WorldWideScience

Sample records for nonmodal emission regime

  1. An emissions trading regime for Canada

    Energy Technology Data Exchange (ETDEWEB)

    Smith, S.L. [National Round Table on the Environment and the Economy, Ottawa, ON (Canada)

    2001-07-01

    In 1998, over twelve papers were published on emissions trading regimes in Canada by the National Round Table on the Environment and the Economy (NRTEE), a federal government agency whose members represent stakeholders as varied as business, environmental groups, academics, aboriginal groups and others. One of the recommendations that emerged was for the computer modelling of the possibilities that had been identified for a domestic trading regime in Canada for greenhouse gases. It is unclear whether the modelling was ever performed as the file was taken over by the Finance Department under the umbrella of a special emission trading table that examined Canada's commitment under the Kyoto Protocol. The author examined questions pertaining to whether a domestic trading regime is essential, and what its characteristics should be in case it was deemed essential or advisable to have one. The upstream versus downstream application was looked at, as well as grand-fathering versus auction. Provincial issues were then addressed, followed by meshing with a credit system. International systems were reviewed. Early action was discussed, whereby an emitter seeks credit for action taken toward reductions since the original reference year of 1990. The case of emitters having bought or sold permits since the original reference years will also want those trades recognized under a trading regime. The author indicated that it seems probable that an emission trading system will eventually be implemented and that a debate on the issue should be initiated early.

  2. Nonmodal phenomena in differentially rotating dusty plasmas

    Science.gov (United States)

    Poedts, Stefaan; Rogava, Andria D.

    2000-10-01

    In this paper the foundation is layed for the nonmodal investigation of velocity shear induced phenomena in a differentially rotating flow of a dusty plasma. The simplest case of nonmagnetized flow is considered. It is shown that, together with the innate properties of the dusty plasma, the presence of differential rotation, Coriolis forces, and self-gravity casts a considerable richness on the nonmodal dynamics of linear perturbations in the flow. In particular: (i) dust-acoustic waves acquire the ability to extract energy from the mean flow and (ii) shear-induced, nonperiodic modes of collective plasma behavior-shear-dust-acoustic vortices-are generated. The presence of self-gravity and the nonzero Coriolis parameter (``epicyclic shaking'') makes these collective modes transiently unstable. .

  3. Non-modal linear stability analysis of miscible viscous fingering in a Hele-Shaw cell

    CERN Document Server

    Hota, Tapan Kumar; Mishra, Manoranjan

    2015-01-01

    For miscible viscous fingering (VF) in a Hele-Shaw cell or in two dimensional homogeneous porous media, the transient growth of disturbances is investigated by non-modal linear stability analysis (NMA). Due to the non-autonomous nature of the linearized perturbed equations, the linear stability theory prohibits using the normal mode analysis. The linearized perturbed equations for Darcy's law coupled with a convection-diffusion equation is discretized using finite difference method. The resultant matrix valued initial value problem is then solved by fourth order Runge-Kutta method, followed by a singular value decomposition (SVD) of the propagator matrix. We demonstrate the dominant perturbation that experiences the maximum amplification within the linear regime which lead to the transient growth. This feature was previously unattained in the existing linear stability methods for miscible VF. To explore the relevance of the optimal perturbation obtained from non-modal analysis of the physical system, we perfo...

  4. On Super-Planckian thermal emission in far field regime

    CERN Document Server

    Biehs, Svend-Age

    2016-01-01

    We study, in the framework of the Landauer theory, the thermal emission in far-field regime, of arbitrary indefinite planar media and finite size systems. We prove that the flux radiated by the former is bounded by the blackbody emission while, for the second, there is in principle, no upper limit demonstrating so the possibility for a super-Planckian thermal emission with finite size systems.

  5. Nonmodal analysis of helical and azimuthal magnetorotational instabilities

    CERN Document Server

    Mamatsashvili, G

    2016-01-01

    The helical and the azimuthal magnetorotational instabilities operate in rotating magnetized flows with relatively steep negative or extremely steep positive shear. The corresponding lower and upper Liu limits of the shear, which determine the threshold of modal growth of these instabilities, are continuously connected when some axial electrical current is allowed to pass through the rotating fluid. We investigate the nonmodal dynamics of these instabilities arising from the nonnormality of shear flow in the local approximation, generalizing the results of the modal approach. It is demonstrated that moderate transient/nonmodal amplification of both types of magnetorotational instability occurs within the Liu limits, where the system is stable according to modal analysis. We show that for the helical magnetorotational instability this magnetohydrodynamic behavior is closely connected with the nonmodal growth of the underlying purely hydrodynamic problem.

  6. Enforcement of emissions trading - sanction regimes of greenhouse gas emissions trading in the EU and China

    NARCIS (Netherlands)

    Peeters, Marjan; Chen, Huizhen; Weishaar, Stefan

    2016-01-01

    This chapter aims to further the debate regarding the role of law for establishing an adequate enforcement strategy for an emissions trading scheme. We focus on sanction regimes within the EU ETS and the Chinese emissions trading pilot projects. Section 2 sets the scene by pointing at the need of an

  7. Enforcement of emissions trading: Sanction regimes of greenhouse gas emissions trading in the EU and China

    NARCIS (Netherlands)

    Peeters, M.G.W.M.; Chen, H.

    2015-01-01

    Abstract: This chapter aims to further the debate regarding the role of law for establishing an adequate enforcement strategy for an emissions trading scheme. We focus on sanction regimes within the EU ETS and the Chinese emissions trading pilot projects. Section 2 sets the scene by pointing at the

  8. Enforcement of emissions trading - sanction regimes of greenhouse gas emissions trading in the EU and China

    NARCIS (Netherlands)

    Peeters, Marjan; Chen, Huizhen; Weishaar, Stefan

    2016-01-01

    This chapter aims to further the debate regarding the role of law for establishing an adequate enforcement strategy for an emissions trading scheme. We focus on sanction regimes within the EU ETS and the Chinese emissions trading pilot projects. Section 2 sets the scene by pointing at the need of an

  9. Employing Acoustic Emission for Monitoring Oil Film Regimes

    Directory of Open Access Journals (Sweden)

    David Mba

    2013-07-01

    Full Text Available The major purpose of a gear lubricant is to provide adequate oil film thickness to reduce and prevent gear tooth surface failures. Real time monitoring for gear failures is important in order to predict and prevent unexpected failures which would have a negative impact on the efficiency, performance and safety of the gearbox. This paper presents experimental results on the influence of specific oil film thickness on Acoustic Emission (AE activity for operational helical gears. Variation in film thickness during operations was achieved by spraying liquid nitrogen onto the rotating gear wheel. The experimental results demonstrated a clear relationship between the root mean square (r.m.s value of the AE signal and the specific film thickness. The findings demonstrate the potential of Acoustic Emission technology to quantify lubrication regimes on operational gears.

  10. Charging regime of pur spinel studied by secondary electron emission

    Energy Technology Data Exchange (ETDEWEB)

    Boughariou, A., E-mail: aicha_boughariou@yahoo.fr [LaMaCoP, Université de Sfax pour le sud, Faculté des Sciences, 3038 Sfax (Tunisia); Kallel, A. [LaMaCoP, Université de Sfax pour le sud, Faculté des Sciences, 3038 Sfax (Tunisia); Blaise, G. [LPS, Université Paris-Sud XI, Batiment 510, Orsay 91405 (France)

    2013-04-01

    Insulators are currently used in high technological devices. They are chosen because of their electrical properties of insulation and their thermal properties. It is well known that the presence of space charge in an insulator is correlated with an electric breakdown. Charging phenomena of insulator were studied thanks to a scanning electron microscope (SEM) which allows the injection of few electrons doses in a large domain of energies. SEM permits also the measurements of the secondary electron emission and the induced current created in the sample holder by the charges generated in the sample. The results showed that the secondary electron emission yield (SEE) σ is a very sensitive parameter to characterize the charging state of an insulator. In this work we investigate the charging effect of insulator surfaces like pur spinel (MgAl{sub 2}O{sub 4}) during 1.1, 5 and 15 keV. The results showed that the fundamental parameter controlling the charging kinetic is the current density J{sub 0}. At low energies 1.1 and 5 keV, two different kinds of self-regulated regime (σ=1) were observed as a function of current density. At 15 keV energy, the electron emission appears to be stimulated by the current density, due to the Poole–Frenkel effect.

  11. Pulsar emission in the very-high-energy regime

    CERN Document Server

    Breed, M; Harding, A K

    2016-01-01

    The vast majority of the pulsars detected by the Fermi Large Area Telescope (LAT) display spectra with exponential cutoffs falling in a narrow range around a few GeV. Early spectral modelling predicted spectral cutoff energies of up to 100 GeV. More modern studies estimated spectral cutoff energies in the 1-20 GeV range. It was therefore not expected that pulsars would be visible in the very-high-energy (VHE; >100 GeV) regime. The VERITAS detection (confirmed by MAGIC) of pulsed emission from the Crab pulsar up to 400 GeV (and now possibly up to 1 TeV) therefore raised important questions about our understanding of the electrodynamics and local environment of pulsars. H.E.S.S. has now detected pulsed emission from the Vela pulsar in the 20-120 GeV range, making this the second pulsar detected by a ground-based Cherenkov telescope. We will review the latest developments in VHE pulsar science, including an overview of recent observations and refinements to radiation models and magnetic field structures. This wi...

  12. Orbital motion theory and operational regimes for cylindrical emissive probes

    Science.gov (United States)

    Chen, Xin; Sanchez-Arriaga, G.

    2017-02-01

    A full-kinetic model based on the orbital-motion theory for cylindrical emissive probes (EPs) is presented. The conservation of the distribution function, the energy, and the angular momentum for cylindrical probes immersed in collisionless and stationary plasmas is used to write the Vlasov-Poisson system as a single integro-differential equation. It describes self-consistently the electrostatic potential profile and, consequently, the current-voltage (I-V) probe characteristics. Its numerical solutions are used to identify different EP operational regimes, including orbital-motion-limited (OML)/non-OML current collection and monotonic/non-monotonic potential, in the parametric domain of probe bias and emission level. The most important features of the potential and density profiles are presented and compared with common approximations in the literature. Conventional methods to measure plasma potential with EPs are briefly revisited. A direct application of the model is to estimate plasma parameters by fitting I-V measurements to the theoretical results.

  13. Dynamic Hysteresis Probes High-{\\beta} Nanolaser Emission Regimes

    CERN Document Server

    Pan, Si Hui; Amili, Abdelkrim El; Vallini, Felipe; Fainman, Yeshaiahu

    2016-01-01

    The quest for an integrated light source that promises high energy efficiency and fast modulation for high-performance photonic circuits has led to the development of room-temperature telecom-wavelength nanoscale laser with high spontaneous emission factors, \\beta. The coherence characterization of this type of lasers is inherently difficult with the conventional measurement of output light intensity versus input pump intensity due to the diminishing kink in the measurement curve. We demonstrate the transition from chaotic to coherent emission of a high-{\\beta} pulse-pump metallo-dielectric nanolaser can be determined by examining the width of a second order intensity correlation peak, which shrinks below and broadens above threshold. Photon fluctuation study, first one ever reported for this type of nanolaser, confirms the validity of this measurement technique. Additionally, we show that the width variation above threshold results from the delayed threshold phenomenon, providing the first indirect observati...

  14. Regimes of enhanced electromagnetic emission in beam-plasma interactions

    Energy Technology Data Exchange (ETDEWEB)

    Timofeev, I. V.; Annenkov, V. V.; Arzhannikov, A. V. [Budker Institute of Nuclear Physics, SB RAS, 630090 Novosibirsk, Russia and Novosibirsk State University, 630090 Novosibirsk (Russian Federation)

    2015-11-15

    The ways to improve the efficiency of electromagnetic waves generation in laboratory experiments with high-current relativistic electron beams injected into a magnetized plasma are discussed. It is known that such a beam can lose, in a plasma, a significant part of its energy by exciting a high level of turbulence and heating plasma electrons. Beam-excited plasma oscillations may simultaneously participate in nonlinear processes resulting in a fundamental and second harmonic emissions. It is obvious, however, that in the developed plasma turbulence the role of these emissions in the total energy balance is always negligible. In this paper, we investigate whether electromagnetic radiation generated in the beam-plasma system can be sufficiently enhanced by the direct linear conversion of resonant beam-driven modes into electromagnetic ones on preformed regular inhomogeneities of plasma density. Due to the high power of relativistic electron beams, the mechanism discussed may become the basis for the generator of powerful sub-terahertz radiation.

  15. Regimes of enhanced electromagnetic emission in beam-plasma interactions

    Science.gov (United States)

    Timofeev, I. V.; Annenkov, V. V.; Arzhannikov, A. V.

    2015-11-01

    The ways to improve the efficiency of electromagnetic waves generation in laboratory experiments with high-current relativistic electron beams injected into a magnetized plasma are discussed. It is known that such a beam can lose, in a plasma, a significant part of its energy by exciting a high level of turbulence and heating plasma electrons. Beam-excited plasma oscillations may simultaneously participate in nonlinear processes resulting in a fundamental and second harmonic emissions. It is obvious, however, that in the developed plasma turbulence the role of these emissions in the total energy balance is always negligible. In this paper, we investigate whether electromagnetic radiation generated in the beam-plasma system can be sufficiently enhanced by the direct linear conversion of resonant beam-driven modes into electromagnetic ones on preformed regular inhomogeneities of plasma density. Due to the high power of relativistic electron beams, the mechanism discussed may become the basis for the generator of powerful sub-terahertz radiation.

  16. Nonmodal Growth Of Kelvin-Helmholtz Instability In Compressible Flows

    Science.gov (United States)

    Karimi, Mona; Girimaji, Sharath

    2016-11-01

    Kelvin-helmholtz instability (khi) is central to the vertical mixing in shear flows and is known to be suppressed in compressible flows. To understand the inhibition of mixing under the influence of compressibility, we analyze the linear growth of khi in the short-time limit using initial value analysis. The evolution of perturbations is studied from a nonmodal standpoint. As the underlying suppression mechanism can be understood by considering primarily linear physics, the effect of compressibility on khi is scrutinized by linear analysis. Then its inferences are verified against direct numerical simulations. It has been demonstrated that compressibility forces the dominance of dilatational, rather than shear, dynamics at the interface of two fluids of different velocities. Within the dilatiatonal interface layer, pressure waves cause the velocity perturbation to become oscillatory [karimi and girimaji, 2016]. Thereupon, the focus is to examine the effect of the initial perturbation wavenumber on the formation of this layer and eventually the degree of khi suppression in compressible flows. We demonstrate that the degree of suppression decreases with the increase the wavenumbers of the initial perturbation of dilatational, rather than shear, dynamics at the interface of two fluids of different velocities. Within the dilatiatonal interface layer, pressure waves cause the velocity perturbation to become oscillatory [karimi and girimaji, 2016]. Thereupon, the focus is to examine the effect of the initial perturbation wavenumber on the formation of this layer and eventually the degree of khi suppression in compressible flows. We demonstrate that the degree of suppression decreases with the increase the wavenumbers of the initial perturbation.

  17. Efficient regime of electromagnetic emission in a plasma with counterstreaming electron beams

    Science.gov (United States)

    Timofeev, I. V.; Annenkov, V. V.

    2014-08-01

    Efficiency of electromagnetic emission produced in a magnetized plasma with counterstreaming electron beams was investigated using both the linear kinetic theory and particle-in-cell simulations. We calculated the growth rate of the beam-plasma instability taking into account both kinetic and relativistic effects and showed that there exists a regime in which transversely propagating electromagnetic waves can be generated by the coupling of the most unstable oblique beam-driven modes. It was confirmed by numerical simulations that such a tune-up of system parameters for a specific nonlinear process can lead to a substantial increase in electromagnetic emission efficiency. It was found that electromagnetic radiation emerging from the plasma in such a regime is generated near the harmonics of the pump frequency that is determined by the typical eigenfrequency of the beam-driven modes. It was also shown that the peak emission power can reach 5% of the maximal power lost by beam electrons.

  18. Efficient regime of electromagnetic emission in a plasma with counterstreaming electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Timofeev, I. V.; Annenkov, V. V. [Budker Institute of Nuclear Physics SB RAS and Novosibirsk State University, 630090 Novosibirsk (Russian Federation)

    2014-08-15

    Efficiency of electromagnetic emission produced in a magnetized plasma with counterstreaming electron beams was investigated using both the linear kinetic theory and particle-in-cell simulations. We calculated the growth rate of the beam-plasma instability taking into account both kinetic and relativistic effects and showed that there exists a regime in which transversely propagating electromagnetic waves can be generated by the coupling of the most unstable oblique beam-driven modes. It was confirmed by numerical simulations that such a tune-up of system parameters for a specific nonlinear process can lead to a substantial increase in electromagnetic emission efficiency. It was found that electromagnetic radiation emerging from the plasma in such a regime is generated near the harmonics of the pump frequency that is determined by the typical eigenfrequency of the beam-driven modes. It was also shown that the peak emission power can reach 5% of the maximal power lost by beam electrons.

  19. Modelling radiation emission in the transition from the classical to the quantum regime

    CERN Document Server

    Martins, J L; Grismayer, T; Vieira, J; Fonseca, R A; Silva, L O

    2015-01-01

    An emissivity formula is derived using the generalised Fermi-Weizacker-Williams method of virtual photons which accounts for the recoil the charged particle experiences as it emits radiation. It is found that through this derivation the formula obtained by Sokolov et al using QED perturbation theory is recovered. The corrected emissivity formula is applied to nonlinear Thomson scattering scenarios in the transition from the classical to the quantum regime, for small values of the nonlinear quantum parameter \\chi. Good agreement is found between this method and a QED probabilistic approach for scenarios where both are valid. In addition, signatures of the quantum corrections are identified and explored.

  20. A positron emission particle tracking investigation of the flow regimes in tumbling mills

    Science.gov (United States)

    Govender, I.; Pathmathas, T.

    2017-01-01

    Using positron emission particle tracking (PEPT) data we recover key granular rheology ingredients (velocity, shear rate, volume concentration, bed depth) for developing, testing and calibrating granular flow models. In this regard, 5 mm glass beads were rotated within a 476 mm diameter mill fitted with angled lifter bars along the inner azimuthal walls and operated in batch mode across a range of drum rotation speeds that span cascading and cataracting Froude regimes. After averaging the PEPT outputs into representative volume elements, subsequent continuum analysis of the flowing layer revealed a rich coexistence of flow regimes: a quasi-static layer dominated by frictional interactions, a dense, liquid-like layer that is stressed by frictional and collisional interactions, and an inertial layer that interacts mainly through collisions. Combining the inertial number with an empirically formulated dilatancy law and the measured granular rheological ingredients then facilitated the recovery of the total depth-dependent pressure of the free surface layer.

  1. Magnetorotational instability: nonmodal growth and the relationship of global modes to the shearing box

    Energy Technology Data Exchange (ETDEWEB)

    Squire, J.; Bhattacharjee, A. [Department of Astrophysical Sciences and Princeton Plasma Physics Laboratory, Princeton University, Princeton, NJ 08543 (United States)

    2014-12-10

    We study magnetorotational instability (MRI) using nonmodal stability techniques. Despite the spectral instability of many forms of MRI, this proves to be a natural method of analysis that is well-suited to deal with the non-self-adjoint nature of the linear MRI equations. We find that the fastest growing linear MRI structures on both local and global domains can look very different from the eigenmodes, invariably resembling waves shearing with the background flow (shear waves). In addition, such structures can grow many times faster than the least stable eigenmode over long time periods, and be localized in a completely different region of space. These ideas lead—for both axisymmetric and non-axisymmetric modes—to a natural connection between the global MRI and the local shearing box approximation. By illustrating that the fastest growing global structure is well described by the ordinary differential equations (ODEs) governing a single shear wave, we find that the shearing box is a very sensible approximation for the linear MRI, contrary to many previous claims. Since the shear wave ODEs are most naturally understood using nonmodal analysis techniques, we conclude by analyzing local MRI growth over finite timescales using these methods. The strong growth over a wide range of wave-numbers suggests that nonmodal linear physics could be of fundamental importance in MRI turbulence.

  2. Magnetorotational Instability: Nonmodal Growth and the Relationship of Global Modes to the Shearing Box

    Energy Technology Data Exchange (ETDEWEB)

    J Squire, A Bhattacharjee [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)

    2014-07-01

    We study the magnetorotational instability (MRI) (Balbus & Hawley 1998) using non-modal stability techniques.Despite the spectral instability of many forms of the MRI, this proves to be a natural method of analysis that is well-suited to deal with the non-self-adjoint nature of the linear MRI equations. We find that the fastest growing linear MRI structures on both local and global domains can look very diff erent to the eigenmodes, invariably resembling waves shearing with the background flow (shear waves). In addition, such structures can grow many times faster than the least stable eigenmode over long time periods, and be localized in a completely di fferent region of space. These ideas lead – for both axisymmetric and non-axisymmetric modes – to a natural connection between the global MRI and the local shearing box approximation. By illustrating that the fastest growing global structure is well described by the ordinary diff erential equations (ODEs) governing a single shear wave, we find that the shearing box is a very sensible approximation for the linear MRI, contrary to many previous claims. Since the shear wave ODEs are most naturally understood using non-modal analysis techniques, we conclude by analyzing local MRI growth over finite time-scales using these methods. The strong growth over a wide range of wave-numbers suggests that non-modal linear physics could be of fundamental importance in MRI turbulence (Squire & Bhattacharjee 2014).

  3. The influence of thermal regime on gasoline direct injection engine performance and emissions

    Science.gov (United States)

    Leahu, C. I.; Tarulescu, S.

    2016-08-01

    This paper presents the experimental research regarding to the effects of a low thermal regime on fuel consumption and pollutant emissions from a gasoline direct injection (GDI) engine. During the experimental researches, the temperature of the coolant and oil used by the engine were modified 4 times (55, 65, 75 and 85 oC), monitoring the effects over the fuel consumption and emissions (CO2, CO and NOx). The variations in temperature of the coolant and oil have been achieved through AVL coolant and oil conditioning unit, integrated in the test bed. The obtained experimental results reveals the poor quality of exhaust gases and increases of fuel consumption for the gasoline direct injection engines that runs outside the optimal ranges for coolant and oil temperatures.

  4. METHANE EMISSION FROM PADDY FIELDS AS INFLUENCED BY DIFFERENT WATER REGIMES IN CENTRAL JAVA

    Directory of Open Access Journals (Sweden)

    Prihasto Setyanto

    2013-07-01

    Full Text Available The concentration of methane (CH4 in the atmosphere is increasing at 1% per annum and rice fields are one of the sources that contribute to about 10-15% of the atmospheric CH4. One of the options to reduce greenhouse gas emission from rice fields is probably through water management. A field study was conducted to investigate the effects of water management practices on CH4 emission from rice field plots on a silty sand Aeric Tropaquept soil at Research Station for Agricultural Environment Preservation, Jakenan, Central Java, Indonesia, during the dry season of March to June 2002. Four water regimes tested were: (1 5 cm continuous flooding (CF, (2 0-1 cm continuous flooding (ST, (3 intermittent irrigation (IR where plots received continuously 5 cm of flooding with two times of draining at 15-20 and 25-30 days after transplanting (DAT, and (4 pulse irrigation (PI where plots were watered until 5 cm level and left to dry by itself until the water table reached 30 cm beneath soil surface then watered again. The total CH4 emissions of the four water treatments were 254, 185, 136 and 96 kg CH4 ha-1 for CF, ST, IR and PI, respectively. Methane emission increased during the early growing season, which coincided with the low redox potential of -100 to -150 mV in all treatments. Dry matter weight of straw and filled grain among the water treatments did not show significant differences. Likewise, total grain yield at 14% moisture content was not significantly different among treatments. However, this result should be carefully interpreted because the rice plants in all water treatments were infested by stem borer, which reduced the total grain yield of IR64 between 11% and 16%. This study suggests that intermittent and pulse irrigation practices will be important not only for water use efficiency, but also for CH4 emission reduction.

  5. Nitrous oxide and greenhouse gas emissions from grazed pastures as affected by use of nitrification inhibitor and restricted grazing regime.

    Science.gov (United States)

    Luo, Jiafa; Ledgard, Stewart F; Lindsey, Stuart B

    2013-11-01

    Integration of a restricted grazing regime in winter with the use of a nitrification inhibitor can potentially reduce N2O emissions from grazed pasture systems. A three year field study was conducted to compare annual N2O emission rates from a "tight nitrogen" grazed farmlet with those from a control farmlet. The control farmlet was managed under a conventional rotational all-year grazing regime, while the "tight nitrogen" farmlet was under a similar grazing regime, except during winter and early spring seasons when cows grazed for about 6h per day. A nitrification inhibitor (dicyandiamide, DCD) was applied onto the "tight nitrogen" farmlet immediately after grazing through winter and early spring. A chamber technique was used to measure N2O emissions in several paddocks from each farmlet during three contrasting seasons each year. The IPCC (Intergovernmental Panel on Climate Change) inventory methodology was used to estimate CH4 and indirect N2O emissions and the life cycle assessment (LCA) methodology was used to calculate CO2 emissions from the farm systems. The individual and combined effects of restricted grazing and DCD use on N2O emissions were also determined. During the late spring/summer and autumn periods, N2O emission rates were generally similar between the two farmlets. The use of a restricted grazing regime and DCD reduced N2O emissions from the grazed farmlet during the winter/early spring seasons by 43-55%, 64-79% and 45-60% over each of the three years, respectively. The use of restricted grazing and DCD both resulted in a similar reduction in N2O emissions, but there was no significant further reduction from the combination of these technologies. For the three study years, the annual N2O emission rate from the "tight nitrogen" farmlet was 20% lower, on average, than from the control. Total annual greenhouse gas (GHG) emissions, however, were only 5% less in the "tight nitrogen" system.

  6. Responses of Soil CO2 Emissions to Extreme Precipitation Regimes: a Simulation on Loess Soil in Semi-arid Regions

    Science.gov (United States)

    Wang, R.; Zhao, M.; Hu, Y.; Guo, S.

    2016-12-01

    Responses of soil CO2 emission to natural precipitation play an essential role in regulating regional C cycling. With more erratic precipitation regimes, mostly likely of more frequent heavy rainstorms, projected into the future, extreme precipitation would potentially affect local soil moisture, plant growth, microbial communities, and further soil CO2 emissions. However, responses of soil CO2 emissions to extreme precipitation have not yet been systematically investigated. Such performances could be of particular importance for rainfed arable soil in semi-arid regions where soil microbial respiration stress is highly sensitive to temporal distribution of natural precipitation.In this study, a simulated experiment was conducted on bare loess soil from the semi-arid Chinese Loess Plateau. Three precipitation regimes with total precipitation amounts of 150 mm, 300 mm and 600 mm were carried out to simulate the extremely dry, business as usual, and extremely wet summer. The three regimes were individually materialized by wetting soils in a series of sub-events (10 mm or 150 mm). Co2 emissions from surface soil were continuously measured in-situ for one month. The results show that: 1) Evident CO2 emission pulses were observed immediately after applying sub-events, and cumulative CO2 emissions from events of total amount of 600 mm were greater than that from 150 mm. 3) In particular, for the same total amount of 600 mm, wetting regimes by applying four times of 150 mm sub-events resulted in 20% less CO2 emissions than by applying 60 times of 10 mm sub-events. This is mostly because its harsh 150 mm storms introduced more over-wet soil microbial respiration stress days (moisture > 28%). As opposed, for the same total amount of 150 mm, CO2 emissions from wetting regimes by applying 15 times of 10 mm sub-events were 22% lower than by wetting at once with 150 mm water, probably because its deficiency of soil moisture resulted in more over-dry soil microbial respiration

  7. Sunflower N2O emissions under two different water regimes in Mediterranean climate

    Science.gov (United States)

    Monaco, Eugenia; Vitale, Luca; Di Tommasi, Paul; Tedeschi, Anna; Tosca, Maurizio; Magliulo, Vincenzo

    2017-04-01

    Human activities are altering the atmospheric greenhouse gases (GHGs) concentration with negative effects on global climate and environment. Cropland represents about 12 % of earth's surface and largely contribute to GHGs production, in particular N2O, due to a massive use of nitrogen fertilization. In particular, agriculture and intensive livestock farming may significantly affect biogeochemical cycles included nitrogen cycle. However, it is often difficult to predict the total amount of fluxes caused by agricultural management, which impact on both the whole agro-ecosystem. The objective of the experiment was to evaluate soil N2O fluxes under two different irrigation managements. The experimental trial was conducted in a farm in surrounding of Naples, southern Italy. The crop monitored was sunflower for biomass uses. Two irrigation levels were performed: returning 100% (optimal irrigation) and 50% (deficit irrigation) of soil field capacity for the layer 0.0-0.50 m. 314 Kg ha-1 of urea fertilizer was supplied in two times: at sowing and 40 days later. Before sowing, six autochambers were inserted 3 cm into the soil and connected to a gas chromatograph and a scanning apparatus. A program for chambers' management was implemented to monitor soil N2O fluxes measured different times of the day. Biometric parameters such as LAI, root depth, above- and below-ground biomass were monitored during the experiment. Results shows that soil N2O fluxes were affected by irrigation regime; in particular, the deficit irrigation determined lower N2O fluxes compared to optimal irrigation but the total biomass production and yield were comparable between the two water regimes. So low input farm management could be take in account to reduce the total N2O emission and maintain at the same time high productivity level in terms of biomass and yield. Keywords: N2O fluxes, Irrigation schedule, sunflower

  8. Non-modal theory of the kinetic ion temperature gradient driven instability of plasma shear flows across the magnetic field

    Science.gov (United States)

    Mikhailenko, V. V.; Mikhailenko, V. S.; Lee, Hae June

    2016-06-01

    The temporal evolution of the kinetic ion temperature gradient driven instability and of the related anomalous transport of the ion thermal energy of plasma shear flow across the magnetic field is investigated analytically. This instability develops in a steady plasma due to the inverse ion Landau damping and has the growth rate of the order of the frequency when the ion temperature is equal to or above the electron temperature. The investigation is performed employing the non-modal methodology of the shearing modes which are the waves that have a static spatial structure in the frame of the background flow. The solution of the governing linear integral equation for the perturbed potential displays that the instability experiences the non-modal temporal evolution in the shearing flow during which the unstable perturbation becomes very different from a canonical modal form. It transforms into the non-modal structure with vanishing frequency and growth rate with time. The obtained solution of the nonlinear integral equation, which accounts for the random scattering of the angle of the ion gyro-motion due to the interaction of ions with ensemble of shearing waves, reveals similar but accelerated process of the transformations of the perturbations into the zero frequency structures. It was obtained that in the shear flow the anomalous ion thermal conductivity decays with time. It is a strictly non-modal effect, which originates from the temporal evolution of the shearing modes turbulence.

  9. Estimation of metabolic heat production and methane emission in Sahiwal and Karan Fries heifers under different feeding regimes

    Directory of Open Access Journals (Sweden)

    Sunil Kumar

    2016-05-01

    Full Text Available Aim: The objective of this study was designed to estimate the metabolic heat production and methane emission in Sahiwal and Karan Fries (Holstein-Friesian X Tharparkar heifers under two different feeding regimes, i.e., feeding regime-1 as per the National Research Council (NRC (2001 and feeding regime-2 having 15% higher energy (supplementation of molasses than NRC (2001. Materials and Methods: Six (n = 6 healthy heifers of Sahiwal and Karan Fries with 18-24 months of age were selected from Indian Council of Agricultural Research-National Dairy Research Institute, Karnal. An initial 15 days was maintained under feeding regime-1 and feeding regime-2 as adaptation period; actual experiment was conducted from 16th day onward for next 15 days. At the end of feeding regimes (on day 15th and 16th, expired air and volume were collected in Douglas bag for two consecutive days (morning [6:00 am] and evening [4:00 pm]. The fraction of methane and expired air volume were measured by methane analyzer and wet test meter, respectively. The oxygen consumption and carbon dioxide production were measured by iWorx LabScribe2. Results: The heat production (kcal/day was significantly (p0.05. The energy loss as methane (% from total heat production was significantly (p<0.05 higher in feeding regime-1. The body weight (kg, metabolic body weight (W0.75, and basal metabolic rate (kcal/kg0.75 were significantly (p<0.05 higher in feeding regime-2 in both breeds. Conclusions: This study indicates that higher energy diet by supplementing molasses may reduce energy loss as methane and enhance the growth of Sahiwal and Karan Fries heifers.

  10. Non-modal stability analysis and transient growth in a magnetized Vlasov plasma

    CERN Document Server

    Ratushnaya, Valeria

    2014-01-01

    Collisionless plasmas, such as those encountered in tokamaks, exhibit a rich variety of instabilities. The physical origin, triggering mechanisms and fundamental understanding of many plasma instabilities, however, are still open problems. We investigate the stability properties of a collisionless Vlasov plasma in a stationary homogeneous magnetic field. We narrow the scope of our investigation to the case of Maxwellian plasma. For the first time using a fully kinetic approach we show the emergence of the local instability, a transient growth, followed by classical Landau damping in a stable magnetized plasma. We show that the linearized Vlasov operator is non-normal leading to the algebraic growth of the perturbations using non-modal stability theory. The typical time scales of the obtained instabilities are of the order of several plasma periods. The first-order distribution function and the corresponding electric field are calculated and the dependence on the magnetic field and perturbation parameters is s...

  11. The stability of a rising droplet: an inertialess nonmodal growth mechanism

    CERN Document Server

    Gallino, Giacomo; Gallaire, Francois

    2015-01-01

    Past modal stability analysis (Kojima et al. 1984) predicted that a rising or sedimenting droplet in a viscous fluid is stable in the presence of surface tension no matter how small, in contrast with experimental and numerical results. By performing a non-modal stability analysis, we demonstrate the potential for transient growth of the interfacial energy of a rising droplet in the limit of inertialess Stokes equations. The predicted critical capillary numbers agree well with that from direct numerical simulations reported in the literature (Koh & Leal 1989). Boundary integral simulations are used to delineate the critical amplitude of the most destabilizing perturbations. The critical amplitude is negatively correlated with the linear optimal energy growth, implying that the transient growth is responsible for reducing the necessary perturbation amplitude required to escape the basin of attraction of the spherical solution.

  12. Modal and nonmodal stability analysis of electrohydrodynamic flow with and without cross-flow

    CERN Document Server

    Zhang, Mengqi; Wu, Jian; Schmid, Peter J; Quadrio, Maurizio

    2015-01-01

    We report the results of a complete modal and nonmodal linear stability analysis of the electrohydrodynamic flow (EHD) for the problem of electroconvection in the strong injection region. Convective cells are formed by Coulomb force in an insulating liquid residing between two plane electrodes subject to unipolar injection. Besides pure electroconvection, we also consider the case where a cross-flow is present, generated by a streamwise pressure gradient, in the form of a laminar Poiseuille flow. The effect of charge diffusion, often neglected in previous linear stability analyses, is included in the present study and a transient growth analysis, rarely considered in EHD, is carried out. In the case without cross-flow, a non-zero charge diffusion leads to a lower linear stability threshold and thus to a more unstable low. The transient growth, though enhanced by increasing charge diffusion, remains small and hence cannot fully account for the discrepancy of the linear stability threshold between theoretical a...

  13. Black hole nonmodal linear stability: the Schwarzschild (A)dS cases

    CERN Document Server

    Dotti, Gustavo

    2016-01-01

    The nonmodal linear stability of the Schwarzschild black hole established in Phys.\\ Rev.\\ Lett.\\ {\\bf 112} (2014) 191101 is generalized to the case of nonnegative cosmological constant $\\Lambda$. Two gauge invariant combinations $G_{\\pm}$ of perturbed scalars made out of the Weyl tensor and its first covariant derivative are found such that the map $[h_{\\alpha \\beta}] \\to \\left( G_- \\left([h_{\\alpha \\beta}] \\right), G_+ \\left([h_{\\alpha \\beta}] \\right) \\right)$, $[h_{\\alpha \\beta}]$ an equivalence class under gauge transformations of a solution of the linearized Einstein's equation, is invertible. The way to reconstruct a representative of $[h_{\\alpha \\beta}]$ in terms of $(G_-,G_+)$ is given. It is proved that, for an arbitrary perturbation consistent with the background asymptote, $G_+$ and $G_-$ are bounded in the the outer static region. At large times, the perturbation decays leaving a linearized Kerr black hole around the Schwarzschild or Schwarschild de Sitter background solution. For negative cosmolog...

  14. River bedform inception by flow unsteadiness: A modal and nonmodal analysis

    Science.gov (United States)

    Caruso, Alice; Vesipa, Riccardo; Camporeale, Carlo; Ridolfi, Luca; Schmid, Peter J.

    2016-05-01

    River bedforms arise as a result of morphological instabilities of the stream-sediment interface. Dunes and antidunes constitute the most typical patterns, and their occurrence and dynamics are relevant for a number of engineering and environmental applications. Although flow variability is a typical feature of all rivers, the bedform-triggering morphological instabilities have generally been studied under the assumption of a constant flow rate. In order to partially address this shortcoming, we here discuss the influence of (periodic) flow unsteadiness on bedform inception. To this end, our recent one-dimensional validated model coupling Dressler's equations with a refined mechanistic sediment transport formulation is adopted, and both the asymptotic and transient dynamics are investigated by modal and nonmodal analyses.

  15. Developing a regional scale approach for modelling the impacts of fertiliser regime on N2O emissions in Ireland

    Science.gov (United States)

    Zimmermann, Jesko; Jones, Michael

    2016-04-01

    Agriculture can be significant contributor to greenhouse gas emissions, this is especially prevalent in Ireland where the agricultural sector accounts for a third of total emissions. The high emissions are linked to both the importance of agriculture in the Irish economy and the focus on dairy and beef production. In order to reduce emissions three main categories are explored: (1) reduction of methane emissions from cattle, (2) reduction of nitrous oxide emissions from fertilisation, and (3) fostering the carbon sequestration potential of soils. The presented research focuses on the latter two categories, especially changes in fertiliser amount and composition. Soil properties and climate conditions measured at the four experimental sites (two silage and two spring barley) were used to parameterise four biogeochemical models (DayCent, ECOSSE, DNDC 9.4, and DNDC 9.5). All sites had a range of different fertiliser regimes applied. This included changes in amount (0 to 500 kg N/ha on grassland and 0 to 200 kg N/ha on arable fields), fertiliser type (calcium ammonium nitrate and urea), and added inhibitors (the nitrification inhibitor DCD, and the urease inhibitor Agrotain). Overall, 20 different treatments were applied to the grassland sites, and 17 to the arable sites. Nitrous oxide emissions, measured in 2013 and 2014 at all sites using closed chambers, were made available to validate model results for these emissions. To assess model performance for the daily measurements, the Root Mean Square Error (RMSE) was compared to the measured 95% confidence interval of the measured data (RMSE95). Bias was tested comparing the relative error (RE) the 95 % confidence interval of the relative error (RE95). Preliminary results show mixed model performance, depending on the model, site, and the fertiliser regime. However, with the exception of urea fertilisation and added inhibitors, all scenarios were reproduced by at least one model with no statistically significant total

  16. Axial light emission and Ar metastable densities in a parallel plate dc micro discharge in steady state and transient regimes

    CERN Document Server

    Kuschel, T; Stefanović, I; Böke, M; Skoro, N; Marić, D; Petrović, Z Lj; Winter, J

    2011-01-01

    Axial emission profiles in a parallel plate dc micro discharge (feedgas: argon; discharge gap d=1mm; pressure p=10Torr) were studied by means of time resolved imaging with a fast ICCD camera. Additionally, volt-ampere (V-A) characteristics were recorded and Ar* metastable densities were measured by tunable diode laser absorption spectroscopy (TDLAS). Axial emission profiles in the steady state regime are similar to corresponding profiles in standard size discharges (d=1cm, p=1Torr). For some discharge conditions relaxation oscillations are present when the micro discharge switches periodically between low current Townsend-like mode and normal glow. At the same time the axial emission profile shows transient behavior, starting with peak distribution at the anode, which gradually moves towards the cathode during the normal glow. The development of argon metastable densities highly correlates with the oscillating discharge current. Gas temperatures in the low current Townsend-like mode (T= 320-400K) and the high...

  17. Nitrous oxide emission and reduction in a laboratory-incubated paddy soil response to pretreatment of water regime

    Institute of Scientific and Technical Information of China (English)

    WANG Lian-feng; CAI Zu-cong; YAN Hong

    2004-01-01

    A laboratory incubation experiment was conducted to investigate nitrous oxide(N2O) emission and reduction in a paddy soil(Stagnic Anthrosol) response to the pretreatment of water regime. The paddy soil was maintained under either air-dried(sample D) or submerged(sample F) conditions for 110 d before the soil was adjusted into soil moisture of 20%, 40%, 60%, 80% and 100% water holding capacity(WHC) respectively, and then incubated with or without 10%(v/v) acetylene for 138 h at 25℃. At lower soil water content ((60% WHC), N2O emission from the sample F was 2.29 times higher than that from the sample D(P<0.01). While, N2O emission from the sample F was only 29 and 14 percent of that from the sample D at the soil moisture of 80% and 100% WHC, respectively(P<0.01). The maximal N2O emissions observed at soil moisture of 80% WHC were about 24 and 186 times higher than the minima obtained at the soil moisture of 20% WHC for the sample F and D, respectively. But at the soil moisture of 80% and 100% WHC, N2O emission from the sample F with acetylene(F+ACE) was comparable to that of the sample D with acetylene (D+ACE). The results showed that the F sample produced N2O ability in denitrification was similar to the sample D, however, the sample F was in the better reduction of N2O to N2 than the sample D even after the soil moisture was adjusted into the same level of 80% or 100% WHC. Therefore, the pretreatment of water regime influenced the strength and product composition of denitrification and N2O emission from the paddy soil.

  18. Influence of Ion Effects on a Space Charge Limited Field Emission Flow: From Classical to ultrarelativistic regimes

    Science.gov (United States)

    Lin, M. C.; Chang, P. C.; Verboncoeur, J. P.

    2009-05-01

    The effects of ions in space charge limited field emission flow is studied using a self-consistent model, and confirmed by particle-in-cell (PIC) simulations. The field emission of electrons is described quantum mechanically by the Fowler--Nordheim equation. The cathode plasma and surface properties are considered within the framework of the effective work function approximation. Ionization effects at the anode as well as electron space-charge effects are described by Poisson's equation coupled with the energy conservation equation including relativistic effects. The closed form of formulas has been derived and the numerical calculations are carried out self-consistently to yield the steady state of the bipolar flow from classical to ultrarelativistic regimes. The upstream ion current included in Poisson's equation has been treated as a tuning parameter. The field-emission currents in the presence of saturated ion currents are enhanced by 1.8, 1.5, and 1.4 times of the case with no ion current in the classical, intermediate, and ultrarelativistic regimes, respectively. The solutions have also been verified using 1D PIC simulations as implemented in the OOPD1 code developed by the PTSG of UC Berkeley.

  19. Auroral Radio Emission from Late L and T Dwarfs: A New Constraint on Dynamo Theory in the Substellar Regime

    Science.gov (United States)

    Kao, Melodie M.; Hallinan, Gregg; Pineda, J. Sebastian; Escala, Ivanna; Burgasser, Adam; Bourke, Stephen; Stevenson, David

    2016-02-01

    We have observed six late L and T dwarfs with the Karl G. Jansky Very Large Array (VLA) to investigate the presence of highly circularly polarized radio emission, associated with large-scale auroral currents. Previous surveys encompassing ∼60 L6 or later targets have yielded only one detection. Our sample includes the previously detected T6.5 dwarf 2MASS 10475385+2124234, as well as five new targets selected for the presence of Hα emission and/or optical infrared photometric variability, which are possible manifestations of auroral activity. We detect 2MASS 10475385+2124234, as well as four of the five targets in our biased sample, including the strong IR-variable source SIMP J01365662+0933473 and bright Hα emitter 2MASS 12373919+6526148, reinforcing the possibility that activity at these disparate wavelengths is related. The radio emission frequency corresponds to a precise determination of the lower-bound magnetic field strength near the surface of each dwarf, and this new sample provides robust constraints on dynamo theory in the low-mass brown dwarf regime. Magnetic fields ≳ 2.5 kG are confirmed for five of six targets. Our results provide tentative evidence that the dynamo operating in this mass regime may be inconsistent with predicted values from a recently proposed model. Further observations at higher radio frequencies are essential for verifying this assertion.

  20. Greenhouse gas emissions from a wheat-maize double cropping system with different nitrogen fertilization regimes.

    Science.gov (United States)

    Hu, Xiao-Kang; Su, Fang; Ju, Xiao-Tang; Gao, Bing; Oenema, Oene; Christie, Peter; Huang, Bin-Xiang; Jiang, Rong-Feng; Zhang, Fu-Suo

    2013-05-01

    Here, we report on a two-years field experiment aimed at the quantification of the emissions of nitrous oxide (N2O) and methane (CH4) from the dominant wheat-maize double cropping system in North China Plain. The experiment had 6 different fertilization strategies, including a control treatment, recommended fertilization, with and without straw and manure applications, and nitrification inhibitor and slow release urea. Application of N fertilizer slightly decreased CH4 uptake by soil. Direct N2O emissions derived from recommended urea application was 0.39% of the annual urea-N input. Both straw and manure had relatively low N2O emissions factors. Slow release urea had a relatively high emission factor. Addition of nitrification inhibitor reduced N2O emission by 55%. We conclude that use of nitrification inhibitors is a promising strategy for N2O mitigation for the intensive wheat-maize double cropping systems.

  1. Black hole nonmodal linear stability: the Reissner-Nordstr\\"om case

    CERN Document Server

    Tío, Julián M Fernández

    2016-01-01

    Following a program on black hole nonmodal linear stability initiated in \\cite{Dotti:2013uxa}, we study odd linear perturbations of the Einstein-Maxwell equations around a Reissner-Nordstr\\"om (A)dS black hole. We show that all the gauge invariant information in the metric and Maxwell field perturbations is encoded in the spacetime scalars $\\mathcal{F} =\\delta (F^*_{\\alpha \\beta} F^{\\alpha \\beta})$ and $\\mathcal{Q} =\\delta (\\tfrac{1}{48} C^*_{\\alpha \\beta \\gamma \\delta} C^{\\alpha \\beta \\gamma \\delta})$, where $C_{\\alpha \\beta \\gamma \\delta}$ is the Weyl tensor, $F_{\\alpha \\beta}$ the Maxwell field, a star denotes Hodge dual and $\\delta$ means first order variation. We show that the linearized Einstein-Maxwell equations are equivalent to a coupled system of wave equations for the fields$\\mathcal{F}$ and $\\mathcal{Q}$. For nonnegative cosmological constant we prove that $\\mathcal{F}$ and $\\mathcal{Q}$ are pointwise bounded on the static outer region. In the asymptotically AdS casethe dynamics depends on the bou...

  2. Black hole non-modal linear stability: the Schwarzschild (A)dS cases

    Science.gov (United States)

    Dotti, Gustavo

    2016-10-01

    The non-modal linear stability of the Schwarzschild black hole established in Dotti (2014 Phys. Rev. Lett. 112 191101) is generalized to the case of a non-negative cosmological constant Λ. Two gauge invariant combinations G ± of perturbed scalars made out of the Weyl tensor and its first covariant derivative are found such that the map [{h}α β ]\\to ({G}-([{h}α β ]),{G}+([{h}α β ])) with domain the set of equivalent classes [{h}α β ] under gauge transformations of solutions of the linearized Einstein’s equation, is invertible. The way to reconstruct a representative of [{h}α β ] in terms of ({G}-,{G}+) is given. It is proved that, for an arbitrary perturbation consistent with the background asymptote, {G}+ and {G}- are bounded in the the outer static region. At large times, the perturbation decays leaving a linearized Kerr black hole around the Schwarzschild or Schwarschild de Sitter background solution. For negative cosmological constant it is shown that there are choices of boundary conditions at the time-like boundary under which the Schwarzschild anti de Sitter black hole is unstable. The root of Chandrasekhar’s duality relating odd and even modes is exhibited, and some technicalities related to this duality and omitted in the original proof of the {{Λ }}=0 case are explained in detail.

  3. Non-modal stability analysis and transient growth in a magnetized Vlasov plasma

    KAUST Repository

    Ratushnaya, V.

    2014-12-01

    Collisionless plasmas, such as those encountered in tokamaks, exhibit a rich variety of instabilities. The physical origin, triggering mechanisms and fundamental understanding of many plasma instabilities, however, are still open problems. We investigate the stability properties of a 3-dimensional collisionless Vlasov plasma in a stationary homogeneous magnetic field. We narrow the scope of our investigation to the case of Maxwellian plasma and examine its evolution with an electrostatic approximation. For the first time using a fully kinetic approach we show the emergence of the local instability, a transient growth, followed by classical Landau damping in a stable magnetized plasma. We show that the linearized Vlasov operator is non-normal leading to the algebraic growth of the perturbations using non-modal stability theory. The typical time scales of the obtained instabilities are of the order of several plasma periods. The first-order distribution function and the corresponding electric field are calculated and the dependence on the magnetic field and perturbation parameters is studied. Our results offer a new scenario of the emergence and development of plasma instabilities on the kinetic scale.

  4. Greenhouse gas emissions from a wheat-maize double cropping system with different nitrogen fertilization regimes

    NARCIS (Netherlands)

    Hu, X.K.; Su, F.; Ju, X.T.; Gao, B.; Oenema, O.; Christie, P.; Huang, B.X.; Jiang, R.F.; Zhang, F.S.

    2013-01-01

    Here, we report on a two-years field experiment aimed at the quantification of the emissions of nitrous oxide (N2O) and methane (CH4) from the dominant wheat maize double cropping system in North China Plain. The experiment had 6 different fertilization strategies, including a control treatment, rec

  5. Greenhouse gas emissions from a wheat-maize double cropping system with different nitrogen fertilization regimes

    NARCIS (Netherlands)

    Hu, X.K.; Su, F.; Ju, X.T.; Gao, B.; Oenema, O.; Christie, P.; Huang, B.X.; Jiang, R.F.; Zhang, F.S.

    2013-01-01

    Here, we report on a two-years field experiment aimed at the quantification of the emissions of nitrous oxide (N2O) and methane (CH4) from the dominant wheat maize double cropping system in North China Plain. The experiment had 6 different fertilization strategies, including a control treatment,

  6. Photon emission by ultra-relativistic positrons in crystalline undulators: the high-energy regime

    CERN Document Server

    Krause, W; Solov'yov, A V; Greiner, W

    2015-01-01

    This paper discusses the undulator radiation emitted by high-energy positrons during planar channeling in periodically bent crystals. We demonstrate that the construction of the undulator for positrons with energies of 10 GeV and above is only possible if one takes into account the radiative energy losses. The frequency of the undulator radiation depends on the energy of the particle. Thus the decrease of the particle's energy during the passage of the crystal should result in the destruction of the undulator radiation regime. However, we demonstrate that it is possible to avoid the destructive influence of the radiative losses on the frequency of the undulator radiation by the appropriate variation of the shape of the crystal channels. We also discuss a method by which, to our mind, it would be possible to prepare the crystal with the desired properties of its channels.

  7. Fowler-Nordheim emission modified by laser pulses in the adiabatic regime

    CERN Document Server

    Rokhlenko, Alexander

    2016-01-01

    We investigate enhanced field emission due to a continuous or pulsed oscillating field added to a constant electric field $E$ at the emitter surface. When the frequency of oscillation, field strength, and property of the emitter material satisfy the Keldysh condition $\\gamma<1/2$ one can use the adiabatic approximation for treating the oscillating field, i.e. consider the tunneling through the instantaneous Fowler-Nordheim barrier created by both fields. Due to the great sensitivity of the emission to the field strength the average tunneling current can be much larger than the current produced by only the constant field. We carry out the computations for arbitrary strong constant electric fields, beyond the commonly used Fowler-Nordheim approximation which exhibit in particular an important property of the wave function inside the potential barrier where it is found to be monotonically decreasing without oscillations.

  8. Artificial Neural Network Model for Monitoring Oil Film Regime in Spur Gear Based on Acoustic Emission Data

    Directory of Open Access Journals (Sweden)

    Yasir Hassan Ali

    2015-01-01

    Full Text Available The thickness of an oil film lubricant can contribute to less gear tooth wear and surface failure. The purpose of this research is to use artificial neural network (ANN computational modelling to correlate spur gear data from acoustic emissions, lubricant temperature, and specific film thickness (λ. The approach is using an algorithm to monitor the oil film thickness and to detect which lubrication regime the gearbox is running either hydrodynamic, elastohydrodynamic, or boundary. This monitoring can aid identification of fault development. Feed-forward and recurrent Elman neural network algorithms were used to develop ANN models, which are subjected to training, testing, and validation process. The Levenberg-Marquardt back-propagation algorithm was applied to reduce errors. Log-sigmoid and Purelin were identified as suitable transfer functions for hidden and output nodes. The methods used in this paper shows accurate predictions from ANN and the feed-forward network performance is superior to the Elman neural network.

  9. Single-mode tunable laser emission in the single-exciton regime from colloidal nanocrystals.

    Science.gov (United States)

    Grivas, Christos; Li, Chunyong; Andreakou, Peristera; Wang, Pengfei; Ding, Ming; Brambilla, Gilberto; Manna, Liberato; Lagoudakis, Pavlos

    2013-01-01

    Whispering-gallery-mode resonators have been extensively used in conjunction with different materials for the development of a variety of photonic devices. Among the latter, hybrid structures, consisting of dielectric microspheres and colloidal core/shell semiconductor nanocrystals as gain media, have attracted interest for the development of microlasers and studies of cavity quantum electrodynamic effects. Here we demonstrate single-exciton, single-mode, spectrally tuned lasing from ensembles of optical antenna-designed, colloidal core/shell CdSe/CdS quantum rods deposited on silica microspheres. We obtain single-exciton emission by capitalizing on the band structure of the specific core/shell architecture that strongly localizes holes in the core, and the two-dimensional quantum confinement of electrons across the elongated shell. This creates a type-II conduction band alignment driven by coulombic repulsion that eliminates non-radiative multi-exciton Auger recombination processes, thereby inducing a large exciton-bi-exciton energy shift. Their ultra-low thresholds and single-mode, single-exciton emission make these hybrid lasers appealing for various applications, including quantum information processing.

  10. Systematics of pion emission in heavy ion collisions in the 1A GeV regime

    CERN Document Server

    Reisdorf, W; Barret, V; Basrak, Z; Bastid, N; Benabderrahmane, M L; Caplar, R; Crochet, P; Dupieux, P; Dzelalija, M; Fodor, Z; Grishkin, Y; Hartmann, O N; Herrmann, N; Hildenbrand, K D; Hong, B; Kang, T I; Kecskeméti, J; Kim, Y J; Kirejczyk, M; Kis, M; Koczón, P; Korolija, M; Kotte, R; Kress, T; Lebedev, A; Leifels, Y; López, X; Matulewicz, T; Merschmeyer, M; Neubert, W; Petrovici, M; Rami, F; Ryu, M S; Schüttauf, A; Seres, Z; Sikora, B; Sim, K S; Simion, V; Siwek-Wilczynska, K; Smolyankin, V; Stockmeier, M R; Stoicea, G; Tyminski, Z; Wisniewski, K; Wohlfarth, D; Xiao, Z G; Xu, H S; Yushmanov, I; Zhilin, A; al, et

    2006-01-01

    Using the large acceptance apparatus FOPI, we study pion emission in the reactions (energies in GeV/nucleon are given in parentheses): 40Ca+40Ca (0.4, 0.6, 0.8, 1.0, 1.5, 1.93), 96Ru+96Ru (0.4, 1.0, 1.5), 96Zr+96Zr (0.4, 1.0, 1.5), 197Au+197Au (0.4, 0.6, 0.8, 1.0, 1.2, 1.5). The observables include longitudinal and transverse rapidity distributions and stopping, polar anisotropies, pion multiplicities, transverse momentum spectra, ratios for positively and negatively charged pions of average transverse momenta and of yields, directed flow, elliptic flow. The data are compared to earlier data where possible and to transport model simulations.

  11. On new non-modal hydrodynamic stability modes and resulting non-exponential growth rates - a Lie symmetry approach

    Science.gov (United States)

    Oberlack, Martin; Nold, Andreas; Sanjon, Cedric Wilfried; Wang, Yongqi; Hau, Jan

    2016-11-01

    Classical hydrodynamic stability theory for laminar shear flows, no matter if considering long-term stability or transient growth, is based on the normal-mode ansatz, or, in other words, on an exponential function in space (stream-wise direction) and time. Recently, it became clear that the normal mode ansatz and the resulting Orr-Sommerfeld equation is based on essentially three fundamental symmetries of the linearized Euler and Navier-Stokes equations: translation in space and time and scaling of the dependent variable. Further, Kelvin-mode of linear shear flows seemed to be an exception in this context as it admits a fourth symmetry resulting in the classical Kelvin mode which is rather different from normal-mode. However, very recently it was discovered that most of the classical canonical shear flows such as linear shear, Couette, plane and round Poiseuille, Taylor-Couette, Lamb-Ossen vortex or asymptotic suction boundary layer admit more symmetries. This, in turn, led to new problem specific non-modal ansatz functions. In contrast to the exponential growth rate in time of the modal-ansatz, the new non-modal ansatz functions usually lead to an algebraic growth or decay rate, while for the asymptotic suction boundary layer a double-exponential growth or decay is observed.

  12. High-energy side-peak emission of exciton-polariton condensates in high density regime.

    Science.gov (United States)

    Horikiri, Tomoyuki; Yamaguchi, Makoto; Kamide, Kenji; Matsuo, Yasuhiro; Byrnes, Tim; Ishida, Natsuko; Löffler, Andreas; Höfling, Sven; Shikano, Yutaka; Ogawa, Tetsuo; Forchel, Alfred; Yamamoto, Yoshihisa

    2016-05-19

    In a standard semiconductor laser, electrons and holes recombine via stimulated emission to emit coherent light, in a process that is far from thermal equilibrium. Exciton-polariton condensates-sharing the same basic device structure as a semiconductor laser, consisting of quantum wells coupled to a microcavity-have been investigated primarily at densities far below the Mott density for signatures of Bose-Einstein condensation. At high densities approaching the Mott density, exciton-polariton condensates are generally thought to revert to a standard semiconductor laser, with the loss of strong coupling. Here, we report the observation of a photoluminescence sideband at high densities that cannot be accounted for by conventional semiconductor lasing. This also differs from an upper-polariton peak by the observation of the excitation power dependence in the peak-energy separation. Our interpretation as a persistent coherent electron-hole-photon coupling captures several features of this sideband, although a complete understanding of the experimental data is lacking. A full understanding of the observations should lead to a development in non-equilibrium many-body physics.

  13. Using Poisson statistics to analyze supernova remnant emission in the low counts X-ray regime

    Science.gov (United States)

    Roper, Quentin Jeffrey

    We utilize a Poisson likelihood in a maximum likelihood statistical analysis to analyze X-ray spectragraphic data. Specifically, we examine four extragalactic supernova remnants (SNR). IKT 5 (SNR 0047-73.5), IKT 25 (SNR 0104-72.3), and DEM S 128 (SNR 0103-72.4) which are designated as Type Ia in the literature due to their spectra and morphology. This is troublesome because of their asymmetry, a trait not usually associated with young Type Ia remnants. We present Chandra X-ray Observatory data on these three remnants, and perform a maximum likelihood analysis on their spectra. We find that the X-ray emission is dominated by interactions with the interstellar medium. In spite of this, we find a significant Fe overabundance in all three remnants. Through examination of radio, optical, and infrared data, we conclude that these three remnants are likely not "classical" Type Ia SNR, but may be examples of so-called "prompt" Type Ia SNR. We detect potential point sources that may be members of the progenitor systems of both DEM S 128 and IKT 5, which could suggest a new subclass of prompt Type Ia SNR, Fe-rich CC remnants. In addition, we examine IKT 18. This remnant is positionally coincident with the X-ray point source HD 5980. Due to an outburst in 1994, in which its brightness changed by 3 magnitudes (corrsponding to an increase in luminosity by a factor of 16) HD 5980 was classified as a luminous blue variable star. We examine this point source and the remnant IKT 18 in the X-ray, and find that its non-thermal photon index has decreased from 2002 to 2013, corresponding to a larger proportion of more energetic X-rays, which is unexpected.

  14. Emission Certificate Trade and Costs under Regional Burden-Sharing Regimes for a 2˚C Climate Change Control Target

    NARCIS (Netherlands)

    T. Kober; B.C.C. van der Zwaan; H. Rösler

    2014-01-01

    In this article we explore regional burden-sharing regimes for the allocation of greenhouse gas emission reduction obligations needed to reach a 2°C long-term global climate change control target by performing an integrated energy-economy-climate assessment with the bottom-up TIAM-ECN model. Our mai

  15. Breakdown of a space charge limited regime of a sheath in a weakly collisional plasma bounded by walls with secondary electron emission.

    Science.gov (United States)

    Sydorenko, D; Kaganovich, I; Raitses, Y; Smolyakov, A

    2009-10-02

    A new regime of plasma-wall interaction is identified in particle-in-cell simulations of a hot plasma bounded by walls with secondary electron emission. Such a plasma has a strongly non-Maxwellian electron velocity distribution function and consists of bulk plasma electrons and beams of secondary electrons. In the new regime, the plasma sheath is not in a steady space charge limited state even though the secondary electron emission produced by the plasma bulk electrons is so intense that the corresponding partial emission coefficient exceeds unity. Instead, the plasma-sheath system performs relaxation oscillations by switching quasiperiodically between the space charge limited and non-space-charge limited states.

  16. The long, slow birth of a U.S. emissions trading regime. Recent developments in U.S. climate policy

    Energy Technology Data Exchange (ETDEWEB)

    Freestone, D.; Frenkil, D.J. [George Washington University Law School, Washington D.C. (United States)

    2010-11-15

    On Friday, 23 April 2010, the leadership of the 11th Congress and the Obama Administration were poised to capitalise on recent, unparalleled progress in furtherance of U.S. climate policy. Over the past year, the U.S. House of Representatives passed the first climate bill in United States history, and the Obama Administration quickly initiated the regulation of greenhouse gas ('GHG') emissions, primarily through the U.S. Environmental Protection Agency ('EPA') after years of neglect by the Bush Administration. Just two days were left to go until Monday, 26 April 2010, when CEOs from leading energy, financial and manufacturing corporations were scheduled to join senators from both sides of the aisle to introduce the missing link in a federal 'cap-and-trade' scheme: a climate bill that was 'filibusterproof' in the Senate - i.e. capable of gaining the necessary 60 votes out of the 100 members of the U.S. Senate to pass a procedural motion on the bill that effectively cuts off debate and brings the bill to a vote. The bill was the product of nearly a year of deal-making and compromise between leaders from both parties, which seldom occurs these days on Capital Hill. One of the pivotal aspects of that compromise was that Senate democrats were willing to accept the demand of Republicans to include a provision in the bill that would expand offshore oil drilling. However, in the midst of a turbulent political environment (a controversial immigration bill and the Deepwater Horizon drilling disaster), coupled with an economic downturn, climate policy had to take a backseat on the national agenda to issues like unemployment and the wars in Iraq and Afghanistan in the final months leading up to the November 2, 2010 'mid-term' elections. However slow the momentum of a GHG emission-reducing regime in the United States prior to the 2010 elections, the process came to a crashing halt when American voters handed the U.S. House of

  17. N2O emissions from a cultivated Andisol after application of nitrogen fertilizers with or without nitrification inhibitor under soil moisture regime

    Institute of Scientific and Technical Information of China (English)

    FAN Xiao-hui; Haruo Tsuruta

    2004-01-01

    The aim of this work was to examine the emission of N2O from soils following addition of nitrogen fertilizer with a nitrification inhibitor(+inh) or without the nitrification inhibitor(-inh) at different soil water regime. Higher soil moisture contents increased the total N2O emissions in all treatments with total emissions being 7 times larger for the CK and >20 times larger for the fertilizer treatments at 85% WFPS(soil water filled pore space ) than at 40% WFPS. The rates of N2O emissions at 40% WFPS under all treatments were small. The maximum emission rate at 55% WFPS without the nitrification inhibitor(-inh) occurred later (day 11) than those of 70% WFPS (-inh) samples (day 8). The inhibition period was 4-22 d for 55% WFPS and 1-15 d for 70% WFPS comparing the rates of N2O emissions treated (+inh) with (-inh). The maximum emission rates at 85% WFPS were higher than those at the other levels of soil water content for all treatments. The samples(+inh) released less N2O than (-inh) samples at the early stage. Nevertheless, N2O emissions from (+inh) samples lasted longer than in the (-inh) treatment. Changes in mineral N at 55%, 70% and 85% WFPS followed the same pattern. NH4-N concentrations decreased while NO3-N concentrations increased from the beginning of incubation. NH4-N concentrations from 40% WFPS treatment declined more slowly than those of the other three levels of soil water content. Nitrification was faster in the (-inh) samples with 100% NH4-N nitrified after 22 d(50% WFPS ) and 15 d(70% and 85% WFPS). N2O emissions increased with soil water content. Adding N-fertilizer increased emissions of N2O. The application of the nitrification inhibitor significantly reduced total N2O emissions from 30.5%(at 85%WFPS) to 43.6%(at 55% WFPS).

  18. N2:O emissions from a cultivated Andisol after application of nitrogen fertilizers with or without nitrification inhibitor under soil moisture regime.

    Science.gov (United States)

    Fan, Xiao-Hui; Haruo, Tsuruta

    2004-01-01

    The aim of this work was to examine the emission of N2O from soils following addition of nitrogen fertilizer with a nitrification inhibitor (+inh) or without the nitrification inhibitor(-inh) at different soil water regime. Higher soil moisture contents increased the total N2O emissions in all treatments with total emissions being 7 times larger for the CK and > 20 times larger for the fertilizer treatments at 85% WFPS (soil water filled pore space) than at 40% WFPS. The rates of N2O emissions at 40% WFPS under all treatments were small. The maximum emission rate at 55% WFPS without the nitrification inhibitor (-inh) occurred later (day 11) than those of 70% WFPS (-inh) samples (day 8). The inhibition period was 4-22 d for 55% WFPS and 1-15 d for 70% WFPS comparing the rates of N2O emissions treated (+inh) with (-inh). The maximum emission rates at 85% WFPS were higher than those at the other levels of soil water content for all treatments. The samples (+inh) released less N2O than (-inh) samples at the early stage. Nevertheless, N2O emissions from (+inh) samples lasted longer than in the (-inh) treatment. Changes in mineral N at 55%, 70% and 85% WFPS followed the same pattern. NH4(+) -N concentrations decreased while NO3(-) -N concentrations increased from the beginning of incubation. NH4(+) -N concentrations from 40% WFPS treatment declined more slowly than those of the other three levels of soil water content. Nitrification was faster in the (-inh) samples with 100% NH4(+) -N nitrified after 22 d (50% WFPS) and 15 d (70% and 85% WFPS). N2O emissions increased with soil water content. Adding N-fertilizer increased emissions of N2O. The application of the nitrification inhibitor significantly reduced total N2O emissions from 30.5% (at 85% WFPS) to 43.6% (at 55% WFPS).

  19. Emissions and removals from land-use, land use change and forestry activities in a post-Kyoto regime - quantitative analysis of a framework for reducing deforestation; Beruecksichtigung von Treibhausgasemissionen und -festlegungen durch Landnutzungsmassnahmen (LULUCF) im Post-Kioto-Regime - quantitative Analyse zur Einbeziehung von reduzierter Entwaldung in ein kuenftiges Klimaregime

    Energy Technology Data Exchange (ETDEWEB)

    Herold, Anke; Scheffler, Margarethe [Oeko-Institut e.V., Freiburg (Germany); Cunha Zeri, Gisleine; Dietz, Johannes; Freibauer, Annette; Huettner, Michael; Mollicone, Danilo [Max-Planck Institut fuer Biogeochemie, Jena (Germany); Jung, Martina [ECOFYS GmbH, Koeln (Germany)

    2008-11-15

    Some developing countries (Papua New Guinea, Costa Rica and others) proposed to include emission reductions from reduced deforestation in a post-2012 climate regime. This proposal has gained broad support under the UNFCCC negotiations. This report aims at assessing the implications and implementation needs of a future international regime that provides compensation for reducing emissions from deforestation in developing countries. This assessment includes an analysis of data availability for deforestation and forest area changes and related losses of biomass and GHG emissions, an attempt to quantify the relationship between deforestation drivers and deforestation rates; a detailed discussion of options related to the establishment of reference emission levels and accounting issues for reducing deforestation; an approximation of the possible magnitude of credits from a RED mechanism and a discussion of approaches to implement a compensation scheme for reducing emissions in a post-2012 climate regime. (orig.)

  20. Fuel Consumption and Fire Emissions Estimates in Siberia: Impact of Vegetation Types, Meteorological Conditions, Forestry Practices and Fire Regimes

    Science.gov (United States)

    Kukavskaya, Elena; Conard, Susan; Ivanova, Galina; Buryak, Ludmila; Soja, Amber; Zhila, Sergey

    2015-04-01

    Boreal forests play a crucial role in carbon budgets with Siberian carbon fluxes and pools making a major contribution to the regional and global carbon cycle. Wildfire is the main ecological disturbance in Siberia that leads to changes in forest species composition and structure and in carbon storage, as well as direct emissions of greenhouse gases and aerosols to the atmosphere. At present, the global scientific community is highly interested in quantitative and accurate estimates of fire emissions. Little research on wildland fuel consumption and carbon emission estimates has been carried out in Russia until recently. From 2000 to 2007 we conducted a series of experimental fires of varying fireline intensity in light-coniferous forest of central Siberia to obtain quantitative and qualitative data on fire behavior and carbon emissions due to fires of known behavior. From 2009 to 2013 we examined a number of burned logged areas to assess the potential impact of forest practices on fire emissions. In 2013-2014 burned areas in dark-coniferous and deciduous forests were examined to determine fuel consumption and carbon emissions. We have combined and analyzed the scarce data available in the literature with data obtained in the course of our long-term research to determine the impact of various factors on fuel consumption and to develop models of carbon emissions for different ecosystems of Siberia. Carbon emissions varied drastically (from 0.5 to 40.9 tC/ha) as a function of vegetation type, weather conditions, anthropogenic effects and fire behavior characteristics and periodicity. Our study provides a basis for better understanding of the feedbacks between wildland fire emissions and changing anthropogenic disturbance patterns and climate. The data obtained could be used by air quality agencies to calculate local emissions and by managers to develop strategies to mitigate negative smoke impacts on the environmentand human health.

  1. Biogenic NO emissions from savanna soils as a function of fire regime, soil type, soil nitrogen, and water status

    Science.gov (United States)

    Parsons, Dirk A. B.; Scholes, Mary C.; Scholes, Robert J.; Levine, Joel S.

    1996-10-01

    A study of NOx emissions from soils representative of nutrient-poor and nutrient-rich savannas and their response to burning and soil water content was carried out in the southern Kruger National Park, South Africa. The study spanned the end of the dry season and the beginning of the wet season (September-December 1992). Nitrogen mineralization rates were measured using an in situ technique simultaneously with measurements of NOx emissions. NOx emissions were almost entirely as NO. The relationship between NO emission rate and soil moisture was parabolic regardless of soil type and management practice, with the lowest NO emission rates being measured at low (0.542) water-filled pore space values. The initial increase in NO emission rates with increasing soil moisture are paralleled by increases in the nitrate concentration in the soil. The highest NO emission rates (20 ng N-NO m-2 s-1—excluding the brief initial peak) were measured on plots from which fire had been excluded for 35 years. The next highest rates (8 ng N-NO m-2 s-1) were measured on the more fertile soils. Infertile soils, burned every second year, had rates of 3.5 ng N-NO m-2 s-1. The NO emission rates show a positive correlation with soil total N content and N nitrification rate. The effect of excluding fire from a savanna is to increase the soil nitrogen content through increased litter inputs, which in turn increases nitrification rates and soil NO emissions.

  2. Post-2012 climate regime. How industrial and developing nations can help to reduce emissions - assessing emission trends, reduction potentials, incentive systems and negotiation options

    Energy Technology Data Exchange (ETDEWEB)

    Duscha, Vicki; Graichen, Jakob; Healy, Sean; Schleich, Joachim; Schumacher, Katja [Oeko-Institut e.V., Berlin (Germany); Fraunhofer-Institut fuer System- und Innovationsforschung (ISI), Karlsruhe (Germany)

    2010-06-15

    This report analyses the emissions reduction targets submitted under the Copenhagen Accord by developed and developing countries in matters of four key questions: - Do the pledges add up to the emission reductions required necessary by science? - What are the costs associated with meeting the given targets? - Are the proposed emission reduction efforts of Annex I parties comparable? - What would comparable efforts look like taking country-specific socio-economic indicators into account? Secondary to these questions this report explores the economic and environmental implications of the submitted pledges and NAMAs. Furthermore, we analyze and assess the comparability of efforts of Annex I mitigation pledges compared to a range of socio-economic indicators that may provide a basis for a ''fair'' effort sharing agreement to achieve a given target. (orig.)

  3. Auroral radio emission from late L and T dwarfs: A new constraint on dynamo theory in the substellar regime

    CERN Document Server

    Kao, Melodie M; Pineda, J Sebastian; Escala, Ivanna; Burgasser, Adam; Bourke, Stephen; Stevenson, David

    2015-01-01

    We have observed 6 late-L and T dwarfs with the Karl G. Jansky Very Large Array (VLA) to investigate the presence of highly circularly polarized radio emission, associated with large-scale auroral currents. Previous surveys encompassing ~60 L6 or later targets in this spectral range have yielded only one detection. Our sample includes the previously detected T6.5 dwarf 2MASS 10475385+2124234 as well as 5 new targets selected for the presence of H-alpha emission or optical/infrared photometric variability, which are possible manifestations of auroral activity. We detect 2MASS 10475385+2124234, as well as 4 of the 5 targets in our biased sample, including the strong IR variable SIMP J01365662+0933473 and bright H-alpha emitter 2MASS 12373919+6526148, reinforcing the possibility that activity at these disparate wavelengths is related. The radio emission frequency corresponds to a precise determination of the lower-bound magnetic field strength near the surface of each dwarf and this new sample provides robust co...

  4. Aerosol and NOx emission factors and submicron particle number size distributions in two road tunnels with different traffic regimes

    Directory of Open Access Journals (Sweden)

    D. Imhof

    2006-01-01

    Full Text Available Measurements of aerosol particle number size distributions (18–700 nm, mass concentrations (PM2.5 and PM10 and NOx were performed in the Plabutsch tunnel, Austria, and in the Kingsway tunnel, United Kingdom. These two tunnels show different characteristics regarding the roadway gradient, the composition of the vehicle fleet and the traffic frequency. The submicron particle size distributions contained a soot mode in the diameter range D=80–100 nm and a nucleation mode in the range of D=20–40 nm. In the Kingsway tunnel with a significantly lower particle number and volume concentration level than in the Plabutsch tunnel, a clear diurnal variation of nucleation and soot mode particles correlated to the traffic density was observed. In the Plabutsch tunnel, soot mode particles also revealed a diurnal variation, whereas no substantial variation was found for the nucleation mode particles. During the night a higher number concentration of nucleation mode particles were measured than soot mode particles and vice versa during the day. In this tunnel with very high soot emissions during daytime due to the heavy-duty vehicle (HDV share of 18% and another 40% of diesel driven light-duty vehicles (LDV semivolatile species condense on the pre-existing soot surface area rather than forming new particles by homogeneous nucleation. With the low concentration of soot mode particles in the Kingsway tunnel, also the nucleation mode particles exhibit a diurnal variation. From the measured parameters real-world traffic emission factors were estimated for the whole vehicle fleet as well as differentiated into the two categories LDV and HDV. In the particle size range D=18–700 nm, each vehicle of the mixed fleet emits (1.50±0.08×1014 particles km-1 (Plabutsch and (1.26±0.10×1014 particles km-1 (Kingsway, while particle volume emission factors of 0.209±0.008 cm3 km-1 and 0.036±0.004 cm3 km-1, respectively, were obtained. PM1 emission factors of 104±4 mg

  5. Theory of quasi-elastic secondary emission from a quantum dot in the regime of vibrational resonance.

    Science.gov (United States)

    Rukhlenko, Ivan D; Fedorov, Anatoly V; Baymuratov, Anvar S; Premaratne, Malin

    2011-08-01

    We develop a low-temperature theory of quasi-elastic secondary emission from a semiconductor quantum dot, the electronic subsystem of which is resonant with the confined longitudinal-optical (LO) phonon modes. Our theory employs a generalized model for renormalization of the quantum dot's energy spectrum, which is induced by the polar electron-phonon interaction. The model takes into account the degeneration of electronic states and allows for several LO-phonon modes to be involved in the vibrational resonance. We give solutions to three fundamental problems of energy-spectrum renormalization--arising if one, two, or three LO-phonon modes resonantly couple a pair of electronic states--and discuss the most general problem of this kind that admits an analytical solution. With these results, we solve the generalized master equation for the reduced density matrix, in order to derive an expression for the differential cross section of secondary emission from a single quantum dot. The obtained expression is then analyzed to establish the basics of optical spectroscopy for measuring fundamental parameters of the quantum dot's polaron-like states.

  6. Influence of ion effects on a space charge limited field emission flow: from non-relativistic to ultra-relativistic regimes

    Science.gov (United States)

    Lin, M. C.; Chang, P. C.; Lu, P. S.; Verboncoeur, J. P.

    2011-10-01

    Influence of ion effects on a space charge limited field emission flow has been studied systematically, by employing both analytical and numerical approaches. In our model, the field emission of electrons is described by the Fowler-Nordheim equation. The cathode plasma and surface properties are considered within the framework of an effective work function approximation. Ionization effects at the anode as well as electron space-charge effects are described by Poisson's equation coupled with the energy conservation equation including the relativistic effects. The calculations are carried out self-consistently to yield the steady states of the bipolar flow. The electric field on the cathode surface is found to be saturated due to space charge effects and is determined by the effective work function approximately. In addition, the upstream ion current bas been treated as a tuning parameter. It is found that the field emission currents in the presence of saturated ion currents can be enhanced to be nearly 1.8, 1.5, and 1.4 times of the cases with no upstream ion current in non-relativistic, intermediate, and ultra-relativistic regimes, respectively. The solutions have also been verified using 1D PIC simulations, as implemented in the OOPD1 code developed by PTSG of UC Berkeley. Work supported by the National Science Council, Taiwan, R.O.C. under Grant No. NSC 96-2112-M-030-004-MY3, National Center for Theoretical Sciences, and National Center for High-Performance Computing, Taiwan, ROC which provides the computing resources.

  7. Study of electronic field emission from large surfaces under static operating conditions and hyper-frequency; Etude de l'emision electronique par effet de champ sur des surfaces larges en regime statique et hyperfrequence

    Energy Technology Data Exchange (ETDEWEB)

    Luong, M

    1997-09-01

    The enhanced electronic field emission from large area metallic surfaces lowers performances of industrial devices that have to sustain high electric field under vacuum. Despite of numerous investigations in the past, the mechanisms of such an emission have never been well clarified. Recently, research in our laboratory has pointed out the importance played by conducting sites (particles and protrusions). A refined geometrical model, called superposed protrusions model has been proposed to explain the enhanced emission by local field enhancement. As a logical continuation, the present work aims at testing this model and, in the same time, investigating the means to suppress the emission where it is undesirable. Thus, we have showed: the cause of current fluctuations in a continuous field regime (DC), the identity of emission characteristics ({beta}, A{sub e}) in both radiofrequency (RF) and DC regimes, the effectiveness of a thermal treatment by extern high density electronic bombardment, the effectiveness of a mechanical treatment by high pressure rinsing with ultra pure water, the mechanisms and limits of an in situ RF processing. Furthermore, the electronic emission from insulating particles has also been studied concurrently with a spectral analysis of the associated luminous emission. Finally, the refined geometrical model for conducting sites is reinforced while another model is proposed for some insulating sites. Several emission suppressing treatments has been explored and validated. At last, the characteristic of a RF pulsed field emitted electron beam has been checked for the first time as a possible application of such a field emission. (author)

  8. Macroeconomic regimes

    NARCIS (Netherlands)

    Baele, L.T.M.; Bekaert, G.R.J.; Cho, S.; Inghelbrecht, K.; Moreno, A.

    2015-01-01

    A New-Keynesian macro-model is estimated accommodating regime-switching behavior in monetary policy and macro-shocks. A key to our estimation strategy is the use of survey-based expectations for inflation and output. Output and inflation shocks shift to the low volatility regime around 1985 and 1990

  9. Influence of the ion synthesis and ion doping regimes on the effect of sensitization of erbium emission by silicon nanoclusters in silicon dioxide films

    Science.gov (United States)

    Korolev, D. S.; Kostyuk, A. B.; Belov, A. I.; Mikhaylov, A. N.; Dudin, Yu. A.; Bobrov, A. I.; Malekhonova, N. V.; Pavlov, D. A.; Tetelbaum, D. I.

    2013-11-01

    The photoluminescence spectra of erbium centers in SiO2 films with ion-synthesized silicon nanoclusters under nonresonant excitation were investigated. Erbium was introduced into thermal SiO2 films by ion implantation. The dependences of photoluminescence intensity on the dose, the order of ion implantation of Si and Er, the annealing temperature, and additional Ar+ and P+ ion irradiation regimes, i.e., factors determining the influence of radiation damage and doping on sensitization of erbium luminescence by silicon nanoclusters, were determined. It was found that the sensitization effect and its amplification due to doping with phosphorus are most pronounced under the conditions where nanoclusters are amorphous. The quenching of photoluminescence due to radiation damage in this case manifests itself to a lesser extent than for crystalline nanoclusters. The role of various factors in the observed regularities was discussed in the framework of the existing concepts of the mechanisms of light emission and energy exchange in the system of silicon nanoclusters and erbium centers.

  10. Post2012 climate regime options for global GHG emission reduction. Analysis and evaluation of regime options and reduction potential for achieving the 2 degree target with respect to environmental effectiveness, costs and institutional aspects

    Energy Technology Data Exchange (ETDEWEB)

    Schumacher, Katja; Graichen, Jakob; Healy, Sean [Oeko-Institut, Inst. fuer Angewandte Oekologie e.V., Freiburg im Breisgau (Germany); Schleich, Joachim; Duscha, Vicki [Fraunhofer-Institut fuer Systemtechnik und Innovationsforschung (ISI), Karlsruhe (Germany)

    2011-08-15

    This report explores the environmental and economic effects of the pledges submitted by industrialized and major developing countries for 2020 under the Copenhagen Accord and provides an in-depth comparison with results arrived at in other model analyses. Two scenarios reflect the lower (''weak'') and upper (''ambitious'') bounds of the Copenhagen pledges. In addition, two scenarios in accordance with the IPCC range for reaching a 2 C target are analyzed with industrialized countries in aggregate reducing their CO2 emissions by 30 % in 2020 compared to 1990 levels. For all four policy scenarios the effects of emission paths leading to a global reduction target of 50 % below 1990 levels in 2050 are also simulated for 2030. In addition, a separate scenario is carried out which estimates the costs of an unconditioned EU 30 % emission reduction target, i.e. where the EU adopts a 30 % emission reduction target in 2020 (rather than a 20 % reduction target), while all other countries stick with their ''weak'' pledges. Not included in the calculations is possible financial support for developing countries from industrialized countries as currently discussed in the climate change negotiations and laid out in the Copenhagen Accord. (orig.)

  11. Regimes internacionais

    OpenAIRE

    Meireles, André Bezerra

    2004-01-01

    Dissertação (mestraddo) - Universidade Federal de Santa Catarina, Centro de Ciências Jurídicas. Programa de Pós-Graduação em Direito. Qual o papel dos regimes internacionais com relação ao comportamento dos agentes das relações internacionais contemporâneas, em especial, o Estado? Dentro das negociações de uma esfera internacional caracterizada por uma forte interdependência econômica, verificada a existência de múltiplos canais de conexões entre as sociedades, e uma tendência contínua p...

  12. Effect of aeration regime on N₂O emission from partial nitritation-anammox in a full-scale granular sludge reactor.

    Science.gov (United States)

    Castro-Barros, C M; Daelman, M R J; Mampaey, K E; van Loosdrecht, M C M; Volcke, E I P

    2015-01-01

    N₂O emission from wastewater treatment plants is high of concern due to the strong environmental impact of this greenhouse gas. Good understanding of the factors affecting the emission and formation of this gas is crucial to minimize its impact. This study addressed the investigation of the N₂O emission dynamics in a full-scale one-stage granular sludge reactor performing partial nitritation-anammox (PNA) operated at a N-loading of 1.75 kg NH₄⁺-N m⁻³ d⁻¹. A monitoring campaign was conducted, gathering on-line data of the N₂O concentration in the off-gas of the reactor as well as of the ammonium and nitrite concentrations in the liquid phase. The N₂O formation rate and the liquid N₂O concentration profile were calculated from the gas phase measurements. The mean (gaseous) N₂O-N emission obtained was 2.0% of the total incoming nitrogen during normal reactor operation. During normal operation of the reactor under variable aeration rate, intense aeration resulted in higher N₂O emission and formation than during low aeration periods (mean N₂O formation rate of 0.050 kg N m⁻³ d⁻¹ for high aeration and 0.029 kg N m⁻³ d⁻¹ for low aeration). Accumulation of N₂O in the liquid phase was detected during low aeration periods and was accompanied by a relatively lower ammonium conversion rate, while N₂O stripping was observed once the aeration was increased. During a dedicated experiment, gas recirculation without fresh air addition into the reactor led to the consumption of N₂O, while accumulation of N₂O was not detected. The transition from a prolonged period without fresh air addition and with little recirculation to enhanced aeration with fresh air addition resulted in the highest N₂O formation (0.064 kg N m⁻³ d⁻¹). The results indicate that adequate aeration control may be used to minimize N₂O emissions from PNA reactors.

  13. Modification and control of coherence effects in the spontaneous emission spectrum of a three-level atom at weak field regime

    Science.gov (United States)

    Dutta, Bibhas Kumar; Panchadhyayee, Pradipta

    2016-09-01

    It has been shown that coherence effects have a marked influence in the spontaneous emission spectrum of a three-level Λ -type atom driven by weak coherent and incoherent fields. Phase dependent evolution of interference effects leading to spectral narrowing, generation of spectral hole and dark line are exhibited in the present scheme when the atom does not interact with the incoherent fields. The basic mechanism underlying this scheme seems to be appropriate for a phaseonium. Apart from phase-coherence introduced in the system the phenomenon of line narrowing, in the presence of weak incoherent pumping, can be achieved in a different way as a consequence of two competitive resonant effects: sharp non-Lorentzian and symmetric Fano-like-resonance contributions to the line shape. In both the situations, the evolution of narrow structures in the line shape can be achieved even when the emission is influenced by the dephasing of Raman coherence.

  14. Wavefront analysis of nonlinear self-amplified spontaneous-emission free-electron laser harmonics in the single-shot regime.

    Science.gov (United States)

    Bachelard, R; Mercère, P; Idir, M; Couprie, M-E; Labat, M; Chubar, O; Lambert, G; Zeitoun, Ph; Kimura, H; Ohashi, H; Higashiya, A; Yabashi, M; Nagasono, M; Hara, T; Ishikawa, T

    2011-06-10

    The single-shot spatial characteristics of the vacuum ultraviolet self-amplified spontaneous emission of a free electron laser (FEL) is measured at different stages of amplification up to saturation with a Hartmann wavefront sensor. We show that the fundamental radiation at 61.5 nm tends towards a single-mode behavior as getting closer to saturation. The measurements are found in good agreement with simulations and theory. A near diffraction limited wavefront was measured. The analysis of Fresnel diffraction through the Hartmann wavefront sensor hole array also provides some further insight for the evaluation of the FEL transverse coherence, of high importance for various applications.

  15. Wavefront Analysis of Nonlinear Self-Amplified Spontaneous-Emission Free-Electron Laser Harmonics in the Single-Shot Regime

    Energy Technology Data Exchange (ETDEWEB)

    Bachelard, R.; Chubar, O.; Mercere, P.; Idir, M.; Couprie, M.E.; Lambert, G.; Zeitoun, Ph.; Kimura, H.; Ohashi, H.; Higashiya, A.; Yabashi, M.; Nagasono, M.; Hara, T. and Ishikawa, T.

    2011-06-08

    The single-shot spatial characteristics of the vacuum ultraviolet self-amplified spontaneous emission of a free electron laser (FEL) is measured at different stages of amplification up to saturation with a Hartmann wavefront sensor. We show that the fundamental radiation at 61.5 nm tends towards a single-mode behavior as getting closer to saturation. The measurements are found in good agreement with simulations and theory. A near diffraction limited wavefront was measured. The analysis of Fresnel diffraction through the Hartmann wavefront sensor hole array also provides some further insight for the evaluation of the FEL transverse coherence, of high importance for various applications.

  16. Non-Mode Clustering of Categorical Data with Attributes Weighting%属性加权的类属型数据非模聚类

    Institute of Scientific and Technical Information of China (English)

    陈黎飞; 郭躬德

    2013-01-01

    While categorical data are widely used in many applications such as Bioinformatics, clustering categorical data is a difficult task in the filed of statistical machine learning due to the characteristic of the data which can only take discrete values. Typically, the mainstream methods are dependent on the mode of the categorical attributes in order to optimize the clusters and weight the relevant attributes. A non-mode approach is proposed for statistically clustering of categorical data in this paper. First, based on a newly defined dissimilarity measure, an objective function with attributes weighting is derived for categorical data clustering. The objective function is defined based on the average distance between the objects and the clusters, therefore overcomes the problems in the existing methods based on the mode category. Then, a soft-subspace clustering algorithm is proposed for clustering categorical data. In this algorithm, each attribute is assigned with weights measuring its degree of relevance to the clusters in terms of the overall distribution of categories instead of the mode category, enabling automatic feature selection during the clustering process. Experimental results carried out on some synthetic datasets and real-world datasets demonstrate that the proposed method significantly improves clustering quality.%类属型数据广泛分布于生物信息学等许多应用领域,其离散取值的特点使得类属数据聚类成为统计机器学习领域一项困难的任务。当前的主流方法依赖于类属属性的模进行聚类优化和相关属性的权重计算。提出一种非模的类属型数据统计聚类方法。首先,基于新定义的相异度度量,推导了属性加权的类属数据聚类目标函数。该函数以对象与簇之间的平均距离为基础,从而避免了现有方法以模为中心导致的问题。其次,定义了一种类属型数据的软子空间聚类算法。该算法在聚类过程中根

  17. Laboratory and modeling studies on the effects of water and soot emissions and ambient conditions on the formation of contrail ice particles in the jet regime

    Science.gov (United States)

    Wong, H.-W.; Beyersdorf, A. J.; Heath, C. M.; Ziemba, L. D.; Winstead, E. L.; Thornhill, K. L.; Tacina, K. M.; Ross, R. C.; Albo, S. E.; Bulzan, D. L.; Anderson, B. E.; Miake-Lye, R. C.

    2011-09-01

    Contrails and contrail-induced cirrus clouds are identified as the most uncertain components in determining aviation impacts on global climate change. Parameters affecting contrail ice particle formation immediately after engine exit plane (forcing. Despite this, detailed understanding of these parametric effects is still limited. In this paper, we present results from recent laboratory and modeling studies conducted to investigate the effects of water and soot emissions and ambient conditions on the near-field formation of contrail ice particles. The Particle Aerosol Laboratory (PAL) at the NASA Glenn Research Center and the Aerodyne microphysical parcel model for contrail ice particle formation were employed. Our studies show that exhaust water concentrations have a significant impact on contrail ice particle formation. When soot was introduced, ice particle formation was observed only when exhaust water concentration was above a critical level. When no soot or sulfuric acid was introduced, homogeneous ice particle formation was unfavorable. Soot particles were found to compete for water vapor condensation, and higher soot concentrations emitted into the chamber resulted in smaller ice particles being formed. Chamber conditions corresponding to higher altitude standard day conditions were found to favor ice particle formation as expected. The microphysical model captures experimental trends well, but discrepancies between the model and the experiments exist as the model predicts narrower ice particle size distributions and ice particle sizes nearly a factor of two larger than measured. These discrepancies are likely due to the lack of treatment of turbulent mixing in the model and particle loss and scatter during the experimental sampling process. Future measurement activities are planned to investigate other important parameters, such as soot surface properties and sulfuric acid concentrations, using the PAL and microphysical model.

  18. Soil CO2 and N2O Emissions in Maize Growing Season Under Different Fertilizer Regimes in an Upland Red Soil Region of South China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xu-bo; WU Lian-hai; SUN Nan; DING Xue-shan; LI Jian-wei; WANG Bo-ren; LI Dong-chu

    2014-01-01

    Upland red soils have been identiifed as major CO2 and N2O sources induced by human activities such as fertilization. To monitor characteristics of soil surface CO2 and N2O lfuxes in cropland ecosystems after continuous fertilizer applications over decades and to separate the respective contributions of root and heterotrophic respiration to the total soil CO2 and N2O lfuxes, the measurements of soil surface CO2 and N2O lfuxes throughout the maize growing season in 2009 were carried out based on a fertilization experiment (from 1990) through of the maize (Zea mays L.) growing season in red soil in southern China. Five fertilization treatments were chosen from the experiment for study: zero-fertilizer application (CK), nitrogen-phosphorus-potassium (NPK) fertilizer application only, pig manure (M), NPK plus pig manure (NPKM) and NPK with straw (NPKS). Six chambers were installed in each plot. Three of them are in the inter-row soil (NR) and the others are in the soil within the row (R). Each fertilizer treatment received the same amount of N (300kg ha-1 yr-1). Results showed that cumulative soil CO2 lfuxes in NR or R were both following the order: NPKS>M, NPKM>NPK>CK. The contributions of root respiration to soil CO2 lfuxes was 40, 44, 50, 47 and 35%in CK, NPK, NPKM, M and NPKS treatments, respectively, with the mean value of 43%. Cumulative soil N2O lfuxes in NR or R were both following the order: NPKS, NPKM>M>NPK>CK, and soil N2O lfuxes in R were 18, 20 and 30%higher than that in NR in NPKM, M and NPKS treatments, respectively, but with no difference between NR and R in NPK treatment. Furthermore, combine with soil temperature at -5 cm depth and soil moisture (0-20cm) together could explain 55-70% and 42-59% of soil CO2 and N2O emissions with root interference and 62-78%and 44-63% of that without root interference, respectively. In addition, soil CO2 and N2O lfuxes per unit yield in NPKM (0.55 and 0.10kg Ct-1) and M(0.65 and 0.13g Nt-1) treatments were lower than

  19. Laboratory and modeling studies on the effects of water and soot emissions and ambient conditions on the properties of contrail ice particles in the jet regime

    Directory of Open Access Journals (Sweden)

    H.-W. Wong

    2013-10-01

    Full Text Available Contrails and contrail-induced cirrus clouds are identified as the most uncertain components in determining aviation impacts on global climate change. Parameters affecting contrail ice particle formation immediately after the engine exit plane (< 5 s in plume age may be critical to ice particle properties used in large-scale models predicting contrail radiative forcing. Despite this, detailed understanding of these parametric effects is still limited. In this paper, we present results from recent laboratory and modeling studies conducted to investigate the effects of water and soot emissions and ambient conditions on near-field formation of contrail ice particles and ice particle properties. The Particle Aerosol Laboratory (PAL at the NASA Glenn Research Center and the Aerodyne microphysical parcel model for contrail ice particle formation were employed. Our studies show that exhaust water concentration has a significant impact on contrail ice particle formation and properties. When soot particles were introduced, ice particle formation was observed only when exhaust water concentration was above a critical level. When no soot or sulfuric acid was introduced, no ice particle formation was observed, suggesting that ice particle formation from homogeneous nucleation followed by homogeneous freezing of liquid water was unfavorable. Soot particles were found to compete for water vapor condensation, and higher soot concentrations emitted into the chamber resulted in smaller ice particles being formed. Chamber conditions corresponding to higher cruising altitudes were found to favor ice particle formation. The microphysical model captures trends of particle extinction measurements well, but discrepancies between the model and the optical particle counter measurements exist as the model predicts narrower ice particle size distributions and ice particle sizes nearly a factor of two larger than measured. These discrepancies are likely due to particle

  20. Sustainable urban regime adjustments

    DEFF Research Database (Denmark)

    Quitzau, Maj-Britt; Jensen, Jens Stissing; Elle, Morten

    2013-01-01

    The endogenous agency that urban governments increasingly portray by making conscious and planned efforts to adjust the regimes they operate within is currently not well captured in transition studies. There is a need to acknowledge the ambiguity of regime enactment at the urban scale. This directs...... attention to the transformative implications of conscious strategic maneuvering by incumbent regime actors, when confronting regime structurations. This article provides insight to processes of regime enactment performed by local governments by applying a flow-oriented perspective on regime dynamics...

  1. Measuring autocratic regime stability

    Directory of Open Access Journals (Sweden)

    Joseph Wright

    2016-01-01

    Full Text Available Researchers measure regime stability in autocratic contexts using a variety of data sources that capture distinct concepts. Often this research uses concepts developed for the study of democratic politics, such as leadership change or institutionalized authority, to construct measures of regime breakdown in non-democratic contexts. This article assesses whether the measure a researcher chooses influences the results they obtain by examining data on executive leadership, political authority, and autocratic regimes. We illustrate the conceptual differences between these variables by extending recent studies in the literature on the political consequences of non-tax revenue and unearned foreign income.

  2. Exchange rate regime choice

    Directory of Open Access Journals (Sweden)

    Beker Emilija

    2006-01-01

    Full Text Available The choice of an adequate exchange rate regime proves to be a highly sensitive field within which the economic authorities present and confirm themselves. The advantages and disadvantages of fixed and flexible exchange rate regimes, which have been quite relativized from the conventional point of view, together with simultaneous, but not synchronized effects of structural and external factors, remain permanently questioned throughout a complex process of exchange rate regime decision making. The paper reflects the attempt of critical identification of the key exchange rate performances with emphasis on continuous non-uniformity and (uncertainty of shelf life of a relevant choice.

  3. World Nonproliferation Regime

    Institute of Scientific and Technical Information of China (English)

    Ouyang Liping; Wu Xingzuo

    2007-01-01

    2006 witnessed an intense struggle between nuclear proliferation and nonproliferation. Iran's nuclear issue and North Korea's nuclear test have cast a deep shadow over the current international nonproliferation regime. The international contest for civil nuclear development became especially fierce as global energy prices went up. Such a situation , to some extent, accelerated the pace of nuclear proliferation. Furthermore, the existing international nonproliferation regime, based upon the Nuclear Nonproliferation Treaty (NPT), was affected by loopholes, and the U.S. failed in its ambition to unite other forces to mend fences. The international community needs to come up with a comprehensive and long-term strategy to meet the demand for an effective future nonproliferation regime in a healthy nuclear order.

  4. Regimes of justification

    NARCIS (Netherlands)

    Arts, Irma; Buijs, A.E.; Verschoor, G.M.

    2017-01-01

    Legitimacy of environmental management and policies is an important topic in environmental research. Based on the notion of ‘regimes of justification’, we aim to analyse the dynamics in argumentations used to legitimize and de-legitimize Dutch nature conservation practices. Contrary to prior

  5. Studies of optical emission in the high intensity pumping regime of top-down ZnO nanostructures and thin films grown on c-sapphire substrates by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Divay, L.; Kostcheev, S.; McMurtry, S.; Lerondel, G. [Laboratoire de Nanotechnologie et d' Instrumentation Optique, ICD CNRS (FRE2848), Universite de Technologie de Troyes, Troyes (France); Rogers, D.J.; Teherani, F.H. [Nanovation SARL, Versailles, 91400 Orsay (France); Lusson, A. [GEMaC, CNRS - Universite de Versailles Saint-Quentin en Yvelines,Meudon (France)

    2008-07-01

    We report on the emission of Zinc Oxide (ZnO) thin films obtained by Pulsed Laser Deposition (PLD) under high intensity excitation. In order to clarify the origin of the emission bands, we compared results for high quality thin films (75 nm) before and after 'top-down' nanopatterning. A nanopattering technique was developed for this purpose. The technique combined Electron Beam Lithography (EBL) and lift-off techniques and Inductively Coupled Plasma Reactive Ion Etching (ICP RIE). The emission spectra of the two types of samples were found to have a difference in their fine structure that was attributed, in part, to the existence of guided emission in the thin films and exciton weak confinement effects in the nanostructures. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  6. Regimes Of Helium Burning

    CERN Document Server

    Timmes, F X

    2000-01-01

    The burning regimes encountered by laminar deflagrations and ZND detonations propagating through helium-rich compositions in the presence of buoyancy-driven turbulence are analyzed. Particular attention is given to models of X-ray bursts which start with a thermonuclear runaway on the surface of a neutron star, and the thin shell helium instability of intermediate-mass stars. In the X-ray burst case, turbulent deflagrations propagating in the lateral or radial directions encounter a transition from the distributed regime to the flamlet regime at a density of 10^8 g cm^{-3}. In the radial direction, the purely laminar deflagration width is larger than the pressure scale height for densities smaller than 10^6 g cm^{-3}. Self-sustained laminar deflagrations travelling in the radial direction cannot exist below this density. Similarily, the planar ZND detonation width becomes larger than the pressure scale height at 10^7 g cm^{-3}, suggesting that a steady-state, self-sustained detonations cannot come into exista...

  7. East Asian welfare regime

    DEFF Research Database (Denmark)

    Abrahamson, Peter

    2017-01-01

    . Political science studies tend to conclude that the region has left the old legacies behind and are now welfare states comparable to European states including them either in the conservative type (e.g. Japan), the liberal type (e.g. Korea) or even as a tendency in the Nordic type (e.g. China), while studies......The paper asks if East Asian welfare regimes are still productivist and Confucian? And, have they developed public care policies? The literature is split on the first question but (mostly) confirmative on the second. Care has to a large, but insufficient extent, been rolled out in the region...

  8. Nonlinear double Compton scattering in the full quantum regime

    CERN Document Server

    Mackenroth, F

    2012-01-01

    A detailed analysis of the process of two photon emission by an electron scattered from a high-intensity laser pulse is presented. The calculations are performed in the framework of strong-field QED and include exactly the presence of the laser field, described as a plane wave. We investigate the full quantum regime of interaction, where photon recoil plays an essential role in the emission process, and substantially alters the emitted photon spectra as compared to those in previously-studied regimes. We provide a semiclassical explanation for such differences, based on the possibility of assigning a trajectory to the electron in the laser field before and after each quantum photon emission. Our numerical results indicate the feasibility of investigating experimentally the full quantum regime of nonlinear double Compton scattering with already available plasma-based electron accelerator and laser technology.

  9. Supply regimes in fisheries

    DEFF Research Database (Denmark)

    Nielsen, Max

    2006-01-01

    Supply in fisheries is traditionally known for its backward bending nature, owing to externalities in production. Such a supply regime, however, exist only for pure open access fisheries. Since most fisheries worldwide are neither pure open access, nor optimally managed, rather between the extremes......-economic supply model with mesh sizes is developed. It is found that in the presence of realistic management schemes, the supply curves are close to vertical in the relevant range. Also, the supply curve under open access with mesh size limitations is almost vertical in the relevant range, owing to constant...... recruitment. The implications are that the effects on supply following from e.g. trade liberalisation and reductions of subsidies are small in several and probably most fisheries worldwide. Keywords: backward-bending supply, regulated open access, regulated restricted access, mesh size regulation, Beverton...

  10. Resilience of river flow regimes.

    Science.gov (United States)

    Botter, Gianluca; Basso, Stefano; Rodriguez-Iturbe, Ignacio; Rinaldo, Andrea

    2013-08-06

    Landscape and climate alterations foreshadow global-scale shifts of river flow regimes. However, a theory that identifies the range of foreseen impacts on streamflows resulting from inhomogeneous forcings and sensitivity gradients across diverse regimes is lacking. Here, we derive a measurable index embedding climate and landscape attributes (the ratio of the mean interarrival of streamflow-producing rainfall events and the mean catchment response time) that discriminates erratic regimes with enhanced intraseasonal streamflow variability from persistent regimes endowed with regular flow patterns. Theoretical and empirical data show that erratic hydrological regimes typical of rivers with low mean discharges are resilient in that they hold a reduced sensitivity to climate fluctuations. The distinction between erratic and persistent regimes provides a robust framework for characterizing the hydrology of freshwater ecosystems and improving water management strategies in times of global change.

  11. Effects of fertilizer application regimes on soil N2O emissions in the croplands of purple soil in the Sichuan Basin during wheat season%施肥方式对冬小麦季紫色土N2O排放特征的影响

    Institute of Scientific and Technical Information of China (English)

    柳文丽; 李锡鹏; 沈茜; 朱波

    2014-01-01

    利用紫色土养分循环长期定位施肥试验平台,通过静态箱-气相色谱法,于2012年11月至2013年5月,研究了单施氮肥(N)、猪厩肥(OM)、常规氮磷钾肥(NPK)、猪厩肥配施氮磷钾肥(OMNPK)、秸秆还田配施氮磷钾肥(CRNPK)及对照不施肥(NF)6种施肥方式下,紫色土冬小麦季土壤N2O的排放特征。结果表明,在相同施氮水平[130 kg(N)·hm-2]下,施肥方式对N2O排放量有显著影响(P<0.05)。N、OM、NPK、OMNPK和CRNPK处理下,土壤N2O排放量[kg(N)·hm-2]分别为0.38、0.36、0.29、0.33和0.19, N2O排放系数分别为0.25%、0.23%、0.18%、0.21%和0.10%。NF的土壤N2O排放量为0.06 kg(N)·hm-2。土壤无机氮含量(NO3--N和NH4+-N)是N2O排放的主要影响因子,降雨能有效激发N2O排放。基于小麦产量评价不同施肥方式下的N2O排放,结果表明, N、OM、NPK、OMNPK和CRNPK单位小麦产量N2O的GWP值[yield-scaled GWP, kg(CO2 eq)·t-1]分别为132.57、45.70、49.07、48.92和26.41。CRNPK的小麦产量与6种施肥方式中获得最大产量的OM间没有显著差异,但显著高于其他处理。而且, CRNPK的yield-scaled GWP比紫色土地区冬小麦种植中常规施肥方式(NPK)显著减少46%,并显著低于其他4种施肥方式。可见,秸秆还田配施氮磷钾肥在保证小麦产量的同时,能有效减少因施肥引发的N2O排放,可作为紫色土地区推荐的最佳施肥措施。%Nitrous oxide (N2O) was undoubtedly a key element with respect to global warming and climate change. As about 60%of global anthropogenic N2O emissions have originated from agricultural soils, it has been a huge challenge to maintain high crop yields while reducing N2O emissions under the continued application of nitrogen fertilizers. Limited available field data have explored the effects of fertilizer application regimes on soil N2O emissions in the Sichuan Basin, one of the most intensive agricultural regions in China. Thus the objective of this research was

  12. Unitary Housing Regimes in Transition

    DEFF Research Database (Denmark)

    Bengtsson, Bo; Jensen, Lotte

    2013-01-01

    to the Danish and Swedish housing regimes are analysed and the responses and outcomes in terms of policy change and/or institutional continuity (path dependence) are compared. Overall, the more decentralized Danish housing regime seems to have resisted pressures for change and retrenchment better so far than...

  13. Regime shifts in resource management

    NARCIS (Netherlands)

    de Zeeuw, A.J.

    2014-01-01

    Resource management has to take account of the possibility of tipping points and regime shifts in ecological systems that provide the resources. This article focuses on the typical model of regime shifts in the ecological literature and analyzes optimal management and common-property issues when tra

  14. Examination Regimes and Student Achievement

    Science.gov (United States)

    Cosentino de Cohen, Clemencia

    2010-01-01

    Examination regimes at the end of secondary school vary greatly intra- and cross-nationally, and in recent years have undergone important reforms often geared towards increasing student achievement. This research presents a comparative analysis of the relationship between examination regimes and student achievement in the OECD. Using a micro…

  15. 'Regime shopping' across (blurring) boundaries

    NARCIS (Netherlands)

    Houwerzijl, M.S.; Evju, Stein

    2014-01-01

    This book chapter identifies and explores the (blurring) boundaries between the legal regimes for labour mobility across the EU. In the context of - what is sometimes called - 'regime shopping' a close look is taken into the law on freedom of movement within the EU. Several categories of transnation

  16. 'Regime shopping' across (blurring) boundaries

    NARCIS (Netherlands)

    Houwerzijl, M.S.; Evju, Stein

    2014-01-01

    This book chapter identifies and explores the (blurring) boundaries between the legal regimes for labour mobility across the EU. In the context of - what is sometimes called - 'regime shopping' a close look is taken into the law on freedom of movement within the EU. Several categories of

  17. The Choice of Monetary Regime

    DEFF Research Database (Denmark)

    Østrup, Finn

    , a comparisonbetween monetary regimes suggests that welfare is highest under nominalincome targeting where the nominal income target is determined to bring aboutprice stability.Keywords: Monetary regimes; fiscal policy; monetary non-neutrality.JEL classicification: E42, E61, E62.......The article examines how government spending is determined in a closedeconomy where the nominal wage is pre-set through contracts and the wage settershave perfect foresight regarding subsequent policy decisions. The monetaryregime affects government spending because: (i) with a pre-set nominal wage......, agiven change in government spending has different effects on employment andinflation under different monetary regimes, and (ii) the authorities' inclinationto expand government spending is affected by the inflation rate which dependson the monetary regime. If the costs related to inflation are high...

  18. THE ETHIOPIAN ENVIRONMENTAL REGIME VERSUS ...

    African Journals Online (AJOL)

    Haramaya Law Review ... ozone layer and climate change regimes, among others, to succeed. Id. ... international act dealing with general aspects of air pollution. ..... environmental and developmental decisions that affect their interests or the.

  19. A modelling study of photochemical regimes over Europe: robustness and variability

    Directory of Open Access Journals (Sweden)

    M. Beekmann

    2009-01-01

    Full Text Available The variability of the relative sensitivity to volatile organic compounds (VOC or NOx emissions, the chemical regime, over Europe during summers 2001 to 2003 is simulated with a regional scale transport-chemistry model. The robustness of chemical regimes is shown. A VOC sensitive regime over North-Western Europe and a mainly NOx sensitive regime over the Mediterranean basin and Eastern Europe are found, confirming earlier published results. The chemical regime time variability, its robustness to several environmental factors (seasonality, interannual variability and to model uncertainty are thoroughly analysed. The chemical regime spatial structure only slightly depends on the ozone target considered (daily ozone maximum or AOT40, SOMO35, .... Differences between particular years and summer months are weak. Day to day variability is significant but does not change the occurrence of one or another chemical regime over North-Western Europe and the Mediterranean basin. Expected decreases in anthropogenic NOx emissions over Europe since the last and for the next few decades have shifted and will shift chemical regimes to more NOx sensitive. The predictive and explanatory use of chemical regime indicator species is also investigated. For all cases but near ship tracks over the Mediterranean basin, the spatial pattern of chemical regimes appears to be robust with respect to model uncertainty.

  20. Analysis of thermionic bare tether operation regimes in passive mode

    Science.gov (United States)

    Sanmartín, J. R.; Chen, Xin; Sánchez-Arriaga, G.

    2017-01-01

    A thermionic bare tether (TBT) is a long conductor coated with a low work-function material. In drag mode, a tether segment extending from anodic end A to a zero-bias point B, with the standard Orbital-motion-limited current collection, is followed by a complex cathodic segment. In general, as bias becomes more negative in moving from B to cathodic end C, one first finds space-charge-limited (SCL) emission covering up to some intermediate point B*, then full Richardson-Dushman (RD) emission reaching from B* to end C. An approximate analytical study, which combines the current and voltage profile equations with results from asymptotic studies of the Vlasov-Poisson system for emissive probes, is carried out to determine the parameter domain covering two limit regimes, which are effectively controlled by just two dimensionless parameters involving ambient plasma and TBT material properties. In one such limit regime, no point B* is reached and thus no full RD emission develops. In an opposite regime, SCL segment BB* is too short to contribute significantly to the current balance.

  1. MULTILATERAL DIPLOMACY AND INTERNATIONAL REGIMES

    Directory of Open Access Journals (Sweden)

    BENEA Ciprian-Beniamin

    2014-12-01

    Full Text Available The history of diplomacy can by divided in three main periods: one is that of occasional diplomacy peculiar to Middle Ages, while other belong to permane diplomacy, peculiar to modern times. But this one can be divided in two parts, too: one with a bilateral character, previos to 1st World War, and one with a multilateral character, manifested especially after the end on 1st World War. This third type is the focus of present paper. And it cannot be separated from the newly international constructs: international regimes, and international organizations. International instritutions the area where international regimes are belonging to – are legal constructs which provide the formal (and legal framework for continous negotiations. They are the most visible part of the new diplomacy – the one which has a permanent character, and it has an more open face. Anyway, the most important connection has to do with the international institutions, international regimes, and multilateral international negotiations. In the era of the new diplomacy, they all have a permanent character. International institutions help international negotiations carring on; while in their turn, they provide the base for international regimes’ creation, and especially for their evolution. The international regimes’ evolution is an inseparable part of a permanent international framework. And if there is missing a permanent international framework (international organization connected to a specific regime, this regime is a difuse one, its members have only informal relations among them, while they survey each other, looking at their behavior, but they don’t have a formal relationship among them, which could help them solving their future common interests, and protect them from their common fears. International regimes are very important in the era when evrithing touches, and influences everything. In the same time, the complexity of our present world can be successfully

  2. Great Lakes' regional climate regimes

    Science.gov (United States)

    Kravtsov, Sergey; Sugiyama, Noriyuki; Roebber, Paul

    2016-04-01

    We simulate the seasonal cycle of the Great Lakes' water temperature and lake ice using an idealized coupled lake-atmosphere-ice model. Under identical seasonally varying boundary conditions, this model exhibits more than one seasonally varying equilibrium solutions, which we associate with distinct regional climate regimes. Colder/warmer regimes are characterized by abundant/scarce amounts of wintertime ice and cooler/warmer summer temperatures, respectively. These regimes are also evident in the observations of the Great Lakes' climate variability over recent few decades, and are found to be most pronounced for Lake Superior, the deepest of the Great Lakes, consistent with model predictions. Multiple climate regimes of the Great Lakes also play a crucial role in the accelerated warming of the lakes relative to the surrounding land regions in response to larger-scale global warming. We discuss the physical origin and characteristics of multiple climate regimes over the lakes, as well as their implications for a longer-term regional climate variability.

  3. Friction Regimes in the Lubricants Solid-State Regime

    NARCIS (Netherlands)

    Schipper, D.J.; Maathuis, O.; Dowson, D.; Taylor, C.M.; Childs, T.H.C.; Dalmaz, G.

    1995-01-01

    Friction measurements were performed in the lubricant's solid-state regime to study the transition from full-film lubrication, in which the separation is maintained by a solidified lubricant, to mixed lubrication. Special attention is paid to the influence of temperature (inlet viscosity) and roughn

  4. On the regimes of premixing

    Energy Technology Data Exchange (ETDEWEB)

    Angelini, S.; Theofanous, T.G.; Yuen, W.W. [California Univ., Santa Barbara, CA (United States). Center for Risk Studies and Safety

    1998-01-01

    The conditions of the MAGICO-2000 experiment are extended to more broadly investigate the regimes of premixing, and the corresponding internal structures of mixing zones. With the help of the data and numerical simulations using the computer code PM-ALPHA, we can distinguish extremes of behavior dominated by inertia and thermal effects - we name these the inertia and thermal regimes, respectively. This is an important distinction that should guide future experiments aimed at code verification in this area. Interesting intermediate behaviors are also delineated and discussed. (author)

  5. Variance as a Leading Indicator of Regime Shift in Ecosystem Services

    Directory of Open Access Journals (Sweden)

    William A. Brock

    2006-12-01

    Full Text Available Many environmental conflicts involve pollutants such as greenhouse gas emissions that are dispersed through space and cause losses of ecosystem services. As pollutant emissions rise in one place, a spatial cascade of declining ecosystem services can spread across a larger landscape because of the dispersion of the pollutant. This paper considers the problem of anticipating such spatial regime shifts by monitoring time series of the pollutant or associated ecosystem services. Using such data, it is possible to construct indicators that rise sharply in advance of regime shifts. Specifically, the maximum eigenvalue of the variance-covariance matrix of the multivariate time series of pollutants and ecosystem services rises prior to the regime shift. No specific knowledge of the mechanisms underlying the regime shift is needed to construct the indicator. Such leading indicators of regime shifts could provide useful signals to management agencies or to investors in ecosystem service markets.

  6. Monetary regimes in open economies

    NARCIS (Netherlands)

    Korpos, A.

    2006-01-01

    This thesis presents a two-country open economy framework for the analysis of strategic interactions among monetary authorities and wage bargaining institutions. From this perspective, the thesis investigates the economic consequences of replacing flexible and fixed exchange rate regimes with a mone

  7. Generalized dispersive wave emission in nonlinear fiber optics.

    Science.gov (United States)

    Webb, K E; Xu, Y Q; Erkintalo, M; Murdoch, S G

    2013-01-15

    We show that the emission of dispersive waves in nonlinear fiber optics is not limited to soliton-like pulses propagating in the anomalous dispersion regime. We demonstrate, both numerically and experimentally, that pulses propagating in the normal dispersion regime can excite resonant dispersive radiation across the zero-dispersion wavelength into the anomalous regime.

  8. A modelling study of photochemical regimes over Europe: robustness and variability

    Directory of Open Access Journals (Sweden)

    M. Beekmann

    2010-10-01

    Full Text Available The variability of the relative sensitivity of photochemical ozone formation to volatile organic compounds (VOC and NOx emissions, the chemical regime, over Europe during summers 2001 to 2003 is simulated with a regional scale transport-chemistry model. The robustness and variability of chemical regimes is shown. A VOC sensitive regime over North-Western Europe and a mainly NOx sensitive regime over the Mediterranean basin and Eastern Europe are found, confirming earlier published results. The chemical regime time variability, its robustness with respect to several environmental factors (seasonality, interannual variability and with respect to model uncertainty are thoroughly analysed. For the regions with well pronounced chemical regimes over North-Western Europe and the Mediterranean, the chemical regime occurrence only slightly depends on the ozone target considered – daily ozone or Ox (= O3 + NO2 maximum or mean, AOT's, SOMO35, .... For these regions, differences between particular years and summer months are weak, day to day variability is significant but does not change the occurrence of one or another chemical regime. On the contrary, over North-Eastern Germany, the chemical regime changes form one day to another and is also dependent on the ozone target chosen. Expected decreases in anthropogenic NOx emissions over Europe since the last and for the next few decades have shifted and will shift chemical regimes to more NOx sensitive. The predictive skill of chemical regime indicator species is made evident at continental scale, extending their spatial range of applicability with respect to earlier studies. Several sensitivity tests were performed in order to account for major sources of model uncertainty. With the exception of regions near ship tracks over the Mediterranean basin, the spatial pattern of chemical regimes appears to be robust with respect to model

  9. Exchange rate regimes and monetary arrangements

    Directory of Open Access Journals (Sweden)

    Ivan Ribnikar

    2005-06-01

    Full Text Available There is a close relationship between a country’s exchange rate regime and monetary arrangement and if we are to examine monetary arrangements then exchange rate regimes must first be analysed. Within the conventional and most widely used classification of exchange rate regimes into rigid and flexible or into polar regimes (hard peg and float on one side, and intermediate regimes on the other there, is a much greater variety among intermediate regimes. A more precise and, as will be seen, more useful classification of exchange rate regimes is the first topic of the paper. The second topic is how exchange rate regimes influence or determine monetary arrangements and monetary policy or monetary policy regimes: monetary autonomy versus monetary nonautonomy and discretion in monetary policy versus commitment in monetary policy. Both topics are important for countries on their path to the EU and the euro area

  10. The Concept of Truth Regime

    Directory of Open Access Journals (Sweden)

    Lorna Weir

    2008-07-01

    Full Text Available “Truth regime” is a much used but little theorized concept, with the Foucauldian literature presupposing that truth in modernity is uniformly scientific/quasi-scientific and enhances power. I argue that the forms of truth characteristic of our present are wider than Foucault recognized, their relations to power more various, and their historicity more complex. The truth regime of advanced modernity is characterized by multiple, irreducible truth formulae that co-exist and sometimes vie for dominance. A truth formula stabilizes a network of elements: a relation between representation and presentation (words and things, truth and non-truth, and the place of the subject in discourse. Our contemporary truth regime comprises radically heterogeneous truthful knowledges – science, governance, religion/politics, and common culture – that have distinct histories and relations to power.

  11. Detecting spatial regimes in ecosystems

    Science.gov (United States)

    Sundstrom, Shana M.; Eason, Tarsha; Nelson, R. John; Angeler, David G.; Barichievy, Chris; Garmestani, Ahjond S.; Graham, Nicholas A.J.; Granholm, Dean; Gunderson, Lance; Knutson, Melinda; Nash, Kirsty L.; Spanbauer, Trisha; Stow, Craig A.; Allen, Craig R.

    2017-01-01

    Research on early warning indicators has generally focused on assessing temporal transitions with limited application of these methods to detecting spatial regimes. Traditional spatial boundary detection procedures that result in ecoregion maps are typically based on ecological potential (i.e. potential vegetation), and often fail to account for ongoing changes due to stressors such as land use change and climate change and their effects on plant and animal communities. We use Fisher information, an information theory-based method, on both terrestrial and aquatic animal data (U.S. Breeding Bird Survey and marine zooplankton) to identify ecological boundaries, and compare our results to traditional early warning indicators, conventional ecoregion maps and multivariate analyses such as nMDS and cluster analysis. We successfully detected spatial regimes and transitions in both terrestrial and aquatic systems using Fisher information. Furthermore, Fisher information provided explicit spatial information about community change that is absent from other multivariate approaches. Our results suggest that defining spatial regimes based on animal communities may better reflect ecological reality than do traditional ecoregion maps, especially in our current era of rapid and unpredictable ecological change.

  12. Modeling whistler wave generation regimes in magnetospheric cyclotron maser

    Directory of Open Access Journals (Sweden)

    D. L. Pasmanik

    2004-11-01

    Full Text Available Numerical analysis of the model for cyclotron instability in the Earth's magnetosphere is performed. This model, based on the self-consistent set of equations of quasi-linear plasma theory, describes different regimes of wave generation and related energetic particle precipitation. As the source of free energy the injection of energetic electrons with transverse anisotropic distribution function to the interaction region is considered. A parametric study of the model is performed. The main attention is paid to the analysis of generation regimes for different characteristics of energetic electron source, such as the shape of pitch angle distributions and its intensity. Two mechanisms of removal of energetic electrons from a generation region are considered, one is due to the particle precipitation through the loss cone and another one is related to the magnetic drift of energetic particles.

    It was confirmed that two main regimes occur in this system in the presence of a constant particle source, in the case of precipitation losses. At small source intensity relaxation oscillations were found, whose parameters are in good agreement with simplified analytical theory developed earlier. At a larger source intensity, transition to a periodic generation occurs. In the case of drift losses the regime of self-sustained periodic generation regime is realized for source intensity higher than some threshold. The dependencies of repetition period and dynamic spectrum shape on the source parameters were studied in detail. In addition to simple periodic regimes, those with more complex spectral forms were found. In particular, alteration of spikes with different spectral shape can take place. It was also shown that quasi-stationary generation at the low-frequency band can coexist with periodic modulation at higher frequencies.

    On the basis of the results obtained, the model for explanation of

  13. The january effect across volatility regimes

    OpenAIRE

    Agnani, Betty; Aray, Henry

    2007-01-01

    Using a Markov regime switching model, this article presents evidence on the well-known January effect on stock returns. The specification allows a distinction to be drawn between two regimes, one with high volatility and other with low volatility. We obtain a time-varying January effect that is, in general, positive and significant in both volatility regimes. However, this effect is larger in the high volatility regime. In sharp contrast with most previous literature we find two major result...

  14. Implementation Regimes and Street-Level Bureaucrats

    DEFF Research Database (Denmark)

    Winter, Søren; T. Dinesen, Peter; J. May, Peter

    -government regimes foster greater policy commitment, attention to rules, and adherence among frontline workers than is the case for a local-government implementation regime. These lead to actions of street-level bureaucrats in central-government regimes that are more in line with national policies than those...

  15. Accommodating human values in the climate regime

    NARCIS (Netherlands)

    Cook, Rosalind; Tauschinsky, Eljalill

    2008-01-01

    The climate regime addresses one of the most important challenges facing humankind today. However, while the environmental and economic sides of the problem are well represented, it lacks the inclusion of social and human aspects. The human rights regime, in contrast, is a regime which has been esta

  16. Stochastic Parametrisations and Regime Behaviour of Atmospheric Models

    Science.gov (United States)

    Arnold, Hannah; Moroz, Irene; Palmer, Tim

    2013-04-01

    The presence of regimes is a characteristic of non-linear, chaotic systems (Lorenz, 2006). In the atmosphere, regimes emerge as familiar circulation patterns such as the El-Nino Southern Oscillation (ENSO), the North Atlantic Oscillation (NAO) and Scandinavian Blocking events. In recent years there has been much interest in the problem of identifying and studying atmospheric regimes (Solomon et al, 2007). In particular, how do these regimes respond to an external forcing such as anthropogenic greenhouse gas emissions? The importance of regimes in observed trends over the past 50-100 years indicates that in order to predict anthropogenic climate change, our climate models must be able to represent accurately natural circulation regimes, their statistics and variability. It is well established that representing model uncertainty as well as initial condition uncertainty is important for reliable weather forecasts (Palmer, 2001). In particular, stochastic parametrisation schemes have been shown to improve the skill of weather forecast models (e.g. Berner et al., 2009; Frenkel et al., 2012; Palmer et al., 2009). It is possible that including stochastic physics as a representation of model uncertainty could also be beneficial in climate modelling, enabling the simulator to explore larger regions of the climate attractor including other flow regimes. An alternative representation of model uncertainty is a perturbed parameter scheme, whereby physical parameters in subgrid parametrisation schemes are perturbed about their optimal value. Perturbing parameters gives a greater control over the ensemble than multi-model or multiparametrisation ensembles, and has been used as a representation of model uncertainty in climate prediction (Stainforth et al., 2005; Rougier et al., 2009). We investigate the effect of including representations of model uncertainty on the regime behaviour of a simulator. A simple chaotic model of the atmosphere, the Lorenz '96 system, is used to study

  17. Adaptation in Collaborative Governance Regimes

    Science.gov (United States)

    Emerson, Kirk; Gerlak, Andrea K.

    2014-10-01

    Adaptation and the adaptive capacity of human and environmental systems have been of central concern to natural and social science scholars, many of whom characterize and promote the need for collaborative cross-boundary systems that are seen as flexible and adaptive by definition. Researchers who study collaborative governance systems in the public administration, planning and policy literature have paid less attention to adaptive capacity specifically and institutional adaptation in general. This paper bridges the two literatures and finds four common dimensions of capacity, including structural arrangements, leadership, knowledge and learning, and resources. In this paper, we focus on institutional adaptation in the context of collaborative governance regimes and try to clarify and distinguish collaborative capacity from adaptive capacity and their contributions to adaptive action. We posit further that collaborative capacities generate associated adaptive capacities thereby enabling institutional adaptation within collaborative governance regimes. We develop these distinctions and linkages between collaborative and adaptive capacities with the help of an illustrative case study in watershed management within the National Estuary Program.

  18. Measuring the effectiveness of international environmental regimes

    Energy Technology Data Exchange (ETDEWEB)

    Helm, C.; Sprinz, D.F.

    1999-05-01

    While past research has emphasized the importance of international regimes for international governance, systematic assessments of regime effects are missing. This article derives a standardized measurement concept for the effectiveness of international environmental regimes by developing an operational rational choice calculus to evaluate actual policy simultaneously against a non-regime counterfactual and a collective optimum. Subsequently, the empirical feasibility of the measurement instrument is demonstrated by way of two international treaties regulating transboundary air pollution in Europe. The results demonstrate that the regimes indeed show positive effects - but fall substantially short of the collective optima. (orig.)

  19. Nano-optomechanical measurement in the photon counting regime

    CERN Document Server

    de Lépinay, Laure Mercier; Rohr, Sven; Gloppe, Arnaud; Kuhn, Aurélien; Verlot, Pierre; Dupont-Ferrier, Eva; Besga, Benjamin; Arcizet, Olivier

    2015-01-01

    Optically measuring in the photon counting regime is a recurrent challenge in modern physics and a guarantee to develop weakly invasive probes. Here we investigate this idea on a hybrid nano-optomechanical system composed of a nanowire hybridized to a single Nitrogen-Vacancy (NV) defect. The vibrations of the nanoresonator grant a spatial degree of freedom to the quantum emitter and the photon emission event can now vary in space and time. We investigate how the nanomotion is encoded on the detected photon statistics and explore their spatio-temporal correlation properties. This allows a quantitative measurement of the vibrations of the nanomechanical oscillator at unprecedentedly low light intensities in the photon counting regime when less than one photon is detected per oscillation period, where standard detectors are dark-noise-limited. These results have implications for probing weakly interacting nanoresonators, for low temperature experiments and for investigating single moving markers.

  20. Hall effect in hopping regime

    Energy Technology Data Exchange (ETDEWEB)

    Avdonin, A., E-mail: avdonin@ifpan.edu.pl [Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warszawa (Poland); Skupiński, P. [Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warszawa (Poland); Grasza, K. [Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warszawa (Poland); Institute of Electronic Materials Technology, ul. Wólczyńska 133, 01-919 Warszawa (Poland)

    2016-02-15

    A simple description of the Hall effect in the hopping regime of conductivity in semiconductors is presented. Expressions for the Hall coefficient and Hall mobility are derived by considering averaged equilibrium electron transport in a single triangle of localization sites in a magnetic field. Dependence of the Hall coefficient is analyzed in a wide range of temperature and magnetic field values. Our theoretical result is applied to our experimental data on temperature dependence of Hall effect and Hall mobility in ZnO. - Highlights: • Expressions for Hall coefficient and mobility for hopping conductivity are derived. • Theoretical result is compared with experimental curves measured on ZnO. • Simultaneous action of free and hopping conduction channels is considered. • Non-linearity of hopping Hall coefficient is predicted.

  1. Investigating Satellite Microwave observations of Precipitation in Different Climate Regimes

    Science.gov (United States)

    Wang, N.; Ferraro, R. R.

    2013-12-01

    Microwave satellite remote sensing of precipitation over land is a challenging problem due to the highly variable land surface emissivity, which, if not properly accounted for, can be much greater than the precipitation signal itself, especially in light rain/snow conditions. Additionally, surfaces such as arid land, deserts and snow cover have brightness temperature characteristics similar to precipitation Ongoing work by GPM microwave radiometer team is constructing databases through a variety of means, however, there is much uncertainty as to what is the optimal information needed for the wide array of sensors in the GPM constellation, including examination of regional conditions. The original data sets will focus on stratification by emissivity class, surface temperature and total perceptible water. We'll perform sensitivity studies to determine the potential role of ancillary data (e.g., land surface temperature, snow cover/water equivalent, etc.) to improve precipitation estimation over land in different climate regimes, including rain and snow. In other words, what information outside of the radiances can help describe the background and subsequent departures from it that are active precipitating regions? It is likely that this information will be a function of the various precipitation regimes. Statistical methods such as Principal Component Analysis (PCA) will be utilized in this task. Databases from a variety of sources are being constructed. They include existing satellite microwave measurements of precipitating and non-precipitating conditions, ground radar precipitation rate estimates, surface emissivity climatology from satellites, surface temperature and TPW from NWP reanalysis. Results from the analysis of these databases with respect to the microwave precipitation sensitivity to the variety of environmental conditions in different climate regimes will be discussed.

  2. Emission Trading

    OpenAIRE

    2009-01-01

    The work concerns Emission Trading Scheme from perspektive of taxes and accounting. I should show problems with emission trading. The work concerns practical example of trading with emission allowance.

  3. Dynamics of aircraft exhaust plumes in the jet-regime

    Directory of Open Access Journals (Sweden)

    P. Fabian

    Full Text Available A computational model describing the two-dimensional, turbulent mixing of a single jet of exhaust gas from aircraft engines with the ambient atmosphere is presented. The underlying assumptions and governing equations are examined and supplemented by a discussion of analytical solutions. As an application, the jet dynamics of a B747-400 aircraft engine in cruise and its dependence on key parameters is investigated in detail. The computer code for this dynamical model is computationally fast and can easily be coupled to complex chemical and microphysical models in order to perform comprehensive studies of atmospheric effects from aircraft exhaust emissions in the jet regime.

  4. Equilibrium yield curves under regime switching

    OpenAIRE

    García-Verdú, Santiago

    2010-01-01

    This paper studies how inflation as a macroeconomic indicator affects nominal bond prices. I consider an economy with a representative agent with Epstein- Zin preferences. Regime switching affects the state-space capturing inflation and consumption growth. Thus, the agent is concerned about the intertemporal distribution of risk, which is affected by the persistence of the variables and the regimes. Regime switching allows for structural changes in the volatility of unexpected shocks. To the ...

  5. Implementation of avoided deforestation in a post-2012 climate regime

    Energy Technology Data Exchange (ETDEWEB)

    Soederblom, Johan

    2009-01-15

    this study it is shown that small changes in the initial assumptions might increase the estimated cost severalfold. At the moment there are no incentives for avoided deforestation under the Kyoto Protocol. However, REDD is frequently discussed in the negotiations for a post-2012 climate regime. A central question in these negotiations is how REDD would be financed. This study reviews a selection of the alternatives that are discussed. Some sort of market solution will likely be needed to generate enough funding, though for this to be possible the measurability of the emission reductions must be improved. Extensive capacity building is needed in the host countries of REDD and the easiest way to finance this would be through a voluntary fund or Official Development Assistance

  6. Thermal regime of Negotinska Krajina

    Directory of Open Access Journals (Sweden)

    Živković Ljiljana

    2005-01-01

    Full Text Available Negotin Krajina geographically belongs to Mezian tablet that means it is widely open to the influences from the East but main air influences come from the West and North-West causes specific thermal characteristics. Meteorological station "Negotin" is the only one respectable station in the Krajina then we analyze results from various periods since 1901. It is important to emphasize that station "Negotin" doesn't have work continuity since the beginning of the century, thus for analyzing certain climate elements we have had to use method of analogy with station "Zaječar". A part of that, observations were not done by the same methodology so there is lack of some important indicators for this first period. To determine air thermo-regime of Negotin Krajina during 20 century, standard periods (1901-1930., 1931-1960. and 1961-1990 for analyzing climate elements suggested by WMO, were compared. Also, periods from 1925. to 1940. and from 1990. to 2000. were added to this analysis (according to data we had.

  7. Crustal stress regime in Italy

    Directory of Open Access Journals (Sweden)

    M. Cesaro

    1997-06-01

    Full Text Available In order to obtain a reliable map of the present-day stress field in Italy, needed to better understand the active tectonic processes and to contribute to the assessment of seismic hazard, in 1992 we started to collect and analyze new data from borehole breakouts in deep oil and geothermal wells and focal mechanisms of earthquakes (2.5 < M <5 occurred in Italy between 1988 and 1995. From about 200 deep wells and 300 focal mechanisms analyzed to date, we infer that: the internal (SW sector of the Northern Apenninic arc is extending with minimum compressional stress (Shmin oriented ? ENE, while the external front is thrusting over the Adriatic foreland (Shmin ? NW-SE. The entire Southern Apennine is extending in NE direction (from the Tyrrhenian margin to the Apulian foreland and compression (in the foredeep is no longer active at the outer (NE thrust front. Between these two arcs, an abrupt change in the tectonic regime is detected with directions of horizontal stress changing by as much as 90º in the external front, around latitude 430N. Along the Ionian side of the Calabrian arc the stress directions inferred from breakouts and focal mechanisms are scattered with a hint of rotation from N-S Shmin close to the Southern Apennines, to ~ E-W directions in the Messina Strait. In Sicily, a NW-SE direction of SHmax is evident in the Hyblean foreland, parallel to the direction of plate motion between Africa and Europe. A more complex pattern of stress directions is observed in the thrust belt zone, with rotations from the regional trend (NW í directed SHmax to NE oriented SHmax. A predominant NW direction of SHmax is also detected in mainland Sicily from earthquake focal mechanisms, but no well data are available in this region. In the northern part of Sicily (Aeolian Islands a ~N-S direction of SHmax is observed.

  8. Iterative functionalism and climate management regimes: From intergovernmental panel on climate change to intergovernmental negotiating committee

    Energy Technology Data Exchange (ETDEWEB)

    Feldman, D.L. [Oak Ridge National Lab., TN (United States)]|[Tennessee Univ., Knoxville, TN (United States). Energy, Environment and Resources Center

    1992-06-01

    This paper contends that an iterative ``functionalist`` regime -- comprised of international organizations that monitor the global climate and perform scientific and policy research on prevention, mitigation, and adaptation strategies for response to possible global warming -- has developed over the past decade. A common global effort by scientists, diplomats, and others to negotiate a framework convention that would reduce emissions of carbon dioxide and other ``greenhouse gases`` has been brought about by this regime. Individuals that participate in this regime are engaged in several cooperative activities including: (1) international research on the causes and consequences of global change; (2) global environmental monitoring and standard-setting for analyses of climate data; and (3) negotiating a framework convention that places limits on greenhouse gas emissions by countries. The implications of this iterative approach for successful implementation of a treaty to forestall global climate change are discussed.

  9. Iterative functionalism and climate management regimes: From intergovernmental panel on climate change to intergovernmental negotiating committee

    Energy Technology Data Exchange (ETDEWEB)

    Feldman, D.L. (Oak Ridge National Lab., TN (United States) Tennessee Univ., Knoxville, TN (United States). Energy, Environment and Resources Center)

    1992-01-01

    This paper contends that an iterative functionalist'' regime -- comprised of international organizations that monitor the global climate and perform scientific and policy research on prevention, mitigation, and adaptation strategies for response to possible global warming -- has developed over the past decade. A common global effort by scientists, diplomats, and others to negotiate a framework convention that would reduce emissions of carbon dioxide and other greenhouse gases'' has been brought about by this regime. Individuals that participate in this regime are engaged in several cooperative activities including: (1) international research on the causes and consequences of global change; (2) global environmental monitoring and standard-setting for analyses of climate data; and (3) negotiating a framework convention that places limits on greenhouse gas emissions by countries. The implications of this iterative approach for successful implementation of a treaty to forestall global climate change are discussed.

  10. Framing of regimes and transition strategies

    DEFF Research Database (Denmark)

    Jensen, Jens Stissing

    2012-01-01

    This article suggests that transition strategies are always formulated in the context of specific representations of the regime and the challenges it faces. It is argued that the framing of a regime affects the envisioning of transition strategies. An analysis of the current development agenda...

  11. Multiscale regime shifts and planetary boundaries

    NARCIS (Netherlands)

    Hughes, T.P.; Carpenter, S.; Rockstrom, J.; Scheffer, M.; Walker, B.

    2013-01-01

    Life on Earth has repeatedly displayed abrupt and massive changes in the past, and there is no reason to expect that comparable planetary-scale regime shifts will not continue in the future. Different lines of evidence indicate that regime shifts occur when the climate or biosphere transgresses a ti

  12. LEGAL MATRIMONIAL REGIME IN B&H

    Directory of Open Access Journals (Sweden)

    Boris Krešić

    2011-12-01

    Full Text Available Matrimonial regime between spouses or between extramarital partners, and between parents and children is regulated by the Family Law Act of Bosnia and Herzegovina Federation, hereinafter FLA B&HF (SG FBiH 35/05, 41/05, Family Law Act of the Republic of Srpska, hereinafter FLA RS (SG RS”54/02, 41/08 and the Family Law Act of Brčko District, hereinafter FLA BD (SG RS, 66/07. Legal rules used for the regulation of the matrimonial regime between spouses, as well as between spouses and third parties make matrimonial regime (Ponjavić, 2005, p. 361. Matrimonial regime between spouses in family legislation in Bosnia and Herzegovina (B&H is regulated in two following ways: as legal matrimonial regime and as contract matrimonial regime. Legal regime is the one which applies on spouses if not arranged otherwise prior to contracting marriage or during marriage. In this paper the author indicates the differences between the legal matrimonial regimes of the two entities as well as those between the entities and Brčko District of Bosnia and Herzegovina.

  13. LOW DOSE MAGNESIUM SULPHATE REGIME FOR ECLAMPSIA

    Directory of Open Access Journals (Sweden)

    Bangal V

    2009-09-01

    Full Text Available Pre- eclampsia is one of the commonest medical complications seen during pregnancy. It contributes significantly to maternal and perinatal morbidity and mortality. Dr.J.A.Pritchard in 1955, introduced magnesium sulphate for control of convulsions in eclampsia and is used worldwide. Considering the low body mass index of indian women, a low dose magnesium sulphate regime has been introduced by some authors. Present study was carried out at tertiary care centre in rural area. Fifty cases of eclampsia were randomly selected to find out the efficacy of low dose magnesium sulphate regime to control eclamptic convulsions. Maternal and perinatal outcome and magnesium toxicity were analyzed. It was observed that 86% cases responded to initial intravenous dose of 4 grams of 20% magnesium sulphate . Eight percent cases, who got recurrence of convulsion, were controlled by additional 2 grams of 20% magnesium sulphate. Six percent cases required shifting to standard Pritchard regime, as they did not respond to low dose magnesium sulphate regime. The average total dose of magnesium sulphate required for control of convulsions was 20 grams ie. 54.4% less than that of standard Pritchard regime. The maternal and perinatal morbidity and mortality in the present study werecomparable to those of standard Pritchard regime. The study did not find a single case of magnesium related toxicity with low dose magnesium sulphate regime. Low dose magnesium sulphate regime was found to be safe and effective in eclampsia.

  14. Emissions Trading

    NARCIS (Netherlands)

    Woerdman, Edwin; Backhaus, Juergen

    2014-01-01

    Emissions trading is a market-based instrument to achieve environmental targets in a cost-effective way by allowing legal entities to buy and sell emission rights. The current international dissemination and intended linking of emissions trading schemes underlines the growing relevance of this

  15. Emissions Trading

    NARCIS (Netherlands)

    Woerdman, Edwin; Backhaus, Juergen

    2014-01-01

    Emissions trading is a market-based instrument to achieve environmental targets in a cost-effective way by allowing legal entities to buy and sell emission rights. The current international dissemination and intended linking of emissions trading schemes underlines the growing relevance of this instr

  16. FLOW REGIMES BELOW AERATORS FOR DISCHARGE TUNNELS

    Institute of Scientific and Technical Information of China (English)

    MA Fei; WU Jian-hua

    2012-01-01

    The flow regimes below an aerator influence directly the air entrainment and the cavitation damage control.Based on the theoretical considerations,the experiments of the aerator for a discharge tunnel were conducted,and the relationships between the flow regime and hydraulic and geometric parameters were investigated.The results showed that,there are two kinds of threshold values for the flow regime conversions.One is Fr1-2 standing for the conversion from the fully filled cavity to the partially filled cavity,and the other is Fr2-3 which shows the change from the partially filled cavity to the net air cavity.Two empirical expressions were obtained for the conversions of the flow regimes,which can be used in the designs of the aerators.

  17. US Forest Service LANDFIRE Historical Fire Regimes

    Data.gov (United States)

    US Forest Service, Department of Agriculture — Historical fire regimes, intervals, and vegetation conditions are mapped using the Vegetation Dynamics Development Tool (VDDT). These data support fire and landscape...

  18. Figure 1: Basal-Bolus Regime

    African Journals Online (AJOL)

    Siegal_D

    Breakfast. Lunch. Dinner. Bedtime. Plasma insulin concentrations over time with a twice daily insulin mix regime .... Hypoglycaemia. Frequency, severity, awareness, precipitants, driving, ... Post GDM, family members, IGT etc. EXAMINATION.

  19. Regimes of validity for balanced models

    Science.gov (United States)

    Gent, Peter R.; McWilliams, James C.

    1983-07-01

    Scaling analyses are presented which delineate the atmospheric and oceanic regimes of validity for the family of balanced models described in Gent and McWilliams (1983a). The analyses follow and extend the classical work of Charney (1948) and others. The analyses use three non-dimensional parameters which represent the flow scale relative to the Earth's radius, the dominance of turbulent or wave-like processes, and the dominant component of the potential vorticity. For each regime, the models that are accurate both at leading order and through at least one higher order of accuracy in the appropriate small parameter are then identified. In particular, it is found that members of the balanced family are the appropriate models of higher-order accuracy over a broad range of parameter regimes. Examples are also given of particular atmospheric and oceanic phenomena which are in the regimes of validity for the different balanced models.

  20. The Two Regimes of Postwar Shipping

    DEFF Research Database (Denmark)

    Iversen, Martin Jes; Tenold, Stig

    2014-01-01

    The aim of this article is to illustrate the most important changes in the regulatory framework of the shipping sector from the 1960s to 2010, and to analyse the basis for, and effects of, these changes. In order to explain how the transformation has occurred, we use two traditional maritime...... nations—Denmark and Norway—as case studies. First, we introduce the two regimes of Danish and Norwegian shipping: ‘the national regime’ from the early 1960s to the mid-1970s; and ‘the competitive regime’, which was fully established by the middle of the 1990s and still persists. Then, we briefly sketch...... the bargaining that accompanied the shift from the national regime to the competitive regime. Specifically, we show that the new regime primarily accommodated the interests of private actors such as shipping companies, rather than the interests of the authorities and the trade unions....

  1. Exchange rate regimes and external financial stability

    Directory of Open Access Journals (Sweden)

    Stoica Ovidiu

    2016-01-01

    Full Text Available Financial stability within the framework of the global financial crisis has become a common topic for researchers and practitioners. In order to analyse the impact of exchange rate regimes on financial stability we use both the de jure and de facto exchange rate classifications. We apply the model to a 1999-2010 annual data sample for 135 countries and territories, grouped by the level of economic development. Our second focus is the investigation of the effects of the exchange rate regimes in three economic integration areas (member countries of the European Union 27, the Southern Common Market, and the Association of Southeast Asian Nations on financial stability. Our results generally support the central banks’ concerns that the flexibility of exchange rate regimes should be reduced in order to sustain financial stability; however, the findings are not robust when using alternative regime classifications.

  2. Portfolio Selection with Jumps under Regime Switching

    Directory of Open Access Journals (Sweden)

    Lin Zhao

    2010-01-01

    Full Text Available We investigate a continuous-time version of the mean-variance portfolio selection model with jumps under regime switching. The portfolio selection is proposed and analyzed for a market consisting of one bank account and multiple stocks. The random regime switching is assumed to be independent of the underlying Brownian motion and jump processes. A Markov chain modulated diffusion formulation is employed to model the problem.

  3. International Experiences with Different Monetary Policy Regimes

    OpenAIRE

    Mishkin, Frederic S.

    1999-01-01

    In recent years a growing consensus has emerged for price stability as the overriding, long-run goal of monetary policy. However, despite this consensus, the following question still remains: how should monetary policy be conducted to achieve the price stability goal? This paper examines the experience with different monetary policy regimes currently in use in a number of countries to shed light on this question. A central feature of all of the monetary regimes discussed here is the ise of a ...

  4. Emission Facilities - Air Emission Plants

    Data.gov (United States)

    NSGIC Education | GIS Inventory — Represents the Primary Facility type Air Emission Plant (AEP) point features. Air Emissions Plant is a DEP primary facility type related to the Air Quality Program....

  5. Emission Facilities - Air Emission Plants

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — Represents the Primary Facility type Air Emission Plant (AEP) point features. Air Emissions Plant is a DEP primary facility type related to the Air Quality Program....

  6. Using biofuel tracers to study alternative combustion regimes

    Science.gov (United States)

    Mack, J. H.; Flowers, D. L.; Buchholz, B. A.; Dibble, R. W.

    2007-06-01

    Interest in the use of alternative fuels and engines is increasing as the price of petroleum climbs. The inherently higher efficiency of Diesel engines has led to increased adoption of Diesels in Europe, capturing approximately 40% of the new passenger car market. Unfortunately, lower CO2 emissions are countered with higher nitrogen oxides (NOx) and particulate matter (PM) emissions and higher noise. Adding oxygenated compounds to the fuel helps reduce PM emissions. However, relying on fuel alone to reduce PM is unrealistic due to economic constraints and difficult due to the emerging PM standards. Keeping peak combustion temperature below 1700 K inhibits NOx formation. Altering the combustion regime to burn at temperatures below the NOx threshold and accept a wide variety of fuels seems like a promising alternative for future engines. Homogeneous charge compression ignition (HCCI) is a possible solution. Fuel and air are well mixed prior to intake into a cylinder (homogeneous charge) and ignition occurs by compression of the fuel-air mixture by the piston. HCCI is rapid and relatively cool, producing little NOx and PM. Unfortunately, it is hard to control since HCCI is initiated by temperature and pressure instead of a spark or direct fuel injection. We investigate biofuel HCCI combustion, and use intrinsically labeled biofuels as tracers of HCCI combustion. Data from tracer experiments are used to improve our combustion modeling.

  7. Emission inventory; Inventaire des emissions

    Energy Technology Data Exchange (ETDEWEB)

    Fontelle, J.P. [CITEPA, Centre Interprofessionnel Technique d`Etudes de la Pollution Atmospherique, 75 - Paris (France)

    1997-12-31

    Statistics on air pollutant (sulfur dioxide, nitrogen oxides and ammonium) emissions, acid equivalent emissions and their evolution since 1990 in the various countries of Europe and the USA, are presented. Emission data from the industrial, agricultural, transportation and power sectors are given, and comparisons are carried out between countries based on Gnp and population, pollution import/export fluxes and compliance to the previous emission reduction objectives

  8. Fiscal Policy and Welfare under Different Exchange Rate Regimes

    DEFF Research Database (Denmark)

    Østrup, Finn

    regime in whichthe monetary authority optimises preferences which include an employment targetand an inflation target. As government spending affects the representativeindividual's utility, the choice of exchange rate regime has an impact on welfare.Keywords: exchange rate regimes; fiscal policy...

  9. Causas estruturais e consequências dos regimes internacionais: regimes como variáveis intervenientes

    OpenAIRE

    Stephen D. Krasner

    2012-01-01

    Os regimes internacionais são definidos como princípios, normas, regras e procedimentos de tomada de decisões ao redor dos quais as expectativas dos atores convergem em uma dada área-tema. Como ponto de partida, os regimes são conceituados como variáveis intervenientes, estando entre fatores causais básicos e os resultados e comportamentos relacionados. Há três visões a respeito da importância dos regimes: as orientações estruturais convencionais desvalorizam os regimes como sendo, na melhor ...

  10. Managing the human component of fire regimes: lessons from Africa.

    Science.gov (United States)

    Archibald, Sally

    2016-06-05

    Human impacts on fire regimes accumulated slowly with the evolution of modern humans able to ignite fires and manipulate landscapes. Today, myriad voices aim to influence fire in grassy ecosystems to different ends, and this is complicated by a colonial past focused on suppressing fire and preventing human ignitions. Here, I review available evidence on the impacts of people on various fire characteristics such as the number and size of fires, fire intensity, fire frequency and seasonality of fire in African grassy ecosystems, with the intention of focusing the debate and identifying areas of uncertainty. Humans alter seasonal patterns of fire in grassy systems but tend to decrease total fire emissions: livestock have replaced fire as the dominant consumer in many parts of Africa, and fragmented landscapes reduce area burned. Humans alter the season and time of day when fires occur, with important implications for fire intensity, tree-grass dynamics and greenhouse gas (GHG) emissions. Late season fires are more common when fire is banned or illegal: these later fires are far more intense but emit fewer GHGs. The types of fires which preserve human livelihoods and biodiversity are not always aligned with the goal of reducing GHG concentrations. Current fire management challenges therefore involve balancing the needs of a large rural population against national and global perspectives on the desirability of different types of fire, but this cannot happen unless the interests of all parties are equally represented. In the future, Africa is expected to urbanize and land use to intensify, which will imply different trajectories for the continent's fire regimes.This article is part of the themed issue 'The interaction of fire and mankind.

  11. Regimes of turbulence without an energy cascade

    CERN Document Server

    Barenghi, C F; Baggaley, A W

    2016-01-01

    Experiments and numerical simulations of turbulent $^4$He and $^3$He-B have established that, at hydrodynamic length scales larger than the average distance between quantum vortices, the energy spectrum obeys the same 5/3 Kolmogorov law which is observed in the homogeneous isotropic turbulence of ordinary fluids. The importance of the 5/3 law is that it points to the existence of a Richardson energy cascade from large eddies to small eddies. However, there is also evidence of quantum turbulent regimes without Kolmogorov scaling. This raises the important questions of why, in such regimes, the Kolmogorov spectrum fails to form, what is the physical nature of turbulence without energy cascade, and whether hydrodynamical models can account for the unusual behaviour of turbulent superfluid helium. In this work we describe simple physical mechanisms which prevent the formation of Kolmogorov scaling in the thermal counterflow, and analyze the conditions necessary for emergence of quasiclassical regime in quantum tu...

  12. Interpreting MAD within multiple accretion regimes

    CERN Document Server

    Mocz, Philip

    2014-01-01

    General relativistic magnetohydrodynamic (GRMHD) simulations of accreting black holes in the radiatively inefficient regime show that systems with sufficient magnetic poloidal flux become magnetically arrested disc (MAD) systems, with a well-defined relationship between the magnetic flux and the mass accretion rate. Recently, Zamaninasab (2014) report that the jet magnetic flux and accretion disc luminosity are tightly correlated over 7 orders of magnitude for a sample of 76 radio-loud active galaxies, concluding that the data are explained by the MAD mode of accretion. Their analysis assumes radiatively efficient accretion, and their sample consists primarily of radiatively efficient sources, while GRMHD simulations of MAD thus far have been carried out in the radiatively inefficient regime. We propose a model to interpret MAD systems in the context of multiple accretion regimes, and apply it to the sample in Zamaninasab (2014), along with additional radiatively inefficient sources from archival data. We sho...

  13. Causas estruturais e consequências dos regimes internacionais: regimes como variáveis intervenientes

    Directory of Open Access Journals (Sweden)

    Stephen D. Krasner

    2012-06-01

    Full Text Available Os regimes internacionais são definidos como princípios, normas, regras e procedimentos de tomada de decisões ao redor dos quais as expectativas dos atores convergem em uma dada área-tema. Como ponto de partida, os regimes são conceituados como variáveis intervenientes, estando entre fatores causais básicos e os resultados e comportamentos relacionados. Há três visões a respeito da importância dos regimes: as orientações estruturais convencionais desvalorizam os regimes como sendo, na melhor das hipóteses, ineficazes; as orientações grocianas vêem os regimes como componentes íntimos do sistema internacional; as perspectivas estruturalistas modificadas vêem os regimes como significativos somente em certas condições restritas. Para os argumentos grociano e estruturalista modificado - que concordam com a visão de que os regimes podem influenciar resultados e comportamentos - , o desenvolvimento de regimes é visto como uma função de cinco variáveis causais básicas: auto-interesse egoísta; poder político; normas e princípios difusos; usos e costumes; conhecimento.

  14. Regimes, Non-State Actors and the State System: A 'Structurational' Regime Model

    NARCIS (Netherlands)

    Arts, B.J.M.

    2000-01-01

    Regime analysis has become a popular approach in International Relations theory and in international policy studies. However, current regime models exhibit some shortcomings with regard to (1) addressing non-state actors, and in particular nongovernmental organizations (NGOs), (2) the balancing of

  15. Regimes, Non-State Actors and the State System: A 'Structurational' Regime Model

    NARCIS (Netherlands)

    Arts, B.J.M.

    2000-01-01

    Regime analysis has become a popular approach in International Relations theory and in international policy studies. However, current regime models exhibit some shortcomings with regard to (1) addressing non-state actors, and in particular nongovernmental organizations (NGOs), (2) the balancing of a

  16. Early detection of ecosystem regime shifts

    DEFF Research Database (Denmark)

    Lindegren, Martin; Dakos, Vasilis; Groeger, Joachim P.;

    2012-01-01

    methods may have limited utility in ecosystem-based management as they show no or weak potential for early-warning. We therefore propose a multiple method approach for early detection of ecosystem regime shifts in monitoring data that may be useful in informing timely management actions in the face......Critical transitions between alternative stable states have been shown to occur across an array of complex systems. While our ability to identify abrupt regime shifts in natural ecosystems has improved, detection of potential early-warning signals previous to such shifts is still very limited...

  17. Bank Liquidity and Exchange Rate Regimes

    OpenAIRE

    Bunda, Irina; Desquilbet, Jean-Baptiste

    2003-01-01

    International audience; Combining panel data on bank liquidity at the individual level and data on their macroeconomic environment, for a sample of commercial banks in emerging countries between 1995 and 2000, we show that their exists a “bank liquidity smile across exchange rate regimes”. In extreme regimes at both ends of the line, i.e. for pure floating exchange rate regimes at one end and currency boards and dollarized economies at the other end, bank assets are more liquid than in interm...

  18. Markovian quantum master equation beyond adiabatic regime

    Science.gov (United States)

    Yamaguchi, Makoto; Yuge, Tatsuro; Ogawa, Tetsuo

    2017-01-01

    By introducing a temporal change time scale τA(t ) for the time-dependent system Hamiltonian, a general formulation of the Markovian quantum master equation is given to go well beyond the adiabatic regime. In appropriate situations, the framework is well justified even if τA(t ) is faster than the decay time scale of the bath correlation function. An application to the dissipative Landau-Zener model demonstrates this general result. The findings are applicable to a wide range of fields, providing a basis for quantum control beyond the adiabatic regime.

  19. WELFARE REGIMES IN LATIN AMERICA AND CARIBBEAN

    Directory of Open Access Journals (Sweden)

    Melisa Campana-Alabarce

    2015-06-01

    Full Text Available This article provides a characterization of Latin American and Caribbean Welfare regimes in historiographical perspective. Firstly, it makes a review of the emergence conditions of Welfare States in Western Europe and its core features, with particular emphasis on its role as a method to regulate inequalities in industrial capitalism. Dialoguing with it, then stops in the specific configurations that welfare regimes have taken in Latin America during the course of the twentieth century. Finally, it provides a map of its contemporary features and the major challenges that the States of the region face in his capacity as right guarantors for the future.

  20. Light focusing in the Anderson Regime

    CERN Document Server

    Leonetti, Marco; Mafi, Arash; Conti, Claudio

    2014-01-01

    Anderson localization is a regime in which diffusion is inhibited and waves (also electromagnetic waves) get localized. Here we exploit adaptive optics to achieve focusing in disordered optical fibers in the Anderson regime. By wavefront shaping and optimization, we observe the generation of a propagation invariant beam, where light is trapped transversally by disorder, and show that Anderson localizations can be also excited by extended speckled beams. We demonstrate that disordered fibers allow a more efficient focusing action with respect to standard fibers in a way independent of their length, because of the propagation invariant features and cooperative action of transverse localizations.

  1. Convective Regimes in Crystallizing Basaltic Magma Chambers

    Science.gov (United States)

    Gilbert, A. J.; Neufeld, J. A.; Holness, M. B.

    2015-12-01

    Cooling through the chamber walls drives crystallisation in crustal magma chambers, resulting in a cumulate pile on the floor and mushy regions at the walls and roof. The liquid in many magma chambers, either the bulk magma or the interstitial liquid in the mushy regions, may convect, driven either thermally, due to cooling, or compositionally, due to fractional crystallization. We have constructed a regime diagram of the possible convective modes in a system containing a basal mushy layer. These modes depend on the large-scale buoyancy forcing characterised by a global Rayleigh number and the proportion of the chamber height constituting the basal mushy region. We have tested this regime diagram using an analogue experimental system composed of a fluid layer overlying a pile of almost neutrally buoyant inert particles. Convection in this system is driven thermally, simulating magma convection above and within a porous cumulate pile. We observe a range of possible convective regimes, enabling us to produce a regime diagram. In addition to modes characterised by convection of the bulk and interstitial fluid, we also observe a series of regimes where the crystal pile is mobilised by fluid motions. These regimes feature saltation and scouring of the crystal pile by convection in the bulk fluid at moderate Rayleigh numbers, and large crystal-rich fountains at high Rayleigh numbers. For even larger Rayleigh numbers the entire crystal pile is mobilised in what we call the snowglobe regime. The observed mobilisation regimes may be applicable to basaltic magma chambers. Plagioclase in basal cumulates crystallised from a dense magma may be a result of crystal mobilisation from a plagioclase-rich roof mush. Compositional convection within such a mush could result in disaggregation, enabling the buoyant plagioclase to be entrained in relatively dense descending liquid plumes and brought to the floor. The phenocryst load in porphyritic lavas is often interpreted as a

  2. Supercurrent in the quantum Hall regime

    Science.gov (United States)

    Amet, F.; Ke, C. T.; Borzenets, I. V.; Wang, J.; Watanabe, K.; Taniguchi, T.; Deacon, R. S.; Yamamoto, M.; Bomze, Y.; Tarucha, S.; Finkelstein, G.

    2016-05-01

    A promising route for creating topological states and excitations is to combine superconductivity and the quantum Hall (QH) effect. Despite this potential, signatures of superconductivity in the QH regime remain scarce, and a superconducting current through a QH weak link has been challenging to observe. We demonstrate the existence of a distinct supercurrent mechanism in encapsulated graphene samples contacted by superconducting electrodes, in magnetic fields as high as 2 tesla. The observation of a supercurrent in the QH regime marks an important step in the quest for exotic topological excitations, such as Majorana fermions and parafermions, which may find applications in fault-tolerant quantum computing.

  3. The oil tax regime of Azerbaijan

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Gerard

    1998-07-01

    Azerbaijan has a long history in the oil business and a chance of a spectacular future. To understand why the oil tax regime evolved into its present form and how it is likely to develop, it is necessary to know something of the country's history and the commercial environment. Consequently the presentation begins by discussing these items. It then outlines the Production Sharing Agreement regime in Azerbaijan and then deals with the Kazakh and Georgian Tax Codes, as these are likely to be the basis of a new general tax law in Azerbaijan from 1999. The presentation includes comments on the New Draft Tax Code of 1998.

  4. Clearing the way for reducing emissions from tropical deforestation

    NARCIS (Netherlands)

    Skutsch, M.; Bird, N.; Trines, E.; Dutschke, M.; Frumhoff, P.; Jong, de B.H.J.; Laake, van P.; Masera, O.; Murdiyarso, D.

    2007-01-01

    Carbon emissions from tropical deforestation account for about 25% of all anthropogenic carbon dioxide emissions but cannot be credited under current climate change agreements. In the discussions around the architecture of the post-2012 climate regime, the possibility of including credits for reduce

  5. Clearing the Way for Reducing Emissions from Tropical Deforestation

    NARCIS (Netherlands)

    Skutsch, Margaret; Bird, N.; Trines, E.; Dutschke, M.; Frumhoff, P.; de Jong, B.H.J.; van Laake, P.E.; Masera, O.; Murdiyarso, D.

    2007-01-01

    Carbon emissions from tropical deforestation account for about 25% of all anthropogenic carbon dioxide emissions but cannot be credited under current climate change agreements. In the discussions around the architecture of the post-2012 climate regime, the possibility of including credits for reduce

  6. Mass spectrometric identification of C60 fragmentation regimes under energetic Cs+ bombardment

    CERN Document Server

    Zeeshan, Sumaira; Ahmad, Shoaib

    2016-01-01

    Three C60 fragmentation regimes in fullerite bombarded by Cs+ are identified as a function of its energy. C2 is the major species sputtered at all energies. For E(Cs+) < 1 keV C2 emissions dominate. C2 and C1 have highest intensities between 1 and 3 keV with increasing contributions from C3 and C4. Intensities of all fragments maximize around 2 keV. Above 3 keV, fragments densities stabilize. The roles of and the contributions from direct recoils and collision cascades are determined. Maximum direct recoil energy delivered to the C60 fullerite cage is 210 eV at which only C2 emissions occur is identified and an explanation provided. The three fragmentation regimes under continued Cs+ bombardment eventually lead to complete destruction of the C60 cages transforming fullerite into amorphous carbon

  7. In Search of the Chiral Regime

    CERN Document Server

    Beane, S R

    2004-01-01

    A critical appraisal is given of a recent analysis of the quark-mass and finite-size dependence of unquenched lattice QCD data for the nucleon mass. We use this forum to estimate the boundary of the chiral regime for nucleon properties.

  8. Developmental Regimes in Africa synthesis report

    NARCIS (Netherlands)

    Booth, D.; Dietz, A.J.; Golooba-Mutebi, F.; Fuady, A.H.; Henley, D.; Kelsall, T.; Leliveld, A.H.M.; Donge, van J.K.

    2015-01-01

    Many African countries have experienced sustained economic growth, but few have achieved the type of structural change, driven by rising productivity, that has transformed mass living standards in parts of Asia. In the Developmental Regimes in Africa Synthesis Report, editor David Booth examines how

  9. Regimes of flow past a vortex generator

    DEFF Research Database (Denmark)

    Velte, Clara Marika; Okulov, V.L.; Naumov, I.V.

    2012-01-01

    A complete parametric investigation of the development of multi-vortex regimes in a wake past simple vortex generator has been carried out. It is established that the vortex structure in the wake is much more complicated than a simple monopole tip vortex. The vortices were studied by stereoscopic...

  10. Developmental Regimes in Africa synthesis report

    NARCIS (Netherlands)

    Booth, D.; Dietz, A.J.; Golooba-Mutebi, F.; Fuady, A.H.; Henley, D.; Kelsall, T.; Leliveld, A.H.M.; Donge, van J.K.

    2015-01-01

    Many African countries have experienced sustained economic growth, but few have achieved the type of structural change, driven by rising productivity, that has transformed mass living standards in parts of Asia. In the Developmental Regimes in Africa Synthesis Report, editor David Booth examines how

  11. Regime Change and the Role of Airpower

    Science.gov (United States)

    2006-08-01

    that connects the target sets with anticipated actions that lead to defeat of the regime. The theory’s mechanism relies on collective action theory as...collective action theory and Ted Gurr’s deprived actor theory to offer a theory of collective dissent. 7. Bueno de Mesquita et al., “Policy Failure

  12. A Global Classification of Contemporary Fire Regimes

    Science.gov (United States)

    Norman, S. P.; Kumar, J.; Hargrove, W. W.; Hoffman, F. M.

    2014-12-01

    Fire regimes provide a sensitive indicator of changes in climate and human use as the concept includes fire extent, season, frequency, and intensity. Fires that occur outside the distribution of one or more aspects of a fire regime may affect ecosystem resilience. However, global scale data related to these varied aspects of fire regimes are highly inconsistent due to incomplete or inconsistent reporting. In this study, we derive a globally applicable approach to characterizing similar fire regimes using long geophysical time series, namely MODIS hotspots since 2000. K-means non-hierarchical clustering was used to generate empirically based groups that minimized within-cluster variability. Satellite-based fire detections are known to have shortcomings, including under-detection from obscuring smoke, clouds or dense canopy cover and rapid spread rates, as often occurs with flashy fuels or during extreme weather. Such regions are free from preconceptions, and the empirical, data-mining approach used on this relatively uniform data source allows the region structures to emerge from the data themselves. Comparing such an empirical classification to expectations from climate, phenology, land use or development-based models can help us interpret the similarities and differences among places and how they provide different indicators of changes of concern. Classifications can help identify where large infrequent mega-fires are likely to occur ahead of time such as in the boreal forest and portions of the Interior US West, and where fire reports are incomplete such as in less industrial countries.

  13. Can Old Regimes Handle New Wars?

    DEFF Research Database (Denmark)

    Henningsen, Troels

    2017-01-01

    Research on New Wars argues that since the 1980s states and regimes have become more vulnerable to violence from non-state actors. Two developments in the Sahel region support the New Wars thesis: an increase in Islamist radicalization and new access to the global black market, both of which stre...

  14. The Forex Regime and EMU Expansion

    NARCIS (Netherlands)

    P.W. van Foreest; C.G. de Vries (Casper)

    2002-01-01

    textabstractThis paper provides empirical evidence that, irrespective of the foreign exchange rate regime, countries with high monetary volatility have lower relative output growth rates. It is argued that due to the forward looking nature of the foreign exchange market, exchange rate stability

  15. The Forex Regime and EMU Expansion

    NARCIS (Netherlands)

    P.W. van Foreest; C.G. de Vries (Casper)

    2002-01-01

    textabstractThis paper provides empirical evidence that, irrespective of the foreign exchange rate regime, countries with high monetary volatility have lower relative output growth rates. It is argued that due to the forward looking nature of the foreign exchange market, exchange rate stability hing

  16. Optimal dividend distribution under Markov regime switching

    NARCIS (Netherlands)

    Jiang, Z.; Pistorius, M.

    2012-01-01

    We investigate the problem of optimal dividend distribution for a company in the presence of regime shifts. We consider a company whose cumulative net revenues evolve as a Brownian motion with positive drift that is modulated by a finite state Markov chain, and model the discount rate as a determini

  17. Proliferation Control Regimes: Background and Status

    Science.gov (United States)

    2012-10-25

    1984 OPCW U.N. Conference on Disarmament EAA, 1979 AECA, 1976 Biological Weapons Anti- Terrorism Act Chem- Bio Weapons Control Warfare...Deauville, France. They reaffirmed the goals set out at the 2010 Summit for future Global Partnership activities: nuclear and radiological security, bio ... herbicides and riot control agents. Proliferation Control Regimes: Background and Status Congressional Research Service 44 Author Contact

  18. Organic random lasers in the weak-scattering regime

    CERN Document Server

    Polson, R C; 10.1103/PhysRevB.71.045205

    2005-01-01

    We used the ensemble-averaged power Fourier transform (PFT) of random laser emission spectra over the illuminated area to study random lasers with coherent feedback in four different disordered organic gain media in the weak scattering regime, where the light mean free path, l* is much larger than the emission wavelength. The disordered gain media include a pi -conjugated polymer film, an opal photonic crystal infiltrated with a laser dye (rhodamine 6G; R6G) having optical gain in the visible spectral range, a suspension of titania balls in R6G solution, and biological tissues such as chicken breast infiltrated with R6G. We show the existence of universality among the random resonators in each gain medium that we tested, in which at the same excitation intensity a dominant random cavity is excited in different parts of the sample. We show a second universality when scaling the average PFT of the four different media by l*; we found that the dominant cavity in each disordered gain medium scales with l *. The e...

  19. Scaling Fire Regimes in Space and Time.

    Science.gov (United States)

    Falk, D. A.

    2004-12-01

    Spatial and temporal variability are important properties of the forest fire regimes of coniferous forests of southwestern North America. We use a variety of analytical techniques to examine scaling in a surface fire regime in the Jemez Mountains of northern New Mexico, USA, based on an original data set collected from Monument Canyon Research Natural Area (MCN). Spatio-temporal scale dependence in the fire regime can be analyzed quantitatively using statistical descriptors of the fire regime, such as fire frequency and mean fire interval. We describe a theory of the event-area (EA) relationship, an extension of the species-area relationship for events distributed in space and time; the interval-area (IA) relationship, is a related form for fire intervals. We use the EA and IA to demonstrate scale dependence in the MCN fire regime. The slope and intercept of these functions are influenced by fire size, frequency, and spatial distribution, and thus are potentially useful metrics of spatio-temporal synchrony of events in the paleofire record. Second, we outline a theory of fire interval probability, working from first principles in fire ecology and statistics. Fires are conditional events resulting from the interaction of multiple contingent factors that must be satisfied for an event to occur. Outcomes of this kind represent a multiplicative process for which a lognormal model is the limiting distribution. We examine the application of this framework to two probability models, the Weibull and lognormal distributions, which can be used to characterize the distribution of fire intervals over time. Lastly, we present a general model for the collector's curve, with application to the theory and effects of sample size in fire history. Sources of uncertainty in fire history can be partitioned into an error typology; analytical methods used in fire history (particularly the formation of composite fire records) are designed to minimize certain types of error in inference

  20. Probing the strong gravity regime with eLISA: Progress on EMRIs

    CERN Document Server

    Sopuerta, Carlos F

    2012-01-01

    The capture of a stellar-mass compact object by a supermassive black hole and the subsequent inspiral (driven by gravitational radiation emission) constitute one of the most important sources of gravitational waves for space-based observatories like eLISA/NGO. In this article we describe their potential as high-precision tools that can be used to perform tests of the geometry of black holes and also of the strong field regime of gravity.

  1. The Determinants of Exchange Rate Regimes in Emerging Market Economies

    OpenAIRE

    Mehmet Guclu

    2008-01-01

    The choice of exchange rate regime has become one of the most important issues one more time in many economies after the financial crises in recent years. In the wake of the financial crises, many countries, especially emerging market economies, opted for floating exchange rate regimes by forsaking the pegged regimes. Consequently, an old debate on the choice and determinants of exchange rate regimes has been triggered. Economists have started to debate what appropriate exchange rate regime f...

  2. Observable Signatures of Classical T Tauri Stars Accreting in an Unstable Regime

    Directory of Open Access Journals (Sweden)

    Kurosawa Ryuichi

    2014-01-01

    Full Text Available We discuss key observational signatures of Classical T Tauri stars (CTTSs accreting through Rayleigh-Taylor instability, which occurs at the interface between an accretion disk and a stellar magnetosphere. In this study, the results of global 3-D MHD simulations of accretion flows, in both stable and unstable regimes, are used to predict the variability of hydrogen emission lines and light curves associated with those two distinctive accretion flow patterns. In the stable regime, a redshifted absorption component (RAC periodically appears in some hydrogen lines, but only during a fraction of a stellar rotation period. In the unstable regime, the RAC is present rather persistently during a whole stellar rotation period, and its strength varies non-periodically. The latter is caused by multiple accreting streams, formed randomly due to the instability, passing across the line of sight to an observer during one stellar rotation. This results in the quasi-stationarity appearance of the RAC because at least one of the accretion stream is almost always in the line of sight to an observer. In the stable regime, two stable hot spots produce a smooth and periodic light curve that shows only one or two peaks per stellar rotation. In the unstable regime, multiple hot spots formed on the surface of the star, produce the stochastic light curve with several peaks per rotation period.

  3. Choice of exchange rate regimes for African countries: Fixed or Flexible Exchange rate regimes?

    OpenAIRE

    Simwaka, Kisu

    2010-01-01

    The choice of an appropriate exchange rate regime has been a subject of ongoing debate in international economics. The majority of African countries are small open economies and thus where the choice of the exchange rate regime is an important policy issue. Aside from factors such as interest rates and inflation, the exchange rate is one of the most important determinants of a country’s relative level of economic health. For this reason, exchange rates are among the most watched analyzed and ...

  4. Parametric studies of contrail ice particle formation in jet regime using microphysical parcel modeling

    Directory of Open Access Journals (Sweden)

    H.-W. Wong

    2010-04-01

    Full Text Available Condensation trails (contrails formed from water vapor emissions behind aircraft engines are the most uncertain components of the aviation impacts on climate change. To gain improved knowledge of contrail and contrail-induced cirrus cloud formation, understanding of contrail ice particle formation immediately after aircraft engines is needed. Despite many efforts spent in modeling the microphysics of ice crystal formation in jet regime (with a plume age <5 s, systematic understanding of parametric effects of variables affecting contrail ice particle formation is still limited. In this work, we apply a microphysical parcel modeling approach to study contrail ice particle formation in near-field aircraft plumes up to 1000 m downstream of an aircraft engine in the soot-rich regime (soot number emission index >1×1015 (kg-fuel−1 at cruise. The effects of dilution history, ion-mediated nucleation, ambient relative humidity, fuel sulfur contents, and initial soot emissions were investigated. Our simulation results suggest that ice particles are mainly formed by water condensation on emitted soot particles. The growth of ice coated soot particles is driven by water vapor emissions in the first 1000 m and by ambient relative humidity afterwards. The presence of chemi-ions does not significantly contribute to the formation of ice particles in the soot-rich regime, and the effect of fuel sulfur contents is small over the range typical of standard jet fuels. The initial properties of soot emissions play the most critical role, and our calculations suggest that higher number concentration and smaller size of contrail particle nuclei may be able to effectively suppress the formation of contrail ice particles. Further modeling and experimental studies are needed to verify if our findings can provide a possible approach for contrail mitigation.

  5. Spontaneous Photon Emission in Cavities

    Directory of Open Access Journals (Sweden)

    Alber G.

    2014-01-01

    Full Text Available We investigate spontaneous photon emission processes of two-level atoms in parabolic and ellipsoidal cavities thereby taking into account the full multimode scenario. In particular, we calculate the excitation probabilities of the atoms and the energy density of the resulting few-photon electromagnetic radiation field by using semiclassical methods for the description of the multimode scenario. Based on this approach photon path representations are developed for relevant transition probability amplitudes which are valid in the optical frequency regime where the dipole and the rotating-wave approximations apply. Comparisons with numerical results demonstrate the quality of these semiclassical results even in cases in which the wave length of a spontaneously emitted photon becomes comparable or even larger than characteristic length scales of the cavity. This is the dynamical regime in which diffraction effects become important so that geometric optical considerations are typically not applicable.

  6. Regime variance testing - a quantile approach

    CERN Document Server

    gajda, Janusz; Wyłomańska, Agnieszka

    2012-01-01

    This paper is devoted to testing time series that exhibit behavior related to two or more regimes with different statistical properties. Motivation of our study are two real data sets from plasma physics with observable two-regimes structure. In this paper we develop estimation procedure for critical point of division the structure change of a time series. Moreover we propose three tests for recognition such specific behavior. The presented methodology is based on the empirical second moment and its main advantage is lack of the distribution assumption. Moreover, the examined statistical properties we express in the language of empirical quantiles of the squared data therefore the methodology is an extension of the approach known from the literature. The theoretical results we confirm by simulations and analysis of real data of turbulent laboratory plasma.

  7. Regimes de espaço

    Directory of Open Access Journals (Sweden)

    Eric Landowski

    2015-06-01

    Full Text Available Space Regimes - Based on a general model of interaction, the present analysis attempts to account for the diversity of the ways space may be apprehended in lived experience. It leads to the definition of four configurations that correspond to as many regimes of relation with the environing world. The conventional space of the circulation of values takes the archetypical shape of the net (incarnated today by Internet. The operational space is that of our dealing with objects within a material environment seen as a tissue of stable and intelligible relations. The experienced space of bodies’ movement, to which one may give as an emblem the spiral, expresses the dynamics of sensitive relationships between the self and the other. The existential space is that of our presence in a universe without boundaries, which no one can properly represent oneself but that nonetheless haunts art and thought: its figure is the abyss.

  8. Online recognition of the multiphase flow regime

    Institute of Scientific and Technical Information of China (English)

    BAI BoFeng; ZHANG ShaoJun; ZHAO Liang; ZHANG XiMin; GUO LieJin

    2008-01-01

    The key reasons that the present method cannot be used to solve the industrial multi-phase flow pattern recognition are clarified firstly. The prerequisite to realize the online recognition is proposed and recognition rules for partial flow pattern are obtained based on the massive experimental data. The standard templates for every flow regime feature are calculated with self-organization cluster algorithm. The multi-sensor data fusion method is proposed to realize the online recognition of multiphase flow regime with the pressure and differential pressure signals, which overcomes the severe influence of fluid flow velocity and the oil fraction on the recognition. The online recognition method is tested in the practice, which has less than 10 percent measurement error. The method takes advantages of high confidence, good fault tolerance and less requirement of single sensor performance.

  9. Online recognition of the multiphase flow regime

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The key reasons that the present method cannot be used to solve the industrial multi- phase flow pattern recognition are clarified firstly. The prerequisite to realize the online recognition is proposed and recognition rules for partial flow pattern are obtained based on the massive experimental data. The standard templates for every flow regime feature are calculated with self-organization cluster algorithm. The multi-sensor data fusion method is proposed to realize the online recognition of multiphase flow regime with the pressure and differential pressure signals, which overcomes the severe influence of fluid flow velocity and the oil fraction on the recognition. The online recognition method is tested in the practice, which has less than 10 percent measurement error. The method takes advantages of high confidence, good fault tolerance and less requirement of single sensor performance.

  10. Cluster analysis of multiple planetary flow regimes

    Science.gov (United States)

    Mo, Kingtse; Ghil, Michael

    1988-01-01

    A modified cluster analysis method developed for the classification of quasi-stationary events into a few planetary flow regimes and for the examination of transitions between these regimes is described. The method was applied first to a simple deterministic model and then to a 500-mbar data set for Northern Hemisphere (NH), for which cluster analysis was carried out in the subspace of the first seven empirical orthogonal functions (EOFs). Stationary clusters were found in the low-frequency band of more than 10 days, while transient clusters were found in the band-pass frequency window between 2.5 and 6 days. In the low-frequency band, three pairs of clusters determined EOFs 1, 2, and 3, respectively; they exhibited well-known regional features, such as blocking, the Pacific/North American pattern, and wave trains. Both model and low-pass data exhibited strong bimodality.

  11. Flamelet Regime Diagram for Turbulent Combustion Simulations

    Science.gov (United States)

    Chan, Wai Lee; Ihme, Matthias; Kolla, Hemanth; Chen, Jacqueline

    2016-11-01

    The flamelet model has been widely used in numerical combustion investigations, particularly for the closure of large-eddy simulations (LES) of turbulent reacting flows. In most cases, the simulation results demonstrated good agreements with their experimental counterparts. However, a systematic analysis of the flamelet model's applicability, as well as its potential limitations, is seldom conducted, and the model performance is usually based only on a-posteriori comparisons. The objective of this work is to derive a metric that can formally quantify the suitability of the flamelet model in different flame configurations. For this purpose, a flamelet regime diagram has been developed and studied in the context of direct numerical simulations (DNS) of a turbulent lifted jet flame. The implementation of the regime diagram in LES has been investigated through explicit filtering of the DNS results.

  12. Stochastic Functional Differential Equation under Regime Switching

    Directory of Open Access Journals (Sweden)

    Ling Bai

    2012-01-01

    Full Text Available We discuss stochastic functional differential equation under regime switching dx(t=f(xt,r(t,tdt+q(r(tx(tdW1(t+σ(r(t|x(t|βx(tdW2(t. We obtain unique global solution of this system without the linear growth condition; furthermore, we prove its asymptotic ultimate boundedness. Using the ergodic property of the Markov chain, we give the sufficient condition of almost surely exponentially stable of this system.

  13. Effect of water regime on poplar cultivation

    Directory of Open Access Journals (Sweden)

    Letić Ljubomir

    2006-01-01

    Full Text Available The effect of water regime on the growth and development of plantations of hydrologically conditioned species, poplars was researched in the alluvial plain of the river Tamiš. The investigations were carried out during the period 2000-2003 on the area of FA "Opovo", KO Sakule, and the study results elucidate the very complex relationships between the hydrological conditions of the site and the growth and increment of the study poplar plantations, cl. I-214. .

  14. Fiscal Policy Regimes and Household Consumption

    OpenAIRE

    Jönsson, Kristian

    2004-01-01

    In this paper, we study the effects of fiscal policy during different fiscal policy regimes. More specifically, we investigate how different factors, such as size, duration and composition of fiscal changes, can alter the effects of fiscal policy on private consumption. Using an unbalanced panel of 19 OECD countries during the period 1960-2000, we find that transfer changes are believed to be permanent during fiscal contractions. Hence, it is more likely that an expansionary fiscal contractio...

  15. Deuteron structure in the deep inelastic regime

    CERN Document Server

    Canal, C A Garcìa; Vento, V

    2016-01-01

    We study nuclear effects on the deuteron in the deep inelastic regime using the newest available data analyzing their $Q^2$ dependence. We conclude that precise EMC ratios for large $Q^2$ (> 30, GeV$^2$) cannot be obtained without considering these nuclear effects. For this purpose we use a scheme which parametrizes these effects in a simple manner and compare our results with other recent proposals.

  16. Economic Performance and North Korean Regime Legitimacy

    Science.gov (United States)

    2014-06-01

    As Cha and Anderson note, free markets have become the reliable means of survival in North Korea and these “markets create entrepreneurship , and... entrepreneurship creates an individualist way of thinking alien to the government.”9 If this case is true, the regime’s demise could very well be at...arguments on how the regime works, what has driven its survival, and the social and economic situations that have developed as a result. D. THESIS

  17. Dynamic Regime of Ignition of Solid Propellant

    Directory of Open Access Journals (Sweden)

    Zolotorev Nikolay

    2016-01-01

    Full Text Available This article presents a dynamic regime of exposure of the radiant flux on the sample of gun-cotton. Obtained time the ignition of gun-cotton in the heating conditions of increasing heat flux in the range from 0.2 W/cm2 to 22 W/cm2. A comparison of the delay times of the ignition when heated variable and constant heat flux.

  18. Ion Acceleration in the Laser Transparency Regime

    OpenAIRE

    Steinke, Sven

    2011-01-01

    Im Rahmen dieser Arbeit wurden neue, verbesserte Ansätze zur Ionenbeschleunigung mit kurzen, intensiven Laser Pulsen untersucht und charakterisiert. Die verwendeten Laser Pulse mit relativistischer Intensität und sehr hohem Intensitätskontrast ermöglichten die Verwendung von Folien-Targets mit Dicken unterhalb der Eindringtiefe des Laserspulses (~nm) und somit erstmals Experimente im sog transparenten Regime. Im Gegensatz zu undurchsichtigen, dicken Folientargets, erlauben transparente Target...

  19. Nature of the soft ULX in NGC 247: super-Eddington outflow and transition between the supersoft and soft ultraluminous regimes

    CERN Document Server

    Feng, Hua; Kaaret, Philip; Grise, Fabien

    2016-01-01

    We report on XMM-Newton/Chandra/Swift/HST observations of the ultraluminous X-ray source (ULX) in NGC 247, which is found to make transitions between the supersoft ultraluminous (SSUL) regime with a spectrum dominated by a cool ($\\sim 0.1$ keV) blackbody component and the soft ultraluminous (SUL) regime with comparable luminosities shared by the blackbody and power-law components. Multi-epoch observations revealed an anti-correlation between the blackbody radius and temperature, $R_{\\rm bb} \\propto T_{\\rm bb}^{-2.8 \\pm 0.3}$, ruling out a standard accretion disk as the origin of the soft X-ray emission. The soft X-ray emission is much more variable on both short and long timescales in the SSUL regime than in the SUL regime. We suggest that the SSUL regime may be an extension of the ultraluminous state toward the high accretion end, being an extreme case of the SUL regime, with the blackbody emission arising from the photosphere of thick outflows and the hard X-rays being emission leaked from the embedded accr...

  20. Lubrication regimes in lumbar total disc arthroplasty.

    Science.gov (United States)

    Shaheen, A; Shepherd, D E T

    2007-08-01

    A number of total disc arthroplasty devices have been developed. Some concern has been expressed that wear may be a potential failure mode for these devices, as has been seen with hip arthroplasty. The aim of this paper was to investigate the lubrication regimes that occur in lumbar total disc arthroplasty devices. The disc arthroplasty was modelled as a ball-and-socket joint. Elastohydrodynamic lubrication theory was used to calculate the minimum film thickness of the fluid between the bearing surfaces. The lubrication regime was then determined for different material combinations, size of implant, and trunk velocity. Disc arthroplasties with a metal-polymer or metal-metal material combination operate with a boundary lubrication regime. A ceramic-ceramic material combination has the potential to operate with fluid-film lubrication. Disc arthroplasties with a metal-polymer or metal-metal material combination are likely to generate wear debris. In future, it is worth considering a ceramic-ceramic material combination as this is likely to reduce wear.

  1. Detecting spatial regimes in ecosystems | Science Inventory ...

    Science.gov (United States)

    Research on early warning indicators has generally focused on assessing temporal transitions with limited application of these methods to detecting spatial regimes. Traditional spatial boundary detection procedures that result in ecoregion maps are typically based on ecological potential (i.e. potential vegetation), and often fail to account for ongoing changes due to stressors such as land use change and climate change and their effects on plant and animal communities. We use Fisher information, an information theory based method, on both terrestrial and aquatic animal data (US Breeding Bird Survey and marine zooplankton) to identify ecological boundaries, and compare our results to traditional early warning indicators, conventional ecoregion maps, and multivariate analysis such as nMDS (non-metric Multidimensional Scaling) and cluster analysis. We successfully detect spatial regimes and transitions in both terrestrial and aquatic systems using Fisher information. Furthermore, Fisher information provided explicit spatial information about community change that is absent from other multivariate approaches. Our results suggest that defining spatial regimes based on animal communities may better reflect ecological reality than do traditional ecoregion maps, especially in our current era of rapid and unpredictable ecological change. Use an information theory based method to identify ecological boundaries and compare our results to traditional early warning

  2. Utilizing Surface Sensors to Identify Wake Regimes

    Science.gov (United States)

    Wang, Mengying; Hemati, Maziar S.

    2016-11-01

    Marine swimmers often exploit external flow structures to reduce locomotive effort. To achieve this advantage, these swimmers utilize mechanosensory organs on the surface of their bodies to detect hydrodynamic signals from the surrounding fluid, which can then be used to inform the control task. Recently, there has been a growing interest in developing similar flow sensing systems to achieve enhanced propulsive efficiency and maneuverability in human-engineered underwater vehicles. In particular, much attention has been given to the problem of wake sensing; however, these investigations have concentrated on a restricted class of wakes-i.e., Kármán-type vortex streets-whereas more complicated wake structures can arise in practice. In this talk, we will explore the possibility of identifying wake regimes through the use of surface sensors. Potential flow theory is adopted to simulate the interactions of various wakes with a fish-like body. Wakes in different dynamical regimes impart distinct hydrodynamic signatures on the body, which permits these regimes to be distinguished from one another in an automated fashion. Our results can provide guidance for improving flow sensing capabilities in human-engineered systems and hint at how marine swimmers may sense their hydrodynamic surroundings.

  3. QCD in the {delta}-regime

    Energy Technology Data Exchange (ETDEWEB)

    Bietenholz, W. [Universidad Nacional Autonoma de Mexico, Mexico City (Mexico). Inst. de Ciencias Nucleares; Cundy, N. [Seoul National Univ. (Korea, Republic of). Lattice Gauge Theory Research Center; Goeckeler, M. [Regensburg Univ. (Germany). Inst. fuer Theoretische Physik; Horsley, R.; Zanotti, J.M. [Edinburgh Univ. (United Kingdom). School of Physics; Nakamura, Y. [Tsukuba Univ., Ibaraki (Japan). Center for Computational Sciences; Pleiter, D. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Rakow, P.E.L. [Liverpool Univ. (United Kingdom). Theoretical Physics Div.; Schierholz, G. [Regensburg Univ. (Germany). Inst. fuer Theoretische Physik; Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2011-03-15

    The {delta}-regime of QCD is characterised by light quarks in a small spatial box, but a large extent in (Euclidean) time. In this setting a specific variant of chiral perturbation theory - the {delta}-expansion - applies, based on a quantum mechanical treatment of the quasi onedimensional system. In particular, for vanishing quark masses one obtains a residual pion mass M{sup R}{sub {pi}}, which has been computed to the third order in the {delta}-expansion. A comparison with numerical measurements of this residual mass allows for a new determination of some Low Energy Constants, which appear in the chiral Lagrangian. We first review the attempts to simulate 2-flavour QCD directly in the {delta}-regime. This is very tedious, but results compatible with the predictions for M{sup R}{sub {pi}} have been obtained. Then we show that an extrapolation of pion masses measured in a larger volume towards the {delta}-regime leads to good agreement with the theoretical predictions. From those results, we also extract a value for the (controversial) sub-leading Low Energy Constant anti l{sub 3}. (orig.)

  4. Global biogeochemical modeling of contemporary fire emissions

    Science.gov (United States)

    Randerson, J. T.; Depaz, J. M.; van der Werf, G. R.; Giglio, L.; Morton, D. C.; Kasibhatla, P.; Defries, R. S.; Jin, Y.; Mu, M.; Collatz, G. J.

    2008-12-01

    Improved estimates of contemporary fire emissions are needed to better understand the effects of a changing fire regime on climate and air quality. At a global scale, uncertainties in fire emissions arise from several sources, including estimates of burned area, aboveground biomass, combustion completeness, and emission factors. The development of long-term time series requires addressing additional sources of uncertainty related to the integration of different satellite fire products, the representation of organic soils and peatlands, and the use of fire in the deforestation process. Here we describe improvements to a global fire emissions time series (Global Fire Emissions Database version 3) that reduce uncertainties associated with many of the factors described above. We then characterized long-term trends in fire emissions for different continental-scale regions during 1996-2007. Using South America as an example, we show how climate and human activity contribute to interannual variability in emissions and how the spatial pattern of emissions has changed over time. In a final step we use atmospheric observations of carbon monoxide (CO) from Measurements Of Pollution In The Troposphere (MOPITT) and Tropospheric Emission Spectrometer (TES) to refine and validate our bottom-up emissions estimates for South America.

  5. Diurnal cycling of urban aerosols under different weather regimes

    Science.gov (United States)

    Gregorič, Asta; Drinovec, Luka; Močnik, Griša; Remškar, Maja; Vaupotič, Janja; Stanič, Samo

    2016-04-01

    A one month measurement campaign was performed in summer 2014 in Ljubljana, the capital of Slovenia (population 280,000), aiming to study temporal and spatial distribution of urban aerosols and the mixing state of primary and secondary aerosols. Two background locations were chosen for this purpose, the first one in the city center (urban background - KIS) and the second one in the suburban background (Brezovica). Simultaneous measurements of black carbon (BC) and particle number size distribution of submicron aerosols (PM1) were conducted at both locations. In the summer season emission from traffic related sources is expected to be the main local contribution to BC concentration. Concentrations of aerosol species and gaseous pollutants within the planetary boundary layer are controlled by the balance between emission sources of primary aerosols and gases, production of secondary aerosols, chemical reactions of precursor gases under solar radiation and the rate of dilution by mixing within the planetary boundary layer (PBL) as well as with tropospheric air. Only local emission sources contribute to BC concentration during the stable PBL with low mixing layer height, whereas during the time of fully mixed PBL, regionally transported BC and other aerosols can contribute to the surface measurements. The study describes the diurnal behaviour of the submicron aerosol at the urban and suburban background location under different weather regimes. Particles in three size modes - nucleation (black carbon concentrations were observed at the urban background (KIS) than at the suburban background location (Brezovica). Significant diurnal pattern of total particle concentration and black carbon concentration was observed at both locations, with a distinct morning and late afternoon peak. As a consequence of different PBL dynamics and atmospheric processes (photochemical effects, humidity, wind speed and direction), diurnal profile differs for sunny, cloudy and rainy days

  6. Fish Springs National Wildlife Refuge water regime map

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Water regime map for Fish Springs National Wildlife Refuge. This map of water regimes on the refuge was created along with the National Vegetation Classification...

  7. Injection locking of quantum dot microlasers operating in the few photon regime

    CERN Document Server

    Schlottmann, Elisabeth; Lingnau, Benjamin; Lüdge, Kathy; Schneider, Christian; Kamp, Martin; Höfling, Sven; Wolters, Janik; Reitzenstein, Stephan

    2016-01-01

    We experimentally and theoretically investigate injection locking of quantum dot (QD) microlasers in the regime of cavity quantum electrodynamics (cQED). We observe frequency locking and phase-locking where cavity enhanced spontaneous emission enables simultaneous stable oscillation at the master frequency and at the solitary frequency of the slave microlaser. Measurements of the second-order autocorrelation function prove this simultaneous presence of both master and slave-like emission, where the former has coherent character with $g^{(2)}(0)=1$ while the latter one has thermal character with $g^{(2)}(0)=2$. Semi-classical rate-equations explain this peculiar behavior by cavity enhanced spontaneous emission and a low number of photons in the laser mode.

  8. The discrete regime of flame propagation

    Science.gov (United States)

    Tang, Francois-David; Goroshin, Samuel; Higgins, Andrew

    The propagation of laminar dust flames in iron dust clouds was studied in a low-gravity envi-ronment on-board a parabolic flight aircraft. The elimination of buoyancy-induced convection and particle settling permitted measurements of fundamental combustion parameters such as the burning velocity and the flame quenching distance over a wide range of particle sizes and in different gaseous mixtures. The discrete regime of flame propagation was observed by substitut-ing nitrogen present in air with xenon, an inert gas with a significantly lower heat conductivity. Flame propagation in the discrete regime is controlled by the heat transfer between neighbor-ing particles, rather than by the particle burning rate used by traditional continuum models of heterogeneous flames. The propagation mechanism of discrete flames depends on the spa-tial distribution of particles, and thus such flames are strongly influenced by local fluctuations in the fuel concentration. Constant pressure laminar dust flames were observed inside 70 cm long, 5 cm diameter Pyrex tubes. Equally-spaced plate assemblies forming rectangular chan-nels were placed inside each tube to determine the quenching distance defined as the minimum channel width through which a flame can successfully propagate. High-speed video cameras were used to measure the flame speed and a fiber optic spectrometer was used to measure the flame temperature. Experimental results were compared with predictions obtained from a numerical model of a three-dimensional flame developed to capture both the discrete nature and the random distribution of particles in the flame. Though good qualitative agreement was obtained between model predictions and experimental observations, residual g-jitters and the short reduced-gravity periods prevented further investigations of propagation limits in the dis-crete regime. The full exploration of the discrete flame phenomenon would require high-quality, long duration reduced gravity environment

  9. REVIEW OF REGIME THEORY OF ALLUVIAL CHANNELS

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    One of the most important problems in river engineering is to determine a stable cross section geomenry and slope for an alluvial channel. This has been the subject of considerable research for about a century and continues to be of great practical interest. Lgnoring plan geometry, an alluvi-al channel can adjust its slope, depth and width, to develop a dynamic stable condition in which it can transport a certain a-mount of water and sediment. The brief history of regime the-ory and its new development are reviewed in this paper.

  10. Electron acceleration in the bubble regime

    Energy Technology Data Exchange (ETDEWEB)

    Jansen, Oliver

    2014-02-03

    The bubble regime of laser-wakefield acceleration has been studied over the recent years as an important alternative to classical accelerators. Several models and theories have been published, in particular a theory which provides scaling laws for acceleration parameters such as energy gain and acceleration length. This thesis deals with numerical simulations within the bubble regime, their comparison to these scaling laws and data obtained from experiments, as well as some specific phenomenona. With a comparison of the scaling laws with numerical results a parameter scan was able to show a large parameter space in which simulation and theory agree. An investigation of the limits of this parameter space revealed boundaries to other regimes, especially at very high (a{sub 0} > 100) and very low laser amplitudes (a{sub 0} < 4). Comparing simulation data with data from experiments concerning laser pulse development and electron energies, it was found that experimental results can be adequately reproduced using the Virtual-Laser-Plasma-Laboratory code. In collaboration with the Institut fuer Optik und Quantenelektronik at the Friedrich-Schiller University Jena synchrotron radiation emitted from the inside of the bubble was investigated. A simulation of the movement of the electrons inside the bubble together with time dependent histograms of the emitted radiation helped to prove that the majority of radiation created during a bubble acceleration originates from the inside of the bubble. This radiation can be used to diagnose the amplitude of oscillation of the trapped electrons. During a further study it was proven that the polarisation of synchrotron radiation from a bubble contains information about the exact oscillation direction. This oscillation was successfully controlled by using either a laser pulse with a tilted pulse front or an asymmetric laser pulse. First results of ongoing studies concerning injecting electrons into an existing bubble and a scheme called

  11. Efficiency of Rectification: Reversible vs. Irreversible Regimes

    Science.gov (United States)

    Sokolov, I. M.

    2002-11-01

    Both man-made locomotive devices and molecular motors use gears to transform a reciprocating motion into a directed one. One of the most common gears is a rectifier, a mechanically irreversible appliance. The maximal energetic efficiency of an isothermic gear is bounded by unity, as a consequence of the Second Law. However, approaching this ideal efficiency does not imply approaching reversibility. We discuss what properties of a rectifier mostly influence the transduction efficiency and show that an appliance which locks under backward force is just the one which can approach the ideal efficiency either in the reversible or in the irreversible regime.

  12. Muscle's Motion in an Overdamped Regime

    Institute of Scientific and Technical Information of China (English)

    AI Bao-Quan; WANG Xian-Ju; LIU Liang-Gang; M. Nakano; H. Matsuura

    2002-01-01

    Based on the stochastic inclined rods model proposed by H. Matsuura et al., we study the motion of actin myosin system in an overdamped regime. Our model is composed ofan inclined spring (rod), a myosin head and a myosin filament. The results of calculation show that the modelcan convert the random motion to one-directional motion, and the myosin head works as a resonator of random noise, which absorbs the energy through a stochastic resonance. The results show that the inclined rod and the intermolecular potential are very important for the system to move.

  13. Ultracold Molecules: Physics in the Quantum Regime

    Energy Technology Data Exchange (ETDEWEB)

    Doyle, John [Harvard Univ., Cambridge, MA (United States). Dept. of Physics

    2014-11-17

    Our research encompasses approaches to the trapping of diatomic molecules at low temperature plus the cooling and detection of polyatomic molecules in the kelvin temperature regime. We have cooled and trapped CaF and/or CaH molecules, loaded directly from a molecular beam. As part of this work, we are continuing to develop an important trapping technique, optical loading from a buffer-gas beam. This method was invented in our lab. We are also studying cold polyatomic molecules and their interactions with cold atoms.

  14. Langmuir wave filamentation in the kinetic regime

    CERN Document Server

    Silantyev, Denis A; Rose, Harvey A

    2016-01-01

    Nonlinear Langmuir wave in the kinetic regime $k\\lambda_D\\gtrsim0.2$ has a transverse instability, where $k$ is the wavenumber and $\\lambda_D$ is the Debye length. The nonlinear stage of that instability development leads to the filamentation of Langmuir waves. Here we study the linear stage of transverse instability of both Bernstein-Greene-Kruskal (BGK) modes and dynamically prepared BGK-like initial conditions to find the same instability growth rate suggesting the universal mechanism for the kinetic saturation of stimulated Raman scatter in laser-plasma interaction experiments. Multidimensional Vlasov simulations results are compared to the theoretical predictions.

  15. Reconfigurable photoinduced metamaterials in the microwave regime

    CERN Document Server

    Rizza, Carlo; De Paulis, Francesco; Palange, Elia; Orlandi, Antonio; Columbo, Lorenzo; Prati, Franco

    2014-01-01

    We investigate optically reconfigurable dielectric metamaterials at gigahertz frequencies. More precisely, we study the microwave response of a subwavelength grating optically imprinted into a semiconductor slab. In the homogenized regime, we analytically evaluate the ordinary and extraordinary component of the effective permittivity tensor by taking into account the photo-carrier dynamics described by the ambipolar diffusion equation. We analyze the impact of semiconductor parameters on the gigahertz metamaterial response which turns out to be highly reconfigurable by varying the photogenerated grating and which can show a marked anisotropic behavior.

  16. Quality Regimes in Agro-Food Industries

    DEFF Research Database (Denmark)

    Staricco, Juan Ignacio; Ponte, Stefano

    2015-01-01

    In this article, we examine the transformative potential of changing quality regimes in agro-food industries through the analysis of whether Fair Trade wine in Argentina provides a meaningful economic alternative that goes beyond the impact it has on direct beneficiaries. The wine sector has a lo...... producing table wine for the domestic market, Fair Trade is actually further marginalizing them......., challenge and re-interpretation of different quality content. Through the lenses of a sector-adjusted version of regulation theory, we show that the Fair Trade wine sector does not substantially deviate from the conventional wine economy in Argentina. Instead of empowering the most vulnerable groups, those...

  17. Hard and Soft Excitation Regimes of Kerr Frequency Combs

    CERN Document Server

    Matsko, Andrey B; Ilchenko, Vladimir S; Seidel, David; Maleki, Lute

    2011-01-01

    We theoretically study the stability conditions and excitation regimes of hyper-parametric oscillation and Kerr frequency comb generation in continuously pumped nonlinear optical resonators possessing anomalous group velocity dispersion. We show that both hard and soft excitation regimes are possible in the resonators. Selection between the regimes is achieved via change in the parameters of the pumping light.

  18. Level-ARCH Short Rate Models with Regime Switching

    DEFF Research Database (Denmark)

    Christiansen, Charlotte

    This paper introduces regime switching volatility into level- ARCH models for the short rates of the US, the UK, and Germany. Once regime switching and level effects are included there are no gains from including ARCH effects. It is of secondary importance exactly how the regime switching...

  19. The relationship between void waves and flow regime transition

    Energy Technology Data Exchange (ETDEWEB)

    Lahey, R.T. Jr.; Drew, D.A.; Kalkach-Navarro, S.; Park, J.W.

    1992-12-31

    The results of an extensive experimental and analytical study on the relationship between void waves and flow regime transition are presented, in particular, the bubbly/slug flow regime transition. It is shown that void wave instability signals a flow regime transition.

  20. Low-frequency regime transitions and predictability of regimes in a barotropic model

    CERN Document Server

    Nadiga, B T

    2016-01-01

    Predictability of flow is examined in a barotropic vorticity model that admits low frequency regime transitions between zonal and dipolar states. Such transitions in the model were first studied by Bouchet and Simonnet (2009) and are reminiscent of regime change phenomena in the weather and climate systems wherein extreme and abrupt qualitative changes occur, seemingly randomly, after long periods of apparent stability. Mechanisms underlying regime transitions in the model are not well understood yet. From the point of view of atmospheric and oceanic dynamics, a novel aspect of the model is the lack of any source of background gradient of potential-vorticity such as topography or planetary gradient of rotation rate (e.g., as in Charney & DeVore '79). We consider perturbations that are embedded onto the system's chaotic attractor under the full nonlinear dynamics as bred vectors---nonlinear generalizations of the leading (backward) Lyapunov vector. We find that ensemble predictions that use bred vector per...

  1. Variety of synchronous regimes in neuronal ensembles

    Science.gov (United States)

    Komarov, M. A.; Osipov, G. V.; Suykens, J. A. K.

    2008-09-01

    We consider a Hodgkin-Huxley-type model of oscillatory activity in neurons of the snail Helix pomatia. This model has a distinctive feature: It demonstrates multistability in oscillatory and silent modes that is typical for the thalamocortical neurons. A single neuron cell can demonstrate a variety of oscillatory activity: Regular and chaotic spiking and bursting behavior. We study collective phenomena in small and large arrays of nonidentical cells coupled by models of electrical and chemical synapses. Two single elements coupled by electrical coupling show different types of synchronous behavior, in particular in-phase and antiphase synchronous regimes. In an ensemble of three inhibitory synaptically coupled elements, the phenomenon of sequential synchronous dynamics is observed. We study the synchronization phenomena in the chain of nonidentical neurons at different oscillatory behavior coupled with electrical and chemical synapses. Various regimes of phase synchronization are observed: (i) Synchronous regular and chaotic spiking; (ii) synchronous regular and chaotic bursting; and (iii) synchronous regular and chaotic bursting with different numbers of spikes inside the bursts. We detect and study the effect of collective synchronous burst generation due to the cluster formation and the oscillatory death.

  2. Characterizing multistationarity regimes in biochemical reaction networks.

    Directory of Open Access Journals (Sweden)

    Irene Otero-Muras

    Full Text Available Switch like responses appear as common strategies in the regulation of cellular systems. Here we present a method to characterize bistable regimes in biochemical reaction networks that can be of use to both direct and reverse engineering of biological switches. In the design of a synthetic biological switch, it is important to study the capability for bistability of the underlying biochemical network structure. Chemical Reaction Network Theory (CRNT may help at this level to decide whether a given network has the capacity for multiple positive equilibria, based on their structural properties. However, in order to build a working switch, we also need to ensure that the bistability property is robust, by studying the conditions leading to the existence of two different steady states. In the reverse engineering of biological switches, knowledge collected about the bistable regimes of the underlying potential model structures can contribute at the model identification stage to a drastic reduction of the feasible region in the parameter space of search. In this work, we make use and extend previous results of the CRNT, aiming not only to discriminate whether a biochemical reaction network can exhibit multiple steady states, but also to determine the regions within the whole space of parameters capable of producing multistationarity. To that purpose we present and justify a condition on the parameters of biochemical networks for the appearance of multistationarity, and propose an efficient and reliable computational method to check its satisfaction through the parameter space.

  3. Pulse regime in formation of fractal fibers

    Science.gov (United States)

    Smirnov, B. M.

    2016-11-01

    The pulse regime of vaporization of a bulk metal located in a buffer gas is analyzed as a method of generation of metal atoms under the action of a plasma torch or a laser beam. Subsequently these atoms are transformed into solid nanoclusters, fractal aggregates and then into fractal fibers if the growth process proceeds in an external electric field. We are guided by metals in which transitions between s and d-electrons of their atoms are possible, since these metals are used as catalysts and filters in interaction with gas flows. The resistance of metal fractal structures to a gas flow is evaluated that allows one to find optimal parameters of a fractal structure for gas flow propagation through it. The thermal regime of interaction between a plasma pulse or a laser beam and a metal surface is analyzed. It is shown that the basic energy from an external source is consumed on a bulk metal heating, and the efficiency of atom evaporation from the metal surface, that is the ratio of energy fluxes for vaporization and heating, is 10-3-10-4 for transient metals under consideration. A typical energy flux ( 106 W/cm2), a typical surface temperature ( 3000 K), and a typical pulse duration ( 1 μs) provide a sufficient amount of evaporated atoms to generate fractal fibers such that each molecule of a gas flow collides with the skeleton of fractal fibers many times.

  4. Microgravity two-phase flow regime modeling

    Energy Technology Data Exchange (ETDEWEB)

    Lee, D.; Best, F.R.; Faget, N.

    1987-01-01

    A flow pattern or flow regime is the characteristics spatial distribution of the phases of fluid in a duct. Since heat transfer and pressure drop are dependent on the characteristic distribution of the phases, it is necessary to describe flow patterns in an appropriate manner so that a hydrodynamic or heat transfer theory applicable to that pattern can be chosen. The objective of the present analysis is to create a flow regime map based on physical modeling of vapor/liquid interaction phenomena in a microgravity environment. In the present work, four basic flow patterns are defined: dispersed flow, stratified flow, slug flow, and annular flow. Fluid properties, liquid and vapor flow rates, and pipe size were chosen as the principal parameters. It is assumed that a transition from one flow pattern to another will occur when there is a change in the dominant force which controls that flow pattern. The forces considered in this modeling are surface tension force, both force, inertial force, friction, and turbulent fluctuations.

  5. Distinct transport regimes for two elastically coupled molecular motors.

    Science.gov (United States)

    Berger, Florian; Keller, Corina; Klumpp, Stefan; Lipowsky, Reinhard

    2012-05-18

    Cooperative cargo transport by two molecular motors involves an elastic motor-motor coupling, which can reduce the motors' velocity and/or enhance their unbinding from the filament. We show theoretically that these interference effects lead, in general, to four distinct transport regimes. In addition to a weak coupling regime, kinesin and dynein motors are found to exhibit a strong coupling and an enhanced unbinding regime, whereas myosin motors are predicted to attain a reduced velocity regime. All of these regimes, which we derive by explicit calculations and general time scale arguments, can be explored experimentally by varying the elastic coupling strength.

  6. Essence and Prospect of International Export Control Regimes

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ International export control regimes are referring to the regimes and systems concerning limitation of export and transference of military-use and dual-use items and related parts as well as technologies. In the past couple of years, the control regimes have shown a strengthening posture. In addition, a new global export control regime is brewing. Hence export control has caught the attention of the international community, and particularly of the circles of armament control and commerce. The author would like to make some analyses of the posture and then try to predict the trend of international export control regimes.

  7. Cointegration and causal linkages in fertilizer markets across different regimes

    Science.gov (United States)

    Lahmiri, Salim

    2017-04-01

    Cointegration and causal linkages among five different fertilizer markets are investigated during low and high market regimes. The database includes prices of rock phosphate (RP), triple super phosphate (TSP), diammonium phosphate (DAP), urea, and potassium chloride (PC). It is found that fertilizer markets are closely linked to each other during low and high regimes; and, particularly during high regime (after 2007 international financial crisis). In addition, there is no evidence of bidirectional linear relationship between markets during low and high regime time periods. Furthermore, all significant linkages are only unidirectional. Moreover, some causality effects have emerged during high regime. Finally, the effect of an impulse during high regime time period persists longer and is stronger than the effect of an impulse during low regime time period (before 2007 international financial crisis).

  8. Modern fire regime resembles historical fire regime in a ponderosa pine forest on Native American land

    Science.gov (United States)

    Amanda B. Stan; Peter Z. Fule; Kathryn B. Ireland; Jamie S. Sanderlin

    2014-01-01

    Forests on tribal lands in the western United States have seen the return of low-intensity surface fires for several decades longer than forests on non-tribal lands. We examined the surface fire regime in a ponderosa pinedominated (Pinus ponderosa) forest on the Hualapai tribal lands in the south-western United States. Using fire-scarred trees, we inferred temporal (...

  9. Enhanced amplified spontaneous emission in III-V semiconductor photonic crystal waveguides

    DEFF Research Database (Denmark)

    Ek, Sara; Schubert, Martin; Yvind, Kresten;

    2010-01-01

    We experimentally demonstrate enhanced amplified spontaneous emission in the slow light regime of an active photonic crystal waveguide slab. This promises great opportunities for future devices such as miniaturized semiconductor optical amplifiers and mode-locked lasers.......We experimentally demonstrate enhanced amplified spontaneous emission in the slow light regime of an active photonic crystal waveguide slab. This promises great opportunities for future devices such as miniaturized semiconductor optical amplifiers and mode-locked lasers....

  10. Superfluorescent emission in electrically pumped semiconductor laser

    CERN Document Server

    Boiko, D L; Stadelmann, T; Grossmann, S; Hoogerwerf, A; Weig, T; Schwarz, U T; Sulmoni, L; Lamy, J -M; Grandjean, N

    2013-01-01

    We report superfluorescent (SF) emission in electrically pumped InGaN/InGaN QW lasers with saturable absorber. In particular, we observe a superlinear growth of the peak power of SF pulses with increasing amplitude of injected current pulses and attribute it to cooperative pairing of electron-hole (e-h) radiative recombinations. The phase transitions from amplified spontaneous emission to superfluorescence and then to lasing regime is confirmed by observing (i) superlinear peak power growth, (ii) spectral shape with hyperbolic secant envelope and (iii) red shift of central wavelength of SF emission pulse. The observed red shift of SF emission is shown to be caused by the pairing of e-h pairs in an indirect cooperative X-transition.

  11. A transdisciplinary approach to understanding the health effects of wildfire and prescribed fire smoke regimes

    Science.gov (United States)

    Williamson, G. J.; Bowman, D. M. J. S.; Price, O. F.; Henderson, S. B.; Johnston, F. H.

    2016-12-01

    Prescribed burning is used to reduce the occurrence, extent and severity of uncontrolled fires in many flammable landscapes. However, epidemiologic evidence of the human health impacts of landscape fire smoke emissions is shaping fire management practice through increasingly stringent environmental regulation and public health policy. An unresolved question, critical for sustainable fire management, concerns the comparative human health effects of smoke from wild and prescribed fires. Here we review current knowledge of the health effects of landscape fire emissions and consider the similarities and differences in smoke from wild and prescribed fires with respect to the typical combustion conditions and fuel properties, the quality and magnitude of air pollution emissions, and the potential for dispersion to large populations. We further examine the interactions between these considerations, and how they may shape the longer term smoke regimes to which populations are exposed. We identify numerous knowledge gaps and propose a conceptual framework that describes pathways to better understanding of the health trade-offs of prescribed and wildfire smoke regimes.

  12. Institutional design and regime effectiveness in transboundary river management – the Elbe water quality regime

    Directory of Open Access Journals (Sweden)

    I. Dombrowsky

    2007-06-01

    Full Text Available The literature on transboundary river management suggests that institutions play an important role in bringing cooperation about. However, the knowledge on how they should be designed in order to do so remains limited. One way to learn more about adequate institutional design is to assess the effectiveness of existing regimes, and to trace the causal relationships leading to the respective outcomes. In order to gain further insights into the relationship of institutional design and regime effectiveness, this paper presents a study on the water quality regime of the International Commission for the Protection of the Elbe (ICPE. The analysis is based on a review of pertinent documents and ten qualitative interviews with Czech and German Commission members and NGO representatives. Particular emphasis has been put on determining the ICPE's specific contribution and the no-regime counterfactual as well as on the perceived expedience of the institutional arrangements. The study shows that overall due to external as well as internal institutional factors the ICPE proved relatively successful, and as such it also provides insights into how institutions matter: The commission served as platform for joint problem solving by identifying priorities for action. These international obligations increased the power of national administrations and their access to funds. At the same time, the Commission's reporting to the public served as an enforcement mechanism. However, the ICPE's contribution towards achieving the various goals varied significantly between the different areas of activity. It was high where the main responsibility for action was with the public authorities, such as in the area of wastewater treatment and the establishment of an international alarm plan and model. It was practically non existent in the reduction of non-point pollution from agriculture, where the success depended on the behavior of individual private actors (farmers. From a

  13. Mobile Networks: Visualizing the Global Refugee Regime

    Directory of Open Access Journals (Sweden)

    Bennett Gabriel Sherry

    2015-08-01

    Full Text Available This article identifies conceptual issues surrounding the visualization of refugee movement in relation to state borders. It argues that social-network-analysis software provides a tool for the creation of visualizations of human movement that are removed from geolocation. Such a method disassociates forced migration from preconceived notions about the importance of geographical proximity and the fixity of state borders. This article provides some brief examples of ways that these methods might be utilized to graph and visualize aspects of the global refugee regime. The global-scale, transnational conceptualization and new visualizations show networks of movement centered on new inter-state communities and highlights the role of non-state actors.

  14. Nonlinear regimes of forced magnetic reconnection

    Energy Technology Data Exchange (ETDEWEB)

    Vekstein, G., E-mail: g.vekstein@manchester.ac.uk [JBCA, School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom); STEL, Nagoya University, Nagoya, Aichi 464-8601 (Japan); Kusano, K. [STEL, Nagoya University, Nagoya, Aichi 464-8601 (Japan)

    2015-09-15

    This letter presents a self-consistent description of nonlinear forced magnetic reconnection in Taylor's model of this process. If external boundary perturbation is strong enough, nonlinearity in the current sheet evolution becomes important before resistive effects come into play. This terminates the current sheet shrinking that takes place at the linear stage and brings about its nonlinear equilibrium with a finite thickness. Then, in theory, this equilibrium is destroyed by a finite plasma resistivity during the skin-time, and further reconnection proceeds in the Rutherford regime. However, realization of such a scenario is unlikely because of the plasmoid instability, which is fast enough to develop before the transition to the Rutherford phase occurs. The suggested analytical theory is entirely different from all previous studies and provides proper interpretation of the presently available numerical simulations of nonlinear forced magnetic reconnection.

  15. Wilson fermions in the epsilon regime

    CERN Document Server

    Bär, Oliver; Schaefer, Stefan

    2009-01-01

    We extend the epsilon-expansion of continuum chiral perturbation theory to nonzero lattice spacing in the framework of Wilson Chiral Perturbation Theory. We distinguish various regimes by defining the relative power counting of the quark mass m and the lattice spacing a. We observe that for m ~ a Lambda^2_QCD, the explicit breaking of chiral symmetry in Wilson fermions is still driven by the quark mass and lattice corrections are highly suppressed. The lattice spacing effects become more pronounced for smaller quark masses and may lead to non-trivial corrections of the continuum results at next-to-leading order. We compute these corrections for standard current and density correlation functions. A fit to lattice data shows that these corrections are small, as expected.

  16. The Great Lakes' regional climate regimes

    Science.gov (United States)

    Sugiyama, Noriyuki

    For the last couple of decades, the Great Lakes have undergone rapid surface warming. In particular, the magnitude of the summer surface-warming trends of the Great Lakes have been much greater than those of surrounding land (Austin and Colman, 2007). Among the Great Lakes, the deepest Lake Superior exhibited the strongest warming trend in its annual, as well as summer surface water temperature. We find that many aspects of this behavior can be explained in terms of the tendency of deep lakes to exhibit multiple regimes characterized, under the same seasonally varying forcing, by the warmer and colder seasonal cycles exhibiting different amounts of wintertime lake-ice cover and corresponding changes in the summertime lake-surface temperatures. In this thesis, we address the problem of the Great Lakes' warming using one-dimensional lake modeling to interpret diverse observations of the recent lake behavior. (Abstract shortened by ProQuest.).

  17. Quantum Error Correction in the Zeno Regime

    CERN Document Server

    Erez, N; Reznik, B; Vaidman, L; Erez, Noam; Aharonov, Yakir; Reznik, Benni; Vaidman, Lev

    2003-01-01

    In order to reduce errors, error correction codes (ECCs) need to be implemented fast. They can correct the errors corresponding to the first few orders in the Taylor expansion of the Hamiltonian of the interaction with the environment. If implemented fast enough, the zeroth order error predominates and the dominant effect is of error prevention by measurement (Zeno Effect) rather than correction. In this ``Zeno Regime'', codes with less redundancy are sufficient for protection. We describe such a simple scheme, which uses two ``noiseless'' qubits to protect a large number, $n$, of information qubits from noise from the environment. The ``noisless qubits'' can be realized by treating them as logical qubits to be encoded by one of the previously introduced encoding schemes.

  18. Regime shifts in models of dryland vegetation

    CERN Document Server

    Zelnik, Yuval R; Yizhaq, Hezi; Bel, Golan; Meron, Ehud

    2013-01-01

    Drylands are pattern-forming systems showing self-organized vegetation patchiness, multiplicity of stable states and fronts separating domains of alternative stable states. Pattern dynamics, induced by droughts or disturbances, can result in desertification shifts from patterned vegetation to bare soil. Pattern-formation theory suggests various scenarios for such dynamics; an abrupt global shift involving a fast collapse to bare soil, a gradual global shift involving the expansion and coalescence of bare-soil domains, and an incipient shift to a hybrid state consisting of stationary bare-soil domains in an otherwise periodic pattern. Using models of dryland vegetation we address the question which of these scenarios can be realized. We found that the models can be split into two groups: models that exhibit multiplicity of periodic-pattern and bare-soil states, and models that exhibit, in addition, multiplicity of hybrid states. Furthermore, in all models we could not identify parameter regimes in which bare-s...

  19. Dynamic Recrystallization: The Dynamic Deformation Regime

    Science.gov (United States)

    Murr, L. E.; Pizaña, C.

    2007-11-01

    Severe plastic deformation (PD), especially involving high strain rates (>103 s 1), occurs through solid-state flow, which is accommodated by dynamic recrystallization (DRX), either in a continuous or discontinuous mode. This flow can be localized in shear instability zones (or adiabatic shear bands (ASBs)) with dimensions smaller than 5 μ, or can include large volumes with flow zone dimensions exceeding centimeters. This article illustrates these microstructural features using optical and electron metallography to examine a host of dynamic deformation examples: shaped charge jet formation, high-velocity and hypervelocity impact crater formation, rod penetration into thick targets (which includes rod and target DRX flow and mixing), large projectile-induced target plug formation and failure, explosive welding, and friction-stir welding and processing. The DRX is shown to be a universal mechanism that accommodates solid-state flow in extreme (or severe) PD regimes.

  20. Parametric studies of contrail ice particle formation in jet regime using one-dimensional microphysical modeling

    Directory of Open Access Journals (Sweden)

    H.-W. Wong

    2009-10-01

    Full Text Available Condensation trails (contrails formed from water vapor emissions behind aircraft engines are the most uncertain components of the aviation impacts on climate change. To gain improved knowledge of contrail and contrail-induced cirrus cloud formation, understanding of contrail ice particle formation immediately after aircraft engines is needed. Despite many efforts spent in modeling the microphysics of ice crystal formation in jet regime (with a plume age <5 s, systematic understanding of parametric effects of variables affecting contrail ice particle formation is still limited. In this work, we apply a one-dimensional modeling approach to study contrail ice particle formation in near-field aircraft plumes up to 1000 m downstream of an aircraft engine in the soot-rich regime (soot number emission index >1×1015 (kg-fuel−1 at cruise. The effects of ion-mediated nucleation, ambient relative humidity, fuel sulfur content, and initial soot emissions were investigated. Our simulation results suggest that ice particles are mainly formed by water condensation on emitted soot particles. The growth of ice coated soot particles is driven by water vapor emissions in the first 1000 m and by ambient relative humidity afterwards. The presence of chemi-ions does not significantly contribute to the formation of ice particles, and the effect of fuel sulfur content is small over the range typical of standard jet fuels. The initial properties of soot emissions play the most critical role, and our calculations suggest that higher number concentration and smaller size of contrail particle nuclei may be able to effectively suppress the formation of contrail ice particles, providing a possible approach for contrail mitigation.

  1. The Quantum-Gravity Regime under Microgravity

    Science.gov (United States)

    Laemmerzahl, Claus; Könemann, Thorben

    Gravity is the weakest of the four known interactions. Accordingly, one needs either huge masses to explore this interaction or a long time to accumulate its small influence. The latter is possible only under microgravity conditions. In this contribution we would like to focus on three issues related to basic problems in the quantum-gravity regime: (i) Search for fundamental decoherence: Decoherence describes the transition from the quantum world to the classical regime. There are many technical sources of decoherence but the question is whether there is a fundamental mechanism for such a decoherence which would be a solution for the measurement problem in quantum mechanics. Here we describe the estimates on such a fundamental decoherence from experiments with Bose-Einstein condensates in microgravity. (ii) Search for possible self-gravity effects: Self gravity has been proposed e.g. by Penrose to resolve the measurement problem. Self gravitating systems are also give Bose stars which are a model for the pyhsics around black holes or for dark matter. Here we would like to describe effects of self gravity in Bose-Einstein condensates. We calculate stationary spherically symmetric states and discuss the possibility to measure such effects related to self gravity. (iii) Test of the semiclassical Einstein equations. Since General Relativity and quantum theory appear to be incompatible, it has been discussed whether the semiclassical Einstein equations might be valid. Here we would like to discuss a proposal made by Peres and Lindner to use Bose-Einstein condensates for a true quantum test of these semiclassical Einstein equations from which one can decide whether such an ansatz is valid or not.

  2. Cavity Optomechanics in the Quantum Regime

    Science.gov (United States)

    Botter, Thierry Claude Marc

    An exciting scientific goal, common to many fields of research, is the development of ever-larger physical systems operating in the quantum regime. Relevant to this dissertation is the objective of preparing and observing a mechanical object in its motional quantum ground state. In order to sense the object's zero-point motion, the probe itself must have quantum-limited sensitivity. Cavity optomechanics, the interactions between light and a mechanical object inside an optical cavity, provides an elegant means to achieve the quantum regime. In this dissertation, I provide context to the successful cavity-based optical detection of the quantum-ground-state motion of atoms-based mechanical elements; mechanical elements, consisting of the collective center-of-mass (CM) motion of ultracold atomic ensembles and prepared inside a high-finesse Fabry-Perot cavity, were dispersively probed with an average intracavity photon number as small as 0.1. I first show that cavity optomechanics emerges from the theory of cavity quantum electrodynamics when one takes into account the CM motion of one or many atoms within the cavity, and provide a simple theoretical framework to model optomechanical interactions. I then outline details regarding the apparatus and the experimental methods employed, highlighting certain fundamental aspects of optical detection along the way. Finally, I describe background information, both theoretical and experimental, to two published results on quantum cavity optomechanics that form the backbone of this dissertation. The first publication shows the observation of zero-point collective motion of several thousand atoms and quantum-limited measurement backaction on that observed motion. The second publication demonstrates that an array of near-ground-state collective atomic oscillators can be simultaneously prepared and probed, and that the motional state of one oscillator can be selectively addressed while preserving the near-zero-point motion of

  3. The role of the media in establishing international security regimes

    Directory of Open Access Journals (Sweden)

    Chanan Naveh

    2005-04-01

    Full Text Available This article focuses primarily on the media's impact on international security regimes. It explores the ways in which the media affect the lifecycles of international regimes, from the time they are first conceived of, through their establishment, consolidation and stabilization, up until their ultimate demise. Although this paper highlights the media's role in the evolution of security regimes, it is clear that, regardless of the regime in question, media play a role throughout the lifecycle of all international regimes, whatever their character. In order to analyze the relationships of the media with security regimes in general, and specifically their contribution to each stage in their development, the article utilizes methodologies from the field of communication studies. It examines the media's agenda, "news values" and various functions, and their ability to mobilize public support for the particular issue of the regime. To date, most studies have explored the interaction between media communication patterns and global developments at the state level, or in relation to the formulation of foreign policy, while largely ignoring the international dimension of the relationship. This article attempts to remedy this situation, and the relevant processes are analysed in a case study of the anti-Iraq international security regime. It should be noted that although the paper focuses on the specific anti-Iraqi regime, it is part of a more general Anti-Rogue actors regime which includes the war against global terrorism. The study of the development of the anti-Iraq press-security regime teaches us that during international crises the media mobilize and unanimously support the regime fighting the "bad guys." But, when the regime develops and enters disputed turfs and begins to lose its legitimacy, media support diminishes, and the media may even develop into an opposing force and may join the actors fighting against this regime. Moreover, the study of

  4. Thermal regimes and effusive trends at Nyamuragira volcano (DRC) from MODIS infrared data

    Science.gov (United States)

    Coppola, D.; Cigolini, C.

    2013-08-01

    Nyamuragira volcano is one of the most active African volcanoes. Eruptions have been occurring every 3-4 years throughout the last century. Here, we analyse satellite infrared data, collected by MODIS sensor to estimate the volcanic radiative power (VRP, in W) and energy (VRE; in J) released during the 2001, 2002, 2004, 2006-2007, 2010 and 2011-2012 eruptions. Based on the statistical distribution of VRP measurements, we found that thermal emissions at Nyamuragira fall into three distinct radiating regimes. The high-radiating regime occurs during the emplacement of poorly insulated lava flows and characterise most of the effusive activity. The moderate-radiating regime is associated with open-vent activity (Strombolian explosions and/or lava lake activity) eventually accompanied by the emplacement of short-lived and well-insulated flows. A third radiating regime (low-radiating regime) occurs during periods, which may last weeks to months, that follow each eruption and are associated with the cooling of the effused lava flows. By applying the radiant density approach to MODIS-derived VRP we also estimated the time-averaged lava discharge rates (TADR; in m3 s-1) and we analysed the effusive trends of the above eruptions. We found that the transition between the effusive and open-vent activity typically takes place when TADR reduces to low values (<5 m3 s-1) and marks a change in the eruptive style of the volcano. Finally, we observed a clear correlation between the volume of erupted lava and its cooling time. This suggests that the average thickness of the analysed lava flows is more variable than previously thought and sheds light on the uncertainty in calculating erupted volumes assuming that lava flow areas have uniform thickness.

  5. Bichromatic emission and multimode dynamics in bidirectional ring lasers

    Science.gov (United States)

    Pérez-Serrano, Antonio; Javaloyes, Julien; Balle, Salvador

    2010-04-01

    The multimode dynamics of a two-level ring laser is explored numerically using a bidirectional traveling wave model retaining the spatial effects due to the presence of counter-propagating electric fields in the population inversion. Dynamical regimes where the emission in each direction occurs at different wavelengths are studied. Mode-locked unidirectional emission for large gain bandwidth and relatively small detuning is reported.

  6. Adaptation or innovation? The effectiveness of global environmental regimes

    OpenAIRE

    2009-01-01

    The growing importance of the discourse on climate change raises some interesting questions regarding the creation and evaluation of international regimes. When is a regime effective? Through analyzing two competing approaches to evaluating regimes, the instrumentalists and critical theorists, this project shows the deficiencies in the current discourse. Instrumentalists focus on observable means-ends standards of efficiency, while critical theorists ask fundamental questions regarding inters...

  7. Space charge saturated sheath regime and electron temperature saturation in Hall thrusters

    Science.gov (United States)

    Raitses, Y.; Staack, D.; Smirnov, A.; Fisch, N. J.

    2005-07-01

    Existing electron-wall interaction models predict that secondary electron emission in Hall thrusters is significant and that the near-wall sheaths are space charge saturated. The experimental electron-wall collision frequency is computed using plasma parameters measured in a laboratory Hall thruster. In spite of qualitative similarities between the measured and predicted dependencies of the maximum electron temperature on the discharge voltage, the deduced electron-wall collision frequency for high discharge voltages is much lower than the theoretical value obtained for space charge saturated sheath regime, but larger than the wall recombination frequency. The observed electron temperature saturation appears to be directly associated with a decrease of the Joule heating rather than with the enhancement of the electron energy loss at the walls due to a strong secondary electron emission. Another interesting experimental result is related to the near-field plasma plume, where electron energy balance appears to be independent on the magnetic field.

  8. Flow regimes in a trapped vortex cell

    Science.gov (United States)

    Lasagna, D.; Iuso, G.

    2016-03-01

    This paper presents results of an experimental investigation on the flow in a trapped vortex cell, embedded into a flat plate, and interacting with a zero-pressure-gradient boundary layer. The objective of the work is to describe the flow features and elucidate some of the governing physical mechanisms, in the light of recent investigations on flow separation control using vortex cells. Hot-wire velocity measurements of the shear layer bounding the cell and of the boundary layers upstream and downstream are reported, together with spectral and correlation analyses of wall-pressure fluctuation measurements. Smoke flow visualisations provide qualitative insight into some relevant features of the internal flow, namely a large-scale flow unsteadiness and possible mechanisms driving the rotation of the vortex core. Results are presented for two very different regimes: a low-Reynolds-number case where the incoming boundary layer is laminar and its momentum thickness is small compared to the cell opening, and a moderately high-Reynolds-number case, where the incoming boundary layer is turbulent and the ratio between the momentum thickness and the opening length is significantly larger than in the first case. Implications of the present findings to flow control applications of trapped vortex cells are also discussed.

  9. Crossing into the substellar regime in Praesepe

    CERN Document Server

    Chappelle, R J; Steele, I A; Dobbie, P D; Magazzù, A

    2005-01-01

    We present the results of a deep optical 2.6 square degree survey with near infrared follow-up measurements of the intermediate-aged Praesepe open cluster. The survey is complete to I=21.3, Z=20.5, corresponding to ~0.06 Solar Masses assuming a cluster age of 0.5 Gyrs. Using 3-5 pass-bands to constrain cluster membership, we identify 32 new low mass cluster members, at least 4 of which are likely to be substellar. We use the low mass census to trace the region where the sequence moves away from the NEXTGEN towards the Dusty regime at Teff = 2200K. In doing so, we identify four unresolved binaries, yielding a substellar binary fraction of ~30 percent. The binary fractions appear to decrease below 0.1 Solar Masses, in contrast to the rising fractions found in the Pleiades. We also identify a paucity of late M dwarfs, thought to be due to a steepening in the mass-luminosity relation at these spectral types, and compare the properties of this gap in the sequence to those observed in younger clusters. We note an o...

  10. On the ontological emergence from quantum regime

    Energy Technology Data Exchange (ETDEWEB)

    Luty, Damian [Adam Mickiewicz University, Poznan (Poland)

    2014-07-01

    There are several views on the relation between quantum physics and theory of relativity (especially General Relativity, GR). A popular perspective is this: GR with its macroscopic gravitational effects will turn out to be a limit of a more fundamental theory which should consider discrete physics and not deal with continuity (like theory of relativity). Thus, GR will emerge from a more basic theory, which should be quantum-like. One could call this an epistemic emergence view towards fundamental theories. The question is, given that scientific realism is valid: should emergence be a fundamental notion in our ontological view about the evolving, physical Universe? Is there an ontological emergence fully compatible with the notion of fundamentality? I argue that if we want to defend ontological emergence (from quantum to macroscopic regime) as something fundamental, we will arrive at the position of metaphysics of dispositions (and I argue, why this is undesirable), or conclude, that we cannot square fully fundamental ontology with the notion of emergence, and that we have to accept an ontological pluralism relativised to a certain scale. I defend the latter proposition, showing, that epistemic emergence doesn't entail (logically) ontological emergence.

  11. Legal regime of water management facilities

    Directory of Open Access Journals (Sweden)

    Salma Jožef

    2013-01-01

    Full Text Available The paper analyzes the legal regime of water management facilities in the light of Serbian, foreign and European law. Different divisions of water management facilities are carried out (to public and private ones, natural and artificial ones, etc., with determination of their legal relevance. Account is taken of the issue of protection from harmful effects of waters to such facilities, as well. The paper points also to rules on the water management facilities, from acts of planning, to individual administrative acts and measures for maintenance of required qualitative and quantitative condition of waters, depending on their purpose (general use or special, commercial use o waters. Albeit special rules on water management facilities exist, due to the natural interlocking between all the components of the environment (water, air and soil, a comprehensive approach is required. A reference is made to other basic principles of protection of water management facilities as well, such as the principle of prevention, principle of sustainable development and the principle "polluter pays". The last one represents the achievement of contemporary law, which deviates from the idea accepted in the second half of 20th century that supported the socialization of risk from harmful effects of waters.

  12. Multimode optomechanical system in the quantum regime

    CERN Document Server

    Nielsen, William H P; Møller, Christoffer B; Polzik, Eugene S; Schliesser, Albert

    2016-01-01

    We realise a simple and robust optomechanical system with a multitude of long-lived ($Q>10^7$) mechanical modes in a phononic-bandgap shielded membrane resonator. An optical mode of a compact Fabry-Perot resonator detects these modes' motion with a measurement rate ($96~\\mathrm{kHz}$) that exceeds the mechanical decoherence rates already at moderate cryogenic temperatures ($10\\,\\mathrm{K}$). Reaching this quantum regime entails, i.~a., quantum measurement backaction exceeding thermal forces, and thus detectable optomechanical quantum correlations. In particular, we observe ponderomotive squeezing of the output light mediated by a multitude of mechanical resonator modes, with quantum noise suppression up to -2.4 dB (-3.6 dB if corrected for detection losses) and bandwidths $\\lesssim 90\\,\\mathrm{ kHz}$. The multi-mode nature of the employed membrane and Fabry-Perot resonators lends itself to hybrid entanglement schemes involving multiple electromagnetic, mechanical, and spin degrees of freedom.

  13. Photonic Crystal Waveguides in Terahertz Regime

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Huaiwu, E-mail: hwzhang@uestc.edu.cn [State Key Laboratory of Electronic Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 610054 (China)

    2011-02-01

    Using the finite difference time domain method, the electromagnetic field distribution of THz waves in photonic crystals (PCs) T-splitters and Y-splitters had been simulated. The simulation results show that those different T-splitters and Y-splitters can divide the power in an input wave guide equally between two output waveguides. By the improved T-splitter with a rod in the junction, we achieved the 84% amplitude- frequency characteristics consistency of pass-band from 1.12 THz to 1.22 THz, and surpass the 76% consistency of common T-splitter. The improved Y-splitter with a rod in the junction and without rod in the corners has widest -3db bandwidth 0.224 THz, and the amplitude reaches 1655.727. The improved Y-splitter has better performance than other Y-splitters. Introducing the photonic band gap structure with L-type defect composed of three defects. Three high-Q resonant frequencies appeared simultaneously in some monitor coordinates. The wavelength-add-drop properties of L-type defects may be used in multi-carrier communication and multi-frequency-monitoring for the THz regime. Also, a carefully designed PCs can be used as high Q narrowband filter in THz band. These results provide a useful guide and a theoretical basis for the developments of THz functional components.

  14. Legal Regime of Shale Gas Extraction

    Directory of Open Access Journals (Sweden)

    Ovidiu – Horia Maican

    2013-12-01

    Full Text Available Some countries with large reserves intend to promote shale gas production, in order to reduce their dependency on imported gas. Shale gas will be an important new aspect in the world energy scene, with many effects.European Union wants secure and affordable sources of energy. Natural gas is the cleanest fossil fuel and a vital component of European Union's energy strategy. One of the most important aspects is that gas produces significantly cleaner energy than other fossil fuels.From a legal point of view, extraction of oil and natural gas is one of the most highly-regulated activities.In European Union, the regulation of shale gas activities is different if we compare with United States. United States has a complete framework of federal and state regulation of shale gas extraction. More than that, these regulations have evolved in order to respond to the United States shale gas boom.Legal regime of shale gas extraction in every member state of European Union must put together national and European Union regulations in this field of activity.

  15. Global fishery prospects under contrasting management regimes

    Science.gov (United States)

    Costello, Christopher; Ovando, Daniel; Clavelle, Tyler; Strauss, C. Kent; Hilborn, Ray; Melnychuk, Michael C.; Branch, Trevor A.; Gaines, Steven D.; Szuwalski, Cody S.; Cabral, Reniel B.; Rader, Douglas N.; Leland, Amanda

    2016-01-01

    Data from 4,713 fisheries worldwide, representing 78% of global reported fish catch, are analyzed to estimate the status, trends, and benefits of alternative approaches to recovering depleted fisheries. For each fishery, we estimate current biological status and forecast the impacts of contrasting management regimes on catch, profit, and biomass of fish in the sea. We estimate unique recovery targets and trajectories for each fishery, calculate the year-by-year effects of alternative recovery approaches, and model how alternative institutional reforms affect recovery outcomes. Current status is highly heterogeneous—the median fishery is in poor health (overfished, with further overfishing occurring), although 32% of fisheries are in good biological, although not necessarily economic, condition. Our business-as-usual scenario projects further divergence and continued collapse for many of the world’s fisheries. Applying sound management reforms to global fisheries in our dataset could generate annual increases exceeding 16 million metric tons (MMT) in catch, $53 billion in profit, and 619 MMT in biomass relative to business as usual. We also find that, with appropriate reforms, recovery can happen quickly, with the median fishery taking under 10 y to reach recovery targets. Our results show that commonsense reforms to fishery management would dramatically improve overall fish abundance while increasing food security and profits. PMID:27035953

  16. Exploiting the downhill folding regime via experiment

    Science.gov (United States)

    Muñoz, Victor; Sadqi, Mourad; Naganathan, Athi N.; de Sancho, David

    2008-01-01

    Traditionally, folding experiments have been directed at determining equilibrium and relaxation rate constants of proteins that fold with two-state-like kinetics. More recently, the combination of free energy surface approaches inspired by theory with the discovery of proteins that fold in the downhill regime has greatly widened the battlefield for experimentalists. Downhill folding proteins cross very small or no free energy barrier at all so that all relevant partially folded conformations become experimentally accessible. From these combined efforts we now have tools to estimate the height of thermodynamic and kinetic folding barriers. Procedures to measure with atomic resolution the structural heterogeneity of conformational ensembles at varying unfolding degrees are also available. Moreover, determining the dynamic modes driving folding and how they change as folding proceeds is finally at our fingertips. These developments allow us to address via experiment fundamental questions such as the origin of folding cooperativity, the relationship between structure and stability, or how to engineer folding barriers. Moreover, the level of detail attained in this new breed of experiments should provide powerful benchmarks for computer simulations of folding and force-field refinement. PMID:19436488

  17. Scaling regimes in spherical shell rotating convection

    CERN Document Server

    Gastine, T; Aubert, J

    2016-01-01

    Rayleigh-B\\'enard convection in rotating spherical shells can be considered as a simplified analogue of many astrophysical and geophysical fluid flows. Here, we use three-dimensional direct numerical simulations to study this physical process. We construct a dataset of more than 200 numerical models that cover a broad parameter range with Ekman numbers spanning $3\\times 10^{-7} \\leq E \\leq 10^{-1}$, Rayleigh numbers within the range $10^3 < Ra < 2\\times 10^{10}$ and a Prandtl number unity. We investigate the scaling behaviours of both local (length scales, boundary layers) and global (Nusselt and Reynolds numbers) properties across various physical regimes from onset of rotating convection to weakly-rotating convection. Close to critical, the convective flow is dominated by a triple force balance between viscosity, Coriolis force and buoyancy. For larger supercriticalities, a subset of our numerical data approaches the asymptotic diffusivity-free scaling of rotating convection $Nu\\sim Ra^{3/2}E^{2}$ in ...

  18. Institutional design and regime effectiveness in transboundary river management – the Elbe water quality regime

    Directory of Open Access Journals (Sweden)

    I. Dombrowsky

    2008-02-01

    Full Text Available The literature on transboundary river management suggests that institutions play an important role in bringing about cooperation. However, knowledge about how such institutions should be designed in order to do so remains limited. One way to learn more about adequate institutional design is to assess the effectiveness of existing regimes, and to trace the causal relationships that lead to the respective outcomes. In order to gain further insights into the relationship between institutional design and regime effectiveness, this paper presents a study on the water quality regime of the International Commission for the Protection of the Elbe (ICPE. The analysis is based on a review of pertinent documents and ten qualitative interviews with Czech and German Commission members and NGO representatives. Particular emphasis has been put on determining the ICPE's specific contribution and the no-regime counterfactual as well as on the perceived expediency of the institutional arrangements. The study shows overall that the countries were relatively successful in improving water quality in the Elbe basin. However, this outcome can only partly be attributed to the ICPE itself. Furthermore, the ICPE's contribution towards achieving the various goals varied significantly between the different areas of activity: it was relatively significant where the main responsibility for action lay with the public authorities, such as in the area of wastewater treatment and the establishment of an international alarm plan and model, but was practically non-existent in the reduction of non-point pollution from agriculture, where success depended on the behavior of individual private actors (farmers. The commission contributed towards problem solving by serving as a forum for the joint identification of priorities for action from a basin-wide perspective. The resulting international obligations increased the power of national water administrations and their access to funds

  19. Binary System with Components of Different Masses in the Linear Regime of the Characteristic Formulation of General Relativity

    CERN Document Server

    M., C E Cedeño

    2015-01-01

    A study of binary systems composed of two point particles with different masses in the linear regime of the characteristic formulation of general relativity is provided. The boundary conditions at the world tubes generated by the particle's orbits are explored, when the metric variables are decomposed in spin-weighted spherical harmonics. The power lost by the emission of gravitational waves is computed using the News Bondi's functions, and the contribution to the gravitational radiation of several multipole terms is shown.

  20. Ionic emission from Taylor cones

    Science.gov (United States)

    Castro Reina, Sergio

    Electrified Taylor cones have been seen as an efficient way to generate thrust for space propulsion. Especially the pure ionic regime (PIR) combines a very high specific impulse (thrust per unit mass) and efficiency, which is very important to reduce fuel transportation costs. The PIR has been primarily based on electrosprays of liquid metals [Swatik and Hendricks 1968, Swatik 1969]. However, emissions dominated by or containing exclusively ions have also been observed from nonmetallic purely ionic substances, initially sulfuric acid [Perel et al. 1969], and more recently room temperature molten salts referred to as ionic liquids (ILs) [Romero-Sanz et al. 2003]. The recent use of the liquid metal ion source (LMIS) with ILs, becoming this "new" source to be known as ionic liquid ion source (ILIS) [Lozano and Martinez-Sanchez 2005], has shown important differences on the emission from Taylor cones with the traditional hollow capillary. This new source seems to be more flexible than the capillary [Paulo, Sergio, carlos], although its low emission level (low thrust) is an important drawback from the space propulsion point of view. Throughout the thesis I have studied some aspects of the ionic emission from ionic liquid Taylor cones and the influence of the properties of the liquids and the characteristic of source on the emission. I have unraveled the reason why ILIS emits such low currents (˜200 nA) and found a way to solve this problem increasing the current up to capillary levels (˜1000 nA) [Castro and Fernandez de la Mora 2009]. I have also tried to reduce ion evaporation while reducing the emitted droplet size in order to increase the thrust generated while keeping the efficiency relatively high and I have measured the energy of evaporation of several cations composing ionic liquids, mandatory step to understand ionic evaporation.

  1. A post-Kyoto partner: considering the stratospheric ozone regime as a tool to manage nitrous oxide.

    Science.gov (United States)

    Kanter, David; Mauzerall, Denise L; Ravishankara, A R; Daniel, John S; Portmann, Robert W; Grabiel, Peter M; Moomaw, William R; Galloway, James N

    2013-03-19

    Nitrous oxide (N2O) is the largest known remaining anthropogenic threat to the stratospheric ozone layer. However, it is currently only regulated under the 1997 Kyoto Protocol because of its simultaneous ability to warm the climate. The threat N2O poses to the stratospheric ozone layer, coupled with the uncertain future of the international climate regime, motivates our exploration of issues that could be relevant to the Parties to the ozone regime (the 1985 Vienna Convention and its 1987 Montreal Protocol) should they decide to take measures to manage N2O in the future. There are clear legal avenues to regulate N2O under the ozone regime as well as several ways to share authority with the existing and future international climate treaties. N2O mitigation strategies exist to address the most significant anthropogenic sources, including agriculture, where behavioral practices and new technologies could contribute significantly to reducing emissions. Existing policies managing N2O and other forms of reactive nitrogen could be harnessed and built on by the ozone regime to implement N2O controls. There are several challenges and potential cobenefits to N2O control which we discuss here: food security, equity, and implications of the nitrogen cascade. The possible inclusion of N2O in the ozone regime need not be viewed as a sign of failure of the United Nations Framework Convention on Climate Change to adequately deal with climate change. Rather, it could represent an additional valuable tool in sustainable development diplomacy.

  2. Ultrastrong coupling of a single artificial atom to an electromagnetic continuum in the nonperturbative regime

    Science.gov (United States)

    Forn-Díaz, P.; García-Ripoll, J. J.; Peropadre, B.; Orgiazzi, J.-L.; Yurtalan, M. A.; Belyansky, R.; Wilson, C. M.; Lupascu, A.

    2017-01-01

    The study of light-matter interaction has led to important advances in quantum optics and enabled numerous technologies. Over recent decades, progress has been made in increasing the strength of this interaction at the single-photon level. More recently, a major achievement has been the demonstration of the so-called strong coupling regime, a key advancement enabling progress in quantum information science. Here, we demonstrate light-matter interaction over an order of magnitude stronger than previously reported, reaching the nonperturbative regime of ultrastrong coupling (USC). We achieve this using a superconducting artificial atom tunably coupled to the electromagnetic continuum of a one-dimensional waveguide. For the largest coupling, the spontaneous emission rate of the atom exceeds its transition frequency. In this USC regime, the description of atom and light as distinct entities breaks down, and a new description in terms of hybrid states is required. Beyond light-matter interaction itself, the tunability of our system makes it a promising tool to study a number of important physical systems, such as the well-known spin-boson and Kondo models.

  3. Role of quantum trajectory in high-order harmonic generation in the Keldysh multiphoton regime.

    Science.gov (United States)

    Li, Peng-Cheng; Jiao, Yuan-Xiang; Zhou, Xiao-Xin; Chu, Shih-I

    2016-06-27

    We present a systematic study of spectral and temporal structure of high-order harmonic generation (HHG) by solving accurately the time-dependent Schrödinger equation for a hydrogen atom in the multiphoton regime where the Keldysh parameter is greater unity. Combining with a time-frequency transform and an extended semiclassical analysis, we explore the role of quantum trajectory in HHG. We find that the time-frequency spectra of the HHG plateau near cutoff exhibit a decrease in intensity associated with the short- and long-trajectories when the ionization process is pushed from the multiphoton regime into the tunneling regime. This implies that the harmonic emission spectra in the region of the HHG plateau near and before the cutoff are suppressed. To see the generality of this prediction, we also present a time-dependent density-functional theoretical study of the effect of correlated multi-electron responses on the spectral and temporal structure of the HHG plateau of the Ar atom.

  4. The seismology of geothermal regimes. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Aki, K.

    1997-04-01

    The authors have been developing seismological interpretation theory and methods applicable to complex structures encountered in geothermal areas for a better understanding of the earth`s geothermal regimes. The questions the y have addressed in their research may be summarized as ``What is going on in the earth`s crust under tectonically active regions; what are the structures and processes responsible for such activities as earthquakes and volcanic eruptions; and how can one capture their essence effectively by means of seismological studies?`` First, the authors found clear evidence for localization of scattered seismic energy in the deep magmatic system of the volcano on the island of Reunion in the Indian Ocean. The seismic coda of local earthquakes show concentrated energy in the intrusive zones as late as 30 to 40 seconds after the origin time. This offers a very effective method for defining a zone of strong heterogeneity on a regional scale, complementary to the high resolution study using trapped modes as pursued in the past project. Secondly, the authors identified about 700 long-period events with various frequencies and durations from the data collected during the past 5 years which included three episodes of eruption. They are applying a finite-element method to the simplest event with the longest period and the shortest duration in order to find the location, geometry and physical properties of their source deterministically. The preliminary result described here suggests that their sources may be a horizontally lying magma-filled crack at a shallow depth under the summit area. In addition to the above work on the Reunion data, they have continued the theoretical and observational studies of attenuation and scattering of seismic waves.

  5. CSDP: Seismology of continental thermal regime

    Energy Technology Data Exchange (ETDEWEB)

    Aki, K.

    1989-04-01

    This is a progress report for the past one year of research (year 2 of 5-year project) under the project titled CSDP: Seismology of Continental Thermal Regime'', in which we proposed to develop seismological interpretation theory and methods applicable to complex structures encountered in continental geothermal areas and apply them to several candidate sites for the Continental Scientific Drilling Project. During the past year, two Ph.D. thesis works were completed under the present project. One is a USC thesis on seismic wave propagation in anisotropic media with application to defining fractures in the earth. The other is a MIT thesis on seismic Q and velocity structure for the magma-hydrothermal system of the Valles Caldera, New Mexico. The P.I. co-organized the first International Workshop on Volcanic Seismology at Capri, Italy in October 1988, and presented the keynote paper on the state-of-art of volcanic seismology''. We presented another paper at the workshop on Assorted Seismic Signals from Kilauea Volcano, Hawaii. Another international meeting, namely, the Chapman Conference on seismic anisotropy in the earth's crust at Berkeley, California in May 1988, was co-organized by the co-P.I. (P.C.L), and we presented our work on seismic waves in heterogeneous and anisotropic media. Adding the publications and presentations made in the past year to the list for the preceding year, the following table lists 21 papers published, submitted or presented in the past two years of the present project. 65 refs., 334 figs., 1 tab.

  6. CFD SIMULATION OF AIR ION REGIME IN WORK AREAS AT CONDITION OF ARTIFICIAL AIR IONIZATION

    Directory of Open Access Journals (Sweden)

    M. M. Biliaiev

    2016-02-01

    Full Text Available Purpose. The paper supposes creation of a CFD model for calculating the air ion regime in the premises and in work areas at artificial ionization of the air by the ionizer installation indoors with considering the most important physical factors that influence the formation of ions concentration field. Methodology. The proposed CFD model for calculation of the air ion regime in work areas at artificial ionization of the air by installing ionizer indoors is based on the application of aerodynamics, electrostatics and mass transfer equations. The mass transfer equation takes into account the interaction of different polarities of ions with each other and with the dust particles. The calculation of air flow rate in the room is realized on the basis of the potential flow model by using the Laplace equation for the stream function. Poisson equation for the electric potential is used for calculation of the charged particles drift in an electric field. At the simulation to take into account: 1 influence of the working area geometric characteristics; 2 location of the ventilation holes; 3 placement of furniture and equipment; 4 ventilation regime in the room; 5 presence of obstacles on the ions dispersion process; 6 specific location of dust particles emission and ions of different polarity, and their interaction in the room and in the working zones. Findings. The developed CFD model allows determining the concentration of negative ions in the room and in the area of the human respiratory organs. The distribution of the negative ions concentration is presented in the form of concentration field isolines. Originality. The 2D CFD model for calculating the air ion regime in working areas, providing the ability to determine the ions concentration in a given place in the room was created. The proposed model is developed taking into account: placement of furniture and equipment in the room; geometric characteristics of the room; location of dust emissions

  7. Transition to ballistic regime for heat transport in helium II

    Energy Technology Data Exchange (ETDEWEB)

    Sciacca, Michele, E-mail: michele.sciacca@unipa.it [Dipartimento Scienze Agrarie e Forestali, Università degli studi di Palermo, Viale delle Scienze, 90128 Palermo (Italy); Departament de Física, Universitat Autònoma de Barcelona, 08193 Bellaterra, Catalonia (Spain); Sellitto, Antonio, E-mail: ant.sellitto@gmail.com [Dipartimento di Matematica, Informatica ed Economia, Università della Basilicata, Campus Macchia Romana, 85100 Potenza (Italy); Jou, David, E-mail: david.jou@uab.cat [Departament de Física, Universitat Autònoma de Barcelona, 08193 Bellaterra, Catalonia (Spain); Institut d' Estudis Catalans, Carme 47, 08001 Barcelona, Catalonia (Spain)

    2014-07-04

    The size-dependent and flux-dependent effective thermal conductivity of narrow capillaries filled with superfluid helium is analyzed from a thermodynamic continuum perspective. The classical Landau evaluation of the effective thermal conductivity of quiescent superfluid, or the Gorter–Mellinck regime of turbulent superfluids, is extended to describe the transition to ballistic regime in narrow channels wherein the radius R is comparable to (or smaller than) the phonon mean-free path ℓ in superfluid helium. To do so, we start from an extended equation for the heat flux incorporating non-local terms, and take into consideration a heat slip flow along the walls of the tube. This leads from an effective thermal conductivity proportional to R{sup 2} (Landau regime) to another one proportional to Rℓ (ballistic regime). We consider two kinds of flows: along cylindrical pipes and along two infinite parallel plates. - Highlights: • Heat transport in counterflow helium in the ballistic regime. • The one-fluid model based on the Extended Thermodynamics is used. • The transition from the Landau regime to the ballistic regime. • The transition from quantum turbulence to ballistic regime.

  8. Disciplinary Regimes of "Care" and Complementary Alternative Education

    Science.gov (United States)

    Thomson, Pat; Pennacchia, Jodie

    2016-01-01

    In schools, the notion of "care" is often synonymous with welfare and disciplinary regimes. Drawing on Foucault, and a study of alternative education (AE) across the UK, and looking in depth at two cases of complementary AE, we identify three types of disciplinary regimes at work in schools: (1) dominant performative reward and…

  9. European gas market liberalisation: are regulatory regimes moving towards convergence?

    NARCIS (Netherlands)

    Haase, N.

    2008-01-01

    This study has assessed the evolution of regulatory regimes in European gas markets on the basis of panel data from the old member states (EU15) for the period between 2000 and 2005. The methodology used enabled us to assess whether regulatory regimes are converging. In this context, an index has

  10. Spectral classification of coupling regimes in the quantum Rabi model

    Science.gov (United States)

    Rossatto, Daniel Z.; Villas-Bôas, Celso J.; Sanz, Mikel; Solano, Enrique

    2017-07-01

    The quantum Rabi model is in the scientific spotlight due to the recent theoretical and experimental progress. Nevertheless, a full-fledged classification of its coupling regimes remains as a relevant open question. We propose a spectral classification dividing the coupling regimes into three regions based on the validity of perturbative criteria on the quantum Rabi model, which allows us the use of exactly solvable effective Hamiltonians. These coupling regimes are (i) the perturbative ultrastrong coupling regime which comprises the Jaynes-Cummings model, (ii) a region where nonperturbative ultrastrong and nonperturbative deep strong coupling regimes coexist, and (iii) the perturbative deep strong coupling regime. We show that this spectral classification depends not only on the ratio between the coupling strength and the natural frequencies of the unperturbed parts, but also on the energy to which the system can access. These regimes additionally discriminate the completely different behaviors of several static physical properties, namely the total number of excitations, the photon statistics of the field, and the cavity-qubit entanglement. Finally, we explain the dynamical properties which are traditionally associated with the deep strong coupling regime, such as the collapses and revivals of the state population, in the frame of the proposed spectral classification.

  11. Bargaining among Nations: Culture, History, and Perceptions in Regime Formation.

    Science.gov (United States)

    Lipschutz, Ronnie D.

    1991-01-01

    The formation of regimes (collective international schemes) for managing global problems depends on culture, history, and perceptions. The ways in which these elements affect bargaining among nations over issues of the global commons are discussed. Implications are reviewed for a regime to deal with atmospheric conditions and global warming. (SLD)

  12. Welfare regimes and the incentives to work and get educated

    NARCIS (Netherlands)

    Rodriguez-Pose, Andres; Tselios, Vassilis

    This paper examines whether differences in welfare regimes shape the incentives to work and get educated. Using microeconomic data for more than 100 ON European individuals, we show that welfare regimes make a difference for wages and education. First, people-based and household-based effects

  13. Welfare regimes and the incentives to work and get educated

    NARCIS (Netherlands)

    Rodriguez-Pose, Andres; Tselios, Vassilis

    2012-01-01

    This paper examines whether differences in welfare regimes shape the incentives to work and get educated. Using microeconomic data for more than 100 ON European individuals, we show that welfare regimes make a difference for wages and education. First, people-based and household-based effects (inter

  14. Minxin Pei, China's Crony Capitalism: The Dynamics of Regime Decay

    DEFF Research Database (Denmark)

    Brødsgaard, Kjeld Erik

    2017-01-01

    Book review of: Minxin Pei, China's Crony Capitalism: The Dynamics of Regime Decay. Cambridge, Mass.: Harvard University Press, 2016. 365 pp., including references and index. ISBN 9780674737297.......Book review of: Minxin Pei, China's Crony Capitalism: The Dynamics of Regime Decay. Cambridge, Mass.: Harvard University Press, 2016. 365 pp., including references and index. ISBN 9780674737297....

  15. Silver Nanoshell Plasmonically Controlled Emission of Semiconductor Quantum Dots in the Strong Coupling Regime.

    Science.gov (United States)

    Zhou, Ning; Yuan, Meng; Gao, Yuhan; Li, Dongsheng; Yang, Deren

    2016-04-26

    Strong coupling between semiconductor excitons and localized surface plasmons (LSPs) giving rise to hybridized plexciton states in which energy is coherently and reversibly exchanged between the components is vital, especially in the area of quantum information processing from fundamental and practical points of view. Here, in photoluminescence spectra, rather than from common extinction or reflection measurements, we report on the direct observation of Rabi splitting of approximately 160 meV as an indication of strong coupling between excited states of CdSe/ZnS quantum dots (QDs) and LSP modes of silver nanoshells under nonresonant nanosecond pulsed laser excitation at room temperature. The strong coupling manifests itself as an anticrossing-like behavior of the two newly formed polaritons when tuning the silver nanoshell plasmon energies across the exciton line of the QDs. Further analysis substantiates the essentiality of high pump energy and collective strong coupling of many QDs with the radiative dipole mode of the metallic nanoparticles for the realization of strong coupling. Our finding opens up interesting directions for the investigation of strong coupling between LSPs and excitons from the perspective of radiative recombination under easily accessible experimental conditions.

  16. Global hydrological droughts in the 21st century under a changing hydrological regime

    Directory of Open Access Journals (Sweden)

    N. Wanders

    2014-06-01

    Full Text Available Climate change very likely impacts future hydrological drought characteristics across the world. Here, we quantify the impact of climate change on future low flows and associated hydrological drought characteristics on a global scale using an alternative drought identification approach that considers adaptation to future changes in hydrological regime. The global hydrological model PCR-GLOBWB was used to simulate daily discharge at 0.5° globally for 1971–2099. The model was forced with CMIP5 climate projections taken from five GCMs and four emission scenarios (RCPs, from the Inter-Sectoral Impact Model Intercomparison Project. Drought events occur when discharge is below a threshold. The conventional variable threshold (VTM was calculated by deriving the threshold from the period 1971–2000. The transient variable threshold (VTMt is a non-stationary approach, where the threshold is based on the discharge values of the previous 30 years implying the threshold to vary every year during the 21st century. The VTMt adjusts to gradual changes in the hydrological regime as response to climate change. Results show a significant negative trend in the low flow regime over the 21st century for large parts of South America, southern Africa, Australia and the Mediterranean. In 40–52% of the world reduced low flows are projected, while increased low flows are found in the snow dominated climates. In 27% of the global area both the drought duration and the deficit volume are expected to increase when applying the VTMt. However, this area will significantly increase to 62% when the VTM is applied. The mean global area in drought, with the VTMt, remains rather constant (11.7 to 13.4%, compared to the substantial increase when the VTM is applied (11.7 to 20%. The study illustrates that an alternative drought identification that considers adaptation to an altered hydrological regime, has a substantial influence on future hydrological drought characteristics.

  17. Global hydrological droughts in the 21st century under a changing hydrological regime

    Science.gov (United States)

    Van Lanen, Henny A. J.; Wanders, Niko; Wada, Yoshihide

    2015-04-01

    Climate change very likely impacts future hydrological drought characteristics across the world. Here, we quantify the impact of climate change on future low flows and associated hydrological drought characteristics on a global scale using an alternative drought identification approach that considers adaptation to future changes in hydrological regime. The global hydrological model PCR-GLOBWB was used to simulate daily discharge at 0.5o globally for 1971-2099. The model was forced with CMIP5 climate projections taken from five global circulation models (GCMs) and four emission scenarios (representative concentration pathways, RCPs), from the Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP). Drought events occur when discharge is below a threshold. The conventional variable threshold (VTM) was calculated by deriving the threshold from the period 1971-2000. The transient variable threshold (VTMt) is a non-stationary approach, where the threshold is based on the discharge of the previous 30 years implying the threshold to vary every year during the 21st century. The VTMt adjusts to gradual changes in the hydrological regime as response to climate change. Results show a significant negative trend in the low flow regime over the 21st century for large parts of South America, southern Africa, Australia and the Mediterranean. In 40-52% of the world reduced low flows are projected, while increased low flows are found in the snow-dominated climates. In 27% of the global area both the drought duration and the deficit volume are expected to increase when applying the VTMt. However, this area will significantly increase to 62% when the VTM is applied. The mean global area in drought, with the VTMt, remains rather constant (11.7 to 13.4 %), compared to the substantial increase when the VTM is applied (11.7 to 20 %). The study illustrates that an alternative drought identification that considers adaptation to an altered hydrological regime has a substantial

  18. Global hydrological droughts in the 21st century under a changing hydrological regime

    Directory of Open Access Journals (Sweden)

    N. Wanders

    2015-01-01

    Full Text Available Climate change very likely impacts future hydrological drought characteristics across the world. Here, we quantify the impact of climate change on future low flows and associated hydrological drought characteristics on a global scale using an alternative drought identification approach that considers adaptation to future changes in hydrological regime. The global hydrological model PCR-GLOBWB was used to simulate daily discharge at 0.5° globally for 1971–2099. The model was forced with CMIP5 climate projections taken from five global circulation models (GCMs and four emission scenarios (representative concentration pathways, RCPs, from the Inter-Sectoral Impact Model Intercomparison Project. Drought events occur when discharge is below a threshold. The conventional variable threshold (VTM was calculated by deriving the threshold from the period 1971–2000. The transient variable threshold (VTMt is a non-stationary approach, where the threshold is based on the discharge values of the previous 30 years implying the threshold to vary every year during the 21st century. The VTMt adjusts to gradual changes in the hydrological regime as response to climate change. Results show a significant negative trend in the low flow regime over the 21st century for large parts of South America, southern Africa, Australia and the Mediterranean. In 40–52% of the world reduced low flows are projected, while increased low flows are found in the snow-dominated climates. In 27% of the global area both the drought duration and the deficit volume are expected to increase when applying the VTMt. However, this area will significantly increase to 62% when the VTM is applied. The mean global area in drought, with the VTMt, remains rather constant (11.7 to 13.4%, compared to the substantial increase when the VTM is applied (11.7 to 20%. The study illustrates that an alternative drought identification that considers adaptation to an altered hydrological regime has a

  19. Boundary between Stable and Unstable Regimes of Accretion. Ordered and Chaotic Unstable Regimes

    CERN Document Server

    Blinova, A A; Lovelace, R V E

    2015-01-01

    We search for the boundary between stable and Rayleigh-Taylor unstable regimes of accretion to magnetized stars in a new set of high grid resolution simulations. We found that the boundary between stable and unstable regimes is mainly determined by the ratio of the corotation radius r_cor (where the Keplerian angular velocity in the disc matches the angular velocity of the star) to the magnetospheric radius r_m (where the magnetic stress in the magnetosphere matches the matter stress in the disc). Instability is stronger when r_cor is larger with respect to r_m, that is, when the gravitational force is larger than the centrifugal force at the inner disc. In the cases of a small tilt of the magnetosphere, Theta=5 deg, and a small alpha-parameter of viscosity, alpha=0.02, the boundary is located at r_cor approx. 1.4 r_m. Instability becomes stronger at higher values of viscosity, and occurs at lower values of r_cor/r_m. At higher values of Theta, the variability associated with instability decreases. Simulation...

  20. Emissions trading and the negotiation of pollution credits

    Energy Technology Data Exchange (ETDEWEB)

    Black A.J.

    2000-07-01

    A new market is emerging based on greenhouse gas emissions and the trading of pollution credits. While the structure of the primary market is being planned, many businesses are already positioning themselves in the nascent secondary market. This trend is based on corporate 'realpolitik' a recognition that tougher environmental regulation is inevitable. But the development of an emissions trading regime is lagging behind commercial reality. This article examines the state of play in the development of a market for carbon emissions trading.

  1. Emission Inventory for Fugitive Emissions in Denmark

    DEFF Research Database (Denmark)

    Plejdrup, Marlene Schmidt; Nielsen, Ole-Kenneth; Nielsen, Malene

    This report presents the methodology and data used in the Danish inventory of fugitive emissions from fuels for the years until 2007. The inventory of fugitive emissions includes CO2, CH4, N2O, NOx, CO, NMVOC, SO2, dioxin, PAH and particulate matter. In 2007 the total Danish emission of greenhouse...

  2. THE OXYGEN REGIME OF A SHALLOW LAKE

    Directory of Open Access Journals (Sweden)

    Galina Zdorovennova

    2016-01-01

    Full Text Available The year-round measurement data of water temperature and dissolved oxygen content in a small boreal Lake Vendyurskoe in 2007–2013 were used to explore the hydrophysical prerequisits of anoxia and accumulation and emission of greenhouse gases. Typically, anoxia appears in the bottom layers of lakes in mid-winter and during the summer  stagnation. The thickness of the benthic anaerobic zone (dissolved oxygen concentration <2 mg·l–1 reached one meter in the end of the winter and at the peak of the summer stratification, except for the extremely hot summer of 2010, when it reached five meters. Synoptic conditions had a crucial influence on the formation and destruction of the benthic anaerobic zones in summer. The most favorable oxygen dynamics was observed during the cold summers of 2008, 2009, and 2012, when the repeated full mixings of the water column occurred under conditions of the cyclonic weather. In the winter periods, the early dates of ice season resulted in the most pronounced deficiency of oxygen.

  3. Spontaneous emission effects in optically pumped x-ray FEL

    Energy Technology Data Exchange (ETDEWEB)

    Smetanin, I.V.; Grigor`ev, S.V. [P.N. Lebedev Physics Institute, Moscow (Russian Federation)

    1995-12-31

    An effect of spontaneous emission in both quantum and classical regimes of the optically pumped X-ray free electron laser (FEL) in investigated. The quantum properties of an FEL are determined by the ratio of the separation {h_bar} between the absorption and emission lines (i.e. the quanta emitted) and their effective width {Delta}{epsilon} {eta}={h_bar}/{Delta}{epsilon}. In the conventional classical regime {eta} {much_lt} 1 an electron emits and absorbes a great number of shortwavelength photons over the interaction region, the gain in FEL being the result of these competitive processes. In the quantum limit {eta} {much_gt} 1 the emission and absorption lines are completely separated and thus the FEL becomes a two-level quantum oscillator with a completely inverted active medium. Spontaneous emission causes the electron to leave the range of energies where resonant interaction with the laser field occurs, thus effectively reducing the number of particles that take part in generating the induced X-ray signal. This effect is found to be crucial for lasing in optically pumped X-ray FEL. The characteristic relaxation times are calculated for both classical and quantum FEL regimes. It is shown that spontaneous emission results in FEL electron beam threshold current, which is of rather high value. An optimal range of pumping laser intensities is determined.

  4. Tropical deforestation in the context of the post-2012 Climate Change Regime

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, J.L. [WWF International, Global Climate Change Program, Washington DC (United States); Maretti, C. [WWF Brazil, Brasilia (Brazil); Volpi, G. [WWF Latin American Climate Change Program, Brasilia (Brazil)

    2005-07-01

    There is overwhelming evidence and consensus that climate change is real and happening now. In fact, the impacts of climate change are occurring faster than what many scientists first predicted. Whether assessing impacts to coral reefs, the arctic, sub-Saharan Africa or the tropical rainforests, change is happening and time is short to avoid the most devastating impacts. In order to prevent dangerous climate change, governments, WWF and other NGOs have stated that global average temperature must stay well below a 2 degrees C rise in comparison to pre-industrial temperature. In order to ensure that this dangerous threshold is not crossed, global greenhouse gas emissions will have to be rapidly and deeply reduced over the next one to two decades. The sources of emissions are clear. An estimated 75 to 80% of global emissions stem from industrial sources, specifically, the burning of fossil fuels. The remaining 20 to 25% can be sourced to deforestation emissions, predominantly in the tropics. Both, the burning of fossil fuels and deforestation, must be urgently and effectively addressed in order to save the world's biodiversity and people from catastrophic climate change. At this time, a new opportunity exists to address the issue of deforestation within the climate change regime. The Kyoto Protocol entered into force in February 2005, thus setting the stage for the first Meeting of the Protocol Parties in late 2005 in Montreal, Canada. The Protocol requires that already in 2005, Parties begin assessing and negotiating changes to the Protocol, as noted in Articles 3.9 and 9.2. Due to the urgency of emissions reductions, it is clear that each country will have to commit to more action than in the past, whether it be an Annex I developed country Party or a non-Annex I developing country Party. The Climate Action Network (CAN), a network of over three hundred NGOs worldwide, has put forth a concrete proposal on how such commitments could (a) evolve over time and (b

  5. Conceptualization of UN Peacekeeping as an International Regime

    Directory of Open Access Journals (Sweden)

    Jana Urbanovská

    2012-12-01

    Full Text Available It is widely recognized that UN peacekeeping operations are an undertheorized topic. In this respect, scholars call to devote more attention to the incorporation of the study of UN peacekeeping operations into the framework of international relations theories. The article responds to these calls and suggests conceptualizing UN peacekeeping as an international regime. Some authors have already referred to UN peacekeeping as an international regime, however, the references have been rather fragmentary and there is no detailed identification of individual dimensions of this regime. The article uses the conception of Stephen Krasner who defines regimes as “principles, norms, rules, and decision-making procedures around which actors’ expectations converge in a given area of international relations” to carefully identify and characterize the dimensions of the UN peacekeeping regime. The conceptualization of UN peacekeeping as an international regime is understood as a first and necessary step to opening new ground to the theoretical study of UN peacekeeping operations within the regime analysis.

  6. Perspectives on the International and Internal Nuclear Security Regime

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Sung Soon [Korea Nuclear Non-proliferation and Control, Daejeon (Korea, Republic of)

    2015-10-15

    The term, 'Nuclear Security' became more familiar to Korean public after the government hosted 2012 Seoul Nuclear Security Summit. Nuclear Security is prevention of, detection of and response to criminal or intentional unauthorized acts involving or directed at nuclear material, other radioactive material, associated facilities, or associated activities. Nuclear Security includes physical protection, security of radioactive sources, nuclear forensics, nuclear smuggling prevention, border monitoring, and cyber security with regard to nuclear and other radiological materials. This abstract will review recent international trends and discuss the nuclear security regime in the Republic of Korea (ROK). The international Nuclear Security Regime has been strengthened. The upcoming Chicago Summit in 2016 and the entry into force of the Amendment of Convention on Physical Protection of Nuclear Materials (CPPNM) will bring major changes in nuclear security. The Republic of Korea hosted the 2012 Seoul Summit and strengthened domestic regime to meet international standards. The ROK has worked hard to contribute to the international security regime and to establish a robust domestic security regime against terrorist threats. Even if the nuclear security regime is robust, Risk-informed Nuclear Security management should be established to meet international standards and to implement effective as well as an efficient nuclear security regime.

  7. [Heath and political regimes: presidential or parliamentary government for Colombia?].

    Science.gov (United States)

    Idrovo, Alvaro J

    2007-01-01

    Changing the presidential regime for a parliamentarian one is currently be-ing discussed in Colombia. This preliminary study explores the potential effects on health of both presidential and parliamentary regimes by using world-wide data. An ecological study was undertaken using countries from which comparable information concerning life-expectancy at birth, political regime, economic development, inequality in income, social capital (as measured by general-ised trust or Corruption Perceptions Index), political rights, civil freedom and cultural diversity could be obtained. Life-expectancy at birth and macro-determinants were compared between both political regimes. The co-relationship between these macro-determinants was estimated and the relationship between political regimen and life-expectancy at birth was estimated using robust regression. Crude analysis revealed that parliamentary countries have greater life-expectancy at birth than countries having a presidential regime. Significant co-relationships between all macro-determinants were observed. No differential effects were observed between both political regimes regarding life-expectancy at birth in multiple robust regressions. There is no evidence that presidential or parliamentary regimes provide greater levels of health for the population. It is suggested that public health policies be focused on other macro-determinants having more known effects on health, such as income inequality.

  8. Marine regime shifts: drivers and impacts on ecosystems services

    Science.gov (United States)

    Rocha, J.; Yletyinen, J.; Biggs, R.; Blenckner, T.; Peterson, G.

    2015-01-01

    Marine ecosystems can experience regime shifts, in which they shift from being organized around one set of mutually reinforcing structures and processes to another. Anthropogenic global change has broadly increased a wide variety of processes that can drive regime shifts. To assess the vulnerability of marine ecosystems to such shifts and their potential consequences, we reviewed the scientific literature for 13 types of marine regime shifts and used networks to conduct an analysis of co-occurrence of drivers and ecosystem service impacts. We found that regime shifts are caused by multiple drivers and have multiple consequences that co-occur in a non-random pattern. Drivers related to food production, climate change and coastal development are the most common co-occurring causes of regime shifts, while cultural services, biodiversity and primary production are the most common cluster of ecosystem services affected. These clusters prioritize sets of drivers for management and highlight the need for coordinated actions across multiple drivers and scales to reduce the risk of marine regime shifts. Managerial strategies are likely to fail if they only address well-understood or data-rich variables, and international cooperation and polycentric institutions will be critical to implement and coordinate action across the scales at which different drivers operate. By better understanding these underlying patterns, we hope to inform the development of managerial strategies to reduce the risk of high-impact marine regime shifts, especially for areas of the world where data are not available or monitoring programmes are not in place.

  9. Considerations on nonproliferation regime meeting in a changing world

    Energy Technology Data Exchange (ETDEWEB)

    Kurihara, Hiroyoshi; Kikuchi, Masahiro [Nuclear Material Control Center, Tokyo (Japan)

    1994-12-31

    This paper summarizes the past history of worldwide nonproliferation regime, then proposes the future improvements on the regime. Present worldwide nonproliferation regime have been formulated during the cold war era. Therefore, the structure and measures of the regime were heavily influenced by the features of cold war era. Though the cold war was over, still new international order does not seem to be on the horizon, we need to review the present regime and to improve the regime compatible to new world situation. Generally speaking, the nonproliferation regime have gained moderate success so far. We could point out the following features as a kind of success: (1) No increase of overt Nuclear Weapon State (NWS), (2) All five NWSs have finally participated to the NPT, (3) South Africa has destroyed its nuclear weapons and became Non-Nuclear Weapon State (NNWS), (4) Successful conclusions of some regional arrangements, such as Tlatelolco, Ralotonga, and (5) Strengthening of export control on sensitive items. On the other hand, we recognize the following points as the failures of the regime. (6) India, Pakistan and Israel reject to join the NPT, (7) Existence of some violation against NPT regime, i.e. Iraqi case and DPRK case, (8) Insufficient effective measures against brain drain problem, (9) Risk exists for the long term extension of NPT, and (10) Insufficient flexibility to meet changing boundary conditions. We would propose the various measures for strengthening to meet changing boundary conditions, as follows: (11) Measures to be taken along with future civil use of Plutonium, (12) Strengthening and rationalizing international safeguards, (13) Countermeasures for emerging new types of nuclear proliferation, (14) Strengthening nuclear material control in NWS, (15) Measures to be taken for nuclear material from dismantled nuclear weapons, and (16) Nuclear disarmament. (author).

  10. Diversity-Multiplexing Tradeoff in the Low-SNR Regime

    CERN Document Server

    Loyka, Sergey

    2011-01-01

    An extension of the popular diversity-multiplexing tradeoff framework to the low-SNR (or wideband) regime is proposed. The concept of diversity gain is shown to be redundant in this regime since the outage probability is SNR-independent and depends on the multiplexing gain and the channel power gain statistics only. The outage probability under the DMT framework is obtained in an explicit, closed form for a broad class of channels. The low and high-SNR regime boundaries are explicitly determined for the scalar Rayleigh-fading channel, indicating a significant limitation of the SNR-asymptotic DMT when the multiplexing gain is small.

  11. Raman amplification in the broken-wave regime

    CERN Document Server

    Farmer, John P

    2015-01-01

    In regimes far beyond the wavebreaking theshold of Raman amplification, we show that significant amplifcation can occur after the onset of wavebreaking, before phase mixing destroys the coupling between pump and probe. The amplification efficiency in this regime is therefore strongly dependent on the energy-transfer rate when wavebreaking occurs, and is, as such, sensitive to both the probe amplitude and profile. In order to access the higher-efficiency broken-wave regime, a short, intense probe is required. Parameter scans show the marked difference in behaviour compared to below wavebreaking, where longer, more energetic pulses lead to improved efficiencies.

  12. A thermodynamic view of heat transfer in different transport regimes

    Science.gov (United States)

    Schubler, Gulru Babac

    2016-11-01

    The nature of the heat transfer process changes substantially according to transport regime. A thermodynamic view to micro/nano scale flows is considered to get a better understanding within this regime dependent change. The transport processes are expressed as a polytropic process and T-s diagram of different transport regimes are presented. In addition, a molecular dynamic simulation of nano channel flows is presented. Since the polytropic processes are strongly related with the heat capacities, the heat capacity calculations are also taken into account in MD simulations. The theoretical predictions are approved with the molecular dynamic simulations for monatomic gases.

  13. Policy Ideas, Knowledge Regimes and Comparative Political Economy

    DEFF Research Database (Denmark)

    Campbell, John L.; Pedersen, Ove K.

    2015-01-01

    Despite much attention to how ideas affect policy making, where these ideas come from is a blind spot in comparative political economy. We show that an important source of policy ideas are knowledge regimes—fields of policy research organizations. We show as well that the organization of knowledge......, France and Germany. Theoretical implications are explored for two literatures in comparative political economy: ideational analysis and the varieties of capitalism....... regimes is heavily influenced by the organization of their surrounding political economies such that knowledge regimes have particular national characters. Furthermore, when people perceive that the utility of their knowledge regime for the rest of the political economy breaks down, they often try...

  14. Boundary between stable and unstable regimes of accretion. Ordered and chaotic unstable regimes

    Science.gov (United States)

    Blinova, A. A.; Romanova, M. M.; Lovelace, R. V. E.

    2016-07-01

    We present a new study of the Rayleigh-Taylor unstable regime of accretion on to rotating magnetized stars in a set of high grid resolution three-dimensional magnetohydrodynamic simulations performed in low-viscosity discs. We find that the boundary between the stable and unstable regimes is determined almost entirely by the fastness parameter ωs = Ω⋆/ΩK(rm), where Ω⋆ is the angular velocity of the star and ΩK(rm) is the angular velocity of the Keplerian disc at the disc-magnetosphere boundary r = rm. We found that accretion is unstable if ωs ≲ 0.6. Accretion through instabilities is present in stars with different magnetospheric sizes. However, only in stars with relatively small magnetospheres, rm/R⋆ ≲ 7, do the unstable tongues produce chaotic hotspots on the stellar surface and irregular light curves. At even smaller values of the fastness parameter, ωs ≲ 0.45, multiple irregular tongues merge, forming one or two ordered unstable tongues that rotate with the angular frequency of the inner disc. This transition occurs in stars with even smaller magnetospheres, rm/R⋆ ≲ 4.2. Most of our simulations were performed at a small tilt of the dipole magnetosphere, Θ = 5°, and a small viscosity parameter α = 0.02. Test simulations at higher α values show that many more cases become unstable, and the light curves become even more irregular. Test simulations at larger tilts of the dipole Θ show that instability is present, however, accretion in two funnel streams dominates if Θ ≳ 15°. The results of these simulations can be applied to accreting magnetized stars with relatively small magnetospheres: Classical T Tauri stars, accreting millisecond X-ray pulsars, and cataclysmic variables.

  15. Analysis of light regime in continuous light distributions in photobioreactors.

    Science.gov (United States)

    Brindley, Celeste; Fernández, F G Acién; Fernández-Sevilla, J M

    2011-02-01

    Maximum photobioreactor (PBR) efficiency is a must in applications such as the obtention of microalgae-derived fuels. Improving PBR performance requires a better understanding of the "light regime", the varying irradiance that microalgal cells moving in a dense culture are exposed to. We propose a definition of light regime that can be used consistently to describe the continuously varying light patterns in PBRs as well as in light/dark cycles. Equivalent continuous and light/dark regimes have been experimentally compared and the results show that continuous variations are not well represented by light/dark cycles, as had been widely accepted. It has been shown that a correct light regime allows obtaining photosynthetic rates higher than the corresponding to continuous light, the so-called "flashing light effect" and that this is possible in commercial PBRs. A correct PBR operation could result in photosynthetic efficiency close to the optimum eight quanta per O(2).

  16. Regime-Switching Risk: To Price or Not to Price?

    Directory of Open Access Journals (Sweden)

    Tak Kuen Siu

    2011-01-01

    “normative” issues to be addressed in pricing contingent claims under a Markovian, regime-switching, Black-Scholes-Merton model. We address this issue using a minimal relative entropy approach. Firstly, we apply a martingale representation for a double martingale to characterize the canonical space of equivalent martingale measures which may be viewed as the largest space of equivalent martingale measures to incorporate both the diffusion risk and the regime-switching risk. Then we show that an optimal equivalent martingale measure over the canonical space selected by minimizing the relative entropy between an equivalent martingale measure and the real-world probability measure does not price the regime-switching risk. The optimal measure also justifies the use of the Esscher transform for option valuation in the regime-switching market.

  17. Nonequilibrium electron transport through quantum dots in the Kondo regime

    DEFF Research Database (Denmark)

    Wölfle, Peter; Paaske, Jens; Rosch, Achim

    2005-01-01

    Electron transport at large bias voltage through quantum dots in the Kondo regime is described within the perturbative renormalization group extended to nonequilibrium. The conductance, local magnetization, dynamical spin susceptibility and local spectral function are calculated. We show how the ...

  18. Evolution of human-driven fire regimes in Africa

    CSIR Research Space (South Africa)

    Archibald, S

    2012-01-01

    Full Text Available Human ability to manipulate fire and the landscape has increased over evolutionary time, but the impact of this on fire regimes and consequences for biodiversity and biogeochemistry are hotly debated. Reconstructing historical changes in human...

  19. A new regime for future telecommunication network operations

    NARCIS (Netherlands)

    Gustafsson, S.; Trommelen, P.H.; Vos, C. de

    2010-01-01

    The increasingly crucial role that telecommunications plays in today's information society calls for a new regime for telecommunication network operations. An unbundling of business roles and associated responsibilities is proposed, providing more economic network operations and higher availability

  20. The organization of global negotiations: constructing the climate change regime

    National Research Council Canada - National Science Library

    Depledge, Joanna

    2005-01-01

    "Using a theatrical metaphor, this book describes the enormous and skilful organization required by the UN to create an effective international regime, producing the UN Framework Convention on Climate...

  1. Determination of three characteristic regimes of weakly charged polyelectrolytes monolayers

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, Farhan [Department of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); Shin, Kwanwoo [Department of Chemistry and Interdisciplinary Program of Integrated Biotechnology, Sogang University, Seoul 121-742 (Korea, Republic of)], E-mail: kshin@sogang.ac.kr; Choi, Jae-Hak [Advanced Radiation Technology Institute, KAERI, Jeongeup 580-185 (Korea, Republic of); Satija, Sushil K. [National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Kim, Joon-Seop [Department of Polymer Science and Engineering, Chosun University (Korea, Republic of); Rafailovich, Miriam H.; Sokolov, Jon [Department of Materials Science and Engineering, Stony Brook University, Stony Brook, NY 11794 (United States)

    2008-09-15

    We have demonstrated that monolayer films of randomly charged polystyrene sulfonated acid (PSSA) can be produced by the Langmuir technique, and observed the micro-domain structures, produced by the phase separation of electrostatically charged moieties and the hydrophobic moieties. Using atomic force microscopy and Langmuir isotherm, we found three specific regimes for the polyelectrolytes with various degrees of sulfonation (4-35%); very low charged PSSA (4-5%) in the hydrophobic regime, moderately charged PSSA (6-16%) which possessed a well-balanced nature between electrostatic and the hydrophobic interactions, and strongly amphiphilic nature of PSSA (6-16%) in the ionomer regime. Finally, we could categorize PSSA 35% in the polyelectrolyte regime, due to the dominance of the electrostatic interactions over the hydrophobic interactions.

  2. Regime change and oscillation thresholds in recorder-like instruments.

    Science.gov (United States)

    Auvray, Roman; Fabre, Benoît; Lagrée, Pierre-Yves

    2012-02-01

    Based on results from the literature, a description of sound generation in a recorder is developed. Linear and non-linear analysis are performed to study the dependence of the frequency on the jet velocity. The linear analysis predicts that the frequency is a function of the jet velocity. The non-linear resolution provides information about limit cycle oscillation and hysteretic regime change thresholds. A comparison of the frequency between linear theory and experiments on a modified recorder shows good agreement except at very low jet velocities. Although the predicted threshold for the onset of the first regime shows an important deviation from experiments, the hysteresis of threshold to higher regimes is accurately estimated. Furthermore, a qualitative analysis of the influence of different parameters in the model on the sound generation and regime changes is presented.

  3. Crossflow and water banks in viscous dominant regimes of waterflooding

    DEFF Research Database (Denmark)

    Yuan, Hao; Zhang, Xuan; Shapiro, Alexander

    2014-01-01

    Understanding the crossflow in multilayered reservoirs is of great importance for designing mobility control methods for enhanced oil recovery. The authors reveal saturation profiles in stratified reservoirs to study the interlayer communication in the viscous dominant regime. The displacement...

  4. Regime shifts and resilience in China's coastal ecosystems.

    Science.gov (United States)

    Zhang, Ke

    2016-02-01

    Regime shift often results in large, abrupt, and persistent changes in the provision of ecosystem services and can therefore have significant impacts on human wellbeing. Understanding regime shifts has profound implications for ecosystem recovery and management. China's coastal ecosystems have experienced substantial deterioration within the past decades, at a scale and speed the world has never seen before. Yet, information about this coastal ecosystem change from a dynamics perspective is quite limited. In this review, I synthesize existing information on coastal ecosystem regime shifts in China and discuss their interactions and cascading effects. The accumulation of regime shifts in China's coastal ecosystems suggests that the desired system resilience has been profoundly eroded, increasing the potential of abrupt shifts to undesirable states at a larger scale, especially given multiple escalating pressures. Policy and management strategies need to incorporate resilience approaches in order to cope with future challenges and avoid major losses in China's coastal ecosystem services.

  5. Constraining Substellar Magnetic Dynamos using Auroral Radio Emission

    Science.gov (United States)

    Kao, Melodie; Hallinan, Gregg; Pineda, J. Sebastian; Escala, Ivanna; Burgasser, Adam J.; Stevenson, David J.

    2017-01-01

    An important outstanding problem in dynamo theory is understanding how magnetic fields are generated and sustained in fully convective stellar objects. A number of models for possible dynamo mechanisms in this regime have been proposed but constraining data on magnetic field strengths and topologies across a wide range of mass, age, rotation rate, and temperature are sorely lacking, particularly in the brown dwarf regime. Detections of highly circularly polarized pulsed radio emission provide our only window into magnetic field measurements for objects in the ultracool brown dwarf regime. However, these detections are very rare; previous radio surveys encompassing ˜60 L6 or later targets have yielded only one detection. We have developed a selection strategy for biasing survey targets based on possible optical and infrared tracers of auroral activity. Using our selection strategy, we previously observed six late L and T dwarfs with the Jansky Very Large Array (VLA) and detected the presence of highly circularly polarized radio emission for five targets. Our initial detections at 4-8 GHz provided the most robust constraints on dynamo theory in this regime, confirming magnetic fields >2.5 kG. To further develop our understanding of magnetic fields in the ultracool brown dwarf mass regime bridging planets and stars, we present constraints on surface magnetic field strengths for two Y-dwarfs as well as higher frequency observations of the previously detected L/T dwarfs corresponding ~3.6 kG fields. By carefully comparing magnetic field measurements derived from auroral radio emission to measurements derived from Zeeman broadening and Zeeman Doppler imaging, we provide tentative evidence that the dynamo operating in this mass regime may be inconsistent with predicted values from currently in vogue models. This suggests that parameters beyond convective flux may influence magnetic field generation in brown dwarfs.

  6. Shock-Induced Flows through Packed Beds: Transient Regimes

    CERN Document Server

    Shtemler, Yuri M; Britan, Alex

    2006-01-01

    The early stage of the transient regimes in the shock-induced flows within solid-packed beds are investigated in the linear longwave and high-frequency approximation. The transient resistance law is refined as the Duhameltime integral that follows from the general concept of dynamic tortuosity and compressibility of the packed beds. A closed-form solution is expected to describe accurately the early stage of the transient regime flow and is in qualitative agreement with available experimental data.

  7. Ignition Regime for Fusion in a Degenerate Plasma

    Energy Technology Data Exchange (ETDEWEB)

    Son, S.; Fisch, N.J.

    2005-12-01

    We identify relevant parameter regimes in which aneutronic fuels can undergo fusion ignition in hot-ion degenerate plasma. Because of relativistic effects and partial degeneracy, the self-sustained burning regime is considerably larger than previously calculated. Inverse bremsstrahlung plays a major role in containing the reactor energy. We solve the radiation transfer equation and obtain the contribution to the heat conductivity from inverse bremsstrahlung.

  8. Observation of Modulation Transfer Spectroscopy in the Deep Modulation Regime

    Institute of Scientific and Technical Information of China (English)

    ZHOU Zi-Chao; WEI Rong; SHI Chun-Yan; WANG Yu-Zhu

    2010-01-01

    @@ We observe the modulation transfer spectroscopy on the D2 line of87 Rb in a rubidium cell with acoustic-optic modulator in the deep modulation regime.In this regime,the sidebands of the pump beam are involved in the four-wave mixing processes,which increase the signM gradients and the peak-to-peak amplitudes of both the absorption and dispersion components.

  9. Peaceful Protest, Political Regimes, and the Social Media Challenge

    Science.gov (United States)

    2016-06-01

    asserts democracies must meet the following conditions to fulfill the democratic promises; empowerment of its citizens, free supply, free demand...techniques, such as its “Great Firewall” and government-employed Internet police, to filter Internet users ’ content. China’s restrictions...peaceful protest as its social media user rates rise. Anocratic regimes, or intermediate regimes, display both democratic and authoritarian

  10. INTRODUCTION OF A SECTORAL APPROACH TO TRANSPORT SECTOR FOR POST-2012 CLIMATE REGIME

    Directory of Open Access Journals (Sweden)

    Atit TIPPICHAI

    2009-01-01

    Full Text Available Recently, the concept of sectoral approaches has been discussed actively under the UNFCCC framework as it could realize GHG mitigations for the Kyoto Protocol and beyond. However, most studies have never introduced this approach to the transport sector explicitly or analyzed its impacts quantitatively. In this paper, we introduce a sectoral approach which aims to set sector-specific emission reduction targets for the transport sector for the post-2012 climate regime. We suppose that developed countries will commit to the sectoral reduction target and key developing countries such as China and India will have the sectoral no-lose targets — no penalties for the failure to meet targets but the right to sell exceeding reductions — for the medium term commitment, i.e. 2013–2020. Six scenarios of total CO2 emission reduction target in the transport sector in 2020, varying from 5% to 30% reductions from the 2005 level are established. The paper preliminarily analyzes shares of emission reductions and abatement costs to meet the targets for key developed countries including the USA, EU-15, Russia, Japan and Canada. To analyze the impacts of the proposed approach, we generate sectoral marginal abatement cost (MAC curves by region through extending a top-down economic model, namely the AIM/CGE model. The total emission reduction targets are analyzed against the developed MAC curves for the transport sector in order to obtain an equal marginal abatement cost which derives optimal emission reduction for each country and minimizes total abatement cost. The results indicate that the USA will play a crucial role in GHG mitigations in the transport sector as it is most responsible for emission reductions (i.e. accounts for more than 70% while Japan will least reduce (i.e. accounts for about 3% for all scenarios. In the case of a 5% reduction, the total abatement is equal to 171.1 MtCO2 with a total cost of 1.61 billion USD; and in the case of a 30

  11. International regime formation: Ozone depletion and global climate change

    Energy Technology Data Exchange (ETDEWEB)

    Busmann, N.E.

    1994-03-01

    Two theoretical perspectives, neorealism and neoliberal institutionalism, dominate in international relations. An assessment is made of whether these perspectives provide compelling explanations of why a regime with specific targets and timetables was formed for ozone depletion, while a regime with such specificity was not formed for global climate change. In so doing, the assumptions underlying neorealism and neoliberal institutionalism are examined. A preliminary assessment is offered of the policymaking and institutional bargaining process. Patterns of interstate behavior are evolving toward broader forms of cooperation, at least with regard to global environmental issues, although this process is both slow and cautious. State coalitions on specific issues are not yet powerful enough to create a strong community of states in which states are willing to devolve power to international institutions. It is shown that regime analysis is a useful analytic framework, but it should not be mistaken for theory. Regime analysis provides an organizational framework offering a set of questions regarding the principles and norms that govern cooperation and conflict in an issue area, and whether forces independent of states exist which affect the scope of state behavior. An examination of both neorealism and neoliberal institutionalism, embodied by four approaches to regime formation, demonstrates that neither has sufficient scope to account for contextual dynamics in either the ozone depletion or global climate change regime formation processes. 261 refs.

  12. Do family policy regimes matter for children's well-being?

    Science.gov (United States)

    Engster, Daniel; Stensöta, Helena Olofsdotter

    2011-01-01

    Researchers have studied the impact of different welfare state regimes, and particularly family policy regimes, on gender equality. Very little research has been conducted, however, on the association between different family policy regimes and children's well-being. This article explores how the different family policy regimes of twenty OECD countries relate to children's well-being in the areas of child poverty, child mortality, and educational attainment and achievement. We focus specifically on three family policies: family cash and tax benefits, paid parenting leaves, and public child care support. Using panel data for the years 1995, 2000, and 2005, we test the association between these policies and child well-being while holding constant for a number of structural and policy variables. Our analysis shows that the dual-earner regimes, combining high levels of support for paid parenting leaves and public child care, are strongly associated with low levels of child poverty and child mortality. We find little long-term effect of family policies on educational achievement, but a significant positive correlation between high family policy support and higher educational attainment. We conclude that family policies have a significant impact on improving children's well-being, and that dual-earner regimes represent the best practice for promoting children's health and development.

  13. Oscillations of a highly discrete breather with a critical regime

    Science.gov (United States)

    Coquet; Remoissenet; Dinda

    2000-10-01

    We analyze carefully the essential features of the dynamics of a stationary discrete breather in the ultimate degree of energy localization in a nonlinear Klein-Gordon lattice with an on-site double-well potential. We demonstrate the existence of three different regimes of oscillatory motion in the breather dynamics, which are closely related to the motion of the central particle in an effective potential having two nondegenerate wells. In given parameter regions, we observe an untrapped regime, in which the central particle executes large-amplitude oscillations from one to the other side of the potential barrier. In other parameter regions, we find the trapped regime, in which the central particle oscillates in one of the two wells of the effective potential. Between these two regimes we find a critical regime in which the central particle undergoes several temporary trappings within an untrapped regime. Importantly, our study reveals that in the presence of purely anharmonic coupling forces, the breather compactifies, i.e., the energy becomes abruptly localized within the breather.

  14. Sensitivity of streamflows to hydroclimatic fluctuations: resilience and regime shifts

    Science.gov (United States)

    Botter, Gianluca; Basso, Stefano; Rodriguez-Iturbe, Ignacio; Rinaldo, Andrea

    2016-04-01

    Landscape and climate alterations foreshadow global-scale shifts of river flow regimes. However, a theory that identifies the range of foreseen impacts on streamflows resulting from inhomogeneous forcings and sensitivity gradients across diverse regimes is lacking. In this contribution, we use a dimensionless index embedding simple climate and landscape attributes (the ratio of the mean interarrival of streamflow-producing rainfall events and the mean catchment response time) to discriminate erratic regimes with enhanced intra-seasonal streamflow variability from persistent regimes endowed with regular flow patterns. The proposed classification is successfully applied to 110 seasonal streamflow distributions observed in 44 catchments of the Alps and the United States, allowing the identification of emerging patterns in space and time. In the same framework, the impact of multi-scale fluctuations of the underlying climatic drivers (temperature, precipitation) on the streamflow distributions can be analyzed. Theoretical and empirical data show that erratic regimes, typical of rivers with low mean discharges, are highly resilient in that they hold a reduced sensitivity to variations in the external forcing. Specific temporal trajectories of streamflow distributions and flow regime shifts driven by land-cover change and rainfall patterns can be also evidenced. The approach developed offers an objective basis for the analysis and prediction of the impact of climate/landscape change on water resources.

  15. O-regime dynamics and modeling in Tore Supra

    Science.gov (United States)

    Turco, F.; Giruzzi, G.; Imbeaux, F.; Udintsev, V. S.; Artaud, J. F.; Barana, O.; Dumont, R.; Mazon, D.; Ségui, J.-L.

    2009-06-01

    The regime of nonlinear temperature oscillations (O-regime), characteristic of noninductive discharges on Tore Supra [Équipe Tore Supra, Proceedings of the 12th International Conference on Plasma Physics and Controlled Nuclear Fusion Research, Nice, France, 1988 (International Atomic Energy Agency, Vienna, 1989), Vol. 1, p. 9], is investigated in its triggering and suppressing mechanism. This regime can be described by two nonlinearly coupled equations for the current density j(r ) and the electron temperature Te(r) where the equation coefficients are functions of j and Te themselves. Both the integrated modeling code CRONOS [V. Basiuk et al., Nucl. Fusion 43, 822 (2003)] and a two-patch predator-prey system with diffusion and noise have been used and results have been compared to the experimental observations of the O-regime. A database of discharges is analyzed which features monotonic, flat, and reversed safety factor (q) profiles in order to characterize the action of external actuators on the regime dynamics with the widest generality. Electron cyclotron current drive and neutral beam injections have been used in order to induce localized perturbations in the total current profile j(r ) as well as to change the plasma confinement conditions in the central region. Magnetic shear perturbations and modifications of the heat transport turn out to be the central parameters governing the dynamics of the O-regime.

  16. Considering WTO law in the design of climate change regimes beyond Kyoto

    Science.gov (United States)

    Gaines, Sanford E.

    2009-11-01

    This article describes the most important provisions of World Trade Organization (WTO) agreements that should be considered in designing laws and regulations under likely post-Kyoto climate change mitigation regimes. The Kyoto Protocol and the expected post-Kyoto international climate agreement depend on national measures to implement market-based mitigation measures. This market strategy promotes international exchanges of goods, investments, and services such as cross-border trading of credits for emissions reductions and transnational financing for projects that avoid emissions through the Clean Development Mechanism. Moreover, the United States and other countries, concerned over "leakage" of greenhouse gas (GHG) emissions through relocation of industry to other countries coupled with political worry over manufacturing competitiveness, have proposed national climate legislation containing border adjustments on imported goods or implicit subsidies for national producers, raising additional WTO considerations. The article assesses the likely effectiveness of such trade-related measures in achieving climate change mitigation goals and the potential trade policy infringements and trade distortions that they might bring about. Alternative strategies for achieving GHG mitigation goals in closer conformity with WTO law and policy will be suggested.

  17. Ion cyclotron emission by spontaneous emission

    Energy Technology Data Exchange (ETDEWEB)

    Da Costa, O. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Gresillon, D. [Ecole Polytechnique, 91 - Palaiseau (France). Lab. de Physique des Milieux Ionises

    1994-07-01

    The goal of the study is to examine whether the spontaneous emission can account for ICE (ion cyclotron emission) experimental results, or part of them. A straightforward approach to plasma emission is chosen, investigating the near equilibrium wave radiation by gyrating ions, and thus building from the majority and fast fusion ions the plasma fluctuations and emission on the fast magnetoacoustic or compressional Alfven wave mode in the IC frequency range. Similarities with the ICE experiments are shown: the emission temperature in the presence of fast ions (even in a very small amount), the strong fast ion emission increase with the harmonic, the fine double-line splitting of each peak, the linear but not proportional increase of the peak width with the harmonic. 3 refs., 2 figs.

  18. Exchange Rate Regimes – A periodical overview and a critical analysis of exchange rate regimes in Kosovo

    OpenAIRE

    Flamur Bunjaku

    2015-01-01

    Exchange rate regimes and the monetary policy are the key instruments governments use to achieve their economic and financial objectives. Moreover, due to global financial crisis the latter instruments get more importance. Empirical evidences show that exchange rate regimes in Kosovo and its monetary policy throughout their development were mainly influenced by different political and historical developments. In regard of Euroisation of monetary system in Kosovo it was found that this action ...

  19. The Fall of the Vanishing Interim Regime Hypothesis: Towards a New Paradigm of the Choice of the Exchange Rate Regimes

    OpenAIRE

    Michal Jurek

    2010-01-01

    This paper verifies strong and weak versions of the vanishing interim regime hypothesis (so-called bipolar view). It is shown herein that the strong as well as weak version of this hypothesis can be discredited. Empirical observations support the bipolar view only for the advanced countries, but not for emerging and developing ones. On the contrary – the number of interim regimes, used by emerging and developing countries more than doubled in the 1999–2008 period. Results of the logistic regr...

  20. Control of Chaotic Regimes in Encryption Algorithm Based on Dynamic Chaos

    OpenAIRE

    Sidorenko, V.; Mulyarchik, K. S.

    2013-01-01

    Chaotic regime of a dynamic system is a necessary condition determining cryptographic security of an encryption algorithm. A chaotic dynamic regime control method is proposed which uses parameters of nonlinear dynamics regime for an analysis of encrypted data.

  1. Thermal emission of neutron stars with internal heaters

    CERN Document Server

    Kaminker, A D; Potekhin, A Y; Yakovlev, D G

    2014-01-01

    Using 1D and 2D cooling codes we study thermal emission from neutron stars with steady state internal heaters of various intensities and geometries (blobs or spherical layers) located at different depths in the crust. The generated heat tends to propagate radially, from the heater down to the stellar core and up to the surface; it is also emitted by neutrinos. In local regions near the heater the results are well described with the 1D code. The heater's region projects onto the stellar surface forming a hot spot. There are two heat propagation regimes. In the first, conduction outflow regime (realized at heat rates $H_0 \\lesssim 10^{20}$ erg cm$^{-3}$ s$^{-1}$ or temperatures $T_\\mathrm{h} \\lesssim 10^9$ K in the heater) the thermal surface emission of the star depends on the heater's power and neutrino emission in the stellar core. In the second, neutrino outflow regime ($H_0 \\gtrsim 10^{20}$ erg cm$^{-3}$ s$^{-1}$ or $T_\\mathrm{h} \\gtrsim 10^9$ K) the surface thermal emission becomes independent of heater's...

  2. Clearing the way for reducing emissions from tropical deforestation

    Energy Technology Data Exchange (ETDEWEB)

    Skutsch, M. [Department of Technology and Sustainable Development, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands); Bird, N. [Joanneum Research, Elizabethstrasse 5/1, A-8010 Graz (Austria); Trines, E. [Gramserweg 2, 3711 AW Austerlitz (Netherlands); Dutschke, M. [Biocarbon, Badstrasse 41, 77652 Offenburg (Germany); Frumhoff, P. [Union of Concerned Scientists, 2 Brattle Square, Cambridge, MA 02238-9105 (United States); De Jong, B.H.J. [El Colegio de la Frontera Sur, Unidad Villahermosa, Carr. Vhsa-Reforma Km. 15.5, C.P. 86280, Ra Guineo 2da Secc, Villahermosa, Tabasco (Mexico); Van Laak, P. [ITC, Department of Natural Resources, P.O. Box 6, 7500 AA Enschede (Netherlands); Masera, O. [Centro de Investigaciones en Ecosistemas, UNAMAP 27-3 Xangari 58089, Morelia, Michoacan (Mexico); Murdiyarso, D. [Center for International Forestry Research, Jl. CIFOR, Situ Gede Sindangbarang, Bogor 16680 (Indonesia)

    2007-06-15

    Carbon emissions from tropical deforestation account for about 25% of all anthropogenic carbon dioxide emissions but cannot be credited under current climate change agreements. In the discussions around the architecture of the post-2012 climate regime, the possibility of including credits for reduced emissions from deforestation arises. The paper reviews two approaches for this, compensated reductions (CR) as proposed by Santilli et al. and the Joint Research Centre proposal that combine voluntary commitments by non-Annex I countries to reduce emissions from deforestation with carbon market financing. Both approaches have the clear advantages of simplicity and the possibility of fitting to an evolving greenhouse gas emission reduction regime. The authors consider the strengths and limitations of each proposal and build upon them to address several implementation challenges and options for improvement. Given the urgency of avoiding dangerous climate change, the timely development of technically sound, politically acceptable, cost-effective and practicable measures to reduce emissions from deforestation and forest degradation is essential. These two approaches take us a step closer to this goal, but they need to be refined rapidly to enable this goal to be realised.

  3. C, N, P export regimes in rivers from headwater to downstream catchments

    Science.gov (United States)

    Dupas, Rémi; Musolff, Andreas; Jawitz, James W.; Rao, P. Suresh C.; Fleckenstein, Jan H.; Rode, Michael; Borchardt, Dietrich

    2017-04-01

    Excessive amounts of nutrients and dissolved organic matter in freshwater bodies affect aquatic ecosystems. In this study, the spatial and temporal variability of nitrate (NO3), dissolved organic carbon (DOC) and soluble reactive phosphorus (SRP) was analyzed along the Selke river continuum from 1 - 3 km2 headwater catchments to 184 - 456 km2 downstream catchments, within the TERENO Harz/Central German Lowland Observatory. Three headwater catchments were selected as archetypes of the main landscape units (land use x soil type) present in the Selke catchment. Export regimes in these catchments were interpreted in terms of NO3, DOC and SRP land-to-stream transfer processes. Differences between export regimes in headwater and downstream catchments were interpreted in terms of in-stream processes and contribution of point source emissions. The results showed that the NO3 seasonal dynamics were opposite compared to DOC and SRP in all three headwater catchments. These dynamics were interpreted as the result of the interplay of hydrological and biogeochemical processes, for which riparian wetlands were hypothesized to play a determining role. In the two downstream catchments, NO3 was transported almost conservatively, except during the summer period where in-stream retention could exceed 50%. Allochtonous DOC was consumed in the upstream river section (with low light and nutrient availability) and autochthonous DOC was produced in the downstream river section (with high light and nutrients availability); the natural export regime of SRP mimicked a point source signal, which may lead to misattribution and thus overestimation of domestic contribution to phosphorus loads in rivers. Monitoring the river continuum from headwater to downstream rivers proved effective to investigate jointly land-to-stream and in-stream transport and transformation processes.

  4. Operation regimes and electrical transport of steep slope Schottky Si-FinFETs

    Science.gov (United States)

    Jeon, Dae-Young; Zhang, Jian; Trommer, Jens; Park, So Jeong; Gaillardon, Pierre-Emmanuel; De Micheli, Giovanni; Mikolajick, Thomas; Weber, Walter M.

    2017-02-01

    In the quest for energy efficient circuits, considerable focus has been given to steep slope and polarity-controllable devices, targeting low supply voltages and reduction of transistor count. The recently proposed concept of the three-independent gated Si-FinFETs with Schottky-barriers (SBs) has proven to bring both functionalities even in a single device. However, the complex combination of transport properties including Schottky emission and weak impact ionization as well as the body effect makes the design of such devices challenging. In this work, we perform a deep electrical characterization analysis to visualize and decouple the different operation regimes and electrical properties of the SB Si-FinFETs using a graphical transport map. From these, we give important guidelines for the design of future devices.

  5. High-order harmonic generation at high laser intensities beyond the tunnel regime

    CERN Document Server

    Pérez-Hernández, J A; Lewenstein, M; Zaïr, A; Roso, L

    2014-01-01

    We present studies of high-order harmonic generation (HHG) at laser intensities well above saturation. We use driving laser pulses which present a particular electron dynamics in the turn-on stage. Our results predict an increasing on the harmonic yield, after an initial dropping, when the laser intensity is increased. This fact contradicts the general belief of a progressive degradation of the harmonic emission at ultrahigh intensities. We have identified a particular set of trajectories which emerges in the turn-on stage of these singular laser pulses, responsible of the unexpected growth on the harmonic efficiency at this high intensity regime. Our study combines two complementary approaches: classical analysis and full quantum mechanical calculations resulting from the numerical integration of the 3-dimensional time-dependent Schr\\"odinger equation complemented with the time-frequency analysis.

  6. Numerical simulation of DPF filter for selected regimes with deposited soot particles

    Directory of Open Access Journals (Sweden)

    Kovařík Petr

    2012-04-01

    Full Text Available For the purpose of accumulation of particulate matter from Diesel engine exhaust gas, particle filters are used (referred to as DPF or FAP filters in the automotive industry. However, the cost of these filters is quite high. As the emission limits become stricter, the requirements for PM collection are rising accordingly. Particulate matters are very dangerous for human health and these are not invisible for human eye. They can often cause various diseases of the respiratory tract, even what can cause lung cancer. Performed numerical simulations were used to analyze particle filter behavior under various operating modes. The simulations were especially focused on selected critical states of particle filter, when engine is switched to emergency regime. The aim was to prevent and avoid critical situations due the filter behavior understanding. The numerical simulations were based on experimental analysis of used diesel particle filters.

  7. 50 pico arcsecond astrometry of pulsar emission

    CERN Document Server

    Pen, Ue-Li; Deller, Adam; Brisken, Walter

    2013-01-01

    We use VLBI imaging of the interstellar scattering speckle pattern associated with the pulsar PSR 0834+06 to measure the astrometric motion of its emission. The ~ 5AU interstellar baselines, provided by interference between speckles spanning the scattering disk, enable us to detect motions with sub nanoarcsecond accuracy. We measure a small pulse deflection of ~8+/-2 km (not including geometric uncertainties), which is 100 times smaller than the native resolution of this interstellar interferometer. This implies that the emission region is small, and at an altitude of a few hundred km, with the exact value depending on field geometry. This is substantially closer to the star than to the light cylinder. Future VLBI measurements can improve on this finding. This new regime of ultra-precise astrometry may enable precision parallax distance determination of pulsar binary displacements.

  8. Ammonia emissions in Europe

    DEFF Research Database (Denmark)

    Jacobsen, Brian H.

    2012-01-01

    The NEC (National Emission Ceiling) directive has set targets for the 2010 ammonia emissions from a number of European countries. The target will be reached by most EU-countries and the total emission for EU-27 has been reduced by 22% from 1990 to 2007. Denmark is one of the countries with the la......The NEC (National Emission Ceiling) directive has set targets for the 2010 ammonia emissions from a number of European countries. The target will be reached by most EU-countries and the total emission for EU-27 has been reduced by 22% from 1990 to 2007. Denmark is one of the countries...

  9. Experimental investigations of synchrotron radiation at the onset of the quantum regime

    CERN Document Server

    Andersen, Kristoffer K; Knudsen, H; Thomsen, H D; Uggerhøj, U I; Sona, P; Mangiarotti, A; Ketel, T J; Dizdar, A; Ballestrero, S

    2012-01-01

    The classical description of synchrotron radiation fails at large Lorentz factors, $\\gamma$, for relativistic electrons crossing strong transverse magnetic fields $B$. In the rest frame of the electron this field is comparable to the so-called critical field $B_0 = 4.414\\cdot10^9$ T. For $\\chi = \\gamma B/B_0 \\simeq 1$ quantum corrections are essential for the description of synchrotron radiation to conserve energy. With electrons of energies 10-150 GeV penetrating a germanium single crystal along the $$ axis, we have experimentally investigated the transition from the regime where classical synchrotron radiation is an adequate description, to the regime where the emission drastically changes character; not only in magnitude, but also in spectral shape. The spectrum can only be described by quantum synchrotron radiation formulas. Apart from being a test of strong-field quantum electrodynamics, the experimental results are also relevant for the design of future linear colliders where beamstrahlung - a closely r...

  10. How Welfare Regimes Generate and Erode Social Capital

    DEFF Research Database (Denmark)

    Larsen, Christian Albrekt

    2007-01-01

    Comparative studies of social capital, operationalised as social trust between citizens, have revealed two major puzzles. The first puzzle has to do with the decline in social trust in the USA, which fuelled considerable debate about social capital. The question is why social capital erodes in th...... with the presence or absence of a poor and culturally distinct underclass. The social democratic welfare regimes hinder – while the liberal welfare regime generate – such underclass phenomena.......Comparative studies of social capital, operationalised as social trust between citizens, have revealed two major puzzles. The first puzzle has to do with the decline in social trust in the USA, which fuelled considerable debate about social capital. The question is why social capital erodes...... in the USA and other liberal welfare regimes, while social capital is stable in the so-called social democratic and conservative welfare regimes. The second puzzle is why the group of social democratic regimes have extremely high levels of social trust. It is argued that both puzzles have to do...

  11. Early signatures of regime shifts in complex dynamical systems

    Indian Academy of Sciences (India)

    Indrani Bose; Mainak Pal

    2015-02-01

    A large number of studies have recently been carried out on the early signatures of regime shifts in a number of dynamical systems, e.g., ecosystems, the climate, fish and wildlife populations, financial markets, complex diseases and gene circuits. The underlying model in most cases is that of the fold-bifurcation in which a sudden regime shift occurs at a bifurcation point. The shift involves a discontinuous jump from one type of stable steady state to another. The dynamics of natural systems have both deterministic and stochastic components. The early signatures of abrupt regime shifts include the critical slowing down as a transition point is approached, rising variance and the lag-1 autocorrelation function, increased skewness of the steady-state probability distribution and the ratio of two mean first passage times for the exits from the stable steady states as the bifurcation point is approached. Noise-induced regime shifts are also possible for which the vicinity of the bifurcation point is not essential. In this paper, we review examples of regime shifts in natural systems and the associated early signatures. We further discuss how such approaches provide useful insights on a cell biological process involving the fold-bifurcation.

  12. Control of Synchronization Regimes in Networks of Mobile Interacting Agents

    Science.gov (United States)

    Perez-Diaz, Fernando; Zillmer, Ruediger; Groß, Roderich

    2017-05-01

    We investigate synchronization in a population of mobile pulse-coupled agents with a view towards implementations in swarm-robotics systems and mobile sensor networks. Previous theoretical approaches dealt with range and nearest-neighbor interactions. In the latter case, a synchronization-hindering regime for intermediate agent mobility is found. We investigate the robustness of this intermediate regime under practical scenarios. We show that synchronization in the intermediate regime can be predicted by means of a suitable metric of the phase response curve. Furthermore, we study more-realistic K -nearest-neighbor and cone-of-vision interactions, showing that it is possible to control the extent of the synchronization-hindering region by appropriately tuning the size of the neighborhood. To assess the effect of noise, we analyze the propagation of perturbations over the network and draw an analogy between the response in the hindering regime and stable chaos. Our findings reveal the conditions for the control of clock or activity synchronization of agents with intermediate mobility. In addition, the emergence of the intermediate regime is validated experimentally using a swarm of physical robots interacting with cone-of-vision interactions.

  13. The political use of psychiatry: A comparison between totalitarian regimes.

    Science.gov (United States)

    Buoli, Massimiliano; Giannuli, Aldo Sabino

    2017-03-01

    After the end of Second World War, the recent experience of the Nazi horrors stimulated a debate about the political use of psychiatry. Over the years, the focus shifted on major dictatorships of the time and especially on Soviet Union. This article aims to provide a critical review of the ways in which psychiatry was used by totalitarian regimes of the 20th century. We summarized relevant literature about political use of psychiatry in totalitarian regimes of the 20th century, with particular focus on Fascism, Nazism, Argentina dictatorship, Soviet Union and China. One of the features that are common to most of the dictatorships is that the use of psychiatry has become more prominent when the regimes have had the need to make more acceptable the imprisonment of enemies in the eyes of the world. This for example happened in the Nazi regime when sterilization and killing of psychiatric patients was explained as a kind of euthanasia, or in the Soviet Union after the formal closure of the corrective labor camps and the slow resumption of relations with the capitalistic world, or in China to justify persecution of religious minorities and preserve economic relations with Western countries. Psychiatry has been variously used by totalitarian regimes as a means of political persecution and especially when it was necessary to make acceptable to public opinion the imprisonment of political opponents.

  14. Differentially Rotating White Dwarfs I: Regimes of Internal Rotation

    Science.gov (United States)

    Ghosh, Pranab; Wheeler, J. Craig

    2017-01-01

    Most viable models of Type Ia supernovae (SNe Ia) require the thermonuclear explosion of a carbon/oxygen white dwarf that has evolved in a binary system. Rotation could be an important aspect of any model for SNe Ia, whether single or double degenerate, with the white dwarf mass at, below, or above the Chandrasekhar limit. Differential rotation is specifically invoked in attempts to account for the apparent excess mass in the super-Chandrasekhar events. Some earlier work has suggested that only uniform rotation is consistent with the expected mechanisms of angular momentum transport in white dwarfs, while others have found pronounced differential rotation. We show that if the baroclinic instability is active in degenerate matter and the effects of magnetic fields are neglected, both nearly uniform rotation and strongly differential rotation are possible. We classify rotation regimes in terms of the Richardson number, Ri. At small values of Ri ≤slant 0.1, we find both the low-viscosity Zahn regime with a nonmonotonic angular velocity profile and a new differential rotation regime for which the viscosity is high and scales linearly with the shear, σ. Employment of Kelvin–Helmholtz viscosity alone yields differential rotation. Large values of Ri ≫ 1 produce a regime of nearly uniform rotation for which the baroclinic viscosity is of intermediate value and scales as {σ }3. We discuss the gap in understanding of the behavior at intermediate values of Ri and how observations may constrain the rotation regimes attained by nature.

  15. Weather Regimes: The Challenge in Extended-Range Forecasting

    Science.gov (United States)

    Reinhold, Brian

    1987-01-01

    A hypothesis to explain the low-frequency (10- to 90-day) variance of the mid-latitude atmosphere is presented. In this hypothesis it is proposed that the planetary-scale waves forced by topography or other zonal inhomogeneities and the day-to-day weather disturbances (synoptic scales) influence each other to generate weather regimes. These quasi-stable flow configurations are responsible for short-range climate anomalies such as droughts, heat waves, deep freezes, and excessive precipitation, as the weather-producing disturbances are organized into storm tracks. Onset and disruption of the weather regimes may be induced by the anomalous development of perhaps a single cyclonic disturbance, which can throw the quasi equilibrium out of balance. Thus, rapid changes in flow regimes can occur almost at random. The development and transition of weather regimes may then be purely internal (that is, depending only upon the properties of the fluid motions themselves) to the atmospheric dynamics. This internal quality suggests that the chaotic, abrupt short-range climatic behavior of the mid-latitudes is a natural behavior of the system that requires no assistance from the outside. The weather regime concept presents a different view of the extended-range atmospheric behavior than the stimulus-response model, such as the atmospheric response to the El Nino.

  16. Regime switching model for financial data: Empirical risk analysis

    Science.gov (United States)

    Salhi, Khaled; Deaconu, Madalina; Lejay, Antoine; Champagnat, Nicolas; Navet, Nicolas

    2016-11-01

    This paper constructs a regime switching model for the univariate Value-at-Risk estimation. Extreme value theory (EVT) and hidden Markov models (HMM) are combined to estimate a hybrid model that takes volatility clustering into account. In the first stage, HMM is used to classify data in crisis and steady periods, while in the second stage, EVT is applied to the previously classified data to rub out the delay between regime switching and their detection. This new model is applied to prices of numerous stocks exchanged on NYSE Euronext Paris over the period 2001-2011. We focus on daily returns for which calibration has to be done on a small dataset. The relative performance of the regime switching model is benchmarked against other well-known modeling techniques, such as stable, power laws and GARCH models. The empirical results show that the regime switching model increases predictive performance of financial forecasting according to the number of violations and tail-loss tests. This suggests that the regime switching model is a robust forecasting variant of power laws model while remaining practical to implement the VaR measurement.

  17. Nonlinear regime-switching state-space (RSSS) models.

    Science.gov (United States)

    Chow, Sy-Miin; Zhang, Guangjian

    2013-10-01

    Nonlinear dynamic factor analysis models extend standard linear dynamic factor analysis models by allowing time series processes to be nonlinear at the latent level (e.g., involving interaction between two latent processes). In practice, it is often of interest to identify the phases--namely, latent "regimes" or classes--during which a system is characterized by distinctly different dynamics. We propose a new class of models, termed nonlinear regime-switching state-space (RSSS) models, which subsumes regime-switching nonlinear dynamic factor analysis models as a special case. In nonlinear RSSS models, the change processes within regimes, represented using a state-space model, are allowed to be nonlinear. An estimation procedure obtained by combining the extended Kalman filter and the Kim filter is proposed as a way to estimate nonlinear RSSS models. We illustrate the utility of nonlinear RSSS models by fitting a nonlinear dynamic factor analysis model with regime-specific cross-regression parameters to a set of experience sampling affect data. The parallels between nonlinear RSSS models and other well-known discrete change models in the literature are discussed briefly.

  18. Burning plasma regime for Fussion-Fission Research Facility

    Science.gov (United States)

    Zakharov, Leonid E.

    2010-11-01

    The basic aspects of burning plasma regimes of Fusion-Fission Research Facility (FFRF, R/a=4/1 m/m, Ipl=5 MA, Btor=4-6 T, P^DT=50-100 MW, P^fission=80-4000 MW, 1 m thick blanket), which is suggested as the next step device for Chinese fusion program, are presented. The mission of FFRF is to advance magnetic fusion to the level of a stationary neutron source and to create a technical, scientific, and technology basis for the utilization of high-energy fusion neutrons for the needs of nuclear energy and technology. FFRF will rely as much as possible on ITER design. Thus, the magnetic system, especially TFC, will take advantage of ITER experience. TFC will use the same superconductor as ITER. The plasma regimes will represent an extension of the stationary plasma regimes on HT-7 and EAST tokamaks at ASIPP. Both inductive discharges and stationary non-inductive Lower Hybrid Current Drive (LHCD) will be possible. FFRF strongly relies on new, Lithium Wall Fusion (LiWF) plasma regimes, the development of which will be done on NSTX, HT-7, EAST in parallel with the design work. This regime will eliminate a number of uncertainties, still remaining unresolved in the ITER project. Well controlled, hours long inductive current drive operation at P^DT=50-100 MW is predicted.

  19. Emissivity and specific electrical resistivity of compositions in the LaB/sub 6/-ZrB/sub 2/ system

    Energy Technology Data Exchange (ETDEWEB)

    Zapadaeva, T.E.; Nikolaeva, E.E.; Ordan' yan, S.S.; Petrov, V.A.

    1987-12-01

    The authors investigate the thermionic emissivity and specific electrical resistivity of several lanthanum boride-zirconium boride systems and the dependence of these properties on the sintering regime, temperature, and structural considerations such as porosity and grain size. Emissivity was determined by calorimetry in an argon atmosphere. Results are tabulated.

  20. An improved data base for the description of dairy cows in the German agricultural emission model GAS-EM

    DEFF Research Database (Denmark)

    Dämmgen, Ulrich; Haenel, Hans-Dieter; Rösemann, Claus

    2010-01-01

    The application of the previously published detailed model describing dairy cow husbandry in the German agricultural emission model requires an extended and improved data base. This concerns animal weights, weight gains, regional feed regimes, feeding requirements and feed properties as well...... of animal performance. The knowledge of hitherto unpublished data allows for a recalculation and revaluation of nitrogen excretions and ammonia emission factors....

  1. Assessing the ammonium nitrate formation regime in the Paris megacity and its representation in the CHIMERE model

    Directory of Open Access Journals (Sweden)

    H. Petetin

    2015-09-01

    Full Text Available Secondary inorganic compounds represent a major fraction of fine aerosol in the Paris megacity. The thermodynamics behind their formation is now relatively well constrained, but due to sparse direct measurements of their precursors (in particular NH3 and HNO3, uncertainties remain on their concentrations and variability as well as the formation regime of ammonium nitrate (in terms of limited species, among NH3 and HNO3 in urban environments such as Paris. This study presents the first urban background measurements of both inorganic aerosol compounds and their gaseous precursors during several months within the city of Paris. Intense agriculture-related NH3 episodes are observed in spring/summer while HNO3 concentrations remain relatively low, even during summer, which leads to a NH3-rich regime in Paris. The local formation of ammonium nitrate within the city appears low, despite high NOx emissions. The dataset is also used to evaluate the CHIMERE chemistry-transport model (CTM. Interestingly, the rather good results obtained on ammonium nitrates hide significant errors on gaseous precursors (e.g. mean bias of −75 and +195 % for NH3 and HNO3, respectively. It thus leads to a mis-representation of the nitrate formation regime through a highly underestimated Gas Ratio metric (introduced by Ansari and Pandis, 1998 and a much higher sensitivity of nitrate concentrations to ammonia changes. Several uncertainty sources are investigated, pointing out the importance of better assessing both NH3 emissions and OH concentrations in the future. These results finally remind the caution required in the use of CTMs for emission scenario analysis, highlighting the importance of prior diagnostic and dynamic evaluations.

  2. Assessing the ammonium nitrate formation regime in the Paris megacity and its representation in the CHIMERE model

    Science.gov (United States)

    Petetin, Hervé; Sciare, Jean; Bressi, Michael; Gros, Valérie; Rosso, Amandine; Sanchez, Olivier; Sarda-Estève, Roland; Petit, Jean-Eudes; Beekmann, Matthias

    2016-08-01

    Secondary inorganic compounds represent a major fraction of fine aerosol in the Paris megacity. The thermodynamics behind their formation is now relatively well constrained but, due to sparse direct measurements of their precursors (in particular NH3 and HNO3), uncertainties remain on their concentrations and variability as well as the formation regime of ammonium nitrate (in terms of limited species among NH3 and HNO3) in urban environments such as Paris. This study presents the first urban background measurements of both inorganic aerosol compounds and their gaseous precursors during several months within the city of Paris. Intense agriculture-related NH3 episodes are observed in spring/summer while HNO3 concentrations remain relatively low, even during summer, which leads to a NH3-rich regime in Paris. The local formation of ammonium nitrate within the city appears low, despite high NOx emissions. The data set also allows evaluating the CHIMERE chemistry-transport model (CTM). Interestingly, the rather good results obtained on ammonium nitrates hide significant errors on gaseous precursors (e.g., mean bias of -75 and +195 % for NH3 and HNO3, respectively). This leads to a misrepresentation of the nitrate formation regime through a highly underestimated gas ratio metric (introduced by Ansari and Pandis, 1998) and a much higher sensitivity of nitrate concentrations to ammonia changes. Several uncertainty sources are investigated, pointing out the importance of better assessing both NH3 agricultural emissions and OH concentrations in the future. These results remind us of the caution required when using of CTMs for emission scenario analysis, highlighting the importance of prior diagnostic and dynamic evaluations.

  3. Adelie penguin foraging location predicted by tidal regime switching.

    Directory of Open Access Journals (Sweden)

    Matthew J Oliver

    Full Text Available Penguin foraging and breeding success depend on broad-scale environmental and local-scale hydrographic features of their habitat. We investigated the effect of local tidal currents on a population of Adélie penguins on Humble Is., Antarctica. We used satellite-tagged penguins, an autonomous underwater vehicle, and historical tidal records to model of penguin foraging locations over ten seasons. The bearing of tidal currents did not oscillate daily, but rather between diurnal and semidiurnal tidal regimes. Adélie penguins foraging locations changed in response to tidal regime switching, and not to daily tidal patterns. The hydrography and foraging patterns of Adélie penguins during these switching tidal regimes suggest that they are responding to changing prey availability, as they are concentrated and dispersed in nearby Palmer Deep by variable tidal forcing on weekly timescales, providing a link between local currents and the ecology of this predator.

  4. The history of research into improved confinement regimes

    Science.gov (United States)

    Wagner, F.

    2017-01-01

    Increasing the pressure by additional heating of magnetically confined plasmas had the consequence that turbulent processes became more violent and plasma confinement degraded. Since this experience from the early 1980ies, fusion research was dominated by the search for confinement regimes with improved properties. It was a gratifying experience that toroidally confined plasmas are able to self-organise in such a way that turbulence diminishes, resulting in a confinement with good prospects to reach the objectives of fusion R&D. The understanding of improved confinement regimes revolutionized the understanding of turbulent transport in high-temperature plasmas. In this paper the story of research into improved confinement regimes will be narrated starting with 1980.

  5. Inhomogeneous stationary and oscillatory regimes in coupled chaotic oscillators.

    Science.gov (United States)

    Liu, Weiqing; Volkov, Evgeny; Xiao, Jinghua; Zou, Wei; Zhan, Meng; Yang, Junzhong

    2012-09-01

    The dynamics of linearly coupled identical Lorenz and Pikovsky-Rabinovich oscillators are explored numerically and theoretically. We concentrate on the study of inhomogeneous stable steady states ("oscillation death (OD)" phenomenon) and accompanying periodic and chaotic regimes that emerge at an appropriate choice of the coupling matrix. The parameters, for which OD occurs, are determined by stability analysis of the chosen steady state. Three model-specific types of transitions to and from OD are observed: (1) a sharp transition to OD from a nonsymmetric chaotic attractor containing random intervals of synchronous chaos; (2) transition to OD from the symmetry-breaking chaotic regime created by negative coupling; (3) supercritical bifurcation of OD into inhomogeneous limit cycles and further evolution of the system to inhomogeneous chaotic regimes that coexist with complete synchronous chaos. These results may fill a gap in the understanding of the mechanism of OD in coupled chaotic systems.

  6. Adaptive management of ecosystem services across different land use regimes.

    Science.gov (United States)

    Ruhl, J B

    2016-12-01

    Using adaptive management to manage desired flows of ecosystem services may seem on the surface to be a good fit, but many social, economic, environmental, legal, and political factors influence how good a fit. One strongly influential factor is the land use regime within which the profile of ecosystem services is being managed. Shaped largely by legal mandates, market forces, and social and cultural practices, different land use regimes present different opportunities for and constraints on goals for ecosystem services and pose different decision making environments. Even where all other conditions appear amenable to using adaptive management, therefore, it is essential to consider the constraining (or liberating) effects of different land use regimes when deciding whether to adopt adaptive management to achieve those goals and, if so, how to implement it. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. The difficulties of the Chinese and Indian exchange rate regimes

    Directory of Open Access Journals (Sweden)

    Ila Patnaik

    2009-06-01

    Full Text Available China and India have both sought control over the exchange rate in order to maintain export competitiveness, manage current account balance, and pursue independent monetary policy. In this paper, we examine structural change in the Chinese and Indian de facto exchange rate regimes, focusing on the period from 1998 to 2007. With increasing capital account openness, exchange rate inflexibility has been associated with significant monetary policy distortions. In both countries, the short-term rate expressed in real terms dropped, and achieved very low values, in the unprecedented business cycle expansion of the early 2000s. In the Indian case, difficulties of sterilisation led to a modification of the exchange rate regime, moving towards greater flexibility. In China, in contrast, the exchange rate regime did not change.

  8. Hydrodynamic interaction of swimming organisms in an inertial regime

    Science.gov (United States)

    Li, Gaojin; Ostace, Anca; Ardekani, Arezoo M.

    2016-11-01

    We numerically investigate the hydrodynamic interaction of swimming organisms at small to intermediate Reynolds number regimes, i.e., Re˜O (0.1 -100 ) , where inertial effects are important. The hydrodynamic interaction of swimming organisms in this regime is significantly different from the Stokes regime for microorganisms, as well as the high Reynolds number flows for fish and birds, which involves strong flow separation and detached vortex structures. Using an archetypal swimmer model, called a "squirmer," we find that the inertial effects change the contact time and dispersion dynamics of a pair of pusher swimmers, and trigger hydrodynamic attraction for two pullers. These results are potentially important in investigating predator-prey interactions, sexual reproduction, and the encounter rate of marine organisms such as copepods, ctenophora, and larvae.

  9. A Markov Switching Regime Model of Malaysia Property Cycle

    Directory of Open Access Journals (Sweden)

    Abdul M. Beksin

    2011-01-01

    Full Text Available Problem statement: Non-linear models such as the Markov Switching regime (MS method of modelling business cycles, in principle can be used to model property cyle. Approach: The MS model can distinguish property cycle in recession and expansion phases and is sufficiently flexible to allow different relationships to apply over these phases. In this study, the Malaysian property cycle is modelled using a MS model. Results: This technique can be used to simultaneously estimate the data generating process of real GDP growth and classify each observation into one of two regimes (i.e., low-growth and high-growth regimes. Conclusions: This finding has important policy implications, since the yield spread was used to generate the time-varying probabilities of the MS model as well as the recession probabilities of the logit model. In other words, a strong relationship exists between interest rates and the business cycle, where interest rates lead the business cycle.

  10. Emissions Modeling Clearinghouse

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Emissions Modeling Clearinghouse (EMCH) supports and promotes emissions modeling activities both internal and external to the EPA. Through this site, the EPA...

  11. Walkable dual emissions

    National Research Council Canada - National Science Library

    Xu, Hai-Bing; Jiao, Peng-Chong; Kang, Bin; Deng, Jian-Guo; Zhang, Yan

    2013-01-01

    Walkable dual emissions, in which the emission bands of the walker reversibly cross or leave those of the stationary ones depending on temperature and concentration, have been demonstrated in cyclic...

  12. National Emission Inventory

    Data.gov (United States)

    U.S. Environmental Protection Agency — The National Emission Inventory contains measured, modeled, and estimated data for emissions of all known source categories in the US (stationary sources, fires,...

  13. World Emission RETRO ANTHRO

    Data.gov (United States)

    Washington University St Louis — Anthropogenic and vegetation fire emissions data were generated monthly covering a period of 1960 to 2000. Anthropogenic emissions in the RETRO inventory are derived...

  14. Emissions & Measurements - Black Carbon

    Science.gov (United States)

    Emissions and Measurement (EM) research activities performed within the National Risk Management Research Lab NRMRL) of EPA's Office of Research and Development (ORD) support measurement and laboratory analysis approaches to accurately characterize source emissions, and near sour...

  15. What Is Emissions Trading?

    Science.gov (United States)

    Learn the basics about how emissions trading uses a market-based policy tool used to control large amounts of pollution emissions from a group of sources in order to protect human health and the environment.

  16. National Emission Inventory

    Data.gov (United States)

    U.S. Environmental Protection Agency — The National Emission Inventory contains measured, modeled, and estimated data for emissions of all known source categories in the US (stationary sources, fires,...

  17. How will climate change modify river flow regimes in Europe?

    Directory of Open Access Journals (Sweden)

    C. Schneider

    2013-01-01

    Full Text Available Worldwide, flow regimes are being modified by various anthropogenic impacts and climate change induces an additional risk. Rising temperatures, declining snow cover and changing precipitation patterns will interact differently at different locations. Consequently, in distinct climate zones, unequal consequences can be expected in matters of water stress, flood risk, water quality, and food security. In particular, river ecosystems and their vital ecosystem services will be compromised as their species richness and composition have evolved over long time under natural flow conditions. This study aims at evaluating the exclusive impacts of climate change on river flow regimes in Europe. Various flow characteristics are taken into consideration and diverse dynamics are identified for each distinct climate zone in Europe. In order to simulate present-day natural flow regimes and future flow regimes under climate change, the global hydrology model WaterGAP3 is applied. All calculations for current and future conditions (2050s are carried out on a 5' × 5' European grid. To address uncertainty, bias-corrected climate forcing data of three different global climate models are used to drive WaterGAP3. Finally, the hydrological alterations of different flow characteristics are quantified by the Indicators of Hydrological Alteration approach. Results of our analysis indicate that on the European scale, climate change can be expected to modify flow regimes remarkably. This is especially the case in the Mediterranean (due to drier conditions with reduced precipitation across the year and in the boreal climate zone (due to reduced snowmelt, increased precipitation, and strong temperature rises. In the temperate climate zone, impacts increase from oceanic to continental. Regarding single flow characteristics, strongest impacts on timing were found for the boreal climate zone. This applies for both high and low flows. Flow magnitudes, in turn, will be

  18. Jovem aprisionado em regime semi-aberto: um estudo transdisciplinar

    OpenAIRE

    Lazzaron, Leandra Regina

    2008-01-01

    A presente dissertação, vinculada à linha de pesquisa “Criminologia e Controle Social”, do Programa de Pós-Graduação em Ciências Criminais, da Faculdade de Direito da Pontifícia Universidade Católica do Rio Grande do Sul, identifica o perfil do jovem apenado, aprisionado em regime semi-aberto, no Instituto Penal de Viamão, com base na escala PCL-R. O estudo de campo foi realizado na instituição prisional e avaliou 40 jovens, com idade de 18 a 23 anos, que cumprem pena em regime semi-aberto. O...

  19. Measurement of flow in supercritical flow regime using cutthroat flumes

    Indian Academy of Sciences (India)

    Shrikant A Tekade; Avinash D Vasudeo; Aniruddha D Ghare; Ramesh N Ingle

    2016-02-01

    Cutthroat flume is commonly used for measurement of subcritical flow in open channel because of its simplicity and ease of construction. No experimental data is available in literature for measurement of flow in supercritical regime using cutthroat flume. The present paper finds the feasibility of cutthroat flume as a measurement device for flow in supercritical regime. Experimental data are generated to develop the relation between discharge and observed head at a specified location on upstream of throat section. Regression analysis for discharge and head indicated a good correlation. Based on all the experimental data generated, a relationship between discharge and head is proposed.

  20. The Semiclassical Regime of the Chaotic Quantum-Classical Transition

    CERN Document Server

    Greenbaum, B D; Shizume, K; Sundaram, B; Greenbaum, Benjamin D.; Habib, Salman; Shizume, Kosuke; Sundaram, Bala

    2004-01-01

    An analysis of the semiclassical regime of the quantum-classical transition is given for open, bounded, one dimensional chaotic dynamical systems. Previous numerical work has shown that in this regime, the results from a quantum master equation are very close to those obtained from a classical Fokker-Planck equation. We provide an explanation of these results by demonstrating that environmental noise plays the dual roles of suppressing the development of fine structure in classical phase space and damping nonlocal contributions to the semiclassical Wigner function. A numerical investigation of the chaotic Duffing oscillator supports these conclusions.

  1. Terahertz Quantum Plasmonics of Nanoslot Antennas in Nonlinear Regime.

    Science.gov (United States)

    Kim, Joon-Yeon; Kang, Bong Joo; Park, Joohyun; Bahk, Young-Mi; Kim, Won Tae; Rhie, Jiyeah; Jeon, Hyeongtag; Rotermund, Fabian; Kim, Dai-Sik

    2015-10-14

    Quantum tunneling in plasmonic nanostructures has presented an interesting aspect of incorporating quantum mechanics into classical optics. However, the study has been limited to the subnanometer gap regime. Here, we newly extend quantum plasmonics to gap widths well over 1 nm by taking advantage of the low-frequency terahertz regime. Enhanced electric fields of up to 5 V/nm induce tunneling of electrons in different arrays of ring-shaped nanoslot antennas of gap widths from 1.5 to 10 nm, which lead to a significant nonlinear transmission decrease. These observations are consistent with theoretical calculations considering terahertz-funneling-induced electron tunneling across the gap.

  2. PREDICTION OF FLOW REGIMES IN SPOUT-FLUIDIZED BEDS

    Institute of Scientific and Technical Information of China (English)

    Jiyu Zhang; Fengxiang Tang

    2006-01-01

    Five main flow regimes in spout-fluidized bed were identified in this study, namely, fixed bed, spout with aeration, spout-fluidization, jet in fluidized bed and slugging, together with their corresponding major frequencies translated from pressure signals. The empirical equation A=aBb, in which A=Fr* /(H/Di) and B=(Fr*/(H/D))/(μg/μmf) are respectively the spout-geometry and spout-geometry-fluidization dimensionless numbers, was proposed to distinguish these flow regimes.

  3. Explicit Mapping of Acoustic Regimes For Wind Instruments

    CERN Document Server

    Missoum, Samy; Doc, Jean-Baptiste

    2014-01-01

    This paper proposes a methodology to map the various acoustic regimes of wind instruments. The maps can be generated in a multi-dimensional space consisting of design, control parameters, and initial conditions. The bound- aries of the maps are obtained explicitly in terms of the parameters using a support vector machine (SVM) classifier as well as a dedicated adaptive sam- pling scheme. The approach is demonstrated on a simplified clarinet model for which several maps are generated based on different criteria. Examples of computation of the probability of occurrence of a specific acoustic regime are also provided. In addition, the approach is demonstrated on a design optimization example for optimal intonation.

  4. THE CASE FOR AN INTERMEDIATE EXCHANGE RATE REGIME

    OpenAIRE

    JOHN WILLIAMSON

    2007-01-01

    The argument that any exchange rate regimes other than firmly fixed and freely floating rates were infeasible — the so-called bipolarity thesis — acquired great popularity in the wake of the Asian crisis of a decade ago, but it has almost vanished today. One reason is surely the unkind empirical evidence, which shows that intermediate regimes — measured as those where both reserve and exchange rate changes lie in an intermediate range — are not in fact tending to disappear (Levy Yeyati and St...

  5. Synchronization of Spatiotemporal Chaos The regime of coupled Spatiotemporal Intermittency

    CERN Document Server

    Amengual, A; Montagne, R; Miguel, M S

    1996-01-01

    Synchronization of spatiotemporally chaotic extended systems is considered in the context of coupled one-dimensional Complex Ginzburg-Landau equations (CGLE). A regime of coupled spatiotemporal intermittency (STI) is identified and described in terms of the space-time synchronized chaotic motion of localized structures. A quantitative measure of synchronization as a function of coupling parameter is given through distribution functions and information measures. The coupled STI regime is shown to dissapear into regular dynamics for situations of strong coupling, hence a description in terms of a single CGLE is not appropiate.

  6. Selection Criteria in Regime Switching Conditional Volatility Models

    Directory of Open Access Journals (Sweden)

    Thomas Chuffart

    2015-05-01

    Full Text Available A large number of nonlinear conditional heteroskedastic models have been proposed in the literature. Model selection is crucial to any statistical data analysis. In this article, we investigate whether the most commonly used selection criteria lead to choice of the right specification in a regime switching framework. We focus on two types of models: the Logistic Smooth Transition GARCH and the Markov-Switching GARCH models. Simulation experiments reveal that information criteria and loss functions can lead to misspecification ; BIC sometimes indicates the wrong regime switching framework. Depending on the Data Generating Process used in the experiments, great care is needed when choosing a criterion.

  7. Regime Switches in the Risk-Return Trade-off

    OpenAIRE

    Ghysels, Eric; Guérin, Pierre; Marcellino, Massimiliano

    2013-01-01

    This paper deals with the estimation of the risk-return trade-off. We use a MIDAS model for the conditional variance and allow for possible switches in the risk-return relation through a Markov-switching specification. We find strong evidence for regime changes in the risk-return relation. This finding is robust to a large range of specifications. In the first regime characterized by low ex-post returns and high volatility, the risk-return relation is reversed, whereas the intuitive positive ...

  8. Space as a low-temperature regime of graphs

    CERN Document Server

    Conrady, Florian

    2010-01-01

    I define a statistical model of graphs in which 2-dimensional spaces arise at low temperature. The configurations are given by graphs with a fixed number of edges and the Hamiltonian is a simple, local function of the graphs. Simulations show that there is a transition between a low-temperature regime in which the graphs form triangulations of 2-dimensional surfaces and a high-temperature regime, where the surfaces disappear. I use data for the specific heat and other observables to discuss whether this is a phase transition. The surface states are analyzed with regard to topology and defects.

  9. Political humor as a confrontational tool against the syrian regime

    OpenAIRE

    Camps-Febrer, Blanca

    2012-01-01

    The aim of this working paper is to analyze the inclusion of political humor into the set of actions used by opponents to the Syrian regime during the first year of a state-wide uprising in 2011. The research ar-gues that although political humor has traditionally been seen mainly as a concealed voice against dominant elites, it can nevertheless take a confrontational stance and challenge a regime. In this paper we assess the role of political humor in challenging the legitimacy of the Syrian...

  10. The rise of a learning regime in Europe

    DEFF Research Database (Denmark)

    Ehlers, Søren

    2017-01-01

    Policy terms lead to change. They appear and disappear in policy papers across time and space and instigate continuity or discontinuity. To understand how this happens, policy terms need to be mapped. It could be done through a systematic analysis of models, hypotheses, quantitative data, antonyms...... and studies of time and space – in comparison. Appearance of the term Lifelong Learning and the change from Teaching Regime to Learning Regime is used as an example in this paper to show how this mapping could be done....

  11. Using Clustering to Establish Climate Regimes from PCM Output

    Science.gov (United States)

    Oglesby, Robert; Arnold, James E. (Technical Monitor); Hoffman, Forrest; Hargrove, W. W.; Erickson, D.

    2002-01-01

    A multivariate statistical clustering technique--based on the k-means algorithm of Hartigan has been used to extract patterns of climatological significance from 200 years of general circulation model (GCM) output. Originally developed and implemented on a Beowulf-style parallel computer constructed by Hoffman and Hargrove from surplus commodity desktop PCs, the high performance parallel clustering algorithm was previously applied to the derivation of ecoregions from map stacks of 9 and 25 geophysical conditions or variables for the conterminous U.S. at a resolution of 1 sq km. Now applied both across space and through time, the clustering technique yields temporally-varying climate regimes predicted by transient runs of the Parallel Climate Model (PCM). Using a business-as-usual (BAU) scenario and clustering four fields of significance to the global water cycle (surface temperature, precipitation, soil moisture, and snow depth) from 1871 through 2098, the authors' analysis shows an increase in spatial area occupied by the cluster or climate regime which typifies desert regions (i.e., an increase in desertification) and a decrease in the spatial area occupied by the climate regime typifying winter-time high latitude perma-frost regions. The patterns of cluster changes have been analyzed to understand the predicted variability in the water cycle on global and continental scales. In addition, representative climate regimes were determined by taking three 10-year averages of the fields 100 years apart for northern hemisphere winter (December, January, and February) and summer (June, July, and August). The result is global maps of typical seasonal climate regimes for 100 years in the past, for the present, and for 100 years into the future. Using three-dimensional data or phase space representations of these climate regimes (i.e., the cluster centroids), the authors demonstrate the portion of this phase space occupied by the land surface at all points in space and time

  12. Educational differentials in disability vary across and within welfare regimes

    DEFF Research Database (Denmark)

    Cambois, Emmanuelle; Solé-Auró, Aïda; Brønnum-Hansen, Henrik;

    2016-01-01

    groups (referred to as disability disadvantage) and of the lower prevalence in high social groups (disability advantage); country-specific advantages/disadvantages are discussed regarding the possible influence of welfare regimes. METHODS: Cross-sectional disability prevalence is measured by longstanding...... health-related activity limitation (AL) in the 2009 European Statistics on Income and Living Conditions (EU-SILC) across 26 countries classified into four welfare regime groups. Logistic models adjusted by country, age and sex (in all 30-79 years and in three age-bands) measured the country-specific ORs...

  13. A faster switching regime for zenithal bistable nematic displays

    Energy Technology Data Exchange (ETDEWEB)

    Rudin, J

    1997-12-01

    A simpler and faster switching regime for Zenithal Bistable Nematic displays is reported. A cell, based on homeotropic alignment of nematic liquid crystal over a continuous blazed monograting on one surface, can be switched using bipolar pulses an order of magnitude faster than monopolar pulses of the same voltage. We propose that this regime relies on simple dielectric coupling to drive the cell into a higher energy state with a long pulse time, and the relaxation into a lower energy state after the creation of surface defects from a shorter applied pulse. Although flexoelectric effects are observed, they do not form the basis of state selection as was proposed for the monopolar pulses

  14. Quantum regime of a free-electron laser: relativistic approach

    Science.gov (United States)

    Kling, Peter; Sauerbrey, Roland; Preiss, Paul; Giese, Enno; Endrich, Rainer; Schleich, Wolfgang P.

    2017-01-01

    In the quantum regime of the free-electron laser, the dynamics of the electrons is not governed by continuous trajectories but by discrete jumps in momentum. In this article, we rederive the two crucial conditions to enter this quantum regime: (1) a large quantum mechanical recoil of the electron caused by the scattering with the laser and the wiggler field and (2) a small energy spread of the electron beam. In contrast to our recent approach based on nonrelativistic quantum mechanics in a co-moving frame of reference, we now pursue a model in the laboratory frame employing relativistic quantum electrodynamics.

  15. NAZI REGIME IN THE PERIODICAL A NOTÍ­CIA.

    Directory of Open Access Journals (Sweden)

    Bruna Luíza Barcellos

    2009-08-01

    Full Text Available The periodical A Notícia, of Joinville, city colonized for Germans, supported the nazi regime since the ascension of Adolf Hitler to the power. Between 1932 and 1944, some editions had printed the figure of Hitler and the nazi symbol, beyond dither messages to that regime. Based in the Análise de conteúdo (BARDIN, 1977, this article searchs to understand the representation made for the periodical A Notícia on this historical landmark, in other words, bring to the light the consequences of a part of occured world-wide history in catarinense territory.

  16. Is the Economic Crisis Challenging the Prevailing Gender Regime?

    DEFF Research Database (Denmark)

    Leschke, Janine; Jepsen, Maria

    2014-01-01

    This paper addresses the question of whether the current economic and financial crisis is challenging the prevailing gender-equality model in four European countries: Denmark, Germany, Slovakia, and the United Kingdom. After situating the countries in relation to the underlying gender regime...... and analysing the corresponding position of women and men in paid and unpaid work, the paper contains an in-depth discussion of the short- and medium-term policy responses to the crisis. Our analysis shows that independent of the prevailing gender regime, scant public attention has been directed to gender...

  17. Using Clustering to Establish Climate Regimes from PCM Output

    Science.gov (United States)

    Oglesby, Robert; Arnold, James E. (Technical Monitor); Hoffman, Forrest; Hargrove, W. W.; Erickson, D.

    2002-01-01

    A multivariate statistical clustering technique--based on the k-means algorithm of Hartigan has been used to extract patterns of climatological significance from 200 years of general circulation model (GCM) output. Originally developed and implemented on a Beowulf-style parallel computer constructed by Hoffman and Hargrove from surplus commodity desktop PCs, the high performance parallel clustering algorithm was previously applied to the derivation of ecoregions from map stacks of 9 and 25 geophysical conditions or variables for the conterminous U.S. at a resolution of 1 sq km. Now applied both across space and through time, the clustering technique yields temporally-varying climate regimes predicted by transient runs of the Parallel Climate Model (PCM). Using a business-as-usual (BAU) scenario and clustering four fields of significance to the global water cycle (surface temperature, precipitation, soil moisture, and snow depth) from 1871 through 2098, the authors' analysis shows an increase in spatial area occupied by the cluster or climate regime which typifies desert regions (i.e., an increase in desertification) and a decrease in the spatial area occupied by the climate regime typifying winter-time high latitude perma-frost regions. The patterns of cluster changes have been analyzed to understand the predicted variability in the water cycle on global and continental scales. In addition, representative climate regimes were determined by taking three 10-year averages of the fields 100 years apart for northern hemisphere winter (December, January, and February) and summer (June, July, and August). The result is global maps of typical seasonal climate regimes for 100 years in the past, for the present, and for 100 years into the future. Using three-dimensional data or phase space representations of these climate regimes (i.e., the cluster centroids), the authors demonstrate the portion of this phase space occupied by the land surface at all points in space and time

  18. Using Clustering to Establish Climate Regimes from PCM Output

    Science.gov (United States)

    Hoffman, F.; Oglesby, R.; Hargrove, W. W.; Erickson, D.

    2002-12-01

    A multivariate statistical clustering technique--based on the k-means algorithm of Hartigan--has been used to extract patterns of climatological significance from 200 years of general circulation model (GCM) output. Originally developed and implemented on a Beowulf-style parallel computer constructed by Hoffman and Hargrove from surplus commodity desktop PCs, the high performance parallel clustering algorithm was previously applied to the derivation of ecoregions from map stacks of 9 and 25 geophysical conditions or variables for the conterminous U.S. at a resolution of 1 sq km. Now applied both across space and through time, the clustering technique yields temporally-varying climate regimes predicted by transient runs of the Parallel Climate Model (PCM). Using a business-as-usual (BAU) scenario and clustering four fields of significance to the global water cycle (surface temperature, precipitation, soil moisture, and snow depth) from 1871 through 2098, the authors' analysis shows an increase in spatial area occupied by the cluster or climate regime which typifies desert regions (i.e., an increase in desertification) and a decrease in the spatial area occupied by the climate regime typifying winter-time high latitude perma-frost regions. The patterns of cluster changes have been analyzed to understand the predicted variability in the water cycle on global and continental scales. In addition, representative climate regimes were determined by taking three 10-year averages of the fields 100 years apart for northern hemisphere winter (December, January, and February) and summer (June, July, and August). The result is global maps of typical seasonal climate regimes for 100 years in the past, for the present, and for 100 years into the future. Using three-dimensional data or phase space representations of these climate regimes (i.e., the cluster centroids), the authors demonstrate the portion of this phase space occupied by the land surface at all points in space and

  19. Light emission and finite-frequency shot noise in molecular junctions: from tunneling to contact

    DEFF Research Database (Denmark)

    Lu, Jing Tao; Christensen, Rasmus Bjerregaard; Brandbyge, Mads

    2013-01-01

    Scanning tunneling microscope induced light emission from an atomic or molecular junction has been probed from the tunneling to contact regime in recent experiments. There, the measured light emission yields suggest a strong correlation with the high-frequency current/charge fluctuations. We show...... that this is consistent with the established theory in the tunneling regime, by writing the finite-frequency shot noise as a sum of inelastic transitions between different electronic states. Based on this, we develop a practical scheme to perform calculations on realistic structures using nonequilibrium Green's functions...

  20. Impact of air conditioning system operation on increasing gases emissions from automobile

    Science.gov (United States)

    Burciu, S. M.; Coman, G.

    2016-08-01

    The paper presents a study concerning the influence of air conditioning system operation on the increase of gases emissions from cars. The study focuses on urban operating regimes of the automobile, regimes when the engines have low loads or are operating at idling. Are presented graphically the variations of pollution emissions (CO, CO2, HC) depending of engine speed and the load on air conditioning system. Additionally are presented, injection duration, throttle position, the mechanical power required by the compressor of air conditioning system and the refrigerant pressure variation on the discharge path, according to the stage of charging of the air conditioning system.

  1. A generation mechanism of chorus emissions using BWO theory

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Ashutosh K; Singh, K K; Singh, A K; Patel, R P [Department of Physics, M. M. H. P. G. College, Ghaziabad (India); Singh, R, E-mail: abhay_s@rediffmail.co [Indian Institute of Geomagnetism, Navi Mumbai (India)

    2010-02-01

    In this paper, discrete VLF chorus emissions recorded at low latitude ground station Jammu (geomag. Lat. = 22{sup 0} 26{sup /} N, L = 1.17) are reported and their characteristics based on complete spectral analysis have been carried out. These discrete chorus emissions are generated during a strong geomagnetic storm period of 2-7 May, 1998. We have computed the sweep rate, repetition period, source region, and drift rate of the individual chorus elements. It is observed that the sweep rate increases with time. To explain the various temporal and spectral features of these emissions, a possible generation mechanism has been presented based on the backward wave oscillator (BWO) regime in the magnetospheric cyclotron maser. On the basis of this model, we have computed some discrete chorus emission parameters as well as magnetospheric parameters relevant to the generation process. A comparison of the computed and observed magnetospheric parameters has been presented. These results show a good agreement with the BWO model.

  2. Investigating ambient ozone formation regimes in neighboring cities of shale plays in the Northeast United States using photochemical modeling and satellite retrievals

    Science.gov (United States)

    Chang, Chih-Yuan; Faust, Eric; Hou, Xiangting; Lee, Pius; Kim, Hyun Cheol; Hedquist, Brent C.; Liao, Kuo-Jen

    2016-10-01

    This study investigates long-term (i.e., 2007-2014) fluctuations in ambient ozone formation regimes for cities adjacent to shale plays in the Northeast United States (U.S.). Ozone air quality in many cities of the Northeast U.S. does not meet the U.S. National Ambient Air Quality Standards (NAAQS), and understanding ambient ozone formation regimes is essential to develop effective air pollution mitigation strategies for cities violating the air quality standards. Since 2013, the U.S. has become the world's largest producer of tight oil and natural gas from shale rock, and previous studies show that emissions of air pollutant precursors from shale oil and gas-related activities would have the potential to affect ambient ozone air quality in adjacent cities of shale plays. This work leveraged (1) satellite-retrieved column densities of formaldehyde (HCHO) and nitrogen dioxide (NO2) from multiple instruments (i.e., Ozone Monitoring Instrument (OMI) and Global Ozone Monitoring Experiment-2 (GOME-2)); (2) photochemical air quality modeling and sensitivity analysis; and (3) ratios of satellite-retrieved air pollutant column densities to investigate ambient ozone formation regimes in neighboring cities of shale plays (i.e., Marcellus Shale) in the Northeast U.S. from 2007 to 2014. Our results show that ambient ozone formation in Boston, Pittsburgh, Philadelphia and Washington, D.C. (which are close to Marcellus Shale) was in the NOx -limited or transition regime during the period of study. Ambient ozone formation in New York City was in the transition regime during 2010-2013 and VOC -limited regime during 2007-2009 and in 2014. Based on the result of this study, we conclude that controls NOx emissions would mitigate ozone air pollution from 2007 to 2014 in most of the cities examined in this study. Controls of local VOC emissions would ease ozone air pollution in New York City during the study period. With projected increases in oil and gas production from shale plays in

  3. Shipping emissions in ports

    OpenAIRE

    2014-01-01

    Shipping emissions in ports are substantial, accounting for 18 million tonnes of CO2 emissions, 0.4 million tonnes of NOx, 0.2 million of SOx and 0.03 million tonnes of PM10 in 2011. Around 85% of emissions come from containerships and tankers. Containerships have short port stays, but high emissions during these stays. Most of CO2 emissions in ports from shipping are in Asia and Europe (58%), but this share is low compared to their share of port calls (70%). European ports have much less emi...

  4. International emissions trading

    DEFF Research Database (Denmark)

    Boom, Jan Tjeerd

    This thesis discusses the design and political acceptability of international emissions trading. It is shown that there are several designs options for emissions trading at the national level that have a different impact on output and thereby related factors such as employment and consumer prices....... The differences in impact of the design make that governments may prefer different designs of emissions trading in different situations. The thesis furthermore establishes that international emissions trading may lead to higher overall emissions, which may make it a less attractive instrument....

  5. Syria: The Consolidation of the Asad Regime, 1970-1975.

    Science.gov (United States)

    Olson, Robert W.

    1982-01-01

    Up to 1975-76, Syria's Hafiz al-Asad was successful in consolidating his power, securing the maintenance of his regime, and broadening his base of political power. His system started weakening in 1975 due to increased opposition stemming from Syria's intervention in the Lebanese civil war. (AM)

  6. Political Regime and Human Capital: A Cross-Country Analysis

    Science.gov (United States)

    Klomp, Jeroen; de Haan, Jakob

    2013-01-01

    We examine the relationship between different dimensions of the political regime in place and human capital using a two-step structural equation model. In the first step, we employ factor analysis on 16 human capital indicators to construct two new human capital measures (basic and advanced human capital). In the second step, we estimate the…

  7. Accessing Imagined Communities and Reinscribing Regimes of Truth

    Science.gov (United States)

    Carroll, Sherrie; Motha, Suhanthie; Price, Jeremy N.

    2008-01-01

    In this article, we explore the complex and nebulous terrain between two theoretical concepts, imagined communities (Norton, 2000, 2001), that is, individuals' imagined affiliations with certain groups, and regimes of truth (Foucault, 1980), dominant images inscribed and reinscribed into individual consciousness until they become normative. Using…

  8. Primordial black holes in linear and non-linear regimes

    CERN Document Server

    Allahyari, Alireza; Abolhasani, Ali Akbar

    2016-01-01

    Using the concept of apparent horizon for dynamical black holes, we revisit the formation of primordial black holes (PBH) in the early universe for both linear and non-linear regimes. First, we develop the perturbation theory for spherically symmetric spacetimes to study the formation of spherical PBHs in linear regime and we fix two gauges. We also introduce a well defined gauge invariant quantity for the expansion. Using this quantity, we argue that PBHs do not form in the linear regime. Finally, we study the non-linear regime. We adopt the spherical collapse picture by taking a closed FRW model in the radiation dominated era to investigate PBH formation. Taking the initial condition of the spherical collapse from the linear theory of perturbations, we allow for both density and velocity perturbations. Our model gives a constraint on the velocity perturbation. This model also predicts that the apparent horizon of PBHs forms when $\\delta > 3$. Applying the sound horizon constraint, we have shown the threshol...

  9. Regular and Chaotic Regimes in Scalar Field Cosmology

    Directory of Open Access Journals (Sweden)

    Alexey V. Toporensky

    2006-03-01

    Full Text Available A transient chaos in a closed FRW cosmological model with a scalar field is studied. We describe two different chaotic regimes and show that the type of chaos in this model depends on the scalar field potential. We have found also that for sufficiently steep potentials or for potentials with large cosmological constant the chaotic behavior disappears.

  10. Exploring the epsilon regime with twisted mass fermions

    CERN Document Server

    Jansen, K; Shindler, A; Urbach, C; Wenger, U

    2007-01-01

    In this proceeding contribution we report on a first study in order to explore the so called epsilon regime with Wilson twisted mass (Wtm) fermions. To show the potential of this approach we give a preliminary determination of the chiral condensate.

  11. Consumption, investment and life insurance under different tax regimes

    DEFF Research Database (Denmark)

    Bruun, Kenneth

    2013-01-01

    We study the effects of introducing taxation in classical continuous-time optimization problems with utility from consumption, bequest and retirement savings. Inspired by actual tax favoured retirement savings programs, we formulate and solve the optimization problem for various tax regimes, and ...

  12. Politics, welfare regimes, and population health: controversies and evidence.

    Science.gov (United States)

    Muntaner, Carles; Borrell, Carme; Ng, Edwin; Chung, Haejoo; Espelt, Albert; Rodriguez-Sanz, Maica; Benach, Joan; O'Campo, Patricia

    2011-09-01

    In recent years, a research area has emerged within social determinants of health that examines the role of politics, expressed as political traditions/parties and welfare state characteristics, on population health. To better understand and synthesise this growing body of evidence, the present literature review, informed by a political economy of health and welfare regimes framework, located 73 empirical and comparative studies on politics and health, meeting our inclusion criteria in three databases: PubMed (1948-), Sociological Abstracts (1953-), and ISI Web of Science (1900-). We identified two major research programmes, welfare regimes and democracy, and two emerging programmes, political tradition and globalisation. Primary findings include: (1) left and egalitarian political traditions on population health are the most salutary, consistent, and substantial; (2) the health impacts of advanced and liberal democracies are also positive and large; (3) welfare regime studies, primarily conducted among wealthy countries, find that social democratic regimes tend to fare best with absolute health outcomes yet consistently in terms of relative health inequalities; and (4) globalisation defined as dependency indicators such as trade, foreign investment, and national debt is negatively associated with population health. We end by discussing epistemological, theoretical, and methodological issues for consideration for future research.

  13. Welfare Attitudes and Social Expenditure: Do Regimes Shape Public Opinion?

    Science.gov (United States)

    Jakobsen, Tor Georg

    2011-01-01

    This article examines the link between regime types, social expenditure, and welfare attitudes. By employing data on 19 countries taken from the World Values Survey, the main aim is to see to what degree the institutions of a country affect the attitudes of its citizens. According to Esping-Andersen ("The three worlds of welfare…

  14. Predicting weather regime transitions in Northern Hemisphere datasets

    Energy Technology Data Exchange (ETDEWEB)

    Kondrashov, D. [University of California, Department of Atmospheric and Oceanic Sciences and Institute of Geophysics and Planetary Physics, Los Angeles, CA (United States); Shen, J. [UCLA, Department of Statistics, Los Angeles, CA (United States); Berk, R. [UCLA, Department of Statistics, Los Angeles, CA (United States); University of Pennsylvania, Department of Criminology, Philadelphia, PA (United States); D' Andrea, F.; Ghil, M. [Ecole Normale Superieure, Departement Terre-Atmosphere-Ocean and Laboratoire de Meteorologie Dynamique (CNRS and IPSL), Paris Cedex 05 (France)

    2007-10-15

    A statistical learning method called random forests is applied to the prediction of transitions between weather regimes of wintertime Northern Hemisphere (NH) atmospheric low-frequency variability. A dataset composed of 55 winters of NH 700-mb geopotential height anomalies is used in the present study. A mixture model finds that the three Gaussian components that were statistically significant in earlier work are robust; they are the Pacific-North American (PNA) regime, its approximate reverse (the reverse PNA, or RNA), and the blocked phase of the North Atlantic Oscillation (BNAO). The most significant and robust transitions in the Markov chain generated by these regimes are PNA {yields} BNAO, PNA {yields} RNA and BNAO {yields} PNA. The break of a regime and subsequent onset of another one is forecast for these three transitions. Taking the relative costs of false positives and false negatives into account, the random-forests method shows useful forecasting skill. The calculations are carried out in the phase space spanned by a few leading empirical orthogonal functions of dataset variability. Plots of estimated response functions to a given predictor confirm the crucial influence of the exit angle on a preferred transition path. This result points to the dynamic origin of the transitions. (orig.)

  15. Microgravity Flow Regime Data: Buoyancy and Mixing Apparatus Effects

    Science.gov (United States)

    Shephard, Adam; Best, Frederick

    2010-01-01

    Zero-g two-phase flow data set qualification and flight experiment design have not been standardized and as a result, agreement among researchers has not been reached regarding what experimental conditions adequately approximate those of microgravity. The effects of buoyancy forces and mixing apparatus on the flow regime transitions are presented in this study. The gravity conditions onboard zero-g aircraft are at best 10-3 g which is used to approximate the 10-5 g conditions of microgravity, thus the buoyancy forces present on zero-g aircraft can become significantly large and unrepresentative of microgravity. When buoyancy forces approach those of surface tension forces, buoyancy induced coalescence occurs. When discussing flow regime transitions, these large buoyancy forces lead to flow regime transitions which otherwise would not occur. The buoyancy attributes of the two-phase flow data sets available in the literature are evaluated to determine which data sets exhibit buoyancy induced transitions. Upon comparison of the representative data sets, the affects of different mixing apparatus can be seen in the superficial velocity flow regime maps.

  16. Political Regime and Human Capital: A Cross-Country Analysis

    Science.gov (United States)

    Klomp, Jeroen; de Haan, Jakob

    2013-01-01

    We examine the relationship between different dimensions of the political regime in place and human capital using a two-step structural equation model. In the first step, we employ factor analysis on 16 human capital indicators to construct two new human capital measures (basic and advanced human capital). In the second step, we estimate the…

  17. Regime shifts limit the predictability of land-system change

    DEFF Research Database (Denmark)

    Müller, Daniel; Sun, Zhanli; Vongvisouk, Thoumthone

    2014-01-01

    (China, Laos, Vietnam and Indonesia). The results show how sudden events and gradual changes in underlying drivers caused rapid, surprising and widespread land-system changes, including shifts to different regimes in China, Vietnam and Indonesia, whereas land systems in Laos remained stable in the study...

  18. Operating regimes of signaling cycles: statics, dynamics, and noise filtering.

    Directory of Open Access Journals (Sweden)

    Carlos Gomez-Uribe

    2007-12-01

    Full Text Available A ubiquitous building block of signaling pathways is a cycle of covalent modification (e.g., phosphorylation and dephosphorylation in MAPK cascades. Our paper explores the kind of information processing and filtering that can be accomplished by this simple biochemical circuit. Signaling cycles are particularly known for exhibiting a highly sigmoidal (ultrasensitive input-output characteristic in a certain steady-state regime. Here, we systematically study the cycle's steady-state behavior and its response to time-varying stimuli. We demonstrate that the cycle can actually operate in four different regimes, each with its specific input-output characteristics. These results are obtained using the total quasi-steady-state approximation, which is more generally valid than the typically used Michaelis-Menten approximation for enzymatic reactions. We invoke experimental data that suggest the possibility of signaling cycles operating in one of the new regimes. We then consider the cycle's dynamic behavior, which has so far been relatively neglected. We demonstrate that the intrinsic architecture of the cycles makes them act--in all four regimes--as tunable low-pass filters, filtering out high-frequency fluctuations or noise in signals and environmental cues. Moreover, the cutoff frequency can be adjusted by the cell. Numerical simulations show that our analytical results hold well even for noise of large amplitude. We suggest that noise filtering and tunability make signaling cycles versatile components of more elaborate cell-signaling pathways.

  19. Welfare Attitudes and Social Expenditure: Do Regimes Shape Public Opinion?

    Science.gov (United States)

    Jakobsen, Tor Georg

    2011-01-01

    This article examines the link between regime types, social expenditure, and welfare attitudes. By employing data on 19 countries taken from the World Values Survey, the main aim is to see to what degree the institutions of a country affect the attitudes of its citizens. According to Esping-Andersen ("The three worlds of welfare…

  20. Redox regime shifts in microbially-mediated biogeochemical cycles

    Science.gov (United States)

    Bush, T.; Butler, I. B.; Free, A.; Allen, R. J.

    2015-02-01

    Understanding how the Earth's biogeochemical cycles respond to environmental change is a prerequisite for the prediction and mitigation of the effects of anthropogenic perturbations. Microbial populations mediate key steps in these cycles, yet are often crudely represented in biogeochemical models. Here, we show that microbial population dynamics can qualitatively affect the response of biogeochemical cycles to environmental change. Using simple and generic mathematical models, we find that nutrient limitations on microbial population growth can lead to regime shifts, in which the redox state of a biogeochemical cycle changes dramatically as the availability of a redox-controlling species, such as oxygen or acetate, crosses a threshold (a "tipping point"). These redox regime shifts occur in parameter ranges that are relevant to the sulfur and nitrogen cycles in the present-day natural environment, and may also have relevance to iron cycling in the iron-containing Proterozoic and Archean oceans. We show that redox regime shifts also occur in models with physically realistic modifications, such as additional terms, chemical states, or microbial populations. Our work reveals a possible new mechanism by which regime shifts can occur in nutrient-cycling ecosystems and biogeochemical cycles, and highlights the importance of considering microbial population dynamics in models of biogeochemical cycles.

  1. Redox regime shifts in microbially mediated biogeochemical cycles

    Science.gov (United States)

    Bush, T.; Butler, I. B.; Free, A.; Allen, R. J.

    2015-06-01

    Understanding how the Earth's biogeochemical cycles respond to environmental change is a prerequisite for the prediction and mitigation of the effects of anthropogenic perturbations. Microbial populations mediate key steps in these cycles, yet they are often crudely represented in biogeochemical models. Here, we show that microbial population dynamics can qualitatively affect the response of biogeochemical cycles to environmental change. Using simple and generic mathematical models, we find that nutrient limitations on microbial population growth can lead to regime shifts, in which the redox state of a biogeochemical cycle changes dramatically as the availability of a redox-controlling species, such as oxygen or acetate, crosses a threshold (a "tipping point"). These redox regime shifts occur in parameter ranges that are relevant to the present-day sulfur cycle in the natural environment and the present-day nitrogen cycle in eutrophic terrestrial environments. These shifts may also have relevance to iron cycling in the iron-containing Proterozoic and Archean oceans. We show that redox regime shifts also occur in models with physically realistic modifications, such as additional terms, chemical states, or microbial populations. Our work reveals a possible new mechanism by which regime shifts can occur in nutrient-cycling ecosystems and biogeochemical cycles, and highlights the importance of considering microbial population dynamics in models of biogeochemical cycles.

  2. Analysis of the Two-Regime Method on Square Meshes

    KAUST Repository

    Flegg, Mark B.

    2014-01-01

    The two-regime method (TRM) has been recently developed for optimizing stochastic reaction-diffusion simulations [M. Flegg, J. Chapman, and R. Erban, J. Roy. Soc. Interface, 9 (2012), pp. 859-868]. It is a multiscale (hybrid) algorithm which uses stochastic reaction-diffusion models with different levels of detail in different parts of the computational domain. The coupling condition on the interface between different modeling regimes of the TRM was previously derived for onedimensional models. In this paper, the TRM is generalized to higher dimensional reaction-diffusion systems. Coupling Brownian dynamics models with compartment-based models on regular (square) two-dimensional lattices is studied in detail. In this case, the interface between different modeling regimes contains either flat parts or right-angle corners. Both cases are studied in the paper. For flat interfaces, it is shown that the one-dimensional theory can be used along the line perpendicular to the TRM interface. In the direction tangential to the interface, two choices of the TRM parameters are presented. Their applicability depends on the compartment size and the time step used in the molecular-based regime. The two-dimensional generalization of the TRM is also discussed in the case of corners. © 2014 Society for Industrial and Applied Mathematics.

  3. The essence of fire regime-condition class assessment

    Science.gov (United States)

    McKinley-Ben Miller

    2008-01-01

    The interagency-Fire Regime / Condition Class - assessment process (FRCC) represents a contemporary and effective means of estimating the relative degree of difference or "departure" a subject landscape condition is currently in, as compared to the historic or reference ecological conditions. This process generally applied to fire adapted systems is science-...

  4. Sputtering of Ge(001): transition between dynamic scaling regimes

    DEFF Research Database (Denmark)

    Smilgies, D.-M.; Eng, P.J.; Landemark, E.;

    1997-01-01

    We have studied the dynamic behavior of the Ge(001) surface during sputtering in situ and in real time using synchrotron X-ray diffraction. We find two dynamic regimes as a function of surface temperature and sputter current which are separated by a sharp transition. The boundary between these two...

  5. Regime Change in North Africa and Implications for

    African Journals Online (AJOL)

    MUMO

    regime changes in North Africa; the role of ICT and its social media networks ... Journal of Language, Technology & Entrepreneurship in Africa Vol. ... in academic, social media and political and/or political circles. ... one can easily view the US and NATO involvement in Libya as a disguised ..... As such the role Facebook,.

  6. Nonlinear regimes in mean-field full-sphere dynamo

    CERN Document Server

    Pipin, V V

    2016-01-01

    The mean-field dynamo model is employed to study the non-linear dynamo regimes in a fully convective star of mass 0.3$M_{\\odot}$ rotating with period of 10 days. The differential rotation law was estimated using the mean-field hydrodynamic and heat transport equations. For the intermediate parameter of the turbulent magnetic Reynolds number, $Pm_{T}=3$ we found the oscillating dynamo regimes with period about 40Yr. The higher $Pm_{T}$ results to longer dynamo periods. The meridional circulation has one cell per hemisphere. It is counter-clockwise in the Northen hemisphere. The amplitude of the flow at the surface around 1 m/s. Tne models with regards for meridional circulation show the anti-symmetric relative to equator magnetic field. If the large-scale flows is fixed we find that the dynamo transits from axisymmetric to non-axisymmetric regimes for the overcritical parameter of the $\\alpha$effect. The change of dynamo regime occurs because of the non-axisymmetric non-linear $\\alpha$-effect. The situation pe...

  7. Optimal ranking regime analysis of TreeFlow dendrohydrological reconstructions

    Science.gov (United States)

    The Optimal Ranking Regime (ORR) method was used to identify 6-100 year time windows containing significant ranking sequences in 55 western U.S. streamflow reconstructions, and reconstructions of the level of the Great Salt Lake and San Francisco Bay salinity during 1500-2007. The method’s ability t...

  8. Root response of Jerusalem artichoke genotypes to different water regimes

    Science.gov (United States)

    The objective of this study was to determine effects of drought on selected root growth parameters and develop relationships between root parameters and tuber yield for selected Jerusalem artichoke (JA) genotypes. Three water regimes (Field capacity, 50% available water (AW) and 25% AW) and five JA...

  9. Dealing with incumbent regimes: Deliberateness and serendipity of innovation agency

    NARCIS (Netherlands)

    Klerkx, L.W.A.; Aarts, M.N.C.; Leeuwis, C.

    2010-01-01

    This paper addresses how actors in niche innovation projects interact with existing socio-technical regimes. The focus is on actor strategies deployed to create changes in the institutional environment of projects in order to establish a more conducive environment for niche projects. The paper

  10. Political regime and human capital : A cross-country analysis

    NARCIS (Netherlands)

    Klomp, J.G.; de Haan, J.

    2013-01-01

    We examine the relationship between different dimensions of the political regime in place and human capital using a two-step structural equation model. In the first step, we employ factor analysis on 16 human capital indicators to construct two new human capital measures (basic and advanced human ca

  11. Political regime and human capital: A cross-country analysis

    NARCIS (Netherlands)

    Klomp, J.G.; Haan, de J.

    2013-01-01

    We examine the relationship between different dimensions of the political regime in place and human capital using a two-step structural equation model. In the first step, we employ factor analysis on 16 human capital indicators to construct two new human capital measures (basic and advanced human ca

  12. Shape and motion of drops in the inertial regime

    CERN Document Server

    Vijaya, Senthil Kumar K

    2010-01-01

    In this paper, we report experimental results on the shape and motion of a mercury droplet, placed in a horizontally rotating cylinder in the rpm range 8-93, so that the Reynolds number of the drop 2500regimes identified with varying speeds of rotation (i) oval or rounded regime (ii) corner regime and (iii) cusping regime. The oval to corner transition happens at a finite receding contact angle of 950. The ratio of critical contact angle ({\\theta}c) at which the transition occurs to the static receding contact ang...

  13. Just for Fun? The Emotional Regime of Experiential Consumption

    DEFF Research Database (Denmark)

    Jantzen, Christian; Fitchett, James; Østergaard, Per

    2012-01-01

    experiential appetites. The development of a regime of experiences is outlined, consisting of a set of techniques to bring about sensual pleasure, a discourse to verbalize the methods of pleasure seeking, and an ideology that turns pleasure into a legitimate existential goal in life for the sake of self-actualization....

  14. Political regime and human capital : A cross-country analysis

    NARCIS (Netherlands)

    Klomp, J.G.; de Haan, J.

    2013-01-01

    We examine the relationship between different dimensions of the political regime in place and human capital using a two-step structural equation model. In the first step, we employ factor analysis on 16 human capital indicators to construct two new human capital measures (basic and advanced human ca

  15. Political regime and human capital: A cross-country analysis

    NARCIS (Netherlands)

    Klomp, J.G.; Haan, de J.

    2013-01-01

    We examine the relationship between different dimensions of the political regime in place and human capital using a two-step structural equation model. In the first step, we employ factor analysis on 16 human capital indicators to construct two new human capital measures (basic and advanced human ca

  16. Regimes of flow induced vibration for tandem, tethered cylinders

    Science.gov (United States)

    Nave, Gary; Stremler, Mark

    2015-11-01

    In the wake of a bluff body, there are a number of dynamic response regimes that exist for a trailing bluff body depending on spacing, structural restoring forces, and the mass-damping parameter m* ζ . For tandem cylinders with low values of m* ζ , two such regimes of motion are Gap Flow Switching and Wake Induced Vibration. In this study, we consider the dynamics of a single degree-of-freedom rigid cylinder in the wake of another in these regimes for a variety of center-to-center cylinder spacings (3-5 diameters) and Reynolds numbers (4,000-11,000). The system consists of a trailing cylinder constrained to a circular arc around a fixed leading cylinder, which, for small angle displacements, bears a close resemblance to the transversely oscillating cylinders found more commonly in existing literature. From experiments on this system, we compare and contrast the dynamic response within these two regimes. Our results show sustained oscillations in the absence of a structural restoring force in all cases, providing experimental support for the wake stiffness assumption, which is based on the mean lift toward the center line of flow.

  17. Welfare Regimes and Educational Inequality: A Cross-National Exploration

    Science.gov (United States)

    Peter, Tracey; Edgerton, Jason D.; Roberts, Lance W.

    2010-01-01

    Research on welfare state regimes and research on educational policy share a common concern for the reduction of social inequality. On one hand, welfare state research is typically designed within a comparative approach where scholars investigate similarities and differences in social institutions across selected countries. On the other hand, the…

  18. Shearing box simulations in the Rayleigh unstable regime

    DEFF Research Database (Denmark)

    Nauman, Farrukh; Blackman, Eric G.

    2015-01-01

    We study the stability properties of Rayleigh unstable flows both in the purely hydrodynamic and magnetohydrodynamic (MHD) regimes for two different values of the shear $q=2.1, 4.2$ ($q = - d\\ln\\Omega / d\\ln r$) and compare it with the Keplerian case $q=1.5$. The Rayleigh stability criterion states...

  19. Defocusing regimes of nonlinear waves in media with negative dispersion

    DEFF Research Database (Denmark)

    Bergé, L.; Kuznetsov, E.A.; Juul Rasmussen, J.

    1996-01-01

    Defocusing regimes of quasimonochromatic waves governed by a nonlinear Schrodinger equation with mixed-sign dispersion are investigated. For a power-law nonlinearity, we show that localized solutions to this equation defined at the so-called critical dimension cannot collapse in finite time...

  20. Regime shifts, resilience and recovery of a cod stock

    DEFF Research Database (Denmark)

    Lindegren, Martin; Diekmann, Rabea; Möllmann, Christian

    2010-01-01

    In the North and Baltic seas Atlantic cod Gadus morhua stocks collapsed as part or one of the major factors inducing large-scale ecosystem regime shifts. Determining the relative contribution of overfishing and climate variability in causing these shifts has proven difficult. While facing similar...

  1. Ranking Regime and the Future of Vernacular Scholarship

    Science.gov (United States)

    Ishikawa, Mayumi

    2014-01-01

    World university rankings and their global popularity present a number of far-reaching impacts for vernacular scholarship. This article employs a multidimensional approach to analyze the ranking regime's threat to local scholarship and knowledge construction through a study of Japanese research universities. First, local conditions that have led…

  2. The political constitution of the EU citizen rights regime

    DEFF Research Database (Denmark)

    Olsen, Tore Vincents

    2011-01-01

    communities and institutions to the good life of citizens, both individually and collectively. Taking the contestation between the different views seriously, the article argues in favour of political constitutionalism, according to which the development of the EU citizen rights regime is the responsibility...

  3. Scale invariance and scaling law of Thomson backscatter spectra by electron moving in laser-magnetic resonance regime

    CERN Document Server

    Fu, Yi-Jia; Wan, Feng; Sang, Hai-Bo; Xie, Bai-Song

    2016-01-01

    The Thomson scattering spectra by an electron moving in the laser-magnetic resonance acceleration regime are computed numerically and analytically. The dependence of fundamental frequency on the laser intensity and magnetic resonance parameter is examined carefully. By calculating the emission of a single electron in a circularly polarized plane-wave laser field and constant external magnetic field, the scale invariance of the radiation spectra is evident in terms of harmonic orders. The scaling law of backscattered spectra are exhibited remarkably for the laser intensity as well for the initial axial momentum of the electron when the cyclotron frequency of the electron approaches the laser frequency. The results indicate that the magnetic resonance parameter plays an important role on the strength of emission. And the rich features of scattering spectra found may be applicable to the radiation source tunability.

  4. Statistical study of undulator radiated power by a classical detection system in the mm-wave regime

    Directory of Open Access Journals (Sweden)

    A. Eliran

    2009-05-01

    Full Text Available The statistics of FEL spontaneous emission power detected with a detector integration time much larger than the slippage time has been measured in many previous works at high frequencies. In such cases the quantum (shot noise generated in the detection process is dominant. We have measured spontaneous emission in the Israeli electrostatic accelerator FEL (EA-FEL operating in the mm-wave lengths. In this regime the detector is based on a diode rectifier for which the detector quantum noise is negligible. The measurements were repeated numerous times in order to create a sample space with sufficient data enabling evaluation of the statistical features of the radiated power. The probability density function of the radiated power was found and its moments were calculated. The results of analytical and numerical models are compared to those obtained in experimental measurements.

  5. Polarimetric phenomenology in the reflective regime: a case study using polarized hyperspectral data

    Science.gov (United States)

    Gibney, Mark

    2016-05-01

    Understanding the phenomenology of polarimetric data is necessary if we want to obtain the maximum benefit when we exploit that data. To first order, polarimetric phenomenology is driven by two things; the target material type (specular or diffuse) and the illuminating source (point (sun) or extended (body emission)). Polarimetric phenomenology can then be broken into three basic categories; ([specular material/sun source], [diffuse/sun], [specular/body]) where we have assigned body emission to the IR passband where materials are generally specular. The task of interest determines the category of interest since the task determines the dominant target material and the illuminating source (eg detecting diffuse targets under trees in VNIR = [diffuse/sun] category). In this paper, a specific case study for the important [diffuse/sun] category will be presented. For the reflective regime (0.3 - 3.0um), the largest polarimetric signal is obtained when the sun illuminates a significant portion of the material BRDF lobe. This naturally points us to problems whose primary target materials are diffuse since the BRDF lobe for specular materials is tiny (low probability of acquiring on the BRDF lobe) and glinty (high probability of saturating the sensor when on lobe). In this case study, we investigated signatures of solar illuminated diffuse paints acquired by a polarimetric hyperspectral sensor. We will discuss the acquisition, reduction and exploitation of that data, and use it to illustrate the primary characteristics of reflective polarimetric phenomenology.

  6. The human dimension of fire regimes on Earth

    Science.gov (United States)

    Bowman, David M.J.S.; Balch, Jennifer; Artaxo, Paulo; Bond, William J.; Cochrane, Mark A.; D'Antonio, Carla M.; DeFries, Ruth; Johnston, Fay H.; Keeley, Jon E.; Krawchuk, Meg A.; Kull, Christian A.; Michelle, Mack; Moritz, Max A.; Pyne, Stephen; Roos, Christopher I.; Scott, Andrew C.; Sodhi, Navjot S.; Swetnam, Thomas W.

    2011-01-01

    Humans and their ancestors are unique in being a fire-making species, but 'natural' (i.e. independent of humans) fires have an ancient, geological history on Earth. Natural fires have influenced biological evolution and global biogeochemical cycles, making fire integral to the functioning of some biomes. Globally, debate rages about the impact on ecosystems of prehistoric human-set fires, with views ranging from catastrophic to negligible. Understanding of the diversity of human fire regimes on Earth in the past, present and future remains rudimentary. It remains uncertain how humans have caused a departure from 'natural' background levels that vary with climate change. Available evidence shows that modern humans can increase or decrease background levels of natural fire activity by clearing forests, promoting grazing, dispersing plants, altering ignition patterns and actively suppressing fires, thereby causing substantial ecosystem changes and loss of biodiversity. Some of these contemporary fire regimes cause substantial economic disruptions owing to the destruction of infrastructure, degradation of ecosystem services, loss of life, and smoke-related health effects. These episodic disasters help frame negative public attitudes towards landscape fires, despite the need for burning to sustain some ecosystems. Greenhouse gas-induced warming and changes in the hydrological cycle may increase the occurrence of large, severe fires, with potentially significant feedbacks to the Earth system. Improved understanding of human fire regimes demands: (1) better data on past and current human influences on fire regimes to enable global comparative analyses, (2) a greater understanding of different cultural traditions of landscape burning and their positive and negative social, economic and ecological effects, and (3) more realistic representations of anthropogenic fire in global vegetation and climate change models. We provide an historical framework to promote understanding

  7. How will climate change modify river flow regimes in Europe?

    Directory of Open Access Journals (Sweden)

    C. Schneider

    2012-08-01

    Full Text Available Worldwide, flow regimes are being modified by various anthropogenic impacts and climate change induces an additional risk. Rising evapotranspiration rates, declining snow cover and changing precipitation patterns will interact differently at different locations. Consequently, in distinct climate zones, unequal consequences can be expected in matters of water stress, flood risk, water quality, and food security. In particular, river ecosystems and their vital ecosystem services will be compromised as their species richness and composition have evolved over long time under natural flow conditions. This study aims at evaluating the exclusive impacts of climate change on river flow regimes in Europe. Various flow characteristics are taken into consideration and diverse dynamics are identified for each distinct climate zone in Europe. In order to simulate natural and modified flow regimes, the global hydrology model WaterGAP3 is applied. All calculations for current and future conditions (2050s are carried out on a 5' × 5' European grid. To address uncertainty, climate forcing data of three different global climate models are used to drive WaterGAP3. Finally, the hydrological alterations of different flow characteristics are quantified by the Indicators of Hydrological Alteration approach. Results of our analysis indicate that on European scale, climate change can be expected to modify flow regimes significantly. This is especially the case in the Mediterranean climate zone (due to drier conditions with reduced precipitation across the year and in the continental climate zone (due to reduced snowmelt and drier summers. Regarding single flow characteristics, strongest impacts on timing were found for the boreal climate zone. This applies for both, high and low flows. While low flow magnitudes are likely to be stronger influenced in the Mediterranean climate, high flow magnitudes will be mainly altered in snow climates with warmer summers. At the end

  8. Climate change and future fire regimes: Examples from California

    Science.gov (United States)

    Keeley, Jon E.; Syphard, Alexandra D.

    2016-01-01

    Climate and weather have long been noted as playing key roles in wildfire activity, and global warming is expected to exacerbate fire impacts on natural and urban ecosystems. Predicting future fire regimes requires an understanding of how temperature and precipitation interact to control fire activity. Inevitably this requires historical analyses that relate annual burning to climate variation. Fuel structure plays a critical role in determining which climatic parameters are most influential on fire activity, and here, by focusing on the diversity of ecosystems in California, we illustrate some principles that need to be recognized in predicting future fire regimes. Spatial scale of analysis is important in that large heterogeneous landscapes may not fully capture accurate relationships between climate and fires. Within climatically homogeneous subregions, montane forested landscapes show strong relationships between annual fluctuations in temperature and precipitation with area burned; however, this is strongly seasonal dependent; e.g., winter temperatures have very little or no effect but spring and summer temperatures are critical. Climate models that predict future seasonal temperature changes are needed to improve fire regime projections. Climate does not appear to be a major determinant of fire activity on all landscapes. Lower elevations and lower latitudes show little or no increase in fire activity with hotter and drier conditions. On these landscapes climate is not usually limiting to fires but these vegetation types are ignition-limited. Moreover, because they are closely juxtaposed with human habitations, fire regimes are more strongly controlled by other direct anthropogenic impacts. Predicting future fire regimes is not rocket science; it is far more complicated than that. Climate change is not relevant to some landscapes, but where climate is relevant, the relationship will change due to direct climate effects on vegetation trajectories, as well as

  9. Vegetation management with fire modifies peatland soil thermal regime.

    Science.gov (United States)

    Brown, Lee E; Palmer, Sheila M; Johnston, Kerrylyn; Holden, Joseph

    2015-05-01

    Vegetation removal with fire can alter the thermal regime of the land surface, leading to significant changes in biogeochemistry (e.g. carbon cycling) and soil hydrology. In the UK, large expanses of carbon-rich upland environments are managed to encourage increased abundance of red grouse (Lagopus lagopus scotica) by rotational burning of shrub vegetation. To date, though, there has not been any consideration of whether prescribed vegetation burning on peatlands modifies the thermal regime of the soil mass in the years after fire. In this study thermal regime was monitored across 12 burned peatland soil plots over an 18-month period, with the aim of (i) quantifying thermal dynamics between burned plots of different ages (from management. Compared to plots burned 15 + years previously, plots recently burned (soil temperatures, and lower minima. Statistical models (generalised least square regression) were developed to predict daily mean and maximum soil temperature in plots burned 15 + years prior to the study. These models were then applied to predict temperatures of plots burned 2, 4 and 7 years previously, with significant deviations from predicted temperatures illustrating the magnitude of burn management effects. Temperatures measured in soil plots burned Soil temperatures in plots burnt 7 years previously were most similar to plots burned 15 + years ago indicating the potential for soil temperatures to recover as vegetation regrows. Our findings that prescribed peatland vegetation burning alters soil thermal regime should provide an impetus for further research to understand the consequences of thermal regime change for carbon processing and release, and hydrological processes, in these peatlands.

  10. Climate Change and Future Fire Regimes: Examples from California

    Directory of Open Access Journals (Sweden)

    Jon E. Keeley

    2016-08-01

    Full Text Available Climate and weather have long been noted as playing key roles in wildfire activity, and global warming is expected to exacerbate fire impacts on natural and urban ecosystems. Predicting future fire regimes requires an understanding of how temperature and precipitation interact to control fire activity. Inevitably this requires historical analyses that relate annual burning to climate variation. Fuel structure plays a critical role in determining which climatic parameters are most influential on fire activity, and here, by focusing on the diversity of ecosystems in California, we illustrate some principles that need to be recognized in predicting future fire regimes. Spatial scale of analysis is important in that large heterogeneous landscapes may not fully capture accurate relationships between climate and fires. Within climatically homogeneous subregions, montane forested landscapes show strong relationships between annual fluctuations in temperature and precipitation with area burned; however, this is strongly seasonal dependent; e.g., winter temperatures have very little or no effect but spring and summer temperatures are critical. Climate models that predict future seasonal temperature changes are needed to improve fire regime projections. Climate does not appear to be a major determinant of fire activity on all landscapes. Lower elevations and lower latitudes show little or no increase in fire activity with hotter and drier conditions. On these landscapes climate is not usually limiting to fires but these vegetation types are ignition-limited. Moreover, because they are closely juxtaposed with human habitations, fire regimes are more strongly controlled by other direct anthropogenic impacts. Predicting future fire regimes is not rocket science; it is far more complicated than that. Climate change is not relevant to some landscapes, but where climate is relevant, the relationship will change due to direct climate effects on vegetation

  11. How do Macroeconomic and Political Variables Affect the Flexibility of Exchange Rate Regime?

    OpenAIRE

    Mehmet Guclu

    2009-01-01

    The choice of exchange rate regime has become one of the most important issues once more in many economies after the financial crises in recent years. In the wake of the financial crises, many countries, especially emerging market economies, opted for floating exchange rate regimes by forsaking the pegged regimes. Consequently, an old debate on the choice and determinants of exchange rate regimes has been triggered. Economists have started to debate what appropriate exchange rate regime for a...

  12. Optimal choice of an exchange rate regime: a critical literature review

    OpenAIRE

    Ouchen, Mariam

    2013-01-01

    This paper set out to review the main theories and empirical methods employed in selecting an appropriate exchange rate regime.In order to achieve this, the paper is organized as follows : Section 2 introduces the distinct classifications of exchange regimes(de jure exchange rate regimes versus the facto exchange rate regimes), and the different theoretical approaches which illustrate how an optimal exchange rate regime is determined . Despite their initial popularity, the theoretical consi...

  13. Quantifying emission reduction contributions by emerging economics

    Energy Technology Data Exchange (ETDEWEB)

    Moltmann, Sara; Hagemann, Markus; Eisbrenner, Katja; Hoehne, Niklas [Ecofys GmbH, Koeln (Germany); Sterk, Wolfgang; Mersmann, Florian; Ott, Hermann E.; Watanabe, Rie [Wuppertal Institut (Germany)

    2011-04-15

    regime under the UNFCCC post 2012'' published 2008. The analysis for this report was completed before the UN climate summit in Copenhagen in December 2009. Hence, it predates the notification of NAMAs under the ''Copenhagen Accord''. However, the NAMAs discussed in this report and the NAMAs notified under the Copenhagen Accord operate at different levels. With the exception of Brazil, all the countries discussed in this report notified aggregate national targets under the Copenhagen Accord, either in terms of emission intensity targets or in terms of a reduction of national emissions below ''business as usual.'' By contrast, this report discusses sector- or technology-specific NAMAs. The NAMAs discussed in this report can therefore be seen as possible ways of achieving the aggregate NAMAs notified under the Copenhagen Accord. (orig.)

  14. The emission of Gamma Ray Bursts as a test-bed for modified gravity

    Energy Technology Data Exchange (ETDEWEB)

    Capozziello, S., E-mail: capozziello@na.infn.it [Dipartimento di Fisica, Universitá di Napoli “Federico II”, Via Cinthia, I-80126, Napoli (Italy); INFN Sez. di Napoli, Compl. Univ. di Monte S. Angelo, Edificio G, Via Cinthia, I-80126, Napoli (Italy); Gran Sasso Science Institute (INFN), Via F. Crispi 7, I-67100, L' Aquila (Italy); Lambiase, G. [Dipartimento di Fisica “E.R. Caianiello”, Universitá di Salerno, I-84084, Fisciano (Italy); INFN – Gruppo Collegato di Salerno (Italy)

    2015-11-12

    The extreme physical conditions of Gamma Ray Bursts can constitute a useful observational laboratory to test theories of gravity where very high curvature regimes are involved. Here we propose a sort of curvature engine capable, in principle, of explaining the huge energy emission of Gamma Ray Bursts. Specifically, we investigate the emission of radiation by charged particles non-minimally coupled to the gravitational background where higher order curvature invariants are present. The coupling gives rise to an additional force inducing a non-geodesic motion of particles. This fact allows a strong emission of radiation by gravitationally accelerated particles. As we will show with some specific model, the energy emission is of the same order of magnitude of that characterizing the Gamma Ray Burst physics. Alternatively, strong curvature regimes can be considered as a natural mechanism for the generation of highly energetic astrophysical events. Possible applications to cosmology are discussed.

  15. The emission of Gamma Ray Bursts as a test-bed for modified gravity

    Directory of Open Access Journals (Sweden)

    S. Capozziello

    2015-11-01

    Full Text Available The extreme physical conditions of Gamma Ray Bursts can constitute a useful observational laboratory to test theories of gravity where very high curvature regimes are involved. Here we propose a sort of curvature engine capable, in principle, of explaining the huge energy emission of Gamma Ray Bursts. Specifically, we investigate the emission of radiation by charged particles non-minimally coupled to the gravitational background where higher order curvature invariants are present. The coupling gives rise to an additional force inducing a non-geodesic motion of particles. This fact allows a strong emission of radiation by gravitationally accelerated particles. As we will show with some specific model, the energy emission is of the same order of magnitude of that characterizing the Gamma Ray Burst physics. Alternatively, strong curvature regimes can be considered as a natural mechanism for the generation of highly energetic astrophysical events. Possible applications to cosmology are discussed.

  16. Exchange Rate Regimes – A periodical overview and a critical analysis of exchange rate regimes in Kosovo

    Directory of Open Access Journals (Sweden)

    Flamur Bunjaku

    2015-03-01

    Full Text Available Exchange rate regimes and the monetary policy are the key instruments governments use to achieve their economic and financial objectives. Moreover, due to global financial crisis the latter instruments get more importance. Empirical evidences show that exchange rate regimes in Kosovo and its monetary policy throughout their development were mainly influenced by different political and historical developments. In regard of Euroisation of monetary system in Kosovo it was found that this action generated macro - financial stability in terms of inflation and price fluctuation. However, in terms of microeconomic aspects, the unilateral adaptation of Euro as the official currency of Kosovo failed to provide microeconomic advantages such as to export stimulation, and so forth. The main exchange rate regime systems were discussed focusing in their advantages and disadvantages, and it was concluded that there is no commonly accepted theory regarding the optimality of exchange rate regimes. In addition, the global financial crisis impact in the financial system of Kosovo is also discussed and it was found that negative impacts of global financial crisis were moderate and indirect.

  17. Anomalous Microwave Emission

    CERN Document Server

    Kogut, A J

    1999-01-01

    Improved knowledge of diffuse Galactic emission is important to maximize the scientific return from scheduled CMB anisotropy missions. Cross-correlation of microwave maps with maps of the far-IR dust continuum show a ubiquitous microwave emission component whose spatial distribution is traced by far-IR dust emission. The spectral index of this emission, beta_{radio} = -2.2 (+0.5 -0.7) is suggestive of free-free emission but does not preclude other candidates. Comparison of H-alpha and microwave results show that both data sets have positive correlations with the far-IR dust emission. Microwave data, however, are consistently brighter than can be explained solely from free-free emission traced by H-alpha. This ``anomalous'' microwave emission can be explained as electric dipole radiation from small spinning dust grains. The anomalous component at 53 GHz is 2.5 times as bright as the free-free emission traced by H-alpha, providing an approximate normalization for models with significant spinning dust emission.

  18. Tuning contact transport mechanisms in bilayer MoSe2 transistors up to Fowler-Nordheim regime

    Science.gov (United States)

    Mouafo, L. D. N.; Godel, F.; Froehlicher, G.; Berciaud, S.; Doudin, B.; Venkata Kamalakar, M.; Dayen, J.-F.

    2017-03-01

    Atomically thin molybdenum diselenide (MoSe2) is an emerging two-dimensional (2D) semiconductor with significant potential for electronic, optoelectronic, spintronic applications and a common platform for their possible integration. Tuning interface charge transport between such new 2D materials and metallic electrodes is a key issue in 2D device physics and engineering. Here, we report tunable interface charge transport in bilayer MoSe2 field effect transistors with Ti/Au contacts showing high on/off ratio up to 107 at room temperature. Our experiments reveal a detailed map of transport mechanisms obtained by controlling the interface band bending profile via temperature, gate and source-drain bias voltages. This comprehensive investigation leads to demarcating regimes and tuning in transport mechanisms while controlling the interface barrier profile. The careful analysis allows us to identify thermally activated regime at low carrier density, and Schottky barrier driven mechanisms at higher carrier density demonstrating the transition from low-field direct tunneling/ thermionic emission to high-field Fowler-Nordheim tunneling. Furthermore, we show that the transition voltage V trans to Fowler-Nordheim correlates directly to the difference between the chemical potential of the metal electrode and the conduction band minimum in the 2D semiconductor, which opens up opportunities for new theoretical and experimental investigations. Our approach being generic can be extended to other 2D materials, and the possibility of tuning contact transport regimes is promising for designing MoSe2 device applications.

  19. Global Seabird Ammonia Emissions

    Science.gov (United States)

    Riddick, S. N.; Blackall, T. D.; Dragosits, U.; Daunt, F. H.; Braban, C. F.; Tang, Y. S.; Trathan, P.; Wanless, S.; Sutton, M. A.

    2010-12-01

    Seabird colonies represent a major source of atmospheric ammonia (NH3) in remote coastal and marine systems in temperate, tropical and polar regions. Previous studies have shown that NH3 emissions from Scottish seabird colonies were substantial - of similar magnitude to the most intensive agricultural point source emissions. The UK data were used to model global seabird NH3 emissions and suggested that penguins are a major source of emissions on and around the Antarctic continent. The largest seabird colonies are in the order of millions of seabirds. Due to the isolation of these colonies from anthropogenic nitrogen sources, they may play a major role in the nitrogen cycle within these ecosystems. A global seabird database was constructed and used in conjunction with a species-specific seabird bioenergetics model to map the locations of NH3 emissions from seabird colonies. The accuracy of the modelled emissions was validated with field data of NH3 emissions measured at key seabird colonies in different climatic regions of the world: temperate (Isle of May, Scotland), tropical (Ascension Island) and polar (Signy Island, South Georgia). The field data indicated good agreement between modelled and measured NH3 emissions. The measured NH3 emissions also showed the variability of emission with climate. Climate dependence of seabird NH3 emissions may have further implications under a changing global climate. Seabird colonies represent NH3 emission ‘hotspots’, often far from anthropogenic sources, and are likely to be the major source of nitrogen input to these remote coastal ecosystems. The direct manuring by seabirds at colony locations may strongly influence species richness and biodiversity. The subsequent volatilisation and deposition of NH3 increases the spatial extent of seabird influence on nitrogen cycling in their local ecosystem. As many seabird populations are fluctuating due to changing food supply, climate change or anthropogenic pressures, these factors

  20. Carbon emissions Inventory Games

    OpenAIRE

    Al-Emadi, Eiman Ali

    2016-01-01

    Carbon emissions reduction has been the center of attention in many organizations during the past few decades. Many international entities developed rules and regulations to monitor and control carbon emissions especially under supply chain context. Furthermore, researchers investigated techniques and methods on how reduce carbon emissions under operational adjustment which can be done by cooperation or coordination. The main contribution of this thesis is to measure to what extend cooperatio...

  1. Managing Refrigerant Emissions

    Science.gov (United States)

    Access information on EPA's efforts to address ozone layer depletion by reducing emissions of refrigerants from stationary refrigeration and air conditioning systems and motor vehicle air conditioning systems.

  2. VOC emissions chambers

    Data.gov (United States)

    Federal Laboratory Consortium — In order to support the development of test methods and reference materials for volatile organic compounds (VOC) emissions from building materials and furnishings,...

  3. Microgravity Emissions Laboratory (MEL)

    Data.gov (United States)

    Federal Laboratory Consortium — The Microgravity Emissions Laboratory (MEL) utilizes a low-frequency acceleration measurement system for the characterization of rigid body inertial forces generated...

  4. Toluene emissions from plants

    Science.gov (United States)

    Heiden, A. C.; Kobel, K.; Komenda, M.; Koppmann, R.; Shao, M.; Wildt, J.

    The emission of toluene from different plants was observed in continuously stirred tank reactors and in field measurements. For plants growing without stress, emission rates were low and ranged from the detection limit up to 2·10-16 mol·cm-2·s-1. Under conditions of stress, the emission rates exceeded 10-14 mol·cm-2·s-1. Exposure of sunflower (Helianthus annuus L. cv. Gigantheus) to 13CO2 resulted in 13C-labeling of the emitted toluene on a time scale of hours. Although no biochemical pathway for the production of toluene is known, these results indicate that toluene is synthesized by the plants. The emission rates of toluene from sunflower are dependent on nutrient supply and wounding. Since α-pinene emission rates are also influenced by these factors, toluene and α-pinene emissions show a high correlation. During pathogen attack on Scots pines (Pinus sylvestris L.) significant toluene emissions were observed. In this case emissions of toluene and α-pinene also show a good correlation. Toluene emissions were also found in field experiments with pines using branch enclosures.

  5. THE POLICY AND THE TRADE REGIME IN ROMANIA AFTER 1990

    Directory of Open Access Journals (Sweden)

    Dobrotă Gabriela

    2009-11-01

    Full Text Available The growth of connections between national economies has generated a consolidation of foreign currency activities, requiring a continuous adjusting regime, both for the foreign currency policy and for the exchange rate to the market mechanisms. In Romania, there have been frequent alterations of the foreign currency policy, requiring the need to create a juridical framework adequate for the market economy and the evolution of financial instruments. This paper presents the main characteristics of the trade regime and the exchange rate policy in Romania after 1990. Practically, the paper reflects a radiography of the main events on the Romanian foreign exchange rate within the context of specific conditions of the Romanian economy and in correlation with the measures adopted by countries from the Central Europe.

  6. THE POLICY AND THE TRADE REGIME IN ROMANIA AFTER 1990

    Directory of Open Access Journals (Sweden)

    Dobrotă Gabriela

    2009-11-01

    Full Text Available The growth of connections between national economies has generated a consolidation of foreign currency activities, requiring a continuous adjusting regime, both for the foreign currency policy and for the exchange rate to the market mechanisms. In Romania, there have been frequent alterations of the foreign currency policy, requiring the need to create a juridical framework adequate for the market economy and the evolution of financial instruments. This paper presents the main characteristics of the trade regime and the exchange rate policy in Romania after 1990. Practically, the paper reflects a radiography of the main events on the Romanian foreign exchange rate within the context of specific conditions of the Romanian economy and in correlation with the measures adopted by countries from the Central Europe

  7. Automatic Classification of Offshore Wind Regimes With Weather Radar Observations

    DEFF Research Database (Denmark)

    Trombe, Pierre-Julien; Pinson, Pierre; Madsen, Henrik

    2014-01-01

    Weather radar observations are called to play an important role in offshore wind energy. In particular, they can enable the monitoring of weather conditions in the vicinity of large-scale offshore wind farms and thereby notify the arrival of precipitation systems associated with severe wind...... and amplitude) using reflectivity observations from a single weather radar system. A categorical sequence of most likely wind regimes is estimated from a wind speed time series by combining a Markov-Switching model and a global decoding technique, the Viterbi algorithm. In parallel, attributes of precipitation...... systems are extracted from weather radar images. These attributes describe the global intensity, spatial continuity and motion of precipitation echoes on the images. Finally, a CART classification tree is used to find the broad relationships between precipitation attributes and wind regimes...

  8. A Cold-Strontium Laser in the Superradiant Crossover Regime

    CERN Document Server

    Norcia, Matthew A

    2015-01-01

    Recent proposals suggest that lasers based on narrow dipole-forbidden transitions in cold alkaline earth atoms could achieve linewidths that are orders of magnitude smaller than linewidths of any existing lasers. Here, we demonstrate a laser based on the 7.5 kHz linewidth dipole forbidden $^3 $P$_1$ to $^1 $S$_0$ transition in laser-cooled and tightly confined $^{88}$Sr. We can operate this laser in the bad-cavity regime, where coherence is primarily stored in the atoms, or continuously tune to the more conventional good-cavity regime, where coherence is primarily stored in the light field. We show that the cold-atom gain medium can be repumped to achieve quasi steady-state lasing, and demonstrate up to an order of magnitude suppression in the sensitivity of laser frequency to changes in cavity length, the primary limitation for the most frequency stable lasers today.

  9. Regimes of the electron diffusion region in magnetic reconnection.

    Science.gov (United States)

    Le, A; Egedal, J; Ohia, O; Daughton, W; Karimabadi, H; Lukin, V S

    2013-03-29

    The electron diffusion region during magnetic reconnection lies in different regimes depending on the pressure anisotropy, which is regulated by the properties of thermal electron orbits. In kinetic simulations at the weakest guide fields, pitch angle mixing in velocity space causes the outflow electron pressure to become nearly isotropic. Above a threshold guide field that depends on a range of parameters, including the normalized electron pressure and the ion-to-electron mass ratio, electron pressure anisotropy develops in the exhaust and supports extended current layers. This new regime with electron current sheets extending to the system size is also reproduced by fluid simulations with an anisotropic closure for the electron pressure. It offers an explanation for recent spacecraft observations.

  10. Envisioning, quantifying, and managing thermal regimes on river networks

    Science.gov (United States)

    Steel, E. Ashley; Beechie, Timothy J.; Torgersen, Christian; Fullerton, Aimee H.

    2017-01-01

    Water temperatures fluctuate in time and space, creating diverse thermal regimes on river networks. Temporal variability in these thermal landscapes has important biological and ecological consequences because of nonlinearities in physiological reactions; spatial diversity in thermal landscapes provides aquatic organisms with options to maximize growth and survival. However, human activities and climate change threaten to alter the dynamics of riverine thermal regimes. New data and tools can identify particular facets of the thermal landscape that describe ecological and management concerns and that are linked to human actions. The emerging complexity of thermal landscapes demands innovations in communication, opens the door to exciting research opportunities on the human impacts to and biological consequences of thermal variability, suggests improvements in monitoring programs to better capture empirical patterns, provides a framework for suites of actions to restore and protect the natural processes that drive thermal complexity, and indicates opportunities for better managing thermal landscapes.

  11. Dynamic two state stochastic models for ecological regime shifts

    DEFF Research Database (Denmark)

    Møller, Jan Kloppenborg; Carstensen, Niels Jacob; Madsen, Henrik

    2009-01-01

    A simple non-linear stochastic two state, discrete-time model is presented. The interaction between benthic and pelagic vegetation in aquatic ecosystems subject to changing external nutrient loading is described by the nonlinear functions. The dynamical behavior of the deterministic part...... of regimes, depending on how the noise propagates through the system. The dynamical properties of a system should therefore be described through propagation of the state distributions rather than the state means and consequently, stochastic models should be compared in a probabilistic framework....... of the model illustrates that hysteresis effect and regime shifts can be obtained for a limited range of parameter values only. The effect of multiplicative noise components entering at different levels of the model is presented and discussed. Including noise leads to very different results on the stability...

  12. Optically implemented broadband blueshift switch in the terahertz regime.

    Science.gov (United States)

    Shen, Nian-Hai; Massaouti, Maria; Gokkavas, Mutlu; Manceau, Jean-Michel; Ozbay, Ekmel; Kafesaki, Maria; Koschny, Thomas; Tzortzakis, Stelios; Soukoulis, Costas M

    2011-01-21

    We experimentally demonstrate, for the first time, an optically implemented blueshift tunable metamaterial in the terahertz (THz) regime. The design implies two potential resonance states, and the photoconductive semiconductor (silicon) settled in the critical region plays the role of intermediary for switching the resonator from mode 1 to mode 2. The observed tuning range of the fabricated device is as high as 26% (from 0.76 THz to 0.96 THz) through optical control to silicon. The realization of broadband blueshift tunable metamaterial offers opportunities for achieving switchable metamaterials with simultaneous redshift and blueshift tunability and cascade tunable devices. Our experimental approach is compatible with semiconductor technologies and can be used for other applications in the THz regime.

  13. Option Pricing when the Regime-Switching Risk is Priced

    Institute of Scientific and Technical Information of China (English)

    Tak Kuen Siu; Hailiang Yang

    2009-01-01

    We study the pricing of an option when the price dynamic of the underlying risky asset is governed by a Markov-modulated geometric Brownian motion. We suppose that the drift and volatility of the underlying risky asset are modulated by an observable continuous-time, finite-state Markov chain. We develop a twostage pricing model which can price both the diffusion risk and the regime-switching risk based on the Esscher transform and the minimization of the maximum entropy between an equivalent martingale measure and the real-world probability measure over different states. Numerical experiments are conducted and their results reveal that the impact of pricing regime-switching risk on the option prices is significant.

  14. Challenges in Finding AGNs in the Low Luminosity Regime

    Science.gov (United States)

    Satyapal, Shobita; Abel, Nick; Secrest, Nathan; Singh, Amrit; Ellison, Sara

    2016-08-01

    Low luminosity AGNs are an important component of the AGN population. They are often found in the lowest mass galaxies or galaxies that lack classical bulges, a demographic that places important constraints to models of supermassive black hole seed formation and merger-free models of AGN fueling. The detection of AGNs in this low luminosity regime is challenging both because star formation in the host galaxy can dominate the optical spectrum and gas and dust can obscure the central engine at both optical and X-ray wavelengths. Thus while mid-infrared color selection and X-ray observations at energies review the effectiveness of uncovering AGNs in the low luminosity regime using multiwavength investigations, with a focus on infrared spectroscopic signatures.

  15. The short bunch blow-out regime in RF photoinjectors

    Energy Technology Data Exchange (ETDEWEB)

    Serafini, L. [INFN and Universita di Milano, Via Celoria 16, 20133Milano (Italy)

    1997-06-01

    A new beam dynamics regime of RF Photoinjectors is presented here, dealing with a violent bunch elongation under the action of longitudinal space charge forces. It is shown that such a blow-out expansion of the electron bunch can lead to highly linear behaviors of both the longitudinal and the transverse space charge field, a well known prerequisite to achieve minimum emittance dilution in photoinjectors. If operated in the ultra-short pancake-like bunch regime, such an effect can be very beneficial to the emittance correction mechanism, making it effective also for ultra-short pancake like bunches. The anticipated performances are presented: kA peak current beams can be generated directly out of the photoinjector (10 to 20 MeV exit energy) with rms normalized emittances below 1mm{center_dot}mrad. {copyright} {ital 1997 American Institute of Physics.}

  16. Accretion to a Magnetized Neutron Star in the "Propeller" Regime

    CERN Document Server

    Toropina, O D; Lovelace, R V E

    2006-01-01

    We investigate spherical accretion to a rotating magnetized star in the "propeller" regime using axisymmetric resistive magnetohydrodynamic simulations. The regime is predicted to occur if the magnetospheric radius is larger than the corotation radius and smaller than the light cylinder radius. The simulations show that accreting matter is expelled from the equatorial region of the magnetosphere and that it moves away from the star in a supersonic, disk-shaped outflow. At larger radial distances the outflow slows down and becomes subsonic. The equatorial matter outflow is initially driven by the centrifugal force, but at larger distances the pressure gradient force becomes significant. We find the fraction of the Bondi accretion rate which accretes to the surface of the star.

  17. Onset of the Asymptotic Regime for Finite Orders

    CERN Document Server

    Henson, Joe; Sorkin, Rafael D; Surya, Sumati

    2015-01-01

    We describe a Markov-Chain-Monte-Carlo algorithm which can be used to generate naturally labeled n-element posets at random with a probability distribution of one's choice. Implementing this algorithm for the uniform distribution, we explore the approach to the asymptotic regime in which almost every poset takes on the three-layer structure described by Kleitman and Rothschild (KR). By tracking the n-dependence of several order-invariants, among them the height of the poset, we observe an oscillatory behavior which is very unlike a monotonic approach to the KR regime. Only around n=40 or so does this "finite size dance" appear to give way to a gradual crossover to asymptopia which lasts until n=85, the largest n we have simulated.

  18. Transient regimes of the three-phase power transformers

    Directory of Open Access Journals (Sweden)

    Olivian Chiver

    2015-12-01

    Full Text Available The transient regimes of a three-phase power transformer will be studied in this paper. The transient currents in the windings will be determined both analytically and by finite elements method (FEM. The no load and short circuit regimes will be considered. The current dependence of the instantaneous phase voltage and of the initial current value will be highlighted, by FEM. In order to determine analytically the transient currents, for inductances the analytical and FEM values will be used. The inductances are determined with FEM through the simulation of experimental tests. With FEM, the transient currents will be determined using transient analysis. Finally, the FEM and analytical results will be compared and discussed.

  19. Heavy ion acceleration in the Breakout Afterburner regime

    CERN Document Server

    Petrov, G M; Thomas, A G R; Krushelnick, K; Beg, F N

    2015-01-01

    Theoretical study of heavy ion acceleration from an ultrathin (20 nm) gold foil irradiated by sub-picosecond lasers is presented. Using two dimensional particle-in-cell simulations we identified two highly efficient ion acceleration schemes. By varying the laser pulse duration we observed a transition from Radiation Pressure Acceleration to the Breakout Afterburner regime akin to light ions. The underlying physics and ion acceleration regimes are similar to that of light ions, however, nuances of the acceleration process make the acceleration of heavy ions more challenging. Two laser systems are studied in detail: the Texas Petawatt Laser and the Trident laser, the former having pulse duration 180 fs, intermediate between very short femtosecond pulses and picosecond pulses. Both laser systems generated directional gold ions beams (~10 degrees half-angle) with fluxes in excess of 1011 ion/sr and normalized energy >10 MeV/nucleon.

  20. Spherical convective dynamos in the rapidly rotating asymptotic regime

    CERN Document Server

    Aubert, Julien; Fournier, Alexandre

    2016-01-01

    Self-sustained convective dynamos in planetary systems operate in an asymptotic regime of rapid rotation, where a balance is thought to hold between the Coriolis, pressure, buoyancy and Lorentz forces (the MAC balance). Classical numerical solutions have previously been obtained in a regime of moderate rotation where viscous and inertial forces are still significant. We define a unidimensional path in parameter space between classical models and asymptotic conditions from the requirements to enforce a MAC balance and to preserve the ratio between the magnetic diffusion and convective overturn times (the magnetic Reynolds number). Direct numerical simulations performed along this path show that the spatial structure of the solution at scales larger than the magnetic dissipation length is largely invariant. This enables the definition of large-eddy simulations resting on the assumption that small-scale details of the hydrodynamic turbulence are irrelevant to the determination of the large-scale asymptotic state...

  1. Intergenerational Justice Perceptions and the Role of Welfare Regimes

    DEFF Research Database (Denmark)

    Sabbagh, Clara; Vanhuysse, Pieter

    2010-01-01

    -statist' ideological frame (the endorsement of egalitarian redistribution and broad state responsibility for welfare provision and the attribution of social inequality to external causes), and negatively with a 'market-based' frame (individualism, a work ethic, and internal attribution). Regarding actual outcomes......This article studies perceptions of intergenerational justice among 2,075 undergraduate university students from eight democracies spanning four different models, or 'worlds,' of welfare. We examine two different, though interrelated, aspects of intergenerational justice: (1) whether, and how...... justness of actual outcomes of resource transfers between age-groups. We find that support of transfers from the young to the old is higher in social-democratic and conservative welfare regimes than in liberal and radical regimes. Support of resource transfers also correlates positively with a 'welfare...

  2. Quarks with Twisted Boundary Conditions in the Epsilon Regime

    Energy Technology Data Exchange (ETDEWEB)

    Thomas Mehen; Brian C. Tiburzi

    2005-05-01

    We study the effects of twisted boundary conditions on the quark fields in the epsilon regime of chiral perturbation theory. We consider the SU(2){sub L} x SU(2){sub R} chiral theory with non-degenerate quarks and the SU(3){sub L} x SU(3){sub R} chiral theory with massless up and down quarks and massive strange quarks. The partition function and condensate are derived for each theory. Because flavor-neutral Goldstone bosons are unaffected by twisted boundary conditions chiral symmetry is still restored in finite volumes. The dependence of the condensate on the twisting parameters can be used to extract the pion decay constant from simulations in the epsilon regime. The relative contribution to the partition function from sectors of different topological charge is numerically insensitive to twisted boundary conditions.

  3. The regime and the constitutional principles from 1938

    Directory of Open Access Journals (Sweden)

    Florin Grecu

    2012-12-01

    Full Text Available The authoritarian monarchy regime, from 1938-1940, functioned based on an exceptional status, because it was founded on a decree-law of state of siege and therefore all the power in the State was held in the hands of the army colonels and generals. By suspending the political parties, the political pluralism and the Parliament, the basic institutions of a democratic regime were abolished. Press censorship, the denying of the right to manifest and gather were assigned to the army and the militarization of the State institutions became a reality. The proclamation of the King as an absolute leader of the unique party and of the government transformed Romania into a ministerial and undemocratic monarchy, with authoritarian valence.

  4. Above-threshold ionization in the x-ray regime.

    Energy Technology Data Exchange (ETDEWEB)

    Varma, H. R.; Ciappina, M. F.; Rohringer, N.; Santra, R.; Chemical Sciences and Engineering Division; Inst. of High Performance Computing; LLNL; Univ. of Chicago

    2009-11-01

    Two-photon above-threshold ionization processes in the x-ray regime are studied using atomic hydrogen as a model system. Within the minimal-coupling formalism of nonrelativistic quantum electrodynamics, two distinct interactions - A{sup -} {center_dot} p{sup -} in second order and A{sup -2} in first order - contribute to the two-photon absorption amplitude. The relative importance of these two interactions is assessed. It is found that above a photon energy of 6.8 keV, the contribution from A{sup -2} to the total two-photon absorption cross section dominates. In this high-energy regime, above-threshold ionization is a nonsequential purely nondipole process. Rate equations are employed to calculate the probabilities of ionization by Compton scattering, one-photon absorption, and two-photon absorption.

  5. Vertical Interplay among Scale-dependent Environmental and Resource Regimes

    Directory of Open Access Journals (Sweden)

    Oran Young

    2006-06-01

    Full Text Available Environmental and resource regimes, operating at different levels of social organization, vary in terms of factors such as the sources of actor behavior, the knowledge available to actors, the operation of compliance mechanisms, the use of policy instruments, and the nature of the broader social setting. Cross-level interactions among scale-dependent regimes can result in patterns of dominance, separation, merger, negotiated agreement, or system change. The mechanisms that determine which of these patterns will occur include authority/power differentials, limits of decentralization, dueling discourses, cognitive transitions, and blocking coalitions. Recurrent linkages or syndromes occur in this realm, e.g., limitations of authority and power regularly produce negotiated agreements in such forms as comanagement arrangements. The consequences of these interactions are often far-reaching as measured in terms of ecological sustainability, social welfare/efficiency, cultural values, and robustness.

  6. Kolmogorov entropy of magnetic field lines in the percolation regime

    Energy Technology Data Exchange (ETDEWEB)

    Zimbardo, G; Bitane, R; Pommois, P; Veltri, P [Physics Department, University of Calabria, Arcavacata di Rende (Italy)

    2009-01-15

    We report the first numerical computation of the Kolmogorov entropy h of magnetic field lines extending from the quasilinear up to the percolation regime, using a numerical code where one can change both the turbulence level {delta}B/B{sub 0} and the turbulence anisotropy l{sub ||}/l{sub p}erpendicular. We find that the proposed percolation scaling of h is not reproduced, but rather a saturation of h is obtained. Also, we find that the Kolmogorov entropy depends solely on the Kubo number R = ({delta}B/B{sub 0})(l{sub ||}/l{sub p}erpendicular), and not separately on {delta}B/B{sub 0} and l{sub ||}/l{sub p}erpendicular. We apply the results to electron transport in solar coronal loops, which involves the use of the Rechester and Rosenbluth diffusion coefficient, and show that the study of transport in the percolation regime is required.

  7. Disorder-assisted quantum transport in suboptimal decoherence regimes.

    Science.gov (United States)

    Novo, Leonardo; Mohseni, Masoud; Omar, Yasser

    2016-01-04

    We investigate quantum transport in binary tree structures and in hypercubes for the disordered Frenkel-exciton Hamiltonian under pure dephasing noise. We compute the energy transport efficiency as a function of disorder and dephasing rates. We demonstrate that dephasing improves transport efficiency not only in the disordered case, but also in the ordered one. The maximal transport efficiency is obtained when the dephasing timescale matches the hopping timescale, which represent new examples of the Goldilocks principle at the quantum scale. Remarkably, we find that in weak dephasing regimes, away from optimal levels of environmental fluctuations, the average effect of increasing disorder is to improve the transport efficiency until an optimal value for disorder is reached. Our results suggest that rational design of the site energies statistical distributions could lead to better performances in transport systems at nanoscale when their natural environments are far from the optimal dephasing regime.

  8. Self-interacting scalar fields in their strong regime

    CERN Document Server

    Deur, A

    2016-01-01

    We study two self-interacting scalar field theories in their strong regime. We numerically investigate them in the static limit using path integrals on a lattice. We first recall the formalism and then recover known static potentials to validate the method and verify that calculations are independent of the choice of the simulation's arbitrary parameters, such as the space discretization size. The calculations in the strong field regime yield linear potentials for both theories. We discuss how these theories can represent the Strong Interaction and General Relativity in their static and classical limits. In the case of Strong Interaction, the model suggests an origin for the emergence of the confinement scale from the approximately conformal Lagrangian. The model also underlines the role of quantum effects in the appearance of the long-range linear quark-quark potential. For General Relativity, the results have important implications on the nature of Dark Matter. In particular, non-perturbative effects natura...

  9. A Cold-Strontium Laser in the Superradiant Crossover Regime

    Science.gov (United States)

    Norcia, Matthew; Thompson, James

    2016-05-01

    We demonstrate and study a laser based on the 7.5 kHz linewidth dipole forbidden 3 P1 to 1 S0 transition in laser-cooled and tightly confined 88 Sr. We can operate this laser in the bad-cavity or superradiant regime, where coherence is primarily stored in the atoms, or continuously tune to the more conventional good-cavity regime, where coherence is primarily stored in the light field. We show that the cold-atom gain medium can be repumped to achieve quasi steady-state lasing. We also demonstrate up to an order of magnitude suppression in the sensitivity of laser frequency to changes in cavity length, verifying a key feature of proposed narrow linewidth lasers based on dipole-forbidden transitions in alkaline earth atoms.

  10. Hanle Effect in the Paschen-Back Regime

    Science.gov (United States)

    Shapiro, A. I.; Fluri, D. M.; Berdyugina, S. V.; Stenflo, J. O.

    2006-12-01

    The second solar spectrum resulting from coherent scattering is an important tool for the diagnostics of turbulent magnetic fields on the Sun. Molecular scattering plays an important role in forming this spectrum, and even dominates in some spectral regions. We present a theory that allows us to calculate the Mueller matrix for coherent scattering from diatomic molecules in Hund's intermediate coupling case (a-b) for arbitrary molecular transitions. We performed the calculation of the molecular Hanle effect in the Paschen-Back regime. We found significant differences from the Zeeman regime, and as an example we discuss here, both qualitatively and quantitatively, the effects on observed polarization signals for the CN violet system.

  11. Adult learning, education, and the labour market inthe employability regime

    Directory of Open Access Journals (Sweden)

    Staffan Nilsson

    2013-10-01

    Full Text Available The purpose of this paper is to draw on the research and scholarly literature to explorethe changing discourses and perspectives concerning adult learning, education, and thelabour market in the employability regime. The focus of the nalysis is a Nordic context.The dominant employability regime maintains a technical-rational perspective onlearning and employability. Education is predominantly regarded as an instrumentalpreparation for the labour market. The future demands of the labour market are largelyunknown, however, and vocational and professional training may not provide sufficientpreparation for the increasing complexities of work. Theoretical discussions have beendominated by an alleged mismatch between individual competence and thequalifications that are required in the world of work. There is no consensus regardinghow the gap should be described, explained, or bridged. New demands on educationaldesign have emerged, and ideas related to liberal education and ‘bildung’ have beenreinserted into the political agenda, offering general preparation for a wider array ofchallenges.

  12. Relationship between fire regime and vegetation symphenological timing in Sardinia

    Directory of Open Access Journals (Sweden)

    Carlo Ricotta

    2008-01-01

    Full Text Available Fire is a basic ecological factor that contributes to determine vegetation biodiversity and dynamics in time and space. Fuel characteristics play an essential role in fire ignition and propagation; for instance fuel availability and flammability are closely related to the coarse-scale vegetation phenological trends that directly affect wildfire distribution in time and space. In this perspective, the annual NDVI profiles derived from high temporal resolution satellite images like SPOT Vegetation represent an effective tool for monitoring plant seasonal dynamics at the landscape scale. The objective of this study consists in relating the wildfire regime in Sardinia during 2000-2004 with the remotely sensed phenological parameters of the vegetation, segmented according to potential natural vegetation characteristics. The results of our study highlight a good correspondence between the NDVI temporal dynamics of the potential natural vegetation of Sardinia and the corresponding fires regime characteristics.

  13. Bit-interleaved coded modulation in the wideband regime

    CERN Document Server

    Martinez, Alfonso; Caire, Giuseppe; Willems, Frans

    2007-01-01

    The wideband regime of bit-interleaved coded modulation (BICM) in Gaussian channels is studied. The Taylor expansion of the coded modulation capacity for generic signal constellations at low signal-to-noise ratio (SNR) is derived and used to determine the corresponding expansion for the BICM capacity. Simple formulas for the minimum energy per bit and the wideband slope are given. BICM is found to be suboptimal in the sense that its minimum energy per bit can be larger than the corresponding value for coded modulation schemes. The minimum energy per bit using standard Gray mapping on M-PAM or M^2-QAM is given by a simple formula and shown to approach -0.34 dB as M increases. Using the low SNR expansion, a general trade-off between power and bandwidth in the wideband regime is used to show how a power loss can be traded off against a bandwidth gain.

  14. Giant magnetoresistance in the variable-range hopping regime

    Energy Technology Data Exchange (ETDEWEB)

    Ioffe, L. B., E-mail: ioffe@physics.rutgers.edu [Universite Pierre et Marie Curie, LPTHE (France); Spivak, B. Z. [University of Washington, Department of Physics (United States)

    2013-09-15

    We predict the universal power-law dependence of the localization length on the magnetic field in the strongly localized regime. This effect is due to the orbital quantum interference. Physically, this dependence shows up in an anomalously large negative magnetoresistance in the hopping regime. The reason for the universality is that the problem of the electron tunneling in a random media belongs to the same universality class as the directed polymer problem even in the case of wave functions of random sign. We present numerical simulations that prove this conjecture. We discuss the existing experiments that show anomalously large magnetoresistance. We also discuss the role of localized spins in real materials and the spin polarizing effect of the magnetic field.

  15. Management of exchange rate regimes in emerging Asia

    Directory of Open Access Journals (Sweden)

    Ramkishen S. Rajan

    2012-04-01

    Full Text Available This paper revisits the issue of exchange rate regimes in emerging Asia over the decade 1999–2009. It finds that while Asia is home to a wide array of exchange rate regimes, there are signs of gradual movement toward somewhat greater exchange rate flexibility in many of the regional countries. There appears to be evidence of an apparent “fear of appreciation” which is manifested in asymmetric exchange rate intervention—i.e., a willingness to allow depreciations but reluctance to allow appreciations. This policy of effective exchange rate undervaluation is rather unorthodox from a neoclassical sense, but is consistent with a development policy centered on suppressing the price of non-tradable goods relative to tradables (i.e., real exchange rate undervaluation.

  16. $H_{2}$ Formation on Interstellar Grains in Different Physical Regimes

    CERN Document Server

    Biham, O; Katz, N; Pirronello, V; Vidali, G

    1998-01-01

    An analysis of the kinetics of H2 formation on interstellar dust grains is presented using rate equations. It is shown that semi-empirical expressions that appeared in the literature represent two different physical regimes. In particular, it is shown that the expression given by Hollenbach, Werner and Salpeter [ApJ, 163, 165 (1971)] applies when high flux, or high mobility, of H atoms on the surface of a grain, makes it very unlikely that H atoms evaporate before they meet each other and recombine. The expression of Pirronello et al.\\ [ApJ, 483, L131 (1997)] -- deduced on the basis of accurate measurements on realistic dust analogue -- applies to the opposite regime (low coverage and low mobility). The implications of this analysis for the understanding of the processes dominating in the Interstellar Medium are discussed.

  17. Computer Language Choices in Arms Control and Nonproliferation Regimes

    Energy Technology Data Exchange (ETDEWEB)

    White, G K

    2005-06-10

    The U.S. and Russian Federation continue to make substantive progress in the arms control and nonproliferation transparency regimes. We are moving toward an implementation choice for creating radiation measurement systems that are transparent in both their design and in their implementation. In particular, the choice of a programming language to write software for such regimes can decrease or significantly increase the costs of authentication. In this paper, we compare procedural languages with object-oriented languages. In particular, we examine the C and C++ languages; we compare language features, code generation, implementation details, and executable size and demonstrate how these attributes aid or hinder authentication and backdoor threats. We show that programs in lower level, procedural languages are more easily authenticated than are object-oriented ones. Potential tools and methods for authentication are covered. Possible mitigations are suggested for using object-oriented programming languages.

  18. Multi-band metamaterial absorber topology for infrared frequency regime

    Science.gov (United States)

    Mulla, Batuhan; Sabah, Cumali

    2017-02-01

    In this paper, a new multiband metamaterial absorber design is proposed and the numerical characterization is carried out. The design is composed of three layers with differently sized quadruplets in which the interaction among them causes the multiband absorption response in the infrared frequency regime. In order to characterize the absorber and explain the multiband topology, some parametric studies with respect to the dimensions of the structure are carried out and the contributions of the quadruplets to the absorption spectrum are analyzed. According to the results, it is found that the proposed metamaterial absorber has five bands in the infrared frequency regime with the absorption levels of: 98.90%, 99.39%, 86.46%, 92.80% and 97.96%. Moreover, the polarization dependency of the structure is examined and it is found that the design operates well as a perfect absorber with polarization independency in the studied frequency range.

  19. Pulsar Timing Arrays and Gravity Tests in the Radiative Regime

    CERN Document Server

    Lee, K J

    2014-01-01

    In this paper, we focus on testing gravity theories in the radiative regime using pulsar timing array observations. After reviewing current techniques to measure the dispersion and alternative polarization of gravitational waves, we extend the framework to the most general situations, where the combinations of a massive graviton and alternative polarization modes are considered. The atlas of the Hellings-Downs functions is completed by the new calculations for these dispersive alternative polarization modes. We find that each mode and corresponding graviton mass introduce characteristic features in the Hellings-Downs function. Thus, in principal, we can not only detect each polarization mode, measure the corresponding graviton mass, but also discriminate the different scenarios. In this way, we can test gravity theories in the radiative regime in a generalized fashion, and such method is a direct experiment, where one can address the gauge symmetry of the gravity theories in their linearised limits. Although ...

  20. Scattering in the ultrastrong regime: nonlinear optics with one photon

    OpenAIRE

    Sánchez-Burillo, Eduardo; Zueco, David; García-Ripoll, Juanjo; Martín-Moreno, Luis

    2014-01-01

    The scattering of a flying photon by a two-level system ultrastrongly coupled to a one-dimensional photonic waveguide is studied numerically. The photonic medium is modeled as an array of coupled cavities and the whole system is analyzed beyond the rotating wave approximation using Matrix Product States. It is found that the scattering is strongly influenced by the single- and multi-photon dressed bound states present in the system. In the ultrastrong coupling regime a new channel for inelast...

  1. Numerical techniques for lattice QCD in the $\\epsilon$--regime

    OpenAIRE

    Giusti, L; Hoelbling, C.; Lüscher, M.; Wittig, H.

    2002-01-01

    In lattice QCD it is possible, in principle, to determine the parameters in the effective chiral lagrangian (including weak interaction couplings) by performing numerical simulations in the $\\epsilon$--regime, i.e. at quark masses where the physical extent of the lattice is much smaller than the Compton wave length of the pion. The use of a formulation of the lattice theory that preserves chiral symmetry is attractive in this context, but the numerical implementation of any such approach requ...

  2. Amendment of the Foreign lnvestment Juridical regime in Colombia

    Directory of Open Access Journals (Sweden)

    Cristina Vargas Guzman

    1992-12-01

    Full Text Available Colombia, integrated in the Andean Group, is now going through a period of economic and institutional modernization and has initiated a serie of modifications, specially of its international trade, finantial, tax, exchange and labour regimes. These have involved some changes which guarantee legislative stability to investors and thus set the grounds for the foreign participation in the economic modernization and internationalization process in Colombia. These facilities need the support of developed countries to achieve its aims.

  3. TYPES OF FI SCAL REGIME IN HYDROCARBON EXPLORATION AND PRODUCTION

    Directory of Open Access Journals (Sweden)

    Daria Karasalihović-Sedlar

    2017-01-01

    Full Text Available The choice of the right fi scal regime represents the main object of the energy policy concerning hydrocarbon exploration and production for the state government. For the operator and service companies it represents the terms and conditions for practical conducting of the process in whole. This paper analyse aspects of agreements used in the petroleum indus-try. Elements of agreement, regardless of regime, have been described together with their advantages and disadvantages. Due to the fact that the fi scal regime has to be chosen to attract companies willing to invest in exploration and produc-tion, it represents a relevant part of the business strategy and also a base for the decision making process during start up. It has to minimize the risk for the both parties involved and maximize the state’s share during the exploitation phase. For the companies, it has to be attractive enough to balance risks during the exploration phase with profi ts gained during the exploitation phase. The aim of this paper is to show the existing fi scal systems in the petroleum industry and to analyze the process for concluding a contract regarding the exploration and production of hydrocarbons. An overview of diff er-ent business practices in the oil and gas industry with a detailed breakdown of the contract terms between the parties involved have been described in the paper. The aim of this paper is to show the diff erent possibilities of fi nancial regimes which could help during the negotiation process for conducting hydrocarbon exploration and production for everyone involved.

  4. Heterogeneous Consumers, Demand Regimes, Monetary Policy and Equilibrium Determinacy

    OpenAIRE

    Di Bartolomeo, Giovanni; Rossi, Lorenza

    2005-01-01

    This paper investigates the effects of monetary policy in presence of heterogeneous consumers. We study the effectiveness (quantitative effects) of monetary policy and equilibrium determinacy properties of a New Keynesian DSGE model where a fraction of households cannot smooth consumption. We show that two-demand regimes can emerge (according to the “slope” of IS curve) and that the main unconventional results, stressed by recent literature, only hold in the unconventional case of an IS curve...

  5. Simulation of weak and strong Langmuir collapse regimes

    Energy Technology Data Exchange (ETDEWEB)

    Hadzievski, L.R.; Skoric, M.M. [Vinca Inst. of Nuclear Sciences, Belgrade (Yugoslavia); Kono, M.; Sato, T.

    1998-01-01

    In order to check the validity of the self-similar solutions and the existence of weak and strong collapse regimes, direct two dimensional simulation of the time evolution of a Langmuir soliton instability is performed. Simulation is based on the Zakharov model of strong Langmuir turbulence in a weakly magnetized plasma accounting for the full ion dynamics. For parameters considered, agreement with self-similar dynamics of the weak collapse type is found with no evidence of the strong Langmuir collapse. (author)

  6. Cosmological bulk viscosity, the Burnett regime, and the BGK equation

    CERN Document Server

    Sandoval-Villalbazo, A

    2002-01-01

    Einstein's field equations in FRW space-times are coupled to the BGK equation in order to derive the stress energy tensor including dissipative effects up to second order in the thermodynamical forces. The space-time is assumed to be matter-dominated, but in a low density regime for which a second order (Burnett) coefficient becomes relevant. Cosmological implications of the solutions, as well as the physical meaning of transport coefficients in an isotropic homogeneous universe are discussed.

  7. Practical stability and instability of regime-switching diffusions

    Institute of Scientific and Technical Information of China (English)

    G.George YIN; Bo ZHANG; Chao ZHU

    2008-01-01

    This work is devoted to practical stability of a class of regime-switching diffusions.First,the notion of practical stability is introduced.Then,sufficient conditions for practical stability and practical instability in probability and in pth mean are provided using a Lyapunov function argument.In addition,easily verifiable conditions on drift and diffusion coefficients are also given.Moreover,examples are supplied for demonstration purposes.

  8. The relevance of universal jurisdiction in the complementarity regime

    OpenAIRE

    Kvarme, Sigbjørn

    2012-01-01

    This study examines the relevance universal jurisdiction can have in the ICC complementarity regime. It argues that universal jurisdiction is an underdeveloped principle for exercising jurisdiction, and that the shortcomings of the principle therefore provide it to be exercised with restraint. However, this study also argues that there is a place for universal jurisdiction in those situations where the jurisdiction of the ICC leaves an impunity gap.

  9. International arbitration and its exclusion from the Brussels regime

    Directory of Open Access Journals (Sweden)

    Hamed Alavi

    2016-06-01

    Full Text Available The Brussels regime, which regulates the matters of transnational litigation excludes arbitration from its scope. Upon formation of the Brussels regime the existing instruments concerning arbitration - the United Nations Convention on Recognition and Enforcement of Foreign Arbitral Awards and the 1961 European Convention on International Commercial Arbitration - were believed to be sufficient. The original Brussels Convention 1968 on recognition and enforcement of judgments delivered in the courts of the EU Member States expressly provided for the exclusion of arbitration. The following Brussels I Regulation followed the trend and reinforced the exclusion of arbitration from their material scopes. The rationale for doing so was primarily the prevention of parallel proceedings and irreconcilable judgments. The arbitration exclusion from the Brussels regime has caused a fair amount of confusion, especially regarding the extent and limits of the exclusion. That is, whether the arbitration agreement, the arbitral award and its consequences are covered by the exclusion or they may fall under the scope of the Brussels regulation if they constitute only an incidental question to the main cause of action? The confusion was illustrated in the ECJ judgment West Tankers, which generated negative feedback from the arbitration community and indicated the need for reform. The recently adopted Recast Regulation took it upon itself to clarify the relationship between arbitration and the EU regime of transnational litigation. The exclusion is reinforced ye again and its boundaries are specified in the Preamble. However, whether or not the concerns about the extent and objectives of arbitration exclusion have been at present eliminated, remains to be seen.

  10. Transparent electrodes in the terahertz regime – a new approach

    DEFF Research Database (Denmark)

    Malureanu, Radu; Song, Z.; Zalkovskij, Maksim

    We suggest a new possibility for obtaining a transparent metallic film, thus allowing for completely transparent electrodes. By placing a complementary composite layer on top of the electrode, we can cancel the back-scattering of the latter thus obtaining a perfectly transparent structure. For ea...... of fabrication, we performed the first experiments in the THz regime, but the concept is applicable to the entire electromagnetic waves spectrum. We show that the experiments and theory match each other perfectly....

  11. Analytic expression for poloidal flow velocity in the banana regime

    Energy Technology Data Exchange (ETDEWEB)

    Taguchi, M. [College of Industrial Technology, Nihon University, Narashino 275-8576 (Japan)

    2013-01-15

    The poloidal flow velocity in the banana regime is calculated by improving the l = 1 approximation for the Fokker-Planck collision operator [M. Taguchi, Plasma Phys. Controlled Fusion 30, 1897 (1988)]. The obtained analytic expression for this flow, which can be used for general axisymmetric toroidal plasmas, agrees quite well with the recently calculated numerical results by Parker and Catto [Plasma Phys. Controlled Fusion 54, 085011 (2012)] in the full range of aspect ratio.

  12. On the Asymptotics of Bessel Functions in the Fresnel Regime

    Science.gov (United States)

    2014-07-10

    We introduce a version of the asymptotic expansions for Bessel functions Jν(z), Yν(z) that is valid whenever |z| > ν (which is deep in the Fresnel...equations, to be reported at a later date. On the asymptotics of Bessel functions in the Fresnel regime Z. Heitman‡ , J. Bremer?⊕, V. Rokhlin‡ , B...48109 ‡ Dept. of Mathematics, Yale University, New Haven CT 06511 Approved for public release: distribution is unlimited. Keywords: Bessel Functions

  13. Rapidity gap survival in the black-disk regime

    OpenAIRE

    Frankfurt, Leonid; Hyde, Charles Earl; Strikman, Mark; Weiss, Christian

    2007-01-01

    We summarize how the approach to the black--disk regime (BDR) of strong interactions at TeV energies influences rapidity gap survival in exclusive hard diffraction pp--> p + H + p (H =dijet, \\bar Q Q, Higgs). Employing a recently developed partonic description of such processes, we discuss (a) the suppression of diffraction at small impact parameters by soft spectator interactions in the BDR/ (b) further suppression by inelastic interactions of hard spectator partons in the BDR/ (c) effects o...

  14. Capacity of Fading Channels in the Low Power Regime

    KAUST Repository

    Benkhelifa, Fatma

    2013-01-01

    The low power regime has attracted various researchers in the information theory and communication communities to understand the performance limits of wireless systems. Indeed, the energy consumption is becoming one of the major limiting factors in wireless systems. As such, energy-efficient wireless systems are of major importance to the next generation wireless systems designers. The capacity is a metric that measures the performance limit of a wireless system. The study of the ergodic capacity of some fading channels in the low power regime is the main subject of this thesis. In our study, we consider that the receiver has always a full knowledge of the channel state information. However, we assume that the transmitter has possibly imperfect knowledge of the channel state information, i.e. he knows either perfectly the channel or only an estimated version of the channel. Both radio frequency and free space optical communication channel models are considered. The main contribution of this work is the explicit characterization of how the capacity scales as function of the signal-to-noise ratio in the low power regime. This allows us to characterize the gain due to the perfect knowledge compared to no knowledge of the channel state information at the transmitter. In particular, we show that the gain increases logarithmically for radio frequency communication. However, the gain increases as log2(Pavg) or log4(Pavg) for free-space optical communication, where Pavg is the average power constraint imposed to the input. Furthermore, we characterize the capacity of cascaded fading channels and we applied the result to Rayleigh-product fading channel and to a free-space optical link over gamma-gamma atmospheric turbulence in the presence of pointing errors. Finally, we study the capacity of Nakagami-m fading channel under quality of service constraints, namely the effective capacity. We have shown that the effective capacity converges to Shannon capacity in the very low

  15. Moving History: The Cinematic Regime of Historicity in Weimar Germany

    OpenAIRE

    Allred, Mason Kamana

    2015-01-01

    This study shows how historical film confronted popular memory and the dominant sense of history, to deconstruct and supplant these modes, resulting in a media revolution for historical transmission and experience. With its inherent potential and oft-lamented drawbacks, I argue that film came to shape a primary regime of historicity, one that made history internationally shared, primarily imagistic rather than narrative, explicitly constructed and a sensory experience specifically for embodie...

  16. Power Counting Regime of Chiral Extrapolation and Beyond

    CERN Document Server

    Leinweber, D B; Young, R D; Leinweber, Derek B; Thomas, Anthony W; Young, Ross D

    2005-01-01

    Finite-range regularised (FRR) chiral effective field theory is presented in the context of approximation schemes ubiquitous in modern lattice QCD calculations. Using FRR techniques, the power-counting regime (PCR) of chiral perturbation theory can be estimated. To fourth-order in the expansion at the 1% tolerance level, we find m_\\pi < 180 MeV for the PCR, extending only a small distance beyond the physical pion mass.

  17. Electron plasma wave filamentation in the kinetic regime

    Science.gov (United States)

    Lushnikov, Pavel; Rose, Harvey; Silantyev, Denis

    2016-10-01

    We consider nonlinear electron plasma wave (EPW) dynamics in the kinetic wavenumber regime, 0.25 Bernstein-Greene-Kruskal (BGK) mode. Transverse perturbations of any of these initial conditions grow with time eventually producing strongly nonlinear filamentation followed by plasma turbulence. We compared these simulations with the theoretical results on growth rates of the transverse instability BGK mode showing the satisfactory agreement. Supported by the New Mexico Consortium and NSF DMS-1412140.

  18. Trade Regimes, Liberalization and Macroeconomic Instability in Africa

    OpenAIRE

    Chantal Dupasquier; Patrick N. Osakwe

    2006-01-01

    Trade policy has been a very contentious issue in the discourse on African development. Using panel data for 33 African countries spanning the period 1986-2000, we examine the relationship between trade liberalization and macroeconomic instability in Africa. We focus on instabilities in output, consumption and investment, and use both single and system estimation techniques as well as different measures of trade regimes. After controlling for key potential sources of macroeconomic instability...

  19. Study of the Transition Flow Regime using Monte Carlo Methods

    Science.gov (United States)

    Hassan, H. A.

    1999-01-01

    This NASA Cooperative Agreement presents a study of the Transition Flow Regime Using Monte Carlo Methods. The topics included in this final report are: 1) New Direct Simulation Monte Carlo (DSMC) procedures; 2) The DS3W and DS2A Programs; 3) Papers presented; 4) Miscellaneous Applications and Program Modifications; 5) Solution of Transitional Wake Flows at Mach 10; and 6) Turbulence Modeling of Shock-Dominated Fows with a k-Enstrophy Formulation.

  20. Nano-plasmonic antennas in the near infrared regime.

    Science.gov (United States)

    Berkovitch, N; Ginzburg, P; Orenstein, M

    2012-02-22

    Plasmonic nano-antennas constitute a central research topic in current science and engineering with an enormous variety of potential applications. Here we review the recent progress in the niche of plasmonic nano-antennas operating in the near infrared part of the spectrum which is important for a variety of applications. Tuning of the resonance into the near infrared regime is emphasized in the perspectives of fabrication, measurement, modeling, and analytical treatments, concentrating on the vast recent achievements in these areas.