject of revolution socialist orientation. This increases the danger of dominance of the social protest of extremist nationalist and religious political spectra. The author offers two models of response to this threat: the growing influence of the reigning centre-right conservative parties of Russia; return to center-left positions of the social democratic movement of the countries of the European Union.

  2. LOS FANTASMAS DEL COMUNISMO Y MARX EN CHILE EN LA DÉCADA DE 1870

    Directory of Open Access Journals (Sweden)

    LUIS ORTEGA MARTÍNEZ

    2011-10-01

    Full Text Available La instalación y el trágico fin de la Comuna de París a comienzos de 1871 fueron cubiertos con particular atención por la prensa de Valparaíso y Santiago. Ese interés no fue sólo el de espectadores distantes ante un suceso de por sí dramático. Sus reportajes fueron vinculados a las transformaciones en el ámbito productivo que había comenzado a experimentar la sociedad chilena desde la década de 1850, que paulatinamente comenzaron a generar un mundo de asalariados en las principales ciudades del país. Conjuntos de trabajadores cada vez más numerosos se formaron en la construcción ferroviaria y de otras obras civiles; también ello se verificó en las nuevas actividades productivas, en particular en la industria fabril y la producción de carbón. Los reportajes acerca de los sucesos de París fueron un llamado de atención de la prensa a la élite, pues en Chile poco a poco se comenzaba formar el mundo de los trabajadores. Con ello, el fantasma del Comunismo y del propio Karl Marx comenzaban a asomarse en el hasta entonces bucólico horizonte chileno.

  3. The Developmental Trajectory of Nonword Repetition

    Science.gov (United States)

    Chiat, Shula

    2006-01-01

    In line with the original presentation of nonword repetition as a measure of phonological short-term memory (Gathercole & Baddeley, 1989), the theoretical account Gathercole (2006) puts forward in her Keynote Article focuses on phonological storage as the key capacity common to nonword repetition and vocabulary acquisition. However, evidence that…

  4. REPETITIVE STRENGTH AMONG STUDENTS OF AGE 14

    Directory of Open Access Journals (Sweden)

    Besim Halilaj

    2014-06-01

    Full Text Available The study involved 82 male students of the primary school “Qamil Ilazi” in Kaçanik-Kosovo.Four movement tests, which test the repetitive strength, were conducted: 1. Pull-up, 2. Sit-Up, 3. Back extension, 4. Push-up.The main goal of this study was to verify the actual motor status, respectively the component of the repetitive strength among students of age 14 of masculine gender. In addition to verifying the actual motor status, another objective was to verify the relationship between the variables employed.Basic statistical parameters show a distribution which is not significantly different from the normal distribution, yielded highly correlative values among the repetitive strength tests. Space factorization resulted in extracting two latent squares defined as repetitive strength of arms factor, and repetitive strength of body factor.

  5. Repetitive transcranial magnetic stimulation for hallucination in schizophrenia spectrum disorders: A meta-analysis.

    Science.gov (United States)

    Zhang, Yingli; Liang, Wei; Yang, Shichang; Dai, Ping; Shen, Lijuan; Wang, Changhong

    2013-10-05

    This study assessed the efficacy and tolerability of repetitive transcranial magnetic stimulation for treatment of auditory hallucination of patients with schizophrenia spectrum disorders. Online literature retrieval was conducted using PubMed, ISI Web of Science, EMBASE, Medline and Cochrane Central Register of Controlled Trials databases from January 1985 to May 2012. Key words were "transcranial magnetic stimulation", "TMS", "repetitive transcranial magnetic stimulation", and "hallucination". Selected studies were randomized controlled trials assessing therapeutic efficacy of repetitive transcranial magnetic stimulation for hallucination in patients with schizophrenia spectrum disorders. Experimental intervention was low-frequency repetitive transcranial magnetic stimulation in left temporoparietal cortex for treatment of auditory hallucination in schizophrenia spectrum disorders. Control groups received sham stimulation. The primary outcome was total scores of Auditory Hallucinations Rating Scale, Auditory Hallucination Subscale of Psychotic Symptom Rating Scale, Positive and Negative Symptom Scale-Auditory Hallucination item, and Hallucination Change Scale. Secondary outcomes included response rate, global mental state, adverse effects and cognitive function. Seventeen studies addressing repetitive transcranial magnetic stimulation for treatment of schizophrenia spectrum disorders were screened, with controls receiving sham stimulation. All data were completely effective, involving 398 patients. Overall mean weighted effect size for repetitive transcranial magnetic stimulation versus sham stimulation was statistically significant (MD = -0.42, 95%CI: -0.64 to -0.20, P = 0.000 2). Patients receiving repetitive transcranial magnetic stimulation responded more frequently than sham stimulation (OR = 2.94, 95%CI: 1.39 to 6.24, P = 0.005). No significant differences were found between active repetitive transcranial magnetic stimulation and sham stimulation for

  6. Design and implementation of fast charging circuit for repetitive compact torus injector

    International Nuclear Information System (INIS)

    Onchi, T.; McColl, D.; Dreval, M.; Wolfe, S.; Xiao, C.; Hirose, A.

    2014-01-01

    A novel circuit for compact torus (CT) injector operated at high repetition rates has been developed. The core technology adopted in the present work is to charge a large storage capacitor bank and quickly charge the CT capacitor bank through a stack of insulated-gate bipolar transistors (IGBTs). A system consisting of IGBTs and slow banks for the repetitive operation has been developed and installed for each discharge circuit of the University of Saskatchewan Compact Torus Injector (USCTI). A repetition rate up to 1.7 Hz and a burst of 8 CTs have been achieved

  7. Subjective duration distortions mirror neural repetition suppression.

    Science.gov (United States)

    Pariyadath, Vani; Eagleman, David M

    2012-01-01

    Subjective duration is strongly influenced by repetition and novelty, such that an oddball stimulus in a stream of repeated stimuli appears to last longer in duration in comparison. We hypothesize that this duration illusion, called the temporal oddball effect, is a result of the difference in expectation between the oddball and the repeated stimuli. Specifically, we conjecture that the repeated stimuli contract in duration as a result of increased predictability; these duration contractions, we suggest, result from decreased neural response amplitude with repetition, known as repetition suppression. Participants viewed trials consisting of lines presented at a particular orientation (standard stimuli) followed by a line presented at a different orientation (oddball stimulus). We found that the size of the oddball effect correlates with the number of repetitions of the standard stimulus as well as the amount of deviance from the oddball stimulus; both of these results are consistent with a repetition suppression hypothesis. Further, we find that the temporal oddball effect is sensitive to experimental context--that is, the size of the oddball effect for a particular experimental trial is influenced by the range of duration distortions seen in preceding trials. Our data suggest that the repetition-related duration contractions causing the oddball effect are a result of neural repetition suppression. More generally, subjective duration may reflect the prediction error associated with a stimulus and, consequently, the efficiency of encoding that stimulus. Additionally, we emphasize that experimental context effects need to be taken into consideration when designing duration-related tasks.

  8. A clinical repetitive transcranial magnetic stimulation service in Australia: 6 years on.

    Science.gov (United States)

    Galletly, Cherrie A; Clarke, Patrick; Carnell, Benjamin L; Gill, Shane

    2015-11-01

    There is considerable research evidence for the effectiveness of repetitive transcranial magnetic stimulation in the treatment of depression. However, there is little information about its acceptability and outcomes in clinical settings. This naturalistic study reports on a clinical repetitive transcranial magnetic stimulation service that has been running in Adelaide, South Australia (SA), for 6 years. During this time, 214 complete acute courses were provided to patients with treatment-resistant Major Depressive Disorder. Patients received either sequential bilateral or right unilateral repetitive transcranial magnetic stimulation treatment involving either 18 or 20 sessions given over 6 or 4 weeks respectively. Data included patient demographic details, duration of depression, and medication at the beginning of their repetitive transcranial magnetic stimulation course. The Hamilton Depression Rating Scale was used to assess response to repetitive transcranial magnetic stimulation. Of those undergoing a first-time acute treatment course of repetitive transcranial magnetic stimulation (N = 167), 28% achieved remission, while a further 12% met the criteria for a response to treatment. Most patients (N = 123, 77%) had previously been treated with five or more antidepressant medications, and 77 (47%) had previously received electroconvulsive therapy. Referral rates remained high over the 6 years, indicating acceptance of the treatment by referring psychiatrists. There were no significant adverse events, and the treatment was generally well tolerated. In all, 41 patients (25%) had a second course of repetitive transcranial magnetic stimulation and 6 (4%) patients had a third course; 21 patients subsequently received maintenance repetitive transcranial magnetic stimulation. This naturalistic study showed that repetitive transcranial magnetic stimulation was well accepted by both psychiatrists and patients, and has good efficacy and safety. Furthermore

  9. Repetitive nanosecond electron accelerators type URT-1 for radiation technology

    Science.gov (United States)

    Sokovnin, S. Yu.; Balezin, M. E.

    2018-03-01

    The electron accelerator URT-1М-300 for mobile installation was created for radiation disinfecting to correct drawbacks that were found the URT-1M electron accelerator operation (the accelerating voltage up to 1 МV, repetition rate up to 300 pps, electron beam size 400 × 100 mm, the pulse width about 100 ns). Accelerator configuration was changed that allowed to reduce significantly by 20% tank volume with oil where is placed the system of formation high-voltage pulses, thus the average power of the accelerator is increased by 6 times at the expense of increase in pulses repetition rate. Was created the system of the computerized monitoring parameters (output parameters and thermal mode) and remote control of the accelerator (charge voltage, pulse repetition rate), its elements and auxiliary systems (heat of the thyratron, vacuum system), the remote control panel is connected to the installation by the fiber-optical channel, what lightens the work for service personnel. For generating an electron beam up to 400 mm wide there are used metal- ceramic] and metal-dielectric cold cathodes of several emission elements (plates) with a non-uniform distribution of the electron beam current density on the output foil ± 15%. It was found that emission drop of both type of cathodes, during the operation at the high repetition rate (100 pps) is substantial at the beginning of the process, and then proceeds rather slowly that allows for continuous operation up to 40 h. Experiments showed that linear dependence of the voltage and a signal from the pin-diode remains within the range of the charge voltage 45-65 kV. Thus, voltage increases from 690 to 950 kV, and the signal from the pin-diode - from (2,8-4,6)*104 Gy/s. It allows to select electron energy quite precisely with consideration of the radiation technology requirements.

  10. A compact, repetitive accelerator for military and industrial applications

    International Nuclear Information System (INIS)

    Zutavern, F.J.; O'Malley, M.W.; Ruebush, M.H.; Rinehart, L.F.; Loubriel, G.M.; Babcock, S.R.; Denison, G.J.

    1998-04-01

    A compact, short pulse, repetitive accelerator has many useful military and commercial applications in biological counter proliferation, materials processing, radiography, and sterilization (medical instruments, waste, and food). The goal of this project was to develop and demonstrate a small, 700 kV accelerator, which can produce 7 kA particle beams with pulse lengths of 10--30 ns at rates up to 50 Hz. At reduced power levels, longer pulses or higher repetition rates (up to 10 kHz) could be achieved. Two switching technologies were tested: (1) spark gaps, which have been used to build low repetition rate accelerators for many years; and (2) high gain photoconductive semiconductor switches (PCSS), a new solid state switching technology. This plan was economical, because it used existing hardware for the accelerator, and the PCSS material and fabrication for one module was relatively inexpensive. It was research oriented, because it provided a test bed to examine the utility of other emerging switching technologies, such as magnetic switches. At full power, the accelerator will produce 700 kV and 7 kA with either the spark gap or PCSS pulser

  11. LA ENAJENACIÓN DEL TRABAJO EN LOS MANUSCRITOS ECONÓMICO-FILOSÓFICOS DE 1844 DE KARL MARX

    Directory of Open Access Journals (Sweden)

    Marvin Estrada

    2014-10-01

    Full Text Available This relationship is expressed in four different ways: alienation from the product, alienation from productive activity, alienation from the human species-being and finally alienation from other human beings. In this paper I offer an analysis of the idea of alienated labour and a description of its four expressions that can be found in the Manuscripts. Finally I will try to relate alienated labour with the appearance of private property and I will try to show briefly why Marx introduces communism as a solution to the problems generated by the alienation of labour

  12. Labor as a source of value and capital formation:Ibn Khaldun, Ricardo and Marx – A Comparison

    OpenAIRE

    Hasan, Zubair

    2007-01-01

    Exclusive writings on the contribution of Ibn Khaldun to economics in the English language have not been many, the references to his work also remain scanty and far between. Even in what little is available mostly authors talk about his views on professions, markets and the cloud he castes on merchants. The present paper avoids treading the familiar tracks. It sees close similarities between the views of Ibn Khaldun (1332 – 1406), David Ricardo (1772 – 1823) and Karl Marx (1818 -I823) in...

  13. Repetitive Bibliographical Information in Relational Databases.

    Science.gov (United States)

    Brooks, Terrence A.

    1988-01-01

    Proposes a solution to the problem of loading repetitive bibliographic information in a microcomputer-based relational database management system. The alternative design described is based on a representational redundancy design and normalization theory. (12 references) (Author/CLB)

  14. Contribution of fronto-striatal regions to emotional valence and repetition under cognitive conflict.

    Science.gov (United States)

    Chun, Ji-Won; Park, Hae-Jeong; Kim, Dai Jin; Kim, Eosu; Kim, Jae-Jin

    2017-07-01

    Conflict processing mediated by fronto-striatal regions may be influenced by emotional properties of stimuli. This study aimed to examine the effects of emotion repetition on cognitive control in a conflict-provoking situation. Twenty-one healthy subjects were scanned using functional magnetic resonance imaging while performing a sequential cognitive conflict task composed of emotional stimuli. The regional effects were analyzed according to the repetition or non-repetition of cognitive congruency and emotional valence between the preceding and current trials. Post-incongruence interference in error rate and reaction time was significantly smaller than post-congruence interference, particularly under repeated positive and non-repeated positive, respectively, and post-incongruence interference, compared to post-congruence interference, increased activity in the ACC, DLPFC, and striatum. ACC and DLPFC activities were significantly correlated with error rate or reaction time in some conditions, and fronto-striatal connections were related to the conflict processing heightened by negative emotion. These findings suggest that the repetition of emotional stimuli adaptively regulates cognitive control and the fronto-striatal circuit may engage in the conflict adaptation process induced by emotion repetition. Both repetition enhancement and repetition suppression of prefrontal activity may underlie the relationship between emotion and conflict adaptation. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Document retrieval on repetitive string collections.

    Science.gov (United States)

    Gagie, Travis; Hartikainen, Aleksi; Karhu, Kalle; Kärkkäinen, Juha; Navarro, Gonzalo; Puglisi, Simon J; Sirén, Jouni

    2017-01-01

    Most of the fastest-growing string collections today are repetitive, that is, most of the constituent documents are similar to many others. As these collections keep growing, a key approach to handling them is to exploit their repetitiveness, which can reduce their space usage by orders of magnitude. We study the problem of indexing repetitive string collections in order to perform efficient document retrieval operations on them. Document retrieval problems are routinely solved by search engines on large natural language collections, but the techniques are less developed on generic string collections. The case of repetitive string collections is even less understood, and there are very few existing solutions. We develop two novel ideas, interleaved LCPs and precomputed document lists , that yield highly compressed indexes solving the problem of document listing (find all the documents where a string appears), top- k document retrieval (find the k documents where a string appears most often), and document counting (count the number of documents where a string appears). We also show that a classical data structure supporting the latter query becomes highly compressible on repetitive data. Finally, we show how the tools we developed can be combined to solve ranked conjunctive and disjunctive multi-term queries under the simple [Formula: see text] model of relevance. We thoroughly evaluate the resulting techniques in various real-life repetitiveness scenarios, and recommend the best choices for each case.

  16. Technical innovation in Marx and Mill and the roots of contemporary ambientalist thought A inovação técnica em Mill e Marx e as raízes do pensamento preservacionista contemporâneo

    Directory of Open Access Journals (Sweden)

    Marcia Regina Gabardo da Camara

    1994-08-01

    Full Text Available This article discusses the views of Mill and Marx on technical innovation and ambiental preservations necessities. Although innovation brings wealth to some people and some nations; the heritage to the population is the depredation and degradation of earth -land and men. These are the roots of contemporary ambientalist thought. O artigo apresenta a visão dos economistas clássicos ingleses Mill e Marx acerca da inovação técnica e destaca que o progresso técnico não deve causar a destruição do meio ambiente em sentido amplo -terra e homem. O caráter inédito do artigo é destacar que embora estivessem em pólos opostos os autores concordaram que os frutos do progresso técnico não foram igualmente distribuídos e o patrim6nio ambiental na fase inicial da revolução industrial foi dilapidado, quando poderiam ter conduzido a um mundo melhor as populações miseráveis dos países desenvolvidos e em desenvolvimento. Os dois autores se constituem nas matrizes do pensamento preservacionista contemporâneo.

  17. O discurso capitalista de Marx a Lacan: algumas consequências para o laço social The capitalist speech from Marx to Lacan: some consequences for the social bond

    Directory of Open Access Journals (Sweden)

    Rosane Zétola Lustoza

    2009-06-01

    Full Text Available Investigam-se algumas consequências geradas pelo discurso capitalista no laço social. Tomando como ponto de partida a obra de Karl Marx e o ensino de Jacques Lacan, buscou-se caracterizar o capitalismo, enfatizando a acumulação da mais-valia como um movimento sem ponto de basta, deixando o sujeito num estado de insatisfação constante, e este estado, em contrapartida, vem sempre acompanhado pelo gozo de algum gadget. O caráter ilimitado desse processo acarreta uma modificação na relação do sujeito com a natureza, com os outros homens e com ele mesmo, em que tudo se transforma em mercadoria. O sujeito passa a habitar um mundo previamente condenado a tornar-se dejeto.The article investigates the consequences of the capitalist discourse for the social bond. Taking the works of Karl Marx and Jacques Lacan as point of departure, one aimed to characterize capitalism emphasizing the accumulation of surplus-value as a movement without point of enough that causes in the subject a state of constant insatisfaction that on the other hand is always followed by the enjoyment of some gadget. The limitless character of this process causes an modification on the relationship of the subjetc with the nature, with the other men and with himself, where everything becomes commodities. The subject starts to inhabit a world previoulsy condamned to become a deject.

  18. Sustainment of spherical tokamak by means of repetitive injection of compact torus plasma

    International Nuclear Information System (INIS)

    Shimamura, Shin; Matsura, Ken; Takahashi, Tsutomu; Nogi, Yasuyuki

    2000-01-01

    Sustainment of spherical tokamak (S.T.) has been studied. A compact torus (C.T.) plasma was injected into confinement region by magnetized coaxial gun. For start-up and sustainment of large main spherical tokamak, single pulsed injection of small C.T. is not sufficient in many cases. C.T.plasma injection of high repetition rate is required. For this purpose magnetized coaxial gun was driven with high repetition rate current. The first injected C.T. plasma could start-up S.T. without other help. The repetitive C.T. injection grew and sustained the S.T. plasma. A CCD camera with fast gated image intensifier took a cross sectional view of S.T. during the repetitive C.T. injection. (author)

  19. A dispersion-balanced Discrete Fourier Transform of repetitive pulse sequences using temporal Talbot effect

    Science.gov (United States)

    Fernández-Pousa, Carlos R.

    2017-11-01

    We propose a processor based on the concatenation of two fractional temporal Talbot dispersive lines with balanced dispersion to perform the DFT of a repetitive electrical sequence, for its use as a controlled source of optical pulse sequences. The electrical sequence is used to impart the amplitude and phase of a coherent train of optical pulses by use of a modulator placed between the two Talbot lines. The proposal has been built on a representation of the action of fractional Talbot effect on repetitive pulse sequences and a comparison with related results and proposals. It is shown that the proposed system is reconfigurable within a few repetition periods, has the same processing rate as the input optical pulse train, and requires the same technical complexity in terms of dispersion and pulse width as the standard, passive pulse-repetition rate multipliers based on fractional Talbot effect.

  20. O sistema alexandrino e o sistema epicurista na filosofia da história do jovem Marx

    Directory of Open Access Journals (Sweden)

    Júlia Lemos Vieira

    2017-10-01

    Full Text Available Nos Cadernos preparatórios de sua Tese de Doutorado intitulada Diferença entre as filosofias de Demócrito e Epicuro, esboçados em 1839, Marx se contrapôs a um conteúdo teológico em Hegel através de uma crítica à tendência tradicional da filosofia em teologizar-se dada numa revisão do ocaso da filosofia grega em dois sistemas opostos. O primeiro teria sido o misticismo da filosofia alexandrina; o segundo, o atomismo epicurista que desenvolveu uma dialética peculiar. Sugerindo uma filosofia da história alternativa à de Hegel, Marx pretendia indicar que a democracia não sofreu ocaso na Grécia por conta do desenvolvimento da razão genuinamente filosófica, e sim por conta da vitória da razão filosófica tergiversada em teologia. Era preciso, neste sentido, resgatar a filosofia do sistema epicurista.

  1. SCIENTIFIC METHODOLOGY FOR THE APPLIED SOCIAL SCIENCES: CRITICAL ANALYSES ABOUT RESEARCH METHODS, TYPOLOGIES AND CONTRIBUTIONS FROM MARX, WEBER AND DURKHEIM

    Directory of Open Access Journals (Sweden)

    Mauricio Corrêa da Silva

    2015-06-01

    Full Text Available This study aims to discuss the importance of the scientific method to conduct and advertise research in applied social sciences and research typologies, as well as to highlight contributions from Marx, Weber and Durkheim to the scientific methodology. To reach this objective, we conducted a review of the literature on the term research, the scientific method,the research techniques and the scientific methodologies. The results of the investigation revealed that it is fundamental that the academic investigator uses a scientific method to conduct and advertise his/her academic works in applied social sciences in comparison with the biochemical or computer sciences and in the indicated literature. Regarding the contributions to the scientific methodology, we have Marx, dialogued, the dialectical, striking analysis, explicative of social phenomenon, the need to understand the phenomena as historical and concrete totalities; Weber, the distinction between “facts” and “value judgments” to provide objectivity to the social sciences and Durkheim, the need to conceptualize very well its object of study, reject sensible data and imbue with the spirit of discovery and of being surprised with the results.

  2. Democracia em Marx: o necessário resgate da crítica no Direito Constitucional da atualidade

    Directory of Open Access Journals (Sweden)

    Rômulo Guilherme Leitão

    2006-12-01

    Full Text Available O texto trata da crítica ao descritivismono âmbito do Direito Constitucional, que procuraexplicar os fenômenos das decisões judiciais a partirda análise interna dos dispositivos legais,desconsiderando as tensões políticas presentes emtodas as sociedades. Sugerindo-se a retomada doselementos concretos e objetivos para além danormatividade, o ensaio busca explicações na obramarxiana, não para justificar a existência de umateoria do direito em Marx, mas para sugerir que oconstitucionalismo tem muito a ganhar com a análisemarxista das sociedades do capitalismo atual.The text is faces a critical view ofdescritivism on Constitutional Law studies. Thesestudies, traditionally, try to understand judicialdecisions as an internal analysis – specially thosedecisions on constitutional questions – that ignorepolitical tensions in modern societies.Reconsidering elements of Marx’s theory onconcrete and objective reality, the essay does notsupport the existence of a law theory in Marx,rather explains what could be won toconstitucionalism from Marx’s point of view andpolitical philosophy.

  3. Do individual e do coletivo: sobre aproximações entre o pensamento de Freud e Marx

    Directory of Open Access Journals (Sweden)

    Patrícia Magri Granúzzio

    2011-01-01

    Full Text Available O objetivo deste artigo é discutir a aproximação teórica entre duas vertentes distintas de pensamento que, inicialmente, pode parecer improvável: a psicanálise e o marxismo. O texto discorre sobre a reflexão da gênesis do problema político, interpretando sociedade e indivíduo como inter-relação da natureza humana, conectando, a partir desse princípio, o problema político e o problema psicológico, este se situando como base original daquele. Portanto, no entrecruzamento de sociedade, poder político e natureza humana, expande-se um campo de investigação que se abre a diversas possibilidades, inclusive à aproximação teórica entre as ideias de Marx e Freud. Dentre diversos autores que discutem o freudomarxismo e o posicionamento de Sigmund Freud, diante das ideias de Karl Marx, será dada exclusividade a Wilhelm Reich, Herbert Marcuse e a Ludwig Marcuse. Para uma crítica às ideias de Herbert Marcuse e análise da inter-relação entre marxismo e psicanálise, por sua vez, recorre-se ao filósofo marxista Louis Althusser e a outros analistas e críticos dessas mesmas ideias.

  4. Subjective duration distortions mirror neural repetition suppression.

    Directory of Open Access Journals (Sweden)

    Vani Pariyadath

    Full Text Available Subjective duration is strongly influenced by repetition and novelty, such that an oddball stimulus in a stream of repeated stimuli appears to last longer in duration in comparison. We hypothesize that this duration illusion, called the temporal oddball effect, is a result of the difference in expectation between the oddball and the repeated stimuli. Specifically, we conjecture that the repeated stimuli contract in duration as a result of increased predictability; these duration contractions, we suggest, result from decreased neural response amplitude with repetition, known as repetition suppression.Participants viewed trials consisting of lines presented at a particular orientation (standard stimuli followed by a line presented at a different orientation (oddball stimulus. We found that the size of the oddball effect correlates with the number of repetitions of the standard stimulus as well as the amount of deviance from the oddball stimulus; both of these results are consistent with a repetition suppression hypothesis. Further, we find that the temporal oddball effect is sensitive to experimental context--that is, the size of the oddball effect for a particular experimental trial is influenced by the range of duration distortions seen in preceding trials.Our data suggest that the repetition-related duration contractions causing the oddball effect are a result of neural repetition suppression. More generally, subjective duration may reflect the prediction error associated with a stimulus and, consequently, the efficiency of encoding that stimulus. Additionally, we emphasize that experimental context effects need to be taken into consideration when designing duration-related tasks.

  5. Sylos Labini sobre Marx: implicaciones para la política económica

    Directory of Open Access Journals (Sweden)

    Massimo Cingolani

    2016-09-01

    Full Text Available La presente colaboración aborda algunos aspectos postulados por Sylos Labini en su interpretación de la economía de Carlos Marx, sin duda polémica pero necesaria. Para ello se retoma la amplia discusión teórica realizada en torno a esos temas por varios académicos, que de una manera u otra, han participado e influido en dicho debate. Esta reflexión, importante en sí misma, se vuelve imprescindible en referencia a determinadas implicaciones de gran envergadura sobre la aplicación de la política económica impuesta en los últimos más de 25 años en la Unión Europea, bajo los estrechos criterios de la política fiscal y monetaria impuesta. El autor expresa su opinión a título personal. Este ensayo es una traducción realizada por Glenda Lao Largaespada y Michele Cingolani y revisada por el autor de un artículo publicado con el mismo título en el vol. 68, n. 269 (2015, pp. 81- 147 de Moneta e Credito. El trabajo desarrolla un informe presentado el 25 de Octubre de 2013 en Bolonia en la 54a Reunión Científica Anual de la Sociedad Italiana de los Economistas, que se desarrolló en una lección en la Universidad de Bérgamo el 9 de Mayo de 2014. Sin implicar su adhesión a las tesis presentadas, el autor desea agradecer a Jean-Luc Bailly, Riccardo Bellofiore, Claude Berthomieu, Luca Cefisi, Nadia Garbellini, Lorenzo Esposito, Joseph Halevi, Eckhard Hein, Stefano Lucarelli, Fabio Petri, Antonella Rancan, Roberto Romano, Alessandro Roncaglia, Andrea Salanti, Claudio Sardoni, Andrew Trigg, Jan Toporowski, Ariel Wirkierman, los referees anónimos y los traductores por los comentarios, críticas y apoyo recibidos. El autor asume plena responsabilidad por los errores que persistan.

  6. Word Recognition during Reading: The Interaction between Lexical Repetition and Frequency

    Science.gov (United States)

    Lowder, Matthew W.; Choi, Wonil; Gordon, Peter C.

    2013-01-01

    Memory studies utilizing long-term repetition priming have generally demonstrated that priming is greater for low-frequency words than for high-frequency words and that this effect persists if words intervene between the prime and the target. In contrast, word-recognition studies utilizing masked short-term repetition priming typically show that the magnitude of repetition priming does not differ as a function of word frequency and does not persist across intervening words. We conducted an eye-tracking while reading experiment to determine which of these patterns more closely resembles the relationship between frequency and repetition during the natural reading of a text. Frequency was manipulated using proper names that were high-frequency (e.g., Stephen) or low-frequency (e.g., Dominic). The critical name was later repeated in the sentence, or a new name was introduced. First-pass reading times and skipping rates on the critical name revealed robust repetition-by-frequency interactions such that the magnitude of the repetition-priming effect was greater for low-frequency names than for high-frequency names. In contrast, measures of later processing showed effects of repetition that did not depend on lexical frequency. These results are interpreted within a framework that conceptualizes eye-movement control as being influenced in different ways by lexical- and discourse-level factors. PMID:23283808

  7. First high-repetition-rate Thomson scattering for fusion plasmas

    International Nuclear Information System (INIS)

    Roehr, H.; Steuer, K.H.; Schramm, G.; Hirsch, K.; Salzmann, H.

    1982-01-01

    Electron temperature and density measurements by Thomson scattering were performed for the first time for the whole duration of a tokamak discharge. A Nd:YAG laser of 60 pulses per second at 1.06μm was used in ASDEX in combination with silicon avalanche photodiode detectors. Density calibration was done by rotational anti-Stokes Raman scattering from hydrogen. The system is used for measurements at electron densities as low as 3x10 12 cm -3 . (author)

  8. Properties of water surface discharge at different pulse repetition rates

    Czech Academy of Sciences Publication Activity Database

    Ruma, R.; Hosseini, S.H.R.; Yoshihara, K.; Akiyama, M.; Sakugawa, T.; Lukeš, Petr; Akiyama, H.

    2014-01-01

    Roč. 116, č. 12 (2014), s. 123304-123304 ISSN 0021-8979 Grant - others:Rada Programu interní podpory projektů mezinárodní spolupráce AV ČR(CZ) M100431203 Program:M Institutional support: RVO:61389021 Keywords : plasma in air * water surface discharge * pulse frequency * hydrogen peroxide * organic dye Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.183, year: 2014 http://dx.doi.org/ 10.1063/1.4896266

  9. Evolution of repetitive explosive instabilities in space and time

    International Nuclear Information System (INIS)

    Wilhelmsson, H.

    1984-01-01

    A nonlinear rate equation describing nonlinear, explosive type interaction of waves in plasmas is studied, assuming that amplitude saturation occurs due to nonlinear frequency shifts. Emphasis is put on the space dependence of the solution caused by the assumption of a given initial amplitude distribution in space. An analysis is given of the problem of repetitive peaks governed by the nonlinear rate equation for the time development of the amplitudes of plasma waves and by a Lorentzian shape distribution of the initial amplitudes. For the one-dimensional case, the peaks developed by explosive instability move in the direction of lower initial amplitude values, and the speed and the repetition rate of the peaks are determined. The possible forms of equilibria for the nonlinear rate equation in the explosive case are also studied, including, in addition to the quadratic nonlinearity, diffusion and linear damping effects. A solution to the nonlinear rate equation including diffusion is also given for the case where the quadratic nonlinearity represents recombination. (Auth.)

  10. Mouro desmostificou a riqueza e Deu (aDeus à miséria: a educação no interior da família MARX

    Directory of Open Access Journals (Sweden)

    João dos Santos Filho

    2006-01-01

    Full Text Available El presente texto retrata la relación de Karl Marx en el interior de su espacio familiar, su convívio con esposa e hijos, bien como, los sentimientos que el mismo poseía para con la situación de miseria y pobreza de la población trabajadora.

  11. Marx and the critique of capitalist society: critique of labor/Marx e a crítica ontológica da sociedade capitalista: crítica do trabalho

    Directory of Open Access Journals (Sweden)

    Mario Duayer

    2012-07-01

    Full Text Available The paper seeks to emphasize what in my opinion can be consideredthe main thrust of Marxian work: the critique of political economy as an ontological critique of the modern capitalist society. Such critique begins to take its ultimate form with the Grundrisse. The argument runs as follows. Firstly, it tries to show briefly the debilitating effects, both in theory and practice, brought about in the last decades by the dissolution of the Marxian ontological critique. Secondly, it argues that real critique is ontological critique and, consequently, has to explain what such a critique consists of. Finally, agreeing with Postone’s suggested reinterpretation of Marx’s ideas, but diverging from him precisely with respect to ontology, it suggests that the ontological critique produced by Marx is a critique of labor or, in other words, critique of the centrality of labor, which is specific of the capitalist society.O artigo pretende destacar o que constitui para mim o propósitocentral da obra marxiana que, nos Grundrisse, começa a tomar forma acabada,a saber, a crítica da economia política como crítica ontológica da modernasociedade capitalista. O argumento está assim estruturado. Em primeiro lugar,inicio procurando mostrar de maneira sintética os efeitos paralisantes, teóricose práticos, da dissolução da crítica ontológica marxiana nas últimas décadas.Em segundo lugar, e justamente por isso, tento sustentar que crítica de fato écrítica ontológica e, em consequência, devo mostrar de que se trata essa crítica.Por último, concordando com a interpretação da obra de Marx proposta porMoishe Postone, mas diferindo dela precisamente no que diz respeito à onto-logia, procuro demonstrar que a crítica ontológica elaborada por Marx é críticado trabalho, ou, caso se queira, crítica da centralidade do trabalho, própria eespecífica da sociedade capitalista.

  12. A feasible repetitive transcranial magnetic stimulation clinical protocol in migraine prevention.

    Science.gov (United States)

    Zardouz, Shawn; Shi, Lei; Leung, Albert

    2016-01-01

    This case series was conducted to determine the clinical feasibility of a repetitive transcranial magnetic stimulation protocol for the prevention of migraine (with and without aura). Five patients with migraines underwent five repetitive transcranial magnetic stimulation sessions separated in 1- to 2-week intervals for a period of 2 months at a single tertiary medical center. Repetitive transcranial magnetic stimulation was applied to the left motor cortex with 2000 pulses (20 trains with 1s inter-train interval) delivered per session, at a frequency of 10 Hz and 80% resting motor threshold. Pre- and post-treatment numerical rating pain scales were collected, and percent reductions in intensity, frequency, and duration were generated. An average decrease in 37.8%, 32.1%, and 31.2% were noted in the intensity, frequency, and duration of migraines post-repetitive transcranial magnetic stimulation, respectively. A mean decrease in 1.9±1.0 (numerical rating pain scale ± standard deviation; range: 0.4-2.8) in headache intensity scores was noted after the repetitive transcranial magnetic stimulation sessions. The tested repetitive transcranial magnetic stimulation protocol is a well-tolerated, safe, and effective method for migraine prevention.

  13. Laterality of repetitive finger movement performance and clinical features of Parkinson's disease.

    Science.gov (United States)

    Stegemöller, Elizabeth; Zaman, Andrew; MacKinnon, Colum D; Tillman, Mark D; Hass, Chris J; Okun, Michael S

    2016-10-01

    Impairments in acoustically cued repetitive finger movement often emerge at rates near to and above 2Hz in persons with Parkinson's Disease (PD) in which some patients move faster (hastening) and others move slower (bradykinetic). The clinical features impacting this differential performance of repetitive finger movement remain unknown. The purpose of this study was to compare repetitive finger movement performance between the more and less affected side, and the difference in clinical ratings among performance groups. Forty-one participants diagnosed with idiopathic PD completed an acoustically cued repetitive finger movement task while "on" medication. Eighteen participants moved faster, 10 moved slower, and 13 were able to maintain the appropriate rate at rates above 2Hz. Clinical measures of laterality, disease severity, and the UPDRS were obtained. There were no significant differences between the more and less affected sides regardless of performance group. Comparison of disease severity, tremor, and rigidity among performance groups revealed no significant differences. Comparison of posture and postural instability scores revealed that the participants that demonstrated hastening had worse posture and postural instability scores. Consideration of movement rate during the clinical evaluation of repetitive finger movement may provide additional insight into varying disease features in persons with PD. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Desemprego tecnológico: Ricardo, Marx e o caso da indústria de transformação Brasileira (1990-2007 Technological unemployment: Ricardo, Marx, and the case of the manufacturing industry in Brazil (1990-2007

    Directory of Open Access Journals (Sweden)

    Joaquim Miguel Couto

    2011-08-01

    Full Text Available A questão do desemprego tecnológico preocupou a mente de dois dos maiores pensadores da ciência econômica: David Ricardo e Karl Marx. Ambos acreditaram que a introdução de novas máquinas poderia causar uma situação de desemprego crônico durante certo período de tempo. No entanto, esta era apenas uma possibilidade, que já havia ocorrido no capitalismo industrial inglês, mas que poderia ser evitada caso novos investimentos absorvessem a mão de obra dispensada pela introdução de nova maquinaria. O Brasil, por sua vez, passou, ao longo da década de 1990, por um período de reestruturação de seu parque industrial que, mediante a metodologia utilizada em nosso estudo, resultou na conclusão da existência do fenômeno do desemprego tecnológico durante boa parte da referida década.The issue of technological unemployment was a cause for concern for two of the greatest thinkers in the field of economic science: David Ricardo and Karl Marx. Both believed that the introduction of new machines could bring about chronic unemployment for a certain period of time. However, this was only a possibility that had already taken place within English industrial capitalism, but that could be avoid if new investments absorbed the workforce laid off by the introduction of new machinery. In the case of Brazil, the country underwent a restructuring period of its industrial base during the 1990s, which according to the methodology employed in our study, verified the existence of the technological unemployment phenomenon during much of the aforementioned decade.

  15. Storytelling and Repetitive Narratives for Design Empathy

    DEFF Research Database (Denmark)

    Fritsch, Jonas; Judice, Andrea; Soini, Katja

    2007-01-01

    study. In this paper, we show how we attained an empathic understanding through storytelling and aroused empathy to others using repetitive narratives in an experimental presentation bringing forth factual, reflective and experiential aspects of the user information. Taking as a starting point our...

  16. Matriculation Research Report: Course Repetition Data & Analysis.

    Science.gov (United States)

    Gerda, Joe

    Due to concerns that its policy on class repetition was not promoting student success, California's College of the Canyons (CoC) undertook a project to analyze student course-taking patterns and make recommendations to modify the policy. Existing college policy did not follow Section 58161 of the State Educational Code that allows colleges to…

  17. Reducing Repetitive Speech: Effects of Strategy Instruction.

    Science.gov (United States)

    Dipipi, Caroline M.; Jitendra, Asha K.; Miller, Judith A.

    2001-01-01

    This article describes an intervention with an 18-year-old young woman with mild mental retardation and a seizure disorder, which focused on her repetitive echolalic verbalizations. The intervention included time delay, differential reinforcement of other behaviors, and self-monitoring. Overall, the intervention was successful in facilitating…

  18. Neurobehavioural Correlates of Abnormal Repetitive Behaviour

    Directory of Open Access Journals (Sweden)

    R. A. Ford

    1991-01-01

    Full Text Available Conditions in which echolalia and echopraxia occur are reviewed, followed by an attempt to elicit possible mechanisms of these phenomena. A brief description of stereotypical and perseverative behaviour and obsessional phenomena is given. It is suggested that abnormal repetitive behaviour may occur partly as a result of central dopaminergic dysfunction.

  19. Verbal Repetitions and Echolalia in Alzheimer's Discourse

    Science.gov (United States)

    Da Cruz, Fernanda Miranda

    2010-01-01

    This article reports on an investigation of echolalic repetition in Alzheimer's disease (AD). A qualitative analysis of data from spontaneous conversations with MHI, a woman with AD, is presented. The data come from the DALI Corpus, a corpus of spontaneous conversations involving subjects with AD. This study argues that echolalic effects can be…

  20. Bystanders' Reactions to Witnessing Repetitive Abuse Experiences

    Science.gov (United States)

    Janson, Gregory R.; Carney, JoLynn V.; Hazler, Richard J.; Oh, Insoo

    2009-01-01

    The Impact of Event Scale-Revised (D. S. Weiss & C. R. Marmar, 1997) was used to obtain self-reported trauma levels from 587 young adults recalling childhood or adolescence experiences as witnesses to common forms of repetitive abuse defined as bullying. Mean participant scores were in a range suggesting potential need for clinical assessment…

  1. High-repetition intra-cavity source of Compton radiation

    International Nuclear Information System (INIS)

    Pogorelsky, I; Polyanskiy, M; Agustsson, R; Campese, T; Murokh, A; Ovodenko, A; Shaftan, T

    2014-01-01

    We report our progress in developing a high-power Compton source for a diversity of applications ranging from university-scale compact x-ray light sources and metrology tools for EUV lithography, to high-brilliance gamma-sources for nuclear analysis. Our conceptual approach lies in multiplying the source’s repetition rate and increasing its average brightness by placing the Compton interaction point inside the optical cavity of an active laser. We discuss considerations in its design, our simulations, and tests of the laser’s cavity that confirm the feasibility of the proposed concept. (paper)

  2. High energy metal ion implantation using 'Magis', a novel, broad-beam, Marx-generator-based ion source

    International Nuclear Information System (INIS)

    Anders, A.; Brown, I.G.; Dickinson, M.R.; MacGill, R.A.

    1996-08-01

    Ion energy of the beam formed by an ion source is proportional to extractor voltage and ion charge state. Increasing the voltage is difficult and costly for extraction voltage over 100 kV. Here we explore the possibility of increasing the charge states of metal ions to facilitate high-energy, broad beam ion implantation at a moderate voltage level. Strategies to enhance the ion charge state include operating in the regimes of high-current vacuum sparks and short pulses. Using a time-of-flight technique we have measured charge states as high as 7+ (73 kA vacuum spark discharge) and 4+ (14 kA short pulse arc discharge), both for copper, with the mean ion charge states about 6.0 and 2.5, respectively. Pulsed discharges can conveniently be driven by a modified Marx generator, allowing operation of ''Magis'' with a single power supply (at ground potential) for both plasma production and ion extraction

  3. Fundamentos macroeconômicos nas perspectivas de Marx e Keynes: contribuições para a heterodoxia

    Directory of Open Access Journals (Sweden)

    PEDRO GARRIDO DA COSTA LIMA

    2016-09-01

    Full Text Available RESUMO: A necessidade de definir fundamentos microeconômicos para os modelos macroeconômicos, presente no pensamento dominante na economia contemporânea, pode ser questionada com base em diferentes abordagens teóricas. Posições como as de Marx e Keynes permitem a apreensão das ações dos agentes econômicos (grupos ou classes como influenciadas e limitadas pelo ambiente social e macroeconômico, fornecendo visões de fundamentos macroeconômicos da microeconomia, ao invés da visão ortodoxa de fundamentos micro da macroeconomia. Essa forma de apreensão lança luz sobre diferenças de perspectivas da heterodoxia quando se trata de intervir sobre o contexto macroeconômico.

  4. READING SLOW ART WORK AS A MOTION FOR AESTHETIC EDUCATION ON THE BASIS OF MARX AND VYGOTSKY CONTRIBUTIONS

    Directory of Open Access Journals (Sweden)

    Priscila de Souza Chiste

    2015-06-01

    Full Text Available The article signals a proposal for Aesthetic Education, from literature search, in dialogue with studies of Marx and Vygotsky. According to the Marxist theory presents reflections on aesthetics in the contemporary context and seeks to understand Vygotsky assumptions of Aesthetic Education. Suggests a path through the visual arts, to educate aesthetically from the concept of slow reading of the artwork. Considers that one of the possibilities to achieve such intent is to provide intense, diverse and ongoing encounters with works of art; mediate readings pictures that show both poetic and intertextual aspects as formal of these works, magnified by the knowledge of the artist's universe and the legitimation modes and dissemination of works and, finally, to propose matters relating to the interests of students.

  5. Trabalho, racionalização e emancipação: de Marx ao Marxismo, e a volta

    Directory of Open Access Journals (Sweden)

    Marcílio Rodrigues Lucas

    Full Text Available Resumo Este ensaio propõe uma reflexão sobre a relação entre trabalho e emancipação no pensamento marxista, à luz dos dilemas enfrentados pela esquerda e pelas organizações da classe trabalhadora no século XX. O objetivo central foi indicar como importantes pensadores e grupos vinculados ao marxismo contribuíram, de diferentes formas, na formação das bases ideológicas e na constituição concreta dos dois modelos de organização da produção e da vida social que predominaram após a Segunda Guerra Mundial: o compromisso fordista nos países de capitalismo avançado e o modelo soviético implantado na União das Repúblicas Socialistas Soviéticas e difundido pelos países-satélites que formavam o bloco socialista. Nesse sentido, buscou-se mostrar que essa atuação implicou dilemas e tensões importantes, sobretudo quanto ao posicionamento em relação à racionalização do trabalho e aos métodos tayloristas de organização da produção. Além disso, indicou-se que a tendência predominante foi uma interpretação da teoria de Marx que reduzia a importância da crítica ao trabalho industrial e assalariado, legitimando um projeto de 'sociedade do trabalho' estranho aos fundamentos essenciais do legado marxiano. No entanto, a crise desses modelos, verificada nas últimas décadas do século passado, abre espaço para o revigoramento dos aspectos mais férteis da crítica de Marx à sociabilidade capitalista.

  6. Relationship to carcinogenesis of repetitive low-dose radiation exposure

    International Nuclear Information System (INIS)

    Ootsuyama, Akira

    2016-01-01

    We studied the carcinogenic effects caused by repetitive irradiation at a low dose, which has received attention in recent years, and examined the experimental methods used to evaluate radiation-induced carcinogenesis. For this experiment, we selected a mouse with as few autochthonous cancers as possible. Skin cancer was selected as the target for analysis, because it is a rare cancer in mice. Beta-rays were selected as the radiation source. The advantage of using beta-rays is weaker penetration power into tissues, thus protecting organs, such as the digestive and hematogenous organs. The benefit of our experimental method is that only skin cancer requires monitoring, and it is possible to perform long-term experiments. The back skin of mice was exposed repetitively to beta-rays three times a week until the occurrence of cancer or death, and the dose per exposure ranged from 0.5 to 11.8 Gy. With the high-dose range (2.5-11.8 Gy), the latency period and carcinogenic rate were almost the same in each experimental group. When the dose was reduced to 1-1.5 Gy, the latency period increased, but the carcinogenic rate remained. When the dose was further reduced to 0.5 Gy, skin cancer never happened, even though we continued irradiation until death of the last mouse in this group. The lifespan of 0.5 Gy group mice was the same as that of the controls. We showed that the 0.5 Gy dose did not cause cancer, even in mice exposed repetitively throughout their life span, and thus refer to 0.5 Gy as the threshold-like dose. (author)

  7. Sustainability and Counteracting Factors to Profit Rate Decline

    DEFF Research Database (Denmark)

    Ougaard, Morten

    2014-01-01

    This paper discusses sustainability implications of barriers to growth as specified in the theory of the long-term falling rate of profit but focusing on the counteracting factors (CFs) specified by Marx. These depend much on political processes and are important in state theory for understanding...... policies of national and international institutions. Fourteen partly overlapping factors are identified and grouped in five categories: increased pressure on labor, geographical expansion, resource efficiency, technological progress, and destruction or devaluation of capital. It is suggested...

  8. Repetitive transcranial magnetic stimulation for hallucination in schizophrenia spectrum disorders A meta-analysis***

    Institute of Scientific and Technical Information of China (English)

    Yingli Zhang; Wei Liang; Shichang Yang; Ping Dai; Lijuan Shen; Changhong Wang

    2013-01-01

    OBJECTIVE: This study assessed the efficacy and tolerability of repetitive transcranial magnetic stimulation for treatment of auditory hal ucination of patients with schizophrenia spectrum disorders. DATA SOURCES: Online literature retrieval was conducted using PubMed, ISI Web of Science, EMBASE, Medline and Cochrane Central Register of Control ed Trials databases from January 1985 to May 2012. Key words were “transcranial magnetic stimulation”, “TMS”, “repetitive transcranial magnetic stimulation”, and “hal ucination”. STUDY SELECTION: Selected studies were randomized control ed trials assessing therapeutic ef-ficacy of repetitive transcranial magnetic stimulation for hal ucination in patients with schizophrenia spectrum disorders. Experimental intervention was low-frequency repetitive transcranial magnetic stimulation in left temporoparietal cortex for treatment of auditory hal ucination in schizophrenia spectrum disorders. Control groups received sham stimulation. MAIN OUTCOME MEASURES: The primary outcome was total scores of Auditory Hal ucinations Rating Scale, Auditory Hal ucination Subscale of Psychotic Symptom Rating Scale, Positive and Negative Symptom Scale-Auditory Hal ucination item, and Hal ucination Change Scale. Secondary outcomes included response rate, global mental state, adverse effects and cognitive function. RESULTS: Seventeen studies addressing repetitive transcranial magnetic stimulation for treatment of schizophrenia spectrum disorders were screened, with controls receiving sham stimulation. Al data were completely effective, involving 398 patients. Overal mean weighted effect size for repeti-tive transcranial magnetic stimulation versus sham stimulation was statistical y significant (MD =-0.42, 95%CI: -0.64 to -0.20, P = 0.000 2). Patients receiving repetitive transcranial magnetic stimulation responded more frequently than sham stimulation (OR = 2.94, 95%CI: 1.39 to 6.24, P =0.005). No significant differences were found

  9. Prediction of the Maximum Number of Repetitions and Repetitions in Reserve From Barbell Velocity.

    Science.gov (United States)

    García-Ramos, Amador; Torrejón, Alejandro; Feriche, Belén; Morales-Artacho, Antonio J; Pérez-Castilla, Alejandro; Padial, Paulino; Haff, Guy Gregory

    2018-03-01

    To provide 2 general equations to estimate the maximum possible number of repetitions (XRM) from the mean velocity (MV) of the barbell and the MV associated with a given number of repetitions in reserve, as well as to determine the between-sessions reliability of the MV associated with each XRM. After determination of the bench-press 1-repetition maximum (1RM; 1.15 ± 0.21 kg/kg body mass), 21 men (age 23.0 ± 2.7 y, body mass 72.7 ± 8.3 kg, body height 1.77 ± 0.07 m) completed 4 sets of as many repetitions as possible against relative loads of 60%1RM, 70%1RM, 80%1RM, and 90%1RM over 2 separate sessions. The different loads were tested in a randomized order with 10 min of rest between them. All repetitions were performed at the maximum intended velocity. Both the general equation to predict the XRM from the fastest MV of the set (CV = 15.8-18.5%) and the general equation to predict MV associated with a given number of repetitions in reserve (CV = 14.6-28.8%) failed to provide data with acceptable between-subjects variability. However, a strong relationship (median r 2  = .984) and acceptable reliability (CV  .85) were observed between the fastest MV of the set and the XRM when considering individual data. These results indicate that generalized group equations are not acceptable methods for estimating the XRM-MV relationship or the number of repetitions in reserve. When attempting to estimate the XRM-MV relationship, one must use individualized relationships to objectively estimate the exact number of repetitions that can be performed in a training set.

  10. If you negate, you may forget: negated repetitions impair memory compared with affirmative repetitions.

    Science.gov (United States)

    Mayo, Ruth; Schul, Yaacov; Rosenthal, Meytal

    2014-08-01

    One of the most robust laws of memory is that repeated activation improves memory. Our study shows that the nature of repetition matters. Specifically, although both negated repetition and affirmative repetition improve memory compared with no repetition, negated repetition hinders memory compared with affirmative repetition. After showing participants different entities, we asked them about features of these entities, leading to either "yes" or "no" responses. Our findings show that correctly negating an incorrect feature of an entity elicits an active forgetting effect compared with correctly affirming its true features. For example, after seeing someone drink a glass of white wine, answering "no" to "was it red wine?" may lead one to greater memory loss of the individual drinking wine at all compared with answering "yes" to "was it white wine?" We find this negation-induced forgetting effect in 4 experiments that differ in (a) the meaning given for the negation, (b) the type of stimuli (visual or verbal), and (c) the memory measure (recognition or free recall). We discuss possible underlying mechanisms and offer theoretical and applied implications of the negation-induced forgetting effect in relation to other known inhibition effects. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  11. Multivariate prediction of spontaneous repetitive responses in ventricular myocardium exposed in vitro to simulated ischemic conditions.

    Science.gov (United States)

    Schiariti, M; Puddu, P E; Rouet, R

    1994-06-01

    Guinea-pig ventricular myocardium was partly exposed to normal Tyrode's superfusion and partly to altered conditions (using modified Tyrode's solution) set to simulate acute myocardial ischemia (PO2 80 +/- 10 mmHg; no glucose; pH 7.00 +/- 0.05; K+ 12 mM). Using a double-chamber tissue bath and standard microelectrode technique, the occurrence of spontaneous repetitive responses was investigated during simulated ischemia (occlusion) and after reperfusing the previously ischemic superfused tissue with normal Tyrode's solution (reperfusion). In 62 experiments (42 animals) the effects of: (1) duration of simulated ischemia (1321 +/- 435 s), (2) stimulation rate (1002 +/- 549 ms) and (3) number of successive simulated ischemic periods (occlusions) (1.58 +/- 0.92) on: (1) resting membrane potential, (2) action potential amplitude, (3) duration of 50 and 90% action potentials and (4) maximal upstroke velocity of action potential were studied. All variables were considered as gradients (delta) between normal and ischemic tissue. Both during occlusion and upon reperfusion, spontaneous repetitive responses were coded as single, couplets, salvos (three to nine and > 10) or total spontaneous repetitive responses (coded present when at least one of the above-mentioned types was seen). The incidence of total spontaneous repetitive responses was 31% (19/62) on occlusion and 85% (53/62) upon reperfusion. Cox's models (forced and stepwise) were used to predict multivariately the occurrence of arrhythmic events considered as both total spontaneous repetitive responses and as separate entities. These models were applicable since continuous monitoring of the experiments enabled exact timing of spontaneous repetitive response onset during both occlusion and reperfusion. In predicting reperfusion spontaneous repetitive responses, total spontaneous repetitive responses and blocks observed during the occlusion period were also considered. Total occlusion spontaneous repetitive responses

  12. Comparison of the recently proposed super-Marx generator approach to thermonuclear ignition with the deuterium-tritium laser fusion-fission hybrid concept by the Lawrence Livermore National Laboratory

    International Nuclear Information System (INIS)

    Winterberg, F.

    2009-01-01

    The recently proposed super-Marx generator pure deuterium microdetonation ignition concept is compared to the Lawrence Livermore National Ignition Facility (NIF) Laser deuterium-tritium fusion-fission hybrid concept (LIFE). In a super-Marx generator, a large number of ordinary Marx generators charge up a much larger second stage ultrahigh voltage Marx generator from which for the ignition of a pure deuterium microexplosion an intense GeV ion beam can be extracted. Typical examples of the LIFE concept are a fusion gain of 30 and a fission gain of 10, making up a total gain of 300, with about ten times more energy released into fission as compared to fusion. This means the substantial release of fission products, as in fissionless pure fission reactors. In the super-Marx approach for the ignition of pure deuterium microdetonation, a gain of the same magnitude can, in theory, be reached. If feasible, the super-Marx generator deuterium ignition approach would make lasers obsolete as a means for the ignition of thermonuclear microexplosions

  13. A repetitive elements perspective in Polycomb epigenetics.

    Directory of Open Access Journals (Sweden)

    Valentina eCasa

    2012-10-01

    Full Text Available Repetitive elements comprise over two-thirds of the human genome. For a long time, these elements have received little attention since they were considered non functional. On the contrary, recent evidence indicates that they play central roles in genome integrity, gene expression and disease. Indeed, repeats display meiotic instability associated with disease and are located within common fragile sites, which are hotspots of chromosome rearrangements in tumors. Moreover, a variety of diseases have been associated with aberrant transcription of repetitive elements. Overall this indicates that appropriate regulation of repetitive elements’ activity is fundamental.Polycomb group (PcG proteins are epigenetic regulators that are essential for the normal development of multicellular organisms. Mammalian PcG proteins are involved in fundamental processes, such as cellular memory, cell proliferation, genomic imprinting, X-inactivation, and cancer development. PcG proteins can convey their activity through long-distance interactions also on different chromosomes. This indicates that the 3D organization of PcG proteins contributes significantly to their function. However, it is still unclear how these complex mechanisms are orchestrated and which role PcG proteins play in the multi-level organization of gene regulation. Intriguingly, the greatest proportion of Polycomb-mediated chromatin modifications is located in genomic repeats and it has been suggested that they could provide a binding platform for Polycomb proteins.Here, these lines of evidence are woven together to discuss how repetitive elements could contribute to chromatin organization in the 3D nuclear space.

  14. Modeling repetitive motions using structured light.

    Science.gov (United States)

    Xu, Yi; Aliaga, Daniel G

    2010-01-01

    Obtaining models of dynamic 3D objects is an important part of content generation for computer graphics. Numerous methods have been extended from static scenarios to model dynamic scenes. If the states or poses of the dynamic object repeat often during a sequence (but not necessarily periodically), we call such a repetitive motion. There are many objects, such as toys, machines, and humans, undergoing repetitive motions. Our key observation is that when a motion-state repeats, we can sample the scene under the same motion state again but using a different set of parameters; thus, providing more information of each motion state. This enables robustly acquiring dense 3D information difficult for objects with repetitive motions using only simple hardware. After the motion sequence, we group temporally disjoint observations of the same motion state together and produce a smooth space-time reconstruction of the scene. Effectively, the dynamic scene modeling problem is converted to a series of static scene reconstructions, which are easier to tackle. The varying sampling parameters can be, for example, structured-light patterns, illumination directions, and viewpoints resulting in different modeling techniques. Based on this observation, we present an image-based motion-state framework and demonstrate our paradigm using either a synchronized or an unsynchronized structured-light acquisition method.

  15. Repetitive Elements in Mycoplasma hyopneumoniae Transcriptional Regulation.

    Directory of Open Access Journals (Sweden)

    Amanda Malvessi Cattani

    Full Text Available Transcriptional regulation, a multiple-step process, is still poorly understood in the important pig pathogen Mycoplasma hyopneumoniae. Basic motifs like promoters and terminators have already been described, but no other cis-regulatory elements have been found. DNA repeat sequences have been shown to be an interesting potential source of cis-regulatory elements. In this work, a genome-wide search for tandem and palindromic repetitive elements was performed in the intergenic regions of all coding sequences from M. hyopneumoniae strain 7448. Computational analysis demonstrated the presence of 144 tandem repeats and 1,171 palindromic elements. The DNA repeat sequences were distributed within the 5' upstream regions of 86% of transcriptional units of M. hyopneumoniae strain 7448. Comparative analysis between distinct repetitive sequences found in related mycoplasma genomes demonstrated different percentages of conservation among pathogenic and nonpathogenic strains. qPCR assays revealed differential expression among genes showing variable numbers of repetitive elements. In addition, repeats found in 206 genes already described to be differentially regulated under different culture conditions of M. hyopneumoniae strain 232 showed almost 80% conservation in relation to M. hyopneumoniae strain 7448 repeats. Altogether, these findings suggest a potential regulatory role of tandem and palindromic DNA repeats in the M. hyopneumoniae transcriptional profile.

  16. Repetitive Elements in Mycoplasma hyopneumoniae Transcriptional Regulation.

    Science.gov (United States)

    Cattani, Amanda Malvessi; Siqueira, Franciele Maboni; Guedes, Rafael Lucas Muniz; Schrank, Irene Silveira

    2016-01-01

    Transcriptional regulation, a multiple-step process, is still poorly understood in the important pig pathogen Mycoplasma hyopneumoniae. Basic motifs like promoters and terminators have already been described, but no other cis-regulatory elements have been found. DNA repeat sequences have been shown to be an interesting potential source of cis-regulatory elements. In this work, a genome-wide search for tandem and palindromic repetitive elements was performed in the intergenic regions of all coding sequences from M. hyopneumoniae strain 7448. Computational analysis demonstrated the presence of 144 tandem repeats and 1,171 palindromic elements. The DNA repeat sequences were distributed within the 5' upstream regions of 86% of transcriptional units of M. hyopneumoniae strain 7448. Comparative analysis between distinct repetitive sequences found in related mycoplasma genomes demonstrated different percentages of conservation among pathogenic and nonpathogenic strains. qPCR assays revealed differential expression among genes showing variable numbers of repetitive elements. In addition, repeats found in 206 genes already described to be differentially regulated under different culture conditions of M. hyopneumoniae strain 232 showed almost 80% conservation in relation to M. hyopneumoniae strain 7448 repeats. Altogether, these findings suggest a potential regulatory role of tandem and palindromic DNA repeats in the M. hyopneumoniae transcriptional profile.

  17. El temporalismo de Marx y las revoluciones en el valor de las mercancías El temporalismo de Marx y las revoluciones en el valor de las mercancías

    Directory of Open Access Journals (Sweden)

    Alejandro Ramos M.

    2003-01-01

    Full Text Available This article explores some aspects of Marx’s method for calculating the value of commodities in simple dynamic situations. His method is considered «temporalist» because it pays careful attention to the temporal sequence in which social labor-time is spent in the production sphere. This contrasts with the interpretation of Marx’s calculation proposed by Bródy, Morishima and others for whom value is determined by means of simultaneous equations. For these authors, constant capital is equal to the «replacement cost» of the inputs, instead of being the monetary representation of the «past labor» spent in a previous stage of production. It is argued that simultaneism disregards the set of conditions that Marx actually takes into account in his calculation, specially the existence of stocks of both inputs and outputs as well as ongoing production processes. In addition, simultaneism neglects the continuity of the reproduction process, the existence of capital in its three forms —as money, productive and commodity capital— and the correlative intertwining of the three circuits of capital. Textual evidence concerning this issue is discussed and a numerical example contrasting both methods is presented.Este artículo investiga algunos aspectos del método utilizado por Marx para calcular el valor de las mercancías en situaciones dinámicas simples. Se considera que ese método es «temporalista» porque presta atención a la secuencia temporal en que se gasta el trabajo social en la producción. Esto difiere de la interpretación propuesta por Bródy, Morishima y otros autores para quienes el valor se determina mediante un sistema de ecuaciones simultáneas. Para esos autores, el capital constante corresponde al «costo de reposición» de los insumos, en lugar de ser la representación monetaria del «trabajo pasado » gastado en una etapa previa de la producción. Se argumenta que el método simultáneo pasa por alto las condiciones

  18. Feature-based motion control for near-repetitive structures

    NARCIS (Netherlands)

    Best, de J.J.T.H.

    2011-01-01

    In many manufacturing processes, production steps are carried out on repetitive structures which consist of identical features placed in a repetitive pattern. In the production of these repetitive structures one or more consecutive steps are carried out on the features to create the final product.

  19. Lingual Kinematics during Rapid Syllable Repetition in Parkinson's Disease

    Science.gov (United States)

    Wong, Min Ney; Murdoch, Bruce E.; Whelan, Brooke-Mai

    2012-01-01

    Background: Rapid syllable repetition tasks are commonly used in the assessment of motor speech disorders. However, little is known about the articulatory kinematics during rapid syllable repetition in individuals with Parkinson's disease (PD). Aims: To investigate and compare lingual kinematics during rapid syllable repetition in dysarthric…

  20. Grade Repetition and Primary School Dropout in Uganda

    Science.gov (United States)

    Kabay, Sarah

    2016-01-01

    Research on education in low-income countries rarely focuses on grade repetition. When addressed, repetition is typically presented along with early school dropout as the "wasting" of educational resources. Simplifying grade repetition in this way often fails to recognize significant methodological concerns and also overlooks the unique…

  1. Solid-state Marx based two-switch voltage modulator for the On-Line Isotope Mass Separator accelerator at the European Organization for Nuclear Research.

    Science.gov (United States)

    Redondo, L M; Silva, J Fernando; Canacsinh, H; Ferrão, N; Mendes, C; Soares, R; Schipper, J; Fowler, A

    2010-07-01

    A new circuit topology is proposed to replace the actual pulse transformer and thyratron based resonant modulator that supplies the 60 kV target potential for the ion acceleration of the On-Line Isotope Mass Separator accelerator, the stability of which is critical for the mass resolution downstream separator, at the European Organization for Nuclear Research. The improved modulator uses two solid-state switches working together, each one based on the Marx generator concept, operating as series and parallel switches, reducing the stress on the series stacked semiconductors, and also as auxiliary pulse generator in order to fulfill the target requirements. Preliminary results of a 10 kV prototype, using 1200 V insulated gate bipolar transistors and capacitors in the solid-state Marx circuits, ten stages each, with an electrical equivalent circuit of the target, are presented, demonstrating both the improved voltage stability and pulse flexibility potential wanted for this new modulator.

  2. La filosofía como praxis La idea de superación mundana de la filosofía en Marx

    OpenAIRE

    Grueso, Delfín Ignacio

    2008-01-01

    Cuando Marx dice: “Los filósofos hasta ahora se han dedicado a interpretar el mundo en varios sentidos, cuando de lo que se trata es de cambiarlo”, ¿está sugiriendo superar la filosofía o abrirnos a una nueva forma de filosofía? ¿Qué tiene, entonces, de filosófica la obra de Marx y qué futuro le aguarda a la filosofía, según él? ¿Es su obra sólo posible gracias a la muerte de la filosofía? Y el concepto de praxis ¿qué tiene que ver con la visión marxiana de la filosofía?

  3. Specificities of Sightseeing Foot Tour Arrangement for History Related Street with Regard to Karl Marx Street in the Town of Irkutsk

    Science.gov (United States)

    Kulakov, A. I.; Shishkanov, V. S.

    2017-11-01

    The paper is devoted to the preparation of an innovative foot itinerary for tourists in Karl Marx Street in the town of Irkutsk. Methodology on preparation of sightseeing tours has been analysed by the authors. The analysis of the methodology has facilitated selecting the criteria to classify the excursions as well as the criteria for assessing and shortlisting the objects for excursion exposure. Some chosen criteria being used in tour arrangement and certain specificities of tour preparation have been revealed which are characteristic particularly for Karl Marx Street as a history-related one. It is also proved in the paper that the itinerary prepared for tourists is in full correspondence with the key innovation objectives in tourism.

  4. Jean-Jacques Rousseau y Karl Marx: estudio comparativo de dos críticas a la economía de mercado

    Directory of Open Access Journals (Sweden)

    Andrés Álvarez

    2008-06-01

    Full Text Available Este trabajo hace una comparación de las teorías monetarias de dos grandes críticos de la economía de mercado: Rousseau y Marx. Muestra sus similitudes y divergencias; entre éstas la más importante es el lugar del análisis económico en sus proyectos intelectuales y políticos. Mientras que Marx fundó su crítica político-científica en el análisis económico, Rousseau pensaba que el análisis económico no podía ser la base para entender la organización social. Sus teorías monetarias pueden explicar esta divergencia.

  5. Angelita La Escapía e a fotografia viva de Marx: feminismo e passados presentes em Almanac of the Dead

    Directory of Open Access Journals (Sweden)

    VILELA LÚCIA HELENA DE AZEVEDO

    2002-01-01

    Full Text Available Análise de Almanac of the Dead à luz de teorias feministas e de uma perspectiva pós-moderna segundo a qual a noção de passados presentes é enfatizada através da exploração da metáfora da fotografia viva de Marx, mostrada no romance. A paixão da personagem Angelita pela fotografia de Marx é vista como uma forma de síntese entre a percepção indígena do tempo como eternos presentes - que é também resistência à opressão, uma vez que o passado não é jamais esquecido - e os conceitos marxistas de tempo e história.

  6. Entre la economía política de Karl Marx y la economía ecológica

    Directory of Open Access Journals (Sweden)

    Julián Sabogal Tamayo

    2012-12-01

    Full Text Available Este artículo intenta contribuir a la discusión sobre las diferencias y afinidades entre la economía política de Marx y la economía ecológica. Se centra en las diferencias de objetivos, de temas de estudio y de métodos. También señala los puntos de convergencia y la necesidad de la solidaridad y del aprendizaje mutuo.

  7. Algunas consideraciones sobre el concepto de trabajo en Karl Marx y el análisis crítico de Jürgen Habermas

    Directory of Open Access Journals (Sweden)

    Juan A. Fraiman

    2015-07-01

    Full Text Available En la literatura marxista, la categoría de “trabajo” es revalorizada con la publicación tardía de los denominados Manuscritos económico-filosóficos del joven Marx. Entre las diversas lecturas contemporáneas, Habermas efectuará una interpretación crítica de esos escritos de carácter más bien filosófico-antropológicos para reformular así su conceptualización del Trabajo. No obstante, Habermas no abandonará su interés por Marx y el trabajo; se aproximará al fenómeno de la “reificación”, aunque sólo tomando la posterior crítica que Marx desarrolla en El Capital, sobre todo en la exposición del fetichismo de la mercancía, con intenciones de retraducirlo en términos de una teoría de la comunicación.

  8. História, marxismo e questão social: um diálogo com Max Web e Karl Marx

    Directory of Open Access Journals (Sweden)

    Daniela Oliveira Ramos Passos

    2011-12-01

    Full Text Available O campo de investigação tanto de Karl Marx quanto de Max Weber é o mesmo, ou seja, ambos estudam o caráter “capitalista” da moderna economia e sociedade, isto é, o capitalismo industrial e os desenvolvimentos sociais advindos deste. Porém, suas análises conclusivas são diferenciadas, e porque não, opostas. Marx via a ideologia como uma variável dependente no processo de transformação social. Weber, ao contrário, procurou mostrar que o caráter ideológico não deriva automaticamente da posição social, mas constitui um meio para explicar esta posição. Assim, conforme o exposto, o objetivo deste ensaio é o de tentar explicar os principais aspectos dos estudos de Max Weber e Karl Marx – um possível diálogo entre eles e suas principais diferenças - além de procurar entender a questão social nas obras de ambos.

  9. Repetitive pulse accelerator technology for light ion inertial confinement fusion

    International Nuclear Information System (INIS)

    Buttram, M.T.

    1985-01-01

    Successful ignition of an inertial confinement fusion (ICF) pellet is calculated to require that several megajoules of energy be deposited in the pellet's centimeter-sized shell within 10 ns. This implies a driver power of several hundreds of terawatts and power density around 100 TW/cm 2 . The Sandia ICF approach is to deposit the energy with beams of 30 MV lithium ions. The first accelerator capable of producing these beams (PBFA II, 100 TW) will be used to study beam formation and target physics on a single pulse basis. To utilize this technology for power production, repetitive pulsing at rates that may be as high as 10 Hz will be required. This paper will overview the technologies being studied for a repetitively pulsed ICF accelerator. As presently conceived, power is supplied by rotating machinery providing 16 MJ in 1 ms. The generator output is transformed to 3 MV, then switched into a pulse compression system using laser triggered spark gaps. These must be synchronized to about 1 ns. Pulse compression is performed with saturable inductor switches, the output being 40 ns, 1.5 MV pulses. These are transformed to 30 MV in a self-magnetically insulated cavity adder structure. Space charge limited ion beams are drawn from anode plasmas with electron counter streaming being magnetically inhibited. The ions are ballistically focused into the entrances of guiding discharge channels for transport to the pellet. The status of component development from the prime power to the ion source will be reviewed

  10. New solid state opening switches for repetitive pulsed power technology

    Energy Technology Data Exchange (ETDEWEB)

    Lyubutin, S K; Mesyats, G A; Rukin, S N; Slovikovskii, B G; Turov, A M [Russian Academy of Sciences, Ekaterinburg (Russian Federation). Inst. of Electrophysics

    1997-12-31

    In 1991 the authors discovered a semiconductor opening switch (SOS) effect that occurs in p{sup +}-p-n-n{sup +} silicon structures at a current density of up to 60 kA/cm{sup 2}. This effect was used to develop high-power semiconductor opening switches in intermediate inductive storage circuits. The breaking power of the opening switches was as high as 5 GW, the interrupted current being up to 45 kA, reverse voltage up to 1 MV and the current interruption time between 10 and 60 ns. The opening switches were assembled from quantity-produced Russian-made rectifying diodes type SDL with hard recovery characteristic. On the basis of experimental and theoretical investigations of the SOS effect, new SOS diodes were designed and manufactured by the Electrophysical Institute. The paper gives basic parameters of the SOS diodes. The new diodes offer higher values of interrupted current and shorter times of current interruption together with a considerable increase in the energy switching efficiency. The new SOS diodes were used to develop repetitive all-solid-state pulsed generators with an output voltage of up to 250 kV, pulse repetition rate up to 5 kHz, and pulse duration between 10 and 30 ns. (author). 2 tabs., 3 figs., 4 refs.

  11. Application of repetitive pulsed power technology to chemical processing

    International Nuclear Information System (INIS)

    Kaye, R.J.; Hamil, R.

    1995-01-01

    The numerous sites of soil and water contaminated with organic chemicals present an urgent environmental concern that continues to grow. Electron and x-ray irradiation have been shown to be effective methods to destroy a wide spectrum of organic chemicals, nitrates, nitrites, and cyanide in water by breaking molecules to non-toxic products or entirely mineralizing the by-products to gas, water, and salts. Sandia National Laboratories is developing Repetitive High Energy Pulsed Power (RHEPP) technology capable of producing high average power, broad area electron or x-ray beams. The 300 kW RHEPP-II facility accelerates electrons to 2.5 MeV at 25 kA over 1,000 cm 2 in 60 ns pulses at repetition rates of over 100 Hz. Linking this modular treatment capability with the rapid optical-sensing diagnostics and neutral network characterization software algorithms will provide a Smart Waste Treatment (SWaT) system. Such a system would also be applicable for chemical manufacture and processing of industrial waste for reuse or disposal. This talk describes both the HREPP treatment capability and sensing technologies. Measurements of the propagated RHEPP-II beam and dose profiles are presented. Sensors and rapid detection software are discussed with application toward chemical treatment

  12. Karl Marx vis-à-vis Max Weber: perspectiva comparada das visões acerca do Estado

    Directory of Open Access Journals (Sweden)

    Felippe Ramos

    2010-12-01

    Full Text Available Este trabalho aborda a distinção analítica entre Marx e Weber, em relação ao tema do Estado. A hipótese é de que ambos os autores, a despeito do que pode parecer à primeira vista, estavam imbuídos da impossibilidade de um Estado impessoal, o que remete, em última instância, à politização do Estado. O que parece claro na visão de Marx é, contudo, obscurecido pela construção metodológica (e epistemológica de Weber, com base na busca constante da objetividade do conhecimento, a partir de uma ciência que se afasta do engajamento político e da importância das categorias analíticas da burocracia e racionalização. Essa dificuldade de construir uma análise crítica da proposta weberiana pode ser esclarecida, contudo, constituindo uma análise do Estado, em oposição à esfera de legitimação do Estado moderno que se encontra claramente na burocracia, cuja característica maior é a impessoalidade, a partir da descrição de suas instâncias de decisão – um elemento político sobre a burocracia. A análise marxiana do Estado classista, por sua vez, também precisa ter suas nuances analisadas de acordo com o próprio amadurecimento teórico do autor, que, em suas obras de análise de eventos históricos escritas tardiamente, torna complexa a classificação do Estado, demonstrando suas aporias e disputas internas, para além de sua visão inicialmente instrumental do Estado.

  13. Imbalance between abstract and concrete repetitive thinking modes in schizophrenia.

    Science.gov (United States)

    Maurage, Pierre; Philippot, Pierre; Grynberg, Delphine; Leleux, Dominique; Delatte, Benoît; Mangelinckx, Camille; Belge, Jan-Baptist; Constant, Eric

    2017-10-01

    Repetitive thoughts can be divided in two modes: abstract/analytic (decontextualized and dysfunctional) and concrete/experiential (problem-focused and adaptive). They constitute a transdiagnostic process involved in many psychopathological states but have received little attention in schizophrenia, as earlier studies only indexed increased ruminations (related to dysfunctional repetitive thoughts) without jointly exploring both modes. This study explored the two repetitive thinking modes, beyond ruminations, to determine their imbalance in schizophrenia. Thirty stabilized patients with schizophrenia and 30 matched controls completed the Repetitive Response Scale and the Mini Cambridge-Exeter Repetitive Thought Scale, both measuring repetitive thinking modes. Complementary measures related to schizophrenic symptomatology, depression and anxiety were also conducted. Compared to controls, patients with schizophrenia presented an imbalance between repetitive thinking modes, with increased abstract/analytic and reduced concrete/experiential thoughts, even after controlling for comorbidities. Schizophrenia is associated with stronger dysfunctional repetitive thoughts (i.e. abstract thinking) and impaired ability to efficiently use repetitive thinking for current problem-solving (i.e. concrete thinking). This imbalance confirms the double-faced nature of repetitive thinking modes, whose influence on schizophrenia's symptomatology should be further investigated. The present results also claim for evaluating these processes in clinical settings and for rehabilitating the balance between opposite repetitive thinking modes. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Repetitive thinking, executive functioning, and depressive mood in the elderly.

    Science.gov (United States)

    Philippot, Pierre; Agrigoroaei, Stefan

    2017-11-01

    Previous findings and the depressive-executive dysfunction hypothesis suggest that the established association between executive functioning and depression is accounted for by repetitive thinking. Investigating the association between executive functioning, repetitive thinking, and depressive mood, the present study empirically tested this mediational model in a sample of older adults, while focusing on both concrete and abstract repetitive thinking. This latter distinction is important given the potential protective role of concrete repetitive thinking, in contrast to the depletive effect of abstract repetitive thinking. A sample of 43 elderly volunteers, between 75 and 95 years of age, completed tests of executive functioning (the Stroop test, the Trail Making test, and the Fluency test), and questionnaires of repetitive thinking and depression. Positive correlations were observed between abstract repetitive thinking and depressive mood, and between concrete repetitive thinking and executive functioning; a negative correlation was observed between depressive mood and executive functioning. Further, mediational analysis evidenced that the relation between executive functioning and depressive mood was mediated by abstract repetitive thinking. The present data provide, for the first time, empirical support to the depressive-executive dysfunction hypothesis: the lack of executive resources would favor a mode of abstract repetitive thinking, which in turn would deplete mood. It suggests that clinical intervention targeting depression in the elderly should take into consideration repetitive thinking modes and the executive resources needed to disengage from rumination.

  15. Transcription of repetitive DNA in Neurospora crassa

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, S K; Chaudhuri, R K

    1975-01-01

    Repeated DNA sequences of Neurospora crassa were isolated and characterized. Approximately 10 to 12 percent of N. crassa DNA sequence were repeated, of which 7.3 percent were found to be transcribed in mid-log phase of mycelial growth as measured by DNA:RNA hybridization. It is suggested that part of repetitive DNA transcripts in N. crassa were mitochondrial and part were nuclear DNA. Most of the nuclear repeated DNAs, however, code for rRNA and tRNA in N. crassa. (auth)

  16. Effects of message repetition and negativity on credibility judgments and political attitudes

    NARCIS (Netherlands)

    Ernst, N.; Kühne, R.; Wirth, W.

    2017-01-01

    Research on the truth effect has demonstrated that statements are rated as more credible when they are repeatedly presented. However, current research indicates that there are limits to the truth effect and that too many repetitions can decrease message credibility. This study investigates whether

  17. 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

  18. Muscle activation strategies during strength training with heavy loading versus repetitions to failure

    DEFF Research Database (Denmark)

    Sundstrup, Emil; Jakobsen, Markus D; Andersen, Christoffer H

    2012-01-01

    . Electromyographic (EMG) amplitude and median power frequency (MPF) of specific shoulder and neck muscles was analysed and the Borg CR10 scale was used to rate perceived loading immediately after each set of exercise. During the failure set normalized EMG was significantly lower during the first repetition...

  19. Dual-Comb Coherent Raman Spectroscopy with Lasers of 1-GHz Pulse Repetition Frequency

    OpenAIRE

    Mohler, Kathrin J.; Bohn, Bernhard J.; Yan, Ming; Hänsch, Theodor W.; Picqué, Nathalie

    2016-01-01

    We extend the technique of multiplex coherent Raman spectroscopy with two femtosecond mode-locked lasers to oscillators of a pulse repetition frequency of 1 GHz. We demonstrate spectra of liquids, which span 1100 cm$^{-1}$ of Raman shifts. At a resolution of 6 cm$^{-1}$, their measurement time may be as short as 5 microseconds for a refresh rate of 2 kHz. The waiting period between acquisitions is improved ten-fold compared to previous experiments with two lasers of 100-MHz repetition frequen...

  20. Dual-comb coherent Raman spectroscopy with lasers of 1-GHz pulse repetition frequency.

    Science.gov (United States)

    Mohler, Kathrin J; Bohn, Bernhard J; Yan, Ming; Mélen, Gwénaëlle; Hänsch, Theodor W; Picqué, Nathalie

    2017-01-15

    We extend the technique of multiplex coherent Raman spectroscopy with two femtosecond mode-locked lasers to oscillators of a pulse repetition frequency of 1 GHz. We demonstrate a spectra of liquids, which span 1100  cm-1 of Raman shifts. At a resolution of 6  cm-1, their measurement time may be as short as 5 μs for a refresh rate of 2 kHz. The waiting period between acquisitions is improved 10-fold compared to previous experiments with two lasers of 100-MHz repetition frequencies.

  1. Repetition Enhancement of Amygdala and Visual Cortex Functional Connectivity Reflects Nonconscious Memory for Negative Visual Stimuli.

    Science.gov (United States)

    Kark, Sarah M; Slotnick, Scott D; Kensinger, Elizabeth A

    2016-12-01

    Most studies using a recognition memory paradigm examine the neural processes that support the ability to consciously recognize past events. However, there can also be nonconscious influences from the prior study episode that reflect repetition suppression effects-a reduction in the magnitude of activity for repeated presentations of stimuli-that are revealed by comparing neural activity associated with forgotten items to correctly rejected novel items. The present fMRI study examined the effect of emotional valence (positive vs. negative) on repetition suppression effects. Using a standard recognition memory task, 24 participants viewed line drawings of previously studied negative, positive, and neutral photos intermixed with novel line drawings. For each item, participants made an old-new recognition judgment and a sure-unsure confidence rating. Collapsed across valence, repetition suppression effects were found in ventral occipital-temporal cortex and frontal regions. Activity levels in the majority of these regions were not modulated by valence. However, repetition enhancement of the amygdala and ventral occipital-temporal cortex functional connectivity reflected nonconscious memory for negative items. In this study, valence had little effect on activation patterns but had a larger effect on functional connectivity patterns that were markers of nonconscious memory. Beyond memory and emotion, these findings are relevant to other cognitive and social neuroscientists that utilize fMRI repetition effects to investigate perception, attention, social cognition, and other forms of learning and memory.

  2. Genomic Organization and Physical Mapping of Tandemly Arranged Repetitive DNAs in Sterlet (Acipenser ruthenus).

    Science.gov (United States)

    Biltueva, Larisa S; Prokopov, Dimitry Y; Makunin, Alexey I; Komissarov, Alexey S; Kudryavtseva, Anna V; Lemskaya, Natalya A; Vorobieva, Nadezhda V; Serdyukova, Natalia A; Romanenko, Svetlana A; Gladkikh, Olga L; Graphodatsky, Alexander S; Trifonov, Vladimir A

    2017-01-01

    Acipenseriformes represent a phylogenetically basal clade of ray-finned fish characterized by unusual genomic traits, including paleopolyploid states of extant genomes with high chromosome numbers and slow rates of molecular evolution. Despite a high interest in this fish group, only a limited number of studies have been accomplished on the isolation and characterization of repetitive DNA, karyotype standardization is not yet complete, and sex chromosomes are still to be identified. Here, we applied next-generation sequencing and cluster analysis to characterize major fractions of sterlet (Acipenser ruthenus) repetitive DNA. Using FISH, we mapped 16 tandemly arranged sequences on sterlet chromosomes and found them to be unevenly distributed in the genome with a tendency to cluster in particular regions. Some of the satellite DNAs might be used as specific markers to identify individual chromosomes and their paralogs, resulting in the unequivocal identification of at least 18 chromosome pairs. Our results provide an insight into the characteristic genomic distribution of the most common sterlet repetitive sequences. Biased accumulation of repetitive DNAs in particular chromosomes makes them especially interesting for further search for cryptic sex chromosomes. Future studies of these sequences in other acipenserid species will provide new perspectives regarding the evolution of repetitive DNA within the genomes of this fish order. © 2017 S. Karger AG, Basel.

  3. Education between theory and praxis: the legacy of Marx with regard to the crisis of contemporary capitalism

    Directory of Open Access Journals (Sweden)

    Renato Crioni

    2012-01-01

    Full Text Available “The philosophers have only interpreted the world in various ways; the point is, however, to change it.” It was from the superficial premises of the 11ththesis on Feuerbach that Marx’s thought received its most distinguished exaltations and its hardest refutations. In the XX century stage, the Marxist “labeling” reached its apex with the labor movement and the actual socialism. However, in the twilight of the XX century, the unexpected collapse of the Soviet “state capitalism” model paralyzed the left’s thought and the Marxist capitalist criticism, which remained, at most, as a defensive nostalgic claim. But Marx himself conceived his political economy criticism as a reflection surpassing its practical applicability. If this aspect of the categorical criticism of capitalism shows up, on one hand, as something freezing action, on the other, it shows up suitable to interpret the global crisis which it triggers. At the same time that it disassembles the current hegemonic discourse of progress, efficiency, and productivity, it opens space for a perspective of educative experience appreciating the sensitive vital relations, the arts, and the idle culture, imputed as superfluous and put at the service of the omnipresent coercion of abstract wealth production.

  4. Educação, escola e humanização em Marx, Engels e Lukács

    Directory of Open Access Journals (Sweden)

    Liliam Faria Porto Borges

    2017-09-01

    Full Text Available O trabalho discute o entendimento da escola a partir dos conceitos de trabalho e humanização em Marx, Engels e Lukács. A constituição humana por meio da sua intervenção junto à natureza e o estabelecimento das relações sociais são processos educativos que se repetem, tanto na história do homem, quanto no desenvolvimento individual, recolocando, nos processos educativos, a construção do homem como ser social e construindo o longo caminho de distanciamento de sua condição animal. Com base nesse breve panorama, propõe uma análise acerca da escola e do ensino no Brasil, indicando a função social da educação escolar e o significado das perspectivas pedagógicas que secundarizam a relação entre ensinar e aprender.

  5. A vacuum-sealed, gigawatt-class, repetitively pulsed high-power microwave source

    Science.gov (United States)

    Xun, Tao; Fan, Yu-wei; Yang, Han-wu; Zhang, Zi-cheng; Chen, Dong-qun; Zhang, Jian-de

    2017-06-01

    A compact L-band sealed-tube magnetically insulated transmission line oscillator (MILO) has been developed that does not require bulky external vacuum pump for repetitive operations. This device with a ceramic insulated vacuum interface, a carbon fiber array cathode, and non-evaporable getters has a base vacuum pressure in the low 10-6 Pa range. A dynamic 3-D Monte-Carlo model for the molecular flow movement and collision was setup for the MILO chamber. The pulse desorption, gas evolution, and pressure distribution were exactly simulated. In the 5 Hz repetition rate experiments, using a 600 kV diode voltage and 48 kA beam current, the average radiated microwave power for 25 shots is about 3.4 GW in 45 ns pulse duration. The maximum equilibrium pressure is below 4.0 × 10-2 Pa, and no pulse shortening limitations are observed during the repetitive test in the sealed-tube condition.

  6. Effect of loading on unintentional lifting velocity declines during single sets of repetitions to failure during upper and lower extremity muscle actions.

    Science.gov (United States)

    Izquierdo, M; González-Badillo, J J; Häkkinen, K; Ibáñez, J; Kraemer, W J; Altadill, A; Eslava, J; Gorostiaga, E M

    2006-09-01

    The purpose of this study was to examine the effect of different loads on repetition speed during single sets of repetitions to failure in bench press and parallel squat. Thirty-six physical active men performed 1-repetition maximum in a bench press (1 RM (BP)) and half squat position (1 RM (HS)), and performed maximal power-output continuous repetition sets randomly every 10 days until failure with a submaximal load (60 %, 65 %, 70 %, and 75 % of 1RM, respectively) during bench press and parallel squat. Average velocity of each repetition was recorded by linking a rotary encoder to the end part of the bar. The values of 1 RM (BP) and 1 RM (HS) were 91 +/- 17 and 200 +/- 20 kg, respectively. The number of repetitions performed for a given percentage of 1RM was significantly higher (p bench press performance. Average repetition velocity decreased at a greater rate in bench press than in parallel squat. The significant reductions observed in the average repetition velocity (expressed as a percentage of the average velocity achieved during the initial repetition) were observed at higher percentage of the total number of repetitions performed in parallel squat (48 - 69 %) than in bench press (34 - 40 %) actions. The major finding in this study was that, for a given muscle action (bench press or parallel squat), the pattern of reduction in the relative average velocity achieved during each repetition and the relative number of repetitions performed was the same for all percentages of 1RM tested. However, relative average velocity decreased at a greater rate in bench press than in parallel squat performance. This would indicate that in bench press the significant reductions observed in the average repetition velocity occurred when the number of repetitions was over one third (34 %) of the total number of repetitions performed, whereas in parallel squat it was nearly one half (48 %). Conceptually, this would indicate that for a given exercise (bench press or squat) and

  7. Pull-production in repetitive remanufacturing

    Energy Technology Data Exchange (ETDEWEB)

    McCaskey, D.W. Jr.

    1992-09-01

    In the past, production activity control practices in most repetitive remanufacturing facilities resembled those used in intermittent production operations. These operations were characterized by large amounts of work-in-process (WIP), frequent work stoppages due to part shortages, excessive overtime, low product velocity, informal scheduling between dependent operations, low employee and management moral, and a lot of wasted time, material, labor, and space. Improvement in production activity control (PAC) methods for repetitive remanufactures has been hampered by uncertainty in: supply of incoming assets, configuration of assets, process times to refurbish assets, and yields in reclamation processes. collectively these uncertainties make shop floor operations seem uncontrollable. However, one United States Army depot has taken on the challenge. Through management supported, cross-functional teams, the Tooele Army Depot has designed and implemented pull-production systems for two of its major products, with several others to follow. This article presents a generalized version of Tooele`s pull-production system and highlights design characteristics which are specific to remanufacturing applications.

  8. Pull-production in repetitive remanufacturing

    Energy Technology Data Exchange (ETDEWEB)

    McCaskey, D.W. Jr.

    1992-09-01

    In the past, production activity control practices in most repetitive remanufacturing facilities resembled those used in intermittent production operations. These operations were characterized by large amounts of work-in-process (WIP), frequent work stoppages due to part shortages, excessive overtime, low product velocity, informal scheduling between dependent operations, low employee and management moral, and a lot of wasted time, material, labor, and space. Improvement in production activity control (PAC) methods for repetitive remanufactures has been hampered by uncertainty in: supply of incoming assets, configuration of assets, process times to refurbish assets, and yields in reclamation processes. collectively these uncertainties make shop floor operations seem uncontrollable. However, one United States Army depot has taken on the challenge. Through management supported, cross-functional teams, the Tooele Army Depot has designed and implemented pull-production systems for two of its major products, with several others to follow. This article presents a generalized version of Tooele's pull-production system and highlights design characteristics which are specific to remanufacturing applications.

  9. Synergy Repetition Training versus Task Repetition Training in Acquiring New Skill.

    Science.gov (United States)

    Patel, Vrajeshri; Craig, Jamie; Schumacher, Michelle; Burns, Martin K; Florescu, Ionut; Vinjamuri, Ramana

    2017-01-01

    Traditionally, repetitive practice of a task is used to learn a new skill, exhibiting as immediately improved performance. Research suggests, however, that a more experience-based rather than exposure-based training protocol may allow for better transference of the skill to related tasks. In synergy-based motor control theory, fundamental motor skills, such as hand grasping, are represented with a synergy subspace that captures essential motor patterns. In this study, we propose that motor-skill learning through synergy-based mechanisms may provide advantages over traditional task repetition learning. A new task was designed to highlight the range of motion and dexterity of the human hand. Two separate training strategies were tested in healthy subjects: task repetition training and synergy training versus a control. All three groups showed improvements when retested on the same task. When tested on a similar, but different set of tasks, only the synergy group showed improvements in accuracy (9.27% increase) compared to the repetition (3.24% decline) and control (3.22% decline) groups. A kinematic analysis revealed that although joint angular peak velocities decreased, timing benefits stemmed from the initial feed-forward portion of the task (reaction time). Accuracy improvements may have derived from general improved coordination among the four involved fingers. These preliminary results warrant further investigation of synergy-based motor training in healthy individuals, as well as in individuals undergoing hand-based rehabilitative therapy.

  10. Relationship between redistribution on exercise thallium-201 scintigraphy and repetitive ventricular premature beats in patients with recent myocardial infarction

    International Nuclear Information System (INIS)

    Tsuji, H.; Iwasaka, T.; Sugiura, T.; Shimada, T.; Nakamori, H.; Kimura, Y.; Inada, M.

    1991-01-01

    The relationship between myocardial ischemia detected by exercise thallium-201 scintigraphy and repetitive ventricular premature beats (VPBs) during ambulatory monitoring was evaluated in 57 patients with recent myocardial infarction. Multivariate analysis was performed to obtain the relatively important factor related to repetitive VPBs with the use of the following variables: age, redistribution, left ventricular ejection fraction, serum potassium and magnesium concentration, QRS score, left ventricular aneurysm, and the number of diseased vessels. Thirty-five patients had redistribution, but only three of them had repetitive VPBs during exercise testing. The average heart rate before 79% of 398 episodes of repetitive VPBs during ambulatory monitoring was in the range of 56 to 70/min. These data indicate that most of repetitive VPBs during ambulatory monitoring were not provoked by exercise-induced acute myocardial ischemia. However, redistribution was found to be an important factor associated with repetitive VPBs. The electrical abnormality relating to a substrate characterized by chronic reversible ischemia may explain the association between redistribution and repetitive VPBs

  11. On the non-Poissonian repetition pattern of FRB121102

    Science.gov (United States)

    Oppermann, Niels; Yu, Hao-Ran; Pen, Ue-Li

    2018-04-01

    The Fast Radio Burst FRB121102 has been observed to repeat in an irregular fashion. Using published timing data of the observed bursts, we show that Poissonian statistics are not a good description of this random process. As an alternative, we suggest to describe the intervals between bursts with a Weibull distribution with a shape parameter smaller than one, which allows for the clustered nature of the bursts. We quantify the amount of clustering using the parameters of the Weibull distribution and discuss the consequences that it has for the detection probabilities of future observations and for the optimization of observing strategies. Allowing for this generalization, we find a mean repetition rate of r=5.7^{+3.0}_{-2.0} per day and index k=0.34^{+0.06}_{-0.05} for a correlation function ξ(t) = (t/t0)k - 1.

  12. The role of short-term memory impairment in nonword repetition, real word repetition, and nonword decoding: A case study.

    Science.gov (United States)

    Peter, Beate

    2018-01-01

    In a companion study, adults with dyslexia and adults with a probable history of childhood apraxia of speech showed evidence of difficulty with processing sequential information during nonword repetition, multisyllabic real word repetition and nonword decoding. Results suggested that some errors arose in visual encoding during nonword reading, all levels of processing but especially short-term memory storage/retrieval during nonword repetition, and motor planning and programming during complex real word repetition. To further investigate the role of short-term memory, a participant with short-term memory impairment (MI) was recruited. MI was confirmed with poor performance during a sentence repetition and three nonword repetition tasks, all of which have a high short-term memory load, whereas typical performance was observed during tests of reading, spelling, and static verbal knowledge, all with low short-term memory loads. Experimental results show error-free performance during multisyllabic real word repetition but high counts of sequence errors, especially migrations and assimilations, during nonword repetition, supporting short-term memory as a locus of sequential processing deficit during nonword repetition. Results are also consistent with the hypothesis that during complex real word repetition, short-term memory is bypassed as the word is recognized and retrieved from long-term memory prior to producing the word.

  13. Política e economia como formas de dominação: o trabalho intelectual em Marx Politics and economy as form of domination: intellectual labor in Marx

    Directory of Open Access Journals (Sweden)

    Sedi Hirano

    2001-11-01

    Full Text Available Este ensaio procura sistematizar a análise teórica que Marx faz do pré-capitalismo e do capitalismo como estruturas sociais de poder, predominando naquele as relações políticas e neste as relações econômicas como formas de dominação. Procura-se demonstrar que no pré-capitalismo o poder político e o exercício monopolizado da violência física, social e psicológica são determinados pela forma como os agentes sociais se apropriam das condições objetivas, materiais e simbólicas da produção social. No capitalismo, a produção, quando já é comandada pelo capital, além de produzir a mais-valia, também produz um sistema de exploração geral das propriedades naturais e humanas tendo como suporte a ciência. Ou seja, ela realiza a apropriação através da ciência, e não da violência e do poder pessoal, colocando o saber científico ao seu serviço, na espécie de capital fixo. Essa extração da mais-valia assume, apesar de ser resultante da relação econômica, a forma de atividade científica. É dentro desse contexto que se analisa a questão do trabalho intelectual não só como produtor de valor mas, também, como produtor de concepções justificadoras da forma histórica de poder e de dominação capitalista.This essay aims at systematizing the theoretical analysis that Marx makes of pre-capitalism and of capitalism as social structures of power, bearing in mind that political relations predominate in the former and economic relations in the latter as forms of domination. In pre-capitalism, political power and the monopolized exercise of physical, social and psychological violence are determined by the manner in which social agents appropriate objective, material and symbolic conditions of social production. In capitalism, production, when it is already commanded by capital, on top of producing surplus value, it also produces a system of general exploitation of the natural and human properties with the support of

  14. A long-pulse repetitive operation magnetically insulated transmission line oscillator

    International Nuclear Information System (INIS)

    Fan, Yu-Wei; Zhong, Hui-Huang; Zhang, Jian-De; Shu, Ting; Liu, Jin Liang

    2014-01-01

    The improved magnetically insulated transmission line oscillator (MILO) is a gigawatt-class L-band high power microwave tube. It has allowed us to generate 3.1 GW pulse of 40 ns duration in the single-pulse operation and 500 MW pulse of 25 ns duration in the repetition rate operation. However, because of the severe impedance mismatch, the power conversion efficiency is only about 4% in the repetition rate operation. In order to eliminate the impedance mismatch and obtain repetitive long-pulse high-power microwave (HPM), a series of experiments are carried out and the recent progress is presented in this paper. In the single-pulse operation, when the diode voltage is 466 kV and current is 41.6 kA, the radiated microwave power is above 2.2 GW, the pulse duration is above 102 ns, the microwave frequency is about 1.74 GHz, and the power conversion efficiency is about 11.5%. In the repetition rate operation, under the condition of the diode voltage about 400 kV, beam current about 38 kA, the radiated microwave power is about 1.0 GW, the pulse duration is about 85 ns. Moreover, the radiated microwave power and the pulse duration decline little by little when the shot numbers increase gradually. The experimental results show that the impedance matching is a vital factor for HPM systems and one of the major technical challenges is to improve the cathode for the repetition rate operation MILO

  15. A long-pulse repetitive operation magnetically insulated transmission line oscillator

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Yu-Wei; Zhong, Hui-Huang; Zhang, Jian-De; Shu, Ting; Liu, Jin Liang [College of Optoelectric Science and Engineering, National University of Defense Technology, Changsha 410073 (China)

    2014-05-15

    The improved magnetically insulated transmission line oscillator (MILO) is a gigawatt-class L-band high power microwave tube. It has allowed us to generate 3.1 GW pulse of 40 ns duration in the single-pulse operation and 500 MW pulse of 25 ns duration in the repetition rate operation. However, because of the severe impedance mismatch, the power conversion efficiency is only about 4% in the repetition rate operation. In order to eliminate the impedance mismatch and obtain repetitive long-pulse high-power microwave (HPM), a series of experiments are carried out and the recent progress is presented in this paper. In the single-pulse operation, when the diode voltage is 466 kV and current is 41.6 kA, the radiated microwave power is above 2.2 GW, the pulse duration is above 102 ns, the microwave frequency is about 1.74 GHz, and the power conversion efficiency is about 11.5%. In the repetition rate operation, under the condition of the diode voltage about 400 kV, beam current about 38 kA, the radiated microwave power is about 1.0 GW, the pulse duration is about 85 ns. Moreover, the radiated microwave power and the pulse duration decline little by little when the shot numbers increase gradually. The experimental results show that the impedance matching is a vital factor for HPM systems and one of the major technical challenges is to improve the cathode for the repetition rate operation MILO.

  16. A long-pulse repetitive operation magnetically insulated transmission line oscillator.

    Science.gov (United States)

    Fan, Yu-Wei; Zhong, Hui-Huang; Zhang, Jian-De; Shu, Ting; Liu, Jin Liang

    2014-05-01

    The improved magnetically insulated transmission line oscillator (MILO) is a gigawatt-class L-band high power microwave tube. It has allowed us to generate 3.1 GW pulse of 40 ns duration in the single-pulse operation and 500 MW pulse of 25 ns duration in the repetition rate operation. However, because of the severe impedance mismatch, the power conversion efficiency is only about 4% in the repetition rate operation. In order to eliminate the impedance mismatch and obtain repetitive long-pulse high-power microwave (HPM), a series of experiments are carried out and the recent progress is presented in this paper. In the single-pulse operation, when the diode voltage is 466 kV and current is 41.6 kA, the radiated microwave power is above 2.2 GW, the pulse duration is above 102 ns, the microwave frequency is about 1.74 GHz, and the power conversion efficiency is about 11.5%. In the repetition rate operation, under the condition of the diode voltage about 400 kV, beam current about 38 kA, the radiated microwave power is about 1.0 GW, the pulse duration is about 85 ns. Moreover, the radiated microwave power and the pulse duration decline little by little when the shot numbers increase gradually. The experimental results show that the impedance matching is a vital factor for HPM systems and one of the major technical challenges is to improve the cathode for the repetition rate operation MILO.

  17. Object color affects identification and repetition priming.

    Science.gov (United States)

    Uttl, Bob; Graf, Peter; Santacruz, Pilar

    2006-10-01

    We investigated the influence of color on the identification of both non-studied and studied objects. Participants studied black and white and color photos of common objects and memory was assessed with an identification test. Consistent with our meta-analysis of prior research, we found that objects were easier to identify from color than from black and white photos. We also found substantial priming in all conditions, and study-to-test changes in an object's color reduced the magnitude of priming. Color-specific priming effects were large for color-complex objects, but minimal for color-simple objects. The pattern and magnitude of priming effects was not influenced either by the extent to which an object always appears in the same color (i.e., whether a color is symptomatic of an object) or by the object's origin (natural versus fabricated). We discuss the implications of our findings for theoretical accounts of object perception and repetition priming.

  18. PROJECT IMPLEMENTATION IN ORGANISATIONS OF REPETITIVE ACTIVITIES

    Directory of Open Access Journals (Sweden)

    Marek WIRKUS

    2015-04-01

    Full Text Available The study presents the implementation of projects in organisations that achieve business objectives through the imple-mentation of repetitive actions. Projects in these organisations are, on the one hand, treated as marginal activities, while the results of these projects have significant impact on the delivery of main processes, e.g. through the introduction of new products. Human capital and solutions in this field bear impact on the success of projects in these organisations, which is not always conducive to smooth implementation of projects. Conflict results from the nature of a project, which is a one-time and temporary process, so organisational solutions are also temporary. It influences on attitudes and com-mitment of the project contractors. The paper identifies and analyses factors which affect the success of the projects.

  19. Low-Intensity Repetitive Exercise Induced Rhabdomyolysis

    Directory of Open Access Journals (Sweden)

    Mina Tran

    2015-01-01

    Full Text Available Rhabdomyolysis is a rare condition caused by the proteins of damaged muscle cells entering the bloodstream and damaging the kidneys. Common symptoms of rhabdomyolysis are muscle pain and fatigue in conjunction with dark urine; kidney damage is a common symptom among these patients. We present a case of a 23-year-old woman who displayed myalgia in the upper extremities caused by low-intensity and high-repetition exercise. She was successfully diagnosed and treated for exertional rhabdomyolysis. This patient had no significant medical history that would induce this condition. We urge the emergency medical community to observe and monitor patients that complain of myalgia to ensure they are not suffering from rhabdomyolysis even in atypical cases.

  20. FEMA Hazard Mitigation Assistance Severe Repetitive Loss (SRL) Data

    Data.gov (United States)

    Department of Homeland Security — This dataset contains closed and obligated projects funded under the following Hazard Mitigation Assistance (HMA) grant programs: Severe Repetitive Loss (SRL). The...