Effect of the meniscus contact angle during early regimes of spontaneous imbibition in nanochannels.

Science.gov (United States)

Karna, Nabin Kumar; Oyarzua, Elton; Walther, Jens H; Zambrano, Harvey A

2016-11-30

Nanoscale capillarity has been extensively investigated; nevertheless, many fundamental questions remain open. In spontaneous imbibition, the classical Lucas-Washburn equation predicts a singularity as the fluid enters the channel consisting of an anomalous infinite velocity of the capillary meniscus. Bosanquet's equation overcomes this problem by taking into account fluid inertia predicting an initial imbibition regime with constant velocity. Nevertheless, the initial constant velocity as predicted by Bosanquet's equation is much greater than those observed experimentally. In the present study, large scale atomistic simulations are conducted to investigate capillary imbibition of water in slit silica nanochannels with heights between 4 and 18 nm. We find that the meniscus contact angle remains constant during the inertial regime and its value depends on the height of the channel. We also find that the meniscus velocity computed at the channel entrance is related to the particular value of the meniscus contact angle. Moreover, during the subsequent visco-inertial regime, as the influence of viscosity increases, the meniscus contact angle is found to be time dependent for all the channels under study. Furthermore, we propose an expression for the time evolution of the dynamic contact angle in nanochannels which, when incorporated into Bosanquet's equation, satisfactorily explains the initial capillary rise.

Effect of Uniaxial Tensile Cyclic Loading Regimes on Matrix Organization and Tenogenic Differentiation of Adipose-Derived Stem Cells Encapsulated within 3D Collagen Scaffolds

Directory of Open Access Journals (Sweden)

Gayathri Subramanian

2017-01-01

Full Text Available Adipose-derived mesenchymal stem cells have become a popular cell choice for tendon repair strategies due to their relative abundance, ease of isolation, and ability to differentiate into tenocytes. In this study, we investigated the solo effect of different uniaxial tensile strains and loading frequencies on the matrix directionality and tenogenic differentiation of adipose-derived stem cells encapsulated within three-dimensional collagen scaffolds. Samples loaded at 0%, 2%, 4%, and 6% strains and 0.1 Hz and 1 Hz frequencies for 2 hours/day over a 7-day period using a custom-built uniaxial tensile strain bioreactor were characterized in terms of matrix organization, cell viability, and musculoskeletal gene expression profiles. The results displayed that the collagen fibers of the loaded samples exhibited increased matrix directionality with an increase in strain values. Gene expression analyses demonstrated that ASC-encapsulated collagen scaffolds loaded at 2% strain and 0.1 Hz frequency showed significant increases in extracellular matrix genes and tenogenic differentiation markers. Importantly, no cross-differentiation potential to osteogenic, chondrogenic, and myogenic lineages was observed at 2% strain and 0.1 Hz frequency loading condition. Thus, 2% strain and 0.1 Hz frequency were identified as the appropriate mechanical loading regime to induce tenogenic differentiation of adipose-derived stem cells cultured in a three-dimensional environment.

Effect of Uniaxial Tensile Cyclic Loading Regimes on Matrix Organization and Tenogenic Differentiation of Adipose-Derived Stem Cells Encapsulated within 3D Collagen Scaffolds.

Science.gov (United States)

Subramanian, Gayathri; Stasuk, Alexander; Elsaadany, Mostafa; Yildirim-Ayan, Eda

2017-01-01

Adipose-derived mesenchymal stem cells have become a popular cell choice for tendon repair strategies due to their relative abundance, ease of isolation, and ability to differentiate into tenocytes. In this study, we investigated the solo effect of different uniaxial tensile strains and loading frequencies on the matrix directionality and tenogenic differentiation of adipose-derived stem cells encapsulated within three-dimensional collagen scaffolds. Samples loaded at 0%, 2%, 4%, and 6% strains and 0.1 Hz and 1 Hz frequencies for 2 hours/day over a 7-day period using a custom-built uniaxial tensile strain bioreactor were characterized in terms of matrix organization, cell viability, and musculoskeletal gene expression profiles. The results displayed that the collagen fibers of the loaded samples exhibited increased matrix directionality with an increase in strain values. Gene expression analyses demonstrated that ASC-encapsulated collagen scaffolds loaded at 2% strain and 0.1 Hz frequency showed significant increases in extracellular matrix genes and tenogenic differentiation markers. Importantly, no cross-differentiation potential to osteogenic, chondrogenic, and myogenic lineages was observed at 2% strain and 0.1 Hz frequency loading condition. Thus, 2% strain and 0.1 Hz frequency were identified as the appropriate mechanical loading regime to induce tenogenic differentiation of adipose-derived stem cells cultured in a three-dimensional environment.

Control of power distribution and the safety of a WWER-1000 reactor during operation in a load-following regime

International Nuclear Information System (INIS)

Filipchuk, E.V.; Dunaev, V.G.; Luk'yanets, I.A.; Potapenko, P.T.; Timokhin, E.S.; Voznesenskij, V.A.; Mitin, V.I.

1984-01-01

An important task in ensuring the operational safety of a nuclear power plant with a vessel-type water-cooled, water-moderated reactor is the development of algorithms for controlling power distribution in base-load and load-following regimes. The control strategy must ensure that the form of power distribution is maintained within the permissible limits in the case of situations presenting a nuclear hazard and of xenon fluctuations when there are variations in power output. The task of controlling power distribution can be broken down into an axial problem and a radial-azimuthal problem. For maintenance of the form of axial power distribution an algorithm of optimum fast-action control is proposed; for maintenance of the radial-azimuthal form, an algorithm of optimum (i.e. best) approximation to the given distribution of control. The two control problems are solved by using a single computerized procedure based on mathematical programming. The algorithms are designed for use in computerized control. The paper presents the results of algorithm simulation. The authors propose that in the first stage, activation of the control systems should involve the operator, who can view the sequence of actions on a display screen. (author)

Multi-Fluid Modeling of Low-Recycling Divertor Regimes

International Nuclear Information System (INIS)

Smirnov, R.D.; Pigarov, A.Y.; Krasheninnikov, S.I.; Rognlien, T.D.; Soukhanovskii, V.A.; Rensink, M.E.; Maingi, R.; Skinner, C.H.; Stotler, D.P.; Bell, R.E.; Kugel, H.W.

2010-01-01

The low-recycling regimes of divertor operation in a single-null NSTX magnetic configuration are studied using computer simulations with the edge plasma transport code UEDGE. The edge plasma transport properties pertinent to the low-recycling regimes are demonstrated. These include the flux-limited character of the parallel heat transport and the high plasma temperatures with the flattened profiles in the scrape-off-layer. It is shown that to maintain the balance of particle fluxes at the core interface the deuterium gas puffing rate should increase as the divertor recycling coefficient decreases. The radial profiles of the heat load to the outer divertor plate, the upstream radial plasma profiles, and the effects of the cross-field plasma transport in the low-recycling regimes are discussed. It is also shown that recycling of lithium impurities evaporating from the divertor plate at high surface temperatures can reverse the low-recycling divertor operational regime to the high-recycling one and may cause thermal instability of the divertor plate.

A gravity loading countermeasure skinsuit

Science.gov (United States)

Waldie, James M.; Newman, Dava J.

2011-04-01

Despite the use of several countermeasures, significant physiological deconditioning still occurs during long duration spaceflight. Bone loss - primarily due to the absence of loading in microgravity - is perhaps the greatest challenge to resolve. This paper describes a conceptual Gravity Loading Countermeasure Skinsuit (GLCS) that induces loading on the body to mimic standing and - when integrated with other countermeasures - exercising on Earth. Comfort, mobility and other operational issues were explored during a pilot study carried out in parabolic flight for prototype suits worn by three subjects. Compared to the 1- or 2-stage Russian Pingvin Suits, the elastic mesh of the GLCS can create a loading regime that gradually increases in hundreds of stages from the shoulders to the feet, thereby reproducing the weight-bearing regime normally imparted by gravity with much higher resolution. Modelling shows that the skinsuit requires less than 10 mmHg (1.3 kPa) of compression for three subjects of varied gender, height and mass. Negligible mobility restriction and excellent comfort properties were found during the parabolic flights, which suggests that crewmembers should be able to work normally, exercise or sleep while wearing the suit. The suit may also serve as a practical 1 g harness for exercise countermeasures and vibration applications to improve dynamic loading.

Operation regimes of a dielectric laser accelerator

Science.gov (United States)

Hanuka, Adi; Schächter, Levi

2018-04-01

We investigate three operation regimes in dielectric laser driven accelerators: maximum efficiency, maximum charge, and maximum loaded gradient. We demonstrate, using a self-consistent approach, that loaded gradients of the order of 1 to 6 [GV/m], efficiencies of 20% to 80%, and electrons flux of 1014 [el/s] are feasible, without significant concerns regarding damage threshold fluence. The latter imposes that the total charge per squared wavelength is constant (a total of 106 per μm2). We conceive this configuration as a zero-order design that should be considered for the road map of future accelerators.

Multi-fluid modeling of low-recycling divertor regimes

International Nuclear Information System (INIS)

Smirnov, R.D.; Pigarov, A.Yu.; Krasheninnikov, S.I.; Rognlien, T.D.; Soukhanovskii, V.A.; Rensink, M.E.; Maingi, R.; Skinner, C.H.; Stotler, D.P.; Bell, R.E.; Kugel, H.W.

2010-01-01

The low-recycling regimes of divertor operation in a single-null NSTX magnetic configuration are studied using computer simulations with the edge plasma transport code UEDGE. The edge plasma transport properties pertinent to the low-recycling regimes are demonstrated. These include the flux-limited character of the parallel heat transport and the high plasma temperatures with the flattened profiles in the scrape-off-layer. It is shown that to maintain the balance of particle fluxes at the core interface the deuterium gas puffing rate should increase as the divertor recycling coefficient decreases. The radial profiles of the heat load to the outer divertor plate, the upstream radial plasma profiles, and the effects of the cross-field plasma transport in the low-recycling regimes are discussed. It is also shown that recycling of lithium impurities evaporating from the divertor plate at high surface temperatures can reverse the low-recycling divertor operational regime to the high-recycling one and may cause thermal instability of the divertor plate (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Generation and development of damage in double forged tungsten in different combined regimes of irradiation with extreme heat loads

Science.gov (United States)

Paju, Jana; Väli, Berit; Laas, Tõnu; Shirokova, Veroonika; Laas, Katrin; Paduch, Marian; Gribkov, Vladimir A.; Demina, Elena V.; Prusakova, Marina D.; Pimenov, Valeri N.; Makhlaj, Vadym A.; Antonov, Maksim

2017-11-01

Armour materials in fusion devices, especially in the region of divertor, are exposed to a continuous heat and particle load. In addition, several off-normal events can reach the material during a work session. Calculations show that the effects of plasma and heat during such events can lead to cracking, erosion and detachment of the armour material. On the other hand, mutual and combined influences of different kinds of heat and particle loads can lead to the amplification of defects or vice versa, to the mitigation of damages. Therefore, the purpose of the study is to investigate the plasma induced damages on samples of double forged tungsten, which is considered a potential candidate for armour material of future tokamak's divertor. The combined effect of different kinds of plasma induced damages was investigated and analysed in this research. The study was conducted by irradiating the samples in various irradiation regimes twice, to observe the accumulation of the damages. Afterwards the analysis of micro-topography, scanning electron microscopy images and electrical conductivity measurements was used. Results indicate that double-forging improved the tungsten's durability to irradiation. Nevertheless, powerful pulses lead to significant damage of the sample, which will lead to further deterioration in the bulk. Although the average micro-roughness on the sample's surface does not change, the overall height/depth ratios can change.

Effect of different number of players and training regimes on physiological and technical demands of ball-drills in basketball.

Science.gov (United States)

Conte, Daniele; Favero, Terence G; Niederhausen, Meike; Capranica, Laura; Tessitore, Antonio

2016-01-01

This study aimed to analyse the effects of two factors (number of players and training regimes) on players' physiological and technical demands in basketball ball-drills. Twenty-one young basketball players performed four different ball-drills (two levels for each factor). The number of players involved was 2vs2 and 4vs4, while ball-drill regimes were continuous and intermittent. Physiological demand was assessed using the percentage of maximal heart rate (%HRmax), Edwards' training load and rating of perceived exertion (RPE). Furthermore, the following technical actions were collected: dribbles, steals, rebounds, turnovers, passes (total, correct, wrong and % of correct pass) and shots (total, scored, missed and % of made shot). A 2 × 2 (number of players × regime) two-way ANOVA with repeated measures was applied for physiological parameters and technical actions. The 2vs2 condition showed higher %HRmax (P training load (P training load (P < 0.001), RPE (P = 0.006) and dribbles (P < 0.001) than the intermittent regime. This study showed that both number of players and regime are useful variables able to modify basketball ball-drills workload.

Two lighter than air systems in opposing flight regimes: An unmanned short haul, heavy load transport balloon and a manned, light payload airship

Science.gov (United States)

Pohl, R. A.

1975-01-01

Lighter Than Air vehicles are generally defined or categorized by the shape of the balloon, payload capacity and operational flight regime. Two balloon systems that are classed as being in opposite categories are described. One is a cable guided, helium filled, short haul, heavy load transport Lighter Than Air system with a natural shaped envelope. The other is a manned, aerodynamic shaped airship which utilizes hot air as the buoyancy medium and is in the light payload class. While the airship is in the design/fabrication phase with flight tests scheduled for the latter part of 1974, the transport balloon system has been operational for some eight years.

Computation of shakedown loads feasibility study

International Nuclear Information System (INIS)

Save, M.; Saxce, G. de; Borkowski, A.

1991-01-01

Structures submitted to variable loads and temperature fields may enter in a regime of ratcheting where strains and hence structural deflections increase cycle by cycle. It is important to demonstrate that ratcheting is avoided. This happens of course if the structure remains entirely in the elastic regime. However, for more severe loadings, plastic deformations occur and the analyst must then demonstrate that the structure shakes down or adapts. Shakedown may be elastic if after a transient period all strain variations become elastic, or plastic when alternating plasticity occurs. This report addresses plastic shakedown. The problem is treated from the theoretical point of view but also - and this is a very important part of the work - from the numerical and software point of view

Vibration analysis of a hydro generator for different operating regimes

Science.gov (United States)

Haţiegan, C.; Pădureanu, I.; Jurcu, M.; Nedeloni, M. D.; Hamat, C. O.; Chioncel, C. P.; Trocaru, S.; Vasile, O.; Bădescu, O.; Micliuc, D.; (Filip Nedeloni, L.; Băra, A.; (Barboni Haţiegan, L.

2017-01-01

Based on experimental measurements, this paper presents the vibration analysis of a hydro generator that equips a Kaplan hydraulic turbine of a Hydropower plant in Romania. This analysis means vibrations measurement to different operating regimes of the hydro generator respectively before installing it and into operation, namely putting off load mode (unexcited and excited) respectively putting on load mode. By comparing, through the experimental results obtained before and after the operation of hydro aggregates are observed vibrations improvements.

Effect of Stagger on the Vibroacoustic Loads from Clustered Rockets

Science.gov (United States)

Rojo, Raymundo; Tinney, Charles E.; Ruf, Joseph H.

2016-01-01

The effect of stagger startup on the vibro-acoustic loads that form during the end- effects-regime of clustered rockets is studied using both full-scale (hot-gas) and laboratory scale (cold gas) data. Both configurations comprise three nozzles with thrust optimized parabolic contours that undergo free shock separated flow and restricted shock separated flow as well as an end-effects regime prior to flowing full. Acoustic pressure waveforms recorded at the base of the nozzle clusters are analyzed using various statistical metrics as well as time-frequency analysis. The findings reveal a significant reduction in end- effects-regime loads when engine ignition is staggered. However, regardless of stagger, both the skewness and kurtosis of the acoustic pressure time derivative elevate to the same levels during the end-effects-regime event thereby demonstrating the intermittence and impulsiveness of the acoustic waveforms that form during engine startup.

Compliance variations in the fatigue thresold regime of a low alloy ferritic steel under closure-free testing conditions

International Nuclear Information System (INIS)

Vaidya, W.V.

1991-01-01

Compliance variations in the threshold regime of a high strength ferritic steel tested under closure-free conditions at room temperature and in air are reported. In contrast to the Paris regime, and irrespective of whether the data during load shedding, at threshold or after postthreshold load increase are considered, it is found that comparatively compliance varies inconsistently in the threshold regime. Therefore, a 1:1 correlation between the averaged optical crack length and that inferred from compliance was not observed. This discrepancy is analyzed. The variations in compliance are utilized to infer the crack front behavior, and the results are discussed in terms of the microstructural impedance. (orig.) With 22 figs., 2 appendices [de

Crack growth prediction for low-cycle fatigue regime

International Nuclear Information System (INIS)

Kamaya, Masayuki

2017-01-01

The objective of this study is to show a crack growth prediction procedure for the low-cycle fatigue regime. First, fatigue crack growth tests using Type 316 stainless steel specimens at room temperature were reviewed. It was seen that the crack growth rates correlated well with the equivalent stress intensify factor, which was derived using strain range instead of stress range. Furthermore, the effective equivalent stress intensify factor derived using the effective strain range exhibited excellent correlation with the crack growth rates obtained under various specimen geometries and loading conditions including high and low-cycle regimens. The obtained crack growth rates were also compared with the growth rate prescribed in the fitness-for-service code of the Japan Society of Mechanical Engineers (JSME). The test results agreed with the growth rate of JSME code. Finally, the procedure for predicting the low-cycle fatigue crack growth was shown. Although the JSME code is aimed at predicting fatigue crack growth for the so-called small scale yielding condition (high-cycle fatigue regime), the material constants determined for the high-cycle fatigue regime can be used even for the low-cycle fatigue regime. (author)

Flow regime and deposition pattern of evaporating binary mixture droplet suspended with particles.

Science.gov (United States)

Zhong, Xin; Duan, Fei

2016-02-01

The flow regimes and the deposition pattern have been investigated by changing the ethanol concentration in a water-based binary mixture droplet suspended with alumina nanoparticles. To visualize the flow patterns, Particle Image Velocimetry (PIV) has been applied in the binary liquid droplet containing the fluorescent microspheres. Three distinct flow regimes have been revealed in the evaporation. In Regime I, the vortices and chaotic flows are found to carry the particles to the liquid-vapor interface and to promote the formation of particle aggregation. The aggregates move inwards in Regime II as induced by the Marangoni flow along the droplet free surface. Regime III is dominated by the drying of the left water and the capillary flow driving particles radially outward is observed. The relative weightings of Regimes I and II, which are enhanced with an increasing load of ethanol, determine the motion of the nanoparticles and the formation of the final drying pattern.

Immune networks: multi-tasking capabilities at medium load

International Nuclear Information System (INIS)

Agliari, E; Annibale, A; Barra, A; Coolen, A C C; Tantari, D

2013-01-01

Associative network models featuring multi-tasking properties have been introduced recently and studied in the low-load regime, where the number P of simultaneously retrievable patterns scales with the number N of nodes as P ∼ log N. In addition to their relevance in artificial intelligence, these models are increasingly important in immunology, where stored patterns represent strategies to fight pathogens and nodes represent lymphocyte clones. They allow us to understand the crucial ability of the immune system to respond simultaneously to multiple distinct antigen invasions. Here we develop further the statistical mechanical analysis of such systems, by studying the medium-load regime, P ∼ N δ with δ ∈ (0, 1]. We derive three main results. First, we reveal the nontrivial architecture of these networks: they exhibit a high degree of modularity and clustering, which is linked to their retrieval abilities. Second, by solving the model we demonstrate for δ < 1 the existence of large regions in the phase diagram where the network can retrieve all stored patterns simultaneously. Finally, in the high-load regime δ = 1 we find that the system behaves as a spin-glass, suggesting that finite-connectivity frameworks are required to achieve effective retrieval. (paper)

Load-induced modulation of signal transduction networks.

Science.gov (United States)

Jiang, Peng; Ventura, Alejandra C; Sontag, Eduardo D; Merajver, Sofia D; Ninfa, Alexander J; Del Vecchio, Domitilla

2011-10-11

Biological signal transduction networks are commonly viewed as circuits that pass along information--in the process amplifying signals, enhancing sensitivity, or performing other signal-processing tasks--to transcriptional and other components. Here, we report on a "reverse-causality" phenomenon, which we call load-induced modulation. Through a combination of analytical and experimental tools, we discovered that signaling was modulated, in a surprising way, by downstream targets that receive the signal and, in doing so, apply what in physics is called a load. Specifically, we found that non-intuitive changes in response dynamics occurred for a covalent modification cycle when load was present. Loading altered the response time of a system, depending on whether the activity of one of the enzymes was maximal and the other was operating at its minimal rate or whether both enzymes were operating at submaximal rates. These two conditions, which we call "limit regime" and "intermediate regime," were associated with increased or decreased response times, respectively. The bandwidth, the range of frequency in which the system can process information, decreased in the presence of load, suggesting that downstream targets participate in establishing a balance between noise-filtering capabilities and a circuit's ability to process high-frequency stimulation. Nodes in a signaling network are not independent relay devices, but rather are modulated by their downstream targets.

Modification of Hertzian behaviour in heavily loaded contact in the DMT regime

International Nuclear Information System (INIS)

Wu, J-J

2008-01-01

The adhesive contact between spheres for a small Tabor parameter is investigated. It is found that the DMT model cannot describe the adhesive contact for a small Tabor parameter. By assuming a new contact distance, the modified Hertzian contact is proposed. For a small Tabor parameter, the rigid-sphere model can describe the adhesive contact behaviour for a small load and the modified Hertzian model can describe the adhesive contact behaviour for a large load

Facilitated movement of inertial Brownian motors driven by a load under an asymmetric potential.

Science.gov (United States)

Ai, Bao-quan; Liu, Liang-gang

2007-10-01

Based on recent work [L. Machura, M. Kostur, P. Talkner, J. Luczka, and P. Hanggi, Phys. Rev. Lett. 98, 040601 (2007)], we extend the study of inertial Brownian motors to the case of an asymmetric potential. It is found that some transport phenomena appear in the presence of an asymmetric potential. Within tailored parameter regimes, there exists two optimal values of the load at which the mean velocity takes its maximum, which means that a load can facilitate the transport in the two parameter regimes. In addition, the phenomenon of multiple current reversals can be observed when the load is increased.

Low Flow Regimes of the Tarim River Basin, China: Probabilistic Behavior, Causes and Implications

Directory of Open Access Journals (Sweden)

Peng Sun

2018-04-01

Full Text Available Droughts are a frequent occurrence in Xinjiang, China, and therefore fundamental to determining their hydrologic characteristics is low flow analysis. To that end, 11 probability distribution functions and 26 copulas functions were employed to analyze the changing characteristics of low flow regime (defined as seven-day low flow of the Tarim River Basin. Results indicated that: (1 The Wakeby distribution satisfactorily described the probabilistic behavior of the low flow regime. According to Akaike Information Criterion (AIC, Bayesian Information Criterions (BIC, maximum likelihood, and other residual-based metrics, Tawn copula, Farlie–Gumbel–Morgenstern copula and Frank copula were the best choice and used in this current study. (2 After 1987, hydrological droughts of longer return periods were prone to higher occurrence frequency. (3 The low flow volume has been increasing in recent years due to the temperature-induced increase of snowmelt and increasing precipitation. However, hydrological droughts can be expected to occur due to the massive increase in water demand from the development of irrigated agriculture, increasing arable land and livestock farming. As a result, the water shortage in the lower Tarim River Basin will be increasingly severe under the influence of climate change and human activities. To alleviate the shortage would call for the development of water-saving agricultural irrigation, water-saving technology, conservation of eco-environment and sustainable development of local socio-economy.

Using neutral models to identify constraints on low-severity fire regimes.

Science.gov (United States)

Donald McKenzie; Amy E. Hessl; Lara-Karena B. Kellogg

2006-01-01

Climate, topography, fuel loadings, and human activities all affect spatial and temporal patterns of fire occurrence. Because fire is modeled as a stochastic process, for which each fire history is only one realization, a simulation approach is necessary to understand baseline variability, thereby identifying constraints, or forcing functions, that affect fire regimes...

Male Sexual Quality Of Life Is Maintained Satisfactorily Throughout Life In The Amazon Rainforest.

Science.gov (United States)

Teixeira, Thiago; Nazima, Maira; Hallak, Jorge

2018-06-01

The Amazon Rainforest is a cradle of biodiversity, where different ethnic groups have specific sexual habits. To define the average sexual quality of life of Amazonian men 18 to 69 years old, evaluate the influence of aging on their sexual function, and calculate the prevalence of premature ejaculation, delayed ejaculation, and hypoactive sexual desire disorder. A cross-sectional quantitative probability sample study was performed with a demographically representative population (N = 385), with data collected privately at participants' houses, including men who had been sexually active for a minimum of 6 months. The Male Sexual Quotient (MSQ) was used to measure sexual satisfaction and function. Statistical analysis was performed with SPSS 21.0 using the Kruskal-Wallis test (P quality of sexual life. MSQ scores. The response rate was 81.69%. The mean age was 36.00 ± 12.95 years, and most men had mixed ethnicity (63.11%), were self-employed (42.07%), had a monthly earned income of US$0 to US$460 (46.75%), and were single (36.10%). The mean MSQ score was 80.39 ± 12.14 (highly satisfied). None of the demographic characteristics showed a statistically significant influence on sexual satisfaction. The difference in quality of sexual life was statistically significant compared with age (P quality (P quality of sexual life. Sexual domains such as desire, partner satisfaction, and erection quality are related to the correlation between sexual quality of life and aging. However, the prevalence of premature ejaculation seems to be slightly higher than in other parts of the world. Teixeira T, Nazima M, Hallak J. Male Sexual Quality Of Life Is Maintained Satisfactorily Throughout Life In The Amazon Rainforest. Sex Med 2018;6:90-96. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Flow Regimes of Air-Water Counterflow Through Cross Corrugated Parallel Plates

Energy Technology Data Exchange (ETDEWEB)

de Almeida, V.F.

2000-06-07

Heretofore unknown flow regimes of air-water counterflow through a pair of transparent vertical parallel cross corrugated plates were observed via high-speed video. Air flows upward driven by pressure gradient and water, downward driven by gravity. The crimp geometry of the corrugations was drawn from typical corrugated sheets used as filling material in modern structured packed towers. Four regimes were featured, namely, rivulet, bicontinuous, flooding fronts, and flooding waves. It is conceivable that the regimes observed might constitute the basis for understanding how gas and liquid phases contend for available space in the interstices of structured packings in packed towers. Flow regime transitions were expressed in terms of liquid load (liquid superficial velocity) and gas flow factor parameters commonly used in pressure drop and capacity curves. We have carefully examined the range of parameters equivalent to the ill-understood high-liquid-flow operation in packed towers. More importantly, our findings should prove valuable in validating improved first-principles modeling of gas-liquid flows in these industrially important devices.

Flow regimes

International Nuclear Information System (INIS)

Kh'yuitt, G.

1980-01-01

An introduction into the problem of two-phase flows is presented. Flow regimes arizing in two-phase flows are described, and classification of these regimes is given. Structures of vertical and horizontal two-phase flows and a method of their identification using regime maps are considered. The limits of this method application are discussed. The flooding phenomena and phenomena of direction change (flow reversal) of the flow and interrelation of these phenomena as well as transitions from slug regime to churn one and from churn one to annular one in vertical flows are described. Problems of phase transitions and equilibrium are discussed. Flow regimes in tubes where evaporating liquid is running, are described [ru

Dynamical Model of Rocket Propellant Loading with Liquid Hydrogen

Data.gov (United States)

National Aeronautics and Space Administration — A dynamical model describing the multi-stage process of rocket propellant loading has been developed. It accounts for both the nominal and faulty regimes of...

Study and optimization of operating regimes of NPP district heating system

International Nuclear Information System (INIS)

Bunin, V.S.; Vasil'ev, M.K.; Kudryavtsev, A.A.; Gorbashev, Yu.B.; Gadzhij, V.M.

1980-01-01

Thermal tests of the system with two reactors and four turbines have been carried out for the purpose of verification of operating regimes of the NPP district heating system with boiling single-curcuit RBMK-1000 reactors and K-500-65/3000 turbines. The system is designed for heat supply of habitable settlement and industrial site. The data processing have been carried out by the BESM-6 computer representing distributions of heat flow, steam, water and their parameters and determining the main energy indices of the system. Calculations of the system operating regime variables during the year have been carried out with the help of this program. It has been expected that the system provided heat consumption of 232 MW at calculated regime of thermal loading of the district, temperature regime of the system water of 130/170 deg C, relative load of hot water supply of 0.2 and duration of heating period of 4800 h. Calculations demonstrated that distric heat supply by NPP allowed one to supplant about 85 thous. of reference fuel/year of organic fuel. About 63 thous. of reference fuel/year are required for compensation of decrease of electric energy production in a condensation cycle. It has been also shown, that replacing the four-stroke system heaters by one-stroke heaters permits to drop system water underheating 1.5 times and, respectively, electric energy underproduction to 72 mln Mj (20 mln, kWxh). It produces additional economy of 6.6 thous. reference fuel/year. Calculations of its heat system have been conducted in order to determine the influence of water consumption in an intermediate circuit on the system efficiency. It has been shown that with the increase of water consumption energy power losses decrease. Thus, the above studied have demonstrated that the use of the single-circuit NPP district heating systems leads to considerable economy of fuel

Upregulation of matrix synthesis in chondrocyte-seeded agarose following sustained bi-axial cyclic loading

Directory of Open Access Journals (Sweden)

Belinda Pingguan-Murphy

2012-08-01

Full Text Available OBJECTIVES: The promotion of extracellular matrix synthesis by chondrocytes is a requisite part of an effective cartilage tissue engineering strategy. The aim of this in vitro study was to determine the effect of bi-axial cyclic mechanical loading on cell proliferation and the synthesis of glycosaminoglycans by chondrocytes in threedimensional cultures. METHOD: A strain comprising 10% direct compression and 1% compressive shear was applied to bovine chondrocytes seeded in an agarose gel during two 12-hour conditioning periods separated by a 12-hour resting period. RESULTS: The bi-axial-loaded chondrocytes demonstrated a significant increase in glycosaminoglycan synthesis compared with samples exposed to uni-axial or no loading over the same period (p<0.05. The use of a free-swelling recovery period prior to the loading regime resulted in additional glycosaminoglycan production and a significant increase in DNA content (p<0.05, indicating cell proliferation. CONCLUSIONS: These results demonstrate that the use of a bi-axial loading regime results in increased matrix production compared with uni-axial loading.

Study of a spur gear dynamic behavior in transient regime

Science.gov (United States)

Khabou, M. T.; Bouchaala, N.; Chaari, F.; Fakhfakh, T.; Haddar, M.

2011-11-01

In this paper the dynamic behavior of a single stage spur gear reducer in transient regime is studied. Dynamic response of the single stage spur gear reducer is investigated at different rotating velocities. First, gear excitation is induced by the motor torque and load variation in addition to the fluctuation of meshing stiffness due to the variation of input rotational speed. Then, the dynamic response is computed using the Newmark method. After that, a parameter study is made on spur gear powered in the first place by an electric motor and in the second place by four strokes four cylinders diesel engine. Dynamic responses come to confirm a significant influence of the transient regime on the dynamic behavior of a gear set, particularly in the case of engine acyclism condition.

Liquid aerosol filtration by fibrous filters in interception and inertial regimes; Filtration des aerosols liquides par les filtres a fibres en regimes d`interception et d`inertie

Energy Technology Data Exchange (ETDEWEB)

Gougeon, R

1994-09-26

In most previous studies of aerosol filtration, attention is focused on the maximum penetrating particle size region where the predominant mechanisms for collection are brownian diffusion and interception. In contrary the inertial regime remains poorly understood. Therefore, the aim of this study was to improve understanding of the behaviour of fibrous filters with liquid aerosols ar high frontal velocities both in the stationary and nonstationary filtration. Stationary filtration is first investigated. Experiments are done with special filters called `formettes` which have well defined structural characteristics. Precise results obtained with those filters allow us to select two relations quoted in the literature in order to describe the diffusion and the interception and to determine an empirical correlation describing the inertial impaction. Then this correlation with an industrial filter. In the second part, the evolution of the performances of fibrous filters loaded with liquid aerosols is studied experimentally and theoretically. We show that, in the inertial regime the filter efficiency first decreases and then increases rapidly with the loading rate. This increase is particularly important at high frontal velocities and with big particles. Macroscopic observations of high loaded filters show that the liquid is located in the fibre`s intersections to form big flat surfaces. A tentative of describing the evolution of the filter efficiency in modifying our stationary filtration model in order to take into account those liquid surfaces in the filter gives encouraging results. (authors). 92 refs., 93 figs., 11 tabs., 4 appends.

Ratcheting of pressurized piping subjected to seismic loading

International Nuclear Information System (INIS)

Scavuzzo, R.J.; Lam, P.C.; Gau, J.S.

1992-01-01

The ABAQUS finite element code was used to model a pressurized pipe and subjected to cyclic bending loads to investigate ratcheting. A 1-in. schedule 40 pipe was loaded with a slow (static) cyclic load. The pipe internal pressure was varied from 0 to 6000 psi. In this paper, two types of materials were considered: an elastic perfectly plastic and a bilinear elastic-plastic material. Two types of finite elements of the ABAQUS program were compared to analytical solutions to evaluate the element accuracy in the plastic regime. Depending upon loading conditions and specified material properties, three different responses were observed from the finite element analyses: cyclic plasticity, ratcheting of the hoop strain, or shakedown. These analytical results are compared to some experimental measurements

Dynamics of levitated nanospheres: towards the strong coupling regime

International Nuclear Information System (INIS)

Monteiro, T S; Millen, J; Pender, G A T; Barker, P F; Marquardt, Florian; Chang, D

2013-01-01

The use of levitated nanospheres represents a new paradigm for the optomechanical cooling of a small mechanical oscillator, with the prospect of realizing quantum oscillators with unprecedentedly high quality factors. We investigate the dynamics of this system, especially in the so-called self-trapping regime, where one or more optical fields simultaneously trap and cool the mechanical oscillator. The determining characteristic of this regime is that both the mechanical frequency ω M and single-photon optomechanical coupling strength parameters g are a function of the optical field intensities, in contrast to usual set-ups where ω M and g are constant for the given system. We also measure the characteristic transverse and axial trapping frequencies of different sized silica nanospheres in a simple optical standing wave potential, for spheres of radii r = 20–500 nm, illustrating a protocol for loading single nanospheres into a standing wave optical trap that would be formed by an optical cavity. We use these data to confirm the dependence of the effective optomechanical coupling strength on sphere radius for levitated nanospheres in an optical cavity and discuss the prospects for reaching regimes of strong light–matter coupling. Theoretical semiclassical and quantum displacement noise spectra show that for larger nanospheres with r ∼> 100 nm a range of interesting and novel dynamical regimes can be accessed. These include simultaneous hybridization of the two optical modes with the mechanical modes and parameter regimes where the system is bistable. We show that here, in contrast to typical single-optical mode optomechanical systems, bistabilities are independent of intracavity intensity and can occur for very weak laser driving amplitudes. (paper)

Macro-grazer herbivory regulates seagrass response to pulse and press nutrient loading.

Science.gov (United States)

Ravaglioli, Chiara; Capocchi, Antonella; Fontanini, Debora; Mori, Giovanna; Nuccio, Caterina; Bulleri, Fabio

2018-05-01

Coastal ecosystems are exposed to multiple stressors. Predicting their outcomes is complicated by variations in their temporal regimes. Here, by means of a 16-month experiment, we investigated tolerance and resistance traits of Posidonia oceanica to herbivore damage under different regimes of nutrient loading. Chronic and pulse nutrient supply were combined with simulated fish herbivory, treated as a pulse stressor. At ambient nutrient levels, P. oceanica could cope with severe herbivory, likely through an increase in photosynthetic activity. Elevated nutrient levels, regardless of the temporal regime, negatively affected plant growth and increased leaf nutritional quality. This ultimately resulted in a reduction of plant biomass that was particularly severe under chronic fertilization. Our results suggest that both chronic and pulse nutrient loadings increase plant palatability to macro-grazers. Strategies for seagrass management should not be exclusively applied in areas exposed to chronic fertilization since even short-term nutrient pulses could alter seagrass meadows. Copyright © 2018 Elsevier Ltd. All rights reserved.

Immune networks: multi-tasking capabilities at medium load

Science.gov (United States)

Agliari, E.; Annibale, A.; Barra, A.; Coolen, A. C. C.; Tantari, D.

2013-08-01

Associative network models featuring multi-tasking properties have been introduced recently and studied in the low-load regime, where the number P of simultaneously retrievable patterns scales with the number N of nodes as P ˜ log N. In addition to their relevance in artificial intelligence, these models are increasingly important in immunology, where stored patterns represent strategies to fight pathogens and nodes represent lymphocyte clones. They allow us to understand the crucial ability of the immune system to respond simultaneously to multiple distinct antigen invasions. Here we develop further the statistical mechanical analysis of such systems, by studying the medium-load regime, P ˜ Nδ with δ ∈ (0, 1]. We derive three main results. First, we reveal the nontrivial architecture of these networks: they exhibit a high degree of modularity and clustering, which is linked to their retrieval abilities. Second, by solving the model we demonstrate for δ frameworks are required to achieve effective retrieval.

Code systems for effective and precise calculation of the basic neutron characteristics, core loading optimization, analysis and estimation of the operation regimes of WWER type reactors

International Nuclear Information System (INIS)

Apostolov, T.; Ivanov, K.; Prodanova, R.; Manolova, M.; Petrova, T.; Alekova, G.

1993-01-01

Two directions for investigations are suggested: 1) Analysis and evaluation of the real loading patterns and operational regimes for Kozloduy NPP WWER-440 and WWER-1000 in the frame of the recent safety criteria and nuclear power plant operating limits. 2) Development of modern code system for WWER type reactor core analysis with advanced features: new design and materials for fuel and control rods, increasing the fuel enrichment, using the integral and discrete burnable absorbers etc. The fuel technology design evolution maximizes the fuel utilization efficiency, improves operation performance and enhances safety margins. By the joint efforts of specialists from INRNE, Sofia (BG) and KAB, Berlin (GE), the codes NESSEL-IV-EC, PYTHIA and DERAB have been developed and verified. In the frame of the PHARE programme the joint project ASPERCA has been proposed intended for reactor physics calculations with PHYBER-WWER code for safety enhancement and operation reliability improvement. In-core fuel management benchmarks for 4 cycles of unit 2 (WWER-440) and 2 cycles of unit 5 (WWER-1000) have been performed. The coordination of burnable absorber design implementation, low leakage loadings usage, reloading enrichment increase and steel content reduction in the core have made the reactor core analysis more demanding and the definition of loading patterns - more difficult. This complexity requires routine use of three-dimensional fast accurate core model with extended and updated cross section libraries. To meet the needs of WWER advanced loading patterns and in-core fuel management improvements the HEXANES code systems is being developed and qualified. Some test calculations have been carried out by the HEXANES code system investigating the influence of Gd in the fuel on the main reactor physics parameters. For reevaluation of the core safety-related design limits forming the basis of licensing procedure, the code DYN3D/M2 is used. 16 refs., 3 figs. (author)

Layer-dependent role of collagen recruitment during loading of the rat bladder wall.

Science.gov (United States)

Cheng, Fangzhou; Birder, Lori A; Kullmann, F Aura; Hornsby, Jack; Watton, Paul N; Watkins, Simon; Thompson, Mark; Robertson, Anne M

2018-04-01

In this work, we re-evaluated long-standing conjectures as to the source of the exceptionally large compliance of the bladder wall. Whereas these conjectures were based on indirect measures of loading mechanisms, in this work we take advantage of advances in bioimaging to directly assess collagen fibers and wall architecture during biaxial loading. A custom biaxial mechanical testing system compatible with multiphoton microscopy was used to directly measure the layer-dependent collagen fiber recruitment in bladder tissue from 9 male Fischer rats (4 adult and 5 aged). As for other soft tissues, the bladder loading curve was exponential in shape and could be divided into toe, transition and high stress regimes. The relationship between collagen recruitment and loading curves was evaluated in the context of the inner (lamina propria) and outer (detrusor smooth muscle) layers. The large extensibility of the bladder was found to be possible due to folds in the wall (rugae) that provide a mechanism for low resistance flattening without any discernible recruitment of collagen fibers throughout the toe regime. For more extensible bladders, as the loading extended into the transition regime, a gradual coordinated recruitment of collagen fibers between the lamina propria layer and detrusor smooth muscle layer was found. A second important finding was that wall extensibility could be lost by premature recruitment of collagen in the outer wall that cut short the toe region. This change was correlated with age. This work provides, for the first time, a mechanistic understanding of the role of collagen recruitment in determining bladder extensibility and capacitance.

Flow regimes

International Nuclear Information System (INIS)

Liles, D.R.

1982-01-01

Internal boundaries in multiphase flow greatly complicate fluid-dynamic and heat-transfer descriptions. Different flow regimes or topological configurations can have radically dissimilar interfacial and wall mass, momentum, and energy exchanges. To model the flow dynamics properly requires estimates of these rates. In this paper the common flow regimes for gas-liquid systems are defined and the techniques used to estimate the extent of a particular regime are described. Also, the current computer-code procedures are delineated and introduce a potentially better method is introduced

Benthic-planktonic coupling, regime shifts, and whole-lake primary production in shallow lakes.

Science.gov (United States)

Genkai-Kato, Motomi; Vadeboncoeur, Yvonne; Liboriussen, Lone; Jeppesen, Erik

2012-03-01

Alternative stable states in shallow lakes are typically characterized by submerged macrophyte (clear-water state) or phytoplankton (turbid state) dominance. However, a clear-water state may occur in eutrophic lakes even when macrophytes are absent. To test whether sediment algae could cause a regime shift in the absence of macrophytes, we developed a model of benthic (periphyton) and planktonic (phytoplankton) primary production using parameters derived from a shallow macrophyte-free lake that shifted from a turbid to a clear-water state following fish removal (biomanipulation). The model includes a negative feedback effect of periphyton on phosphorus (P) release from sediments. This in turn induces a positive feedback between phytoplankton production and P release. Scenarios incorporating a gradient of external P loading rates revealed that (1) periphyton and phytoplankton both contributed substantially to whole-lake production over a broad range of external P loading in a clear-water state; (2) during the clear-water state, the loss of benthic production was gradually replaced by phytoplankton production, leaving whole-lake production largely unchanged; (3) the responses of lakes to biomanipulation and increased external P loading were both dependent on lake morphometry; and (4) the capacity of periphyton to buffer the effects of increased external P loading and maintain a clear-water state was highly sensitive to relationships between light availability at the sediment surface and the of P release. Our model suggests a mechanism for the persistence of alternative states in shallow macrophyte-free lakes and demonstrates that regime shifts may trigger profound changes in ecosystem structure and function.

Male Sexual Quality Of Life Is Maintained Satisfactorily Throughout Life In The Amazon Rainforest

Directory of Open Access Journals (Sweden)

Thiago Teixeira, MD, MSc

2018-06-01

correlation between sexual quality of life and aging. However, the prevalence of premature ejaculation seems to be slightly higher than in other parts of the world.Teixeira T, Nazima M, Hallak J. Male Sexual Quality Of Life Is Maintained Satisfactorily Throughout Life In The Amazon Rainforest. Sex Med 2018;6:90–96. Key Words: Quality of Life, Sexual Health, Men’s Health, Premature Ejaculation

Compressed magnetic flux amplifier with capacitive load

International Nuclear Information System (INIS)

Stuetzer, O.M.

1980-03-01

A first-order analysis is presented for a compressed magnetic flux (CMF) current amplifier working into a load with a capacitive component. Since the purpose of the investigation was to gain a general understanding of the arrangement, a number of approximations and limitations were accepted. The inductance of the transducer varies with time; the inductance/resistance/capacitance (LRC) circuit therefore is parametric and solutions are different for the stable regime (high C), the oscillation regime (low C), and the transition case. Solutions and performance depend strongly on circuit boundary conditions, i.e., energization of the circuit by either an injected current or by an applied capacitor charge. The behavior of current and energy amplification for the various cases are discussed in detail. A number of experiments with small CMF devices showed that the first-order theory presented predicts transducer performance well in the linear regime

Microprocessor control unit of thyristor regulator of microhydroelectric power station ballast load

International Nuclear Information System (INIS)

Nomokonova, Yu; Bogdanov, E

2014-01-01

The operational principle of microhydroelectric power station ballast load is presented. The comparative overview of the mathematical modeling methods is performed. The ranges of thyristors optimal work are shown as a result of the regulator regimes analysis. Shows the necessity of regulation the ballast load in microhydroelectric power station with help of developed algorithm of the program for microprocessor control

Quiescent double barrier regime in the DIII-D tokamak.

Science.gov (United States)

Greenfield, C M; Burrell, K H; DeBoo, J C; Doyle, E J; Stallard, B W; Synakowski, E J; Fenzi, C; Gohil, P; Groebner, R J; Lao, L L; Makowski, M A; McKee, G R; Moyer, R A; Rettig, C L; Rhodes, T L; Pinsker, R I; Staebler, G M; West, W P

2001-05-14

A new sustained high-performance regime, combining discrete edge and core transport barriers, has been discovered in the DIII-D tokamak. Edge localized modes (ELMs) are replaced by a steady oscillation that increases edge particle transport, thereby allowing particle control with no ELM-induced pulsed divertor heat load. The core barrier resembles those usually seen with a low (L) mode edge, without the degradation often associated with ELMs. The barriers are separated by a narrow region of high transport associated with a zero crossing in the E x B shearing rate.

MEMS-based contact stress field measurements at a rough elastomeric layer: local test of Amontons’ friction law in static and steady sliding regimes

Directory of Open Access Journals (Sweden)

Debrégeas G.

2010-06-01

Full Text Available We present the results of recent friction experiments in which a MEMS-based sensing device is used to measure both the normal and tangential stress fields at the base of a rough elastomer film in frictional contact with smooth, rigid, glass indentors. We consider successively multicontacts under (i static normal loading by a spherical indentor and (ii frictional steady sliding conditions against a cylindrical indentor, for an increasing normal load. In both cases, the measured fields are compared to elastic calculations assuming (i a smooth interface and (ii Amontons’ friction law. In the static case, significant deviations are observed which decrease with increasing load and which vanish when a lubricant is used. In the steady sliding case, Amontons’ law reproduces rather satisfactorily the experiments provided that the normal/tangential coupling at the contact interface is taken into account. We discuss the origin of the difference between the Amontons fields and the measured ones, in particular the effect of the finite normal and tangential compliances of the multicontact interface.

Codimension-two bifurcation of axial loaded beam bridge subjected to an infinite series of moving loads

International Nuclear Information System (INIS)

Yang Xin-Wei; Tian Rui-Lan; Li Hai-Tao

2013-01-01

A novel model is proposed which comprises of a beam bridge subjected to an axial load and an infinite series of moving loads. The moving loads, whose distance between the neighbouring ones is the length of the beam bridge, coupled with the axial force can lead the vibration of the beam bridge to codimension-two bifurcation. Of particular concern is a parameter regime where non-persistence set regions undergo a transition to persistence regions. The boundary of each stripe represents a bifurcation which can drive the system off a kind of dynamics and jump to another one, causing damage due to the resulting amplitude jumps. The Galerkin method, averaging method, invertible linear transformation, and near identity nonlinear transformations are used to obtain the universal unfolding for the codimension-two bifurcation of the mid-span deflection. The efficiency of the theoretical analysis obtained in this paper is verified via numerical simulations. (general)

Transition from weak wave turbulence regime to solitonic regime

Science.gov (United States)

Hassani, Roumaissa; Mordant, Nicolas

2017-11-01

The Weak Turbulence Theory (WTT) is a statistical theory describing the interaction of a large ensemble of random waves characterized by very different length scales. For both weak non-linearity and weak dispersion a different regime is predicted where solitons propagate while keeping their shape unchanged. The question under investigation here is which regime between weak turbulence or soliton gas does the system choose ? We report an experimental investigation of wave turbulence at the surface of finite depth water in the gravity-capillary range. We tune the wave dispersion and the level of nonlinearity by modifying the depth of water and the forcing respectively. We use space-time resolved profilometry to reconstruct the deformed surface of water. When decreasing the water depth, we observe a drastic transition between weak turbulence at the weakest forcing and a solitonic regime at stronger forcing. We characterize the transition between both states by studying their Fourier Spectra. We also study the efficiency of energy transfer in the weak turbulence regime. We report a loss of efficiency of angular transfer as the dispersion of the wave is reduced until the system bifurcates into the solitonic regime. This project has recieved funding from the European Research Council (ERC, Grant Agreement No. 647018-WATU).

FY 93 thermal loading systems study final report: Volume 1. Revision 1

International Nuclear Information System (INIS)

Saterlie, S.F.; Thomson, B.H.

1994-01-01

The ability to meet the overall performance requirements for the proposed Mined Geology Disposal System at Yucca Mountain, Nevada requires the two major subsystem (natural barriers and engineered barriers) to positively contribute to containment and radionuclide isolation. In addition to the postclosure performance the proposed repository must meet preclosure requirements of safety, retrievability, and operability. Cost and schedule were also considered. The thermal loading strategy chosen may significantly affect both the postclosure and preclosure performance of the proposed repository. Although the current Site Characterization Plan reference case is 57 kilowatts (kW)/acre, other thermal loading strategies (different areal mass loadings) have been proposed which possess both advantages and disadvantages. The objectives of the FY 1993 Thermal Loading Study were to (1) place bounds on the thermal loading which would establish the loading regime that is ''too hot'' and the loading regime that is ''too cold'', to (2) ''grade'' or evaluate the performance, as a function of thermal loading, of the repository to contain high level wastes against performance criteria and to (3) evaluate the performance of the various options with respect to cost, safety, and operability. Additionally, the effort was to (4) identify important uncertainties that need to be resolved by tests and/or analyses in order to complete a performance assessment on the effects of thermal loading. The FY 1993 Thermal Loading Study was conducted from December 1, 1992 to December 30, 1993 and this final report provides the findings of the study. Volume 1 contains the Introduction; Performance requirements; Input and assumptions; Near-field thermal analysis; Far-field thermal analysis; Cost analysis; Other considerations; System analysis; Additional thermal analysis; and Conclusions and recommendations. 71 refs., 54 figs

Crack path in aeronautical titanium alloy under ultrasonic torsion loading

Directory of Open Access Journals (Sweden)

A. Nikitin

2016-01-01

Full Text Available This paper discusses features of fatigue crack initiation and growth in aeronautical VT3-1 titanium alloy under pure torsion loading in gigacycle regime. Two materials: extruded and forged VT3-1 titanium alloys were studied. Torsion fatigue tests were performed up to fatigue life of 109 cycles. The results of the torsion tests were compared with previously obtained results under fully reversed axial loading on the same alloys. It has been shown that independently on production process as surface as well subsurface crack initiation may appear under ultrasonic torsion loading despite the maximum stress amplitude located at the specimen surface. In the case of surface crack initiation, a scenario of crack initiation and growth is similar to HCF regime except an additional possibility for internal crack branching. In the case of subsurface crack, the initiation site is located below the specimen surface (about 200 μm and is not clearly related to any material flaw. Internal crack initiation is produced by shear stress in maximum shear plane and early crack growth is in Mode II. Crack branching is limited in the case of internal crack initiation compared to surface one. A typical ‘fish-eye’ crack can be observed at the torsion fracture surface, but mechanism of crack initiation seems not to be the same than under axial fatigue loading.

The Impact of Roof Pitch and Ceiling Insulation on Cooling Load of Naturally-Ventilated Attics

Directory of Open Access Journals (Sweden)

Linxia Gu

2012-07-01

Full Text Available A 2D unsteady computational fluid dynamics (CFD model is employed to simulate buoyancy-driven turbulent ventilation in attics with different pitch values and ceiling insulation levels under summer conditions. The impacts of roof pitch and ceiling insulation on the cooling load of gable-roof residential buildings are investigated based on the simulation of turbulent air flow and natural convection heat transfer in attic spaces with roof pitches from 3/12 to 18/12 combined with ceiling insulation levels from R-1.2 to R-40. The modeling results show that the air flows in the attics are steady and exhibit a general streamline pattern that is qualitatively insensitive to the investigated variations of roof pitch and ceiling insulation. Furthermore, it is predicted that the ceiling insulation plays a control role on the attic cooling load and that an increase of roof pitch from 3/12 to 8/12 results in a decrease in the cooling load by around 9% in the investigated cases. The results suggest that the increase of roof pitch alone, without changing other design parameters, has limited impact on attics cooling load and airflow pattern. The research results also suggest both the predicted ventilating mass flow rate and attic cooling load can be satisfactorily correlated by simple relationships in terms of appropriately defined Rayleigh and Nusselt numbers.

Sliding friction in the hydrodynamic lubrication regime for a power-law fluid

International Nuclear Information System (INIS)

Warren, P B

2017-01-01

A scaling analysis is undertaken for the load balance in sliding friction in the hydrodynamic lubrication regime, with a particular emphasis on power-law shear-thinning typical of a structured liquid. It is argued that the shear-thinning regime is mechanically unstable if the power-law index n   <  1/2, where n is the exponent that relates the shear stress to the shear rate. Consequently the Stribeck (friction) curve should be discontinuous, with possible hysteresis. Further analysis suggests that normal stress and flow transience (stress overshoot) do not destroy this basic picture, although they may provide stabilising mechanisms at higher shear rates. Extensional viscosity is also expected to be insignificant unless the Trouton ratio is large. A possible application to shear thickening in non-Brownian particulate suspensions is indicated. (paper)

Hydrological regulation drives regime shifts: evidence from paleolimnology and ecosystem modeling of a large shallow Chinese lake.

Science.gov (United States)

Kong, Xiangzhen; He, Qishuang; Yang, Bin; He, Wei; Xu, Fuliu; Janssen, Annette B G; Kuiper, Jan J; van Gerven, Luuk P A; Qin, Ning; Jiang, Yujiao; Liu, Wenxiu; Yang, Chen; Bai, Zelin; Zhang, Min; Kong, Fanxiang; Janse, Jan H; Mooij, Wolf M

2017-02-01

Quantitative evidence of sudden shifts in ecological structure and function in large shallow lakes is rare, even though they provide essential benefits to society. Such 'regime shifts' can be driven by human activities which degrade ecological stability including water level control (WLC) and nutrient loading. Interactions between WLC and nutrient loading on the long-term dynamics of shallow lake ecosystems are, however, often overlooked and largely underestimated, which has hampered the effectiveness of lake management. Here, we focus on a large shallow lake (Lake Chaohu) located in one of the most densely populated areas in China, the lower Yangtze River floodplain, which has undergone both WLC and increasing nutrient loading over the last several decades. We applied a novel methodology that combines consistent evidence from both paleolimnological records and ecosystem modeling to overcome the hurdle of data insufficiency and to unravel the drivers and underlying mechanisms in ecosystem dynamics. We identified the occurrence of two regime shifts: one in 1963, characterized by the abrupt disappearance of submerged vegetation, and another around 1980, with strong algal blooms being observed thereafter. Using model scenarios, we further disentangled the roles of WLC and nutrient loading, showing that the 1963 shift was predominantly triggered by WLC, whereas the shift ca. 1980 was attributed to aggravated nutrient loading. Our analysis also shows interactions between these two stressors. Compared to the dynamics driven by nutrient loading alone, WLC reduced the critical P loading and resulted in earlier disappearance of submerged vegetation and emergence of algal blooms by approximately 26 and 10 years, respectively. Overall, our study reveals the significant role of hydrological regulation in driving shallow lake ecosystem dynamics, and it highlights the urgency of using multi-objective management criteria that includes ecological sustainability perspectives when

Analysis of the Effect of Loading Process on Tribological System Properties

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Radoslav Majdan

2016-01-01

Full Text Available The effect of loading on the properties of selected sliding pair is monitored and analysed in the submitted contribution. The obtained results of dynamic loading were also compared with static loading. The experimental tests were performed using the testing machine Tribotestor M10. Steel 11 600 was selected as a material sample for the shaft as it belongs to commonly used materials in the manufacturing of agricultural components of shaft type or pin type. A full-bronze centrifugally moulded bearing shell from the material CuSn12 was selected as the second element of friction pair. Two oils were selected for lubrication of friction node – the mineral gear oil Madit PP80 and ecological oil Plantohyd 46 S. The selected friction pairs were tested in three loading regimes according to the methodology (two dynamic processes and one static process. 60 tribological tests were performed, i.e. 10 for each type of loading and lubrication. The weight losses of the friction pair elements were part of the tracked and analysed parameters. The polluted oil was examined using the ferrographic analysis to verify the weight losses. The abrasion particles of friction pair and their contribution to oil pollution were also analysed. Following the performed experiments different effects of loading regimes may be concluded, essentially in terms of wear size and the number and size of wear particles as well. The obtained results confirmed that the power spectral density of generated signal is probably an important criterion for assessment in terms of simulated random dynamic load in given experiment. In terms of technical application in loading processes – power spectral density is actually the amount of energy supplied to the process.

Regime change?

International Nuclear Information System (INIS)

Pilat, Joseph F.; Budlong-Sylvester, K.W.

2004-01-01

Following the 1998 nuclear tests in South Asia and later reinforced by revelations about North Korean and Iraqi nuclear activities, there has been growing concern about increasing proliferation dangers. At the same time, the prospects of radiological/nuclear terrorism are seen to be rising - since 9/11, concern over a proliferation/terrorism nexus has never been higher. In the face of this growing danger, there are urgent calls for stronger measures to strengthen the current international nuclear nonproliferation regime, including recommendations to place civilian processing of weapon-useable material under multinational control. As well, there are calls for entirely new tools, including military options. As proliferation and terrorism concerns grow, the regime is under pressure and there is a temptation to consider fundamental changes to the regime. In this context, this paper will address the following: Do we need to change the regime centered on the Treaty on the Nonproliferation of Nuclear Weapons (NPT) and the International Atomic Energy Agency (IAEA)? What improvements could ensure it will be the foundation for the proliferation resistance and physical protection needed if nuclear power grows? What will make it a viable centerpiece of future nonproliferation and counterterrorism approaches?

Arctic circulation regimes.

Science.gov (United States)

Proshutinsky, Andrey; Dukhovskoy, Dmitry; Timmermans, Mary-Louise; Krishfield, Richard; Bamber, Jonathan L

2015-10-13

Between 1948 and 1996, mean annual environmental parameters in the Arctic experienced a well-pronounced decadal variability with two basic circulation patterns: cyclonic and anticyclonic alternating at 5 to 7 year intervals. During cyclonic regimes, low sea-level atmospheric pressure (SLP) dominated over the Arctic Ocean driving sea ice and the upper ocean counterclockwise; the Arctic atmosphere was relatively warm and humid, and freshwater flux from the Arctic Ocean towards the subarctic seas was intensified. By contrast, during anticylonic circulation regimes, high SLP dominated driving sea ice and the upper ocean clockwise. Meanwhile, the atmosphere was cold and dry and the freshwater flux from the Arctic to the subarctic seas was reduced. Since 1997, however, the Arctic system has been under the influence of an anticyclonic circulation regime (17 years) with a set of environmental parameters that are atypical for this regime. We discuss a hypothesis explaining the causes and mechanisms regulating the intensity and duration of Arctic circulation regimes, and speculate how changes in freshwater fluxes from the Arctic Ocean and Greenland impact environmental conditions and interrupt their decadal variability. © 2015 The Authors.

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

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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.

Fabrication of high-uranium-loaded U/sub 3/O/sub 8/-Al developmental fuel plates

Energy Technology Data Exchange (ETDEWEB)

Copeland, G.L.; Martin, M.M.

1980-12-01

A common plate-type fuel for research and test reactors is U/sub 3/O/sub 8/ dispersed in aluminum and clad with an aluminum alloy. There is an impetus to reduce the /sup 235/U enrichment from above 90% to below 20% for these fuels to lessen the risk of diversion of the uranium for nonpeaceful uses. Thus, the uranium content of the fuel plates has to be increased to maintain the performance of the reactors. This paper describes work at ORNL to determine the maximal uranium loading for these fuels that can be fabricated with commercially proven materials and techniques and that can be expected to perform satisfactorily in service.

Completion of UO2 pellets production and fuel rods load for the RA-8 critical facility

International Nuclear Information System (INIS)

Marajofsky, Adolfo; Perez, Lidia E.; Thern, Gerardo G.; Altamirano, Jorge S.; Benitez, Ana M.; Cardenas, Hugo R.; Becerra, Fabian A.; Perez, Aldo E.; Fuente, Mariano de la

1999-01-01

The Advanced Fuels Division produced fuel pellets of 235 U with 1.8% and 3.6% enrichment and Zry-4 cladding loads for the RA-8 reactor at Pilcaniyeu Technological Unit. For economical and availability reasons, the powder acquired was initially UO 2 with 3.4% enrichment in 235 U, therefore the 235 U powder with 1.8% enrichment was produced by mechanical mixture. The production of fuel pellets for both enrichments was carried out by cold pressing and sintering processes in reducing atmosphere. The load of Zry-4 claddings was performed manually. The production stages can be divided into setup, qualification and production. This production allows not only to fulfill satisfactorily the new fuel rods supply for the RA-8 reactor but also to count with a new equipment and skilled personnel as well as to meet quality and assurance control methods for future pilot-scale production and even new fuel elements production. (author)

Modelling the drained response of bucket foundations for offshore wind turbines under general monotonic and cyclic loading

DEFF Research Database (Denmark)

Foglia, Aligi; Gottardi, Guido; Govoni, Laura

2015-01-01

The response of bucket foundations on sand subjected to planar monotonic and cyclic loading is investigated in the paper. Thirteen monotonic and cyclic laboratory tests on a skirted footing model having a 0.3 m diameter and embedment ratio equal to 1 are presented. The loading regime reproduces t...

Proposed Suitable Methods to Detect Transient Regime Switching to Improve Power Quality with Wavelet Transform

Directory of Open Access Journals (Sweden)

Javad Safaee Kuchaksaraee

2016-10-01

Full Text Available The increasing consumption of electrical energy and the use of non-linear loads that create transient regime states in distribution networks is increasing day by day. This is the only reason due to which the analysis of power quality for energy sustainability in power networks has become more important. Transients are often created by energy injection through switching or lightning and make changes in voltage and nominal current. Sudden increase or decrease in voltage or current makes characteristics of the transient regime. This paper shed some lights on the capacitor bank switching, which is one of the main causes for oscillatory transient regime states in the distribution network, using wavelet transform. The identification of the switching current of capacitor bank and the internal fault current of the transformer to prevent the unnecessary outage of the differential relay, it propose a new smart method. The accurate performance of this method is shown by simulation in EMTP and MATLAB (matrix laboratory software.

Prediction of fatigue crack growth behaviour of an α-β titanium alloy in Paris-regime using LCF properties

International Nuclear Information System (INIS)

Varma, V.K.; Saxena, V.K.; Srinivas, M.

1993-01-01

A model has been developed in the recent past to predict fatigue crack growth (FCG) behaviour in the Paris-regime of various steels by employing low cycle fatigue (LCF) properties. The model forms its basis on the assumption that the cyclic damage process immediately ahead of a crack-tip, restricted in a small zone termed as process zone, is identical to those experienced in the LCF loading of a smooth specimen. Within the process zone, fatigue damage has been assumed in terms of product of stress and plastic strain which is analogous to the plastic strain energy density of the smooth specimen under fatigue loading. In this paper the model developed by Kujawski and Ellyin has been used to predict the FCG behaviour of an α-β titanium alloy in the Paris-regime by employing the experimentally obtained LCF properties. The FCG behaviour thus theoretically predicted was compared with the experimentally determined FCG behaviour

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

Alumina strength degradation in the elastic regime

International Nuclear Information System (INIS)

Furnish, Michael D.; Chhabildas, Lalit C.

1998-01-01

Measurements of Kanel et al. [1991] have suggested that deviatoric stresses in glasses shocked to nearly the Hugoniot Elastic Limit (HEL) relax over a time span of microseconds after initial loading. 'Failure' (damage) waves have been inferred on the basis of these measurements using time-resolved manganin normal and transverse stress gauges. Additional experiments on glass by other researchers, using time-resolved gauges, high-speed photography and spall strength determinations have also lead to the same conclusions. In the present study we have conducted transmitted-wave experiments on high-quality Coors AD995 alumina shocked to roughly 5 and 7 GPa (just below or at the HEL). The material is subsequently reshocked to just above its elastic limit. Results of these experiments do show some evidence of strength degradation in the elastic regime

Minimizing Load Effects on NA4 Gear Vibration Diagnostic Parameter

Science.gov (United States)

Dempsey, Paula J.; Zakrajsek, James J.

2001-01-01

NA4 is a vibration diagnostic parameter, developed by researchers at NASA Glenn Research Center, for health monitoring of gears in helicopter transmissions. The NA4 reacts to the onset of gear pitting damage and continues to react to the damage as it spreads. This research also indicates NA4 reacts similarly to load variations. The sensitivity of NA4 to load changes will substantially affect its performance on a helicopter gearbox that experiences continuously changing load throughout its flight regimes. The parameter NA4 has been used to monitor gear fatigue tests at constant load. At constant load, NA4 effectively detects the onset of pitting damage and tracks damage severity. Previous research also shows that NA4 reacts to changes in load applied to the gears in the same way it reacts to the onset of pitting damage. The method used to calculate NA4 was modified to minimize these load effects. The modified NA4 parameter was applied to four sets of experimental data. Results indicate the modified NA4 is no longer sensitive to load changes, but remains sensitive to pitting damage.

Low-temperature operating regime of the tokamak evacuating limiter

International Nuclear Information System (INIS)

Tokar', M.Z.

1987-01-01

The conditions for realizing the regime of strong recycling of a cold dense plasma of an evacuating limiter were determined based on a previously proposed model for describing the limiter layer of a tokamak. The scaling for the dependence of the gas pressure in the evacuation system on the average plasma density in the limiter layer was found, and agreed quantitatively with the results of measurements on the Alcator and ISX-B tokamaks. For the tokamak reactor of the INTOR scale the calculations show that the low-temperature operating regime of the evacuating limiter can be realized with a quite low pumping rate. It has the advantages of reduced erosion of the limiter and small fluxes of impurities into the working volume of the reactor. In addition, the relative concentration of the helium ash in the limiter layer does not exceed 2-3%, but the density of the main plasma is comparable to the proposed average density in the reactor. The concept of a stochastic limiter is of interest for lowering the plasma density in the limiter layer and lowering the thermal loads on the limiter

Ensuring dynamic load smoothness in problem of controlling Atomic Electric Power Stations exclusive mechanisms

International Nuclear Information System (INIS)

Shumilov, V.F.

2003-01-01

New methods for the investigation of automatic systems based on the inverse tasks of dynamics with the use of rational, trigonometric and polynomial spline functions are discussed. By means of SH function the technological regimes: start-up, steadiness, racing, braking, reverse, stop were determined. Procedure for the provision of dynamic load smoothness is suggested, and example of control over the transport systems for fuel load is considered [ru

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

OpenAIRE

Krasner, Stephen D.

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 ...

A Hybrid Forecasting Model Based on Empirical Mode Decomposition and the Cuckoo Search Algorithm: A Case Study for Power Load

Directory of Open Access Journals (Sweden)

Jiani Heng

2016-01-01

Full Text Available Power load forecasting always plays a considerable role in the management of a power system, as accurate forecasting provides a guarantee for the daily operation of the power grid. It has been widely demonstrated in forecasting that hybrid forecasts can improve forecast performance compared with individual forecasts. In this paper, a hybrid forecasting approach, comprising Empirical Mode Decomposition, CSA (Cuckoo Search Algorithm, and WNN (Wavelet Neural Network, is proposed. This approach constructs a more valid forecasting structure and more stable results than traditional ANN (Artificial Neural Network models such as BPNN (Back Propagation Neural Network, GABPNN (Back Propagation Neural Network Optimized by Genetic Algorithm, and WNN. To evaluate the forecasting performance of the proposed model, a half-hourly power load in New South Wales of Australia is used as a case study in this paper. The experimental results demonstrate that the proposed hybrid model is not only simple but also able to satisfactorily approximate the actual power load and can be an effective tool in planning and dispatch for smart grids.

Sensitivity to spatial and temporal scale and fire regime inputs in deriving fire regime condition class

Science.gov (United States)

Linda Tedrow; Wendel J. Hann

2015-01-01

The Fire Regime Condition Class (FRCC) is a composite departure measure that compares current vegetation structure and fire regime to historical reference conditions. FRCC is computed as the average of: 1) Vegetation departure (VDEP) and 2) Regime (frequency and severity) departure (RDEP). In addition to the FRCC rating, the Vegetation Condition Class (VCC) and Regime...

Polyethyleneimine-loaded bimodal porous silica as low-cost and high-capacity sorbent for CO{sub 2} capture

Energy Technology Data Exchange (ETDEWEB)

Witoon, Thongthai, E-mail: fengttwi@ku.ac.th [National Center of Excellence for Petroleum, Petrochemicals and Advance Material, Department of Chemical Engineering, Faculty of Engineering, Kasetsart University, Bangkok 10900 (Thailand); Center for Advanced Studies in Nanotechnology and Its Applications in Chemical Food and Agricultural Industries, Kasetsart University, Bangkok 10900 (Thailand)

2012-11-15

In this work, bimodal (meso-macro) porous silicas with different mesopore diameters synthesized by using rice husk ash as a low-cost silica source and chitosan as a natural template were used as a polyethyleneimine (PEI) support for CO{sub 2} capture. Unimodal porous silica supports with equivalent mesopore diameters to bimodal porous silica supports have been prepared for purpose of comparison. Effects of different PEI contents (10, 20, 30, 40 and 50 wt%) on CO{sub 2} sorption capacity have been systematically investigated. The porous silica supports and the PEI-loaded porous silica supports were characterized by N{sub 2}-sorption analysis, scanning electron microscopy, Fourier transform infrared spectroscopy and thermal gravimetric analysis. CO{sub 2} sorption measurements of all PEI-loaded porous silica supports were performed at different adsorption temperatures (60, 75, 85, 90, 95 and 105 Degree-Sign C). At low PEI contents (10-20 wt%), the CO{sub 2} sorption of all adsorbents was found to decrease as a function of adsorption temperature, which was a characteristic of a thermodynamically-controlled regime. A transition from the thermodynamically-controlled regime to a kinetically-controlled regime was found when the PEI content was increased up to 30 wt% for PEI-loaded unimodal porous silicas and 40 wt% for PEI-loaded bimodal porous silicas. At high PEI contents (40-50 wt%), the CO{sub 2} capturing efficiency of the PEI-loaded bimodal porous silicas was found to be considerably greater than that of the PEI-loaded unimodal porous silicas, indicating that most of the amine groups of PEI molecules loaded on the unimodal porous silica supports was useless, and thus the appeared macroporosity of the bimodal porous silica supports could provide a higher effective amine density to adsorb CO{sub 2}. Highlights: Black-Right-Pointing-Pointer PEI-impregnated bimodal porous silica as low-cost sorbent for CO{sub 2} capture. Black-Right-Pointing-Pointer Macropores enhances

Stability Estimates for a Twisted Rod Under Terminal Loads: A Three-dimensional Study

KAUST Repository

Majumdar, Apala

2012-03-01

The stability of an inextensible unshearable elastic rod with quadratic strain energy density subject to end loads is considered. We study the second variation of the corresponding rod-energy, making a distinction between in-plane and out-of-plane perturbations and isotropic and anisotropic cross-sections, respectively. In all cases, we demonstrate that the naturally straight state is a local energy minimizer in parameter regimes specified by material constants. These stability results are also accompanied by instability results in parameter regimes defined in terms of material constants. © 2012 Springer Science+Business Media B.V.

Stability Estimates for a Twisted Rod Under Terminal Loads: A Three-dimensional Study

KAUST Repository

Majumdar, Apala; Prior, Christopher; Goriely, Alain

2012-01-01

The stability of an inextensible unshearable elastic rod with quadratic strain energy density subject to end loads is considered. We study the second variation of the corresponding rod-energy, making a distinction between in-plane and out-of-plane perturbations and isotropic and anisotropic cross-sections, respectively. In all cases, we demonstrate that the naturally straight state is a local energy minimizer in parameter regimes specified by material constants. These stability results are also accompanied by instability results in parameter regimes defined in terms of material constants. © 2012 Springer Science+Business Media B.V.

Physics Based Model for Cryogenic Chilldown and Loading. Part I: Algorithm

Science.gov (United States)

Luchinsky, Dmitry G.; Smelyanskiy, Vadim N.; Brown, Barbara

2014-01-01

We report the progress in the development of the physics based model for cryogenic chilldown and loading. The chilldown and loading is model as fully separated non-equilibrium two-phase flow of cryogenic fluid thermally coupled to the pipe walls. The solution follow closely nearly-implicit and semi-implicit algorithms developed for autonomous control of thermal-hydraulic systems developed by Idaho National Laboratory. A special attention is paid to the treatment of instabilities. The model is applied to the analysis of chilldown in rapid loading system developed at NASA-Kennedy Space Center. The nontrivial characteristic feature of the analyzed chilldown regime is its active control by dump valves. The numerical predictions are in reasonable agreement with the experimental time traces. The obtained results pave the way to the development of autonomous loading operation on the ground and space.

Strengthening the nuclear non-proliferation regime

International Nuclear Information System (INIS)

Carlson, J.

2003-01-01

Although the nuclear non-proliferation regime has enjoyed considerable success, today the regime has never been under greater threat. Three states have challenged the objectives of the NPT, and there is a technology challenge - the spread of centrifuge enrichment technology and know-how. A major issue confronting the international community is, how to deal with a determined proliferator? Despite this gloomy scenario, however, the non-proliferation regime has considerable strengths - many of which can be developed further. The regime comprises complex interacting and mutually reinforcing elements. At its centre is the NPT - with IAEA safeguards as the Treaty's verification mechanism. Important complementary elements include: restraint in the supply and the acquisition of sensitive technologies; multilateral regimes such as the CTBT and proposed FMCT; various regional and bilateral regimes; the range of security and arms control arrangements outside the nuclear area (including other WMD regimes); and the development of proliferation-resistant technologies. Especially important are political incentives and sanctions in support of non-proliferation objectives. This paper outlines some of the key issues facing the non-proliferation regime

Autonomia e relevância dos regimes The autonomy and relevance of regimes

Directory of Open Access Journals (Sweden)

Gustavo Seignemartin de Carvalho

2005-12-01

Full Text Available Teorias institucionalistas na disciplina de relações internacionais usualmente definem regimes como um conjunto de normas e regras formais ou informais que permitem a convergência de expectativas ou a padronização do comportamento de seus participantes em uma determinada área de interesses com o objetivo de resolver problemas de coordenação que tenderiam a resultados não pareto-eficientes. Como estas definições baseadas meramente na "eficiência" dos regimes não parecem suficientes para explicar sua efetividade, o presente artigo propõe uma definição diferente para regimes: a de arranjos políticos que permitem a redistribuição dos ganhos da cooperação pelos participantes em uma determinada área de interesses em um contexto de interdependência. Regimes possuiriam efetividade pela sua autonomia e relevância, ou seja, por possuírem existência objetiva autônoma da de seus participantes e por influenciarem seu comportamento e expectativas de maneiras que não podem ser reduzidas à ação individual de nenhum deles. O artigo inicia-se com uma breve discussão sobre as dificuldades terminológicas associadas ao estudo de regimes e a definição dos conceitos de autonomia e relevância. Em seguida, classifica os diversos autores participantes do debate em duas perspectivas distintas, uma que nega (não-autonomistas e outra que atribui (autonomistas aos regimes autonomia e relevância, e faz uma breve análise dos autores e tradições mais significativos para o debate, aprofundando-se nos autonomistas e nos argumentos que reforçam a hipótese aqui apresentada. Ao final, o artigo propõe uma decomposição analítica dos regimes nos quatro elementos principais que lhes propiciam autonomia e relevância: normatividade, atores, especificidade da área de interesses e interdependência complexa com o contexto.Regimes are defined by institutionalist theories in the discipline of International Relations as formal or informal sets

Static converters power supply: transient regimes; Alimentation par convertisseurs statiques: regimes transitoires

Energy Technology Data Exchange (ETDEWEB)

Pasqualini, G. [Ecole Superieure d`Electricite (France)

1997-08-01

Direct current motors, asynchronous and variable speed synchronous motors are generally supplied with static converters. Speed variation is obtained by voltage variation in DC motors and by frequency variation in AC motors. In these conditions, these motors are running continuously in transient regimes: the DC motors current is not direct and the AC motors current is not sinusoidal. This situation leads to pulsing couples in the shaft line and to an increase of Joule effect losses. The aim of this paper is to present the methods of study of the electric motors functioning using the shape of the power voltages given by converters and mathematical models of these machines. The synchronous machines are rapidly described while the asynchronous machines are studied using Ku`s transformation instead of Park`s transformation for simplification. For each type of machine, calculation methods allow to determine their current, additional losses and couple characteristics. The transient regimes considered are those remaining when the motor is running at a constant speed and defined regime (supply voltages are periodical functions of time). These transient regimes are identically reproducing with a frequency which is a multiple of the converters supply frequency. Transient regimes due to functioning changes of the motor, such as resisting couple or power supply frequency variations, are not considered in this study. (J.S.) 9 refs.

Thermodynamic energy and exergy analysis of three different engine combustion regimes

International Nuclear Information System (INIS)

Li, Yaopeng; Jia, Ming; Chang, Yachao; Kokjohn, Sage L.; Reitz, Rolf D.

2016-01-01

Highlights: • Energy and exergy distributions of three different combustion regimes are studied. • CDC demonstrates the highest utilization efficiency of heat transfer and exhaust. • HCCI achieves the highest energy and exergy efficiencies over CDC and RCCI. • HCCI and RCCI demonstrate lower exergy destruction than CDC. • Combustion temperature, rate, duration and regime affect exergy destruction. - Abstract: Multi-dimensional models were coupled with a detailed chemical mechanism to investigate the energy and exergy distributions of three different combustion regimes in internal combustion engines. The results indicate that the 50% heat release point (CA50) considerably affects fuel efficiency and ringing intensity (RI), in which RI is used to quantify the knock level. Moreover, the burn duration from the 10% heat release point (CA10) to CA50 dominates RI, and the position of 90% heat release point (CA90) affects fuel efficiency. The heat transfer losses of conventional diesel combustion (CDC) strongly depend on the local temperature gradient, while it is closely related to the heat transfer area for homogeneous charge compression ignition (HCCI) and reactivity controlled compression ignition (RCCI). Among the three combustion regimes, CDC has the largest utilization efficiency for heat transfer and exhaust energy due to its higher temperature in the heat transfer layer and higher exhaust pressure and temperature. The utilization efficiency of heat transfer and exhaust in RCCI is less affected by the variation of CA50 compared to those in CDC and HCCI. Exergy destruction is closely related to the homogeneity of in-cylinder temperature and equivalence ratio during combustion process, the combustion temperature, the chemical reaction rate, and the combustion duration. Under the combined effect, HCCI and RCCI demonstrate lower exergy destruction than CDC at the same load. Overall, the variations of the exergy distribution for the three combustion regimes

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 direc...

Damage accumulation of bovine bone under variable amplitude loads

Directory of Open Access Journals (Sweden)

Abbey M. Campbell

2016-12-01

Full Text Available Stress fractures, a painful injury, are caused by excessive fatigue in bone. This study on damage accumulation in bone sought to determine if the Palmgren-Miner rule (PMR, a well-known linear damage accumulation hypothesis, is predictive of fatigue failure in bone. An electromagnetic shaker apparatus was constructed to conduct cyclic and variable amplitude tests on bovine bone specimens. Three distinct damage regimes were observed following fracture. Fractures due to a low cyclic amplitude loading appeared ductile (4000 μϵ, brittle due to high cyclic amplitude loading (>9000 μϵ, and a combination of ductile and brittle from mid-range cyclic amplitude loading (6500 –6750 μϵ. Brittle and ductile fracture mechanisms were isolated and mixed, in a controlled way, into variable amplitude loading tests. PMR predictions of cycles to failure consistently over-predicted fatigue life when mixing isolated fracture mechanisms. However, PMR was not proven ineffective when used with a single damage mechanism. Keywords: Bone fatigue, Bone fracture, Health system monitoring, Failure prediction

Predicting climate-driven regime shifts versus rebound potential in coral reefs.

Science.gov (United States)

Graham, Nicholas A J; Jennings, Simon; MacNeil, M Aaron; Mouillot, David; Wilson, Shaun K

2015-02-05

Climate-induced coral bleaching is among the greatest current threats to coral reefs, causing widespread loss of live coral cover. Conditions under which reefs bounce back from bleaching events or shift from coral to algal dominance are unknown, making it difficult to predict and plan for differing reef responses under climate change. Here we document and predict long-term reef responses to a major climate-induced coral bleaching event that caused unprecedented region-wide mortality of Indo-Pacific corals. Following loss of >90% live coral cover, 12 of 21 reefs recovered towards pre-disturbance live coral states, while nine reefs underwent regime shifts to fleshy macroalgae. Functional diversity of associated reef fish communities shifted substantially following bleaching, returning towards pre-disturbance structure on recovering reefs, while becoming progressively altered on regime shifting reefs. We identified threshold values for a range of factors that accurately predicted ecosystem response to the bleaching event. Recovery was favoured when reefs were structurally complex and in deeper water, when density of juvenile corals and herbivorous fishes was relatively high and when nutrient loads were low. Whether reefs were inside no-take marine reserves had no bearing on ecosystem trajectory. Although conditions governing regime shift or recovery dynamics were diverse, pre-disturbance quantification of simple factors such as structural complexity and water depth accurately predicted ecosystem trajectories. These findings foreshadow the likely divergent but predictable outcomes for reef ecosystems in response to climate change, thus guiding improved management and adaptation.

A Coupled Model for Simulating Future Wildfire Regimes in the Western U.S.

Science.gov (United States)

Bart, R. R.; Kennedy, M. C.; Tague, C.; Hanan, E. J.

2017-12-01

Higher temperatures and larger fuel loads in the western U.S. have increased the size and intensity of wildfires over the past decades. However, it is unclear if this trend will continue over the long-term since increased wildfire activity has the countering effect of reducing landscape fuel loads, while higher temperatures alter the rate of vegetation recovery following fire. In this study, we introduce a coupled ecohydrologic-fire model for investigating how changes in vegetation, forest management, climate, and hydrology may affect future fire regimes. The spatially-distributed ecohydrologic model, RHESSys, simulates hydrologic, carbon and nutrient fluxes at watershed scales; the fire-spread model, WMFire, stochastically propagates fire on a landscape based on conditions in the ecohydrologic model. We use the coupled model to replicate fire return intervals in multiple ecoregions within the western U.S., including the southern Sierra Nevada and southern California. We also examine the sensitivity of fire return intervals to various model processes, including litter production, fire severity, and post-fire vegetation recovery rates. Results indicate that the coupled model is able to replicate expected fire return intervals in the selected locations. Fire return intervals were highly sensitive to the rate of vegetation growth, with longer fire return intervals associated with slower growing vegetation. Application of the model is expected to aid in our understanding of how fuel treatments, climate change and droughts may affect future fire regimes.

International Food Regime

Directory of Open Access Journals (Sweden)

A. V. Malov

2018-01-01

Full Text Available The review article reveals the content of the concept of Food Regime, which is little-known in the Russian academic reference. The author monitored and codified the semantic dynamic of the terminological unit from its original interpretations to modern formulations based on the retrospective analysis. The rehabilitation of the academic merits of D. Puchala and R. Hopkins — authors who used the concept Food Regime for a few years before its universally recognized origin and official scientific debut, was accomplished with help of historical and comparative methods. The author implemented the method of ascension from the abstract to the concrete to demonstrating the classification of Food Regimes compiled on the basis of geopolitical interests in the sphere of international production, consumption, and distribution of foodstuffs. The characteristic features of historically formed Food Regime were described in the chronological order, as well as modern tendencies possessing reformist potential were identified. In particular, it has been established that the idea of Food Sovereignty (which is an alternative to the modern Corporate Food Regime is the subject for acute academic disputes. The discussion between P. McMichael P. and H. Bernstein devoted to the “peasant question” — mobilization frame of the Food Sovereignty strategy was analyzed using the secondary data processing method. Due to the critical analysis, the author comes to the conclusion that it is necessary to follow the principles of the Food Sovereignty strategy to prevent the catastrophic prospects associated with ecosystem degradation, accelerated erosion of soils, the complete disappearance of biodiversity and corporate autoc racy successfully. The author is convinced that the idea of Food Sovereignty can ward off energetic liberalization of nature, intensive privatization of life and rapid monetization of unconditioned human reflexes.

Ecohydrological modelling of water discharge and nitrate loads in a mesoscale lowland catchment, Germany

Directory of Open Access Journals (Sweden)

N. Fohrer

2009-08-01

Full Text Available The aims of this study are to identify the capacities of applying an ecohydrological model for simulating flow and to assess the impact of point and non-point source pollution on nitrate loads in a complex lowland catchment, which has special hydrological characteristics in comparison with those of other catchments. The study area Kielstau catchment has a size of approximately 50 km² and is located in the North German lowlands. The water quality is not only influenced by the predominating agricultural land use in the catchment as cropland and pasture, but also by six municipal wastewater treatment plants.

Ecohydrological models like the SWAT model (Soil and Water Assessment Tool are useful tools for simulating nutrient loads in river catchments. Diffuse entries from the agriculture resulting from fertilizers as well as punctual entries from the wastewater treatment plants are implemented in the model set-up.

The results of this study show good agreement between simulated and measured daily discharges with a Nash-Sutcliffe efficiency and a correlation coefficient of 0.76 and 0.88 for the calibration period (November 1998 to October 2004; 0.75 and 0.92 for the validation period (November 2004 to December 2007. The model efficiency for daily nitrate loads is 0.64 and 0.5 for the calibration period (June 2005 to May 2007 and the validation period (June 2007 to December 2007, respectively. The study revealed that SWAT performed satisfactorily in simulating daily flow and nitrate loads at the lowland catchment in Northern Germany.

Vortex rope patterns at different load of hydro turbine model

Directory of Open Access Journals (Sweden)

Skripkin Sergey

2017-01-01

Full Text Available Operation of hydraulic turbines beyond optimal conditions leads to formation of precessing vortex core in a draft tube that generates powerful pressure pulsations in a hydraulic system. In case of resonance it leads to stability decreasing of hydraulic unit and electrical grid on the whole. In present work, such regimes are explored in a conical part of simplified turbine model. Studies are performed at constant flowrate Q = 70 m3/h and varying the runner rotational speed to explore different loads of the hydroturbine unit. The experiments involve pressure measurements, high speed-visualization and velocity measurements by means of laser Doppler anemometer technique. Interesting finding is related with abrupt increasing precession frequency at low swirl parameter of flow near optimal regime.

Antecedents of Teachers Fostering Effort within Two Different Management Regimes: An Assessment-Based Accountability Regime and Regime without External Pressure on Results

Science.gov (United States)

Christophersen, Knut-Andreas; Elstad, Eyvind; Turmo, Are

2012-01-01

This article focuses on the comparison of organizational antecedents of teachers' fostering of students' effort in two quite different accountability regimes: one management regime with an external-accountability system and one with no external accountability devices. The methodology involves cross-sectional surveys from two different management…

Visões de um objeto incômodo: o regime militar brasileiro An undesirable subject: the Brazilian military regime

Directory of Open Access Journals (Sweden)

Angelo Del Vecchio

2007-05-01

Full Text Available O presente artigo visa a qualificação do regime político vigente no Brasil entre 1964-1985. Para tanto, desenvolvo o resgate do conceito de ditadura, especialmente a partir da obra de Carl Schimitt, e busco aferir a sua adequação à análise do período militar. Palavras-chave: Estado. Regime político. Ditadura. Regime militar. The present article tries to qualify the political regime in Brazil from 1964 to 1985, using the concept of dictatorship mainly developed by Carl Schimitt in his writings and tries to adequate this concept to the Brazilian military regime. Keywords: State. Political regime. Dictatorship. Military regime.

THE INFLUENCED FLOW REGIMES

Directory of Open Access Journals (Sweden)

Gavril PANDI

2011-03-01

Full Text Available The influenced flow regimes. The presence and activities ofhumanity influences the uniform environmental system, and in this context, therivers water resources. In concordance with this, the natural runoff regime suffersbigger and deeper changes. The nature of these changes depending on the type anddegree of water uses. The multitude of the use cause different types of influence,whit different quantitative aspects. In the same time, the influences havequalitative connotations, too, regarding to the modifications of the yearly watervolume runoff. So the natural runoff regime is modified. After analyzing thedistribution laws of the monthly runoff, there have been differenced four types ofinfluenced runoff regimes. In the excess type the influenced runoff is bigger thanthe natural, continuously in the whole year. The deficient type is characterized byinverse rapports like the first type, in the whole year. In the sinusoidal type, theinfluenced runoff is smaller than the natural in the period when the water isretained in the lake reservoirs, and in the depletion period the situation inverts. Atthe irregular type the ratio between influenced and natural runoff is changeable ina random meaner monthly. The recognition of the influenced regime and the gradeof influence are necessary in the evaluation and analysis of the usable hydrologicalriver resources, in the flood defence activities, in the complex scheme of thehydrographic basins, in the environment design and so on.

Research and Application of Hybrid Forecasting Model Based on an Optimal Feature Selection System—A Case Study on Electrical Load Forecasting

Directory of Open Access Journals (Sweden)

Yunxuan Dong

2017-04-01

Full Text Available The process of modernizing smart grid prominently increases the complexity and uncertainty in scheduling and operation of power systems, and, in order to develop a more reliable, flexible, efficient and resilient grid, electrical load forecasting is not only an important key but is still a difficult and challenging task as well. In this paper, a short-term electrical load forecasting model, with a unit for feature learning named Pyramid System and recurrent neural networks, has been developed and it can effectively promote the stability and security of the power grid. Nine types of methods for feature learning are compared in this work to select the best one for learning target, and two criteria have been employed to evaluate the accuracy of the prediction intervals. Furthermore, an electrical load forecasting method based on recurrent neural networks has been formed to achieve the relational diagram of historical data, and, to be specific, the proposed techniques are applied to electrical load forecasting using the data collected from New South Wales, Australia. The simulation results show that the proposed hybrid models can not only satisfactorily approximate the actual value but they are also able to be effective tools in the planning of smart grids.

Flux scaling: Ultimate regime

Indian Academy of Sciences (India)

First page Back Continue Last page Overview Graphics. Flux scaling: Ultimate regime. With the Nusselt number and the mixing length scales, we get the Nusselt number and Reynolds number (w'd/ν) scalings: and or. and. scaling expected to occur at extremely high Ra Rayleigh-Benard convection. Get the ultimate regime ...

Thermal ice loads on dams and ancillary structures: A brief review

International Nuclear Information System (INIS)

Gerard, R.

1989-01-01

A major consideration in the design of low to medium head dams in cold regions is the thrust exerted by thermal expansion of a solid ice sheet. Such loads are also of concern in the design of gates, intakes and other ancillary structures. Such loads can be greater than 300-400 kilo Newtons per meter, and are of greatest concern when ice is unshielded by snow from temperature fluctuations. Details are presented of calculation of thermal ice loads, and field measurements of thermal ice forces. Past structural failures, field and laboratory investigations, and analyses, all confirm that thermal ice loads on wide structures such as dams, and isolated structures such as bridge piers and water intakes, can be much more significant than is suggested by the loads currently specified in various North American design guidelines for hydraulic structures. While some guidelines for thermal ice loads are excessively conservative, particularly for protected situations such as gates set between piers, in other more common situations they are dangerously low. Three useful approaches that would yield information for improving thermal ice load specification are: hindcast upper bounds on thermal ice loads by assessing the ice regime and load bearing capacity of existing structures; field measurement of thermal ice loads and stresses using modern instrumentation; and measurement and analysis of the formation and movement of lake and reservoir ice covers. 23 refs., 4 figs

Abrupt climate-independent fire regime changes

Science.gov (United States)

Pausas, Juli G.; Keeley, Jon E.

2014-01-01

Wildfires have played a determining role in distribution, composition and structure of many ecosystems worldwide and climatic changes are widely considered to be a major driver of future fire regime changes. However, forecasting future climatic change induced impacts on fire regimes will require a clearer understanding of other drivers of abrupt fire regime changes. Here, we focus on evidence from different environmental and temporal settings of fire regimes changes that are not directly attributed to climatic changes. We review key cases of these abrupt fire regime changes at different spatial and temporal scales, including those directly driven (i) by fauna, (ii) by invasive plant species, and (iii) by socio-economic and policy changes. All these drivers might generate non-linear effects of landscape changes in fuel structure; that is, they generate fuel changes that can cross thresholds of landscape continuity, and thus drastically change fire activity. Although climatic changes might contribute to some of these changes, there are also many instances that are not primarily linked to climatic shifts. Understanding the mechanism driving fire regime changes should contribute to our ability to better assess future fire regimes.

Low cycle fatigue strength of austenitic stainless steel under large strain regime

International Nuclear Information System (INIS)

Sakai, Michiya; Saito, Kiyoshi; Matsuura, Shinichi

1998-01-01

In order to establish realistic seismic safety of nuclear power plants, it is necessary to clarify the failure mode of each components and prepare a damage evaluation method. The authors have proposed the damage evaluation method based on the fully numerical approach to evaluate the low cycle fatigue (LCF) failure under seismic loadings. This method has been validated by comparison with the dynamic failure tests of thin elbows which should be the one of the important components of the FBR primary piping system. However, since there exists limited LCF data, fatigue lives under large strain regime have been extrapolated by available fatigue data. In this study, LCF tests have been conducted over a large strain range from 2% to 10% on austenitic stainless steel SUS304. From the results, the regressive LCF curve has been proposed to modify the Wada's best-fit LCF curve under large strain regime. The usage factors calculated by author's numerical approach using proposed LCF curve have been improved to correct the underestimation of the fatigue damage. (author)

Superelastic load cycling of Gum Metal

International Nuclear Information System (INIS)

Vorontsov, V.A.; Jones, N.G.; Rahman, K.M.; Dye, D.

2015-01-01

The superelastic beta titanium alloy, Gum Metal, has been found to accumulate plastic strain during tensile load cycling in the superelastic regime. This is evident from the positive drift of the macroscopic stress vs. strain hysteresis curve parallel to the strain axis and the change in its geometry subsequent to every load–unload cycle. In addition, there is a progressive reduction in the hysteresis loop width and in the stress at which the superelastic transition occurs. In situ synchrotron X-ray diffraction has shown that the lattice strain exhibited the same behaviour as that observed in macroscopic measurements and identified further evidence of plastic strain accumulation. The mechanisms responsible for the observed behaviour have been evaluated using transmission electron microscopy, which revealed a range of different defects that formed during load cycling. The formation of these defects is consistent with the classical mathematical theory for the bcc to orthorhombic martensitic transformation. It is the accumulation of these defects over time that alters its superelastic behaviour

The trade regime and the climate regime. Institutional evolution and adaptation

International Nuclear Information System (INIS)

Brewer, Thomas L.

2003-01-01

This article addresses concerns that the multilateral trade regime centered in the WTO and the emerging climate regime may conflict in ways that could be damaging to either or both. The article discusses the institutional and diplomatic context of these concerns, and it identifies the kinds of issues that are in question. The analysis suggests that there are opportunities for win-win outcomes in the interactions of the two regimes, for instance in the possibility of reducing fossil fuel subsidies. However, there are also problematic areas where they intersect. A core issue-and as yet an unresolved one-is whether and how emission credit trading and other activities envisioned by the Kyoto Protocol would be subject to WTO rules. The resolution of this issue will affect many other issues as well. Additional specific issues about the interactions of particular provisions in WTO agreements and the Kyoto Protocol are analyzed in a subsequent companion article in Climate Policy

Changing Feeding Regimes To Demonstrate Flexible Biogas Production: Effects on Process Performance, Microbial Community Structure, and Methanogenesis Pathways

Science.gov (United States)

Mulat, Daniel Girma; Jacobi, H. Fabian; Feilberg, Anders; Adamsen, Anders Peter S.; Richnow, Hans-Hermann

2015-01-01

Flexible biogas production that adapts biogas output to energy demand can be regulated by changing feeding regimes. In this study, the effect of changes in feeding intervals on process performance, microbial community structure, and the methanogenesis pathway was investigated. Three different feeding regimes (once daily, every second day, and every 2 h) at the same organic loading rate were studied in continuously stirred tank reactors treating distiller's dried grains with solubles. A larger amount of biogas was produced after feeding in the reactors fed less frequently (once per day and every second day), whereas the amount remained constant in the reactor fed more frequently (every 2 h), indicating the suitability of the former for the flexible production of biogas. Compared to the conventional more frequent feeding regimes, a methane yield that was up to 14% higher and an improved stability of the process against organic overloading were achieved by employing less frequent feeding regimes. The community structures of bacteria and methanogenic archaea were monitored by terminal restriction fragment length polymorphism (T-RFLP) analysis of 16S rRNA and mcrA genes, respectively. The results showed that the composition of the bacterial community varied under the different feeding regimes, and the observed T-RFLP patterns were best explained by the differences in the total ammonia nitrogen concentrations, H2 levels, and pH values. However, the methanogenic community remained stable under all feeding regimes, with the dominance of the Methanosarcina genus followed by that of the Methanobacterium genus. Stable isotope analysis showed that the average amount of methane produced during each feeding event by acetoclastic and hydrogenotrophic methanogenesis was not influenced by the three different feeding regimes. PMID:26497462

Synergies between nonproliferation regimes: A pragmatic approach

International Nuclear Information System (INIS)

Findlay, Trevor; Meier, Oliver

2001-01-01

Full text: With the recent progress in establishing international nonproliferation regimes, the question of synergies between different verification and monitoring regimes is becoming more acute. Three multilateral and universal nonproliferation organisations covering safeguards on civil nuclear materials, nuclear testing, and chemical weapons are up and running. A regime on biological weapons is under negotiation. Several regional organisations concerned with monitoring nonproliferation commitments in the nuclear field are in place; others are being established. Past discussions on synergies between these regimes have suffered from being too far-reaching. These discussions often have not reflected adequately the political difficulties of cooperation between regimes with different membership, scope and institutional set-up. This paper takes a pragmatic look at exploiting synergies and identifies some potential and real overlaps in the work between different verification regimes. It argues for a bottom-up approach and identifies building blocks for collaboration between verification regimes. By realising such, more limited potential for cooperation, the ground could be prepared for exploiting other synergies between these regimes. (author)

De Facto Regimes in International Law

Directory of Open Access Journals (Sweden)

Jonte van Essen

2012-02-01

Full Text Available The ambiguous position of de facto regimes in international law has long been the subject of scholarly debate and a source of political conflict. An assessment of the current standing of these regimes in international law and the consequences of actions by international actors on this status has, however, been long overdue. The manner in which de facto regimes are regarded internationally has serious consequences for the individuals under the influence of this legal grey area. Therefore, the study into this problem and possible solutions is of great significance. The 2011 developments in Northern Africa underline the need of contemporary research into this area. This essay aims to clarify the position of de facto regimes in international law and the influence on their status by actions of international actors. The author first argues that de facto regimes have rights and obligations under international law, which provide them with (some form of international legal personality. He then pleads for a reconsideration of the contemporary legal treatment of these regimes. The author argues against the current system of government recognition and proposes a system that better addresses the needs of both de facto regimes and the international community. 

Multiple growth regimes: Insights from unified growth theory

OpenAIRE

Galor, Oded

2007-01-01

Unified Growth Theory uncovers the forces that contributed to the existence of multiple growth regimes and the emergence of convergence clubs. It suggests that differential timing of take-offs from stagnation to growth segmented economies into three fundamental regimes: slow growing economies in a Malthusian regime, fast growing countries in a sustained growth regime, and economies in the transition between these regimes. In contrast to existing research that links regime switching thresholds...

Dependence of offshore wind turbine fatigue loads on atmospheric stratification

International Nuclear Information System (INIS)

Hansen, K S; Larsen, G C; Ott, S

2014-01-01

The stratification of the atmospheric boundary layer (ABL) is classified in terms of the M-O length and subsequently used to determine the relationship between ABL stability and the fatigue loads of a wind turbine located inside an offshore wind farm. Recorded equivalent fatigue loads, representing blade-bending and tower bottom bending, are combined with the operational statistics from the instrumented wind turbine as well as with meteorological statistics defining the inflow conditions. Only a part of all possible inflow conditions are covered through the approximately 8200 hours of combined measurements. The fatigue polar has been determined for an (almost) complete 360° inflow sector for both load sensors, representing mean wind speeds below and above rated wind speed, respectively, with the inflow conditions classified into three different stratification regimes: unstable, neutral and stable conditions. In general, impact of ABL stratification is clearly seen on wake affected inflow cases for both blade and tower fatigue loads. However, the character of this dependence varies significantly with the type of inflow conditions – e.g. single wake inflow or multiple wake inflow

Generating Quasi-Isentropic Loading to Targets via Flier-Plate Technique

International Nuclear Information System (INIS)

Shen Qiang; Su Xiaopeng; Wang Chuanbin; Zhang Lianmeng; Hua Jinsong; Tan Hua

2008-01-01

The quasi-isentropic loading technique allows investigation of material properties in a high-pressure, low-temperature regime that is inaccessible by conventional shock wave experiments. In the present paper, the layered flier-plate and graded density flier-plate, which have different variations in the density gradient along the thickness direction but the same density range, were designed and fabricated. Impact experiments were then performed on a two-stage light gas gun. VISAR-measured results show that wave profiles with an initial jump followed by a slowly-rising front to the peak velocity amplitude are generated by using both types of the flier-plate, indicating that quasi-isentropic loading to the targets have been successfully realized. The process of quasi-isentropic loading can be seen as the successive overlap of a series of small shock waves by the transient layers in the flier-plate. It is obvious that the graded density flier-plate creates a more smoothly rising front, and the compression effect must be closer to isentropic loading than that of the layered flier-plate with the same density range

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.)

Accommodating human values in the climate regime

Directory of Open Access Journals (Sweden)

Rosalind Cook

2008-12-01

Full Text Available 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 established precisely to implement human values. This article ex-plains the problems of climate change in terms of human values and argues that some proce-dures from the human rights regime offer possibilities for improvement. It is submitted that through the inclusion of human rights instruments, such as individual communication, pro-gressive realisation and authoritative interpretation, the inclusion of human values into the climate regime will be facilitated. This article presents these instruments and discusses their potential for inclusion in the climate regime.

State Structure and Political Regime Structure

Directory of Open Access Journals (Sweden)

Paul – Iulian Nedelcu

2012-05-01

Full Text Available The political regime is the concrete form of organization and functioning of political system andtherefore, the regime means the concrete way of organize, institutionalize and function a political systemand of the exercise of political power by a social-political force in a social community or global socialistem. The political regime is not limited to institutions and state bodies, but it covers the entire politicalsystem. Form of expression in social practice plan is the result of balance of forces between classes ofcitizens, organizations, between them and civil society and politics.Designates the concrete form ofgovernment formation and organization, of state bodies, in aspect of their characteristics and principles, therelations between them and other state bodies, and also as the relationship between them and otherinstitutionalized forms of political systems. Instead, the political regime is an explicit realization ofaxiological operations, a specific hierarchy of values, in general and political values, in particular. Even ifsome elements of the political regime overlap to some extent and in some respects, those of form orstructure of guvernamnt state, thus they dissolve his identity, distinct quality of being specific traits of thepolitical regime.

Totalitäre Regimes

OpenAIRE

Merkel, Wolfgang

2004-01-01

"The development of the term and the analytical concept of totalitarianism have gone through several stages since the 1920s. However, even in its most sophisticated form, the version seen in Friedrich/ Brzezinski, the concept exhibits substantial systematic classification problems and analytical weaknesses. This article attempts to frame the type of totalitarian regime within a general typology of political regimes. Special attention is dedicated to the problem of distinguishing autocra...

Loads and loads and loads: The influence of prospective load, retrospective load, and ongoing task load in prospective memory

Directory of Open Access Journals (Sweden)

Beat eMeier

2015-06-01

Full Text Available In prospective memory tasks different kinds of load can occur. Adding a prospective memory task can impose a load on ongoing task performance. Adding ongoing task load can affect prospective memory performance. The existence of multiple target events increases prospective load and adding complexity to the to-be-remembered action increases retrospective load. In two experiments, we systematically examined the effects of these different types of load on prospective memory performance. Results showed an effect of prospective load on costs in the ongoing task for categorical targets (Experiment 2, but not for specific targets (Experiment 1. Retrospective load and ongoing task load both affected remembering the retrospective component of the prospective memory task. We suggest that prospective load can enhance costs in the ongoing task due to additional monitoring requirements. Retrospective load and ongoing task load seem to impact the division of resources between the ongoing task and retrieval of the retrospective component, which may affect disengagement from the ongoing task. In general, the results demonstrate that the different types of load affect prospective memory differentially.

'CANDLE' burnup regime after LWR regime

International Nuclear Information System (INIS)

Sekimoto, Hiroshi; Nagata, Akito

2008-01-01

CANDLE (Constant Axial shape of Neutron flux, nuclide densities and power shape During Life of Energy producing reactor) burnup strategy can derive many merits. From safety point of view, the change of excess reactivity along burnup is theoretically zero, and the core characteristics, such as power feedback coefficients and power peaking factor, are not changed along burnup. Application of this burnup strategy to neutron rich fast reactors makes excellent performances. Only natural or depleted uranium is required for the replacing fuels. About 40% of natural or depleted uranium undergoes fission without the conventional reprocessing and enrichment. If the LWR produced energy of X Joules, the CANDLE reactor can produce about 50X Joules from the depleted uranium left at the enrichment facility for the LWR fuel. If we can say LWRs have produced energy sufficient for full 20 years, we can produce the energy for 1000 years by using the CANDLE reactors with depleted uranium. We need not mine any uranium ore, and do not need reprocessing facility. The burnup of spent fuel becomes 10 times. Therefore, the spent fuel amount per produced energy is also reduced to one-tenth. The details of the scenario of CANDLE burnup regime after LWR regime will be presented at the symposium. (author)

Changing Feeding Regimes To Demonstrate Flexible Biogas Production: Effects on Process Performance, Microbial Community Structure, and Methanogenesis Pathways.

Science.gov (United States)

Mulat, Daniel Girma; Jacobi, H Fabian; Feilberg, Anders; Adamsen, Anders Peter S; Richnow, Hans-Hermann; Nikolausz, Marcell

2016-01-15

Flexible biogas production that adapts biogas output to energy demand can be regulated by changing feeding regimes. In this study, the effect of changes in feeding intervals on process performance, microbial community structure, and the methanogenesis pathway was investigated. Three different feeding regimes (once daily, every second day, and every 2 h) at the same organic loading rate were studied in continuously stirred tank reactors treating distiller's dried grains with solubles. A larger amount of biogas was produced after feeding in the reactors fed less frequently (once per day and every second day), whereas the amount remained constant in the reactor fed more frequently (every 2 h), indicating the suitability of the former for the flexible production of biogas. Compared to the conventional more frequent feeding regimes, a methane yield that was up to 14% higher and an improved stability of the process against organic overloading were achieved by employing less frequent feeding regimes. The community structures of bacteria and methanogenic archaea were monitored by terminal restriction fragment length polymorphism (T-RFLP) analysis of 16S rRNA and mcrA genes, respectively. The results showed that the composition of the bacterial community varied under the different feeding regimes, and the observed T-RFLP patterns were best explained by the differences in the total ammonia nitrogen concentrations, H2 levels, and pH values. However, the methanogenic community remained stable under all feeding regimes, with the dominance of the Methanosarcina genus followed by that of the Methanobacterium genus. Stable isotope analysis showed that the average amount of methane produced during each feeding event by acetoclastic and hydrogenotrophic methanogenesis was not influenced by the three different feeding regimes. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Physics Based Model for Online Fault Detection in Autonomous Cryogenic Loading System

Science.gov (United States)

Kashani, Ali; Devine, Ekaterina Viktorovna P; Luchinsky, Dmitry Georgievich; Smelyanskiy, Vadim; Sass, Jared P.; Brown, Barbara L.; Patterson-Hine, Ann

2013-01-01

We report the progress in the development of the chilldown model for rapid cryogenic loading system developed at KSC. The nontrivial characteristic feature of the analyzed chilldown regime is its active control by dump valves. The two-phase flow model of the chilldown is approximated as one-dimensional homogeneous fluid flow with no slip condition for the interphase velocity. The model is built using commercial SINDAFLUINT software. The results of numerical predictions are in good agreement with the experimental time traces. The obtained results pave the way to the application of the SINDAFLUINT model as a verification tool for the design and algorithm development required for autonomous loading operation.

Power load limits of the WENDELSTEIN 7-X target elements-comparison of experimental results and design values for power loads up to the critical heat flux

International Nuclear Information System (INIS)

Greuner, H; Boeswirth, B; Boscary, J; Leuprecht, A; Plankensteiner, A

2007-01-01

The power load limits of the WENDELSTEIN7-X divertor target elements were experimentally evaluated with heat loads considerably exceeding the expected operating conditions. The water-cooled elements are designed for steady-state heat flux of 10 MW m -2 and to remove a power load up to 100 kW. The elements must allow a limited operation time at 12 MW m -2 steady-state and should not fail for short pulses of up to 15 MW m -2 for cooling conditions in the subcooled nucleate boiling regime. In the framework of the qualification phase, pre-series target elements were loaded up to 24 MW m -2 without loss of CFC tiles. A critical heat flux at the target of 31 MW m -2 was achieved. The paper discusses the results of the tests performed at the high heat flux test facility GLADIS. The experimental results compared to transient nonlinear fine element method (FEM) calculations confirm a high thermal safety margin of the target design sufficient for plasma operation in W7-X

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......, the traditional understanding of supply regimes in fisheries needs modification. This paper identifies through a case study of the East Baltic cod fishery supply regimes in fisheries, taking alternative fisheries management schemes and mesh size limitations into account. An age-structured Beverton-Holt based bio......-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...

Stochastic dynamical models for ecological regime shifts

DEFF Research Database (Denmark)

Møller, Jan Kloppenborg; Carstensen, Jacob; Madsen, Henrik

the physical and biological knowledge of the system, and nonlinearities introduced here can generate regime shifts or enhance the probability of regime shifts in the case of stochastic models, typically characterized by a threshold value for the known driver. A simple model for light competition between...... definition and stability of regimes become less subtle. Ecological regime shifts and their modeling must be viewed in a probabilistic manner, particularly if such model results are to be used in ecosystem management....

Finite element analysis of the biaxial cyclic tensile loading of the elastoplastic plate with the central hole: asymptotic regimes

Science.gov (United States)

Turkova, Vera; Stepanova, Larisa

2018-03-01

For elastistoplastic structure elements under cyclic loading three types of asymptotic behavior are well known: shakedown, cyclic plasticity or ratcheting. In structure elements operating in real conditions ratcheting must always be excluded since it caused the incremental fracture of structure by means of the accumulation of plastic strains. In the present study results of finite-element (FEM) calculations of the asymptotical behavior of an elastoplastic plate with the central circular and elliptic holes under the biaxial cyclic loading for three different materials are presented. Incremental cyclic loading of the sample with stress concentrator (the central hole) is performed in the multifunctional finite-element package SIMULIA Abaqus. The ranges of loads found for shakedown, cyclic plasticity and ratcheting are presented. The results obtained are generalized and analyzed. Convenient normalization is suggested. The chosen normalization allows us to present all computed results, corresponding to separate materials, within one common curve with minimum scattering of the points. Convenience of the generalized diagram consists in a possibility to find an asymptotical behavior of an inelastic structure for materials for which computer calculations were not made.

Surface pressure and aerodynamic loads determination of a transonic airfoil based on particle image velocimetry

International Nuclear Information System (INIS)

Ragni, D; Ashok, A; Van Oudheusden, B W; Scarano, F

2009-01-01

The present investigation assesses a procedure to extract the aerodynamic loads and pressure distribution on an airfoil in the transonic flow regime from particle image velocimetry (PIV) measurements. The wind tunnel model is a two-dimensional NACA-0012 airfoil, and the PIV velocity data are used to evaluate pressure fields, whereas lift and drag coefficients are inferred from the evaluation of momentum contour and wake integrals. The PIV-based results are compared to those derived from conventional loads determination procedures involving surface pressure transducers and a wake rake. The method applied in this investigation is an extension to the compressible flow regime of that considered by van Oudheusden et al (2006 Non-intrusive load characterization of an airfoil using PIV Exp. Fluids 40 988–92) at low speed conditions. The application of a high-speed imaging system allows the acquisition in relatively short time of a sufficient ensemble size to compute converged velocity statistics, further translated in turbulent fluctuations included in the pressure and loads calculation, notwithstanding their verified negligible influence in the computation. Measurements are performed at varying spatial resolution to optimize the loads determination in the wake region and around the airfoil, further allowing us to assess the influence of spatial resolution in the proposed procedure. Specific interest is given to the comparisons between the PIV-based method and the conventional procedures for determining the pressure coefficient on the surface, the drag and lift coefficients at different angles of attack. Results are presented for the experiments at a free-stream Mach number M = 0.6, with the angle of attack ranging from 0° to 8°

De Facto Regimes in International Law

OpenAIRE

Essen, Jonte van

2012-01-01

The ambiguous position of de facto regimes in international law has long been the subject of scholarly debate and a source of political conflict. An assessment of the current standing of these regimes in international law and the consequences of actions by international actors on this status has, however, been long overdue. The manner in which de facto regimes are regarded internationally has serious consequences for the individuals under the influence of this legal grey area. Therefore, the ...

Transient regimes in a heavy water reactor; Regimes transitoires dans un reacteur a eau lourde

Energy Technology Data Exchange (ETDEWEB)

Raievski, V [Commissariat a l' Energie Atomique, Saclay(France). Centre d' Etudes Nucleaires

1953-07-01

We studied the variations of power and reactivity of a reactor when we raise in a continuous way the starting plates. During the subcritical regime (negative reactivity), the power is determined by reactivity and by the intensity of the sources of photo neutrons, produced during the previous work of the reactor. When, during the rise of the plates, the reactor, pass by the critical regime (zero reactivity), one notes that the reached power is independent of the initial reactivity. During the sur-critical regime (positive reactivity), the elevation of temperature of the uranium bars slows down the growth of reactivity due to the movements of the plates. The power stretches then toward a value that depends only on the regime of cooling of the reactor and the excess of the available reactivity. This survey permits to choose such a rise speed, that reactivity remains constantly lower to a value beyond which the piloting of the reactor becomes difficult. This result is not more valid, if the intensity of the sources is insufficient, what takes place during the first divergences and after a stop of long length. (author) [French] On etudie les variations de puissance et de reactivite d'un reacteur quand on leve d'une facon continue les plaques de demarrage. Pendant le regime subcritique (reactivite negative), la puissance est determinee par la reactivite et par l'intensite des sources de photoneutrons, produites pendant la marche anterieure du reacteur. Quand, au cours de la montee des plaques, le reacteur passe par le regime critique (reactivite nulle), on constate que la puissance atteinte est independante de la reactivite initiale. Pendant le regime surcritique (reactivite positive), l'elevation de temperature des barres d'uranium ralentit l'accroissement de reactivite due aux mouvements des plaques. La puissance tend alors vers une valeur qui ne depend plus que du regime de refroidissement du reacteur et de l'exces de la reactivite disponible. Cette etude permet de

Fire Regime Characteristics along Environmental Gradients in Spain

Directory of Open Access Journals (Sweden)

María Vanesa Moreno

2016-11-01

Full Text Available Concern regarding global change has increased the need to understand the relationship between fire regime characteristics and the environment. Pyrogeographical theory suggests that fire regimes are constrained by climate, vegetation and fire ignition processes, but it is not obvious how fire regime characteristics are related to those factors. We used a three-matrix approach with a multivariate statistical methodology that combined an ordination method and fourth-corner analysis for hypothesis testing to investigate the relationship between fire regime characteristics and environmental gradients across Spain. Our results suggest that fire regime characteristics (i.e., density and seasonality of fire activity are constrained primarily by direct gradients based on climate, population, and resource gradients based on forest potential productivity. Our results can be used to establish a predictive model for how fire regimes emerge in order to support fire management, particularly as global environmental changes impact fire regime characteristics.

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...... for the housing construction sector in Denmark reveals the relevance and impacts of different regime framings. It is proposed that the ability to cope with framing issues as situated and political processes is at the core of the governance of transitions....

Methodology for the selection of the regime of flow in lagoons of stabilization

International Nuclear Information System (INIS)

Cruz T, Luis Eduardo; Alayon Torres, Walter E; Monsegny S, Carlos Emilio

2000-01-01

advantages in front of the regime of piston flow like: the consumption of oxygen for the microorganisms it is uniform, the crash loads are muffled easily without the population of organisms is gravely affected. Most of the stabilization lagoons don't reach the conditions of complete mixture. This model is a reasonable approach of the process of hydraulic transport in lagoons, alone for the cases where the volume of the active area is almost half of the volume of the lagoon

Ecosystem regime shifts disrupt trophic structure.

Science.gov (United States)

Hempson, Tessa N; Graham, Nicholas A J; MacNeil, M Aaron; Hoey, Andrew S; Wilson, Shaun K

2018-01-01

Regime shifts between alternative stable ecosystem states are becoming commonplace due to the combined effects of local stressors and global climate change. Alternative states are characterized as substantially different in form and function from pre-disturbance states, disrupting the delivery of ecosystem services and functions. On coral reefs, regime shifts are typically characterized by a change in the benthic composition from coral to macroalgal dominance. Such fundamental shifts in the benthos are anticipated to impact associated fish communities that are reliant on the reef for food and shelter, yet there is limited understanding of how regime shifts propagate through the fish community over time, relative to initial or recovery conditions. This study addresses this knowledge gap using long-term data of coral reef regime shifts and recovery on Seychelles reefs following the 1998 mass bleaching event. It shows how trophic structure of the reef fish community becomes increasingly dissimilar between alternative reef ecosystem states (regime-shifted vs. recovering) with time since disturbance. Regime-shifted reefs developed a concave trophic structure, with increased biomass in base trophic levels as herbivorous species benefitted from increased algal resources. Mid trophic level species, including specialists such as corallivores, declined with loss of coral habitat, while biomass was retained in upper trophic levels by large-bodied, generalist invertivores. Recovering reefs also experienced an initial decline in mid trophic level biomass, but moved toward a bottom-heavy pyramid shape, with a wide range of feeding groups (e.g., planktivores, corallivores, omnivores) represented at mid trophic levels. Given the importance of coral reef fishes in maintaining the ecological function of coral reef ecosystems and their associated fisheries, understanding the effects of regime shifts on these communities is essential to inform decisions that enhance ecological

Feasibility of a dual regime gyrotron

International Nuclear Information System (INIS)

Sawant, Ashwini; Jain, Prerit; Kartikeyan, M.V.

2012-01-01

The design concept of a 42/84 GHz, 500 kW, CW, dual-regime gyrotron for ECRH of plasma in an experimental Tokamak will be presented in this paper. Operation at 42 GHz is fundamental where as that in 84 GHz will be second harmonic so that a similar guidance system will be retained for dual regime operation. In this paper, the mode competition and mode selection procedures are presented for such a dual regime operation. Cold cavity design and self-consistent calculations will be carried out for power and efficiencies. (author)

Material Surface Damage under High Pulse Loads Typical for ELM Bursts and Disruptions in ITER

Energy Technology Data Exchange (ETDEWEB)

Landman, I.S.; Pestchanyi, S.E.; Bazylev, B.N [Forschungszentrum Karlsruhe (Germany). Inst. for Pulsed Power and Microwave Technology; Safronov, V.M. [Troitsk Inst. for Innovation and Fusion Research (TRINITI) (Russian Federation); Garkusha, I.E. [Kharkov Inst. of Physics and Technology (KIPT) (Ukraine). Inst. of Plasma Physics

2004-08-01

The divertor armour material for the tokamak ITER will probably be carbon manufactured as fibre composites (CFC) and tungsten as either brush-like structures or thin plates. Disruptive pulse loads where the heat deposition Q may reach 10{sup 2} MJ/m{sup 2} on a time scale {tau} of 3 ms, or operation in the ELMy H-mode at repetitive loads with Q {approx} 3MJ/m{sup 2} and {tau}{approx}0.3 ms; deteriorate armour performance. This work surveys recent numerical and experimental investigations of erosion mechanisms at these off-normal regimes carried out at FZK, TRINITI, and IPP-Kharkov. The modelling uses the anisotropic thermomechanics code PEGASUS-3D for the simulation of CFC brittle destruction, the surface melt motion code MEMOS-1.5D for tungsten targets, and the radiation-magnetohydrodynamics code FOREV-2D for calculating the plasma impact and simulating the heat loads for the ITER regime. Experiments aimed at validating these codes are being carried out at the plasma gun facilities MK-200UG, QSPA-T, and QSPA-Kh50 which produce powerful streams of hydrogen plasma with Q=10-30MJ/m{sup 2} and {tau} = 0.03-0.5 ms. Essential results are, for CFC targets, the experiments at high heat loads and the development of a local overheating model incorporated in PEGASUS-3D, and for the tungsten targets the analysis of evaporation- and melt motion erosion on the base of MEMOS-1.5D calculations for repetitive ELMs.

Material Surface Damage under High Pulse Loads Typical for ELM Bursts and Disruptions in ITER

Science.gov (United States)

Landman, I. S.; Pestchanyi, S. E.; Safronov, V. M.; Bazylev, B. N.; Garkusha, I. E.

The divertor armour material for the tokamak ITER will probably be carbon manufactured as fibre composites (CFC) and tungsten as either brush-like structures or thin plates. Disruptive pulse loads where the heat deposition Q may reach 102 MJ/m 2 on a time scale Ïä of 3 ms, or operation in the ELMy H-mode at repetitive loads with Q âe 1/4 3 MJ/m2 and Ïä âe 1/4 0.3 ms, deteriorate armour performance. This work surveys recent numerical and experimental investigations of erosion mechanisms at these off-normal regimes carried out at FZK, TRINITI, and IPP-Kharkov. The modelling uses the anisotropic thermomechanics code PEGASUS-3D for the simulation of CFC brittle destruction, the surface melt motion code MEMOS-1.5D for tungsten targets, and the radiation-magnetohydrodynamics code FOREV-2D for calculating the plasma impact and simulating the heat loads for the ITER regime. Experiments aimed at validating these codes are being carried out at the plasma gun facilities MK-200UG, QSPA-T, and QSPA-Kh50 which produce powerful streams of hydrogen plasma with Q = 10–30 MJ/m2 and Ïä = 0.03–0.5 ms. Essential results are, for CFC targets, the experiments at high heat loads and the development of a local overheating model incorporated in PEGASUS-3D, and for the tungsten targets the analysis of evaporation- and melt motion erosion on the base of MEMOS-1.5D calculations for repetitive ELMs.

Regime identification in ASDEX Upgrade

International Nuclear Information System (INIS)

Giannone, L; Sips, A C C; Kardaun, O; Spreitler, F; Suttrop, W

2004-01-01

The ability to recognize the transition from the L-mode to the H-mode or from the H-mode to the improved H-mode reliably from a conveniently small number of measurements in real time is of increasing importance for machine control. Discriminant analysis has been applied to regime identification of plasma discharges in the ASDEX Upgrade tokamak. An observation consists of a set of plasma parameters averaged over a time slice in a discharge. The data set consists of all observations over different discharges and time slices. Discriminant analysis yields coefficients allowing the classification of a new observation. The results of a frequentist and a formal Bayesian approach to discriminant analysis are compared. With five plasma variables, a failure rate of 1.3% for predicting the L-mode and the H-mode confinement regime was achieved. With five plasma variables, a failure rate of 5.3% for predicting the H-mode and the improved H-mode confinement regime was achieved. The coefficients derived by discriminant analysis have been applied subsequently to discharges to illustrate the operation of regime identification in a real time control system

Fiscal Policy and Welfare under Different Exchange Rate Regimes

DEFF Research Database (Denmark)

Østrup, Finn

a representativeindividual's utility, it is demonstrated that there are differences betweenexchange rate regimes with respect to the level of government spending. Thesedifferences arise first because a rise in government spending affects macroeconomicvariables differently under different exchange rate regimes......, and secondbecause the government's inclination to expand government spending is affectedby inflation which depends on the exchange rate regime. At low rates of inflation,the government is inclined to set a higher level of government spending under afixed exchange rate regime than under a floating exchange rate...... 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...

The Two Regimes of Postwar Shipping

DEFF Research Database (Denmark)

Iversen, Martin Jes; Tenold, Stig

2014-01-01

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.......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...

Endogenous Monetary Policy Regime Change

OpenAIRE

Troy Davig; Eric M. Leeper

2006-01-01

This paper makes changes in monetary policy rules (or regimes) endogenous. Changes are triggered when certain endogenous variables cross specified thresholds. Rational expectations equilibria are examined in three models of threshold switching to illustrate that (i) expectations formation effects generated by the possibility of regime change can be quantitatively important; (ii) symmetric shocks can have asymmetric effects; (iii) endogenous switching is a natural way to formally model preempt...

LCF life prediction for waspaloy in the creep-fatigue interaction regime

International Nuclear Information System (INIS)

Yeom, Jong Taek; Park, Nho Kwang

2001-01-01

This paper describes the empirical rule of strain rate modified linear accumulation of creep damage(SRM rule) for Low-Cycle Fatigue(LCF) life prediction of Waspaloy in the creep-fatigue interaction regime and Chaboche type unified viscoplastic model predicting the stress-strain response in various cyclic loading conditions. The comparison of the experimental data and the predictions for strain controlled LCF tests carried out for various strain ranges at 600 .deg. C and 650 .deg. C was made. Chaboche type unified viscoplastic model described efficiently the inelastic deformation behavior during LCF tests. Crack-initiation lifting method to predict the material life was investigated with Strain Rate Modification(SRM) rule. The application of SRM rule to LCF tests on Waspaloy indicated a good agreement between measured and predicted cycles to failure

Statistics of exchange rate regimes in Nigeria | Iwueze | Global ...

African Journals Online (AJOL)

The three distinct exchange rate regimes of Nigeria were subjected to Autoregressive Integrated Moving Average (ARIMA) modeling in order to compare them with respect to model structure. It was found that the three regimes admit different models. Regime one admits Moving average model of order 2, Regime two admits ...

Elasto-plastic behavior of pipe subjected to steady axial load and cyclic bending

International Nuclear Information System (INIS)

Yao Yanping; Lu Mingwan; Zhang Xiong

2004-01-01

The elasto-plastic behavior of a pipe subjected to a steady axial force and a cyclic bending moment is studied. By using two parameters c and d, which describe the elasto-plastic interfaces of beam cross-section, the boundary curve equations between various types of elasto-plastic behavior, such as shakedown, plastic fatigue, ratcheting, and plastic collapse, are derived. The results are applicable for beams of any cross-section with two orthogonal axes of symmetry. As a result, the load regime diagram for a pipe is obtained, which gives an intuitive picture of the elasto-plastic behavior of the pipe under a given combination of constant axial load and cyclic bending moment

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 ...

Eccentric exercise: mechanisms and effects when used as training regime or training adjunct.

Science.gov (United States)

Vogt, Michael; Hoppeler, Hans H

2014-06-01

The aim of the current review is to discuss applications and mechanism of eccentric exercise in training regimes of competitive sports. Eccentric muscle work is important in most sports. Eccentric muscle contractions enhance the performance during the concentric phase of stretch-shortening cycles, which is important in disciplines like sprinting, jumping, throwing, and running. Muscles activated during lengthening movements can also function as shock absorbers, to decelerate during landing tasks or to precisely deal with high external loading in sports like alpine skiing. The few studies available on trained subjects reveal that eccentric training can further enhance maximal muscle strength and power. It can further optimize muscle length for maximal tension development at a greater degree of extension, and has potential to improve muscle coordination during eccentric tasks. In skeletal muscles, these functional adaptations are based on increases in muscle mass, fascicle length, number of sarcomeres, and cross-sectional area of type II fibers. Identified modalities for eccentric loading in athletic populations involve classical isotonic exercises, accentuated jumping exercises, eccentric overloading exercises, and eccentric cycle ergometry. We conclude that eccentric exercise offers a promising training modality to enhance performance and to prevent injuries in athletes. However, further research is necessary to better understand how the neuromuscular system adapts to eccentric loading in athletes. Copyright © 2014 the American Physiological Society.

Capacitance densitometer for flow regime identification

International Nuclear Information System (INIS)

Shipp, R.L. Jr.

1978-01-01

This invention relates to a capacitance densitometer for determining the flow regime of a two-phase flow system. A two-element capacitance densitometer is used in conjunction with a conventional single-beam gamma densitometer to unambiguously identify the prevailing flow regime and the average density of a flowing fluid

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

Short-range wakefields generated in the blowout regime of plasma-wakefield acceleration

Science.gov (United States)

Stupakov, G.

2018-04-01

In the past, calculation of wakefields generated by an electron bunch propagating in a plasma has been carried out in linear approximation, where the plasma perturbation can be assumed small and plasma equations of motion linearized. This approximation breaks down in the blowout regime where a high-density electron driver expels plasma electrons from its path and creates a cavity void of electrons in its wake. In this paper, we develop a technique that allows us to calculate short-range longitudinal and transverse wakes generated by a witness bunch being accelerated inside the cavity. Our results can be used for studies of the beam loading and the hosing instability of the witness bunch in plasma-wakefield and laser-wakefield acceleration.

Bed Load Variability and Morphology of Gravel Bed Rivers Subject to Unsteady Flow: A Laboratory Investigation

Science.gov (United States)

Redolfi, M.; Bertoldi, W.; Tubino, M.; Welber, M.

2018-02-01

Measurement and estimation of bed load transport in gravel bed rivers are highly affected by its temporal fluctuations. Such variability is primarily driven by the flow regime but is also associated with a variety of inherent channel processes, such as flow turbulence, grain entrainment, and bed forms migration. These internal and external controls often act at comparable time scales, and are therefore difficult to disentangle, thus hindering the study of bed load variability under unsteady flow regime. In this paper, we report on laboratory experiments performed in a large, mobile bed flume where typical hydromorphological conditions of gravel bed rivers were reproduced. Data from a large number of replicated runs, including triangular and square-wave hydrographs, were used to build a statistically sound description of sediment transport processes. We found that the inherent variability of bed load flux strongly depends on the sampling interval, and it is significantly higher in complex, wandering or braided channels. This variability can be filtered out by computing the mean response over the experimental replicates, which allows us to highlight two distinctive phenomena: (i) an overshooting (undershooting) response of the mean bed load flux to a sudden increase (decrease) of discharge, and (ii) a clockwise hysteresis in the sediment rating curve. We then provide an interpretation of these findings through a conceptual mathematical model, showing how both phenomena are associated with a lagging morphological adaptation to unsteady flow. Overall, this work provides basic information for evaluating, monitoring, and managing gravel transport in morphologically active rivers.

Current US nuclear liability regime

International Nuclear Information System (INIS)

Brown, O.F.

2000-01-01

The Price-Anderson Act Adopted by US Congress in 1957 as the world's first national nuclear liability regime. It is a comprehensive, complicated and unique system and stems from special features of US legal regime and federal system of government. It differs from other systems by providing for 'economic', not legal; channeling of liability to facility operator and not recommended as model for other states, but most features adopted by other states and international conventions

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 is spec...

How Welfare Regimes Generate and Erode Social Capital

DEFF Research Database (Denmark)

Larsen, Christian Albrekt

2007-01-01

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......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...... 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....

Can Old Regimes Handle New Wars?

DEFF Research Database (Denmark)

Henningsen, Troels

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......, the paper finds that regimes in the Sahel region are still able to cope with the rise in non-state threats. The paper first shortly compares the longevity of the present regimes in the Sahel region to all previous ones, second examines in-depth how Chad and Mali fight the insurgents. Findings are that since...

FEL in transverse optical klystron regime

International Nuclear Information System (INIS)

Scarlat, F.; Baltateanu, N.

1994-01-01

Among all operational regimes of free electron laser (FEL), the transverse optical regime (TOK) requires the least stringent electron beam parameters. The device associated to this regime, also defined as FEL with two or more components, consists of two or more identical interaction sections separated by one or more drift distances among themselves. Starting from the motion equations which describe the interaction between an electron and the radiation inside the undulator, one can obtain some practical expressions for the calculation of the efficiency of the energy transfer from the electron to the radiation, and the gain of the external coherent radiation for a FEL in TOK with three cavities. (Author)

Fuel element cladding state change mathematical model for a WWER-1000 plant operated in the mode of varying loading

Directory of Open Access Journals (Sweden)

S. N. Pelykh

2010-09-01

Full Text Available Main features of a fuel element cladding state change mathematical model for a WWER-1000 reactor plant operated in the mode of varying loading are listed. The integrated model is based on the energy creep theory, uses the finite element method for imultaneous solution of the fuel element heat conduction and mechanical deformation equa-tions. Proposed mathematical model allows us to determine the influence of the WWER-1000 regime parameters and fuel assembly design characteristics on the change of cladding properties under different loading conditions of normal operation, as well as the cladding limiting state at variable loading depending on the length, depth and number of cycles.

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

Regimes of mini black hole abandoned to accretion

Science.gov (United States)

Paik, Biplab

2018-01-01

Being inspired by the Eddington’s idea, along with other auxiliary arguments, it is unveiled that there exist regimes of a black hole that would prohibit accretion of ordinary energy. In explicit words, there exists a lower bound to black hole mass below which matter accretion process does not run for black holes. Not merely the baryonic matter, but, in regimes, also the massless photons could get prohibited from rushing into a black hole. However, unlike the baryon accretion abandoned black hole regime, the mass-regime of a black hole prohibiting accretion of radiation could vary along with its ambient temperature. For example, we discuss that earlier to 10‑8 s after the big-bang, as the cosmological temperature of the Universe grew above ˜ 1014 K, the mass range of black hole designating the radiation accretion abandoned regime, had to be in varying state being connected with the instantaneous age of the evolving Universe by an “one half” power law. It happens to be a fact that a black hole holding regimes prohibiting accretion of energy is gigantic by its size in comparison to the Planck length-scale. Hence the emergence of these regimes demands mini black holes for not being viable as profound suckers of energy. Consideration of accretion abandoned regimes could be crucial for constraining or judging the evolution of primordial black holes over the age of the Universe.

Statistical estimation of loads from gas explosions

Energy Technology Data Exchange (ETDEWEB)

Hoeiset, Stian

1998-12-31

In the design of structures in the offshore and process industries, the possibility of a gas explosion must always be considered. The main uncertainties in computerized simulation of gas explosions are the assumptions of the gas cloud, the location of the ignition point and the properties of the simulator itself. This thesis quantifies the levels of these uncertainties by performing a large number of simulations on three offshore modules and one onshore plant. It is found that (1) there is an approximate linear relation between pressure and gas volume, (2) it may be possible to find a linear relation between pressure and impulse, (3) there is an inverse relation between pressure and duration, (4) the response of offshore structures exposed to gas explosions are rarely in the impulsive regime, (5) loading rates vary widely in magnitude, (6) an assumption of a triangular explosion pulse is often correct, (7) louvres increase pressure, impulse and duration of an explosion. The effect of ignition point location is studied in detail. It is possible to derive an ignition point uncertainty load factor that shows predictable behaviour by generalizing the non-parametric properties of the explosion pressure. A model for taking into account the uncertainties regarding gas volume, ignition point location and simulator imperfectness is proposed. The model is intended to produce a characteristic load for structural design. 68 refs., 51 figs., 36 tabs.

Active Boundary Layer Control on a Highly Loaded Turbine Exit Case Profile

Directory of Open Access Journals (Sweden)

Julia Kurz

2018-03-01

Full Text Available A highly loaded turbine exit guide vane with active boundary layer control was investigated experimentally in the High Speed Cascade Wind Tunnel at the University of the German Federal Armed Forces, Munich. The experiments include profile Mach number distributions, wake traverse measurements as well as boundary layer investigations with a flattened Pitot probe. Active boundary layer control by fluidic oscillators was applied to achieve improved performance in the low Reynolds number regime. Low solidity, which can be applied to reduce the number of blades, increases the risk of flow separation resulting in increased total pressure losses. Active boundary layer control is supposed to overcome these negative effects. The experiments show that active boundary layer control by fluidic oscillators is an appropriate way to suppress massive open separation bubbles in the low Reynolds number regime.

TARIFFS AND REGIMES OF POWER CONSUMPTION

Directory of Open Access Journals (Sweden)

S. V. Batsova

2010-01-01

Full Text Available Analysis of regimes of electro-consumption at RUP «BMZ» is carried out. It is shown that in conditions of rapid growth of prices for electric power one of the conditions of reduction of production expenses is to be the increase of efficiency of the electro-consumption regimes control.

Loads and loads and loads: the influence of prospective load, retrospective load, and ongoing task load in prospective memory

Science.gov (United States)

Meier, Beat; Zimmermann, Thomas D.

2015-01-01

In prospective memory tasks different kinds of load can occur. Adding a prospective memory task can impose a load on ongoing task performance. Adding ongoing task load (OTL) can affect prospective memory performance. The existence of multiple target events increases prospective load (PL) and adding complexity to the to-be-remembered action increases retrospective load (RL). In two experiments, we systematically examined the effects of these different types of load on prospective memory performance. Results showed an effect of PL on costs in the ongoing task for categorical targets (Experiment 2), but not for specific targets (Experiment 1). RL and OTL both affected remembering the retrospective component of the prospective memory task. We suggest that PL can enhance costs in the ongoing task due to additional monitoring requirements. RL and OTL seem to impact the division of resources between the ongoing task and retrieval of the retrospective component, which may affect disengagement from the ongoing task. In general, the results demonstrate that the different types of load affect prospective memory differentially. PMID:26082709

Loads and loads and loads: the influence of prospective load, retrospective load, and ongoing task load in prospective memory.

Science.gov (United States)

Meier, Beat; Zimmermann, Thomas D

2015-01-01

In prospective memory tasks different kinds of load can occur. Adding a prospective memory task can impose a load on ongoing task performance. Adding ongoing task load (OTL) can affect prospective memory performance. The existence of multiple target events increases prospective load (PL) and adding complexity to the to-be-remembered action increases retrospective load (RL). In two experiments, we systematically examined the effects of these different types of load on prospective memory performance. Results showed an effect of PL on costs in the ongoing task for categorical targets (Experiment 2), but not for specific targets (Experiment 1). RL and OTL both affected remembering the retrospective component of the prospective memory task. We suggest that PL can enhance costs in the ongoing task due to additional monitoring requirements. RL and OTL seem to impact the division of resources between the ongoing task and retrieval of the retrospective component, which may affect disengagement from the ongoing task. In general, the results demonstrate that the different types of load affect prospective memory differentially.

A study on the optimal hydraulic loading rate and plant ratios in recirculation aquaponic system.

Science.gov (United States)

Endut, Azizah; Jusoh, A; Ali, N; Wan Nik, W B; Hassan, A

2010-03-01

The growths of the African catfish (Clarias gariepinus) and water spinach (Ipomoea aquatica) were evaluated in recirculation aquaponic system (RAS). Fish production performance, plant growth and nutrient removal were measured and their dependence on hydraulic loading rate (HLR) was assessed. Fish production did not differ significantly between hydraulic loading rates. In contrast to the fish production, the water spinach yield was significantly higher in the lower hydraulic loading rate. Fish production, plant growth and percentage nutrient removal were highest at hydraulic loading rate of 1.28 m/day. The ratio of fish to plant production has been calculated to balance nutrient generation from fish with nutrient removal by plants and the optimum ratio was 15-42 gram of fish feed/m(2) of plant growing area. Each unit in RAS was evaluated in terms of oxygen demand. Using specified feeding regime, mass balance equations were applied to quantify the waste discharges from rearing tanks and treatment units. The waste discharged was found to be strongly dependent on hydraulic loading rate. 2009 Elsevier Ltd. All rights reserved.

Cargo liability regimes

Science.gov (United States)

2001-01-01

There are at present at least three international regimes of maritime cargo liability in force in different countries of the world - the original Hague rules (1924), the updated version known as the Hague-Visby rules (1968, further amended 1979), and...

Simulating the transient regime for main condensate system at Cernavoda NPP

International Nuclear Information System (INIS)

Nita, Iulian; Gheorghiu, Mihai; Prisecaru, Ilie; Dupleac, Daniel

2005-01-01

The purpose of this project is to make a Thermal Hydraulic Analysis of Main Condensate System for getting real-time answer of installation during regimes occurring during normal and abnormal operation. To obtain the analyses the MMS code was used. The boundaries of the systems analysis are extended to Main Feedwater System in order to get a realistic response of Deaerator equipment which are situated between those two systems and have entrances from both systems. In this way we made a complex analysis with main condenser and steam generators as boundaries. We obtained a model for the entire chain of condensate and feedwater preheater with interface just turbine bleed steam. From that we could reduce the number of assumptions necessary to make the analysis. The analyses consist in hydraulics and thermal hydraulics analyses, respectively. For the first case analysed are: - the nominal operation regime with main condensate pumps; - start-up regime with total circulate of condensate to condenser; - 25% MCR (Maximum Continuous Rate) regime (this regime was used in designing the condensate regulating valves at low flow; - 40% MCR regime (with circulate of some condensate flow to condenser); - operating regime of 60% MCR with one main condensate pump operating; - operating regime with auxiliary condensate pump; - operating regime with discharging a condensate flow to condensate storage tank. The thermal hydraulic analyses deal with normal and abnormal operating regimes, respectively. In the first case analysed are the following regimes: - nominal operating regime with main condensate pump operating 100% MCR; - transient regime, 100-80% MCR; - transient regime, 100-80-60% MCR with two pumps in operation and 60 % MCR with one main condensate pump in operation; - transient regime, 100-80-60-60-40 % MCR; - shut-down regime; - start-up regime from Hot zero power to rated power regime. Finally, for the abnormal operating regimes the analyses concerned: - transient regime 100

Prediction of a Densely Loaded Particle-Laden Jet using a Euler-Lagrange Dense Spray Model

Science.gov (United States)

Pakseresht, Pedram; Apte, Sourabh V.

2017-11-01

Modeling of a dense spray regime using an Euler-Lagrange discrete-element approach is challenging because of local high volume loading. A subgrid cluster of droplets can lead to locally high void fractions for the disperse phase. Under these conditions, spatio-temporal changes in the carrier phase volume fractions, which are commonly neglected in spray simulations in an Euler-Lagrange two-way coupling model, could become important. Accounting for the carrier phase volume fraction variations, leads to zero-Mach number, variable density governing equations. Using pressure-based solvers, this gives rise to a source term in the pressure Poisson equation and a non-divergence free velocity field. To test the validity and predictive capability of such an approach, a round jet laden with solid particles is investigated using Direct Numerical Simulation and compared with available experimental data for different loadings. Various volume fractions spanning from dilute to dense regimes are investigated with and without taking into account the volume displacement effects. The predictions of the two approaches are compared and analyzed to investigate the effectiveness of the dense spray model. Financial support was provided by National Aeronautics and Space Administration (NASA).

Asymptotic preserving and all-regime Lagrange-Projection like numerical schemes: application to two-phase flows in low mach regime

International Nuclear Information System (INIS)

Girardin, Mathieu

2014-01-01

Two-phase flows in Pressurized Water Reactors belong to a wide range of Mach number flows. Computing accurate approximate solutions of those flows may be challenging from a numerical point of view as classical finite volume methods are too diffusive in the low Mach regime. In this thesis, we are interested in designing and studying some robust numerical schemes that are stable for large time steps and accurate even on coarse meshes for a wide range of flow regimes. An important feature is the strategy to construct those schemes. We use a mixed implicit-explicit strategy based on an operator splitting to solve fast and slow phenomena separately. Then, we introduce a modification of a Suliciu type relaxation scheme to improve the accuracy of the numerical scheme in some regime of interest. Two approaches have been used to assess the ability of our numerical schemes to deal with a wide range of flow regimes. The first approach, based on the asymptotic preserving property, has been used for the gas dynamics equations with stiff source terms. The second approach, based on the all-regime property, has been used for the gas dynamics equations and the homogeneous two-phase flows models HRM and HEM in the low Mach regime. We obtained some robustness and stability properties for our numerical schemes. In particular, some discrete entropy inequalities are shown. Numerical evidences, in 1D and in 2D on unstructured meshes, assess the gain in term of accuracy and CPU time of those asymptotic preserving and all-regime numerical schemes in comparison with classical finite volume methods. (author) [fr

Modeling pesticide loadings from the San Joaquin watershed into the Sacramento-San Joaquin Delta using SWAT

Science.gov (United States)

Chen, H.; Zhang, M.

2016-12-01

The Sacramento-San Joaquin Delta is an ecologically rich, hydrologically complex area that serves as the hub of California's water supply. However, pesticides have been routinely detected in the Delta waterways, with concentrations exceeding the benchmark for the protection of aquatic life. Pesticide loadings into the Delta are partially attributed to the San Joaquin watershed, a highly productive agricultural watershed located upstream. Therefore, this study aims to simulate pesticide loadings to the Delta by applying the Soil and Water Assessment Tool (SWAT) model to the San Joaquin watershed, under the support of the USDA-ARS Delta Area-Wide Pest Management Program. Pesticide use patterns in the San Joaquin watershed were characterized by combining the California Pesticide Use Reporting (PUR) database and GIS analysis. Sensitivity/uncertainty analyses and multi-site calibration were performed in the simulation of stream flow, sediment, and pesticide loads along the San Joaquin River. Model performance was evaluated using a combination of graphic and quantitative measures. Preliminary results indicated that stream flow was satisfactorily simulated along the San Joaquin River and the major eastern tributaries, whereas stream flow was less accurately simulated in the western tributaries, which are ephemeral small streams that peak during winter storm events and are mainly fed by irrigation return flow during the growing season. The most sensitive parameters to stream flow were CN2, SOL_AWC, HRU_SLP, SLSUBBSN, SLSOIL, GWQMN and GW_REVAP. Regionalization of parameters is important as the sensitivity of parameters vary significantly spatially. In terms of evaluation metric, NSE tended to overrate model performance when compared to PBIAS. Anticipated results will include (1) pesticide use pattern analysis, (2) calibration and validation of stream flow, sediment, and pesticide loads, and (3) characterization of spatial patterns and temporal trends of pesticide yield.

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...... to restore it by transforming their knowledge regimes, albeit in ways that are still shaped by the surrounding political and economic institutions. The effectiveness of their efforts is not guaranteed. The argument is based on an analysis of the evolution of knowledge regimes since the 1970s in the USA...... 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...

Femoral loading mechanics in the Virginia opossum, Didelphis virginiana: torsion and mediolateral bending in mammalian locomotion.

Science.gov (United States)

Gosnell, W Casey; Butcher, Michael T; Maie, Takashi; Blob, Richard W

2011-10-15

Studies of limb bone loading in terrestrial mammals have typically found anteroposterior bending to be the primary loading regime, with torsion contributing minimally. However, previous studies have focused on large, cursorial eutherian species in which the limbs are held essentially upright. Recent in vivo strain data from the Virginia opossum (Didelphis virginiana), a marsupial that uses a crouched rather than an upright limb posture, have indicated that its femur experiences appreciable torsion during locomotion as well as strong mediolateral bending. The elevated femoral torsion and strong mediolateral bending observed in D. virginiana might result from external forces such as a medial inclination of the ground reaction force (GRF), internal forces deriving from a crouched limb posture, or a combination of these factors. To evaluate the mechanism underlying the loading regime of opossum femora, we filmed D. virginiana running over a force platform, allowing us to measure the magnitude of the GRF and its three-dimensional orientation relative to the limb, facilitating estimates of limb bone stresses. This three-dimensional analysis also allows evaluations of muscular forces, particularly those of hip adductor muscles, in the appropriate anatomical plane to a greater degree than previous two-dimensional analyses. At peak GRF and stress magnitudes, the GRF is oriented nearly vertically, inducing a strong abductor moment at the hip that is countered by adductor muscles on the medial aspect of the femur that place this surface in compression and induce mediolateral bending, corroborating and explaining loading patterns that were identified in strain analyses. The crouched orientation of the femur during stance in opossums also contributes to levels of femoral torsion as high as those seen in many reptilian taxa. Femoral safety factors were as high as those of non-avian reptiles and greater than those of upright, cursorial mammals, primarily because the load

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.

[Effect of antecedent dry weather period on urban storm runoff pollution load].

Science.gov (United States)

Li, Li-qing; Yin, Cheng-qing; Kong, Ling-li; He, Qing-ci

2007-10-01

Twelve storm events were surveyed at Shilipu catchment in Wuhan City through three-year monitoring regime. The flow discharges, total suspended solids (TSS), chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) in runoff were measured to study the mechanism of urban stormwater runoff pollution. The relationship between the event pollution load and the antecedent dry weather period was identified to discuss the influence of the urban surface sanitation management, operation of sewer pipe maintenance and rainfall characteristics on the urban stormwater runoff pollution. It was found that the antecedent dry weather period and runoff amount were the important determining factors in the generation of urban stormwater runoff pollution. The event pollution load was positively correlated to the antecedent dry weather period between two rainfall events (R2 = 0.95, p pollution loads. The best regression equation to estimate pollution load for storm events was developed based on the antecedent dry weather period and runoff depth. Source control including improving urban street sweeping activities and operation of sewer pipe maintenance should be made to reduce the amount of available pollutant over the dry days. It is important alternative to control urban stormwater runoff pollution for Hanyang District.

Transient dynamics of a quantum-dot: From Kondo regime to mixed valence and to empty orbital regimes

Science.gov (United States)

Cheng, YongXi; Li, ZhenHua; Wei, JianHua; Nie, YiHang; Yan, YiJing

2018-04-01

Based on the hierarchical equations of motion approach, we study the time-dependent transport properties of a strongly correlated quantum dot system in the Kondo regime (KR), mixed valence regime (MVR), and empty orbital regime (EOR). We find that the transient current in KR shows the strongest nonlinear response and the most distinct oscillation behaviors. Both behaviors become weaker in MVR and diminish in EOR. To understand the physical insight, we examine also the corresponding dot occupancies and the spectral functions, with their dependence on the Coulomb interaction, temperature, and applied step bias voltage. The above nonlinear and oscillation behaviors could be understood as the interplay between dynamical Kondo resonance and single electron resonant-tunneling.

The Fracture of Plasma-Treated Polyurethane Surface under Fatigue Loading

Directory of Open Access Journals (Sweden)

Ilya A. Morozov

2018-02-01

Full Text Available Plasma treatment of soft polymers is a promising technique to improve biomedical properties of the materials. The response to the deformation of such materials is not yet clear. Soft elastic polyurethane treated with plasma immersion ion implantation is subjected to fatigue uniaxial loading. The influence of the strain amplitude and the plasma treatment regime on damage character is discussed. Surface defects are studied in unloaded and stretched states of the material. As a result of fatigue loading, transverse cracks (with closed overlapping edges as well as with open edges deeply propagating into the polymer and longitudinal folds which are break and bend inward, appear on the surface. Hard edges of cracks cut the soft polymer which is squeezed from the bulk to the surface. The observed damages are related to the high stiffness of the modified surface and its transition to the polymer substrate.

Time-lapse nanoscopy of friction in the non-Amontons and non-Coulomb regime.

Science.gov (United States)

Ishida, Tadashi; Sato, Takaaki; Ishikawa, Takahiro; Oguma, Masatsugu; Itamura, Noriaki; Goda, Keisuke; Sasaki, Naruo; Fujita, Hiroyuki

2015-03-11

Originally discovered by Leonard da Vinci in the 15th century, the force of friction is directly proportional to the applied load (known as Amontons' first law of friction). Furthermore, kinetic friction is independent of the sliding speed (known as Coulomb's law of friction). These empirical laws break down at high normal pressure (due to plastic deformation) and low sliding speed (in the transition regime between static friction and kinetic friction). An important example of this phenomenon is friction between the asperities of tectonic plates on the Earth. Despite its significance, little is known about the detailed mechanism of friction in this regime due to the lack of experimental methods. Here we demonstrate in situ time-lapse nanoscopy of friction between asperities sliding at ultralow speed (∼0.01 nm/s) under high normal pressure (∼GPa). This is made possible by compressing and rubbing a pair of nanometer-scale crystalline silicon anvils with electrostatic microactuators and monitoring its dynamical evolution with a transmission electron microscope. Our analysis of the time-lapse movie indicates that superplastic behavior is induced by decrystallization, plastic deformation, and atomic diffusion at the asperity-asperity interface. The results hold great promise for a better understanding of quasi-static friction under high pressure for geoscience, materials science, and nanotechnology.

Unified flow regime predictions at earth gravity and microgravity

International Nuclear Information System (INIS)

Crowley, C.J.

1990-01-01

This paper illustrates the mechanistic models developed to predict flow regime transitions at earth gravity for various pipe inclinations can be successfully applied to existing microgravity flow regime data from several experiments. There is a tendency in the literature for flow regime comparisons in several inclination ranges and at various gravity (acceleration) levels to be treated by separate models, resulting in a proliferation of models for the prediction of flow regimes. One set of mechanistic models can be used to model the transitions between stratified, slug, bubbly, and annular flow regimes in pipes for all acceleration vectors and magnitudes from earth gravity to microgravity

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)

Refrigeration. Two-Phase Flow. Flow Regimes and Pressure Drop

DEFF Research Database (Denmark)

Knudsen, Hans-Jørgen Høgaard

2002-01-01

The note gives the basic definitions used in two-phase flow. Flow regimes and flow regimes map are introduced. The different contributions to the pressure drop are stated together with an imperical correlation from the litterature.......The note gives the basic definitions used in two-phase flow. Flow regimes and flow regimes map are introduced. The different contributions to the pressure drop are stated together with an imperical correlation from the litterature....

Transition from the constant ion mobility regime to the ion-atom charge-exchange regime for bounded collisional plasmas

International Nuclear Information System (INIS)

Poggie, Jonathan; Sternberg, Natalia

2005-01-01

A numerical and analytical study of a planar, collisional, direct-current, plasma-wall problem is presented. The fluid model for the problem is first validated by comparing numerical solutions with experimental data for low-pressure (∼0.1 Pa) electrode sheaths with wall potentials on the order of -100 V. For electric potential, ion number density, and ion velocity, good agreement was found between theory and experiment from within the sheath out to the bulk plasma. The frictional drag resulting from ion-neutral collisions is described by a model incorporating both linear and quadratic velocity terms. In order to study the transition from the constant ion mobility regime (linear friction) to the ion-atom charge-exchange collision regime (quadratic friction), the theoretical model was examined numerically for a range of ion temperatures and ion-neutral collision rates. It was found that the solution profiles in the quasineutral plasma depend on the ion temperature. For low ion temperatures they are governed mainly by the ion-atom charge-exchange regime, whereas for high temperatures they are governed by the constant ion mobility regime. Quasineutral plasma models corresponding to these two limiting cases were solved analytically. In particular, an analytical plasma solution is given for the ion-atom charge exchange regime that includes the effects of ion inertia. In contrast to the quasineutral plasma, the sheath is always governed for low to moderate collision rates by the ion-atom charge-exchange regime, independent of the ion temperature. Varying the collision rate, it was shown that when the wall potential is sufficiently high, the sheath cannot be considered collisionless, even if the collision rate is quite small

Yukon's common oil and gas regime

International Nuclear Information System (INIS)

Love, B.

1998-01-01

The Yukon's common oil and gas regime was developed in partnership with First Nations and it sets out the rules that will apply throughout the Yukon and on Yukon and First Nation lands. While separate and distinct, it conforms with and is compatible with other government systems and regimes. The major elements of the common regime include the Oil and Gas Act, regulations, policies, processes and agreements. The specific opportunities that are available in each phase of oil and gas development in the Yukon are described, with a map showing all basins, reserves and sites of current oil and gas activity. The Yukon has eight potential oil and gas basins: North Coast, Old Crow, Kandik, Eagle Plain, Peel Plateau, Bonnet Plume, Whitehorse Trough, and Liard Plateau. Only three of the eight, the Liard Plateau, Whitehorse Trough and Eagle Plain, have been explored. No wells have been drilled in several of Yukon's basins. Factors influencing economic opportunities in the Territory are also described, including: (1) international events and energy markets, (2) North American gas markets, (3) environmental factors, (4) competitiveness of the Yukon regime, and (5) the commitment of industry resources. 4 figs

Brazil in the global anticorruption regime

Directory of Open Access Journals (Sweden)

Marcos Tourinho

2018-03-01

Full Text Available Abstract Brazilian anticorruption law and institutions were significantly transformed in recent decades. This article traces those transformations and explains how the international anticorruption and money laundering regimes contributed to their development. It argues that those international regimes were internalised in the Brazilian system through three mechanisms: inspiration and legitimation, coercion, and implementation support, and were critical to the transformation of Brazilian institutions.

Antenna–load interactions at optical frequencies: impedance matching to quantum systems

International Nuclear Information System (INIS)

Olmon, R L; Raschke, M B

2012-01-01

The goal of antenna design at optical frequencies is to deliver optical electromagnetic energy to loads in the form of, e.g., atoms, molecules or nanostructures, or to enhance the radiative emission from such structures, or both. A true optical antenna would, on a qualitatively new level, control the light–matter interaction on the nanoscale for controlled optical signal transduction, radiative decay engineering, quantum coherent control, and super-resolution microscopy, and provide unprecedented sensitivity in spectroscopy. Resonant metallic structures have successfully been designed to approach these goals. They are called optical antennas in analogy to radiofrequency (RF) antennas due to their capability to collect and control electromagnetic fields at optical frequencies. However, in contrast to the RF, where exact design rules for antennas, waveguides, and antenna–load matching in terms of their impedances are well established, substantial physical differences limit the simple extension of the RF concepts into the optical regime. Key distinctions include, for one, intrinsic material resonances including quantum state excitations (metals, metal oxides, semiconductor homo- and heterostructures) and extrinsic resonances (surface plasmon/phonon polaritons) at optical frequencies. Second, in the absence of discrete inductors, capacitors, and resistors, new design strategies must be developed to impedance match the antenna to the load, ultimately in the form of a vibrational, electronic, or spin excitation on the quantum level. Third, there is as yet a lack of standard performance metrics for characterizing, comparing and quantifying optical antenna performance. Therefore, optical antenna development is currently challenged at all the levels of design, fabrication, and characterization. Here we generalize the ideal antenna–load interaction at optical frequencies, characterized by three main steps: (i) far-field reception of a propagating mode exciting an

Antenna-load interactions at optical frequencies: impedance matching to quantum systems.

Science.gov (United States)

Olmon, R L; Raschke, M B

2012-11-09

The goal of antenna design at optical frequencies is to deliver optical electromagnetic energy to loads in the form of, e.g., atoms, molecules or nanostructures, or to enhance the radiative emission from such structures, or both. A true optical antenna would, on a qualitatively new level, control the light-matter interaction on the nanoscale for controlled optical signal transduction, radiative decay engineering, quantum coherent control, and super-resolution microscopy, and provide unprecedented sensitivity in spectroscopy. Resonant metallic structures have successfully been designed to approach these goals. They are called optical antennas in analogy to radiofrequency (RF) antennas due to their capability to collect and control electromagnetic fields at optical frequencies. However, in contrast to the RF, where exact design rules for antennas, waveguides, and antenna-load matching in terms of their impedances are well established, substantial physical differences limit the simple extension of the RF concepts into the optical regime. Key distinctions include, for one, intrinsic material resonances including quantum state excitations (metals, metal oxides, semiconductor homo- and heterostructures) and extrinsic resonances (surface plasmon/phonon polaritons) at optical frequencies. Second, in the absence of discrete inductors, capacitors, and resistors, new design strategies must be developed to impedance match the antenna to the load, ultimately in the form of a vibrational, electronic, or spin excitation on the quantum level. Third, there is as yet a lack of standard performance metrics for characterizing, comparing and quantifying optical antenna performance. Therefore, optical antenna development is currently challenged at all the levels of design, fabrication, and characterization. Here we generalize the ideal antenna-load interaction at optical frequencies, characterized by three main steps: (i) far-field reception of a propagating mode exciting an antenna

The application of neural networks to flow regime identification

International Nuclear Information System (INIS)

Embrechts, M.; Yapo, T.C.; Lahey, R.T. Jr.

1993-01-01

This paper deals with the application of a Kohonen map for the identification of two-phase flow regimes where a mixture of gas and fluid flows through a horizontal tube. Depending on the relative flow velocities of the gas and the liquid phase, four distinct flow regimes can be identified: Wavy flow, plug flow, slug flow and annular flow. A schematic of these flow regimes is presented. The objective identification of two-phase flow regimes constitutes an important and challenging problem for the design of safe and reliable nuclear power plants. Previous attempts to classify these flow regimes are reviewed by Franca and Lahey. The authors describe how a Kohonen map can be applied to distinguish between flow regimes based on the Fourier power spectra and wavelet transforms of pressure drop fluctuations. The Fourier power spectra allowed the Kohonen map to identify the flow regimes successfully. In contrast, the Kohonen maps based on a wavelet transform could only distinguish between wavy and annular flows. An analysis of typical two-phase pressure drop data for an air/water mixture in a horizontal pipe is presented. Use of the wavelet transform and the Kohonen feature map are discussed

Macro and Microscopic Investigation on Fracture Specimen of Alloy 617 Base Metal and Weldment in Low Cycle Fatigue Regime

International Nuclear Information System (INIS)

Kim, Seon Jin; Dewa, Rando Tungga; Kim, Won Gon

2016-01-01

This paper investigates macro- and microscopic fractography performed on fracture specimens from low cycle fatigue (LCF) testings through an Alloy 617 base metal and weldments. The weldment specimens were taken from gas tungsten arc welding (GTAW) pad of Alloy 617. The aim of the present study is to investigate the macro- and microscopic aspects of the low cycle fatigue fracture mode and mechanism of Alloy 617 base metal and GTAWed weldment specimens. Fully axial total strain controlled fatigue tests were conducted at room temperature with total strain ranges of 0.6, 0.9, 1.2 and 1.5%. Macroscopic fracture surfaces of Alloy 617 base metal specimens showed a flat type normal to the fatigue loading direction, whereas the GTAWed weldment specimens were of a shear/star type. The fracture surfaces of both the base metal and weldment specimens revealed obvious fatigue striations at the crack propagation regime. In addition, the fatigue crack mechanism of the base metal showed a transgranular normal to fatigue loading direction; however, the GTAWed weldment specimens showed a transgranular at approximately 45° to the fatigue loading direction

Macro and Microscopic Investigation on Fracture Specimen of Alloy 617 Base Metal and Weldment in Low Cycle Fatigue Regime

Energy Technology Data Exchange (ETDEWEB)

Kim, Seon Jin; Dewa, Rando Tungga [Pukyung National Univ., Busan (Korea, Republic of); Kim, Won Gon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-06-15

This paper investigates macro- and microscopic fractography performed on fracture specimens from low cycle fatigue (LCF) testings through an Alloy 617 base metal and weldments. The weldment specimens were taken from gas tungsten arc welding (GTAW) pad of Alloy 617. The aim of the present study is to investigate the macro- and microscopic aspects of the low cycle fatigue fracture mode and mechanism of Alloy 617 base metal and GTAWed weldment specimens. Fully axial total strain controlled fatigue tests were conducted at room temperature with total strain ranges of 0.6, 0.9, 1.2 and 1.5%. Macroscopic fracture surfaces of Alloy 617 base metal specimens showed a flat type normal to the fatigue loading direction, whereas the GTAWed weldment specimens were of a shear/star type. The fracture surfaces of both the base metal and weldment specimens revealed obvious fatigue striations at the crack propagation regime. In addition, the fatigue crack mechanism of the base metal showed a transgranular normal to fatigue loading direction; however, the GTAWed weldment specimens showed a transgranular at approximately 45° to the fatigue loading direction.

Regimes of the magnetized Rayleigh endash Taylor instability

International Nuclear Information System (INIS)

Winske, D.

1996-01-01

Hybrid simulations with kinetic ions and massless fluid electrons are used to investigate the linear and nonlinear behavior of the magnetized Rayleigh endash Taylor instability in slab geometry with the plasma subject to a constant gravity. Three regimes are found, which are determined by the magnitude of the complex frequency ω=ω r +iγ. For |ω| i (Ω i = ion gyrofrequency), one finds the typical behavior of the usual fluid regime, namely the development of open-quote open-quote mushroom-head close-quote close-quote spikes and bubbles in the density and a strongly convoluted boundary between the plasma and magnetic field, where the initial gradient is not relaxed much. A second regime, where |ω|∼0.1Ω i , is characterized by the importance of the Hall term. Linearly, the developing flute modes are more finger-like and tilted along the interface; nonlinearly, clump-like structures form, leading to a significant broadening of the interface. The third regime is characterized by unmagnetized ion behavior, with |ω|∼Ω i . Density clumps, rather than flutes, form in the linear stage, while nonlinearly, longer-wavelength modes that resemble those in fluid regime dominate. Finite Larmor radius stabilization of short-wavelength modes is observed in each regime. copyright 1996 American Institute of Physics

Numerical simulation of transitions between back discharge regimes

International Nuclear Information System (INIS)

Jansky, Jaroslav; Lemont, Florent; Bessieres, Delphine; Paillol, Jean

2014-01-01

This paper presents numerical simulations of transitions between back discharge regimes. Back discharge refers to any discharge initiated at or near a dielectric layer covering a passive electrode. In this work, a pinhole in a dielectric layer on a plane anode serves as a model for back discharge activity. We have studied transitions between back discharge regimes by varying the surface charge density on the dielectric layer and the electric field in front of the pinhole. From the variation of these two independent parameters, the back discharge regimes have been depicted as a mode diagram inspired by the experimental study of Masuda and Mizuno. The resulting diagram includes the different discharge regimes that are commonly observed in experiments. The propagation of a positive ionizing wave inside the pinhole toward its edge, and the resulting formation of a plasma zone at its exit constitute the onset stage of back discharge. From this stage, the transitions to volume discharge or surface discharge can occur. The volume discharge regime consists of the propagation of a discharge in space toward the cathode which can be superimposed with the propagation of a discharge above the dielectric layer surface. The diagram reveals the conditions for transitions between back discharge regimes. (authors)

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.)

QCD in the δ-regime

International Nuclear Information System (INIS)

Bietenholz, W.; Rakow, P.E.L.

2011-03-01

The δ-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 δ-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 R π , which has been computed to the third order in the δ-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 δ-regime. This is very tedious, but results compatible with the predictions for M R π have been obtained. Then we show that an extrapolation of pion masses measured in a larger volume towards the δ-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 3 . (orig.)

Competition Regime

Directory of Open Access Journals (Sweden)

Danilo Icaza Ortiz

2013-01-01

Full Text Available This paper is a review of the competition regime works of various authors, published under the auspices of the University of the Hemispheres and the Corporation for Studies and Publications. Analyzes the structure, the general concepts, case law taken for development. Includes comments on the usefulness of this work for the study of competition law and the contribution to the lawyers who want to practice in this branch of economic law.

The international climate regime: towards consolidation collapse

International Nuclear Information System (INIS)

Berthaud, P.; Cavard, D.; Criqui, P.

2003-10-01

This article deals with the different modalities that exist to manage a problem of collective action in the field of climate negotiation. It uses two concepts of the International Political Economy (IPE): the concept of International Regime (IR) and the concept of Hegemony and / or Leadership. The course the international negotiation has taken between 1992 (Rio Convention) and march 2001 (the US rejection of the Kyoto Protocol of 1997) leads us, first, to question the conditions of existence as well as the viability of a non-hegemonic International Regime (Part One). Then, we discuss the perspectives for the 'post - Kyoto' era. After having examined the preferences of the three most active actors in the negotiation (USA, Europe, G77 + China) combined with the leadership capacities they possess, we identify three scenarios for the future: i) anarchy, ii) an international regime under the American hegemony, iii) an international regime under the European leadership (Part Two). (author)

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

On the dynamic stability of shear deformable beams under a tensile load

Science.gov (United States)

Caddemi, S.; Caliò, I.; Cannizzaro, F.

2016-07-01

Loss of stability of beams in a linear static context due to the action of tensile loads has been disclosed only recently in the scientific literature. However, tensile instability in the dynamic regime has been only marginally covered. Several aspects concerning the role of shear deformation on the tensile dynamic instability on continuous and discontinuous beams are still to be addressed. It may appear as a paradox, but also for the case of the universally studied Timoshenko beam model, despite its old origin, frequency-axial load diagrams in the range of negative values of the load (i.e. tensile load) has never been brought to light. In this paper, for the first time, the influence of a conservative tensile axial loads on the dynamic behaviour of the Timoshenko model, according to the Haringx theory, is assessed. It is shown that, under increasing tensile loads, regions of positive/negative fundamental frequency variations can be distinguished. In addition, the beam undergoes eigen-mode changes, from symmetric to anti-symmetric shapes, until tensile instability of divergence type is reached. As a further original contribution on the subject, taking advantage of a new closed form solution, it is shown that the same peculiarities are recovered for an axially loaded Euler-Bernoulli vibrating beam with multiple elastic sliders. This latter model can be considered as the discrete counterpart of the Timoshenko beam-column in which the internal sliders concentrate the shear deformation that in the Timoshenko model is continuously distributed. Original aspects regarding the evolution of the vibration frequencies and the relevant mode shapes with the tensile load value are highlighted.

Global regime shift dynamics of catastrophic sea urchin overgrazing

Science.gov (United States)

Ling, S. D.; Scheibling, R. E.; Rassweiler, A.; Johnson, C. R.; Shears, N.; Connell, S. D.; Salomon, A. K.; Norderhaug, K. M.; Pérez-Matus, A.; Hernández, J. C.; Clemente, S.; Blamey, L. K.; Hereu, B.; Ballesteros, E.; Sala, E.; Garrabou, J.; Cebrian, E.; Zabala, M.; Fujita, D.; Johnson, L. E.

2015-01-01

A pronounced, widespread and persistent regime shift among marine ecosystems is observable on temperate rocky reefs as a result of sea urchin overgrazing. Here, we empirically define regime-shift dynamics for this grazing system which transitions between productive macroalgal beds and impoverished urchin barrens. Catastrophic in nature, urchin overgrazing in a well-studied Australian system demonstrates a discontinuous regime shift, which is of particular management concern as recovery of desirable macroalgal beds requires reducing grazers to well below the initial threshold of overgrazing. Generality of this regime-shift dynamic is explored across 13 rocky reef systems (spanning 11 different regions from both hemispheres) by compiling available survey data (totalling 10 901 quadrats surveyed in situ) plus experimental regime-shift responses (observed during a total of 57 in situ manipulations). The emergent and globally coherent pattern shows urchin grazing to cause a discontinuous ‘catastrophic’ regime shift, with hysteresis effect of approximately one order of magnitude in urchin biomass between critical thresholds of overgrazing and recovery. Different life-history traits appear to create asymmetry in the pace of overgrazing versus recovery. Once shifted, strong feedback mechanisms provide resilience for each alternative state thus defining the catastrophic nature of this regime shift. Importantly, human-derived stressors can act to erode resilience of desirable macroalgal beds while strengthening resilience of urchin barrens, thus exacerbating the risk, spatial extent and irreversibility of an unwanted regime shift for marine ecosystems.

Insights in the Rhodium-Catalyzed Tandem Isomerization-Hydroformylation of 10-Undecenitrile: Evidence for a Fast Isomerization Regime

Directory of Open Access Journals (Sweden)

Lucas Le Goanvic

2018-04-01

Full Text Available The tandem isomerization-hydroformylation of 10-undecenitrile (1 into the corresponding linear aldehyde (2 with a Rh-biphephos system was studied and the formation of internal olefin isomers (1-int-x was monitored over time. The existence of an “isomerization phenomenon” was evidenced, where fast isomerization of 1 into up to 70% of 1-int-x followed by fast back-isomerization of 1-int-x into 1 and, in turn, into 2 occurs. This fast dynamic isomerization regime is favored at high syngas pressure (40 bar and low biphephos-to-Rh ratio (5–10, and it is best observed at relatively high catalyst loadings ([1]0/[Rh] ≤ 3000. The latter regime is indeed evanescent, and gives place to a second stage in which isomerization of internal olefins (and eventual conversion into 2 proceeds much more slowly. The results are tentatively rationalized by the formation of an unstable species that promotes dynamic isomerization and which slowly vanishes or collapses into a Rh-biphephos species which is the one responsible for hydroformylation.

Perspectives on the International and Internal Nuclear Security Regime

International Nuclear Information System (INIS)

Jang, Sung Soon

2015-01-01

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

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.

Change of secondary water regime of Paks NPP. Change of secondary water regime at Unit 2

International Nuclear Information System (INIS)

Doma, A.; Patek, G.; Pinter, T.; Bajari, M.; Tilky, P.

2001-01-01

The installation of high pH water regime during the 17th cycle of Unit 2 aimed to decrease the amount of transportation inlet of erosion-corrosion products (magnitude) in feedwater to SGs. The resolution of OAH-NBI permitting the installation ordained to make an evaluation of the process. The main conclusions and results are discussed. The high pH water regime proved to be adequate in the case of Unit 2 as well, similarly to Units 3, 4 and 1. (R.P.)

Institutional effectiveness in international regimes. An analysis of the effectiveness of the nuclear non-proliferation regime coping with the political malignity in the case of Iran

Energy Technology Data Exchange (ETDEWEB)

Oezden, Tugba

2015-07-01

Among the international security regimes, the Nuclear Non-Proliferation Regime has a prominent ranking due to the destructive power of the nuclear weapons over regional and global peace and stability. The NPT Regime has come across with two major challenges in the recent decade: North Korea and Iran. Contrary to North Korea, Iran is determined to stay as a state party to the Nuclear Non-Proliferation Treaty. The Regime still did not confirm the character and extent of Iranian nuclear program. The question of this study is ''why the processes of the NPT Regime cannot specify the nature and scope of Irans nuclear program?'' The three main the processes of the regime, which are the International Atomic Energy Agency (IAEA), the UN Security Council (UNSC) and the multilateral negotiations, are examined to determine the weaknesses of the regime. This study argues that the regime is modulated to cope with operational challenges and it remains relatively incompetent when a political challenge arises.

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.

Considerations on nonproliferation regime meeting in a changing world

International Nuclear Information System (INIS)

Kurihara, Hiroyoshi; Kikuchi, Masahiro

1994-01-01

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)

Beta Risk and Regime Shift in Market Volatility

OpenAIRE

Don U.A. Galagedera; Roland G. Shami

2004-01-01

In this paper, we relate security returns in the thirty securities in the Dow Jones index to regime shifts in the market portfolio (S&P500) volatility. We model market volatility as a multiple-state Markov switching process of order one and estimate non-diversifiable security risk (beta) in the different market volatility regimes. We test the significance of the premium of the beta risk associated with the different market regimes and find evidence of a relationship between security return an...

The concept of regime values: Are revitalization and regime change possible?

NARCIS (Netherlands)

Overeem, P.

2015-01-01

Among the plethora of public values, one special class is that of “regime values.” This notion plays a central role in the constitutional approach to public administration mainly developed by the late John A. Rohr. In this article, an attempt is made to assess the viability of Rohr’s concept of

Radiative effects of global MODIS cloud regimes

Science.gov (United States)

Oreopoulos, Lazaros; Cho, Nayeong; Lee, Dongmin; Kato, Seiji

2018-01-01

We update previously published MODIS global cloud regimes (CRs) using the latest MODIS cloud retrievals in the Collection 6 dataset. We implement a slightly different derivation method, investigate the composition of the regimes, and then proceed to examine several aspects of CR radiative appearance with the aid of various radiative flux datasets. Our results clearly show the CRs are radiatively distinct in terms of shortwave, longwave and their combined (total) cloud radiative effect. We show that we can clearly distinguish regimes based on whether they radiatively cool or warm the atmosphere, and thanks to radiative heating profiles to discern the vertical distribution of cooling and warming. Terra and Aqua comparisons provide information about the degree to which morning and afternoon occurrences of regimes affect the symmetry of CR radiative contribution. We examine how the radiative discrepancies among multiple irradiance datasets suffering from imperfect spatiotemporal matching depend on CR, and whether they are therefore related to the complexity of cloud structure, its interpretation by different observational systems, and its subsequent representation in radiative transfer calculations. PMID:29619289

Negotiating a regime to control global warming

International Nuclear Information System (INIS)

Sebenius, J.K.

1991-01-01

For purposes of analysis, this paper has uncritically maintained that the prospect of a serious climate problem exists and has only lightly examined the broader advantages and drawbacks of various proposed policy and institutional responses. Crucial as they are to a full treatment of the issues, these underlying substantive and policy questions enter the analysis primarily insofar as they affect the likely outcomes of pending and potential negotiations. To an advocate of a new greenhouse control regime, the fundamental negotiating task is to craft and sustain a meaningful winning coalition of countries backing such a regime. Two centrally necessary conditions for the fundamental task are: (1) that each member of the coalition see enough gain in the regime relative to the alternatives to adhere and (2) the potential and actual blocking coalitions of interests opposed to the regime be prevented from forming and from being acceptably accommodated or otherwise neutralized. The analysis of this paper is organized around key questions whose answers will influence whether and how these two necessary conditions might (or might not) be met

Radiative Effects of Global MODIS Cloud Regimes

Science.gov (United States)

Oraiopoulos, Lazaros; Cho, Nayeong; Lee, Dong Min; Kato, Seiji

2016-01-01

We update previously published MODIS global cloud regimes (CRs) using the latest MODIS cloud retrievals in the Collection 6 dataset. We implement a slightly different derivation method, investigate the composition of the regimes, and then proceed to examine several aspects of CR radiative appearance with the aid of various radiative flux datasets. Our results clearly show the CRs are radiatively distinct in terms of shortwave, longwave and their combined (total) cloud radiative effect. We show that we can clearly distinguish regimes based on whether they radiatively cool or warm the atmosphere, and thanks to radiative heating profiles to discern the vertical distribution of cooling and warming. Terra and Aqua comparisons provide information about the degree to which morning and afternoon occurrences of regimes affect the symmetry of CR radiative contribution. We examine how the radiative discrepancies among multiple irradiance datasets suffering from imperfect spatiotemporal matching depend on CR, and whether they are therefore related to the complexity of cloud structure, its interpretation by different observational systems, and its subsequent representation in radiative transfer calculations.

Emerging Trends in Development of International Information Security Regime

Directory of Open Access Journals (Sweden)

Elena S. Zinovieva

2016-01-01

Full Text Available The article discusses the key trends shaping the international regime on information security. International cooperation in this area at the global level encounters contradictions of state interest. The main actors of the information security are the United States, Russia, China and the EU countries (Britain, France and Germany. The main contradiction is developing between the US on one side and Russia and China on the other. EU countries occupy the middle position, gravitating to that of US. The article proves that international cooperation on information security will reflect the overall logic of the development of international cooperation, which is characterized by a new model of cooperation, with the participation of state and non-state actors, known as multi-stakeholder partnerships and multi-level cooperation. The logic of the formation of an international regime on information security is closest to the logic of the formation of the international non-proliferation regime. It is in the interest of Russia to support the trend towards regionalization of information security regime. Russia can form a regional information security regime in the former Soviet Union on the basis of the CSTO and SCO and potentially on a wider Eurasian space. Such regional regime would give Russia an opportunity to shape the international regime and closely monitor emerging information security issues in the former Soviet Union, and remove the potential threat of "color revolutions".

Dune growth under multidirectional wind regimes

Science.gov (United States)

Gadal, C.; Rozier, O.; Claudin, P.; Courrech Du Pont, S.; Narteau, C.

2017-12-01

Under unidirectional wind regimes, flat sand beds become unstable to produce periodic linear dunes, commonly called transverse dunes because their main ridges are oriented perpendicular to the air flow. In areas of low sediment availability, the same interactions between flow, transport and topography produce barchan dunes, isolated sand-pile migrating over long distances with a characteristic crescentic shape. For the last fifteen years, barchan dunes and the instability at the origin of transverse dunes have been the subject of numerous studies that have identified a set of characteristic length and time scales with respect to the physical properties of both grains and fluid. This is not the case for dunes developing under multidirectional wind regimes. Under these conditions, dune orientation is measured with respect to the direction of the resultant sand flux. Depending on the wind regime, dunes do not always line up perpendicularly to the resultant sand flux, but can also be at an oblique angle or even parallel to it. These oblique and longitudinal dunes are ubiquitous in all deserts on Earth and planetary bodies because of the seasonal variability of wind orientation. They are however poorly constrained by observations and there is still no complete theoretical framework providing a description of their orientation and initial wavelength. Here, we extend the linear stability analysis of a flat sand of bed done in two dimensions for a unidirectional flow to three dimensions and multidirectional flow regimes. We are able to recover transitions from transverse to oblique or longitudinal dune patterns according to changes in wind regimes. We besides give a prediction for the initial dune wavelength. Our results compare well to previous theory of dune orientation and to field, experimental and numerical data.

The Gulf crisis (1990-91) and the Kuwait regime : legitimacy and stability in a rentier state Gulf crisis (1990-91) and the Kuwait regime

OpenAIRE

Maktabi, Rania

1992-01-01

THE GULF CRISIS (1990-91) & THE KUWAITI REGIME - LEGITIMACY AND STABILITY IN A RENTIER STATE Among the central questions I address are: What are the factors that contribute to regime stability in Kuwait? How do we understand the relationship between rulers and ruled? In which ways did the regime maintain political authority during the Crisis, and how does it ensure its stability after the experience of the Crisis? It is argued that the legitimacy of the Kuwaiti regime could be seen a...

Using Long-Term Satellite Observations to Identify Sensitive Regimes and Active Regions of Aerosol Indirect Effects for Liquid Clouds Over Global Oceans

Science.gov (United States)

Zhao, Xuepeng; Liu, Yangang; Yu, Fangquan; Heidinger, Andrew K.

2018-01-01

Long-term (1981-2011) satellite climate data records of clouds and aerosols are used to investigate the aerosol-cloud interaction of marine water cloud from a climatology perspective. Our focus is on identifying the regimes and regions where the aerosol indirect effects (AIEs) are evident in long-term averages over the global oceans through analyzing the correlation features between aerosol loading and the key cloud variables including cloud droplet effective radius (CDER), cloud optical depth (COD), cloud water path (CWP), cloud top height (CTH), and cloud top temperature (CTT). An aerosol optical thickness (AOT) range of 0.13 change of long-term averaged CDER appears only in limited oceanic regions. The signature of aerosol invigoration of water clouds as revealed by the increase of cloud cover fraction (CCF) and CTH with increasing AOT at the middle/high latitudes of both hemispheres is identified for a pristine atmosphere (AOT polluted marine atmosphere (AOT > 0.3) in the tropical convergence zones. The regions where the second AIE is likely to manifest in the CCF change are limited to several oceanic areas with high CCF of the warm water clouds near the western coasts of continents. The second AIE signature as represented by the reduction of the precipitation efficiency with increasing AOT is more likely to be observed in the AOT regime of 0.08 < AOT < 0.4. The corresponding AIE active regions manifested themselves as the decline of the precipitation efficiency are mainly limited to the oceanic areas downwind of continental aerosols. The sensitive regime of the conventional AIE identified in this observational study is likely associated with the transitional regime from the aerosol-limited regime to the updraft-limited regime identified for aerosol-cloud interaction in cloud model simulations.

Ion-neutral Clustering of Bile Acids in Electrospray Ionization Across UPLC Flow Regimes

Science.gov (United States)

Brophy, Patrick; Broeckling, Corey D.; Murphy, James; Prenni, Jessica E.

2018-02-01

Bile acid authentic standards were used as model compounds to quantitatively evaluate complex in-source phenomenon on a UPLC-ESI-TOF-MS operated in the negative mode. Three different diameter columns and a ceramic-based microfluidic separation device were utilized, allowing for detailed descriptions of bile acid behavior across a wide range of flow regimes and instantaneous concentrations. A custom processing algorithm based on correlation analysis was developed to group together all ion signals arising from a single compound; these grouped signals produce verified compound spectra for each bile acid at each on-column mass loading. Significant adduction was observed for all bile acids investigated under all flow regimes and across a wide range of bile acid concentrations. The distribution of bile acid containing clusters was found to depend on the specific bile acid species, solvent flow rate, and bile acid concentration. Relative abundancies of each cluster changed non-linearly with concentration. It was found that summing all MS level (low collisional energy) ions and ion-neutral adducts arising from a single compound improves linearity across the concentration range (0.125-5 ng on column) and increases the sensitivity of MS level quantification. The behavior of each cluster roughly follows simple equilibrium processes consistent with our understanding of electrospray ionization mechanisms and ion transport processes occurring in atmospheric pressure interfaces. [Figure not available: see fulltext.

Socio-ecological regime transitions in Austria and the United Kingdom

International Nuclear Information System (INIS)

Krausmann, Fridolin; Schandl, Heinz; Sieferle, Rolf Peter

2008-01-01

We employ the concepts of socio-ecological regime and regime transition to better understand the biophysical causes and consequences of industrialization. For two case studies, the United Kingdom and Austria we describe two steps in a major transition from an agrarian to an industrial socio-ecological regime and the resulting consequences for energy use, land use and labour organization. In a first step, the coal based industrial regime co-existed with an agricultural sector remaining within the bounds of the old regime. In a second step, the oil/electricity based industrial regime, agriculture was integrated into the new pattern and the socio-ecological transition had been completed. Industrialization offers an answer to the input and growth related sustainability problems of the agrarian regime but creates new sustainability problems of a larger scale. While today's industrial societies are stabilizing their resource use albeit at an unsustainable level large parts of the global society are in midst of the old industrial transition. This poses severe problems for global sustainability. (author)

Socio-ecological regime transitions in Austria and the United Kingdom

Energy Technology Data Exchange (ETDEWEB)

Krausmann, Fridolin [Institute of Social Ecology, Klagenfurt University, Klagenfurt (Austria); Schandl, Heinz [CSIRO Sustainable Ecosystems, Canberra (Australia); Sieferle, Rolf Peter [Department of Humanities and Social Sciences, University of St. Gallen, Sankt Gallen (Switzerland)

2008-03-15

We employ the concepts of socio-ecological regime and regime transition to better understand the biophysical causes and consequences of industrialization. For two case studies, the United Kingdom and Austria we describe two steps in a major transition from an agrarian to an industrial socio-ecological regime and the resulting consequences for energy use, land use and labour organization. In a first step, the coal based industrial regime co-existed with an agricultural sector remaining within the bounds of the old regime. In a second step, the oil/electricity based industrial regime, agriculture was integrated into the new pattern and the socio-ecological transition had been completed. Industrialization offers an answer to the input and growth related sustainability problems of the agrarian regime but creates new sustainability problems of a larger scale. While today's industrial societies are stabilizing their resource use albeit at an unsustainable level large parts of the global society are in midst of the old industrial transition. This poses severe problems for global sustainability. (author)

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.

Cloud regimes as phase transitions

Science.gov (United States)

Stechmann, Samuel; Hottovy, Scott

2017-11-01

Clouds are repeatedly identified as a leading source of uncertainty in future climate predictions. Of particular importance are stratocumulus clouds, which can appear as either (i) closed cells that reflect solar radiation back to space or (ii) open cells that allow solar radiation to reach the Earth's surface. Here we show that these clouds regimes - open versus closed cells - fit the paradigm of a phase transition. In addition, this paradigm characterizes pockets of open cells (POCs) as the interface between the open- and closed-cell regimes, and it identifies shallow cumulus clouds as a regime of higher variability. This behavior can be understood using an idealized model for the dynamics of atmospheric water as a stochastic diffusion process. Similar viewpoints of deep convection and self-organized criticality will also be discussed. With these new conceptual viewpoints, ideas from statistical mechanics could potentially be used for understanding uncertainties related to clouds in the climate system and climate predictions. The research of S.N.S. is partially supported by a Sloan Research Fellowship, ONR Young Investigator Award N00014-12-1-0744, and ONR MURI Grant N00014-12-1-0912.

Peaceful Protest, Political Regimes, and the Social Media Challenge

Science.gov (United States)

2016-06-01

University, 2012 Randolph J. Fleming, II Major, United States Army B.A., Virginia Commonwealth University, 2004 Submitted in partial fulfillment of...intermediate regimes or transitioning regimes carrying the burden of instability and conflict.23 In a similar vein, Henderson identifies democracies, as...spreading infectious ideologies through ICT.25 Furthermore, Regan and Henderson indicate that intermediate, anocratic regimes tend to oppress

Water regime of steam power plants

International Nuclear Information System (INIS)

Oesz, Janos

2011-01-01

The water regime of water-steam thermal power plants (secondary side of pressurized water reactors (PWR); fossil-fired thermal power plants - referred to as steam power plants) has changed in the past 30 years, due to a shift from water chemistry to water regime approach. The article summarizes measures (that have been realised by chemists of NPP Paks) on which the secondary side of NPP Paks has become a high purity water-steam power plant and by which the water chemistry stress corrosion risk of heat transfer tubes in the VVER-440 steam generators was minimized. The measures can also be applied to the water regime of fossil-fired thermal power plants with super- and subcritical steam pressure. Based on the reliability analogue of PWR steam generators, water regime can be defined as the harmony of construction, material(s) and water chemistry, which needs to be provided in not only the steam generators (boiler) but in each heat exchanger of steam power plant: - Construction determines the processes of flow, heat and mass transfer and their local inequalities; - Material(s) determines the minimal rate of general corrosion and the sensitivity for local corrosion damage; - Water chemistry influences the general corrosion of material(s) and the corrosion products transport, as well as the formation of local corrosion environment. (orig.)

Direct-contact condensation regime map for core makeup tank of passive reactors

International Nuclear Information System (INIS)

Lee, Sang Il; No, Hee Cheon

1998-01-01

The condensation regime map in the core makeup tank of passive reactors is experimentally investigated. The condensation regimes identified through the experiments are divided into three distinct ones: sonic jet, subsonic jet, and steam cavity. The steam cavity regime is a unique regime of downward injection with the present geometry not previously observed in other experiments. The condensation regime map is constructed using Froude number and Jacob number. It turns out that the buoyancy force has a large influence on the regime transition because the regime map using the Froude number better fits data with different geometries than other dimensionless parameters. Simple correlations for the regime boundaries are proposed using the Froude number and the Jacob number

The Effects of Constant and Fluctuating Thermal Regimes for Reducing Chill Injuries During Cold Storage of Late-Instar Larva of Lysiphlebus fabarum (Hym., Braconidae

Directory of Open Access Journals (Sweden)

Hossein Mahi

2016-09-01

Full Text Available Introduction: Mass production of natural enemies has been considered a necessity for biological control programs. Most beneficial insects have a relatively short shelf-life, so suppliers do not have a sufficient number of biocontrol agents. The development of storage techniques for biocontrol agents provides flexibility and efficiency in mass production. Cold storage by prolonging insect development times provides a steady and sufficient supply of insects and synchronizes a desired developmental stage of biocontrol agents with times of pest outbreaks; so it reduces the cost of biocontrol programs by enlarging the production period over several months. Cold storage is usually associated with major fitness costs. Even if the insects remain alive after cold storage, a reduction of fitness may be observed, so the production of high quality natural enemies must be ensured. Developing effective methods is necessary in mass-producing. It has been reported that using fluctuating thermal regimes (FTR (i.e. cold exposure interrupted by periodic short pulses of high temperature versus constant thermal regimes (CTR can progress the quality of biological control agents and significantly reduce rates of mortality. In this study, the impact of fluctuating thermal regimes versus constant low temperatures on the emergence rate, sex ratio, post-storage development time, adult size, egg load and egg size of the parasitoid wasp, Lysiphlebus fabarum (Marshall was studied. The test was examined in three cold storage periods (1, 2, or 3 weeks. Lysiphlebus fabarum is an aphidiine parasitoid which attacks more than 70 species of aphids. Although both sexual (arrhenotokous and asexual (thelytokous populations of L. fabarum have been reported in Iran, the former population has been studied in this research. Materials and Methods: A stock colony of black bean aphid, Aphis fabae Scopoli (Hemi., Aphididae was established from material collected in bean fields in Khuzestan

Flow regimes in vertical gas-solid contact systems

Energy Technology Data Exchange (ETDEWEB)

Yerushalmi, J.; Cankurt, N. T.; Geldart, D.; Liss, B.

1976-01-01

The flow characteristics in fluidized beds, i.e., gas-solid systems, was studied to determine the flow regimes, the interaction of gas and solid in the various flow regimes and the dependence of this interaction and of transition between flow regimes on the properties of the gas and solid, on the gas and solid flow rates, and on the containing vessel. Fluidized beds with both coarse and fine particles are considered. Test results using high speed photography to view the operation of a 2-dimensional bed are discussed. (LCL)

Terms of trade and exchange rate regimes in developing countries

OpenAIRE

Christian Broda

2002-01-01

Since Friedman (1953), an advantage often attributed to flexible exchange rate regimes over fixed regimes is their ability to insulate more effectively the economy against real shocks. I use a post-Bretton Woods sample (1973-96) of seventy-five developing countries to assess whether the responses of real GDP, real exchange rates, and prices to terms-of-trade shocks differ systematically across exchange rate regimes. I find that responses are significantly different across regimes in a way tha...

Trust in regulatory regimes

NARCIS (Netherlands)

Six, Frédérique; Verhoest, Koen

2017-01-01

Within political and administrative sciences generally, trust as a concept is contested, especially in the field of regulatory governance. This groundbreaking book is the first to systematically explore the role and dynamics of trust within regulatory regimes. Conceptualizing, mapping and analyzing

ACCESSORIES OF FISCAL OBLIGATION. LEGAL REGIME

Directory of Open Access Journals (Sweden)

RADA POSTOLACHE

2012-05-01

Full Text Available The interest – which is an institution typical to private law, has been taken over by the fiscal field and adapted to the specific features of fiscal obligation – being defined by its imperative legal regime, which has at the least the following characteristic elements: unitary character, imposed legal percentage, compulsory demand of interest, automatic application. In order to render responsible fiscal debtors, the lawmaker has reintroduced, as an accessory of fiscal obligation, delayed payment penalties, which have a distinct nature and legal regime, but without the principle non bis in idem being transgressed. Our study aims to establish the legal regime ofaccessories typical to fiscal obligation, from the perspective of special normative acts, but also of the common law within the field – Civil Code and Government Ordinance No. 13/2011 – by pointing out at the same time both the particular circumstances and procedural ones regulated by the Fiscal Procedure Code, shedding light upon the controversial legal nature of accessories.

Mainstreaming solar : Stretching the regulatory regime through business model innovation

NARCIS (Netherlands)

Huijben, J.C.C.M.; Verbong, G.P.J.; Podoynitsyna, K.S.

This paper explores how the regulatory regime for Solar PV, defined as a combination of niche shielding and mainstream regulations, affects niche business models, using the Dutch and Flemish regulatory regimes as examples. The regulatory regime does not influence all components of the business

An Examination of the Nature of Global MODIS Cloud Regimes

Science.gov (United States)

Oreopoulos, Lazaros; Cho, Nayeong; Lee, Dongmin; Kato, Seiji; Huffman, George J.

2014-01-01

We introduce global cloud regimes (previously also referred to as "weather states") derived from cloud retrievals that use measurements by the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard the Aqua and Terra satellites. The regimes are obtained by applying clustering analysis on joint histograms of retrieved cloud top pressure and cloud optical thickness. By employing a compositing approach on data sets from satellites and other sources, we examine regime structural and thermodynamical characteristics. We establish that the MODIS cloud regimes tend to form in distinct dynamical and thermodynamical environments and have diverse profiles of cloud fraction and water content. When compositing radiative fluxes from the Clouds and the Earth's Radiant Energy System instrument and surface precipitation from the Global Precipitation Climatology Project, we find that regimes with a radiative warming effect on the atmosphere also produce the largest implied latent heat. Taken as a whole, the results of the study corroborate the usefulness of the cloud regime concept, reaffirm the fundamental nature of the regimes as appropriate building blocks for cloud system classification, clarify their association with standard cloud types, and underscore their distinct radiative and hydrological signatures.

Political regime change, economic liberalization and growth accelerations

NARCIS (Netherlands)

Jong-A-Pin, Richard; De Haan, Jakob

We examine whether the type of political regime, regime changes, and economic liberalization are related to economic growth accelerations. Our results show that growth accelerations are preceded by economic liberalizations. We also find that growth accelerations are less likely to happen the longer

Exchange-rate regimes and economic growth: An empirical evaluation

OpenAIRE

Simón Sosvilla-Rivero; María del Carmen Ramos-Herrera

2014-01-01

Based on a dataset of 123 economies, this paper empirically investigates the relation between exchange-rate regimes and economic growth. We find that growth performance is best under intermediate exchange rate regimes, while the smallest growth rates are associated with flexible exchange rates. Nevertheless, this conclusion is tempered when we analyze the countries by income level: even though countries that adopt intermediate exchange-rate regimes are characterized by higher economic growth,...

Transitions in European land-management regimes between 1800 and 2010

DEFF Research Database (Denmark)

Jepsen, Martin Rudbeck; Kuemmerle, Tobias; Müller, Daniel

2015-01-01

, and how they play out in different environmental, socio-economic and cultural contexts, is therefore important for identifying effective policies to successfully address these challenges. In this regard, much can be learned from studying long-term land-use change. We examined the evolution of European...... countries in Europe. We qualitatively grouped drivers into land-management regimes, and compared changes in management regimes across Europe. Our results allowed discerning seven land-management regimes, and highlighted marked heterogeneity regarding the types of management regimes occurring in a particular...

Experimental study of steam condensation regime map for simplified spargers

International Nuclear Information System (INIS)

Kim, Y. S.; Yoon, Y. J.; Song, C. H.; Park, C. K.; Kang, H. S.; Jun, H. K.

2003-01-01

An experimental study was conducted to produce a condensation regime map for single-hole and 4-hole steam spargers using GIRLS facility. The regime map for a single-hole sparger was derived using parameters such as the frequency and magnitude of the dynamic pressure. For 4-hole sparager, the regime map was derived using the trends of sound and dynamic pressure. Using the single-hole and 4-hole data, a steam jet condensation regime map was suggested with respect to pool temperature and steam mass flux

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.

Information management in NACD regimes: a comparative analysis

International Nuclear Information System (INIS)

Unger, R.

1998-01-01

While all non-proliferation, arms control and disarmament (NACD) regimes must address the issue of information management, this area has remained an under-explored part of the arms control field. This paper compares information management processes across a variety of NACD regimes for the purpose of identifying potential synergies between regimes and suggesting means by which to strengthen future arms control verification efforts. The paper explores the information management systems of the International Atomic Energy Agency (IAEA), the United Nations Special Commission in Iraq (UNSCOM), the Conventional Forces in Europe Agreement (CFE), and the Comprehensive Test Ban Treaty (CTBT). (author)

An emissions trading regime for Canada

International Nuclear Information System (INIS)

Smith, S.L.

2001-01-01

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

Regimes of operation in the Princeton Large Torus

Energy Technology Data Exchange (ETDEWEB)

Hosea, J.C.

1979-10-01

In the quest for optimum discharge conditions in the Princeton Large Torus (PLT), a variety of discharge regimes have been produced. These separate broadly into two main categories - those regimes with m greater than or equal to 2 oscillatory MHD instabilities and often hollow electron profiles for tungsten limiters, and those regimes for which the electron temperature is sufficiently peaked to support the internal sawtooth or near-sawtooth (m = 1) instability. The internal sawtooth regime is found to be optimum for confinement but to be more difficult to select when low-Z impurity concentrations have been reduced with low power discharge cleaning or gettering to permit extension of the high density operation limit. Gas programming is used to cool the plasma periphery, thereby reducing the high-Z impurity concentrations and causing the current channel to constrict into the sawtooth regime, and then to attain the desired plasma density. With discharges selected in this manner, gross energetic confinement times up to approx. 100 msec have been obtained at densities of approx. 10/sup 14/ cm/sup -3/, and very high ion and electron temperatures have been produced with neutral beam injection heating at lower densities with no observable deleterious effect on energy confinement.

Asset allocation and regime switching on Croatian financial market

Directory of Open Access Journals (Sweden)

Tihana Škrinjarić

2016-12-01

Full Text Available It has been known for quite some time now that financial markets exhibit changes in regimes over time. A majority of the literature tends to support that financial markets undergo regimes of bull and bear markets. This characteristic should be modeled in a proper way as investors are always interested in beating the market: either by achieving better returns than others, or by minimizing their portfolio risks. There exist many mathematical and statistical models that are used as tools to achieve the mentioned goals. Introducing the regime switching methodology in existing models has proven to be facilitate achieving such goals. Therefore, the objective of this study is to utilize the regime switching methodology on the Croatian financial market to ascertain its usefulness for Croatian investors. Multivariate regime switching and non-switching models were estimated using daily data from the period 2 January 2007 to 31 December 2015. The assumption is that the investor is interested in stock and bond markets. The results from the MGARCH and regime switching MGARCH models are then compared in order to give answers as to whether the respective methodology applied to the Croatian market is useful and how it may benefit investors. Most of the results support the presumption of incorporating this particular methodology in financial modeling for the Croatia markets. This is the first research that applies the regime switching MGARCH methodology in Croatia (including the Balkan region, hence we expect that this will be a significant contribution to existing methodologies in literature.

Coulomb drag in the mesoscopic regime

DEFF Research Database (Denmark)

Mortensen, N. Asger; Flensberg, Karsten; Jauho, Antti-Pekka

2002-01-01

We present a theory for Coulomb drug between two mesoscopic systems which expresses the drag in terms of scattering matrices and wave functions. The formalism can be applied to both ballistic and disordered systems and the consequences can be studied either by numerical simulations or analytic...... means such as perturbation theory or random matrix theory. The physics of Coulomb drag in the mesoscopic regime is very different from Coulomb drag between extended electron systems. In the mesoscopic regime we in general find fluctuations of the drag comparable to the mean value. Examples are vanishing...

Coulomb drag in the mesoscopic regime

DEFF Research Database (Denmark)

Mortensen, N.A.; Flensberg, Karsten; Jauho, Antti-Pekka

2002-01-01

We present a theory for Coulomb drag between two mesoscopic systems which expresses the drag in terms of scattering matrices and wave functions. The formalism can be applied to both ballistic and disordered systems and the consequences can be studied either by numerical simulations or analytic...... means such as perturbation theory or random matrix theory. The physics of Coulomb drag in the mesoscopic regime is very different from Coulomb drag between extended electron systems. In the mesoscopic regime we in general find fluctuations of the drag comparable to the mean value. Examples are vanishing...

Smith-Purcell oscillator in an exponential gain regime

International Nuclear Information System (INIS)

Schachter, L.; Ron, A.

1988-01-01

A Smith-Purcell oscillator with a thick electron beam is analyzed in its exponential gain regime. A threshold current less than 1[A] is found for a 1 mm wavelength; this threshold is much lower than that of a similar oscillator operating in a linear gain regime

Progress towards a global nuclear liability regime

International Nuclear Information System (INIS)

2014-01-01

During its April 2014 meeting, the Steering Committee for Nuclear Energy held a policy debate on 'Progress towards a Global Nuclear Liability Regime'. The Steering Committee heard presentations from several experts on nuclear liability issues. To prepare the delegates to the Steering Committee for the policy debate, the NEA Secretariat prepared a background note on the status of the nuclear liability regimes, as well as on current issues and challenges in implementing the regimes. This article is based on the background note and is intended to provide basic information on the relevant international conventions and an overview of recent developments to enhance the understanding of the legal framework in which policy-makers and practitioners are engaging to respond to the call for broader adherence to the international liability instruments. (authors)

Regime-Based Versus Static Asset Allocation: Letting the Data Speak

DEFF Research Database (Denmark)

Nystrup, Peter; Hansen, Bo William; Madsen, Henrik

2015-01-01

Regime shifts present a big challenge to traditional strategic asset allocation. This article investigates whether regimebased asset allocation can effectively respond to changes in financial regimes at the portfolio level, in an effort to provide better long-term results than more static...... approaches can offer. The authors center their regime-based approach around a regime-switching model with time-varying parameters that can match financial markets’ tendency to change behavior abruptly and the fact that the new behavior often persists for several periods after a change. In an asset universe...

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.

[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.

JT-60U high performance regimes

International Nuclear Information System (INIS)

Ishida, S.

1999-01-01

High performance regimes of JT-60U plasmas are presented with an emphasis upon the results from the use of a semi-closed pumped divertor with W-shaped geometry. Plasma performance in transient and quasi steady states has been significantly improved in reversed shear and high- βp regimes. The reversed shear regime elevated an equivalent Q DT eq transiently up to 1.25 (n D (0)τ E T i (0)=8.6x10 20 m-3·s·keV) in a reactor-relevant thermonuclear dominant regime. Long sustainment of enhanced confinement with internal transport barriers (ITBs) with a fully non-inductive current drive in a reversed shear discharge was successfully demonstrated with LH wave injection. Performance sustainment has been extended in the high- bp regime with a high triangularity achieving a long sustainment of plasma conditions equivalent to Q DT eq ∼0.16 (n D (0)τ E T i (0)∼1.4x10 20 m -3 ·s·keV) for ∼4.5 s with a large non-inductive current drive fraction of 60-70% of the plasma current. Thermal and particle transport analyses show significant reduction of thermal and particle diffusivities around ITB resulting in a strong Er shear in the ITB region. The W-shaped divertor is effective for He ash exhaust demonstrating steady exhaust capability of τ He */τ E ∼3-10 in support of ITER. Suppression of neutral back flow and chemical sputtering effect have been observed while MARFE onset density is rather decreased. Negative-ion based neutral beam injection (N-NBI) experiments have created a clear H-mode transition. Enhanced ionization cross- section due to multi-step ionization processes was confirmed as theoretically predicted. A current density profile driven by N-NBI is measured in a good agreement with theoretical prediction. N-NBI induced TAE modes characterized as persistent and bursting oscillations have been observed from a low hot beta of h >∼0.1-0.2% without a significant loss of fast ions. (author)

The global nuclear safety regime and its impact in Brazil

International Nuclear Information System (INIS)

Almeida, C.

2004-01-01

This work describes the Global Nuclear Safety Regime that was established worldwide after the accident at the Tchernobyl nuclear power plant. This regime is composed of biding international safety conventions, globally accepted safety standard, and a voluntary peer review system. The impact of this Global Regime in Brazil is also discussed. (Author)

Experimental investigation of the failure envelope of unidirectional carbon-epoxy composite under high strain rate transverse and off-axis tensile loading

Directory of Open Access Journals (Sweden)

Kuhn Peter

2015-01-01

Full Text Available The mechanical response of the carbon-epoxy material system HexPly IM7-8552 was investigated under transverse tension and combined transverse tension / in-plane shear loading at quasi-static and dynamic strain rates. The dynamic tests of the transverse tension and off-axis tension specimens were carried out on a split-Hopkinson tension bar system, while the quasi-static reference tests were performed on a standard electro-mechanical testing machine. Digital image correlation was used for data reduction at both strain rate regimes. For the high rate tests, the strain rate in loading direction was adjusted to reach approximately the same strain rate value in the fracture plane for each specimen. The measured axial strengths were transformed from the global coordinate system into the combined transverse tension-shear stress space of the material coordinate system and compared with the Puck Mode A criterion for inter-fibre failure. A good correlation between the experimental data and the predicted failure envelopes was found for both investigated strain rate regimes.

Evaluation of Five Different Regimes For the Treatment of Vitiligo

Directory of Open Access Journals (Sweden)

J S Pasricha

1989-01-01

Full Text Available Response of vitiligo patients to five different regimes was evaluated taking only those patients who had either static or progressively increasing lesions. Selection of the regimen depended upon the clinical characteristics of the disease. Each regime was tried for at least 4 months and if a patient didnot improve with one regime, he was shifted to another regime. A patient was considered to have improved, if the lesions started regimenting or the previously progressive lesions stopped increasing further. Regime I consisted of 150 mg levamisol orally on two consecutive days per week, given to 13 cases, it resulted in improvement in 7 (53.80/o. Regime II consisted of levamisole in the same dose combined with once a day topical massage with 0.1% fluocinolone acetonide acetate cream; it led to improvement in 27 (81.8% of the 33 cases. Regime III consisted of 3 mg betamethasone orally on alternate days combined with levamisole and topical fluocinolone; given to 32 cases, it was successful in 28 (87.50/o. A combination of 2 mg betamethasone orally alternating with 20 mg 8-methoxypsoralen and sun exposure (regime IV caused improvement in 17 (85% of the 20 cases. An oral mini pulse consisting of 5 mg betamethasone orally twice a week combined with 50 mg cyclophosphimide daily orally (regime V was successful in 20 (90.9% of the 22 cases, the remaining two cases showed unprovement when the dose ofbetamethasonc .was increased from 5 mg to 7.5 mg twice a week. Thus ultimately each one of the 91 patients responded to one or the other regime. The side effects were minimal and insignificant.The degree of improvement at the time of analysis was 100% in 23.3% cases, 50-100% in 44.2′Yo cases and less than 50% in 32.5%, after 4-14 months of treatment. It is felt that the results may be better after a longer follow-up although all patients are not expected to get complete repigmentation.

Dynamic Effect of a Change in the Exchange Rate System: From a Fixed Regime to a Basket-Peg or a Floating Regime

OpenAIRE

Yoshino, Naoyuki; Kaji, Sahoko; Asonuma, Tamon

2015-01-01

This paper theoretically evaluates the dynamic effects of a shift in an exchange rate system from a fixed regime to a basket peg, or to a floating regime, and obtains transition paths for the shift based on a dynamic stochastic general equilibrium model of a small open economy. We apply quantitative analysis using data from the People's Republic of China and Thailand and find that a small open country would be better off shifting to a basket peg or to a floating regime than maintaining a doll...

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.

Rat disc torsional mechanics: effect of lumbar and caudal levels and axial compression load.

Science.gov (United States)

Espinoza Orías, Alejandro A; Malhotra, Neil R; Elliott, Dawn M

2009-03-01

Rat models with altered loading are used to study disc degeneration and mechano-transduction. Given the prominent role of mechanics in disc function and degeneration, it is critical to measure mechanical behavior to evaluate changes after model interventions. Axial compression mechanics of the rat disc are representative of the human disc when normalized by geometry, and differences between the lumbar and caudal disc have been quantified in axial compression. No study has quantified rat disc torsional mechanics. Compare the torsional mechanical behavior of rat lumbar and caudal discs, determine the contribution of combined axial load on torsional mechanics, and compare the torsional properties of rat discs to human lumbar discs. Cadaveric biomechanical study. Cyclic torsion without compressive load followed by cyclic torsion with a fixed compressive load was applied to rat lumbar and caudal disc levels. The apparent torsional modulus was higher in the lumbar region than in the caudal region: 0.081+/-0.026 (MPa/degrees, mean+/-SD) for lumbar axially loaded; 0.066+/-0.028 for caudal axially loaded; 0.091+/-0.033 for lumbar in pure torsion; and 0.056+/-0.035 for caudal in pure torsion. These values were similar to human disc properties reported in the literature ranging from 0.024 to 0.21 MPa/degrees. Use of the caudal disc as a model may be appropriate if the mechanical focus is within the linear region of the loading regime. These results provide support for use of this animal model in basic science studies with respect to torsional mechanics.

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.

Consideration on non-proliferation regime meeting in a changing world

International Nuclear Information System (INIS)

Kurihara, Hiroyoshi; Kikuchi, Masahiro

1995-01-01

This paper presents some proposals for improvement of non-proliferation regime including safeguards structures with historical changes of international regime. Current non-proliferation regime was established under the circumstances of Cold War, and it's structure and measures were influenced by the situation of these time. Although, a couple of years have passed from end of Cold War, new world order has not established yet. Therefore, it is expected that the current regime could be improved in accordance with new world order. Generally speaking, it could be welcomed that the current regime has got some successes from two points of views, namely no new nuclear weapon states have emerged and after the establishment of NPT and all nuclear weapon state is joined NPT finally. However, it is the authors' concern that some gray countries, such as India, Pakistan and Israel, have not joined the NPT yet and cases of Iraqi and DPRK have occurred. After reviewing of such new situation, some proposals will be presented in order to strengthen the nonproliferation regime to meet current world conditions

A critical review of the Chilean civil nuclear liability regime

International Nuclear Information System (INIS)

Gonzalez Cruz, Francisco Javier; Acevedo Ferrer, Santiago

2013-01-01

This article reviews the Chilean civil nuclear liability regime. The Nuclear Security Act (Law 18.302), enacted in 1984, and the Vienna Convention on Civil Liability for Nuclear Damage, ratified ed by Chile in 1989, are the fundamental laws of the current regime. Although Chile has no nuclear power plants, it is still important to analyze how the Chilean legislation would protect citizens from nuclear damages. This paper does not consider the policy reasons for and against the promotion of atomic energy. Rather, it critically examines the current status of the Chilean nuclear regime. Undoubtedly, if in the future Chile chooses to include nuclear sources in its energy mix, it will not be enough to introduce some isolated legal amendments, but it will be necessary to build a new Chilean Energy Regime which includes nuclear energy. In that scenario, though, it will be useful to know and understand how the current nuclear liability regime works. From this point of view, the reforms this article proposes to the current nuclear liability regime might be helpful to academics and policy makers alike

International regime formation: Ozone depletion and global climate change

International Nuclear Information System (INIS)

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

Impacts of Exchange Rate Regime Choice on Macroeconomic Performance in Emerging Markets

Directory of Open Access Journals (Sweden)

Rüstem Yanar

2008-12-01

Full Text Available This paper investigates the impact of exchange rate regime choice on macroeconomic performance after Bretton Woods in emerging market countries. It is studied especially inflation, growth and financial crises. It’s found that for emerging market countries, fixed regimes are associated with lower inflation than floats. On growth effect of exchange rate regime choice is not same all period. Fixed regimes are associated with faster growth but after 1990 fixed regimes brought about slower growth. At the same time, fixed exchange rate regimes are associated with financial fragility after 1990 in emerging markets

Calculation of loading on pipes during filling processes

International Nuclear Information System (INIS)

Thiele, Thomas; Swidersky, Harald

2013-01-01

Filling processes in pipe systems do normally not belong to load design cases for which the integrity of pipelines and their mountings are verified with fluid- and structure-dynamic analysis. However, their frequency of occurrence is several times higher than those of the postulated incident-induced transients. That is why they have to be taken into consideration within fatigue analysis. The loading on pipes or rather on their mountings during filling processes originates from differences in the density of the transported fluids, e.g. at transport of gas slugs within water flow. The exposure time of the flow momentum force is fixed by the height of the flow velocity and by the length of discontinuities in the pipeline sections. Filling procedures frequently end with a pressure surge which was caused by the impingement and decelaration of the water plug at orifices in pipe systems. The calculation of such processes with 1D fluid-dynamic or rather thermal-hydraulic programs requires an idealization of the real form of the two phase flow or respectively of the two phase interface. In the past, several two phase flow regime maps were developed and implemented in codes for this. In this paper, the applicability of the thermo-hydraulic program RELAP5/MOD3.3 which is established in nuclear engineering is examined in order to calculate realistic loads from plug flows during the filling processes. For this, post-test calculations of experiments have been performed and the results have been compared with the experimental results as well as with the classical analytical approach according to Joukowsky. The comparison shows that, dependent on the discretization, the calculated loads are indeed partly underestimated, though the calculation results according to the Joukowsky-approach lie above the measurements. (orig.)

Searching for an Appropriate Exchange Rate Regime

Directory of Open Access Journals (Sweden)

Yunjong Wang

2001-06-01

Full Text Available This paper attempts to survey current debates on the choice of exchange rate regime in emerging market economies. The issue of choosing an appropriate exchange rate regime is being actively discussed since the recent Asian crisis. As a lesson from the recent crises, one widely shared conclusion is that soft peg exchange rate regimes are extremely vulnerable in a world of volatile capital movements. Consequently, new orthodoxy based on the impossible trinity hypothesis favours two corner solutions ― greater flexibility or credible institutional assurance, like a currency board system or dollarization. Nevertheless, questions whether such corner solutions are adequate for developing countries are rising of late. "Fear of floating" is still conspicuous in many developing countries having adopted nominally a free-floating exchange rate regime. Developing countries are sensitive to exchange rate fluctuations because the cost of exchange rate volatility is greater than the benefit when compared to developed countries. Monitoring bands is a compromise solution, but it still needs further enhancement of estimation techniques for fundamental equilibrium exchange rates in order to make those estimation results more workable in practice. Other alternatives include the creation of soft peg of the G-3 currencies. Despite counterarguments, the stability of G-3 currencies could prove to be beneficial to emerging market economies.

Determination of the Hall Thruster Operating Regimes

International Nuclear Information System (INIS)

L. Dorf; V. Semenov; Y. Raitses; N.J. Fisch

2002-04-01

A quasi one-dimensional (1-D) steady-state model of the Hall thruster is presented. For the same discharge voltage two operating regimes are possible -- with and without the anode sheath. For given mass flow rate, magnetic field profile and discharge voltage a unique solution can be constructed, assuming that the thruster operates in one of the regimes. However, we show that for a given temperature profile the applied discharge voltage uniquely determines the operating regime: for discharge voltages greater than a certain value, the sheath disappears. That result is obtained over a wide range of incoming neutral velocities, channel lengths and widths, and cathode plane locations. It is also shown that a good correlation between the quasi 1-D model and experimental results can be achieved by selecting an appropriate electron mobility and temperature profile

East Asian welfare regime

DEFF Research Database (Denmark)

Abrahamson, Peter

2017-01-01

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...

Political Regime and Sustainable Development: A Comparative Analysis of Muslim Countries

Directory of Open Access Journals (Sweden)

Ataul Huq Pramanik

2002-06-01

Full Text Available Normal 0 false false false MicrosoftInternetExplorer4 This paper examines the interrelationship between regime type and development. It argues that proper resource utilization through investment in a stable environment constitutes the vital element of growth, which in turn, can be translated into materializing human development based on longevity, literacy and real purchasing power. Apart from the type of the regime, the ideological commitment also has a bearing on regime performance. A comparative study of six Muslim countries from three regions suggests that political stability in concomitant with dynamism, flexibility, and continuity of appropriate and effective policies play a vital role in regime performance. The most important observation is the role of a stable democratic regime in ensuring a sustainable development based on a balance between economic and political democracy. It appears that an authoritarian regime can survive only with faster rate of growth while a regime with reasonable degree of economic and political democracy can survive even with a moderately lower but sustainable rate of growth.

Improving the taxation regime for electric power

International Nuclear Information System (INIS)

Fjermeros, Morten; Ilstad, Kristine

2003-01-01

In Norway, the present taxation regime for electric power is very complex. The power companies are currently charged with ordinary tax on profits, tax on economic rent, tax on natural resources and land tax. In addition there are the rules about licence fees, yield of power due to concession conditions, and reversion. The Norwegian Electricity Industry Association (EBL), assisted by a firm of lawyers, has proposed an improvement over the current taxation regime

Do discriminatory pay regimes unleash antisocial behavior?

OpenAIRE

Grosch, Kerstin; Rau, Holger A.

2017-01-01

In this paper, we analyze how pay-regime procedures affect antisocial behavior at the workplace. In a real-effort experiment we vary two determinants of pay regimes: discrimination and justification of payments by performance. In our Discrimination treatment half of the workforce is randomly selected and promoted and participate in a tournament (high-income workers) whereas the other half receives no payment (lowincome workers). Afterwards, antisocial behavior is measured by a Joy-of-Destruct...

Thermal and water regime of green roof segments filled with Technosol

Science.gov (United States)

Jelínková, Vladimíra; Šácha, Jan; Dohnal, Michal; Skala, Vojtěch

2016-04-01

Artificial soil systems and structures comprise appreciable part of the urban areas and are considered to be perspective for number of reasons. One of the most important lies in contribution of green roofs and facades to the heat island effect mitigation, air quality improvement, storm water reduction, etc. The aim of the presented study is to evaluate thermal and water regime of the anthropogenic soil systems during the first months of the construction life cycle. Green roof test segments filled with two different anthropogenic soils were built to investigate the benefits of such systems in the temperate climate. Temperature and water balance measurements complemented with meteorological observations and knowledge of physical properties of the soil substrates provided basis for detailed analysis of thermal and hydrological regime. Water balance of green roof segments was calculated for available vegetation seasons and individual rainfall events. On the basis of an analysis of individual rainfall events rainfall-runoff dependency was found for green roof segments. The difference between measured actual evapotranspiration and calculated potential evapotranspiration was discussed on period with contrasting conditions in terms of the moisture stress. Thermal characteristics of soil substrates resulted in highly contrasting diurnal variation of soils temperatures. Green roof systems under study were able to reduce heat load of the roof construction when comparing with a concrete roof construction. Similarly, received rainfall was significantly reduced. The extent of the rainfall reduction mainly depends on soil, vegetation status and experienced weather patterns. The research was realized as a part of the University Centre for Energy Efficient Buildings supported by the EU and with financial support from the Czech Science Foundation under project number 14-10455P.

Permeability changes induced by microfissure closure and opening in tectonized materials. Effect on slope pore pressure regime.

Science.gov (United States)

De la Fuente, Maria; Vaunat, Jean; Pedone, Giuseppe; Cotecchia, Federica; Sollecito, Francesca; Casini, Francesca

2015-04-01

Tectonized clays are complex materials characterized by several levels of structures that may evolve during load and wetting/drying processes. Some microstructural patterns, as microfissures, have a particular influence on the value of permeability which is one of the main factors controlling pore pressure regime in slopes. In this work, the pore pressure regime measured in a real slope of tectonized clay in Southern Italy is analyzed by a numerical model that considers changes in permeability induced by microfissure closure and opening during the wetting and drying processes resulting from climatic actions. Permeability model accounts for the changes in Pore Size Distribution observed by Microscopy Intrusion Porosimetry. MIP tests are performed on representative samples of ground in initial conditions ("in situ" conditions) and final conditions (deformed sample after applying a wetting path that aims to reproduce the saturation of the soil under heavy rains). The resulting measurements allow for the characterization at microstructural level of the soil, identifying the distribution of dominant families pores in the sample and its evolution under external actions. Moreover, comparison of pore size density functions allows defining a microstructural parameter that depends on void ratio and degree of saturation and controls the variation of permeability. Model has been implemented in a thermo-hydro-mechanical code provided with a special boundary condition for climatic actions. Tool is used to analyze pore pressure measurements obtained in the tectonized clay slope. Results are analyzed at the light of the effect that permeability changes during wetting and drying have on the pore pressure regime.

Effects of mechanical loading on human mesenchymal stem cells for cartilage tissue engineering.

Science.gov (United States)

Choi, Jane Ru; Yong, Kar Wey; Choi, Jean Yu

2018-03-01

Today, articular cartilage damage is a major health problem, affecting people of all ages. The existing conventional articular cartilage repair techniques, such as autologous chondrocyte implantation (ACI), microfracture, and mosaicplasty, have many shortcomings which negatively affect their clinical outcomes. Therefore, it is essential to develop an alternative and efficient articular repair technique that can address those shortcomings. Cartilage tissue engineering, which aims to create a tissue-engineered cartilage derived from human mesenchymal stem cells (MSCs), shows great promise for improving articular cartilage defect therapy. However, the use of tissue-engineered cartilage for the clinical therapy of articular cartilage defect still remains challenging. Despite the importance of mechanical loading to create a functional cartilage has been well demonstrated, the specific type of mechanical loading and its optimal loading regime is still under investigation. This review summarizes the most recent advances in the effects of mechanical loading on human MSCs. First, the existing conventional articular repair techniques and their shortcomings are highlighted. The important parameters for the evaluation of the tissue-engineered cartilage, including chondrogenic and hypertrophic differentiation of human MSCs are briefly discussed. The influence of mechanical loading on human MSCs is subsequently reviewed and the possible mechanotransduction signaling is highlighted. The development of non-hypertrophic chondrogenesis in response to the changing mechanical microenvironment will aid in the establishment of a tissue-engineered cartilage for efficient articular cartilage repair. © 2017 Wiley Periodicals, Inc.

Completion of UO{sub 2} pellets production and fuel rods load for the RA-8 critical facility; Finalizacion de la produccion de pastillas y carga de barras combustibles de UO{sub 2} para el conjunto critico RA-8

Energy Technology Data Exchange (ETDEWEB)

Marajofsky, Adolfo; Perez, Lidia E; Thern, Gerardo G; Altamirano, Jorge S; Benitez, Ana M; Cardenas, Hugo R; Becerra, Fabian A; Perez, Aldo E; Fuente, Mariano de la [Comision Nacional de Energia Atomica, General San Martin (Argentina). Dept. de Combustibles Nucleares

1999-07-01

The Advanced Fuels Division produced fuel pellets of {sup 235}U with 1.8% and 3.6% enrichment and Zry-4 cladding loads for the RA-8 reactor at Pilcaniyeu Technological Unit. For economical and availability reasons, the powder acquired was initially UO{sub 2} with 3.4% enrichment in {sup 235}U, therefore the {sup 235}U powder with 1.8% enrichment was produced by mechanical mixture. The production of fuel pellets for both enrichments was carried out by cold pressing and sintering processes in reducing atmosphere. The load of Zry-4 claddings was performed manually. The production stages can be divided into setup, qualification and production. This production allows not only to fulfill satisfactorily the new fuel rods supply for the RA-8 reactor but also to count with a new equipment and skilled personnel as well as to meet quality and assurance control methods for future pilot-scale production and even new fuel elements production. (author)

Biomechanical Modeling Analysis of Loads Configuration for Squat Exercise

Science.gov (United States)

Gallo, Christopher A.; Thompson, William K.; Lewandowski, Beth E.; Jagodnik, Kathleen; De Witt, John K.

2017-01-01

INTRODUCTION: Long duration space travel will expose astronauts to extended periods of reduced gravity. Since gravity is not present to assist loading, astronauts will use resistive and aerobic exercise regimes for the duration of the space flight to minimize loss of bone density, muscle mass and aerobic capacity that occurs during exposure to a reduced gravity environment. Unlike the International Space Station (ISS), the area available for an exercise device in the next generation of spacecraft for travel to the Moon or to Mars is limited and therefore compact resistance exercise device prototypes are being developed. The Advanced Resistive Exercise Device (ARED) currently on the ISS is being used as a benchmark for the functional performance of these new devices. Biomechanical data collection and computational modeling aid the device design process by quantifying the joint torques and the musculoskeletal forces that occur during exercises performed on the prototype devices. METHODS The computational models currently under development utilize the OpenSim [1] software platform, consisting of open source code for musculoskeletal modeling, using biomechanical input data from test subjects for estimation of muscle and joint loads. The OpenSim Full Body Model [2] is used for all analyses. The model incorporates simplified wrap surfaces, a new knee model and updated lower body muscle parameters derived from cadaver measurements and magnetic resonance imaging of young adults. The upper body uses torque actuators at the lumbar and extremity joints. The test subjects who volunteer for this study are instrumented with reflective markers for motion capture data collection while performing squat exercising on the Hybrid Ultimate Lifting Kit (HULK) prototype device (ZIN Technologies, Middleburg Heights, OH). Ground reaction force data is collected with force plates under the feet, and device loading is recorded through load cells internal to the HULK. Test variables include

Passive phloem loading and long-distance transport in a synthetic tree-on-a-chip

DEFF Research Database (Denmark)

Comtet, Jean; Jensen, Kaare Hartvig; Turgeon, Robert

2017-01-01

Vascular plants rely on differences in osmotic pressure to export sugars from regions of synthesis (mature leaves) to sugar sinks (roots, fruits). In this process, known as Münch pressure flow, the loading of sugars from photosynthetic cells to the export conduit (the phloem) is crucial, as it sets...... the pressure head necessary to power long-distance transport. Whereas most herbaceous plants use active mechanisms to increase phloem sugar concentration above that of the photosynthetic cells, in most tree species, for which transport distances are largest, loading seems, counterintuitively, to occur by means......, diffusion-limited export leads to small phloem concentrations and weak scaling of flow rates with hydraulic resistance. We then show that the effective regime of convection-limited export is predominant in plants with large transport resistances and low xylem pressures. Moreover, hydrostatic pressures...

A computational and experimental investigation of wall loading near the DITE limiters

International Nuclear Information System (INIS)

Maddison, G.P.; Allen, J.; Fielding, S.J.; Johnson, P.C.; Matthews, G.F.

1987-01-01

Recycling from the DITE fixed limiter has been simulated employing a three-dimensional version of the DEGAS Monte Carlo neutral particle transport code. Experimental plasma data are used for input, in conjunction with a reasonable approximation to the DITE geometry. Between basic cases, moments of the neutral distribution function exhibit a scaling with limiter ion flux which becomes increasingly non-linear with order, a prominent instance being the first wall power loading. This reflects principally the influence of charge exchange neutrals sensing the ion temperature profiles. By also modifying the geometry, the neutral distribution is found for the regime investigated to depend primarily on plasma properties in velocity space and confining geometry in configuration space. On DITE, a so-called 'energy sensor array' (ESA) of bolometers detects wall loading adjacent to the limiter directly. Supposing a homogeneous radiation background, the computational model agress with ESA data roughly within a factor of 2. (orig.)

Prolonged Instability Prior to a Regime Shift | Science ...

Science.gov (United States)

Regime shifts are generally defined as the point of ‘abrupt’ change in the state of a system. However, a seemingly abrupt transition can be the product of a system reorganization that has been ongoing much longer than is evident in statistical analysis of a single component of the system. Using both univariate and multivariate statistical methods, we tested a long-term high-resolution paleoecological dataset with a known change in species assemblage for a regime shift. Analysis of this dataset with Fisher Information and multivariate time series modeling showed that there was a∼2000 year period of instability prior to the regime shift. This period of instability and the subsequent regime shift coincide with regional climate change, indicating that the system is undergoing extrinsic forcing. Paleoecological records offer a unique opportunity to test tools for the detection of thresholds and stable-states, and thus to examine the long-term stability of ecosystems over periods of multiple millennia. This manuscript explores various methods of assessing the transition between alternative states in an ecological system described by a long-term high-resolution paleoecological dataset.

Triggered dynamics in a model of different fault creep regimes.

Science.gov (United States)

Kostić, Srđan; Franović, Igor; Perc, Matjaž; Vasović, Nebojša; Todorović, Kristina

2014-06-23

The study is focused on the effect of transient external force induced by a passing seismic wave on fault motion in different creep regimes. Displacement along the fault is represented by the movement of a spring-block model, whereby the uniform and oscillatory motion correspond to the fault dynamics in post-seismic and inter-seismic creep regime, respectively. The effect of the external force is introduced as a change of block acceleration in the form of a sine wave scaled by an exponential pulse. Model dynamics is examined for variable parameters of the induced acceleration changes in reference to periodic oscillations of the unperturbed system above the supercritical Hopf bifurcation curve. The analysis indicates the occurrence of weak irregular oscillations if external force acts in the post-seismic creep regime. When fault motion is exposed to external force in the inter-seismic creep regime, one finds the transition to quasiperiodic- or chaos-like motion, which we attribute to the precursory creep regime and seismic motion, respectively. If the triggered acceleration changes are of longer duration, a reverse transition from inter-seismic to post-seismic creep regime is detected on a larger time scale.

Regime-switching stochastic volatility. Evidence from the crude oil market

International Nuclear Information System (INIS)

Vo, Minh T.

2009-01-01

This paper incorporates regime-switching into the stochastic volatility (SV) framework in an attempt to explain the behavior of crude oil prices in order to forecast their volatility. More specifically, it models the volatility of oil return as a stochastic volatility process whose mean is subject to shifts in regime. The shift is governed by a two-state first-order Markov process. The Bayesian Markov Chain Monte Carlo method is used to estimate the models. The main findings are: first, there is clear evidence of regime-switching in the oil market. Ignoring it will lead to a false impression that the volatility is highly persistent and therefore highly predictable. Second, incorporating regime-switching into the SV framework significantly enhances the forecasting power of the SV model. Third, the regime-switching stochastic volatility model does a good job in capturing major events affecting the oil market. (author)

Modeling Whistler Wave Generation Regimes In Magnetospheric Cyclotron Maser

Science.gov (United States)

Pasmanik, D. L.; Demekhov, A. G.; Trakhtengerts, V. Y.; Parrot, M.

Numerical analysis of the model for cyclotron instability development in the Earth magnetosphere is made.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. Two different mechanisms of energetic electron loss from the interaction region are discussed. The first one is precipitation of energetic particles via the loss cone. The other mechanism is drift of particles away from the interaction region across the mag- netic field line. In the case of interaction in plasmasphere or rather large areas of cold plasma density enhancement the loss cone precipitation are dominant. For interaction in a subauroral duct losses due to drift are most effective. A parametric study of the model for both mechanisms of particle losses is made. 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 elec- tron density. We show that in addition to the well-known stationary generation and periodic regime with successive spikes of similar shape, more complex forms of wave spectrum exist. In particular, we found a periodic regime, in which a single period in- cludes two separate spikes with different spectral shapes. In another regime, periodic generation of spikes at higher frequencies together with quasi-stationary generation at lower frequencies occurs. Quasi-periodic regime with spike overlapping, i.e. when generation of a new spike begins before the previous one is over is also found. Results obtained are compared with experimental data on quasi-periodic regimes of whistler wave generation.

FISHER INFORMATION OF DYNAMIC REGIME TRANSITIONS IN ECOLOGICAL SYSTEMS

Science.gov (United States)

Ecosystems often exhibit transitions between multiple dynamic regimes (or steady states). As ecosystems experience perturbations of varying regularity and intensity, they may either remain within the state space neighborhood of the current regime, or ?flip? into the neighborhood ...

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.

The global safety regime - Setting the stage

International Nuclear Information System (INIS)

Meserve, R.A.

2005-01-01

The existing global safety regime has arisen from the exercise of sovereign authority, with an overlay of voluntary international cooperation from a network of international and regional organizations and intergovernmental agreements. This system has, in the main, served us well. For several reasons, the time is ripe to consider the desired shape of a future global safety regime and to take steps to achieve it. First, every nation's reliance on nuclear power is hostage to some extent to safety performance elsewhere in the world because of the effects on public attitudes and hence there is an interest in ensuring achievement of common standards. Second, the world is increasingly interdependent and the vendors of nuclear power plants seek to market their products throughout the globe. Efficiency would arise from the avoidance of needless differences in approach that require custom modifications from country to country. Finally, we have much to learn from each other and a common effort would strengthen us all. Such an effort might also serve to enhance public confidence. Some possible characteristics of such a regime can be identified. The regime should reflect a global consensus on the level of safety that should be achieved. There should be sufficient standardization of approach so that expertise and equipment can be used everywhere without significant modification. There should be efforts to ensure a fundamental commitment to safety and the encouragement of a safety culture. And there should be efforts to adopt more widely the best regulatory practices, recognizing that some modifications in approach may be necessary to reflect each nation's legal and social culture. At the same type, the regime should have the characteristics of flexibility, transparency, stability, practicality, and encouragement of competence. (author)

Regimes of Two-Phase Flow in Short Rectangular Channel

Science.gov (United States)

Chinnov, Evgeny A.; Guzanov, Vladimir V.; Cheverda, Vyacheslav; Markovich, Dmitry M.; Kabov, Oleg A.

2009-08-01

Experimental study of two-phase flow in the short rectangular horizontal channel with height 440 μm has been performed. Characteristics of liquid motion inside the channel have been registered and measured by the Laser Induced Fluorescence technique. New information has allowed determining more precisely the characteristics of churn regime and boundaries between different regimes of two-phase flow. It was shown that formation of some two-phase flow regimes and transitions between them are determined by instability of the flow in the lateral parts of the channel.

Kondo and mixed-valence regimes in multilevel quantum dots

International Nuclear Information System (INIS)

Chudnovskiy, A. L.; Ulloa, S. E.

2001-01-01

We investigate the dependence of the ground state of a multilevel quantum dot on the coupling to an external fermionic system and on the interactions in the dot. As the coupling to the external system increases, the rearrangement of the effective energy levels in the dot signals the transition from the Kondo regime to a mixed-valence (MV) regime. The MV regime in a two-level dot is characterized by an intrinsic mixing of the levels in the dot, resulting in nonperturbative subtunneling and supertunneling phenomena that strongly influence the Kondo effect

Using MODIS Cloud Regimes to Sort Diagnostic Signals of Aerosol-Cloud-Precipitation Interactions.

Science.gov (United States)

Oreopoulos, Lazaros; Cho, Nayeong; Lee, Dongmin

2017-05-27

Coincident multi-year measurements of aerosol, cloud, precipitation and radiation at near-global scales are analyzed to diagnose their apparent relationships as suggestive of interactions previously proposed based on theoretical, observational, and model constructs. Specifically, we examine whether differences in aerosol loading in separate observations go along with consistently different precipitation, cloud properties, and cloud radiative effects. Our analysis uses a cloud regime (CR) framework to dissect and sort the results. The CRs come from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor and are defined as distinct groups of cloud systems with similar co-variations of cloud top pressure and cloud optical thickness. Aerosol optical depth used as proxy for aerosol loading comes from two sources, MODIS observations, and the MERRA-2 re-analysis, and its variability is defined with respect to local seasonal climatologies. The choice of aerosol dataset impacts our results substantially. We also find that the responses of the marine and continental component of a CR are frequently quite disparate. Overall, CRs dominated by warm clouds tend to exhibit less ambiguous signals, but also have more uncertainty with regard to precipitation changes. Finally, we find weak, but occasionally systematic co-variations of select meteorological indicators and aerosol, which serves as a sober reminder that ascribing changes in cloud and cloud-affected variables solely to aerosol variations is precarious.

TYPES OF POLITICAL REGIMES IN THE IRKUTSK REGION

Directory of Open Access Journals (Sweden)

И В Орлова

2017-12-01

Full Text Available The authors consider contemporary western and Russian classifications of regional political regimes and their applicability for Russia. Based on the analysis of political theories, the authors chose the traditional typology of regional political regimes focusing on the minimalist interpretation of democracy (electoral competition and methods for identifying regional scenarios introduced by V.Ya. Gelman. The authors study the case of the Irkutsk Region as a region with conflicting elites, in which in a short period several regional heads were replaced. Based on the contemporary political history, the authors analyze the regional political regime using the following criteria: democracy/autocracy, consolidation/oligo-poly, compromise/conflict relations within the ruling elite. The results of the analysis prove the existence of checks and balances in the political system of the Irkutsk Region. Such a system restrains strong politicians attempts to monopolize the political power in the region. When any political player gains too much influence, other centers of power unite against him and together return the situation to the status quo. The political regime of the Irkutsk Region ensures a relatively high level of political competition, at the same time it is a part of the uncompetitive political regime of the Russian Federation, therefore it is a ‘hybrid democracy’. The authors’ analysis of intra-elite relations in the region revealed a high predisposition to conflicts with the dominant scenario of ‘war of all against all’.

European welfare regimes: Political orientations versus poverty

Directory of Open Access Journals (Sweden)

Josifidis Kosta

2011-01-01

Full Text Available This inquiry analyzes how political orientations shape welfare states and labour market institutions when seeking to reduce poverty. In order to identify effects of these two key variables, we conduct a panel regression analysis that includes two poverty measures: poverty rates before and after social spending. This inquiry considers 14 EU countries, and in the period from 1995 to 2008, which are grouped according to welfare state regimes. We consider Social Democratic, Corporatist, Mediterranean and Liberal welfare state regimes. Panel regression results indicate that political orientation engenders no significant statistically measurable effects on poverty rates before social spending. Effects register, however, as significant when considering poverty rates after social spending. With respect to the first set of results, we advance two key explanations. First, we note a longer period of time is necessary in order to observe actual effects of political orientation on market generated poverty. Second, political parties with their respective programs do not register as influential enough to solve social problems related to income distribution when taken alone. Influences register as indirect and are expressed through changes in employment rates and social spending. The second set of results support the hypothesis that a selected political regime does indeed contribute to poverty reduction. In sum, political orientation and political regime does indeed affect poverty through welfare state institutions, as well as through labour market institutions.

Comparison of Theory and Experiment on Aeroacoustic Loads and Deflections

Science.gov (United States)

Campos, L. M. B. C.; Bourgine, A.; Bonomi, B.

1999-01-01

The correlation of acoustic pressure loads induced by a turbulent wake on a nearby structural panel is considered: this problem is relevant to the acoustic fatigue of aircraft, rocket and satellite structures. Both the correlation of acoustic pressure loads and the panel deflections, were measured in an 8-m diameter transonic wind tunnel. Using the measured correlation of acoustic pressures, as an input to a finite-element aeroelastic code, the panel response was reproduced. The latter was also satisfactorily reproduced, using again the aeroelastic code, with input given by a theoretical formula for the correlation of acoustic pressures; the derivation of this formula, and the semi-empirical parameters which appear in it, are included in this paper. The comparison of acoustic responses in aeroacoustic wind tunnels (AWT) and progressive wave tubes (PWT) shows that much work needs to be done to bridge that gap; this is important since the PWT is the standard test means, whereas the AWT is more representative of real flight conditions but also more demanding in resources. Since this may be the first instance of successful modelling of acoustic fatigue, it may be appropriate to list briefly the essential ``positive'' features and associated physical phenomena: (i) a standard aeroelastic structural code can predict acoustic fatigue, provided that the correlation of pressure loads be adequately specified; (ii) the correlation of pressure loads is determined by the interference of acoustic waves, which depends on the exact evaluation of multiple scattering integrals, involving the statistics of random phase shifts; (iii) for the relatively low frequencies (one to a few hundred Hz) of aeroacoustic fatigue, the main cause of random phase effects is scattering by irregular wakes, which are thin on wavelength scale, and appear as partially reflecting rough interfaces. It may also be appropriate to mention some of the ``negative'' features, to which may be attached illusory

Summary Authoritarialism as Political Regime: Analysis of Historical and Empirical Studies

Directory of Open Access Journals (Sweden)

O. D. Grossman

2016-01-01

Full Text Available This article is devoted to the problems of existence of authoritarian regimes. The ambiguity of the resulting data determines the importance of the considered research. Authoritarianism is quite complicated socio-political phenomenon. For this reason, there are a lot of typologies and special features of authoritarianism as a political regime. Authoritarianism is not only a political regime, but it is also a set of social and political characteristics. Some countries, where the authoritarian tendencies dominate, are economically developed, and they have a competitive economy, but other countries, which are steeped in a reactionary authoritarian, do not develop properly. From the materials of this article it should be concluded that the political regime in Russia is principally authoritarian, or to be specific it is liberal authoritarian regime. This political regime has been established for the whole history of our country, and it is supported by paternalistic political culture and special mindset our nation.

Private actor accountability on international regimes

Directory of Open Access Journals (Sweden)

Wahyudi Purnomo

2017-12-01

Full Text Available Public-Private Partnerships (PPPs have emerged along with the growing role of corporations in global development. One of the largest forms of PPP today is the UN Global Compact. The UN Global Compact involves of companies, NGOs, IGOs and state governments. All of them are trying to realize globalization with a more humanist face with attention to the protection of human rights, environment, labor standards and anti-corruption. Engaging private actors in global governance, The UN Global Compact raises many issues such as power, authority, and legitimacy. The effort to tackle it all is to increase PPP accountability. This research seeks to describe what efforts can be made to enhance private accountability within the international regime. The research undertaken is a descriptive study, focuses on public-private partnerships in the UN Global Compact regime. The study found that there were two attempts that could be done. First, by involving the stakeholders in the development of procedures, mechanisms, reporting and monitoring associated with trying to improve the company’s reputation. Second, by looking at corporate relations as agent and UN Global Compact as principal in principal-agent relation in the international regime.

Load research manual. Volume 1. Load research procedures

Energy Technology Data Exchange (ETDEWEB)

Brandenburg, L.; Clarkson, G.; Grund, Jr., C.; Leo, J.; Asbury, J.; Brandon-Brown, F.; Derderian, H.; Mueller, R.; Swaroop, R.

1980-11-01

This three-volume manual presents technical guidelines for electric utility load research. Special attention is given to issues raised by the load data reporting requirements of the Public Utility Regulatory Policies Act of 1978 and to problems faced by smaller utilities that are initiating load research programs. In Volumes 1 and 2, procedures are suggested for determining data requirements for load research, establishing the size and customer composition of a load survey sample, selecting and using equipment to record customer electricity usage, processing data tapes from the recording equipment, and analyzing the data. Statistical techniques used in customer sampling are discussed in detail. The costs of load research also are estimated, and ongoing load research programs at three utilities are described. The manual includes guides to load research literature and glossaries of load research and statistical terms.

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.

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.

Socioeconomic inequalities in oral health in different European welfare state regimes.

Science.gov (United States)

Guarnizo-Herreño, Carol C; Watt, Richard G; Pikhart, Hynek; Sheiham, Aubrey; Tsakos, Georgios

2013-09-01

There is very little information about the relationship between welfare regimes and oral health inequalities. We compared socioeconomic inequalities in adults' oral health in five European welfare-state regimes: Scandinavian, Anglo-Saxon, Bismarckian, Southern and Eastern. Using data from the oral health module of the Eurobarometer 72.3 survey, we assessed inequalities in two self-reported oral health measures: no functional dentition (less than 20 natural teeth) and edentulousness (no natural teeth). Occupational social class, education and subjective social status (SSS) were included as socioeconomic position indicators. We estimated age-standardised prevalence rates, ORs, the Relative Index of Inequality (RII) and the Slope Index of Inequality (SII). The Scandinavian regime showed the lowest prevalence rates of the two oral health measures while the Eastern showed the highest. In all welfare regimes there was a general pattern of social gradients by occupational social class and education. Relative educational inequalities in no functional dentition were largest in the Scandinavian welfare regime (RII=3.81; 95% CI 2.68 to 5.42). The Scandinavian and Southern regimes showed the largest relative inequalities in edentulousness by occupation and education, respectively. There were larger absolute inequalities in no functional dentition in the Eastern regime by occupation (SII=42.16; 95% CI 31.42 to 52.89) and in the Southern by SSS (SII=27.92; 95% CI 17.36 to 38.47). Oral health inequalities in adults exist in all welfare-state regimes, but contrary to what may be expected from theory, they are not smaller in the Scandinavian regime. Future work should examine the potential mechanisms linking welfare provision and oral health inequalities.

Cost-effectiveness of HPV vaccination regime: comparing twice versus thrice vaccinations dose regime among adolescent girls in Malaysia.

Science.gov (United States)

Aljunid, Syed; Maimaiti, Namaitijiang; Nur, Amrizal M; Noor, Mohd Rushdan Md; Wan Puteh, Sharifa Ezat

2016-01-23

The HPV vaccine was introduced to Malaysian national immunization programme in 2010. The current implementation age of HPV vaccination in Malaysian is at the age of 13 years school girls, given according to a 3 doses protocol which may complicate implementation and compliance. Aim of the study is to determine the cost-effectiveness of HPV vaccination regime comparing twice versus thrice HPV vaccinations dose regime among adolescent girls in Malaysia. A Markov cohort model reflecting the natural history of HPV infection accounting for oncogenic and low-risk HPV was adapted for 13 year old Malaysian girls cohort (n = 274,050). Transition probabilities, utilities values, epidemiological and cost data were sourced from published literature and local data. Vaccine effectiveness was based on overall efficacy reported from 3-doses clinical trials, with the assumption that the 2-doses is non-inferior to the 3-doses allowing overall efficacy to be inferred from the 3-doses immunogenicity data. Price parity and life-long protection were assumed. The payer perspective was adopted, with appropriate discounting for costs (3 %) and outcomes (3 %). One way sensitivity analysis was conducted. The sensitivity analysis on cost of vaccine, vaccine coverage and discount rate with a 2-doses protocol was performed. The 3-doses and 2-doses regimes showed same number of Cervical Cancers averted (361 cases); QALYs saved at 7,732,266. However, the lifetime protection under the 2-doses regime, showed a significant cost-savings of RM 36, 722,700 compared to the 3-doses scheme. The MOH Malaysia could vaccinate 137,025 more girls in this country using saving 2-doses regime vaccination programme. The model predicted that 2-doses HPV vaccination schemes can avoid additional 180 Cervical Cancers and 63 deaths compare to 3-doses. A 2-doses HPV vaccination scheme may enable Malaysian women to be protected at a lower cost than that achievable under a 3-doses scheme, while avoiding the same number of

Load power device, system and method of load control and management employing load identification

Science.gov (United States)

Yang, Yi; Luebke, Charles John; Schoepf, Thomas J.

2018-01-09

A load power device includes a power input, at least one power output for at least one load, a plurality of sensors structured to sense voltage and current at the at least one power output, and a processor. The processor provides: (a) load identification based upon the sensed voltage and current, and (b) load control and management based upon the load identification.

Variations of Hydrological Regime in the Jingjiang Reach of the Yangtze River after Operation of the Three Gorges Project

Science.gov (United States)

Zhu, Y.-H.; Guo, X.-H.; Hu, W.; Qu, G.; He, G.-S.

2012-04-01

The Three Gorges Project (TGP) of China has been in operation since 2003. In October 2010 the water level at the Three Gorges Dam (TGD) rose to the normal storage water level of 175 m, indicting the realization of the integrated targets of the TGP in terms of flood protection, electricity generation, navigation, etc. The operation of the TGP has changed the flow and sediment conditions (i.e. the hydrological regime) of the river channel downstream. The 347.2 km Jingjiang Reach, part of the middle reach of the Yangtze River, is very closely dowstream of the TGD and is affected relatively earlier and significant by the project operation. Based on the measured prototype hydrological data from 1950 to 2010, variations of the hydrological regime in the Jingjiang Reach after operation of the TGP are analyzed. The results showing that the runoff of the river is of no clear variation tendency during the last 60 years. However, after the operation of the TGP, the sediment concentration of the flow in the Jingjiang Reach decreased by 75%; coarsening of the suspended load and bed load in the river is evident; the water level at the same flow rate has a tendency to decline, with the margin of decline of the upper Jingjiang Reach being larger than that of the lower Reach, and that at smaller flow rate being larger than at larger flow rate. The flow and sediment diversion from the Yangtze River to the Dongting Lake via the three outlets also has a tendency to decrease; the degree of dcrease of the sediment diversion is much larger than that of the flow diversion. After the operation of the TGP, except the 2006 is a special low flow year, in which the decrease of the ratios of flow and sediment diversion are relatively large, the ratios are of no clear unidirectional variation tendency in the other years. Due to the operation of the TGP, within one year, the flow diversion in October is decreased comparing with that before the operation. Keywords: The Three Gorges Project, the

Flow regime classification in air-magnetic fluid two-phase flow.

Science.gov (United States)

Kuwahara, T; De Vuyst, F; Yamaguchi, H

2008-05-21

A new experimental/numerical technique of classification of flow regimes (flow patterns) in air-magnetic fluid two-phase flow is proposed in the present paper. The proposed technique utilizes the electromagnetic induction to obtain time-series signals of the electromotive force, allowing us to make a non-contact measurement. Firstly, an experiment is carried out to obtain the time-series signals in a vertical upward air-magnetic fluid two-phase flow. The signals obtained are first treated using two kinds of wavelet transforms. The data sets treated are then used as input vectors for an artificial neural network (ANN) with supervised training. In the present study, flow regimes are classified into bubbly, slug, churn and annular flows, which are generally the main flow regimes. To validate the flow regimes, a visualization experiment is also performed with a glycerin solution that has roughly the same physical properties, i.e., kinetic viscosity and surface tension, as a magnetic fluid used in the present study. The flow regimes from the visualization are used as targets in an ANN and also used in the estimation of the accuracy of the present method. As a result, ANNs using radial basis functions are shown to be the most appropriate for the present classification of flow regimes, leading to small classification errors.

What Do We Know about Hybrid Regimes after Two Decades of Scholarship?

Directory of Open Access Journals (Sweden)

Mariam Mufti

2018-06-01

Full Text Available In two decades of scholarship on hybrid regimes two significant advancements have been made. First, scholars have emphasized that the hybrid regimes that emerged in the post-Cold War era should not be treated as diminished sub-types of democracy, and second, regime type is a multi-dimensional concept. This review essay further contends that losing the lexicon of hybridity and focusing on a single dimension of regime type—flawed electoral competition—has prevented an examination of extra-electoral factors that are necessary for understanding how regimes are differently hybrid, why there is such immense variation in the outcome of elections and why these regimes are constantly in flux. Therefore, a key recommendation emerging from this review of the scholarship is that to achieve a more thorough, multi-dimensional assessment of hybrid regimes, further research ought to be driven by nested research designs in which qualitative and quantitative approaches can be used to advance mid-range theory building.

Misalignment under different exchange rate regimes: the case of Turkey

OpenAIRE

Dağdeviren, Sengül; Ogus Binatli, Ayla; Sohrabji, Niloufer

2011-01-01

The paper examines misalignment of the Turkish lira between 1998 to 2008. Misalignment, specifically overvaluation has been linked to fixed exchange rate regimes. By studying the case of Turkey during this period which covers both a fixed and floating exchange rate regime, we contribute to the literature on the relation between misalignment and exchange rate regimes. We first estimate the equilibrium real exchange rate for Turkey, then compute misalignment and finally test for structural brea...

A study on fatigue crack growth model considering high mean loading effects based on structural stress

International Nuclear Information System (INIS)

Kim, Jong Sung; Kim, Cheol; Jin, Tae Eun; Dong, P.

2004-01-01

The mesh-insensitive structural stress procedure by Dong is modified to apply to the welded joints with local thickness variation and inarguable shear/normal stresses along local discontinuity surface. In order to make use of the structural stress based K solution for fatigue correlation of welded joints, a proper crack growth model needs to be developed. There exist some significant discrepancies in inferring the slope or crack growth exponent in the conventional Paris law regime. Two-stage crack growth model was not considered since its applications are focused upon the fatigue behavior in welded joints in which the load ratio effects are considered negligible. In this paper, a two-stage crack growth law considering high mean loading is proposed and proven to be effective in unifying the so-called anomalous short crack growth data

Alternative pricing regimes in Ontario : exploring the impacts

International Nuclear Information System (INIS)

Rowlands, I.H.

2006-01-01

Legislative goals were recently established in Ontario to promote reliability and quality of electricity service and to ensure that distribution rates for customers remain reasonable. This presentation explored the effect of changing electricity pricing structures on residential customers in Ontario. This study investigated a period between May to December 2005, in the town of Milton, Ontario. Monthly demand was measured for each month, and monthly weighted averages were presented. Residents with electric heating were removed from the sample. Four pricing structure scenarios were examined: (1) flat rates; (2) time-of-use pricing regimes; (3) real time pricing regimes; and (4) critical peak pricing. Average monthly consumption rates for July and August for all 4 scenarios were presented. Results for time-of-use were compared to flat rates, which showed a slight increase in monthly costs. Real time average monthly electricity costs were significantly higher. Time-of-use costs increased by 57 per cent during the periods examined. Real time pricing regimes resulted in a 196 per cent rise in costs. It was concluded that more research must be done to explore the policy implications of pricing regimes and their effect on consumer behaviour. refs., tabs., figs

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 post burning), and (ii) developing statistical models to determine the magnitude of thermal change caused by vegetation management. Compared to plots burned 15 + years previously, plots recently burned (management effects. Temperatures measured in soil plots burned 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. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Evaluation and Comparison of Extremal Hypothesis-Based Regime Methods

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Ishwar Joshi

2018-03-01

Full Text Available Regime channels are important for stable canal design and to determine river response to environmental changes, e.g., due to the construction of a dam, land use change, and climate shifts. A plethora of methods is available describing the hydraulic geometry of alluvial rivers in the regime. However, comparison of these methods using the same set of data seems lacking. In this study, we evaluate and compare four different extremal hypothesis-based regime methods, namely minimization of Froude number (MFN, maximum entropy and minimum energy dissipation rate (ME and MEDR, maximum flow efficiency (MFE, and Millar’s method, by dividing regime channel data into sand and gravel beds. The results show that for sand bed channels MFN gives a very high accuracy of prediction for regime channel width and depth. For gravel bed channels we find that MFN and ‘ME and MEDR’ give a very high accuracy of prediction for width and depth. Therefore the notion that extremal hypotheses which do not contain bank stability criteria are inappropriate for use is shown false as both MFN and ‘ME and MEDR’ lack bank stability criteria. Also, we find that bank vegetation has significant influence in the prediction of hydraulic geometry by MFN and ‘ME and MEDR’.

Extending the collisional fluid equations into the long mean-free-path regime in toroidal plasmas. IV. Banana regime

International Nuclear Information System (INIS)

Shaing, K. C.

2007-01-01

In Part I [Phys. Fluids B 2, 1190 (1990)] and Part II [Phys. Plasmas 12, 082508 (2005)], it was emphasized that the equilibrium plasma viscous forces when applied for the magnetohydrodynamic (MHD) modes are only rigorously valid at the mode rational surface where m-nq=0. Here, m is the poloidal mode number, n is the toroidal mode number, and q is the safety factor. This important fact has been demonstrated explicitly by calculating the viscous forces in the plateau regime in Parts I and II. Here, the effective viscous forces in the banana regime are calculated for MHD modes by solving the linear drift kinetic equation that is driven by the plasma flows first derived in Part I. At the mode rational surface, the equilibrium plasma viscous forces are reproduced. However, it is found that away from the mode rational surface, the viscous forces for MHD modes decrease, a behavior similar to that observed in the viscous forces for the plateau regime. The proper form of the momentum equation that is appropriate for the modeling of the MHD modes is also discussed

Flocking regimes in a simple lattice model.

Science.gov (United States)

Raymond, J R; Evans, M R

2006-03-01

We study a one-dimensional lattice flocking model incorporating all three of the flocking criteria proposed by Reynolds [Computer Graphics 21, 4 (1987)]: alignment, centering, and separation. The model generalizes that introduced by O. J. O'Loan and M. R. Evans [J. Phys. A. 32, L99 (1999)]. We motivate the dynamical rules by microscopic sampling considerations. The model exhibits various flocking regimes: the alternating flock, the homogeneous flock, and dipole structures. We investigate these regimes numerically and within a continuum mean-field theory.

Legal Regimes of Official Information in Ukraine

Directory of Open Access Journals (Sweden)

Serhii Yesimov

2018-04-01

Full Text Available In the article on the basis of the methodology of system analysis the legal nature and sources of legal regulation of the legal regime of official information in Ukraine in the conditions of adaptation of Ukrainian legislation to the legislation of the European Union are considered. A comparative legal analysis of official information in the public-law and private-law spheres in the context of legal regimes of restricted information, confidential information and information classified as state secrets has been conducted.

What is the New Chinese Currency Regime?

OpenAIRE

Shah, Ajay; Zeileis, Achim; Patnaik, Ila

2005-01-01

The revaluation of the yuan in July 2005 was described by the Chinese central bank as a change in the currency regime, rather than merely a changed level of the exchange rate. The reform was said to involve a shift away from the fixed exchange rate, a gradual movement towards greater flexibility, and a peg to a basket of currencies. This paper closely examines the post-July Chinese currency regime utilising contemporary ideas in the econometrics of structural change. We find that the yuan has...

Search for a new exchange-rate regime.

Science.gov (United States)

Williamson, J

1987-07-31

The regime of unmanaged floating exchange rates was implicitly judged a failure when, with the Plaza Agreement, attempts at cooperative exchange-rate management were reintroduced primarily because of concern at the size of misalignments. Any satisfactory successor regime will need to limit misalignments while retaining the genuine social benefits of exchange-rate flexibility. It is argued that a system of target zones for exchange rates, ideally embedded in a more comprehensive set of guidelines for international economic policy coordination, could best reconcile these needs.

Investigation on reinforced concrete slabs subjeted to impact loading

International Nuclear Information System (INIS)

Freiman, M.; Krutzik, N.J.; Tropp, R.; Zorn, N.F.

1984-01-01

A comparison of experimental and computational results for tests of reinforced concrete slabs subjected to soft missile impact is presented. Numerical simulation techniques were employed to predict the target response. The objective of the calculations was to validate the material model for reinforced concrete implemented in a finite difference code. The computational results regarding displacements or strains in the reinforcement conform satisfactorily with the experimental values. (Author) [pt

Proliferation Control Regimes: Background and Status

National Research Council Canada - National Science Library

Nikitin, Mary B; Kerr, Paul; Bowman, Steve; Hildreth, Steven A

2008-01-01

.... national security interests. Multilateral regimes were established to restrict trade in nuclear, chemical, and biological weapons and missile technologies, and to monitor their civil applications...

Proliferation Control Regimes: Background and Status

National Research Council Canada - National Science Library

Squassoni, Sharon; Bowman, Steve; Hildreth, Steven A

2006-01-01

.... national security interests. Multilateral regimes were established to restrict trade in nuclear, chemical, and biological weapons and missile technologies, and to monitor their civil applications...

Ignition Regime for Fusion in a Degenerate Plasma

International Nuclear Information System (INIS)

Son, S.; Fisch, N.J.

2005-01-01

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

Equilibrium current-driven tearing mode in the hydrodynamic regime

International Nuclear Information System (INIS)

Cozzani, F.; Mahajan, S.

1984-12-01

The effect of the parallel equilibrium current on the linear stability of the drift-tearing mode in the collisional regime is investigated analytically. In the appropriate parameter regime, a new unstable mode, driven by equilibrium current, is found and its relevance to tokamak discharges is discussed

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

The perturbative Regge-calculus regime of loop quantum gravity

International Nuclear Information System (INIS)

Bianchi, Eugenio; Modesto, Leonardo

2008-01-01

The relation between loop quantum gravity and Regge calculus has been pointed out many times in the literature. In particular the large spin asymptotics of the Barrett-Crane vertex amplitude is known to be related to the Regge action. In this paper we study a semiclassical regime of loop quantum gravity and show that it admits an effective description in terms of perturbative area-Regge-calculus. The regime of interest is identified by a class of states given by superpositions of four-valent spin networks, peaked on large spins. As a probe of the dynamics in this regime, we compute explicitly two- and three-area correlation functions at the vertex amplitude level. We find that they match with the ones computed perturbatively in area-Regge-calculus with a single 4-simplex, once a specific perturbative action and measure have been chosen in the Regge-calculus path integral. Correlations of other geometric operators and the existence of this regime for other models for the dynamics are briefly discussed

Water-chemical regime of a fast reactor ower complex

International Nuclear Information System (INIS)

Musikhin, R.N.; Piskunov, E.M.; Samarkin, A.A.; Yurchenko, D.S.

1983-01-01

Some peculiarities of water-chemical regime of a power compleX in Shevchenko are considered. The complex comprises a desalination unit, a gas-masout heating-and-power plant and the BN-350 reactor. The compleX is used for the production of electric and thermal energy and fresh water. The power complex peculiarity is the utilization of disalinated seawater in a technological cycle along with highly mineralized seawater with a total salt content of 13.5 g/l (for cooling) in heat exchanges. A regime of ammoniacal correction of feed water was used as a basic water-chemical regime in the initial period of the BN-350 steam generator operation. Deposits composed mainly of iron oxide slime were observed on steam generator surfaces during the operation under these conditions. A conclusion is made that the regime with chelating agent providing steam generator safe operation without chemical cleaning is the most expedient one

Transport regimes spanning magnetization-coupling phase space

Science.gov (United States)

Baalrud, Scott D.; Daligault, Jérôme

2017-10-01

The manner in which transport properties vary over the entire parameter-space of coupling and magnetization strength is explored. Four regimes are identified based on the relative size of the gyroradius compared to other fundamental length scales: the collision mean free path, Debye length, distance of closest approach, and interparticle spacing. Molecular dynamics simulations of self-diffusion and temperature anisotropy relaxation spanning the parameter space are found to agree well with the predicted boundaries. Comparison with existing theories reveals regimes where they succeed, where they fail, and where no theory has yet been developed.

Development of Risk Assessment Methodology for State's Nuclear Security Regime

International Nuclear Information System (INIS)

Jang, Sung Soon; Seo, Hyung Min; Lee, Jung Ho; Kwak, Sung Woo

2011-01-01

Threats of nuclear terrorism are increasing after 9/11 terrorist attack. Treats include nuclear explosive device (NED) made by terrorist groups, radiological damage caused by a sabotage aiming nuclear facilities, and radiological dispersion device (RDD), which is also called 'dirty bomb'. In 9/11, Al Qaeda planed to cause radiological consequences by the crash of a nuclear power plant and the captured airplane. The evidence of a dirty bomb experiment was found in Afganistan by the UK intelligence agency. Thus, the international communities including the IAEA work substantial efforts. The leaders of 47 nations attended the 2010 nuclear security summit hosted by President Obama, while the next global nuclear summit will be held in Seoul, 2012. Most states established and are maintaining state's nuclear security regime because of the increasing threat and the international obligations. However, each state's nuclear security regime is different and depends on the state's environment. The methodology for the assessment of state's nuclear security regime is necessary to design and implement an efficient nuclear security regime, and to figure out weak points. The IAEA's INPRO project suggests a checklist method for State's nuclear security regime. The IAEA is now researching more quantitative methods cooperatively with several countries including Korea. In this abstract, methodologies to evaluate state's nuclear security regime by risk assessment are addressed

PARTICULARITIES OF PARLIAMENTARY OVERSIGHT IN DIFFERENT POLITICAL REGIMES

Directory of Open Access Journals (Sweden)

Silvia-Claudia CĂLIN-MIHALCEA

2015-07-01

Full Text Available The quality and intensity of the parliamentary oversight performed over the Government are shaped by several major criteria: political regime, electoral system, structure of the Parliament (unicameral/bicameral, parliamentary culture and tradition. This paper emphasizes some distinctive elements and particular mechanisms of the control exercised over the activities of the executive power, from the point of view of the political regime established in states with modern democracies.

How Do Countries Choose their Exchange Rate Regime?

OpenAIRE

Helene Poirson Ward

2001-01-01

This paper investigates the determinants of exchange rate regime choice in 93 countries during 1990-98. Cross-country analysis of variations in international reserves and nominal exchange rates shows that (i) truly fixed pegs and independent floats differ significantly from other regimes and (ii) significant discrepancies exist between de jure and de facto flexibility. Regression results highlight the influence of political factors (political instability and government temptation to inflate),...

Tidal regimes and salt marshes - the River Hamble analogue

International Nuclear Information System (INIS)

Gray, A.J.; Moy, I.L.; Warman, E.A.; Dawson, F.H.; Henville, P.

1993-01-01

Construction of estuarine tidal-energy barrages has a potentially major effect on the tidal regime of the estuary, particularly upstream of a barrage. Because tidal regime largely controls the distribution and species composition of intertidal plant and animal communities, it is important to understand how barrages may affect such communities. The main objectives of the research described in this report were to relate recent changes in tidal regime within an embanked area of salt marsh and mudflat to changes in the distribution of plant species. This was to test predictions about tidal control of species' range and to assess the site's suitability as an analogue of post-barrage conditions. (author)

Effect of Temperature Regimes on Seed Germination Asafoetida (Ferula Assafoetida L.

Directory of Open Access Journals (Sweden)

Zangoie M.

2014-12-01

Full Text Available Asafoetida is a medicinal plant belonging to the Apiaceae family. Gum obtained from the lower part of the stem and roots of this plant has many industrial and pharmaceutical applications. This plant is subject to extinction in its natural habitats due to over-utilization. Understanding the biology of seed germination can help to restore such degradation by implementing agricultural development programs. The present study is an attempt to determine the germination responses to two temperature regimes (constant and fluctuating during the course of the study. The experiment was planned based on a factorial-completely randomized design with two factors (constant and fluctuating temperature regimes at 3 levels each (15, 20 and 25°C with 4 replications. The results showed that the characteristics of germination in asafoetida were significantly improved under the fluctuating temperature as compared with the constant regime. It showed a mean germination time of 1.88 days for the fluctuating regime, while it was 4.88 days for the constant regime. The same results were found on germination rates in favor of fluctuating (0.62 per day in comparison with constant regime (0.33 per day. Under the fluctuating regime, the lowest level of imposed temperature (daily application of 10 and 20 degree during the first and the second 12 hours, respectively was the best for seed germination in this experiment.

REGIME SWITCHING DETERMINANTS OF SOVEREIGN CDS SPREADS: EVIDENCE FROM TURKEY

Directory of Open Access Journals (Sweden)

Umurcan Polat

2017-12-01

Full Text Available In this study, it is assessed the main determinants of sovereign CDS spreads in Turkey from January 2006 to December 2015. Before delving into the nonlinear Markov regime-switching model estimation, a conventional one-state linear model is estimated answering to what extent the sovereign credit risk is affected in between global and country-specific market variables and by credit ratings announcement changes. In broad strokes, the regime-switching analysis reveals that among domestic variables, it is the foreign exchange rate that affects the sovereign credit risk more in more volatile periods and among global variables, the indicators standing for global volatility risk premiums and international liquidity primarily influence the changes in the sovereign CDS spread in turbulent regimes whereas proxies for global risk free rate are significant more in tranquil regimes.

The differential effects of core stabilization exercise regime and conventional physiotherapy regime on postural control parameters during perturbation in patients with movement and control impairment chronic low back pain

Directory of Open Access Journals (Sweden)

Fernandes Svetlana

2010-05-01

Full Text Available Abstract Background The purpose of the present study was to examine the differential effect of core stability exercise training and conventional physiotherapy regime on altered postural control parameters in patients with chronic low back pain (CLBP. As heterogeneity in CLBP population moderates the effect of intervention on outcomes, in this study, interventions approaches were used based on sub-groups of CLBP. Methods This was an allocation concealed, blinded, sequential and pragmatic control trial. Three groups of participants were investigated during postural perturbations: 1 CLBP patients with movement impairment (n = 15, MI group randomized to conventional physiotherapy regime 2 fifteen CLBP patients with control impairment randomized to core stability group (CI group and 3 fifteen healthy controls (HC. Results The MI group did not show any significant changes in postural control parameters after the intervention period however they improved significantly in disability scores and fear avoidance belief questionnaire work score (P 0.8 after 8 weeks of core stability exercises for the adjusted p values. Postural control parameters of HC group were analyzed independently with pre and post postural control parameters of CI and MI group. This revealed the significant improvements in postural control parameters in CI group compared to MI group indicating the specific adaptation to the core stability exercises in CI group. Though the disability scores were reduced significantly in CI and MI groups (p Conclusions In this study core stability exercise group demonstrated significant improvements after intervention in ground reaction forces (Fz, Mz; g > 0.8 indicating changes in load transfer patterns during perturbation similar to HC group. Trial registration UTRN095032158-06012009423714

Characterization of the Tokamak Novillo in cleaning regime

International Nuclear Information System (INIS)

Lopez C, R.; Melendez L, L.; Valencia A, R.; Chavez A, E.; Colunga S, S.; Gaytan G, E.

1992-02-01

In this work the obtained results of the investigation about the experimental characterization of those low energy pulsed discharges of the Tokamak Novillo are reported. With this it is possible to fix the one operation point but appropriate of the Tokamak to condition the chamber in the smallest possible time for the cleaning discharges regime before beginning the main discharge. The characterization of the cleaning discharges in those Tokamaks is an unique process and characteristic of each device, since the good points of operation are consequence of those particularities of the design of the machine. In the case of the Tokamak Novillo, besides characterizing it a contribution is made to the cleaning discharges regime which consists on the one product of the current peak to peak of plasma by the duration of the discharge Ip t like reference parameter for the optimization of the operation of the device in the cleaning discharge regime. The maximum value of the parameter I (p) t, under different work conditions, allowed to find the good operation point to condition the discharges chamber of the Tokamak Novillo in short time and to arrive to a regime in which is not necessary the preionization for the obtaining of the cleaning discharges. (Author)

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.)

British Columbia's new coalbed methane royalty regime

International Nuclear Information System (INIS)

Molinski, D.

2002-01-01

The British Columbia Ministry of Energy and Mines is promoting the development of the coalbed methane (CBM) industry in the province in order to make CBM a viable and competitive investment option for industry. It is establishing a regulatory and fiscal regime for CBM development. Issues of concern regarding CBM development include water production, gas production rates, well numbers, and marginal economics. The features of the CBM royalty regime include a new producer cost of service allowance, the creation of a CBM royalty tax bank to collect excess PCOS allowances, and a royalty tax credit for wells drilled by the end of February, 2004. The marginal well adjustment factor threshold has been raised from 180 mcf per day to 600 mcf per day for CBM only. It was noted that royalties will probably not be payable for several years following the first commercial well because royalties are very depending on capital and operating costs, local infrastructure and price. Royalty regimes cannot save CBM from low gas prices, poor resources or economics. 2 figs

Determination of the Hall Thruster Operating Regimes; TOPICAL

International Nuclear Information System (INIS)

L. Dorf; V. Semenov; Y. Raitses; N.J. Fisch

2002-01-01

A quasi one-dimensional (1-D) steady-state model of the Hall thruster is presented. For the same discharge voltage two operating regimes are possible - with and without the anode sheath. For given mass flow rate, magnetic field profile and discharge voltage a unique solution can be constructed, assuming that the thruster operates in one of the regimes. However, we show that for a given temperature profile the applied discharge voltage uniquely determines the operating regime: for discharge voltages greater than a certain value, the sheath disappears. That result is obtained over a wide range of incoming neutral velocities, channel lengths and widths, and cathode plane locations. It is also shown that a good correlation between the quasi 1-D model and experimental results can be achieved by selecting an appropriate electron mobility and temperature profile

Second regime tokamak operation at large aspect ratio

International Nuclear Information System (INIS)

Navratil, G.A.

1989-01-01

This paper reviews the need for high beta in economic tokamak reactors and summarizes recent results on the scaling of the second regime beta limit for high-n ballooning modes using optimized pressure profiles as well as results on low-n mode stability at the first regime beta limit from the Columbia HBT tokamak. While several experiments have studied ballooning limits using high εβ p plasmas, the most important question for the use of the second stability regime for tokamak reactor improvement is how to achieve these high values of εβ p while at the same time increasing the value of beta to several times the Troyon beta limit. An approach to the study of this key question on beta limits using modest sized, large aspect ratio tokamaks is described. (author). 28 refs, 7 figs, 1 tab

Unravelling the relative contribution of bed and suspended sediment load on a large alluvial river

Science.gov (United States)

Darby, S. E.; Hackney, C. R.; Parsons, D. R.; Leyland, J.; Aalto, R. E.; Nicholas, A. P.; Best, J.

2017-12-01

The world's largest rivers transport 19 billion tonnes of sediment to the coastal zone annually, often supporting large deltas that rely on this sediment load to maintain their elevation in the face of rising sea level, and to sustain high levels of agricultural productivity and biodiversity. However, the majority of estimates of sediment delivery to coastal regions pertain solely to the suspended fraction of the sediment load, with the bedload fraction often being neglected due to the difficulty in estimating bedload flux and the assumption that bedload contributes a minor (management plans, improved estimates of all fractions of the sediment load are essential. Recent advances in non-intrusive, high-resolution, technology have begun to enable more accurate estimates of bedload transport rates. However, the characterisation of the holistic sediment transport regime of large alluvial rivers is still lacking. Here, we develop a sediment transport rating curve, combining both suspended- and bed- load sediment fractions, for the Lower Mekong River. We define suspended sediment rating curves using the inversion of acoustic return data from a series of acoustic Doppler current profiler surveys conducted through the Lower Mekong River in Cambodia, and into the bifurcating channels of the Mekong delta in Vietnam. Additionally, we detail estimates of bed-load sediment transport determined using repeat multibeam echo sounder surveys of the channel bed. By combining estimates of both fractions of the sediment load, we show the spatial and temporal contribution of bedload to the total sediment load of the Mekong and refine estimates of sediment transport to the Mekong delta. Our results indicate that the time-averaged suspended load transport rates for the Mekong River are 87 MT/yr, whilst bedload transport forms c. management within this highly threatened river basin.

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.

Conceptual proposals for measuring the impact of international regimes on energy security

International Nuclear Information System (INIS)

Sander, Michael

2013-01-01

The paper proposes two concepts to assess the effect of international regimes on energy security. Existing indicators focus mainly on state-level factors, excluding international influences. International relation scholars on the other hand see a clear connection between international regimes and stable energy relations. International regimes stabilise energy relations by providing frameworks for negotiations, defining, controlling and sanctioning compliance and allowing the actors to engage in package deals. The researcher needs to include these factors in a complete assessment of political energy security risks. As first step, the paper uses the effectiveness of control mechanisms as basis for such consideration. It refers specifically to international arbitration as the most important control mechanism in international energy relations. The simplest measurement option is the share of a county's energy imports covered by a certain regime. The paper applies the Oslo-Potsdam-Solution to account for outcome effectiveness. It applies a variant of the International Regimes Data Base protocol to account for effective regime structures. In a last section, the paper proposes some possible paths for future research. - Highlights: • International regimes mitigate political risks for energy supply and must be considered. • The paper proposes two concepts to measure energy regime effectiveness. • The OPS-variant measures output, the IRDB-variant measures structure effectiveness. • The paper offers a preliminary feasibility test for the concepts. • Finally, it suggests further roads for research

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

Which currency exchange regime for emerging markets?: Corner solutions under question

Directory of Open Access Journals (Sweden)

Allegret Jean-Pierre

2007-01-01

Full Text Available During the 90s, recurrent exchange rate crises in emerging markets have shown the extreme fragility of soft pegs, the so-called intermediate exchange rate regimes. As a result, numerous academic economists but also International institutions have promoted a new consensus: domestic authorities have to choose their exchange rate regime between only two solutions called corner solutions or extreme regimes: hard pegs or independent floating. This paper questions de relevance of this consensus. We stress the main advantages and costs of each corner solution. We conclude by stressing that intermediate regimes associated to an inflation targeting framework seem a better solution for emerging countries than corner solutions.

Effect of random microstructure on crack propagation in cortical bone tissue under dynamic loading

International Nuclear Information System (INIS)

Gao, X; Li, S; Adel-Wahab, A; Silberschmidt, V

2013-01-01

A fracture process in a cortical bone tissue depends on various factors, such as bone loss, heterogeneous microstructure, variation of its material properties and accumulation of microcracks. Therefore, it is crucial to comprehend and describe the effect of microstructure and material properties of the components of cortical bone on crack propagation in a dynamic loading regime. At the microscale level, osteonal bone demonstrates a random distribution of osteons imbedded in an interstitial matrix and surrounded by a thin layer known as cement line. Such a distribution of osteons can lead to localization of deformation processes. The global mechanical behavior of bone and the crack-propagation process are affected by such localization under external loads. Hence, the random distribution of microstructural features plays a key role in the fracture process of cortical bone. The purpose of this study is two-fold: firstly, to develop two-dimensional microstructured numerical models of cortical bone tissue in order to examine the interaction between the propagating crack and bone microstructure using an extended finite-element method under both quasi-static and dynamic loading conditions; secondly, to investigate the effect of randomly distributed microstructural constituents on the crack propagation processes and crack paths. The obtained results of numerical simulations showed the influence of random microstructure on the global response of bone tissue at macroscale and on the crack-propagation process for quasi-static and dynamic loading conditions

The thermal-mechanical behavior of fuel pins during power's maneuvering regime at stationary core loading on 2nd unit of KHNPP

International Nuclear Information System (INIS)

Ieremenko, M.; Ovdiyenko, Y.; Khalimonchuk, V.

2007-01-01

Results of thermal-mechanical behaviour of fuel pins during daily power's maneuvering regime that were proposed for second unit of Khmelnitsky NPP are presented. Calculations were performed for campaign's moments 100 and 160 fpd and for different type of regulation. Additionally calculations were performed for campaign 7. It is the design variant of the campaign and reactor core contains the high burnt fuel. Calculations of macro-core parameters (Kq, Kv) was performed by spatial computer code DYN3D. Calculations of micro-core parameters (fuel pin power) was performed by computer code DERAB. Calculations of thermal-mechanical behaviour of fuel pins was performed by computer code TRANSURANUS (Authors)

Effective thermal conductivity of superfluid helium: laminar, turbulent and ballistic regimes

Directory of Open Access Journals (Sweden)

Sciacca Michele

2016-06-01

Full Text Available In this paper we extend previous results on the effective thermal conductivity of liquid helium II in cylindrical channels to rectangular channels with high aspect ratio. The aim is to compare the results in the laminar regime, the turbulent regime and the ballistic regime, all of them obtained within a single mesoscopic formalism of heat transport, with heat flux as an independent variable.

Boolean logic analysis for flow regime recognition of gas–liquid horizontal flow

International Nuclear Information System (INIS)

Ramskill, Nicholas P; Wang, Mi

2011-01-01

In order to develop a flowmeter for the accurate measurement of multiphase flows, it is of the utmost importance to correctly identify the flow regime present to enable the selection of the optimal method for metering. In this study, the horizontal flow of air and water in a pipeline was studied under a multitude of conditions using electrical resistance tomography but the flow regimes that are presented in this paper have been limited to plug and bubble air–water flows. This study proposes a novel method for recognition of the prevalent flow regime using only a fraction of the data, thus rendering the analysis more efficient. By considering the average conductivity of five zones along the central axis of the tomogram, key features can be identified, thus enabling the recognition of the prevalent flow regime. Boolean logic and frequency spectrum analysis has been applied for flow regime recognition. Visualization of the flow using the reconstructed images provides a qualitative comparison between different flow regimes. Application of the Boolean logic scheme enables a quantitative comparison of the flow patterns, thus reducing the subjectivity in the identification of the prevalent flow regime

The legacy of large regime shifts in shallow lakes.

Science.gov (United States)

Ramstack Hobbs, Joy M; Hobbs, William O; Edlund, Mark B; Zimmer, Kyle D; Theissen, Kevin M; Hoidal, Natalie; Domine, Leah M; Hanson, Mark A; Herwig, Brian R; Cotner, James B

2016-12-01

Ecological shifts in shallow lakes from clear-water macrophyte-dominated to turbid-water phytoplankton-dominated are generally thought of as rapid short-term transitions. Diatom remains in sediment records from shallow lakes in the Prairie Pothole Region of North America provide new evidence that the long-term ecological stability of these lakes is defined by the legacy of large regime shifts. We examine the modern and historical stability of 11 shallow lakes. Currently, four of the lakes are in a clear-water state, three are consistently turbid-water, and four have been observed to change state from year to year (transitional). Lake sediment records spanning the past 150-200 yr suggest that (1) the diatom assemblage is characteristic of either clear or turbid lakes, (2) prior to significant landscape alteration, all of the lakes existed in a regime of a stable clear-water state, (3) lakes that are currently classified as turbid or transitional have experienced one strong regime shift over the past 150-200 yr and have since remained in a regime where turbid-water predominates, and (4) top-down impacts to the lake food-web from fish introductions appear to be the dominant driver of strong regime shifts and not increased nutrient availability. Based on our findings we demonstrate a method that could be used by lake managers to identify lakes that have an ecological history close to the clear-turbid regime threshold; such lakes might more easily be returned to a clear-water state through biomanipulation. The unfortunate reality is that many of these lakes are now part of a managed landscape and will likely require continued intervention. © 2016 by the Ecological Society of America.

Weather regimes in past climate atmospheric general circulation model simulations

Energy Technology Data Exchange (ETDEWEB)

Kageyama, M.; Ramstein, G. [CEA Saclay, Gif-sur-Yvette (France). Lab. des Sci. du Climat et de l' Environnement; D' Andrea, F.; Vautard, R. [Laboratoire de Meteorologie Dynamique, Ecole Normale Superieure, Paris (France); Valdes, P.J. [Department of Meteorology, University of Reading (United Kingdom)

1999-10-01

We investigate the climates of the present-day, inception of the last glaciation (115000 y ago) and last glacial maximum (21000 y ago) in the extratropical north Atlantic and Europe, as simulated by the laboratoire de Meteorologie dynamique atmospheric general circulation model. We use these simulations to investigate the low-frequency variability of the model in different climates. The aim is to evaluate whether changes in the intraseasonal variability, which we characterize using weather regimes, can help describe the impact of different boundary conditions on climate and give a better understanding of climate change processes. Weather regimes are defined as the most recurrent patterns in the 500 hPa geopotential height, using a clustering algorithm method. The regimes found in the climate simulations of the present-day and inception of the last glaciation are similar in their number and their structure. It is the regimes' populations which are found to be different for these climates, with an increase of the model's blocked regime and a decrease in the zonal regime at the inception of the last glaciation. This description reinforces the conclusions from a study of the differences between the climatological averages of the different runs and confirms the northeastward shift to the tail of the Atlantic storm-track, which would favour more precipitation over the site of growth of the Fennoscandian ice-sheet. On the other hand, the last glacial maximum results over this sector are not found to be classifiable, showing that the change in boundary conditions can be responsible for severe changes in the weather regime and low-frequency dynamics. The LGM Atlantic low-frequency variability appears to be dominated by a large-scale retrogressing wave with a period 40 to 50 days. (orig.)

Design and testing of a surface switch for the dynamic load current multiplier on the SPHINX microsecond LTD

International Nuclear Information System (INIS)

Maysonnave, T.; Bayol, F.; Demol, G.; Almeida, T. d'; Morell, A.; Lassalle, F.; Grunenwald, J.; Chuvatin, A.S.; Pecastaing, L.; De Ferron, A.S.

2013-01-01

SPHINX is a microsecond linear transformer driver located at Atomic Energy Commission (CEA) Gramat (France), which can deliver a current pulse of 6 MA within 800 ns in a Z-pinch load. Using the concept of the dynamic load current multiplier (DLCM), which was proposed by Chuvatin, we expect to increase the load current above 6 MA, while decreasing its rise time to ∼300 ns. The DLCM developed by the CEA Gramat and International Technologies for High Pulsed Power (ITHPP) is a compact system made up of concentric electrodes (auto-transformer), a dynamic flux extruder (cylindrical wire array), a vacuum convolute (eight post-hole rods), and a closing switch (compact vacuum surface switch). The latter is a key component of the system, which is used to prevent the current from flowing into the load until the inductance builds up due to the implosion of the wire array. This paper presents the design and testing of the DLCM surface switch, resulting from both electrostatic simulations and experiments on the SPHINX generator. These studies, carried out either with or without load (open circuit), were valuable for a first experimental evaluation of the DLCM scheme in a microsecond regime and provided detailed information on the surface switch behavior. (authors)

Early signatures of regime shifts in gene expression dynamics

Science.gov (United States)

Pal, Mainak; Pal, Amit Kumar; Ghosh, Sayantari; Bose, Indrani

2013-06-01

Recently, a large number of studies have been carried out on the early signatures of sudden regime shifts in systems as diverse as ecosystems, financial markets, population biology and complex diseases. The signatures of regime shifts in gene expression dynamics are less systematically investigated. In this paper, we consider sudden regime shifts in the gene expression dynamics described by a fold-bifurcation model involving bistability and hysteresis. We consider two alternative models, models 1 and 2, of competence development in the bacterial population B. subtilis and determine some early signatures of the regime shifts between competence and noncompetence. We use both deterministic and stochastic formalisms for the purpose of our study. The early signatures studied include the critical slowing down as a transition point is approached, rising variance and the lag-1 autocorrelation function, skewness and a ratio of two mean first passage times. Some of the signatures could provide the experimental basis for distinguishing between bistability and excitability as the correct mechanism for the development of competence.

Early signatures of regime shifts in gene expression dynamics

International Nuclear Information System (INIS)

Pal, Mainak; Pal, Amit Kumar; Ghosh, Sayantari; Bose, Indrani

2013-01-01

Recently, a large number of studies have been carried out on the early signatures of sudden regime shifts in systems as diverse as ecosystems, financial markets, population biology and complex diseases. The signatures of regime shifts in gene expression dynamics are less systematically investigated. In this paper, we consider sudden regime shifts in the gene expression dynamics described by a fold-bifurcation model involving bistability and hysteresis. We consider two alternative models, models 1 and 2, of competence development in the bacterial population B. subtilis and determine some early signatures of the regime shifts between competence and noncompetence. We use both deterministic and stochastic formalisms for the purpose of our study. The early signatures studied include the critical slowing down as a transition point is approached, rising variance and the lag-1 autocorrelation function, skewness and a ratio of two mean first passage times. Some of the signatures could provide the experimental basis for distinguishing between bistability and excitability as the correct mechanism for the development of competence. (paper)

THE IMPACT OF THE GLOBAL NUCLEAR SAFETY REGIME IN BRAZIL

International Nuclear Information System (INIS)

Almeida, C.

2004-01-01

A turning point of the world nuclear industry with respect to safety occurred due to the accident at Chernobyl, in 1986. A side from the tragic personal losses and the enormous financial damage, the Chernobyl accident has literally demonstrated that ''a nuclear accident anywhere is an accident everywhere''. The impact was felt immediately by the nuclear industry, with plant cancellations (e.g. Austria), elimination of national programs (e.g. Italy) and general construction delays. However, the reaction of the nuclear industry was equally immediate, which led to the proposal and establishment of a Global Nuclear Safety Regime. This regime is composed of biding international safety conventions, globally accepted safety standard, and a voluntary peer review system. In a previous work, the author has presented in detail the components of this Regime, and briefly discussed its impact in the Brazilian nuclear power organizations, including the Regulatory Body. This work, on the opposite, briefly reviews the Global Nuclear Safety Regime, and concentrates in detail in the discussion of its impact in Brazil, showing how it has produced some changes, and where the peer pressure regime has failed to produce real results

Transition between laser absorption dominated regimes in carbon-based plasma

Directory of Open Access Journals (Sweden)

K. Hajisharifi

2017-09-01

Full Text Available In this work, we investigate the energy absorption enhancement of a laser by adding a variety of light ion species to a primarily carbon-based plasma during the high-power laser interaction with the finite size targets. A developed Particle-In-Cell simulation code is used to study the reduction of laser reflectivity (stimulated backward scatterings in both Brillouin- and Raman-dominated regimes. The simulation is performed in various Carbon-light ion plasmas such as Carbon-Hydrogen, Carbon-Helium, Carbon-Deuterium, and Carbon-Tritium. The results show that, in the optimized condition, the inclusion of light Hydrogen ions into the Carbon-based plasma up to 50%-50% mixture enhances the laser absorption exceeding 20% in the Brillouin regime due to the suppression of laser reflectivity in contract to 4% in the Raman-dominated regime. Moreover, the absorption dominated regime switches from Raman to Brillouin regime by adding 50% of Hydrogen ions to a purely carbon target. The results of this investigation will be applicable to the laser-plasma experiments so long as the laser energy absorption in the Carbon plasma target, the most readily available material in laboratory, is concerned.

Distribution load forecast with interactive correction of horizon loads

International Nuclear Information System (INIS)

Glamochanin, V.; Andonov, D.; Gagovski, I.

1994-01-01

This paper presents the interactive distribution load forecast application that performs the distribution load forecast with interactive correction of horizon loads. It consists of two major parts implemented in Fortran and Visual Basic. The Fortran part is used for the forecasts computations. It consists of two methods: Load Transfer Coupling Curve Fitting (LTCCF) and load Forecast Using Curve Shape Clustering (FUCSC). LTCCF is used to 'correct' the contaminated data because of load transfer among neighboring distribution areas. FUCSC uses curve shape clustering to forecast the distribution loads of small areas. The forecast for each small area is achieved by using the shape of corresponding cluster curve. The comparison of forecasted loads of the area with historical data will be used as a tool for the correction of the estimated horizon load. The Visual Basic part is used to provide flexible interactive user-friendly environment. (author). 5 refs., 3 figs

Development of a Solid State RF Amplifier in the kW Regime for Application with Low Beta Superconducting RF Cavities

CERN Document Server

Piel, Christian; Borisov, A; Kolesov, Sergej; Piel, Helmut

2005-01-01

Projects based on the use of low beta superconducting cavities for ions are under operation or development at several labs worldwide. Often these cavities are individually driven by RF power sources in the kW regime. For an ongoing project a modular 2 kW, 176 MHz unconditionally stable RF amplifier for CW and pulsed operation was designed, built, and tested. Extended thermal analysis was used to develop a water cooling system in order to optimize the performance of the power transistors and other thermally loaded components. The paper will outline the design concept of the amplifier and present first results on the test of the amplifier with a superconducting cavity.

Technical efficiency under alternative environmental regulatory regimes: The case of Dutch horticulture

International Nuclear Information System (INIS)

Van der Vlist, Arno J.; Withagen, Cees; Folmer, Henk

2007-01-01

We consider the performance of small and medium sized enterprises in Dutch horticulture under different environmental policy regimes across time. We address the question whether technical performance differs under these alternative regulatory regimes to test Porter's hypothesis that stricter environmental regulation reduces technical inefficiency. For this purpose, we use a stochastic production frontier framework allowing for inclusion of policy variables to measure the effect of alternative environmental policy regimes on firms' performance. The main result is that stricter environmental policy regimes have indeed reduced technical inefficiencies in Dutch horticulture. The estimation results indicate amongst others that the 1997 agreement on energy, nutrient and pesticides use enhances technical efficiency. Firms under the strict environmental policy regime are found to be more technically efficient than those under a lax regime, thereby supporting the claims by Porter and Van der Linde (Porter, M., Van der Linde, C., 1995. Green and Competitive: Ending the stalemate. Harvard Business Review 73, pp. 120-137) concerning Dutch horticulture. (author)

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.

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...... particle image velocimetry (SPIV). Based on the obtained SPIV data, a map of the regimes of flow past the vortex generator has been constructed. One region with a developed stable multivortex system on this map reaches the vicinity of the optimum angle of attack of the vortex generator....

Effects of temperature anisotropy on neoclassical transport in the plateau and banana-plateau regimes

International Nuclear Information System (INIS)

Taguchi, Masayoshi

1999-01-01

The neoclassical transport theory in a presence of temperature anisotropy is investigated in the low to the intermediate collision frequency regimes for a large aspect-ratio tokamak plasma. The standard procedure for an isotropic plasma in the plateau regime is extended to an anisotropic plasma, and the neoclassical transport coefficients in this regime are explicitly calculated. By interpolating the results in the plateau regime and the previously obtained ones in the banana regime, the expressions for the neoclassical transport coefficients which are continuously valid from the banana to the plateau regimes are presented. (author)

Fatigue performance of laser additive manufactured Ti-6Al-4V in very high cycle fatigue (VHCF regime up to 10⁹ cycles

Directory of Open Access Journals (Sweden)

Eric eWycisk

2015-12-01

Full Text Available Additive manufacturing technologies are in the process of establishing themselves as an alternative production technology to conventional manufacturing such as casting or milling. Especially laser additive manufacturing (LAM enables the production of metallic parts with mechanical properties comparable to conventionally manufactured components. Due to the high geometrical freedom in LAM the technology enables the production of ultra-light weight designs and therefore gains increasing importance in aircraft and space industry. The high quality standards of these industries demand predictability of material properties for static and dynamic load cases. However, fatigue properties especially in the very high cycle fatigue regime until 109 cycles have not been sufficiently determined yet. Therefore this paper presents an analysis of fatigue properties of laser additive manufactured Ti-6Al-4V under cyclic tension-tension until 107 cycles and tension-compression load until 109 cycles.For the analysis of laser additive manufactured titanium alloy Ti-6Al-4V Woehler fatigue tests under tension-tension and tension-compression were carried out in the high cycle and very high cycle fatigue regime. Specimens in stress-relieved as well as hot-isostatic-pressed conditions were analyzed regarding crack initiation site, mean stress sensitivity and overall fatigue performance. The determined fatigue properties show values in the range of conventionally manufactured Ti-6Al-4V with particularly good performance for hot-isostatic-pressed additive-manufactured material. For all conditions the results show no conventional fatigue limit but a constant increase in fatigue life with decreasing loads. No effects of test frequency on life span could be determined. However, independently of testing principle, a shift of crack initiation from surface to internal initiation could be observed with increasing cycles to failure.

Regime-Dependent Differences in Surface Freshwater Exchange Estimates Over the Ocean

Science.gov (United States)

Wong, Sun; Behrangi, Ali

2018-01-01

Differences in gridded precipitation (P), surface evaporation (E), and the resultant surface freshwater exchange (P - E) among different products over the ocean are diagnosed as functions of moisture advection (Qadvt) and moisture tendency by dynamical convergence (Qcnvg). Compared to the GPCP product, the TRMM3B42 product captures higher frequency of precipitation with larger extreme precipitation rates in regimes of deep convection and more light rain detections in regimes of frequent occurrence of boundary layer clouds. Discrepancies in E depend on moisture flux divergence, with the OAFlux product having the largest E in regimes of divergence. Discrepancies in mean P - E in deep convective regimes are highly influenced by differences in precipitation, with the TRMM3B42 product yielding P - E histograms closer to those inferred from the reanalysis moisture flux convergence. In nonconvergent regimes, observation-based P - E histograms skew toward positive values while the inferred reanalysis histograms are symmetric about the means.

Transfer cell wall ingrowths and vein loading characteristics in pea leaf discs

International Nuclear Information System (INIS)

Wimmers, L.E.; Turgeon, R.

1987-01-01

Transfer cell wall ingrowths are thought to increase transport capacity by increasing plasmalemma surface area. Leaf minor vein phloem transfer cells presumably enhance phloem loading. In Pisum sativum cv. Little marvel grown under different light regimes (150 to 1000 μmol photons m -2 sec -1 ) there is a positive correlation between light intensity and wall ingrowth area in phloem transfer cells. The extent of ingrowth and correlation to light intensity is greatest in minor veins, decreasing as vein size increases. Vein loading was assayed by floating abraded leaf discs on 14 C-sucrose (10 mM). There is a positive correlation between uptake and transfer cell wall area, although the latter increased more than the former. The difference in uptake is stable throughout the photoperiod, and is also stable in mature leaves for at least four days after plants are transfered to a different light intensity. Sucrose uptake is biphasic. The saturable component of uptake is sensitive to light intensity, the Km for sucrose is negatively correlated to light intensity, while V/sub max/remains unchanged

Salix response to different flow regimes in controlled experiments: first results

Science.gov (United States)

Gorla, Lorenzo; Signarbieux, Constant; Buttler, Alexandre; Perona, Paolo

2013-04-01

Dams and water management for hydropower production, agriculture and other human activities alter the natural flow regime of rivers. The new river hydrograph components depend on the type of impoundment and the policy of regulation but such a different flow regime will likely affect the riparian environment. The main challenge in order to define sustainable flow releases is to quantify hydrological effects in terms of geomorphology and ecosystem response. A considerable lack of knowledge still affects the link hydrology-ecology and inadequate flow rules (e.g., minimal or residual flows) are consequently still widespread: further research in this direction is urgently required. We present an experiment, which aims to investigate the effects of different water stage regimes on riparian vegetation (salix Viminalis cuttings) development in a temperate region (Switzerland). This work describes the installation setup, together with the first results concerning the first of the two scheduled seasons of campaign. Sixty Salix cuttings were planted in non-cohesive sandy-gravel sediment within 1 meter tall plastic pots installed outside in the EPFL campus. After grouping them in three batteries, the water level within them has been varying following three river regimes simulated by adjusting the water level within the pots by means of an automatic hydraulic system. The three water level regimes reproduce a natural flow regime, a minimum residual flow policy, which only conserves peaks during flooding conditions, and an artificial regime conserving only low frequencies (e.g., seasonality) of the natural dynamic. The natural flow regime of the first battery has been applied for two months to the entire system; the three regimes above said started in June 2012. This triggered a plant response transitory regime, which we monitored by measuring plant growth, soil and atmospheric variables. Particularly, measures concern with branches development leaves photosynthesis and

In vivo strains in the femur of the Virginia opossum (Didelphis virginiana) during terrestrial locomotion: testing hypotheses of evolutionary shifts in mammalian bone loading and design.

Science.gov (United States)

Butcher, Michael T; White, Bartholomew J; Hudzik, Nathan B; Gosnell, W Casey; Parrish, John H A; Blob, Richard W

2011-08-01

Terrestrial locomotion can impose substantial loads on vertebrate limbs. Previous studies have shown that limb bones from cursorial species of eutherian mammals experience high bending loads with minimal torsion, whereas the limb bones of non-avian reptiles (and amphibians) exhibit considerable torsion in addition to bending. It has been hypothesized that these differences in loading regime are related to the difference in limb posture between upright mammals and sprawling reptiles, and that the loading patterns observed in non-avian reptiles may be ancestral for tetrapod vertebrates. To evaluate whether non-cursorial mammals show loading patterns more similar to those of sprawling lineages, we measured in vivo strains in the femur during terrestrial locomotion of the Virginia opossum (Didelphis virginiana), a marsupial that uses more crouched limb posture than most mammals from which bone strains have been recorded, and which belongs to a clade phylogenetically between reptiles and the eutherian mammals studied previously. The presence of substantial torsion in the femur of opossums, similar to non-avian reptiles, would suggest that this loading regime likely reflects an ancestral condition for tetrapod limb bone design. Strain recordings indicate the presence of both bending and appreciable torsion (shear strain: 419.1 ± 212.8 με) in the opossum femur, with planar strain analyses showing neutral axis orientations that placed the lateral aspect of the femur in tension at the time of peak strains. Such mediolateral bending was unexpected for a mammal running with near-parasagittal limb kinematics. Shear strains were similar in magnitude to peak compressive axial strains, with opossum femora experiencing similar bending loads but higher levels of torsion compared with most previously studied mammals. Analyses of peak femoral strains led to estimated safety factor ranges of 5.1-7.2 in bending and 5.5-7.3 in torsion, somewhat higher than typical mammalian values

The National Security Strategy of the United Kingdom: Security in an Interdependent World

Science.gov (United States)

2008-03-01

security architecture has yet to adapt satisfactorily to the new landscape. The UN Security Council has failed to adapt to the rise of new powers. Across...including cinemas , theatres, pubs, nightclubs, restaurants, hotels and commercial centres, hospitals, schools and places of worship); work with architects...and export control regimes, and improving the international monitoring architecture . Countering the threat of nuclear weapons and other weapons of

Effects and empirical critical loads of Nitrogen for ecoregions of the United States

Science.gov (United States)

Pardo, Linda H.; Robin-Abbott, Molly J.; Fenn, Mark E.; Goodale, Christine L.; Geiser, Linda H.; Driscoll, Charles T.; Allen, Edith B.; Baron, Jill S.; Bobbink, Roland; Bowman, William D.; Clark, C M; Emmett, B.; Gilliam, Frank S; Greaver, Tara L.; Hall, Sharon J; Lilleskov, Erik A.; Liu, Lingli; Lynch, Jason A.; Nadelhoffer, Knute J; Perakis, Steven; Stoddard, John L; Weathers, Kathleen C.; Dennis, Robin L.

2015-01-01

Human activity in the last century has increased nitrogen (N) deposition to a level that has caused or is likely to cause alterations to the structure and function of many ecosystems across the United States. We synthesized current research relating atmospheric N deposition to effects on terrestrial and freshwater ecosystems in the United States, and estimated associated empirical critical loads of N for several receptors: freshwater diatoms, mycorrhizal fungi, lichens, bryophytes, herbaceous plants, shrubs, and trees. Biogeochemical responses included increased N mineralization and nitrification, increased gaseous N losses, and increased N leaching. Individual species, population, and community responses included increased tissue N, physiological and nutrient imbalances, increased growth, altered root-shoot ratios, increased susceptibility to secondary stresses, altered fire regime, shifts in competitive interactions and community composition, changes in species richness and other measures of biodiversity, and increases in invasive species. The range of critical loads of nutrient N reported for U.S. ecoregions, inland surface waters, and freshwater wetlands is 1–39 kg N ha−1 yr−1, spanning the range of N deposition observed over most of the country. The empirical critical loads of N tend to increase in the following sequence: diatoms, lichens and bryophytes, mycorrhizal fungi, herbaceous plants and shrubs, trees.

"International regime for advancing lunar development"

Science.gov (United States)

Beldavs, VZ

2017-09-01

A specific concern regarding the Moon Treaty is the provision for sharing the wealth gained from space with developing countries that have not invested and taken risks in making possible space materials utilization. Article 11, par. 7 states "The main purposes of the international regime to be established shall include: (a) The orderly and safe development of the natural resources of the moon; (b) The rational management of those resources; (c) The expansion of opportunities in the use of those resources; (d) An equitable sharing by all States Parties in the benefits derived from those resources, whereby the interests and needs of the developing countries, as well as the efforts of those countries which have contributed either directly or indirectly to the exploration of the moon, shall be given special consideration." Whether the Moon Treaty in its present form or modified to be acceptable to more parties or the Moon Treaty is ignored, the language of Article 11, paragraph 7 can be used to construct an international regime for lunar development that can meet the requirements of commercial business as well as of states that provide support for lunar development as well as developing countries that may have played a modest role in making lunar development possible. This paper will consider options for constructing an international regime for lunar development.

Intense electron-beam transport in the ion-focused regime through the collision-dominated regime

International Nuclear Information System (INIS)

Sanford, T.W.L.; Poukey, J.W.; Welch, D.R.; Mock, R.C.

1993-01-01

This paper reviews the transport of the 19-MeV, 700-kA, 25-ns Hermes-III electron beam in long gas cells filled with N 2 gas spanning six decades in pressure from 10 3 to ∼10 3 Torr. We show through measurements and theoretical analyses that the beam has two windows of stable transport: a low-pressure window (between ∼1 and ∼100 mTorr) that is dominated by propagation in the semi-collisionless IFR (ion-focused regime), and a high-pressure window (between ∼1 and ∼100 Torr) that is dominated by propagation in the resistive CDR (collision-dominated regime). In the CDR, 79±1.5% of the beam energy is transported over 11 m at 20 Torr. In the IFR, we show that intense radiation fields with controllable rise times and pulse widths can be generated on axis at a bremsstrahlung target. In summary, the measurements and analyses presented here provide a quantitative description of the Hermes-III beam transport over six decades in pressure

Effect of initial conditions on combustion generated loads

International Nuclear Information System (INIS)

Tieszen, S.R.

1993-01-01

This analytical study examines the effect of initial thermodynamic conditions on the loads generated by the combustion of homogeneous hydrogen-air-steam mixtures. The effect of initial temperature, pressure, hydrogen concentration, and steam concentration is evaluated for two cases, (1) constant volume and (2) constant initial pressure. For each case, the Adiabatic, Isochoric, Complete Combustion (AICC), Chapman-Jouguet (CJ), and normally reflected CJ pressures are calculated for a range of hydrogen and steam concentrations representative of the entire flammable regime. For detonation loads, pressure profiles and time-histories are also evaluated in one-dimensional Cartesian geometry. The results show that to a first approximation, the AICC and CJ pressures are directly proportional to the initial density. Increasing the hydrogen concentration up to stoichiometric concentrations significantly increases the AICC, CJ, and reflected CJ pressures. For the constant volume case, the AICC, CJ, and reflected CJ pressures increase with increasing hydrogen concentration on the rich side of stoichiometric concentrations. For the constant initial pressure case, the AICC, CJ, and reflected CJ pressures decrease with increasing hydrogen concentration on the rich side of stoichiometric values. The addition of steam decreases the AICC, CJ, and reflected CJ pressures for the constant initial pressure case, but increases them for the constant volume case. For detonations, the pressure time-histories can be normalized with the AICC pressure and the reverberation time for Cartesion geometry. (orig.)

How does technological regime affect performance of technology development projects?

NARCIS (Netherlands)

Song, Michael; Hooshangi, Soheil; Zhao, Y. Lisa; Halman, Johannes I.M.

2014-01-01

In this study, we examine how technological regime affects the performance of technology development projects (i.e., project quality, sales, and profit). Technological regime is defined as the set of attributes of a technological environment where the innovative activities of firms take place.

Interacting Regional-Scale Regime Shifts for Biodiversity and Ecosystem Services

NARCIS (Netherlands)

Leadley, P.; Proenca, V.; Fernandez-Manjarres, J.; Pereira, H.M.; Alkemade, J.R.M.; Biggs, R.; Bruley, E.; Cheung, W.; Cooper, D.; Figueiredo, J.; Gilman, E.; Guenette, S.; Hurtt, G.; Mbow, C.; Oberdorff, T.; Revenga, C.; Scharlemann, J.P.W.; Scholes, R.; Smith, M.S.; Sumaila, U.R.; Walpole, M.

2014-01-01

Current trajectories of global change may lead to regime shifts at regional scales, driving coupled human-environment systems to highly degraded states in terms of biodiversity, ecosystem services, and human well-being. For business-as-usual socioeconomic development pathways, regime shifts are

Characteristics of radiated power for various TFTR [Tokamak Fusion Test Reactor] regimes

International Nuclear Information System (INIS)

Bush, C.E.; Schivell, J.; McNeill, D.H.

1988-04-01

Power loss studies were carried out to determine the impurity radiation and energy transport characteristics of various TFTR operation and confinement regimes including L-Mode, detached plasma, co-only neutral beam injection (energetic ion regime), and the enhanced confinement (''supershot'') regime. Combined bolometric, spectroscopic, and infrared photometry measurements provide a picture of impurity behavior and power accounting in TFTR. The purpose of this paper is to make a survey of the various regimes with the aim of determining the radiated power signatures of each. 10 refs., 6 figs., 1 tab

Monitoring, Accounting and Enforcement in Emissions Trading Regimes

International Nuclear Information System (INIS)

Peterson, S.

2003-01-01

Monitoring, accounting and enforcement have been addressed in quite a number of presentations, papers and discussions in the past four CATEP workshops. Besides drawing conclusions from the experiences with existing trading regimes, different aspects of compliance have been analysed in more detail and finally there has been a special focus on standardised accounting systems. This paper tries to summarise the diverse findings to get a comprehensive picture of what is needed to assure high compliance in emissions trading regimes and identify any specific problems. The first section focuses on real trading regimes that are all local or at most national. It describes the monitoring, accounting and enforcement systems in existing and planned trading regimes to get an idea of what such systems include and to draw conclusions from experience. One focus is on enforcement mechanisms, as different from monitoring and accounting, which are basically a question of regulation and technology, penalties and compliance are a question of choices by participants and can be analysed with analytic tools. Section 3 deals with specific monitoring, accounting and enforcement problems in international emissions trading. It describes the development of internationally standardised systems and discusses the commitment period reserve as one instrument to avoid overselling of permits in international emission trading under the Kyoto Protocol. Section 5 provides a summary and conclusion

Et dansk regime for overgang fra uddannelse til arbejde?

DEFF Research Database (Denmark)

Jørgensen, Christian Helms

2008-01-01

I dette kapitel vil jeg først gennemgå en række forskningstilgange som på forskellig måde kan begribe de særlige træk ved unges overgang i Danmark i det man kan kalde et dansk 'regime for overgang' (transition regime). Dernæst følger en mere beskrivende gennemgang af det danske uddannelsessystem ...

Fabrication of high-uranium-loaded U{sub 3}O{sub 8}-Al developmental fuel plates

Energy Technology Data Exchange (ETDEWEB)

Copeland, G L; Martin, M M [Oak Ridge National Laboratory, TN (United States)

1983-08-01

A common plate-type fuel for Research and Test Reactors (RERTR) is U{sub 3}0{sub 8} dispersed in aluminum and clad with an aluminum alloy. There is an impetus to reduce the {sup 235}U enrichment from above 90% to below 20% for these fuels to lessen the risk of diversion of the uranium for non-peaceful uses. Thus, the uranium content of the fuel plates has to be increased to maintain the performance of the reactors. This paper describes work at ORNL to determine the maximal uranium loading for these fuels that can be fabricated with commercially proven materials and techniques and that can be expected to perform satisfactorily in service. We fabricated developmental fuel plates with cores containing from 60 to 100 wt U{sub 3}0{sub 8} in aluminum encapsulated in 6061 aluminum alloy and evaluated them for aspects of fabricability, nondestructive testing, and expected performance. We recommend 75 wt U{sub 3}0{sub 8}-Al 3.1 Mg U/m{sup 3}) as the highest loading in the initial irradiation test. This upper limit is based on a qualitative assessment of the mechanical integrity of the core made by using current fabrication techniques and materials. As the oxide loading is increased beyond this point, planar areas and extensive stringers of oxide and voids develop, which leave little strength in the thickness direction. Fuel plates may then blister over these areas as fission gases collect during irradiation. Current size plates are easily fabricable to the 75 wt % U{sub 3}0{sub 8}-Al core loading by current fabrication techniques. Dogboning is a potential problem at this loading for some applications; however, this can be easily solved by using tapered compact ends. Current nondestructive radiography and transmission x-ray scanning are applicable to the highly loaded plates. Ultrasonic testing for non-bonds is marginal because of the abrupt change in conductance at the cladding-core interface. Plate thickness can be increased if desired; we fabricated 75 wt % plates with

Land degradation and property regimes

Science.gov (United States)

Paul M. Beaumont; Robert T. Walker

1996-01-01

This paper addresses the relationship between property regimes and land degradation outcomes, in the context of peasant agriculture. We consider explicitly whether private property provides for superior soil resource conservation, as compared to common property and open access. To assess this we implement optimization algorithms on a supercomputer to address resource...

Do housing regimes matter? : Assessing the concept of housing regimes through configurations of housing outcomes

NARCIS (Netherlands)

Dewilde, C.L.

2017-01-01

Based on a conceptualisation of de-commodification as the right to decent and affordable housing, we assessed to what extent this right is realised for low-to-moderate-income owners and renters across Western European housing regimes in 1995 and 2012. If differences in the social production of

Study on a constant-tip-speed-ratio operation of wind power generation system. Effect of load control system on dynamic behavior; Furyoku hatsuden system no hensoku seigyo unten ni kansuru kenkyu. Fuka seigyokei ga system no rikigakuteki kyodo ni oyobosu eikyo

Energy Technology Data Exchange (ETDEWEB)

Wakui, T.; Yamaguchi, K. [Waseda University, Tokyo (Japan); Tanzawa, Y. [Nippon Institute of Technology, Saitama (Japan); Hashizume, T.; Ota, E. [Waseda University, Tokyo (Japan). School of Science and Engineering

1998-06-01

The effect that the set data of the load control system in a wind power generation system exerts on the dynamic behavior of a system was investigated. The wind power generation system consists of a hybrid wind turbine with combined Darrieus and Savonius rotors, load with a generator and battery in the center, and a controller. A constant-tip-speed ratio operation that holds the circumferential speed ratio in which the power coefficient is maximized irrespective of the change in wind velocity was used to extract and convert the wind energy more effectively. In a high-wind velocity area, the system is operated at a fixed speed, and the increase in rotation is suppressed to protect the wing strength. In a large system, the response characteristics are only slightly improved by the limited load operation range and influenced rotor inertial. Power cannot be fully extracted even if the control system is changed in setting, and the applicability to the wind situation remains low. During the actual operation, the adjustment value of the control system should be set so that the output operation is satisfactorily possible in the specified load operation range, that is, the change in the instantaneous value of an effective power coefficient indicates almost flat gain characteristics in frequency characteristics. 14 refs., 10 figs., 2 tabs.

Regime switches in the risk-return trade-off

OpenAIRE

Marcellino, Massimiliano; Ghysels, Eric; Guerin, Pierre

2014-01-01

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 ...

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

Damage assessment in CFRP laminates exposed to impact fatigue loading

International Nuclear Information System (INIS)

Tsigkourakos, George; Silberschmidt, Vadim V; Ashcroft, I A

2011-01-01

Demand for advanced engineering composites in the aerospace industry is increasing continuously. Lately, carbon fibre reinforced polymers (CFRPs) became one of the most important structural materials in the industry due to a combination of characteristics such as: excellent stiffness, high strength-to-weight ratio, and ease of manufacture according to application. In service, aerospace composite components and structures are exposed to various transient loads, some of which can propagate in them as cyclic impacts. A typical example is an effect of the wind gusts during flight. This type of loading is known as impact fatigue (IF); it is a repetition of low-energy impacts. Such loads can cause various types of damage in composites: fibre breaking, transverse matrix cracking, de-bonding between fibres and matrix and delamination resulting in reduction of residual stiffness and loss of functionality. Furthermore, this damage is often sub-surface, which reinforces the need for more regular inspection. The effects of IF are of major importance due its detrimental effect on the structural integrity of components that can be generated after relatively few impacts at low force levels compared to those in a standard fatigue regime. This study utilises an innovative testing system with the capability of subjecting specimens to a series of repetitive impacts. The primary subject of this paper is to assess the damaging effect of IF on the behaviour of drilled CFRP specimens, exposed to such loading. A detailed damage analysis is implemented utilising an X-ray micro computed tomography system. The main findings suggested that at early stages of life damage is governed by o degree splits along the length of the specimens resulting in a 20% reduction of stiffness. The final failure damage scenario indicated that transverse crasks in the 90 degree plies are the main reason for complete delamination which can be translated to a 50% stiffness reduction.

Load theory behind the wheel; perceptual and cognitive load effects.

Science.gov (United States)

Murphy, Gillian; Greene, Ciara M

2017-09-01

Perceptual Load Theory has been proposed as a resolution to the longstanding early versus late selection debate in cognitive psychology. There is much evidence in support of Load Theory but very few applied studies, despite the potential for the model to shed light on everyday attention and distraction. Using a driving simulator, the effect of perceptual and cognitive load on drivers' visual search was assessed. The findings were largely in line with Load Theory, with reduced distractor processing under high perceptual load, but increased distractor processing under high cognitive load. The effect of load on driving behaviour was also analysed, with significant differences in driving behaviour under perceptual and cognitive load. In addition, the effect of perceptual load on drivers' levels of awareness was investigated. High perceptual load significantly increased inattentional blindness and deafness, for stimuli that were both relevant and irrelevant to driving. High perceptual load also increased RTs to hazards. The current study helps to advance Load Theory by illustrating its usefulness outside of traditional paradigms. There are also applied implications for driver safety and roadway design, as the current study suggests that perceptual and cognitive load are important factors in driver attention. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Energy saving in the auxiliaries consumption for circulation water pumps optimizing the thermal regime; Ahorro en el consumo de auxiliares por bombas de agua de circulacion optimando el regimen termico

Energy Technology Data Exchange (ETDEWEB)

Orozco Martinez, Roni [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1999-12-31

A methodology is proposed that should be followed in any thermal electric power plant to determine the load value at which a unit requires a second circulation water pump without affecting the thermal regime and avoiding an excessive auxiliaries consumption in partial loads. In applying this method the power plant would have an energy saving equivalent to the auxiliaries consumption during an hour, when the unit as operating at full load. [Espanol] Se propone una metodologia que debe seguirse en cualquier central termoelectrica para determinar el valor de la carga en la cual una unidad requiere de la segunda bomba de agua de circulacion sin afectar el regimen termico y evitadose un excesivo consumo de auxiliares en cargas parciales. Al aplicar este metodo la central tendria un ahorro de energia equivalente al consumo de auxiliares durante una hora cuando la unidad esta generando su maxima carga.

Energy saving in the auxiliaries consumption for circulation water pumps optimizing the thermal regime; Ahorro en el consumo de auxiliares por bombas de agua de circulacion optimando el regimen termico

Energy Technology Data Exchange (ETDEWEB)

Orozco Martinez, Roni [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1998-12-31

A methodology is proposed that should be followed in any thermal electric power plant to determine the load value at which a unit requires a second circulation water pump without affecting the thermal regime and avoiding an excessive auxiliaries consumption in partial loads. In applying this method the power plant would have an energy saving equivalent to the auxiliaries consumption during an hour, when the unit as operating at full load. [Espanol] Se propone una metodologia que debe seguirse en cualquier central termoelectrica para determinar el valor de la carga en la cual una unidad requiere de la segunda bomba de agua de circulacion sin afectar el regimen termico y evitadose un excesivo consumo de auxiliares en cargas parciales. Al aplicar este metodo la central tendria un ahorro de energia equivalente al consumo de auxiliares durante una hora cuando la unidad esta generando su maxima carga.

The Displacement of Regimes of Action in the Armed Forces

DEFF Research Database (Denmark)

Holsting, Vilhelm Stefan

The aim of this paper is to explore how one might approach the profession of military command using the concepts of regimes of justification by Luc Boltanski and Laurent Thévenot in an analysis of the contemporary disputes and tensions between political and professional actors and in a time where...... of their contemporary role, responsibility and challenges) and an analysis of the displacement of military regimes in the light of economic and security changes at the societal level. I am arguing that the entrance of new regimes of justification are challenging and displacing the traditional professional justificatory...

Early Regimes of Water Capillary Flow in Slit Silica Nanochannels

DEFF Research Database (Denmark)

Oyarzua, Elton; Walther, Jens Honore; Mejia, Andres

2015-01-01

on the dynamics of capillaryfilling. The results indicate that the nanoscale imbibition process is divided into three main flow regimes:an initial regime where the capillary force is balanced only by the inertial drag and characterized by aconstant velocity and a plug flow profile. In this regime, the meniscus...... velocity profiles identify the passage froman inviscid flow to a developing Poiseuille flow. Gas density profiles ahead of the capillary front indicatea transient accumulation of air on the advancing meniscus. Furthermore, slower capillary filling ratescomputed for higher air pressures reveal a significant...... retarding effect of the gas displaced by the advancing meniscus....

The source regime for irradiation plant operated with fuel elements

International Nuclear Information System (INIS)

Suckow, W.

1976-11-01

The rapid and irregular decay of the gamma radiation from reactor fuel elements requires the establishment of an optimal source regime in order to utilise reactor fuel elements as radiation sources on a technological basis. Critical values have been derived which enable the determination of optimal conditions. In this context all technologically interesting types of source regimes have been examined. Methods to achieve a high gamma yield and a satisfactory dose consistency with time have been developed and important values for these two aspects have been derived. The conditions for optimal radiation source regimes are described in the final conclusions. (author)

Plastic limit loads for cylindrical shell intersections under combined loading

International Nuclear Information System (INIS)

Skopinsky, V.N.; Berkov, N.A.; Vogov, R.A.

2015-01-01

In this research, applied methods of nonlinear analysis and results of determining the plastic limit loads for shell intersection configurations under combined internal pressure, in-plane moment and out-plane moment loadings are presented. The numerical analysis of shell intersections is performed using the finite element method, geometrically nonlinear shell theory in quadratic approximation and plasticity theory. For determining the load parameter of proportional combined loading, the developed maximum criterion of rate of change of relative plastic work is employed. The graphical results for model of cylindrical shell intersection under different two-parameter combined loadings (as generalized plastic limit load curves) and three-parameter combined loading (as generalized plastic limit load surface) are presented on the assumption that the internal pressure, in-plane moment and out-plane moment loads were applied in a proportional manner. - Highlights: • This paper presents nonlinear two-dimensional FE analysis for shell intersections. • Determining the plastic limit loads under combined loading is considered. • Developed maximum criterion of rate of change of relative plastic work is employed. • Plastic deformation mechanism in shell intersections is discussed. • Results for generalized plastic limit load curves of branch intersection are presented

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.

Integrity of reinforced concrete cooling towers under extreme loads: Wind and earthquake

International Nuclear Information System (INIS)

Louhi, Amine

2015-01-01

The authorities have planned to increase the lifetime of currently operating nuclear power plants. The ageing of reinforced concrete structures such as cooling towers should be evaluated and its impact on the bearing capacity calculated. In the case of significant damage, the strengthening must be considered to ensure the sustainability of these towers facing the risk of storms and earthquakes becoming more and more frequent. This work aims to quantify the adverse effects that can generate concrete cracks and rebar section loss induced by corrosion, especially on the bearing capacity of nuclear power plant cooling towers under monotonic or cyclic extreme load conditions (wind and earthquake). These loads are certainly the most severe, since they take the structure into the nonlinear domain and can induce or amplify cracking damage. Numerical simulations are proposed to determine the quasi-static or dynamic response of the structure, taking into account appearance of concrete cracks and their evolution via an appropriate material concrete law and rebar's yielding. In the case of a seismic load, the responses are evaluated by three different methods; the nonlinear response history analysis (NLRHA), the response spectrum analysis and the modal response history analysis (MRHA) in order to compare the earthquake modeling approaches and to evaluate the robustness of the results. Parametric studies on damping, load combinations and structural configurations, are also performed. In the case of a wind load, the strengthening technique using composite materials, such as carbon fiber reinforced plastic (CFRP) is modeled. The behavior of the damaged structure with an advanced corrosion rate is estimated in the pre- and post-cracking regime, compared to the undamaged structure. The drop of bearing capacity is quantified, a reinforcement designed is proposed to restore the integrity and thus increase the lifetime of the structure. (author)

Civic Capacity in Educational Reform Efforts: Emerging and Established Regimes in Rust Belt Cities

Science.gov (United States)

Mitra, Dana L.; Frick, William C.

2011-01-01

Using urban regime theory, the article examines two Rust Belt cities that tried to break the cycle of social reproduction in their communities by reforming their schools. The article contributes to the development of urban regime theory by comparing an "emerging" regime to an "established" regime. The comparison highlights the interdependent…

Leverage effect, economic policy uncertainty and realized volatility with regime switching

Science.gov (United States)

Duan, Yinying; Chen, Wang; Zeng, Qing; Liu, Zhicao

2018-03-01

In this study, we first investigate the impacts of leverage effect and economic policy uncertainty (EPU) on future volatility in the framework of regime switching. Out-of-sample results show that the HAR-RV including the leverage effect and economic policy uncertainty with regimes can achieve higher forecast accuracy than RV-type and GARCH-class models. Our robustness results further imply that these factors in the framework of regime switching can substantially improve the HAR-RV's forecast performance.

Nondimensional characterization and asymptotic model development for multifunctional structures with application to load-bearing antennas

International Nuclear Information System (INIS)

Santapuri, Sushma; Bechtel, Stephen E

2014-01-01

This paper (i) presents a mathematical approach to formulate leading-order models for complex multifunctional systems with coupled thermomechanical and electromagnetic field interactions, and (ii) demonstrates its applicability to the modeling and analysis of a load-bearing antenna, a multifunctional sensing and transmitting device integrated with a load-bearing structure. Starting from first-principle equations, i.e. the thermomechanical balance laws coupled with Maxwell’s equations, nondimensionalization and perturbation techniques are employed to formulate a leading-order model for the coupled system. Depending on the design of the structure and nature of the excitation, the nondimensional numbers arising in the coupled multifunctional system are quantified, and through a relative ordering of these quantities, the dominant physical effects are extracted. The resulting dominant effects determine the regime of operation of the structure, and in turn dictate the appropriate computational model. This approach is demonstrated through an application to a load-bearing antenna for a prototypical design. The resulting leading-order model is subsequently solved, and the electrical and structural response of the load-bearing antenna is analyzed and compared for different combinations of material properties. The framework introduced in this paper is envisioned to have applications in developing leading-order models for a wide range of complex multifunctional systems and can be utilized for their efficient design. (paper)

Fire regime of the Kruger National Park for the period 1980 -1992

Directory of Open Access Journals (Sweden)

W.S.W. Trollope

1993-09-01

Full Text Available Fire regime refers to the type and intensity of fire and the season and frequency of burning. In the Kruger National Park it varies according to the source of ignition of the fires. Since 1985 the different ignition sources have been controlled bums (47, refugees (23, others (20 and lightning (10. The data showed that anthropogenic fires were the most common fires and evidence on a global scale would suggest that the status quo will be maintained even if controlled burning is discontinued as is currently being considered by the National Parks Board. The most common type of fires that occur in the park are surface head fires burning with the wind but back fires and crown fires do also occur. The intensity of the fires is primarily a function of the grass fuel load which is dependent on the rainfall and consequently varies enormously from year to year. The type of fire also influences the intensity and research conducted during 1992 showed that head fires burning under similar environmental conditions were on average 36 times more intense than back fires. Anthropogenic fires generally occurred during the dry, dormant, winter period while lightning fires were more associated with the spring and summer period when dry lightning storms occur. The frequency of burning varied significantly between sourveld and sweetveld. The mean frequency of burning in sourveld areas was triennial and in the sweetveld areas octennial. Finally the general conclusion that can be drawn about the fire regime of the Kruger National Park is that it is highly variable and will continue to be so in the future. This is a very positive feature that ensures a wide diversity of habitat types.

Variation of high-power aluminum-wire array z-pinch dynamics with wire number, load mass, and array radius

Energy Technology Data Exchange (ETDEWEB)

Sanford, T.W.L.; Mock, R.C.; Marder, B.M. [and others

1997-12-01

A systematic study of annular aluminum-wire z-pinches on the Saturn accelerator shows that the quality of the implosion, (as measured by the radial convergence, the radiated energy, pulse width, and power), increases with wire number. Radiation magnetohydrodynamic (RMHC) xy simulations suggest that the implosion transitions from that of individual wire plasmas to that of a continuous plasma shell when the interwire spacing is reduced below {approximately} 1.4 mm. In this plasma-shell regime, many of the global radiation and plasma characteristics are in agreement with those simulated by 2D-RMHC rz simulations. In this regime, measured changes in the radiation pulse width with variations in load mass and array radius are consistent with the simulations and are explained by the development of 2D fluid motion in the rz plane. Associated variations in the K-shell yield are qualitatively explained by simple radiation-scaling models.

Variation of high-power aluminum-wire array z-pinch dynamics with wire number, load mass, and array radius

International Nuclear Information System (INIS)

Sanford, T.W.L.; Mock, R.C.; Marder, B.M.

1997-01-01

A systematic study of annular aluminum-wire z-pinches on the Saturn accelerator shows that the quality of the implosion, (as measured by the radial convergence, the radiated energy, pulse width, and power), increases with wire number. Radiation magnetohydrodynamic (RMHC) xy simulations suggest that the implosion transitions from that of individual wire plasmas to that of a continuous plasma shell when the interwire spacing is reduced below ∼ 1.4 mm. In this plasma-shell regime, many of the global radiation and plasma characteristics are in agreement with those simulated by 2D-RMHC rz simulations. In this regime, measured changes in the radiation pulse width with variations in load mass and array radius are consistent with the simulations and are explained by the development of 2D fluid motion in the rz plane. Associated variations in the K-shell yield are qualitatively explained by simple radiation-scaling models

Variation of high-power aluminum-wire array Z-pinch dynamics with wire number, load mass, and array radius

Science.gov (United States)

Sanford, T. W. L.; Mock, R. C.; Marder, B. M.; Nash, T. J.; Spielman, R. B.; Peterson, D. L.; Roderick, N. F.; Hammer, J. H.; De Groot, J. S.; Mosher, D.; Whitney, K. G.; Apruzese, J. P.

1997-05-01

A systematic study of annular aluminum-wire z-pinches on the Saturn accelerator shows that the quality of the implosion, (as measured by the radial convergence, the radiated energy, pulse width, and power), increases with wire number. Radiation magnetohydrodynamic (RMHC) xy simulations suggest that the implosion transitions from that of individual wire plasmas to that of a continuous plasma shell when the interwire spacing is reduced below ˜1.4 mm. In this "plasma-shell regime," many of the global radiation and plasma characteristics are in agreement with those simulated by 2D-RMHC rz simulations. In this regime, measured changes in the radiation pulse width with variations in load mass and array radius are consistent with the simulations and are explained by the development of 2D fluid motion in the rz plane. Associated variations in the K-shell yield are qualitatively explained by simple radiation-scaling models.

Variation of high-power aluminum-wire array Z-pinch dynamics with wire number, load mass, and array radius

International Nuclear Information System (INIS)

Sanford, T. W. L.; Mock, R. C.; Marder, B. M.; Nash, T. J.; Spielman, R. B.; Peterson, D. L.; Roderick, N. F.; Hammer, J. H.; De Groot, J. S.; Mosher, D.; Whitney, K. G.; Apruzese, J. P.

1997-01-01

A systematic study of annular aluminum-wire z-pinches on the Saturn accelerator shows that the quality of the implosion, (as measured by the radial convergence, the radiated energy, pulse width, and power), increases with wire number. Radiation magnetohydrodynamic (RMHC) xy simulations suggest that the implosion transitions from that of individual wire plasmas to that of a continuous plasma shell when the interwire spacing is reduced below ∼1.4 mm. In this ''plasma-shell regime,'' many of the global radiation and plasma characteristics are in agreement with those simulated by 2D-RMHC rz simulations. In this regime, measured changes in the radiation pulse width with variations in load mass and array radius are consistent with the simulations and are explained by the development of 2D fluid motion in the rz plane. Associated variations in the K-shell yield are qualitatively explained by simple radiation-scaling models

Opposite effects of capacity load and resolution load on distractor processing.

Science.gov (United States)

Zhang, Weiwei; Luck, Steven J

2015-02-01

According to the load theory of attention, an increased perceptual load reduces distractor processing whereas an increased working memory load facilitates distractor processing. Here we raise the possibility that the critical distinction may instead be between an emphasis on resolution and an emphasis on capacity. That is, perceptual load manipulations typically emphasize resolution (fine-grained discriminations), whereas working memory load manipulations typically emphasize capacity (simultaneous processing of multiple relevant stimuli). To test the plausibility of this hypothesis, we used a visual working memory task that emphasized either the number of items to be stored (capacity load, retaining 2 vs. 4 colors) or the precision of the representations (resolution load, detecting small vs. large color changes). We found that an increased capacity load led to increased flanker interference (a measure of distractor processing), whereas an increased resolution load led to reduced flanker interference. These opposite effects of capacity load and resolution load on distractor processing mirror the previously described opposite effects of perceptual load and working memory load.

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

[Distribution of neural memory, loading factor, its regulation and optimization].

Science.gov (United States)

Radchenko, A N

1999-01-01

Recording and retrieving functions of the neural memory are simulated as a control of local conformational processes in neural synaptic fields. The localization of conformational changes is related to the afferent temporal-spatial pulse pattern flow, the microstructure of connections and a plurality of temporal delays in synaptic fields and afferent pathways. The loci of conformations are described by sets of afferent addresses named address domains. Being superimposed on each other, address domains form a multilayer covering of the address space of the neuron or the ensemble. The superposition factor determines the dissemination of the conformational process, and the fuzzing of memory, and its accuracy and reliability. The engram is formed as detects in the packing of the address space and hence can be retrieved in inverse form. The accuracy of the retrieved information depends on the threshold level of conformational transitions, the distribution of conformational changes in synaptic fields of the neuronal population, and the memory loading factor. The latter is represented in the model by a slow potential. It reflects total conformational changes and displaces the membrane potential to monostable conformational regimes, by governing the exit from the recording regime, the potentiation of the neurone, and the readiness to reproduction. A relative amplitude of the slow potential and the coefficient of postconformational modification of ionic conductivity, which provides maximum reliability, accuracy, and capacity of memory, are calculated.

Revisiting democratic civil peace: Electoral regimes and civil conflict

DEFF Research Database (Denmark)

Bartusevicius, Henrikas; Skaaning, Svend-Erik

2018-01-01

to use force. Building on this framework, we distinguish between five regime types according to their electoral features—non-electoral autocracies, single-party autocracies, multi-party autocracies, minimalist democracies, and polyarchies—and specify hypotheses regarding the likelihood of conflict...... in each. In a global statistical analysis spanning 1817‒2006 and employing the new Lexical Index of Electoral Democracy (LIED), we find that polyarchies, characterized by unconstrained contestation, have a lower risk of conflict than any other regime type (although minimalist democracies are only slightly......) elections and minimal electoral competition. Overall, our study underscores the importance of focusing on the central attributes of democracy and sheds new light on the relationship between particular regime features (or types) and conflict, thereby contributing to the growing efforts in conflict research...

Intergenerational Justice Perceptions and the Role of Welfare Regimes

DEFF Research Database (Denmark)

Sabbagh, Clara; Vanhuysse, Pieter

2010-01-01

, different welfare regimes structure young people's perceptions of the justness of public resources transfers from young to elderly age-groups and (2) the perceived relative contributions and rewards of various age-groups. Thus we inquire about both the perceived support in principle and about the perceived...... 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......-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...

The political constitution of the EU citizen rights regime

DEFF Research Database (Denmark)

Olsen, Tore Vincents

2011-01-01

Reactions to decisions by the European Court of Justice (ECJ) demonstrate that the political institutions in the Union should take responsibility for the development of the structure of the European Union's (EU) citizen rights regime. This article analyses different political views on the EU...... 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...... citizen rights regime. It argues that the disagreement between them is largely a disagreement between ‘reasonable views’. The disagreement is mainly based on different views about the levels (European, national) at which individuals are to be seen as equals and about the contribution of different...

Load testing circuit

DEFF Research Database (Denmark)

2009-01-01

A load testing circuit a circuit tests the load impedance of a load connected to an amplifier. The load impedance includes a first terminal and a second terminal, the load testing circuit comprising a signal generator providing a test signal of a defined bandwidth to the first terminal of the load...

From Malthus to Modern Growth: Can Epidemics Explain the Three Regimes?

OpenAIRE

Lagerlöf, Nils-Petter

2001-01-01

These are the stylized facts of long-run economic and demographic development, as described by Galor and Weil (AER 1999, 2000): Under an initial Malthusian Regime the growth rates of population and per-capita income are both low. Then follows a Post-Malthusian Regime, with higher growth rates of both population and per-capita income. Finally, the economy transits into a Modern Growth Regime, with falling population growth rates, but accelerated growth rates of per-capita inocme. This paper mo...

Turbulent regimes in the tokamak scrape-off layer

International Nuclear Information System (INIS)

Mosetto, A.

2014-01-01

The tokamak scrape-off layer (SOL) is the plasma region characterized by open field lines that start and end on the vessel walls. The plasma dynamics in the SOL plays a crucial role in determining the overall performance of a tokamak, since it controls the plasma-wall interactions, being responsible of exhausting the tokamak power, it regulates the overall plasma confinement, and it governs the plasma refueling and the removal of fusion ashes. Scrape-off layer physics is intrinsically non-linear and characterized by phenomena that occur on a wide range of spatio-temporal scales. Free energy sources drive a number of unstable modes that develop into turbulence and lead to transport of particles and heat across the magnetic field lines. Depending on the driving instability, different SOL turbulent regimes can be identified. As the SOL turbulent regimes determine the plasma confinement properties and the SOL width (and, consequently, the power flux on the vessel wall, for example), it is of crucial importance to understand which turbulent regimes are active in the SOL, under which conditions they develop, and which are the main properties of the associated turbulent transport. In the present thesis we define the SOL turbulent regimes, and we provide a framework to identify them, given the operational SOL parameters. Our study is based on the drift-reduced Braginskii equations and it is focused on a limited tokamak SOL configuration. We first describe the main SOL linear instabilities, such as the inertial and resistive branches of the drift waves, the resistive, inertial and ideal branches of the ballooning modes, and the ion temperature gradient mode. Then, we find the SOL turbulent regimes depending on the instability driving turbulent transport, assuming that turbulence saturates when the radial gradient associated to the pressure fluctuations is comparable to the equilibrium one. Our methodology for the turbulent regime identification is supported by the analysis

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.

Time-dependent fiber bundles with local load sharing. II. General Weibull fibers.

Science.gov (United States)

Phoenix, S Leigh; Newman, William I

2009-12-01

Fiber bundle models (FBMs) are useful tools in understanding failure processes in a variety of material systems. While the fibers and load sharing assumptions are easily described, FBM analysis is typically difficult. Monte Carlo methods are also hampered by the severe computational demands of large bundle sizes, which overwhelm just as behavior relevant to real materials starts to emerge. For large size scales, interest continues in idealized FBMs that assume either equal load sharing (ELS) or local load sharing (LLS) among fibers, rules that reflect features of real load redistribution in elastic lattices. The present work focuses on a one-dimensional bundle of N fibers under LLS where life consumption in a fiber follows a power law in its load, with exponent rho , and integrated over time. This life consumption function is further embodied in a functional form resulting in a Weibull distribution for lifetime under constant fiber stress and with Weibull exponent, beta. Thus the failure rate of a fiber depends on its past load history, except for beta=1 . We develop asymptotic results validated by Monte Carlo simulation using a computational algorithm developed in our previous work [Phys. Rev. E 63, 021507 (2001)] that greatly increases the size, N , of treatable bundles (e.g., 10(6) fibers in 10(3) realizations). In particular, our algorithm is O(N ln N) in contrast with former algorithms which were O(N2) making this investigation possible. Regimes are found for (beta,rho) pairs that yield contrasting behavior for large N. For rho>1 and large N, brittle weakest volume behavior emerges in terms of characteristic elements (groupings of fibers) derived from critical cluster formation, and the lifetime eventually goes to zero as N-->infinity , unlike ELS, which yields a finite limiting mean. For 1/21 but with 0

46 CFR 154.1730 - Ethylene oxide: Loading and off loading.

Science.gov (United States)

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Ethylene oxide: Loading and off loading. 154.1730... Operating Requirements § 154.1730 Ethylene oxide: Loading and off loading. (a) The master shall ensure that before ethylene oxide is loaded into a cargo tank: (1) The tank is thoroughly clean, dry, and free of...

Development of objective flow regime identification method using self-organizing neural network

International Nuclear Information System (INIS)

Lee, Jae Young; Kim, Nam Seok; Kwak, Nam Yee

2004-01-01

Two-phase flow shows various flow patterns according to the amount of the void and its relative velocity to the liquid flow. This variation directly affect the interfacial transfer which is the key factor for the design or analysis of the phase change systems. Especially the safety analysis of the nuclear power plant has been performed based on the numerical code furnished with the proper constitutive relations depending highly upon the flow regimes. Heavy efforts have been focused to identify the flow regime and at this moment we stand on relative very stable engineering background compare to the other research field. However, the issues related to objectiveness and transient flow regime are still open to study. Lee et al. and Ishii developed the method for the objective and instantaneous flow regime identification based on the neural network and new index of probability distribution of the flow regime which allows just one second observation for the flow regime identification. In the present paper, we developed the self-organized neural network for more objective approach to this problem. Kohonen's Self-Organizing Map (SOM) has been used for clustering, visualization, and abstraction. The SOM is trained through unsupervised competitive learning using a 'winner takes it all' policy. Therefore, its unsupervised training character delete the possible interference of the regime developer to the neural network training. After developing the computer code, we evaluate the performance of the code with the vertically upward two-phase flow in the pipes of 25.4 and 50.4 cmm I.D. Also, the sensitivity of the number of the clusters to the flow regime identification was made

Experimental study on the unstable direct contact condensation regimes

International Nuclear Information System (INIS)

Damasio, C.; Del Tin, G.; Fiegna, G.; Malandrone, M.

1985-01-01

Vapour-liquid interface fluctuation frequencies have been measured by means of electrical resistive probes. Frequency data from these probes have been compared with measured frequencies from a Kistler piezoelectric pressure transducer in the pool near the steam-water interaction region. An attempt has been made to correlate measured frequencies to the observed condensation regimes. Experimental data concerning ''steam chugging'' and condensation oscillation regimes have been correlated in terms of dimensionless parameters

The natural sediment regime in rivers: broadening the foundation for ecosystem management

Science.gov (United States)

Wohl, Ellen E.; Bledsoe, Brian P.; Jacobson, Robert B.; Poff, N. LeRoy; Rathburn, Sara L.; Walters, David M.; Wilcox, Andrew C.

2015-01-01

Water and sediment inputs are fundamental drivers of river ecosystems, but river management tends to emphasize flow regime at the expense of sediment regime. In an effort to frame a more inclusive paradigm for river management, we discuss sediment inputs, transport, and storage within river systems; interactions among water, sediment, and valley context; and the need to broaden the natural flow regime concept. Explicitly incorporating sediment is challenging, because sediment is supplied, transported, and stored by nonlinear and episodic processes operating at different temporal and spatial scales than water and because sediment regimes have been highly altered by humans. Nevertheless, managing for a desired balance between sediment supply and transport capacity is not only tractable, given current geomorphic process knowledge, but also essential because of the importance of sediment regimes to aquatic and riparian ecosystems, the physical template of which depends on sediment-driven river structure and function.

The Kyoto protocol: assessment and perspectives. Towards a new regime up to the climate stake

International Nuclear Information System (INIS)

Gautier, Celia

2012-01-01

This report proposes an analysis within the context of transition of the climate regime from the 'before-2012' regime to the 'post-2020' regime. It first gives an overview of international stakes and context (lack of ambition for climate policy, perspective of an international agreement from 2020). Then, the authors recall the history and achievements of the Kyoto protocol which is the basis of the present climate policy regime. They propose an assessment of actions performed by countries during the first period of the protocol, and focus on the present climate regime elements which are to be safeguarded. They analyse the weaknesses of the present regime, and propose possible improvements for the future post-2020 climate regime

The French regime of civil liability for nuclear

International Nuclear Information System (INIS)

Leger, Marc

2013-01-01

As civil liability for nuclear is a matter of discussion and initiatives at the European and international levels, the author proposes an overview of the legal framework of the French regime of civil liability for nuclear which is a combination of two international treaties (Paris and Brussels conventions) and a national arrangement (a 1968 law). He presents and comments the main characteristics of this regime (geographical scope of application, concerned activities, excluded events, covered damages, principles regarding operator's liability) and the improvements brought by Paris and Brussels convention review protocols

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.

Floquet prethermalization and regimes of heating in a periodically driven, interacting quantum system

Science.gov (United States)

Weidinger, Simon; Knap, Michael

We study the regimes of heating in the periodically driven O (N) -model, which represents a generic model for interacting quantum many-body systems. By computing the absorbed energy with a non-equilibrium Keldysh Green's function approach, we establish three dynamical regimes: at short times a single-particle dominated regime, at intermediate times a stable Floquet prethermal regime in which the system ceases to absorb, and at parametrically late times a thermalizing regime. Our simulations suggest that in the thermalizing regime the absorbed energy grows algebraically in time with an the exponent that approaches the universal value of 1 / 2 , and is thus significantly slower than linear Joule heating. Our results demonstrate the parametric stability of prethermal states in a generic many-body system driven at frequencies that are comparable to its microscopic scales. This paves the way for realizing exotic quantum phases, such as time crystals or interacting topological phases, in the prethermal regime of interacting Floquet systems. We acknowledge support from the Technical University of Munich - Institute for Advanced Study, funded by the German Excellence Initiative and the European Union FP7 under Grant agreement 291763, and from the DFG Grant No. KN 1254/1-1.

Monetary Regimes and External Shocks Reaction: Empirical Investigations on Eastern European Economies

Directory of Open Access Journals (Sweden)

Muhammad Khan

2017-12-01

Full Text Available In the late 90's, after severe financial crisis, accompanied by inflation and exchange rate instability, Eastern Europe emerged into two radically contrasting monetary regimes (Currency Boards and Inflation targeting. The task of our study is to compare econometrically the performance of these two regimes in terms of their resilience to the external real and nominal shocks, coming from Euro area. In other words, we test the non-neutrality of exchange rate regimes with respect to these connections. Our PVAR model results reveal that the choice of monetary regimes indeed determines the ability of a country to absorb the external shocks.

Peak load-impulse characterization of critical pulse loads in structural dynamics

International Nuclear Information System (INIS)

Abrahamson, G.R.; Lindberg, H.E.

1975-01-01

In presenting the characterization scheme, some general features are described first. A detailed analysis is given for the rigid-plastic system of one degree of freedom to illustrate the calculation of critical load curves in terms of peak load and impulse. This is followed by the presentation of critical load curves for uniformly loaded rigid-plastic beams and plates and for dynamic buckling of cylindrical shells under uniform lateral loads. The peak load-impulse characterization of critical pulse loads is compared with the dynamic load factor characterization, and some aspects of the history of the peak load-pulse scheme are presented. (orig./HP) [de

Extensive and intensive margins and the choice of exchange rate regimes

OpenAIRE

Masashige Hamano; Pierre M. Picard

2013-01-01

This paper studies how the choice of fixed or flexible exchange rate regimes is affected by the existence of intensive and extensive margins. We study two models where firms enter during or before each period of production. We show how the the choice of those regimes depend on the level and the volatily of the intensive and extensive margins as well as on the congruence between consumers' preferences and the supply and diversity of products. We show that fixed exchange rate regimes are prefer...

Technological regimes and sources of entrepreneurship

NARCIS (Netherlands)

Marsili, O.

2000-01-01

This paper concerns the technological detenninants of entrepreneurial behaviour. By applying a typology of technological regimes, which describes the nature of the technological environment in which finns operate, this paper examines the sources and obstacle to entrepreneurial entry related to the

Technological regimes and sources of entrepreneurship

NARCIS (Netherlands)

Marsili, O.

2002-01-01

This paper concerns the technological determinants of entrepreneurial behaviour. By applying a typology of technological regimes, which describes the nature of the technological environment in which firms operate, this paper examines the sources and obstacles to entrepreneurial entry related to the

Floating Exchange Rate Regime

OpenAIRE

Quader, Syed Manzur

2004-01-01

In recent years, many developing countries having a history of high inflation, unfavorable balance of payment situation and a high level of foreign currencies denominated debt, have switched or are in the process of switching to a more flexible exchange rate regime. Therefore, the stability of the exchange rate and the dynamics of its volatility are more crucial than before to prevent financial crises and macroeconomic disturbances. This paper is designed to find out the reasons behind Bangla...

Regimes internacionais e o contencioso das patentes para medicamentos: estratégias para países em desenvolvimento International regimes and the medical patent dispute: strategies for developing countries

Directory of Open Access Journals (Sweden)

Gabriel Cepaluni

2005-06-01

Full Text Available Este artigo mostra que não existe apenas uma única teoria sobre regimes internacionais, mas um conjunto de estudos teóricos e empíricos que, isoladamente ou em conjunto, não constituem uma "teoria geral" das relações internacionais. Três abordagens resumem os principais debates sobre os regimes: o realismo-estrutural, o neoliberalismo e o cognitivismo. A primeira perspectiva - a realista - considera que o poder é o principal conceito para explicar os regimes internacionais. O neoliberalismo considera que o interesse é a principal noção analítica para entender a criação e a manutenção dos regimes. Finalmente, o cognitivismo coloca as idéias e os valores no centro de suas explicações. Feitas essas considerações, analisa-se o contencioso das patentes farmacêuticas entre o Brasil e os Estados Unidos (1988-2001 utilizando insights fornecidos pelos estudos de regimes internacionais - privilegiando-se a abordagem neoliberal. A partir do conflito entre o Brasil e os Estados Unidos, também são desenhadas algumas estratégias que podem ser utilizadas pelos países em desenvolvimento para maximizar seus ganhos no cenário internacional.This article demonstrates that there is not one international regime theory, but a set of theoretical and empirical studies that, alone or together, do not constitute a "general theory" of International Relations. Three approaches summarise the main debates on regimes: structural realism, neoliberalism, and cognitivism. The first perspective - the realist - considers power as the main concept for explaining international regimes. Neoliberalism considers interest as the main analytical tool to understand the creation and maintenance of regimes. Finally, cognitivism places ideas and values at the center of its explanations. After establishing these perspectives, the pharmaceutical patents dispute between Brazil and the United States (1988-2001 is analyzed, utilizing insights gained by the study of

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; Mack, Michelle; Moritz, Max A; Pyne, Stephen; Roos, Christopher I; Scott, Andrew C; Sodhi, Navjot S; Swetnam, Thomas W; Whittaker, Robert

2011-12-01

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

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

Fire regime characterization in Mediterranean ecosystems of Southern Italy

Science.gov (United States)

Lanorte, A.; Lasaponara, R.

2009-04-01

This paper addresses the wildfire regime in Mediterranean ecosystems of Southern Italy. Fire regimes refer to average fire conditions (including fire size, fire density, fire frequency, fire seasonality, fire intensity, fire severity, fire thresholds, etc.) occurring over a long period of time. Information on spatial pattern of forest fire locations is a key point in the study of the dynamics of fire disturbance, and allows us to improve the knowledge of past and current role of fire. Historical evidence clearly shows what did happen and this can fruitfully help to understand what is happening and what could happen in the next future. Mapping fire regimes is very challenging, because fire ocurrence features are the expression of the interactions between climate, fire, vegetation, topography, social factors. The main objective of this work is to provide a comprehensive characterization of the fire regime in Italy based on a recently updated national wildfire database. Fire data were obtained from the Italian National Forestry Service. This national database is comprised of information contained in individual fire reports completed for every fire that occurs on public lands in the Italian peninsula. Complete data were only available for 1996-2006 at the time we accessed the database, which determined the years we analysed. The primary fire history variables that we reported were number of fires, area burned, burning time and duration, and fire size (average size of individual fires) The wildfire records (wildfire area, location, time, vegetation) were analysed with other environmental (fuel availability and type), topographic features, and meteorological/climatological data. Results of our analysis could help better understand the different factors on the wildfire regime in Mediterranean ecosystems of Southern Italy.

Synchrotron X-ray diffraction measurements of internal stresses during loading of steel-based metal matrix composites reinforced with TiB2 particles

International Nuclear Information System (INIS)

Bacon, D.H.; Edwards, L.; Moffatt, J.E.; Fitzpatrick, M.E.

2011-01-01

Highlights: → Synchrotron X-ray diffraction was used to measure internal stresses in Fe-TiB 2 MMCs. → Samples of the MMCs were loaded to failure in situ in the X-ray beam. → The results show good elastic load transfer from the matrix to the reinforcement. → There is good agreement with the predicted elastic stresses from Eshelby modeling. → During plastic deformation there is increasing load transfer to the reinforcement. - Abstract: High-energy synchrotron X-ray diffraction was used to measure the internal strain evolution in the matrix and reinforcement of steel-based metal matrix composites reinforced with particulate titanium diboride (TiB 2 ). Two systems were studied: a 316L matrix with 25% TiB 2 by volume and a W1.4418 matrix with 10% reinforcement. In situ loading experiments were performed, where the materials were loaded uniaxially in the X-ray beam. The results show the strain partitioning between the phases in the elastic regime, and the evolution of the strain partitioning once plasticity occurs. The results are compared with results from Eshelby modelling, and very good agreement is seen between the measured and modelled response for elastic loading of the material. Heat treatment of the 316-based material did not affect the elastic internal strain response.

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

Study on flow regimes of high-pressure and dense-phase pneumatic conveying

International Nuclear Information System (INIS)

Lu Peng; Chen Xiaoping; Liang Cai; Pu Wenhao; Zhou Yun; Xu Pan; Zhao Changsui

2009-01-01

High-pressure and dense-phase pneumatic conveying of pulverized coal is a key technology in the field of large-scale entrained bed coal gasification. Flow regime plays an important role in two-phase flow because it affects not only flow behavior and safety operation, but also the reliability of practical processes. Few references and experiences in high-pressure and dense-phase conveying are available, especially for the flow regimes. And because of the high stickiness and electrostatic attraction of pulverized coal to the pipe wall, it is very difficult to make out the flow regimes in the conveying pipe by visualization method. Thus quartz powder was chosen as the conveyed material to study the flow regime. High-speed digital video camera was employed to photograph the flow patterns. Experiments were conducted on a pilot scale experimental setup at the pressure up to 3.6MPa. With the decrease in superficial gas velocity, three distinguishable flow regimes were observed: stratified flow, dune flow and plug flow. The characteristics of pressure traces acquired by high frequency response pressure transmitter and their EMD (Empirical Mode Decomposition) characteristics were correlated strongly with the flow regimes. Combining high-speed photography and pressure signal analysis together can make the recognition of flow patterns in the high-pressure and dense-phase pneumatic conveying system more accurate. The present work will lead to better understanding of the flow regime transition under high-pressure.

System and method employing a minimum distance and a load feature database to identify electric load types of different electric loads

Science.gov (United States)

Lu, Bin; Yang, Yi; Sharma, Santosh K; Zambare, Prachi; Madane, Mayura A

2014-12-23

A method identifies electric load types of a plurality of different electric loads. The method includes providing a load feature database of a plurality of different electric load types, each of the different electric load types including a first load feature vector having at least four different load features; sensing a voltage signal and a current signal for each of the different electric loads; determining a second load feature vector comprising at least four different load features from the sensed voltage signal and the sensed current signal for a corresponding one of the different electric loads; and identifying by a processor one of the different electric load types by determining a minimum distance of the second load feature vector to the first load feature vector of the different electric load types of the load feature database.

Land-use regime shifts: an analytical framework and agenda for future land-use research

Directory of Open Access Journals (Sweden)

Navin Ramankutty

2016-06-01

Full Text Available A key research frontier in global change research lies in understanding processes of land change to inform predictive models of future land states. We believe that significant advances in the field are hampered by limited attention being paid to critical points of change termed land-use regime shifts. We present an analytical framework for understanding land-use regime shifts. We survey historical events of land change and perform in-depth case studies of soy and shrimp development in Latin America to demonstrate the role of preconditions, triggers, and self-reinforcing processes in driving land-use regime shifts. Whereas the land-use literature demonstrates a good understanding of within-regime dynamics, our understanding of the drivers of land-use regime shifts is limited to ex post facto explications. Theoretical and empirical advances are needed to better understand the dynamics and implications of land-use regime shifts. We draw insights from the regime-shifts literature to propose a research agenda for studying land change.

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.

Problems of mixed convection flow regime map in a vertical cylinder

International Nuclear Information System (INIS)

Kang, Gyeong Uk; Chung, Bum Jin

2012-01-01

One of the technical issues by the development of the VHTR is the mixed convection, which is the regime of heat transfer that occurs when the driving forces of both forced and natural convection are of comparable orders of magnitude. In vertical internal flows, the buoyancy force acts upward only, but forced flows can move either upward or downward. Thus, there are two types of mixed convection flows, depending on the direction of the forced flow. When the directions of the forced flow and buoyancy are the same, the flow is a buoyancy aided flow; when they are opposite, the flow is a buoyancy opposed flow. In laminar flows, buoyancy aided flow shows enhanced heat transfer compared to the pure forced convection and buoyancy opposed flow shows impaired heat transfer due to the flow velocity affected by the buoyancy forces. In turbulent flows, however, buoyancy opposed flows shows enhanced heat transfer due to increased turbulence production and buoyancy aided flow shows impaired heat transfer at low buoyancy forces and as the buoyancy increases, the heat transfer restores and at further increases of the buoyancy forces, the heat transfer is enhanced. It is of primary interests to classify which convection regime is mainly dominant. The methods most used to classify between forced, mixed and natural convection have been to refer to the classical flow regime map suggested by Meta is and Eckert. During the course of fundamental literature studies on this topic, it is found that there are some problems on the flow regime map in a vertical cylinder. This paper is to discuss problems identified through reviewing the papers composed in the classical flow regime map. We have tried to reproduce the flow regime map independently using the data obtained from the literatures and compared with the classical flow regime map and finally, the problems on this topic were discussed

Internet Censorship Circumvention Tools: Escaping the Control of the Syrian Regime

Directory of Open Access Journals (Sweden)

Walid Al-Saqaf

2016-02-01

Full Text Available Studies have shown that authoritarian regimes tend to censor the media to limit potential threats to the status quo. While such censorship practices were traditionally aimed at broadcast and print media, the emergence of the Internet and social media in particular, prompted some authoritarian regimes, such as the Assad regime in Syria, to try and exert a similar level of censorship on the Internet as well. During the Arab Spring, the Syrian regime blocked hundreds of websites that provided social networking, news, and other services. Taking Syria as a case study, this paper examines whether Internet censorship succeeded in preventing Internet users from reaching censored online content during 2010−2012. By analyzing the use of Alkasir, a censorship circumvention tool created by the author, the paper provides empirical evidence demonstrating that users were in fact able to bypass censorship and access blocked websites. The findings demonstrate that censorship circumvention tools constituted a threat to the information control systems of authoritarian regimes, highlighting the potential of such tools to promote online freedom of expression in countries where Internet censorship is prevalent.

Dynamic Modeling Strategy for Flow Regime Transition in Gas-Liquid Two-Phase Flows

Directory of Open Access Journals (Sweden)

Xia Wang

2012-12-01

Full Text Available In modeling gas-liquid two-phase flows, the concept of flow regimes has been widely used to characterize the global interfacial structure of the flows. Nearly all constitutive relations that provide closures to the interfacial transfers in two-phase flow models, such as the two-fluid model, are flow regime dependent. Current nuclear reactor safety analysis codes, such as RELAP5, classify flow regimes using flow regime maps or transition criteria that were developed for steady-state, fully-developed flows. As two-phase flows are dynamic in nature, it is important to model the flow regime transitions dynamically to more accurately predict the two-phase flows. The present work aims to develop a dynamic modeling strategy to determine flow regimes in gas-liquid two-phase flows through introduction of interfacial area transport equations (IATEs within the framework of a two-fluid model. The IATE is a transport equation that models the interfacial area concentration by considering the creation of the interfacial area, fluid particle (bubble or liquid droplet disintegration, boiling and evaporation, and the destruction of the interfacial area, fluid particle coalescence and condensation. For flow regimes beyond bubbly flows, a two-group IATE has been proposed, in which bubbles are divided into two groups based on their size and shapes, namely group-1 and group-2 bubbles. A preliminary approach to dynamically identify the flow regimes is discussed, in which discriminators are based on the predicted information, such as the void fraction and interfacial area concentration. The flow regime predicted with this method shows good agreement with the experimental observations.

System and method employing a self-organizing map load feature database to identify electric load types of different electric loads

Science.gov (United States)

Lu, Bin; Harley, Ronald G.; Du, Liang; Yang, Yi; Sharma, Santosh K.; Zambare, Prachi; Madane, Mayura A.

2014-06-17

A method identifies electric load types of a plurality of different electric loads. The method includes providing a self-organizing map load feature database of a plurality of different electric load types and a plurality of neurons, each of the load types corresponding to a number of the neurons; employing a weight vector for each of the neurons; sensing a voltage signal and a current signal for each of the loads; determining a load feature vector including at least four different load features from the sensed voltage signal and the sensed current signal for a corresponding one of the loads; and identifying by a processor one of the load types by relating the load feature vector to the neurons of the database by identifying the weight vector of one of the neurons corresponding to the one of the load types that is a minimal distance to the load feature vector.

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

Influence of curing regimes on compressive strength of ultra high

Indian Academy of Sciences (India)

The present paper is aimed to identify an efficient curing regime for ultra high performance concrete (UHPC), to achieve a target compressive strength more than 150 MPa, using indigenous materials. The thermal regime plays a vital role due to the limited fineness of ingredients and low water/binder ratio. By activation of the ...

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....

Transport processes in magnetically confined plasmas in the nonlinear regime.

Science.gov (United States)

Sonnino, Giorgio

2006-06-01

A field theory approach to transport phenomena in magnetically confined plasmas is presented. The thermodynamic field theory (TFT), previously developed for treating the generic thermodynamic system out of equilibrium, is applied to plasmas physics. Transport phenomena are treated here as the effect of the field linking the thermodynamic forces with their conjugate flows combined with statistical mechanics. In particular, the Classical and the Pfirsch-Schluter regimes are analyzed by solving the thermodynamic field equations of the TFT in the weak-field approximation. We found that, the TFT does not correct the expressions of the ionic heat fluxes evaluated by the neoclassical theory in these two regimes. On the other hand, the fluxes of matter and electronic energy (heat flow) is further enhanced in the nonlinear Classical and Pfirsch-Schluter regimes. These results seem to be in line with the experimental observations. The complete set of the electronic and ionic transport equations in the nonlinear Banana regime, is also reported. A paper showing the comparison between our theoretic results and the experimental observations in the JET machine is currently in preparation.

Regimes of spray formation in gas-centered swirl coaxial atomizers

Energy Technology Data Exchange (ETDEWEB)

Sivakumar, D.; Kulkarni, V. [Indian Institute of Science, Department of Aerospace Engineering, Bangalore (India)

2011-09-15

Spray formation in ambient atmosphere from gas-centered swirl coaxial atomizers is described by carrying out experiments in a spray test facility. The atomizer discharges a circular air jet and an axisymmetric swirling water sheet from its coaxially arranged inner and outer orifices. A high-speed digital imaging system along with a backlight illumination arrangement is employed to record the details of liquid sheet breakup and spray development. Spray regimes exhibiting different sheet breakup mechanisms are identified and their characteristic features presented. The identified spray regimes are wave-assisted sheet breakup, perforated sheet breakup, segmented sheet breakup, and pulsation spray regime. In the regime of wave-assisted sheet breakup, the sheet breakup shows features similar to the breakup of two-dimensional planar air-blasted liquid sheets. At high air-to-liquid momentum ratios, the interaction process between the axisymmetric swirling liquid sheet and the circular air jet develops spray processes which are more specific to the atomizer studied here. The spray exhibits a periodic ejection of liquid masses whose features are dominantly controlled by the central air jet. (orig.)

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

Extreme Temperature Regimes during the Cool Season and their Associated Large-Scale Circulations

Science.gov (United States)

Xie, Z.

2015-12-01

In the cool season (November-March), extreme temperature events (ETEs) always hit the continental United States (US) and provide significant societal impacts. According to the anomalous amplitudes of the surface air temperature (SAT), there are two typical types of ETEs, e.g. cold waves (CWs) and warm waves (WWs). This study used cluster analysis to categorize both CWs and WWs into four distinct regimes respectively and investigated their associated large-scale circulations on intra-seasonal time scale. Most of the CW regimes have large areal impact over the continental US. However, the distribution of cold SAT anomalies varies apparently in four regimes. In the sea level, the four CW regimes are characterized by anomalous high pressure over North America (near and to west of cold anomaly) with different extension and orientation. As a result, anomalous northerlies along east flank of anomalous high pressure convey cold air into the continental US. To the middle troposphere, the leading two groups feature large-scale and zonally-elongated circulation anomaly pattern, while the other two regimes exhibit synoptic wavetrain pattern with meridionally elongated features. As for the WW regimes, there are some patterns symmetry and anti-symmetry with respect to CW regimes. The WW regimes are characterized by anomalous low pressure and southerlies wind over North America. The first and fourth groups are affected by remote forcing emanating from North Pacific, while the others appear mainly locally forced.

Studies on Ytterbium-doped Fibre Laser Operating in Different Regimes

International Nuclear Information System (INIS)

Gan, Y; Xiang, W H; Zhang, G Z

2006-01-01

An ytterbium-doped fibre laser with a unidirectional ring cavity containing a polarizer placed between two in-line polarization controllers is presented. Depending on an equivalent saturable absorber, this laser operates in continuous, Q-switched mode-locked or CW mode-locked regimes. The passive method described here allowed us to choose the operating regime of the fibre laser by rotating the two polarization controllers and adjusting the pump power. Results of numerical simulations of pulse propagation in such a mode-locked fibre ring laser are presented, which reveals that the Q-switched mode-locked or CW modelocked regimes can be achieved by aligning the polarizer near the slow or the fast axes of the fibre

Demand Response Load Following of Source and Load Systems

DEFF Research Database (Denmark)

Hu, Jianqiang; Cao, Jinde; Yong, Taiyou

2017-01-01

This paper presents a demand response load following strategy for an interconnected source and load system, in which we utilize traditional units and population of cooling thermostatically controlled loads (TCLs) to follow the mismatched power caused by the load activities and the renewable power...... injection in real time. In the demand side of power systems, these TCLs are often affiliated to a bus load agent and can be aggregated to multiple TCL aggregators. Firstly, aggregate evaluation of the TCL aggregator is carried out based on a bilinear aggregate model so as to derive the available regulation...

Service regime: An empirical analysis of innovation patterns in service firms.

NARCIS (Netherlands)

Chang, Y.C.; Linton, J.D.; Linton, Jonathan; Chen, M.N.

2012-01-01

The concept of service regime is developed to extend and test Miozzo and Soete's service taxonomy. Derived from the synthesis approach of service innovation, the service regime considers sources of innovation, innovation trajectories, and appropriability. Hypotheses on firm patterns of innovation

Cognitive Load Theory: How Many Types of Load Does It Really Need?

Science.gov (United States)

Kalyuga, Slava

2011-01-01

Cognitive load theory has been traditionally described as involving three separate and additive types of load. Germane load is considered as a learning-relevant load complementing extraneous and intrinsic load. This article argues that, in its traditional treatment, germane load is essentially indistinguishable from intrinsic load, and therefore…

A study of Two-Phase Flow Regime Maps in Vertical and Horizontal Pipes

International Nuclear Information System (INIS)

Kim, Kyung Doo; Kang, Doo Hyuk

2007-10-01

A safety analysis code to design a pressurized water reactor and to obtain the licences including entire proprietary rights is under development in domestic research and development project. The purpose and scope of this report is to develop the flow regimes related models for inter-phase friction, wall frictions, wall heat transfer, and inter-phase heat and mass transfer in two-phase three-field equations. In order to choose choose the flow regime criteria, we have investigated various exiting best-estimate T/H codes in this chapter 2. They are the RELAP5-3D, TRAC-M, CATHARE, MARS codes. Around 500 references used in these codes have been collected and reviewed. Also we have investigated eleven papers in detail. In chapter 3, based on the selected flow regimes, the flow regime maps for a gas-liquid flow in horizontal and vertical tubes have decided including the mechanisms of flow regime transition regions. Conclusively, the process will be presented for choosing the best flow regime maps which occur in gas-liquid two-phase flow in horizontal and vertical pipes. We will look forward to decide the constitutive relations based upon the flow regime maps that are determined in this works. The constitutive relations will be used for the code under development

Economic analysis of the CLC/FC regime as an oil pollution prevention instrument

International Nuclear Information System (INIS)

Hay, J.

2006-09-01

The aim of this research is to discuss the effectiveness of CLC/IOPC (Civil Liability Convention) liability regime in the field of oil pollution prevention. This study is mainly carried out from a law and economics perspective, although reference is also made to the economic analysis of international environmental agreements. The first two chapters explore the deterrent potential of the international regime in terms of oil spill prevention, from a theoretical and empirical perspective. The analysis of the effectiveness of the regime as such consists in, on the one hand, considering the ability of the international regime to compensate the entire social costs of oil spills (chapter 3) and, on the other hand, to examine the incentives given to operators in maritime oil transport to prevent accidental pollution (chapters 4 and 5). Sixth chapter considers the impacts of the voluntary nature of the international regime on its deterrent potential. The results obtained from this analysis enable to identify several mechanisms by which the deterrent effect of the existing regime could be increased. However, the overall effectiveness of the international regime appears to be limited by several factors that can not be corrected by means of a modification of the CLC and IOPC conventions. (author)

Relic dark energy from the trans-Planckian regime

International Nuclear Information System (INIS)

Mersini, Laura; Bastero-Gil, Mar; Kanti, Panagiota

2001-01-01

As yet, there is no underlying fundamental theory for the trans-Planckian regime. There is a need to address the issue of how the observables in our present Universe are affected by processes that may have occurred at super-Planckian energies (referred to as the trans-Planckian regime). Specifically, we focus on the impact the trans-Planckian regime has on two observables: namely, dark energy and the cosmic microwave background radiation (CMBR) spectrum. We model the trans-Planckian regime by introducing a 1-parameter family of smooth non-linear dispersion relations which modify the frequencies at very short distances. A particular feature of the family of dispersion functions chosen is the production of ultralow frequencies at very high momenta k (for k>M P ). We name the range of the ultralow energy modes (of very short distances) that have frequencies equal to or less than the current Hubble rate H 0 as the tail modes. These modes are still frozen today due to the expansion of the Universe. We calculate their energy today and show that the tail provides a strong candidate for the dark energy of the Universe. During inflation, their energy is about 122 to 123 orders of magnitude smaller than the total energy, for any random value of the free parameter in the family of dispersion relations. For this family of dispersions, we present the exact solutions and show that the CMBR spectrum is that of a (nearly) blackbody, and that the adiabatic vacuum is the only choice for the initial conditions

Zero-G two phase flow regime modeling in adiabatic flow

International Nuclear Information System (INIS)

Reinarts, T.R.; Best, F.R.; Wheeler, M.; Miller, K.M.

1993-01-01

Two-phase flow, thermal management systems are currently being considered as an alternative to conventional, single phase systems for future space missions because of their potential to reduce overall system mass, size, and pumping power requirements. Knowledge of flow regime transitions, heat transfer characteristics, and pressure drop correlations is necessary to design and develop two-phase systems. This work is concerned with microgravity, two-phase flow regime analysis. The data come from a recent sets of experiments. The experiments were funded by NASA Johnson Space Center (JSC) and conducted by NASA JSC with Texas A ampersand M University. The experiment was on loan to NASA JSC from Foster-Miller, Inc., who constructed it with funding from the Air Force Phillips Laboratory. The experiment used R12 as the working fluid. A Foster-Miller two phase pump was used to circulate the two phase mixture and allow separate measurements of the vapor and liquid flow streams. The experimental package was flown 19 times for 577 parabolas aboard the NASA KC-135 aircraft which simulates zero-G conditions by its parabolic flight trajectory. Test conditions included bubbly, slug and annular flow regimes in 0-G. The superficial velocities of liquid and vapor have been obtained from the measured flow rates and are presented along with the observed flow regimes and several flow regime transition predictions. None of the predictions completely describe the transitions as indicated by the data

Optimization of multi-stage dynamic treatment regimes utilizing accumulated data.

Science.gov (United States)

Huang, Xuelin; Choi, Sangbum; Wang, Lu; Thall, Peter F

2015-11-20

In medical therapies involving multiple stages, a physician's choice of a subject's treatment at each stage depends on the subject's history of previous treatments and outcomes. The sequence of decisions is known as a dynamic treatment regime or treatment policy. We consider dynamic treatment regimes in settings where each subject's final outcome can be defined as the sum of longitudinally observed values, each corresponding to a stage of the regime. Q-learning, which is a backward induction method, is used to first optimize the last stage treatment then sequentially optimize each previous stage treatment until the first stage treatment is optimized. During this process, model-based expectations of outcomes of late stages are used in the optimization of earlier stages. When the outcome models are misspecified, bias can accumulate from stage to stage and become severe, especially when the number of treatment stages is large. We demonstrate that a modification of standard Q-learning can help reduce the accumulated bias. We provide a computational algorithm, estimators, and closed-form variance formulas. Simulation studies show that the modified Q-learning method has a higher probability of identifying the optimal treatment regime even in settings with misspecified models for outcomes. It is applied to identify optimal treatment regimes in a study for advanced prostate cancer and to estimate and compare the final mean rewards of all the possible discrete two-stage treatment sequences. Copyright © 2015 John Wiley & Sons, Ltd.

A Comparative Typology of Pension Regimes

NARCIS (Netherlands)

Arjan Soede; Cok Vrooman

2008-01-01

This report presents an empirical typology of pension regimes in the European Union, the US, Canada, Australia and Norway. The categorisation is based on 34 quantitative and qualitative characteristics of the mandatory parts of the pension systems in these countries. The empirical analysis shows

Assembling an experimentalist regime: transnational governance interactions in the forest sector

NARCIS (Netherlands)

Overdevest, C.; Zeitlin, J.

2014-01-01

Transnational governance initiatives increasingly face the problem of regime complexity in which a proliferation of regulatory schemes operate in the same policy domain, supported by varying combinations of public and private actors. The literature suggests that such regime complexity can lead to

Emerging search regimes: measuring co-evolutions among research, science, and society

NARCIS (Netherlands)

Heimeriks, G.; Leydesdorff, L.

2012-01-01

Scientometric data is used to investigate empirically the emergence of search regimes in biotechnology, genomics and nanotechnology. Complex regimes can emerge when three independent sources of variance interact. In our model, researchers can be considered as the nodes that carry the science system.

Variation of high-power aluminum-wire array Z-pinch dynamics with wire number, load mass, and array radius

Energy Technology Data Exchange (ETDEWEB)

Sanford, T.W.; Mock, R.C.; Marder, B.M.; Nash, T.J.; Spielman, R.B. [Sandia National Laboratories, Albuquerque, New Mexico87185 (United States); Peterson, D.L.; Roderick, N.F. [Los Alamos National Laboratory, Los Alamos, New Mexico87545 (United States); Hammer, J.H.; De Groot, J.S. [Lawrence Livermore National Laboratory, Livermore, California94550 (United States); Mosher, D. [Naval Research Laboratory, Pulsed Power Physics Branch, Washington, District of Columbia20375 (United States); Whitney, K.G.; Apruzese, J.P. [Naval Research Laboratory, Radiation Hydrodynamics Branch, Washington, District of Columbia20375 (United States)

1997-05-01

A systematic study of annular aluminum-wire z-pinches on the Saturn accelerator shows that the quality of the implosion, (as measured by the radial convergence, the radiated energy, pulse width, and power), increases with wire number. Radiation magnetohydrodynamic (RMHC) xy simulations suggest that the implosion transitions from that of individual wire plasmas to that of a continuous plasma shell when the interwire spacing is reduced below {approximately}1.4mm. In this {open_quotes}plasma-shell regime,{close_quotes} many of the global radiation and plasma characteristics are in agreement with those simulated by 2D-RMHC rz simulations. In this regime, measured changes in the radiation pulse width with variations in load mass and array radius are consistent with the simulations and are explained by the development of 2D fluid motion in the rz plane. Associated variations in the K-shell yield are qualitatively explained by simple radiation-scaling models. {copyright} {ital 1997 American Institute of Physics.}

Variation of high-power aluminum-wire array Z-pinch dynamics with wire number, load mass, and array radius

International Nuclear Information System (INIS)

Sanford, T.W.; Mock, R.C.; Marder, B.M.; Nash, T.J.; Spielman, R.B.; Peterson, D.L.; Roderick, N.F.; Hammer, J.H.; De Groot, J.S.; Mosher, D.; Whitney, K.G.; Apruzese, J.P.

1997-01-01

A systematic study of annular aluminum-wire z-pinches on the Saturn accelerator shows that the quality of the implosion, (as measured by the radial convergence, the radiated energy, pulse width, and power), increases with wire number. Radiation magnetohydrodynamic (RMHC) xy simulations suggest that the implosion transitions from that of individual wire plasmas to that of a continuous plasma shell when the interwire spacing is reduced below ∼1.4mm. In this open-quotes plasma-shell regime,close quotes many of the global radiation and plasma characteristics are in agreement with those simulated by 2D-RMHC rz simulations. In this regime, measured changes in the radiation pulse width with variations in load mass and array radius are consistent with the simulations and are explained by the development of 2D fluid motion in the rz plane. Associated variations in the K-shell yield are qualitatively explained by simple radiation-scaling models. copyright 1997 American Institute of Physics

Temporal responses of coastal hypoxia to nutrient loading and physical controls

Directory of Open Access Journals (Sweden)

W. M. Kemp

2009-12-01

Full Text Available The incidence and intensity of hypoxic waters in coastal aquatic ecosystems has been expanding in recent decades coincident with eutrophication of the coastal zone. Worldwide, there is strong interest in reducing the size and duration of hypoxia in coastal waters, because hypoxia causes negative effects for many organisms and ecosystem processes. Although strategies to reduce hypoxia by decreasing nutrient loading are predicated on the assumption that this action would reverse eutrophication, recent analyses of historical data from European and North American coastal systems suggest little evidence for simple linear response trajectories. We review published parallel time-series data on hypoxia and loading rates for inorganic nutrients and labile organic matter to analyze trajectories of oxygen (O₂ response to nutrient loading. We also assess existing knowledge of physical and ecological factors regulating O₂ in coastal marine waters to facilitate analysis of hypoxia responses to reductions in nutrient (and/or organic matter inputs. Of the 24 systems identified where concurrent time series of loading and O₂ were available, half displayed relatively clear and direct recoveries following remediation. We explored in detail 5 well-studied systems that have exhibited complex, non-linear responses to variations in loading, including apparent "regime shifts". A summary of these analyses suggests that O₂ conditions improved rapidly and linearly in systems where remediation focused on organic inputs from sewage treatment plants, which were the primary drivers of hypoxia. In larger more open systems where diffuse nutrient loads are more important in fueling O₂ depletion and where climatic influences are pronounced, responses to remediation tended to follow non-linear trends that may include hysteresis and time-lags. Improved understanding of hypoxia remediation requires that future studies use

Recent Activities on Global Nuclear Safety Regime

International Nuclear Information System (INIS)

Cho, Kun-Woo; Park, Jeong-Seop; Kim, Do-Hyoung

2006-01-01

Recently, rapid progress on the globalization of the nuclear safety issues is being made in IAEA (International Atomic Energy Agency) and its member states. With the globalization, the need for international cooperation among international bodies and member states continues to grow for resolving these universal nuclear safety issues. Furthermore, the importance of strengthening the global nuclear safety regime is emphasized through various means, such as efforts in application of IAEA safety standards to all nuclear installations in the world and in strengthening the code of conduct and the convention on nuclear safety. In this regards, it is important for us to keep up with the activities related with the global nuclear safety regime as an IAEA member state and a leading country in nuclear safety regulation

Methodology for local verification of flow regimes in fuel assemblies charts

International Nuclear Information System (INIS)

Igor, Sharaevsky; Elena, Sharaevskaya; Domashev, E.D.; Alexander, Arkhypov; Vladimir, Kolochko

2003-01-01

The best estimate thermal hydraulic codes describe adequately two-phase flows in nuclear energy facilities if there is proper system of closed relations. It could be obtained from the reliable information on structure forms of two-phase flows, its boundaries and reliable regime charts. In the paper the methodology of automatic recognition of the boundaries of the main types of two phase flows for rod fuel assemblies is presented. The methodology is based on definition of thermal hydraulic parameters distribution in experimental fuel assembly. The measurements were carried out using ASD signals of acoustic noise. In the paper data on two-phase flow regimes boundaries recognition especially low boundaries of bubble flow are summarized for experimental fuel assembly. The methodology of flow regimes charts applied to recognition of upper boundaries of boiling crisis regime was verificated. The satisfactory coincidence with experimental results have been shown. (author)

Dynamical load factor of impact loaded shell structures

International Nuclear Information System (INIS)

Hammel, J.

1977-01-01

Dynamical loaded structures can be analysed by spectral representations, which usually lead to an enormous computational effort. If it is possible to find a fitting dynamical load factor, the dynamical problem can be reduced to a statical one. The computation of this statical problem is much simpler. The disadvantage is that the dynamical load factor usually leads to a very rough approximation. In this paper it will be shown, that by combination of these two methods, the approximation of the dynamical load factor can be improved and the consumption of computation time can be enormously reduced. (Auth.)

Terminal area energy management regime investigations utilizing an 0.030-scale model (47-0) of the space shuttle vehicle orbiter configuration 140A/B/C/R in the Ames Research Center 11 x 11 foot transonic wind tunnel (OA148), volume 5

Science.gov (United States)

Hawthorne, P. J.

1976-01-01

Data obtained in wind tunnel test OA148 are presented. The objectives of the test series were to: (1) obtain pressure distributions, forces and moments over the vehicle 5 orbiter in the thermal area energy management (TAEM) and approach phases of flight; (2) obtain elevon and rudder hinge moments in the TAEM and approach phases of flight; (3) obtain body flap and elevon loads for verification of loads balancing with integrated pressure distributions; and (4) obtain pressure distributions near the short OMS pods in the high subsonic, transonic and low supersonic Mach number regimes.

Two regimes of the Arctic's circulation from ocean models with ice and contaminants.

Science.gov (United States)

Proshutinsky, A Y; Johnson, M

2001-01-01

A two-dimensional barotropic, coupled, ocean-ice model with a space resolution of 55.5 km and driven by atmospheric forces, river run-off, and sea-level slope between the Pacific and the Arctic Oceans, has been used to simulate the vertically averaged currents and ice drift in the Arctic Ocean. Results from 43 years of numerical simulations of water and ice motions demonstrate that two wind-driven circulation regimes are possible in the Arctic, a cyclonic and an anti-cyclonic circulation. These two regimes appear to alternate at 5-7 year intervals with the 10-15 year period. It is important to pollution studies to understand which circulation regime prevails at any time. It is anticipated that 1995 is a year with a cyclonic regime, and during this cyclonic phase and possibly during past cyclonic regimes as well, pollutants may reach the Alaskan shelf. The regime shifts demonstrated in this paper are fundamentally important to understanding the Arctic's general circulation and particularly important for estimating pollution transport.

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 <10 keV are often powerful tools in uncovering optically unidentified AGNs at higher luminosities, this is not the case in the low luminosity regime. In this talk, I will review the effectiveness of uncovering AGNs in the low luminosity regime using multiwavength investigations, with a focus on infrared spectroscopic signatures.

Dispersive regime of the Jaynes–Cummings and Rabi lattice

International Nuclear Information System (INIS)

Zhu, Guanyu; Koch, Jens; Schmidt, Sebastian

2013-01-01

Photon-based strongly correlated lattice models like the Jaynes–Cummings and Rabi lattices differ from their more conventional relatives like the Bose–Hubbard model by the presence of an additional tunable parameter: the frequency detuning between the pseudo-spin degree of freedom and the harmonic mode frequency on each site. Whenever this detuning is large compared to relevant coupling strengths, the system is said to be in the dispersive regime. The physics of this regime is well-understood at the level of a single Jaynes–Cummings or Rabi site. Here, we extend the theoretical description of the dispersive regime to lattices with many sites, for both strong and ultra-strong coupling. We discuss the nature and spatial range of the resulting qubit–qubit and photon–photon coupling, demonstrate the emergence of photon-pairing and squeezing and illustrate our results by exact diagonalization of the Rabi dimer. (paper)

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

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

Research of Impact Load in Large Electrohydraulic Load Simulator

Directory of Open Access Journals (Sweden)

Yongguang Liu

2014-01-01

Full Text Available The stronger impact load will appear in the initial phase when the large electric cylinder is tested in the hardware-in-loop simulation. In this paper, the mathematical model is built based on AMESim, and then the reason of the impact load is investigated through analyzing the changing tendency of parameters in the simulation results. The inhibition methods of impact load are presented according to the structural invariability principle and applied to the actual system. The final experimental result indicates that the impact load is inhibited, which provides a good experimental condition for the electric cylinder and promotes the study of large load simulator.

Load research manual. Volume 2. Fundamentals of implementing load research procedures

Energy Technology Data Exchange (ETDEWEB)

Brandenburg, L.; Clarkson, G.; Grund, Jr., C.; Leo, J.; Asbury, J.; Brandon-Brown, F.; Derderian, H.; Mueller, R.; Swaroop, R.

1980-11-01

This three-volume manual presents technical guidelines for electric utility load research. Special attention is given to issues raised by the load data reporting requirements of the Public Utility Regulatory Policies Act of 1978 and to problems faced by smaller utilities that are initiating load research programs. In Volumes 1 and 2, procedures are suggested for determining data requirements for load research, establishing the size and customer composition of a load survey sample, selecting and using equipment to record customer electricity usage, processing data tapes from the recording equipment, and analyzing the data. Statistical techniques used in customer sampling are discussed in detail. The costs of load research also are estimated, and ongoing load research programs at three utilities are described. The manual includes guides to load research literature and glossaries of load research and statistical terms.

State-of-the-art review of liquid loading in gas wells

Energy Technology Data Exchange (ETDEWEB)

Falcone, G. [Technische Univ. Clausthal, Clausthal-Zellerfeld (Germany). ITE; Barbosa, J.R. Jr. [Universidade Federal de Santa Catarina, Florianopolis, SC (Brazil). Dept. of Mechanical Engineering

2013-08-01

Gas wells suffering from liquid loading are incapable of removing the liquid associated with produced gas from the wellbore. This phenomenon is initiated when the upward gas velocity in the well falls below a critical value at which point the liquid that was initially flowing upwards, begins to fall back. This liquid accumulates downhole, where it increases the hydrostatic back-pressure on the reservoir, destabilises the multiphase flow in the well (following flow regime changes), decreases production rate and, in severe cases, kills the well. The typical liquid loading sequence begins with a gas flow rate that is high enough to transport all liquids to surface and there is no liquid fall-back in the well. However, as the gas velocity slows or the liquid content in the well rises, there is insufficient energy in the well to carry all liquids to surface and some begins to flow backwards. As the hydrostatic head downhole increases, the liquid column that has accumulated in the well can re-enter the near-wellbore region of the reservoir. This results in the well becoming 'unloaded' so that it can flow once more, with the gas carrying all liquids to surface. However, the reinjection of liquids into the reservoir may cause formation damage, which will impair the well productivity. This cycle continues, providing the typical intermittent response of liquid-loaded gas wells, until the reservoir potential starts to fall or the liquid yield rises. Diagnosing liquid loading is often difficult as the affected well(s) may continue production without any substantial performance impairment for a long period of time. Typical symptoms of liquid loading include sharp drops in the cumulative production decline curve, the onset of liquid slugs in the surface facilities, abrupt changes in the flowing pressure gradient, low temperature spikes at the wellhead and declining water production or condensate-gas-ratio. Many remedial lifting options have been developed for use in

Frequency domain design of gain scheduling control for large wind systems in full-load region

International Nuclear Information System (INIS)

Burlibaşa, A.; Ceangă, E.

2014-01-01

Highlights: • A large wind energy system, operating under full-load regime, is considered. • According to its particularities in frequency domain, control law design is provided. • These particularities are influenced by the interactions of wind–tower–blade ensemble. • Control low, within gain scheduling strategy, is achieved imposing stability reserve. • Supplementary a criterion, aimed at reducing mechanical loads, is imposed. - Abstract: The paper presents the issue of power control law synthesis, in the case of a large wind system that operates under full-load regime, based on dynamic properties details in frequency domain. Solving this problem involves two phases: the establishment of a linearized model as faithfully as possible in various operating points of the full-load region, and synthesis of the power controller, considered with classic structure, taking into account frequency particularities of the obtained linearized model. Obtained linear model of the controlled process is of order 16 and encloses subsystems for tower fore-aft oscillations damping, and for drive-train torsion oscillations damping. The designed controller contains a PI component and a lag compensator for dynamic correction at high frequencies. It is known that the main features of wind system dynamics generated by the interaction of wind–tower–blade ensemble cause a gap in the gain characteristic of the model and complex conjugate zeros, which can move between right and left half-planes, depending on the average wind speed value. Consequently, for control law synthesis an interactive frequency solution is adopted. This is “transparent” in relation to particularities induced by wind–tower–blade interaction. This solution allows evaluation of the extent to which control law is affected by the subsystem for tower oscillations damping. Given the strong dependence between the model and the mean wind speed value, a gain scheduling control law is designed. At

Temporal variation of streamflow, sediment load and their relationship in the Yellow River basin, China.

Directory of Open Access Journals (Sweden)

Guangju Zhao

Full Text Available Variation of streamflow and sediment load in the Yellow River basin has received considerable attention due to its drastic reduction during the past several decades. This paper presents a detailed investigation on the changes of streamflow and sediment load from 1952 to 2011 using monthly observations at four gauging stations along the Yellow River. The results show significant decreasing trends for both streamflow and sediment load at all four gauging stations over the past 60 years. The wavelet transform demonstrated discontinuous periodicities from 1969 to 1973 and after 1986 due to the construction of large reservoirs and implementation of numerous soil and water conservations practices. The sediment rating curves with the power-law function was applied to investigate the relationship between discharge and sediment load. The results indicate distinct variations of the relationship between streamflow and sediment and implied significant hydro-morphological changes within different periods. The reducing sediment supply from the source region and the increased erosive power of the river are detected at Lanzhou station, while the decrease of the transport capacity at Toudaoguai is caused by severe siltation. Significant changes in the relationship between streamflow and sediment load are found at Huayuankou and Gaocun stations, which are largely induced by evident sediment income and trapping effects of large reservoirs. It is estimated that numerous reservoirs have strongly altered the regime and magnitude of streamflow and trapped large amount of sediment, leading to severe siltation and evident reduction of their total volumes. A decrease in precipitation, incoming water from the upper reaches, soil and water conservation measures as well as water consumption contribute most to the significant reduction of streamflow. The decrease of sediment load mainly resulted from various soil and water conservation measures and trapping in reservoirs

Effect of ripple loads on sustained-load cracking in titanium alloys

International Nuclear Information System (INIS)

Pao, P.S.; Meyn, D.A.; Bayles, R.A.; Feng, C.R.; Yoder, G.R.

1995-01-01

In the present paper, the authors have extended their study on the effect of the ripple loads on the sustained-load cracking (SLC) behavior of two titanium alloys, Ti-6Al-4V (an α-β alloy) and Ti-15V-3Cr-3Al-3Sn (a β-α alloy), in an ambient air environment. The methodology which has been used successfully to treat ripple effects on stress-corrosion cracking (SCC) is employed again to address the influence of ripple loads on sustained-load cracking. Ripple loads can significantly reduce the apparent sustained load cracking resistance of titanium alloys in a relatively benign environment such as ambient air. For a ripple-load amplitude equal to 5% of the sustained load, the ripple-load cracking thresholds (K IRLC ) of beta-annealed Ti-6Al-4V and Ti-15V-3Cr-3al-3Sn are less than half of the respective sustained-load cracking thresholds (K ISLC ). The extent of ripple-load degradation for these alloys in ambient air -- relative to K ISLC , were found comparable to those observed in a much more aggressive 3.5% NaCl aqueous solution

Conservation performance of different conservation governance regimes in the Peruvian Amazon.

Science.gov (United States)

Schleicher, Judith; Peres, Carlos A; Amano, Tatsuya; Llactayo, William; Leader-Williams, Nigel

2017-09-12

State-controlled protected areas (PAs) have dominated conservation strategies globally, yet their performance relative to other governance regimes is rarely assessed comprehensively. Furthermore, performance indicators of forest PAs are typically restricted to deforestation, although the extent of forest degradation is greater. We address these shortfalls through an empirical impact evaluation of state PAs, Indigenous Territories (ITs), and civil society and private Conservation Concessions (CCs) on deforestation and degradation throughout the Peruvian Amazon. We integrated remote-sensing data with environmental and socio-economic datasets, and used propensity-score matching to assess: (i) how deforestation and degradation varied across governance regimes between 2006-2011; (ii) their proximate drivers; and (iii) whether state PAs, CCs and ITs avoided deforestation and degradation compared with logging and mining concessions, and the unprotected landscape. CCs, state PAs, and ITs all avoided deforestation and degradation compared to analogous areas in the unprotected landscape. CCs and ITs were on average more effective in this respect than state PAs, showing that local governance can be equally or more effective than centralized state regimes. However, there were no consistent differences between conservation governance regimes when matched to logging and mining concessions. Future impact assessments would therefore benefit from further disentangling governance regimes across unprotected land.

Oil Regime Change in Iraq. Possible Strategic Implications for OPEC

International Nuclear Information System (INIS)

Boon Von Ochssee, T.A.

2006-06-01

The potential strategic impact of regime change in Iraq and Iran on OPEC in the long-run is explored. In the first part of the paper short overviews are given of the present international oil market; of US oil import issues and energy policy; of the strategic position of the US in the Persian Gulf and of geopolitical developments in the Persian Gulf at large. Also, attention is paid to the OPEC and the role of a 'new' Iraq. In the second part the game of 'boxed pigs' is used to explore the possible strategic impact of regime change in Iraq and possible regime change in Iran on OPEC. This exploration takes place within four possible futures for the Gulf

Experience in verification regimes. United States On-Site Inspection Agency

International Nuclear Information System (INIS)

Reppert, J.

1998-01-01

Experiences are described of the United States On-site Inspection Agency in verification regimes all over the world where it has been applied in the last 30 years. The challenge for the future is to extend the benefits of the applied tools to all states in all regions to enhance stability and to create conditions for peace at lower levels of armaments than currently exist. The USA need to engage states currently caught in cycles of violence and arms escalation. They must examine technologies which together with on-site aspects of verification or transparency regimes can provide a comprehensive picture at affordable costs. They foresee a growth in combined training with new states entering for the first time into regime that include arms control and transparency measure

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. © 2011 The Authors. Sociology of Health & Illness © 2011 Foundation for the Sociology of Health & Illness/Blackwell Publishing Ltd.

Lognormal firing rate distribution reveals prominent fluctuation-driven regime in spinal motor networks

DEFF Research Database (Denmark)

Petersen, Peter C.; Berg, Rune W.

2016-01-01

fraction that operates within either a ‘mean-driven’ or a ‘fluctuation–driven’ regime. Fluctuation-driven neurons have a ‘supralinear’ input-output curve, which enhances sensitivity, whereas the mean-driven regime reduces sensitivity. We find a rich diversity of firing rates across the neuronal population...... as reflected in a lognormal distribution and demonstrate that half of the neurons spend at least 50 %% of the time in the ‘fluctuation–driven’ regime regardless of behavior. Because of the disparity in input–output properties for these two regimes, this fraction may reflect a fine trade–off between stability...

Mechanisms of ignition by transient energy deposition: Regimes of combustion wave propagation

OpenAIRE

Kiverin, A. D.; Kassoy, D. R.; Ivanov, M. F.; Liberman, M. A.

2013-01-01

Regimes of chemical reaction wave propagating in reactive gaseous mixtures, whose chemistry is governed by chain-branching kinetics, are studied depending on the characteristics of a transient thermal energy deposition localized in a finite volume of reactive gas. Different regimes of the reaction wave propagation are initiated depending on the amount of deposited thermal energy, power of the source, and the size of the hot spot. The main parameters which define regimes of the combustion wave...

Two-phase interfacial area and flow regime modeling in FLOWTRAN-TF code

International Nuclear Information System (INIS)

Smith, F.G. III; Lee, S.Y.; Flach, G.P.; Hamm, L.L.

1992-01-01

FLOWTRAN-TF is a new two-component, two-phase thermal-hydraulics code to capture the detailed assembly behavior associated with loss-of-coolant accident analyses in multichannel assemblies of the SRS reactors. The local interfacial area of the two-phase mixture is computed by summing the interfacial areas contributed by each of three flow regimes. For smooth flow regime transitions, the code uses an interpolation technique in terms of component void fraction for each basic flow regime

The determination of capital controls: Which role do exchange rate regimes play?

OpenAIRE

von Hagen, Jürgen; Zhou, Jizhong

2003-01-01

This paper investigates the role of exchange rate regime choices in the determination of capital controls in transition economies. We first use a simultaneous equations model to allow direct interactions between decisions on capital controls and on exchange rate regimes. We find that exchange rate regime choices strongly influence the imposition or removal of capital controls, but the feed-back effect is weak. We further estimate a single equation model for capital controls with exchange rate...

Creep testing and creep loading experiments on friction stir welds in copper at 75 deg C

International Nuclear Information System (INIS)

Andersson, Henrik C.M.; Seitisleam, Facredin; Sandstroem, Rolf

2007-08-01

Specimens cut from friction stir welds in copper canisters for nuclear waste have been used for creep experiments at 75 deg C. The specimens were taken from a cross-weld position as well as heat affected zone and weld metal. The parent metal specimens exhibited longer creep lives than the weld specimens by a factor of three in time. They in turn were longer than those for the crossweld and HAZ specimens by an order of magnitude. The creep exponent was in the interval 50 to 69 implying that the material was well inside the power-law breakdown regime. The ductility properties expressed as reduction in area were not significantly different and all the rupture specimens demonstrated values exceeding 80%. Experiments were also carried out on the loading procedure of a creep test. Similar parent metal specimens and test conditions were used and the results show that the loading method has a large influence on the strain response of the specimen

Creep testing and creep loading experiments on friction stir welds in copper at 75 deg C

Energy Technology Data Exchange (ETDEWEB)

Andersson, Henrik C.M.; Seitisleam, Facredin; Sandstroem, Rolf [Corrosion an d Metals Research Institute, Stockholm (Sweden)

2007-08-15

Specimens cut from friction stir welds in copper canisters for nuclear waste have been used for creep experiments at 75 deg C. The specimens were taken from a cross-weld position as well as heat affected zone and weld metal. The parent metal specimens exhibited longer creep lives than the weld specimens by a factor of three in time. They in turn were longer than those for the crossweld and HAZ specimens by an order of magnitude. The creep exponent was in the interval 50 to 69 implying that the material was well inside the power-law breakdown regime. The ductility properties expressed as reduction in area were not significantly different and all the rupture specimens demonstrated values exceeding 80%. Experiments were also carried out on the loading procedure of a creep test. Similar parent metal specimens and test conditions were used and the results show that the loading method has a large influence on the strain response of the specimen.

The world's non-proliferation regime in time

International Nuclear Information System (INIS)

Bunn, George

2005-01-01

The idea for a treaty to prevent the spread of nuclear weapons to more countries was supported unanimously by the UN General Assembly in 1961. The NPT permits the P-5 to have nuclear weapons. All other NPT signatories are 'non-nuclear-weapon States' who are prohibited from acquiring nuclear weapons. To gain their signatures, the NPT promises assistance to them in the peaceful uses of nuclear energy and negotiations toward nuclear disarmament. Besides the P-5, the treaty now has 184 countries that have promised not to have nuclear weapons and that have agreed to accept inspections by the IAEA to verify that they are carrying out their promises. However, India, Pakistan, and Israel refused to join the treaty, and the Democratic People's Republic of Korea (North Korea) withdrew from it. Of these four countries, only India and Pakistan have tested nuclear weapons. Israel and North Korea are assumed to have them. The non-proliferation regime today includes much more than the NPT. The IAEA standards for inspection were the next most important element. The IAEA inspection requirements negotiated in the early 1970s were shown to be inadequate by Iraq's success in hiding its nuclear-weapon efforts before and during the Gulf War of 1991. The Additional Protocol of 1997 is slowly replacing these requirements, but, as of December 2004, was in effect in only 62 NPT member countries. The regime includes the agreements creating nuclear-weapon free zones in Africa, Latin America, Southeast Asia, the South Pacific, and Mongolia. The countries that formed these zones are also members of the NPT. The regime includes suggestions for standards and financial assistance plus requirements for physical protection of nuclear material from theft by terrorists or others. These efforts range from the Convention on Physical Protection of Nuclear Material, to the technical assistance provided by the IAEA and some countries, to the financial assistance offered by the G-8 and some other IAEA

Flow regime identification methodology with MCNP-X code and artificial neural network

International Nuclear Information System (INIS)

Salgado, Cesar M.; Instituto de Engenharia Nuclear; Schirru, Roberto; Brandao, Luis E.B.; Pereira, Claudio M.N.A.

2009-01-01

This paper presents flow regimes identification methodology in multiphase system in annular, stratified and homogeneous oil-water-gas regimes. The principle is based on recognition of the pulse height distributions (PHD) from gamma-ray with supervised artificial neural network (ANN) systems. The detection geometry simulation comprises of two NaI(Tl) detectors and a dual-energy gamma-ray source. The measurement of scattered radiation enables the dual modality densitometry (DMD) measurement principle to be explored. Its basic principle is to combine the measurement of scattered and transmitted radiation in order to acquire information about the different flow regimes. The PHDs obtained by the detectors were used as input to ANN. The data sets required for training and testing the ANN were generated by the MCNP-X code from static and ideal theoretical models of multiphase systems. The ANN correctly identified the three different flow regimes for all data set evaluated. The results presented show that PHDs examined by ANN may be applied in the successfully flow regime identification. (author)

DETERMINANTS OF FOREIGN DIRECT INVESTMENT IN NIGERIA: A MARKOV REGIME-SWITCHING APPROACH

Directory of Open Access Journals (Sweden)

Akinlo A. Enisan

2017-04-01

Full Text Available Several studies have analyzed the movement of foreign direct investment in Nigeria using linear approach. In contrast with all existing studies in Nigeria, this paper runs several non linear FDI equations where the main determinants of FDI are determined using Markov- Regime Switching Model (MSMs. The approach enables us to observe structural changes, where exist, in FDI equations through time. Asides, where FDI regression equation is truly nonlinear, MSMs fit data better than the linear models. The paper adopts maximum likelihood methodology of Markov-Regime Model (MSM to identify possible structural changes in level and/or trends and possible changes in parameters of independent variables through the transition probabilities. The results show that FDI process in Nigeria is governed by two different regimes and a shift from one regime to another regime depends on transition probabilities. The results show that the main determinants of FDI are GDP growth, macro instability, financial development, exchange rate, inflation and discount rate. This implies liberalization that stems inflation and enhance the value of domestic currency will attract more FDI into the country.

Low cognitive load strengthens distractor interference while high load attenuates when cognitive load and distractor possess similar visual characteristics.

Science.gov (United States)

Minamoto, Takehiro; Shipstead, Zach; Osaka, Naoyuki; Engle, Randall W

2015-07-01

Studies on visual cognitive load have reported inconsistent effects of distractor interference when distractors have visual characteristic that are similar to the cognitive load. Some studies have shown that the cognitive load enhances distractor interference, while others reported an attenuating effect. We attribute these inconsistencies to the amount of cognitive load that a person is required to maintain. Lower amounts of cognitive load increase distractor interference by orienting attention toward visually similar distractors. Higher amounts of cognitive load attenuate distractor interference by depleting attentional resources needed to process distractors. In the present study, cognitive load consisted of faces (Experiments 1-3) or scenes (Experiment 2). Participants performed a selective attention task in which they ignored face distractors while judging a color of a target dot presented nearby, under differing amounts of load. Across these experiments distractor interference was greater in the low-load condition and smaller in the high-load condition when the content of the cognitive load had similar visual characteristic to the distractors. We also found that when a series of judgments needed to be made, the effect was apparent for the first trial but not for the second. We further tested an involvement of working memory capacity (WMC) in the load effect (Experiment 3). Interestingly, both high and low WMC groups received an equivalent effect of the cognitive load in the first distractor, suggesting these effects are fairly automatic.