Investigation of the statistical distance to reach stationary distributions
International Nuclear Information System (INIS)
Nicholson, S.B.; Kim, Eun-jin
2015-01-01
The thermodynamic length gives a Riemannian metric to a system's phase space. Here we extend the traditional thermodynamic length to the information length (L) out of equilibrium and examine its properties. We utilise L as a useful methodology of analysing non-equilibrium systems without evoking conventional assumptions such as Gaussian statistics, detailed balance, priori-known constraints, or ergodicity and numerically examine how L evolves in time for the logistic map in the chaotic regime depending on initial conditions. To this end, we propose a discrete version of L which is mathematically well defined by taking a set theoretic approach. We identify the areas of phase space where the loss of information of the system takes place most rapidly. In particular, we present an interesting result that the unstable fixed points turn out to most efficiently drive the logistic map towards a stationary distribution through L. - Highlights: • Define a set theoretic version of the discrete thermodynamic length. • These sets allow one to analyse systems having zero probabilities in their evolution. • Numerically analyse the Logistic map using the thermodynamic length. • Show how the unstable fixed points most efficiently lead the system to equilibrium
The meaning of the body schema in reaching maturity during late adolescence
Directory of Open Access Journals (Sweden)
Mirucka Beata
2016-04-01
Full Text Available The objective of the research presented in this paper was to investigate whether an association existed between the activation of the body schema and reaching adulthood among people in late adolescence. Three activities that are known to enjoy popularity among young people were analysed, namely: dancing, playing computer games that require motor involvement (e.g. Kinect, and playing computer games of an educational and entertaining character. It was assumed that the chosen forms of activity correspond to three levels of activation of the body schema. The following research methods have been applied to this study: the Rosenberg Self-Esteem Scale (SES, the Defence Style Questionnaire (DSQ, and the Bodily Self Representation Questionnaire. The study has proven that the activation of body schema through dance is significantly related to high self-esteem and the use of mainly mature and neurotic defence mechanisms in threat situations.
de Almeida Soares, Daniele; Cunha, Andréa Baraldi; Tudella, Eloisa
2014-11-01
This study compared the effects of a short bout of practice on reaching behavior between late preterm and full-term infants at the onset of goal-directed reaching. Twelve late preterm infants and twelve full-term infants received reaching practice based on a serial schedule. Late preterm and full-term infants were assessed in 3.3±1.4 and 2.6±1.0 days after the onset of goal-directed reaching in two measures in a single day: immediately before practice (pre-test) and immediately after practice (post-test). During the assessments, the infants were placed in a baby chair and a rubber toy was presented at their midline within reaching distance for 2 min. Between assessments, the infants received practice of toy-oriented reaching in 3 activities repeated for approximately 4 min. The activities were elicited in a pre-established serial sequence and were applied by a physical therapist. During the pre-test, late preterm infants presented lower range of proximal adjustments, greater proportion of reaches with semi-open hand, and greater proportion of reaches without grasping than the full-term infants. During the post-test, late preterm infants presented greater motor variability of proximal adjustments, but explored and selected distal control and grasping outcomes less compared to the full-term group. Differences in reaching and gross motor behavior between late preterm and full-term infants can be found at the age of reaching onset. Practice provided new opportunities for late preterm infants to improve perception-action coupling to reach; however, relative to full-terms, they seemed less advanced in benefiting from the experience for more refined manual tasks. Copyright © 2014 Elsevier Ltd. All rights reserved.
Chen, F.
2017-12-01
Because of the reported decreasing trends in precipitation and streamflow in north-central China (Starting point of Ancient Silk Road), it is essential to understand long-term in water resource availability in this area. Thus, this research presents a new February-August PDSI reconstruction spanning CE 1615-2013 for the southern edge of the Gobi Desert under a highly variable arid and semi-arid climate in northern China. In addition to this new PDSI reconstruction, some previously published annual precipitation/PDSI reconstructions from the neighbouring regions were also used to infer the large-scale hydro-climatic signal of the middle reach of the Yellow River. Spatial correlation analyses with gridded precipitation data showed that the tree-ring records were indeed able to capture much of the regional interannual hydro-climatic signal variability. Using principal component analyses on the reconstructions and documentary records, many large-scale dry and flood events were found during the period AD 1615-2006. Many of these dry events have had profound impacts on the people of the study area over the past several centuries. Temporal correlations among the reconstruction and climatic indices, such as the El Niño-Southern Oscillation, demonstrate that water availability is influenced by tropical and high-latitude forcings in the Pacific rim. Continued work in this direction should enable us to understand better the hydrological change under global warming and the past climate variability of the silk road over long temporal and large spatial scales.
Directory of Open Access Journals (Sweden)
John M Morrison
2012-03-01
Full Text Available The modulation of mRNA turnover is gaining recognition as a mechanism by which Staphylococcus aureus regulates gene expression, but the factors that orchestrate alterations in transcript degradation are poorly understood. In that regard, we previously found that 138 mRNA species, including the virulence factors protein A (spa and collagen binding protein (cna, are stabilized in a sarA-dependent manner during exponential phase growth, suggesting that SarA protein may directly or indirectly effect the RNA turnover properties of these transcripts. Herein, we expanded our characterization of the effects of sarA on mRNA turnover during late exponential and stationary phases of growth. Results revealed that the locus affects the RNA degradation properties of cells during both growth phases. Further, using gel mobility shift assays and RIP-ChIP, it was found that SarA protein is capable of binding mRNA species that it stabilizes both in vitro and within bacterial cells. Taken together, these results suggest that SarA post-transcriptionally regulates S. aureus gene expression in a manner that involves binding to and consequently altering the mRNA turnover properties of target transcripts.
Bhiwandi, P; Campbell, M; Potts, M
1994-01-01
The 1994 International Conference on Population and Development proposed increasing contraceptive couple protection from 550 million in 1995 to 880 million in 2015. The task for family planning (FP) programs is to provide access to services for, sometimes, inaccessible rural populations. FP need based on desire for no more children has ranged from under 20% in Senegal to almost 80% in Peru. Socioeconomic development was found not to be a prerequisite for fertility change. Gender inequalities in education and social autonomy must be changed. FP access is very important among women with a disadvantaged background or among women unsure about FP. Bangladesh is a good example of a country with increased contraceptive prevalence despite low income. The rule of thumb is that contraception increases of 15% contribute to a drop in family size of about one child. Program effectiveness is related to a variety of factors: contraceptive availability at many locations, acceptable price of contraception, delivery of the oral contraceptives without prescriptions, and other strategies. FP is a service not a medical treatment. A range of methods must be promoted and available from a range of facilities. Contraceptive use is dependent on the woman's stage in her lifecycle and is dependent on informed choice. Community-based distribution systems are effective, whereas free distribution by poorly-trained field workers is not always very effective because patient payment of all or part of the cost assures quality and freedom of choice. Effective programs for underprivileged groups involve aggressive, easy to manage programs that can be replicated rapidly. FP serves a useful function in depressing maternal mortality among the poor in Africa, who have no access to quality health services. Social marketing is an effective strategy for reaching remote areas. Political will and robust management are necessary commodities.
Stationary nonlinear Airy beams
International Nuclear Information System (INIS)
Lotti, A.; Faccio, D.; Couairon, A.; Papazoglou, D. G.; Panagiotopoulos, P.; Tzortzakis, S.; Abdollahpour, D.
2011-01-01
We demonstrate the existence of an additional class of stationary accelerating Airy wave forms that exist in the presence of third-order (Kerr) nonlinearity and nonlinear losses. Numerical simulations and experiments, in agreement with the analytical model, highlight how these stationary solutions sustain the nonlinear evolution of Airy beams. The generic nature of the Airy solution allows extension of these results to other settings, and a variety of applications are suggested.
Stationary radiation of objects with scattering media
International Nuclear Information System (INIS)
Vasil'eva, Inna A
2001-01-01
The radiation observed inside or outside a stationary radiator with a scattering medium is a sum of components, each being determined by, first, the primary radiation from some part of the radiator and, second, the probability of this radiation reaching the region where it is observed. In this review, general and rather simple relations between these components are discussed. These relations, unlike the components themselves, are independent of the specific optical characteristics of the object as well as of its geometry, inhomogeneity, etc. In deriving the relations, the situations in which geometrical optics is either applicable or inapplicable to radiation in a scattering medium are considered. For the case where geometrical optics does apply, stationary relations are derived from the probabilistic stationarity condition for radiation passing through the medium, i.e., from the fact that all radiation emitted in a stationary regime disappears with probability unity. Equilibrium relations are derived from the stationary relations in the particular case of a thermal radiator in an isothermal cavity. To derive the stationary relations in the geometrical optics approximation, we obtain general solutions of the linear equation of transfer using the Green function approach. If geometrical optics cannot be applied to a scattering and radiating medium, only relations for the components of outgoing thermal radiation are obtained, and the generalized Kirchhoff law, obtained by Levin and Rytov using statistical radio-physics methods, is employed. In this case, stationary relations are also derived from a probabilistic stationarity condition; the equilibrium relations follow from the stationary ones as well as from the equilibrium condition for radiation in the isothermal cavity. The quantities involved in all the relations obtained are a subject of experimental and computational spectroscopic studies. Examples of current and potential applications are given. The relations
International Nuclear Information System (INIS)
Combes, J.M.
1980-10-01
A complementary approach to the time dependent scattering theory for one-body Schroedinger operators is presented. The stationary theory is concerned with objects of quantum theory like scattering waves and amplitudes. In the more recent abstract stationary theory some generalized form of the Lippman-Schwinger equation plays the basic role. Solving this equation leads to a linear map between generalized eigenfunctions of the perturbed and unperturbed operators. This map is the section at fixed energy of the wave-operator from the time dependent theory. Although the radiation condition does not appears explicitely in this formulation it can be shown to hold a posteriori in a variety of situations thus restoring the link with physical theories
Stationary theory of scattering
International Nuclear Information System (INIS)
Kato, T.
1977-01-01
A variant of the stationary methods is described, and it is shown that it is useful in a wide range of problems, including scattering, by long-range potentials, two-space scattering, and multichannel scattering. The method is based on the notion of spectral forms. The paper is restricted to the simplest case of continuous spectral forms defined on a Banach space embedded in the basic Hilbert space. (P.D.)
North American Drought and Links to Northern Eurasia: The Role of Stationary Rossby Waves
Wang, Hailan; Schubert, Siegfried D.; Koster, Randal D.
2017-01-01
This chapter provides an overview of the role of stationary Rossby waves in the sub-seasonal development of warm season drought over North America and subsequent downstream development of climate anomalies over northern Eurasia. The results are based on a case study of a stationary Rossby wave event that developed during 20 May 15 June 1988. Simulations with the NASA Goddard Earth Observing System (GEOS-5) atmospheric general circulation model highlight the importance of the mean jet streams in guiding and constraining the path and speed of wave energy propagation. In particular, convective anomalies that developed over the western Pacific in late May (in the presence of the strong North Pacific jet) produce a predilection for persistent upper-level high anomalies over central North America about ten days later, leading to the rapid development of severe dry conditions there. There are indications of continued downstream wave energy propagation that reaches northern Eurasia about two weeks later, leading to the development of dry conditions over eastern Europe and western Russia, and cool and wet conditions over western Europe and central northern Eurasia. The results suggest that stationary Rossby waves can serve as a source of predictability for sub-seasonal development of droughts over North America and northern Eurasia.
Stationary solutions and asymptotic flatness I
International Nuclear Information System (INIS)
Reiris, Martin
2014-01-01
In general relativity, a stationary isolated system is defined as an asymptotically flat (AF) stationary spacetime with compact material sources. Other definitions that are less restrictive on the type of asymptotic could in principle be possible. Between this article and its sequel, we show that under basic assumptions, asymptotic flatness indeed follows as a consequence of Einstein's theory. In particular, it is proved that any vacuum stationary spacetime-end whose (quotient) manifold is diffeomorphic to R 3 minus a ball and whose Killing field has its norm bounded away from zero, is necessarily AF with Schwarzschildian fall off. The ‘excised’ ball would contain (if any) the actual material body, but this information is unnecessary to reach the conclusion. In this first article, we work with weakly asymptotically flat (WAF) stationary ends, a notion that generalizes as much as possible that of the AF end, and prove that WAF ends are AF with Schwarzschildian fall off. Physical and mathematical implications are also discussed. (paper)
Directory of Open Access Journals (Sweden)
Reinhold Steinacker
2016-12-01
Full Text Available In 1906, the Austrian scientist Max Margules published a paper on temperature stratification in resting and non-accelerated moving air. The paper derives conditions for stationary slopes of air mass boundaries and was an important forerunner of frontal theories. Its formulation of relations between changes in density and geostrophic wind across the front is basically a discrete version of the thermal wind balance equation. The paper was highly influential and is still being cited to the present day. This paper accompanies an English translation of Margules’ seminal paper. We conclude here our “Classic Papers” series of the Meteorologische Zeitschrift.
Berger, Jorge
2018-06-01
In the customary mode of operation of a SQUID, the electromagnetic field in the SQUID is an oscillatory function of time. In this situation, electromagnetic radiation is emitted and couples to the sample. This is a back action that can alter the state that we intend to measure. A circuit that could perform as a stationary SQUID consists of a loop of superconducting material that encloses the magnetic flux, connected to a superconducting and to a normal electrode. This circuit does not contain Josephson junctions, or any other miniature feature. We study the evolution of the order parameter and of the electrochemical potential in this circuit; they converge to a stationary regime, and the voltage between the electrodes depends on the enclosed flux. We obtain expressions for the power dissipation and for the heat transported by the electric current; the validity of these expressions does not rely on a particular evolution model for the order parameter. We evaluate the influence of fluctuations. For a SQUID perimeter of the order of 1μ m and temperature 0.9T_c, we obtain a flux resolution of the order of 10^{-5}Φ _0/Hz^{1/2}; the resolution is expected to improve as the temperature is lowered.
Stationary flywheel energy storage
Energy Technology Data Exchange (ETDEWEB)
Gilhaus, A; Hau, E; Gassner, G; Huss, G; Schauberger, H
1981-01-01
The aim of this system study is to find out industrial applications of stationary flywheel energy accumulators. The economic value for the consumer and the effects on the power supply grid are investigated. Up to now, stationary flywheel energy accumulators have only been used in a small range. The main reason for thinking of the application in a wider range was the hope that those could be used economically for lowering the maximum output demand of the power supply grid. The possible savings in energy costs, however, proved to be too small for paying back the investment costs. Further benefits are necessary for advantageous application. As to overall economy, compensation of short time maximum power output seems to be more favorable at the power stations. An additional possibility for energy storage by flywheels is given where otherwise lost energy can be used effectively, according to the successful brake energy storage in vehicles. Under this aspect the future use of flywheels in wind-power-plants seems to be promising. Attractive savings of energy can be obtained by introducing modern flywheel technology for emergency power supply units which are employed for instance in telecommunication systems. Especially the application for emergency power supply, in power stations and in combustion with wind energy converters need further investigation.
Investigation of the stationary-thermonuclear-reaction realization possibility in a tokamak device
International Nuclear Information System (INIS)
Kolesnichenko, Ya.I.; Reznik, S.N.; Fursa, A.D.
1976-01-01
The stationary (quasistationary) selfsustaining thermonuclear D-T reaction is shown to be possible in a toroidal device such as 'Tokamak' with large enough plasma radius. The stationary temperature of the plasma can be quite high. Thus when the transport processes are assumed to be neoclassical the temperature of the central part of a plasma colomn of radius approximately 10-200 cm in the stationary state is 70 keV.The stationary temperature distribution is reached spontaneously as a result of the thermal instability development if plasma is preheated to 10 keV. The stationary thermonuclear burning is also possible at lower temperatures if plasma energy balance is controlled
Stationary and Transient Response Statistics
DEFF Research Database (Denmark)
Madsen, Peter Hauge; Krenk, Steen
1982-01-01
The covariance functions for the transient response of a linear MDOF-system due to stationary time limited excitation with an arbitrary frequency content are related directly to the covariance functions of the stationary response. For rational spectral density functions closed form expressions fo...
Generating stationary entangled states in superconducting qubits
International Nuclear Information System (INIS)
Zhang Jing; Liu Yuxi; Li Chunwen; Tarn, T.-J.; Nori, Franco
2009-01-01
When a two-qubit system is initially maximally entangled, two independent decoherence channels, one per qubit, would greatly reduce the entanglement of the two-qubit system when it reaches its stationary state. We propose a method on how to minimize such a loss of entanglement in open quantum systems. We find that the quantum entanglement of general two-qubit systems with controllable parameters can be controlled by tuning both the single-qubit parameters and the two-qubit coupling strengths. Indeed, the maximum fidelity F max between the stationary entangled state, ρ ∞ , and the maximally entangled state, ρ m , can be about 2/3≅max(tr(ρ ∞ ρ m ))=F max , corresponding to a maximum stationary concurrence, C max , of about 1/3≅C(ρ ∞ )=C max . This is significant because the quantum entanglement of the two-qubit system can be produced and kept, even for a long time. We apply our proposal to several types of two-qubit superconducting circuits and show how the entanglement of these two-qubit circuits can be optimized by varying experimentally controllable parameters.
U.S. Environmental Protection Agency — The Reach Address Database (RAD) stores the reach address of each Water Program feature that has been linked to the underlying surface water features (streams,...
Valdes, C
1992-01-01
Guatemala's family planning (FP) programs are innovative but contraceptive use is only 23%. Total fertility is 5.3 children/woman, and the 9.5 million population will double in 23 years. The problem is poverty and illiteracy among rural residents removed from health services. 80% live in poverty and 80% are illiterate. Government effort is devoted to combating diseases such as diarrhea so there are few funds for implementing a comprehensive population policy. There is support within the national government but FP lacks priority status. APROFAM's goals are to use innovative marketing methods to inform the rural population who lack access to and knowledge about FP. Service delivery is constrained by the difficulty in reaching remote areas where 4 out of 10 indigenous Guatemalans live. Infant mortality can reach as high as 200/1000 live births. Population growth has slowed, and APROFAM plans to reach 16,000 more in the future. Promotions are conducted in several languages and aired on radio, television, and in the print media. It has been found that market research is the most effective strategy in reaching indigenous families. APROFAM has also been effective in upgrading service facilities through training, client surveys, and setting improved clinic standards. Breastfeeding, training, and voluntary sterilization programs contribute to the primary care effort. The example is given of Paulina Lebron from a very poor area who has learned how to space her children and thus improve the standard of living for her family. Eventually, she convinced herself and her family that sterilization was necessary, and now the couple enjoy the bliss of newlyweds without fear of pregnancy.
International Nuclear Information System (INIS)
Peculea, M.; Beca, T.; Constantinescu, D.M.; Dumitrescu, M.; Dimulescu, A.; Isbasescu, G.; Stefanescu, I.; Mihai, M.; Dogaru, C.; Marinescu, M.; Olariu, S.; Constantin, T.; Necula, A.
1995-01-01
This paper refers to testing procedures of the production capacity of heavy water production pilot, industrial scale plants and of heavy water reconcentration facilities. Simulation codes taking into account the mass and heat transfers inside the exchange columns were developed. These codes provided valuable insight about the isotope build-up of the installation which allowed estimating the time of reaching the stationary regime. Also transient regimes following perturbations in the operating parameters (i.e. temperature, pressure, fluid rates) of the installation were simulated and an optimal rate of routine inspections and adjustments was thus established
The stationary neutron radiography system
International Nuclear Information System (INIS)
Weeks, A.A.; Newell, D.L.; Heidel, C.C.
1990-01-01
To provide the high intensity neutron beam and support systems necessary for radiography, the Stationary Neutron Radiography System was constructed at McClellan Air Force Base. The Stationary Neutron Radiography System utilizes a one megawatt TRIGA reactor contained in an Aluminium tank surrounded by eight foot thick concrete walls. There are four neutron beam tubes at inclined angles from the reactor core to separate radiography bays. In three of the bays, robotic systems manipulate aircraft components in the neutron beam, while real-time imaging systems provide images concurrent with the irradiation. Film radiography of smaller components is performed in the remaining bay
Stationary measure in the multiverse
International Nuclear Information System (INIS)
Linde, Andrei; Vanchurin, Vitaly; Winitzki, Sergei
2009-01-01
We study the recently proposed ''stationary measure'' in the context of the string landscape scenario. We show that it suffers neither from the ''Boltzmann brain'' problem nor from the ''youngness'' paradox that makes some other measures predict a high CMB temperature at present. We also demonstrate a good performance of this measure in predicting the results of local experiments, such as proton decay
Teratology testing under REACH.
Barton, Steve
2013-01-01
REACH guidelines may require teratology testing for new and existing chemicals. This chapter discusses procedures to assess the need for teratology testing and the conduct and interpretation of teratology tests where required.
2016-09-01
Popular culture reflects both the interests of and the issues affecting the general public. As concerns regarding climate change and its impacts grow, is it permeating into popular culture and reaching that global audience?
Virtual Stationary Automata for Mobile Networks
National Research Council Canada - National Science Library
Dolev, Shlomi; Gilbert, Seth; Lahiani, Limor; Lynch, Nancy; Nolte, Tina
2005-01-01
We define a programming abstraction for mobile networks called the Virtual Stationary Automata programming layer, consisting of real mobile clients, virtual timed I/O automata called virtual stationary automata (VSAs...
Stationary measure in the multiverse
Energy Technology Data Exchange (ETDEWEB)
Linde, Andrei [Department of Physics, Stanford University, Stanford, CA 94305 (United States); Vanchurin, Vitaly; Winitzki, Sergei, E-mail: alinde@stanford.edu, E-mail: vitaly@cosmos2.phy.tufts.edu, E-mail: winitzki@physik.uni-muenchen.de [Department of Physics, Ludwig-Maximilians University, Munich (Germany)
2009-01-15
We study the recently proposed ''stationary measure'' in the context of the string landscape scenario. We show that it suffers neither from the ''Boltzmann brain'' problem nor from the ''youngness'' paradox that makes some other measures predict a high CMB temperature at present. We also demonstrate a good performance of this measure in predicting the results of local experiments, such as proton decay.
Mallak, Saed
1996-01-01
Ankara : Department of Mathematics and Institute of Engineering and Sciences of Bilkent University, 1996. Thesis (Master's) -- Bilkent University, 1996. Includes bibliographical references leaves leaf 29 In thi.s work, we studierl the Ergodicilv of Non-Stationary .Markov chains. We gave several e.xainples with different cases. We proved that given a sec[uence of Markov chains such that the limit of this sec|uence is an Ergodic Markov chain, then the limit of the combination ...
Radio-Oxidation in Polyolefins: Non-Stationary Kinetic Conditions
International Nuclear Information System (INIS)
Dely, N.
2006-01-01
In the last fifty years, many authors have been interested in the radio-oxidation processes occurring in polymers. The polymer degradation under ionising radiations in presence of dioxygen is well described by a radical chemistry. The radio-oxidation process occurs in three steps: the first one is the production of radicals P degree by interaction between the polymer and the ionising radiations; then radicals P degree react spontaneously with O 2 solved in the polymer giving a peroxy radical POO degree which attacks the polymer forming a hydroperoxide POOH and a new radical P degree (propagation). The third step corresponds to the termination step, that is bimolecular reactions between radicals. It is generally assumed that the stationary state is rapidly reached and consequently that the oxidation induced during the built-up period of the radical concentration can be neglected. However, to our best knowledge, the temporal evolution of radical concentrations before reaching the steady state regime has never been studied in details. We recently performed a complete study of oxygen consumption under electron irradiation for an EPDM elastomer. An analysis, as function of dose rate and oxygen pressure, and assuming steady state conditions, allowed extracting all the kinetic constants. Starting for these experimental data, we calculated the build-up of the radical concentration by solving numerically the differential equations with help of the Minichem code. We conclude that, in fact, the oxidation induced during the built-up period is negligible. In this paper we show that [P degree] could present a quasi-stationary plateau before reaching its stationary level. Consequently, the full radical time evolution is essentially determined by two characteristic times for reaching the quasi and stationary levels and three concentrations: [P degree] and [POO degree] at the stationary level and [P degree] at the quasi-stationary plateau. We show that realistic approximations can
Climatic feedbacks between stationary and transient eddies
International Nuclear Information System (INIS)
Branscome, L.E.
1994-01-01
Stationary eddies make a significant contribution to poleward heat transport during Northern Hemisphere winter, equaling the transport by transient eddies. On the other hand, stationary eddy transport during the summer is negligible. The effect of topography on time-mean stationary waves and low-frequency variability has been widely studied. In contrast, little attention has been given to the climatic feedbacks associated with stationary eddies. Furthermore, the relationship between stationary and transient eddies in the context of global and regional climate is not well understood. The response of the climate system to anthropogenic forcing is likely to have some dependence on stationary wave transport and its interaction with transient eddies. Some early GCM simulations and observational analyses indicate a strong feedback between the meridional heat fluxes of stationary and transient eddies
Quantum cosmology and stationary states
International Nuclear Information System (INIS)
Padmanabhan, T.
1983-01-01
A model for quantum gravity, in which the conformal part of the metric is quantized using the path integral formalism, is presented. Einstein's equations can be suitably modified to take into account the effects of quantum conformal fluctuations. A closed Friedman model can be described in terms of well-defined stationary states. The ''ground state'' sets a lower bound (at Planck length) to the scale factor preventing the collapse. A possible explanation for matter creation and quantum nature of matter is suggested. (author)
Ariyaratne, A T
1989-01-01
Embodied in the child survival revolution are ideological, methodological, and organizational innovations aimed at radical change in the condition of the world's children as rapidly as possible. In countries such as Sri Lanka, child survival and health for all by the year 2000 often seem to be impossible goals, given the tumultuous socioeconomic and political conditions. In Sri Lanka, the quality of life has been eroded, not enhanced, by the importation of Western technology and managerial capitalism and the destruction of indigenous processes. The chaos and violence that have been brought into the country have made it difficult to reach the poor children, women, and refugees in rural areas with primary health care interventions. Sri Lanka's unreachable--the decision making elites--have blocked access to the unreached--the urban and rural poor. If governments are to reach the unreached, they must remove the obstacles to a people-centered, community development process. It is the people themselves, and the institutions of their creation, that can reach the children amidst them in greatest need. To achieve this task, local communities must be provided with basic human rights, the power to make decisions that affect their lives, necessary resources, and appropriate technologies. Nongovernmental organizations can play a crucial role as bridges between the unreached and the unreachable by promoting community empowerment, aiding in the formation of networks of community organizations, and establishing linkages with government programs. If the ruling elites in developing countries can be persuaded to accommodate the needs and aspirations of those who, to date, have been excluded from the development process, the child survival revolution can be a nonviolent one.
Solar Hydrogen Reaching Maturity
Directory of Open Access Journals (Sweden)
Rongé Jan
2015-09-01
Full Text Available Increasingly vast research efforts are devoted to the development of materials and processes for solar hydrogen production by light-driven dissociation of water into oxygen and hydrogen. Storage of solar energy in chemical bonds resolves the issues associated with the intermittent nature of sunlight, by decoupling energy generation and consumption. This paper investigates recent advances and prospects in solar hydrogen processes that are reaching market readiness. Future energy scenarios involving solar hydrogen are proposed and a case is made for systems producing hydrogen from water vapor present in air, supported by advanced modeling.
David, L
1996-05-01
The distant shores of Mars were reached by numerous U.S. and Russian spacecraft throughout the 1960s to mid 1970s. Nearly 20 years have passed since those successful missions which orbited and landed on the Martian surface. Two Soviet probes headed for the planet in July, 1988, but later failed. In August 1993, the U.S. Mars Observer suddenly went silent just three days before it was to enter orbit around the planet and was never heard from again. In late 1996, there will be renewed activity on the launch pads with three probes departing for the red planet: 1) The U.S. Mars Global Surveyor will be launched in November on a Delta II rocket and will orbit the planet for global mapping purposes; 2) Russia's Mars '96 mission, scheduled to fly in November on a Proton launcher, consists of an orbiter, two small stations which will land on the Martian surface, and two penetrators that will plow into the terrain; and finally, 3) a U.S. Discovery-class spacecraft, the Mars Pathfinder, has a December launch date atop a Delta II booster. The mission features a lander and a microrover that will travel short distances over Martian territory. These missions usher in a new phase of Mars exploration, setting the stage for an unprecedented volley of spacecraft that will orbit around, land on, drive across, and perhaps fly at low altitudes over the planet.
BROOKHAVEN: Proton goal reached
International Nuclear Information System (INIS)
Anon.
1995-01-01
On March 30 the 35-year old Alternating Gradient Synchrotron (AGS) exceeded its updated design goal of 6 x 10 13 protons per pulse (ppp), by accelerating 6.3 x 10 13 ppp, a world record intensity. This goal was set 11 years ago and achieving it called for the construction of a new booster and the reconstruction of much of the AGS. The booster was completed in 1991, and reached its design intensity of 1.5 x 10 13 ppp in 1993. The AGS reconstruction was finished in 1994, and by July of that year the AGS claimed a new US record intensity for a proton synchrotron of 4 x 10 13 ppp, using four booster pulses. Reaching the design intensity was scheduled for 1995. In 1994, the AGS had seemed to be solidly limited to 4 x 10 13 ppp, but in 1995 the operations crew, working on their own in the quiet of the owl shift, steadily improved the intensity, regularly setting new records, much to the bemusement of the machine physicists. The physicists, however, did contribute. A second harmonic radiofrequency cavity in the booster increased the radiofrequency bucket area for capture, raising the booster intensity from 1.7 to 2.1 x 10 13 ppp. In the AGS, new radiofrequency power supplies raised the available voltage from 8 to 13 kV, greatly enhancing the beam loading capabilities of the system. A powerful new transverse damping system successfully controlled instabilities that otherwise would have destroyed the beam in less than a millisecond. Also in the AGS, 35th harmonic octupole resonances were found
BROOKHAVEN: Proton goal reached
Energy Technology Data Exchange (ETDEWEB)
Anon.
1995-09-15
On March 30 the 35-year old Alternating Gradient Synchrotron (AGS) exceeded its updated design goal of 6 x 10{sup 13} protons per pulse (ppp), by accelerating 6.3 x 10{sup 13} ppp, a world record intensity. This goal was set 11 years ago and achieving it called for the construction of a new booster and the reconstruction of much of the AGS. The booster was completed in 1991, and reached its design intensity of 1.5 x 10{sup 13} ppp in 1993. The AGS reconstruction was finished in 1994, and by July of that year the AGS claimed a new US record intensity for a proton synchrotron of 4 x 10{sup 13} ppp, using four booster pulses. Reaching the design intensity was scheduled for 1995. In 1994, the AGS had seemed to be solidly limited to 4 x 10{sup 13} ppp, but in 1995 the operations crew, working on their own in the quiet of the owl shift, steadily improved the intensity, regularly setting new records, much to the bemusement of the machine physicists. The physicists, however, did contribute. A second harmonic radiofrequency cavity in the booster increased the radiofrequency bucket area for capture, raising the booster intensity from 1.7 to 2.1 x 10{sup 13} ppp. In the AGS, new radiofrequency power supplies raised the available voltage from 8 to 13 kV, greatly enhancing the beam loading capabilities of the system. A powerful new transverse damping system successfully controlled instabilities that otherwise would have destroyed the beam in less than a millisecond. Also in the AGS, 35th harmonic octupole resonances were found.
Scaling law of resistance fluctuations in stationary random resistor networks
Pennetta; Trefan; Reggiani
2000-12-11
In a random resistor network we consider the simultaneous evolution of two competing random processes consisting in breaking and recovering the elementary resistors with probabilities W(D) and W(R). The condition W(R)>W(D)/(1+W(D)) leads to a stationary state, while in the opposite case, the broken resistor fraction reaches the percolation threshold p(c). We study the resistance noise of this system under stationary conditions by Monte Carlo simulations. The variance of resistance fluctuations is found to follow a scaling law |p-p(c)|(-kappa(0)) with kappa(0) = 5.5. The proposed model relates quantitatively the defectiveness of a disordered media with its electrical and excess-noise characteristics.
Strong Stationary Duality for Diffusion Processes
Fill, James Allen; Lyzinski, Vince
2014-01-01
We develop the theory of strong stationary duality for diffusion processes on compact intervals. We analytically derive the generator and boundary behavior of the dual process and recover a central tenet of the classical Markov chain theory in the diffusion setting by linking the separation distance in the primal diffusion to the absorption time in the dual diffusion. We also exhibit our strong stationary dual as the natural limiting process of the strong stationary dual sequence of a well ch...
Mexican agencies reach teenagers.
Brito Lemus, R; Beamish, J
1992-08-01
The Gente Joven project of the Mexican Foundation for Family Planning (MEXFAM) trains young volunteers in 19 cities to spread messages about sexually transmitted diseases and population growth to their peers. They also distribute condoms and spermicides. It also uses films and materials to spread its messages. The project would like to influence young men's behavior, but the Latin image of machismo poses a big challenge. It would like to become more responsible toward pregnancy prevention. About 50% of adolescents have sexual intercourse, but few use contraceptives resulting in a high adolescent pregnancy rate. Many of these pregnant teenagers choose not to marry. Adolescent pregnancy leads to girls leaving school, few marketable skills, and rearing children alone. Besides women who began childbearing as a teenager have 1.5 times more children than other women. Male involvement in pregnancy prevention should improve these statistics. As late as 1973, the Health Code banned promotion and sales of contraceptives, but by 1992 about 50% of women of reproductive age use contraceptives. The Center for the Orientation of Adolescents has organized 8 Young Men's Clubs in Mexico City to involve male teenagers more in family planning and to develop self-confidence. It uses a holistic approach to their development through discussions with their peers. A MEXFAM study shows that young men are not close with their fathers who tend to exude a machismo attitude, thus the young men do not have a role model for responsible sexual behavior. MEXFAM's work is cut out for them, however, since the same study indicates that 50% of the young men believe it is fine to have 1 girlfriend and 33% think women should earn more than men. A teenager volunteer reports, however, that more boys have been coming to him for contraception and information than girls in 1992 while in other years girls outnumbered the boys.
Growth of microalgae in autotrophic stationary systems
Directory of Open Access Journals (Sweden)
Paulo Cunha
2008-06-01
Full Text Available In this paper we evaluate the growth of nine marine microalgae species (Nannochloropsis oculata, Thalassiosira pseudonana, Phaeodactylum tricornutum, Isochrysis galbana, Tetraselmis suecica, Tetraselmis chuii, Chaetoceros muelleri, Thalassiosira fluviatilis and Isochrysis sp. and one freshwater species (Chlorella vulgaris under stationary autotrophy conditions, using erlenmeyers fl asks with 800mL of culture medium exposed to constant light intensities providing a photon flux density of about 150μmol.m-2.s-1 and 25±2oC temperature and constant air flow. The experiment was carried out in a controlled environment considering a block delineating randomized over time with three replicates. The Nannochloropsis oculata showed the highest value of maximum cellular density, but with a longer period of time and a lower growth rate. This was probably due to its tiny cell size, demanding a large number of cells per volume to attain its optimum conditions for light, nutrients, water and atmospheric carbon dioxide. In addition, in spite of showing one of the lowest values of maximum cellular density, Thalassiosira fluviatilis was the species that reached its maximum in a short period of time at the highest growth rate. Chlorella vulgaris was the only freshwater species tested and it showed the poorest performance for all the variables analyzed in the current study.
Condensational theory of stationary tornadoes
International Nuclear Information System (INIS)
Makarieva, A.M.; Gorshkov, V.G.; Nefiodov, A.V.
2011-01-01
Using the Bernoulli integral for air streamline with condensing water vapor a stationary axisymmetric tornado circulation is described. The obtained profiles of vertical, radial and tangential velocities are in agreement with observations for the Mulhall tornado, world's largest on record and longest-lived among the three tornadoes for which 3D velocity data are available. Maximum possible vortex velocities are estimated. -- Highlights: → Water vapor condensation causes a logarithmic drop of air pressure towards tornado center. → The first ever theoretical description of tornado velocities is obtained. → The maximum vortex velocity grows logarithmically with decreasing tornado eye radius. → Air motion with high velocities can only develop in sufficiently large condensation areas.
Baker, Mariah; Rosenthal, L.; Gaughan, A.; Hopkins, E.
2014-01-01
Strawbridge Observatory at Haverford College is home to a undergraduate-led public observing program. Our program holds ~once monthly public events throughout the academic year that take advantage of eyepiece observing on our 16-inch and 12-inch telescopes as well as of the classroom, library, and projection system. These resources allow us to organize a variety of astronomy related activities that are engaging for individuals of all ages: accessible student talks, current film screenings and even arts and crafts for the families who attend with young children. These events aim to spark curiosity in others about scientific discovery and about the remarkable nature of the world in which we live. In addition to exciting local families about astronomy, this program has excited Haverford students from a range of disciplines about both science and education. Being entirely student led means that we are able to take the initiative in planning, coordinating and running all events, fostering an atmosphere of collaboration, experimentation and commitment amongst our volunteers. Additionally, this program is one of the few at Haverford that regularly reaches beyond the campus walls to promote and build relationships with the outside community. In light of this, our program presents a distinctive and enlightening opportunity for student volunteers: we get to use our scientific backgrounds to educate a general audience, while also learning from them about how to communicate and inspire in others the excitement we feel about the subject of astronomy. The work on this project has been supported by NSF AST-1151462.
Lewis-Fernández, Roberto; Raggio, Greer A.; Gorritz, Magdaliz; Duan, Naihua; Marcus, Sue; Cabassa, Leopoldo J.; Humensky, Jennifer; Becker, Anne E.; Alarcón, Renato D.; Oquendo, María A.; Hansen, Helena; Like, Robert C.; Weiss, Mitchell; Desai, Prakash N.; Jacobsen, Frederick M.; Foulks, Edward F.; Primm, Annelle; Lu, Francis; Kopelowicz, Alex; Hinton, Ladson; Hinton, Devon E.
2015-01-01
Growing awareness of health and health care disparities highlights the importance of including information about race, ethnicity, and culture (REC) in health research. Reporting of REC factors in research publications, however, is notoriously imprecise and unsystematic. This article describes the development of a checklist to assess the comprehensiveness and the applicability of REC factor reporting in psychiatric research publications. The 16-itemGAP-REACH© checklist was developed through a rigorous process of expert consensus, empirical content analysis in a sample of publications (N = 1205), and interrater reliability (IRR) assessment (N = 30). The items assess each section in the conventional structure of a health research article. Data from the assessment may be considered on an item-by-item basis or as a total score ranging from 0% to 100%. The final checklist has excellent IRR (κ = 0.91). The GAP-REACH may be used by multiple research stakeholders to assess the scope of REC reporting in a research article. PMID:24080673
2001-01-01
The creation of the world's largest sandstone cavern, not a small feat! At the bottom, cave-in preventing steel mesh can be seen clinging to the top of the tunnel. The digging of UX-15, the cavern that will house ATLAS, reached the upper ceiling of LEP on October 10th. The breakthrough which took place nearly 100 metres underground occurred precisely on schedule and exactly as planned. But much caution was taken beforehand to make the LEP breakthrough clean and safe. To prevent the possibility of cave-ins in the side tunnels that will eventually be attached to the completed UX-15 cavern, reinforcing steel mesh was fixed into the walls with bolts. Obviously no people were allowed in the LEP tunnels below UX-15 as the breakthrough occurred. The area was completely evacuated and fences were put into place to keep all personnel out. However, while personnel were being kept out of the tunnels below, this has been anything but the case for the work taking place up above. With the creation of the world's largest...
Only adding stationary storage to vaccine supply chains may create and worsen transport bottlenecks.
Haidari, Leila A; Connor, Diana L; Wateska, Angela R; Brown, Shawn T; Mueller, Leslie E; Norman, Bryan A; Schmitz, Michelle M; Paul, Proma; Rajgopal, Jayant; Welling, Joel S; Leonard, Jim; Claypool, Erin G; Weng, Yu-Ting; Chen, Sheng-I; Lee, Bruce Y
2013-01-01
Although vaccine supply chains in many countries require additional stationary storage and transport capacity to meet current and future needs, international donors tend to donate stationary storage devices far more often than transport equipment. To investigate the impact of only adding stationary storage equipment on the capacity requirements of transport devices and vehicles, we used HERMES (Highly Extensible Resource for Modeling Supply Chains) to construct a discrete event simulation model of the Niger vaccine supply chain. We measured the transport capacity requirement for each mode of transport used in the Niger vaccine cold chain, both before and after adding cold rooms and refrigerators to relieve all stationary storage constraints in the system. With the addition of necessary stationary storage, the average transport capacity requirement increased from 88% to 144% for cold trucks, from 101% to 197% for pickup trucks, and from 366% to 420% for vaccine carriers. Therefore, adding stationary storage alone may worsen or create new transport bottlenecks as more vaccines flow through the system, preventing many vaccines from reaching their target populations. Dynamic modeling can reveal such relationships between stationary storage capacity and transport constraints.
Cappell, M S; Spray, D C; Bennett, M V
1988-06-28
Protractor muscles in the gastropod mollusc Navanax inermis exhibit typical spontaneous miniature end plate potentials with mean amplitude 1.71 +/- 1.19 (standard deviation) mV. The evoked end plate potential is quantized, with a quantum equal to the miniature end plate potential amplitude. When their rate is stationary, occurrence of miniature end plate potentials is a random, Poisson process. When non-stationary, spontaneous miniature end plate potential occurrence is a non-stationary Poisson process, a Poisson process with the mean frequency changing with time. This extends the random Poisson model for miniature end plate potentials to the frequently observed non-stationary occurrence. Reported deviations from a Poisson process can sometimes be accounted for by the non-stationary Poisson process and more complex models, such as clustered release, are not always needed.
Impact of the Injection Protocol on an Impurity's Stationary State
Gamayun, Oleksandr; Lychkovskiy, Oleg; Burovski, Evgeni; Malcomson, Matthew; Cheianov, Vadim V.; Zvonarev, Mikhail B.
2018-06-01
We examine stationary-state properties of an impurity particle injected into a one-dimensional quantum gas. We show that the value of the impurity's end velocity lies between zero and the speed of sound in the gas and is determined by the injection protocol. This way, the impurity's constant motion is a dynamically emergent phenomenon whose description goes beyond accounting for the kinematic constraints of the Landau approach to superfluidity. We provide exact analytic results in the thermodynamic limit and perform finite-size numerical simulations to demonstrate that the predicted phenomena are within the reach of the ultracold gas experiments.
Noise Diagnostics of Stationary and Non-Stationary Reactor Processes
Energy Technology Data Exchange (ETDEWEB)
Sunde, Carl
2007-04-15
This thesis concerns the application of noise diagnostics on different problems in the area of reactor physics involving both stationary and non-stationary core processes. Five different problems are treated, divided into three different parts. The first problem treated in the first part is the classification of two-phase flow regimes from neutron radiographic and visible light images with a neuro-wavelet algorithm. The algorithm consists of wavelet pre-processing and of an artificial neural network. The result indicates that the wavelet pre-processing is improving the training of the neural network. Next, detector tubes which are suspected of impacting on nearby fuel-assemblies in a boiling water reactor (BWR) are identified by both a classical spectral method and wavelet-based methods. It was found that there is good agreement between the different methods as well as with visual inspections of detector tube and fuel assembly damage made during the outage at the plant. The third problem addresses the determination of the decay ratio of a BWR from the auto-correlation function (ACF). Here wavelets are used, with some success, both for de-trending and de-nosing of the ACF and also for direct estimation of the decay ratio from the ACF. The second part deals with the analysis of beam-mode and shell-mode core-barrel vibrations in pressurised water reactors (PWRs). The beam-mode vibrations are analysed by using parameters of the vibration peaks, in spectra from ex core detectors. A trend analysis of the peak amplitude shows that the peak amplitude is changing during the fuel cycle. When it comes to the analysis of the shell-mode vibration, 1-D analytical and numerical calculations are performed in order to calculate the neutron noise induced in the core. The two calculations are in agreement and show that a large local noise component is present in the core which could be used to classify the shell-mode vibrations. However, a measurement made in the PWR Ringhals-3 shows
Noise Diagnostics of Stationary and Non-Stationary Reactor Processes
International Nuclear Information System (INIS)
Sunde, Carl
2007-01-01
This thesis concerns the application of noise diagnostics on different problems in the area of reactor physics involving both stationary and non-stationary core processes. Five different problems are treated, divided into three different parts. The first problem treated in the first part is the classification of two-phase flow regimes from neutron radiographic and visible light images with a neuro-wavelet algorithm. The algorithm consists of wavelet pre-processing and of an artificial neural network. The result indicates that the wavelet pre-processing is improving the training of the neural network. Next, detector tubes which are suspected of impacting on nearby fuel-assemblies in a boiling water reactor (BWR) are identified by both a classical spectral method and wavelet-based methods. It was found that there is good agreement between the different methods as well as with visual inspections of detector tube and fuel assembly damage made during the outage at the plant. The third problem addresses the determination of the decay ratio of a BWR from the auto-correlation function (ACF). Here wavelets are used, with some success, both for de-trending and de-nosing of the ACF and also for direct estimation of the decay ratio from the ACF. The second part deals with the analysis of beam-mode and shell-mode core-barrel vibrations in pressurised water reactors (PWRs). The beam-mode vibrations are analysed by using parameters of the vibration peaks, in spectra from ex core detectors. A trend analysis of the peak amplitude shows that the peak amplitude is changing during the fuel cycle. When it comes to the analysis of the shell-mode vibration, 1-D analytical and numerical calculations are performed in order to calculate the neutron noise induced in the core. The two calculations are in agreement and show that a large local noise component is present in the core which could be used to classify the shell-mode vibrations. However, a measurement made in the PWR Ringhals-3 shows
Stationary black holes as holographs
Energy Technology Data Exchange (ETDEWEB)
Racz, Istvan [Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-01 (Japan); MTA KFKI, Reszecske- es Magfizikai Kutatointezet, H-1121 Budapest, Konkoly Thege Miklos ut 29-33 (Hungary)
2007-11-21
Smooth spacetimes possessing a (global) one-parameter group of isometries and an associated Killing horizon in Einstein's theory of gravity are investigated. No assumption concerning the asymptotic structure is made; thereby, the selected spacetimes may be considered as generic distorted stationary black holes. First, spacetimes of arbitrary dimension, n {>=} 3, with matter satisfying the dominant energy condition and allowing a non-zero cosmological constant are investigated. In this part, complete characterization of the topology of the event horizon of 'distorted' black holes is given. It is shown that the topology of the event horizon of 'distorted' black holes is allowed to possess a much larger variety than that of the isolated black hole configurations. In the second part, four-dimensional (non-degenerate) electrovac distorted black hole spacetimes are considered. It is shown that the spacetime geometry and the electromagnetic field are uniquely determined in the black hole region once the geometry of the bifurcation surface and one of the electromagnetic potentials are specified there. Conditions guaranteeing the same type of determinacy, in a neighbourhood of the event horizon, on the domain of outer communication side are also investigated. In particular, they are shown to be satisfied in the analytic case.
HIGH PERFORMANCE STATIONARY DISCHARGES IN THE DIII-D TOKAMAK
International Nuclear Information System (INIS)
Luce, T.C.; Wade, M.R.; Ferron, J.R.; Politzer, P.A.; Hyatt, A.W.; Sips, A.C.C.; Murakami, M.
2003-01-01
Recent experiments in the DIII-D tokamak [J.L. Luxon, Nucl. Fusion 42,614 (2002)] have demonstrated high β with good confinement quality under stationary conditions. Two classes of stationary discharges are observed--low q 95 discharges with sawteeth and higher q 95 without sawteeth. The discharges are deemed stationary when the plasma conditions are maintained for times greater than the current profile relaxation time. In both cases the normalized fusion performance (β N H 89P /q 95 2 ) reaches or exceeds the value of this parameter projected for Q fus = 10 in the International Thermonuclear Experimental Reactor (ITER) design [R. Aymar, et al., Plasma Phys. Control. Fusion 44, 519 (2002)]. The presence of sawteeth reduces the maximum achievable normalized β, while confinement quality (confinement time relative to scalings) is largely independent of q 95 . Even with the reduced β limit, the normalized fusion performance maximizes at the lowest q 95 . Projections to burning plasma conditions are discussed, including the methodology of the projection and the key physics issues which still require investigation
DEFF Research Database (Denmark)
Andersen, Asger Lau; Lassen, David Dreyer; Nielsen, Lasse Holbøll Westh
are negative rather than positive; and when there is divided government. We test the hypotheses of the model using a unique data set of late budgets for US state governments, based on dates of budget approval collected from news reports and a survey of state budget o¢ cers for the period 1988...
Dampers for Stationary Labyrinth Seals
El-Aini, Yehia; Mitchell, William; Roberts, Lawrence; Montgomery, Stuart; Davis, Gary
2011-01-01
Vibration dampers have been invented that are incorporated as components within the stationary labyrinth seal assembly. These dampers are intended to supplement other vibration-suppressing features of labyrinth seals in order to reduce the incidence of high-cycle-fatigue failures, which have been known to occur in the severe vibratory environments of jet engines and turbopumps in which labyrinth seals are typically used. A vibration damper of this type includes several leaf springs and/or a number of metallic particles (shot) all held in an annular seal cavity by a retaining ring. The leaf springs are made of a spring steel alloy chosen, in conjunction with design parameters, to maintain sufficient preload to ensure effectiveness of damping at desired operating temperatures. The cavity is vented via a small radial gap between the retaining ring and seal housing. The damping mechanism is complex. In the case of leaf springs, the mechanism is mainly friction in the slippage between the seal housing and individual dampers. In the case of a damper that contains shot, the damping mechanism includes contributions from friction between individual particles, friction between particles and cavity walls, and dissipation of kinetic energy of impact. The basic concept of particle/shot vibration dampers has been published previously; what is new here is the use of such dampers to suppress traveling-wave vibrations in labyrinth seals. Damping effectiveness depends on many parameters, including, but not limited to, coefficient of friction, mode shape, and frequency and amplitude of vibrational modes. In tests, preloads of the order of 6 to 15 lb (2.72 to 6.8 kilograms) per spring damper were demonstrated to provide adequate damping levels. Effectiveness of shot damping of vibrations having amplitudes from 20 to 200 times normal terrestrial gravitational acceleration (196 to 1,960 meters per square second) and frequencies up to 12 kHz was demonstrated for shot sizes from 0.032 to
Stationary axisymmetric Einstein--Maxwell field equations
International Nuclear Information System (INIS)
Catenacci, R.; Diaz Alonso, J.
1976-01-01
We show the existence of a formal identity between Einstein's and Ernst's stationary axisymmetric gravitational field equations and the Einstein--Maxwell and the Ernst equations for the electrostatic and magnetostatic axisymmetric cases. Our equations are invariant under very simple internal symmetry groups, and one of them appears to be new. We also obtain a method for associating two stationary axisymmetric vacuum solutions with every electrostatic known
Stationary inﬁnitely divisible processes
DEFF Research Database (Denmark)
Barndorff-Nielsen, Ole E.
Several recent strands of work has led to the consideration of various types of continuous time stationary and infinitely divisible processes. A review of these types, with some new results, is presented.......Several recent strands of work has led to the consideration of various types of continuous time stationary and infinitely divisible processes. A review of these types, with some new results, is presented....
Stationary Liquid Fuel Fast Reactor
International Nuclear Information System (INIS)
Yang, Won Sik; Grandy, Andrew; Boroski, Andrew; Krajtl, Lubomir; Johnson, Terry
2015-01-01
For effective burning of hazardous transuranic (TRU) elements of used nuclear fuel, a transformational advanced reactor concept named SLFFR (Stationary Liquid Fuel Fast Reactor) was proposed based on stationary molten metallic fuel. The fuel enters the reactor vessel in a solid form, and then it is heated to molten temperature in a small melting heater. The fuel is contained within a closed, thick container with penetrating coolant channels, and thus it is not mixed with coolant nor flow through the primary heat transfer circuit. The makeup fuel is semi- continuously added to the system, and thus a very small excess reactivity is required. Gaseous fission products are also removed continuously, and a fraction of the fuel is periodically drawn off from the fuel container to a processing facility where non-gaseous mixed fission products and other impurities are removed and then the cleaned fuel is recycled into the fuel container. A reference core design and a preliminary plant system design of a 1000 MWt TRU- burning SLFFR concept were developed using TRU-Ce-Co fuel, Ta-10W fuel container, and sodium coolant. Conservative design approaches were adopted to stay within the current material performance database. Detailed neutronics and thermal-fluidic analyses were performed to develop a reference core design. Region-dependent 33-group cross sections were generated based on the ENDF/B-VII.0 data using the MC2-3 code. Core and fuel cycle analyses were performed in theta-r-z geometries using the DIF3D and REBUS-3 codes. Reactivity coefficients and kinetics parameters were calculated using the VARI3D perturbation theory code. Thermo-fluidic analyses were performed using the ANSYS FLUENT computational fluid dynamics (CFD) code. Figure 0.1 shows a schematic radial layout of the reference 1000 MWt SLFFR core, and Table 0.1 summarizes the main design parameters of SLFFR-1000 loop plant. The fuel container is a 2.5 cm thick cylinder with an inner radius of 87.5 cm. The fuel
Stationary Liquid Fuel Fast Reactor
Energy Technology Data Exchange (ETDEWEB)
Yang, Won Sik [Purdue Univ., West Lafayette, IN (United States); Grandy, Andrew [Argonne National Lab. (ANL), Argonne, IL (United States); Boroski, Andrew [Argonne National Lab. (ANL), Argonne, IL (United States); Krajtl, Lubomir [Argonne National Lab. (ANL), Argonne, IL (United States); Johnson, Terry [Argonne National Lab. (ANL), Argonne, IL (United States)
2015-09-30
For effective burning of hazardous transuranic (TRU) elements of used nuclear fuel, a transformational advanced reactor concept named SLFFR (Stationary Liquid Fuel Fast Reactor) was proposed based on stationary molten metallic fuel. The fuel enters the reactor vessel in a solid form, and then it is heated to molten temperature in a small melting heater. The fuel is contained within a closed, thick container with penetrating coolant channels, and thus it is not mixed with coolant nor flow through the primary heat transfer circuit. The makeup fuel is semi- continuously added to the system, and thus a very small excess reactivity is required. Gaseous fission products are also removed continuously, and a fraction of the fuel is periodically drawn off from the fuel container to a processing facility where non-gaseous mixed fission products and other impurities are removed and then the cleaned fuel is recycled into the fuel container. A reference core design and a preliminary plant system design of a 1000 MWt TRU- burning SLFFR concept were developed using TRU-Ce-Co fuel, Ta-10W fuel container, and sodium coolant. Conservative design approaches were adopted to stay within the current material performance database. Detailed neutronics and thermal-fluidic analyses were performed to develop a reference core design. Region-dependent 33-group cross sections were generated based on the ENDF/B-VII.0 data using the MC2-3 code. Core and fuel cycle analyses were performed in theta-r-z geometries using the DIF3D and REBUS-3 codes. Reactivity coefficients and kinetics parameters were calculated using the VARI3D perturbation theory code. Thermo-fluidic analyses were performed using the ANSYS FLUENT computational fluid dynamics (CFD) code. Figure 0.1 shows a schematic radial layout of the reference 1000 MWt SLFFR core, and Table 0.1 summarizes the main design parameters of SLFFR-1000 loop plant. The fuel container is a 2.5 cm thick cylinder with an inner radius of 87.5 cm. The fuel
Mitavskiy, Boris; Cannings, Chris
2009-01-01
The evolutionary algorithm stochastic process is well-known to be Markovian. These have been under investigation in much of the theoretical evolutionary computing research. When the mutation rate is positive, the Markov chain modeling of an evolutionary algorithm is irreducible and, therefore, has a unique stationary distribution. Rather little is known about the stationary distribution. In fact, the only quantitative facts established so far tell us that the stationary distributions of Markov chains modeling evolutionary algorithms concentrate on uniform populations (i.e., those populations consisting of a repeated copy of the same individual). At the same time, knowing the stationary distribution may provide some information about the expected time it takes for the algorithm to reach a certain solution, assessment of the biases due to recombination and selection, and is of importance in population genetics to assess what is called a "genetic load" (see the introduction for more details). In the recent joint works of the first author, some bounds have been established on the rates at which the stationary distribution concentrates on the uniform populations. The primary tool used in these papers is the "quotient construction" method. It turns out that the quotient construction method can be exploited to derive much more informative bounds on ratios of the stationary distribution values of various subsets of the state space. In fact, some of the bounds obtained in the current work are expressed in terms of the parameters involved in all the three main stages of an evolutionary algorithm: namely, selection, recombination, and mutation.
Henry, Tom F. K.; Joannides, Paul; González Mozo, Ana; Martín, Bruno
2012-01-01
Exhibition catalogue (co-authored with P. Joannides) in English, Spanish and French by the Museo del Prado and the Musée du Louvre, 2012. English edition, publisher: Museo Nacional del Prado (ISBN 978-84-8480-237-2). 382 pages, of which 300 were co-authored with P. Joannides. This publication was the catalogue of the major exhibtion of Raphael's late work which was at the Prado and the Louvre in 2012-13. The exhibition was seen by more than 650,000 visitors, and was widely reviewed in the int...
Analyzing Non Stationary Processes in Radiometers
Racette, Paul
2010-01-01
The lack of well-developed techniques for modeling changing statistical moments in our observations has stymied the application of stochastic process theory for many scientific and engineering applications. Non linear effects of the observation methodology is one of the most perplexing aspects to modeling non stationary processes. This perplexing problem was encountered when modeling the effect of non stationary receiver fluctuations on the performance of radiometer calibration architectures. Existing modeling approaches were found not applicable; particularly problematic is modeling processes across scales over which they begin to exhibit non stationary behavior within the time interval of the calibration algorithm. Alternatively, the radiometer output is modeled as samples from a sequence random variables; the random variables are treated using a conditional probability distribution function conditioned on the use of the variable in the calibration algorithm. This approach of treating a process as a sequence of random variables with non stationary stochastic moments produce sensible predictions of temporal effects of calibration algorithms. To test these model predictions, an experiment using the Millimeter wave Imaging Radiometer (MIR) was conducted. The MIR with its two black body calibration references was configured in a laboratory setting to observe a third ultra-stable reference (CryoTarget). The MIR was programmed to sequentially sample each of the three references in approximately a 1 second cycle. Data were collected over a six-hour interval. The sequence of reference measurements form an ensemble sample set comprised of a series of three reference measurements. Two references are required to estimate the receiver response. A third reference is used to estimate the uncertainty in the estimate. Typically, calibration algorithms are designed to suppress the non stationary effects of receiver fluctuations. By treating the data sequence as an ensemble
Stability and instability of stationary solutions for sublinear parabolic equations
Kajikiya, Ryuji
2018-01-01
In the present paper, we study the initial boundary value problem of the sublinear parabolic equation. We prove the existence of solutions and investigate the stability and instability of stationary solutions. We show that a unique positive and a unique negative stationary solutions are exponentially stable and give the exact exponent. We prove that small stationary solutions are unstable. For one space dimensional autonomous equations, we elucidate the structure of stationary solutions and study the stability of all stationary solutions.
Towards Gravitating Discs around Stationary Black Holes
Semerák, Oldřich
This article outlines the search for an exact general relativistic description of the exterior(vacuum) gravitational field of a rotating spheroidal black hole surrounded by a realistic axially symmetric disc of matter. The problem of multi-body stationary spacetimes is first exposed from the perspective of the relativity theory (section 1) and astrophysics (section 2), listing the basic methods employed and results obtained. Then (in section 3) basic formulas for stationary axisymmetric solutions are summarized. Sections 4 and 5 review what we have learnt with Miroslav Žáček and Tomáš Zellerin about certain static and stationary situations recently. Concluding remarks are given in section 6. Although the survey part is quite general, the list of references cannot be complete.Our main desideratum was the informative value rather than originality — novelties have been preferred, mainly reviews and those with detailed introductions.
Stationary Double Layers in a Collisionless Magnetoplasma
DEFF Research Database (Denmark)
Noriyoshi, Sato; Mieno, Tetsu; Hatakeyama, Rikizo
1983-01-01
of the plate on the low-potential side, being accompanied with current limitation. This localized potential drop moves along the plasma column, but finally stops and results in the formation of the stationary double layer in the presence of sufficient plasma supply from the plate on the high-potential side.......Stationary double layers are generated in a magnetoplasma by applying potential differences between two heated plates on which the plasma is produced by surface ionization. By measuring the double-layer formation process, a localized potential drop is found to be formed initially in front...
Reaching ignition in the tokamak
International Nuclear Information System (INIS)
Furth, H.P.
1985-06-01
This review covers the following areas: (1) the physics of burning plasmas, (2) plasma physics requirements for reaching ignition, (3) design studies for ignition devices, and (4) prospects for an ignition project
A Two-Dimensional Solar Tracking Stationary Guidance Method Based on Feature-Based Time Series
Directory of Open Access Journals (Sweden)
Keke Zhang
2018-01-01
Full Text Available The amount of satellite energy acquired has a direct impact on operational capacities of the satellite. As for practical high functional density microsatellites, solar tracking guidance design of solar panels plays an extremely important role. Targeted at stationary tracking problems incurred in a new system that utilizes panels mounted in the two-dimensional turntable to acquire energies to the greatest extent, a two-dimensional solar tracking stationary guidance method based on feature-based time series was proposed under the constraint of limited satellite attitude coupling control capability. By analyzing solar vector variation characteristics within an orbit period and solar vector changes within the whole life cycle, such a method could be adopted to establish a two-dimensional solar tracking guidance model based on the feature-based time series to realize automatic switching of feature-based time series and stationary guidance under the circumstance of different β angles and the maximum angular velocity control, which was applicable to near-earth orbits of all orbital inclination. It was employed to design a two-dimensional solar tracking stationary guidance system, and a mathematical simulation for guidance performance was carried out in diverse conditions under the background of in-orbit application. The simulation results show that the solar tracking accuracy of two-dimensional stationary guidance reaches 10∘ and below under the integrated constraints, which meet engineering application requirements.
Main principles of development stationary training facilities
International Nuclear Information System (INIS)
Tsiptsyura, R.D.
1986-01-01
The designation of stationary training facilities is shown and the main requirements for them are formulated. When considering the above-mentioned requirements, special attention was paid to obligatory correspondence between training experience and practical skill of an operator. It is shown, that the switchboard block is the major unit of the training facility, which should develop skills and habits of an operator
Stone Stability under Stationary Nonuniform Flows
Steenstra, Remco; Hofland, B.; Paarlberg, Andries; Smale, Alfons; Huthoff, Fredrik; Uijttewaal, W.S.J.
2016-01-01
A stability parameter for rock in bed protections under nonuniform stationary flow is derived. The influence of the mean flow velocity, turbulence, and mean acceleration of the flow are included explicitly in the parameter. The relatively new notion of explicitly incorporating the mean acceleration
New interval forecast for stationary autoregressive models ...
African Journals Online (AJOL)
In this paper, we proposed a new forecasting interval for stationary Autoregressive, AR(p) models using the Akaike information criterion (AIC) function. Ordinarily, the AIC function is used to determine the order of an AR(p) process. In this study however, AIC forecast interval compared favorably with the theoretical forecast ...
Relativistic elasticity of stationary fluid branes
DEFF Research Database (Denmark)
Armas, J.; Obers, N.A.
2013-01-01
under certain conditions that a given stationary fluid configuration living on a dynamical surface of vanishing thickness and satisfying locally the first law of thermodynamics will behave like an elastic brane when the surface is subject to small deformations. These results, which are independent...
Characterization of Stationary Distributions of Reflected Diffusions
2014-01-01
operations research to finance and mathemat- ical physics , and their stationary distributions often serve to characterize or approximate important...REFERENCES [1] Atar , R., Budhiraja, A. and Dupuis, P. (2001). On positive recurrence of constrained diffusion processes. Ann. Probab., 29 No. 2, 979-1000
The stationary states of interacting fields
Frazer, W.R.; Hove, Léon van
1958-01-01
As an application of a time-independent perturbation formalism developed earlier for systems with many degrees of freedom, we give in terms of diagrams the general perturbation expressions for the exact stationary states of interacting fields. The physical vacuum is obtained by applying to the bare
Calendar Year 2016 Stationary Source Emissions Inventory
Energy Technology Data Exchange (ETDEWEB)
Evelo, Stacie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
2017-01-01
The City of Albuquerque (COA) Environmental Health Department Air Quality Program has issued stationary source permits and registrations the Department of Energy/Sandia Field Office for operations at the Sandia National Laboratories/New Mexico. This emission inventory report meets the annual reporting compliance requirements for calendar year (CY) 2016 as required by the COA.
Chaotic Bohmian trajectories for stationary states
International Nuclear Information System (INIS)
Cesa, Alexandre; Martin, John; Struyve, Ward
2016-01-01
In Bohmian mechanics, the nodes of the wave function play an important role in the generation of chaos. However, so far, most of the attention has been on moving nodes; little is known about the possibility of chaos in the case of stationary nodes. We address this question by considering stationary states, which provide the simplest examples of wave functions with stationary nodes. We provide examples of stationary wave functions for which there is chaos, as demonstrated by numerical computations, for one particle moving in three spatial dimensions and for two and three entangled particles in two dimensions. Our conclusion is that the motion of the nodes is not necessary for the generation of chaos. What is important is the overall complexity of the wave function. That is, if the wave function, or rather its phase, has a complex spatial variation, it will lead to complex Bohmian trajectories and hence to chaos. Another aspect of our work concerns the average Lyapunov exponent, which quantifies the overall amount of chaos. Since it is very hard to evaluate the average Lyapunov exponent analytically, which is often computed numerically, it is useful to have simple quantities that agree well with the average Lyapunov exponent. We investigate possible correlations with quantities such as the participation ratio and different measures of entanglement, for different systems and different families of stationary wave functions. We find that these quantities often tend to correlate to the amount of chaos. However, the correlation is not perfect, because, in particular, these measures do not depend on the form of the basis states used to expand the wave function, while the amount of chaos does. (paper)
Framework for Assessing Biogenic CO2 Emissions from Stationary Sources
This revision of the 2011 report, Accounting Framework for Biogenic CO2 Emissions from Stationary Sources, evaluates biogenic CO2 emissions from stationary sources, including a detailed study of the scientific and technical issues associated with assessing biogenic carbon dioxide...
Learning Markov models for stationary system behaviors
DEFF Research Database (Denmark)
Chen, Yingke; Mao, Hua; Jaeger, Manfred
2012-01-01
to a single long observation sequence, and in these situations existing automatic learning methods cannot be applied. In this paper, we adapt algorithms for learning variable order Markov chains from a single observation sequence of a target system, so that stationary system properties can be verified using......Establishing an accurate model for formal verification of an existing hardware or software system is often a manual process that is both time consuming and resource demanding. In order to ease the model construction phase, methods have recently been proposed for automatically learning accurate...... the learned model. Experiments demonstrate that system properties (formulated as stationary probabilities of LTL formulas) can be reliably identified using the learned model....
Stationary nonimaging lenses for solar concentration.
Kotsidas, Panagiotis; Chatzi, Eleni; Modi, Vijay
2010-09-20
A novel approach for the design of refractive lenses is presented, where the lens is mounted on a stationary aperture and the Sun is tracked by a moving solar cell. The purpose of this work is to design a quasi-stationary concentrator by replacing the two-axis tracking of the Sun with internal motion of the miniaturized solar cell inside the module. Families of lenses are designed with a variation of the simultaneous multiple surface technique in which the sawtooth genetic algorithm is implemented to optimize the geometric variables of the optic in order to produce high fluxes for a range of incidence angles. Finally, we show examples of the technique for lenses with 60° and 30° acceptance half-angles, with low to medium attainable concentrations.
Relativistic elasticity of stationary fluid branes
Armas, Jay; Obers, Niels A.
2013-02-01
Fluid mechanics can be formulated on dynamical surfaces of arbitrary codimension embedded in a background space-time. This has been the main object of study of the blackfold approach in which the emphasis has primarily been on stationary fluid configurations. Motivated by this approach we show under certain conditions that a given stationary fluid configuration living on a dynamical surface of vanishing thickness and satisfying locally the first law of thermodynamics will behave like an elastic brane when the surface is subject to small deformations. These results, which are independent of the number of space-time dimensions and of the fluid arising from a gravitational dual, reveal the (electro)elastic character of (charged) black branes when considering extrinsic perturbations.
Danish emission inventories for stationary combustion plants
DEFF Research Database (Denmark)
Nielsen, M.; Illerup, J. B.
Emission inventories for stationary combustion plants are presented and the methodologies and assumptions used for the inventories are described. The pollutants considered are: SO2, NOx, NMVOC, CH4, CO, CO2, N2O, particulate matter, heavy metals, dioxins and PAH. Since 1990 the fuel consumption...... in stationary combustion has increased by 12% - the fossil fuel consumption however only by 6%. Despite the increased fuel consumption the emission of several pollutants have decreased due to the improved flue gas cleaning technology, improved burner technology and the change of fuel type used. A considerable...... plants. The emission of PAH increased as a result of the increased combustion of wood in residential boilers and stoves. Uncertainties for the emissions and trends have been estimated....
Danish emission inventories for stationary combustion plants
DEFF Research Database (Denmark)
Nielsen, M.; Illerup, J. B.
Emission inventories for stationary combustion plants are presented and the methodologies and assumptions used for the inventories are described. The pollutants considered are SO2, NOX, NMVOC, CH4, CO, CO2, N2O, particulate matter, heavy metals, dioxins and PAH. Since 1990 the fuel consumption...... in stationary combustion has increased by 14% - the fossil fuel consumption however only by 8%. Despite the increased fuel consumption the emission of several pollutants has decreased due to the improved flue gas cleaning technology, improved burner technology and the change of fuel type used. A considerable...... plants. The emission of PAH increased as a result of the increased combustion of wood in residential boilers and stoves. Uncertainties for the emissions and trends have been estimated...
Solar radiation on Mars: Stationary photovoltaic array
Appelbaum, J.; Sherman, I.; Landis, G. A.
1993-01-01
Solar energy is likely to be an important power source for surface-based operation on Mars. Photovoltaic cells offer many advantages. In this article we have presented analytical expressions and solar radiation data for stationary flat surfaces (horizontal and inclined) as a function of latitude, season and atmospheric dust load (optical depth). The diffuse component of the solar radiation on Mars can be significant, thus greatly affecting the optimal inclination angle of the photovoltaic surface.
Covariance matrix estimation for stationary time series
Xiao, Han; Wu, Wei Biao
2011-01-01
We obtain a sharp convergence rate for banded covariance matrix estimates of stationary processes. A precise order of magnitude is derived for spectral radius of sample covariance matrices. We also consider a thresholded covariance matrix estimator that can better characterize sparsity if the true covariance matrix is sparse. As our main tool, we implement Toeplitz [Math. Ann. 70 (1911) 351–376] idea and relate eigenvalues of covariance matrices to the spectral densities or Fourier transforms...
Quantum field theory in stationary coordinate systems
International Nuclear Information System (INIS)
Pfautsch, J.D.
1981-01-01
Quantum field theory is examined in stationary coordinate systems in Minkowski space. Preliminary to quantization of the scalar field, all of the possible stationary coordinate systems in flat spacetime are classified and explicitly constructed. Six distinct classes of such systems are found. Of these six, three have (identical) event horizons associated with them and five have Killing horizons. Two classes have distinct Killing and event horizons, with an intervening region analogous to the ergosphere in rotating black holes. Particular representatives of each class are selected for subsequent use in the quantum field theory. The scalar field is canonically quantized and a vacuum defined in each of the particular coordinate systems chosen. The vacuum states can be regarded as adapted to the six classes of stationary motions. There are only two vacuum states found, the Minkowski vacuum in those coordinate systems without event horizons and the Fulling vacuum in those with event horizons. The responses of monopole detectors traveling along stationary world lines are calculated in both the Minkowski and Fulling vacuums. The responses for each class of motions are distinct from those for every other class. A vacuum defined by the response of a detector must therefore not be equivalent in general to a vacuum defined by canonical quantization. Quantization of the scalar field within a rotating wedge is examined. It has not been possible to construct mode functions satisfying appropriate boundary conditions on the surface of the wedge. The asymptotic form of the renormalized stress tensor near the surfaces had been calculated and is found to include momentum terms which represent a circulation of energy within the wedge
RECORDS REACHING RECORDING DATA TECHNOLOGIES
Directory of Open Access Journals (Sweden)
G. W. L. Gresik
2013-07-01
Full Text Available The goal of RECORDS (Reaching Recording Data Technologies is the digital capturing of buildings and cultural heritage objects in hard-to-reach areas and the combination of data. It is achieved by using a modified crane from film industry, which is able to carry different measuring systems. The low-vibration measurement should be guaranteed by a gyroscopic controlled advice that has been , developed for the project. The data were achieved by using digital photography, UV-fluorescence photography, infrared reflectography, infrared thermography and shearography. Also a terrestrial 3D laser scanner and a light stripe topography scanner have been used The combination of the recorded data should ensure a complementary analysis of monuments and buildings.
Records Reaching Recording Data Technologies
Gresik, G. W. L.; Siebe, S.; Drewello, R.
2013-07-01
The goal of RECORDS (Reaching Recording Data Technologies) is the digital capturing of buildings and cultural heritage objects in hard-to-reach areas and the combination of data. It is achieved by using a modified crane from film industry, which is able to carry different measuring systems. The low-vibration measurement should be guaranteed by a gyroscopic controlled advice that has been , developed for the project. The data were achieved by using digital photography, UV-fluorescence photography, infrared reflectography, infrared thermography and shearography. Also a terrestrial 3D laser scanner and a light stripe topography scanner have been used The combination of the recorded data should ensure a complementary analysis of monuments and buildings.
DEFF Research Database (Denmark)
Turcan, Romeo V.
2016-01-01
literature on late globalization from sociocultural and economic perspectives. It illustrates in a vignette the character and features of late globalization observable in the withdrawal from foreign locations or deinternationalization of universities, as late globalizing entitis. The paper discusses...
Stationary black holes: large D analysis
International Nuclear Information System (INIS)
Suzuki, Ryotaku; Tanabe, Kentaro
2015-01-01
We consider the effective theory of large D stationary black holes. By solving the Einstein equations with a cosmological constant using the 1/D expansion in near zone of the black hole we obtain the effective equation for the stationary black hole. The effective equation describes the Myers-Perry black hole, bumpy black holes and, possibly, the black ring solution as its solutions. In this effective theory the black hole is represented as an embedded membrane in the background, e.g., Minkowski or Anti-de Sitter spacetime and its mean curvature is given by the surface gravity redshifted by the background gravitational field and the local Lorentz boost. The local Lorentz boost property of the effective equation is observed also in the metric itself. In fact we show that the leading order metric of the Einstein equation in the 1/D expansion is generically regarded as a Lorentz boosted Schwarzschild black hole. We apply this Lorentz boost property of the stationary black hole solution to solve perturbation equations. As a result we obtain an analytic formula for quasinormal modes of the singly rotating Myers-Perry black hole in the 1/D expansion.
Stationary stochastic processes theory and applications
Lindgren, Georg
2012-01-01
Some Probability and Process BackgroundSample space, sample function, and observablesRandom variables and stochastic processesStationary processes and fieldsGaussian processesFour historical landmarksSample Function PropertiesQuadratic mean propertiesSample function continuityDerivatives, tangents, and other characteristicsStochastic integrationAn ergodic resultExercisesSpectral RepresentationsComplex-valued stochastic processesBochner's theorem and the spectral distributionSpectral representation of a stationary processGaussian processesStationary counting processesExercisesLinear Filters - General PropertiesLinear time invariant filtersLinear filters and differential equationsWhite noise in linear systemsLong range dependence, non-integrable spectra, and unstable systemsThe ARMA-familyLinear Filters - Special TopicsThe Hilbert transform and the envelopeThe sampling theoremKarhunen-Loève expansionClassical Ergodic Theory and MixingThe basic ergodic theorem in L2Stationarity and transformationsThe ergodic th...
Backset-stationary and during car driving.
Jonsson, Bertil; Stenlund, Hans; Björnstig, Ulf
2008-12-01
The aim of the study was to measure and analyze backset, defined as the horizontal distance between the back of the occupant's head and a point located on the ventral/top aspect of the sewn rim of the head restraint, with the car stationary and during driving, in the driver's position in a modern car. A population of 65 subjects, 35 males and 30 females, was studied in a Volvo V70 car, model year 2007. The subjects were studied in the driver's position, in a self-selected posture. Stationary backset was measured with the technique described by Jonsson et al. (2007) and backset during driving with video analysis. Descriptive data were calculated, and variability and correlation analyses were performed. A t-test was used to test differences of means. Significance level was set to 0.05. In comparison to stationary backset, mean backset during driving was 43 mm greater in males and 41 mm greater in females. Driving backset was 44 mm larger in males than in females. Driving backset was moderately correlated (0.37-0.43) to stature, seated height, and seat back angle in males and moderately correlated (0.44-0.52) to hip width, waist circumference, and weight in females. The overall intraclass correlation coefficient for backset during driving was 0.81 (CI: 0.75-0.86). These results may be of use in designing future updates of test protocols/routines for geometric backset, such as RCAR and RCAR-IIWPG.
30 CFR 57.14115 - Stationary grinding machines.
2010-07-01
... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Stationary grinding machines. 57.14115 Section... and Equipment Safety Devices and Maintenance Requirements § 57.14115 Stationary grinding machines. Stationary grinding machines, other than special bit grinders, shall be equipped with— (a) Peripheral hoods...
30 CFR 77.401 - Stationary grinding machines; protective devices.
2010-07-01
... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Stationary grinding machines; protective... OF UNDERGROUND COAL MINES Safeguards for Mechanical Equipment § 77.401 Stationary grinding machines; protective devices. (a) Stationary grinding machines other than special bit grinders shall be equipped with...
30 CFR 75.1723 - Stationary grinding machines; protective devices.
2010-07-01
... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Stationary grinding machines; protective....1723 Stationary grinding machines; protective devices. (a) Stationary grinding machines other than... the wheel. (3) Safety washers. (b) Grinding wheels shall be operated within the specifications of the...
30 CFR 56.14115 - Stationary grinding machines.
2010-07-01
... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Stationary grinding machines. 56.14115 Section... Equipment Safety Devices and Maintenance Requirements § 56.14115 Stationary grinding machines. Stationary grinding machines, other than special bit grinders, shall be equipped with— (a) Peripheral hoods capable of...
Experimental Investigations of a Krypton Stationary Plasma Thruster
Directory of Open Access Journals (Sweden)
A. I. Bugrova
2013-01-01
Full Text Available Stationary plasma thrusters are attractive electric propulsion systems for spacecrafts. The usual propellant is xenon. Among the other suggested propellants, krypton could be one of the best candidates. Most studies have been carried out with a Hall effect thruster previously designed for xenon. The ATON A-3 developed by MSTU MIREA (Moscow initially defined for xenon has been optimized for krypton. The stable high-performance ATON A-3 operation in Kr has been achieved after optimization of its magnetic field configuration and its optimization in different parameters: length and width of the channel, buffer volume dimensions, mode of the cathode operation, and input parameters. For a voltage of 400 V and the anode mass flow rate of 2.5 mg/s the anode efficiency reaches 60% and the specific impulse reaches 2900 s under A-3 operating with Kr. The achieved performances under operation A-3 with Kr are presented and compared with performances obtained with Xe.
REACH and nanomaterials: current status
International Nuclear Information System (INIS)
Alessandrelli, Maria; Di Prospero Fanghella, Paola; Polci, Maria Letizia; Castelli, Stefano; Pettirossi, Flavio
2015-01-01
New challenges for regulators are emerging about a specific assessment and appropriate management of the potential risks of nanomaterials. In the framework of European legislation on chemicals, Regulation (EC) No. 1907/2006 REACH aims to ensure the safety of human health and the environment through the collection of information on the physico-chemical characteristics of the substances and on their profile (eco) toxicological and the identification of appropriate risk management linked to 'exposure to these substances without impeding scientific progress and the competitiveness of industry. In order to cover the current shortage of information on the safety of nanomaterials and tackle the acknowledged legal vacuum, are being a rich activities, carried out both by regulators both by stake holders, and discussions on the proposals for adapting the European regulatory framework for chemicals . The European Commission is geared to strengthen the REACH Regulation by means of updates of its annexes. The importance of responding to the regulatory requirements has highlighted the need for cooperation between European organizations, scientists and industries to promote and ensure the safe use of nanomaterials. [it
Stationary and non-stationary extreme value modeling of extreme temperature in Malaysia
Hasan, Husna; Salleh, Nur Hanim Mohd; Kassim, Suraiya
2014-09-01
Extreme annual temperature of eighteen stations in Malaysia is fitted to the Generalized Extreme Value distribution. Stationary and non-stationary models with trend are considered for each station and the Likelihood Ratio test is used to determine the best-fitting model. Results show that three out of eighteen stations i.e. Bayan Lepas, Labuan and Subang favor a model which is linear in the location parameter. A hierarchical cluster analysis is employed to investigate the existence of similar behavior among the stations. Three distinct clusters are found in which one of them consists of the stations that favor the non-stationary model. T-year estimated return levels of the extreme temperature are provided based on the chosen models.
Dynamics of relaxation to a stationary state for interacting molecular motors
Gomes, Luiza V. F.; Kolomeisky, Anatoly B.
2018-01-01
Motor proteins are active enzymatic molecules that drive a variety of biological processes, including transfer of genetic information, cellular transport, cell motility and muscle contraction. It is known that these biological molecular motors usually perform their cellular tasks by acting collectively, and there are interactions between individual motors that specify the overall collective behavior. One of the fundamental issues related to the collective dynamics of motor proteins is the question if they function at stationary-state conditions. To investigate this problem, we analyze a relaxation to the stationary state for the system of interacting molecular motors. Our approach utilizes a recently developed theoretical framework, which views the collective dynamics of motor proteins as a totally asymmetric simple exclusion process of interacting particles, where interactions are taken into account via a thermodynamically consistent approach. The dynamics of relaxation to the stationary state is analyzed using a domain-wall method that relies on a mean-field description, which takes into account some correlations. It is found that the system quickly relaxes for repulsive interactions, while attractive interactions always slow down reaching the stationary state. It is also predicted that for some range of parameters the fastest relaxation might be achieved for a weak repulsive interaction. Our theoretical predictions are tested with Monte Carlo computer simulations. The implications of our findings for biological systems are briefly discussed.
Localization and stationary phase approximation on supermanifolds
Zakharevich, Valentin
2017-08-01
Given an odd vector field Q on a supermanifold M and a Q-invariant density μ on M, under certain compactness conditions on Q, the value of the integral ∫Mμ is determined by the value of μ on any neighborhood of the vanishing locus N of Q. We present a formula for the integral in the case where N is a subsupermanifold which is appropriately non-degenerate with respect to Q. In the process, we discuss the linear algebra necessary to express our result in a coordinate independent way. We also extend the stationary phase approximation and the Morse-Bott lemma to supermanifolds.
Non-stationary compositions of Anosov diffeomorphisms
International Nuclear Information System (INIS)
Stenlund, Mikko
2011-01-01
Motivated by non-equilibrium phenomena in nature, we study dynamical systems whose time-evolution is determined by non-stationary compositions of chaotic maps. The constituent maps are topologically transitive Anosov diffeomorphisms on a two-dimensional compact Riemannian manifold, which are allowed to change with time—slowly, but in a rather arbitrary fashion. In particular, such systems admit no invariant measure. By constructing a coupling, we prove that any two sufficiently regular distributions of the initial state converge exponentially with time. Thus, a system of this kind loses memory of its statistical history rapidly
Stationary stochastic processes for scientists and engineers
Lindgren, Georg; Sandsten, Maria
2013-01-01
""This book is designed for a first course in stationary stochastic processes in science and engineering and does a very good job in introducing many concepts and ideas to students in these fields. … the book has probably been tested in the classroom many times, which also manifests itself in its virtual lack of typos. … Another great feature of the book is that it contains a wealth of worked example from many different fields. These help clarify concepts and theorems and I believe students will appreciate them-I certainly did. … The book is well suited for a one-semester course as it contains
Stationary Black Holes: Uniqueness and Beyond
Directory of Open Access Journals (Sweden)
Heusler Markus
1998-01-01
Full Text Available The spectrum of known black hole solutions to the stationary Einstein equations has increased in an unexpected way during the last decade. In particular, it has turned out that not all black hole equilibrium configurations are characterized by their mass, angular momentum and global charges. Moreover, the high degree of symmetry displayed by vacuum and electro-vacuum black hole space-times ceases to exist in self-gravitating non-linear field theories. This text aims to review some of the recent developments and to discuss them in the light of the uniqueness theorem for the Einstein-Maxwell system.
Stationary Black Holes: Uniqueness and Beyond
Directory of Open Access Journals (Sweden)
Piotr T. Chruściel
2012-05-01
Full Text Available The spectrum of known black-hole solutions to the stationary Einstein equations has been steadily increasing, sometimes in unexpected ways. In particular, it has turned out that not all black-hole-equilibrium configurations are characterized by their mass, angular momentum and global charges. Moreover, the high degree of symmetry displayed by vacuum and electro vacuum black-hole spacetimes ceases to exist in self-gravitating non-linear field theories. This text aims to review some developments in the subject and to discuss them in light of the uniqueness theorem for the Einstein-Maxwell system.
Population inversion in a stationary recombining plasma
International Nuclear Information System (INIS)
Otsuka, M.
1980-01-01
Population inversion, which occurs in a recombining plasma when a stationary He plasma is brought into contact with a neutral gas, is examined. With hydrogen as a contact gas, noticeable inversion between low-lying levels of H as been found. The overpopulation density is of the order of 10 8 cm -3 , which is much higher then that (approx. =10 5 cm -3 ) obtained previously with He as a contact gas. Relations between these experimental results and the conditions for population inversion are discussed with the CR model
Cai, Jianfeng; Cheng, Lingping; Zhao, Jianchao; Fu, Qing; Jin, Yu; Ke, Yanxiong; Liang, Xinmiao
2017-11-17
A hydrophilic interaction liquid chromatography (HILIC) stationary phase was prepared by a two-step synthesis method, immobilizing polyacrylamide on silica sphere particles. The stationary phase (named PA, 5μm dia) was evaluated using a mixture of carbohydrates in HILIC mode and the column efficiency reached 121,000Nm -1 . The retention behavior of carbohydrates on PA stationary phase was investigated with three different organic solvents (acetonitrile, ethanol and methanol) employed as the weak eluent. The strongest hydrophilicity of PA stationary phase was observed in both acetonitrile and methanol as the weak eluent, when compared with another two amide stationary phases. Attributing to its high hydrophilicity, three oligosaccharides (xylooligosaccharide, fructooligosaccharide and chitooligosaccharides) presented good retention on PA stationary phase using alcohols/water as mobile phase. Finally, PA stationary phase was successfully applied for the purification of galactooligosaccharides and saponins of Paris polyphylla. It is feasible to use safer and cheaper alcohols to replace acetonitrile as the weak eluent for green analysis and purification of polar compounds on PA stationary phase. Copyright © 2017. Published by Elsevier B.V.
GRAN SASSO: Reaching the parts that accelerators cannot reach
International Nuclear Information System (INIS)
Anon.
1995-01-01
With most of the current experiments at Italy's Gran Sasso Laboratory now well underway, a workshop held earlier this year looked to the future. Gran Sasso was established in the late 1980s to study low rate processes where the laboratory's 1400 metre rock overburden and low natural radioactivity provide an ideal environment. Since then, it has become a major research centre, hosting several international collaborations. The workshop devoted half a day each to four key areas of underground physics, and clearly showed how the non-accelerator approach complements today's accelerator physics achievements. Solar neutrino physics is one of Gran Sasso's main activities, with the Gallex detector half filling one of the laboratory's three experimental halls. Gallex has already made important measurements of the solar neutrino flux, providing first evidence for the proton-proton fusion mechanism which is the solar powerhouse. The next generation experiment, Borexino, will go one step further, measuring the energy distribution of solar neutrinos as well as their flux. The experiment will also be sensitive to neutrino oscillations through its ability to pick out muon and tau neutrinos. Borexino uses boron instead of gallium as the active medium, and is currently in the trial phase. Benchmarking tests with the counter test facility (CTF) have already demonstrated the experiment's feasibility, paving the way for full scale construction. Further ideas for future detectors based on several different active media were also discussed, and a proposal for a helium TPC detector, HELLAZ, was presented. With a threshold of around 240 keV, comparable to that of Gallex and Borexino, HELLAZ would give another handle on neutrinos from the proton-proton reaction, the most abundant source of solar neutrinos. Neutrinoless double beta decay, dark matter searches, and certain low rate processes in nuclear physics all require the quiet, low radiation surroundings
Ionic liquid stationary phases for gas chromatography.
Poole, Colin F; Poole, Salwa K
2011-04-01
This article provides a summary of the development of ionic liquids as stationary phases for gas chromatography beginning with early work on packed columns that established details of the retention mechanism and established working methods to characterize selectivity differences compared with molecular stationary phases through the modern development of multi-centered cation and cross-linked ionic liquids for high-temperature applications in capillary gas chromatography. Since there are many reviews on ionic liquids dealing with all aspects of their chemical and physical properties, the emphasis in this article is placed on the role of gas chromatography played in the design of ionic liquids of low melting point, high thermal stability, high viscosity, and variable selectivity for separations. Ionic liquids provide unprecedented opportunities for extending the selectivity range and temperature-operating range of columns for gas chromatography, an area of separation science that has otherwise been almost stagnant for over a decade. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Eddy current inspection of stationary blade rings
International Nuclear Information System (INIS)
Krzywosz, K.J.; Hastings, S.N.
1994-01-01
Stationary turbine blade rings in a US power plant have experienced chloride-induced cracking. Failure analysis determined two types of cracking mechanisms: corrosion fatigue cracking confined to the leading edge of the outer shroud; and stress corrosion cracking present all over the blade surface. Fluorescent dye penetrant is typically used to detect and size cracks. However, it requires cleaning the blade rings by sandblasting to obtain reliable inspection results. Sand blasting in turn requires sealing the lower half of the turbine housing to prevent sand from contaminating the rest of the power plant components. Furthermore, both the penetrant examination and the removal of the sand are time consuming and costly. An alternative NDE technique is desirable which requires no pre-cleaning of the blade and a quick go/no-go inspection with the capability of estimating the crack length. This paper presents an innovative eddy current technique which meets the desired objectives by incorporating the use of specially designed contoured scanners equipped with an array of pancake coils. A set of eddy current pancake coils housed in three different scanners is used to manually scan and inspect the convex side of the stationary blade rings. The pancake coils are operated in a transmit/receive mode using two separate eddy current instruments. This paper presents the inspection concept, including scanner and probe designs, and test results from the various stages of multiple blade rings
Concentration and limit behaviors of stationary measures
Huang, Wen; Ji, Min; Liu, Zhenxin; Yi, Yingfei
2018-04-01
In this paper, we study limit behaviors of stationary measures of the Fokker-Planck equations associated with a system of ordinary differential equations perturbed by a class of multiplicative noise including additive white noise case. As the noises are vanishing, various results on the invariance and concentration of the limit measures are obtained. In particular, we show that if the noise perturbed systems admit a uniform Lyapunov function, then the stationary measures form a relatively sequentially compact set whose weak∗-limits are invariant measures of the unperturbed system concentrated on its global attractor. In the case that the global attractor contains a strong local attractor, we further show that there exists a family of admissible multiplicative noises with respect to which all limit measures are actually concentrated on the local attractor; and on the contrary, in the presence of a strong local repeller in the global attractor, there exists a family of admissible multiplicative noises with respect to which no limit measure can be concentrated on the local repeller. Moreover, we show that if there is a strongly repelling equilibrium in the global attractor, then limit measures with respect to typical families of multiplicative noises are always concentrated away from the equilibrium. As applications of these results, an example of stochastic Hopf bifurcation and an example with non-decomposable ω-limit sets are provided. Our study is closely related to the problem of noise stability of compact invariant sets and invariant measures of the unperturbed system.
Stationary two-variable gravitational vortex fields
International Nuclear Information System (INIS)
Koppel, A.
1974-01-01
Some properties of stationary two-variable solutions of the Einstein equations were studied on the basis of rigorous analysis of the nonrelativistic limit of the relativistic gravitation theory. For this case a particular method was developed of determining so-called vortex gravitational fields described by vortex solutions, which in the nonrelativistic limit transform from → infinity to the nonnewtonian type solutions. The main formulae for such fields are derived and a scheme for their calculation is presented. It is shown that under certain conditions the exact stationary solutions of the Papapetrou type for vacuum relativistic equations are vortical. From this fact, first, the presence of particular exact vortical solutions for the Einstein equations is proved, and secondly, a new possibility of a physical interpretation is proposed for the Papapetrou solutions. It is also shown that the nonrelativistic limit of this class of solutions strongly depends on the structure of solution parameters (under certain conditions these solutions may also have the Newtonian limit). 'Multipole' and 'one-variable' partial solutions of the Papapetrou class solution are derived as particular examples of vortical solutions. It is shown that for a specific parameter structure the known NUT solution is also vortical, since it belongs to the Papapetrou class [ru
Minetti, Andrea; Hurtado, Northan; Grais, Rebecca F.; Ferrari, Matthew
2014-01-01
Current mass vaccination campaigns in measles outbreak response are nonselective with respect to the immune status of individuals. However, the heterogeneity in immunity, due to previous vaccination coverage or infection, may lead to potential bias of such campaigns toward those with previous high access to vaccination and may result in a lower-than-expected effective impact. During the 2010 measles outbreak in Malawi, only 3 of the 8 districts where vaccination occurred achieved a measureable effective campaign impact (i.e., a reduction in measles cases in the targeted age groups greater than that observed in nonvaccinated districts). Simulation models suggest that selective campaigns targeting hard-to-reach individuals are of greater benefit, particularly in highly vaccinated populations, even for low target coverage and with late implementation. However, the choice between targeted and nonselective campaigns should be context specific, achieving a reasonable balance of feasibility, cost, and expected impact. In addition, it is critical to develop operational strategies to identify and target hard-to-reach individuals. PMID:24131555
Metasurface holograms reaching 80% efficiency.
Zheng, Guoxing; Mühlenbernd, Holger; Kenney, Mitchell; Li, Guixin; Zentgraf, Thomas; Zhang, Shuang
2015-04-01
Surfaces covered by ultrathin plasmonic structures--so-called metasurfaces--have recently been shown to be capable of completely controlling the phase of light, representing a new paradigm for the design of innovative optical elements such as ultrathin flat lenses, directional couplers for surface plasmon polaritons and wave plate vortex beam generation. Among the various types of metasurfaces, geometric metasurfaces, which consist of an array of plasmonic nanorods with spatially varying orientations, have shown superior phase control due to the geometric nature of their phase profile. Metasurfaces have recently been used to make computer-generated holograms, but the hologram efficiency remained too low at visible wavelengths for practical purposes. Here, we report the design and realization of a geometric metasurface hologram reaching diffraction efficiencies of 80% at 825 nm and a broad bandwidth between 630 nm and 1,050 nm. The 16-level-phase computer-generated hologram demonstrated here combines the advantages of a geometric metasurface for the superior control of the phase profile and of reflectarrays for achieving high polarization conversion efficiency. Specifically, the design of the hologram integrates a ground metal plane with a geometric metasurface that enhances the conversion efficiency between the two circular polarization states, leading to high diffraction efficiency without complicating the fabrication process. Because of these advantages, our strategy could be viable for various practical holographic applications.
The application of unattended ground sensors to stationary targets
International Nuclear Information System (INIS)
Sleefe, G.E.; Peglow, S.; Hamrick, R.
1997-01-01
The unattended sensing of stationary (i.e. non-mobile) targets is important in applications ranging from counter-proliferation to law enforcement. With stationary targets, sources of seismic, acoustic, and electro-magnetic emissions can potentially be used to detect, identify, and locate the target. Stationary targets have considerably different sensing requirements than the traditional mobile-target unattended ground sensor applications. This paper presents the novel features and requirements of a system for sensing stationary targets. In particular, issues associated with long-listen time signal processing for signal detection, and array processing techniques for signal localization are presented. Example data and signal processing outputs from a stationary target will be used to illustrate these issues. The impact on sensor, electronic signal processing, battery subsystem, and communication requirements will also be discussed. The paper will conclude with a detailed comparison between mobile-target and stationary-target unattended ground sensor architectures
Stationary high confinement plasmas with large bootstrap current fraction in JT-60U
International Nuclear Information System (INIS)
Sakamoto, Y.; Fujita, T.; Ide, S.; Isayama, A.; Takechi, M.; Suzuki, T.; Takenaga, H.; Oyama, N.; Kamada, Y.
2005-01-01
This paper reports the results of the progress in stationary discharges with a large bootstrap current fraction in JT-60U towards steady-state tokamak operation. In the weak shear plasma regime, high-β p ELMy H-mode discharges have been optimized under nearly full non-inductive current drive conditions by the large bootstrap current fraction (f BS ∼ 45%) and the beam driven current fraction (f BD ∼ 50%), which was sustained for 5.8 s in the stationary condition. This duration corresponds to ∼26τ E and ∼2.8τ R , which was limited by the pulse length of negative-ion-based neutral beams. The high confinement enhancement factor H 89 ∼ 2.2 (HH 98y2 ∼ 1.0) was obtained and the profiles of current and pressure reached the stationary condition. In the reversed shear plasma regime, a large bootstrap current fraction (f BS ∼ 75%) has been sustained for 7.4 s under nearly full non-inductive current drive conditions. This duration corresponds to ∼16τ E and ∼2.7τ R . The high confinement enhancement factor H 89 ∼ 3.0 (HH 98y2 ∼ 1.7) was also sustained, and the profiles of current and pressure reached the stationary condition. The large bootstrap current and the off-axis beam driven current sustained this reversed q profile. This duration was limited only by the duration of the neutral beam injection
Hydrogen Storage using Metal Hydrides in a Stationary Cogeneration System
International Nuclear Information System (INIS)
Botzung, Maxime; Chaudourne, Serge; Perret, Christian; Latroche, Michel; Percheron-Guegan, Annick; Marty Philippe
2006-01-01
In the frame of the development of a hydrogen production and storage unit to supply a 40 kW stationary fuel cell, a metal hydride storage tank was chosen according to its reliability and high energetic efficiency. The study of AB5 compounds led to the development of a composition adapted to the project needs. The absorption/desorption pressures of the hydride at 75 C (2 / 1.85 bar) are the most adapted to the specifications. The reversible storage capacity (0.95 %wt) has been optimized to our work conditions and chemical kinetics is fast. The design of the Combined Heat and Power CHP system requires 5 kg hydrogen storage but in a first phase, only a 0.1 kg prototype has been realised and tested. Rectangular design has been chosen to obtain good compactness with an integrated plate fin type heat exchanger designed to reach high absorption/desorption rates. In this paper, heat and mass transfer characteristics of the Metal Hydride tank (MH tank) during absorption/desorption cycles are given. (authors)
Stationary closed strings in five-dimensional flat spacetime
Igata, Takahisa; Ishihara, Hideki; Nishiwaki, Keisuke
2012-11-01
We investigate stationary rotating closed Nambu-Goto strings in five-dimensional flat spacetime. The stationary string is defined as a world sheet that is tangent to a timelike Killing vector. The Nambu-Goto equation of motion for the stationary string is reduced to the geodesic equation on the orbit space of the isometry group action generated by the Killing vector. We take a linear combination of a time-translation vector and space-rotation vectors as the Killing vector, and explicitly construct general solutions of stationary rotating closed strings in five-dimensional flat spacetime. We show a variety of their configurations and properties.
Effective Complexity of Stationary Process Realizations
Directory of Open Access Journals (Sweden)
Arleta Szkoła
2011-06-01
Full Text Available The concept of effective complexity of an object as the minimal description length of its regularities has been initiated by Gell-Mann and Lloyd. The regularities are modeled by means of ensembles, which is the probability distributions on finite binary strings. In our previous paper [1] we propose a definition of effective complexity in precise terms of algorithmic information theory. Here we investigate the effective complexity of binary strings generated by stationary, in general not computable, processes. We show that under not too strong conditions long typical process realizations are effectively simple. Our results become most transparent in the context of coarse effective complexity which is a modification of the original notion of effective complexity that needs less parameters in its definition. A similar modification of the related concept of sophistication has been suggested by Antunes and Fortnow.
Quantum teleportation between stationary macroscopic objects
Energy Technology Data Exchange (ETDEWEB)
Bao, Xiao-Hui; Yuan, Zhen-Sheng; Pan, Jian-Wei [Physikalisches Institut, Universitaet Heidelberg (Germany); Hefei National Laboratory for Physical Sciences at Microscale, Department of Modern Physics, University of Science and Technology of China, Hefei (China); Xu, Xiao-Fan [Physikalisches Institut, Universitaet Heidelberg (Germany); Li, Che-Ming [Physikalisches Institut, Universitaet Heidelberg (Germany); Department of Physics, National Center for Theoretical Sciences, National Cheng Kung University, Tainan (China)
2010-07-01
Quantum teleportation is a process to transfer a quantum state of an object without transferring the state carrier itself. So far, most of the teleportation experiments realized are within the photonic regime. For the teleportation of stationary states, the largest system reported is a single ion. We are now performing an experiment to teleport the state of an macroscopic atomic cloud which consists about 10{sup 6} single atoms. In our experiment two atomic ensembles are utilized. In the first ensemble A we prepare the collective atomic state to be teleported using the quantum feedback technique. The second ensemble B is utilized to generate entanglement between it collective state with a scattered single-photon. Teleportation is realized by converting the atomic state of A to a single-photon and making a Bell state measurement with the scattered single-photon from ensemble B.
Landau superfluids as nonequilibrium stationary states
International Nuclear Information System (INIS)
Wreszinski, Walter F.
2015-01-01
We define a superfluid state to be a nonequilibrium stationary state (NESS), which, at zero temperature, satisfies certain metastability conditions, which physically express that there should be a sufficiently small energy-momentum transfer between the particles of the fluid and the surroundings (e.g., pipe). It is shown that two models, the Girardeau model and the Huang-Yang-Luttinger (HYL) model, describe superfluids in this sense and, moreover, that, in the case of the HYL model, the metastability condition is directly related to Nozières’ conjecture that, due to the repulsive interaction, the condensate does not suffer fragmentation into two (or more) parts, thereby assuring its quantum coherence. The models are rigorous examples of NESS in which the system is not finite, but rather a many-body system
Modified method of perturbed stationary states. I
International Nuclear Information System (INIS)
Green, T.A.
1978-10-01
The reaction coordinate approach of Mittleman is used to generalize the method of Perturbed Stationary States. A reaction coordinate is defined for each state in the scattering expansion in terms of parameters which depend on the internuclear separation. These are to be determined from a variational principle described by Demkov. The variational result agrees with that of Bates and McCarroll in the limit of separated atoms, but is generally different elsewhere. The theory is formulated for many-electron systems, and the construction of the scattering expansion is discussed for simple one-, two-, and three-electron systsm. The scattering expansion and the Lagrangian for the radial scattering functions are given in detail for a heteronuclear one-electron system. 2 figures
Danish emission inventories for stationary combustion plants
DEFF Research Database (Denmark)
Nielsen, Malene; Nielsen, Ole-Kenneth; Plejdrup, Marlene Schmidt
Emission inventories for stationary combustion plants are presented and the methodologies and assumptions used for the inventories are described. The pollutants considered are SO2, NOx, NMVOC, CH4, CO, CO2, N2O, NH3, particulate matter, heavy metals, PCDD/F, HCB and PAH. The CO2 emission in 2011...... of decreased emissions from large power plants and waste incineration plants. The combustion of wood in residential plants has increased considerably until 2007 resulting in increased emission of PAH and particulate matter. The emission of NMVOC has increased since 1990 as a result of both the increased...... combustion of wood in residential plants and the increased emission from lean-burn gas engines. The PCDD/F emission decreased since 1990 due to flue gas cleaning on waste incineration plants....
Danish emission inventories for stationary combustion plants
DEFF Research Database (Denmark)
Nielsen, Malene; Nielsen, Ole-Kenneth; Plejdrup, Marlene Schmidt
Emission inventories for stationary combustion plants are presented and the methodologies and assumptions used for the inventories are described. The pollutants considered are SO2, NOx, NMVOC, CH4, CO, CO2, N2O, NH3, particulate matter, heavy metals, dioxins, HCB and PAH. The CO2 emission in 2008...... incineration plants. The combustion of wood in residential plants has increased considerably in recent years resulting in increased emission of PAH, particulate matter and CO. The emission of NMVOC has increased since 1990 as a result of both the increased combustion of wood in residential plants...... and the increased emission from lean-burn gas engines. The dioxin emission decreased since 1990 due to flue gas cleaning on waste incineration plants. However in recent years the emission has increased as a result of the increased combustion of wood in residential plants....
Danish emission inventories for stationary combustion plants
DEFF Research Database (Denmark)
Nielsen, Malene; Nielsen, Ole-Kenneth; Plejdrup, Marlene Schmidt
Emission inventories for stationary combustion plants are presented and the methodologies and assumptions used for the inventories are described. The pollutants considered are SO2, NOx, NMVOC, CH4, CO, CO2, N2O, particulate matter, heavy metals, dioxins, HCB and PAH. The CO2 emission in 2007 was 10...... incineration plants. The combustion of wood in residential plants has increased considerably in recent years resulting in increased emission of PAH, particulate matter and CO. The emission of NMVOC has increased since 1990 as a result of both the increased combustion of wood in residential plants...... and the increased emission from lean-burn gas engines. The dioxin emission decreased since 1990 due to flue gas cleaning on waste incineration plants. However in recent years the emission has increased as a result of the increased combustion of wood in residential plants....
Stationary spiral flow in polytropic stellar models
Pekeris, C. L.
1980-01-01
It is shown that, in addition to the static Emden solution, a self-gravitating polytropic gas has a dynamic option in which there is stationary flow along spiral trajectories wound around the surfaces of concentric tori. The motion is obtained as a solution of a partial differential equation which is satisfied by the meridional stream function, coupled with Poisson's equation and a Bernoulli-type equation for the pressure (density). The pressure is affected by the whole of the Bernoulli term rather than by the centrifugal part only, which acts for a rotating model, and it may be reduced down to zero at the center. The spiral type of flow is illustrated for an incompressible fluid (n = 0), for which an exact solution is obtained. The features of the dynamic constant-density model are discussed as a basis for future comparison with the solution for compressible models. PMID:16592825
Flood frequency analysis of historical flood data under stationary and non-stationary modelling
Machado, M. J.; Botero, B. A.; López, J.; Francés, F.; Díez-Herrero, A.; Benito, G.
2015-06-01
Historical records are an important source of information on extreme and rare floods and fundamental to establish a reliable flood return frequency. The use of long historical records for flood frequency analysis brings in the question of flood stationarity, since climatic and land-use conditions can affect the relevance of past flooding as a predictor of future flooding. In this paper, a detailed 400 yr flood record from the Tagus River in Aranjuez (central Spain) was analysed under stationary and non-stationary flood frequency approaches, to assess their contribution within hazard studies. Historical flood records in Aranjuez were obtained from documents (Proceedings of the City Council, diaries, chronicles, memoirs, etc.), epigraphic marks, and indirect historical sources and reports. The water levels associated with different floods (derived from descriptions or epigraphic marks) were computed into discharge values using a one-dimensional hydraulic model. Secular variations in flood magnitude and frequency, found to respond to climate and environmental drivers, showed a good correlation between high values of historical flood discharges and a negative mode of the North Atlantic Oscillation (NAO) index. Over the systematic gauge record (1913-2008), an abrupt change on flood magnitude was produced in 1957 due to constructions of three major reservoirs in the Tagus headwaters (Bolarque, Entrepeñas and Buendia) controlling 80% of the watershed surface draining to Aranjuez. Two different models were used for the flood frequency analysis: (a) a stationary model estimating statistical distributions incorporating imprecise and categorical data based on maximum likelihood estimators, and (b) a time-varying model based on "generalized additive models for location, scale and shape" (GAMLSS) modelling, which incorporates external covariates related to climate variability (NAO index) and catchment hydrology factors (in this paper a reservoir index; RI). Flood frequency
A stationary evacuated collector with integrated concentrator
Energy Technology Data Exchange (ETDEWEB)
Snail, K.A.; O' Gallagher, J.J.; Winston, R.
1984-01-01
A comprehensive set of experimental tests and detailed optical and thermal models are presented for a newly developed solar thermal collector. The new collector has an optical efficiency of 65 per cent and achieves thermal efficiencies of better than 50 per cent at fluid temperatures of 200/sup 0/C without tracking the sun. The simultaneous features of high temperature operation and a fully stationary mount are made possible by combining vacuum insulation, spectrally selective coatings, and nonimaging concentration in a novel way. These 3 design elements are ''integrated'' together in a self containe unit by shaping the outer glass envelope of a conventional evacuated tube into the profile of a nonimaging CPC-type concentrator. This permits the use of a first surface mirror and eliminates the need for second cover glazing. The new collector has been given the name ''Integrated Stationary Evacuated Concentrator'', or ISEC collector. Not only is the peak thermal efficiency of the ISEC comparable to that of commercial tracking parabolic troughs, but projections of the average yearly energy delivery also show competitive performance with a net gain for temperatures below 200/sup 0/C. In addition, the ISEC is less subject to exposure induced degradation and could be mass produced with assembly methods similar to those used with fluorescent lamps. Since no tracking or tilt adjustments are ever required and because its sensitive optical surfaces are protected from the environment, the ISEC collector provides a simple, easily maintained solar thermal collector for the range 100-300/sup 0/C which is suitable for most climates and atmospheric conditions. Potential applications include space heating, air conditioning, and industrial process heat.
Stationary flow in magnetic tubes of force
International Nuclear Information System (INIS)
Engvold, O.; Jensen, E.
1976-01-01
For one particular set of boundary conditions Pikel'ner obtained a stationary solution displaying a condensation, which he applied to quiescent prominences. Calculations in the stationary case for a range of parameters have been carried out, after some modifications of the basic equations. These modifications involved a complete non-LTE formulation of the ionization equilibrium, an improved radiative loss-function and more accurate values of the thermodynamic parameters. The calculations were carried out for a hydrogen helium mixture with B = 10 and for a pure hydrogen gas. The solutions were terminated where the optical thickness in lyα along the tube exceeded unity, corresponding to T approx.equal to 20 000K. The solutions are strongly dependent upon the geometry of the tube of force. Condensations may be made to appear on the ascending as well as on the descending branch of the magnetic arch by varying the parameters. Solutions also depend strongly upon the energy input into the tube at the footpoint, mainly determined by the injection velocity and the starting value of the temperature gradient. The radiative loss is of less importance for the values of the gas pressure close to the Pikel'ner case. Recent observational data indicate gas pressure in the chromosphere corona transition region as much as 4 times the boundary pressure assumed by Pikel'ner. Such a high initial pressure, however, produce no condensation. In the temperature range 1.2x10 5 K > T > 5x10 4 K the temperature gradients in the condensations are in fair agreement with observations of the CIII lines in the EUV-region. For higher temperatures 5x10 5 K > T > 2x10 5 K our temperature gradients are much smaller than those indicated by observations. (Auth.)
International Nuclear Information System (INIS)
La Pointe, P.R.
1994-11-01
This report describes the comparison of stationary and non-stationary geostatistical models for the purpose of inferring block-scale hydraulic conductivity values from packer tests at Aespoe. The comparison between models is made through the evaluation of cross-validation statistics for three experimental designs. The first experiment consisted of a 'Delete-1' test previously used at Finnsjoen. The second test consisted of 'Delete-10%' and the third test was a 'Delete-50%' test. Preliminary data analysis showed that the 3 m and 30 m packer test data can be treated as a sample from a single population for the purposes of geostatistical analyses. Analysis of the 3 m data does not indicate that there are any systematic statistical changes with depth, rock type, fracture zone vs non-fracture zone or other mappable factor. Directional variograms are ambiguous to interpret due to the clustered nature of the data, but do not show any obvious anisotropy that should be accounted for in geostatistical analysis. Stationary analysis suggested that there exists a sizeable spatially uncorrelated component ('Nugget Effect') in the 3 m data, on the order of 60% of the observed variance for the various models fitted. Four different nested models were automatically fit to the data. Results for all models in terms of cross-validation statistics were very similar for the first set of validation tests. Non-stationary analysis established that both the order of drift and the order of the intrinsic random functions is low. This study also suggests that conventional cross-validation studies and automatic variogram fitting are not necessarily evaluating how well a model will infer block scale hydraulic conductivity values. 20 refs, 20 figs, 14 tabs
[The REACH legislation: the consumer and environment protection perspective].
Gundert-Remy, Ursula
2008-12-01
REACH has been initiated with the aim of improving existing legislation. In order to assist in the interpretation of the REACH legislation, guidance documents have been developed, which have only lately become available. According to the REACH annexes and supported by guidance documents, waiving of test requirements will be possible, thus, opening the possibility that under REACH no new (eco)toxicological data will be required. Concerning products, a guidance document was released in April 2008 stating that the substance concentration threshold of 0.1 % (w/w) applies to the article as produced or imported and it does not relate to the homogeneous materials or parts of an article, but relates to the article as such (i.e., as produced or imported). Hence, notification will not be required for many products containing chemicals with properties which place them on the candidate list for authorization. In summary, it is at present not foreseeable whether the expected benefit of the REACH legislation will materialise for the environment and for the health of consumers and at the work place.
ALMA Telescope Reaches New Heights
2009-09-01
ball at a distance of nine miles, and to keep their smooth reflecting surfaces accurate to less than the thickness of a human hair. Once the transporter reached the high plateau it carried the antenna to a concrete pad -- a docking station with connections for power and fiber optics -- and positioned it with an accuracy of a small fraction of an inch. The transporter is guided by a laser steering system and, just like some cars, also has ultrasonic collision detectors. These sensors ensure the safety of the state-of-the-art antennas as the transporter drives them across what will soon be a rather crowded plateau. Ultimately, ALMA will have at least 66 antennas distributed over about 200 pads, spread over distances of up to 11.5 miles and operating as a single, giant telescope. Even when ALMA is fully operational, the transporters will be used to move the antennas between pads to reconfigure the telescope for different kinds of observations. This first ALMA antenna at the high site will soon be joined by others, and the ALMA team looks forward to making their first observations from the Chajnantor plateau. They plan to link three antennas by early 2010, and to make the first scientific observations with ALMA in the second half of 2011. ALMA will help astronomers answer important questions about our cosmic origins. The telescope will observe the Universe using light with millimeter and submillimeter wavelengths, between infrared light and radio waves in the electromagnetic spectrum. Light at these wavelengths comes from some of the coldest, and from some of the most distant objects in the cosmos. These include cold clouds of gas and dust where new stars are being born, or remote galaxies towards the edge of the observable universe. The Universe is relatively unexplored at submillimeter wavelengths, as the telescopes need extremely dry atmospheric conditions, such as those at Chajnantor, and advanced detector technology. The Atacama Large Millimeter/submillimeter Array
Analysis of stress and deformation in non-stationary creep
International Nuclear Information System (INIS)
Feijoo, R.A.; Taroco, E.; Guerreiro, J.N.C.
1980-12-01
A variational method and its algorithm are presented; they permit the analysis of stress and deformation in non-stationary creep. This algorithm is applied to an infinite cylinder submitted to an internal pressure. The solution obtained is compared with the solution of non-stationary creep problems [pt
Stationary states of two-level open quantum systems
International Nuclear Information System (INIS)
Gardas, Bartlomiej; Puchala, Zbigniew
2011-01-01
A problem of finding stationary states of open quantum systems is addressed. We focus our attention on a generic type of open system: a qubit coupled to its environment. We apply the theory of block operator matrices and find stationary states of two-level open quantum systems under certain conditions applied on both the qubit and the surrounding.
Modeling stationary and moving pebbles in a pebble bed reactor
International Nuclear Information System (INIS)
Zhao, Xiang; Montgomery, Trent; Zhang, Sijun
2015-01-01
Highlights: • The stationary and moving pebbles in a PBR are numerically studied by DEM. • The packing structure of stationary pebbles is simulated by a filling process. • The packing structural properties are obtained and analyzed. • The dynamic behavior of pebbles is predicted and discussed. - Abstract: This paper presents a numerical study of the stationary and moving pebbles in a pebble bed reactor (PBR) by means of discrete element method (DEM). The packing structure of stationary pebbles is simulated by a filling process that terminates with the settling of the pebbles into a PBR. The packing structural properties are obtained and analyzed. Subsequently, when the outlet of the PBR is opened during the operation of the PBR, the stationary pebbles start to flow downward and are removed at the bottom of the PBR. The dynamic behavior of pebbles is predicted and discussed. Our results indicate the DEM can offer both macroscopic and microscopic information for PBR design calculations and safety assessment
Direct imaging of slow, stored and stationary EIT polaritons
Campbell, Geoff T.; Cho, Young-Wook; Su, Jian; Everett, Jesse; Robins, Nicholas; Lam, Ping Koy; Buchler, Ben
2017-09-01
Stationary and slow light effects are of great interest for quantum information applications. Using laser-cooled Rb87 atoms, we performed side imaging of our atomic ensemble under slow and stationary light conditions, which allows direct comparison with numerical models. The polaritons were generated using electromagnetically induced transparency (EIT), with stationary light generated using counter-propagating control fields. By controlling the power ratio of the two control fields, we show fine control of the group velocity of the stationary light. We also compare the dynamics of stationary light using monochromatic and bichromatic control fields. Our results show negligible difference between the two situations, in contrast to previous work in EIT-based systems.
DEFF Research Database (Denmark)
Lu, Xiaonan; Guerrero, Josep M.; Teodorescu, Remus
2011-01-01
With the penetration of renewable energy in modern power system, microgrid has become a popular application worldwide. In this paper, parallel-connected bidirectional converters for AC and DC hybrid microgrid application are proposed as an efficient interface. To reach the goal of bidirectional...... power conversion, both rectifier and inverter modes are analyzed. In order to achieve high performance operation, hierarchical control system is accomplished. The control system is designed in stationary frame, with harmonic compensation in parallel and no coupled terms between axes. In this control...
Operational Reach: Is Current Army Doctrine Adequate?
National Research Council Canada - National Science Library
Heintzelman, Scott
2003-01-01
The term operational reach, an element of operational design, is new to U.S. Army doctrine. Operational reach is not found in the previous edition of the Army's basic operational doctrine, Field Manual...
Stream Habitat Reach Summary - NCWAP [ds158
California Natural Resource Agency — The Stream Habitat - NCWAP - Reach Summary [ds158] shapefile contains in-stream habitat survey data summarized to the stream reach level. It is a derivative of the...
Secondary instabilities of hypersonic stationary crossflow waves
Edelman, Joshua B.
A sharp, circular 7° half-angle cone was tested in the Boeing/AFOSR Mach-6 Quiet Tunnel at 6° angle of attack. Using a variety of roughness configurations, measurements were made using temperature-sensitive paint (TSP) and fast pressure sensors. High-frequency secondary instabilities of the stationary crossflow waves were detected near the aft end of the cone, from 110° to 163° from the windward ray. At least two frequency bands of the secondary instabilities were measured. The secondary instabilities have high coherence between upstream and downstream sensor pairs. In addition, the amplitudes of the instabilities increase with the addition of roughness elements near the nose of the cone. Two of the measured instabilities were captured over a range of axial Reynolds numbers of about 1 - 2 million, with amplitudes ranging from low to turbulent breakdown. For these instabilities, the wave speed and amplitude growth can be calculated. The wave speeds were all near the edge velocity. Measured growth before breakdown for the two instabilities are between e3 and e4 from background noise levels. The initial linear growth rates for the instabilities are near 50 /m. Simultaneous measurement of two frequency bands of the secondary instabilities was made during a single run. It was found that each mode was spatially confined within a small azimuthal region, and that the regions of peak amplitude for one mode correspond to regions of minimal amplitude for the other.
Stationary intraoral tomosynthesis for dental imaging
Inscoe, Christina R.; Wu, Gongting; Soulioti, Danai E.; Platin, Enrique; Mol, Andre; Gaalaas, Laurence R.; Anderson, Michael R.; Tucker, Andrew W.; Boyce, Sarah; Shan, Jing; Gonzales, Brian; Lu, Jianping; Zhou, Otto
2017-03-01
Despite recent advances in dental radiography, the diagnostic accuracies for some of the most common dental diseases have not improved significantly, and in some cases remain low. Intraoral x-ray is the most commonly used x-ray diagnostic tool in dental clinics. It however suffers from the typical limitations of a 2D imaging modality including structure overlap. Cone-beam computed tomography (CBCT) uses high radiation dose and suffers from image artifacts and relatively low resolution. The purpose of this study is to investigate the feasibility of developing a stationary intraoral tomosynthesis (s-IOT) using spatially distributed carbon nanotube (CNT) x-ray array technology, and to evaluate its diagnostic accuracy compared to conventional 2D intraoral x-ray. A bench-top s-IOT device was constructed using a linear CNT based X-ray source array and a digital intraoral detector. Image reconstruction was performed using an iterative reconstruction algorithm. Studies were performed to optimize the imaging configuration. For evaluation of s-IOT's diagnostic accuracy, images of a dental quality assurance phantom, and extracted human tooth specimens were acquired. Results show s-IOT increases the diagnostic sensitivity for caries compared to intraoral x-ray at a comparable dose level.
Stationary power fuel cell commercialization status worldwide
Energy Technology Data Exchange (ETDEWEB)
Williams, M.C. [Dept. of Energy, Morgantown, WV (United States)
1996-12-31
Fuel cell technologies for stationary power are set to play a role in power generation applications worldwide. The worldwide fuel cell vision is to provide powerplants for the emerging distributed generation and on-site markets. Progress towards commercialization has occurred in all fuel cell development areas. Around 100 ONSI phosphoric acid fuel cell (PAFC) units have been sold, with significant foreign sales in Europe and Japan. Fuji has apparently overcome its PAFC decay problems. Industry-driven molten carbonate fuel cell (MCFC) programs in Japan and the U.S. are conducting megawatt (MW)-class demonstrations, which are bringing the MCFC to the verge of commercialization. Westinghouse Electric, the acknowledged world leader in tubular solid oxide fuel cell (SOFC) technology, continues to set performance records and has completed construction of a 4-MW/year manufacturing facility in the U.S. Fuel cells have also taken a major step forward with the conceptual development of ultra-high efficiency fuel cell/gas turbine plants. Many SOFC developers in Japan, Europe, and North America continue to make significant advances.
Stationary quenching wave in magnetized plasma
International Nuclear Information System (INIS)
Alikhanov, S.G.; Glushkov, I.S.
1976-01-01
The interaction of a magnetized hot plasma (ωsub(e)tau sub(e)>>1) with cold plasma or a gas leads to the appearanci of a cooling wave. The transition layer between hot and cold plasma is the main source of radiation losses which should be compensated by a heat flow from the hot region. A stationary state is considered, equations are written in the system in which temperature and magnetic field profiles are steady, and the plasma flux with magnetic field passes through the cooling wave. Calculations, have been carried out on a computer. The dependence of the magnetized plasma flux velocity Vsub(r) on the ratio p/Hsub(r) is shown, where p is the pressure, Hsub(r) is the magnetic field in the hot reqion. The dependence of the characteristic dimension of the cooling wave on the magnetic field is determined for the hot plasma region. A considerable fraction of the rediation losses is shown to fall to the region of (ωsub(e)tausub(e)< or approximately)1
Stationary black holes with stringy hair
Boos, Jens; Frolov, Valeri P.
2018-01-01
We discuss properties of black holes which are pierced by special configurations of cosmic strings. For static black holes, we consider radial strings in the limit when the number of strings grows to infinity while the tension of each single string tends to zero. In a properly taken limit, the stress-energy tensor of the string distribution is finite. We call such matter stringy matter. We present a solution of the Einstein equations for an electrically charged static black hole with the stringy matter, with and without a cosmological constant. This solution is a warped product of two metrics. One of them is a deformed 2-sphere, whose Gaussian curvature is determined by the energy density of the stringy matter. We discuss the embedding of a corresponding distorted sphere into a three-dimensional Euclidean space and formulate consistency conditions. We also found a relation between the square of the Weyl tensor invariant of the four-dimensional spacetime of the stringy black holes and the energy density of the stringy matter. In the second part of the paper, we discuss test stationary strings in the Kerr geometry and in its Kerr-NUT-(anti-)de Sitter generalizations. Explicit solutions for strings that are regular at the event horizon are obtained. Using these solutions, the stress-energy tensor of the stringy matter in these geometries is calculated. Extraction of the angular momentum from rotating black holes by such strings is also discussed.
REACH: impact on the US cosmetics industry?
Pouillot, Anne; Polla, Barbara; Polla, Ada
2009-03-01
The Registration, Evaluation, Authorization and restriction of Chemicals (REACH) is a recent European regulation on chemical substances meant to protect human health and the environment. REACH imposes the "precautionary principle" where additional data and definitive action are required when uncertainty is identified. The cosmetics industry is only partially concerned by REACH: while the stages of registration and evaluation apply to cosmetics, those of authorization and restriction most likely will not, as cosmetic ingredients are already subject to regulation by various agencies and directives. REACH has potential benefits to the industry including the possibility of reassuring consumers and improving their image of chemicals and cosmetics. However, REACH also has potential disadvantages, mainly with regard to impeding innovation. The American cosmetics industry will be affected by REACH, because all US manufacturers who export substances to Europe will have to fully comply with REACH.
Urban Noise Recorded by Stationary Monitoring Stations
Bąkowski, Andrzej; Radziszewski, Leszek; Dekýš, Vladimir
2017-10-01
The paper presents the analysis results of equivalent sound level recorded by two road traffic noise monitoring stations. The stations were located in Kielce (an example of a medium-size town in Poland) at the roads in the town in the direction of Łódź and Lublin. The measurements were carried out through stationary stations monitoring the noise and traffic of motor vehicles. The RMS values based on A-weighted sound level were recorded every 1 s in the buffer and the results were registered every 1 min over the period of investigations. The registered data were the basis for calculating the equivalent sound level for three time intervals: from 6:00 to 18:00, from 18:00 to 22:00 and from 22:00 to 6:00. Analysis included the values of the equivalent sound level recorded for different days of the week split into 24h periods, nights, days and evenings. The data analysed included recordings from 2013. The agreement of the distribution of the variable under analysis with normal distribution was evaluated. It was demonstrated that in most cases (for both roads) there was sufficient evidence to reject the null hypothesis at the significance level of 0.05. It was noted that compared with Łódź Road, in the case of Lublin Road data, more cases were recorded for which the null hypothesis could not be rejected. Uncertainties of the equivalent sound level measurements were compared within the periods under analysis. The standard deviation, coefficient of variation, the positional coefficient of variation, the quartile deviation was proposed for performing a comparative analysis of the obtained data scattering. The investigations indicated that the recorded data varied depending on the traffic routes and time intervals. The differences concerned the values of uncertainties and coefficients of variation of the equivalent sound levels.
Stationary phases for superheated water chromatography
International Nuclear Information System (INIS)
Saha, Shikha
2002-01-01
This project focused on the comparison of conventional liquid chromatography and superheated water chromatography. It examined the differences in efficiency and retention of a range of different stationary phases. Alkyl aryl ketones and eight aromatic compounds were separated on PBD-zirconia, Xterra RP 18, Luna C 18 (2) and Oasis HLB columns using conventional LC and superheated water chromatography system. The retention indices were determined in the different eluents. On changing the organic component of the eluent from methanol to acetonitrile to superheated water considerable improvements were found in the peak shapes and column efficiencies on the PBD-zirconia and Oasis HLB columns. PS-DVB, PBD-zirconia and Xterra RP 18 columns have been used in efficiency studies. It was found that simply elevating the column temperature did not increase the efficiency of a separation in superheated water chromatography. The efficiency depended on flow rate, injection volume and also mobile phase preheating system. Although high efficiencies were not achieved with superheated water on PS-DVB and Xterra RP 18 columns, a higher efficiency was achieved on a PBD-zirconia column with superheated water than with 25-35% ACN at room temperature. The proposed theoretical increases in u opt were measured on three columns using superheated water as the mobile phase. The application of the superheated water chromatographic method to the separation of the pungent constituents of ginger by superheated water chromatography-NMR coupling system was studied. The coupling of superheated water chromatography using deuterium oxide to NMR spectroscopy for the separation of dry ginger extract was successful, although the NMR sensitivity in on-line mode coupling system was low. However, four compounds were identified in the ginger extract by stop-flow mode on superheated water chromatography-UV-NMR detection system. (author)
Modeling stationary and dynamic pebbles in a pebble bed reactor
International Nuclear Information System (INIS)
Zhao, Xiang; Montgomery, Trent; Zhang, Sijun
2011-01-01
This paper presents a numerical study of the stationary and dynamic pebbles in a pebble bed reactor (PBR) by means of discrete element method (DEM). At first, the packing structure of stationary pebbles is simulated by filling process until the settling of pebbles into PBR. The packing structural properties are obtained and analyzed. Subsequently, when the outlet of PBR is open during the operational maintenance of PBR, the stationary pebbles start to flow downward and are removed at the bottom of PBR. The dynamic behavior of pebbles is predicted and discussed. Our results indicate the DEM can offer both macroscopic and microscopic information for PBR design calculations and safety assessment. (author)
Cosmological red shift in the Seeliger-Einstein stationary Universe
International Nuclear Information System (INIS)
Kropotkin, P.N.
1988-01-01
A problem of Seeliger-Einstein stationary Universe is considered. Simple empirical relations between cosmological and physical constants to which attention was paid by Stanukovich K., Dikke R., Dirac P. testify to the supposition on stationary Universe. The Universe expansion being absent, a hypothesis of ''photon aging'' suggested in 1929 by Belopolskij A. and Zwicky F. must be accepted for explanation of Hubble effect. It is stated that abandon the Seeliger-Einstein stationary cosmological model would be premature. Study and comparison of different mechanisms suggested for validation of photon aging hypothesis is necessary
Membrane oscillations in the channel of a stationary plasma motor
International Nuclear Information System (INIS)
Bugrova, A.I.; Lipatov, A.S.; Morozov, A.I.; Kharchevnikov, V.K.
1999-01-01
Results of measuring the ion flux density in the channel of the stationary plasma drive are presented. Two plane easters move both along and transverse to the plasma flux. During the experiment, the strong low-frequency oscillations (∼ 35 kHz) are observed in the channel of the stationary plasma drive. It is found that membrane oscillations are accompanied by oscillations of the electron temperature. These membrane oscillations affect the divergence of the output plasma jet and the erosion of the output part of the channel of the stationary plasma drive [ru
DEFF Research Database (Denmark)
Mortensen, Erik Lykke; Flensborg-Madsen, Trine; Molbo, Drude
2014-01-01
To analyze associations in late midlife between sex, age, education and social class, and the Big Five personality traits; to analyze associations between personality traits and cognitive ability in late midlife; and to evaluate how these associations are influenced by demographic factors....
Asymptotic Theory for the QMLE in GARCH-X Models with Stationary and Non-Stationary Covariates
DEFF Research Database (Denmark)
Han, Heejoon; Kristensen, Dennis
as captured by its long-memory parameter dx; in particular, we allow for both stationary and non-stationary covariates. We show that the QMLE'’s of the regression coefficients entering the volatility equation are consistent and normally distributed in large samples independently of the degree of persistence....... This implies that standard inferential tools, such as t-statistics, do not have to be adjusted to the level of persistence. On the other hand, the intercept in the volatility equation is not identifi…ed when the covariate is non-stationary which is akin to the results of Jensen and Rahbek (2004, Econometric...
STABLE STATIONARY STATES OF NON-LOCAL INTERACTION EQUATIONS
FELLNER, KLEMENS
2010-12-01
In this paper, we are interested in the large-time behaviour of a solution to a non-local interaction equation, where a density of particles/individuals evolves subject to an interaction potential and an external potential. It is known that for regular interaction potentials, stable stationary states of these equations are generically finite sums of Dirac masses. For a finite sum of Dirac masses, we give (i) a condition to be a stationary state, (ii) two necessary conditions of linear stability w.r.t. shifts and reallocations of individual Dirac masses, and (iii) show that these linear stability conditions imply local non-linear stability. Finally, we show that for regular repulsive interaction potential Wε converging to a singular repulsive interaction potential W, the Dirac-type stationary states ρ̄ ε approximate weakly a unique stationary state ρ̄ ∈ L∞. We illustrate our results with numerical examples. © 2010 World Scientific Publishing Company.
Genetics Home Reference: autosomal dominant congenital stationary night blindness
... collapse boxes. Description Autosomal dominant congenital stationary night blindness is a disorder of the retina , which is the specialized tissue at the back of the eye that detects light and color. People with this condition typically have difficulty seeing ...
Genetics Home Reference: X-linked congenital stationary night blindness
... collapse boxes. Description X-linked congenital stationary night blindness is a disorder of the retina , which is the specialized tissue at the back of the eye that detects light and color. People with this condition typically have difficulty seeing ...
Genetics Home Reference: autosomal recessive congenital stationary night blindness
... collapse boxes. Description Autosomal recessive congenital stationary night blindness is a disorder of the retina , which is the specialized tissue at the back of the eye that detects light and color. People with this condition typically have difficulty seeing ...
Acoustic Characterization of a Stationary Field Synchronous Motor
National Research Council Canada - National Science Library
Woodward, E
2001-01-01
.... We investigate the gross acoustic signature of a notional stationary field synchronous motor utilized as a marine propulsion motor in a naval combatant using the following methodology: (1) model the forces...
New source review for stationary sources of air pollution
National Research Council Canada - National Science Library
Committee on Changes in New Source Review Programs for Stationary Sources of Air Pollution, National Research Council
2006-01-01
The Clean Air Act established a pair of programsâ€"known as New Source Review (NSR)â€"that regulate large stationary sources of air pollution, such as factories and electricity-generating facilities...
Vacillations induced by interference of stationary and traveling planetary waves
Salby, Murry L.; Garcia, Rolando R.
1987-01-01
The interference pattern produced when a traveling planetary wave propagates over a stationary forced wave is explored, examining the interference signature in a variety of diagnostics. The wave field is first restricted to a diatomic spectrum consisting of two components: a single stationary wave and a single monochromatic traveling wave. A simple barotropic normal mode propagating over a simple stationary plane wave is considered, and closed form solutions are obtained. The wave fields are then restricted spatially, providing more realistic structures without sacrificing the advantages of an analytical solution. Both stationary and traveling wave fields are calculated numerically with the linearized Primitive Equations in a realistic basic state. The mean flow reaction to the fluctuating eddy forcing which results from interference is derived. Synoptic geopotential behavior corresponding to the combined wave and mean flow fields is presented, and the synoptic signature in potential vorticity on isentropic surfaces is examined.
Expansions of general stationary stochastic optical fields: general formalism
International Nuclear Information System (INIS)
Martinez-Herrero, R.; Mejias, P.M.
1985-01-01
A new expansion of a general stationary stochastic optical field is derived. Each term of the series is seen to represent a recently defined new class of optical fields, the so-called spectrally quasi-factorizable fields. Alternative expansion in terms of nonstationary fields that obey the wave equation is also shown. A relationship between temporal and spatial features of stationary free optical fields is discussed
Stationary Density Variation Produced by a Standing Plasma Wave
DEFF Research Database (Denmark)
Michelsen, Poul; Pécseli, Hans; Juul Rasmussen, Jens
1977-01-01
Measurements are presented of a stationary density modulation produced by a standing electron plasma wave. The experimental results are well explained by taking into account the ponderomotive forces on the electrons exerted by the high frequency field.......Measurements are presented of a stationary density modulation produced by a standing electron plasma wave. The experimental results are well explained by taking into account the ponderomotive forces on the electrons exerted by the high frequency field....
Similarity flows between a rotating and a stationary disk
International Nuclear Information System (INIS)
Buchmann, J.H.; Qassim, R.Y.
1981-07-01
The radial distribution of fluid pressure on a stationary disk coaxial with a rotating disk is determined experimentally for various inter-disc spacings. The results show that similarity flows are only possible for both small and large values of this distance. In the former case, the flow faraway from the stationary disk appears to be that suggested by Batchelor, while in the latter case, the flow turns out to be in accordance with the assumption of Stewartson. (Author) [pt
The computation of stationary distributions of Markov chains through perturbations
Directory of Open Access Journals (Sweden)
Jeffery J. Hunter
1991-01-01
Full Text Available An algorithmic procedure for the determination of the stationary distribution of a finite, m-state, irreducible Markov chain, that does not require the use of methods for solving systems of linear equations, is presented. The technique is based upon a succession of m, rank one, perturbations of the trivial doubly stochastic matrix whose known steady state vector is updated at each stage to yield the required stationary probability vector.
Costationarity of Locally Stationary Time Series Using costat
Cardinali, Alessandro; Nason, Guy P.
2013-01-01
This article describes the R package costat. This package enables a user to (i) perform a test for time series stationarity; (ii) compute and plot time-localized autocovariances, and (iii) to determine and explore any costationary relationship between two locally stationary time series. Two locally stationary time series are said to be costationary if there exists two time-varying combination functions such that the linear combination of the two series with the functions produces another time...
Pushing concentration of stationary solar concentrators to the limit.
Winston, Roland; Zhang, Weiya
2010-04-26
We give the theoretical limit of concentration allowed by nonimaging optics for stationary solar concentrators after reviewing sun- earth geometry in direction cosine space. We then discuss the design principles that we follow to approach the maximum concentration along with examples including a hollow CPC trough, a dielectric CPC trough, and a 3D dielectric stationary solar concentrator which concentrates sun light four times (4x), eight hours per day year around.
Geophysics-based method of locating a stationary earth object
Daily, Michael R [Albuquerque, NM; Rohde, Steven B [Corrales, NM; Novak, James L [Albuquerque, NM
2008-05-20
A geophysics-based method for determining the position of a stationary earth object uses the periodic changes in the gravity vector of the earth caused by the sun- and moon-orbits. Because the local gravity field is highly irregular over a global scale, a model of local tidal accelerations can be compared to actual accelerometer measurements to determine the latitude and longitude of the stationary object.
Tightly localized stationary pulses in a multilevel atomic system
International Nuclear Information System (INIS)
Liu, Xiong-Jun; Oh, C. H.; Liu, Xin; Liu, Zheng-Xin; Kwek, L. C.
2007-01-01
We show that the pulse matching phenomenon can be obtained in the general multilevel system with electromagnetically induced transparency. For this we find a different way to create tightly localized stationary pulses by using counterpropagating pump fields. The present process is a spatial compression of excitation so that it allows us to shape and further intensify the localized stationary pulses, without using standing waves of pump fields or spatially modulated pump fields
Influence of Stationary Crossflow Modulation on Secondary Instability
Choudhari, Meelan M.; Li, Fei; Paredes, Pedro
2016-01-01
A likely scenario for swept wing transition on subsonic aircraft with natural laminar flow involves the breakdown of stationary crossflow vortices via high frequency secondary instability. A majority of the prior research on this secondary instability has focused on crossflow vortices with a single dominant spanwise wavelength. This paper investigates the effects of the spanwise modulation of stationary crossflow vortices at a specified wavelength by a subharmonic stationary mode. Secondary instability of the modulated crossflow pattern is studied using planar, partial-differential-equation based eigenvalue analysis. Computations reveal that weak modulation by the first subharmonic of the input stationary mode leads to mode splitting that is particularly obvious for Y-type secondary modes that are driven by the wall-normal shear of the basic state. Thus, for each Y mode corresponding to the fundamental wavelength of results in unmodulated train of crossflow vortices, the modulated flow supports a pair of secondary modes with somewhat different amplification rates. The mode splitting phenomenon suggests that a more complex stationary modulation such as that induced by natural surface roughness would yield a considerably richer spectrum of secondary instability modes. Even modest levels of subharmonic modulation are shown to have a strong effect on the overall amplification of secondary disturbances, particularly the Z-modes driven by the spanwise shear of the basic state. Preliminary computations related to the nonlinear breakdown of these secondary disturbances provide interesting insights into the process of crossflow transition in the presence of the first subharmonic of the dominant stationary vortex.
Stationary shear flows in CGL anisotropic toroidal plasmas
International Nuclear Information System (INIS)
Pastukhov, V.P.; Ilgisonis, V.I.
1996-01-01
Recently a general structure of stationary shear flows in toroidal plasmas was obtained in the frame of ideal isotropic-pressure MHD model. The structure of the stationary plasma flows was shown to be determined by a hidden symmetry of MHD equations inherent in the toroidal systems with nested magnetic surfaces. However, the characteristic frequencies of the stationary plasma motion can considerably exceed the collisional frequencies in real plasma experiments. In this case the CGL collisionless MHD model seems to be more adequate than the simplified isotropic-pressure MHD model to describe the stationary plasma flows. In this paper we have generalized our approach to analyze the stationary plasma flows in the frame of the collisionless CGL model. We have found again that the hidden symmetry inherent in the toroidal topology results in two integral invariants which depend on two independent surface functions. The structure of stationary flows for CGL model is still the same as for isotropic MHD, however, the pressure tensor components satisfy a appreciably modifies the steady state force-balance equation. These results are applied to analyze the generalized equilibrium in axisymmetric (tokamak-like) magnetic confinement systems
REACH: Evaluation Report and Executive Summary
Sibieta, Luke
2016-01-01
REACH is a targeted reading support programme designed to improve reading accuracy and comprehension in pupils with reading difficulties in Years 7 and 8. It is based on research by the Centre for Reading and Language at York and is delivered by specially trained teaching assistants (TAs). This evaluation tested two REACH interventions, one based…
Haddock, Bryan L; Siegel, Shannon R; Wikin, Linda D
2009-01-01
INTRODUCTION: The prevalence of obesity in children has reached epidemic proportions with over 37% of children aged 6-11 years in the U.S. being classified as "at risk for overweight" or "overweight." Utilization of active video games has been proposed as one possible mechanism to help shift the tide of the obesity epidemic. PURPOSE: The purpose of this study was to determine if riding a stationary bike that controlled a video game would lead to significantly greater energy expenditure than riding the same bike without the video game connected. METHODS: Twenty children, 7-14 years old, with a BMI classification of "at risk for overweight" or "overweight" participated in this study. Following familiarization, energy expenditure was evaluated while riding a stationary bike for 20 minutes. One test was performed without the addition of a video game and one test with the bike controlling the speed of a car on the video game. RESULTS: Oxygen consumption and energy expenditure were significantly elevated above baseline in both conditions. Energy expenditure was significantly higher while riding the bike as it controlled the video game (4.4 ± 1.2 Kcal·min(-1)) than when riding the bike by itself (3.7 ± 1.1 Kcal·min(-1)) (p0.05). CONCLUSION: Using a stationary bike to control a video game led to greater energy expenditure than riding a stationary bike without the video game and without a related increase in perceived exertion.
Proteomic Analysis of Stationary Phase in the Marine Bacterium "Candidatus Pelagibacter ubique"
Energy Technology Data Exchange (ETDEWEB)
Sowell, S. M.; Norbeck, A. D.; Lipton, M. S.; Nicora, C. D.; Callister, S. J.; Smith, R. D.; Barofsky, D. F.; Giovannoni, S. J.
2008-05-09
The α-proteobacterium ‘Candidatus Pelagibacter ubique’ str. HTCC1062, and most other members of the SAR11 clade, lack genes for assimilatory sulfate reduction, making them dependent on organosulfur compounds that occur naturally in seawater. To investigate how these cells adapt to sulfur limitation, batch cultures were grown in defined media containing either limiting or non-limiting amounts of dimethylsulfoniopropionate (DMSP) as the sole sulfur source. Protein and mRNA expression were measured during exponential growth, immediately prior to stationary phase, and in late stationary phase. Two distinct responses were observed: one as DMSP became exhausted, and another as cells acclimated to a sulfur-limited environment. The first response was characterized by increased transcription and translation of all Ca. P. ubique genes downstream of previously confirmed S-adenosyl methionine (SAM) riboswitches: bhmT, mmuM, and metY. Proteins encoded by these genes were up to 33 times more abundant as DMSP became limiting. Their predicted function is to shunt all available sulfur to methionine. The secondary response, observed during sulfur-depleted stationary phase, was a 6-10 fold increase in transcription of the heme c shuttle ccmC and two small genes of unknown function (SAR11_1163 and SAR11_1164). This bacterium's strategy for coping with sulfur stress appears to be intracellular redistribution to support methionine biosynthesis, rather than increasing organosulfur import. Many of the genes and SAM riboswitches involved in this response are located in a hypervariable genome region (HVR). One of these HVR genes, ordL, is located downstream of a conserved motif that evidence suggests is a novel riboswitch.
Demaria, E. M.; Goodrich, D. C.; Keefer, T.
2017-12-01
Observed sub-daily precipitation intensities from contrasting hydroclimatic environments in the USA are used to evaluate temporal trends and to develop Intensity-Duration Frequency (IDF) curves under stationary and nonstationary climatic conditions. Analyses are based on observations from two United States Department of Agriculture (USDA)-Agricultural Research Service (ARS) experimental watersheds located in a semi-arid and a temperate environment. We use an Annual Maximum Series (AMS) and a Partial Duration Series (PDS) approach to identify temporal trends in maximum intensities for durations ranging from 5- to 1440-minutes. A Bayesian approach with Monte Carlo techniques is used to incorporate the effect of non-stationary climatic assumptions in the IDF curves. The results show increasing trends in observed AMS sub-daily intensities in both watersheds whereas trends in the PDS observations are mostly positive in the semi-arid site and a mix of positive and negative in the temperate site. Stationary climate assumptions lead to much lower estimated sub-daily intensities than those under non-stationary assumptions with larger absolute differences found for shorter durations and smaller return periods. The risk of failure (R) of a hydraulic structure is increased for non-stationary effects over those of stationary effects, with absolute differences of 25% for a 100-year return period (T) and a project life (n) of 100 years. The study highlights the importance of considering non-stationarity, due to natural variability or to climate change, in storm design.
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The database for reaching experiments and models.
Directory of Open Access Journals (Sweden)
Ben Walker
Full Text Available Reaching is one of the central experimental paradigms in the field of motor control, and many computational models of reaching have been published. While most of these models try to explain subject data (such as movement kinematics, reaching performance, forces, etc. from only a single experiment, distinct experiments often share experimental conditions and record similar kinematics. This suggests that reaching models could be applied to (and falsified by multiple experiments. However, using multiple datasets is difficult because experimental data formats vary widely. Standardizing data formats promises to enable scientists to test model predictions against many experiments and to compare experimental results across labs. Here we report on the development of a new resource available to scientists: a database of reaching called the Database for Reaching Experiments And Models (DREAM. DREAM collects both experimental datasets and models and facilitates their comparison by standardizing formats. The DREAM project promises to be useful for experimentalists who want to understand how their data relates to models, for modelers who want to test their theories, and for educators who want to help students better understand reaching experiments, models, and data analysis.
Numerical investigation of the late-time Kerr tails
Energy Technology Data Exchange (ETDEWEB)
Racz, Istvan; Toth, Gabor Zs, E-mail: iracz@rmki.kfki.hu, E-mail: tgzs@rmki.kfki.hu [RMKI, H-1121 Budapest, Konkoly Thege Miklos ut 29-33 (Hungary)
2011-10-07
The late-time behavior of a scalar field on fixed Kerr background is examined in a numerical framework incorporating the techniques of conformal compactification and hyperbolic initial value formulation. The applied code is 1+(1+2) as it is based on the use of the spectral method in the angular directions while in the time-radial section fourth order finite differencing, along with the method of lines, is applied. The evolution of various types of stationary and non-stationary pure multipole initial states are investigated. The asymptotic decay rates are determined not only in the domain of outer communication but along the event horizon and at future null infinity as well. The decay rates are found to be different for stationary and non-stationary initial data, and they also depend on the fall off properties of the initial data toward future null infinity. The energy and angular momentum transfers are found to show significantly different behavior in the initial phase of the time evolution. The quasinormal ringing phase and the tail phase are also investigated. In the tail phase, the decay exponents for the energy and angular momentum losses at I{sup +} are found to be smaller than at the horizon which is in accordance with the behavior of the field itself and it means that at late times the energy and angular momentum falling into the black hole become negligible in comparison with the energy and angular momentum radiated toward I{sup +}. The energy and angular momentum balances are used as additional verifications of the reliability of our numerical method.
Numerical investigation of the late-time Kerr tails
International Nuclear Information System (INIS)
Racz, Istvan; Toth, Gabor Zs
2011-01-01
The late-time behavior of a scalar field on fixed Kerr background is examined in a numerical framework incorporating the techniques of conformal compactification and hyperbolic initial value formulation. The applied code is 1+(1+2) as it is based on the use of the spectral method in the angular directions while in the time-radial section fourth order finite differencing, along with the method of lines, is applied. The evolution of various types of stationary and non-stationary pure multipole initial states are investigated. The asymptotic decay rates are determined not only in the domain of outer communication but along the event horizon and at future null infinity as well. The decay rates are found to be different for stationary and non-stationary initial data, and they also depend on the fall off properties of the initial data toward future null infinity. The energy and angular momentum transfers are found to show significantly different behavior in the initial phase of the time evolution. The quasinormal ringing phase and the tail phase are also investigated. In the tail phase, the decay exponents for the energy and angular momentum losses at I + are found to be smaller than at the horizon which is in accordance with the behavior of the field itself and it means that at late times the energy and angular momentum falling into the black hole become negligible in comparison with the energy and angular momentum radiated toward I + . The energy and angular momentum balances are used as additional verifications of the reliability of our numerical method.
Enhancing US Operational Reach in Southeast Asia
National Research Council Canada - National Science Library
Hitchcock, David
2003-01-01
.... While this treat continues to exist, the US Pacific Command (PACOM) must also pursue a neat term methodology to expand its operational reach and ability to respond to contingencies throughout the East Asian littoral, especially within Southeast Asia...
Reaching the Overlooked Student in Physical Education
Esslinger, Keri; Esslinger, Travis; Bagshaw, Jarad
2015-01-01
This article describes the use of live action role-playing, or "LARPing," as a non-traditional activity that has the potential to reach students who are not interested in traditional physical education.
Compact muon solenoid magnet reaches full field
2006-01-01
Scientist of the U.S. Department of Energy in Fermilab and collaborators of the US/CMS project announced that the world's largest superconducting solenoid magnet has reached full field in tests at CERN. (1 apge)
Stability of Bifurcating Stationary Solutions of the Artificial Compressible System
Teramoto, Yuka
2018-02-01
The artificial compressible system gives a compressible approximation of the incompressible Navier-Stokes system. The latter system is obtained from the former one in the zero limit of the artificial Mach number ɛ which is a singular limit. The sets of stationary solutions of both systems coincide with each other. It is known that if a stationary solution of the incompressible system is asymptotically stable and the velocity field of the stationary solution satisfies an energy-type stability criterion, then it is also stable as a solution of the artificial compressible one for sufficiently small ɛ . In general, the range of ɛ shrinks when the spectrum of the linearized operator for the incompressible system approaches to the imaginary axis. This can happen when a stationary bifurcation occurs. It is proved that when a stationary bifurcation from a simple eigenvalue occurs, the range of ɛ can be taken uniformly near the bifurcation point to conclude the stability of the bifurcating solution as a solution of the artificial compressible system.
Bacteriophage T4 Infection of Stationary Phase E. coli: Life after Log from a Phage Perspective
Directory of Open Access Journals (Sweden)
Elizabeth Martin Kutter
2016-09-01
Full Text Available Virtually all studies of phage infections investigate bacteria growing exponentially in rich media. In nature, however, phages largely encounter non-growing cells. Bacteria entering stationary phase often activate well-studied stress defense mechanisms that drastically alter the cell, facilitating its long-term survival. An understanding of phage-host interactions in such conditions is of major importance from both an ecological and therapeutic standpoint. Here, we show that bacteriophage T4 can efficiently bind to, infect and kill E. coli in stationary phase, both in the presence and absence of a functional stationary-phase sigma factor, and explore the response of T4-infected stationary phase cells to the addition of fresh nutrients 5 or 24 hours after that infection. An unexpected new mode of response has been identified. Hibernation mode is a persistent but reversible dormant state in which the infected cells make at least some phage enzymes, but halt phage development until appropriate nutrients become available before producing phage particles. Our evidence indicates that the block in hibernation mode occurs after the middle-mode stage of phage development; host DNA breakdown and the incorporation of the released nucleotides into phage DNA indicate that the enzymes of the nucleotide synthesizing complex, under middle-mode control, have been made and assembled into a functional state. Once fresh glucose and amino acids become available, the standard lytic infection process rapidly resumes and concentrations of up to 1011 progeny phage (an average of about 40 phage per initially-present cell are produced. All evidence is consistent with the hibernation-mode control point lying between middle mode and late mode T4 gene expression. We have also observed a scavenger response, where the infecting phage takes advantage of whatever few nutrients are available to produce small quantities of progeny within 2 to 5 hours after infection. The scavenger
Late-onset Huntington's disease: diagnostic and prognostic considerations.
Koutsis, Georgios; Karadima, Georgia; Kladi, Athina; Panas, Marios
2014-07-01
To address diagnostic and prognostic issues in patients with late-onset Huntington's disease (HD). We analyzed a cohort of 41 late-onset (≥60 years) HD patients and compared them to 39 late-onset patients referred for HD testing that were negative for the HD-expansion and to 290 usual-onset (20-59 years) HD patients. Disease severity was assessed by the Total Functional Capacity Scale. Late-onset HD comprised 11.5% of our HD cohort. In total, 70.7% of late-onset HD patients had positive family history compared to 15.4% of late-onset expansion-negative patients (p < 0.001). Clinical features at onset or presentation could not usefully distinguish between late-onset expansion-positive and negative patients, excepting hemichorea, which was absent from the HD group (p = 0.024). Chorea was the first clinical feature in 53.7% and a presenting feature in 90.2% of late-onset HD. The mutation hit rate for late-onset patients was 51.3%, lower than in usual-onset patients (p = 0.04). Frequencies of chorea, cognitive impairment and psychiatric manifestations at onset or presentation were not significantly different between late-onset and usual-onset HD patients. Gait unsteadiness however was more common at presentation in late-onset HD (p = 0.007). Late-onset HD patients reached a severe stage of illness on average 2.8 years earlier than usual-onset HD patients (p = 0.046). A positive family history suggestive of HD, although absent in a third of patients, remains a helpful clue in diagnosing late-onset HD. Prognosis of late-onset HD in terms of Total Functional Capacity appears no better and shows a trend of being somewhat less favorable compared to usual-onset HD. Copyright © 2014 Elsevier Ltd. All rights reserved.
Zhao, Qing; Zhu, Zhiqiang; Chen, Jun
2017-12-01
Organic carbonyl electrode materials that have the advantages of high capacity, low cost and being environmentally friendly, are regarded as powerful candidates for next-generation stationary and redox flow rechargeable batteries (RFBs). However, low carbonyl utilization, poor electronic conductivity and undesired dissolution in electrolyte are urgent issues to be solved. Here, we summarize a molecular engineering approach for tuning the capacity, working potential, concentration of active species, kinetics, and stability of stationary and redox flow batteries, which well resolves the problems of organic carbonyl electrode materials. As an example, in stationary batteries, 9,10-anthraquinone (AQ) with two carbonyls delivers a capacity of 257 mAh g -1 (2.27 V vs Li + /Li), while increasing the number of carbonyls to four with the formation of 5,7,12,14-pentacenetetrone results in a higher capacity of 317 mAh g -1 (2.60 V vs Li + /Li). In RFBs, AQ, which is less soluble in aqueous electrolyte, reaches 1 M by grafting -SO 3 H with the formation of 9,10-anthraquinone-2,7-disulphonic acid, resulting in a power density exceeding 0.6 W cm -2 with long cycling life. Therefore, through regulating substituent groups, conjugated structures, Coulomb interactions, and the molecular weight, the electrochemical performance of carbonyl electrode materials can be rationally optimized. This review offers fundamental principles and insight into designing advanced carbonyl materials for the electrodes of next-generation rechargeable batteries. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Propagation of Boundary-Induced Discontinuity in Stationary Radiative Transfer
Kawagoe, Daisuke; Chen, I.-Kun
2018-01-01
We consider the boundary value problem of the stationary transport equation in the slab domain of general dimensions. In this paper, we discuss the relation between discontinuity of the incoming boundary data and that of the solution to the stationary transport equation. We introduce two conditions posed on the boundary data so that discontinuity of the boundary data propagates along positive characteristic lines as that of the solution to the stationary transport equation. Our analysis does not depend on the celebrated velocity averaging lemma, which is different from previous works. We also introduce an example in two dimensional case which shows that piecewise continuity of the boundary data is not a sufficient condition for the main result.
Impact of the updating scheme on stationary states of networks
International Nuclear Information System (INIS)
Radicchi, F; Ahn, Y Y; Meyer-Ortmanns, H
2008-01-01
From Boolean networks it is well known that the number of attractors as a function of the system size depends on the updating scheme which is chosen either synchronously or asynchronously. In this contribution, we report on a systematic interpolation between synchronous and asynchronous updating in a one-dimensional chain of Ising spins. The stationary state for fully synchronous updating is antiferromagnetic. The interpolation allows us to locate a phase transition between phases with an absorbing and a fluctuating stationary state. The associated universality class is that of parity conservation. We also report on a more recent study of asynchronous updates applied to the yeast cell-cycle network. Compared to the synchronous update, the basin of attraction of the largest attractor considerably shrinks and the convergence to the biological pathway slows down and is less dominant. Both examples illustrate how sensitively the stationary states and the properties of attractors can depend on the updating mode of the algorithm
Recent development of ionic liquid stationary phases for liquid chromatography.
Shi, Xianzhe; Qiao, Lizhen; Xu, Guowang
2015-11-13
Based on their particular physicochemical characteristics, ionic liquids have been widely applied in many fields of analytical chemistry. Many types of ionic liquids were immobilized on a support like silica or monolith as stationary phases for liquid chromatography. Moreover, different approaches were developed to bond covalently ionic liquids onto the supporting materials. The obtained ionic liquid stationary phases show multi-mode mechanism including hydrophobic, hydrophilic, hydrogen bond, anion exchange, π-π, and dipole-dipole interactions. Therefore, they could be used in different chromatographic modes including ion-exchange, RPLC, NPLC and HILIC to separate various classes of compounds. This review mainly summarizes the immobilized patterns and types of ionic liquid stationary phases, their retention mechanisms and applications in the recent five years. Copyright © 2015 Elsevier B.V. All rights reserved.
Non-stationary condition monitoring through event alignment
DEFF Research Database (Denmark)
Pontoppidan, Niels Henrik; Larsen, Jan
2004-01-01
We present an event alignment framework which enables change detection in non-stationary signals. change detection. Classical condition monitoring frameworks have been restrained to laboratory settings with stationary operating conditions, which are not resembling real world operation....... In this paper we apply the technique for non-stationary condition monitoring of large diesel engines based on acoustical emission sensor signals. The performance of the event alignment is analyzed in an unsupervised probabilistic detection framework based on outlier detection with either Principal Component...... Analysis or Gaussian Processes modeling. We are especially interested in the true performance of the condition monitoring performance with mixed aligned and unaligned data, e.g. detection of fault condition of unaligned examples versus false alarms of aligned normal condition data. Further, we expect...
Non-Stationary Internal Tides Observed with Satellite Altimetry
Ray, Richard D.; Zaron, E. D.
2011-01-01
Temporal variability of the internal tide is inferred from a 17-year combined record of Topex/Poseidon and Jason satellite altimeters. A global sampling of along-track sea-surface height wavenumber spectra finds that non-stationary variance is generally 25% or less of the average variance at wavenumbers characteristic of mode-l tidal internal waves. With some exceptions the non-stationary variance does not exceed 0.25 sq cm. The mode-2 signal, where detectable, contains a larger fraction of non-stationary variance, typically 50% or more. Temporal subsetting of the data reveals interannual variability barely significant compared with tidal estimation error from 3-year records. Comparison of summer vs. winter conditions shows only one region of noteworthy seasonal changes, the northern South China Sea. Implications for the anticipated SWOT altimeter mission are briefly discussed.
Non-Stationary Dependence Structures for Spatial Extremes
Huser, Raphaël
2016-03-03
Max-stable processes are natural models for spatial extremes because they provide suitable asymptotic approximations to the distribution of maxima of random fields. In the recent past, several parametric families of stationary max-stable models have been developed, and fitted to various types of data. However, a recurrent problem is the modeling of non-stationarity. In this paper, we develop non-stationary max-stable dependence structures in which covariates can be easily incorporated. Inference is performed using pairwise likelihoods, and its performance is assessed by an extensive simulation study based on a non-stationary locally isotropic extremal t model. Evidence that unknown parameters are well estimated is provided, and estimation of spatial return level curves is discussed. The methodology is demonstrated with temperature maxima recorded over a complex topography. Models are shown to satisfactorily capture extremal dependence.
Integrity assessment of stationary blade ring for nuclear power plant
International Nuclear Information System (INIS)
Park, Jung Yong; Chung, Yong Keun; Park, Jong Jin; Kang, Yong Ho
2004-01-01
The inner side between HP stationary blades in no.1 turbine of nuclear power plant A is damaged by the FAC(Flow Assisted Corrosion) which is exposed to moisture. For many years the inner side is repaired by welding the damaged part, however, the FAC continues to deteriorate the original material of the welded blade ring. In this study, we have two stages to verify the integrity of stationary blade ring in nuclear power plant A. In the stage I, replication of blade ring is performed to survey the microstructure of blade ring. In the stage II, the stress analysis of blade ring is performed to verify the structural safety of blade ring. Throughout the two stages analysis of blade ring, the stationary blade ring had remained undamaged
Inference for local autocorrelations in locally stationary models.
Zhao, Zhibiao
2015-04-01
For non-stationary processes, the time-varying correlation structure provides useful insights into the underlying model dynamics. We study estimation and inferences for local autocorrelation process in locally stationary time series. Our constructed simultaneous confidence band can be used to address important hypothesis testing problems, such as whether the local autocorrelation process is indeed time-varying and whether the local autocorrelation is zero. In particular, our result provides an important generalization of the R function acf() to locally stationary Gaussian processes. Simulation studies and two empirical applications are developed. For the global temperature series, we find that the local autocorrelations are time-varying and have a "V" shape during 1910-1960. For the S&P 500 index, we conclude that the returns satisfy the efficient-market hypothesis whereas the magnitudes of returns show significant local autocorrelations.
Retention of Halogenated Solutes on Stationary Phases Containing Heavy Atoms
Directory of Open Access Journals (Sweden)
Toshio Miwa
2013-05-01
Full Text Available To examine the effects of weak intermolecular interactions on solid-phase extraction (SPE and chromatographic separation, we synthesized some novel stationary phases with a heavy atom effect layer by immobilizing halogenated aromatic rings and hydroxyl groups onto the surface of a hydrophilic base polymer. Using SPE cartridges packed with the functionalized materials, we found that the heavy atom stationary phases could selectively retain halophenols in organic solvents, such as 1-propanol which blocks the hydrogen bonding, or acetonitrile which blocks the p-p interaction. The extraction efficiency of the materials toward the halophenols depended on the dipole moments of phenoxy groups present as functional groups. On the other hand, the extraction efficiency of solutes toward the functional group depended on their molar refractions, i.e., induced dipole moments. The retention of the solutes to the stationary phase ultimately depended on not only strong intermolecular interactions, but also the effects of weak interactions such as the dispersion force.
Pool boiling from rotating and stationary spheres in liquid nitrogen
Cuan, Winston M.; Schwartz, Sidney H.
1988-01-01
Results are presented for a preliminary experiment involving saturated pool boiling at 1 atm from rotating 2 and 3 in. diameter spheres which were immersed in liquid nitrogen (LN2). Additional results are presented for a stationary, 2 inch diameter sphere, quenched in LN2, which were obtained utilizing a more versatile and complete experimental apparatus that will eventually be used for additional rotating sphere experiments. The speed for the rotational tests was varied from 0 to 10,000 rpm. The stationary experiments parametrically varied pressure and subcooling levels from 0 to 600 psig and from 0 to 50 F, respectively. During the rotational tests, a high speed photographic analysis was undertaken to measure the thickness of the vapor film surrounding the sphere. The average Nusselt number over the cooling period was plotted against the rotational Reynolds number. Stationary sphere results included local boiling heat transfer coefficients at different latitudinal locations, for various pressure and subcooling levels.
On Maximal Hard-Core Thinnings of Stationary Particle Processes
Hirsch, Christian; Last, Günter
2018-02-01
The present paper studies existence and distributional uniqueness of subclasses of stationary hard-core particle systems arising as thinnings of stationary particle processes. These subclasses are defined by natural maximality criteria. We investigate two specific criteria, one related to the intensity of the hard-core particle process, the other one being a local optimality criterion on the level of realizations. In fact, the criteria are equivalent under suitable moment conditions. We show that stationary hard-core thinnings satisfying such criteria exist and are frequently distributionally unique. More precisely, distributional uniqueness holds in subcritical and barely supercritical regimes of continuum percolation. Additionally, based on the analysis of a specific example, we argue that fluctuations in grain sizes can play an important role for establishing distributional uniqueness at high intensities. Finally, we provide a family of algorithmically constructible approximations whose volume fractions are arbitrarily close to the maximum.
A Generalized Framework for Non-Stationary Extreme Value Analysis
Ragno, E.; Cheng, L.; Sadegh, M.; AghaKouchak, A.
2017-12-01
Empirical trends in climate variables including precipitation, temperature, snow-water equivalent at regional to continental scales are evidence of changes in climate over time. The evolving climate conditions and human activity-related factors such as urbanization and population growth can exert further changes in weather and climate extremes. As a result, the scientific community faces an increasing demand for updated appraisal of the time-varying climate extremes. The purpose of this study is to offer a robust and flexible statistical tool for non-stationary extreme value analysis which can better characterize the severity and likelihood of extreme climatic variables. This is critical to ensure a more resilient environment in a changing climate. Following the positive feedback on the first version of Non-Stationary Extreme Value Analysis (NEVA) Toolbox by Cheng at al. 2014, we present an improved version, i.e. NEVA2.0. The upgraded version herein builds upon a newly-developed hybrid evolution Markov Chain Monte Carlo (MCMC) approach for numerical parameters estimation and uncertainty assessment. This addition leads to a more robust uncertainty estimates of return levels, return periods, and risks of climatic extremes under both stationary and non-stationary assumptions. Moreover, NEVA2.0 is flexible in incorporating any user-specified covariate other than the default time-covariate (e.g., CO2 emissions, large scale climatic oscillation patterns). The new feature will allow users to examine non-stationarity of extremes induced by physical conditions that underlie the extreme events (e.g. antecedent soil moisture deficit, large-scale climatic teleconnections, urbanization). In addition, the new version offers an option to generate stationary and/or non-stationary rainfall Intensity - Duration - Frequency (IDF) curves that are widely used for risk assessment and infrastructure design. Finally, a Graphical User Interface (GUI) of the package is provided, making NEVA
EDITORIAL: CAMOP: Quantum Non-Stationary Systems CAMOP: Quantum Non-Stationary Systems
Dodonov, Victor V.; Man'ko, Margarita A.
2010-09-01
Although time-dependent quantum systems have been studied since the very beginning of quantum mechanics, they continue to attract the attention of many researchers, and almost every decade new important discoveries or new fields of application are made. Among the impressive results or by-products of these studies, one should note the discovery of the path integral method in the 1940s, coherent and squeezed states in the 1960-70s, quantum tunneling in Josephson contacts and SQUIDs in the 1960s, the theory of time-dependent quantum invariants in the 1960-70s, different forms of quantum master equations in the 1960-70s, the Zeno effect in the 1970s, the concept of geometric phase in the 1980s, decoherence of macroscopic superpositions in the 1980s, quantum non-demolition measurements in the 1980s, dynamics of particles in quantum traps and cavity QED in the 1980-90s, and time-dependent processes in mesoscopic quantum devices in the 1990s. All these topics continue to be the subject of many publications. Now we are witnessing a new wave of interest in quantum non-stationary systems in different areas, from cosmology (the very first moments of the Universe) and quantum field theory (particle pair creation in ultra-strong fields) to elementary particle physics (neutrino oscillations). A rapid increase in the number of theoretical and experimental works on time-dependent phenomena is also observed in quantum optics, quantum information theory and condensed matter physics. Time-dependent tunneling and time-dependent transport in nano-structures are examples of such phenomena. Another emerging direction of study, stimulated by impressive progress in experimental techniques, is related to attempts to observe the quantum behavior of macroscopic objects, such as mirrors interacting with quantum fields in nano-resonators. Quantum effects manifest themselves in the dynamics of nano-electromechanical systems; they are dominant in the quite new and very promising field of circuit
Nilpotent orbits in real symmetric pairs and stationary black holes
International Nuclear Information System (INIS)
Dietrich, Heiko; De Graaf, Willem A.; Ruggeri, Daniele; Trigiante, Mario
2017-01-01
In the study of stationary solutions in extended supergravities with symmetric scalar manifolds, the nilpotent orbits of a real symmetric pair play an important role. In this paper we discuss two approaches to determine the nilpotent orbits of a real symmetric pair. We apply our methods to an explicit example, and thereby classify the nilpotent orbits of (SL 2 (R)) 4 acting on the fourth tensor power of the natural 2-dimensional SL 2 (R)-module. This makes it possible to classify all stationary solutions of the so-called STU-supergravity model. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
Stationary neoclassical profiles of plasma parameters in stellarators
International Nuclear Information System (INIS)
Danilkin, I.S.; Mineev, A.B.
1991-01-01
Peculiarities of neoclassical model of heat and particle transfer, occuring by calculations of plasma stationary profile parameters in stellarators are considered. The main peculiarity out of all consists in ineadequate compatibility with real physical conditions on the boundary, requiring application of supplementary 'anomalous' transfer or special (but technically possible) adjustment of particle and heat sources to achieve solution in form of 'correct' monotonically sloping profile. It is stated, that neoclassical theory does not provide for well-known ambiguity of solutions for ambipolar electrical field by search of monotonous stationary profiles supported by outside sources
Uniqueness of solution to a stationary boundary kinetic problem
International Nuclear Information System (INIS)
Zhykharsky, A.V.
1992-01-01
The paper treats the question of uniqueness of solution to the boundary kinetic problem. This analysis is based on the accurate solutions to the stationary one-dimensional boundary kinetic problem for the limited plasma system. In the paper a simplified problem statement is used (no account is taken of the external magnetic field, a simplest form of boundary conditions is accepted) which, however, covers all features of the problem considered. Omitting the details of the conclusion we will write a set of Vlasov stationary kinetic equations for the cases of plane, cylindrical and spherical geometry of the problem. (author) 1 ref
Non-stationary flow of hydraulic oil in long pipe
Directory of Open Access Journals (Sweden)
Hružík Lumír
2014-03-01
Full Text Available The paper deals with experimental evaluation and numerical simulation of non-stationary flow of hydraulic oil in a long hydraulic line. Non-stationary flow is caused by a quick closing of valves at the beginning and the end of the pipe. Time dependence of pressure is measured by means of pressure sensors at the beginning and the end of the pipe. A mathematical model of a given circuit is created using Matlab SimHydraulics software. The long line is simulated by means of segmented pipe. The simulation is verified by experiment.
Income dynamics with a stationary double Pareto distribution.
Toda, Alexis Akira
2011-04-01
Once controlled for the trend, the distribution of personal income appears to be double Pareto, a distribution that obeys the power law exactly in both the upper and the lower tails. I propose a model of income dynamics with a stationary distribution that is consistent with this fact. Using US male wage data for 1970-1993, I estimate the power law exponent in two ways--(i) from each cross section, assuming that the distribution has converged to the stationary distribution, and (ii) from a panel directly estimating the parameters of the income dynamics model--and obtain the same value of 8.4.
Power variation for Gaussian processes with stationary increments
DEFF Research Database (Denmark)
Barndorff-Nielsen, Ole Eiler; Corcuera, J.M.; Podolskij, Mark
2009-01-01
We develop the asymptotic theory for the realised power variation of the processes X=•G, where G is a Gaussian process with stationary increments. More specifically, under some mild assumptions on the variance function of the increments of G and certain regularity conditions on the path of the pr......We develop the asymptotic theory for the realised power variation of the processes X=•G, where G is a Gaussian process with stationary increments. More specifically, under some mild assumptions on the variance function of the increments of G and certain regularity conditions on the path...... a chaos representation....
Stationary neoclassical profiles of plasma parameters in stellarators
International Nuclear Information System (INIS)
Danilkin, I.S.; Mineev, A.B.
1991-01-01
The properties of the neoclassical model of heat and particle transport are considered in connection with calculations of stationary profiles of the plasma parameters in stellarators. The most important feature is the poor agreement with real physical conditions of the boundary, which imposes the necessity of invoking either an additional anomalous transport or a special (although technically possible) consistency between the particle and heat sources in order to obtain a solution in the form of a correct monotonically decreasing profile. In search for monotonic stationary profiles maintained by external sources, it is ascertained that the neoclassical theory does not give rise to the well-known multivalued solutions for the ambipolar electric field
Randomly forced CGL equation stationary measures and the inviscid limit
Kuksin, S
2003-01-01
We study a complex Ginzburg-Landau (CGL) equation perturbed by a random force which is white in time and smooth in the space variable~$x$. Assuming that $\\dim x\\le4$, we prove that this equation has a unique solution and discuss its asymptotic in time properties. Next we consider the case when the random force is proportional to the square root of the viscosity and study the behaviour of stationary solutions as the viscosity goes to zero. We show that, under this limit, a subsequence of solutions in question converges to a nontrivial stationary process formed by global strong solutions of the nonlinear Schr\\"odinger equation.
Spin in stationary gravitational fields and rotating frames
International Nuclear Information System (INIS)
Obukhov, Yuri N.; Silenko, Alexander J.; Teryaev, Oleg V.
2010-01-01
A spin motion of particles in stationary spacetimes is investigated in the framework of the classical gravity and relativistic quantum mechanics. We bring the Dirac equation for relativistic particles in nonstatic spacetimes to the Hamiltonian form and perform the Foldy-Wouthuysen transformation. We show the importance of the choice of tetrads for description of spin dynamics in the classical gravity. We derive classical and quantum mechanical equations of motion of the spin for relativistic particles in stationary gravitational fields and rotating frames and establish the full agreement between the classical and quantum mechanical approaches.
Do working environment interventions reach shift workers?
Nabe-Nielsen, Kirsten; Jørgensen, Marie Birk; Garde, Anne Helene; Clausen, Thomas
2016-01-01
Shift workers are exposed to more physical and psychosocial stressors in the working environment as compared to day workers. Despite the need for targeted prevention, it is likely that workplace interventions less frequently reach shift workers. The aim was therefore to investigate whether the reach of workplace interventions varied between shift workers and day workers and whether such differences could be explained by the quality of leadership exhibited at different times of the day. We used questionnaire data from 5361 female care workers in the Danish eldercare sector. The questions concerned usual working hours, quality of leadership, and self-reported implementation of workplace activities aimed at stress reduction, reorganization of the working hours, and participation in improvements of working procedures or qualifications. Compared with day workers, shift workers were less likely to be reached by workplace interventions. For example, night workers less frequently reported that they had got more flexibility (OR 0.5; 95 % CI 0.3-0.7) or that they had participated in improvements of the working procedures (OR 0.6; 95 % CI 0.5-0.8). Quality of leadership to some extent explained the lack of reach of interventions especially among fixed evening workers. In the light of the evidence of shift workers' stressful working conditions, we suggest that future studies focus on the generalizability of results of the present study and on how to reach this group and meet their needs when designing and implementing workplace interventions.
Some characteristics of heat production by stationary parabolic, cylindrical solar concentrator
Energy Technology Data Exchange (ETDEWEB)
Bojic, M.; Marjanovic, N.; Miletic, I.; Mitic, A. [Kragujevac Univ., Kragujevac (Serbia). Faculty of Mechanical Engineering; Stefanovic, V. [Nis Univ., Nis (Serbia). Faculty of Mechanical Engineering
2009-07-01
The use of solar energy for heating, cooling and electricity production was discussed with particular reference to the use of a stationary, asymmetric solar concentrator for conversion of solar energy to heat using a reflector and absorber. The infinite length CP-0A type stationary parabolic, cylindrical solar concentrator for heat production consists of the absorber (with water pipes) and parabolic, cylindrical reflector (with a metal surface). It has a geometrical concentration ratio of up to 4. This paper reported on a study that used the CATIA computer software to investigate how direct solar radiation approaches the concentrator aperture and the concentrator reflector. The propagation of light rays inside the concentrator to reach the absorber surface was examined. The study showed that the solar ray either hits the absorber directly or it bounces one or several time from the concentrator reflector. The efficiency of light rays was also calculated as a function of angles of incident of solar rays and type of reflector surface. 5 refs., 8 figs.
Kinetic features and non-stationary electron trapping in paraxial magnetic nozzles
Sánchez-Arriaga, G.; Zhou, J.; Ahedo, E.; Martínez-Sánchez, M.; Ramos, J. J.
2018-03-01
The paraxial expansion of a collisionless plasma jet into vacuum, guided by a magnetic nozzle, is studied with an Eulerian and non-stationary Vlasov-Poisson solver. Parametric analyzes varying the magnetic field expansion rate, the size of the simulation box, and the electrostatic potential fall are presented. After choosing the potential fall leading to a zero net current beam, the steady states of the simulations exhibit a quasi-neutral region followed by a downstream sheath. The latter, an unavoidable consequence of the finite size of the computational domain, does not affect the quasi-neutral region if the box size is chosen appropriately. The steady state presents a strong decay of the perpendicular temperature of the electrons, whose profile versus the inverse of the magnetic field does not depend on the expansion rate within the quasi-neutral region. As a consequence, the electron distribution function is highly anisotropic downstream. The simulations revealed that the ions reach a higher velocity during the transient than in the steady state and their distribution functions are not far from mono-energetic. The density percentage of the population of electrons trapped during the transient, which is computed self-consistently by the code, is up to 25% of the total electron density in the quasi-neutral region. It is demonstrated that the exact amount depends on the history of the system and the steady state is not unique. Nevertheless, the amount of trapped electrons is smaller than the one assumed heuristically by kinetic stationary theories.
Directory of Open Access Journals (Sweden)
Abdulaziz AlHadlaq
2016-04-01
Full Text Available We report an extremely rare presentation of late-onset endophthalmitis in a young adult patient with an unexposed Ahmed tube implant. The implant was inserted 11 years prior to presentation. There was no history of trauma or any obvious exposure on clinical examination and the tube plate was filled with purulent material. After aqueous and vitreous tap, the patient underwent intracameral, intravitreal subconjunctival antibiotic injections and was started on systemic antibiotics with good response. Endophthalmitis associated with tube drainage device can present as late as 11 years and even without an unexposed tube.
Lateness to School Remediation Game
Ugwuegbulam, Charles N.; Ibrahim, Haj. Naheed
2015-01-01
Primary and secondary school in Nigeria encourage punctuality to school yet a good number of the learners came late to school. This is especially true in the case of day students. Learners who come late to school are usually punished in one way or the other yet the lateness to school phenomenon still persist. Lateness to school behaviour affects…
China, The Regional Hegemon with Global Reach
2011-03-07
31 China’s commercial diplomacy has benefitted from the region’s widespread interest in free trade agreements (FTAs) which began to mushroom in...Asia in the late 1990s.32 For China these FTAs offer a means of using the China market to cultivate influence and compete with Japan and the U.S...the least. Current and future U.S. 23 administrations must be able to cultivate those mutual interests: economic and climate change (identified
Guiding Warfare to Reach Sustainable Peace
DEFF Research Database (Denmark)
Vestenskov, David; Drewes, Line
The conference report Guiding Warfare to Reach Sustainable Peace constitutes the primary outcome of the conference It is based on excerpts from the conference presenters and workshop discussions. Furthermore, the report contains policy recommendations and key findings, with the ambition of develo......The conference report Guiding Warfare to Reach Sustainable Peace constitutes the primary outcome of the conference It is based on excerpts from the conference presenters and workshop discussions. Furthermore, the report contains policy recommendations and key findings, with the ambition...... of developing best practices in the education and implementation of IHL in capacity building of security forces....
Do working environment interventions reach shift workers?
DEFF Research Database (Denmark)
Nabe-Nielsen, Kirsten; Jørgensen, Marie Birk; Garde, Anne Helene
2016-01-01
PURPOSE: Shift workers are exposed to more physical and psychosocial stressors in the working environment as compared to day workers. Despite the need for targeted prevention, it is likely that workplace interventions less frequently reach shift workers. The aim was therefore to investigate whether...... the reach of workplace interventions varied between shift workers and day workers and whether such differences could be explained by the quality of leadership exhibited at different times of the day. METHODS: We used questionnaire data from 5361 female care workers in the Danish eldercare sector...
Stationary, high bootstrap fraction plasmas in DIII-D without inductive current control
International Nuclear Information System (INIS)
Politzer, P.A.; Hyatt, A.W.; Luce, T.C.; Prater, R.; Turnbull, A.D.; Ferron, J.R.; Greenfield, C.M.; La Haye, R.J.; Petty, C.C.; Perkins, F.W.; Brennan, D.P.; Lazarus, E.A.; Jayakumar, J.; Wade, M.R.
2005-01-01
We have initiated an experimental program to address some of the questions associated with operation of a tokamak with high bootstrap current fraction under high performance conditions, without assistance from a transformer. In these discharges stationary (or slowly improving) conditions are maintained for > 3.7 s at β N ∼ β p ≤ 3.3. The achievable current and pressure are limited by a relaxation oscillation, involving growth and collapse of an ITB at ρ ≥ 0.6. The pressure gradually increases and the current profile broadens throughout the discharge. Eventually the plasma reaches a more stable, high confinement (H89P ∼ 3) state. Characteristically these plasmas have 65%-85% bootstrap current, 15%-30% NBCD, and 0%-10% ECCD. (author)
Linear simulation of the stationary eddies in a GCM. II - The 'Mountain' model
Nigam, Sumant; Held, Isaac M.; Lyons, Steven W.
1988-01-01
Linear stationary wave theory is used to account for zonal asymmetries of the winter-averaged tropospheric circulation obtained in a GCM. The eddy zonal velocity field in the upper troposphere indicates that the orographic and thermal plus transient contributions are nearly equal in amplitude, while the eddy meridional velocity field (which is dominated by shorter zonal scales) shows the orographic contribution to be dominant. The two contributions are found to be roughly in phase over the east Asian coast, and they contribute roughly equal amounts to the low level Siberian high. Results indicate that the 300 mb extratropical response to tropical forcing reaches 50 gpm over Alaska, and that the responses to sensible heating and lower tropospheric transients are strongly anticorrelated.
Deleer, B. G. M.
1981-11-01
Based on population balance, CSD behavior as a function of geometrical and operating variables was studied, using a crystallizer. A potash alum-water system, involving a separation technique which uses surface active agents and an apolar, organic liquid to separate potash alum crystals from mother liquid under the influence of gravity was used to check experimental findings against literature data. Results show action of annular settling spaces is strongly influenced by fluid velocities perpendicular to those directed upwards. The well-mixed volume decreases with increasing crystallizer size until a minimum effective volume is reached. As supersaturation is constant throughout the crystallizer volume under stationary operating conditions, the annular settling space behaves like a growth chamber for crystals in its volume. Swirl in the lower part of the annular volume introduces significant back mixing. Crystals within this space either grow and return to the well-mixed part, or withdraw from the annular volume permanently.
Late effecten van kankerbehandeling
Langeveld, Nelia E.
2004-01-01
In dit artikel wordt ingegaan op de lange termijn effecten van kanker op de kinderleeftijd. Vervolgens wordt een kort overzicht gegeven van de belangrijkste late gevolgen die kunnen optreden na een oncologische behandeling met radio- en/of chemotherapie toegepast in de kinderleeftijd. Er wordt kort
DEFF Research Database (Denmark)
Andersen, Bjørn Schiermer
2014-01-01
The article deals with the cultural significance of a new figure in late-modern Western culture: the hipster. The current hipster culture, so I argue, can be used as a magnifying glass that makes impending changes to our conception of culture and of cultural development visible. It ushers...
Horstmann, Cay S
2012-01-01
Big Java: Late Objects is a comprehensive introduction to Java and computer programming, which focuses on the principles of programming, software engineering, and effective learning. It is designed for a two-semester first course in programming for computer science students.
Late Embryogenesis Abundant Proteins
Shih, M.D.; Hoekstra, F.A.; Hsing, Y.I.C.
2008-01-01
During the late maturation stage of seed development, water content decreases greatly. One of the most striking characteristics of mature orthodox seeds is their ability to withstand severe desiccation. Mechanisms of plant drought/desiccation tolerance have been studied by numerous groups, and a
Numerical Clifford Analysis for the Non-stationary Schroedinger Equation
International Nuclear Information System (INIS)
Faustino, N.; Vieira, N.
2007-01-01
We construct a discrete fundamental solution for the parabolic Dirac operator which factorizes the non-stationary Schroedinger operator. With such fundamental solution we construct a discrete counterpart for the Teodorescu and Cauchy-Bitsadze operators and the Bergman projectors. We finalize this paper with convergence results regarding the operators and a concrete numerical example
Detection of Multiple Stationary Humans Using UWB MIMO Radar
Directory of Open Access Journals (Sweden)
Fulai Liang
2016-11-01
Full Text Available Remarkable progress has been achieved in the detection of single stationary human. However, restricted by the mutual interference of multiple humans (e.g., strong sidelobes of the torsos and the shadow effect, detection and localization of the multiple stationary humans remains a huge challenge. In this paper, ultra-wideband (UWB multiple-input and multiple-output (MIMO radar is exploited to improve the detection performance of multiple stationary humans for its multiple sight angles and high-resolution two-dimensional imaging capacity. A signal model of the vital sign considering both bi-static angles and attitude angle of the human body is firstly developed, and then a novel detection method is proposed to detect and localize multiple stationary humans. In this method, preprocessing is firstly implemented to improve the signal-to-noise ratio (SNR of the vital signs, and then a vital-sign-enhanced imaging algorithm is presented to suppress the environmental clutters and mutual affection of multiple humans. Finally, an automatic detection algorithm including constant false alarm rate (CFAR, morphological filtering and clustering is implemented to improve the detection performance of weak human targets affected by heavy clutters and shadow effect. The simulation and experimental results show that the proposed method can get a high-quality image of multiple humans and we can use it to discriminate and localize multiple adjacent human targets behind brick walls.
Conserved quantities for stationary Einstein-Maxwell space-times
International Nuclear Information System (INIS)
Esposito, F.P.; Witten, L.
1978-01-01
It is shown that every stationary Einstein-Maxwell space-time has eight divergence-free vector fields and these are isolated in general form. The vector fields and associated conserved quantities are calculated for several families of space-times. (Auth.)
Plasma equilibria and stationary flows in axisymmetric systems. Pt. 2
International Nuclear Information System (INIS)
Zelazny, R.; Stankiewicz, R.; Potempski, S.
1988-05-01
Part I of this report described the computational problems connected with the bifurcating solutions to static and extended Grad-Shafranov-Schlueter equations (with stationary flows). Part II is a listing of the computer program for solving the extended Grad-Shafranov-Schlueter equations developed in Part I. (author)
Bipower variation for Gaussian processes with stationary increments
DEFF Research Database (Denmark)
Barndorff-Nielsen, Ole Eiler; Corcuera, José Manuel; Podolskij, Mark
2009-01-01
Convergence in probability and central limit laws of bipower variation for Gaussian processes with stationary increments and for integrals with respect to such processes are derived. The main tools of the proofs are some recent powerful techniques of Wiener/Itô/Malliavin calculus for establishing...
Stationary solutions of multicomponent chiral and gauge models
International Nuclear Information System (INIS)
Chudnovsky, D.V.; Chudnovsky, G.V.
1979-01-01
The authors examine stationary solutions of completely integrable systems in (x, t) dimensions having infinitely many components. Among the cases under investigation are: (1) the infinite-component non-linear Schroedinger equation; (2) infinite component CPsup(Ω) or SU(N) sigma-models; (3) general gauge and chiral completely integrable systems. (Auth.)
DViN - stationary setup for identification of explosives
International Nuclear Information System (INIS)
Bystritskij, V.M.; Gerasimov, V.V.; Kadyshevskij, V.G.
2007-01-01
A stationary system for identification of hidden explosives has been developed and constructed at the Joint Institute for Nuclear Research (JINR). The results of the examination of the system as well as the operation principle of the system and design of the main elements are presented in this paper
Existence of stationary solutions in the coronal loop problem
Energy Technology Data Exchange (ETDEWEB)
Hulshof, J; Terman, D; Verhulst, F
1988-01-01
The study of a hot plasma confined to a magnetic loop in the sun's corona leads to a singularly perturbed nonlinear reaction-diffusion equation with rather unusual side conditions. Monotone solutions of the stationary problem appear as fixed points of an iteration map which is contractive if the perturbation parameter is sufficiently small.
PSSGP : Program for Simulation of Stationary Gaussian Processes
DEFF Research Database (Denmark)
Sørensen, John Dalsgaard
This report describes the computer program PSSGP. PSSGP can be used to simulate realizations of stationary Gaussian stochastic processes. The simulation algorithm can be coupled with some applications. One possibility is to use PSSGP to estimate the first-passage density function of a given system...
Sigma-convergence of stationary Navier-Stokes type equations
Directory of Open Access Journals (Sweden)
Gabriel Nguetseng
2009-06-01
Full Text Available In the framework of homogenization theory, the Sigma-convergence method is carried out on stationary Navier-Stokes type equations on a fixed domain. Our main tools are the two-scale convergence concept and the so-called homogenization algebras.
On the nonparametric prediction of conditionally stationary sequences
S. Caires; J.A. Ferreira
2003-01-01
textabstractWe prove the strong consistency of estimators of the conditional distribution function and conditional expectation of a future observation of a discrete time stochastic process given a fixed number of past observations. The results apply to conditionally stationary processes (a class of
75 FR 55635 - Restructuring of the Stationary Source Audit Program
2010-09-13
... assurance requirements that would make an additional audit sample redundant. We believe that Method 18 also has sufficient quality assurance measures that make an audit sample unnecessary. This method requires... Stationary Source Audit Program; Final Rule #0;#0;Federal Register / Vol. 75 , No. 176 / Monday, September 13...
Variance-optimal hedging for processes with stationary independent increments
DEFF Research Database (Denmark)
Hubalek, Friedrich; Kallsen, J.; Krawczyk, L.
We determine the variance-optimal hedge when the logarithm of the underlying price follows a process with stationary independent increments in discrete or continuous time. Although the general solution to this problem is known as backward recursion or backward stochastic differential equation, we...
Long time tails in stationary random media. I. Theory
Ernst, M.H.; Machta, J.; Dorfman, J.R.; Beijeren, H. van
1984-01-01
Diffusion of moving particles in stationary disordered media is studied using a phenomenological mode-coupling theory. The presence of disorder leads to a generalized diffusion equation, with memory kernels having power law long time tails. The velocity autocorrelation function is found to decay
The spectral analysis of cyclo-non-stationary signals
Abboud, D.; Baudin, S.; Antoni, J.; Rémond, D.; Eltabach, M.; Sauvage, O.
2016-06-01
Condition monitoring of rotating machines in speed-varying conditions remains a challenging task and an active field of research. Specifically, the produced vibrations belong to a particular class of non-stationary signals called cyclo-non-stationary: although highly non-stationary, they contain hidden periodicities related to the shaft angle; the phenomenon of long term modulations is what makes them different from cyclostationary signals which are encountered under constant speed regimes. In this paper, it is shown that the optimal way of describing cyclo-non-stationary signals is jointly in the time and the angular domains. While the first domain describes the waveform characteristics related to the system dynamics, the second one reveals existing periodicities linked to the system kinematics. Therefore, a specific class of signals - coined angle-time cyclostationary is considered, expressing the angle-time interaction. Accordingly, the related spectral representations, the order-frequency spectral correlation and coherence functions are proposed and their efficiency is demonstrated on two industrial cases.
Inertial algorithms for the stationary Navier-Stokes equations
Hou, Yanren; Mattheij, R.M.M.
2003-01-01
Several kind of new numerical schemes for the stationary Navier-Stokes equations based on the virtue of Inertial Manifold and Approximate Inertial Manifold, which we call them inertial algorithms in this paper, together with their error estimations are presented. All these algorithms are constructed
Two Numerical Approaches to Stationary Mean-Field Games
Almulla, Noha; Ferreira, Rita; Gomes, Diogo A.
2016-01-01
Here, we consider numerical methods for stationary mean-field games (MFG) and investigate two classes of algorithms. The first one is a gradient-flow method based on the variational characterization of certain MFG. The second one uses monotonicity properties of MFG. We illustrate our methods with various examples, including one-dimensional periodic MFG, congestion problems, and higher-dimensional models.
Long time tails in stationary random media II: Applications
Machta, J.; Ernst, M.H.; Dorfman, J.R.; Beijeren, H. van
1984-01-01
In a previous paper we developed a mode-coupling theory to describe the long time properties of diffusion in stationary, statistically homogeneous, random media. Here the general theory is applied to deterministic and stochastic Lorentz models and several hopping models. The mode-coupling theory
Cointegration and Econometric Analysis of Non-Stationary Data in ...
African Journals Online (AJOL)
This is in conformity with the philosophy underlying the cointegration theory. Therefore, ignoring cointegration in non-stationary time series variables could lead to misspecification of the underlying process in the determination of corporate income tax in Nigeria. Thus, the study conclude that cointegration is greatly enhanced ...
Non-Stationary Dependence Structures for Spatial Extremes
Huser, Raphaë l; Genton, Marc G.
2016-01-01
been developed, and fitted to various types of data. However, a recurrent problem is the modeling of non-stationarity. In this paper, we develop non-stationary max-stable dependence structures in which covariates can be easily incorporated. Inference
Methylgroup interaction of hydrocarbon stationary phases and hydrocarbon solutes
Kemenade, van A.W.C.; Groenendijk, H.
1969-01-01
The temperature dependency of the retention behaviour of some alkanes with squalane as stationary phase has been measured at a very high precision level, at temperatures from 30 to 90°C. Besides the retention index itself [1], its temperature dependency appears to be a source of information about
Stationary strings near a higher-dimensional rotating black hole
International Nuclear Information System (INIS)
Frolov, Valeri P.; Stevens, Kory A.
2004-01-01
We study stationary string configurations in a space-time of a higher-dimensional rotating black hole. We demonstrate that the Nambu-Goto equations for a stationary string in the 5D (five-dimensional) Myers-Perry metric allow a separation of variables. We present these equations in the first-order form and study their properties. We prove that the only stationary string configuration that crosses the infinite redshift surface and remains regular there is a principal Killing string. A worldsheet of such a string is generated by a principal null geodesic and a timelike at infinity Killing vector field. We obtain principal Killing string solutions in the Myers-Perry metrics with an arbitrary number of dimensions. It is shown that due to the interaction of a string with a rotating black hole, there is an angular momentum transfer from the black hole to the string. We calculate the rate of this transfer in a space-time with an arbitrary number of dimensions. This effect slows down the rotation of the black hole. We discuss possible final stationary configurations of a rotating black hole interacting with a string
Ceramic stationary gas turbine development. Final report, Phase 1
Energy Technology Data Exchange (ETDEWEB)
NONE
1994-09-01
This report summarizes work performed by Solar Turbines Inc. and its subcontractors during the period September 25, 1992 through April 30, 1993. The objective of the work is to improve the performance of stationary gas turbines in cogeneration through implementation of selected ceramic components.
Two Numerical Approaches to Stationary Mean-Field Games
Almulla, Noha
2016-10-04
Here, we consider numerical methods for stationary mean-field games (MFG) and investigate two classes of algorithms. The first one is a gradient-flow method based on the variational characterization of certain MFG. The second one uses monotonicity properties of MFG. We illustrate our methods with various examples, including one-dimensional periodic MFG, congestion problems, and higher-dimensional models.
Robust Forecasting of Non-Stationary Time Series
Croux, C.; Fried, R.; Gijbels, I.; Mahieu, K.
2010-01-01
This paper proposes a robust forecasting method for non-stationary time series. The time series is modelled using non-parametric heteroscedastic regression, and fitted by a localized MM-estimator, combining high robustness and large efficiency. The proposed method is shown to produce reliable
Reaching Reluctant Students: Insights from Torey Hayden.
Marlowe, Mike
1999-01-01
Illustrates principles of reaching students who fight or avoid adults by using examples drawn from the writings of Torey Hayden. Presents ten concepts that can serve as guidelines for building relationships with resistant children, and gives excerpts from Hayden's works to illustrate each concept. Demonstrates how books provide teachers with…
ATLAS Barrel Toroid magnet reached nominal field
2006-01-01
Â OnÂ 9 November the barrel toroid magnet reached its nominal field of 4 teslas, with an electrical current of 21 000 amperes (21 kA) passing through the eight superconducting coils as shown on this graph
International Nuclear Information System (INIS)
Bocek, M.; Armas, I.
1982-01-01
It was the aim of the present investigation to examine how the recovery rate in creep is influenced by a non-stationary stress. For purposes of phenomenological analysis it is postulated that, irrespective of whether the applied stress is stationary or not, for large strains the mean internal stress sigmasub(i) approaches a stationary value sigmasub(i,s). The stationary recovery rate Rsub(s) for constant load creep turns out be governed by the applied stress indicating that the recovery mechanism is dynamic in nature. For sigma-ramp loading, Rsub(s) is dependent on the stress rate sigma. In tensional stress cycling, Rsub(s) is governed by the maximum stress sigmasub(M) and is also dependent on the ratio of sigmasub(M) to the minimum stress sigma 0 . TEM examination of Zircaloy-4 specimens crept at 800 0 C at constant and cycling load respectively could not reveal any differences in the deformation substructure for the two loading types. Subgrain formation did not appear, individual dislocations were observed only rarely. However, typical networks were formed as well as pileups which perhaps are responsible for the back stress in high temperature plasticity (HTP). (orig.)
The Accelerated Late Adsorption of Pulmonary Surfactant
2011-01-01
Adsorption of pulmonary surfactant to an air−water interface lowers surface tension (γ) at rates that initially decrease progressively, but which then accelerate close to the equilibrium γ. The studies here tested a series of hypotheses concerning mechanisms that might cause the late accelerated drop in γ. Experiments used captive bubbles and a Wilhelmy plate to measure γ during adsorption of vesicles containing constituents from extracted calf surfactant. The faster fall in γ reflects faster adsorption rather than any feature of the equation of state that relates γ to surface concentration (Γ). Adsorption accelerates when γ reaches a critical value rather than after an interval required to reach that γ. The hydrophobic surfactant proteins (SPs) represent key constituents, both for reaching the γ at which the acceleration occurs and for producing the acceleration itself. The γ at which rates of adsorption increase, however, is unaffected by the Γ of protein in the films. In the absence of the proteins, a phosphatidylethanolamine, which, like the SPs, induces fusion of the vesicles with the interfacial film, also causes adsorption to accelerate. Our results suggest that the late acceleration is characteristic of adsorption by fusion of vesicles with the nascent film, which proceeds more favorably when the Γ of the lipids exceeds a critical value. PMID:21417351
Christopoulos, Vassilios N; Bonaiuto, James; Kagan, Igor; Andersen, Richard A
2015-08-19
The posterior parietal cortex (PPC) has traditionally been considered important for awareness, spatial perception, and attention. However, recent findings provide evidence that the PPC also encodes information important for making decisions. These findings have initiated a running argument of whether the PPC is critically involved in decision making. To examine this issue, we reversibly inactivated the parietal reach region (PRR), the area of the PPC that is specialized for reaching movements, while two monkeys performed a memory-guided reaching or saccade task. The task included choices between two equally rewarded targets presented simultaneously in opposite visual fields. Free-choice trials were interleaved with instructed trials, in which a single cue presented in the peripheral visual field defined the reach and saccade target unequivocally. We found that PRR inactivation led to a strong reduction of contralesional choices, but only for reaches. On the other hand, saccade choices were not affected by PRR inactivation. Importantly, reaching and saccade movements to single instructed targets remained largely intact. These results cannot be explained as an effector-nonspecific deficit in spatial attention or awareness, since the temporary "lesion" had an impact only on reach choices. Hence, the PPR is a part of a network for reach decisions and not just reach planning. There has been an ongoing debate on whether the posterior parietal cortex (PPC) represents only spatial awareness, perception, and attention or whether it is also involved in decision making for actions. In this study we explore whether the parietal reach region (PRR), the region of the PPC that is specialized for reaches, is involved in the decision process. We inactivated the PRR while two monkeys performed reach and saccade choices between two targets presented simultaneously in both hemifields. We found that inactivation affected only the reach choices, while leaving saccade choices intact
Improving exposure scenario definitions within REACH
DEFF Research Database (Denmark)
Lee, Jihyun; Pizzol, Massimo; Thomsen, Marianne
In recent years, the paradigm of chemical management system has changed from being toxicity oriented and media based to being risk oriented and receptor based. This trend is evident not only regarding environmental quality standards, but also for industrial chemical regulations. Political...... instruments to support a precautionary chemicals management system and to protect receptor’s health have also been increasing. Since 2007, the European Union adopted REACH (the Regulation on Registration, Evaluation, Authorisation and Restriction of Chemicals): REACH makes industry responsible for assessing...... and managing the risks posed by industrial chemicals and providing appropriate safety information to their users (EC, 2007). However, to ensure a high level of protection of human health and the environment, there is a need to consider ‘aggregate exposure’ including background exposures from environment which...
Does workplace health promotion reach shift workers?
DEFF Research Database (Denmark)
Nabe-Nielsen, Kirsten; Garde, Anne Helene; Clausen, Thomas
2015-01-01
OBJECTIVES: One reason for health disparities between shift and day workers may be that workplace health promotion does not reach shift workers to the same extent as it reaches day workers. This study aimed to investigate the association between shift work and the availability of and participation...... in workplace health promotion. METHODS: We used cross-sectional questionnaire data from a large representative sample of all employed people in Denmark. We obtained information on the availability of and participation in six types of workplace health promotion. We also obtained information on working hours, ie......). RESULTS: In the general working population, fixed evening and fixed night workers, and employees working variable shifts including night work reported a higher availability of health promotion, while employees working variable shifts without night work reported a lower availability of health promotion...
DEFF Research Database (Denmark)
Ulrik, Charlotte Suppli
2017-01-01
Late-onset asthma is common, associated with poor outcome, underdiagnosed and undertreated, possibly due to the modifying effect of ageing on disease expression. Although the diagnostic work-up in elderly individuals suspected of having asthma follows the same steps as in younger individuals (case......, to objectively confirm asthma. If necessary, a trial of oral or inhaled corticosteroid might be necessary. Asthma can be diagnosed when increased airflow variability is identified in a symptomatic patient, and if the patient does not have a history of exposure, primarily smoking, known to cause chronic...... obstructive pulmonary disease, the diagnosis is asthma even if the patient does not have fully reversible airflow obstruction. Pharmacological therapy in patients with late-onset asthma follows international guidelines, including treatment with the lowest effective dose of inhaled corticosteroid to minimize...
Educating Citizens in Late Modern Societies
DEFF Research Database (Denmark)
Christensen, Torben Spanget
2011-01-01
One way or the other democratic states need to take on the task of educating its rising generation in governmental affairs, societal matters and citizenship in order to sustain the democracy itself. This article presents a model for analysing civic education in late modern, globalised world....... The model is based on the fundamental belief that the overall aim of civic education in democratic, late modern and global societies is empowerment of the citizen in order to establish a self governing citizen who simultaneous is capable of managing and keeping together partly contradictory citizens tasks...... studies and evaluations of the Danish upper secondary school completed at my department at University of Southern Denmark in recent years, especially connected to a quite far reaching curriculum reform from 2005. It is assumed that this Danish development is an expression of a more general phenomenon...
Olefins and chemical regulation in Europe: REACH.
Penman, Mike; Banton, Marcy; Erler, Steffen; Moore, Nigel; Semmler, Klaus
2015-11-05
REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) is the European Union's chemical regulation for the management of risk to human health and the environment (European Chemicals Agency, 2006). This regulation entered into force in June 2007 and required manufacturers and importers to register substances produced in annual quantities of 1000 tonnes or more by December 2010, with further deadlines for lower tonnages in 2013 and 2018. Depending on the type of registration, required information included the substance's identification, the hazards of the substance, the potential exposure arising from the manufacture or import, the identified uses of the substance, and the operational conditions and risk management measures applied or recommended to downstream users. Among the content developed to support this information were Derived No-Effect Levels or Derived Minimal Effect Levels (DNELs/DMELs) for human health hazard assessment, Predicted No Effect Concentrations (PNECs) for environmental hazard assessment, and exposure scenarios for exposure and risk assessment. Once registered, substances may undergo evaluation by the European Chemicals Agency (ECHA) or Member State authorities and be subject to requests for additional information or testing as well as additional risk reduction measures. To manage the REACH registration and related activities for the European olefins and aromatics industry, the Lower Olefins and Aromatics REACH Consortium was formed in 2008 with administrative and technical support provided by Penman Consulting. A total of 135 substances are managed by this group including 26 individual chemical registrations (e.g. benzene, 1,3-butadiene) and 13 categories consisting of 5-26 substances. This presentation will describe the content of selected registrations prepared for 2010 in addition to the significant post-2010 activities. Beyond REACH, content of the registrations may also be relevant to other European activities, for
Performance reach in the LHC for 2012
International Nuclear Information System (INIS)
Arduini, G.
2012-01-01
Based on the 2011 experience and Machine Development study results, the performance reach of the LHC with 25 and 50 ns beams will be addressed for operation at 3.5 and 4 TeV. The possible scrubbing scenarios and potential intensity limitations resulting from vacuum, heating will be taken into account wherever possible. The paper mainly covers the performance of the two high luminosity regions in IR1 and IR5. (author)
Steele, John M.
The last five centuries BC saw the development of several new forms of astrology in Babylonia. Key to these new astrological techniques was the invention of the zodiac in about 400 BC. These new forms of astrology include personal horoscopes, astral medicine, and the exploitation of geometrical relationships between the position of heavenly bodies. Several Late Babylonian astrological doctrines were later adopted within Greek astrology.
Feng, Zhuo
2017-09-11
Land plants are one of the major constituents of terrestrial ecosystems on Earth, and play an irreplaceable role in human activities today. If we are to understand the extant plants, it is imperative that we have some understanding of the fossil plants from the deep geological past, particularly those that occurred during their early evolutionary history, in the late Palaeozoic. Copyright © 2017 Elsevier Ltd. All rights reserved.
International Nuclear Information System (INIS)
Gilbert, E.S.
1989-01-01
Late effects are by definition effects that occur at least one year, and in most cases decades, after the time of exposure. The late effects considered in this chapter are limited to latent cancer incidence and mortality, and benign thyroid disease. A model is provided for estimating risks of late effects resulting from the radiation exposure likely to be received in the event of a nuclear power plant accident. It is assumed that exposure to high-LET radiation would be negligible in such an accident, and thus only risks from low-LET exposure are evaluated. Separate estimates are provided for risks of leukemia, bone cancer, lung cancer, gastrointestinal cancers, thyroid cancer, skin cancer, and the residual group of all other cancers; estimates of leukemia and other cancers due to in utero exposure are also provided. Risks are expressed in absolute terms as the number of cancer deaths (or cases) per million persons exposed to a particular dose. Because the time of death is also important in assessing the impact of an accident, and because the quality of life after the occurrence of cancer will often be reduced, the number of years of life lost and the number of years of life lived after the occurrence of cancer are also estimated
Heat-transfer characteristics of flowing and stationary particle-bed-type fusion-reactor blankets
International Nuclear Information System (INIS)
Nietert, R.E.
1983-02-01
The following five appendices are included: (1) physical properties of materials, (2) thermal entrance length Nusselt number variations, (3) stationary particle bed temperature variations, (4) falling bed experimental data and calculations, and (5) stationary bed experimental data and calculations
Energy Technology Data Exchange (ETDEWEB)
Loevgren, Linnea; Wik, Ola
2009-10-15
will have the possibility to leave the waste legislation and be covered by the chemical legislation in becoming a product or an article. It is not know in detail how far the chemical legislation will reach for material having end-of-waste criteria. Currently, end-of-waste criteria have not yet been initiated for ashes. The Swedish Environmental Protection Agency (Naturvaardsverket) is currently elaborating end-of-waste criteria for the use of material in construction works. Recovering waste is according to REACH identical with manufacturing. A chemical substance, preparation/mixture or article manufactured from waste, i.e. via a recovering operation will have to follow chemical legislation. The enterprise responsible for the recovering operation is the legal entity responsible to follow REACH for the manufactured material. One example of recovering ash into a chemical substance is the manufacturing of cement when ash is the raw material. It is the responsibility of the cement plant to have its substance or product REACH-registered before manufactured and provided to a third party. The waste legislation, instead of the chemical legislation, applies when the waste recovering operation does not results in manufacturing of a substance, preparation or article provided to a third party and the waste has a use at the end of its life cycle. This is identified as late recovery. The waste legislation applies during the life cycle of the waste in such cases. Examples in Sweden are ashes used in landfill sealing and covering layers and in roads or soil stabilization. Use of ashes in constructions is covered by the Constructions Product Directive (2008/98/EC), CPD, irrespective if it is identified as a waste or a chemical product. The CPD harmonizes only testing and CE-marking of construction products. Chemical safety requirements originate from national legislation which in many cases is based on chemical regulation. Standardized testing methods to measure emitted hazardous
Cancer treatment can cause late side effects that may not show up for months or years after treatment. These late effects may include heart and lung problems, bone loss, eye and hearing changes, lymphedema, and other problems
Inferential framework for non-stationary dynamics: theory and applications
International Nuclear Information System (INIS)
Duggento, Andrea; Luchinsky, Dmitri G; McClintock, Peter V E; Smelyanskiy, Vadim N
2009-01-01
An extended Bayesian inference framework is presented, aiming to infer time-varying parameters in non-stationary nonlinear stochastic dynamical systems. The convergence of the method is discussed. The performance of the technique is studied using, as an example, signal reconstruction for a system of neurons modeled by FitzHugh–Nagumo oscillators: it is applied to reconstruction of the model parameters and elements of the measurement matrix, as well as to inference of the time-varying parameters of the non-stationary system. It is shown that the proposed approach is able to reconstruct unmeasured (hidden) variables of the system, to determine the model parameters, to detect stepwise changes of control parameters for each oscillator and to track the continuous evolution of the control parameters in the adiabatic limit
On the stationary Einstein-Maxwell-Klein-Gordon equations
International Nuclear Information System (INIS)
Gegenberg, J.D.
1981-05-01
The stationary Einstein-Maxwell-Klein-Gordon (EMKG) equations for interacting gravitational, electromagnetic and meson fields are examined. The theory is cast into the formalism of principal fiber bundles with a connection, wherein its relationship to current trends in theoretical physics is made manifest. The EMKG equations are shown to admit a Higgs-like mechanism for giving mass to the gauge field. A theorem specifying sufficient conditions for the stationarity of the spacetime metric to imply stationarity of the other fields is proved. By imposing additional constraints and symmetries, the EMKG equations are considerably simplified. An attempt is made to apply a solution-generation technique, and this meets with only partial success. Finally, a stationary but non-static solution is found, and the geometric and physical properties are discussed
Nilpotent orbits in real symmetric pairs and stationary black holes
Energy Technology Data Exchange (ETDEWEB)
Dietrich, Heiko [School of Mathematical Sciences, Monash University, VIC (Australia); De Graaf, Willem A. [Department of Mathematics, University of Trento, Povo (Italy); Ruggeri, Daniele [Universita di Torino, Dipartimento di Fisica (Italy); INFN, Sezione di Torino (Italy); Trigiante, Mario [DISAT, Politecnico di Torino (Italy)
2017-02-15
In the study of stationary solutions in extended supergravities with symmetric scalar manifolds, the nilpotent orbits of a real symmetric pair play an important role. In this paper we discuss two approaches to determine the nilpotent orbits of a real symmetric pair. We apply our methods to an explicit example, and thereby classify the nilpotent orbits of (SL{sub 2}(R)){sup 4} acting on the fourth tensor power of the natural 2-dimensional SL{sub 2}(R)-module. This makes it possible to classify all stationary solutions of the so-called STU-supergravity model. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
A simple stationary semi-analytical wake model
DEFF Research Database (Denmark)
Larsen, Gunner Chr.
We present an idealized simple, but fast, semi-analytical algorithm for computation of stationary wind farm wind fields with a possible potential within a multi-fidelity strategy for wind farm topology optimization. Basically, the model considers wakes as linear perturbations on the ambient non......-linear. With each of these approached, a parabolic system are described, which is initiated by first considering the most upwind located turbines and subsequently successively solved in the downstream direction. Algorithms for the resulting wind farm flow fields are proposed, and it is shown that in the limit......-uniform mean wind field, although the modelling of the individual stationary wake flow fields includes non-linear terms. The simulation of the individual wake contributions are based on an analytical solution of the thin shear layer approximation of the NS equations. The wake flow fields are assumed...
Exercise-induced rhabdomyolysis from stationary biking: a case report.
Inklebarger, J; Galanis, N; Kirkos, J; Kapetanos, G
2010-10-01
There are several reports concerning exercise and rabdomyolysis. There has been no report in the English literature of exercise induced rabdomyolisis from a stationary bike.A 63-year-old female recreational athlete presented to our hospital seeking treatment for lower back, leg pain and stiffness after exercising on a stationary bicycle one day prior. Blood work showed a raised CK of 38,120 U/L, a myoglobin of 5330 and an AST 495 U/L with normal urea and electrolytes. Urinalysis remained negative. She was admitted for oral and intravenous hydration and fluid balance monitoringThis is a very rare case of rhabdomyolysis due to exercise. This study highlights the difficulties faced by accident and emergency teams in distinguishing delayed onset muscle soreness (DOMS) from exercise-induced rhabdomyolysis, and reinforces the concept that rhabdomyolysis can occur at any level of exercise intensity.
Learning in Non-Stationary Environments Methods and Applications
Lughofer, Edwin
2012-01-01
Recent decades have seen rapid advances in automatization processes, supported by modern machines and computers. The result is significant increases in system complexity and state changes, information sources, the need for faster data handling and the integration of environmental influences. Intelligent systems, equipped with a taxonomy of data-driven system identification and machine learning algorithms, can handle these problems partially. Conventional learning algorithms in a batch off-line setting fail whenever dynamic changes of the process appear due to non-stationary environments and external influences. Learning in Non-Stationary Environments: Methods and Applications offers a wide-ranging, comprehensive review of recent developments and important methodologies in the field. The coverage focuses on dynamic learning in unsupervised problems, dynamic learning in supervised classification and dynamic learning in supervised regression problems. A later section is dedicated to applications in which dyna...
On the continuity of the stationary state distribution of DPCM
Naraghi-Pour, Morteza; Neuhoff, David L.
1990-03-01
Continuity and singularity properties of the stationary state distribution of differential pulse code modulation (DPCM) are explored. Two-level DPCM (i.e., delta modulation) operating on a first-order autoregressive source is considered, and it is shown that, when the magnitude of the DPCM prediciton coefficient is between zero and one-half, the stationary state distribution is singularly continuous; i.e., it is not discrete but concentrates on an uncountable set with a Lebesgue measure of zero. Consequently, it cannot be represented with a probability density function. For prediction coefficients with magnitude greater than or equal to one-half, the distribution is pure, i.e., either absolutely continuous and representable with a density function, or singular. This problem is compared to the well-known and still substantially unsolved problem of symmetric Bernoulli convolutions.
Stationary density profiles in the Alcator C-mod tokamak
International Nuclear Information System (INIS)
Kesner, J.; Ernst, D.; Hughes, J.; Mumgaard, R.; Shiraiwa, S.; Whyte, D.; Scott, S.
2012-01-01
In the absence of an internal particle source, plasma turbulence will impose an intrinsic relationship between an inwards pinch and an outwards diffusion resulting in a stationary density profile. The Alcator C-mod tokamak utilizes RF heating and current drive so that fueling only occurs in the vicinity of the separatrix. Discharges that transition from L-mode to I-mode are seen to maintain a self-similar stationary density profile as measured by Thomson scattering. For discharges with negative magnetic shear, an observed rise of the safety factor in the vicinity of the magnetic axis appears to be accompanied by a decrease of electron density, qualitatively consistent with the theoretical expectations.
Reduction of NOx emission from stationary combustion sources
International Nuclear Information System (INIS)
Nelson, P.F.
1992-01-01
The environmental impacts of NO x emission from stationary combustion sources are briefly described. These include the formation of both acid rain and photochemical smog, major environmental problems. The three mechanisms which have been identified for the formation of NO x in combustion (thermal, prompt and fuel) are also briefly outlined. Recently stringent standards have been introduced to control emissions of NO x and the review describes the major primary and secondary measures. 10 refs. 2 tabs., 5 figs
Stationary walking solitons in bulk quadratic nonlinear media
Mihalache, Dumitru; Mazilu, D; Crasonavn, L C; Torner Sabata, Lluís
1997-01-01
We study the mutual trapping of fundamental and second-harmonic light beams propagating in bulk quadratic nonlinear media in the presence of Poynting vector beam walk-off. We show numerically the existence of a two-parameter family of (2 + 1)-dimensional stationary, spatial walking solitons. We have found that the solitons exist at various values of material parameters with different wave intensities and soliton velocities. We discuss the differences between (2 + 1) and (1 + 1)-dimensional wa...
On the dynamics of non-stationary binary stellar systems
International Nuclear Information System (INIS)
Bekov, A. A.; Bejsekov, A.N.; Aldibaeva, L.T.
2005-01-01
The motion of test body in the external gravitational field of the binary stellar system with slowly variable some physical parameters of radiating components is considered on the base of restricted non-stationary photo-gravitational three and two bodies problem. The family of polar and coplanar solutions are obtained. These solutions give the possibility of the dynamical and structure interpretation of the binary young evolving stars and galaxies. (author)
Stationary solution of a time dependent density matrix formalism
International Nuclear Information System (INIS)
Tohyama, Mitsuru
1994-01-01
A stationary solution of a time-dependent density-matrix formalism, which is an extension of the time-dependent Hartree-Fock theory to include the effects of two-body correlations, is obtained for the Lipkin model hamiltonian, using an adiabatic treatment of the two-body interaction. It is found that the obtained result is a reasonable approximation for the exact solution of the model. (author)
Occurence of stationary waves in angiography of peripheral vessels
International Nuclear Information System (INIS)
Boettcher, H.D.; Schmilowski, G.M.; Haverkamp, U.; Wagner, W.
1983-01-01
Among 229 angiographies of periphal vascular occlusions performed in 1981 and during the first half of 1982 at the Radiologic Clinic of Muenster University, stationary waves developed in one case in the vascular band before the occlusion. This phenomenon can be a pointer towards assuming that over long distances before the occlusion there is no satisfactory outflow provided for by collaterals, intact arterio-arterial or arterio-venous connections. (orig.) [de
On the instability increments of a stationary pinch
International Nuclear Information System (INIS)
Bud'ko, A.B.
1989-01-01
The stability of stationary pinch to helical modes is numerically studied. It is shown that in the case of a rather fast plasma pressure decrease to the pinch boundary, for example, for an isothermal diffusion pinch with Gauss density distribution instabilities with m=0 modes are the most quickly growing. Instability increments are calculated. A simple analytical expression of a maximum increment of growth of sausage instability for automodel Gauss profiles is obtained
Real Time Indoor Robot Localization Using a Stationary Fisheye Camera
Delibasis , Konstantinos ,; Plagianakos , Vasilios ,; Maglogiannis , Ilias
2013-01-01
Part 7: Intelligent Signal and Image Processing; International audience; A core problem in robotics is the localization of a mobile robot (determination of the location or pose) in its environment, since the robot’s behavior depends on its position. In this work, we propose the use of a stationary fisheye camera for real time robot localization in indoor environments. We employ an image formation model for the fisheye camera, which is used for accelerating the segmentation of the robot’s top ...
Ultrastrong Stationary Double Layers in a Nondischarge Magnetoplasma
DEFF Research Database (Denmark)
Sato, N.; Hatakeyama, R.; Iizuka, S.
1981-01-01
Ultrastrong stationary double layers are generated in a magnetoplasma by simply applying potential differences between two plasma sources. The potential drop ϕD of the double layer is increased up to eϕD/Te≃2×103 (Te is the electron temperature in eV) with no difficulties caused by gas discharge....... There are always large spiky fluctuations on the low-potential tail of the double layers....
Stationary spectra in a quasi neutral current-carrying plasma
International Nuclear Information System (INIS)
Vakulenko, M.O.
1992-01-01
The low-frequency short-wave equilibrium spectra of electromagnetic fluctuations are obtained, accounting for cross-field correlations. The statistical analysis shows that a longitudinal current in a dense quasi neutral (α e ≡4πnomec 2 /Bo 2 >>1) plasma destroys the stationary of fluctuation spectra corresponding to zero fluxes of motion invariants, and may alter also the anomalous electron heat conductivity. 2 refs. (author)
Robust Forecasting of Non-Stationary Time Series
Croux, C.; Fried, R.; Gijbels, I.; Mahieu, K.
2010-01-01
This paper proposes a robust forecasting method for non-stationary time series. The time series is modelled using non-parametric heteroscedastic regression, and fitted by a localized MM-estimator, combining high robustness and large efficiency. The proposed method is shown to produce reliable forecasts in the presence of outliers, non-linearity, and heteroscedasticity. In the absence of outliers, the forecasts are only slightly less precise than those based on a localized Least Squares estima...
Hydrodynamic Limit with Geometric Correction of Stationary Boltzmann Equation
Wu, Lei
2014-01-01
We consider the hydrodynamic limit of a stationary Boltzmann equation in a unit plate with in-flow boundary. We prove the solution can be approximated in $L^{\\infty}$ by the sum of interior solution which satisfies steady incompressible Navier-Stokes-Fourier system, and boundary layer with geometric correction. Also, we construct a counterexample to the classical theory which states the behavior of solution near boundary can be described by the Knudsen layer derived from the Milne problem.
Alpha Channeling in Rotating Plasma with Stationary Waves
International Nuclear Information System (INIS)
Fetterman, A.; Fisch, N.J.
2010-01-01
An extension of the alpha channeling effect to supersonically rotating mirrors shows that the rotation itself can be driven using alpha particle energy. Alpha channeling uses radiofrequency waves to remove alpha particles collisionlessly at low energy. We show that stationary magnetic fields with high n θ can be used for this purpose, and simulations show that a large fraction of the alpha energy can be converted to rotation energy.
Riparian Vegetation Mapping Along the Hanford Reach
International Nuclear Information System (INIS)
FOGWELL, T.W.
2003-01-01
During the biological survey and inventory of the Hanford Site conducted in the mid-1990s (1995 and 1996), preliminary surveys of the riparian vegetation were conducted along the Hanford Reach. These preliminary data were reported to The Nature Conservancy (TNC), but were not included in any TNC reports to DOE or stakeholders. During the latter part of FY2001, PNNL contracted with SEE Botanical, the parties that performed the original surveys in the mid 1990s, to complete the data summaries and mapping associated with the earlier survey data. Those data sets were delivered to PNNL and the riparian mapping by vegetation type for the Hanford Reach is being digitized during the first quarter of FY2002. These mapping efforts provide the information necessary to create subsequent spatial data layers to describe the riparian zone according to plant functional types (trees, shrubs, grasses, sedges, forbs). Quantification of the riparian zone by vegetation types is important to a number of DOE'S priority issues including modeling contaminant transport and uptake in the near-riverine environment and the determination of ecological risk. This work included the identification of vegetative zones along the Reach by changes in dominant plant species covering the shoreline from just to the north of the 300 Area to China Bar near Vernita. Dominant and indicator species included Agropyron dasytachyudA. smithii, Apocynum cannabinum, Aristida longiseta, Artemisia campestris ssp. borealis var scouleriana, Artemisa dracunculus, Artemisia lindleyana, Artemisia tridentata, Bromus tectorum, Chrysothamnus nauseosus, Coreopsis atkinsoniana. Eleocharis palustris, Elymus cinereus, Equisetum hyemale, Eriogonum compositum, Juniperus trichocarpa, Phalaris arundinacea, Poa compressa. Salk exigua, Scirpus acutus, Solidago occidentalis, Sporobolus asper,and Sporobolus cryptandrus. This letter report documents the data received, the processing by PNNL staff, and additional data gathered in FY2002
Long-reach manipulators for decommissioning
International Nuclear Information System (INIS)
Webster, D.A.; Challinor, S.F.
1993-01-01
A survey of redundant facilities at Sellafield has identified that in many cases the conventional means of deploying remote handling equipment are not appropriate and that novel means must be employed. However, decommissioning is not a value adding activity and so expensive one off designs must be avoided. The paper will describe BNFL's approach to the synthesis from proprietary parts of a manipulator which can lift 3 te at a horizontal reach of over 5 metres and yet can still perform the dextrous manipulation necessary to remove small items. It will also cover the development of the manipulator control systems and the adaption of commercial handtools to be manipulator friendly. (author)
Luminosity performance reach after LS1
International Nuclear Information System (INIS)
Herr, W.
2012-01-01
Based on past experience (2010/2011), in particular expected limitations from beam-beam effects, and taking into account the expected beam quality from the LHC injectors, the peak and integrated luminosity at top energy is discussed for different scenarios (e.g. bunch spacing, beta*). In particular it will be shown which are the key parameters to reach the nominal luminosity and it is also shown that peak luminosities two times larger than nominal (or higher) are possible. Possible test in 2012 are discussed
City Reach Code Technical Support Document
Energy Technology Data Exchange (ETDEWEB)
Athalye, Rahul A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Chen, Yan [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Zhang, Jian [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Liu, Bing [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Frankel, Mark [New Buildings Inst., Portland, OR (United States); Lyles, Mark [New Buildings Inst., Portland, OR (United States)
2017-10-31
This report describes and analyzes a set of energy efficiency measures that will save 20% energy over ASHRAE Standard 90.1-2013. The measures will be used to formulate a Reach Code for cities aiming to go beyond national model energy codes. A coalition of U.S. cities together with other stakeholders wanted to facilitate the development of voluntary guidelines and standards that can be implemented in stages at the city level to improve building energy efficiency. The coalition's efforts are being supported by the U.S. Department of Energy via Pacific Northwest National Laboratory (PNNL) and in collaboration with the New Buildings Institute.
On the non-stationary generalized Langevin equation
Meyer, Hugues; Voigtmann, Thomas; Schilling, Tanja
2017-12-01
In molecular dynamics simulations and single molecule experiments, observables are usually measured along dynamic trajectories and then averaged over an ensemble ("bundle") of trajectories. Under stationary conditions, the time-evolution of such averages is described by the generalized Langevin equation. By contrast, if the dynamics is not stationary, it is not a priori clear which form the equation of motion for an averaged observable has. We employ the formalism of time-dependent projection operator techniques to derive the equation of motion for a non-equilibrium trajectory-averaged observable as well as for its non-stationary auto-correlation function. The equation is similar in structure to the generalized Langevin equation but exhibits a time-dependent memory kernel as well as a fluctuating force that implicitly depends on the initial conditions of the process. We also derive a relation between this memory kernel and the autocorrelation function of the fluctuating force that has a structure similar to a fluctuation-dissipation relation. In addition, we show how the choice of the projection operator allows us to relate the Taylor expansion of the memory kernel to data that are accessible in MD simulations and experiments, thus allowing us to construct the equation of motion. As a numerical example, the procedure is applied to Brownian motion initialized in non-equilibrium conditions and is shown to be consistent with direct measurements from simulations.
Plasma oscillations in a stationary external magnetic field
Energy Technology Data Exchange (ETDEWEB)
Ciulli, S [Joint Institute for Nuclear Research, Dubna, Moscow (USSR); Micu, M [Institute of Atomic Physics, Bucharest (Romania)
1958-07-01
The stationary distribution function as well as the small deviations from the stationary state of a gas discharge using the Boltzmann equation is studied as a basis for the calculations. The stationary problem which is discussed corresponds to plasma with cylindrical symmetry. It leads to a Maxwell velocity distribution and to a spatial distribution function which has the asymptotic form 1/r{sup 4}. The plasma perturbations are estimated by the deviations of the first order moments from their Maxwell values. A homogeneous system of differential equations is derived for the Fourier amplitudes of the magnetic field and their asymptotic form is studied. The dispersion relation is obtained by joining smoothly a solution regular at the origin with the regular asymptotic one.A number of idealizations and approximations have been made in the present analysis which limit the utility of the formulae obtained. For example, if the collision term is included in the Boltzmann equation additional quantities appear in the final results, i.e., viscosity, thermal and electrical conductivity, etc. Furthermore, the finite dimensions of linear discharge tubes or the toroidal form of some discharges strongly modify the present results. Taking into account these additional effects, exact solutions are to be obtained numerically for different values of the experimental parameters.
Stationary battery guide: Design, application, and maintenance. Final report
International Nuclear Information System (INIS)
1997-11-01
This guide has been prepared to assist a variety of users with stationary battery design, application, and maintenance. The following battery-related topics are discussed in detail: (1) fundamentals--how batteries are designed and how they work; (2) aging, degradation, and failures with an emphasis on how various maintenance tasks can prevent, detect, or repair certain degradation mechanisms; (3) applications--how batteries are designed for a specific purpose and how the battery industry has evolved; (4) sizing for different applications; (5) protection and charging; (6) periodic inspections and checks; (7) capacity discharge testing; (8) installation and replacement considerations; and (9) problems that can occur with battery systems. Since the original guide was published, new IEEE Recommended Practices related to stationary battery applications have been issued. This revision addresses those industry changes as well as some of the emerging issues related to the development of other industry documents. This guide has been prepared as a comprehensive reference source for stationary batteries and is intended to address the design, application, and maintenance needs of users. The technical discussions are at the application level. Fundamentals of battery design are covered in greater detail in this revision. More details related to internal cell materials, their operational relationship, and performance over the expected life of the battery cell are provided. This information has been included because many changes in battery cell materials, manufacturing and design processes are not always communicated to the user
APLIKASI SIX SIGMA PADA PRODUK CLEAR FILE DI PERUSAHAAN STATIONARY
Directory of Open Access Journals (Sweden)
Desy Emilasari
2007-01-01
Full Text Available This paper describes the application of the Six Sigma methods is used in order to improve quality in manufacturing company that produce stationary product. DMAIC approach is utilized to analyze and improve 'Pocket Clear File' product since this product has more variability and defects. Quality improvement also monitor the process that influenced pocket defect in Bag Making, Kami-ire, Karidome, and Pocket after Karidome Inspections section. Determining of Six Sigma project is based in process and defect type in each section. FMEA also gave the recommendation for quality improvement we need to evaluate the final result of the improvement since some of them were not working properly. Abstract in Bahasa Indonesia : Paper ini menggambarkan bagaimana aplikasi metode Six Sigma digunakan untuk melakukan perbaikan kualitas pada perusahaan manufaktur yang memproduksi produk stationary. Pendekatan DMAIC dipakai untuk menganalisa dan melakukan perbaikan produk 'Pocket Clear File' karena tingginya variabilitas dan cacat dibanding produk lain. Perbaikan kualitas juga memperhatikan proses yang mempengaruhi terjadinya cacat pocket pada section Bag Making, Kami-ire, Karidome, dan Pocket after Karidome Inspection. Penentuan proyek Six Sigma didasarkan atas proses dan jenis cacat pada setiap section. Pendekatan FMEA mampu memberi rekomendasi perbaikan kualitas. Evaluasi dari hasil perbaikan penting untuk dilakukan karena beberapa implementasi perbaikan kualitas tidak berjalan sesuai dengan rencana. kata kunci: six sigma, DMAIC, perusahaan stationary.
Savage, W
1990-09-01
In the UK in 1988, 13.3% of abortions were performed at 13 weeks' gestation or later. Reasons for this delay, in addition to the diagnosis through amniocentesis of a fetal abnormality, include late recognition of pregnancy, a change of mind about completing the pregnancy, a failure of primary care physicians to entertain the diagnosis of pregnancy, travel or financial problems, and referral difficulties and scheduling delays. Women with little education and very young women are most likely to present for late abortions. From 13-16 weeks, dilatation and evacuation is the safest method of pregnancy termination. The procedure can be made easier through preparation of the cervix with a prostaglandin pessary or Foley catheter. After 16 weeks, an instillation method is recommended; prostaglandin administration can be intro- or extra-amniotic. Complication rates at 13-19 weeks are 14.5/1000 for vaginal methods of abortion and 7.2/1000 for prostaglandin methods. The risk of complications is 3 times higher for women who have 2nd-trimester abortions through the National Health Service. Although it is not realistic to expect that late abortions ever can be eliminated, improved sex education and contraceptive reliability as well as reforms in the National Health Service could reduce the number substantially. To reduce delay, it is suggested that the National Health Service set up satellite day care units and 1-2 central units in each region to deal quickly with midtrimester abortions. Delays would be further reduced by legislation to allow abortion on request in at least the 1st trimester of pregnancy.
International Nuclear Information System (INIS)
Morrissey, M.F.
1992-01-01
Interim Waste Technology has demonstrated the Late Washing concept on the Experimental Laboratory Filter (ELF) at TNX. In two tests, washing reduced the [NO 2 - ] from 0.08 M to approximately 0.01 M on slurries with 2 year equivalent radiation exposures and 9.5 wt. % solids. For both washes, the [NO 2 - ] decreased at rates near theoretical for a constant volume stirred vessel, indicating approximately l00% washing efficiency. Permeate flux was greater than 0.05 gpm/ft 2 for both washes at a transmembrane pressure of 50 psi and flow velocity of 9 ft/sec
Directory of Open Access Journals (Sweden)
Piotr Dudek
2017-06-01
Full Text Available In Poland, the number of men over the age of 50 years exceeds 6 million. It is estimated that about 2-6% of this population develops symptoms of late-onset hypogonadism (LOH. In men, testosterone deficiency increases slightly with age. LOH is a clinically and biochemically defined disease of older men with serum testosterone level below the reference parameters of younger healthy men and with symptoms of testosterone deficiency, manifested by pronounced disturbances of quality of life and harmful effects on multiple organ systems. Testosterone replacement therapy may give several benefits regarding body composition, metabolic control, and psychological and sexual parameters.
DEFF Research Database (Denmark)
Christoffersen, Mogens; Lausten, Mette
2009-01-01
The study investigates parental child rearing methods, structural factors relating to the family during adolescence geographic segregation, individual resource deficits and social background of first time late live births among 32 to 37 years old women and compare to teenagers before becoming...... economic and social gradient for first-time teenage mothers. Teenagers who had experienced family separation or who were formerly in out-of-home care in particular had an increased risk of early childbearing. Results showed that teenage mothers were in every respect in a more disadvantaged position than...
Can donated media placements reach intended audiences?
Cooper, Crystale Purvis; Gelb, Cynthia A; Chu, Jennifer; Polonec, Lindsey
2013-09-01
Donated media placements for public service announcements (PSAs) can be difficult to secure, and may not always reach intended audiences. Strategies used by the Centers for Disease Control and Prevention's (CDC) Screen for Life: National Colorectal Cancer Action Campaign (SFL) to obtain donated media placements include producing a diverse mix of high-quality PSAs, co-branding with state and tribal health agencies, securing celebrity involvement, monitoring media trends to identify new distribution opportunities, and strategically timing the release of PSAs. To investigate open-ended recall of PSAs promoting colorectal cancer screening, CDC conducted 12 focus groups in three U.S. cities with men and women either nearing age 50 years, when screening is recommended to begin, or aged 50-75 years who were not in compliance with screening guidelines. In most focus groups, multiple participants recalled exposure to PSAs promoting colorectal cancer screening, and most of these individuals reported having seen SFL PSAs on television, in transit stations, or on the sides of public buses. Some participants reported exposure to SFL PSAs without prompting from the moderator, as they explained how they learned about the disease. Several participants reported learning key campaign messages from PSAs, including that colorectal cancer screening should begin at age 50 years and screening can find polyps so they can be removed before becoming cancerous. Donated media placements can reach and educate mass audiences, including millions of U.S. adults who have not been screened appropriately for colorectal cancer.
Efficacy of REACH Forgiveness across cultures.
Lin, Yin; Worthington, Everett L; Griffin, Brandon J; Greer, Chelsea L; Opare-Henaku, Annabella; Lavelock, Caroline R; Hook, Joshua N; Ho, Man Yee; Muller, Holly
2014-09-01
This study investigates the efficacy of the 6-hour REACH Forgiveness intervention among culturally diverse undergraduates. Female undergraduates (N = 102) and foreign extraction (46.2%) and domestic (43.8%) students in the United States were randomly assigned to immediate treatment or waitlist conditions. Treatment efficacy and the effect of culture on treatment response were assessed using measures of emotional and decisional forgiveness across 3 time periods. Students in the treatment condition reported greater improvement in emotional forgiveness, but not decisional forgiveness, relative to those in the waitlist condition. Gains were maintained at a 1-week follow-up. Although culture did not moderate the effect of treatment, a main effect of culture on emotional forgiveness and marginally significant interaction effect of culture on decisional forgiveness were found. The REACH Forgiveness intervention was efficacious for college students from different cultural backgrounds when conducted in the United States. However, some evidence may warrant development of culturally adapted forgiveness interventions. © 2014 Wiley Periodicals, Inc.
International Nuclear Information System (INIS)
Marseguerra, M.; Minoggio, S.; Rossi, A.; Zio, E.
1992-01-01
The correlated noise affecting many industrial plants under stationary or cyclo-stationary conditions - nuclear reactors included -has been successfully modeled by autoregressive moving average (ARMA) due to the versatility of this technique. The relatively recent neural network methods have similar features and much effort is being devoted to exploring their usefulness in forecasting and control. Identifying a signal by means of an ARMA model gives rise to the problem of selecting its correct order. Similar difficulties must be faced when applying neural network methods and, specifically, particular care must be given to the setting up of the appropriate network topology, the data normalization procedure and the learning code. In the present paper the capability of some neural networks of learning ARMA and seasonal ARMA processes is investigated. The results of the tested cases look promising since they indicate that the neural networks learn the underlying process with relative ease so that their forecasting capability may represent a convenient fault diagnosis tool. (Author)
The stationary Alfven wave in laboratory and space regimes
Finnegan, S. M.
In this thesis, a non-linear, collisional, two-fluid model of uniform plasma convection across field-aligned current (FAC) sheets, describing stationary Alfven (StA) waves is developed in support of laboratory experiments performed to test the hypothesis that a stationary inertial Alfven wave pattern forms within a channel of parallel electron current across which plasma is convected. In a previous work, Knudsen (D. J. Knudsen, J. Geophys. Res. 101, 10,761 (1996)) showed that, for cold, collisionless plasma, stationary inertial Alfven (StIA) waves can accelerate electrons parallel to a background magnetic field and cause large, time-independent plasma-density variations having spatial periodicity in the direction of the convective flow over a broad range of spatial scales and energies. Here, Knudsen's model has been generalized for warm, collisional, anisotropic plasma. The inclusion of parallel electron thermal pressure introduces dispersive effects which extend the model to the kinetic (beta > me/mi) regime. The effects of both ion-neutral and electron-ion collisional resistivity on StIA and stationary kinetic Alfven (StKA) wave solutions is studied. Conditions for both periodic and solitary wave solutions are identified. In the small amplitude limit, it is shown that the StA wave equation reduces to the differential equation describing the behavior of a forced harmonic oscillator. Analytical solutions are obtained for both a step and impulse, of finite width, forcing functions. Plasma rotation experiments in the West Virginia University Q-machine (WVUQ) demonstrate that an electron-emitting spiral electrode produces controllable, parabolic radial profile of floating potential, while the space potential showed no such structure. Laser-induced fluorescence measurements confirmed that the azimuthal ion drift velocity is inconsistent with a drift due to a gradient in the space potential. Experiments designed to produce StIA wave signatures were performed in the
Hammouda, Imen; Mihoubi, Daoued
2017-12-01
This work deals with a numerical study of the response of a porcelain slab when subjected to convective drying in stationary and non-stationary conditions. The used model describes heat, mass, and momentum transfers is applied to an unsaturated viscoelastic medium described by a Maxwell model. The numerical code allows us to determine the effect of the surrounding air temperature on drying kinetics and on mechanical stress intensities. Von Mises stresses are analysed in order to foresee an eventual damage that may occur during drying. Simulation results for several temperatures in the range of [30 °C, 90 °C] shows that for the temperature from 30 °C to 60 °C, Von Mises stresses are always lower than the yield strength. But above 70 °C, Von Mises stresses are higher than the ultimate strength, and consequently there is a risk of crack at the end of the constant drying rate period. The idea proposed in this work is to integrate a reducing temperature phase when the predicted Von Mises stress intensity exceeds the admissible stress. Simulation results shows that a non-stationary convective drying (90-60 °C) allows us to optimize costs and quality by reducing the drying time and maintaining Von Mises stress values under the admissible stress.
Riparian Vegetation Mapping Along the Hanford Reach
Energy Technology Data Exchange (ETDEWEB)
FOGWELL, T.W.
2003-07-11
During the biological survey and inventory of the Hanford Site conducted in the mid-1990s (1995 and 1996), preliminary surveys of the riparian vegetation were conducted along the Hanford Reach. These preliminary data were reported to The Nature Conservancy (TNC), but were not included in any TNC reports to DOE or stakeholders. During the latter part of FY2001, PNNL contracted with SEE Botanical, the parties that performed the original surveys in the mid 1990s, to complete the data summaries and mapping associated with the earlier survey data. Those data sets were delivered to PNNL and the riparian mapping by vegetation type for the Hanford Reach is being digitized during the first quarter of FY2002. These mapping efforts provide the information necessary to create subsequent spatial data layers to describe the riparian zone according to plant functional types (trees, shrubs, grasses, sedges, forbs). Quantification of the riparian zone by vegetation types is important to a number of DOE'S priority issues including modeling contaminant transport and uptake in the near-riverine environment and the determination of ecological risk. This work included the identification of vegetative zones along the Reach by changes in dominant plant species covering the shoreline from just to the north of the 300 Area to China Bar near Vernita. Dominant and indicator species included Agropyron dasytachyudA. smithii, Apocynum cannabinum, Aristida longiseta, Artemisia campestris ssp. borealis var scouleriana, Artemisa dracunculus, Artemisia lindleyana, Artemisia tridentata, Bromus tectorum, Chrysothamnus nauseosus, Coreopsis atkinsoniana. Eleocharis palustris, Elymus cinereus, Equisetum hyemale, Eriogonum compositum, Juniperus trichocarpa, Phalaris arundinacea, Poa compressa. Salk exigua, Scirpus acutus, Solidago occidentalis, Sporobolus asper,and Sporobolus cryptandrus. This letter report documents the data received, the processing by PNNL staff, and additional data gathered in FY
Reach and get capability in a computing environment
Bouchard, Ann M [Albuquerque, NM; Osbourn, Gordon C [Albuquerque, NM
2012-06-05
A reach and get technique includes invoking a reach command from a reach location within a computing environment. A user can then navigate to an object within the computing environment and invoke a get command on the object. In response to invoking the get command, the computing environment is automatically navigated back to the reach location and the object copied into the reach location.
Unified communication to reach vulnerable mothers.
Tezcan, B; Von Rege, I; Henkson, H; Oteng-Ntim, E
2011-01-01
The feasibility of using a mobile text to reach vulnerable patient groups was assessed in this study. A total of 121 pregnant or postnatal women were randomly asked to complete a questionnaire. The questionnaire was given to them in the antenatal clinic, postnatal ward, antenatal ward or in the day assessment unit at St Thomas' Hospital, London. The forms were collected and analysed using an Excel database. The results of this survey show that mobile technology is readily available for 97% of the obstetric population. In mothers from vulnerable groups and in mothers from deprived areas, 61% possessed 3rd generation mobile technology. The majority of mothers surveyed wanted their care supplemented by the use of their mobile phones.
Validity of an Interactive Functional Reach Test.
Galen, Sujay S; Pardo, Vicky; Wyatt, Douglas; Diamond, Andrew; Brodith, Victor; Pavlov, Alex
2015-08-01
Videogaming platforms such as the Microsoft (Redmond, WA) Kinect(®) are increasingly being used in rehabilitation to improve balance performance and mobility. These gaming platforms do not have built-in clinical measures that offer clinically meaningful data. We have now developed software that will enable the Kinect sensor to assess a patient's balance using an interactive functional reach test (I-FRT). The aim of the study was to test the concurrent validity of the I-FRT and to establish the feasibility of implementing the I-FRT in a clinical setting. The concurrent validity of the I-FRT was tested among 20 healthy adults (mean age, 25.8±3.4 years; 14 women). The Functional Reach Test (FRT) was measured simultaneously by both the Kinect sensor using the I-FRT software and the Optotrak Certus(®) 3D motion-capture system (Northern Digital Inc., Waterloo, ON, Canada). The feasibility of implementing the I-FRT in a clinical setting was assessed by performing the I-FRT in 10 participants with mild balance impairments recruited from the outpatient physical therapy clinic (mean age, 55.8±13.5 years; four women) and obtaining their feedback using a NASA Task Load Index (NASA-TLX) questionnaire. There was moderate to good agreement between FRT measures made by the two measurement systems. The greatest agreement between the two measurement system was found with the Kinect sensor placed at a distance of 2.5 m [intraclass correlation coefficient (2,k)=0.786; PNASA/TLX questionnaire. FRT measures made using the Kinect sensor I-FRT software provides a valid clinical measure that can be used with the gaming platforms.
DEFF Research Database (Denmark)
Andersen, Bjørn Schiermer
2015-01-01
Through analysis of key texts, I seek to demonstrate the explanative potential of Durkheim’s sociology of religion in the present context. I critically readdress the idea, found in his early work, that modernity is characterized by a rupture with pre-modern forms of solidarity. First, I investigate...... the ways in which Durkheim sets up a stark distinction between the pre-modern and the modern in his early work, and how this distinction is further cemented by his orthodox critique of the modern economy and its negative effects on social life. Second, I show how another timeless and positive understanding...... of “mechanical” solidarity is to be found behind the “symbolist” template crystalizing in Durkheim’s late work. Third, I develop this template for a modern context by critically addressing and removing other obstacles and prejudices on Durkheim’s part....
International Nuclear Information System (INIS)
Gilbert, E.
1985-01-01
A model is provided for estimating risks of late effects resulting from low-LET radiation exposure likely to be received in the event of a nuclear power plant accident. Separate estimates are provided for risks of leukemia, cancers of the bones, lungs, gastrointestinal tract, thyroid, skin, and the residual group of all other cancers; estimates of leukemia and other cancers due to in utero exposure are also provided. Risks are expressed in absolute terms as the number of cancer deaths (or cases) per million persons exposed to a particular dose. In addition, the number of years of life lost and the number of years of life lived after the occurrence of cancer are also estimated. The model used in the earlier Reactor Safety Study has been modified to reflect additional epidemiological data and these changes are described in detail. 37 references, 1 figure, 13 tables
Toxicological comments to the discussion about REACH.
Greim, Helmut; Arand, Michael; Autrup, Herman; Bolt, Hermann M; Bridges, James; Dybing, Erik; Glomot, Rémi; Foa, Vito; Schulte-Hermann, Rolf
2006-03-01
It is the ultimate goal of the intended REACH process (Registration, Evaluation and Authorization of Chemicals) of the European Union to identify substances of hazardous properties and to evaluate the risks of human and environmental exposure. During the last few months there has been a controversial discussion as to what extent in vitro studies and consideration of structure activity relationship provide sufficient information to waive repeated exposure studies. Industry as well as certain regulatory agencies or NGOs support this approach and propose that repeated dose studies may only be required beyond 100 t/a. From a toxicological point of view it has to be stressed that this discussion primarily considers the cost reduction and protection of animals, whereas protection of human health and the environment are secondary. In vitro studies only allow identification of specific hazardous properties which can be detected by the specific test system. Moreover, appropriate information on the dose response of adverse effects, identification of thresholds and NOELs that are essential for risk characterization cannot be obtained from these studies. Consequently, identification of all relevant hazardous properties and endpoints of adverse effects can only be determined in the intact animal by repeated dose studies such as 28-day or 90-day studies. In the absence of such information the hazard identification is incomplete and there is no basis for appropriate risk assessment of human exposure. Thus, any waiving of repeated dose studies in animals bears the probability of unforeseen effects in case of acute or continuous human exposure. From this the undersigning European Toxicologists conclude: 1. The intention of REACH is to identify hazardous properties in order that a reliable risk assessment can be made and measures taken to deal with chemicals posing a significant risk. 2. The recent debate has centered on ways in which the well established in vivo methods for risk
Assessment of the environmental benefits of transport and stationary fuel
International Nuclear Information System (INIS)
Bauen, A.; Hart, D.
2000-01-01
Fuel cells (FCs) offer significant environmental benefits over competing technologies and hence the environment is a strong driving force behind the development of FC systems for transport and stationary applications. This paper provides a comprehensive comparison of FC and competing systems, and points out strengths and weaknesses of the different FC systems, suggesting areas for improvement. The results presented build on earlier work [D. Hart, G. Hoermandinger, Initial assessment of the environmental characteristics of fuel cells and competing technologies, ETSU F/02/00111/REP/1, ETSU, Harwell, UK, 1997.] and provide a detailed analysis of a wider range of systems, The analysis takes the form of a model, which compares system emissions (global, regional and local pollutants) and energy consumption on a full fuel cycle basis. It considers a variety of primary energy sources, intermediate fuel supply steps and FC systems for transport and stationary end-uses. These are compared with alternative systems for transport and stationary applications. Energy and pollutant emission reductions of FC systems compared to alternative vehicle technology vary considerably, though all FC technologies show reduction in energy use and CO 2 emissions of at least 20%; as well as reductions of several orders of magnitude in regulated pollutants compared to the base-case vehicle. The location of emissions is also of importance, with most emissions in the case of FC vehicles occurring in the fuel supply stage. The energy, CO 2 and regulated emissions advantages of FC systems for distributed and baseload electricity are more consistent than for transport applications, with reductions in regulated pollutants generally larger than one order of magnitude compared to competing technologies. For CHP applications, the advantages of FC systems with regard to regulated pollutants remain large. However, energy and CO 2 emission advantages are reduced, depending largely on the assumptions made
Autocalibration method for non-stationary CT bias correction.
Vegas-Sánchez-Ferrero, Gonzalo; Ledesma-Carbayo, Maria J; Washko, George R; Estépar, Raúl San José
2018-02-01
Computed tomography (CT) is a widely used imaging modality for screening and diagnosis. However, the deleterious effects of radiation exposure inherent in CT imaging require the development of image reconstruction methods which can reduce exposure levels. The development of iterative reconstruction techniques is now enabling the acquisition of low-dose CT images whose quality is comparable to that of CT images acquired with much higher radiation dosages. However, the characterization and calibration of the CT signal due to changes in dosage and reconstruction approaches is crucial to provide clinically relevant data. Although CT scanners are calibrated as part of the imaging workflow, the calibration is limited to select global reference values and does not consider other inherent factors of the acquisition that depend on the subject scanned (e.g. photon starvation, partial volume effect, beam hardening) and result in a non-stationary noise response. In this work, we analyze the effect of reconstruction biases caused by non-stationary noise and propose an autocalibration methodology to compensate it. Our contributions are: 1) the derivation of a functional relationship between observed bias and non-stationary noise, 2) a robust and accurate method to estimate the local variance, 3) an autocalibration methodology that does not necessarily rely on a calibration phantom, attenuates the bias caused by noise and removes the systematic bias observed in devices from different vendors. The validation of the proposed methodology was performed with a physical phantom and clinical CT scans acquired with different configurations (kernels, doses, algorithms including iterative reconstruction). The results confirmed the suitability of the proposed methods for removing the intra-device and inter-device reconstruction biases. Copyright © 2017 Elsevier B.V. All rights reserved.
Non-stationary (13)C-metabolic flux ratio analysis.
Hörl, Manuel; Schnidder, Julian; Sauer, Uwe; Zamboni, Nicola
2013-12-01
(13)C-metabolic flux analysis ((13)C-MFA) has become a key method for metabolic engineering and systems biology. In the most common methodology, fluxes are calculated by global isotopomer balancing and iterative fitting to stationary (13)C-labeling data. This approach requires a closed carbon balance, long-lasting metabolic steady state, and the detection of (13)C-patterns in a large number of metabolites. These restrictions mostly reduced the application of (13)C-MFA to the central carbon metabolism of well-studied model organisms grown in minimal media with a single carbon source. Here we introduce non-stationary (13)C-metabolic flux ratio analysis as a novel method for (13)C-MFA to allow estimating local, relative fluxes from ultra-short (13)C-labeling experiments and without the need for global isotopomer balancing. The approach relies on the acquisition of non-stationary (13)C-labeling data exclusively for metabolites in the proximity of a node of converging fluxes and a local parameter estimation with a system of ordinary differential equations. We developed a generalized workflow that takes into account reaction types and the availability of mass spectrometric data on molecular ions or fragments for data processing, modeling, parameter and error estimation. We demonstrated the approach by analyzing three key nodes of converging fluxes in central metabolism of Bacillus subtilis. We obtained flux estimates that are in agreement with published results obtained from steady state experiments, but reduced the duration of the necessary (13)C-labeling experiment to less than a minute. These results show that our strategy enables to formally estimate relative pathway fluxes on extremely short time scale, neglecting cellular carbon balancing. Hence this approach paves the road to targeted (13)C-MFA in dynamic systems with multiple carbon sources and towards rich media. © 2013 Wiley Periodicals, Inc.
International Nuclear Information System (INIS)
Perry, E.F.
1995-01-01
The Army Reactor Area (ARA) II was constructed in the late 1950s as a test site for the Stationary Low Power Reactor No. 1 (SL-1). The SL-1 was a prototype power and heat source developed for use at remote military bases using a direct cycle, boiling water, natural circulation reactor designed to operate at a thermal power of 3,000 kW. The ARA II compound encompassed 3 acres and was comprised of (a) the SL-1 Reactor Building, (b) eight support facilities, (c) 50,000-gallon raw water storage tank, (d) electrical substation, (e) aboveground 1,400-gallon heating oil tank, (f) underground 1,000-gallon hazardous waste storage tank, and (g) belowground power, sewer, and water systems. The reactor building was a cylindrical, aboveground facility, 39 ft in diameter and 48 ft high. The lower portion of the building contained the reactor pressure vessel surrounded by gravel shielding. Above the pressure vessel, in the center portion of the building, was a turbine generator and plant support equipment. The upper section of the building contained an air cooled condenser and its circulation fan. The major support facilities included a 2,500 ft 2 two story, cinder block administrative building; two 4,000 ft 2 single story, steel frame office buildings; a 850 ft 2 steel framed, metal sided PL condenser building, and a 550 ft 2 steel framed decontamination and laydown building
Automatic Adviser on stationary devices status identification and anticipated change
Shabelnikov, A. N.; Liabakh, N. N.; Gibner, Ya M.; Pushkarev, E. A.
2018-05-01
A task is defined to synthesize an Automatic Adviser to identify the automation systems stationary devices status using an autoregressive model of changing their key parameters. An applied model type was rationalized and the research objects monitoring process algorithm was developed. A complex of mobile objects status operation simulation and prediction results analysis was proposed. Research results are commented using a specific example of a hump yard compressor station. The work was supported by the Russian Fundamental Research Fund, project No. 17-20-01040.
Local polynomial Whittle estimation covering non-stationary fractional processes
DEFF Research Database (Denmark)
Nielsen, Frank
to the non-stationary region. By approximating the short-run component of the spectrum by a polynomial, instead of a constant, in a shrinking neighborhood of zero we alleviate some of the bias that the classical local Whittle estimators is prone to. This bias reduction comes at a cost as the variance is in...... study illustrates the performance of the proposed estimator compared to the classical local Whittle estimator and the local polynomial Whittle estimator. The empirical justi.cation of the proposed estimator is shown through an analysis of credit spreads....
The complex, variable structure of stationary lines in SS433
International Nuclear Information System (INIS)
Falomo, R.; Boksenberg, A.; Tanzi, E.G.; Tarenghi, M.; Treves, A.
1987-01-01
On 1979 June 3-6, a number of spectra of SS433 were obtained using the UCL Image Photon Counting System on the 3.6-m telescope of the European Southern Observatory, La Silla, Chile. The stationary Hα and He I lambdalambda5875, 6678 and 7065 lines have a complex structure which on June 4-5 exhibited a central feature accompanied by two equally displaced (+- 1000 km s -1 ) side components. Variability of the line profile and equivalent width is observed on time-scales as short as a quarter of an hour. (author)
Complex, variable structure of stationary lines in SS433
Energy Technology Data Exchange (ETDEWEB)
Falomo, R.; Boksenberg, A.; Tanzi, E.G.; Tarenghi, M.; Treves, A.
1987-01-15
On 1979 June 3-6, a number of spectra of SS433 were obtained using the UCL Image Photon Counting System on the 3.6-m telescope of the European Southern Observatory, La Silla, Chile. The stationary H..cap alpha.. and He I lambdalambda5875, 6678 and 7065 lines have a complex structure which on June 4-5 exhibited a central feature accompanied by two equally displaced (+- 1000 km s/sup -1/) side components. Variability of the line profile and equivalent width is observed on time-scales as short as a quarter of an hour.
Handbook of differential equations stationary partial differential equations
Chipot, Michel
2006-01-01
This handbook is volume III in a series devoted to stationary partial differential quations. Similarly as volumes I and II, it is a collection of self contained state-of-the-art surveys written by well known experts in the field. The topics covered by this handbook include singular and higher order equations, problems near critically, problems with anisotropic nonlinearities, dam problem, T-convergence and Schauder-type estimates. These surveys will be useful for both beginners and experts and speed up the progress of corresponding (rapidly developing and fascinating) areas of mathematics. Ke
Solid polymer fuel cell stationary power generation design studies
Energy Technology Data Exchange (ETDEWEB)
Pyke, S.H.; Wood, A.; Williams, G.J.; Kearney, P.
2000-07-01
This report summarises the results of a study investigating potential markets for solid polymer fuel cells (SPFC) stationary power generating systems and evaluating design options for grid connected and stand-alone systems. The specification of potential application for SPFC systems, initial modelling and economic analysis of twelve candidate SPFC applications, and the ranking and evaluation of candidate applications are examined. Details are given of performance modelling and economic analysis of four preferred SPFC systems (domestic, commercial, light industrial, and transportable generation), and comparison of SPFC with competing technologies. The economics of SPFC and conventional technologies for commercial applications are compared and market opportunities and potential barriers to commercialisation are identified.
On stationary states of electron beams in drift space
International Nuclear Information System (INIS)
Kovalev, N.F.
2002-01-01
The article is devoted to studying the conditions of formation and existence of virtual cathodes. The problem on stationary states of the strongly magnetized electron beams in the homogeneous drift channels is discussed. The problem on the planar and coaxial moduli of the drift spaces is considered. The possibility of existing the virtual cathodes in the coaxial tubular beams by the injection currents, smaller than the threshold ones is highly proved. The inaccuracy of results of a number of works, studying the properties of the virtual cathodes in the strongly magnetized electron beams, is shown [ru
First-order, stationary mean-field games with congestion
Evangelista, David
2018-04-30
Mean-field games (MFGs) are models for large populations of competing rational agents that seek to optimize a suitable functional. In the case of congestion, this functional takes into account the difficulty of moving in high-density areas. Here, we study stationary MFGs with congestion with quadratic or power-like Hamiltonians. First, using explicit examples, we illustrate two main difficulties: the lack of classical solutions and the existence of areas with vanishing densities. Our main contribution is a new variational formulation for MFGs with congestion. With this formulation, we prove the existence and uniqueness of solutions. Finally, we consider applications to numerical methods.
Effect of multiplicative noise on stationary stochastic process
Kargovsky, A. V.; Chikishev, A. Yu.; Chichigina, O. A.
2018-03-01
An open system that can be analyzed using the Langevin equation with multiplicative noise is considered. The stationary state of the system results from a balance of deterministic damping and random pumping simulated as noise with controlled periodicity. The dependence of statistical moments of the variable that characterizes the system on parameters of the problem is studied. A nontrivial decrease in the mean value of the main variable with an increase in noise stochasticity is revealed. Applications of the results in several physical, chemical, biological, and technical problems of natural and humanitarian sciences are discussed.
On quantization of free fields in stationary space-times
International Nuclear Information System (INIS)
Moreno, C.
1977-01-01
In Section 1 the structure of the infinite-dimensional Hamiltonian system described by the Klein-Gordon equation (free real scalar field) in stationary space-times with closed space sections, is analysed, an existence and uniqueness theorem is given for the Lichnerowicz distribution kernel G 1 together with its proper Fourier expansion, and the Hilbert spaces of frequency-part solutions defined by means of G 1 are constructed. In Section 2 an analysis, a theorem and a construction similar to the above are formulated for the free real field spin 1, mass m>0, in one kind of static space-times. (Auth.)
Improved inventory for heavy metal emissions from stationary combustion plants
DEFF Research Database (Denmark)
Nielsen, Malene; Nielsen, Ole-Kenneth; Hoffmann, Leif
On behalf of the Ministry of the Environment DCE at Aarhus University annually reports heavy metals (HM) emissions to the UNECE CLRTAP (United Nations Economic Commission for Europe Convention on Long-Range Transboundary Air Pollution). This report presents updated heavy metal emission factors......-2009. The report also include methodology, references and an uncertainty estimate. In Denmark, stationary combustion plants are among the most important emission sources for heavy metals. Emissions of all heavy metals have decreased considerably (73 % - 92 %) since 1990. The main HM emission sources are coal...
On Optimal Feedback Control for Stationary Linear Systems
International Nuclear Information System (INIS)
Russell, David L.
2010-01-01
We study linear-quadratic optimal control problems for finite dimensional stationary linear systems AX+BU=Z with output Y=CX+DU from the viewpoint of linear feedback solution. We interpret solutions in relation to system robustness with respect to disturbances Z and relate them to nonlinear matrix equations of Riccati type and eigenvalue-eigenvector problems for the corresponding Hamiltonian system. Examples are included along with an indication of extensions to continuous, i.e., infinite dimensional, systems, primarily of elliptic type.
On the negligible emissions from stationary energy production
International Nuclear Information System (INIS)
Haaland, Leif
2002-01-01
According to this article, the emissions from stationary energy production are so small that it is immaterial which energy carriers are used. Percentage comparison may be misleading. There are many myths about the emissions from various energy carriers, one deals with bio fuel and the emission of cadmium, another with light oil and the emission of SO 2 . However, wood-burning accounts for substantial amounts of dust emission and old-fashioned stoves should have been forbidden in built-up areas. The article concludes by recommending that Norway should use more district heating
Influence of stationary vehicles on bridge aerodynamic and aeroelastic coefficients
Czech Academy of Sciences Publication Activity Database
Pospíšil, Stanislav; Buljac, A.; Kozmar, H.; Kuznetsov, Sergeii; Macháček, Michael; Král, Radomil
2017-01-01
Roč. 22, č. 4 (2017), č. článku 05016012. ISSN 1084-0702 R&D Projects: GA ČR(CZ) GA15-01035S; GA MŠk(CZ) LO1219 Keywords : wind-vehicle-bridge system * cable-supported bridge * bridge aerodynamics and aeroelasticity * stationary vehicles * wind tunnel tests Subject RIV: JM - Building Engineering OBOR OECD: Construction engineering, Municipal and structural engineering Impact factor: 1.476, year: 2016 http://ascelibrary.org/doi/full/10.1061/%28ASCE%29BE.1943-5592.0001017
Detrending of non-stationary noise data by spline techniques
International Nuclear Information System (INIS)
Behringer, K.
1989-11-01
An off-line method for detrending non-stationary noise data has been investigated. It uses a least squares spline approximation of the noise data with equally spaced breakpoints. Subtraction of the spline approximation from the noise signal at each data point gives a residual noise signal. The method acts as a high-pass filter with very sharp frequency cutoff. The cutoff frequency is determined by the breakpoint distance. The steepness of the cutoff is controlled by the spline order. (author) 12 figs., 1 tab., 5 refs
First-order, stationary mean-field games with congestion
Evangelista, David; Ferreira, Rita; Gomes, Diogo A.; Nurbekyan, Levon; Voskanyan, Vardan K.
2018-01-01
Mean-field games (MFGs) are models for large populations of competing rational agents that seek to optimize a suitable functional. In the case of congestion, this functional takes into account the difficulty of moving in high-density areas. Here, we study stationary MFGs with congestion with quadratic or power-like Hamiltonians. First, using explicit examples, we illustrate two main difficulties: the lack of classical solutions and the existence of areas with vanishing densities. Our main contribution is a new variational formulation for MFGs with congestion. With this formulation, we prove the existence and uniqueness of solutions. Finally, we consider applications to numerical methods.
ESO telbib: Linking In and Reaching Out
Grothkopf, U.; Meakins, S.
2015-04-01
Measuring an observatory's research output is an integral part of its science operations. Like many other observatories, ESO tracks scholarly papers that use observational data from ESO facilities and uses state-of-the-art tools to create, maintain, and further develop the Telescope Bibliography database (telbib). While telbib started out as a stand-alone tool mostly used to compile lists of papers, it has by now developed into a multi-faceted, interlinked system. The core of the telbib database is links between scientific papers and observational data generated by the La Silla Paranal Observatory residing in the ESO archive. This functionality has also been deployed for ALMA data. In addition, telbib reaches out to several other systems, including ESO press releases, the NASA ADS Abstract Service, databases at the CDS Strasbourg, and impact scores at Altmetric.com. We illustrate these features to show how the interconnected telbib system enhances the content of the database as well as the user experience.
Using New Media to Reach Broad Audiences
Gay, P. L.
2008-06-01
The International Year of Astronomy New Media Working Group (IYA NMWG) has a singular mission: To flood the Internet with ways to learn about astronomy, interact with astronomers and astronomy content, and socially network with astronomy. Within each of these areas, we seek to build lasting programs and partnerships that will continue beyond 2009. Our weapon of choice is New Media. It is often easiest to define New Media by what it is not. Television, radio, print and their online redistribution of content are not New Media. Many forms of New Media start as user provided content and content infrastructures that answer that individual's creative whim in a way that is adopted by a broader audience. Classic examples include Blogs and Podcasts. This media is typically distributed through content specific websites and RSS feeds, which allow syndication. RSS aggregators (iTunes has audio and video aggregation abilities) allow subscribers to have content delivered to their computers automatically when they connect to the Internet. RSS technology is also being used in such creative ways as allowing automatically updating Google-maps that show the location of someone with an intelligent GPS system, and in sharing 100 word microblogs from anyone (Twitters) through a single feed. In this poster, we outline how the IYA NMWG plans to use New Media to reach target primary audiences of astronomy enthusiasts, image lovers, and amateur astronomers, as well as secondary audiences, including: science fiction fans, online gamers, and skeptics.
Media perspective - new opportunities for reaching audiences
Haswell, Katy
2007-08-01
The world of media is experiencing a period of extreme and rapid change with the rise of internet television and the download generation. Many young people no longer watch standard TV. Instead, they go on-line, talking to friends and downloading pictures, videos, music clips to put on their own websites and watch/ listen to on their laptops and mobile phones. Gone are the days when TV controllers determined what you watched and when you watched it. Now the buzzword is IPTV, Internet Protocol Television, with companies such as JOOST offering hundreds of channels on a wide range of subjects, all of which you can choose to watch when and where you wish, on your high-def widescreen with stereo surround sound at home or on your mobile phone on the train. This media revolution is changing the way organisations get their message out. And it is encouraging companies such as advertising agencies to be creative about new ways of accessing audiences. The good news is that we have fresh opportunities to reach young people through internet-based media and material downloaded through tools such as games machines, as well as through the traditional media. And it is important for Europlanet to make the most of these new and exciting developments.
Has Athletic Performance Reached its Peak?
Berthelot, Geoffroy; Sedeaud, Adrien; Marck, Adrien; Antero-Jacquemin, Juliana; Schipman, Julien; Saulière, Guillaume; Marc, Andy; Desgorces, François-Denis; Toussaint, Jean-François
2015-09-01
Limits to athletic performance have long been a topic of myth and debate. However, sport performance appears to have reached a state of stagnation in recent years, suggesting that the physical capabilities of humans and other athletic species, such as greyhounds and thoroughbreds, cannot progress indefinitely. Although the ultimate capabilities may be predictable, the exact path for the absolute maximal performance values remains difficult to assess and relies on technical innovations, sport regulation, and other parameters that depend on current societal and economic conditions. The aim of this literature review was to assess the possible plateau of top physical capabilities in various events and detail the historical backgrounds and sociocultural, anthropometrical, and physiological factors influencing the progress and regression of athletic performance. Time series of performances in Olympic disciplines, such as track and field and swimming events, from 1896 to 2012 reveal a major decrease in performance development. Such a saturation effect is simultaneous in greyhound, thoroughbred, and frog performances. The genetic condition, exhaustion of phenotypic pools, economic context, and the depletion of optimal morphological traits contribute to the observed limitation of physical capabilities. Present conditions prevailing, we approach absolute physical limits and endure a continued period of world record scarcity. Optional scenarios for further improvements will mostly depend on sport technology and modification competition rules.
LEP Dismantling Reaches Half-Way Stage
2001-01-01
LEP's last superconducting module leaves its home port... Just seven months into the operation, LEP dismantling is forging ahead. Two of the eight arcs which form the tunnel have already been emptied and the last of the accelerator's radiofrequency (RF) cavities has just been raised to the surface. The 160 people working on LEP dismantling have reason to feel pleased with their progress. All of the accelerator's 72 superconducting RF modules have already been brought to the surface, with the last one being extracted on 2nd May. This represents an important step in the dismantling process, as head of the project, John Poole, explains. 'This was the most delicate part of the project, because the modules are very big and they could only come out at one place', he says. The shaft at point 1.8 through which the RF cavity modules pass is 18 metres in diameter, while each module is 11.5 metres long. Some modules had to travel more than 10 kilometres to reach the shaft. ... is lifted up the PM 1.8 shaft, after a m...
CAST reaches milestone but keeps on searching
CERN Courier (september 2011 issue)
2011-01-01
After eight years of searching for the emission of a dark matter candidate particle, the axion, from the Sun, the CERN Axion Solar Telescope (CAST) has fulfilled its original physics programme. Members of the CAST collaboration in July, together with dipole-based helioscope. CAST, the world’s most sensitive axion helioscope, points a recycled prototype LHC dipole magnet at the Sun at dawn and dusk, looking for the conversion of axions to X-rays. It incorporates four state-of-the-art X-ray detectors: three Micromegas detectors and a pn-CCD imaging camera attached to a focusing X-ray telescope that was recovered from the German space programme (see CERN Courier April 2010). Over the years, CAST has operated with the magnet bores - the location of the axion conversion - in different conditions: first in vacuum, covering axion masses up to 20 meV/c2, and then with a buffer gas (4He and later 3He) at various densities, finally reaching the goal of 1.17 eV/c2 on 22 ...
Important ATLAS Forward Calorimeter Milestone Reached
Loch, P.
The ATLAS Forward Calorimeter working group has reached an important milestone in the production of their detectors. The mechanical assembly of the first electromagnetic module (FCal1C) has been completed at the University of Arizona on February 25, 2002, only ten days after the originally scheduled date. The photo shows the University of Arizona FCal group in the clean room, together with the assembled FCal1C module. The module consists of a stack of 18 round copper plates, each about one inch thick. Each plate is about 90 cm in diameter, and has 12260 precision-drilled holes in it, to accommodate the tube/rod electrode assembly. The machining of the plates, which was done at the Science Technology Center (STC) at Carleton University, Ottawa, Canada, required high precision to allow for easy insertion of the electrode copper tube. The plates have been carefully cleaned at the University of Arizona, to remove any machining residue and metal flakes. This process alone took about eleven weeks. Exactly 122...
Do children perceive postural constraints when estimating reach or action planning?
Gabbard, Carl; Cordova, Alberto; Lee, Sunghan
2009-03-01
Estimation of whether an object is reachable from a specific body position constitutes an important aspect in effective motor planning. Researchers who estimate reachability by way of motor imagery with adults consistently report the tendency to overestimate, with some evidence of a postural effect (postural stability hypothesis). This idea suggests that perceived reaching limits depend on an individual's perceived postural constraints. Based on previous work with adults, the authors expected a significant postural effect with the Reach 2 condition, as evidenced by reduced overestimation. Furthermore, the authors hypothesized that the postural effect would be greater in younger children. They then tested these propositions among children aged 7, 9, and 11 years by asking them to estimate reach while seated (Reach 1) and in the more demanding posture of standing on 1 foot and leaning forward (Reach 2). Results indicated no age or condition difference, therefore providing no support for a postural effect. When the authors compared these data to a published report of adults, a developmental difference emerged. That is, adults recognize the perceived postural constraint of the standing position resulting in under- rather than overestimation, as displayed in the seated condition. Although preliminary, these observations suggest that estimates of reach (action planning) continue to be refined between late childhood and young adulthood.
Planning of the Extended Reach well Dieksand 2; Planung der Extended Reach Bohrung Dieksand 2
Energy Technology Data Exchange (ETDEWEB)
Frank, U.; Berners, H. [RWE-DEA AG, Hamburg (Germany). Drilling Team Mittelplate und Dieksand; Hadow, A.; Klop, G.; Sickinger, W. [Wintershall AG Erdoelwerke, Barnstdorf (Germany); Sudron, K.
1998-12-31
The Mittelplate oil field is located 7 km offshore the town of Friedrichskoog. Reserves are estimated at 30 million tonnes of oil. At a production rate of 2,500 t/d, it will last about 33 years. The transport capacity of the offshore platform is limited, so that attempts were made to enhance production by constructing the extended reach borehole Dieksand 2. Details are presented. (orig.) [Deutsch] Das Erdoelfeld Mittelplate liegt am suedlichen Rand des Nationalparks Schleswig Holsteinisches Wattenmeer, ca. 7000 m westlich der Ortschaft Friedrichskoog. Die gewinnbaren Reserven betragen ca. 30 Millionen t Oel. Bei einer Foerderkapazitaet von 2.500 t/Tag betraegt die Foerderdauer ca. 33 Jahre. Aufgrund der begrenzten Transportkapazitaeten von der Insel, laesst sich durch zusaetzliche Bohrungen von der kuenstlichen Insel Mittelplate keine entscheidende Erhoehung der Foerderkapazitaet erzielen. Ab Sommer 1996 wurde erstmals die Moeglichkeit der Lagerstaettenerschliessung von Land untersucht. Ein im Mai 1997 in Hamburg etabliertes Drilling Team wurde mit der Aufgabe betraut, die Extended Reach Bohrung Dieksand 2 zu planen und abzuteufen. Die Planungsphasen fuer die Extended Reach Bohrung Dieksand 2 wurden aufgezeigt. Die fuer den Erfolg einer Extended Reach Bohrung wichtigen Planungsparameter wurden erlaeutert. Es wurden Wege gezeigt, wie bei diesem Projekt technische und geologische Risiken in der Planung mit beruecksichtigt und nach Beginn der Bohrung weiter bearbeitet werden koennen. (orig.)
Duff, Margaret; Chen, Yinpeng; Cheng, Long; Liu, Sheng-Min; Blake, Paul; Wolf, Steven L; Rikakis, Thanassis
2013-05-01
Adaptive mixed reality rehabilitation (AMRR) is a novel integration of motion capture technology and high-level media computing that provides precise kinematic measurements and engaging multimodal feedback for self-assessment during a therapeutic task. We describe the first proof-of-concept study to compare outcomes of AMRR and traditional upper-extremity physical therapy. Two groups of participants with chronic stroke received either a month of AMRR therapy (n = 11) or matched dosing of traditional repetitive task therapy (n = 10). Participants were right handed, between 35 and 85 years old, and could independently reach to and at least partially grasp an object in front of them. Upper-extremity clinical scale scores and kinematic performances were measured before and after treatment. Both groups showed increased function after therapy, demonstrated by statistically significant improvements in Wolf Motor Function Test and upper-extremity Fugl-Meyer Assessment (FMA) scores, with the traditional therapy group improving significantly more on the FMA. However, only participants who received AMRR therapy showed a consistent improvement in kinematic measurements, both for the trained task of reaching to grasp a cone and the untrained task of reaching to push a lighted button. AMRR may be useful in improving both functionality and the kinematics of reaching. Further study is needed to determine if AMRR therapy induces long-term changes in movement quality that foster better functional recovery.
Late Carboniferous to Late Permian carbon isotope stratigraphy
DEFF Research Database (Denmark)
Buggisch, Werner; Krainer, Karl; Schaffhauser, Maria
2015-01-01
An integrated study of the litho-, bio-, and isotope stratigraphy of carbonates in the Southern Alps was undertaken in order to better constrain δ13C variations during the Late Carboniferous to Late Permian. The presented high resolution isotope curves are based on 1299 δ13Ccarb and 396 δ13Corg...
Can coronal hole spicules reach coronal temperatures?
Madjarska, M. S.; Vanninathan, K.; Doyle, J. G.
2011-08-01
Aims: The present study aims to provide observational evidence of whether coronal hole spicules reach coronal temperatures. Methods: We combine multi-instrument co-observations obtained with the SUMER/SoHO and with the EIS/SOT/XRT/Hinode. Results: The analysed three large spicules were found to be comprised of numerous thin spicules that rise, rotate, and descend simultaneously forming a bush-like feature. Their rotation resembles the untwisting of a large flux rope. They show velocities ranging from 50 to 250 kms-1. We clearly associated the red- and blue-shifted emissions in transition region lines not only with rotating but also with rising and descending plasmas. Our main result is that these spicules although very large and dynamic, are not present in the spectral lines formed at temperatures above 300 000 K. Conclusions: In this paper we present the analysis of three Ca ii H large spicules that are composed of numerous dynamic thin spicules but appear as macrospicules in lower resolution EUV images. We found no coronal counterpart of these and smaller spicules. We believe that the identification of phenomena that have very different origins as macrospicules is due to the interpretation of the transition region emission, and especially the He ii emission, wherein both chromospheric large spicules and coronal X-ray jets are present. We suggest that the recent observation of spicules in the coronal AIA/SDO 171 Å and 211 Å channels probably comes from the existence of transition region emission there. Movie is available in electronic form at http://www.aanda.org
When Does the Warmest Water Reach Greenland?
Grist, J. P.; Josey, S. A.; Boehme, L.; Meredith, M. P.; Laidre, K. L.; Heide-Jørgensen, M. P.; Kovacs, K. M.; Lydersen, C.; Davidson, F. J. M.; Stenson, G. B.; Hammill, M. O.; Marsh, R.; Coward, A.
2016-02-01
The warmest water reaching the east and west coast of Greenland is found between 200 and 600 m, in the warm Atlantic Water Layer (WL). Temperature changes within the WL have been highlighted as a possible cause of accelerated melting of tidewater glaciers and therefore are an important consideration for understanding global sea level rise. However, a limited number of winter observations of the WL have prohibited determining its seasonal variability. To address this, temperature data from Argo profiling floats, a range of sources within the World Ocean Database, and unprecedented coverage from marine-mammal borne sensors have been analyzed for the period 2002-2011. A significant seasonal range in temperature ( 1-2°C) is found in the warm layer, in contrast to most of the surrounding ocean. The magnitude of the seasonal cycle is thus comparable with the 1990s warming that was associated with an increased melt rate in a marine terminating glacier of West Greenland. The phase of the seasonal cycle exhibits considerable spatial variability; with high-resolution ocean model trajectory analysis suggesting it is determined by the time taken for waters to be advected from the subduction site in the Irminger Basin. For western Greenland, the annual temperature maximum occurs near or after the turn of the calendar year. This is significant because a recent study suggested that it is in the non-summer months when fjord-shelf exchanges allow the WL to most strongly influence glacier melt rate. However this is also the time of the year when the WL is least well observed. It is therefore clear that year-round subsurface temperature measurements are still required for a complete description of the WL seasonality, and in particular to ensure that the ice-melting potential of the WL is not underestimated.
Calculation of stationary plasma parameters in an electromagnetic trap
International Nuclear Information System (INIS)
Karpukhin, V.I.; Lavrent'ev, O.A.; Sappa, N.N.
1978-01-01
The model of energy and particle balance is considered and the numerical calculations for stationary plasma parameters, supported by the electron injection, are obtained for a hypothetical electromagnetic trap with linear dimensions, magnetic field strength and energy contribution to plasma of the order of these parameters for the modern tokamak-type traps. The process of limitation of an effective injection current and energy contribution to plasma caused by returning of electrons to the injector due to diffusion in the velocity space is simulated. In approximation of a classical diffusion dependences are obtained of the effective energy contribution to plasma and of the parameters ntausub(E) and Tsub(i) (n is a plasma density; tausub(E)- energetic lifetime; Tsub(i) ion temperature) on electron injection current and power and on the confining magnetic field strength. It had been established that at classical character of diffusion in electromagnetic trap with above parameters one could obtain stationary plasma with ntausub(E)=10 12 cm -3 s and Tsub(i)=1keV, maintaining only by electron injection
Dynamic Classification using Multivariate Locally Stationary Wavelet Processes
Park, Timothy
2018-03-11
Methods for the supervised classification of signals generally aim to assign a signal to one class for its entire time span. In this paper we present an alternative formulation for multivariate signals where the class membership is permitted to change over time. Our aim therefore changes from classifying the signal as a whole to classifying the signal at each time point to one of a fixed number of known classes. We assume that each class is characterised by a different stationary generating process, the signal as a whole will however be nonstationary due to class switching. To capture this nonstationarity we use the recently proposed Multivariate Locally Stationary Wavelet model. To account for uncertainty in class membership at each time point our goal is not to assign a definite class membership but rather to calculate the probability of a signal belonging to a particular class. Under this framework we prove some asymptotic consistency results. This method is also shown to perform well when applied to both simulated and accelerometer data. In both cases our method is able to place a high probability on the correct class for the majority of time points.
Dynamic Classification using Multivariate Locally Stationary Wavelet Processes
Park, Timothy; Eckley, Idris A.; Ombao, Hernando
2018-01-01
Methods for the supervised classification of signals generally aim to assign a signal to one class for its entire time span. In this paper we present an alternative formulation for multivariate signals where the class membership is permitted to change over time. Our aim therefore changes from classifying the signal as a whole to classifying the signal at each time point to one of a fixed number of known classes. We assume that each class is characterised by a different stationary generating process, the signal as a whole will however be nonstationary due to class switching. To capture this nonstationarity we use the recently proposed Multivariate Locally Stationary Wavelet model. To account for uncertainty in class membership at each time point our goal is not to assign a definite class membership but rather to calculate the probability of a signal belonging to a particular class. Under this framework we prove some asymptotic consistency results. This method is also shown to perform well when applied to both simulated and accelerometer data. In both cases our method is able to place a high probability on the correct class for the majority of time points.
Stationary bubbles and their tunneling channels toward trivial geometry
Energy Technology Data Exchange (ETDEWEB)
Chen, Pisin; Yeom, Dong-han [Leung Center for Cosmology and Particle Astrophysics, National Taiwan University, Taipei 10617, Taiwan (China); Domènech, Guillem; Sasaki, Misao, E-mail: pisinchen@phys.ntu.edu.tw, E-mail: guillem.domenech@yukawa.kyoto-u.ac.jp, E-mail: misao@yukawa.kyoto-u.ac.jp, E-mail: innocent.yeom@gmail.com [Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan)
2016-04-01
In the path integral approach, one has to sum over all histories that start from the same initial condition in order to obtain the final condition as a superposition of histories. Applying this into black hole dynamics, we consider stable and unstable stationary bubbles as a reasonable and regular initial condition. We find examples where the bubble can either form a black hole or tunnel toward a trivial geometry, i.e., with no singularity nor event horizon. We investigate the dynamics and tunneling channels of true vacuum bubbles for various tensions. In particular, in line with the idea of superposition of geometries, we build a classically stable stationary thin-shell solution in a Minkowski background where its fate is probabilistically given by non-perturbative effects. Since there exists a tunneling channel toward a trivial geometry in the entire path integral, the entire information is encoded in the wave function. This demonstrates that the unitarity is preserved and there is no loss of information when viewed from the entire wave function of the universe, whereas a semi-classical observer, who can see only a definitive geometry, would find an effective loss of information. This may provide a resolution to the information loss dilemma.
Stationary magnetohydrodynamic equilibrium of toroidal plasma in rotation
International Nuclear Information System (INIS)
Missiato, O.
1986-01-01
The stationary equations of classical magnetohydrodynamics are utilized to study the toroidal motion of a thermonuclear magnetically - confined plasma with toroidal symmetry (Tokamak). In the present work, we considered a purely toroidal stationary rotation and te problem is reduced to studing a second order partial differencial equation of eliptic type Maschke-Perrin. Assuming that the temperature remains constant on the magnetic surfaces, an analitic solution, valid for low Mach numbers (M ≤ 0 .4), was obtained for the above-mentioned equation by means of a technique developed by Pantuso Sudano. From the solution found, we traced graphs for the quantities which described the equilibrium state of the plasma, namely: mass density, pressure, temperature, electric current density and toroidal magnetic field. Finally we compare this analitical model with others works which utilized differents analitical models and numerical simulations. We conclude that the solutions obtained are in good agreement with the previos results. In addition, however, our model contains the results of Sudano-Goes with the additional advantage of employing much simple analitical expressions. (author) [pt
Learning Theory Estimates with Observations from General Stationary Stochastic Processes.
Hang, Hanyuan; Feng, Yunlong; Steinwart, Ingo; Suykens, Johan A K
2016-12-01
This letter investigates the supervised learning problem with observations drawn from certain general stationary stochastic processes. Here by general, we mean that many stationary stochastic processes can be included. We show that when the stochastic processes satisfy a generalized Bernstein-type inequality, a unified treatment on analyzing the learning schemes with various mixing processes can be conducted and a sharp oracle inequality for generic regularized empirical risk minimization schemes can be established. The obtained oracle inequality is then applied to derive convergence rates for several learning schemes such as empirical risk minimization (ERM), least squares support vector machines (LS-SVMs) using given generic kernels, and SVMs using gaussian kernels for both least squares and quantile regression. It turns out that for independent and identically distributed (i.i.d.) processes, our learning rates for ERM recover the optimal rates. For non-i.i.d. processes, including geometrically [Formula: see text]-mixing Markov processes, geometrically [Formula: see text]-mixing processes with restricted decay, [Formula: see text]-mixing processes, and (time-reversed) geometrically [Formula: see text]-mixing processes, our learning rates for SVMs with gaussian kernels match, up to some arbitrarily small extra term in the exponent, the optimal rates. For the remaining cases, our rates are at least close to the optimal rates. As a by-product, the assumed generalized Bernstein-type inequality also provides an interpretation of the so-called effective number of observations for various mixing processes.
Traffic State Estimation Using Connected Vehicles and Stationary Detectors
Directory of Open Access Journals (Sweden)
Ellen F. Grumert
2018-01-01
Full Text Available Real-time traffic state estimation is of importance for efficient traffic management. This is especially the case for traffic management systems that require fast detection of changes in the traffic conditions in order to apply an effective control measure. In this paper, we propose a method for estimating the traffic state and speed and density, by using connected vehicles combined with stationary detectors. The aim is to allow fast and accurate estimation of changes in the traffic conditions. The proposed method does only require information about the speed and the position of connected vehicles and can make use of sparsely located stationary detectors to limit the dependence on the infrastructure equipment. An evaluation of the proposed method is carried out by microscopic traffic simulation. The traffic state estimated using the proposed method is compared to the true simulated traffic state. Further, the density estimates are compared to density estimates from one detector-based method, one combined method, and one connected-vehicle-based method. The results of the study show that the proposed method is a promising alternative for estimating the traffic state in traffic management applications.
2010-07-01
... I am a manufacturer of stationary SI internal combustion engines >19 KW (25 HP) that use gasoline or... NEW STATIONARY SOURCES Standards of Performance for Stationary Spark Ignition Internal Combustion... manufacturer of stationary SI internal combustion engines >19 KW (25 HP) that use gasoline or a manufacturer of...
Reaching remote areas in Latin America.
Jaimes, R
1994-01-01
Poor communities in remote and inaccessible areas tend to not only be cut off from family planning education and services, but they are also deprived of basic primary health care services. Efforts to bring family planning to such communities and populations should therefore be linked with other services. The author presents three examples of programs to bring effective family planning services to remote communities in Central and South America. Outside of the municipal center in the Tuxtlas region of Mexico, education and health levels are low and people live according to ancient customs. Ten years ago with the help of MEXFAM, the IPPF affiliate in Mexico, two social promoters established themselves in the town of Catemaco to develop a community program of family planning and health care offering education and prevention to improve the quality of people's lives. Through their health brigades taking health services to towns without an established health center, the program has influenced an estimated 100,000 people in 50 villages and towns. The program also has a clinic. In Guatemala, the Family Welfare Association (APROFAM) gave bicycles to 240 volunteer health care workers to facilitate their outreach work in rural areas. APROFAM since 1988 has operated an integrated program to treat intestinal parasites and promote family planning in San Lucas de Toliman, an Indian town close to Lake Atitlan. Providing health care to more than 10,000 people, the volunteer staff has covered the entire department of Solola, reaching each family in the area. Field educators travel on motorcycles through the rural areas of Guatemala coordinating with the health volunteers the distribution of contraceptives at the community level. The Integrated Project's Clinic was founded in 1992 and currently carries out pregnancy and Pap tests, as well as general lab tests. Finally, Puna is an island in the middle of the Gulf of Guayaquil, Ecuador. Women on the island typically have 10
The late administration of surfactant
African Journals Online (AJOL)
HMD and 4 as having congenital pneumonia. Overall there was a significant and sustained improvement ... 3 infants weighing> 2 400 g with congenital pneumonia responded to a single delayed dose of SRT. Late SRT is ..... pneumonia and meconium aspiration syndrome.' It does not appear that late SRT compromised the ...
Peptidoglycan Recycling in Gram-Positive Bacteria Is Crucial for Survival in Stationary Phase
Borisova, Marina; Gaupp, Rosmarie; Duckworth, Amanda; Schneider, Alexander; Dalügge, Désirée; Mühleck, Maraike; Deubel, Denise; Unsleber, Sandra; Yu, Wenqi; Muth, Günther; Bischoff, Markus; Götz, Friedrich
2016-01-01
ABSTRACT Peptidoglycan recycling is a metabolic process by which Gram-negative bacteria reutilize up to half of their cell wall within one generation during vegetative growth. Whether peptidoglycan recycling also occurs in Gram-positive bacteria has so far remained unclear. We show here that three Gram-positive model organisms, Staphylococcus aureus, Bacillus subtilis, and Streptomyces coelicolor, all recycle the sugar N-acetylmuramic acid (MurNAc) of their peptidoglycan during growth in rich medium. They possess MurNAc-6-phosphate (MurNAc-6P) etherase (MurQ in E. coli) enzymes, which are responsible for the intracellular conversion of MurNAc-6P to N-acetylglucosamine-6-phosphate and d-lactate. By applying mass spectrometry, we observed accumulation of MurNAc-6P in MurNAc-6P etherase deletion mutants but not in either the isogenic parental strains or complemented strains, suggesting that MurQ orthologs are required for the recycling of cell wall-derived MurNAc in these bacteria. Quantification of MurNAc-6P in ΔmurQ cells of S. aureus and B. subtilis revealed small amounts during exponential growth phase (0.19 nmol and 0.03 nmol, respectively, per ml of cells at an optical density at 600 nm [OD600] of 1) but large amounts during transition (0.56 nmol and 0.52 nmol) and stationary (0.53 nmol and 1.36 nmol) phases. The addition of MurNAc to ΔmurQ cultures greatly increased the levels of intracellular MurNAc-6P in all growth phases. The ΔmurQ mutants of S. aureus and B. subtilis showed no growth deficiency in rich medium compared to the growth of the respective parental strains, but intriguingly, they had a severe survival disadvantage in late stationary phase. Thus, although peptidoglycan recycling is apparently not essential for the growth of Gram-positive bacteria, it provides a benefit for long-term survival. PMID:27729505
Functional reach and lateral reach tests adapted for aquatic physical therapy
Directory of Open Access Journals (Sweden)
Ana Angélica Ribeiro de Lima
Full Text Available Abstract Introduction: Functional reach (FR and lateral reach (LR tests are widely used in scientific research and clinical practice. Assessment tools are useful in assessing subjects with greater accuracy and are usually adapted according to the limitations of each condition. Objective: To adapt FR and LR tests for use in an aquatic environment and assess the performance of healthy young adults. Methods: We collected anthropometric data and information on whether the participant exercised regularly or not. The FR and LR tests were adapted for use in an aquatic environment and administered to 47 healthy subjects aged 20-30 years. Each test was repeated three times. Results: Forty-one females and six males were assessed. The mean FR test score for men was 24.06 cm, whereas the mean value for right lateral reach (RLR was 10.94 cm and for left lateral reach (LLR was 9.78 cm. For females, the mean FR score was 17.57 cm, while the mean values for RLR was 8.84cm and for LLR was 7.76 cm. Men performed better in the FR (p < 0.001 and RLR tests than women (p = 0.037. Individuals who exercised regularly showed no differences in performance level when compared with their counterparts. Conclusion: The FR and LR tests were adapted for use in an aquatic environment. Males performed better on the FR and RLR tests, when compared to females. There was no correlation between the FR and LR tests and weight, height, Body Mass Index (BMI, foot length or length of the dominant upper limb.
International Nuclear Information System (INIS)
Rambach, G. D.; Snyder, J. D.
1998-01-01
This paper examines the top-down rationale and methods for using hydrogen as an energy carrier in isolated, stationary power systems. Such an examination can be useful because it provides a framework for detailed research on subsystems and helps clarify why, when and where large-scale hydrogen use would be beneficial. It also helps define the pathway for an evolving hydrogen stationary power market worldwide. Remote, stationary power systems are an ideal market entry opportunity for hydrogen. For example, if it is sufficiently difficult for conventional fuels to reach a community, and indigenous renewable sources are present, then on-site clean energy production becomes economically competitive. Relying heavily on intermittent sources of energy requires an energy carrier system that is efficient over long periods of time. In addition, the energy carrier must not defeat the reasons for initially switching to the clean sources of energy, and must be economically feasible. Hydrogen is an elegant solution to all of these needs. Choices exist for the methods of producing hydrogen, storing and transporting it, and converting it back to useful energy. There is considerable debate about how best to increase the use of renewable hydrogen because it is not yet economically competitive with conventional energy carriers in most applications. The deployment of isolated power systems relying on hydrogen as the energy storage medium requires complex and comprehensive planning and design considerations to provide successful market entry strategies as well as appropriate system engineering. This paper will discuss the criteria and framework necessary to determine how to successfully deploy any specific system or to plan a global marketing strategy. (author)
Fuel quality issues in stationary fuel cell systems.
Energy Technology Data Exchange (ETDEWEB)
Papadias, D.; Ahmed, S.; Kumar, R. (Chemical Sciences and Engineering Division)
2012-02-07
Fuel cell systems are being deployed in stationary applications for the generation of electricity, heat, and hydrogen. These systems use a variety of fuel cell types, ranging from the low temperature polymer electrolyte fuel cell (PEFC) to the high temperature solid oxide fuel cell (SOFC). Depending on the application and location, these systems are being designed to operate on reformate or syngas produced from various fuels that include natural gas, biogas, coal gas, etc. All of these fuels contain species that can potentially damage the fuel cell anode or other unit operations and processes that precede the fuel cell stack. These detrimental effects include loss in performance or durability, and attenuating these effects requires additional components to reduce the impurity concentrations to tolerable levels, if not eliminate the impurity entirely. These impurity management components increase the complexity of the fuel cell system, and they add to the system's capital and operating costs (such as regeneration, replacement and disposal of spent material and maintenance). This project reviewed the public domain information available on the impurities encountered in stationary fuel cell systems, and the effects of the impurities on the fuel cells. A database has been set up that classifies the impurities, especially in renewable fuels, such as landfill gas and anaerobic digester gas. It documents the known deleterious effects on fuel cells, and the maximum allowable concentrations of select impurities suggested by manufacturers and researchers. The literature review helped to identify the impurity removal strategies that are available, and their effectiveness, capacity, and cost. A generic model of a stationary fuel-cell based power plant operating on digester and landfill gas has been developed; it includes a gas processing unit, followed by a fuel cell system. The model includes the key impurity removal steps to enable predictions of impurity breakthrough
Tropical influence on boreal summer mid-latitude stationary waves
Energy Technology Data Exchange (ETDEWEB)
Douville, Herve [Meteo-France/CNRM-GAME, Toulouse (France); CNRM/GMGEC/VDR, Toulouse (France); Bielli, S.; Deque, M.; Tyteca, S.; Voldoire, A. [Meteo-France/CNRM-GAME, Toulouse (France); Cassou, C. [CNRS-Cerfacs, Toulouse (France); Hall, N.M.J. [CNES/LEGOS, Toulouse (France)
2011-11-15
While organized tropical convection is a well-known source of extratropical planetary waves, state-of-the-art climate models still show serious deficiencies in simulating accurately the atmospheric response to tropical sea surface temperature (SST) anomalies and the associated teleconnections. In the present study, the remote influence of the tropical atmospheric circulation is evaluated in ensembles of global boreal summer simulations in which the Arpege-Climat atmospheric General Circulation Model (GCM) is nudged towards 6-h reanalyses. The nudging is applied either in the whole tropical band or in a regional summer monsoon domain. Sensitivity tests to the experimental design are first conducted using prescribed climatological SST. They show that the tropical relaxation does not improve the zonal mean extratropical climatology but does lead to a significantly improved representation of the mid-latitude stationary waves in both hemispheres. Low-pass filtering of the relaxation fields has no major effect on the model response, suggesting that high-frequency tropical variability is not responsible for extratropical biases. Dividing the nudging strength by a factor 10 only decreases the magnitude of the response. Model errors in each monsoon domain contribute to deficiencies in the model's mid-latitude climatology, although an exaggerated large-scale subsidence in the central equatorial Pacific appears as the main source of errors for the representation of stationary waves in the Arpege-Climat model. Case studies are then conducted using either climatological or observed SST. The focus is first on summer 2003 characterized by a strong and persistent anticyclonic anomaly over western Europe. This pattern is more realistic in nudging experiments than in simulations only driven by observed SST, especially when the nudging domain is centred over Central America. Other case studies also show a significant tropical forcing of the summer mid-latitude stationary waves
The Proteome and Lipidome of Thermococcus kodakarensis across the Stationary Phase
Gagen, Emma J.; Yoshinaga, Marcos Y.; Garcia Prado, Franka; Hinrichs, Kai-Uwe; Thomm, Michael
2016-01-01
The majority of cells in nature probably exist in a stationary-phase-like state, due to nutrient limitation in most environments. Studies on bacteria and yeast reveal morphological and physiological changes throughout the stationary phase, which lead to an increased ability to survive prolonged nutrient limitation. However, there is little information on archaeal stationary phase responses. We investigated protein- and lipid-level changes in Thermococcus kodakarensis with extended time in the...
Energy Technology Data Exchange (ETDEWEB)
Gu, Beom W.; Choi, Su Y.; Rim, Chun T. [Dept. of Nuclear and Quantum Engineering, KAIST, Daejeon (Korea, Republic of); Choi, Young Soo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Cai, Guowei; Seneviratne, Lakmal [Dept. of Aerospace Engineering, Khalifa University, Abu Dhabi (United Arab Emirates)
2016-08-15
In this paper, new tethered aerial robots including roaming tethered aerial robots (RTARs) for radioactive material sampling and stationary tethered aerial robots (STARs) for environment monitoring are proposed to meet extremely-long-endurance missions of nuclear power plants. The flight of the proposed tethered aerial robots may last for a few days or even a few months as long as the tethered cable provides continuous power. A high voltage AC or DC power system was newly adopted to reduce the mass of the tethered cable. The RTAR uses a tethered cable spooled from the aerial robot and an aerial tension control system. The aerial tension control system provides the appropriate tension to the tethered cable, which is accordingly laid down on the ground as the RTAR roams. The STAR includes a tethered cable spooled from the ground and a ground tension control system, which enables the STAR to reach high altitudes. Prototypes of the RTAR and STAR were designed and successfully demonstrated in outdoor environments, where the load power, power type, operating frequency, and flight attitude of the RTAR and STAR were: 180 W, AC 100 kHz, and 20 m; and 300 W, AC or DC 100 kHz, and 80 m, respectively.
Directory of Open Access Journals (Sweden)
Beom W. Gu
2016-08-01
Full Text Available In this paper, new tethered aerial robots including roaming tethered aerial robots (RTARs for radioactive material sampling and stationary tethered aerial robots (STARs for environment monitoring are proposed to meet extremely-long-endurance missions of nuclear power plants. The flight of the proposed tethered aerial robots may last for a few days or even a few months as long as the tethered cable provides continuous power. A high voltage AC or DC power system was newly adopted to reduce the mass of the tethered cable. The RTAR uses a tethered cable spooled from the aerial robot and an aerial tension control system. The aerial tension control system provides the appropriate tension to the tethered cable, which is accordingly laid down on the ground as the RTAR roams. The STAR includes a tethered cable spooled from the ground and a ground tension control system, which enables the STAR to reach high altitudes. Prototypes of the RTAR and STAR were designed and successfully demonstrated in outdoor environments, where the load power, power type, operating frequency, and flight attitude of the RTAR and STAR were: 180 W, AC 100 kHz, and 20 m; and 300 W, AC or DC 100 kHz, and 80 m, respectively.
West, Caroline; Konjaria, Mari-Luiza; Shashviashvili, Natia; Lemasson, Elise; Bonnet, Pascal; Kakava, Rusudan; Volonterio, Alessandro; Chankvetadze, Bezhan
2017-05-26
Asymmetric sulfoxides is a particular case of chirality that may be found in natural as well as synthetic products. Twenty-four original molecules containing a sulfur atom as a centre of chirality were analyzed in supercritical fluid chromatography on seven polysaccharide-based chiral stationary phases (CSP) with carbon dioxide - methanol mobile phases. While all the tested CSP provided enantioseparation for a large part of the racemates, chlorinated cellulosic phases proved to be both highly retentive and highly enantioselective towards these species. Favourable structural features were determined by careful comparison of the enantioseparation of the probe molecules. Molecular modelling studies indicate that U-shaped (folded) conformations were most favorable to achieve high enantioresolution on these CSP, while linear (extended) conformations were not so clearly discriminated. For a subset of these species adopting different conformations, a broad range of mobile phase compositions, ranging from 20 to 100% methanol in carbon dioxide, were investigated. While retention decreased continuously in this range, enantioseparation varied in a non-monotonous fashion. Abrupt changes in the tendency curves of retention and selectivity were observed when methanol proportion reaches about 60%, suggesting that a change in the conformation of the analytes and/or chiral selector is occurring at this point. Copyright © 2017 Elsevier B.V. All rights reserved.
Optimizing a Military Supply Chain in the Presence of Random, Non-Stationary Demands
National Research Council Canada - National Science Library
Yew
2003-01-01
... logistics supply chain that satisfies uncertain, non-stationary demands, while taking into account the volatility and singularity of military operations This research focuses on the development...
Stationary distribution and ergodicity of a stochastic food-chain model with Lévy jumps
Yu, Jingyi; Liu, Meng
2017-09-01
In this paper, a three-species stochastic food-chain model with Lévy jumps is proposed and analyzed. Sharp sufficient criteria for the existence and uniqueness of an ergodic stationary distribution are established. The effects of Lévy jumps on the existence of the stationary distribution are revealed: in some cases, the Lévy jumps could make the stationary distribution appear, while in some cases, the Lévy jumps could make the stationary distribution disappear. Some numerical simulations are introduced to illustrate the theoretical results.
Stereotypical reaching movements of the octopus involve both bend propagation and arm elongation.
Hanassy, S; Botvinnik, A; Flash, T; Hochner, B
2015-05-13
The bend propagation involved in the stereotypical reaching movement of the octopus arm has been extensively studied. While these studies have analyzed the kinematics of bend propagation along the arm during its extension, possible length changes have been ignored. Here, the elongation profiles of the reaching movements of Octopus vulgaris were assessed using three-dimensional reconstructions. The analysis revealed that, in addition to bend propagation, arm extension movements involve elongation of the proximal part of the arm, i.e., the section from the base of the arm to the propagating bend. The elongations are quite substantial and highly variable, ranging from an average strain along the arm of -0.12 (i.e. shortening) up to 1.8 at the end of the movement (0.57 ± 0.41, n = 64 movements, four animals). Less variability was discovered in an additional set of experiments on reaching movements (0.64 ± 0.28, n = 30 movements, two animals), where target and octopus positions were kept more stationary. Visual observation and subsequent kinematic analysis suggest that the reaching movements can be broadly segregated into two groups. The first group involves bend propagation beginning at the base of the arm and propagating towards the arm tip. In the second, the bend is formed or present more distally and reaching is achieved mainly by elongation and straightening of the segment proximal to the bend. Only in the second type of movements is elongation significantly positively correlated with the distance of the bend from the target. We suggest that reaching towards a target is generated by a combination of both propagation of a bend along the arm and arm elongation. These two motor primitives may be combined to create a broad spectrum of reaching movements. The dynamical model, which recapitulates the biomechanics of the octopus muscular hydrostatic arm, suggests that achieving the observed elongation requires an extremely low ratio of longitudinal to transverse muscle
Enhancement of Non-Stationary Speech using Harmonic Chirp Filters
DEFF Research Database (Denmark)
Nørholm, Sidsel Marie; Jensen, Jesper Rindom; Christensen, Mads Græsbøll
2015-01-01
In this paper, the issue of single channel speech enhancement of non-stationary voiced speech is addressed. The non-stationarity of speech is well known, but state of the art speech enhancement methods assume stationarity within frames of 20–30 ms. We derive optimal distortionless filters that take...... the non-stationarity nature of voiced speech into account via linear constraints. This is facilitated by imposing a harmonic chirp model on the speech signal. As an implicit part of the filter design, the noise statistics are also estimated based on the observed signal and parameters of the harmonic chirp...... model. Simulations on real speech show that the chirp based filters perform better than their harmonic counterparts. Further, it is seen that the gain of using the chirp model increases when the estimated chirp parameter is big corresponding to periods in the signal where the instantaneous fundamental...
Simple relations between mean passage times and Kramers' stationary rate
International Nuclear Information System (INIS)
Boilley, David; Jurado, Beatriz; Schmitt, Christelle
2004-01-01
The classical problem of the escape time of a metastable potential well in a thermal environment is generally studied by various quantities like Kramers' stationary escape rate, mean first passage time, nonlinear relaxation time, or mean last passage time. In addition, numerical simulations lead to the definition of other quantities as the long-time limit escape rate and the transient time. In this paper, we propose some simple analytical relations between all these quantities. In particular, we point out the hypothesis used to evaluate these various times in order to clarify their comparison and applicability, and show how average times include the transient time and the long-time limit of the escape rate
4. Workshop - Measurement techniques of stationary and transient multiphase flow
Energy Technology Data Exchange (ETDEWEB)
Prasser, H.M. (ed.)
2001-05-01
In November 2000, the 4th Workshop on Measurement Techniques for Stationary and Transient Multiphase Flows took place in Rossendorf. Three previous workshops of this series were national meetings; this time participants from different countries took part. The programme comprised 14 oral presentations, 9 of which are included in these proceedings in full length. A special highlight of the meeting was the main lecture ''Ultrasonic doppler method for bubbly flow measurement'' of Professor Masanori Aritomi, Dr. Hiroshige Kikura and Dr. Yumiko Suzuki. The workshop again dealt with high-resolution phase distribution and phase velocity measurement techniques based on electrical conductivity, ultrasound, laser light and high-speed cinematography. A number of presentations were dedicated to the application of wire-mesh sensors developed by FZR for different applications used by the Technical Universities of Delft and Munich and the Tokyo Institute of Technology. (orig.)
Laboratory evidence for stationary inertial Alfvén waves
Koepke, M. E.; Finnegan, S. M.; Vincena, S.; Knudsen, D. J.; Nogami, S. H.; Vassiliadis, D.
2016-08-01
Azimuthal convective flow and density-depleted magnetic field-aligned current co-located in the helium plasma produced in the large plasma device (LAPD-U) at UCLA (Gekelman et al 2016 Rev. Sci. Instrum. 87 025105) support an Alfvénic perturbation that is static in the laboratory frame. Electrostatic probes measure the flow and static density perturbations in the 72 cm-diameter, 12 m-long, afterglow plasma, wherein a radially segmented electrode creates the convective flow and an off-cylindrical-axis planar-mesh electrode draws current in a channel parallel to the background magnetic field. This stationary ‘wave’ is measured as a fixed (in the laboratory frame) ion density structure.
Dynamics in stationary, non-globally hyperbolic spacetimes
Energy Technology Data Exchange (ETDEWEB)
Seggev, Itai [Enrico Fermi Institute and Department of Physics, University of Chicago, 5640 S Ellis Avenue, Chicago, IL 60637 (United States)
2004-06-07
Classically, the dynamics of a scalar field in a non-globally hyperbolic spacetime is ill-posed. Previously, a prescription was given for defining dynamics in static spacetimes in terms of a second-order operator acting on a Hilbert space defined on static slices. The present work extends this result by giving a similar prescription for defining dynamics in stationary spacetimes obeying certain mild assumptions. The prescription is defined in terms of a first-order operator acting on a different Hilbert space from that used in the static prescription. It preserves the important properties of the earlier prescription: the formal solution agrees with the Cauchy evolution within the domain of dependence, and smooth data of compact support always give rise to smooth solutions. In the static case, the first-order formalism agrees with the second-order formalism (using specifically the Friedrichs extension). Applications to field quantization are also discussed.
Stationary metrics and optical Zermelo-Randers-Finsler geometry
International Nuclear Information System (INIS)
Gibbons, G. W.; Warnick, C. M.; Herdeiro, C. A. R.; Werner, M. C.
2009-01-01
We consider a triality between the Zermelo navigation problem, the geodesic flow on a Finslerian geometry of Randers type, and spacetimes in one dimension higher admitting a timelike conformal Killing vector field. From the latter viewpoint, the data of the Zermelo problem are encoded in a (conformally) Painleve-Gullstrand form of the spacetime metric, whereas the data of the Randers problem are encoded in a stationary generalization of the usual optical metric. We discuss how the spacetime viewpoint gives a simple and physical perspective on various issues, including how Finsler geometries with constant flag curvature always map to conformally flat spacetimes and that the Finsler condition maps to either a causality condition or it breaks down at an ergo surface in the spacetime picture. The gauge equivalence in this network of relations is considered as well as the connection to analogue models and the viewpoint of magnetic flows. We provide a variety of examples.
Schrodinger's catapult II: entanglement between stationary and flying fields
Pfaff, W.; Axline, C.; Burkhart, L.; Vool, U.; Reinhold, P.; Frunzio, L.; Jiang, L.; Devoret, M.; Schoelkopf, R.
Entanglement between nodes is an elementary resource in a quantum network. An important step towards its realization is entanglement between stationary and flying states. Here we experimentally demonstrate entanglement generation between a long-lived cavity memory and traveling mode in circuit QED. A large on/off ratio and fast control over a parametric mixing process allow us to realize conversion with tunable magnitude and duration between standing and flying mode. In the case of half-conversion, we observe correlations between the standing and flying state that confirm the generation of entangled states. We show this for both single-photon and multi-photon states, paving the way for error-correctable remote entanglement. Our system could serve as an essential component in a modular architecture for error-protected quantum information processing.
On the Field of a Stationary Charged Spherical Source
Directory of Open Access Journals (Sweden)
Stavroulakis N.
2009-04-01
Full Text Available The equations of gravitation related to the field of a spherical charged source imply the existence of an interdependence between gravitation and electricity [5]. The present paper deals with the joint action of gravitation and electricity in the case of a stationary charged spherical source. Let m and " be respectively the mass and the charge of the source, and let k be the gravitational constant. Then the equations of gravitation need specific discussion according as j " j m p k (source strongly charged. In any case the curvature radius of the sphere bounding the matter possesses a strictly positive greatest lower hound, so that the source is necessarily an extended object. Pointwise sources do not exist. In particular, charged black holes do not exist.
Prediction of deformations during gas-tungsten-arc stationary welds
International Nuclear Information System (INIS)
Duncan, D.B.; Giedt, W.H.
1980-10-01
Local temperature measurements on the heated and unheated surfaces, and strain measurements on the unheated surfaces of unrestrained circular weld specimens of annealed and cold-rolled Nitronic 40 stainless steel during stationary welding, are compared with values predicted from finite-element programs for temperature and strain variations. Experimental and predicted temperature histories agree within 10%. Predicted and measured hoop strain profiles (using a moire fringe technique), for the unheated surface are compared, showing significant deviations near the central region. Transient deflection measurements of the unheated specimen surfaces show good agreement with theory during the period the arc is operating. Close agreement in deflection behavior was observed during the cooling portion of the weld cycle for the annealed specimen, whereas substantial deviations occurred for the cold-rolled specimens
Statistics of stationary points of random finite polynomial potentials
International Nuclear Information System (INIS)
Mehta, Dhagash; Niemerg, Matthew; Sun, Chuang
2015-01-01
The stationary points (SPs) of the potential energy landscapes (PELs) of multivariate random potentials (RPs) have found many applications in many areas of Physics, Chemistry and Mathematical Biology. However, there are few reliable methods available which can find all the SPs accurately. Hence, one has to rely on indirect methods such as Random Matrix theory. With a combination of the numerical polynomial homotopy continuation method and a certification method, we obtain all the certified SPs of the most general polynomial RP for each sample chosen from the Gaussian distribution with mean 0 and variance 1. While obtaining many novel results for the finite size case of the RP, we also discuss the implications of our results on mathematics of random systems and string theory landscapes. (paper)
Integrated stationary Ornstein-Uhlenbeck process, and double integral processes
Abundo, Mario; Pirozzi, Enrica
2018-03-01
We find a representation of the integral of the stationary Ornstein-Uhlenbeck (ISOU) process in terms of Brownian motion Bt; moreover, we show that, under certain conditions on the functions f and g , the double integral process (DIP) D(t) = ∫βt g(s) (∫αs f(u) dBu) ds can be thought as the integral of a suitable Gauss-Markov process. Some theoretical and application details are given, among them we provide a simulation formula based on that representation by which sample paths, probability densities and first passage times of the ISOU process are obtained; the first-passage times of the DIP are also studied.
Thin viscoelastic disc subjected to radial non-stationary loading
Directory of Open Access Journals (Sweden)
Adámek V.
2010-07-01
Full Text Available The investigation of non-stationary wave phenomena in isotropic viscoelastic solids using analytical approaches is the aim of this paper. Concretely, the problem of a thin homogeneous disc subjected to radial pressure load nonzero on the part of its rim is solved. The external excitation is described by the Heaviside function in time, so the nonstationary state of stress is induced in the disc. Dissipative material behaviour of solid studied is represented by the discrete material model of standard linear viscoelastic solid in the Zener configuration. After the derivation of motion equations final form, the method of integral transforms in combination with the Fourier method is used for finding the problem solution. The solving process results in the derivation of integral transforms of radial and circumferential displacement components. Finally, the type of derived functions singularities and possible methods for their inverse Laplace transform are mentioned.
Stationary Response of Lotka—Volterra System with Real Noises
International Nuclear Information System (INIS)
Qi Lu-Yuan; Xu Wei; Gao Wei-Ting
2013-01-01
A stochastic version of Lotka—Volterra model subjected to real noises is proposed and investigated. The approximate stationary probability densities for both predator and prey are obtained analytically. The original system is firstly transformed to a pair of Itô stochastic differential equations. The Itô formula is then carried out to obtain the Itô stochastic differential equation for the period orbit function. The orbit function is considered as slowly varying process under reasonable assumptions. By applying the stochastic averaging method to the orbit function in one period, the averaged Itô stochastic differential equation of the motion orbit and the corresponding Fokker—Planck equation are derived. The probability density functions of the two species are thus formulated. Finally, a classical real noise model is given as an example to show the proposed approximate method. The accuracy of the proposed procedure is verified by Monte Carlo simulation. (interdisciplinary physics and related areas of science and technology)
The stationary storage of energy. Available technologies and CEA researches
International Nuclear Information System (INIS)
2012-01-01
After a discussion of the main challenges related to the stationary storage of energy, this publication proposes an overview of the different available technologies: plant for transfer of energy by pumping, compressed air, energy flywheels, hydrogen, lithium-ion battery, redox-flow battery, thermal storage by sensitive heat, thermal-chemical storage coupled to a thermal solar system, thermal storage by phase change, superconductive inductance storage, super-capacitors. It discusses the criteria of choice of storage technology, either for electric energy storage or for heat storage. It proposes an overview of researches performed within the CEA on storage systems: electrochemical, thermal, and hydrogen-based storages. The final chapter addresses current fundamental researches on storage in the field of lithium-ion batteries, hydrogen as a fuel, and thermoelectricity
Effect of turbulent collisions on diffusion in stationary plasma turbulence
International Nuclear Information System (INIS)
Xia, H.; Ishihara, O.
1990-01-01
Recently the velocity diffusion process was studied by the generalized Langevin equation derived by the projection operator method. The further study shows that the retarded frictional function plays an important role in suppressing particle diffusion in the velocity space in stronger turbulence as much as the resonance broadening effect. The retarded frictional effect, produced by the effective collisions due to the plasma turbulence is assumed to be a Gaussian, but non-Markovian and non-wide-sense stationary process. The relations between the proposed formulation and the extended resonance broadening theory is discussed. The authors also carry out test particle numerical experiment for Langmuir turbulence to test the theories. In a stronger turbulence a deviation of the diffusion rate from the one predicted by both the quasilinear and the extended resonance theories has been observed and is explained qualitatively by the present formulation
Grid Converters for Stationary Battery Energy Storage Systems
DEFF Research Database (Denmark)
Trintis, Ionut
The integration of renewable energy sources in the power system, with high percentage, is a well known challenge nowadays. Power sources like wind and solar are highly volatile, with uctuations on various time scales. One long term solution is to build a continentwide or worldwide supergrid....... Another solution is to use distributed energy storage units, and create virtual power plants. Stationary energy storage is a complementary solution, which can postpone the network expansion and can be optimized for dierent kind of grid services. As an energy storage solution with timing for few seconds...... multilevel converter structure with integrated energy storage is introduced. This converter structure is suitable to interface low and medium voltage energy storage units to medium and high voltage grids. It can also interconnect a DC and AC grid with bidirectional power ow, were both can be backed...
4. Workshop - Measurement techniques of stationary and transient multiphase flow
International Nuclear Information System (INIS)
Prasser, H.M.
2001-05-01
In November 2000, the 4th Workshop on Measurement Techniques for Stationary and Transient Multiphase Flows took place in Rossendorf. Three previous workshops of this series were national meetings; this time participants from different countries took part. The programme comprised 14 oral presentations, 9 of which are included in these proceedings in full length. A special highlight of the meeting was the main lecture ''Ultrasonic doppler method for bubbly flow measurement'' of Professor Masanori Aritomi, Dr. Hiroshige Kikura and Dr. Yumiko Suzuki. The workshop again dealt with high-resolution phase distribution and phase velocity measurement techniques based on electrical conductivity, ultrasound, laser light and high-speed cinematography. A number of presentations were dedicated to the application of wire-mesh sensors developed by FZR for different applications used by the Technical Universities of Delft and Munich and the Tokyo Institute of Technology. (orig.)
Non-stationary vibrations of a thin viscoelastic orthotropic beam
Czech Academy of Sciences Publication Activity Database
Adámek, V.; Valeš, František; Tikal, B.
2009-01-01
Roč. 71, č. 12 (2009), e2569-e2576 ISSN 0362-546X R&D Projects: GA ČR(CZ) GA101/07/0946 Institutional research plan: CEZ:AV0Z20760514 Keywords : thin beam * non-stationary vibration * analytical solution Subject RIV: BI - Acoustics Impact factor: 1.487, year: 2009 http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V0Y-4WB3N8S-4&_user=640952&_rdoc=1&_fmt=&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=1156243286&_rerunOrigin= google &_acct=C000034318&_version=1&_urlVersion=0&_userid=640952&md5=ce096901a3382058455e822a20645820
Stationary spherical shells around Kerr-Newman naked singularities
International Nuclear Information System (INIS)
Zdenek Stuchlik; Stanislav Hledik
1998-01-01
It is shown that in the field of some Kerr-Newman naked singularities a stationary spherical shell of charged dust can exist, with the specific charge being the same for all particles of the dusty shell. Gravitational attractions acting on the particles are balanced by electromagnetic repulsion in such a way that the shell is stable against radial perturbations. Particles of the shell move along orbits with constant latitude and radius. Rotation of the shell is differential. The shell is corotating relative to static observers at infinity, but it is counter rotating relative to the family of locally non-rotating observers. No such a shell can exist in the field of Kerr-Newman black holes. (authors)
VRACK: measuring pedal kinematics during stationary bike cycling.
Farjadian, Amir B; Kong, Qingchao; Gade, Venkata K; Deutsch, Judith E; Mavroidis, Constantinos
2013-06-01
Ankle impairment and lower limb asymmetries in strength and coordination are common symptoms for individuals with selected musculoskeletal and neurological impairments. The virtual reality augmented cycling kit (VRACK) was designed as a compact mechatronics system for lower limb and mobility rehabilitation. The system measures interaction forces and cardiac activity during cycling in a virtual environment. The kinematics measurement was added to the system. Due to the constrained problem definition, the combination of inertial measurement unit (IMU) and Kalman filtering was recruited to compute the optimal pedal angular displacement during dynamic cycling exercise. Using a novel benchmarking method the accuracy of IMU-based kinematics measurement was evaluated. Relatively accurate angular measurements were achieved. The enhanced VRACK system can serve as a rehabilitation device to monitor biomechanical and physiological variables during cycling on a stationary bike.
Generalized Predictive Control for Non-Stationary Systems
DEFF Research Database (Denmark)
Palsson, Olafur Petur; Madsen, Henrik; Søgaard, Henning Tangen
1994-01-01
This paper shows how the generalized predictive control (GPC) can be extended to non-stationary (time-varying) systems. If the time-variation is slow, then the classical GPC can be used in context with an adaptive estimation procedure of a time-invariant ARIMAX model. However, in this paper prior...... knowledge concerning the nature of the parameter variations is assumed available. The GPC is based on the assumption that the prediction of the system output can be expressed as a linear combination of present and future controls. Since the Diophantine equation cannot be used due to the time......-variation of the parameters, the optimal prediction is found as the general conditional expectation of the system output. The underlying model is of an ARMAX-type instead of an ARIMAX-type as in the original version of the GPC (Clarke, D. W., C. Mohtadi and P. S. Tuffs (1987). Automatica, 23, 137-148) and almost all later...
A He-gas Cooled, Stationary Granular Target
Pugnat, P
2003-01-01
In the CERN approach to the design of a neutrino factory, the repetition frequency of the proton beam is high enough to consider stationary solid targets as a viable solution for multi-MW beams. The target consists of high density tantalum spheres of 2 mm diameter which can efficiently be cooled by passing a high mass flow He-gas stream through the voids between the Ta-granules. Very small thermal shocks and stresses will arise in this fine grained structure due to the relatively long burst of 3.3 ms from the SPL-proton linac. In a quadruple target system where each target receives only one quarter of the total beam power of 4 MW, conservative temperature levels and adequate lifetimes of the target are estimated in its very high radiation environment. A conceptual design of the integration of the target into the magnetic horn-pion-collector is presented.
Thermodynamical description of stationary, asymptotically flat solutions with conical singularities
International Nuclear Information System (INIS)
Herdeiro, Carlos; Rebelo, Carmen; Radu, Eugen
2010-01-01
We examine the thermodynamical properties of a number of asymptotically flat, stationary (but not static) solutions having conical singularities, with both connected and nonconnected event horizons, using the thermodynamical description recently proposed in [C. Herdeiro, B. Kleihaus, J. Kunz, and E. Radu, Phys. Rev. D 81, 064013 (2010).]. The examples considered are the double-Kerr solution, the black ring rotating in either S 2 or S 1 , and the black Saturn, where the balance condition is not imposed for the latter two solutions. We show that not only the Bekenstein-Hawking area law is recovered from the thermodynamical description, but also the thermodynamical angular momentum is the Arnowitt-Deser-Misner angular momentum. We also analyze the thermodynamical stability and show that, for all these solutions, either the isothermal moment of inertia or the specific heat at constant angular momentum is negative, at any point in parameter space. Therefore, all these solutions are thermodynamically unstable in the grand canonical ensemble.
de Brito Fontana, Heiliane; Ruschel, Caroline; Dell'Antonio, Elisa; Haupenthal, Alessandro; Pereira, Gustavo Soares; Roesler, Helio
2018-04-01
The aim of this study was to analyze the effect of cadence, immersion level as well as body density on the vertical component (Fy max ) of ground reaction force (GRF) during stationary running (SR). In a controlled, laboratory study, thirty-two subjects ran at a wide range of cadences (85-210 steps/min) in water, immersed to the hip and to the chest, and on dry land. Fy max. was verified by a waterproof force measurement system and predicted based on a statistical model including cadence, immersion ratio and body density. The effect of cadence was shown to depend on the environment: while Fy max increases linearly with increasing cadence on land; in water, Fy max reaches a plateau at both hip and chest immersions. All factors analyzed, cadence, immersion level and body density affected Fy max significantly, with immersion (aquatic × land environment) showing the greatest effect. In water, different cadences may lead to bigger changes in Fy max than the changes obtained by moving subjects from hip to chest immersion. A regression model able to predict 69% of Fy max variability in water was proposed and validated. Cadence, Immersion and body density affect Fy max in a significant and non-independent way. Besides a model of potential use in the prescription of stationary running in water, our analysis provides insights into the different responses of GRF to changes in exercise parameters between land and aquatic environment. Copyright © 2018 Elsevier B.V. All rights reserved.
Wu, Qi; Sun, Yaming; Zhang, Xiaoli; Zhang, Xia; Dong, Shuqing; Qiu, Hongdeng; Wang, Litao; Zhao, Liang
2017-04-07
Graphene quantum dots (GQDs), which possess hydrophobic, hydrophilic, π-π stacking and hydrogen bonding properties, have great prospect in HPLC. In this study, a novel GQDs bonded silica stationary phase was prepared and applied in multiple separation modes including normal phase, reversed phase and hydrophilic chromatography mode. Alkaloids, nucleosides and nucleobases were chosen as test compounds to evaluate the separation performance of this column in hydrophilic chromatographic mode. The tested polar compounds achieved baseline separation and the resolutions reached 2.32, 4.62, 7.79, 1.68 for thymidine, uridine, adenosine, cytidine and guanosine. This new column showed satisfactory chromatographic performance for anilines, phenols and polycyclic aromatic hydrocarbons in normal and reversed phase mode. Five anilines were completely separated within 10min under the condition of mobile phase containing only 10% methanol. The effect of water content, buffer concentration and pH on chromatographic separation was further investigated, founding that this new stationary phase showed a complex retention mechanism of partitioning, adsorption and electrostatic interaction in hydrophilic chromatography mode, and the multiple retention interactions such as π-π stacking and π-π electron-donor-acceptor interaction played an important role during the separation process. This GQDs bonded column, which allows us to adjust appropriate chromatography mode according to the properties of analytes, has possibility in actual application after further research. Copyright © 2017 Elsevier B.V. All rights reserved.
Cross-beam energy transfer: On the accuracy of linear stationary models in the linear kinetic regime
Debayle, A.; Masson-Laborde, P.-E.; Ruyer, C.; Casanova, M.; Loiseau, P.
2018-05-01
We present an extensive numerical study by means of particle-in-cell simulations of the energy transfer that occurs during the crossing of two laser beams. In the linear regime, when ions are not trapped in the potential well induced by the laser interference pattern, a very good agreement is obtained with a simple linear stationary model, provided the laser intensity is sufficiently smooth. These comparisons include different plasma compositions to cover the strong and weak Landau damping regimes as well as the multispecies case. The correct evaluation of the linear Landau damping at the phase velocity imposed by the laser interference pattern is essential to estimate the energy transfer rate between the laser beams, once the stationary regime is reached. The transient evolution obtained in kinetic simulations is also analysed by means of a full analytical formula that includes 3D beam energy exchange coupled with the ion acoustic wave response. Specific attention is paid to the energy transfer when the laser presents small-scale inhomogeneities. In particular, the energy transfer is reduced when the laser inhomogeneities are comparable with the Landau damping characteristic length of the ion acoustic wave.
Late Ordovician brachiopods from eastern North Greenland
DEFF Research Database (Denmark)
Mac Ørum Rasmussen, Christian
2013-01-01
Late Ordovician rhynchonelliformean brachiopods, typical of the North American Red River fauna, are found sporadically in the BOrglum River Formation of the Centrum SO area, Kronprins Christian Land, eastern North Greenland. The geographical distribution of this characteristic brachiopod fauna......) to younger strata exclusively yielding specimens of H.gigas. As H.gigas occurs in the upper part of the Cape Calhoun Formation in Washington Land, it indicates that the upper boundary of the Cape Calhoun Formation is considerably younger than previous estimates, reaching into the uppermost Katian (middle...... (Richmondian), it possesses a strong provincial signal during the later Ordovician. The new occurrences indicate that this fauna extended to the north-eastern margin of the Laurentian Craton. It lived in close association with cosmopolitan faunal elements that may have been the earliest sign of the succeeding...
7 CFR 920.112 - Late payments.
2010-01-01
... Miscellaneous Provisions § 920.112 Late payments. Pursuant to § 920.41(a), interest will be charged at a 1.5 percent monthly simple interest rate. Assessments for kiwifruit shall be deemed late if not received... late charge will be assessed when payment becomes 30 days late. Interest and late payment charges shall...
Belmonti, Vittorio; Cioni, Giovanni; Berthoz, Alain
2015-07-01
Navigational and reaching spaces are known to involve different cognitive strategies and brain networks, whose development in humans is still debated. In fact, high-level spatial processing, including allocentric location encoding, is already available to very young children, but navigational strategies are not mature until late childhood. The Magic Carpet (MC) is a new electronic device translating the traditional Corsi Block-tapping Test (CBT) to navigational space. In this study, the MC and the CBT were used to assess spatial memory for navigation and for reaching, respectively. Our hypothesis was that school-age children would not treat MC stimuli as navigational paths, assimilating them to reaching sequences. Ninety-one healthy children aged 6 to 11 years and 18 adults were enrolled. Overall short-term memory performance (span) on both tests, effects of sequence geometry, and error patterns according to a new classification were studied. Span increased with age on both tests, but relatively more in navigational than in reaching space, particularly in males. Sequence geometry specifically influenced navigation, not reaching. The number of body rotations along the path affected MC performance in children more than in adults, and in women more than in men. Error patterns indicated that navigational sequences were increasingly retained as global paths across development, in contrast to separately stored reaching locations. A sequence of spatial locations can be coded as a navigational path only if a cognitive switch from a reaching mode to a navigation mode occurs. This implies the integration of egocentric and allocentric reference frames, of visual and idiothetic cues, and access to long-term memory. This switch is not yet fulfilled at school age due to immature executive functions. © 2014 John Wiley & Sons Ltd.
Guaranteed performance in reaching mode of sliding mode ...
Indian Academy of Sciences (India)
R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22
addresses the design of constant plus proportional rate reaching law-based SMC for second-order ... Reaching mode; sliding mode controlled systems; output tracking ... The uncertainty in the input distribution function g is expressed as.
Nanomaterials under REACH. Nanosilver as a case study
Pronk MEJ; Wijnhoven SWP; Bleeker EAJ; Heugens EHW; Peijnenburg WJGM; Luttik R; Hakkert BC; SEC; SIR; LER
2009-01-01
Om de risico's van nanomaterialen te kunnen inschatten en beheersen, zijn enkele aanpassingen nodig in de Europese chemicalienwetgeving REACH. De gegevens over stoffen waar REACH standaard om vraagt, zijn namelijk onvoldoende om de specifieke eigenschappen van nanomaterialen te bepalen. Hetzelfde
Reaching Adolescents and Youth in Burkina Faso, Guinea-Bissau
African Journals Online (AJOL)
AJRH Managing Editor
typical profile of individuals in contact with peer educators or attending youth ... being reached (versus not reached) by programs ... characteristics in order to serve groups that may be ... places for counseling services but the frequency of.
Vaginal bleeding in late pregnancy
... this page: //medlineplus.gov/ency/patientinstructions/000627.htm Vaginal bleeding in late pregnancy To use the sharing ... JavaScript. One out of 10 women will have vaginal bleeding during their 3rd trimester. At times, it ...
Late prematurity: a systematic review
Directory of Open Access Journals (Sweden)
Luís Carlos Machado Júnior
2014-06-01
Full Text Available Objective: this study aimed to review the literature regarding late preterm births (34 weeks to 36 weeks and 6 days of gestation in its several aspects. Sources: the MEDLINE, LILACS, and Cochrane Library databases were searched, and the references of the articles retrieved were also used, with no limit of time. Data synthesis: numerous studies showed a recent increase in late preterm births. In all series, late preterm comprised the majority of preterm births. Studies including millions of births showed a strong association between late preterm birth and neonatal mortality. A higher mortality in childhood and among young adults was also observed. Many studies found an association with several neonatal complications, and also with long-term disorders and sequelae: breastfeeding problems, cerebral palsy, asthma in childhood, poor school performance, schizophrenia, and young adult diabetes. Some authors propose strategies to reduce late preterm birth, or to improve neonatal outcome: use of antenatal corticosteroids, changes in some of the guidelines for early delivery in high-risk pregnancies, and changes in neonatal care for this group. Conclusions: numerous studies show greater mortality and morbidity in late preterm infants compared with term infants, in addition to long-term disorders. More recent studies evaluated strategies to improve the outcomes of these neonates. Further studies on these strategies are needed.
Late effects from hadron therapy
Energy Technology Data Exchange (ETDEWEB)
Blakely, Eleanor A.; Chang, Polly Y.
2004-06-01
Successful cancer patient survival and local tumor control from hadron radiotherapy warrant a discussion of potential secondary late effects from the radiation. The study of late-appearing clinical effects from particle beams of protons, carbon, or heavier ions is a relatively new field with few data. However, new clinical information is available from pioneer hadron radiotherapy programs in the USA, Japan, Germany and Switzerland. This paper will review available data on late tissue effects from particle radiation exposures, and discuss its importance to the future of hadron therapy. Potential late radiation effects are associated with irradiated normal tissue volumes at risk that in many cases can be reduced with hadron therapy. However, normal tissues present within hadron treatment volumes can demonstrate enhanced responses compared to conventional modes of therapy. Late endpoints of concern include induction of secondary cancers, cataract, fibrosis, neurodegeneration, vascular damage, and immunological, endocrine and hereditary effects. Low-dose tissue effects at tumor margins need further study, and there is need for more acute molecular studies underlying late effects of hadron therapy.
A Non-Stationary 1981–2012 AVHRR NDVI3g Time Series
Directory of Open Access Journals (Sweden)
Jorge E. Pinzon
2014-07-01
Full Text Available The NDVI3g time series is an improved 8-km normalized difference vegetation index (NDVI data set produced from Advanced Very High Resolution Radiometer (AVHRR instruments that extends from 1981 to the present. The AVHRR instruments have flown or are flying on fourteen polar-orbiting meteorological satellites operated by the National Oceanic and Atmospheric Administration (NOAA and are currently flying on two European Organization for the Exploitation of Meteorological Satellites (EUMETSAT polar-orbiting meteorological satellites, MetOp-A and MetOp-B. This long AVHRR record is comprised of data from two different sensors: the AVHRR/2 instrument that spans July 1981 to November 2000 and the AVHRR/3 instrument that continues these measurements from November 2000 to the present. The main difficulty in processing AVHRR NDVI data is to properly deal with limitations of the AVHRR instruments. Complicating among-instrument AVHRR inter-calibration of channels one and two is the dual gain introduced in late 2000 on the AVHRR/3 instruments for both these channels. We have processed NDVI data derived from the Sea-Viewing Wide Field-of-view Sensor (SeaWiFS from 1997 to 2010 to overcome among-instrument AVHRR calibration difficulties. We use Bayesian methods with high quality well-calibrated SeaWiFS NDVI data for deriving AVHRR NDVI calibration parameters. Evaluation of the uncertainties of our resulting NDVI values gives an error of ± 0.005 NDVI units for our 1981 to present data set that is independent of time within our AVHRR NDVI continuum and has resulted in a non-stationary climate data set.
A Non-Stationary 1981-2012 AVHRR NDVI(sub 3g) Time Series
Pinzon, Jorge E.; Tucker, Compton J.
2014-01-01
The NDVI(sub 3g) time series is an improved 8-km normalized difference vegetation index (NDVI) data set produced from Advanced Very High Resolution Radiometer (AVHRR) instruments that extends from 1981 to the present. The AVHRR instruments have flown or are flying on fourteen polar-orbiting meteorological satellites operated by the National Oceanic and Atmospheric Administration (NOAA) and are currently flying on two European Organization for the Exploitation of Meteorological Satellites (EUMETSAT) polar-orbiting meteorological satellites, MetOp-A and MetOp-B. This long AVHRR record is comprised of data from two different sensors: the AVHRR/2 instrument that spans July 1981 to November 2000 and the AVHRR/3 instrument that continues these measurements from November 2000 to the present. The main difficulty in processing AVHRR NDVI data is to properly deal with limitations of the AVHRR instruments. Complicating among-instrument AVHRR inter-calibration of channels one and two is the dual gain introduced in late 2000 on the AVHRR/3 instruments for both these channels. We have processed NDVI data derived from the Sea-Viewing Wide Field-of-view Sensor (SeaWiFS) from 1997 to 2010 to overcome among-instrument AVHRR calibration difficulties. We use Bayesian methods with high quality well-calibrated SeaWiFS NDVI data for deriving AVHRR NDVI calibration parameters. Evaluation of the uncertainties of our resulting NDVI values gives an error of plus or minus 0.005 NDVI units for our 1981 to present data set that is independent of time within our AVHRR NDVI continuum and has resulted in a non-stationary climate data set.
International Nuclear Information System (INIS)
Kim, Hee Eun; Seo, Na Hyeon; Hyun, Myung Ho
2016-01-01
Cyclometalated iridium (III) complexes formed with three identical cyclometalating (C-N) ligands (homoleptic) or formed with two cyclometalating (C-N) ligands and one ancillary (LX) ligand (heteroleptic) have been known as highly phosphorescent materials and, thus, they have been utilized as efficient phosphorescent dopants in organic light emitting diodes (OLEDs) 1–3 or as effective phosphorescent chemosensors. 4–7 Cylometalated iridium (III) complexes are chiral compounds consisting of lambda (Λ, left-handed) and delta (Δ, right-handed) isomers. Racemic cyclometa- lated iridium (III) complexes emit light with no net polarization, but optically active cyclometalated iridium (III) complexes emit circularly polarized light. 8,9 Circularly polarized light can be used in various fields including highly efficient three dimensional electronic devices, photo nic devices for optical data storage, biological assays, and others. 8,9 In order to obtain optically active cylometalated iridium (III) complexes and to determine the enantiomeric composition of optically active cylometalated iridium (III) complexes, liquid chromatogr aphic enantiomer separation method on chiral stationary phases (CSPs) has been used. For example, Okamoto and coworkers first reported the high performance liquid chromatographic (HPLC) direct enantiomeric separation of two homoleptic cylometalated iridium (III) complexes on immobilized amylose tris(3,5- dimethylphenylcarbamate) (Chiralpak IA), coated cellulose tris(3,5-dimethylphenylcarbamate) (Chiralc el OD), and coated cellulose tris(4-methylbenzoate) (Chiralce l OJ). 10 Supercritical fluid chromatography (SFC) was also used by Bernhard and coworkers for the enantiomeric separation of cylometalated iridium (III) complexes on coated amylose tris(3,5-dimethylphenylcarbamate) (Chiralpak AD-H). 8 However, the general use of the HPLC method for the direct enantiomeric separation of homoleptic
Energy Technology Data Exchange (ETDEWEB)
Kim, Hee Eun; Seo, Na Hyeon; Hyun, Myung Ho [Dept. of Chemistry and Chemistry Institute for Functional Materials, Pusan National University, Busan (Korea, Republic of)
2016-12-15
Cyclometalated iridium (III) complexes formed with three identical cyclometalating (C-N) ligands (homoleptic) or formed with two cyclometalating (C-N) ligands and one ancillary (LX) ligand (heteroleptic) have been known as highly phosphorescent materials and, thus, they have been utilized as efficient phosphorescent dopants in organic light emitting diodes (OLEDs) 1–3 or as effective phosphorescent chemosensors. 4–7 Cylometalated iridium (III) complexes are chiral compounds consisting of lambda (Λ, left-handed) and delta (Δ, right-handed) isomers. Racemic cyclometa- lated iridium (III) complexes emit light with no net polarization, but optically active cyclometalated iridium (III) complexes emit circularly polarized light. 8,9 Circularly polarized light can be used in various fields including highly efficient three dimensional electronic devices, photo nic devices for optical data storage, biological assays, and others. 8,9 In order to obtain optically active cylometalated iridium (III) complexes and to determine the enantiomeric composition of optically active cylometalated iridium (III) complexes, liquid chromatogr aphic enantiomer separation method on chiral stationary phases (CSPs) has been used. For example, Okamoto and coworkers first reported the high performance liquid chromatographic (HPLC) direct enantiomeric separation of two homoleptic cylometalated iridium (III) complexes on immobilized amylose tris(3,5- dimethylphenylcarbamate) (Chiralpak IA), coated cellulose tris(3,5-dimethylphenylcarbamate) (Chiralc el OD), and coated cellulose tris(4-methylbenzoate) (Chiralce l OJ). 10 Supercritical fluid chromatography (SFC) was also used by Bernhard and coworkers for the enantiomeric separation of cylometalated iridium (III) complexes on coated amylose tris(3,5-dimethylphenylcarbamate) (Chiralpak AD-H). 8 However, the general use of the HPLC method for the direct enantiomeric separation of homoleptic.
Non-stationary covariance function modelling in 2D least-squares collocation
Darbeheshti, N.; Featherstone, W. E.
2009-06-01
Standard least-squares collocation (LSC) assumes 2D stationarity and 3D isotropy, and relies on a covariance function to account for spatial dependence in the observed data. However, the assumption that the spatial dependence is constant throughout the region of interest may sometimes be violated. Assuming a stationary covariance structure can result in over-smoothing of, e.g., the gravity field in mountains and under-smoothing in great plains. We introduce the kernel convolution method from spatial statistics for non-stationary covariance structures, and demonstrate its advantage for dealing with non-stationarity in geodetic data. We then compared stationary and non- stationary covariance functions in 2D LSC to the empirical example of gravity anomaly interpolation near the Darling Fault, Western Australia, where the field is anisotropic and non-stationary. The results with non-stationary covariance functions are better than standard LSC in terms of formal errors and cross-validation against data not used in the interpolation, demonstrating that the use of non-stationary covariance functions can improve upon standard (stationary) LSC.
Bridging the gap between a stationary point process and its Palm distribution
Nieuwenhuis, G.
1994-01-01
In the context of stationary point processes measurements are usually made from a time point chosen at random or from an occurrence chosen at random. That is, either the stationary distribution P or its Palm distribution P° is the ruling probability measure. In this paper an approach is presented to
2010-11-05
... Standards of Performance for New Stationary Sources and Emission Guidelines for Existing Sources: Sewage... ``Standards of Performance for New Stationary Sources and Emission Guidelines for Existing Sources: Sewage... performance standards for new units and emission guidelines for existing units for specific categories of...
A new derivation of the conformally flat stationary cyclic non-circular spacetimes
International Nuclear Information System (INIS)
Ayon-Beato, Eloy; Campuzano, Cuauhtemoc; GarcIa, Alberto
2007-01-01
We present an alternative way to derive the conformally flat stationary cyclic non-circular spacetimes. We show that there is no room for stationary axisymmetric non-circular axisymmetric spacetimes. We reproduce the well know results for this sort of spacetimes recently reported in [1
A new derivation of the conformally flat stationary cyclic non-circular spacetimes
Energy Technology Data Exchange (ETDEWEB)
Ayon-Beato, Eloy [Departamento de Fisica, Facultad de Fisica e Inteligencia Artificial, Universidad Veracruzana, 91000 Xalapa, Veracruz (Mexico); Campuzano, Cuauhtemoc [Departamento de Fisica, Facultad de Fisica e Inteligencia Artificial, Universidad Veracruzana, 91000 Xalapa, Veracruz (Mexico); GarcIa, Alberto [Department of Physics, University of California, Davis, CA 95616 (United States)
2007-11-15
We present an alternative way to derive the conformally flat stationary cyclic non-circular spacetimes. We show that there is no room for stationary axisymmetric non-circular axisymmetric spacetimes. We reproduce the well know results for this sort of spacetimes recently reported in [1].
On the Oracle Property of the Adaptive LASSO in Stationary and Nonstationary Autoregressions
DEFF Research Database (Denmark)
Kock, Anders Bredahl
We show that the Adaptive LASSO is oracle efficient in stationary and non-stationary autoregressions. This means that it estimates parameters consistently, selects the correct sparsity pattern, and estimates the coefficients belonging to the relevant variables at the same asymptotic efficiency...
Nonparametric estimation of the stationary M/G/1 workload distribution function
DEFF Research Database (Denmark)
Hansen, Martin Bøgsted
2005-01-01
In this paper it is demonstrated how a nonparametric estimator of the stationary workload distribution function of the M/G/1-queue can be obtained by systematic sampling the workload process. Weak convergence results and bootstrap methods for empirical distribution functions for stationary associ...
2011-10-28
...-Pavement Stationary Runway Weather Information Systems AGENCY: Federal Aviation Administration (FAA), U.S. DOT. ACTION: Notice to Manufacturers of In-Pavement Stationary Runway Weather Information Systems... Operations. This notice requests information from manufacturers of systems meeting the technical requirements...
Energy Technology Data Exchange (ETDEWEB)
K.R. Fecht, T.E. Marceau
2006-03-28
This report presents the results of a geologic study conducted on the lower slopes of the Columbia River Valley in south-central Washington. The study was designed to investigate glaciofluvial and fluvial sediments and bedforms that are present in the river valley and formed subsequent to Pleistocene large-scale cataclysmic flooding of the region.
Teaching geographical hydrology in a non-stationary world
Hendriks, Martin R.; Karssenberg, Derek
2010-05-01
Understanding hydrological processes in a non-stationary world requires knowledge of hydrological processes and their interactions. Also, one needs to understand the (non-linear) relations between the hydrological system and other parts of our Earth system, such as the climate system, the socio-economic system, and the ecosystem. To provide this knowledge and understanding we think that three components are essential when teaching geographical hydrology. First of all, a student needs to acquire a thorough understanding of classical hydrology. For this, knowledge of the basic hydrological equations, such as the energy equation (Bernoulli), flow equation (Darcy), continuity (or water balance) equation is needed. This, however, is not sufficient to make a student fully understand the interactions between hydrological compartments, or between hydrological subsystems and other parts of the Earth system. Therefore, secondly, a student also needs to be knowledgeable of methods by which the different subsystems can be coupled; in general, numerical models are used for this. A major disadvantage of numerical models is their complexity. A solution may be to use simpler models, provided that a student really understands how hydrological processes function in our real, non-stationary world. The challenge for a student then lies in understanding the interactions between the subsystems, and to be able to answer questions such as: what is the effect of a change in vegetation or land use on runoff? Thirdly, knowledge of field hydrology is of utmost importance. For this a student needs to be trained in the field. Fieldwork is very important as a student is confronted in the field with spatial and temporal variability, as well as with real life uncertainties, rather than being lured into believing the world as presented in hydrological textbooks and models, e.g. the world under study is homogeneous, isotropic, or lumped (averaged). Also, students in the field learn to plan and
Energy Technology Data Exchange (ETDEWEB)
Iben, I. Jr.; Tutukov, A.V. (Illinois Univ., Urbana (USA); Astronomicheskii Sovet, Moscow (USSR))
1989-07-01
The characteristics of model stars consisting of a degenerate dwarf core and an envelope which is burning a nuclear fuel or fuels in its interior are explored. The models are relevant to stars which are accreting matter from a companion, to single stars in late stages of evolution, to stripped noninteracting remnants of binary star evolution, and to merging and merged degenerate dwarfs. For any given mass and choice of nuclear fuels, a sequence of models is constructed which differ with respect to the mass of the degenerate core and the envelope characteristics. Each sequence has at least three distinct branches: a degenerate dwarf branch along which envelope mass increases with decreasing luminosity, a plateau branch characterized by a very small envelope mass and by a nearly constant luminosity which reaches the maximum achievable value for the sequence, and an asymptotic giant branch which is at the lowest temperatures achievable and along which envelope mass decreases with increasing luminosity. 78 refs.
International Nuclear Information System (INIS)
Iben, I. Jr.; Tutukov, A.V.
1989-01-01
The characteristics of model stars consisting of a degenerate dwarf core and an envelope which is burning a nuclear fuel or fuels in its interior are explored. The models are relevant to stars which are accreting matter from a companion, to single stars in late stages of evolution, to stripped noninteracting remnants of binary star evolution, and to merging and merged degenerate dwarfs. For any given mass and choice of nuclear fuels, a sequence of models is constructed which differ with respect to the mass of the degenerate core and the envelope characteristics. Each sequence has at least three distinct branches: a degenerate dwarf branch along which envelope mass increases with decreasing luminosity, a plateau branch characterized by a very small envelope mass and by a nearly constant luminosity which reaches the maximum achievable value for the sequence, and an asymptotic giant branch which is at the lowest temperatures achievable and along which envelope mass decreases with increasing luminosity. 78 refs
Late stage infection in sleeping sickness.
Directory of Open Access Journals (Sweden)
Hartwig Wolburg
Full Text Available At the turn of the 19(th century, trypanosomes were identified as the causative agent of sleeping sickness and their presence within the cerebrospinal fluid of late stage sleeping sickness patients was described. However, no definitive proof of how the parasites reach the brain has been presented so far. Analyzing electron micrographs prepared from rodent brains more than 20 days after infection, we present here conclusive evidence that the parasites first enter the brain via the choroid plexus from where they penetrate the epithelial cell layer to reach the ventricular system. Adversely, no trypanosomes were observed within the parenchyma outside blood vessels. We also show that brain infection depends on the formation of long slender trypanosomes and that the cerebrospinal fluid as well as the stroma of the choroid plexus is a hostile environment for the survival of trypanosomes, which enter the pial space including the Virchow-Robin space via the subarachnoid space to escape degradation. Our data suggest that trypanosomes do not intend to colonize the brain but reside near or within the glia limitans, from where they can re-populate blood vessels and disrupt the sleep wake cycles.
International Nuclear Information System (INIS)
Sanchis, R.; Palomo, M. J.; Munoz-Cobo, J. L.
1998-01-01
The signals registered in the nuclear plants have non stationary characteristics, in numerous times. This made difficult the application of the methods of analysis. There are determinate temporal intervals in that the signal is stationary with determinate mean, value together of zones with corrupt registers, and other zones with mean value distinct, but stationary during a temporal interval. The methodology consist in a stationary analysis to the signal received of the nuclear plant. With the Gabor Transformation are determined the temporal intervals of the stationary signals, synthesised it, as previous phase to the application of the methods of the analysis of stability parameters with methods ARMA, SVD, Neural Net,... to the reconstructed signal. 4 refs. (Author)
Evaluation of the Methods for Response Analysis under Non-Stationary Excitation
Directory of Open Access Journals (Sweden)
R.S. Jangid
1999-01-01
Full Text Available Response of structures to non-stationary ground motion can be obtained either by the evolutionary spectral analysis or by the Markov approach. In certain conditions, a quasi-stationary analysis can also be performed. The first two methods of analysis are difficult to apply for complex situations such as problems involving soil-structure interaction, non-classical damping and primary-secondary structure interaction. The quasi-stationary analysis, on the other hand, provides an easier solution procedure for such cases. Here-in, the effectiveness of the quasi-stationary analysis is examined with the help of the analysis of a single degree-of-freedom (SDOF system under a set of parametric variations. For this purpose, responses of the SDOF system to uniformly modulated non-stationary random ground excitation are obtained by the three methods and they are compared. In addition, the relative computational efforts for different methods are also investigated.
Study of Stationary Phase Metabolism Via Isotopomer Analysis of Amino Acids from an Isolated Protein
Energy Technology Data Exchange (ETDEWEB)
Shaikh, AfshanS.; Tang, YinjieJ.; Mukhopadhyay, Aindrila; Martin, Hector Garcia; Gin, Jennifer; Benke, Peter; Keasling, Jay D.
2009-09-14
Microbial production of many commercially important secondary metabolites occurs during stationary phase, and methods to measure metabolic flux during this growth phase would be valuable. Metabolic flux analysis is often based on isotopomer information from proteinogenic amino acids. As such, flux analysis primarily reflects the metabolism pertinent to the growth phase during which most proteins are synthesized. To investigate central metabolism and amino acids synthesis activity during stationary phase, addition of fully 13C-labeled glucose followed by induction of green fluorescent protein (GFP) expression during stationary phase was used. Our results indicate that Escherichia coli was able to produce new proteins (i.e., GFP) in the stationary phase, and the amino acids in GFP were mostly from degraded proteins synthesized during the exponential growth phase. Among amino acid biosynthetic pathways, only those for serine, alanine, glutamate/glutamine, and aspartate/asparagine had significant activity during the stationary phase.
Exponentially Stable Stationary Solutions for Stochastic Evolution Equations and Their Perturbation
International Nuclear Information System (INIS)
Caraballo, Tomas; Kloeden, Peter E.; Schmalfuss, Bjoern
2004-01-01
We consider the exponential stability of stochastic evolution equations with Lipschitz continuous non-linearities when zero is not a solution for these equations. We prove the existence of anon-trivial stationary solution which is exponentially stable, where the stationary solution is generated by the composition of a random variable and the Wiener shift. We also construct stationary solutions with the stronger property of attracting bounded sets uniformly. The existence of these stationary solutions follows from the theory of random dynamical systems and their attractors. In addition, we prove some perturbation results and formulate conditions for the existence of stationary solutions for semilinear stochastic partial differential equations with Lipschitz continuous non-linearities
Directory of Open Access Journals (Sweden)
Xiaoli Li
2016-11-01
Full Text Available A ‘two birds, one stone’ strategy was developed via a one-pot click reaction to simultaneously prepare a novel cyclodextrin (CD dimer based aggregation induced emission (AIE sensor (AIE-DCD and a monomer based chiral stationary phase (CSP-MCD for chiral high performance liquid chromatography (CHPLC. AIE-DCD was found to afford satisfactory AIE response for specific detection of Zn2+ with a detection limit of 50 nM. CSP-MCD exhibits excellent enantioseparation ability toward dansyl amino acids, where the resolution of dansyl amino leucine reaches 5.43.
International Nuclear Information System (INIS)
Baranya, Sandor; Jozsa, Janos; Goda, Laszlo; Rakoczi, Laszlo
2008-01-01
Detailed hydrodynamic survey of two critical river reaches has been performed from hydro- and sediment dynamics points of view, in order to explore the main features, moreover, provide calibration and verification data to related 3D flow and sediment transport modelling. Special attention has been paid to compare moving and fix boat measurement modes for estimating various flow and large-scale bed form features, resulting in recommendations e.g. on the time period needed in stationary mode operation to obtain sufficiently stabilized average velocity profiles and related parameter estimations. As to the study reaches, the first comprises a 5 km long sandy-gravel bed reach of river Danube located in Central-Hungary, presenting problems for navigation. As a conventional remedy, groyne fields have been implemented to make and maintain the reach sufficiently deep, navigable even in low flow periods. As is usually the case, these works resulted in rather complex flow characteristics and related bed topography at places. The second site is another 5 km long reach of river Danube, close to the southern border to Serbia. There the river presents navigational problems similar to the previously mentioned reach, however, having entirely sand bed conditions, abundant in a variety of dunes, especially in the shallower parts. In both study reaches ADCP measurements were done with around 2.5 Hz sampling frequency both in moving boat operation mode providing overall, though locally moderately representative picture, and in fixed boat mode at a considerable number of selected verticals with 10 minutes long measuring time.
The reach and adoption of a coach-led exercise training programme in community football.
Finch, Caroline F; Diamantopoulou, Kathy; Twomey, Dara M; Doyle, Tim L A; Lloyd, David G; Young, Warren; Elliott, Bruce C
2014-04-01
To determine the reach and adoption of a coach-led exercise training programme for lower limb injury prevention. Secondary analysis of data from a group-clustered randomised controlled trial. A periodised exercise training warm-up programme was delivered to players during training sessions over an 8-week preseason (weeks 1-8) and 18-week playing season. 1564 community Australian football players. Reach, measured weekly, was the number of players who attended training sessions. Adoption was the number of attending players who completed the programme in full, partially or not at all. Reasons for partial or non-participation were recorded. In week 1, 599 players entered the programme; 55% attended 1 training session and 45% attended > 1 session. By week 12, 1540 players were recruited but training attendance (reach) decreased to <50%. When players attended training, the majority adopted the full programme-ranging from 96% (week 1) to above 80% until week 20. The most common reasons for low adoption were players being injured, too sore, being late for training or choosing their own warm-up. The training programme's reach was highest preseason and halved at the playing season's end. However, when players attended training sessions, their adoption was high and remained close to 70% by season end. For sports injury prevention programmes to be fully effective across a season, attention also needs to be given to (1) encouraging players to attend formal training sessions and (2) considering the possibility of some form of programme delivery outside of formal training.
Thin accretion disks in stationary axisymmetric wormhole spacetimes
International Nuclear Information System (INIS)
Harko, Tiberiu; Kovacs, Zoltan; Lobo, Francisco S. N.
2009-01-01
In this paper, we study the physical properties and the equilibrium thermal radiation emission characteristics of matter forming thin accretion disks in stationary axially symmetric wormhole spacetimes. The thin disk models are constructed by taking different values of the wormhole's angular velocity, and the time averaged energy flux, the disk temperature, and the emission spectra of the accretion disks are obtained. Comparing the mass accretion in a rotating wormhole geometry with the one of a Kerr black hole, we verify that the intensity of the flux emerging from the disk surface is greater for wormholes than for rotating black holes with the same geometrical mass and accretion rate. We also present the conversion efficiency of the accreting mass into radiation, and show that the rotating wormholes provide a much more efficient engine for the transformation of the accreting mass into radiation than the Kerr black holes. Therefore specific signatures appear in the electromagnetic spectrum of thin disks around rotating wormholes, thus leading to the possibility of distinguishing wormhole geometries by using astrophysical observations of the emission spectra from accretion disks.
Stationary drift-Rossby vortices in shear flows
International Nuclear Information System (INIS)
Horihata, Satoshi; Irie, Haruyuki; Sato, Masatomo
1990-01-01
Starting from Hasegawa-Mima equation with the generalized vorticity q which describes both electrostatic drift waves in plasmas and Rossby waves in the atmosphere of rotating planets, the stationary solutions of this equation in the (x, y) plane were considered assuming that the equilibrium density no depends on x and the electron temperature T 0 is constant. The arbitrary function F(φ) yielded from integration of transformed Hasegawa-Mima equation was taken either linear or nonlinear in φ, where φ is the stream function. When F is linear, vortex solutions were obtained by dividing the entire plane into internal and external regions by a closed boundary curve. Imposing the boundary conditions at the boundary curve, the constants in the solutions φ ex and φ in were determined. 4 examples are figured. When F is nonlinear, isolated (localized) vortex was considered. Deriving the equation to determine F, the equation for ψ, the internal vortical motion beyond the boundary was given. 2 examples are shown. (M.T.)
Plasma equilibria and stationary flows in axisymmetric systems. Pt. 3
International Nuclear Information System (INIS)
Zelazny, R.; Stankiewicz, R.; Galkowski, A.; Potempski, S.; Pietak, R.
1990-08-01
The problem of the importance of poloidal flows for the behaviour of plasmas in axisymmetric systems has caused a lot of discussion and controversy during the last 15 years. There is no doubt that the mere existence of poloidal flow transforms the elliptic Grad-Shafranov-Schlueter equation into a system of mixed type partial differential equation and an algebraic multivalued Bernoulli equation. This fact leads to the appearance of Bernoulli branches in the solutions. Then, one can come across three branches of elliptic solutions as well as two branches of hyperbolic solutions with the possible appearance of phenomena connected with ''transsonic'' effects. Problems connected with such a mathematical situation have been extensively discussed in the report with the same title, dated May 1988, which we shall call later Part I of our studies on this subject. The present report, considered as Part III, is devoted to the presentation of results of efforts aimed at constructing programmes which allow us to solve the extended Grad-Shafranov-Schlueter equation (EGSS) (with stationary flows) in a more realistic situation relevant to the JET operating conditions. The main problem is to specify for a wider class of profiles the boundary conditions at the magnetic axis for a system of nonlinear ordinary differential equations ODE, resulting from EGSS equation after application of Fourier transformation techniques and of inverse method approach. The present report elaborates a much more general case and describes the computational framework enabling us to derive those boundary conditions. (author)
New lube oil for stationary heavy fuel engines
Energy Technology Data Exchange (ETDEWEB)
NONE
1996-12-01
An extensively field-tested diesel engine lubricating oil for medium speed, heavy fuel stationary engine applications has been introduced by Caltex Petroleum, in Dallas, Texas. The new oil is similar to a product developed and marketed for marine medium speed heavy fuel propulsion and auxillary engine applications by one of its two parent companies, Chevron. Detailed are results of two field evaluations in Caterpillar 3600 series engines installed at Kimberly Clark (KCPI) and Sime Darby (SDPI), both in the Philippines. Both were one year, 7000-plus hour field evaluations of a new, 40 BN trunk piston engine oil (TPEO), identified as Caltex Delo 3400, SAE 40 engine lube oil. The oil uses the new Phenalate additive technology developed by Chevron Chemical Company`s Oronite Additives Division. This technology is designed to improve engine cleanliness in regard to soft black sludge and piston deposits. The focus of the field evaluations was the performance of the lubricating oil. During controlled tests at Sime Darby, the most noticeable improvement over another technology was in the control of sludge deposits. This improvement was seen in all areas where black sludge forms, such as the rocker cover, crankcase cover and valve assemblies. 4 figs.
Investigation and modelling of rubber stationary friction on rough surfaces
International Nuclear Information System (INIS)
Le Gal, A; Klueppel, M
2008-01-01
This paper presents novel aspects regarding the physically motivated modelling of rubber stationary sliding friction on rough surfaces. The description of dynamic contact is treated within the framework of a generalized Greenwood-Williamson theory for rigid/soft frictional pairings. Due to the self-affinity of rough surfaces, both hysteresis and adhesion friction components arise from a multi-scale excitation of surface roughness. Beside a complete analytical formulation of contact parameters, the morphology of macrotexture is considered via the introduction of a second scaling range at large length scales which mostly contribute to hysteresis friction. Moreover, adhesion friction is related to the real area of contact combined with the kinetics of interfacial peeling effects. Friction experiments carried out with different rubbers on rough granite and asphalt point out the relevance of hysteresis and adhesion friction concepts on rough surfaces. The two scaling ranges approach significantly improves the description of wet and dry friction behaviour within the range of low sliding velocity. In addition, material and surface effects are predicted and understood on a physical basis. The applicability of such modelling is of high interest for materials developers and road constructors regarding the prediction of wet grip performance of tyres on road tracks
Removal of Stationary Sinusoidal Noise from Random Vibration Signals.
Energy Technology Data Exchange (ETDEWEB)
Johnson, Brian; Cap, Jerome S.
2018-02-01
In random vibration environments, sinusoidal line noise may appear in the vibration signal and can affect analysis of the resulting data. We studied two methods which remove stationary sine tones from random noise: a matrix inversion algorithm and a chirp-z transform algorithm. In addition, we developed new methods to determine the frequency of the tonal noise. The results show that both of the removal methods can eliminate sine tones in prefabricated random vibration data when the sine-to-random ratio is at least 0.25. For smaller ratios down to 0.02 only the matrix inversion technique can remove the tones, but the metrics to evaluate its effectiveness also degrade. We also found that using fast Fourier transforms best identified the tonal noise, and determined that band-pass-filtering the signals prior to the process improved sine removal. When applied to actual vibration test data, the methods were not as effective at removing harmonic tones, which we believe to be a result of mixed-phase sinusoidal noise.
New Splitting Criteria for Decision Trees in Stationary Data Streams.
Jaworski, Maciej; Duda, Piotr; Rutkowski, Leszek; Jaworski, Maciej; Duda, Piotr; Rutkowski, Leszek; Rutkowski, Leszek; Duda, Piotr; Jaworski, Maciej
2018-06-01
The most popular tools for stream data mining are based on decision trees. In previous 15 years, all designed methods, headed by the very fast decision tree algorithm, relayed on Hoeffding's inequality and hundreds of researchers followed this scheme. Recently, we have demonstrated that although the Hoeffding decision trees are an effective tool for dealing with stream data, they are a purely heuristic procedure; for example, classical decision trees such as ID3 or CART cannot be adopted to data stream mining using Hoeffding's inequality. Therefore, there is an urgent need to develop new algorithms, which are both mathematically justified and characterized by good performance. In this paper, we address this problem by developing a family of new splitting criteria for classification in stationary data streams and investigating their probabilistic properties. The new criteria, derived using appropriate statistical tools, are based on the misclassification error and the Gini index impurity measures. The general division of splitting criteria into two types is proposed. Attributes chosen based on type- splitting criteria guarantee, with high probability, the highest expected value of split measure. Type- criteria ensure that the chosen attribute is the same, with high probability, as it would be chosen based on the whole infinite data stream. Moreover, in this paper, two hybrid splitting criteria are proposed, which are the combinations of single criteria based on the misclassification error and Gini index.
Accelerating particles in general relativity (stationary C-metric)
International Nuclear Information System (INIS)
Farhoosh, H.
1979-01-01
The purpose of this thesis is to study the physical and geometrical properties of uniformly accelerating particles in the general theory of relativity and it consists of four main parts. In the first part the structure of the Killing horizons in the static vacuum C-metric which represents the gravitational field of a uniformly accelerating Schwarzschild like particle (non-rotating and spherically symmetric) is studied. In the second part these results are generalized to include the effects of the rotation of the source. For small acceleration and small rotation this solution reveals the existance of three Killing horizons. Two the these horizons are the Schwarzschild and the Rindler surfaces which are mainly due to the mass and the acceleration of the particle, respectively. In part three the radial geodesic and non-geodesic motions in the static vacuum C-metric (non-rotating case) are investigated. The effect of the dragging of the inertial frame is also shown in this part. In part four the radiative behavior of the stationary charged C-metric representing the electro-gravitational field of a uniformly accelerating and rotating charged particle with magnetic monopole and the NUT-parameter are investigated. The physical quantities - the news function, mass loss, mass, charge and the multipole moments - are calculated. It is also shown in this part that the magnetic monopole in the presence of rotation and acceleration affects the electric charge
Damping of Quasi-stationary Waves Between Two Miscible Liquids
Duval, Walter M. B.
2002-01-01
Two viscous miscible liquids with an initially sharp interface oriented vertically inside a cavity become unstable against oscillatory external forcing due to Kelvin-Helmholtz instability. The instability causes growth of quasi-stationary (q-s) waves at the interface between the two liquids. We examine computationally the dynamics of a four-mode q-s wave, for a fixed energy input, when one of the components of the external forcing is suddenly ceased. The external forcing consists of a steady and oscillatory component as realizable in a microgravity environment. Results show that when there is a jump discontinuity in the oscillatory excitation that produced the four-mode q-s wave, the interface does not return to its equilibrium position, the structure of the q-s wave remains imbedded between the two fluids over a long time scale. The damping characteristics of the q-s wave from the time history of the velocity field show overdamped and critically damped response; there is no underdamped oscillation as the flow field approaches steady state. Viscous effects serve as a dissipative mechanism to effectively damp the system. The stability of the four-mode q-s wave is dependent on both a geometric length scale as well as the level of background steady acceleration.
Optimal operation of stationary and mobile batteries in distribution grids
International Nuclear Information System (INIS)
Wang, Yubo; Shi, Wenbo; Wang, Bin; Chu, Chi-Cheng; Gadh, Rajit
2017-01-01
Highlights: • A DSM minimizes both nodal operational cost and network power losses is proposed. • Uncertainties in distribution grids are captured with stochastic programming. • An ADMM based distributed method is applied for scalability and privacy preserving. - Abstract: The trending integrations of Battery Energy Storage System (BESS, stationary battery) and Electric Vehicles (EV, mobile battery) to distribution grids call for advanced Demand Side Management (DSM) technique that addresses the scalability concerns of the system and stochastic availabilities of EVs. Towards this goal, a stochastic DSM is proposed to capture the uncertainties in EVs. Numerical approximation is then used to make the problem tractable. To accelerate the computational speed, the proposed DSM is tightly relaxed to a convex form using second-order cone programming. Furthermore, in light of the continuous increasing problem size, a distributed method with a guaranteed convergence is applied to shift the centralized computational burden to distributed controllers. To verify the proposed DSM, real-life EV data collected on UCLA campus is used to test the proposed DSM in an IEEE benchmark test system. Numerical results demonstrate the correctness and merits of the proposed approach.
Principles of Security Vulnerability Analysis of stationary industrial installations
International Nuclear Information System (INIS)
Borysiewicz, M.
2006-01-01
Security and safety have been key priorities at facilities that manufacture, store, use, or handle hazardous chemicals, after the terrorist attacks on the United States of September 11, 2001. Security improvements may be needed, especially at sites that pose a more attractive target to terrorists due to their economic importance, perceived level of consequences, and other factors. The first step in the process of managing security risks is to identify and analyze the threats and the vulnerabilities facing a facility by conducting a Security Vulnerability Analysis (SVA). The SVA is a systematic process that evaluates the likelihood that a threat against a facility will be successful. It considers the potential severity of consequences to the facility itself, to the surrounding community and on the energy supply chain. The objective of conducting a SVA is to identify security hazards, threats, and vulnerabilities facing a facility, and to evaluate the countermeasures to provide for the protection of the public, workers, national interests, the environment, and the company. With this information security risks can be assessed and strategies can be formed to reduce vulnerabilities as required. SVA is a tool to assist management in making decisions on the need for countermeasures to address the threats and vulnerabilities. The paper provides an overview of fundamental steps of SVA for stationary industrial installations. (author)
Investigation and modelling of rubber stationary friction on rough surfaces
Energy Technology Data Exchange (ETDEWEB)
Le Gal, A; Klueppel, M [Deutsches Institut fuer Kautschuktechnologie, Eupener Strasse 33, D-30519 Hannover (Germany)
2008-01-09
This paper presents novel aspects regarding the physically motivated modelling of rubber stationary sliding friction on rough surfaces. The description of dynamic contact is treated within the framework of a generalized Greenwood-Williamson theory for rigid/soft frictional pairings. Due to the self-affinity of rough surfaces, both hysteresis and adhesion friction components arise from a multi-scale excitation of surface roughness. Beside a complete analytical formulation of contact parameters, the morphology of macrotexture is considered via the introduction of a second scaling range at large length scales which mostly contribute to hysteresis friction. Moreover, adhesion friction is related to the real area of contact combined with the kinetics of interfacial peeling effects. Friction experiments carried out with different rubbers on rough granite and asphalt point out the relevance of hysteresis and adhesion friction concepts on rough surfaces. The two scaling ranges approach significantly improves the description of wet and dry friction behaviour within the range of low sliding velocity. In addition, material and surface effects are predicted and understood on a physical basis. The applicability of such modelling is of high interest for materials developers and road constructors regarding the prediction of wet grip performance of tyres on road tracks.
Variability of road traffic noise recorded by stationary monitoring stations
Bąkowski, Andrzej; Radziszewski, Leszek
2017-11-01
The paper presents the analysis results of equivalent sound level recorded by two road traffic noise monitoring stations. The stations were located in Kielce (an example of a medium-size town in Poland) at the roads out of the town in the direction of Kraków and Warszawa. The measurements were carried out through stationary stations monitoring the noise and traffic of motor vehicles. The RMS values based on A-weighted sound level were recorded every 1 s in the buffer and the results were registered every 1 min over the period of investigations. The registered data were the basis for calculating the equivalent sound level for three time intervals: from 6:00 to 18:00, from 18:00 to 22:00 and from 22:00 to 6:00. Analysis included the values of the equivalent sound level recorded for different days of the week split into 24h periods, nights, days and evenings. The data analysed included recordings from 2013. The coefficient of variation and positional variation were proposed for performing comparative analysis of the obtained data scattering. The investigations indicated that the recorded data varied depending on the traffic routes. The differences concerned the values of coefficients of variation of the equivalent sound levels.
Abou Rafee, Sameh A.; Martins, Leila D.; Kawashima, Ana B.; Almeida, Daniela S.; Morais, Marcos V. B.; Souza, Rita V. A.; Oliveira, Maria B. L.; Souza, Rodrigo A. F.; Medeiros, Adan S. S.; Urbina, Viviana; Freitas, Edmilson D.; Martin, Scot T.; Martins, Jorge A.
2017-06-01
This paper evaluates the contributions of the emissions from mobile, stationary and biogenic sources on air pollution in the Amazon rainforest by using the Weather Research and Forecasting with Chemistry (WRF-Chem) model. The analyzed air pollutants were CO, NOx, SO2, O3, PM2. 5, PM10 and volatile organic compounds (VOCs). Five scenarios were defined in order to evaluate the emissions by biogenic, mobile and stationary sources, as well as a future scenario to assess the potential air quality impact of doubled anthropogenic emissions. The stationary sources explain the highest concentrations for all air pollutants evaluated, except for CO, for which the mobile sources are predominant. The anthropogenic sources considered resulted an increasing in the spatial peak-temporal average concentrations of pollutants in 3 to 2780 times in relation to those with only biogenic sources. The future scenario showed an increase in the range of 3 to 62 % in average concentrations and 45 to 109 % in peak concentrations depending on the pollutant. In addition, the spatial distributions of the scenarios has shown that the air pollution plume from the city of Manaus is predominantly transported west and southwest, and it can reach hundreds of kilometers in length.
Directory of Open Access Journals (Sweden)
S. A. Abou Rafee
2017-06-01
Full Text Available This paper evaluates the contributions of the emissions from mobile, stationary and biogenic sources on air pollution in the Amazon rainforest by using the Weather Research and Forecasting with Chemistry (WRF-Chem model. The analyzed air pollutants were CO, NOx, SO2, O3, PM2. 5, PM10 and volatile organic compounds (VOCs. Five scenarios were defined in order to evaluate the emissions by biogenic, mobile and stationary sources, as well as a future scenario to assess the potential air quality impact of doubled anthropogenic emissions. The stationary sources explain the highest concentrations for all air pollutants evaluated, except for CO, for which the mobile sources are predominant. The anthropogenic sources considered resulted an increasing in the spatial peak-temporal average concentrations of pollutants in 3 to 2780 times in relation to those with only biogenic sources. The future scenario showed an increase in the range of 3 to 62 % in average concentrations and 45 to 109 % in peak concentrations depending on the pollutant. In addition, the spatial distributions of the scenarios has shown that the air pollution plume from the city of Manaus is predominantly transported west and southwest, and it can reach hundreds of kilometers in length.
International Nuclear Information System (INIS)
Resano-Garcia, A.; Battie, Y.; Koch, A.; En Naciri, A.; Chaoui, N.
2015-01-01
Silver nanoparticles were produced by nanosecond pulsed-laser ablation at 1064 nm of Ag in pure water. These experiments were performed using an alternative ablation cell design where a cylindrical shaped Ag target was horizontally irradiated, while the liquid was stirred by a stir rod coaxially arranged to the target. The repeatability of the generated colloids properties (extinction and size distribution) is assessed by statistical tools. The colloids properties prepared under stationary liquid are found to be unpredictable, while they are highly repeatable at high stirring speed. At the same time, electronic microscopy examinations of the irradiated Ag targets revealed that the width of the laser-machined grooves exponentially decays in stationary liquid and almost linearly under high stirring speed as the ablation proceeds. In the latter case, the decay rate was found to be constant from one experiment to the other, while it was not repeatable stationary liquid. We show that the decay of the groove width is due to an attenuation of the laser energy reaching the target surface due to the formation of a more or less dense NPs layer in front of the target as the ablation proceeds. Using the ablation time-dependence of the groove width, we can quantify the attenuation factor of the laser energy with exposure time. Finally, the relationship between the laser energy attenuation, stirring speed, and repeatability of the colloids properties is interpreted and discussed in terms of mass transfer
Action plans can interact to hinder or facilitate reach performance.
Fournier, Lisa R; Wiediger, Matthew D; Taddese, Ezana F
2015-11-01
Executing a reach action can be delayed while retaining another action in working memory (WM) if the two action plans partly overlap rather than do not overlap. This delay (partial repetition cost) occurs when reach responses are under cognitive control. In this study, we investigated whether facilitation (a partial repetition benefit) occurs when reach responses are automatic. We also examined whether the hemisphere controlling the limb or selection of the preferred limb (based on a free-reach task) influences reach performance when the actions partly overlap. Left- and right-handers reached to different stimulus locations to the left and right of body midline with their ipsilateral hand while maintaining an action plan in WM that required the same or the different hand. The results showed a partial repetition benefit for spatially compatible reaches to left and right stimulus locations far from the body midline, but not for those near the body midline. Also, no partial repetition cost was found at any of the stimulus-reach locations. This indicates that automatic reach responses that partly overlap with an action plan maintained in WM are not delayed, but instead can be facilitated (partial repetition benefit). The roles of hemisphere and reach-hand preference in action control and the importance of the degree of feature overlap in obtaining a partial repetition benefit (and cost) are discussed.
Directory of Open Access Journals (Sweden)
J.-U. Grooß
2011-12-01
Full Text Available Balloon-borne observations of ozone from the South Pole Station have been reported to reach ozone mixing ratios below the detection limit of about 10 ppbv at the 70 hPa level by late September. After reaching a minimum, ozone mixing ratios increase to above 1 ppmv on the 70 hPa level by late December. While the basic mechanisms causing the ozone hole have been known for more than 20 yr, the detailed chemical processes determining how low the local concentration can fall, and how it recovers from the minimum have not been explored so far. Both of these aspects are investigated here by analysing results from the Chemical Lagrangian Model of the Stratosphere (CLaMS. As ozone falls below about 0.5 ppmv, a balance is maintained by gas phase production of both HCl and HOCl followed by heterogeneous reaction between these two compounds in these simulations. Thereafter, a very rapid, irreversible chlorine deactivation into HCl can occur, either when ozone drops to values low enough for gas phase HCl production to exceed chlorine activation processes or when temperatures increase above the polar stratospheric cloud (PSC threshold. As a consequence, the timing and mixing ratio of the minimum ozone depends sensitively on model parameters, including the ozone initialisation. The subsequent ozone increase between October and December is linked mainly to photochemical ozone production, caused by oxygen photolysis and by the oxidation of carbon monoxide and methane.
Chertock, A.; Fellner, K.; Kurganov, A.; Lorz, A.; Markowich, P. A.
2012-01-01
examples, which illustrate (i) the formation of sinking plumes, (ii) the possible merging of neighbouring plumes and (iii) the convergence towards numerically stable stationary plumes. The examples with stable stationary plumes show how the surface
Maleki, Mohammad; Emery, Xavier
2017-12-01
In mineral resources evaluation, the joint simulation of a quantitative variable, such as a metal grade, and a categorical variable, such as a rock type, is challenging when one wants to reproduce spatial trends of the rock type domains, a feature that makes a stationarity assumption questionable. To address this problem, this work presents methodological and practical proposals for jointly simulating a grade and a rock type, when the former is represented by the transform of a stationary Gaussian random field and the latter is obtained by truncating an intrinsic random field of order k with Gaussian generalized increments. The proposals concern both the inference of the model parameters and the construction of realizations conditioned to existing data. The main difficulty is the identification of the spatial correlation structure, for which a semi-automated algorithm is designed, based on a least squares fitting of the data-to-data indicator covariances and grade-indicator cross-covariances. The proposed models and algorithms are applied to jointly simulate the copper grade and the rock type in a Chilean porphyry copper deposit. The results show their ability to reproduce the gradual transitions of the grade when crossing a rock type boundary, as well as the spatial zonation of the rock type.
Hydrogen Fuel Cell Analysis: Lessons Learned from Stationary Power Generation Final Report
Energy Technology Data Exchange (ETDEWEB)
Scott E. Grasman; John W. Sheffield; Fatih Dogan; Sunggyu Lee; Umit O. Koylu; Angie Rolufs
2010-04-30
This study considered opportunities for hydrogen in stationary applications in order to make recommendations related to RD&D strategies that incorporate lessons learned and best practices from relevant national and international stationary power efforts, as well as cost and environmental modeling of pathways. The study analyzed the different strategies utilized in power generation systems and identified the different challenges and opportunities for producing and using hydrogen as an energy carrier. Specific objectives included both a synopsis/critical analysis of lessons learned from previous stationary power programs and recommendations for a strategy for hydrogen infrastructure deployment. This strategy incorporates all hydrogen pathways and a combination of distributed power generating stations, and provides an overview of stationary power markets, benefits of hydrogen-based stationary power systems, and competitive and technological challenges. The motivation for this project was to identify the lessons learned from prior stationary power programs, including the most significant obstacles, how these obstacles have been approached, outcomes of the programs, and how this information can be used by the Hydrogen, Fuel Cells & Infrastructure Technologies Program to meet program objectives primarily related to hydrogen pathway technologies (production, storage, and delivery) and implementation of fuel cell technologies for distributed stationary power. In addition, the lessons learned address environmental and safety concerns, including codes and standards, and education of key stakeholders.
Ortiz-Villanueva, Elena; Tauler, Romà
2017-01-01
Metabolomics is a powerful and widely used approach that aims to screen endogenous small molecules (metabolites) of different families present in biological samples. The large variety of compounds to be determined and their wide diversity of physical and chemical properties have promoted the development of different types of hydrophilic interaction liquid chromatography (HILIC) stationary phases. However, the selection of the most suitable HILIC stationary phase is not straightforward. In this work, four different HILIC stationary phases have been compared to evaluate their potential application for the analysis of a complex mixture of metabolites, a situation similar to that found in non-targeted metabolomics studies. The obtained chromatographic data were analyzed by different chemometric methods to explore the behavior of the considered stationary phases. ANOVA-simultaneous component analysis (ASCA), principal component analysis (PCA) and partial least squares regression (PLS) were used to explore the experimental factors affecting the stationary phase performance, the main similarities and differences among chromatographic conditions used (stationary phase and pH) and the molecular descriptors most useful to understand the behavior of each stationary phase. PMID:29064436
Recent casualties of late globalization
DEFF Research Database (Denmark)
Turcan, Romeo V.
2016-01-01
In this essay I will expand my thoughts on universities as ‘late globalizers’ and the impact ‘being late’ has on university internationalization or globalization activities. In my earlier essay I viewed universities as ‘late globalizers’ and briefly introduced the impact of being ‘late’, e.g., wi.......g., withdrawal or de-internationalization of universities due to incompatibility between university autonomy and the context in the target country or universities unwillingness to compromise on their freedom and autonomy....
Reach/frequency for printed media: Personal probabilities or models
DEFF Research Database (Denmark)
Mortensen, Peter Stendahl
2000-01-01
The author evaluates two different ways of estimating reach and frequency of plans for printed media. The first assigns reading probabilities to groups of respondents and calculates reach and frequency by simulation. the second estimates parameters to a model for reach/frequency. It is concluded ...... and estiamtes from such models are shown to be closer to panel data. the problem, however, is to get valid input for such models from readership surveys. Means for this are discussed....
A new quasi-stationary, very high density plasma regime on the W7-AS stellarator
International Nuclear Information System (INIS)
Jaenicke, R; Baeumel, S; Baldzuhn, J; Brakel, R; Burhenn, R; Ehmler, H; Endler, M; Erckmann, V; Feng, Y; Gadelmeier, F; Geiger, J; Giannone, L; Grigull, P; Hartfuss, H J; Hartmann, D; Hildebrandt, D; Hirsch, M; Holzhauer, E; Kick, M; Kisslinger, J; Klinger, T; Klose, S; Knauer, J; Koenig, R; Kuehner, G; Laqua, H; Maassberg, H; McCormick, K; Narayanan, R; Niedermeyer, H; Pasch, E; Ruhs, N; Rust, N; Saffert, J; Sardei, F; Schneider, F; Schubert, M; Speth, E; Wagner, F; Weller, A; Wenzel, U; Werner, A; Wuersching, E
2002-01-01
Stellarators have the intrinsic property of steady state operation. However, on present-day stellarators the pulse length is usually not only limited due to technical reasons, but also by physical problems. Lack of density control and a subsequent radiation collapse terminate the discharges quite often at high densities. To improve the control of the plasma-wall interaction, the island divertor concept was developed for optimized stellarators. To test this divertor concept on W7-AS, all limiters were removed and replaced by ten divertor modules. In subsequent divertor experiments a promising new plasma operational regime has been discovered which is termed 'high density H-mode' (HDH-mode). During the transition into that regime a clear reduction of ELM-like events and turbulent fluctuations is observed. The HDH-mode combines good energy confinement with very low impurity confinement resulting in low core radiation, but high edge-localized radiation. Consequently, stationary discharges at densities of typically 2x10 20 m -3 can be performed within the accessible pulse length of about 1 s. At densities above 3x10 20 m -3 a controlled transition from attached to partially detached plasmas is observed. The still edge-localized radiation reaches 90% of the heating power so that the power load onto the divertor target plates is further reduced. At a lower toroidal field of 0.9 T average β-values could be raised from earlier 2% to more than 3% in magnetic field configurations with rather smooth flux surfaces at the plasma boundary. The recently obtained results render excellent prospects for W7-X, the larger superconducting successor experiment of W7-AS
Assessing the extent of non-stationary biases in GCMs
Nahar, Jannatun; Johnson, Fiona; Sharma, Ashish
2017-06-01
General circulation models (GCMs) are the main tools for estimating changes in the climate for the future. The imperfect representation of climate models introduces biases in the simulations that need to be corrected prior to their use for impact assessments. Bias correction methods generally assume that the bias calculated over the historical period does not change and can be applied to the future. This study investigates this assumption by considering the extent and nature of bias non-stationarity using 20th century precipitation and temperature simulations from six CMIP5 GCMs across Australia. Four statistics (mean, standard deviation, 10th and 90th quantiles) in monthly and seasonal biases are obtained for three different time window lengths (10, 25 and 33 years) to examine the properties of bias over time. This approach is repeated for two different phases of the Interdecadal Pacific Oscillation (IPO), which is known to have strong influences on the Australian climate. It is found that bias non-stationarity at decadal timescales is indeed an issue over some of Australia for some GCMs. When considering interdecadal variability there are significant difference in the bias between positive and negative phases of the IPO. Regional analyses confirmed these findings with the largest differences seen on the east coast of Australia, where IPO impacts tend to be the strongest. The nature of the bias non-stationarity found in this study suggests that it will be difficult to modify existing bias correction approaches to account for non-stationary biases. A more practical approach for impact assessments that use bias correction maybe to use a selection of GCMs where the assumption of bias non-stationarity holds.
Danish emission inventories for stationary combustion plants. Inventories until 2008
Energy Technology Data Exchange (ETDEWEB)
Nielsen, Malene; Nielsen, Ole-Kenneth; Plejdrup, M.; Hjelgaard, K.
2010-10-15
Emission inventories for stationary combustion plants are presented and the methodologies and assumptions used for the inventories are described. The pollutants considered are SO{sub 2}, NO{sub x}, NMVOC, CH{sub 4}, CO, CO{sub 2}, N{sub 2}O, NH{sub 3}, particulate matter, heavy metals, dioxins, HCB and PAH. The CO{sub 2} emission in 2008 was 16 % lower than in 1990. However, fluctuations in the emission level are large as a result of electricity import/export. The emission of CH{sub 4} has increased due to increased use of lean-burn gas engines in combined heating and power (CHP) plants. However, the emission has decreased in recent years due to structural changes in the Danish electricity market. The N{sub 2}O emission was higher in 2008 than in 1990 but the fluctuations in the time-series are significant. A considerable decrease of the SO{sub 2}, NO{sub x} and heavy metal emissions is mainly a result of decreased emissions from large power plants and waste incineration plants. The combustion of wood in residential plants has increased considerably in recent years resulting in increased emission of PAH, particulate matter and CO. The emission of NMVOC has increased since 1990 as a result of both the increased combustion of wood in residential plants and the increased emission from lean-burn gas engines. The dioxin emission decreased since 1990 due to flue gas cleaning on waste incineration plants. However in recent years the emission has increased as a result of the increased combustion of wood in residential plants. (Author)
H2 emission from non-stationary magnetized bow shocks
Tram, L. N.; Lesaffre, P.; Cabrit, S.; Gusdorf, A.; Nhung, P. T.
2018-01-01
When a fast moving star or a protostellar jet hits an interstellar cloud, the surrounding gas gets heated and illuminated: a bow shock is born that delineates the wake of the impact. In such a process, the new molecules that are formed and excited in the gas phase become accessible to observations. In this paper, we revisit models of H2 emission in these bow shocks. We approximate the bow shock by a statistical distribution of planar shocks computed with a magnetized shock model. We improve on previous works by considering arbitrary bow shapes, a finite irradiation field and by including the age effect of non-stationary C-type shocks on the excitation diagram and line profiles of H2. We also examine the dependence of the line profiles on the shock velocity and on the viewing angle: we suggest that spectrally resolved observations may greatly help to probe the dynamics inside the bow shock. For reasonable bow shapes, our analysis shows that low-velocity shocks largely contribute to H2 excitation diagram. This can result in an observational bias towards low velocities when planar shocks are used to interpret H2 emission from an unresolved bow. We also report a large magnetization bias when the velocity of the planar model is set independently. Our 3D models reproduce excitation diagrams in BHR 71 and Orion bow shocks better than previous 1D models. Our 3D model is also able to reproduce the shape and width of the broad H2 1-0S(1) line profile in an Orion bow shock (Brand et al. 1989).
A statistical physics of stationary and metastable states
International Nuclear Information System (INIS)
Cabo, A; González, A; Curilef, S; Cabo-Bizet, N G; Vera, C A
2011-01-01
We present a generalization of Gibbs statistical mechanics designed to describe a general class of stationary and metastable equilibrium states. It is assumed that the physical system maximizes the entropy functional S subject to the standard conditions plus an extra conserved constraint function F, imposed to force the system to remain in the metastable configuration. After requiring additivity for two quasi-independent subsystems, and the commutation of the new constraint with the density matrix ρ, it is argued that F should be a homogeneous function of ρ, at least for systems in which the spectrum is sufficiently dense to be considered as continuous. Therefore, surprisingly, the analytic form of F turns out to be of the kind F(p i ) = p i q , where the p i are the eigenvalues of the density matrix and q is a real number to be determined. Thus, the discussion identifies the physical relevance of Lagrange multiplier constraints of the Tsallis kind and their q parameter, as enforced by the additivity of the constraint F which fixes the metastable state. An approximate analytic solution for the probability density is found for q close to unity. The procedure is applied to describe the results from the plasma experiment of Huang and Driscoll. For small and medium values of the radial distance, the measured density is predicted with a precision similar to that achieved by minimal enstrophy and Tsallis procedures. Also, the particle density is predicted at all the radial positions. Thus, the discussion gives a solution to the conceptual difficulties of the two above mentioned approaches as applied to this problem, which both predict a non-analytic abrupt vanishing of the density above a critical radial distance
A Low-Cost "Stationary Eye" in the Sky
Koch, R.; Lande, K.; Mitchell, R.; Wildenhain, P.; Hoang, N.; Langford, J.
1997-12-01
We are developing a stationary, near the top of the atmosphere, astronomical observing system. The platform is a high altitude robotic aircraft (THESEUS) flying in anti-sense to Earth's rotation at a latitude where the plane's speed closely matches the local ground spin velocity. Thus, either an extended day or night viewing program of a given object can be achieved. Our intention here concentrates on astronomical targets. The system consists of the following components. (1) A low cost robotic aircraft that can fly at an altitude of about 25 km. for 30 to 40 hours with differential GPS navigation. Real time control of the aircraft and the observing instruments is either by on-board computer or from the ground via low altitude, commercial satellite communications systems (Iridium, Teledesic, etc.). (2) A siderostat-fed telescope of small f-ratio is attached to the aircraft via critically damped mechanical isolators. An electronic camera at the prime focus looks at a chosen astronomical target. (3) Image smear due to aircraft engine vibration will be eliminated by a combination of critically damped mechanical isolators and electronic CCD pixel jogging. Very precise piezo- electric driven transverse translation of the CCD camera will be used to compensate for wind induced drift of the image on the focal plane. Bright field stars will be used to drive the stabilizing system. (4) Data are stored on high capacity ruggedized hard drives similar to that used by the Mars Lander. The Aurora THESEUS aircraft, whose design is based upon earlier models, is under development. The image stabilizing system components have been identified. An off-the-shelf data-storage device has been chosen. A first prototype telescope has been built and tested. Other optical configurations are possible and collaborators will be welcomed.
An inversion-relaxation approach for sampling stationary points of spin model Hamiltonians
International Nuclear Information System (INIS)
Hughes, Ciaran; Mehta, Dhagash; Wales, David J.
2014-01-01
Sampling the stationary points of a complicated potential energy landscape is a challenging problem. Here, we introduce a sampling method based on relaxation from stationary points of the highest index of the Hessian matrix. We illustrate how this approach can find all the stationary points for potentials or Hamiltonians bounded from above, which includes a large class of important spin models, and we show that it is far more efficient than previous methods. For potentials unbounded from above, the relaxation part of the method is still efficient in finding minima and transition states, which are usually the primary focus of attention for atomistic systems
On the Existence of Solutions for Stationary Mean-Field Games with Congestion
Evangelista, David
2017-09-11
Mean-field games (MFGs) are models of large populations of rational agents who seek to optimize an objective function that takes into account their location and the distribution of the remaining agents. Here, we consider stationary MFGs with congestion and prove the existence of stationary solutions. Because moving in congested areas is difficult, agents prefer to move in non-congested areas. As a consequence, the model becomes singular near the zero density. The existence of stationary solutions was previously obtained for MFGs with quadratic Hamiltonians thanks to a very particular identity. Here, we develop robust estimates that give the existence of a solution for general subquadratic Hamiltonians.
International Nuclear Information System (INIS)
1992-10-01
In the Supplement to the Fourth Edition of AP-42 Volume I, new or revised emissions data are presented for Anthracite Coal Combustion; Natural Gas Combustion; Liquified Petroleum Gas Combustion; Wood Waste Combustion In Boilers; Bagasse Combustion In Sugar Mills; Residential Fireplaces; Residential Wood Stoves; Waste Oil Combustion; Automobile Body Incineration; Conical Burners; Open Burning; Stationary Gas Turbines for Electricity Generation; Heavy Duty Natural Gas Fired Pipeline Compressor Engines; Gasoline and Diesel Industrial Engines; Large Stationary Diesel and All Stationary Dual Fuel Engines; Soap and Detergents; and Storage of Organic Liquids
On the Existence of Solutions for Stationary Mean-Field Games with Congestion
Evangelista, David; Gomes, Diogo A.
2017-01-01
Mean-field games (MFGs) are models of large populations of rational agents who seek to optimize an objective function that takes into account their location and the distribution of the remaining agents. Here, we consider stationary MFGs with congestion and prove the existence of stationary solutions. Because moving in congested areas is difficult, agents prefer to move in non-congested areas. As a consequence, the model becomes singular near the zero density. The existence of stationary solutions was previously obtained for MFGs with quadratic Hamiltonians thanks to a very particular identity. Here, we develop robust estimates that give the existence of a solution for general subquadratic Hamiltonians.
Discretization of Stationary Solutions of Stochastic Systems Driven by Fractional Brownian Motion
International Nuclear Information System (INIS)
Garrido-Atienza, Maria J.; Kloeden, Peter E.; Neuenkirch, Andreas
2009-01-01
In this article we study the behavior of dissipative systems with additive fractional noise of any Hurst parameter. Under a one-sided dissipative Lipschitz condition on the drift the continuous stochastic system is shown to have a unique stationary solution, which pathwise attracts all other solutions. The same holds for the discretized stochastic system, if the drift-implicit Euler method is used for the discretization. Moreover, the unique stationary solution of the drift-implicit Euler scheme converges to the unique stationary solution of the original system as the stepsize of the discretization decreases
Groebner Basis Methods for Stationary Solutions of a Low-Dimensional Model for a Shear Flow
Pausch, Marina; Grossmann, Florian; Eckhardt, Bruno; Romanovski, Valery G.
2014-10-01
We use Groebner basis methods to extract all stationary solutions for the nine-mode shear flow model described in Moehlis et al. (New J Phys 6:56, 2004). Using rational approximations to irrational wave numbers and algebraic manipulation techniques we reduce the problem of determining all stationary states to finding roots of a polynomial of order 30. The coefficients differ by 30 powers of 10, so that algorithms for extended precision are needed to extract the roots reliably. We find that there are eight stationary solutions consisting of two distinct states, each of which appears in four symmetry-related phases. We discuss extensions of these results for other flows.
Non-stationary pre-envelope covariances of non-classically damped systems
Muscolino, G.
1991-08-01
A new formulation is given to evaluate the stationary and non-stationary response of linear non-classically damped systems subjected to multi-correlated non-separable Gaussian input processes. This formulation is based on a new and more suitable definition of the impulse response function matrix for such systems. It is shown that, when using this definition, the stochastic response of non-classically damped systems involves the evaluation of quantities similar to those of classically damped ones. Furthermore, considerations about non-stationary cross-covariances, spectral moments and pre-envelope cross-covariances are presented for a monocorrelated input process.
Stationary striations due to interaction of two ionization waves in xenon glow discharge
International Nuclear Information System (INIS)
Maruyama, T.; Nishina, S.; Kitamura, H.; Itagaki, K.; Mizuochi, H.
1990-01-01
Experimental observations on stationary striations in the positive column of xenon discharge are reported. Stationary striations are observed when two ionization waves exist simultaneously in the positive column at low pressure and high current region. These stationary striations are caused by nonlinear interference of two backward ionization waves of which frequencies are either equal or are in the ratio 1:2. The spatial intervals for the striated pattern are equal to the reciprocal of the difference between the wave-numbers of two ionization waves. (orig.)
2010-07-01
... Stationary Combustion Turbines 1 Table 1 to Subpart KKKK of Part 60 Protection of Environment ENVIRONMENTAL... Standards of Performance for Stationary Combustion Turbines Pt. 60, Subpt. KKKK, Table 1 Table 1 to Subpart KKKK of Part 60—Nitrogen Oxide Emission Limits for New Stationary Combustion Turbines Combustion...
2010-07-01
... I am a stationary CI internal combustion engine manufacturer? 60.4210 Section 60.4210 Protection of... CI internal combustion engine manufacturer? (a) Stationary CI internal combustion engine... certified to the standards in 40 CFR part 1039. (b) Stationary CI internal combustion engine manufacturers...
2010-07-01
... I am a manufacturer of stationary SI internal combustion engines >19 KW (25 HP) that are rich burn... I am a manufacturer of stationary SI internal combustion engines >19 KW (25 HP) that are rich burn..., and must test their engines as specified in that part. Stationary SI internal combustion engine...
Late onset globoid cell leukodystrophy.
Grewal, R P; Petronas, N; Barton, N W
1991-01-01
A 29 year old male with onset of globoid cell leukodystrophy at age 14 is described. This is the first case of enzymatically confirmed globoid cell leukodystrophy with onset of symptoms after the age of ten. This patient is unique because of the late onset and slow progression and extends the clinical spectrum of globoid cell leukodystrophy.
Late onset globoid cell leukodystrophy.
Grewal, R P; Petronas, N; Barton, N W
1991-11-01
A 29 year old male with onset of globoid cell leukodystrophy at age 14 is described. This is the first case of enzymatically confirmed globoid cell leukodystrophy with onset of symptoms after the age of ten. This patient is unique because of the late onset and slow progression and extends the clinical spectrum of globoid cell leukodystrophy.
Early and Late Retirement Exits
Brougham, Ruby R.; Walsh, David A.
2009-01-01
The current study proposes that personal need fulfillment (relatedness, generativity, identity, growth, and finances) predicts early and late retirement intentions. The personal needs of 160 full-time older employees were measured by personal goals, job satisfactions, job characteristics, and intrinsic motivation. Results suggest that the personal…
Late onset startle induced tics
Tijssen, MAJ; Brown, P; Morris, HR; Lees, A
1999-01-01
Three cases of late onset Gilles de la Tourette's syndrome are presented. The motor ties were mainly induced by an unexpected startling stimulus, but the startle reflex was not exaggerated. The ties developed after physical trauma or a period of undue emotional stress. Reflex ties may occur in
Late onset startle induced tics
Tijssen, M. A.; Brown, P.; Morris, H. R.; Lees, A.
1999-01-01
Three cases of late onset Gilles de la Tourette's syndrome are presented. The motor tics were mainly induced by an unexpected startling stimulus, but the startle reflex was not exaggerated. The tics developed after physical trauma or a period of undue emotional stress. Reflex tics may occur in
The design of stationary and mobile solid oxide fuel cell-gas turbine systems
Winkler, Wolfgang; Lorenz, Hagen
A general thermodynamic model has shown that combined fuel cell cycles may reach an electric-efficiency of more than 80%. This value is one of the targets of the Department of Energy (DOE) solid oxide fuel cell-gas turbine (SOFC-GT) program. The combination of a SOFC and GT connects the air flow of the heat engine and the cell cooling. The principle strategy in order to reach high electrical-efficiencies is to avoid a high excess air for the cell cooling and heat losses. Simple combined SOFC-GT cycles show an efficiency between 60 and 72%. The combination of the SOFC and the GT can be done by using an external cooling or by dividing the stack into multiple sub-stacks with a GT behind each sub-stack as the necessary heat sink. The heat exchangers (HEXs) of a system with an external cooling have the benefit of a pressurization on both sides and therefore, have a high heat exchange coefficient. The pressurization on both sides delivers a low stress to the HEX material. The combination of both principles leads to a reheat (RH)-SOFC-GT cycle that can be improved by a steam turbine (ST) cycle. The first results of a study of such a RH-SOFC-GT-ST cycle indicate that a cycle design with an efficiency of more than 80% is possible and confirm the predictions by the theoretical thermodynamic model mentioned above. The extremely short heat-up time of a thin tubular SOFC and the market entrance of the micro-turbines give the option of using these SOFC-GT designs for mobile applications. The possible use of hydrocarbons such as diesel oil is an important benefit of the SOFC. The micro-turbine and the SOFC stack will be matched depending on the start-up requirements of the mobile system. The minimization of the volume needed is a key issue. The efficiency of small GTs is lower than the efficiency of large GTs due to the influence of the leakage within the stages of GTs increasing with a decreasing size of the GT. Thus, the SOFC module pressure must be lower than in larger
Progression of Late-Onset Stargardt Disease.
Lambertus, Stanley; Lindner, Moritz; Bax, Nathalie M; Mauschitz, Matthias M; Nadal, Jennifer; Schmid, Matthias; Schmitz-Valckenberg, Steffen; den Hollander, Anneke I; Weber, Bernhard H F; Holz, Frank G; van der Wilt, Gert Jan; Fleckenstein, Monika; Hoyng, Carel B
2016-10-01
Identification of sensitive biomarkers is essential to determine potential effects of emerging therapeutic trials for Stargardt disease. This study aimed to describe the natural history of late-onset Stargardt, and demonstrates the accuracy of retinal pigment epithelium (RPE) atrophy progression as an outcome measure. We performed a retrospective cohort study collecting multicenter data from 47 patients (91 eyes) with late-onset Stargardt, defined by clinical phenotype, at least one ABCA4 mutation, and age at disease onset ≥ 45 years. We analyzed RPE atrophy progression on fundus autofluorescence and near-infrared reflectance imaging using semiautomated software and a linear mixed model. We performed sample size calculations to assess the power in a simulated 2-year interventional study and assessed visual endpoints using time-to-event analysis. Over time, progression of RPE atrophy was observed (mean: 0.22 mm/year, 95% confidence interval [CI]: 0.19-0.27). By including only patients with bilateral RPE atrophy in a future trial, 32 patients are needed to reach a power of 83.9% (95% CI: 83.1-84.6), assuming a fixed therapeutic effect size of 30%. We found a median interval between disease onset and visual acuity decline to 20/32, 20/80, and 20/200 of 2.74 (95% CI: 0.54-4.41), 10.15 (95% CI: 6.13-11.38), and 11.38 (95% CI: 6.13-13.34) years, respectively. We show that RPE atrophy represents a robust biomarker to monitor disease progression in future therapeutic trials. In contrast, the variability in terms of the course of visual acuity was high.
Xiong, Caifeng; Yuan, Jie; Wang, Zhiying; Wang, Siyao; Yuan, Chenchen; Wang, Lili
2018-04-20
In this work, 2-methacryloyloxyethyl phosphorylcholine (MPC) was used as a ligand to prepare a novel mixed-mode chromatography (MMC) stationary phase by the thiol-ene click reaction onto silica (MPC-silica). It was found that this MPC-silica showed the retention characteristics of hydrophilic interaction chromatography (HILIC) and weak cation exchange chromatography (WCX) under suitable mobile phase conditions. In detail, acidic and basic hydrophilic compounds and puerarin from pueraria were separated quickly with HILIC mode. Meanwhile, six standard proteins were allowed to reach baseline separation in WCX mode, and protein separation from egg white was also achieved with this mode. In addition, reduced/denatured lysozyme could be refolded with the MPC-silica column. In the meantime, the MPC-silica has been applied for refolding with simultaneous purification of recombinant human Delta-like1-RGD (rhDll1-RGD) expressed in Escherichia coli. The results show that the mass recovery and purity of rhDll1-RGD could reach 63.4% and 97% by one step, respectively. Furthermore, the reporter assay results demonstrated that refolded with simultaneously purified rhDll1-RGD could efficiently activate the signalling pathway in a dose-dependent manner. In general, this MPC-silica has good resolution and selectivity in the separation of polar compounds and protein samples in different high-performance liquid chromatography (HPLC) modes, and it successfully achieved refolding with simultaneous purification of denatured protein. Copyright © 2018 Elsevier B.V. All rights reserved.
Should these potential CMR substances have been registered under REACH?
DEFF Research Database (Denmark)
Wedebye, Eva Bay; Nikolov, Nikolai Georgiev; Dybdahl, Marianne
2013-01-01
(Q)SAR models were applied to screen around 68,000 REACH pre-registered substances for CMR properties (carcinogenic, mutagenic or toxic to reproduction). Predictions from 14 relevant models were combined to reach overall calls for C, M and R. Combining predictions may reduce “noise” and increase...
CRED REA Fish Team Stationary Point Count Surveys at Pagan, Marianas Archipelago, 2007
National Oceanic and Atmospheric Administration, Department of Commerce — Stationary Point Counts at 4 stations at each survey site were surveyed as part of Rapid Ecological Assessments (REA) conducted at 9 sites around Pagan in the...
CRED REA Fish Team Stationary Point Count Surveys at Niihau, Main Hawaiian Islands, 2006
National Oceanic and Atmospheric Administration, Department of Commerce — Stationary Point Counts at 4 stations at each survey site were surveyed as part of Rapid Ecological Assessments (REA) conducted at 6 sites around Niihau in the Main...
CRED REA Fish Team Stationary Point Count Surveys at Ni'ihau Island, 2005
National Oceanic and Atmospheric Administration, Department of Commerce — Stationary Point Counts at 4 stations at each survey site were surveyed as part of Rapid Ecological Assessments conducted at 9 sites at Ni'ihau in July, 2005 from...
Entropy production of stationary diffusions on non-compact Riemannian manifolds
Institute of Scientific and Technical Information of China (English)
龚光鲁; 钱敏平
1997-01-01
The closed form of the entropy production of stationary diffusion processes with bounded Nelson’s current velocity is given.The limit of the entropy productions of a sequence of reflecting diffusions is also discussed.
CRED REA Fish Team Stationary Point Count Surveys at Agrihan Island, 2003
National Oceanic and Atmospheric Administration, Department of Commerce — Stationary Point Counts at 4 stations at each survey site were surveyed as part of Rapid Ecological Assessments conducted at 3 sites at Agrihan in the Commonwealth...
Gavish, Nir
2018-04-01
We study the existence and stability of stationary solutions of Poisson-Nernst-Planck equations with steric effects (PNP-steric equations) with two counter-charged species. We show that within a range of parameters, steric effects give rise to multiple solutions of the corresponding stationary equation that are smooth. The PNP-steric equation, however, is found to be ill-posed at the parameter regime where multiple solutions arise. Following these findings, we introduce a novel PNP-Cahn-Hilliard model, show that it is well-posed and that it admits multiple stationary solutions that are smooth and stable. The various branches of stationary solutions and their stability are mapped utilizing bifurcation analysis and numerical continuation methods.
Kozachenko, Yuriy; Troshki, Viktor
2015-01-01
We consider a measurable stationary Gaussian stochastic process. A criterion for testing hypotheses about the covariance function of such a process using estimates for its norm in the space $L_p(\\mathbb {T}),\\,p\\geq1$, is constructed.
Large-Deviation Results for Discriminant Statistics of Gaussian Locally Stationary Processes
Directory of Open Access Journals (Sweden)
Junichi Hirukawa
2012-01-01
Full Text Available This paper discusses the large-deviation principle of discriminant statistics for Gaussian locally stationary processes. First, large-deviation theorems for quadratic forms and the log-likelihood ratio for a Gaussian locally stationary process with a mean function are proved. Their asymptotics are described by the large deviation rate functions. Second, we consider the situations where processes are misspecified to be stationary. In these misspecified cases, we formally make the log-likelihood ratio discriminant statistics and derive the large deviation theorems of them. Since they are complicated, they are evaluated and illustrated by numerical examples. We realize the misspecification of the process to be stationary seriously affecting our discrimination.
CRED REA Fish Team Stationary Point Count Surveys at Rose Atoll, 2004
National Oceanic and Atmospheric Administration, Department of Commerce — Stationary Point Counts at 4 stations at each survey site were surveyed as part of Rapid Ecological Assessments conducted at 12 sites at Rose Atoll in American Samoa...
Stability of stationary states of non-local equations with singular interaction potentials
Fellner, Klemens; Raoul, Gaë l
2011-01-01
repulsive interaction potentials we show the stability of stationary states of uniformly bounded solutions under a convexity condition.Finally, we present numerical simulations to illustrate our results. © 2010 Elsevier Ltd.
CRED REA Fish Team Stationary Point Count Surveys at Asuncion, Marianas Archipelago, 2005
National Oceanic and Atmospheric Administration, Department of Commerce — Stationary Point Counts at 4 stations at each survey site were surveyed as part of Rapid Ecological Assessments (REA) conducted at 3 sites around Asuncion in the...
Explicit solutions of one-dimensional, first-order, stationary mean-field games with congestion
Gomes, Diogo A.; Nurbekyan, Levon; Prazeres, Mariana
2017-01-01
Here, we consider one-dimensional first-order stationary mean-field games with congestion. These games arise when crowds face difficulty moving in high-density regions. We look at both monotone decreasing and increasing interactions and construct
International Nuclear Information System (INIS)
Caraballo, T.; Kloeden, P.E.
2006-01-01
Under a one-sided dissipative Lipschitz condition on its drift, a stochastic evolution equation with additive noise of the reaction-diffusion type is shown to have a unique stochastic stationary solution which pathwise attracts all other solutions. A similar situation holds for each Galerkin approximation and each implicit Euler scheme applied to these Galerkin approximations. Moreover, the stationary solution of the Euler scheme converges pathwise to that of the Galerkin system as the stepsize tends to zero and the stationary solutions of the Galerkin systems converge pathwise to that of the evolution equation as the dimension increases. The analysis is carried out on random partial and ordinary differential equations obtained from their stochastic counterparts by subtraction of appropriate Ornstein-Uhlenbeck stationary solutions
CRED REA Fish Team Stationary Point Count Surveys at Kaui Island, 2005
National Oceanic and Atmospheric Administration, Department of Commerce — Stationary Point Counts at 4 stations at each survey site were surveyed as part of Rapid Ecological Assessments conducted at 12 sites at Kaui in July, 2005 from the...
CRED REA Fish Team Stationary Point Count Surveys at Maug, Marianas Archipelago, 2007
National Oceanic and Atmospheric Administration, Department of Commerce — Stationary Point Counts at 4 stations at each survey site were surveyed as part of Rapid Ecological Assessments (REA) conducted at 9 sites around Maug in the...
CRED REA Fish Team Stationary Point Count Surveys at Kaula Rock, Main Hawaiian Islands, 2006
National Oceanic and Atmospheric Administration, Department of Commerce — Stationary Point Counts at 4 stations at each survey site were surveyed as part of Rapid Ecological Assessments (REA) conducted at 2 sites around Kaula Rock in the...
CRED REA Fish Team Stationary Point Count Surveys at Midway Atoll, 2003
National Oceanic and Atmospheric Administration, Department of Commerce — Stationary Point Counts at 4 stations at each survey site were surveyed as part of Rapid Ecological Assessments conducted at 9 sites at Midway Atoll in July and...
CRED REA Fish Team Stationary Point Count Surveys at Kure Atoll, 2004
National Oceanic and Atmospheric Administration, Department of Commerce — Stationary Point Counts at 4 stations at each survey site were surveyed as part of Rapid Ecological Assessments conducted at 9 sites at Kure Atoll in October, 2004...
Stationary Combustion Turbines: National Emission Standards for Hazardous Air Pollutants (NESHAP)
Learn about the NESHAP for stationary combustion turbines by reading the rule history, the rule summary, additional resources, docket folder documents, the economic impact analysis, fact sheet and more
This page contains an August 2003 fact sheet with information regarding the National Emissions Standards for Hazardous Air Pollutants (NESHAP) for Stationary Combustion Turbines. This document provides a summary of the information for this NESHAP.
Kan-On, Yukio
2007-04-01
This paper is concerned with the bifurcation structure of positive stationary solutions for a generalized Lotka-Volterra competition model with diffusion. To establish the structure, the bifurcation theory and the interval arithmetic are employed.
Self-adaptive change detection in streaming data with non-stationary distribution
Zhang, Xiangliang; Wang, Wei
2010-01-01
Non-stationary distribution, in which the data distribution evolves over time, is a common issue in many application fields, e.g., intrusion detection and grid computing. Detecting the changes in massive streaming data with a non
Identifying and tracking switching, non-stationary opponents: a Bayesian approach
CSIR Research Space (South Africa)
Hernandez-Leal, P
2016-02-01
Full Text Available extend BPR to adversarial settings, in particular, to opponents that switch from one stationary strategy to another. Our proposed extension enables learning new models in an online fashion when the learning agent detects that the current policies...
National Oceanic and Atmospheric Administration, Department of Commerce — Stationary Point Counts at 4 stations at each survey site were surveyed as part of Rapid Ecological Assessments (REA) conducted at 10 sites around French Frigate...
Quantum manipulation of two-color stationary light: Quantum wavelength conversion
International Nuclear Information System (INIS)
Moiseev, S. A.; Ham, B. S.
2006-01-01
We present a quantum manipulation of a traveling light pulse using electromagnetically induced transparency-based slow light phenomenon for the generation of two-color stationary light. We theoretically discuss the two-color stationary light for the quantum wavelength conversion process in terms of pulse area, energy transfer, and propagation directions. The condition of the two-color stationary light pulse generation has been found and the quantum light dynamics has been studied analytically in the adiabatic limit. The quantum frequency conversion rate of the traveling light is dependent on the spatial spreading of the two-color stationary light pulse and can be near unity in an optically dense medium for the optimal frequencies of the control laser fields
DEFF Research Database (Denmark)
Kock, Anders Bredahl
2016-01-01
We show that the adaptive Lasso is oracle efficient in stationary and nonstationary autoregressions. This means that it estimates parameters consistently, selects the correct sparsity pattern, and estimates the coefficients belonging to the relevant variables at the same asymptotic efficiency...
CRED REA Fish Team Stationary Point Count Surveys at Ta'u, American Samoa, 2006
National Oceanic and Atmospheric Administration, Department of Commerce — Stationary Point Counts at 4 stations at each survey site were surveyed as part of Rapid Ecological Assessments (REA) conducted at 9 sites around Ta'u in the...
CRED REA Fish Team Stationary Point Count Surveys at Ofu-Olosega, American Samoa, 2006
National Oceanic and Atmospheric Administration, Department of Commerce — Stationary Point Counts at 4 stations at each survey site were surveyed as part of Rapid Ecological Assessments (REA) conducted at 12 sites around Ofu-Olosega in the...
CRED REA Fish Team Stationary Point Count Surveys at Rota Island, 2003
National Oceanic and Atmospheric Administration, Department of Commerce — Stationary Point Counts at 4 stations at each survey site were surveyed as part of Rapid Ecological Assessments conducted at 6 sites at Rota Island in the...
A method for computing the stationary points of a function subject to linear equality constraints
International Nuclear Information System (INIS)
Uko, U.L.
1989-09-01
We give a new method for the numerical calculation of stationary points of a function when it is subject to equality constraints. An application to the solution of linear equations is given, together with a numerical example. (author). 5 refs
The Spectral Web of stationary plasma equilibria. II. Internal modes
Goedbloed, J. P.
2018-03-01
The new method of the Spectral Web to calculate the spectrum of waves and instabilities of plasma equilibria with sizeable flows, developed in the preceding Paper I [Goedbloed, Phys. Plasmas 25, 032109 (2018)], is applied to a collection of classical magnetohydrodynamic instabilities operating in cylindrical plasmas with shear flow or rotation. After a review of the basic concepts of the complementary energy giving the solution path and the conjugate path, which together constitute the Spectral Web, the cylindrical model is presented and the spectral equations are derived. The first example concerns the internal kink instabilities of a cylindrical force-free magnetic field of constant α subjected to a parabolic shear flow profile. The old stability diagram and the associated growth rate calculations for static equilibria are replaced by a new intricate stability diagram and associated complex growth rates for the stationary model. The power of the Spectral Web method is demonstrated by showing that the two associated paths in the complex ω-plane nearly automatically guide to the new class of global Alfvén instabilities of the force-free configuration that would have been very hard to predict by other methods. The second example concerns the Rayleigh-Taylor instability of a rotating theta-pinch. The old literature is revisited and shown to suffer from inconsistencies that are remedied. The most global n = 1 instability and a cluster sequence of more local but much more unstable n =2 ,3 ,…∞ modes are located on separate solution paths in the hydrodynamic (HD) version of the instability, whereas they merge in the MHD version. The Spectral Web offers visual demonstration of the central position the HD flow continuum and of the MHD Alfvén and slow magneto-sonic continua in the respective spectra by connecting the discrete modes in the complex plane by physically meaningful curves towards the continua. The third example concerns the magneto-rotational instability
International Nuclear Information System (INIS)
Lipman, Timothy E.; Edwards, Jennifer L.; Kammen, Daniel M.
2004-01-01
This investigation examines the economics of producing electricity from proton-exchange membrane (PEM) fuel cell systems under various conditions, including the possibility of using fuel cell vehicles (FCVs) to produce power when they are parked at office buildings and residences. The analysis shows that the economics of both stationary fuel cell and FCV-based power vary significantly with variations in key input variables such as the price of natural gas, electricity prices, fuel cell and reformer system costs, and fuel cell system durability levels. The 'central case' results show that stationary PEM fuel cell systems can supply electricity for offices and homes in California at a net savings when fuel cell system costs reach about $6000 for a 5 kW home system ($1200/kW) and $175,000 for a 250 kW commercial system ($700/kW) and assuming somewhat favorable natural gas costs of $6/GJ at residences and $4/GJ at commercial buildings. Grid-connected FCVs in commercial settings can also potentially supply electricity at competitive rates, in some cases producing significant annual benefits. Particularly attractive is the combination of net metering along with time-of-use electricity rates that allow power to be supplied to the utility grid at the avoided cost of central power plant generation. FCV-based power at individual residences does not appear to be as attractive, at least where FCV power can only be used directly or banked with the utility for net metering and not sold in greater quantity, due to the low load levels at these locations that provide a poor match to automotive fuel cell operation, higher natural gas prices than are available at commercial settings, and other factors
Concentration field in traveling-wave and stationary convection in fluid mixtures
International Nuclear Information System (INIS)
Eaton, K.D.; Ohlsen, D.R.; Yamamoto, S.Y.; Surko, C.M.; Barten, W.; Luecke, M.; Kamps, M.; Kolodner, P.
1991-01-01
By comparison of measurements of shadowgraph images of convection in ethanol-water mixtures with the results of recent numerical calculations, we study the role of the concentration field in traveling-wave and stationary convection. The results confirm the existence of a large concentration contrast between adjacent traveling-wave convection rolls. This concentration modulation, which decreases as the Rayleigh number is increased and the transition to stationary convection is approached, is fundamental to the translation of the pattern