Sample records for atterberg limits

  1. Chloride concentration and pHs influence on the Atterberg limits of Søvind Marl

    DEFF Research Database (Denmark)

    Grønbech, Gitte; Nielsen, Benjaminn Nordahl; Ibsen, Lars Bo

    The Atterberg limits play a great role in the assessment and classification of soils. The pore water and it components have a great influence on the behavior of the clay. When finding the Atterberg limits, de-ionised water is used to homogenize the clay. De-ionised water badly resembles the pore...... water in the soil. It is therefor tested how using de-ionised water and a Saline solution resembling the pore water yields different results during laboratory testing. First the Atterberg limits are found using Saline solutions with a Chloride concentration between 0 % and 8 % and a constant p...... that for Søvind Marl, there is a correlation between the liquid limit found and the Chloride concentration and pH of the Saline solution used in laboratory testing, differences in the liquid limit of up to 30 % is observed....

  2. Statistical processing the results of interlaboratory testing the consistency of soil - the Atterberg limits (liquid, plasticity and shrinkage limit)


    Đurđevac-Ignjatović, Lidija; Ignjatović, Dragan; Jovanović, Ivana


    This paper presents the results of interlaboratory testing the soil consistency - the Atterberg limits (liquid, plasticity and shrinkage limit). The tests were performed on representative samples of soil. The results were analyzed in two ways: numerical method - the Cochran test of precision and graphical interpretation - calculation of z value in accordance with the Standard ISO 5725-2 [1]. The followings were calculated: variance of repeatability Sr2, interlaboratory variance SL 2 and repro...

  3. The Atterberg limits and their significance in the ceramic and brick industries

    Directory of Open Access Journals (Sweden)

    Sembenelli, P.


    Full Text Available Not availableLos límites de consistencia de Atterberg suministran los elementos para una rigurosa clasificación de las arcillas y para valorar muchas de sus propiedades. Pueden emplearse con utilidad para emprender un estudio riguroso, bien de los materiales destinados a la industria cerámica y de los ladrillos, o bien para proyectar las plantas de producción, integrando o sustituyendo algunos criterios todavía en uso.

  4. Current limiters

    Energy Technology Data Exchange (ETDEWEB)

    Loescher, D.H. [Sandia National Labs., Albuquerque, NM (United States). Systems Surety Assessment Dept.; Noren, K. [Univ. of Idaho, Moscow, ID (United States). Dept. of Electrical Engineering


    The current that flows between the electrical test equipment and the nuclear explosive must be limited to safe levels during electrical tests conducted on nuclear explosives at the DOE Pantex facility. The safest way to limit the current is to use batteries that can provide only acceptably low current into a short circuit; unfortunately this is not always possible. When it is not possible, current limiters, along with other design features, are used to limit the current. Three types of current limiters, the fuse blower, the resistor limiter, and the MOSFET-pass-transistor limiters, are used extensively in Pantex test equipment. Detailed failure mode and effects analyses were conducted on these limiters. Two other types of limiters were also analyzed. It was found that there is no best type of limiter that should be used in all applications. The fuse blower has advantages when many circuits must be monitored, a low insertion voltage drop is important, and size and weight must be kept low. However, this limiter has many failure modes that can lead to the loss of over current protection. The resistor limiter is simple and inexpensive, but is normally usable only on circuits for which the nominal current is less than a few tens of milliamperes. The MOSFET limiter can be used on high current circuits, but it has a number of single point failure modes that can lead to a loss of protective action. Because bad component placement or poor wire routing can defeat any limiter, placement and routing must be designed carefully and documented thoroughly.

  5. Limiting Skepticism

    DEFF Research Database (Denmark)

    Hendricks, Vincent Fella; Symons, John


    Skeptics argue that the acquisition of knowledge is impossible given the standing possibility of error. We present the limiting convergence strategy for responding to skepticism and discuss the relationship between conceivable error and an agent’s knowledge in the limit. We argue that the skeptic...

  6. Inverse Limits

    CERN Document Server

    Ingram, WT


    Inverse limits provide a powerful tool for constructing complicated spaces from simple ones. They also turn the study of a dynamical system consisting of a space and a self-map into a study of a (likely more complicated) space and a self-homeomorphism. In four chapters along with an appendix containing background material the authors develop the theory of inverse limits. The book begins with an introduction through inverse limits on [0,1] before moving to a general treatment of the subject. Special topics in continuum theory complete the book. Although it is not a book on dynamics, the influen

  7. Limits on $\

    CERN Document Server

    Perego, D L


    A limit on the tau neutrino mass is obtained using all the $Z^{0} \\to \\tau^{+} \\tau^{-}$ data collected at LEP by the DELPHI detector between 1992 and 1995. In this analysis events in which one of the taus decays into one charged particle, while the second $\\tau$ decays into f{}ive charged pions (1-5 topology) have been used. The neutrino mass is determined from a bidimensional \\fit ~on the invariant mass $m^{*}_{5 \\pi}$ and on the energy $E_{5 \\pi}$ of the f{}ive $\\pi^{\\pm}$ system. The result found is $m_{\

  8. Geotechnical properties of two siliceous cores from the central Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Khadge, N.H.

    Physical properties of the siliceous sediments from the Central Indian Basin are measured on two short cores. The properties such as water content, Atterberg limits, porosity specific gravity, wet density show the medium to high plastic sediment...

  9. Physical properties of a sediment core from the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Khadge, N.H.

    A box core of 7.5 m was collected from the Central Indian Basin for the purpose of geotechnical studies and depthwise variation of physical properties and clay mineralogy. Water content, Atterberg limits, specific gravity are measured at regular...

  10. Caractérisation physico-chimique et géotechnique de deux sites ...

    African Journals Online (AJOL)

    Atterberg aussi ont été déterminées et comparées à celle de matériaux utilisés pour réaliser les sols compactés. Le. Tableau 3 présente une récapitulation des spécifications concernant les limites d'Atterberg. Le Tableau 4 présente les résultats de.

  11. HOME Income Limits (United States)

    Department of Housing and Urban Development — HOME Income Limits are calculated using the same methodology that HUD uses for calculating the income limits for the Section 8 program. These limits are based on HUD...

  12. Adaptive limit margin detection and limit avoidance (United States)

    Yavrucuk, Ilkay

    This thesis concerns the development of methods, algorithms, and control laws for the development of an adaptive flight envelope protection system to be used for both manned and unmanned aircraft. The proposed method lifts the requirement for detailed a priori information of aircraft dynamics by enabling adaptation to system uncertainty. The system can be used for limits that can be either measured or related to selected measurable quantities. Specifically, an adaptive technique for predicting limit margins and calculating the corresponding allowable control or controller command margins of an aircraft is described in an effort to enable true carefree maneuvering. This new approach utilizes adaptive neural network based loops for the approximation of required aircraft dynamics. For limits that reach their maximum value in steady state, a constructed estimator model is used to predict the maneuvering quasi-steady response behavior---the so called dynamic trim---of the limit parameters and the corresponding control or command margins. Linearly Parameterized Neural Networks as well as Single Hidden Layer Neural Networks are used for on-line adaptation. The approach does not require any off-line training of the neural networks, instead all learning is achieved during flight. Lyapunov based weight update laws are derived. The method is extended for multi-channelled control limiting for aircraft subject to multiple limits, and for automatic control and command limiting for UAV's. Simulation evaluations of the method using a linear helicopter model and a nonlinear Generalized Tiltrotor Simulation (GTRSIM) model are presented. Limit avoidance methods are integrated and tested through the implementation of an artificial pilot model and an active-stick controller model for tactile cueing in the tiltrotor simulation, GTRSIM. Load factor, angle-of-attack, and torque limits are considered as examples. Similarly, the method is applied to the Georgia Tech's Yamaha R-Max (GTMax

  13. Limit of Blank, Limit of Detection and Limit of Quantitation (United States)

    Armbruster, David A; Pry, Terry


    Summary Limit of Blank (LoB), Limit of Detection (LoD), and Limit of Quantitation (LoQ) are terms used to describe the smallest concentration of a measurand that can be reliably measured by an analytical procedure.LoB is the highest apparent analyte concentration expected to be found when replicates of a blank sample containing no analyte are tested.LoB = meanblank + 1.645(SDblank)LoD is the lowest analyte concentration likely to be reliably distinguished from the LoB and at which detection is feasible. LoD is determined by utilising both the measured LoB and test replicates of a sample known to contain a low concentration of analyte.LoD = LoB + 1.645(SD low concentration sample)LoQ is the lowest concentration at which the analyte can not only be reliably detected but at which some predefined goals for bias and imprecision are met. The LoQ may be equivalent to the LoD or it could be at a much higher concentration. PMID:18852857

  14. VT Limited Access Highways (United States)

    Vermont Center for Geographic Information — A limited-access road, known by various terms worldwide, including limited-access highway, dual carriageway, expressway, and partial controlled access highway, is a...

  15. Robust test limits

    NARCIS (Netherlands)

    Albers, Willem/Wim; Kallenberg, W.C.M.; Otten, G.D.


    Because of inaccuracies of the measurement process inspection of manufactured parts requires test limits which are more strict than the given specification limits. Test limits derived under the assumption of normality for product characteristics turn out to violate the prescribed bound on the

  16. Limits to Inclusion (United States)

    Hansen, Janne Hedegaard


    In this article, I will argue that a theoretical identification of the limit to inclusion is needed in the conceptual identification of inclusion. On the one hand, inclusion is formulated as a vision that is, in principle, limitless. On the other hand, there seems to be an agreement that inclusion has a limit in the pedagogical practice. However,…

  17. Modeling Complex Time Limits

    Directory of Open Access Journals (Sweden)

    Oleg Svatos


    Full Text Available In this paper we analyze complexity of time limits we can find especially in regulated processes of public administration. First we review the most popular process modeling languages. There is defined an example scenario based on the current Czech legislature which is then captured in discussed process modeling languages. Analysis shows that the contemporary process modeling languages support capturing of the time limit only partially. This causes troubles to analysts and unnecessary complexity of the models. Upon unsatisfying results of the contemporary process modeling languages we analyze the complexity of the time limits in greater detail and outline lifecycles of a time limit using the multiple dynamic generalizations pattern. As an alternative to the popular process modeling languages there is presented PSD process modeling language, which supports the defined lifecycles of a time limit natively and therefore allows keeping the models simple and easy to understand.

  18. ACA Federal Upper Limits (United States)

    U.S. Department of Health & Human Services — Affordable Care Act Federal Upper Limits (FUL) based on the weighted average of the most recently reported monthly average manufacturer price (AMP) for...

  19. Limited Denial of Participation (United States)

    Department of Housing and Urban Development — A Limited Denial of Participation (LDP) is an action taken by a HUD Field Office or the Deputy Assistant Secretary for Single Family (DASSF) or Multifamily (DASMF)...

  20. Limited Income and Resources (United States)

    U.S. Department of Health & Human Services — Information for those with limited income and resources (those who may qualify for or already have the Low Income Subsidy to lower their prescription drug coverage...

  1. Limits on panspermia (United States)

    Bochkarev, N. G.


    Problems related to the origin of life and the role of migration of the dust component in the Galaxy and between galaxies in the spreading life are discussed. Limits on possible distances between points of action of panspermia are derived.

  2. Nuclear Test Limitations Issues

    National Research Council Canada - National Science Library

    Mahoney, Rob


    .... It also summarizes public views concerning test limitations and the nuclear stockpile. The second portion of the paper appraises issues that developed during consideration of the CTBT that involve 1...

  3. SIS - Annual Catch Limit (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Annual Catch Limit (ACL) dataset within the Species Information System (SIS) contains information and data related to management reference points and catch data.

  4. HOME Rent Limits (United States)

    Department of Housing and Urban Development — In accordance with 24 CFR Part 92.252, HUD provides maximum HOME rent limits. The maximum HOME rents are the lesser of: The fair market rent for existing housing for...

  5. HUD Program Income Limits (United States)

    Department of Housing and Urban Development — Income limits used to determine the income eligibility of applicants for assistance under three programs authorized by the National Housing Act. These programs are...

  6. Xenotransplantation: Perspectives and limits


    Hammer, Claus


    Xenotransplantation faces the dilemma of an unlimited supply of cells, tissues and organs on the one hand and severe obstacles and limits on the other. One reason for the limitations is that the source animal of choice, the pig, and the human recipient separated 90 million years ago during evolution, a time in which biological characteristics such as anatomy, physiology and immunology have had much time to drift far apart. The acceptance of such an evolutionary widely divergent organ, especia...

  7. Altruism and Reproductive Limitations

    Directory of Open Access Journals (Sweden)

    Carey J. Fitzgerald


    Full Text Available We examined how different types of reproductive limitations — functional (schizoid personality disorder and schizophrenia, physical (malnutrition, and sexual (bisexuality and homosexuality — influenced altruistic intentions toward hypothetical target individuals of differing degrees of relatedness (r = 0, .25, and .50. Participants were 312 undergraduate students who completed a questionnaire on altruism toward hypothetical friends, half-siblings, and siblings with these different types of reproductive limitations. Genetic relatedness and reproductive limitations did not influence altruistic decision-making when the cost of altruism was low but did as the cost of altruism increased, with participants being more likely to help a sibling over a half-sibling and a half-sibling over a friend. Participants also indicated they were more likely to help a healthy (control person over people with a reproductive limitation. Of the three types of reproductive limitations, functional limitations had the strongest effect on altruistic decision-making, indicating that people were less likely to help those who exhibit abnormal social behavior.

  8. Fundamental Limits of Cooperation

    CERN Document Server

    Lozano, Angel; Andrews, Jeffrey G


    Cooperation is viewed as a key ingredient for interference management in wireless systems. This paper shows that cooperation has fundamental limitations. The main result is that even full cooperation between transmitters cannot in general change an interference-limited network to a noise-limited network. The key idea is that there exists a spectral efficiency upper bound that is independent of the transmit power. First, a spectral efficiency upper bound is established for systems that rely on pilot-assisted channel estimation; in this framework, cooperation is shown to be possible only within clusters of limited size, which are subject to out-of-cluster interference whose power scales with that of the in-cluster signals. Second, an upper bound is also shown to exist when cooperation is through noncoherent communication; thus, the spectral efficiency limitation is not a by-product of the reliance on pilot-assisted channel estimation. Consequently, existing literature that routinely assumes the high-power spect...

  9. Information-limiting correlations (United States)

    Moreno-Bote, Rubén; Beck, Jeffrey; Kanitscheider, Ingmar; Pitkow, Xaq; Latham, Peter; Pouget, Alexandre


    Computational strategies used by the brain strongly depend on the amount of information that can be stored in population activity, which in turn strongly depends on the pattern of noise correlations. In vivo, noise correlations tend to be positive and proportional to the similarity in tuning properties. Such correlations are thought to limit information, which has led to the suggestion that decorrelation increases information. In contrast, we found, analytically and numerically, that decorrelation does not imply an increase in information. Instead, the only information-limiting correlations are what we refer to as differential correlations: correlations proportional to the product of the derivatives of the tuning curves. Unfortunately, differential correlations are likely to be very small and buried under correlations that do not limit information, making them particularly difficult to detect. We found, however, that the effect of differential correlations on information can be detected with relatively simple decoders. PMID:25195105

  10. Quantum-Limited Spectroscopy

    CERN Document Server

    Truong, Gar-Wing; May, Eric F; Stace, Thomas M; Luiten, Andre N


    Spectroscopy has an illustrious history delivering serendipitous discoveries and providing a stringent testbed for new physical predictions, including applications from trace materials detection, to understanding the atmospheres of stars and planets, and even constraining cosmological models. Reaching fundamental-noise limits permits optimal extraction of spectroscopic information from an absorption measurement. Here we demonstrate a quantum-limited spectrometer that delivers high-precision measurements of the absorption lineshape. These measurements yield a ten-fold improvement in the accuracy of the excited-state (6P$_{1/2}$) hyperfine splitting in Cs, and reveals a breakdown in the well-known Voigt spectral profile. We develop a theoretical model that accounts for this breakdown, explaining the observations to within the shot-noise limit. Our model enables us to infer the thermal velocity-dispersion of the Cs vapour with an uncertainty of 35ppm within an hour. This allows us to determine a value for Boltzm...

  11. Quantum-limit spectroscopy

    CERN Document Server

    Ficek, Zbigniew


    This book covers the main ideas, methods, and recent developments of quantum-limit optical spectroscopy and applications to quantum information, resolution spectroscopy, measurements beyond quantum limits, measurement of decoherence, and entanglement. Quantum-limit spectroscopy lies at the frontier of current experimental and theoretical techniques, and is one of the areas of atomic spectroscopy where the quantization of the field is essential to predict and interpret the existing experimental results. Currently, there is an increasing interest in quantum and precision spectroscopy both theoretically and experimentally, due to significant progress in trapping and cooling of single atoms and ions. This progress allows one to explore in the most intimate detail the ways in which light interacts with atoms and to measure spectral properties and quantum effects with high precision. Moreover, it allows one to perform subtle tests of quantum mechanics on the single atom and single photon scale which were hardly eve...

  12. Limits to Stability (United States)

    Cottey, Alan


    The author reflects briefly on what limited degree of global ecological stability and human cultural stability may be achieved, provided that humanity retains hope and does not give way to despair or hide in denial. These thoughts were triggered by a recent conference on International Stability and Systems Engineering. (Contains 5 notes.)

  13. Limitation of Auditors' Liability

    DEFF Research Database (Denmark)

    Werlauff, Erik; Foged-Ladefoged, Lise Kolding


    The article examines the question of whether rules on the limitation of auditors’ liability within the perspective of EU law are needed, and if so, which rules can provide an appropriate balance between the potential injured party’s interests and those of the auditing sector, including with respect...

  14. Smoothness of limit functors

    Indian Academy of Sciences (India)

    Annual Meetings · Mid Year Meetings · Discussion Meetings · Public Lectures · Lecture Workshops · Refresher Courses · Symposia · Live Streaming. Home; Journals; Proceedings – Mathematical Sciences; Volume 125; Issue 2. Smoothness of limit functors. Benedictus Margaux. Volume 125 Issue 2 May 2015 pp 161-165 ...

  15. Limited data speaker identification

    Indian Academy of Sciences (India)

    speaker verification task of 10 sec training and testing data followed in NIST speaker recogni- tion evaluations (NIST 2003). Existing .... UBM as model, all for speaker identification under limited training and testing data. The second contribution is the ..... In that condition we benefit more by combining only those integrated ...

  16. Beta limits for torsatrons (United States)

    Bauer, F.; Betancourt, O.; Garabedian, P.; Shohet, J. L.


    An ideal magnetohydrodynamic equilibrium and stability code is used to study ballooning modes in torsatrons. The most dangerous modes turn out to be those with low poloidal and toroidal wave numbers. Beta limits for equilibrium and stability are determined for an [unk] = 2 ultimate torsatron with large [unk] = 1 and [unk] = 3 sidebands. PMID:16592941

  17. Age Limit of Pediatrics. (United States)

    Hardin, Amy Peykoff; Hackell, Jesse M


    Pediatrics is a multifaceted specialty that encompasses children's physical, psychosocial, developmental, and mental health. Pediatric care may begin periconceptionally and continues through gestation, infancy, childhood, adolescence, and young adulthood. Although adolescence and young adulthood are recognizable phases of life, an upper age limit is not easily demarcated and varies depending on the individual patient. The establishment of arbitrary age limits on pediatric care by health care providers should be discouraged. The decision to continue care with a pediatrician or pediatric medical or surgical subspecialist should be made solely by the patient (and family, when appropriate) and the physician and must take into account the physical and psychosocial needs of the patient and the abilities of the pediatric provider to meet these needs. Copyright © 2017 by the American Academy of Pediatrics.

  18. Smoothness of limit functors

    Indian Academy of Sciences (India)

    Indian Acad. Sci. (Math. Sci.) Vol. 125, No. 2, May 2015, pp. 161–165. c Indian Academy of Sciences. Smoothness of limit functors. BENEDICTUS MARGAUX. Laboratoire de Recherche “Princess .... On the same vein, the coaction cλ : A[X] → A[X][t±1] is defined 'at a finite level', that is, there exists α1 ≥ α0 and a Aα1 ...

  19. Limits of Nuclear Stability

    CERN Document Server

    Nerlo-Pomorska, B; Kleban, M


    The modern version of the liquid-drop model (LSD) is compared with the macroscopic part of the binding energy evaluated within the Hartree-Fock- Bogoliubov procedure with the Gogny force and the relativistic mean field theory. The parameters of a liquid-drop like mass formula which approximate on the average the self-consistent results are compared with other models. The limits of nuclear stability predicted by these models are discussed.

  20. Limits of social mobilization. (United States)

    Rutherford, Alex; Cebrian, Manuel; Dsouza, Sohan; Moro, Esteban; Pentland, Alex; Rahwan, Iyad


    The Internet and social media have enabled the mobilization of large crowds to achieve time-critical feats, ranging from mapping crises in real time, to organizing mass rallies, to conducting search-and-rescue operations over large geographies. Despite significant success, selection bias may lead to inflated expectations of the efficacy of social mobilization for these tasks. What are the limits of social mobilization, and how reliable is it in operating at these limits? We build on recent results on the spatiotemporal structure of social and information networks to elucidate the constraints they pose on social mobilization. We use the DARPA Network Challenge as our working scenario, in which social media were used to locate 10 balloons across the United States. We conduct high-resolution simulations for referral-based crowdsourcing and obtain a statistical characterization of the population recruited, geography covered, and time to completion. Our results demonstrate that the outcome is plausible without the presence of mass media but lies at the limit of what time-critical social mobilization can achieve. Success relies critically on highly connected individuals willing to mobilize people in distant locations, overcoming the local trapping of diffusion in highly dense areas. However, even under these highly favorable conditions, the risk of unsuccessful search remains significant. These findings have implications for the design of better incentive schemes for social mobilization. They also call for caution in estimating the reliability of this capability.

  1. Marketing with limited budget


    Smirnova, Daria


    The purpose of this research-based thesis was to get an idea how managers of two small resembling hotels of a specific region deal with marketing process with a limited budget. In addition, the aim of the thesis was to examine if hotel managers who were interviewed perceive marketing only in the way of ‘promotion’ rather than marketing research, marketing mix and marketing environment theories. It was also found out if hotel managers of those hotels consider marketing as a key to successful h...

  2. Limitations of Expert Evidence


    Serpil Salaçin


    Limitations of Expert Evidence Edited by Stephen Leadbeatter MB ChB MCRPath ISBN 1 86016 029 8 Printed in Great Britain by Cathedral Print Services Ltd, Salisbury, 1996 Kitap 25 Ekim 1994 te The Royal College of Physicians ve The Royal College of Pathologists tarafından düzenlenen konferanstan sonra hekimlere ve avukatlara konuyu tartışmaya açmak için basılmış. Bilirkişi görüşünün temel filozofisinin, bu görevi yapanlar ve bu hizmeti alanların yapabileceklerin...

  3. Limitation of Auditors' Liability

    DEFF Research Database (Denmark)

    Werlauff, Erik; Foged-Ladefoged, Lise Kolding


    The article examines the question of whether rules on the limitation of auditors’ liability within the perspective of EU law are needed, and if so, which rules can provide an appropriate balance between the potential injured party’s interests and those of the auditing sector, including with respect...... to the fact that the insurance premiums associated with an unlimited liability must of course make the auditor’s tasks more expensive. Relevant EU recommendations and a comparative glance at other EU countries’ proposed solutions to the problem are included....

  4. Search with Limited Resources. (United States)


    D-R1-76 122 SERCH WITH ’LIMITED RESOURCES(U) DUKE UNIV DURHM NC i/i DEPTOF COMPUTER SCIENCE D C MUTCHLER FEB 83 CS11983-1 USI FE AFOSR-TR-83-i154...over all possible S" g ame trees. How to weight this average has not yet been specified. It is reasonable. glven the lack of additional information, to...complete binary 0-1 tree can be described by two parameters: P a number of goal nodes with value ŕ". and vt = number of goal nodes. This Justifies

  5. (Limiting the greenhouse effect)

    Energy Technology Data Exchange (ETDEWEB)

    Rayner, S.


    Traveler attended the Dahlem Research Conference organized by the Freien Universitat, Berlin. The subject of the conference was Limiting the Greenhouse Effect: Options for Controlling Atmospheric CO{sub 2} Accumulation. Like all Dahlem workshops, this was a meeting of scientific experts, although the disciplines represented were broader than usual, ranging across anthropology, economics, international relations, forestry, engineering, and atmospheric chemistry. Participation by scientists from developing countries was limited. The conference was divided into four multidisciplinary working groups. Traveler acted as moderator for Group 3 which examined the question What knowledge is required to tackle the principal social and institutional barriers to reducing CO{sub 2} emissions'' The working rapporteur was Jesse Ausubel of Rockefeller University. Other working groups examined the economic costs, benefits, and technical feasibility of options to reduce emissions per unit of energy service; the options for reducing energy use per unit of GNP; and the significant of linkage between strategies to reduce CO{sub 2} emissions and other goals. Draft reports of the working groups are appended. Overall, the conference identified a number of important research needs in all four areas. It may prove particularly important in bringing the social and institutional research needs relevant to climate change closer to the forefront of the scientific and policy communities than hitherto.

  6. Limits to biofuels (United States)

    Johansson, S.


    Biofuel production is dependent upon agriculture and forestry systems, and the expectations of future biofuel potential are high. A study of the global food production and biofuel production from edible crops implies that biofuel produced from edible parts of crops lead to a global deficit of food. This is rather well known, which is why there is a strong urge to develop biofuel systems that make use of residues or products from forest to eliminate competition with food production. However, biofuel from agro-residues still depend upon the crop production system, and there are many parameters to deal with in order to investigate the sustainability of biofuel production. There is a theoretical limit to how much biofuel can be achieved globally from agro-residues and this amounts to approximately one third of todays' use of fossil fuels in the transport sector. In reality this theoretical potential may be eliminated by the energy use in the biomass-conversion technologies and production systems, depending on what type of assessment method is used. By surveying existing studies on biofuel conversion the theoretical limit of biofuels from 2010 years' agricultural production was found to be either non-existent due to energy consumption in the conversion process, or up to 2-6000TWh (biogas from residues and waste and ethanol from woody biomass) in the more optimistic cases.

  7. Limits to biofuels

    Directory of Open Access Journals (Sweden)

    Johansson S.


    Full Text Available Biofuel production is dependent upon agriculture and forestry systems, and the expectations of future biofuel potential are high. A study of the global food production and biofuel production from edible crops implies that biofuel produced from edible parts of crops lead to a global deficit of food. This is rather well known, which is why there is a strong urge to develop biofuel systems that make use of residues or products from forest to eliminate competition with food production. However, biofuel from agro-residues still depend upon the crop production system, and there are many parameters to deal with in order to investigate the sustainability of biofuel production. There is a theoretical limit to how much biofuel can be achieved globally from agro-residues and this amounts to approximately one third of todays’ use of fossil fuels in the transport sector. In reality this theoretical potential may be eliminated by the energy use in the biomass-conversion technologies and production systems, depending on what type of assessment method is used. By surveying existing studies on biofuel conversion the theoretical limit of biofuels from 2010 years’ agricultural production was found to be either non-existent due to energy consumption in the conversion process, or up to 2–6000TWh (biogas from residues and waste and ethanol from woody biomass in the more optimistic cases.

  8. Limits of Lubrication in

    DEFF Research Database (Denmark)

    Olsson, David Dam

    using plain mineral oil is possible without any lubricant breakdown. In deep drawing, 2mm stainless steel blanks can be drawn to drawing ratio of DR=2.0 over a die entry radius of rd=3mm again using a plain mineral oil containing no additives. In stretch forming, friction is reduced considerably...... of temperature and contact pressure. The numerical models have been calibrated regarding friction and thermal contact resistance based on experimental results from actual testing conditions. It has been found that predictions of limits of lubrication are possible by numerical means and that the FE...... based on analysis of the appearing backstroke force, which is very sensitive to tribological changes in the punch/workpiece interface, hence to lubricant breakdown. Fundamental studies of pick-up development in punching and blanking show that cold-welding of workpiece particles initially start...

  9. Personal Freedom beyond Limits

    Directory of Open Access Journals (Sweden)

    Juan Fernando Sellés


    Full Text Available In this work we distinguish between freedom in the human manifestations (intelligence, will,actions and personal freedom in the personal intimacy. This second is beyond the freedom reached bythe classic and modern thought, since it takes root in the personnel act of being. Because of it, it is not possible to characterize this freedom like the classic description as ‘domain over the own acts’, becauseit is a description of ‘categorial’ order; neither like present day ‘autonomy’ or ‘independence’, becausethe existence of one person alone is impossible, since ‘person’ means relation, personal free openingto other persons, description of the ‘transcendental’ order and, therefore, to the margin of limits.

  10. Photomask Limitations And Directions (United States)

    Skinner, John G.


    In the vast world of integrated circuits mask making is often taken for granted. This was particularly true a decade ago when the availability of a commercial a-beam machine, MEBES, considerably improved the accuracy of photomasks and simplified the manufacturing process. At present we have the capability to meet today's needs [~ 0.9 micron design rules] but we do not have the capabilities for the next reduction in design rules [~ 0.5 micron in ~1990/1]. Pattern generators, resist, measuring equipment, and defect detection are all suspect as we push photomask tolerances into the sub-micron region. This talk will review some of the limitations in today's photomask fabrication and some of the opportunuities that lie ahead.

  11. Universal Limit on Communication (United States)

    Bousso, Raphael


    I derive a universal upper bound on the capacity of any communication channel between two distant systems. The Holevo quantity, and hence the mutual information, is at most of order E Δ t /ℏ, where E is the average energy of the signal, and Δ t is the amount of time for which detectors operate. The bound does not depend on the size or mass of the emitting and receiving systems, nor on the nature of the signal. No restrictions on preparing and processing the signal are imposed. As an example, I consider the encoding of information in the transverse or angular position of a signal emitted and received by systems of arbitrarily large cross section. In the limit of a large message space, quantum effects become important even if individual signals are classical, and the bound is upheld.

  12. geotechnical examination of the geophysical

    African Journals Online (AJOL)


    Nov 3, 2012 ... Tests were carried out on the sample soil which includes the Atterberg limit tests, particle size distribution analysis ... The liquid limit, plastic limit and plasticity index were found to fall into A-2-7 soil of AASTO classification and SP ... Terzaghi based on this distinction defined soil as natu- ral aggregate of ...

  13. Geo-engineering Characteristics and Behaviour of Coal-reject ...

    African Journals Online (AJOL)

    The influence of raw-meal on the geotechnical properties of Nigerian coal-reject was studied and the behavior of the improved material evaluated based on Atterberg limits, linear shrinkage, compaction, California bearing ratio and strength tests. The results of the tests indicate that the liquid limit, plastic limit and plasticity ...

  14. Limitations of Expert Evidence

    Directory of Open Access Journals (Sweden)

    Serpil Salaçin


    Full Text Available Limitations of Expert Evidence Edited by Stephen Leadbeatter MB ChB MCRPath ISBN 1 86016 029 8 Printed in Great Britain by Cathedral Print Services Ltd, Salisbury, 1996 Kitap 25 Ekim 1994 te The Royal College of Physicians ve The Royal College of Pathologists tarafından düzenlenen konferanstan sonra hekimlere ve avukatlara konuyu tartışmaya açmak için basılmış. Bilirkişi görüşünün temel filozofisinin, bu görevi yapanlar ve bu hizmeti alanların yapabileceklerinin sınırlarının tartışılması amaçlanmış.Seksen altı sayfadan oluşan kitabın fiatı on iki İngiliz Sterlini. Kitap üç bölüm ve bunların altında toplanan on ana başlıktan oluşmakta. Elinize aldığınızda küçük boyutu ve anlaşılır dili ile hemen okunup bitirelecek kitaplardan sanılıyor. En azından ben böyle düşünmüştüm. Ancak daha L A Tuınberg ve A J Bellinham’ın ön yazısında ben çarpıldım. Değerli yazarların kaleme aldığı başlıklar ve gündeme getirdiği tartışmaların tüm Adli Bilimlerle uğraşanların dikkatle okuması gereken cinsten olduğu kanısındayım. Birinci bölüm The Legal Perspective iki anabaşlıktan oluşuyor, The Criminal legal perspective Honour Judje Martin Stephens tarafından yazılmış,bilirkişi olarak görev yapabilmek için belgelenmiş bir eğitim olması gerektiği, mahkemelerde ya da yazılı raporlarda verilebilecek görüşlerin incelikleri tartışılmış. Bu bölümün ikinci anabaşlığı The civil legal perspective avukat Jennifer Cummin tarafından yazılmış. Toplum gözünde bilirkişinin anlamı ve mahkemenin bilirkişi görüşünü değişmez bilimsel doğru gibi algılayarak düştüğü bilimsel yanılgı ve raporlardaki kavram farkı dile getirilmiş. İkinci Bölüm The Medical And Scientific Perspective başlığı altında Roger C Evans MD Clinical evidence başlığında toplumun hasta tedavisi ve bilirkişilik hizmetinden beklentilerinin unrealistik olduğu ve

  15. Charter Halibut Limited Access Program (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This limited access system limits the number of charter vessels that may participate in the guided sport fishery for halibut in area 2C and 3A. NMFS issues a charter...

  16. Guidelines for setting speed limits

    CSIR Research Space (South Africa)

    Wium, DJW


    Full Text Available A method is described for setting the speed limit for a particular road section. Several speed limits based on different criteria are described for each of nine traffic and road factors. The most appropriate speed limit for each relevant factor...

  17. Interference and memory capacity limitations. (United States)

    Endress, Ansgar D; Szabó, Szilárd


    Working memory (WM) is thought to have a fixed and limited capacity. However, the origins of these capacity limitations are debated, and generally attributed to active, attentional processes. Here, we show that the existence of interference among items in memory mathematically guarantees fixed and limited capacity limits under very general conditions, irrespective of any processing assumptions. Assuming that interference (a) increases with the number of interfering items and (b) brings memory performance to chance levels for large numbers of interfering items, capacity limits are a simple function of the relative influence of memorization and interference. In contrast, we show that time-based memory limitations do not lead to fixed memory capacity limitations that are independent of the timing properties of an experiment. We show that interference can mimic both slot-like and continuous resource-like memory limitations, suggesting that these types of memory performance might not be as different as commonly believed. We speculate that slot-like WM limitations might arise from crowding-like phenomena in memory when participants have to retrieve items. Further, based on earlier research on parallel attention and enumeration, we suggest that crowding-like phenomena might be a common reason for the 3 major cognitive capacity limitations. As suggested by Miller (1956) and Cowan (2001), these capacity limitations might arise because of a common reason, even though they likely rely on distinct processes. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  18. Material limitations on the detection limit in refractometry. (United States)

    Skafte-Pedersen, Peder; Nunes, Pedro S; Xiao, Sanshui; Mortensen, Niels Asger


    We discuss the detection limit for refractometric sensors relying on high-Q optical cavities and show that the ultimate classical detection limit is given by min {Δn} ≳ η, with n + iη being the complex refractive index of the material under refractometric investigation. Taking finite Q factors and filling fractions into account, the detection limit declines. As an example we discuss the fundamental limits of silicon-based high-Q resonators, such as photonic crystal resonators, for sensing in a bio-liquid environment, such as a water buffer. In the transparency window (λ ≳ 1100 nm) of silicon the detection limit becomes almost independent on the filling fraction, while in the visible, the detection limit depends strongly on the filling fraction because the silicon absorbs strongly.

  19. Material Limitations on the Detection Limit in Refractometry

    Directory of Open Access Journals (Sweden)

    Niels Asger Mortensen


    Full Text Available We discuss the detection limit for refractometric sensors relying on high-Q optical cavities and show that the ultimate classical detection limit is given by min {Δn} ≳ η with n + iη being the complex refractive index of the material under refractometric investigation. Taking finite Q factors and filling fractions into account, the detection limit declines. As an example we discuss the fundamental limits of silicon-based high-Q resonators, such as photonic crystal resonators, for sensing in a bio-liquid environment, such as a water buffer. In the transparency window (λ ≳ 1100 nm of silicon the detection limit becomes almost independent on the filling fraction, while in the visible, the detection limit depends strongly on the filling fraction because the silicon absorbs strongly.

  20. Thermodynamic limit for coherence-limited solar power conversion (United States)

    Mashaal, Heylal; Gordon, Jeffrey M.


    The spatial coherence of solar beam radiation is a key constraint in solar rectenna conversion. Here, we present a derivation of the thermodynamic limit for coherence-limited solar power conversion - an expansion of Landsberg's elegant basic bound, originally limited to incoherent converters at maximum flux concentration. First, we generalize Landsberg's work to arbitrary concentration and angular confinement. Then we derive how the values are further lowered for coherence-limited converters. The results do not depend on a particular conversion strategy. As such, they pertain to systems that span geometric to physical optics, as well as classical to quantum physics. Our findings indicate promising potential for solar rectenna conversion.

  1. Material limitations on the detection limit in refractometry

    DEFF Research Database (Denmark)

    Skafte-Pedersen, Peder; Nunes, Pedro; Xiao, Sanshui


    and filling fractions into account, the detection limit declines. As an example we discuss the fundamental limits of silicon-based high-Q resonators, such as photonic crystal resonators, for sensing in a bio-liquid environment, such as a water buffer. In the transparency window (λ ≳ 1100 nm) of silicon...

  2. Limit cycles in quantum systems

    Energy Technology Data Exchange (ETDEWEB)

    Niemann, Patrick


    In this thesis we investigate Limit Cycles in Quantum Systems. Limit cycles are a renormalization group (RG) topology. When degrees of freedom are integrated out, the coupling constants flow periodically in a closed curve. The presence of limit cycles is restricted by the necessary condition of discrete scale invariance. A signature of discrete scale invariance and limit cycles is log-periodic behavior. The first part of this thesis is concerned with the study of limit cycles with the similarity renormalization group (SRG). Limit cycles are mainly investigated within conventional renormalization group frameworks, where degrees of freedom, which are larger than a given cutoff, are integrated out. In contrast, in the SRG potentials are unitarily transformed and thereby obtain a band-diagonal structure. The width of the band structure can be regarded as an effective cutoff. We investigate the appearance of limit cycles in the SRG evolution. Our aim is to extract signatures as well as the scaling factor of the limit cycle. We consider the 1/R{sup 2}-potential in a two-body system and a three-body system with large scattering lengths. Both systems display a limit cycle. Besides the frequently used kinetic energy generator we apply the exponential and the inverse generator. In the second part of this thesis, Limit Cycles at Finite Density, we examine the pole structure of the scattering amplitude for distinguishable fermions at zero temperature in the medium. Unequal masses and a filled Fermi sphere for each fermion species are considered. We focus on negative scattering lengths and the unitary limit. The properties of the three-body spectrum in the medium and implications for the phase structure of ultracold Fermi gases are discussed.

  3. New Limit on CPT Violation

    Energy Technology Data Exchange (ETDEWEB)

    Geer, S.; Marriner, J.; Martens, M.; Ray, R. E.; Streets, J.; Wester, W.; Hu, M.; Snow, G. R.; Armstrong, T.; Buchanan, C. (and others)


    A search for antiproton decay has been made at the Fermilab Antiproton Accumulator. Limits are placed on fifteen antiproton decay modes. The results are used to place limits on the characteristic mass scale m{sub X} that could be associated with CPT violation accompanied by baryon number violation. (c) 2000 The American Physical Society.

  4. Regularity of conservative inductive limits

    Directory of Open Access Journals (Sweden)

    Jan Kucera


    Full Text Available A sequentially complete inductive limit of Fréchet spaces is regular, see [3]. With a minor modification, this property can be extended to inductive limits of arbitrary locally convex spaces under an additional assumption of conservativeness.

  5. Space-charge limited photocurrent

    NARCIS (Netherlands)

    Mihailetchi, VD; Wildeman, J; Blom, PWM


    In 1971 Goodman and Rose predicted the occurrence of a fundamental electrostatic limit for the photocurrent in semiconductors at high light intensities. Blends of conjugated polymers and fullerenes are an ideal model system to observe this space-charge limit experimentally, since they combine an

  6. Tachyons in the Galilean limit


    Batlle, Carles; Gomis, Joaquim; Mezincescu, Luca; Townsend, Paul


    The Souriau massless Galilean particle of “colour” k and spin s is shown to be the Galilean limit of the Souriau tachyon of mass m = ik and spin s . We compare and contrast this result with the Galilean limit of the Nambu-Goto string and Green-Schwarz superstring.

  7. Tachyons in the Galilean limit


    Batlle Arnau, Carles; Gomis Torné, Joaquin; Mezincescu, Luca; Townsend, Paul K.


    The Souriau massless Galilean particle of "colour" $k$ and spin $s$ is shown to be the Galilean limit of the Souriau tachyon of mass $m = ik$ and spin $s$. We compare and contrast this result with the recent Galilean limit of the Nambu-Goto string and the Green-Schwarz superstring.

  8. Interpreting Recruitment Limitation in Forests (United States)

    J.S. Clark; B. Beckage; P. Camill; B. Cleveland; J. HilleRisLambers; J. Lichter; J. McLachlan; J. Mohan; P. Wyckoff


    Studies of tree recruitment are many, but they provide few general insights into the role of recruitment limitation for population dynamics. That role depends on the vital rates (transitions) from seed production to sapling stages and on overall population growth. To determine the state of our understanding of recruitment limitation we examined how well we can estimate...

  9. Solubility limits on radionuclide dissolution

    Energy Technology Data Exchange (ETDEWEB)

    Kerrisk, J.F.


    This paper examines the effects of solubility in limiting dissolution rates of a number of important radionuclides from spent fuel and high-level waste. Two simple dissolution models were used for calculations that would be characteristics of a Yucca Mountain repository. A saturation-limited dissolution model, in which the water flowing through the repository is assumed to be saturated with each waste element, is very conservative in that it overestimates dissolution rates. A diffusion-limited dissolution model, in which element-dissolution rates are limited by diffusion of waste elements into water flowing past the waste, is more realistic, but it is subject to some uncertainty at this time. Dissolution rates of some elements (Pu, Am, Sn, Th, Zr, Sm) are always limited by solubility. Dissolution rates of other elements (Cs, Tc, Np, Sr, C, I) are never solubility limited; their release would be limited by dissolution of the bulk waste form. Still other elements (U, Cm, Ni, Ra) show solubility-limited dissolution under some conditions. 9 references, 3 tables.

  10. A response to: Limitations within "The Limits to Tree Height". (United States)

    Koch, George W; Sillett, Stephen C


    Here we respond to the communication in American Journal of Botany (96: 542-544 in this issue) by Netting, who proposes several ways in which our paper "The Limits to Tree Height" (Nature 428: 851-854) may have erred in estimating the biophysical limits to height growth in Sequoia sempervirens. We first explain that because embolism repair requires long time periods and is generally incomplete, xylem vulnerability characteristics offer a sound basis for estimating performance limits in woody plants. We reaffirm our earlier use of vertical gradients of foliar carbon isotope composition with new data for S. sempervirens. We support these arguments with reference to studies in other tree species. We take exception with Netting's view that the turgor pressure-cell expansion relationship for Zea mays is applicable to S. sempervirens. Finally, we second Netting's call for more work on carbon allocation vis a vis height growth limits.

  11. The Limits of Exercise Physiology

    DEFF Research Database (Denmark)

    Gabriel, Brendan M; Zierath, Juleen R


    Many of the established positive health benefits of exercise have been documented by historical discoveries in the field of exercise physiology. These investigations often assess limits: the limits of performance, or the limits of exercise-induced health benefits. Indeed, several key findings have...... been informed by studying highly trained athletes, in addition to healthy or unhealthy people. Recent progress has been made in regard to skeletal muscle metabolism and personalized exercise regimes. In this perspective, we review some of the historical milestones of exercise physiology, discuss how...... these inform contemporary knowledge, and speculate on future questions....

  12. The limits of cosmic shear (United States)

    Kitching, Thomas D.; Alsing, Justin; Heavens, Alan F.; Jimenez, Raul; McEwen, Jason D.; Verde, Licia


    In this paper, we discuss the commonly used limiting cases, or approximations, for two-point cosmic-shear statistics. We discuss the most prominent assumptions in this statistic: the flat-sky (small angle limit), the Limber (Bessel-to-delta function limit) and the Hankel transform (large ℓ-mode limit) approximations; that the vast majority of cosmic-shear results to date have used simultaneously. We find that the combined effect of these approximations can suppress power by ≳ 1 per cent on scales of ℓ ≲ 40. A fully non-approximated cosmic-shear study should use a spherical-sky, non-Limber-approximated power spectrum analysis and a transform involving Wigner small-d matrices in place of the Hankel transform. These effects, unaccounted for, would constitute at least 11 per cent of the total budget for systematic effects for a power spectrum analysis of a Euclid-like experiment; but they are unnecessary.

  13. Multifamily Tax Subsidy Income Limits (United States)

    Department of Housing and Urban Development — Multifamily Tax Subsidy Projects (MTSP) Income Limits were developed to meet the requirements established by the Housing and Economic Recovery Act of 2008 (Public...

  14. Brassicas limited in weed control


    Kristiansen, P


    This article discusses the limitations of using brassica cover crops for weed control. A brief overview of the role of cover crops is provided, followed by a short review of research looking at brassica cover crops.

  15. stabilization of ikpayongo laterite with cement and calcium carbide ...

    African Journals Online (AJOL)


    Laterite obtained from Ikpayongo was stabilized with 2-10 % cement and 2-10 % Calcium Carbide waste, for use as pavement material. Atterberg's limits test, California bearing ratio (CBR) and unconfined compressive strength (UCS) tests were conducted on the natural laterite and the treated soil specimens. The plasticity ...

  16. characterization of geotechnical properties of lateritic soil-bentonite

    African Journals Online (AJOL)


    Mar 1, 2013 ... Abstract. The purpose of this study was to characterize lateritic soil bentonite mixtures intended for use as low-permeability barrier in municipal waste disposal landfill. Characterization of the soil mix- tures included measurement of Atterberg limits, compaction properties, hydraulic conductivity,.

  17. Geotechnical studies of Jaitapur marine clay

    Digital Repository Service at National Institute of Oceanography (India)

    Bhat, S.T.; Nayak, B.U.

    characterisEd. by high water content and high Atterberg limits. Undrained shear strength varied from 1.8 to 6 KPa. These were moderately sensitive clays. Carbonate content which varied from 3 to 27%, was found to influence engineering properties of the soil...

  18. Effect of lime pre-treatment mellowing duration on some ...

    African Journals Online (AJOL)

    The effect of lime pre-treatment duration on some geotechnical properties of shale treated with cement for use as flexible pavement material was studied. Atterberg's limits, compaction, California bearing ratio (CBR) and unconfined compressive strength (UCS) tests were conducted on the natural shale and shale pre-treated ...

  19. Stabilization of Ikpayongo laterite with cement and calcium carbide ...

    African Journals Online (AJOL)

    Laterite obtained from Ikpayongo was stabilized with 2-10 % cement and 2-10 % Calcium Carbide waste, for use as pavement material. Atterberg's limits test, California bearing ratio (CBR) and unconfined compressive strength (UCS) tests were conducted on the natural laterite and the treated soil specimens. The plasticity ...

  20. Modification of strength properties of lime-stabilized laterites with ...

    African Journals Online (AJOL)

    The potential of sawdust ash as a stabilizer for lateritic soils was investigated to determine the modifying effects on strength properties required for road construction. Three laterite samples, A, B and C were collected respect- ively from Akoda, Osogbo and Ile-Ife (Nigeria). Atterberg limits and strength tests were performed on ...

  1. Spatial variability of expansive soil properties at different scales ...

    African Journals Online (AJOL)

    This paper applies statistical and geostatistical procedures to analyse the spatial distribution of several soil properties and use the contribution of ge ostatistics to plan optimal soil sampling and management schemes in. Kibaha, Tanzania. Particle-size distribution, Atterberg limits and potential swell were analysed.

  2. The beneficial usage of water treatment sludge as pottery product ...

    African Journals Online (AJOL)

    Mineralogical compositions were determined using XRD, XRF for chemical composition and physical testing including Atterberg limit test and particles size distribution. Identification of beneficial usage is based on the characteristics of water treatment sludge. Keywords: chemical composition; mineral composition; physical ...

  3. Major Limitations of Satellite images


    Al-Wassai, Firouz A.; Kalyankar, N. V.


    Remote sensing has proven to be a powerful tool for the monitoring of the Earth surface to improve our perception of our surroundings has led to unprecedented developments in sensor and information technologies. However, technologies for effective use of the data and for extracting useful information from the data of Remote sensing are still very limited since no single sensor combines the optimal spectral, spatial and temporal resolution. This paper briefly reviews the limitations of satelli...

  4. Preliminary disposal limits, plume interaction factors, and final disposal limits

    Energy Technology Data Exchange (ETDEWEB)

    Flach, G. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)


    In the 2008 E-Area Performance Assessment (PA), each final disposal limit was constructed as the product of a preliminary disposal limit and a plume interaction factor. The following mathematical development demonstrates that performance objectives are generally expected to be satisfied with high confidence under practical PA scenarios using this method. However, radionuclides that experience significant decay between a disposal unit and the 100-meter boundary, such as H-3 and Sr-90, can challenge performance objectives, depending on the disposed-of waste composition, facility geometry, and the significance of the plume interaction factor. Pros and cons of analyzing single disposal units or multiple disposal units as a group in the preliminary disposal limits analysis are also identified.

  5. Generalized Geometric Quantum Speed Limits

    Directory of Open Access Journals (Sweden)

    Diego Paiva Pires


    Full Text Available The attempt to gain a theoretical understanding of the concept of time in quantum mechanics has triggered significant progress towards the search for faster and more efficient quantum technologies. One of such advances consists in the interpretation of the time-energy uncertainty relations as lower bounds for the minimal evolution time between two distinguishable states of a quantum system, also known as quantum speed limits. We investigate how the nonuniqueness of a bona fide measure of distinguishability defined on the quantum-state space affects the quantum speed limits and can be exploited in order to derive improved bounds. Specifically, we establish an infinite family of quantum speed limits valid for unitary and nonunitary evolutions, based on an elegant information geometric formalism. Our work unifies and generalizes existing results on quantum speed limits and provides instances of novel bounds that are tighter than any established one based on the conventional quantum Fisher information. We illustrate our findings with relevant examples, demonstrating the importance of choosing different information metrics for open system dynamics, as well as clarifying the roles of classical populations versus quantum coherences, in the determination and saturation of the speed limits. Our results can find applications in the optimization and control of quantum technologies such as quantum computation and metrology, and might provide new insights in fundamental investigations of quantum thermodynamics.

  6. Derived limits for surface contamination

    CERN Document Server

    Wrixon, A D; Linsley, G S; White, D F


    Derived limits (DLs) for surface contamination were first established for use in the nuclear energy industry where a wide variety of radionuclides is encountered. They were later used in factories, hospitals, and universities, where the radionuclides used are normally fewer in number, either known or readily identifiable, and often of low toxicity. In these situations the current limits are frequently over-restrictive. This report describes a reassessment of the values in the light of more recent information on the possible pathways of exposure and the dose equivalent limits given in ICRP Publication 26. The reassessment is prompted also by the introduction of SI units. The results of the reassessment are used to produce a classification of DLs for all radionuclides for active and inactive area surfaces and for skin.

  7. Bayesian versus frequentist upper limits

    CERN Document Server

    Rover, Christian; Prix, Reinhard


    While gravitational waves have not yet been measured directly, data analysis from detection experiments commonly includes an upper limit statement. Such upper limits may be derived via a frequentist or Bayesian approach; the theoretical implications are very different, and on the technical side, one notable difference is that one case requires maximization of the likelihood function over parameter space, while the other requires integration. Using a simple example (detection of a sinusoidal signal in white Gaussian noise), we investigate the differences in performance and interpretation, and the effect of the "trials factor", or "look-elsewhere effect".

  8. Flux limiters and Eddington factors

    Energy Technology Data Exchange (ETDEWEB)

    Pomraning, G.C.


    In this paper a closure scheme for the first two angular moments of the time-dependent equation of transfer is presented, either via an Eddington factor which leads to a telegrapher's description, or via a Fick's law which leads to a diffusion description. Points discussed include boundary conditions (both an extension of the classic Marshak-Milne condition and those arising from a boundary layer analysis), the flux limiting feature of the diffusion approximation, and the reduction of the theory to asymptotic diffusion theory in the steady state limit.

  9. The Limits of Collaborative Evaluation. (United States)

    Lewkowicz, Jo A.; Nunan, David


    Describes the development of a collaborative evaluation model and its application to a curricular innovation project within a secondary school system in Hong Kong. Focuses on the limits of collaboration in long-term evaluation projects with multiple stakeholders. (Author/VWL)

  10. Energy Conservative Limit Cycle Oscillations

    NARCIS (Netherlands)

    Stramigioli, Stefano; van Dijk, Michel

    This paper shows how globally attractive limit cycle oscillations can be induced in a system with a nonlinear feedback element. Based on the same principle as the Van der Pol oscillator, the feedback behaves as a negative damping for low velocities but as an ordinary damper for high velocities. This

  11. Limitations of existing web services

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Limitations of existing web services. Uploading or downloading large data. Serving too many user from single source. Difficult to provide computer intensive job. Depend on internet and its bandwidth. Security of data in transition. Maintain confidentiality of data ...

  12. Landscape genetics and limiting factors (United States)

    Samuel A. Cushman; Andrew J. Shirk; Erin L. Landguth


    Population connectivity is mediated by the movement of organisms or propagules through landscapes. However, little is known about how variation in the pattern of landscape mosaics affects the detectability of landscape genetic relationships. The goal of this paper is to explore the impacts of limiting factors on landscape genetic processes using simulation...

  13. 77 FR 76841 - Lending Limits (United States)


    ... surplus if the loan is fully secured. Section 5(u)(1) of the Home Owners' Loan Act (HOLA), 12 U.S.C. 1464...) of HOLA, 12 U.S.C. 1464(u)(2), includes exceptions to the lending limits for certain loans made by savings associations. These HOLA provisions apply to both Federal and state-chartered savings associations...

  14. 78 FR 37930 - Lending Limits (United States)


    ...' Loan Act (HOLA), 12 U.S.C. 1464(u)(1), provides that section 5200 of the Revised Statutes ``shall apply....'' In addition, section 5(u)(2) of HOLA, 12 U.S.C. 1464(u)(2), includes exceptions to the lending limits for certain loans made by savings associations. These HOLA provisions apply to both Federal and state...

  15. 77 FR 37265 - Lending Limits (United States)


    ...)(1) of the Home Owners' Loan Act (HOLA), 12 U.S.C. 1464(u)(1), provides that section 5200 of the... applies to ] national banks.'' In addition, section 5(u)(2) of HOLA, 12 U.S.C. 1464(u)(2), includes exceptions to the lending limits for certain loans made by savings associations. These HOLA provisions apply...

  16. Limited-Access Heart Surgery (United States)

    ... perform videoscopic surgery with even greater precision. In robotic-assisted surgery, surgeons make several small incisions in the chest ... As with other kinds of limited-access surgery, robotic-assisted surgery can mean shorter hospital stays and recovery times ...


    Directory of Open Access Journals (Sweden)

    Karel KUDRNA


    Full Text Available Evaluation of the state of CO2 accumulation in the atmosphere demands knowledge on possibilities of the biosphere – its photosynthetizing apparatus, conditions and limits of absorption. A decisive precondition is to determine relation of CO2 accumulation by photosynthesis in dependence on the water balance, especially on its control quantity – transpiration, which is stabilized by supporting of underground waters.

  18. Historical Drawbacks of Limited Liability

    Directory of Open Access Journals (Sweden)

    Denis Boyle


    Full Text Available Limited liability is a human invention which has facilitated enormous economic growth around the world, particularly since the time of its general application in advanced countries during the nineteenth century. The individual legal identity of companies, coupled with the limited liability of their owners, has provided protection for investors from the risks associated with their investments. It has thus contributed to increase the sources of capital available to finance projects which might otherwise have been considered unviable. However, the legal protection offered to investors has negative consequences for other participants in economies. Speculation in stock markets often damages society. It is very important to study the drawbacks of limited liability and to suggest modifications to achieve a more stable, less volatile, economic growth in the world. Although this article goes to some lengths to recognise the work of authors who emphasise the positive historical economic contribution of limited lability, its main objective is to provoke a reflection around texts which point out the drawbacks and propose solutions.

  19. Accurate test limits under prescribed consumer risk

    NARCIS (Netherlands)

    Albers, Willem/Wim; Arts, G.R.J.; Kallenberg, W.C.M.


    Measurement errors occurring during inspection of manufactured parts force producers to replace specification limits by slightly more strict test limits. Here accurate test limits are presented which maximize the yield while limiting the fraction of defectives reaching the consumer.

  20. Limit of crustal drilling depth

    Directory of Open Access Journals (Sweden)

    Y.S. Zhao


    Full Text Available Deep drilling is becoming the direct and the most efficient means in exploiting deep mineral resources, facilitating to understanding the earthquake mechanism and performing other scientific researches on the Earth's crust. In order to understand the limit of drilling depth in the Earth's crust, we first conducted tests on granite samples with respect to the borehole deformation and stability under high temperature and high pressure using the triaxial servo-controlled rock testing system. Then the critical temperature-pressure coupling conditions that result in borehole instability are derived. Finally, based on the testing results obtained and the requirements for the threshold values of borehole deformations during deep drilling, the limit of drilling depth in the Earth's crust is formulated with ground temperature.

  1. Classical Limit and Quantum Logic (United States)

    Losada, Marcelo; Fortin, Sebastian; Holik, Federico


    The analysis of the classical limit of quantum mechanics usually focuses on the state of the system. The general idea is to explain the disappearance of the interference terms of quantum states appealing to the decoherence process induced by the environment. However, in these approaches it is not explained how the structure of quantum properties becomes classical. In this paper, we consider the classical limit from a different perspective. We consider the set of properties of a quantum system and we study the quantum-to-classical transition of its logical structure. The aim is to open the door to a new study based on dynamical logics, that is, logics that change over time. In particular, we appeal to the notion of hybrid logics to describe semiclassical systems. Moreover, we consider systems with many characteristic decoherence times, whose sublattices of properties become distributive at different times.

  2. Classical Limit and Quantum Logic (United States)

    Losada, Marcelo; Fortin, Sebastian; Holik, Federico


    The analysis of the classical limit of quantum mechanics usually focuses on the state of the system. The general idea is to explain the disappearance of the interference terms of quantum states appealing to the decoherence process induced by the environment. However, in these approaches it is not explained how the structure of quantum properties becomes classical. In this paper, we consider the classical limit from a different perspective. We consider the set of properties of a quantum system and we study the quantum-to-classical transition of its logical structure. The aim is to open the door to a new study based on dynamical logics, that is, logics that change over time. In particular, we appeal to the notion of hybrid logics to describe semiclassical systems. Moreover, we consider systems with many characteristic decoherence times, whose sublattices of properties become distributive at different times.

  3. Hydrodynamic Limit for Interacting Neurons (United States)

    De Masi, A.; Galves, A.; Löcherbach, E.; Presutti, E.


    This paper studies the hydrodynamic limit of a stochastic process describing the time evolution of a system with N neurons with mean-field interactions produced both by chemical and by electrical synapses. This system can be informally described as follows. Each neuron spikes randomly following a point process with rate depending on its membrane potential. At its spiking time, the membrane potential of the spiking neuron is reset to the value 0 and, simultaneously, the membrane potentials of the other neurons are increased by an amount of potential . This mimics the effect of chemical synapses. Additionally, the effect of electrical synapses is represented by a deterministic drift of all the membrane potentials towards the average value of the system. We show that, as the system size N diverges, the distribution of membrane potentials becomes deterministic and is described by a limit density which obeys a non linear PDE which is a conservation law of hyperbolic type.

  4. Surfactants at the Design Limit. (United States)

    Czajka, Adam; Hazell, Gavin; Eastoe, Julian


    This article analyzes how the individual structural elements of surfactant molecules affect surface properties, in particular, the point of reference defined by the limiting surface tension at the aqueous cmc, γcmc. Particular emphasis is given to how the chemical nature and structure of the hydrophobic tails influence γcmc. By comparing the three different classes of surfactants, fluorocarbon, silicone, and hydrocarbon, a generalized surface packing index is introduced which is independent of the chemical nature of the surfactants. This parameter ϕcmc represents the volume fraction of surfactant chain fragments in a surface film at the aqueous cmc. It is shown that ϕcmc is a useful index for understanding the limiting surface tension of surfactants and can be useful for designing new superefficient surfactants.

  5. Nuclear Structure at the Limits

    Energy Technology Data Exchange (ETDEWEB)

    Nazarewicz, W.


    One of the frontiers of today�s nuclear science is the �journey to the limits� of atomic charge and nuclear mass, of neutron-to-proton ratio, and of angular momentum. The tour to the limits is not only a quest for new, exciting phenomena, but the new data are expected, as well, to bring qualitatively new information about the fundamental properties of the nucleonic many-body system, the nature of the nuclear interaction, and nucleonic correlations at various energy-distance scales. In this series of lectures, current developments in nuclear structure at the limits are discussed from a theoretical perspective, mainly concentrating on medium-mass and heavy nuclei.

  6. Limitation and life in space (United States)

    Israel, Marvin; Smith, T. Scott


    ``The Earth is the very quintescence of the human condition...,'' says Hannah Arendt. Georg Simmel writes: ``The stranger is by nature no `owner of soil'—soil not only in the physical, but also in the figurative sense of a life-substance which is fixed, if not in a point in space, at least in an ideal point of social environment.'' How will no longer being Earthbound affect persons' experience of themselves and of others? Space colonization offers an opportunity for new self-definition by the alteration of existing limits. Thus ``limitation'' is a useful concept for exploring the physical, social and psychological significance of the colonization of space. Will people seek the security of routine, of convention, of hierarchy as in the military model governing our present-day astronauts? or will they seek to maximize the freedom inherent in extraordinary living conditions—as bohemians, deviants, travelers?

  7. Adiabatic limit in perturbation theory

    CERN Document Server

    Epstein, H


    It is shown that, with correct mass and wave function renormalization, the time-ordered products for Wick polynomials T(L(y/sub 1/)...L(y/sub n/)) constructed by a method outlined in a previous paper (Epstein and Glaser, 1970) are such that the vectors of the form integral T(L(y/sub 1/)...L(y/sub n/)) g(y/sub 1/)...g(y/sub n/) psi dy/sub 1/...dy/sub n/ have limits when g tends to a constant, provided psi is chosen in a suitable dense domain. It follows that the S-matrix has unitary adiabatic limit as an operator-valued formal power series in Fock space. (4 refs).

  8. Limit laws for exponential families


    Balkema, August A.; Klüppelberg, Claudia; Resnick, Sidney I.


    For a real random variable [math] with distribution function [math] , define ¶ [math] ¶ The distribution [math] generates a natural exponential family of distribution functions [math] , where ¶ [math] ¶ We study the asymptotic behaviour of the distribution functions [math] as [math] increases to [math] . If [math] then [math] pointwise on [math] . It may still be possible to obtain a non-degenerate weak limit law [math] by choosing suitable scaling and centring constants [math] an...

  9. Rationality and concept of limit


    LECORRE, Thomas


    International audience; We present a didactic situation aimed at the formal definition (delta-epsilon) of the limit of a function; the experimentation of this didactic situation has been made many times with French students in the last year of high school and the first year of university using ''scientific debates'' between students. From an excerpt of the script of an experimentation, we study the evolution of students' reasoning. We specifically study the kinds of rationalities used by stud...

  10. Summary of Dissolved Concentration Limits

    Energy Technology Data Exchange (ETDEWEB)

    Yueting Chen


    According to the Technical Work Plan titled Technical Work Plan for Waste Form Degradation Process Model Report for SR (CRWMS M&O 2000a), the purpose of this study is to perform abstractions on solubility limits of radioactive elements based on the process-level information and thermodynamic databases provided by Natural Environment Program Operations (NEPO) and Waste Package Operations (WPO). The scope of this analysis is to produce solubility limits as functions, distributions, or constants for all transported radioactive elements identified by the Performance Assessment Operations (PAO) radioisotope screening. Results from an expert elicitation for solubility limits of most radioactive elements were used in the previous Total System Performance Assessments (TSPAs). However, the elicitation conducted in 1993 does not meet the criteria set forth by the U.S. Nuclear Regulatory Commission (NRC) due to lack of documentation and traceability (Kotra et al. 1996, Section 3). Therefore, at the Waste Form Abstraction Workshop held on February 2-4, 1999, at Albuquerque, New Mexico, the Yucca Mountain Site Characterization Project (YMP) decided to develop geochemical models to study solubility for the proposed Monitored Geologic Repository. WPO/NEPO is to develop process-level solubility models, including review and compilation of relevant thermodynamic data. PAO's responsibility is to perform abstractions based on the process models and chemical conditions and to produce solubility distributions or response surfaces applicable to the proposed repository. The results of this analysis and conceptual model will feed the performance assessment for Total System Performance Assessment--Site Recommendation (TSPA-SR) and Total System Performance Assessment--License Application (TSPA-LA), and to the Waste Form Degradation Process Model Report section on concentration limits.

  11. Problems of anthropogenic tritium limitation

    Directory of Open Access Journals (Sweden)

    Kochetkov О.A.


    Full Text Available This article contains the current situation in respect to the environmental concentrations of anthropogenic and natural tritium. There are presented and analyzed domestic standards for НТО of all Radiation Safety Standards (NRB, as well as the regulations analyzed for tritium in drinking water taken in other countries today. This article deals with the experience of limitation of tritium and focuses on the main problem of rationing of tritium — rationing of organically bound tritium.

  12. MHD limit cycles on FTU (United States)

    Pucella, G.; Giovannozzi, E.; Buratti, P.; Cianfarani, C.


    The development of low-order tearing modes during density ramp-up in the high density regime on the Frascati Tokamak Upgrade is characterized by an initial ordinary stage, with a ‘one-to-one’ relation between mode amplitude and frequency, followed by the formation, on the amplitude/frequency plane, of ‘limit cycles’ with increasing area up to disruption for density limit if the density continues to grow. A critical mode amplitude for transition from smooth to cyclic behavior has been observed in experiments performed changing the line-averaged density, and the existence of such a threshold has been confirmed in experiments of real time control of tearing mode in the high density regime by means of electron cyclotron resonance heating. The amplitude and frequency modulations of the observed m/n=2/1 tearing mode (m and n are the poloidal and toroidal mode number, respectively) occur in few milliseconds, which is not in agreement with the diffusion resistive time of about two hundred milliseconds expected on the q=2 resonance from the non-linear theory. The origin of such modulations has been investigated, taking into account that in the high amplitude stages of the mode temporal evolution it is difficult to discriminate between non-linear effects and mode coupling mechanisms. Our analysis suggests that the formation of limit cycles could be due to a recursive island fragmentation, with a sort of self-healing phenomenon; in fact the island distortion increases before amplitude drops. Concerning the interaction with modes of different helicity, our experiments seem to indicate that the presence of the q=3 resonance in the plasma is necessary for the occurrence of deep and regular limit cycles for the 2/1 tearing mode.

  13. Heisenberg Limit Superradiant Superresolving Metrology


    Wang, Da-Wei; Scully, Marlan O.


    We propose a superradiant metrology technique to achieve the Heisenberg limit super-resolving displacement measurement by encoding multiple light momenta into a three-level atomic ensemble. We use $2N$ coherent pulses to prepare a single excitation superradiant state in a superposition of two timed Dicke states that are $4N$ light momenta apart in momentum space. The phase difference between these two states induced by a uniform displacement of the atomic ensemble has $1/4N$ sensitivity. Expe...


    Directory of Open Access Journals (Sweden)

    Eduard Ionescu


    Full Text Available The recurrence of economic crises serves to illustrate the limits of neoclassical economics and the contemporary established models. The study of complex systems, evolutionary economics and interdisciplinary research offers the possibility of new developments. The concept of emergence represents an insightful argument against the well-planned and ordered nature of the social sciences universe. Complex systems research represents the viable alternative for sustainable growth in the following decades.

  15. Limits to global groundwater consumption (United States)

    de Graaf, I.; Van Beek, L. P.; Sutanudjaja, E.; Wada, Y.; Bierkens, M. F.


    Groundwater is the largest accessible freshwater resource worldwide and is of critical importance for irrigation, and so for global food security. For many regions of the world where groundwater abstraction exceeds groundwater recharge, persistent groundwater depletion occurs. A direct consequence of depletion is falling groundwater levels, reducing baseflows to rivers, harming ecosystems. Also, pumping costs increase, wells dry up and land subsidence can occur. Water demands are expected to increase further due to growing population, economic development and climate change, posing the urgent question how sustainable current water abstractions are worldwide and where and when these abstractions approach conceivable limits with all the associated problems. Here, we estimated past and future trends (1960-2050) in groundwater levels resulting from changes in abstractions and climate and predicted when limits of groundwater consumption are reached. We explored these limits by predicting where and when groundwater levels drop that low that groundwater becomes unattainable for abstractions and how river flows are affected. Water availabilities, abstractions, and lateral groundwater flows are simulated (5 arcmin. resolution) using a coupled version of the global hydrological model PCR-GLOBWB and a groundwater model based on MODFLOW. The groundwater model includes a parameterization of the worlds confined and unconfined aquifer systems, needed for a realistic simulation of groundwater head dynamics. Results show that, next to the existing regions experiencing groundwater depletion (like India, Pakistan, Central Valley) new regions will develop, e.g. Southern Europe, the Middle East, and Africa. Using a limit that reflects present-day feasibility of groundwater abstraction, we estimate that in 2050 groundwater becomes unattainable for 20% of the global population, mainly in the developing countries and pumping cost will increase significantly. Largest impacts are found

  16. Proposed Thermal Limits for Divers (United States)


    recommended minimum inspired gas temperature as a function of depth, or pressure of the respired gas. Braithwaite, 1972. 4 m ersion ( diuresis and...levels of indicators of generalized stress, such as corticoids and catecholamines in blood and a greater urine content of such substances or their...stress that can be limiting io. underwater operations. it may be produced by diuresis , by a lack of ingest I water, or by a loss of water through


    Directory of Open Access Journals (Sweden)

    Dzulkefly Kuang Abdullah


    Full Text Available Ionic liquids are considered as an ideal alternative to volatile organic solvents and chemical industries in the future,because they are non-volatile. Ionic liquids are also considered as new novel chemical agents and widely regarded as agreener alternative to many commonly used solvents. Ionic liquids have been studied for a wide range of syntheticapplications and have attracted considerable interest for use as electrolytes in the areas of organic synthesis, catalysis,solar cell, fuel cells, electrodeposition and supercapacitors. However, some ionic liquids suffer from more or less somedrawbacks such as toxicity, preparation and high cost in the process for use. Most recently, three types of ionic liquidsare attracted much attentions specifically traditional ionic liquid, protic ionic liquid and deep eutectic solvent, wheretheir preparation, mechanism and limitation were differentiated. However, those liquids are having their ownadvantages and limitations based on applications. Traditional ionic liquid and protic ionic liquid are highly cost andtoxic for applied engineering research, but they consist of micro-biphasic systems composed of ionic compounds whichhave more varieties in the applications. The deep eutectic solvent is very economic for large-scale possessing but thereare only limited ionic mixtures to certain application such as electrochemistry.

  18. Revisiting non-relativistic limits

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Kristan [C.N. Yang Institute for Theoretical Physics, SUNY Stony Brook,Stony Brook, NY 11794-3840 (United States); Karch, Andreas [Department of Physics, University of Washington,Seattle, WA 98195 (United States)


    We show that the full spurionic symmetry of Galilean-invariant field theories can be deduced when those theories are the limits of relativistic parents. Under the limit, the non-relativistic daughter couples to Newton-Cartan geometry together with all of the symmetries advocated in previous work, including the recently revived Milne boosts. Our limit is a covariant version of the usual one, where we start with a gapped relativistic theory with a conserved charge, turn on a chemical potential equal to the rest mass of the lightest charged state, and then zoom in to the low energy sector. This procedure gives a simple physical interpretation for the Milne boosts. Our methods even apply when there is a magnetic moment, which is known to modify the non-relativistic symmetry transformations. We focus on two examples. Free scalars are used to demonstrate the basic procedure, whereas hydrodynamics is used in order to exhibit the power of this approach in a fully dynamical setting, correcting several inaccuracies in the existing literature.

  19. Time-limited optimal dynamics beyond the Quantum Speed Limit

    DEFF Research Database (Denmark)

    Gajdacz, Miroslav; Das, Kunal K.; Arlt, Jan


    by a time-varying control. The problem is addressed in the framework of Hilbert space geometry offering an intuitive interpretation of optimal control algorithms. This approach leads to a necessary criterion for control optimality applicable as a measure of algorithm convergence. The time fidelity trade......-off expressed in terms of the direct Hilbert velocity provides a robust prediction of the quantum speed limit and allows to adapt the control optimization such that it yields a predefined fidelity. The results are verified numerically in a multilevel system with a constrained Hamiltonian, and a classification...

  20. Time limited optimal dynamics beyond the Quantum Speed Limit


    Gajdacz, Miroslav; Das, Kunal K.; Arlt, Jan; Sherson, Jacob F.; Opatrný, Tomáš


    The quantum speed limit sets the minimum time required to transfer a quantum system completely into a given target state. At shorter times the higher operation speed has to be paid with a loss of fidelity. Here we quantify the trade-off between the fidelity and the duration in a system driven by a time-varying control. The problem is addressed in the framework of Hilbert space geometry offering an intuitive interpretation of optimal control algorithms. This approach is applied to non-uniform ...

  1. Investigating fuel-cell transport limitations using hydrogen limiting current


    Spingler, FB; Phillips, A; Schuler, T; Tucker, MC; Weber, AZ


    © 2017 Hydrogen Energy Publications LLC Reducing mass-transport losses in polymer-electrolyte fuel cells (PEFCs) is essential to increase their power density and reduce overall stack cost. At the same time, cost also motivates the reduction in expensive precious-metal catalysts, which results in higher local transport losses in the catalyst layers. In this paper, we use a hydrogen-pump limiting-current setup to explore the gas-phase transport losses through PEFC catalyst layers and various ga...

  2. Limits to the growth debate

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, L.

    The first two major studies sponsored by the club of Rome were the report of the Meadows team at MIT, The Limits to Growth, published in 1972, and the Mesarovic and Pestel report, Mankind at the Turning Point, published in 1974. When the Club of Rome met in Philadelphia in April of 1976, its pronouncements reflected a frame of mind quite different from that of 1972. Recently, Herman Kahn and his colleagues at the Hudson Institute have published The Next 200 Years, a book evidently inspired as much by antagonism to the limits-to-growth school of thought as by affirmative faith in its own vision of technological optimism. The author discusses the content of the studies and summarizes his own position in four areas. (1) While no trend of growth of anything can continue indefinitely in the real world, there are not global physical limits to economic growth within a time frame susceptible to plausible foresight or relevant to policy making. (2) In some world regions, notably South Asia and tropical Africa, population growth rates do indeed threaten to create a kind of Malthusian trap, and the rapid reduction of fertility is critically important to their development prospects and urgent in time. (3) For other parts of the world, both rates and directions of growth will be more influenced by changes in preferences for consumption and in attitudes toward production than by physical constraints, although higher energy costs and environmental pressures will also be important influences in generating such changes in growth patterns. (4) Probable changes in directions of growth will generate new and important issues in international economic and political relations, with both dangers and opportunities for the evolving world order. (MCW)

  3. Limits and Accuracy in Measurements

    CERN Document Server

    Ososkov, G A


    Methods of determination of the limit attainable accuracy in measurements are expounded on the basis of the probability theory and the mathematical statistics. Distribution-free and parametric methods, point and interval estimations of the unknown parameters are discussed. The connection between maximum likelihood method and least squares method is shown. A special section is devoted to robust estimations and to resolution of digital signals. It is demonstrated how the Cramer-Rao inequality determines the lower-bound for the accuracy of measurements.

  4. Combination trading with limit orders

    Directory of Open Access Journals (Sweden)

    Henry Schellhorn


    Full Text Available We model the exchange of commodities that are contingent upon each other, when traders place mostly limit orders. Examples include: 1 a market of financial futures where future spreads are also traded, 2 a market of mutual funds and stocks, 3 a market of options and stocks, under the viewpoint that they are both combinations of Arrow-Debreu securities. We prove that consistent prices are optimal. We develop a fixed-point algorithm to compute an optimal price and allocation. The algorithm combines ideas from contraction mapping theory and from homotopy theory. It is much faster than a traditional linear programming approach.

  5. The limits of endurance exercise. (United States)

    Noakes, Timothy David


    A skeletal design which favours running and walking, including the greatest ratio of leg length to body weight of any mammal; the ability to sweat and so to exercise vigorously in the heat; and greater endurance than all land mammals other than the Alaskan Husky, indicates that humans evolved as endurance animals. The development of tools to accurately measure time and distance in the nineteenth century inspired some humans to define the limits of this special capacity. Beginning with Six-Day Professional Pedestrian Races in London and New York in the 1880s, followed a decade later by Six-Day Professional Cycling Races - the immediate precursor of the first six-day Tour de France Cycliste race in 1903, which itself inspired the 1928 and 1929 4,960 km "Bunion Derbies" between Los Angeles and New York across the breadth of the United States of America - established those unique sporting events that continue to challenge the modern limits of human endurance. But an analysis of the total energy expenditure achieved by athletes competing in those events establishes that none approaches those reached by another group - the explorers of the heroic age of polar exploration in the early twentieth century. Thus the greatest recorded human endurance performances occurred during the Antarctic sledding expeditions led by Robert Scott in 1911/12 and Ernest Shackleton in 1914/16. By man-hauling sleds for 10 hours daily for approximately 159 and 160 consecutive days respectively, members of those expeditions would have expended close to a total of 1,000,000 kcal. By comparison completing a Six-Day Pedestrian event (55,000 kcal) or the Tour de France (168,000 kcal), or cycling (180,000 kcal) or running (340,000 kcal) across America, requires a considerably smaller total energy expenditure. Thus the limits of human endurance were set at the start of the twentieth century and have not recently been approached. Given good health and an adequate food supply to prevent starvation and

  6. Electroweak bubble wall speed limit (United States)

    Bödeker, Dietrich; Moore, Guy D.


    In extensions of the Standard Model with extra scalars, the electroweak phase transition can be very strong, and the bubble walls can be highly relativistic. We revisit our previous argument that electroweak bubble walls can "run away," that is, achieve extreme ultrarelativistic velocities γ ~ 1014. We show that, when particles cross the bubble wall, they can emit transition radiation. Wall-frame soft processes, though suppressed by a power of the coupling α, have a significance enhanced by the γ-factor of the wall, limiting wall velocities to γ ~ 1/α. Though the bubble walls can move at almost the speed of light, they carry an infinitesimal share of the plasma's energy.

  7. Large networks and graph limits

    CERN Document Server

    Lovász, László


    Recently, it became apparent that a large number of the most interesting structures and phenomena of the world can be described by networks. Developing a mathematical theory of very large networks is an important challenge. This book describes one recent approach to this theory, the limit theory of graphs, which has emerged over the last decade. The theory has rich connections with other approaches to the study of large networks, such as "property testing" in computer science and regularity partition in graph theory. It has several applications in extremal graph theory, including the exact for

  8. CSS3 pushing the limits

    CERN Document Server

    Greig, Stephen


    Push CSS3 and your design skills to the limit-and beyond! Representing an evolutionary leap forward for CSS, CSS3 is chock-full of new capabilities that dramatically expand the boundaries of what a styling language can do. But many of those new features remain undocumented, making it difficult to learn what they are and how to use them to create the sophisticated sites and web apps clients demand and users have grown to expect. Until now. This book introduces you to all of CSS3's new and advanced features, and, with the help of dozens of real-world examples and live

  9. Nanofabrication principles, capabilities and limits

    CERN Document Server

    Cui, Zheng


    This second edition of Nanofabrication is one of the most comprehensive introductions on nanofabrication technologies and processes. A practical guide and reference, this book introduces readers to all of the developed technologies that are capable of making structures below 100nm. The principle of each technology is introduced and illustrated with minimum mathematics involved. Also analyzed are the capabilities of each technology in making sub-100nm structures, and the limits of preventing a technology from going further down the dimensional scale. This book provides readers with a toolkit that will help with any of their nanofabrication challenges.

  10. Limitations on practical quantum cryptography (United States)

    Brassard; Lutkenhaus; Mor; Sanders


    We provide limits to practical quantum key distribution, taking into account channel losses, a realistic detection process, and imperfections in the "qubits" sent from the sender to the receiver. As we show, even quantum key distribution with perfect qubits might not be achievable over long distances when the other imperfections are taken into account. Furthermore, existing experimental schemes (based on weak pulses) currently do not offer unconditional security for the reported distances and signal strength. Finally we show that parametric down-conversion offers enhanced performance compared to its weak coherent pulse counterpart.

  11. Modern Cosmology: Assumptions and Limits (United States)

    Hwang, Jai-Chan


    Physical cosmology tries to understand the Universe at large with its origin and evolution. Observational and experimental situations in cosmology do not allow us to proceed purely based on the empirical means. We examine in which sense our cosmological assumptions in fact have shaped our current cosmological worldview with consequent inevitable limits. Cosmology, as other branches of science and knowledge, is a construct of human imagination reflecting the popular belief system of the era. The question at issue deserves further philosophic discussions. In Whitehead's words, ``philosophy, in one of its functions, is the critic of cosmologies.'' (Whitehead 1925).

  12. Limits of search filter development. (United States)

    Wilczynski, Nancy L; Lokker, Cynthia; McKibbon, Kathleen Ann; Hobson, Nicholas; Haynes, R Brian


    The research attempted to develop search filters for biomedical literature databases that improve retrieval of studies of clinical relevance for the nursing and rehabilitation professions. Diagnostic testing framework compared machine-culled and practitioner-nominated search terms with a hand-tagged clinical literature database. We were unable to: (1) develop filters for nursing, likely because of the overlapping and expanding scope of practice for nurses in comparison with medical professionals, or (2) develop filters for rehabilitation, because of its broad scope and the profession's multifaceted understanding of "health and ability." We found limitations on search filter development for these health professions: nursing and rehabilitation.

  13. The weak coupling limit as a quantum functional central limit (United States)

    Accardi, L.; Frigerio, A.; Lu, Y. G.


    We show that, in the weak coupling limit, the laser model process converges weakly in the sense of the matrix elements to a quantum diffusion whose equation is explicitly obtained. We prove convergence, in the same sense, of the Heisenberg evolution of an observable of the system to the solution of a quantum Langevin equation. As a corollary of this result, via the quantum Feynman-Kac technique, one can recover previous results on the quantum master equation for reduced evolutions of open systems. When applied to some particular model (e.g. the free Boson gas) our results allow to interpret the Lamb shift as an Ito correction term and to express the pumping rates in terms of quantities related to the original Hamiltonian model.

  14. Does climate limit species richness by limiting individual species’ ranges? (United States)

    Boucher-Lalonde, Véronique; Kerr, Jeremy T.; Currie, David J.


    Broad-scale geographical variation in species richness is strongly correlated with climate, yet the mechanisms underlying this correlation are still unclear. We test two broad classes of hypotheses to explain this pattern. Bottom-up hypotheses propose that the environment determines individual species’ ranges. Ranges then sum up to yield species richness patterns. Top-down hypotheses propose that the environment limits the number of species that occur in a region, but not which ones. We test these two classes of hypotheses using a natural experiment: seasonal changes in environmental variables and seasonal range shifts of 625 migratory birds in the Americas. We show that richness seasonally tracks the environment. By contrast, individual species’ geographical distributions do not. Rather, species occupy different sets of environmental conditions in two seasons. Our results are inconsistent with extant bottom-up hypotheses. Instead, a top-down mechanism appears to constrain the number of species that can occur in a given region. PMID:24352946

  15. The limits of human performance. (United States)

    Beneke, Ralph; Böning, Dieter


    Human performance, defined by mechanical resistance and distance per time, includes human, task and environmental factors, all interrelated. It requires metabolic energy provided by anaerobic and aerobic metabolic energy sources. These sources have specific limitations in the capacity and rate to provide re-phosphorylation energy, which determines individual ratios of aerobic and anaerobic metabolic power and their sustainability. In healthy athletes, limits to provide and utilize metabolic energy are multifactorial, carefully matched and include a safety margin imposed in order to protect the integrity of the human organism under maximal effort. Perception of afferent input associated with effort leads to conscious or unconscious decisions to modulate or terminate performance; however, the underlying mechanisms of cerebral control are not fully understood. The idea to move borders of performance with the help of biochemicals is two millennia old. Biochemical findings resulted in highly effective substances widely used to increase performance in daily life, during preparation for sport events and during competition, but many of them must be considered as doping and therefore illegal. Supplements and food have ergogenic potential; however, numerous concepts are controversially discussed with respect to legality and particularly evidence in terms of usefulness and risks. The effect of evidence-based nutritional strategies on adaptations in terms of gene and protein expression that occur in skeletal muscle during and after exercise training sessions is widely unknown. Biochemical research is essential for better understanding of the basic mechanisms causing fatigue and the regulation of the dynamic adaptation to physical and mental training.

  16. Hamiltonian mechanics limits microscopic engines (United States)

    Anglin, James; Gilz, Lukas; Thesing, Eike


    We propose a definition of fully microscopic engines (micro-engines) in terms of pure mechanics, without reference to thermodynamics, equilibrium, or cycles imposed by external control, and without invoking ergodic theory. This definition is pragmatically based on the observation that what makes engines useful is energy transport across a large ratio of dynamical time scales. We then prove that classical and quantum mechanics set non-trivial limits-of different kinds-on how much of the energy that a micro-engine extracts from its fuel can be converted into work. Our results are not merely formal; they imply manageable design constraints on micro-engines. They also suggest the novel possibility that thermodynamics does not emerge from mechanics in macroscopic regimes, but rather represents the macroscopic limit of a generalized theory, valid on all scales, which governs the important phenomenon of energy transport across large time scale ratios. We propose experimental realizations of the dynamical mechanisms we identify, with trapped ions and in Bose-Einstein condensates (``motorized bright solitons'').

  17. Semiclassical limit and quantum chaos (United States)

    Lecheminant, P.


    In this paper we present the field on which R. Rammal was working in the last moments of his life : quantum chaos. The behavior of various distributions is investigated numerically for different planar billiards in presence of a magnetic field or not. We find exponential laws for the distributions of the trajectory lengths, of the algebraic areas, and of the number of boundary reflections. These results support the conjecture that the signature of the classical chaotic scattering in the quantum description is the appearance of fluctuations of the S-matrix (or conductance for ballistic conductors) in the semiclassical limit. Dans cet article, nous présentons le domaine sur lequel R. Rammal travaillait dans les derniers moments de sa vie : le chaos quantique. Nous étudions numériquement le comportement de plusieurs distributions pour des billards avec ou sans champ magnétique. Nous trouvons des lois exponentielles pour la distribution des longueurs des trajectoires, pour celle de la surface balayée par la particule et ainsi que pour la distribution du nombre de réflections sur les parois du billard. Ces résultats confortent l'hypothèse que la signature de la diffusion classiquement chaotique dans le domaine quantique est l'apparition de fluctuations de la matrice S (ou de conductance pour des conducteurs ballistiques) dans la limite semiclassique.

  18. Mathematical methods for hydrodynamic limits

    CERN Document Server

    Masi, Anna


    Entropy inequalities, correlation functions, couplings between stochastic processes are powerful techniques which have been extensively used to give arigorous foundation to the theory of complex, many component systems and to its many applications in a variety of fields as physics, biology, population dynamics, economics, ... The purpose of the book is to make theseand other mathematical methods accessible to readers with a limited background in probability and physics by examining in detail a few models where the techniques emerge clearly, while extra difficulties arekept to a minimum. Lanford's method and its extension to the hierarchy of equations for the truncated correlation functions, the v-functions, are presented and applied to prove the validity of macroscopic equations forstochastic particle systems which are perturbations of the independent and of the symmetric simple exclusion processes. Entropy inequalities are discussed in the frame of the Guo-Papanicolaou-Varadhan technique and of theKipnis-Oll...

  19. Moral Limits of the Market

    DEFF Research Database (Denmark)

    Ooi, Can-Seng


    Scholars and the practice community unanimously advocate sustainable balanced and sensitive tourism development. Engaging with locals and setting up public-private partnerships are frequently championed. This working paper introduces a set of lenses in the moral philosophy tradition and argues...... that the current pragmatic solutions to sustainable tourism development could not resolve issues of authenticity, equity, rights and fairness. There are three in-built moral limits in the tourism market, and namely: the market assumes it can price everything including culture and nature; the market distributes...... welfare through one's ability to pay rather than one's needs; and the market is structured in ways that benefit some groups more than others. The so-called solutions are compromises, and are tainted ideologically and politically. This work-in-progress is merely a starting point to a longer discussion...

  20. Reverse Flow Pressure Limiting Aperture. (United States)



    The reverse flow pressure limiting aperture is a device that creates and sustains a substantial gas pressure difference between two chambers connected via an aperture. The aperture is surrounded by an annular orifice leading to a third chamber. The third chamber is maintained at a relatively high pressure that forces gas to flow through the annular aperture into the first of said two chambers. The ensuing gas flow develops into a supersonic annular gas jet, the core of which is coaxial with the central aperture. A pumping action is created at the core of the jet and any gas molecules leaking through the aperture from the second chamber are entrained and forced into the first chamber, thus creating a substantial pressure difference between the first and second chamber.


    Directory of Open Access Journals (Sweden)

    Norica-Felicia BUCUR


    Full Text Available Global market forces have determined not only higher education institutions all over the world to include ESP courses in their curriculum to enhance their students’ future employability, but also public and private organisations to offer their employees the opportunity to attend ESP courses in order to meet the continuously growing ESP needs. From this perspective, ESP compentence could become a subcomponent of one of the key competences for lifelong learning, communication in foreign languages. Therefore assessing ESP competence seems to acquire paramount importance since stakeholders need accurate information about the ESP learners’ abilities to cope with specific language tasks. This article offers a concise overview of the principles and practices of ESP assessment, a detailed description of the features of ESP tests, while focusing particularly on the limits of ESP tests in order to identify possible solutions to overcome them.


    CERN Document Server


    On Thursday, September 7, 2000, all restaurants, cafétérias and kiosques will be closed except for restaurant no. 1 and its cafétéria (COOP - building 501 - Meyrin) which will provide a limited service from 8h00 to 21h00. Hot meals will be served from 11h30 to 14h00 and from 18h00 to 19h30. For technical reasons, restaurant no. 2 and its cafétéria (DSR - building 504 - Meyrin) will remain closed on Friday, September 8. They will resume their normal activities on Monday, September 11, 2000. The other restaurants, cafétérias and kiosques will offer their normal service as from Friday, September 8.


    CERN Multimedia

    Restaurant Supervisory Committee


    As Friday, March 29 and Monday, April 1st, 2002 are CERN holidays, restaurants no. 1 (COOP : Bldg. 501- Meyrin) and no. 3 (Avenance : Bldg. 866 - Prévessin) will be closed and will remain so on Saturday and Sunday, March 30 - 31. They will reopen on Tuesday, April 2 at 7h00. During these four days, a limited service will be provided by restaurant no. 2 (DSR : Bldg. 504 - Meyrin) from 8h00 to 21h00 with hot meals served from 11h30 to 14h00 and from 18h00 to 19h30. On Thursday, March 28, all three restaurants will operate according to the usual times except for restaurant no. 1 which will close at 21h00 instead of 1 o'clock in the morning.   Restaurant Supervisory Committee, tel. 77551


    CERN Multimedia

    Restaurant Supervisory Committee


    As Friday 29 March and Monday 1st April 2002 are CERN holidays, restaurants no. 1 (COOP, bldg. 501- Meyrin) and no. 3 (Avenance, bldg. 866 - Prévessin) will be closed and will remain so on Saturday and Sunday 30-31 March. They will reopen on Tuesday 2 April at 7h00. During these four days, a limited service will be provided by restaurant no. 2 (DSR, bldg. 504 - Meyrin) from 8h00 to 21h00 with hot meals served from 11h30 to 14h00 and from 18h00 to 19h30. On Thursday 28 March, all three restaurants will operate according to the usual times except for restaurant no. 1 which will close at 21h00 instead of 1 o'clock in the morning. Restaurant Supervisory Committee Tel. 77551

  5. Homotopy limits, completions and localizations

    CERN Document Server

    Bousfield, Aldridge K


    The main purpose of part I of these notes is to develop for a ring R a functional notion of R-completion of a space X. For R=Zp and X subject to usual finiteness condition, the R-completion coincides up to homotopy, with the p-profinite completion of Quillen and Sullivan; for R a subring of the rationals, the R-completion coincides up to homotopy, with the localizations of Quillen, Sullivan and others. In part II of these notes, the authors have assembled some results on towers of fibrations, cosimplicial spaces and homotopy limits which were needed in the discussions of part I, but which are of some interest in themselves.

  6. Pericytes limit tumor cell metastasis

    DEFF Research Database (Denmark)

    Xian, Xiaojie; Håkansson, Joakim; Ståhlberg, Anders


    Previously we observed that neural cell adhesion molecule (NCAM) deficiency in beta tumor cells facilitates metastasis into distant organs and local lymph nodes. Here, we show that NCAM-deficient beta cell tumors grew leaky blood vessels with perturbed pericyte-endothelial cell-cell interactions...... the microvessel wall. To directly address whether pericyte dysfunction increases the metastatic potential of solid tumors, we studied beta cell tumorigenesis in primary pericyte-deficient Pdgfb(ret/ret) mice. This resulted in beta tumor cell metastases in distant organs and local lymph nodes, demonstrating a role...... and deficient perivascular deposition of ECM components. Conversely, tumor cell expression of NCAM in a fibrosarcoma model (T241) improved pericyte recruitment and increased perivascular deposition of ECM molecules. Together, these findings suggest that NCAM may limit tumor cell metastasis by stabilizing...

  7. Prostatic carcinoma: limited field irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Rounsaville, M.C.; Green, J.P.; Vaeth, J.M.; Purdon, R.P.; Heltzel, M.M.


    This is a retrospective study of 251 patients with histologically proven adenocarcinoma treated primarily with limited field radiotherapy techniques, under the principle direction of authors JMV and JPG, between 1968 and 1981 in San Francisco, California. All patients are followed for a minimum of 3 years; mean follow-up is 7.3 years. Routine clinical staging procedures included: HandP, digital prostate exam, cystoscopy, biopsy, blood studies including serum acid phosphatase, and imaging studies including chest X ray, IVP, bone survey or radionucleotide bone scan, and in recent years, pelvic CT scans. Twelve patients are Stage A1, 37-Stage A2, 50-Stage B, 140-Stage C1 and 12-Stage C2. Ninety percent of all cases and 85% of Stage C patients were treated with limited fields to the prostate and periprostatic volume only. Total doses were prescribed at midplane or isocenter and were generally 6500-7000 cGy, daily doses of 180-200 cGy, 5 days per week. Actuarial 5- and 10-year survival rates are: entire population-69% and 47%; Stage A1-74% and 50%; Stage A2-81% and 67%; Stage B-84% and 53%; Stage C1-63% and 42%; Stage C2-32% and 11%. The 5- and 10-year disease-free actuarial survivals are: entire population-71% and 50%; Stage A1-89% and 74%; Stage A2-82% and 69%; Stage B-71% and 52%; Stage C1-67% and 44%; Stage C2-0%. Sites of recurrence, alone or as a component of the failure pattern are: 37 (15%) local, 11 (4%) symptomatic regional recurrence (lower extremity edema, pelvic pain/sciatica, hydroureteronephrosis), and 87 (35%) distant metastasis. Seven (3%) had unknown sites of failure. Local-regional failure occurred in 42% of Stage C2 patients.

  8. Permissible limit for mandibular expansion. (United States)

    Motoyoshi, Mitsuru; Shirai, Sawa; Yano, Shinya; Nakanishi, Kotoe; Shimizu, Noriyoshi


    In recent years, mandibular expansion has been increasingly performed in conjunction with orthodontic treatment. Lateral tipping of the molars associated with mandibular expansion should, however, be considered, because excessive expansion may result in excessive buccal tooth inclination, which may disturb the occlusal relationship. This study was conducted to quantitatively clarify molar movement during mandibular expansion using the Schwarz appliance to determine the permissible limit of mandibular expansion as a clinical index for inclination movement. Inclinations in the masticatory surface of the first molar and intermolar width were measured before expansion (T1), after expansion (T2), and before edgewise treatment (T3). Lower plaster models from 29 subjects treated with expansion plates were used and compared with models from 11 control subjects with normal occlusion. The average treatment change (T1-T2) in intermolar width was 5.42 mm (standard deviation 1.98), and the average angle of buccal tooth inclination was 10.16 degrees (standard deviation 3.83). No significant correlation was found between age prior to treatment and the treatment period when they were compared with the intermolar width increments and inclination angles. There was a significant positive correlation between retention duration and the amount of expansion. The regression coefficient of the angle of buccal tooth inclination during expansion to the increment of the intermolar width was approximately 0.2. This means that 1 mm of expansion is accompanied by 5 degrees of molar lateral tipping. This coefficient is clinically useful for estimating the permissible limit for mandibular expansion.

  9. Pure Phase Solubility Limits: LANL

    Energy Technology Data Exchange (ETDEWEB)

    C. Stockman


    The natural and engineered system at Yucca Mountain (YM) defines the site-specific conditions under which one must determine to what extent the engineered and the natural geochemical barriers will prevent the release of radioactive material from the repository. Most important mechanisms for retention or enhancement of radionuclide transport include precipitation or co-precipitation of radionuclide-bearing solid phases (solubility limits), complexation in solution, sorption onto surfaces, colloid formation, and diffusion. There may be many scenarios that could affect the near-field environment, creating chemical conditions more aggressive than the conditions presented by the unperturbed system (such as pH changes beyond the range of 6 to 9 or significant changes in the ionic strength of infiltrated waters). For an extended period of time, the near-field water composition may be quite different and more extreme in pH, ionic strength, and CO{sub 2} partial pressure (or carbonate concentration) than waters at some distance from the repository. Reducing conditions, high pH (up to 11), and low carbonate concentration may be present in the near-field after reaction of infiltrating groundwater with engineered barrier systems, such as cementitious materials. In the far-field, conditions are controlled by the rock-mass buffer providing a near-neutral, oxidizing, low-ionic-strength environment that controls radionuclide solubility limits and sorption capacities. There is the need for characterization of variable chemical conditions that affect solubility, speciation, and sorption reactions. Modeling of the groundwater chemistry is required and leads to an understanding of solubility and speciation of the important radionuclides. Because experimental studies cannot be performed under the numerous potential chemical conditions, solubility limitations must rely on geochemical modeling of the radionuclide's chemistry. Fundamental thermodynamic properties, such as solubility

  10. Changing ideas of global limits. (United States)

    Goddy, D


    In this discussion of changing ideas of global limits, attention is directed to world trade, moral restraint, and the "green revolution." A fresh look at the work of those who first considered population problems,, Malthur, can help make some sense of the population problems the world faces today. Malthus, writing in the late 1700s, concluded that population multiplies with each generation. He saw that food production was limited by the amount of available cropland and that the more people there are, the less food they will have to eat -- assuming that all available cropland is planted. This grim view of the future led Malthus to oppose government aid to the poor maintaining that such assistance would only encourage poor people to have large families. His solution was "moral restratin," seeing it as the duty of each individual to refrain from marriage until he was able to support his children. At the time this advice seemed cruel and Malthus was bitterly attacked by writers everywhere in Europe. Karl Marx and other ctitics of Malthus believed that poverty was caused by unjust governments and the selfishness of the rich. Marx clamied that the problem was too few jobs rather than too many people. The dire predictions of Malthus were soon forgotten as manufacturing industries began to transform the economies of Western Europe in the 1800s. Along with soaring economic growth came a host of developments that improved people's lives, e.g., better transportation, better sanitiation and nutrition, and better medicine. New inventions helped farmers fo produce more food. Next came the "demographic transition." Population grew quickly in Europe and North America as people became healthier and lived longer. Gradually, people in the industrial nations began deciding to have smaller families to enable them to afford an even higher living standard. By the late 1920s birthrates in Europe and the US had dropped so low that mention of the "population problem" usually referred

  11. Limits to Drift Chamber Resolution

    CERN Document Server

    Riegler, Werner


    ATLAS (A Large Toroidal LHC Apparatus) will be a general-purpose experiment at the Large Hadron Collider that will be operational at CERN in the year 2004. The ATLAS muon spectrometer aims for a momentum resolution of 10% for a transverse momentum of pT=1TeV. The precision tracking devices in the muon system will be high pressure drift tubes (MDTs) with a single wire resolution of 1100 chambers covering an area of ≈ 2500m2. The high counting rates in the spectrometer as well as the aim for excellent spatial resolution and high efficiency put severe constraints on the MDT operating parameters. This work describes a detailed study of all the resolution limiting factors in the ATLAS environment. A ’full chain’ simulation of the MDT response to photons and charged particles as well as quantitative comparisons with measurements was performed. The good agreement between simulation and measurements resulted in a profound understanding of the drift chamber processes and the individual contributions to the spat...

  12. Observational Research Opportunities and Limitations (United States)

    Boyko, Edward J.


    Medical research continues to progress in its ability to identify treatments and characteristics associated with benefits and adverse outcomes. The principle engine for the evaluation of treatment efficacy is the randomized controlled trial (RCT). Due to the cost and other considerations, RCTs cannot address all clinically important decisions. Observational research often is used to address issues not addressed or not addressable by RCTs. This article provides an overview of the benefits and limitations of observational research to serve as a guide to the interpretation of this category of research designs in diabetes investigations. The potential for bias is higher in observational research but there are design and analysis features that can address these concerns although not completely eliminate them. Pharmacoepidemiologic research may provide important information regarding relative safety and effectiveness of diabetes pharmaceuticals. Such research must effectively address the important issue of confounding by indication in order to produce clinically meaningful results. Other methods such as instrumental variable analysis are being employed to enable stronger causal inference but these methods also require fulfillment of several key assumptions that may or may not be realistic. Nearly all clinical decisions involve probabilistic reasoning and confronting uncertainly, so a realistic goal for observational research may not be the high standard set by RCTs but instead the level of certainty needed to influence a diagnostic or treatment decision. PMID:24055326

  13. Bone densitometry: applications and limitations. (United States)

    Syed, Zeba; Khan, Aliya


    Osteoporosis is clinically diagnosed in its advanced stages, usually following a fracture. Accurate, precise, and noninvasive skeletal assessment is now possible for early detection of osteoporosis at a preclinical stage. Currently, the gold standard in bone mass measurement and fracture prediction is dual energy X-ray absorptiometry (DEXA) of the hip and spine. Exponential increases in fracture risk have been observed with small decreases in bone mineral density. Bone mineral density (BMD) should be considered in conjunction with independent clinical risk factors for fracture, including: low body weight, history of postmenopausal fracture, family history of fracture, and poor neuromuscular function. The World Health Organization (WHO) diagnostic criteria for osteoporosis and osteopenia are appropriate for postmenopausal Caucasian women and are applicable to DEXA assessments at the hip, spine, or forearm. This review explores the relationship between BMD and fracture risk, the principles of bone densitometry interpretation, and the applications as well as the limitations of DEXA technology, and presents cases illustrating common errors seen in the interpretation of DEXA studies.

  14. Photon and graviton mass limits

    Energy Technology Data Exchange (ETDEWEB)

    Nieto, Michael [Los Alamos National Laboratory; Goldhaber Scharff, Alfred [SUNY


    We review past and current studies of possible long-distance, low-frequency deviations from Maxwell electrodynamics and Einstein gravity. Both have passed through three phases: (1) Testing the inverse-square laws of Newton and Coulomb, (2) Seeking a nonzero value for the rest mass of photon or graviton, and (3) Considering more degrees of freedom, allowing mass while preserving gauge or general-coordinate invariance. For electrodynamics there continues to be no sign of any deviation. Since our previous review the lower limit on the photon Compton wavelength (associated with weakening of electromagnetic fields in vacuum over large distance scale) has improved by four orders of magnitude, to about one astronomical unit. Rapid current progress in astronomical observations makes it likely that there will be further advances. These ultimately could yield a bound exceeding galactic dimensions, as has long been contemplated. Meanwhile, for gravity there have been strong arguments about even the concept of a graviton rest mass. At the same time there are striking observations, commonly labeled 'dark matter' and 'dark energy' that some argue imply modified gravity. This makes the questions for gravity much more interesting. For dark matter, which involves increased attraction at large distances, any explanation by modified gravity would be qualitatively different from graviton mass. Because dark energy is associated with reduced attraction at large distances, it might be explained by a graviton-mass-like effect.

  15. Glacial effects limiting mountain height. (United States)

    Egholm, D L; Nielsen, S B; Pedersen, V K; Lesemann, J-E


    The height of mountain ranges reflects the balance between tectonic rock uplift, crustal strength and surface denudation. Tectonic deformation and surface denudation are interdependent, however, and feedback mechanisms-in particular, the potential link to climate-are subjects of intense debate. Spatial variations in fluvial denudation rate caused by precipitation gradients are known to provide first-order controls on mountain range width, crustal deformation rates and rock uplift. Moreover, limits to crustal strength are thought to constrain the maximum elevation of large continental plateaus, such as those in Tibet and the central Andes. There are indications that the general height of mountain ranges is also directly influenced by the extent of glaciation through an efficient denudation mechanism known as the glacial buzzsaw. Here we use a global analysis of topography and show that variations in maximum mountain height correlate closely with climate-controlled gradients in snowline altitude for many high mountain ranges across orogenic ages and tectonic styles. With the aid of a numerical model, we further demonstrate how a combination of erosional destruction of topography above the snowline by glacier-sliding and commensurate isostatic landscape uplift caused by erosional unloading can explain observations of maximum mountain height by driving elevations towards an altitude window just below the snowline. The model thereby self-consistently produces the hypsometric signature of the glacial buzzsaw, and suggests that differences in the height of mountain ranges mainly reflect variations in local climate rather than tectonic forces.

  16. The Moral Limits of Impartiality

    Directory of Open Access Journals (Sweden)



    Full Text Available Our moral perspective should not be limited to the impartial concern for all who share a common humanity with us. It should also include the value of partiality embedded in personal relationships of love and friendship. These personal relationships give shape and meaning to our lives, and they also provide us with a sense of identity. The values that underpin our common humanity are based on the universal features of all human beings, including those who are strangers to us. On the other hand, our special relationships are dependent upon features that distinguish our friends and loved ones from others. These relationships grow out of shared experiences and commitments, and are the products of specific times and places. A balanced moral life will not seek to place one set of values over the other, but will instead have two distinct spheres for both an impartial love of humanity, as well as for the partialities of our particular attachments and special relationships.

  17. Laboratory Limits on Neutrino Masses (United States)

    Weinheimer, Christian

    The recent neutrino oscillation experiments have obtained nonzero differences of squared neutrino masses and therefore proven that neutrinos are massive particles. The values of the neutrino masses have to be determined in a different way. There are two classes of laboratory experiments, both of which have yielded up to now only upper limits on neutrino masses. The direct mass experiments investigate the kinematics of weak decays, obtaining information about the neutrino mass without further requirements. Here, the tritium β decay experiments give the most stringent results. The search for neutrinoless double β decay is also very sensitive to the neutrino mass states. However, this search is complementary to direct neutrino mass experiments, since it requires neutrinos to be identical to their antiparticles and probes a linear combination of neutrino masses including complex phases. This chapter is structured as follows. After an introduction in Sect. 2.1, the two approaches are discussed together with the current experimental results in Sects. 2.2 and 2.3, followed by consideration of the outlook for future activities in Sect. 2.4.

  18. Reservoir characterization with limited information

    Energy Technology Data Exchange (ETDEWEB)

    Sutterlin, P.G. (Wichita State Univ., KS (United States)); Visher, G.S. (Geological Service and Ventures, Inc., Tulsa, OK (United States))


    It is now possible to estimate the external geometry and the internal reservoir heterogeneity of potential producing zones from a single well. Information from logs and samples often is sufficient to make a unique interpretation of the depositional origin of the potential producing zone. Most wells drilled in the Mid-Continent test specific structural or stratigraphic prospects based upon limited subsurface information. Even without core, seismic, and dipmeter information, multivariant analysis of logs and samples is sufficient for comparison to Holocene depositional patterns, Recognition of the origin of the reservoir interval allow a comparison to similar producing reservoirs. Production experience can be used to design both completion and field development programs. Patterns of direction permeability, geometry of flow units, sweep potential, and primary and secondary recovery potential can be estimated. This allows decisions to be made on well spacing, perforation interval, and frac design. The analysis of all available information can make the difference in completing a successful well and in confirming the play concept. A common failure is that an early effort is not made in synthesizing information to make the correct decisions. The expert system illustrated provides the framework for data analysis and the nature of information that can be used for determining probabilities for specific reservoir characteristics.


    Directory of Open Access Journals (Sweden)

    May-Lin Wang


    Full Text Available O presente trabalho toma por base uma abordagem psicossocial para discorrer sobre os limites impostos pelos estereótipos de gênero à construção de uma identidade masculina, em contraposição às possibilidades de subjetivação, num cenário cultural de pluralidade identitária. Ênfase é dada à socialização estereotipada dos meninos, num processo no qual se verifica uma espécie de superposição do contexto socio-histórico em que cresceram os pais àquele no qual o menino é socializado, acentuando determinadas crenças sobre gênero. O modelo tradicional de virilidade, que imperava inquestionável até bem pouco tempo, ignorando as necessidades afetivas e valorizando características como a competitividade, a preocupação com o desempenho, o autoritarismo, a dominação e a opressão, vem sendo questionado como pilar maior da identidade masculina tradicional.

  20. Agriculture: access to technology limited. (United States)


    From country to country and even regionally, the roles of women in agriculture vary, but most of their labor is in unpaid subsistence production and their contributions tend to be underestimated, according to the results of the [UN] Secretary-General's report. Depending on circumstances, they have complementary roles with men, sharing or dividing tasks in the production of crops, care of animals, and forestry management. In sub-Saharan Africa, for example, women contribute 60-80% of labor in food production for both household consumption and sale, while in Malaysia the women account for only 35% of the agricultural labor force, and in Ireland the participation rate is only 10.4%. Although women make this important amount of labor contributions to agricultural production, "development policies tend to favor export crops to earn foreign exchange and the agricultural research tends to address the improvement of production and technologies for commercial production". This results in limited access for women to technical knowledge and innovations, including irrigation, machinery, farming techniques and extension services. This is strengthened by the fact that most of the extension services target farmers who own land and can obtain credit to invest in input and technology. full text

  1. Shear wall ultimate drift limits

    Energy Technology Data Exchange (ETDEWEB)

    Duffey, T.A. [Duffy, (T.A.) Tijeras, NM (United States); Goldman, A. [Goldman, (A.), Sandia, Los Alamos, NM (United States); Farrar, C.R. [Los Alamos National Lab., NM (United States)


    Drift limits for reinforced-concrete shear walls are investigated by reviewing the open literature for appropriate experimental data. Drift values at ultimate are determined for walls with aspect ratios ranging up to a maximum of 3.53 and undergoing different types of lateral loading (cyclic static, monotonic static, and dynamic). Based on the geometry of actual nuclear power plant structures exclusive of containments and concerns regarding their response during seismic (i.e.,cyclic) loading, data are obtained from pertinent references for which the wall aspect ratio is less than or equal to approximately 1, and for which testing is cyclic in nature (typically displacement controlled). In particular, lateral deflections at ultimate load, and at points in the softening region beyond ultimate for which the load has dropped to 90, 80, 70, 60, and 50 percent of its ultimate value, are obtained and converted to drift information. The statistical nature of the data is also investigated. These data are shown to be lognormally distributed, and an analysis of variance is performed. The use of statistics to estimate Probability of Failure for a shear wall structure is illustrated.

  2. Measuring stress: Uses and limitations

    Energy Technology Data Exchange (ETDEWEB)

    Suter, G.W. II [Oak Ridge National Lab., TN (United States). Environmental Sciences Div.


    The topic of the uses and limitations of measuring stress in the oceans is addressed. The use of the term stress in this context is ambiguous. Rather than assuming that stress is an actual measurable property of oceans, one may assume that the term refers to the complex of harmful things that is going on in the oceans. that is, it is a cover term for a complex of processes and states, many of which are unknown or undefined. The appeal of the term stress used in that way is very tempting. Considerable complexity results from the fact that the ocean consists of numerous and diverse species and ecosystems each of which have various properties that have some claim to protection. Another source of complexity is the diversity of factors which constitute threats to the environment. In evaluating the concepts of ecological risk assessment, there are sources of hazardous agents, there are receptors that are affected, and there is a process by which these interact termed exposure. As a result of exposure there is some probability that the actions of the sources have caused or will cause some effect on the receptor, the risk. Assessments may be source driven; they may attempt to determine the risks associated with a waste outfall. Assessments may also be effects driven; they may attempt to determine the cause of a die-off of marine mammals or determine the likelihood of a particular rise in sea-level. Finally, they may be exposure driven. Each of these components of the causal chain might serve as measures of stress.

  3. The limits of racial prejudice (United States)

    Lewis, Kevin


    The racial segregation of romantic networks has been documented by social scientists for generations. However, because of limitations in available data, we still have a surprisingly basic idea of the extent to which this pattern is generated by actual interpersonal prejudice as opposed to structural constraints on meeting opportunities, how severe this prejudice is, and the circumstances under which it can be reduced. I analyzed a network of messages sent and received among 126,134 users of a popular online dating site over a 2.5-mo period. As in face-to-face interaction, online exchanges are structured heavily by race. Even when controlling for regional differences in meeting opportunities, site users—especially minority site users—disproportionately message other users from the same racial background. However, this high degree of self-segregation peaks at the first stage of contact. First, users from all racial backgrounds are equally likely or more likely to cross a racial boundary when reciprocating than when initiating romantic interest. Second, users who receive a cross-race message initiate more new interracial exchanges in the future than they would have otherwise. This effect varies by gender, racial background, and site experience; is specific to the racial background of the original sender; requires that the recipient replied to the original message; and diminishes after a week. In contrast to prior research on relationship outcomes, these findings shed light on the complex interactional dynamics that—under certain circumstances—may amplify the effects of racial boundary crossing and foster greater interracial mixing. PMID:24191008

  4. The limits of racial prejudice. (United States)

    Lewis, Kevin


    The racial segregation of romantic networks has been documented by social scientists for generations. However, because of limitations in available data, we still have a surprisingly basic idea of the extent to which this pattern is generated by actual interpersonal prejudice as opposed to structural constraints on meeting opportunities, how severe this prejudice is, and the circumstances under which it can be reduced. I analyzed a network of messages sent and received among 126,134 users of a popular online dating site over a 2.5-mo period. As in face-to-face interaction, online exchanges are structured heavily by race. Even when controlling for regional differences in meeting opportunities, site users-especially minority site users-disproportionately message other users from the same racial background. However, this high degree of self-segregation peaks at the first stage of contact. First, users from all racial backgrounds are equally likely or more likely to cross a racial boundary when reciprocating than when initiating romantic interest. Second, users who receive a cross-race message initiate more new interracial exchanges in the future than they would have otherwise. This effect varies by gender, racial background, and site experience; is specific to the racial background of the original sender; requires that the recipient replied to the original message; and diminishes after a week. In contrast to prior research on relationship outcomes, these findings shed light on the complex interactional dynamics that-under certain circumstances-may amplify the effects of racial boundary crossing and foster greater interracial mixing.

  5. Limited Deposit Insurance Coverage and Bank Competition


    SHY, Oz; Stenbacka, Rune; Yankov, Vladimir


    Deposit insurance schemes in many countries place a limit on the coverage of deposits in each bank. However, no limits are placed on the number of accounts held with different banks. Therefore, under limited deposit insurance, some consumers open accounts with different banks to achieve higher or full deposit insurance coverage. We compare three regimes of deposit insurance: No deposit insurance, unlimited deposit insurance, and limited deposit insurance. We show that limited deposit insuranc...

  6. On thermodynamic limits of entropy densities

    NARCIS (Netherlands)

    Moriya, H; Van Enter, A

    We give some sufficient conditions which guarantee that the entropy density in the thermodynamic limit is equal to the thermodynamic limit of the entropy densities of finite-volume (local) Gibbs states.

  7. 48 CFR 1417.402 - Limitations. (United States)


    ... CONTRACT TYPES SPECIAL CONTRACTING METHODS Leader Company Contracting 1417.402 Limitations. Use of leader company contracting for a product, subject to the limitations in FAR 17.402, shall require advance...

  8. Setting limits on supersymmetry using simplified models

    CERN Document Server

    Gutschow, C.


    Experimental limits on supersymmetry and similar theories are difficult to set because of the enormous available parameter space and difficult to generalize because of the complexity of single points. Therefore, more phenomenological, simplified models are becoming popular for setting experimental limits, as they have clearer physical implications. The use of these simplified model limits to set a real limit on a concrete theory has not, however, been demonstrated. This paper recasts simplified model limits into limits on a specific and complete supersymmetry model, minimal supergravity. Limits obtained under various physical assumptions are comparable to those produced by directed searches. A prescription is provided for calculating conservative and aggressive limits on additional theories. Using acceptance and efficiency tables along with the expected and observed numbers of events in various signal regions, LHC experimental results can be re-cast in this manner into almost any theoretical framework, includ...

  9. A more intuitive definition of limit


    Baishanski, Bogdan M.


    Limit can be defined by two axioms: 1. Strict inequality between limits implies, ultimately, strict inequality between functions. 2. For constant functions limit is trivial. How can basic results on convergence be derived from these axioms? In this paper we propose two answers: a) at the most elementary level- add two more axioms, b) at somewhat higher level, do it in three steps, and, in our forthcoming paper "Axiomatic definition of limit", a third answer- c) do it neater - in an abstract f...

  10. Limited finger joint mobility in diabetes


    Brice, J E H; Johnston, D I; Noronha, J.L.


    Limited finger joint mobility was assessed in 112 diabetic children, in their first-degree relatives, and in 50 unrelated non-diabetic children. In 42% of the diabetic children there was limited joint mobility, but 14% of them had more severe involvement. Limited joint mobility was correlated with increasing age, early presentation, and longer duration of diabetes. First-degree relatives of affected diabetic children had a higher incidence (35%) of limited joint mobility compared with relativ...

  11. 12 CFR 24.4 - Investment limits. (United States)


    ... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Investment limits. 24.4 Section 24.4 Banks and... ENTITIES, COMMUNITY DEVELOPMENT PROJECTS, AND OTHER PUBLIC WELFARE INVESTMENTS § 24.4 Investment limits. (a) Limits on aggregate outstanding investments. A national bank's aggregate outstanding investments under...

  12. 17 CFR 10.34 - Limited participation. (United States)


    ... 17 Commodity and Securities Exchanges 1 2010-04-01 2010-04-01 false Limited participation. 10.34 Section 10.34 Commodity and Securities Exchanges COMMODITY FUTURES TRADING COMMISSION RULES OF PRACTICE Parties and Limited Participation § 10.34 Limited participation. (a) Petitions for leave to be heard. Any...

  13. High temperature superconducting fault current limiter (United States)

    Hull, John R.


    A fault current limiter (10) for an electrical circuit (14). The fault current limiter (10) includes a high temperature superconductor (12) in the electrical circuit (14). The high temperature superconductor (12) is cooled below its critical temperature to maintain the superconducting electrical properties during operation as the fault current limiter (10).

  14. 12 CFR 616.6600 - Leasing limit. (United States)


    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Leasing limit. 616.6600 Section 616.6600 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM LEASING § 616.6600 Leasing limit. All leases made by Farm Credit System institutions shall be subject to the lending and leasing limit in subpart J...

  15. 45 CFR 5.35 - Time limits. (United States)


    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Time limits. 5.35 Section 5.35 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION FREEDOM OF INFORMATION REGULATIONS Release and Denial of Records § 5.35 Time limits. (a) General. FOIA sets certain time limits for us to decide whether...

  16. 22 CFR 503.4 - Time limits. (United States)


    ... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Time limits. 503.4 Section 503.4 Foreign Relations BROADCASTING BOARD OF GOVERNORS FREEDOM OF INFORMATION ACT REGULATION § 503.4 Time limits. (a) General. The FOIA sets certain time limits for us to decide whether to disclose the records you requested...

  17. 32 CFR 806.22 - Time limits. (United States)


    ... 32 National Defense 6 2010-07-01 2010-07-01 false Time limits. 806.22 Section 806.22 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE ADMINISTRATION AIR FORCE FREEDOM OF INFORMATION ACT PROGRAM § 806.22 Time limits. Any FOIA appeals received after the 60-day time limit are not...

  18. 7 CFR 3200.5 - Dollar limitation. (United States)


    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Dollar limitation. 3200.5 Section 3200.5 Agriculture Regulations of the Department of Agriculture (Continued) OFFICE OF PROCUREMENT AND PROPERTY MANAGEMENT... PERSONAL PROPERTY § 3200.5 Dollar limitation. There is no dollar limitation on excess personal property...

  19. The density limit in JET diverted plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, D.J.; Clement, S.; Gottardi, N.; Gowers, C.; Harbour, P.; Loarte, A.; Horton, L.; Lingertat, J.; Lowry, C.G.; Saibene, G.; Stamp, M.; Stork, D. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Monk, R. [Royal Holloway Coll., London (United Kingdom). Dept. of Physics


    In JET limiter plasmas the density limit is associated with radiated power fractions of 100% and, in plasmas with carbon limiters, it is invariably disruptive. However, in discharges with solid beryllium limiters the limit is identified with the formation of a MARFE and disruptions are less frequent. In addition, the improved conditioning of the vessel arising from the use of beryllium has significantly improved the density limit scaling, so that the maximum density rises with the square root of the input power. In diverted plasmas several confinement regimes exist, making the characterization of the density limit more complex. While the density limit in L-mode plasmas is generally disruptive, the limit in ELMy and ELM-free H-modes generally prompts a return to the L-mode and a disruption is not inevitable. The density limit does rise with the increasing power, but the L-to-H transition complicates the analysis. Nevertheless, at low plasma currents (<2 MA), densities significantly above the Greenwald limit can be achieved, while at higher currents power handling limitations have constrained the range of density which can be achieved. (authors). 7 refs., 4 figs.

  20. 40 CFR 264.94 - Concentration limits. (United States)


    ... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Concentration limits. 264.94 Section... From Solid Waste Management Units § 264.94 Concentration limits. (a) The Regional Administrator will specify in the facility permit concentration limits in the ground water for hazardous constituents...

  1. Students' Formalising Process of the Limit Concept (United States)

    Kabael, Tangul


    The concept of limit is the foundation for many concepts such as the derivative and the integral in advanced mathematics. The limit concept has been a research topic in mathematics education for years and in the literature it is a broadly accepted fact that the limit is a difficult notion for most students. The study presented in this article is a…

  2. Transfer entropy and transient limits of computation. (United States)

    Prokopenko, Mikhail; Lizier, Joseph T


    Transfer entropy is a recently introduced information-theoretic measure quantifying directed statistical coherence between spatiotemporal processes, and is widely used in diverse fields ranging from finance to neuroscience. However, its relationships to fundamental limits of computation, such as Landauer's limit, remain unknown. Here we show that in order to increase transfer entropy (predictability) by one bit, heat flow must match or exceed Landauer's limit. Importantly, we generalise Landauer's limit to bi-directional information dynamics for non-equilibrium processes, revealing that the limit applies to prediction, in addition to retrodiction (information erasure). Furthermore, the results are related to negentropy, and to Bremermann's limit and the Bekenstein bound, producing, perhaps surprisingly, lower bounds on the computational deceleration and information loss incurred during an increase in predictability about the process. The identified relationships set new computational limits in terms of fundamental physical quantities, and establish transfer entropy as a central measure connecting information theory, thermodynamics and theory of computation.

  3. Disparity Limit for Binocular Fusion in Fovea (United States)

    Qin, Damin; Takamatsu, Mamoru; Nakashima, Yoshio

    In the human visual system, binocular disparity limit must be limited within a certain fusional area, called “Panum's fusional area”; otherwise, unsuitable disparity could cause double vision. The previous studies on Panum's fusional area have focused only on the horizontal and vertical meridians. In order to measure this area in more directions, we determined its limits in 16 different directions from 0 to 360° at 22.5° steps in fovea. It was found that: (1) the horizontal disparity limit (about 32-40 arcmin) is larger than the vertical limit (about 19.2 25.6 arcmin); (2) Panum's fusional area is approximately symmetrical around the horizontal meridian; (3) however, it is not symmetrical around the vertical meridian; the nasalward disparity limits are obviously larger than temporalward disparity limits; (4) therefore, the form of Panum's fusional area in fovea could be suggested to be an ellipse off-centered toward the nasal side on the horizontal meridian.

  4. Generalized improper integral definition for finite limit


    Blischke, Michael A.


    A generalization of the definition of a one-dimensional improper integral with a finite limit is presented. The new definition extends the range of valid integrals to include integrals which were previously considered to not be integrable. This definition is shown to be equivalent to the infinite limit definition presented in "Generalized improper integral definition for infinite limit" (arXiv:0805.3559) via a particular change of variable of integration. The definition preserves linearity an...

  5. Momentum limiting velocity controls for robotic manipulators (United States)

    Mcinroy, John E.; Saridis, George N.; Bryan, Tom


    Robotic tasks in space require manipulating massive objects capable of attaining large momentum. The momentum can pose hazardous conditions and introduce destabilizing effects on a space platform. Consequently, a technique for limiting the momentum applied to objects under manipulation subject to arbitrary velocity input commands is proposed. The algorithm does not require mass position or inertia information about the object, and it takes actuator limitations into account in forming the momentum limits. To evaluate the probability that a velocity trajectory will fall within the momentum bounds, reliability theory is employed. This enables autonomously generated trajectories to be validated for compliance with momentum limits.

  6. Central Limit Theorems under additive deformations. (United States)

    Eck, Daniel J; McKeague, Ian W


    Additive deformations of statistical systems arise in various areas of physics. Classical central limit theory is then no longer applicable, even when standard independence assumptions are preserved. This paper investigates ways in which deformed algebraic operations lead to distinctive central limit theory. We establish some general central limit results that are applicable to a range of examples arising in nonextensive statistical mechanics, including the addition of momenta and velocities via Kaniadakis addition, and Tsallis addition. We also investigate extensions to random additive deformations, and find evidence (based on simulation studies) for a universal limit specific to each statistical system.

  7. From the Planar Limit to M Theory (United States)

    Azeyanagi, Tatsuo; Fujita, Mitsutoshi; Hanada, Masanori


    The large-N limit of gauge theories has been playing a crucial role in theoretical physics over the decades. Despite its importance, little is known outside the planar limit where the ’t Hooft couplingλ=gYM2N is fixed. In this Letter we consider more general large-N limit—λ grows with N, e.g., gYM2 is fixed. Such a limit is important particularly in recent attempts to find the nonpertubative formulation of M theory. Based on various supporting evidence, we propose this limit is essentially identical to the planar limit, in the sense the order of the large-N limit and the strong coupling limit commute. For a wide class of large-N gauge theories, these two limits are smoothly connected, and the analytic continuation from the planar limit is justified. As simple examples, we reproduce a few properties of the six-dimensional N=(2,0) theory on S1 from the five-dimensional maximal super Yang-Mills theory, supporting the recent conjecture by Douglas and Lambert et al. that these two theories are identical.

  8. Accurate test limits under nonnormal measurement error

    NARCIS (Netherlands)

    Albers, Willem/Wim; Kallenberg, W.C.M.; Otten, G.D.


    When screening a production process for nonconforming items the objective is to improve the average outgoing quality level. Due to measurement errors specification limits cannot be checked directly and hence test limits are required, which meet some given requirement, here given by a prescribed

  9. Quantum quenches in the thermodynamic limit. (United States)

    Rigol, M


    We introduce a linked-cluster based computational approach that allows one to study quantum quenches in lattice systems in the thermodynamic limit. This approach is used to study quenches in one-dimensional lattices. We provide evidence that, in the thermodynamic limit, thermalization occurs in the nonintegrable regime but fails at integrability. A phase transitionlike behavior separates the two regimes.

  10. 40 CFR 35.9065 - Limitations. (United States)


    ... cost share of the aggregate costs of research, surveys, studies, modeling, and other technical work... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Limitations. 35.9065 Section 35.9065... ASSISTANCE Financial Assistance for the National Estuary Program § 35.9065 Limitations. (a) Management...

  11. Distinguishing Limitation on Constitutional Rights from Their ...

    African Journals Online (AJOL)

    Suspension of and limitation on fundamental rights and freedoms are justified violations of constitutional rights. Temporary suspension of some fundamental rights and freedoms can be made on the ground of a state of emergency. Since most constitutional rights are not absolute, they can be limited on basis of national ...

  12. 48 CFR 5416.203-3 - Limitations. (United States)


    ... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Limitations. 5416.203-3 Section 5416.203-3 Federal Acquisition Regulations System DEFENSE LOGISTICS AGENCY, DEPARTMENT OF DEFENSE TYPES OF CONTRACTS Fixed Price Contracts 5416.203-3 Limitations. (S-90) A fixed price contract with...

  13. 5 CFR 2604.305 - Time limits. (United States)


    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Time limits. 2604.305 Section 2604.305 Administrative Personnel OFFICE OF GOVERNMENT ETHICS ORGANIZATION AND PROCEDURES FREEDOM OF INFORMATION ACT RULES... Disclosure of Records Under FOIA § 2604.305 Time limits. (a)(1) Initial request. Following receipt of a...

  14. 47 CFR 78.115 - Modulation limits. (United States)


    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Modulation limits. 78.115 Section 78.115... SERVICE Technical Regulations § 78.115 Modulation limits. (a) If amplitude modulation is employed, negative modulation peaks shall not exceed 100 percent modulation. Pt. 78, Index Alphabetical Index—Part 78...

  15. 47 CFR 74.663 - Modulation limits. (United States)


    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Modulation limits. 74.663 Section 74.663 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES EXPERIMENTAL RADIO... Stations § 74.663 Modulation limits. If amplitude modulation is employed, negative modulation peaks shall...

  16. Limitations and opportunities of transcutaneous bilirubin measurements

    NARCIS (Netherlands)

    Bosschaart, Nienke; Kok, Joke; Newsum, Astrid; Ouweneel, Dagmar; Mentink, Rosaline; van Leeuwen, Ton; Aalders, Maurice C.G.


    OBJECTIVE: Although transcutaneous bilirubinometers have existed for over 30 years, the clinical utility of the technique is limited to a screening method for hyperbilirubinemia, rather than a replacement for invasive blood sampling. In this study, we investigate the reason for this limited clinical

  17. Common Cause Abduction : Its Scope and Limits

    NARCIS (Netherlands)

    Dziurosz-Serafinowicz, Patryk


    Patryk Dziurosz-Serafmowicz, Common Cause Abduction: Its Scope and Limits This article aims to analyze the scope and limits of common cause abduction which is a version of explanatory abduction based on Hans Reichenbach's Principle of the Common Cause. First, it is argued that common cause abduction

  18. 7 CFR 1a.4 - Limitations. (United States)


    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Limitations. 1a.4 Section 1a.4 Agriculture Office of the Secretary of Agriculture LAW ENFORCEMENT AUTHORITIES § 1a.4 Limitations. The powers granted by... of alleged or suspected felony violations of statutes administered by the Secretary of Agriculture or...

  19. 31 CFR 281.7 - Limitations. (United States)


    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Limitations. 281.7 Section 281.7 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL SERVICE, DEPARTMENT OF THE TREASURY FINANCIAL MANAGEMENT SERVICE FOREIGN EXCHANGE OPERATIONS § 281.7 Limitations. The...

  20. Limitations and Opportunities of Transcutaneous Bilirubin Measurements

    NARCIS (Netherlands)

    Bosschaart, Nienke; Kok, Joke H.; Newsum, Astrid M.; Ouweneel, Dagmar M.; Mentink, Rosaline; van Leeuwen, Ton G.; Aalders, Maurice C. G.


    OBJECTIVE: Although transcutaneous bilirubinometers have existed for over 30 years, the clinical utility of the technique is limited to a screening method for hyperbilirubinemia, rather than a replacement for invasive blood sampling. In this study, we investigate the reason for this limited clinical

  1. Central Limit Theorem for Coloured Hard Dimers

    Directory of Open Access Journals (Sweden)

    Maria Simonetta Bernabei


    Full Text Available We study the central limit theorem for a class of coloured graphs. This means that we investigate the limit behavior of certain random variables whose values are combinatorial parameters associated to these graphs. The techniques used at arriving this result comprise combinatorics, generating functions, and conditional expectations.

  2. 14 CFR 141.23 - Advertising limitations. (United States)


    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Advertising limitations. 141.23 Section 141...) SCHOOLS AND OTHER CERTIFICATED AGENCIES PILOT SCHOOLS General § 141.23 Advertising limitations. (a) The... certificate may not advertise that the school is certificated unless it clearly differentiates between courses...

  3. 14 CFR 142.31 - Advertising limitations. (United States)


    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Advertising limitations. 142.31 Section 142...) SCHOOLS AND OTHER CERTIFICATED AGENCIES TRAINING CENTERS General § 142.31 Advertising limitations. (a) A certificate holder may not conduct, and may not advertise to conduct, any training, testing, and checking that...


    NARCIS (Netherlands)

    BERKES, [No Value; DEHLING, H

    Motivated by recent results on pathwise central limit theorems, we study in a systematic way log-average versions of classical limit theorems. For partial sums S(k) of independent r.v.'s we prove under mild technical conditions that (1/log N)SIGMA(k less-than-or-equal-to N)(1/k)I{S(k)/a(k)

  5. Estimating uncertainty of data limited stock assessments

    DEFF Research Database (Denmark)

    Kokkalis, Alexandros; Eikeset, Anne Maria; Thygesen, Uffe Høgsbro


    Many methods exist to assess the fishing status of data-limited stocks; however, little is known about the accuracy or the uncertainty of such assessments. Here we evaluate a new size-based data-limited stock assessment method by applying it to well-assessed, data-rich fish stocks treated as data......-limited. Particular emphasis is put on providing uncertainty estimates of the data-limited assessment. We assess four cod stocks in the North-East Atlantic and compare our estimates of stock status (F/Fmsy) with the official assessments. The estimated stock status of all four cod stocks followed the established stock...... assessments remarkably well and the official assessments fell well within the uncertainty bounds. The estimation of spawning stock biomass followed the same trends as the official assessment, but not the same levels. We conclude that the data-limited assessment method can be used for stock assessment...

  6. Limiting law excess sum rule for polyelectrolytes. (United States)

    Landy, Jonathan; Lee, YongJin; Jho, YongSeok


    We revisit the mean-field limiting law screening excess sum rule that holds for rodlike polyelectrolytes. We present an efficient derivation of this law that clarifies its region of applicability: The law holds in the limit of small polymer radius, measured relative to the Debye screening length. From the limiting law, we determine the individual ion excess values for single-salt electrolytes. We also consider the mean-field excess sum away from the limiting region, and we relate this quantity to the osmotic pressure of a dilute polyelectrolyte solution. Finally, we consider numerical simulations of many-body polymer-electrolyte solutions. We conclude that the limiting law often accurately describes the screening of physical charged polymers of interest, such as extended DNA.

  7. Limited health literacy in advanced kidney disease. (United States)

    Taylor, Dominic M; Bradley, John A; Bradley, Clare; Draper, Heather; Johnson, Rachel; Metcalfe, Wendy; Oniscu, Gabriel; Robb, Matthew; Tomson, Charles; Watson, Chris; Ravanan, Rommel; Roderick, Paul


    Limited health literacy may reduce the ability of patients with advanced kidney disease to understand their disease and treatment and take part in shared decision making. In dialysis and transplant patients, limited health literacy has been associated with low socioeconomic status, comorbidity, and mortality. Here, we investigated the prevalence and associations of limited health literacy using data from the United Kingdom-wide Access to Transplantation and Transplant Outcome Measures (ATTOM) program. Incident dialysis, incident transplant, and transplant wait-listed patients ages 18 to 75 were recruited from 2011 to 2013 and data were collected from patient questionnaires and case notes. A score >2 in the Single-Item Literacy Screener was used to define limited health literacy. Univariate and multivariate analyses were performed to identify patient factors associated with limited health literacy. We studied 6842 patients, 2621 were incident dialysis, 1959 were wait-listed, and 2262 were incident transplant. Limited health literacy prevalence was 20%, 15%, and 12% in each group, respectively. Limited health literacy was independently associated with low socioeconomic status, poor English fluency, and comorbidity. However, transplant wait-listing, preemptive transplantation, and live-donor transplantation were associated with increasing health literacy. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

  8. Processes and patterns of oceanic nutrient limitation (United States)

    Moore, C. M.; Mills, M. M.; Arrigo, K. R.; Berman-Frank, I.; Bopp, L.; Boyd, P. W.; Galbraith, E. D.; Geider, R. J.; Guieu, C.; Jaccard, S. L.; Jickells, T. D.; La Roche, J.; Lenton, T. M.; Mahowald, N. M.; Marañón, E.; Marinov, I.; Moore, J. K.; Nakatsuka, T.; Oschlies, A.; Saito, M. A.; Thingstad, T. F.; Tsuda, A.; Ulloa, O.


    Microbial activity is a fundamental component of oceanic nutrient cycles. Photosynthetic microbes, collectively termed phytoplankton, are responsible for the vast majority of primary production in marine waters. The availability of nutrients in the upper ocean frequently limits the activity and abundance of these organisms. Experimental data have revealed two broad regimes of phytoplankton nutrient limitation in the modern upper ocean. Nitrogen availability tends to limit productivity throughout much of the surface low-latitude ocean, where the supply of nutrients from the subsurface is relatively slow. In contrast, iron often limits productivity where subsurface nutrient supply is enhanced, including within the main oceanic upwelling regions of the Southern Ocean and the eastern equatorial Pacific. Phosphorus, vitamins and micronutrients other than iron may also (co-)limit marine phytoplankton. The spatial patterns and importance of co-limitation, however, remain unclear. Variability in the stoichiometries of nutrient supply and biological demand are key determinants of oceanic nutrient limitation. Deciphering the mechanisms that underpin this variability, and the consequences for marine microbes, will be a challenge. But such knowledge will be crucial for accurately predicting the consequences of ongoing anthropogenic perturbations to oceanic nutrient biogeochemistry.

  9. The limits on trypanosomatid morphological diversity.

    Directory of Open Access Journals (Sweden)

    Richard John Wheeler

    Full Text Available Cell shape is one, often overlooked, way in which protozoan parasites have adapted to a variety of host and vector environments and directional transmissions between these environments. Consequently, different parasite life cycle stages have characteristic morphologies. Trypanosomatid parasites are an excellent example of this in which large morphological variations between species and life cycle stage occur, despite sharing well-conserved cytoskeletal and membranous structures. Here, using previously published reports in the literature of the morphology of 248 isolates of trypanosomatid species from different hosts, we perform a meta-analysis of the occurrence and limits on morphological diversity of different classes of trypanosomatid morphology (trypomastigote, promastigote, etc. in the vertebrate bloodstream and invertebrate gut environments. We identified several limits on cell body length, cell body width and flagellum length diversity which can be interpreted as biomechanical limits on the capacity of the cell to attain particular dimensions. These limits differed for morphologies with and without a laterally attached flagellum which we suggest represent two morphological superclasses, the 'juxtaform' and 'liberform' superclasses. Further limits were identified consistent with a selective pressure from the mechanical properties of the vertebrate bloodstream environment; trypanosomatid size showed limits relative to host erythrocyte dimensions. This is the first comprehensive analysis of the limits of morphological diversity in any protozoan parasite, revealing the morphogenetic constraints and extrinsic selection pressures associated with the full diversity of trypanosomatid morphology.

  10. Fractional Diffusion Limit for Collisional Kinetic Equations

    KAUST Repository

    Mellet, Antoine


    This paper is devoted to diffusion limits of linear Boltzmann equations. When the equilibrium distribution function is a Maxwellian distribution, it is well known that for an appropriate time scale, the small mean free path limit gives rise to a diffusion equation. In this paper, we consider situations in which the equilibrium distribution function is a heavy-tailed distribution with infinite variance. We then show that for an appropriate time scale, the small mean free path limit gives rise to a fractional diffusion equation. © 2010 Springer-Verlag.

  11. Deficit Limits, Budget Rules, and Fiscal Policy


    Paolo Manasse


    The paper presents a simple model for discussing the effects of deficit limits and budget rules on fiscal policy. I find that limits on deficit- output ratios provide incentives to implement procyclical policies when the economy is in intermediate states, and countercyclical policies only in very “good” and very “bad” economic times. As a result, fiscal “reaction functions” are not monotonically related to the state of the economy. Deficit limits are found to exert discipline only provided th...

  12. 48 CFR 246.705 - Limitations. (United States)


    ... OF DEFENSE CONTRACT MANAGEMENT QUALITY ASSURANCE Warranties 246.705 Limitations. (a) In addition to the exceptions provided in FAR 46.705(a), warranties in the clause at 252.246-7001, Warranty of Data...

  13. Limited english proficiency accessibility program : demonstration program. (United States)


    In 2006, the Tri-County Metropolitan Transportation District of Oregon (TriMet) secured grant funding from the Federal Transit Administration : (FTA) that enabled the agency to launch a creative and ambitious Limited English Proficiency (LEP) demonst...

  14. Are there limits to running world records?

    National Research Council Canada - National Science Library

    Nevill, Alan M; Whyte, Gregory


    ... records could reach their asymptotic limits some time in the future. Middle- and long-distance running world record speeds recorded during the 20th century were modeled using a flattened S-shaped logistic curve...

  15. 41 CFR 109-50.204 - Limitations. (United States)


    ... DISPOSAL AUTHORITIES 50.2-Math and Science Equipment Gift Program § 109-50.204 Limitations. (a) Excess and... (or unlimited) level of authority. (d) Gifts shall be serviceable and in working order. Disposal...

  16. Spending Limitations, Agenda Control and Voters' Expectations. (United States)

    Denzau, Arthur; And Others


    Introduces the notion of spending limitations into an analytical framework in which government possesses a form of monopoly power that results from imperfections in the agenda formation process. Journal availability: see EA 511 898. (Author/IRT)

  17. Limitations of science and adaptive management

    Energy Technology Data Exchange (ETDEWEB)

    Narasimhan, T.N.


    Adaptive management consists in patterning human sustenancewithin the constraints of Earth and biological systems whose behavior isinherently uncertain and difficult to control. For successful adaptivemanagement, a mind-set recognizing the limitations of science isneeded.

  18. Limiting effects in double EEX beamline (United States)

    Ha, G.; Power, J. G.; Conde, M.; Doran, D. S.; Gai, W.


    The double emittance exchange (EEX) beamline is suggested to overcome the large horizontal emittance and transverse jitter issues associated with the single EEX beamline while preserving its powerful phase-space manipulation capability. However, the double EEX beamline also has potential limitations due to coherent synchrotron radiation (CSR) and transverse jitter. The former limitation arises because double EEX uses twice as many bending magnets as single EEX which means stronger CSR effects degrading the beam quality. The latter limitation arises because a longitudinal jitter in front of the first EEX beamline is converted into a transverse jitter in the middle section (between the EEX beamlines) which can cause beam loss or beam degradation. In this paper, we numerically explore the effects of these two limitations on the emittance and beam transport.

  19. Foods to Avoid or Limit during Pregnancy (United States)

    ... Global Map Premature Birth Report Cards Careers Archives Pregnancy Before or between pregnancies Nutrition, weight & fitness Prenatal ... during pregnancy Foods to avoid or limit during pregnancy E-mail to a friend Please fill in ...

  20. Scallop License Limitation Program (SLLP) Permit Program (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A federal Scallop License Limitation Program (SLLP) license is required onboard any vessel deployed in scallop fisheries in Federal waters off Alaska (except for...

  1. Southern Hemisphere Ice Limits, 1973-1978 (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Weekly Southern Ocean ice limits, have been digitized from U.S. Navy Fleet Weather Facility ice charts, at the Max-Planck Institut fur Meteorologie, Hamburg....

  2. 40 CFR 63.802 - Emission limits. (United States)


    ... Standards for Wood Furniture Manufacturing Operations § 63.802 Emission limits. (a) Each owner or operator... 133, the Business and Institutional Furniture Manufacturers Association's (BIFMA's) X5.7, UFAC...

  3. Recreational Limits in a World of Ethics. (United States)

    Dustin, Daniel L.


    The responsibility of recreation professionals is to encourage others to recreate in more sensitive ways, rather than highly consumptive, power-based ways. The psychology of affluence and limits on resources and their influence on recreational activities are discussed. (DF)

  4. Health Outcomes Survey - Limited Data Set (United States)

    U.S. Department of Health & Human Services — The Medicare Health Outcomes Survey (HOS) limited data sets (LDS) are comprised of the entire national sample for a given 2-year cohort (including both respondents...

  5. Optical Limiting in Photonic Crystal Fibers

    National Research Council Canada - National Science Library

    Bloemer, Mark; Scalora, Michael; Davenport, Wayne; Poliakov, Evgeni; Konorov, S. O; Sidorov-Biryukov, D. A; Serebryannikov, E. E; Zheltikov, A. M; Miles, R. B; Bugar, I


    .... We have shown that the limiting energy depends on the effective mode area of the fiber, the passband width of the propagating fiber mode, the length of the fiber, and the nonlinear refractive index of the gas (or other material...

  6. Emotional contagion: its scope and limits. (United States)

    Dezecache, Guillaume; Jacob, Pierre; Grèzes, Julie


    The contagion model of emotional propagation has almost become a dogma in cognitive science. We turn here to the evolutionary approach to communicative interactions to probe the limits of the contagion model. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Limits and signatures of relativistic spaceflight (United States)

    Yurtsever, Ulvi; Wilkinson, Steven


    While special relativity imposes an absolute speed limit at the speed of light, our Universe is not empty Minkowski spacetime. The constituents that fill the interstellar/intergalactic vacuum, including the cosmic microwave background photons, impose a lower speed limit on any object travelling at relativistic velocities. Scattering of cosmic microwave photons from an ultra-relativistic object may create radiation with a characteristic signature allowing the detection of such objects at large distances.

  8. Operating limits Hanford Production Reactors. Revision 2

    Energy Technology Data Exchange (ETDEWEB)

    Owsley, G.F. [comp.


    This report is applicable to the eight operating production reactors, B, C, D, DR, F, H, KE, and KW. It covers the following: operating parameter limitations; reactivity limitations; control and safety systems; reactor fuel loading; coolant requirements with irradiated fuel in reactor; reactor confinement; test facilities; code compliance; safety instrumentation and set points; and control criteria. Also discussed are administrative procedures for process control, training, audits and inspection, and reports and records.

  9. 50 CFR 622.37 - Size limits. (United States)


    ...), TL. (iv) Red snapper -16 inches (40.6 cm), TL, for a fish taken by a person subject to the bag limit... to the bag limit specified in § 622.39(b)(1)(ii)—22 inches (55.9 cm), TL. (iv) Red grouper—(A) For a... inches (30.5 cm), TL. (iii) Blackfin, cubera, dog, gray, mahogany, queen, silk, and yellowtail snappers...

  10. Fundamental limits to extinction by metallic nanoparticles. (United States)

    Miller, O D; Hsu, C W; Reid, M T H; Qiu, W; DeLacy, B G; Joannopoulos, J D; Soljačić, M; Johnson, S G


    We show that there are shape-independent upper bounds to the extinction cross section per unit volume of dilute, randomly arranged nanoparticles, given only material permittivity. Underlying the limits are restrictive sum rules that constrain the distribution of quasistatic eigenvalues. Surprisingly, optimally designed spheroids, with only a single quasistatic degree of freedom, reach the upper bounds for four permittivity values. Away from these permittivities, we demonstrate computationally optimized structures that surpass spheroids and approach the fundamental limits.

  11. Gulf of Mexico mud toxicity limitations

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, H.E.; Beardmore, D.H. (Phillips Petroleum Co., Bartlesville, OK (USA)); Stewart, W.S. (Drilling Specialties Co. (US))


    Because of the Environmental Protection Agency's recent toxicity limits on drilling mud discharges for offshore Gulf of Mexico, Phillips Petroleum conducted a mud toxicity study based on both field and lab tests. The study, discussed in this article, found the polyanionic cellulose-sulfomethylated quebracho-chrome lignosulfonate mud Phillips had been using would comfortably pass the toxicity limitations. The study also found barite and thinners were of low toxicity, and hydrocarbons and surfactants were highly toxic.

  12. Governing economies in areas of limited statehood

    DEFF Research Database (Denmark)

    Rasmussen, Jacob; Varming, Kirstine Strøh

    This DIIS–GOVSEA working paper reviews key debates within economic anthropology and related academic disciplines explaining how economic life is governed in areas of limited statehood. The paper briefly introduces some of the origins of economic anthropology before going into deeper discussions....../non-state, rational/moral, in order to provide insights for the study of economic behaviour and economic governance in areas of limited statehood....

  13. Fundamental Limitations of Phased Array Antenna Elements (United States)


    1327. doi: 10.1109/TAP.2012.2227661 Do-Hoon Kwon, Hsieh -Chi Chang. Bandwidth limitations of linearly polarized infinite planar phased arrays in free...Transactions on Antennas and Propagation (07 2014) Do-Hoon Kwon, Hsieh -Chi Chang. Bandwidth Limitations of Infinite Planar Phased Arrays in Free Space...Students Names of Post Doctorates Received Book TOTAL: Received Book Chapter TOTAL: PERCENT_SUPPORTEDNAME FTE Equivalent: Total Number: Discipline Hsieh -Chi

  14. Fundamental Limits in Wireless Wideband Networking


    Do, Tan Tai


    The rapid growth of the wireless communication industry recently does not only bring opportunities but also challenges on developing radio technologies and solutions that can support high data rate as well as reliable and efficient communications. Two fundamental factors that limit the transmission rate are the available transmit energy and the available bandwidth. In this thesis, we investigate fundamental limits on energy and bandwidth efficiencies in wireless wideband networking. The frame...

  15. Compression limits in cascaded quadratic soliton compression

    DEFF Research Database (Denmark)

    Bache, Morten; Bang, Ole; Krolikowski, Wieslaw


    Cascaded quadratic soliton compressors generate under optimal conditions few-cycle pulses. Using theory and numerical simulations in a nonlinear crystal suitable for high-energy pulse compression, we address the limits to the compression quality and efficiency.......Cascaded quadratic soliton compressors generate under optimal conditions few-cycle pulses. Using theory and numerical simulations in a nonlinear crystal suitable for high-energy pulse compression, we address the limits to the compression quality and efficiency....

  16. Fundamental energetic limits of radio communication systems (United States)

    Baudais, Jean-Yves


    The evaluation of the energy consumption of a radiocommunication requires to analyse the life cycle of the elements used. However, this analysis does not specify the energetic limits. Theoretical approaches allow one to draw these limits, which are known in multiple cases of information transmission. However, the answers are not always satisfactory, in particular in the case of time-varying channels. After a brief presentation of the notion of energetic limits of a radiocommunication, and beginning with a global approach, we show that, contrary to the published results, the energetic limits always differ from zero if the physical constraints are correctly expressed. xml:lang="fr" Cependant, les réponses ne sont pas toujours satisfaisantes, particulièrement dans le cas de canaux variants dans le temps. Après une rapide présentation des notions d'énergie limite d'une radiocommunication, et en commençant par une approche globale du problème, nous montrons que, contrairement aux résultats publiés, les limites énergétiques sont toujours différentes de zéro si les contraintes physiques sont correctement exprimées.

  17. Risk based limits for Operational Safety Requirements

    Energy Technology Data Exchange (ETDEWEB)

    Cappucci, A.J. Jr.


    OSR limits are designed to protect the assumptions made in the facility safety analysis in order to preserve the safety envelope during facility operation. Normally, limits are set based on ``worst case conditions`` without regard to the likelihood (frequency) of a credible event occurring. In special cases where the accident analyses are based on ``time at risk`` arguments, it may be desirable to control the time at which the facility is at risk. A methodology has been developed to use OSR limits to control the source terms and the times these source terms would be available, thus controlling the acceptable risk to a nuclear process facility. The methodology defines a new term ``gram-days``. This term represents the area under a source term (inventory) vs time curve which represents the risk to the facility. Using the concept of gram-days (normalized to one year) allows the use of an accounting scheme to control the risk under the inventory vs time curve. The methodology results in at least three OSR limits: (1) control of the maximum inventory or source term, (2) control of the maximum gram-days for the period based on a source term weighted average, and (3) control of the maximum gram-days at the individual source term levels. Basing OSR limits on risk based safety analysis is feasible, and a basis for development of risk based limits is defensible. However, monitoring inventories and the frequencies required to maintain facility operation within the safety envelope may be complex and time consuming.

  18. 24 CFR 248.127 - Limitations on action pursuant to Federal cost limit. (United States)


    ... cost limit. (b) Transfer of the project. With respect to owners who seek to transfer the project— (1) If the transfer preservation rent does not exceed the Federal cost limit, or if the transfer preservation rent exceeds the Federal cost limit and the owner is willing to transfer the project at a price...

  19. Communicative action as a way of annihilating the human limits. Human limits in transhumanism




    In this paper we aim to analyse the biological limits of the human individual and the limits of knowledge, as well as the way they can be overcome Transhumanism can be defined as: the idea that humans can use reason in order to transcend the limit of the human condition within transhumanism

  20. Limiting factors in caribou population ecology

    Directory of Open Access Journals (Sweden)

    David R. Klein


    Full Text Available Caribou and wild reindeer populations fluctuate over time. On this fact there is general agreement. Factors responsible for population limitation and subsequent declines have been examined within the framework of animal population theory. There is, however, little agreement when factors limiting specific populations are generalized to Rangifer populations over broad geographic regions. Comparative examinations of wild Rangifer populations worldwide discloses that factors that have regulated those populations are highly variable between populations, apparently as a reflection of the differences in environmental variables unique to each population. Examples exist of populations where major regulating factors have been climatic extremes, predation, hunting mortality, food limitation, insects, parasites, disease, interspecific competition, and human developmental impacts or combinations of these factors. This diversity of limiting factors affecting caribou and wild reindeer populations is a reflection of the ecologial complexity of the species, a concept that has often been ignored in past efforts to reach management decisions by extrapolation from the limited localized knowledge available on the species.

  1. The Cognitive Limits to Economic Cluster Formation

    Directory of Open Access Journals (Sweden)

    Michael C. Carrol


    Full Text Available There has been increasing interest in the social dimensions of economic clusters. The literature now includes select examples of social network analysis plus an extensive discussion of learning regions. Unfortunately, much of this work treats the network as the primary unit of analysis. It may be that network attributes such as density, centrality, and power are primarily dependent on human limitations and not instituted factors. In other words, a human’s limited ability to process information may be a better determinant of cluster success than economic or network theory. The purpose of this paper is to highlight human limits in cluster formation. To do this, we draw on recent developments in the cognitive psychology and communications literatures. We explain that many of the factors that lead to underperforming cluster policies are the result of a human’s inability to develop and sustain a large number of social interactions. Any cluster policy must be cognizant of such limitations and carefully address these limits in the formation of the initial strategy.

  2. Limit characteristics of digital optoelectronic processor (United States)

    Kolobrodov, V. G.; Tymchik, G. S.; Kolobrodov, M. S.


    In this article, the limiting characteristics of a digital optoelectronic processor are explored. The limits are defined by diffraction effects and a matrix structure of the devices for input and output of optical signals. The purpose of a present research is to optimize the parameters of the processor's components. The developed physical and mathematical model of DOEP allowed to establish the limit characteristics of the processor, restricted by diffraction effects and an array structure of the equipment for input and output of optical signals, as well as to optimize the parameters of the processor's components. The diameter of the entrance pupil of the Fourier lens is determined by the size of SLM and the pixel size of the modulator. To determine the spectral resolution, it is offered to use a concept of an optimum phase when the resolved diffraction maxima coincide with the pixel centers of the radiation detector.

  3. Resistive Ferroresonance Limiter for Potential Transformers

    Directory of Open Access Journals (Sweden)

    Hamid Radmanesh


    Full Text Available The ferroresonance or nonlinear resonance is a complex phenomenon, which may cause overvoltage in the electrical power system and endangers the system reliability and operation. The ability to predict the ferroresonance in the transformer depends on the accuracy of the transformer model used. In this paper, the effect of the new suggested ferroresonance limiter on the control of the chaotic ferroresonance and duration of chaotic transients in a potential transformer including nonlinear core losses is studied. To study the proposed ferroresonance limiter, a single phase 100 VA, 275 kV potential transformer is simulated. The magnetization characteristic of the potential transformer is modeled by a single-value two-term polynomial. The core losses are modeled by third order power series in terms of voltage and include core nonlinearities. The simulation results show that the ferroresonance limiter has a considerable effect on the ferroresonance overvoltage.

  4. The thermodynamic limits of magnetic recording (United States)

    Richter, H. J.; Lyberatos, A.; Nowak, U.; Evans, R. F. L.; Chantrell, R. W.


    Thermal stability of the recorded information is generally thought to set the limit of the maximum possible density in magnetic recording. It is shown that basic thermodynamics always cause the probability of success of the write process to be less than 100%. This leads to a thermally induced error rate, which eventually limits the maximum possible density beyond that given by the traditional thermal stability limit. While the thermally induced error rate is negligible for recording of simple single domain particles, it rapidly increases in the presence of a write assist, in particular if the write assist is accomplished by an increased recording temperature. For the ultimate recording system that combines thermally assisted writing with a recording scheme that uses one grain per bit, the upper bound for the maximum achievable density is 20 Tbit/inch2 for a bit error rate target of 10-2.

  5. Occupational Exposures and Chronic Airflow Limitation

    Directory of Open Access Journals (Sweden)

    Helen Dimich-Ward


    Full Text Available The recent literature was reviewed to evaluate whether chronic airflow limitation is associated with occupational exposures to dusts. Only those studies that controlled for the effects of smoking were included. There is compelling evidence that exposure to inorganic dusts, such as from coal and hardrock mining or asbestos, are associated with the development of chronic airflow limitation, independently of pneumoconiosis. Nonsmoking gold miners are particularly at high risk of airflow obstruction and emphysema. Findings from studies of organic dusts, such as exposures to wood, cotton, grain or other agricultural dusts, or to mixed dust exposures, were less consistent but tended to show positive dose-response associations. In the majority of studies, no statistical interaction was shown between dust exposures and smoking; however, the effects of the dust exposures were often more pronounced. An occupational history should be considered, in addition to a smoking history, as an integral part of an investigation of chronic airflow limitation in a patient.


    Energy Technology Data Exchange (ETDEWEB)

    Socrates, Aristotle [Institute for Advanced Study, Einstein Drive, Princeton, NJ 08540 (United States); Sironi, Lorenzo, E-mail:, E-mail: [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States)


    Bright star-forming galaxies radiate well below their Eddington limits. The value of the flux-mean opacity that mediates the radiation force onto matter is orders of magnitude smaller than the UV or optical dust opacity. On empirical grounds, it is shown that high-redshift ULIRGs radiate at two orders of magnitude below their Eddington limits, while the local starbursters M82 and Arp 220 radiate at a few percent of their Eddington limits. A model for the radiative transfer of UV and optical light in dust-rich environments is considered. Radiation pressure on dust does not greatly affect the large-scale gas dynamics of star-forming galaxies.

  7. Thermal activation model of endurance limit (United States)

    Lü, Baotong; Zheng, Xiulin


    A thermal activation model of the endurance limit is proposed in the present study. It can quantitatively explain the effects of temperature and frequency on the endurance limit of metals at or below room temperature. Theoretical analysis indicates that the endurance limit, σac, which is considered as a parameter characterizing the resistance of metals to cyclic microplastic deformation, has the same thermally activated nature as the plastic flow stress has and it can be resolved into two independent components: the long-range internal stress (the athermal component), μ(ɛapc), and the short-range effective stress (the thermal component), σa *( T, ɛp). The former is considered as a material constant insensitive to temperature and strain rate (or frequency). The latter, the temperature- and strain rate-dependent part of the endurance limit, is approximately identical with the effective stress component of plastic flow stress (or cyclic yielding stress). In light of the thermal activation model, the temperature and strain-rate dependence of monotonic and cyclic flow stresses in a low alloy steel (16Mn) and a precipitation-hardening aluminum alloy (LY12CZ) were experimentally investigated. The results indicate that the effective stress components of monotonic and cyclic flow stresses are identical, if the temperature and strain rate are held unchanged, and that both of them are approximately independent of the magnitude of plastic strain. On the basis of the thermal activation model, an expression predicting the endurance limit below room temperature is offered. The predicted values of the endurance limit agree with the test data of steels and aluminum alloys available in literature.

  8. The Twist Limit for Bipolar Active Regions (United States)

    Moore, Ron; Falconer, David; Gary, Allen


    We present new evidence that further supports the standard idea that active regions are emerged magnetic-flux-rope omega loops. When the axial magnetic twist of a cylindrical flux rope exceeds a critical amount, the flux rope becomes unstable to kinking, and the excess axial twist is converted into writhe twist by the kinking. This suggests that, if active regions are emerged omega loops, then (1) no active region should have magnetic twist much above the limit set by kinking, (2) active regions having twist near the limit should often arise from kinked omega loops, and (3) since active regions having large delta sunspots are outstandingly twisted, these arise from kinked omega loops and should have twist near the limit for kinking. From each of 36 vector magnetograms of bipolar active regions, we have measured (1) the total flux of the vertical field above 100 G, (2) the area covered by this flux, and (3) the net electric current that arches over the polarity inversion line. These three quantities yield an estimate of the axial magnetic twist in a simple model cylindrical flux rope that corresponds to the top of the active region s hypothetical omega loop prior to emergence. In all 36 cases, the estimated twist is below the critical limit for kinking. The 11 most twisted active regions (1) have estimated twist within a factor of approx.3 of the limit, and (2) include all of our 6 active regions having large delta sunspots. Thus, our observed twist limit for bipolar active regions is in good accord with active regions being emerged omega loops.

  9. Numerical Limit Analysis of Precast Concrete Structures

    DEFF Research Database (Denmark)

    Herfelt, Morten Andersen; Poulsen, Peter Noe; Hoang, Linh Cao


    Design and analysis of precast concrete structures in the ultimate limit state is largely done by simple analytical calculations and linear elastic finite element analysis, which necessarily leads to suboptimal designs. Numerical limit analysis provides a framework well suited for this task...... optimisation as well as material optimisation is given and a four-storey shear wall is analysed using load optimisation. The analysis yields a capacity more than three times larger than the design load for the critical load case, and the collapse mode and stress distribution are analysed. Finally, numerical...

  10. Embracing the quantum limit in silicon computing. (United States)

    Morton, John J L; McCamey, Dane R; Eriksson, Mark A; Lyon, Stephen A


    Quantum computers hold the promise of massive performance enhancements across a range of applications, from cryptography and databases to revolutionary scientific simulation tools. Such computers would make use of the same quantum mechanical phenomena that pose limitations on the continued shrinking of conventional information processing devices. Many of the key requirements for quantum computing differ markedly from those of conventional computers. However, silicon, which plays a central part in conventional information processing, has many properties that make it a superb platform around which to build a quantum computer. © 2011 Macmillan Publishers Limited. All rights reserved

  11. Quantum interference fringes beating the diffraction limit


    Kawabe, Yoshio; Fujiwara, Hideki; Okamoto, Ryo; Sasaki, Keiji; Takeuchi, Shigeki


    Spatially formed two-photon interference fringes with fringe periods smaller than the diffraction limit are demonstrated. In the experiment, a fringe formed by two-photon NOON states with wavelength λ=702.2 nm is observed using a specially developed near-field scanning optical microscope probe and two-photon detection setup. The observed fringe period of 328.2 nm is well below the diffraction limit (351 nm = λ/2). Another experiment with a path-length difference larger than the coherent lengt...

  12. Quantum interference fringes beating the diffraction limit. (United States)

    Kawabe, Yoshio; Fujiwara, Hideki; Okamoto, Ryo; Sasaki, Keiji; Takeuchi, Shigeki


    Spatially formed two-photon interference fringes with fringe periods smaller than the diffraction limit are demonstrated. In the experiment, a fringe formed by two-photon NOON states with wavelength lambda=702.2 nm is observed using a specially developed near-field scanning optical microscope probe and two-photon detection setup. The observed fringe period of 328.2 nm is well below the diffraction limit (351 nm = lambda /2). Another experiment with a path-length difference larger than the coherent length of photons confirms that the observed fringe is due to two-photon interference.

  13. Controlled Limiter in the Synchronous Detection Circuit

    Directory of Open Access Journals (Sweden)

    Yauheni Bialetski


    Full Text Available This variant of construction of the electrical circuit is aimed at reducing the effects of impulse noise. The measuring channels of the primary transducers are subject to interference of various types. In the case of a small ratio between a useful signal and noise level, synchronous detection is used. Impulse noise leaves a big mark even after using synchronous detection. To improve the performance of such measuring devices, it is proposed to use a controlled amplitude limiter at the input. Comparative analysis of solutions with controlled limiters is carried out in the article and conditions for its optimal operation are determined.

  14. Optically Patternable Metamaterial Below Diffraction Limit. (United States)

    Lee, Youngseop; Park, Sang-Gil; Yoo, SeokJae; Kang, Minhee; Jeon, Sang Chul; Kim, Young-Su; Park, Q-Han; Jeong, Ki-Hun


    We report an optically patternable metamaterial (OPM) for ultraviolet nanolithography below the diffraction limit. The OPM features monolayered silver nanoislands embedded within a photosensitive polymer by using spin-coating of an ultrathin polymer, oblique angle deposition, and solid-state embedment of silver nanoislands. This unique configuration simultaneously exhibits both negative effective permittivity and high image contrast in the ultraviolet range, which enables the surface plasmon excitation for the clear photolithographic definition of minimum feature size of 70 nm (≲ λ/5) beyond the near-field zone. This new metamaterial provides a new class of photoresist for ultraviolet nanolithography below the diffraction limit.

  15. Growth Limits in Large Scale Networks

    DEFF Research Database (Denmark)

    Knudsen, Thomas Phillip

    limitations. The rising complexity of network management with the convergence of communications platforms is shown as problematic for both automatic management feasibility and for manpower resource management. In the fourth step the scope is extended to include the present society with the DDN project as its...... main focus. Here the general perception of the nature and role in society of large scale networks as a fundamental infrastructure is analysed. This analysis focuses on the effects of the technical DDN projects and on the perception of network infrastructure as expressed by key decision makers....... A summary of the most pressing growth limits for the coming three decades is given....

  16. Altitudinal distribution limits of aquatic macroinvertebrates

    DEFF Research Database (Denmark)

    Madsen, Philip B.; Morabowen, Andrés; Andino, Patricio


    1. Temperature and oxygen are recognised as the main drivers of altitudinal limits of species distributions. However, the two factors are linked, and both decrease with altitude, why their effects are difficult to disentangle. 2. This was experimentally addressed using aquatic macroinvertebrates...... altitudinal patterns in population densities, (ii) transplants of the five taxa upstream of their natural altitudinal limit to test the short-term (14days) effect on survival, and (iii) in situ experiments of locomotory activity as a proxy for animal response to relatively small differences in temperature (5...

  17. 50 CFR 635.20 - Size limits. (United States)


    ... take, retain or possess a blue marlin taken from its management unit that is less than 99 inches (251 cm), LJFL. (2) No person shall take, retain or possess a white marlin taken from its management unit... (160 cm), LJFL. (4) The Atlantic blue and white marlin minimum size limits, specified in paragraphs (d...

  18. Environmental Risk Limits for Nine Trace Elements

    NARCIS (Netherlands)

    Vlaardingen PLA van; Posthumus R; Posthuma-Doodeman CJAM; SEC


    In this report, we present an update of environmental risk limits (ERLs), based on the literature, for nine trace elements, namely, beryllium (Be), vanadium (V), cobalt (Co), selenium (Se), molybdenum (Mo), tin (Sn), antimony (Sb), barium (Ba) and thallium (Tl). The updated ERLs, established for

  19. Limits of Lubrication in Backward Can Extrusion

    DEFF Research Database (Denmark)

    Bennani, B; Bay, Niels


    material have been performed. These simulations gave good results concerning the prediction of the flow modes and the corresponding surface expansions of the workpiece material occurring at the contact surface between the can and the punch. These predictions set the limits of the can height, depending...... is determined. The numerical and experimental simulations showed good accordance....

  20. Chromatic roots and limits of dense graphs

    Czech Academy of Sciences Publication Activity Database

    Csikvári, P.; Frenkel, E.; Hladký, Jan; Hubai, T.


    Roč. 340, č. 5 (2017), s. 1129-1135 ISSN 0012-365X Institutional support: RVO:67985807 Keywords : chromatic root * graph limit * holomorphic moment Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 0.639, year: 2016

  1. 26 CFR 1.355-2 - Limitations. (United States)


    ..., including, but not limited to, the following factors: (A) The importance of achieving the purpose to the... operates a fast food restaurant in State M and owns all of the stock of corporation Y, which owns and operates a fast food restaurant in State N. X and Y operate their businesses under franchises granted by D...

  2. Temperature limit values for gripping cold surfaces

    NARCIS (Netherlands)

    Malchaire, J.; Geng, Q.; Den Hartog, E.; Havenith, G.; Holmer, I.; Piette, A.; Powell, S.L.; Rintamäki, H.; Rissanen, S.


    Objectives. At the request of the European Commission and in the framework of the European Machinery Directive, research was conducted jointly in five different laboratories to develop specifications for surface temperature limit values for the gripping and handling of cold items. Methods. Four

  3. 26 CFR 1.851-2 - Limitations. (United States)


    ... TAXES Regulated Investment Companies and Real Estate Investment Trusts § 1.851-2 Limitations. (a) Election to be a regulated investment company. Under the provisions of section 851(b)(1), a corporation... taxable year, will not be considered a regulated investment company for such year, within the meaning of...

  4. 48 CFR 1246.705 - Limitations. (United States)


    ... Section 1246.705 Federal Acquisition Regulations System DEPARTMENT OF TRANSPORTATION CONTRACT MANAGEMENT QUALITY ASSURANCE Warranties 1246.705 Limitations. (a) The following restrictions are applicable to DOT contracts: (1) The contractor shall not be required to honor the warranty on any property furnished by the...

  5. The Exact Limit of Some Cubic Towers

    DEFF Research Database (Denmark)

    Anbar Meidl, Nurdagül; Beelen, Peter; Nguyen, Nhut


    Recently, a new explicit tower of function fields was introduced by Bassa, Beelen, Garcia and Stichtenoth (BBGS). This resulted in currently the best known lower bound for Ihara’s constant in the case of non-prime finite fields. In particular over cubic fields, the tower’s limit is at least as good...

  6. 26 CFR 1.856-2 - Limitations. (United States)


    ... Investment Trust R has made no acquisition of stock or other property during such second quarter it will not... TAXES Real Estate Investment Trusts § 1.856-2 Limitations. (a) Effective date. The provisions of part II... estate investment trust beginning after December 31, 1960. (b) Election. Under the provisions of section...

  7. 50 CFR 20.61 - Importation limits. (United States)


    ... Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED... PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Importations § 20.61 Importation limits. No person shall import... wildlife authorities on the first day he hunts in Mexico, he may import the applicable Mexican possession...

  8. Optical Limiting Materials Based on Gold Nanoparticles (United States)


    F. A Review of Optical Limiting Mechanisms and Devices Using Organics, Fullerenes , Semiconductors and Other Materials. Prog. Quant. Electr. 1993...information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering...and maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any

  9. Professional and Legal Limits to Academic Freedom. (United States)

    Metzger, Walter P.


    Discussion of trends concerning academic freedom compares the limits to academic freedom traditionally rooted in professional ethics and applied by the academic profession with the areas of protection prescribed by courts. It is concluded that even when generous, rulings have not necessarily been in the best interest of the academy. (MSE)


    African Journals Online (AJOL)

    ES OBE

    . INTRODUCTION ... This can limit the compressive strength of a composite material to a very low fraction of its tensile strength; a review of the studies on compressive kinking failures in ..... (c) The nodal degree of freedom or displacements at ...

  11. Relation between spectroscopic constants with limited Dunham ...

    Indian Academy of Sciences (India)

    Statement of Kaur and Mahajan [1] about the definition of used by Chandra [2] is not correct. Even if we take = w 2 2 r e 2 / 2 D e , the relation between and (=8ωe/) is obtained as = 4.21452856G, provided the vibrational energy of a diatomic molecule is expressed in terms of limited Dunham coefficients, ...

  12. Fluid Limits of Optimally Controlled Queueing Networks


    Guodong Pang; Day, Martin V.


    We consider a class of queueing processes represented by a Skorokhod problem coupled with a controlled point process. Posing a discounted control problem for such processes, we show that the optimal value functions converge, in the fluid limit, to the value of an analogous deterministic control problem for fluid processes. Peer Reviewed

  13. Fluid Limits of Optimally Controlled Queueing Networks

    Directory of Open Access Journals (Sweden)

    Guodong Pang


    Full Text Available We consider a class of queueing processes represented by a Skorokhod problem coupled with a controlled point process. Posing a discounted control problem for such processes, we show that the optimal value functions converge, in the fluid limit, to the value of an analogous deterministic control problem for fluid processes.

  14. Chromatic roots and limits of dense graphs

    Czech Academy of Sciences Publication Activity Database

    Csikvári, P.; Frenkel, P. E.; Hladký, Jan; Hubai, T.


    Roč. 340, č. 5 (2017), s. 1129-1135 ISSN 0012-365X EU Projects: European Commission(XE) 628974 - PAECIDM Institutional support: RVO:67985840 Keywords : chromatic root * graph limit * holomorphic moment Subject RIV: BA - General Mathematics Impact factor: 0.639, year: 2016

  15. 34 CFR 300.809 - Limitations. (United States)


    ... 34 Education 2 2010-07-01 2010-07-01 false Limitations. 300.809 Section 300.809 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF SPECIAL EDUCATION AND REHABILITATIVE SERVICES, DEPARTMENT OF EDUCATION ASSISTANCE TO STATES FOR THE EDUCATION OF CHILDREN WITH...

  16. 48 CFR 817.402 - Limitations. (United States)


    ... AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Leader Company Contracting 817.402 Limitations. (a) Except as provided in paragraph (b) of this section, the Government shall not initiate or execute leader company contracts. (b) The DSPE may designate a contracting officer to enter into a leader company...

  17. 48 CFR 17.402 - Limitations. (United States)


    ... the Government's requirements without the assistance of a leader company; (3) The assistance required... contracting is used, the Government shall reserve the right to approve subcontracts between the leader company... AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Leader Company Contracting 17.402 Limitations. (a...

  18. 14 CFR 125.93 - Airplane limitations. (United States)


    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Airplane limitations. 125.93 Section 125.93...: AIRPLANES HAVING A SEATING CAPACITY OF 20 OR MORE PASSENGERS OR A MAXIMUM PAYLOAD CAPACITY OF 6,000 POUNDS OR MORE; AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Airplane Requirements § 125.93 Airplane...

  19. Two Different Epistemologies about Limit Concepts (United States)

    Kim, Dong-Joong; Kang, Hyangim; Lee, Hyun-Joo


    The purpose of this study is to investigate characteristics of limit concepts through the simultaneous use of historical and experimental epistemologies. Based on a historical epistemology which is an investigation of historical developments in a mathematical concept raised in the history of mathematics, four different developments of limit…

  20. Activity limitations and participation restrictions experienced by ...

    African Journals Online (AJOL)

    Cite as: Urimubenshi G. Activity limitations and participation restrictions experienced by people with stroke in Musanze district in Rwanda. Afri Health ..... analysis in nursing research: concepts, procedures and measures to achieve trustworthiness. Nurse Education To- day 2004, 24(2), 105–112. 20. Lincoln YS, Guba EA.

  1. Limits of Spalling of Fire Exposed Concrete

    DEFF Research Database (Denmark)

    Hertz, Kristian Dahl


    The supporting document describes the present knowledge about explosive spalling of traditional concrete and dense concrete based on 36 references and the authors own tests and observations.The document concludes that the risk of spalling is limited for traditional concretes within 3-4 percent...

  2. Chemistry Students' Erroneous Conceptions of Limiting Reagent. (United States)

    Mammen, K. J.


    Describes a study of 32 University of Transkei (South Africa) freshmen's conceptualization of "limiting reagent," a basic concept in chemistry, based on student responses to two written test questions and clinical interviews. Results indicated that a high percentage of students had misconceptions and could not apply the concept…

  3. Practical roadmap and limits to nanostructured photovoltaics. (United States)

    Lunt, Richard R; Osedach, Timothy P; Brown, Patrick R; Rowehl, Jill A; Bulović, Vladimir


    The significant research interest in the engineering of photovoltaic (PV) structures at the nanoscale is directed toward enabling reductions in PV module fabrication and installation costs as well as improving cell power conversion efficiency (PCE). With the emergence of a multitude of nanostructured photovoltaic (nano-PV) device architectures, the question has arisen of where both the practical and the fundamental limits of performance reside in these new systems. Here, the former is addressed a posteriori. The specific challenges associated with improving the electrical power conversion efficiency of various nano-PV technologies are discussed and several approaches to reduce their thermal losses beyond the single bandgap limit are reviewed. Critical considerations related to the module lifetime and cost that are unique to nano-PV architectures are also addressed. The analysis suggests that a practical single-junction laboratory power conversion efficiency limit of 17% and a two-cell tandem power conversion efficiency limit of 24% are possible for nano-PVs, which, when combined with operating lifetimes of 10 to 15 years, could position them as a transformational technology for solar energy markets. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Mass limit for the lightest neutralino

    CERN Document Server

    Buskulic, D.; Decamp, D.; Ghez, Philippe; Goy, C.; Lees, J.P.; Lucotte, A.; Minard, M.N.; Nief, J.Y.; Odier, P.; Pietrzyk, B.; Casado, M.P.; Chmeissani, M.; Crespo, J.M.; Delfino, M.; Efthymiopoulos, I.; Fernandez, E.; Fernandez-Bosman, M.; Garrido, L.; Juste, A.; Martinez, M.; Orteu, S.; Padilla, C.; Park, I.C.; Pascual, A.; Perlas, J.A.; Riu, I.; Sanchez, F.; Teubert, F.; Colaleo, A.; Creanza, D.; de Palma, M.; Gelao, G.; Girone, M.; Iaselli, G.; Maggi, G.; Maggi, M.; Marinelli, N.; Nuzzo, S.; Ranieri, A.; Raso, G.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Zito, G.; Huang, X.; Lin, J.; Ouyang, Q.; Wang, T.; Xie, Y.; Xu, R.; Xue, S.; Zhang, J.; Zhang, L.; Zhao, W.; Alemany, R.; Bazarko, A.O.; Bright-Thomas, P.; Cattaneo, M.; Comas, P.; Coyle, P.; Drevermann, H.; Forty, R.W.; Frank, M.; Hagelberg, R.; Harvey, John; Janot, P.; Jost, B.; Kneringer, E.; Knobloch, J.; Lehraus, I.; Lutters, G.; Martin, E.B.; Mato, P.; Minten, A.; Miquel, R.; Mir, L.M.; Moneta, L.; Oest, T.; Pacheco, A.; Pusztaszeri, J.F.; Ranjard, F.; Rensing, P.; Rolandi, Gigi; Schlatter, D.; Schmelling, M.; Schmitt, M.; Schneider, O.; Tejessy, W.; Tomalin, I.R.; Venturi, A.; Wachsmuth, H.; Wagner, A.; Ajaltouni, Z.; Barres, A.; Boyer, C.; Falvard, A.; Gay, P.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Monteil, S.; Montret, J.C.; Pallin, D.; Perret, P.; Podlyski, F.; Proriol, J.; Rosnet, P.; Rossignol, J.M.; Fearnley, T.; Hansen, J.B.; Hansen, J.D.; Hansen, J.R.; Hansen, P.H.; Nilsson, B.S.; Rensch, B.; Waananen, A.; Kyriakis, A.; Markou, C.; Simopoulou, E.; Vayaki, A.; Zachariadou, K.; Blondel, A.; Brient, J.C.; Rouge, A.; Rumpf, M.; Valassi, A.; Videau, H.; Focardi, E.; Parrini, G.; Corden, M.; Georgiopoulos, C.; Jaffe, D.E.; Antonelli, A.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Casper, D.; Chiarella, V.; Felici, G.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G.P.; Passalacqua, L.; Pepe-Altarelli, M.; Curtis, L.; Dorris, S.J.; Halley, A.W.; Knowles, I.G.; Lynch, J.G.; O'Shea, V.; Raine, C.; Reeves, P.; Scarr, J.M.; Smith, K.; Teixeira-Dias, P.; Thompson, A.S.; Thomson, F.; Thorn, S.; Turnbull, R.M.; Becker, U.; Geweniger, C.; Graefe, G.; Hanke, P.; Hansper, G.; Hepp, V.; Kluge, E.E.; Putzer, A.; Schmidt, M.; Sommer, J.; Stenzel, H.; Tittel, K.; Werner, S.; Wunsch, M.; Abbaneo, D.; Beuselinck, R.; Binnie, D.M.; Cameron, W.; Dornan, P.J.; Morawitz, P.; Moutoussi, A.; Nash, J.; Sedgbeer, J.K.; Stacey, A.M.; Williams, M.D.; Dissertori, G.; Girtler, P.; Kuhn, D.; Rudolph, G.; Betteridge, A.P.; Bowdery, C.K.; Colrain, P.; Crawford, G.; Finch, A.J.; Foster, F.; Hughes, G.; Sloan, T.; Whelan, E.P.; Williams, M.I.; Galla, A.; Greene, A.M.; Hoffmann, C.; Jacobs, K.; Kleinknecht, K.; Quast, G.; Renk, B.; Rohne, E.; Sander, H.G.; van Gemmeren, P.; Zeitnitz, C.; Aubert, J.J.; Bencheikh, A.M.; Benchouk, C.; Bonissent, A.; Bujosa, G.; Calvet, D.; Carr, J.; Diaconu, C.; Konstantinidis, N.; Payre, P.; Rousseau, D.; Talby, M.; Sadouki, A.; Thulasidas, M.; Tilquin, A.; Trabelsi, K.; Aleppo, M.; Ragusa, F.; Bauer, C.; Berlich, R.; Blum, W.; Buescher, Volker; Dietl, H.; Dydak, F.; Ganis, G.; Gotzhein, C.; Kroha, H.; Lutjens, G.; Lutz, G.; Manner, W.; Moser, H.G.; Richter, Robert; Rosado-Schlosser, A.; Schael, S.; Settles, R.; Seywerd, H.; St. Denis, Richard Dante; Stenzel, H.; Wiedenmann, W.; Wolf, G.; Boucrot, J.; Callot, O.; Cordier, A.; Davier, M.; Duflot, L.; Grivaz, J.F.; Heusse, P.; Hocker, Andreas; Jacholkowska, A.; Jacquet, M.; Kim, D.W.; Le Diberder, F.; Lefrancois, J.; Lutz, A.M.; Nikolic, Irina; Park, H.J.; Schune, M.H.; Simion, S.; Veillet, J.J.; Videau, I.; Zerwas, D.; Azzurri, P.; Bagliesi, Giuseppe; Batignani, G.; Bettarini, S.; Bozzi, C.; Calderini, G.; Carpinelli, M.; Ciocci, M.A.; Ciulli, V.; Dell'Orso, R.; Fantechi, R.; Ferrante, I.; Giassi, A.; Gregorio, A.; Ligabue, F.; Lusiani, A.; Marrocchesi, P.S.; Messineo, A.; Palla, F.; Rizzo, G.; Sanguinetti, G.; Sciaba, A.; Spagnolo, P.; Steinberger, J.; Tenchini, R.; Tonelli, G.; Vannini, C.; Verdini, P.G.; Walsh, J.; Blair, G.A.; Bryant, L.M.; Cerutti, F.; Chambers, J.T.; Gao, Y.; Green, M.G.; Medcalf, T.; Perrodo, P.; Strong, J.A.; von Wimmersperg-Toeller, J.H.; Botterill, D.R.; Clifft, R.W.; Edgecock, T.R.; Haywood, S.; Maley, P.; Norton, P.R.; Thompson, J.C.; Wright, A.E.; Bloch-Devaux, Brigitte; Colas, P.; Emery, S.; Kozanecki, W.; Lancon, E.; Lemaire, M.C.; Locci, E.; Marx, B.; Perez, P.; Rander, J.; Renardy, J.F.; Roussarie, A.; Schuller, J.P.; Schwindling, J.; Trabelsi, A.; Vallage, B.; Black, S.N.; Dann, J.H.; Johnson, R.P.; Kim, H.Y.; Litke, A.M.; McNeil, M.A.; Taylor, G.; Booth, C.N.; Boswell, R.; Brew, C.A.J.; Cartwright, S.; Combley, F.; Koksal, A.; Letho, M.; Newton, W.M.; Reeve, J.; Thompson, L.F.; Boehrer, Armin; Brandt, S.; Cowan, G.; Grupen, C.; Saraiva, P.; Smolik, L.; Stephan, F.; Apollonio, N.; Bosisio, L.; Della Marina, R.; Giannini, G.; Gobbo, B.; Musolino, G.; Putz, J.; Rothberg, J.; Wasserbaech, S.; Armstrong, S.R.; Elmer, P.; Feng, Z.; Ferguson, D.P.S.; Gao, Y.S.; Gonzales, S.; Grahl, J.; Greening, T.C.; Hayes, O.J.; Hu, H.; McNamara, P.A., III; Nachtman, J.M.; Orejudos, W.; Pan, Y.B.; Saadi, Y.; Scott, I.J.; Walsh, A.M.; Wu, Sau Lan; Wu, X.; Yamartino, J.M.; Zheng, M.; Zobernig, G.


    Indirect limits on the mass of the lightest neutralino are derived from the results of searches for charginos, neutralinos, and sleptons performed with data taken by the ALEPH Collaboration at centre-of-mass energies near the Z peak and at 130 and 136 GeV. Within the context of the Minimal Supersymmetric Standard Model and when $M_{\\tilde\


    Energy Technology Data Exchange (ETDEWEB)



    The purpose of this study is to evaluate dissolved concentration limits (also referred to as solubility limits) of elements with radioactive isotopes under probable repository conditions, based on geochemical modeling calculations using geochemical modeling tools, thermodynamic databases, field measurements, and laboratory experiments. The scope of this modeling activity is to predict dissolved concentrations or solubility limits for 14 elements with radioactive isotopes (actinium, americium, carbon, cesium, iodine, lead, neptunium, plutonium, protactinium, radium, strontium, technetium, thorium, and uranium) important to calculated dose. Model outputs for uranium, plutonium, neptunium, thorium, americium, and protactinium are in the form of tabulated functions with pH and log (line integral) CO{sub 2} as independent variables, plus one or more uncertainty terms. The solubility limits for the remaining elements are either in the form of distributions or single values. The output data from this report are fundamental inputs for Total System Performance Assessment for the License Application (TSPA-LA) to determine the estimated release of these elements from waste packages and the engineered barrier system. Consistent modeling approaches and environmental conditions were used to develop solubility models for all of the actinides. These models cover broad ranges of environmental conditions so that they are applicable to both waste packages and the invert. Uncertainties from thermodynamic data, water chemistry, temperature variation, and activity coefficients have been quantified or otherwise addressed.

  6. 7 CFR 3560.63 - Loan limits. (United States)


    ... receive benefits from the low-income housing tax credit program must make an equity contribution in the... receive low-income housing tax credit benefits and who are comprised solely of nonprofit organizations... housing tax credit benefits, the loan amount will be limited to no more than 97 percent of the security...

  7. Fundamental limits of energy dissipation in computation (United States)

    Boechler, Graham; Whitney, Jean; Lent, Craig; Orlov, Alexei; Snider, Greg


    The limiting factor for microprocessor development in recent years has been heat generation, which has led to a debate regarding the limits of energy dissipation required for computation. Landauer argued that energy is unavoidably lost only when data is erased---the so-called Landauer Principle. Quasi-adiabatic computation is a proposed solution which relies on recycling the energy used during computation. This has been challenged recently by the assertion that recovering the energy is impossible due to a fundamental minimum energy of kTln(2) that must be lost during the charging and discharging of an RC circuit. We experimentally measured the power dissipated in an RC circuit in the time and frequency domains. In both cases, we measure an energy dissipation less than kTln(2) in the resistor while many times kT is delivered to the capacitor. Our experiments demonstrate that there is no fundamental lower limit to the energy that must be dissipated in charging and discharging a capacitor, even for energy losses well below kT. This therefore provides experimental support for the Landauer Principle: there is no fundamental lower limit for energy dissipation required for computation.

  8. Are There Limits to Total Quality Management ?


    Tjitro, Soejono; Firdaus, Firdaus


    Although TQM could solve every problems but it does not mean that TQM is unlimited. There are several limitations on TQM application, some examples from International cases is taken to show the failure of TQM implementation. The understanding of TQM philosophy is really necessary.

  9. Monotonicity in the limited processor sharing queue

    NARCIS (Netherlands)

    M. Nuyens; W. van der Weij (Wemke)


    htmlabstractWe study a processor sharing queue with a limited number of service positions and an infinite buffer. The occupied service positions share an underlying resource. We prove that for service times with a decreasing failure rate, the queue length is stochastically decreasing in the number

  10. Economic Limits to Corporate Growth in America (United States)


    question of how fast the economy can grow. Economists such as Krugman (1997) and Blinder (1997) both predicted inherent limits on U.S. economic growth...Age. Brookings Papers on Economic Activity, 1:2000, 125-235. Krugman , P. (1997). How fast can the U.S. economy grow? Harvard Business Review, (July

  11. 20 CFR 632.85 - Participant limitations. (United States)


    ....85 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR INDIAN AND NATIVE AMERICAN EMPLOYMENT AND TRAINING PROGRAMS Program Design and Management § 632.85 Participant limitations... enrollment in either JTPA or in a program supported by the Comprehensive Employment and Training Act. (c) The...

  12. The semiclassical limit of causal dynamical triangulations

    NARCIS (Netherlands)

    Ambjørn, J.; Görlich, A.T.; Jurkiewicz, J.; Loll, R.|info:eu-repo/dai/nl/304830720; Gizbert-Studnicki, J.; Trześniewski, T.


    Previous work has shown that the macroscopic structure of the theory of quantum gravity defined by causal dynamical triangulations (CDT) is compatible with that of a de Sitter universe. After emphasizing the strictly nonperturbative nature of this semiclassical limit we present a detailed study of

  13. Motorist's attitudes to speed limits in Australia.

    NARCIS (Netherlands)

    Fildes, B. Lahausse, J. Langford, J. Keall, M. & Nes, N. van


    A collaborative research study was undertaken in four Australian states to assess community attitudes towards current speed limits and to identify some of the reasons for these attitudes. An on-line web-based survey conducted in each state yielded a total of 4100 responses from mainly licensed

  14. Incremental Integrity Checking: Limitations and Possibilities

    DEFF Research Database (Denmark)

    Christiansen, Henning; Martinenghi, Davide


    to query containment, we show that no procedure exists that always returns the best incremental test (aka simplification of integrity constraints), and this according to any reasonable criterion measuring the checking effort. In spite of this theoretical limitation, we develop an effective procedure...

  15. Radioactive decays at limits of nuclear stability

    DEFF Research Database (Denmark)

    Pfützner, M.; Karny, M.; Grigorenko, L. V.


    , and their relative probabilities. When approaching limits of nuclear stability, new decay modes set in. First, beta decays are accompanied by emission of nucleons from highly excited states of daughter nuclei. Second, when the nucleon separation energy becomes negative, nucleons start being emitted from the ground...

  16. Accessibility Limits Recall from Visual Working Memory (United States)

    Rajsic, Jason; Swan, Garrett; Wilson, Daryl E.; Pratt, Jay


    In this article, we demonstrate limitations of accessibility of information in visual working memory (VWM). Recently, cued-recall has been used to estimate the fidelity of information in VWM, where the feature of a cued object is reproduced from memory (Bays, Catalao, & Husain, 2009; Wilken & Ma, 2004; Zhang & Luck, 2008). Response…

  17. 38 CFR 3.109 - Time limit. (United States)


    ..., Compensation, and Dependency and Indemnity Compensation Administrative § 3.109 Time limit. (a) Notice of time... from the date of such notification, pension, compensation, or dependency and indemnity compensation may... decision may be extended for good cause shown. Where an extension is requested after expiration of a time...

  18. 31 CFR 210.11 - Limited liability. (United States)


    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Limited liability. 210.11 Section 210.11 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL SERVICE, DEPARTMENT OF THE TREASURY FINANCIAL MANAGEMENT SERVICE FEDERAL GOVERNMENT PARTICIPATION IN THE AUTOMATED...

  19. Limit properties of monotone matrix functions

    NARCIS (Netherlands)

    Behrndt, Jussi; Hassi, Seppo; de Snoo, Henk; Wietsma, Rudi


    The basic objects in this paper are monotonically nondecreasing n x n matrix functions D(center dot) defined on some open interval l = (a, b) of R and their limit values D(a) and D(b) at the endpoints a and b which are, in general, selfadjoint relations in C-n. Certain space decompositions induced

  20. Contributions of Psychology to Limiting Climate Change (United States)

    Stern, Paul C.


    Psychology can make a significant contribution to limiting the magnitude of climate change by improving understanding of human behaviors that drive climate change and human reactions to climate-related technologies and policies, and by turning that understanding into effective interventions. This article develops a framework for psychological…

  1. Limits of functions and elliptic operators

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Elliptic regularity; real-analytic manifolds; hypoelliptic. The limit f of a sequence fn of complex analytical functions (under uniform convergence on compact sets) is complex analytical. Furthermore all partial derivatives of fn converge to the corresponding partial derivatives of f . This is in contrast to the case of real analytical.

  2. 12 CFR 747.100 - Discovery limitations. (United States)


    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Discovery limitations. 747.100 Section 747.100 Banks and Banking NATIONAL CREDIT UNION ADMINISTRATION REGULATIONS AFFECTING CREDIT UNIONS... determine whether the subpoenaed person made an adequate search for, and has produced, all subpoenaed...

  3. The History of the Limits to Growth

    DEFF Research Database (Denmark)

    Nørgaard, Jørgen; Ragnarsdóttir, Kristín Vala; Peet, John


    The report The Limits to Growth was in many ways a breakthrough in the way the future was debated and analysed as far as the physical economy was concerned. The paper describes how the very title seems to have offended many people, leading a cohort of critics to reject the report as a doomsday...

  4. Surface-enhanced Raman spectroscopy: nonlocal limitations

    DEFF Research Database (Denmark)

    Toscano, Giuseppe; Raza, S.; Xiao, Sanshui


    Giant field enhancement and field singularities are a natural consequence of the commonly employed local-response framework. We show that a more general nonlocal treatment of the plasmonic response leads to new and possibly fundamental limitations on field enhancement with important consequences...

  5. Quantum remnants in the classical limit

    Energy Technology Data Exchange (ETDEWEB)

    Kowalski, A.M., E-mail: [Instituto de Física (IFLP-CCT-Conicet), Universidad Nacional de La Plata, C.C. 727, 1900 La Plata (Argentina); Comision de Investigaciones Científicas (CIC) (Argentina); Plastino, A., E-mail: [Instituto de Física (IFLP-CCT-Conicet), Universidad Nacional de La Plata, C.C. 727, 1900 La Plata (Argentina); Argentina' s National Research Council (CONICET) (Argentina); SThAR, EPFL Innovation Park, Lausanne (Switzerland)


    We analyze here the common features of two dynamical regimes: a quantum and a classical one. We deal with a well known semi-classic system in its route towards the classical limit, together with its purely classic counterpart. We wish to ascertain i) whether some quantum remnants can be found in the classical limit and ii) the details of the quantum-classic transition. The so-called mutual information is the appropriate quantifier for this task. Additionally, we study the Bandt–Pompe's symbolic patterns that characterize dynamical time series (representative of the semi-classical system under scrutiny) in their evolution towards the classical limit. - Highlights: • We investigate the classical limit (CL) of a well known semi classical model. • The study is made by reference to the Bandt Pompe symbolic approach. • The number and type of associated symbols changes as one proceeds towards the CL. • We ascertain which symbols pertaining to the quantum zone remain in the CL.

  6. Language and the Limits of Justice (United States)

    Peled, Yael


    Recent years have seen a growing interest in language among political philosophers. While being, on the whole, a positive development, the considerable focus of this literature on the issue of linguistic justice paradoxically limits the breadth and depth of that emerging inquiry, by reducing the conceptual vocabulary intrinsic to the much broader…

  7. Limits on rock strength under high confinement (United States)

    Renshaw, Carl E.; Schulson, Erland M.


    Understanding of deep earthquake source mechanisms requires knowledge of failure processes active under high confinement. Under low confinement the compressive strength of rock is well known to be limited by frictional sliding along stress-concentrating flaws. Under higher confinement strength is usually assumed limited by power-law creep associated with the movement of dislocations. In a review of existing experimental data, we find that when the confinement is high enough to suppress frictional sliding, rock strength increases as a power-law function only up to a critical normalized strain rate. Within the regime where frictional sliding is suppressed and the normalized strain rate is below the critical rate, both globally distributed ductile flow and localized brittle-like failure are observed. When frictional sliding is suppressed and the normalized strain rate is above the critical rate, failure is always localized in a brittle-like manner at a stress that is independent of the degree of confinement. Within the high-confinement, high-strain rate regime, the similarity in normalized failure strengths across a variety of rock types and minerals precludes both transformational faulting and dehydration embrittlement as strength-limiting mechanisms. The magnitude of the normalized failure strength corresponding to the transition to the high-confinement, high-strain rate regime and the observed weak dependence of failure strength on strain rate within this regime are consistent with a localized Peierls-type strength-limiting mechanism. At the highest strain rates the normalized strengths approach the theoretical limit for crystalline materials. Near-theoretical strengths have previously been observed only in nano- and micro-scale regions of materials that are effectively defect-free. Results are summarized in a new deformation mechanism map revealing that when confinement and strain rate are sufficient, strengths approaching the theoretical limit can be achieved in

  8. Limit Shapes in the Six Vertex Model (United States)

    Sridhar, Ananth

    The purpose of this thesis is to present some new results about the six-vertex model and dimer model, andi in particular some aspects of the limit shapes that form in the thermodynamic limit and the partial differential equations that arise in their study. Chapter 1 provides a detailed introduction to limit shape phenomena and its mathematics. Chapter 2 reviews basic facts about the six-vertex model and dimer model and their properties in the thermodynamic limit. Chapter 3 investigates the role of integrability of the six vertex model in the formation of limit shapes. By integrability we mean, on one hand the discrete integrability of the six-vertex model in the sense of commutative families of transfer matrices, and on the other hand the integrability in the continuum limit in the Liouville sense of Poisson commutative families of functions (integrals of motion) on the phase space. The main result is to show that the partial differential equations describing the limit shape have an infinite number of conserved quantities. Chapter 4 explains the results of the previous chapter in a more general setting. The main result is a straightforward theorem in Hamiltonian mechanics, which gives conditions for the Poisson commutativity of two Hamiltonian functions in terms of their principal action functions. It suggests a generalization of our previous results to other integrable lattice models, for example, the generalizations of the six-vertex model related to other Lie algebras. Chapter 5 studies the six-vertex model for a special class of weights called the stochastic six-vertex model. for which the six vertex model is closely related to interacting particle models. The main result of this chapter is the derivation for the partial differential equations for the height function of the stochastic 6-vertex model on the cylinder. Chapter 6 studies models at the intersection of discrete geometry and statistical mechanics. The main result is the asymptotic expansion of the

  9. Determining optimal speed limits in traffic networks

    Directory of Open Access Journals (Sweden)

    Mansour Hadji Hosseinlou


    Full Text Available Determining the speed limit of road transport systems has a significant role in the speed management of vehicles. In most cases, setting a speed limit is considered as a trade-off between reducing travel time on one hand and reducing road accidents on the other, and the two factors of vehicle fuel consumption and emission rate of air pollutants have been neglected. This paper aims to evaluate optimal speed limits in traffic networks in a way that economized societal costs are incurred. In this study, experimental and field data as well as data from simulations are used to determine how speed is related to the emission of pollutants, fuel consumption, travel time, and the number of accidents. This paper also proposes a simple model to calculate the societal costs of travel and relate them to speed. As a case study, using emission test results on cars manufactured domestically and by simulating the suburban traffic flow by Aimsun software, the total societal costs of the Shiraz-Marvdasht motorway, which is one of the most traversed routes in Iran, have been estimated. The results of the study show that from a societal perspective, the optimal speed would be 73 km/h, and from a road user perspective, it would be 82 km/h (in 2011, the average speed of the passing vehicles on that motorway was 82 km/h. The experiments in this paper were run on three different vehicles with different types of fuel. In a comparative study, the results show that the calculated speed limit is lower than the optimal speed limits in Sweden, Norway, and Australia.

  10. Habitable zone limits for dry planets. (United States)

    Abe, Yutaka; Abe-Ouchi, Ayako; Sleep, Norman H; Zahnle, Kevin J


    Most discussion of habitable planets has focused on Earth-like planets with globally abundant liquid water. For an "aqua planet" like Earth, the surface freezes if far from its sun, and the water vapor greenhouse effect runs away if too close. Here we show that "land planets" (desert worlds with limited surface water) have wider habitable zones than aqua planets. For planets at the inner edge of the habitable zone, a land planet has two advantages over an aqua planet: (i) the tropics can emit longwave radiation at rates above the traditional runaway limit because the air is unsaturated and (ii) the dry air creates a dry stratosphere that limits hydrogen escape. At the outer limits of the habitable zone, the land planet better resists global freezing because there is less water for clouds, snow, and ice. Here we describe a series of numerical experiments using a simple three-dimensional global climate model for Earth-sized planets. Other things (CO(2), rotation rate, surface pressure) unchanged, we found that liquid water remains stable at the poles of a low-obliquity land planet until net insolation exceeds 415 W/m(2) (170% that of modern Earth), compared to 330 W/m(2) (135%) for the aqua planet. At the outer limits, we found that a low-obliquity land planet freezes at 77%, while the aqua planet freezes at 90%. High-obliquity land and aqua planets freeze at 58% and 72%, respectively, with the poles offering the last refuge. We show that it is possible that, as the Sun brightens, an aqua planet like Earth can lose most of its hydrogen and become a land planet without first passing through a sterilizing runaway greenhouse. It is possible that Venus was a habitable land planet as recently as 1 billion years ago.

  11. The Mond Limit from Spacetime Scale Invariance (United States)

    Milgrom, Mordehai


    The modified Newtonian dynamics (MOND) limit is shown to follow from a requirement of spacetime scale invariance of the equations of motion for nonrelativistic, purely gravitational systems, i.e., invariance of the equations of motion under (t, r) → (λt, λr) in the limit a 0 → ∞. It is suggested that this should replace the definition of the MOND limit based on the low-acceleration behavior of a Newtonian-MOND interpolating function. In this way, the salient, deep-MOND results—asymptotically flat rotation curves, the mass-rotational-speed relation (baryonic Tully-Fisher relation), the Faber-Jackson relation, etc.,—follow from a symmetry principle. For example, asymptotic flatness of rotation curves reflects the fact that radii change under scaling, while velocities do not. I then comment on the interpretation of the deep-MOND limit as one of "zero mass": rest masses, whose presence obstructs scaling symmetry, become negligible compared to the "phantom," dynamical masses—those that some would attribute to dark matter. Unlike the former masses, the latter transform in a way that is consistent with the symmetry. Finally, I discuss the putative MOND-cosmology connection in light of another, previously known symmetry of the deep-MOND limit. In particular, it is suggested that MOND is related to the asymptotic de Sitter geometry of our universe. It is conjectured, for example that in an exact de Sitter cosmos, deep-MOND physics would exactly apply to local systems. I also point out, in this connection, the possible relevance of a de Sitter-conformal-field-theory (dS/CFT) duality.

  12. Sea-land limits: a case study

    Directory of Open Access Journals (Sweden)

    Afranio R. de Mesquita


    Full Text Available The limits between sea and land were estimated at "Pulso" beach located in the Southeastern Brazilian shelf (φ = 23°33/17.4886"S; Λ = 045° 13'13.0504"W - WGS84, between the island of São Sebastião and the city of Ubatuba, SP, Brazil. The relative sea level of the year 1831 at "Pulso" beach, as per Brazilian law Number 9760 dated from 1946, was estimated and materialized. The retro-estimation allowed the demarcation of the Legal Sea-Land Limits at "Pulso" beach as per the terms of the law. The accuracy of the procedure for the transference of the long-term sea level from the research station of Ubatuba to "Pulso" beach was assessed by parallel work of geometrical leveling referred to the IBGE (Brazilian Institute of Geography and Statistics geodetic network. The motivation, the hypotheses (Brest, Cananeia and IPCC and the methods here used are described, together with a short history of the Legal Sea-Land Limits. The results indicated that the legal Sea-Land Limits at "Pulso" beach are well within the beach area. They were determined as per law 9760, and there is the need to reactivate the national network of sea level gauge.Os limites entre mar e terra foram estimados na praia chamada Pulso, localizada na costa sudeste do Brasil (φ = 23°33'17, 4886"S; Λ = 045°13'13, 0504"W entre a Ilha de São Sebastião e a cidade de Ubatuba, no Estado de São Paulo, SP, Brasil. O nível relativo do mar do ano de 1831 na praia do Pulso, ou "Praia do Pulso" (PP, foi estimado e materializado, de acordo com a Lei brasileira Número 9760 de 1946. A acurácia do procedimento foi acompanhada por trabalho paralelo de nivelamento geométrico referido ao sistema nacional de geodésia do IBGE (Instituto Brasileiro de Geografia e Estatística. A motivação, as hipóteses (Brest, Cananeia e IPCC e os métodos utilizados são descritos, acompanhados por um breve histórico dos "Terrenos de Marinha". Os resultados indicaram que os limites em (PP estão bem dentro

  13. Limitations in global information on species occurrences

    Directory of Open Access Journals (Sweden)

    Carsten Meyer


    Full Text Available Detailed information on species distributions is crucial for answering central questions in biogeography, ecology, evolutionary biology and conservation. Millions of species occurrence records have been mobilized via international data-sharing networks, but inherent biases, gaps and uncertainties hamper broader application. In my PhD thesis, I presented the first comprehensive analyses of global patterns and drivers of these limitations across different taxonomic groups and spatial scales. Integrating 300 million occurrence records for terrestrial vertebrates and plants with comprehensive taxonomic databases, expert range maps and regional checklists, I demonstrated extensive taxonomic, geographical and temporal biases, gaps and uncertainties. I identified key socio-economic drivers of data bias across different taxonomic groups and spatial scales. The results of my dissertation provide an empirical baseline for effectively accounting for data limitations in distribution models, as well as for prioritizing and monitoring efforts to collate additional occurrence information.

  14. Theoretical limits for visibly transparent photovoltaics (United States)

    Lunt, Richard R.


    Transparent photovoltaics (PVs) provide a potentially facile route to building-integrated PVs and seamless energy-harvesting within non-window surfaces such as electronic displays, autonomously powered electronic-glazings, and mobile-electronic accessories. Such devices have been enabled by manipulation of excitons in organic and molecular semiconductors that allow for selective ultraviolet and near-infrared solar conversion. Here, the theoretical efficiency limits of transparent photovoltaics are determined as a function of transparency. Power-production from ultraviolet and near-infrared photons alone leads to a theoretical single-junction efficiency of 21% in transparent structures, compared to 33% for opaque-junctions. Reducing thermal losses via transparent multi-junction stacking these limits increase to 37%.

  15. Numerical Limit Analysis of Reinforced Concrete Structures

    DEFF Research Database (Denmark)

    Larsen, Kasper Paaske

    limit state analysis problems. The work focuses on determination of the load bearing capacity of reinforced concrete structures by employing the lower bound theorem and a finite element method using equilibrium elements is developed. The recent year’s development within the field of convex optimization...... is applied to solve the limit state problems. Three different element types have been developed and tested. The first is a solid tetra- hedral element with a linear stress distribution. The tri-axial stress state in the element is decomposed into concrete and reinforcement stresses, to which separate yield...... section forces such as plate bending and transverse shear. Examples are given which illustrates how the element can model plate and disk structures and the importance of taking transverse shear into account for structural problems with combined bending and transverse shear is illustrated....

  16. Technical Limits of ICT for Enterprises' Innovations

    Directory of Open Access Journals (Sweden)

    Radim Brixi


    Full Text Available The paper deals with technical limits of ICT for enterprises' innovations. ICT is now a key asset for the competitiveness of enterprises. It became the main stream of doing business well. These days we come to era where enterprises are fully dependant on ICT. We would try to describe more deeply the impacts of such a dependence and underlying problems. In context of the necessary new innovations of enterprises, we will focus more on the negative aspects of being dependent on ICT with the technological architecture of hard systems. Based on the need to apply a systems approach we will also provide a suggestion as to how to model these limits in a system's manner.

  17. Regeneration limit of classical Shannon capacity (United States)

    Sorokina, M. A.; Turitsyn, S. K.


    Since Shannon derived the seminal formula for the capacity of the additive linear white Gaussian noise channel, it has commonly been interpreted as the ultimate limit of error-free information transmission rate. However, the capacity above the corresponding linear channel limit can be achieved when noise is suppressed using nonlinear elements; that is, the regenerative function not available in linear systems. Regeneration is a fundamental concept that extends from biology to optical communications. All-optical regeneration of coherent signal has attracted particular attention. Surprisingly, the quantitative impact of regeneration on the Shannon capacity has remained unstudied. Here we propose a new method of designing regenerative transmission systems with capacity that is higher than the corresponding linear channel, and illustrate it by proposing application of the Fourier transform for efficient regeneration of multilevel multidimensional signals. The regenerative Shannon limit—the upper bound of regeneration efficiency—is derived.

  18. Technical presentation: BGM Cryogenic Engineering Limited

    CERN Multimedia

    Caroline Laignel - FI Department


    13 - 14 June 2006 TECHNICAL PRESENTATION BGM Cryogenic Engineering Limited 09:00 - 18:00, 60-2-016, Main Building. Presentation on BGM: 11:00 - 12:00, 60-2-016, Main Building. BGM Cryogenic Engineering Limited manufactures assemblies, sub-assemblies and machined components for the cryogenic technology sector. The primary markets served include superconducting magnets used in the healthcare sector (eg MRI body scanners), spectroscopy and NMR equipment for numerous R & D and technology applications, high vacuum applications and particle physics research. BGM has specialist assembly capability including stainless steel and aluminium welding, vacuum testing, electromechanical assembly and metal finishing. BGM offers a ‘one stop shop'facility to satisfy any customer requirement. Through our design partner we can offer a full design and modelling service, including 3D modelling and production of 2D drawings on your own borders. We can conduct heat load and force calculations and advise on the best...

  19. Limitations of systemic accident analysis methods

    Directory of Open Access Journals (Sweden)

    Casandra Venera BALAN


    Full Text Available In terms of system theory, the description of complex accidents is not limited to the analysis of the sequence of events / individual conditions, but highlights nonlinear functional characteristics and frames human or technical performance in relation to normal functioning of the system, in safety conditions. Thus, the research of the system entities as a whole is no longer an abstraction of a concrete situation, but an exceeding of the theoretical limits set by analysis based on linear methods. Despite the issues outlined above, the hypothesis that there isn’t a complete method for accident analysis is supported by the nonlinearity of the considered function or restrictions, imposing a broad vision of the elements introduced in the analysis, so it can identify elements corresponding to nominal parameters or trigger factors.

  20. Metamaterial polarization converter analysis: limits of performance

    DEFF Research Database (Denmark)

    Markovich, Dmitry L.; Andryieuski, Andrei; Zalkovskij, Maksim


    In this paper, we analyze the theoretical limits of a metamaterial-based converter with orthogonal linear eigenpolarizations that allow linear-to-elliptical polarization transformation with any desired ellipticity and ellipse orientation. We employ the transmission line approach providing a needed...... level of the design generalization. Our analysis reveals that the maximal conversion efficiency for transmission through a single metamaterial layer is 50 %, while the realistic reflection configuration can give the conversion efficiency up to 90 %. We show that a double layer transmission converter...... and a single layer with a ground plane can have 100 % polarization conversion efficiency. We tested our conclusions numerically reaching the designated limits of efficiency using a simple metamaterial design. Our general analysis provides useful guidelines for the metamaterial polarization converter design...

  1. Upper limits of auditory rotational motion perception. (United States)

    Féron, François-Xavier; Frissen, Ilja; Boissinot, Julien; Guastavino, Catherine


    Three experiments are reported, which investigated the auditory velocity thresholds beyond which listeners are no longer able to perceptually resolve a smooth circular trajectory. These thresholds were measured for band-limited noises, white noise, and harmonic sounds (HS), and in different acoustical environments. Experiments 1 and 2 were conducted in an acoustically dry laboratory. Observed thresholds varied as a function of stimulus type and spectral content. Thresholds for band-limited noises were unaffected by center frequency and equal to that of white noise. For HS, however, thresholds decreased as the fundamental frequency of the stimulus increased. The third experiment was a replication of the second in a reverberant concert hall, which produced qualitatively similar results except that thresholds were significantly higher than in the acoustically dry laboratory.

  2. Tolman's length and limiting supersaturation of vapor (United States)

    Alekseechkin, Nikolay V.


    The classical Kelvin formula for the equilibrium vapor pressure over a droplet of radius R is extended to small radii and vapor non-ideality, from where the limiting supersaturation condition is obtained by relating the point R = 0 to the value of limiting (spinodal) supersaturation of vapor. The analysis of different dependences of the Tolman length on radius, δ (R) , obeying this condition suggests that (i) the value of δ (0) is positive and the function δ (R) decreases with increasing radius; (ii) the curvature effect (the dependence of surface tension on radius) in the nucleation region is determined by the value of δ (0) . At the same time, this effect is weakly sensitive to the form of the function δ (R) and insensitive to its asymptotic value δ∞ .

  3. Limited Feedback Precoding for Massive MIMO

    Directory of Open Access Journals (Sweden)

    Xin Su


    Full Text Available The large-scale array antenna system with numerous low-power antennas deployed at the base station, also known as massive multiple-input multiple-output (MIMO, can provide a plethora of advantages over the classical array antenna system. Precoding is important to exploit massive MIMO performance, and codebook design is crucial due to the limited feedback channel. In this paper, we propose a new avenue of codebook design based on a Kronecker-type approximation of the array correlation structure for the uniform rectangular antenna array, which is preferable for the antenna deployment of massive MIMO. Although the feedback overhead is quite limited, the codebook design can provide an effective solution to support multiple users in different scenarios. Simulation results demonstrate that our proposed codebook outperforms the previously known codebooks remarkably.

  4. How energy conservation limits our measurements. (United States)

    Navascués, Miguel; Popescu, Sandu


    Observations in quantum mechanics are subject to complex restrictions arising from the principle of energy conservation. Determining such restrictions, however, has been so far an elusive task, and only partial results are known. In this Letter, we discuss how constraints on the energy spectrum of a measurement device translate into limitations on the measurements which we can effect on a target system with a nonconstant energy operator. We provide efficient algorithms to characterize such limitations and, in case the target is a two-level quantum system, we quantify them exactly. Our Letter, thus, identifies the boundaries between what is possible or impossible to measure, i.e., between what we can see or not, when energy conservation is at stake.

  5. Fastlim: a fast LHC limit calculator

    CERN Document Server

    Papucci, Michele; Weiler, Andreas; Zeune, Lisa


    Fastlim is a tool to calculate conservative limits on extensions of the Standard Model from direct LHC searches without performing any Monte Carlo event generation. The program reconstructs the visible cross sections from pre-calculated efficiency tables and cross section tables for simplified event topologies. As a proof of concept of the approach, we have implemented searches relevant for supersymmetric models with R-parity conservation. Fastlim takes the spectrum and coupling information of a given model point and provides, for each signal region of the implemented analyses, the visible cross sections normalised to the corresponding upper limit, reported by the experiments, as well as the exclusion $p$-value. To demonstrate the utility of the program we study the sensitivity of the recent ATLAS missing energy searches to the parameter space of natural SUSY models. The program structure allows the straight-forward inclusion of external efficiency tables and can be generalised to R-parity violating scenarios...

  6. Limits on silicon nanoelectronics for terascale integration. (United States)

    Meindl, J D; Chen, Q; Davis, J A


    Throughout the past four decades, silicon semiconductor technology has advanced at exponential rates in both performance and productivity. Concerns have been raised, however, that the limits of silicon technology may soon be reached. Analysis of fundamental, material, device, circuit, and system limits reveals that silicon technology has an enormous remaining potential to achieve terascale integration (TSI) of more than 1 trillion transistors per chip. Such massive-scale integration is feasible assuming the development and economical mass production of double-gate metal-oxide-semiconductor field effect transistors with gate oxide thickness of about 1 nanometer, silicon channel thickness of about 3 nanometers, and channel length of about 10 nanometers. The development of interconnecting wires for these transistors presents a major challenge to the achievement of nanoelectronics for TSI.

  7. Quantum speed limits in open system dynamics. (United States)

    del Campo, A; Egusquiza, I L; Plenio, M B; Huelga, S F


    Bounds to the speed of evolution of a quantum system are of fundamental interest in quantum metrology, quantum chemical dynamics, and quantum computation. We derive a time-energy uncertainty relation for open quantum systems undergoing a general, completely positive, and trace preserving evolution which provides a bound to the quantum speed limit. When the evolution is of the Lindblad form, the bound is analogous to the Mandelstam-Tamm relation which applies in the unitary case, with the role of the Hamiltonian being played by the adjoint of the generator of the dynamical semigroup. The utility of the new bound is exemplified in different scenarios, ranging from the estimation of the passage time to the determination of precision limits for quantum metrology in the presence of dephasing noise.

  8. Nuclear Physics Around the Unitarity Limit. (United States)

    König, Sebastian; Grießhammer, Harald W; Hammer, H-W; van Kolck, U


    We argue that many features of the structure of nuclei emerge from a strictly perturbative expansion around the unitarity limit, where the two-nucleon S waves have bound states at zero energy. In this limit, the gross features of states in the nuclear chart are correlated to only one dimensionful parameter, which is related to the breaking of scale invariance to a discrete scaling symmetry and set by the triton binding energy. Observables are moved to their physical values by small perturbative corrections, much like in descriptions of the fine structure of atomic spectra. We provide evidence in favor of the conjecture that light, and possibly heavier, nuclei are bound weakly enough to be insensitive to the details of the interactions but strongly enough to be insensitive to the exact size of the two-nucleon system.

  9. Confinement in Wendelstein 7-X limiter plasmas (United States)

    Hirsch, M.; Dinklage, A.; Alonso, A.; Fuchert, G.; Bozhenkov, S.; Höfel, U.; Andreeva, T.; Baldzuhn, J.; Beurskens, M.; Bosch, H.-S.; Beidler, C. D.; Biedermann, C.; Blanco, E.; Brakel, R.; Burhenn, R.; Buttenschön, B.; Cappa, A.; Czarnecka, A.; Endler, M.; Estrada, T.; Fornal, T.; Geiger, J.; Grulke, O.; Harris, J. H.; Hartmann, D.; Jakubowski, M.; Klinger, T.; Knauer, J.; Kocsis, G.; König, R.; Kornejew, P.; Krämer-Flecken, A.; Krawczyk, N.; Krychowiak, M.; Kubkowska, M.; Ksiazek, I.; Langenberg, A.; Laqua, H. P.; Lazerson, S.; Maaßberg, H.; Marushchenko, N.; Marsen, S.; Moncada, V.; Moseev, D.; Naujoks, D.; Otte, M.; Pablant, N.; Pasch, E.; Pisano, F.; Rahbarnia, K.; Schröder, T.; Stange, T.; Stephey, L.; Szepesi, T.; Pedersen, T. Sunn; Trimino Mora, H.; Thomsen, H.; Tsuchiya, H.; Turkin, Yu.; Wauters, T.; Weir, G.; Wenzel, U.; Werner, A.; Wolf, R.; Wurden, G. A.; Zhang, D.; the W7-X Team


    Observations on confinement in the first experimental campaign on the optimized Stellarator Wendelstein 7-X are summarized. In this phase W7-X was equipped with five inboard limiters only and thus the discharge length restricted to avoid local overheating. Stationary plasmas are limited to low densities  <2-3 · 1019 m-3. With the available 4.3 MW ECR Heating core T e ~ 8 keV, T i ~ 1-2 keV are achieved routinely resulting in energy confinement time τ E between 80 ms to 150 ms. For these conditions the plasmas show characteristics of core electron root confinement with peaked T e-profiles and positive E r up to about half of the minor radius. Profiles and plasma currents respond to on- and off-axis heating and co- and counter ECCD respectively.


    Energy Technology Data Exchange (ETDEWEB)

    P. Bernot


    The purpose of this study is to evaluate dissolved concentration limits (also referred to as solubility limits) of elements with radioactive isotopes under probable repository conditions, based on geochemical modeling calculations using geochemical modeling tools, thermodynamic databases, field measurements, and laboratory experiments. The scope of this activity is to predict dissolved concentrations or solubility limits for elements with radioactive isotopes (actinium, americium, carbon, cesium, iodine, lead, neptunium, plutonium, protactinium, radium, strontium, technetium, thorium, and uranium) relevant to calculated dose. Model outputs for uranium, plutonium, neptunium, thorium, americium, and protactinium are provided in the form of tabulated functions with pH and log fCO{sub 2} as independent variables, plus one or more uncertainty terms. The solubility limits for the remaining elements are either in the form of distributions or single values. Even though selection of an appropriate set of radionuclides documented in Radionuclide Screening (BSC 2002 [DIRS 160059]) includes actinium, transport of Ac is not modeled in the total system performance assessment for the license application (TSPA-LA) model because of its extremely short half-life. Actinium dose is calculated in the TSPA-LA by assuming secular equilibrium with {sup 231}Pa (Section 6.10); therefore, Ac is not analyzed in this report. The output data from this report are fundamental inputs for TSPA-LA used to determine the estimated release of these elements from waste packages and the engineered barrier system. Consistent modeling approaches and environmental conditions were used to develop solubility models for the actinides discussed in this report. These models cover broad ranges of environmental conditions so they are applicable to both waste packages and the invert. Uncertainties from thermodynamic data, water chemistry, temperature variation, and activity coefficients have been quantified or

  11. Cosmetic lengthening: what are the limits?


    Guerreschi, F.; Tsibidakis, H.


    Objectives In the last decades, limb lengthening has not been limited to the treatment of patients with dwarfism and deformities resulting from congenital anomalies, trauma, tumor and infections, but, has also been used for aesthetic reasons. Cosmetic lengthening by the Ilizarov method with circular external fixation has been applied to individuals with constitutional short stature who wish to be taller. Materials and methods From January 1985 to December 2010, the medical records of 63 patie...

  12. Fundamental Limitations for Imaging GEO Satellites (United States)


    path length through the optical system due to vibrations and thermal drift. Employing a metrology system will track these changes, but it will not be...5µm motion, this contributes 50 nm. We will need a metrology system to monitor the telescopes’ positions during the observation. Fortunately, all of...configuration may be possible. It is also important to remember the limitations of this calculation. The largest risk in this calculation is our assumption

  13. Toxicity Data to Determine Refrigerant Concentration Limits

    Energy Technology Data Exchange (ETDEWEB)

    Calm, James M.


    This report reviews toxicity data, identifies sources for them, and presents resulting exposure limits for refrigerants for consideration by qualified parties in developing safety guides, standards, codes, and regulations. It outlines a method to calculate an acute toxicity exposure limit (ATEL) and from it a recommended refrigerant concentration limit (RCL) for emergency exposures. The report focuses on acute toxicity with particular attention to lethality, cardiac sensitization, anesthetic and central nervous system effects, and other escape-impairing effects. It addresses R-11, R-12, R-22, R-23, R-113, R-114, R-116, R-123, R-124, R-125, R-134, R-134a, R-E134, R-141b, R-142b, R-143a, R-152a, R-218, R-227ea, R-236fa, R-245ca, R-245fa, R-290, R-500, R-502, R-600a, R-717, and R-744. It summarizes additional data for R-14, R-115, R-170 (ethane), R-C318, R-600 (n-butane), and R-1270 (propylene) to enable calculation of limits for blends incorporating them. The report summarizes the data a nd related safety information, including classifications and flammability data. It also presents a series of tables with proposed ATEL and RCL concentrations-in dimensionless form and the latter also in both metric (SI) and inch-pound (IP) units of measure-for both the cited refrigerants and 66 zerotropic and azeotropic blends. They include common refrigerants, such as R-404A, R-407C, R-410A, and R-507A, as well as others in commercial or developmental status. Appendices provide profiles for the cited single-compound refrigerants and for R-500 and R-502 as well as narrative toxicity summaries for common refrigerants. The report includes an extensive set of references.

  14. Body composition and functional limitation in COPD

    Directory of Open Access Journals (Sweden)

    Katz Patricia P


    Full Text Available Abstract Background Low body mass index has been associated with increased mortality in severe COPD. The impact of body composition earlier in the disease remains unclear. We studied the impact of body composition on the risk of functional limitation in COPD. Methods We used bioelectrical impedance to estimate body composition in a cohort of 355 younger adults with COPD who had a broad spectrum of severity. Results Among women, a higher lean-to-fat ratio was associated with a lower risk of self-reported functional limitation after controlling for age, height, pulmonary function impairment, race, education, and smoking history (OR 0.45 per 0.50 increment in lean-to-fat ratio; 95% CI 0.28 to 0.74. Among men, a higher lean-to-fat ratio was associated with a greater distance walked in 6 minutes (mean difference 40 meters per 0.50 ratio increment; 95% CI 9 to 71 meters. In women, the lean-to-fat ratio was associated with an even greater distance walked (mean difference 162 meters per 0.50 increment; 95% CI 97 to 228 meters. In women, higher lean-to-fat ratio was also associated with better Short Physical Performance Battery Scores. In further analysis, the accumulation of greater fat mass, and not the loss of lean mass, was most strongly associated with functional limitation among both sexes. Conclusion Body composition is an important non-pulmonary impairment that modulates the risk of functional limitation in COPD, even after taking pulmonary function into account. Body composition abnormalities may represent an important area for screening and preventive intervention in COPD.

  15. Congressional Authority to Limit Military Operations (United States)


    For an overview and criticism of various theories relating to the limits of Congress’s war powers, see David J. Barron & Martin S. Lederman , The...military establishment, see David J. Barron & Martin S. Lederman , The Commander in Chief at the Lowest Ebb—A Constitutional History, 121 HARV. L. REV...941, 956-58 (2008) [hereinafter “Barron & Lederman , Constitutional History”]. 35 But see id. at 991-93 (discussing possible exception when President

  16. The Limits of Special Operations Forces (United States)


    AQAP). Tactical suc- cesses did not yield strategic success as the gov- ernment of Yemen collapsed into civil war, creating an opportunity for AQAP...achieving an outcome such as victory in a major war. Yet policymakers often turn to SOF when seeking a limited liability military option—one just short...size operations, at first, and [name redacted] trained them to operate in three- man fire teams. They immediately grasped the principle of fire-and

  17. Limited Genetic Diversity of Brucella spp.


    Gándara, Benjamín; Merino, Ahidé López; Rogel, Marco Antonio; Martínez-Romero, Esperanza


    Multilocus enzyme electrophoresis (MLEE) of 99 Brucella isolates, including the type strains from all recognized species, revealed a very limited genetic diversity and supports the proposal of a monospecific genus. In MLEE-derived dendrograms, Brucella abortus and a marine Brucella sp. grouped into a single electrophoretic type related to Brucella neotomae and Brucella ovis. Brucella suis and Brucella canis formed another cluster linked to Brucella melitensis and related to Rhizobium tropici....

  18. Generalized improper integral definition for infinite limit


    Blischke, Michael A.


    A generalization of the definition of a one-dimensional improper integral with an infinite limit is presented. The new definition extends the range of valid integrals to include integrals which were previously considered to not be integrable. This definition is shown to preserve linearity and uniqueness. Integrals which are valid under the conventional definition have the same value under the new definition. Criteria for interchanging the order of integration and differentiation, and for inte...

  19. Limitations of PET for imaging lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Barrington, Sally F.; O' Doherty, Michael J. [Clinical PET Centre of Guy' s and St Thomas' Hospitals, St Thomas' Hospital, SE1 7EH, London (United Kingdom)


    The uptake of fluorine-18 fluorodeoxyglucose (FDG) is increased in processes with enhanced glycolysis, including malignancy. It is this property of FDG which is exploited in positron emission tomography (PET) imaging for lymphoma. FDG, whilst a good oncology tracer, is not perfect and there are limitations to its use. FDG may have low uptake in some types of lymphoma, predominantly low-grade lymphomas. High physiological uptake may occur within the bowel, urinary tract, muscle, salivary glands and lymphoid tissue. FDG is not specific for malignancy and increased uptake occurs in benign conditions with increased glycolysis such as infection, inflammation and granulomatous disease. Benign conditions usually have lower uptake than malignancy but there is overlap. These limitations of FDG mean that tumour may be 'missed', 'masked' or 'mimicked' by other pathology. These limitations are described in this article and methods to circumvent them where possible are discussed. These include performing baseline scans at presentation with lymphoma for comparison with post-treatment scans, simple manoeuvres to reduce physiological uptake such as administration of frusemide and diazepam and remaining alert to the possibility of alternative pathology in immunosuppressed patients. Patients with disease secondary to human immunodeficiency virus are a particular challenge in this regard as they often have dual or multiple pathology. One of the most important skills in PET reporting may be to recognise its limitations and be clear when a definitive answer cannot be given to the referring clinician's question. This may require using PET to direct the clinician to biopsy the site most likely to yield the correct diagnosis. (orig.)

  20. Limited Approach in Endoscopic Dacryocystorhinostomy of Pediatrics. (United States)

    Hashemi, Seyyed Mostafa; Eshaghian, Afrooz


    Limited spatial nasal cavity in children, make pediatric dacryocystorhinostomy (DCR) a difficult surgical procedure. We apply a limited approach to pediatric DCR and follow them for their consequences. An experimental study was done in pediatric DCR with limited approach (age consent, with general anesthesia, with nasal endoscopic surgery, lacrimal bone is exposed and extruded. In contrast with routine procedure, ascending process of maxillary sinus reserve; and marsupialization and wide exposure to lacrimal sac was done only by lacrimal bone defect; and cannulation preserve with temporary silicone tube. Between 2006 and 2012, 16 pediatric DCR was done by a unique surgeon in 2 otorhinolaryngologic centers. Before surgery 14 (87.5%) had epiphora, 3 (18.8%) had eye discharge, and 3 (18.8%) had eye sticky eye. Two (12.5%) had history of facial trauma, and 10 (62.5%) had congenital nasolacrimal duct insufficiency. Five (31.3%) had history of dacryocystitis. Patients were followed for 17 ± 9 months. Silicone tube stayed for 4 ± 2.5 months. We could follow 7 patients and minimal improvement or need to revision surgery considered as technical failure. After surgery, 3 patients had no epiphora with complete improvement; 2 had very good improvement with confidence of the patients and parents; 2 cases had unsuccessful surgery in our patients, who needs to another surgery. One of them had several probing and surgery before our endoscopic DCR. Limited approach in endoscopic DCR of pediatrics can be done in noncomplicated patients, with minimal manipulation, more confidence, and acceptable results.

  1. Origins Space Telescope: Breaking the Confusion Limit (United States)

    Wright, Edward L.; Origins Space Telescope Science and Technology Definition Team


    The Origins Space Telescope (OST) is the mission concept for the Far-Infrared Surveyor, one of the four science and technology definition studies of NASA Headquarters for the 2020 Astronomy and Astrophysics Decadal survey. Origins will enable flagship-quality general observing programs led by the astronomical community in the 2030s.OST will have a background-limited sensitivity for a background 27,000 times lower than the Herschel background caused by thermal emission from Herschel's warm telescope. For continuum observations the confusion limit in a diffraction-limited survey can be reached in very short integration times at longer far-infrared wavelengths. But the confusion limit can be pierced for both the nearest and the farthest objects to be observed by OST. For outer the Solar System the targets' motion across the sky will provide a clear signature in surveys repeated after an interval of days to months. This will provide a size-frequency distribution of TNOs that is not biased toward high albedo objects.For the distant Universe the first galaxies and the first metals will provide a third dimension of spectral information that can be measured with a long-slit, medium resolution spectrograph. This will allow 3Dmapping to measure source densities as a function of redshift. The continuum shape associated with sourcesat different redshifts can be derived from correlation analyses of these 3D maps.Fairly large sky areas can be scanned by moving the spacecraft at a constant angular rate perpendicular to the orientation of the long slit of the spectrograph, avoiding the high overhead of step-and-stare surveying with a large space observatory.We welcome you to contact the Science and Technology Definition Team (STDT) with your science needs and ideas by emailing us at

  2. Equilibrium gels of limited valence colloids


    Sciortino, Francesco; Zaccarelli, Emanuela


    Gels are low-packing arrested states of matter which are able to support stress. On cooling, limited valence colloidal particles form open networks stabilized by the progressive increase of the interparticle bond lifetime. These gels, named equilibrium gels, are the focus of this review article. Differently from other types of colloidal gels, equilibrium gels do not require an underlying phase separation to form. Oppositely, they form in a region of densities deprived of thermodynamic instabi...

  3. Transcriptomics of Iron Limitation in Phaeocystis antarctica


    Issak, Mariam Reyad Rizkallah


    Phytoplankton, the hidden trees of the ocean, are responsible for nearly half of global oxygen production. Phytoplankton growth and productivity in high-nitrate low-chlorophyll (HNLC) regions have been demonstrated to be limited by iron availability. One of the most important HNLC regions is the Southern Ocean, as it regulates Earth system climate due to its unique hydrography and consequently its phytoplankton assemblage drives the global carbon cycle. Iron fertilization experiments were con...

  4. Philosophical and Pragmatic Limitations of Business Ethics


    Tadeusz BORKOWSKI


    There are three working theses formulated and proved in the paper. First, business ethics as a science not wishful thinking, encounters the following, impossible to overcome, difficulties: Lack of a precise definition of business ethics, Ethical relativism, Strong competition on national, international, and global market, Shareholders’ interests vs. social responsibility of a company, Objective (based on scientific laws) limitations of business ethics, Ethical codes vs. the rul...



    Firdaus Firdaus; Soejono Tjitro


    Although TQM could solve every problems but it does not mean that TQM is unlimited. There are several limitations on TQM application, some examples from international cases is taken to show the failure of TQM implementation. The understanding of TQM philosophy is really necessary. Abstract in Bahasa Indonesia : Meskipun TQM dapat menyelesaikan semua masalah tetapi bukan berarti bahwa TQM tanpa batas. Ada beberapa keterbatasan penerapan TQM yang berujung pada beberapa kasus dunia yang dapat di...

  6. Injective objects and retracts of Fraisse limits

    Czech Academy of Sciences Publication Activity Database

    Kubiś, Wieslaw


    Roč. 27, č. 2 (2015), s. 807-842 ISSN 0933-7741 R&D Projects: GA ČR(CZ) GAP201/12/0290 Institutional support: RVO:67985840 Keywords : amalgamation * Fraissé limit * injective object Subject RIV: BA - General Mathematics Impact factor: 0.823, year: 2015 xml

  7. Band-limited power flow into enclosures (United States)

    Pope, L. D.; Wilby, J. F.


    Equations for the band-limited power flow to a cavity in the low-frequency regime are derived. The total power to cavity is obtained by summing separate calculations of the power from structural modes resonant in the band and power from structural modes resonant below the band. High-frequency relations compatible with the usual statistical energy analysis and generalized to include other excitations in addition to diffuse fields are also provided.

  8. Method for Predicting Hypergolic Mixture Flammability Limits (United States)


    are immiscible, then reactions at the interface will be important. On the other hand, it could well be that these liquids are partially miscible ...system consuming the species A in the liquid phase. PA is the partial pressure of species A. g, l and i stand for gas, liquid and interface...Gas diffusion in bulk liquids Condensed phase concentration of a gaseous species is limited by its solubility in the liquid of interest. At

  9. Acoustic seafloor classification: Potential and limitations.

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, B.

    Technology, Vol. 9, No. 2, 2014 vCopyright Journal of Ocean Technology 2014 Acoustic Seafloor Classification: Potential and Limitations When sound waves interact with the seafloor and/or penetrate into the sediments beneath, the incident energy... is scattered in all directions. Careful analysis of this acoustic backscatter can tell us important information about the texture and roughness of the seafloor itself, as well as various geophysical and geotechnical characteristics of the underlying...

  10. On the physical limit of radar absorbers


    Karlsson, Anders; Kazemzadeh, Alireza


    A previous investigation has shown that at normal angle of incidence, the integral of the reflectance over wavelength is bounded for a flat metal backed absorber. The bound is applicable to any absorber made of linear, time-invariant, causal and passive materials. We generalize the physical bound to arbitrary angle of incidence and polarization. Different design examples and numerical calculations are provided to investigate the inequalities. It is shown that the theoretical limit for TE pola...

  11. Light Obscuration Particle Counter Fuel Contamination Limits (United States)


    contamination . Based on this work the Department of Defense Tri-Service Petroleum, Oil and Lubricants Technical Steering Committee has recommended...4) (5). The Army utilizes ASTM D4176 – Standard Test Method for Free Water and Particulate Contamination in Distillate Fuels (Visual Inspection...specifies limits for free water and particulate matter in aviation fuels. Specifically, free water contamination in jet fuel cannot exceed 10 parts per

  12. Limits of Commutativity on Abstract Data Types


    Malta, Carmelo; Martinez, José


    International audience; We present some formal properties of (symmetrical) commutativity, the major criterion used in transactional systems, which allow us to fully understand its advantages and disadvantages. The main result is that commutativity is subject to the same limitation as compatibility for arbitrary objects. However, commutativity has also a number of attracting properties, one of which is related to recovery and, to our knowledge, has not been exploited in the literature. Advanta...

  13. Inviscid incompressible limits for rotating fluids

    Czech Academy of Sciences Publication Activity Database

    Caggio, Matteo; Nečasová, Šárka


    Roč. 163, November (2017), s. 1-18 ISSN 0362-546X R&D Projects: GA ČR GA16-03230S Institutional support: RVO:67985840 Keywords : compressible Navier-Stokces system * rotating fluids * incompressible limit Subject RIV: BA - General Mathematics Impact factor: 1.192, year: 2016

  14. Nutrients that limit growth in the ocean. (United States)

    Bristow, Laura A; Mohr, Wiebke; Ahmerkamp, Soeren; Kuypers, Marcel M M


    Phytoplankton form the basis of the marine food web and are responsible for approximately half of global carbon dioxide (CO2) fixation (∼ 50 Pg of carbon per year). Thus, these microscopic, photosynthetic organisms are vital in controlling the atmospheric CO2 concentration and Earth's climate. Phytoplankton are dependent on sunlight and their CO2-fixation activity is therefore restricted to the upper, sunlit surface ocean (that is, the euphotic zone). CO2 usually does not limit phytoplankton growth due to its high concentration in seawater. However, the vast majority of oceanic surface waters are depleted in inorganic nitrogen, phosphorus, iron and/or silica; nutrients that limit primary production in the ocean (Figure 1). Phytoplankton growth is mainly supported by either the recycling of nutrients or by reintroduction of nutrients from deeper waters by mixing. A small percentage of primary production, though, is fueled by 'external' or 'new' nutrients and it is these nutrients that determine the amount of carbon that can be sequestered long term in the deep ocean. For most nutrients such as phosphorus, iron, and silica, the external supply is limited to atmospheric deposition and/or coastal and riverine inputs, whereas their main sink is the sedimentation of particulate matter. Nitrogen, however, has an additional, biological source, the fixation of N2 gas, as well as biological sinks via the processes of denitrification and anammox. Despite the comparatively small contributions to the overall turnover of nutrients in the ocean, it is these biological processes that determine the ocean's capacity to sequester CO2 from the atmosphere on time scales of ocean circulation (∼ 1000 years). This primer will highlight shifts in the traditional paradigms of nutrient limitation in the ocean, with a focus on the uniqueness of the nitrogen cycling and its biological sources and sinks. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Limit cycle dynamics of the gymnastics longswing. (United States)

    Vicinanza, Domenico; Newell, Karl M; Irwin, Gareth; Smith, Lee; Williams, Genevieve K R


    The purpose of the study was to examine the macroscopic dynamics of the longswing through a limit cycle analysis of the motion of the center of mass (CM) as a function of skill level. One elite international, five gymnasts able to perform release and regrasp skills, five gymnasts unable to perform release and regrasp skills, and five novice gymnasts each performed four consecutive longswings on a high bar. Kinematic data were collected to facilitate the calculation of the center of mass position of the performer during swinging. Poincare plots were used to explore the limit cycle dynamics of the center of mass movement. The attractor dynamic was very close to a one-dimensional limit cycle for the elite (D = 1.18) but higher for the release and regrasp group (D = 1.35 ± 0.06) and non-release and regrasp group (D = 1.37 ± 0.07). The novice dynamic was characterized by a two-dimensional limit cycle (D = 2.49 ± 0.28) that also had more variability and lower determinism. In the frequency domain, Inharmonicity was lower and the Q factor higher as a function of increased skill level. The findings show that the dynamical degrees of freedom of the CM in the skilled performance were reduced compared to those of novices and represented a more efficient and predictive, rather than exploratory, technique. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Indications and limits of the microabrasion technique


    Benbachir-Hassani, Nacer; Ardu, Stefano; Krejci, Ivo


    This clinical report illustrates with clinical cases the indications and limits of microabrasion in patients with discolored anterior teeth. The proposed techniques are based on the elimination of the dysplastic external enamel layer through microabrasion, completed by home bleaching and the use of modern adhesive restorative techniques, if necessary. In specific cases, the proposed technique may eliminate dysplastic enamel lesions without being invasive. The use of minimally invasive techniq...

  17. Central limit theorem and almost sure central limit theorem for the ...

    Indian Academy of Sciences (India)

    Home; Journals; Proceedings – Mathematical Sciences; Volume 118; Issue 2. Central Limit Theorem and almost sure Central Limit Theorem for the Product of some Partial Sums. Yu Miao. Research Articles Volume 118 Issue 2 May 2008 pp 289-294 ...

  18. Central limit theorem and almost sure central limit theorem for the ...

    Indian Academy of Sciences (India)

    Department of Mathematics and Statistics, Wuhan University, 430072 Hubei, China. E-mail: MS received 26 January 2007; revised 27 May 2007. Abstract. In this paper, we give the central limit theorem and almost sure central limit theorem for products of some partial sums of independent ...

  19. Time-limited and k-limited polling systems: a matrix analytic solution

    NARCIS (Netherlands)

    Al Hanbali, Ahmad; de Haan, Roland; Boucherie, Richardus J.; van Ommeren, Jan C.W.


    In this paper, we will develop a tool to analyze polling systems with the autonomous-server, the time-limited, and the k-limited service discipline. It is known that these disciplines do not satisfy the well-known branching property in polling system, therefore, hardly any exact result exists in the

  20. Comparison among tomographic reconstruction with limited data

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Eric F.; Dantas, Carlos C.; Vasconcelos, Daniel A.A.; Cadiz, Luis F., E-mail: [Department of Nuclear Energy (DEN). Federal University of Pernambuco (UFPE), Recife, PE (Brazil); Melo, Silvio B., E-mail: [Informatic Center (CIN), Federal University of Pernambuco (UFPE), Recife, PE (Brazil)


    Nowadays there is a continuing interest in applying computed tomography (CT) techniques in non-destructive testing and inspection of many industrial products. These applications of CT usually require a differentiated analysis when there are strong limitations in acquiring a sufficiently large amount of projection data. The use of a low number of tomographic data normally degrades the quality of the reconstructed image, highlighting the formation of artifacts and noise. This work investigates the reconstruction methods most commonly used (FBP, ART, SIRT, MART, SMART) and shows the performance of each one in this limited scenario. For this purpose, all methods were implemented and tested with a phantom of uniform density with well-known distribution, with measures of transmission of gamma radiation in a first generation CT scanner. The phantom is a concentric stainless steel tube coupled with a half - cylinder of aluminum. The measurements were made with an highest root mean square error, with the formation of visible artifacts. The artifacts are diminished but still visible in the ART and SIRT techniques, and the best performance was observed with the techniques MART and SMART. The technical superiority of these multiplicative methods is clearly seen in the reconstructed image quality, endorsing their application to situations of limited input data. (author)

  1. The Limits to Adaptation: A Systems Approach (United States)

    Felgenhauer, T. N.


    The ability to adapt to climate change is delineated by capacity thresholds, after which climate damages begin to overwhelm the adaptation response. Such thresholds depend upon physical properties (natural processes and engineering parameters), resource constraints (expressed through market prices), and societal preferences (from prices as well as cultural norms). Exceedance of adaptation capacity will require substitution either with other pre-existing policy responses or with new adaptation responses that have yet to be developed and tested. Previous modeling research shows that capacity limited adaptation will play a policy-significant role in future climate change decision-making. The aim of this study is to describe different types of adaptation response and climate damage systems and postulate how these systems might behave when the limits to adaptation are reached. The hypothesis is that this behavior will be governed by the characteristics and level of the adaptation limit, the shape of the damage curve in that specific damage area, and the availability of alternative adaptation responses once the threshold is passed, whether it is more of the old technology, a new response type, or a transformation of the climate damage and response system itself.

  2. Nutrient Limitation in Central Red Sea Mangroves

    KAUST Repository

    Almahasheer, Hanan


    As coastal plants that can survive in salt water, mangroves play an essential role in large marine ecosystems (LMEs). The Red Sea, where the growth of mangroves is stunted, is one of the least studied LMEs in the world. Mangroves along the Central Red Sea have characteristic heights of ~2 m, suggesting nutrient limitation. We assessed the nutrient status of mangrove stands in the Central Red Sea and conducted a fertilization experiment (N, P and Fe and various combinations thereof) on 4-week-old seedlings of Avicennia marina to identify limiting nutrients and stoichiometric effects. We measured height, number of leaves, number of nodes and root development at different time periods as well as the leaf content of C, N, P, Fe, and Chl a in the experimental seedlings. Height, number of nodes and number of leaves differed significantly among treatments. Iron treatment resulted in significantly taller plants compared with other nutrients, demonstrating that iron is the primary limiting nutrient in the tested mangrove population and confirming Liebig\\'s law of the minimum: iron addition alone yielded results comparable to those using complete fertilizer. This result is consistent with the biogenic nature of the sediments in the Red Sea, which are dominated by carbonates, and the lack of riverine sources of iron.

  3. Materials analysis of TEXTOR limiter tiles (United States)

    Doerner, R.; Mills, B. E.; Wallura, E.; Walsh, D. S.; Chevalier, G.; Conn, R. W.; Dippel, K. H.; Doyle, B. L.; Esser, H. G.; Finken, K. H.; Gray, D.; Hirooka, Y.; Koizlik, K.; Miyahara, A.; Moyer, R. A.; Watkins, J. G.; Winter, J.


    Graphite tiles from both the ALT-II and inner-bumper limiters were removed from TEXTOR and subjected to materials analysis. Scanning-electron microscopy and energy dispersive X-ray analysis were performed at the Institut für Reaktorwerkstoffe, Forschungszentrum Julich. Deuterium profiles and metallic contamination were examined using external ion beam analysis at Sandia National Laboratory-Albuquerque. The erosion and hydrogen recycling of the tiles, while subjected to plasma bombardment, were studied at University of California, Los Angeles. In-situ analysis of the inner-bumper limiter tiles was performed by Sandia National Laboratory-Livermore using beta backscattering. Results indicate low metallic impurity concentration on the surfaces of both types of tiles. Increased metallic concentration coincides with regions of increased plasma flux to the surface. The ALT-II tiles exhibit a uniformly eroded surface. The inner-bumper limiter tiles show both eroded and redeposited regions, in agreement with power deposition measurements to the tiles in TEXTOR. The redeposited regions show enhanced erosion and recycling when exposed to controlled plasma bombardment.

  4. Sarcopenia With Limited Mobility: An International Consensus (United States)

    Morley, John E.; Abbatecola, Angela Marie; Argiles, Josep M.; Baracos, Vickie; Bauer, Juergen; Bhasin, Shalender; Cederholm, Tommy; Stewart Coats, Andrew J.; Cummings, Steven R.; Evans, William J.; Fearon, Kenneth; Ferrucci, Luigi; Fielding, Roger A.; Guralnik, Jack M.; Harris, Tamara B.; Inui, Akio; Kalantar-Zadeh, Kamyar; Kirwan, Bridget-Anne; Mantovani, Giovanni; Muscaritoli, Maurizio; Newman, Anne B.; Rossi-Fanelli, Filippo; Rosano, Giuseppe M. C.; Roubenoff, Ronenn; Schambelan, Morris; Sokol, Gerald H.; Storer, Thomas W.; Vellas, Bruno; von Haehling, Stephan; Yeh, Shing-Shing; Anker, Stefan D.


    A consensus conference convened by the Society of Sarcopenia, Cachexia and Wasting Disorders has concluded that “Sarcopenia, ie, reduced muscle mass, with limited mobility” should be considered an important clinical entity and that most older persons should be screened for this condition. “Sarcopenia with limited mobility” is defined as a person with muscle loss whose walking speed is equal to or less than 1 m/s or who walks less than 400 m during a 6-minute walk, and who has a lean appendicular mass corrected for height squared of 2 standard deviations or more below the mean of healthy persons between 20 and 30 years of age of the same ethnic group. The limitation in mobility should not clearly be a result of otherwise defined specific diseases of muscle, peripheral vascular disease with intermittent claudication, central and peripheral nervous system disorders, or cachexia. Clinically significant interventions are defined as an increase in the 6-minute walk of at least 50 meters or an increase of walking speed of at least 0.1 m/s. “A word is not a crystal, transparent and unchanged; it is the skin of a living thought and may vary greatly in color and content according to the circumstances and the time when it is used.”—Oliver Wendell Holmes PMID:21640657

  5. Water use by forests, limits and controls. (United States)

    Calder, Ian R.


    Based on a review of several studies that have been carried out to determine the water use of forests in relation to other crops in different regions of the world, it is shown that the principal controls on evaporation from forests and shorter crops vary markedly between the temperate and tropical regions and between the wet and dry zones of these regions. Although there are detailed physical and physiological models available that allow calculation of forest water use, these models are not always readily applicable. It is proposed that a knowledge of the limits on evaporation can be used to devise models of varying complexity for estimating water use of forests in different regions and for predicting differences in water use between forests and shorter crops. Limits on evaporation may be related to radiation, advection, tree physiology, soil water, tree size or drop size. Examples are given of the use of models based on the limits concept for solving forest related water resource problems in Malawi and the U.K.

  6. Beyond Diffraction Limited Seeing Through Polarization Diversity (United States)

    James, S.; Cain, S.

    Dim-object detection and characterization of geosynchronous satellites is one of the Air Force's primary concerns in Space Situational Awareness (SSA). Space-to-Space imaging satellites are costly and require medium to long time scales for useful data collection. Telescope imaging is a more economical solution and can be employed in a much shorter period of time. Atmospheric seeing and the diffraction limit of the optical systems impede our efforts to get the resolutions needed for SSA. The Light collected from satellites and other man-made objects tend to be highly polarized but, distant and/or small objects have low photo-counts in short exposure imagery. Recently, it has been shown that short exposure images of objects that possess spatial polarization diversity can be restored with resolutions as high as twice the diffraction-limit. Also, recent work in blind deconvolution of long exposure imagery and simultaneous estimation of the atmospheric seeing parameter have produced significantly improved image reconstruction, reducing the need for adaptive optics where they are not practical. The goal of this paper is to combine polarization diversity imaging with blind deconvolution of long exposure imagery to produce a new algorithm that gains the benefits of both methods. Simulated long exposure image data was used to test the new algorithm. The results show that resolution beyond the limit imposed by atmospheric seeing are possible when the object being imaged possesses spatial polarization diversity.

  7. The limits of the mean field

    Energy Technology Data Exchange (ETDEWEB)

    Guerra, E.M. de [Inst. de Estructura de la Materia, Consejo Superior de Investigaciones Cientificas (Spain)


    In these talks, we review non relativistic selfconsistent mean field theories, their scope and limitations. We first discuss static and time dependent mean field approaches for particles and quasiparticles, together with applications. We then discuss extensions that go beyond the non-relativistic independent particle limit. On the one hand, we consider extensions concerned with restoration of symmetries and with the treatment of collective modes, particularly by means of quantized ATDHF. On the other hand, we consider extensions concerned with the relativistic dynamics of bound nucleons. We present data on nucleon momentum distributions that show the need for relativistic mean field approach and probe the limits of the mean field concept. Illustrative applications of various methods are presented stressing the role that selfconsistency plays in providing a unifying reliable framework to study all sorts of properties and phenomena. From global properties such as size, mass, lifetime,.., to detailed structure in excitation spectra (high spin, RPA modes,..), as well as charge, magnetization and velocity distributions. (orig.)

  8. Computed tomography urography technique, indications and limitations. (United States)

    Morcos, Sameh K


    The review discusses the different techniques of computed tomography urography reported in the literature and presents the author's preferred approach. Multiphase computed tomography urography offers a comprehensive evaluation of the urinary tract but at the cost of a large dose of contrast medium (100-150 ml), high radiation dose and massive number of images for interpretation. Diuresis induced by frusemide (10 mg) is reported to improve the depiction of ureters in the excretory phase of the examination. The author's preferred approach is a limited computed tomography urography which includes precontrast scanning of the kidneys, followed by an excretory phase 5 min after intravenous injection of 50 ml of contrast medium and 10 mg of frusemide. This limited examination in the author's experience provides a satisfactory evaluation of the urinary tract in the majority of patients, without inflicting a high radiation dose on the patient. A limited computed tomography urography examination is adequate for the majority of patients requiring excretory urography and a superior replacement of conventional intravenous urography. Information provided by a multiphase computed tomography urography examination is beneficial only in a small number of patients.

  9. Nuclear Weapon Testing Limitations and International Security (United States)

    Corden, Pierce S.


    For over 50 years stopping nuclear weapon tests has been sought to support achieving international security without nuclear weapons. Testing is the critical path beyond primitive fission devices, e.g. to develop thermonuclear weapons, reduce weight and volume and increase yield. The 1958 Geneva Conference of Experts considered ways to verify a test ban. With then-limitations on seismology, and lack of in-country monitoring and on-site inspections, the 1963 Limited Test Ban Treaty prohibits testing only in the atmosphere, outer space and under water, and is verified by National Technical Means. The US and USSR agreed to a limit of 150 kilotons on underground explosions in the 1970s-80s. The 1996 Comprehensive Nuclear-Test-Ban Treaty bans all nuclear explosions. Its International Monitoring System - seismic, hydroacoustic, infrasound and radionuclide sensors - is being used, and has easily detected testing by the DPRK. On-site inspections will be available under an in-force Treaty. A 2012 National Academy report concludes that cheating attempts would not undermine U.S. security, and the program for monitoring and extending the life of US weapons has succeeded since US testing ceased in 1992.

  10. MHD stability limits in the TCV Tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Reimerdes, H. [Ecole Polytechnique Federale de Lausanne, Centre de Recherches en Physique des Plasmas (CRPP), CH-1015 Lausanne (Switzerland)


    Magnetohydrodynamic (MHD) instabilities can limit the performance and degrade the confinement of tokamak plasmas. The Tokamak a Configuration Variable (TCV), unique for its capability to produce a variety of poloidal plasma shapes, has been used to analyse various instabilities and compare their behaviour with theoretical predictions. These instabilities are perturbations of the magnetic field, which usually extend to the plasma edge where they can be detected with magnetic pick-up coils as magnetic fluctuations. A spatially dense set of magnetic probes, installed inside the TCV vacuum vessel, allows for a fast observation of these fluctuations. The structure and temporal evolution of coherent modes is extracted using several numerical methods. In addition to the setup of the magnetic diagnostic and the implementation of analysis methods, the subject matter of this thesis focuses on four instabilities, which impose local and global stability limits. All of these instabilities are relevant for the operation of a fusion reactor and a profound understanding of their behaviour is required in order to optimise the performance of such a reactor. Sawteeth, which are central relaxation oscillations common to most standard tokamak scenarios, have a significant effect on central plasma parameters. In TCV, systematic scans of the plasma shape have revealed a strong dependence of their behaviour on elongation {kappa} and triangularity {delta}, with high {kappa}, and low {delta} leading to shorter sawteeth with smaller crashes. This shape dependence is increased by applying central electron cyclotron heating. The response to additional heating power is determined by the role of ideal or resistive MHD in triggering the sawtooth crash. For plasma shapes where additional heating and consequently, a faster increase of the central pressure shortens the sawteeth, the low experimental limit of the pressure gradient within the q = 1 surface is consistent with ideal MHD predictions. The

  11. Limit on the electric charge of antihydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Capra, A., E-mail:; Amole, C. [York University, Department of Physics and Astronomy (Canada); Ashkezari, M. D. [Simon Fraser University, Department of Physics (Canada); Baquero-Ruiz, M. [University of California at Berkeley, Department of Physics (United States); Bertsche, W. [University of Manchester, School of Physics and Astronomy (United Kingdom); Butler, E. [Imperial College, Centre for Cold Matter (United Kingdom); Cesar, C. L. [Universidade Federal do Rio de Janeiro, Instituto de Física (Brazil); Charlton, M.; Eriksson, S. [Swansea University, Department of Physics, College of Science (United Kingdom); Fajans, J. [University of California at Berkeley, Department of Physics (United States); Friesen, T. [University of Calgary, Department of Physics and Astronomy (Canada); Fujiwara, M. C.; Gill, D. R. [TRIUMF (Canada); Gutierrez, A. [University of British Columbia, Department of Physics and Astronomy (Canada); Hangst, J. S. [CERN, Physics Department (Switzerland); Hardy, W. N. [University of British Columbia, Department of Physics and Astronomy (Canada); Hayden, M. E. [Simon Fraser University, Department of Physics (Canada); Isaac, C. A. [Swansea University, Department of Physics, College of Science (United Kingdom); Jonsell, S. [Stockholm University, Department of Physics (Sweden); Kurchaninov, L. [TRIUMF (Canada); and others


    The ALPHA collaboration has successfully demonstrated the production and the confinement of cold antihydrogen, H̅. An analysis of trapping data allowed a stringent limit to be placed on the electric charge of the simplest antiatom. Charge neutrality of matter is known to a very high precision, hence a neutrality limit of H̅ provides a test of CPT invariance. The experimental technique is based on the measurement of the deflection of putatively charged H̅ in an electric field. The tendency for trapped H̅ atoms to be displaced by electrostatic fields is measured and compared to the results of a detailed simulation of H̅ dynamics in the trap. An extensive survey of the systematic errors was performed, and this work focuses on those due to the silicon vertex detector, which is the device used to determine the H̅ annihilation position. The limit obtained on the charge of the H̅ atom is Q = (−1.3 ± 1.8 ± 0.4) × 10{sup −8}, representing the first precision measurement with H̅ [1].

  12. Geophysical limits to global wind power (United States)

    Marvel, Kate; Kravitz, Ben; Caldeira, Ken


    There is enough power in Earth's winds to be a primary source of near-zero-emission electric power as the global economy continues to grow through the twenty-first century. Historically, wind turbines are placed on Earth's surface, but high-altitude winds are usually steadier and faster than near-surface winds, resulting in higher average power densities. Here, we use a climate model to estimate the amount of power that can be extracted from both surface and high-altitude winds, considering only geophysical limits. We find wind turbines placed on Earth's surface could extract kinetic energy at a rate of at least 400TW, whereas high-altitude wind power could extract more than 1,800TW. At these high rates of extraction, there are pronounced climatic consequences. However, we find that at the level of present global primary power demand (~ 18TW ref. ), uniformly distributed wind turbines are unlikely to substantially affect the Earth's climate. It is likely that wind power growth will be limited by economic or environmental factors, not global geophysical limits.

  13. The Limits of Life on Earth (United States)

    Deming, J. W.


    Microorganisms inhabit environments more extreme than those of higher organisms, and recent research results are vastly expanding our notion of where life may occur elsewhere in the Universe. These "extremophiles" have evolved to handle conditions previously thought impossible for life. The temperature limits of microbial activity currently stand at -20 deg C in Arctic winter sea-ice brines (psychrophiles) and 113 deg C in the pressurized water emerging from seafloor hydrothermal vents (hyperthermophiles). Moreover, indirect evidence exists that this upper temperature limit may be significantly higher. The pressure limits on microbial activity are unknown, since some cultures (barophiles) continue to metabolize at the highest pressures tested (1100 atm, mimicking the deepest trench in the ocean). Recent studies have extended the pressure for metabolic activity in bacteria to greater than 10,000 atm. Certain types of microorganisms (acidophiles) are also known to grow in the extreme acidic conditions (pH = 0) found in some geothermal vents and mine waste sites, as well as others (alkalophiles) in alkaline environments such as high-carbonate lakes (pH = 12). Other microbes (halophiles) have evolved to grow in saturated brines (5 Molar NaCl), with heavy metals (e.g., 5mMolar Cd), and under levels of DNA-damaging radiation up to 6000 rad/hr and 15 Mrad total.

  14. Animal models of preeclampsia; uses and limitations.

    LENUS (Irish Health Repository)

    McCarthy, F P


    Preeclampsia remains a leading cause of maternal and fetal morbidity and mortality and has an unknown etiology. The limited progress made regarding new treatments to reduce the incidence and severity of preeclampsia has been attributed to the difficulties faced in the development of suitable animal models for the mechanistic research of this disease. In addition, animal models need hypotheses on which to be based and the slow development of testable hypotheses has also contributed to this poor progress. The past decade has seen significant advances in our understanding of preeclampsia and the development of viable reproducible animal models has contributed significantly to these advances. Although many of these models have features of preeclampsia, they are still poor overall models of the human disease and limited due to lack of reproducibility and because they do not include the complete spectrum of pathophysiological changes associated with preeclampsia. This review aims to provide a succinct and comprehensive assessment of current animal models of preeclampsia, their uses and limitations with particular attention paid to the best validated and most comprehensive models, in addition to those models which have been utilized to investigate potential therapeutic interventions for the treatment or prevention of preeclampsia.


    Energy Technology Data Exchange (ETDEWEB)

    Fraser, Wesley C.; Gwyn, Stephen; Kavelaars, J. J. [Herzberg Institute of Astrophysics, 5071 W. Saanich Rd. Victoria, BCV9E 2E7 (Canada); Trujillo, Chad; Stephens, Andrew W. [Gemini Observatory, Northern Operations Center, 670 N A' ohoku Place, Hilo, HI 96720 (United States); Gimeno, German [Gemini Observatory, Southern Operations Center, c/o AURA, Casilla 603, La Serena (Chile); Brown, Michael E., E-mail: [California Institute of Technology, Division of Geological and Planetary Sciences, 1200 E. California Blvd., Pasadena, CA 91101 (United States)


    Here we present high cadence photometry taken by the Acquisition Camera on Gemini South, of a close passage by the {approx}540 km radius Kuiper belt object, (50000) Quaoar, of a r' = 20.2 background star. Observations before and after the event show that the apparent impact parameter of the event was 0.''019 {+-} 0.''004, corresponding to a close approach of 580 {+-} 120 km to the center of Quaoar. No signatures of occultation by either Quaoar's limb or its potential atmosphere are detectable in the relative photometry of Quaoar and the target star, which were unresolved during closest approach. From this photometry we are able to put constraints on any potential atmosphere Quaoar might have. Using a Markov chain Monte Carlo and likelihood approach, we place pressure upper limits on sublimation supported, isothermal atmospheres of pure N{sub 2}, CO, and CH{sub 4}. For N{sub 2} and CO, the upper limit surface pressures are 1 and 0.7 {mu}bar, respectively. The surface temperature required for such low sublimation pressures is {approx}33 K, much lower than Quaoar's mean temperature of {approx}44 K measured by others. We conclude that Quaoar cannot have an isothermal N{sub 2} or CO atmosphere. We cannot eliminate the possibility of a CH{sub 4} atmosphere, but place upper surface pressure and mean temperature limits of {approx}138 nbar and {approx}44 K, respectively.

  16. Necessary and inherent limits to internet surveillance

    Directory of Open Access Journals (Sweden)

    Joss Wright


    Full Text Available Information technologies now play a huge role in both personal and institutional life, playing the role of a global communications medium. As our means of interaction increasingly centre on the internet, there is a desire from nation states to exercise control and obtain access to the communications of citizens. The stated reasons for this access and control are to prevent or investigate crimes, and to protect national security. This article argues that mass untargeted surveillance of internet-based communications is an excessive tool with respect to its potential for abuse against both society and individuals, and that its ability to prevent crime or terrorism are limited. By looking at existing technologies and example cases where surveillance has been applied, this article demonstrates that there are both inherent mathematical and technical limits to the potential for surveillance to achieve broad-scale prevention of crime and terrorism. In addition, the potential of surveillance to result in real harm to society necessarily places severe limits on how this technique should be applied in a free and democratic society.

  17. Experimental Realization of a Reflective Optical Limiter

    CERN Document Server

    Vella, Jarrett H; Browning, Andrew T; Limberopoulos, Nicholaos I; Vitebskiy, Ilya; Makri, Eleana; Kottos, Tsampikos


    Optical limiters transmit low-intensity light, while blocking laser radiation with excessively high intensity or fluence. A typical passive optical limiter absorbs most of the high level radiation, which can cause irreversible damage. In this communication we report the first experimental realization of a reflective optical limiter, which does not absorb the high-level laser radiation, but rather reflects it back to space. The design is based on a periodic layered structure composed of alternating SiO2 and Si3N4 layers with a single GaAs defect layer in the middle. At low intensities, the layered structure displays a strong resonant transmission via the localized defect mode. At high intensities, the two-photon absorption in the GaAs layer suppresses the localized mode along with the resonant transmission, the entire layered structure turns highly reflective within a broad frequency range covering the entire photonic band gap of the periodic layered structure. By contrast, a stand-alone GaAs layer would absor...


    Energy Technology Data Exchange (ETDEWEB)

    Owen, James E. [Institute for Advanced Study, Einstein Drive, Princeton NJ, 08540 (United States); Alvarez, Marcelo A., E-mail: [Canadian Institute for Theoretical Astrophysics, 60 St George Street, Toronto, M5S 3H8, ON (Canada)


    We have investigated the evaporation of close-in exoplanets irradiated by ionizing photons. We find that the properties of the flow are controlled by the ratio of the recombination time to the flow timescale. When the recombination timescale is short compared to the flow timescale, the flow is in approximate local ionization equilibrium with a thin ionization front where the photon mean free path is short compared to the flow scale. In this “recombination-limited” flow the mass-loss scales roughly with the square root of the incident flux. When the recombination time is long compared to the flow timescale the ionization front becomes thick and encompasses the entire flow with the mass-loss rate scaling linearly with flux. If the planet's potential is deep, then the flow is approximately “energy-limited”; however, if the planet's potential is shallow, then we identify a new limiting mass-loss regime, which we term “photon-limited.” In this scenario, the mass-loss rate is purely limited by the incoming flux of ionizing photons. We have developed a new numerical approach that takes into account the frequency dependence of the incoming ionizing spectrum and performed a large suite of 1D simulations to characterize UV driven mass-loss around low-mass planets. We find that the flow is “recombination-limited” at high fluxes but becomes “energy-limited” at low fluxes; however, the transition is broad occurring over several orders of magnitude in flux. Finally, we point out that the transitions between the different flow types do not occur at a single flux value but depend on the planet's properties, with higher-mass planets becoming “energy-limited” at lower fluxes.

  19. Limitations and opportunities of transcutaneous bilirubin measurements. (United States)

    Bosschaart, Nienke; Kok, Joke H; Newsum, Astrid M; Ouweneel, Dagmar M; Mentink, Rosaline; van Leeuwen, Ton G; Aalders, Maurice C G


    Although transcutaneous bilirubinometers have existed for over 30 years, the clinical utility of the technique is limited to a screening method for hyperbilirubinemia, rather than a replacement for invasive blood sampling. In this study, we investigate the reason for this limited clinical value and address possibilities for improvement. To obtain better insight into the physiology of bilirubin measurements, we evaluated a transcutaneous bilirubinometer that determines not only the cutaneous bilirubin concentration (TcB) but also the blood volume fraction (BVF) in the investigated skin volume. For 49 neonates (gestational age 30 ± 3.1 weeks, postnatal age 6 [4-10] days) at our NICU, we performed 124 TcB and 55 BVF measurements. The TcB correlated well with the total serum bilirubin concentration (TSB) (r = 0.88) with an uncertainty of 55 µmol/L. The BVF in the measured skin volume ranged between 0.1% and 0.75%. The performance of our bilirubinometer is comparable to existing transcutaneous devices. The limited clinical value of current bilirubinometers can be explained by the low BVF in the skin volume that is probed by these devices. Because the TcB depends for over 99% on the contribution of extravascular bilirubin, it is a physiologically different parameter from the TSB. Hence, the standard method of evaluation that compares the TcB to the TSB is insufficient to fully investigate the clinical value of transcutaneous bilirubinometers, ie, their predictive value for kernicterus. We suggest that the clinical value may be improved considerably by changing either the method of evaluation or the technological design of transcutaneous bilirubinometers.

  20. Dissolved Concentration Limits of Radioactive Elements

    Energy Technology Data Exchange (ETDEWEB)

    Y. Chen; E.R. Thomas; F.J. Pearson; P.L. Cloke; T.L. Steinborn; P.V. Brady


    The purpose of this study is to evaluate dissolved concentration limits (also referred to as solubility limits) of radioactive elements under possible repository conditions, based on geochemical modeling calculations using geochemical modeling tools, thermodynamic databases, and measurements made in laboratory experiments and field work. The scope of this modeling activity is to predict dissolved concentrations or solubility limits for 14 radioactive elements (actinium, americium, carbon, cesium, iodine, lead, neptunium, plutonium, protactinium, radium, strontium, technetium, thorium, and uranium), which are important to calculated dose. Model outputs are mainly in the form of look-up tables plus one or more uncertainty terms. The rest are either in the form of distributions or single values. The results of this analysis are fundamental inputs for total system performance assessment to constrain the release of these elements from waste packages and the engineered barrier system. Solubilities of plutonium, neptunium, uranium, americium, actinium, thorium, protactinium, lead, and radium have been re-evaluated using the newly updated thermodynamic database (Data0.ymp.R2). For all of the actinides, identical modeling approaches and consistent environmental conditions were used to develop solubility models in this revision. These models cover broad ranges of environmental conditions so that they are applicable to both waste packages and the invert. Uncertainties from thermodynamic data, water chemistry, temperature variation, activity coefficients, and selection of solubility controlling phase have been quantified or otherwise addressed. Moreover, a new blended plutonium solubility model has been developed in this revision, which gives a mean solubility that is three orders of magnitude lower than the plutonium solubility model used for the Total System Performance Assessment for the Site Recommendation. Two alternative neptunium solubility models have also been

  1. Scattering resonances in the extreme quantum limit (United States)

    Hersch, Jesse Shines

    This thesis addresses topics in low energy scattering in quantum mechanics, in particular, resonance phenomena. Hence the title: the phrase ``extreme quantum limit'' refers to the situation when the wavelengths of the particles in the system are larger than every other scale, so that the behavior is far into the quantum regime. A powerful tool in the problems of low energy scattering is the point scatterer model, and will be used extensively throughout the thesis. Therefore, we begin with a thorough introduction to this model in Chapter 2. As a first application of the point scatterer model, we will investigate the phenomenon of the proximity resonance, which is one example of strange quantum behavior appearing at low energy. Proximity resonances will be addressed theoretically in Chapter 3, and experimentally in Chapter 4. Threshold resonances, another type of low energy scattering resonance, are considered in Chapter 5, along with their connection to the Efimov and Thomas effects, and scattering in the presence of an external confining potential. Although the point scatterer model will serve us well in the work presented here, it does have its limitations. These limitations will be removed in Chapter 6, where we describe how to extend the model to include higher partial waves. In Chapter 7, we extend the model one step further, and illustrate how to treat vector wave scattering with the model. Finally, in Chapter 8 we will depart from the topic of low energy scattering and investigate the influence of diffraction on an open quantum mechanical system, again both experimentally and theoretically.

  2. Classical limit for semirelativistic Hartree systems

    KAUST Repository

    Aki, Gonca L.


    We consider the three-dimensional semirelativistic Hartree model for fast quantum mechanical particles moving in a self-consistent field. Under appropriate assumptions on the initial density matrix as a (fully) mixed quantum state we prove by using Wigner transformation techniques that its classical limit yields the well known relativistic Vlasov-Poisson system. The result holds for the case of attractive and repulsive mean-field interactions, with an additional size constraint in the attractive case. © 2008 American Institute of Physics.

  3. Limitation of Electrical Power in January

    CERN Multimedia


    During maintenance work on CERN's 400 kV main electrical supply in Prevessin, the laboratory will be connected to the 130 kV Suisse network in Meyrin from 4 to 22 January. Due to the on-going LHC activities during this period, the power demand will be very close to the technical limitations of this source. The effort of every one to reduce the consumption of electrical energy during this period is vital to avoid powercuts caused by exceeding the maximum capacity of the system. Mario Batz TS/CV Gerard Cumer TS/EL

  4. Limitation of Electrical Power in January

    CERN Multimedia


    During maintenance work on CERN's 400 kV main electrical supply in Prevessin, the laboratory will be connected to the 130 kV Suisse network in Meyrin from 4 to 22 January. Due to the on-going LHC activities during this period, the power demand will be very close to the technical limitations of this source. The effort of every one to reduce the consumption of electrical energy during this period is vital to avoid powercuts caused by exceeding the maximum capacity of the system. Mario Batz TS/CV Gerard Cumer TS/EL

  5. Limitations to performance during alpine skiing. (United States)

    Ferguson, Richard A


    Alpine skiing is characterized by high-intensity exercise of between 90 and 120 s duration that requires repeated phases of high-force isometric and eccentric contractions. The nature of these contractions, during which all fibre types are active, results in restricted blood flow to the working muscle, thereby reducing oxygen delivery and increasing metabolite accumulation. The consequence of this will be skeletal muscle fatigue, through both central and peripheral mechanisms, and a potential loss of motor control which will ultimately limit skiing performance.

  6. Limited Range Sesame EOS for Ta

    Energy Technology Data Exchange (ETDEWEB)

    Greeff, Carl William [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Crockett, Scott [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rudin, Sven Peter [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Burakovsky, Leonid [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)


    A new Sesame EOS table for Ta has been released for testing. It is a limited range table covering T ≤ 26, 000 K and ρ ≤ 37.53 g/cc. The EOS is based on earlier analysis using DFT phonon calculations to infer the cold pressure from the Hugoniot. The cold curve has been extended into compression using new DFT calculations. The present EOS covers expansion into the gas phase. It is a multi-phase EOS with distinct liquid and solid phases. A cold shear modulus table (431) is included. This is based on an analytic interpolation of DFT calculations.

  7. Pushing the Limits of Kinetic Arts: Strandbeests

    KAUST Repository

    Jansen, Theo


    In 1990, Dutch artist Theo Jansen introduced the world to his newest creation, the strandbeests. Kenetic sculptures created from plastic tubing, water bottles, and pipes, these beests survive on their own. These herds live on beaches all around the world, surviving on their waterfeelers and sandfeelers to remain safely on the sand. Powered by wind, these new life forms do not require food! Join us for a keynote lecture with Theo as he discusses the story behind the strandbeests as he pushes the limits with these beautiful and unique animals.

  8. Metamaterial localized resonance sensors: prospects and limitations

    DEFF Research Database (Denmark)

    Jeppesen, Claus; Xiao, Sanshui; Mortensen, Asger


    The prospects and limitations of metamaterial localized resonance sensors are investigated theoretically and experimentally. Gold split-ring resonators are employed as the model system where the light induced LC-resonance yields a figure-of-merit, sensitivity divided by linewidth, up to 54...... depending on the split-ring resonator design and engineering of the light-plasmon coupling. This highest measured value is comparable to quasi-static predictions, suggesting incremental improvements beyond this point. Further optimization attempts show the effect of inhomogeneous broadening giving some...

  9. Is Science Nearing Its Limits ? Summarizing Dialogue

    CERN Document Server

    Luminet, J -P


    In 2007 an international conference engaged a reflection on the present conditions for sciences and scientific practice, to initiate a dialogue between science, philosophy, epistemology and sociology. Starting from many examples taken from the history of sciences and the present status of astrophysics, cosmology and fundamental physics, I analyze various issues such as the possible limits of theoretical and technological advances, the paradox of non-verifiability in string theory, incompleteness, the role of imagination in scientific research along with educational aspects, the epistemological value of the Ockham's razor principle for constraining theories, and our undersanding of man's place in Creation.

  10. Bohmian measures and their classical limit

    KAUST Repository

    Markowich, Peter


    We consider a class of phase space measures, which naturally arise in the Bohmian interpretation of quantum mechanics. We study the classical limit of these so-called Bohmian measures, in dependence on the scale of oscillations and concentrations of the sequence of wave functions under consideration. The obtained results are consequently compared to those derived via semi-classical Wigner measures. To this end, we shall also give a connection to the theory of Young measures and prove several new results on Wigner measures themselves. Our analysis gives new insight on oscillation and concentration effects in the semi-classical regime. © 2010 Elsevier Inc.

  11. Cryocoolers near their low-temperature limit (United States)

    de Waele, A. T. A. M.


    This paper analyses the recently-observed temperature-time dependence in a GM-cooler near its low-temperature limit. The paper mainly focusses on GM-coolers with 4He as the working fluid, but some attention is also paid to pulse-tube refrigerators (PTR's) using 3He and many features of the treatment equally apply to Stirling coolers. Ample attention is paid to the thermodynamics of the cycle by considering the isentropes in the Tp-diagrams of 4He and 3He. The role of the line, where the thermal expansion coefficient is zero, is emphasized. Some fundamental thermodynamic relationships are derived.

  12. Ethnomathematics and the limits of culture

    DEFF Research Database (Denmark)

    Pais, Alexandre


    of a learning device. Such a development of ethnomathematics research is problematic and, in some instances, contradictory. In this article, I briefly point out some of the problems I see in the educational implications of ethnomathematics, and suggest a political reading of mathematics education that shows......Research in ethnomathematics has become predominantly focused on "local cultures" and non-scholarized forms of mathematics, thus becoming less a critical reflection on the sociopolitical roots of academic mathematics and the place it occupies in the popular imagination and in schooling, and more...... the limitations of culture when confronting the economic role of schooling....

  13. Particle Count Limits Recommendation for Aviation Fuel (United States)


    Filtration – gravimetric limit 1.0 mg/L (MIL-STD-3004) • ASTM D3240 – Undissolved Water in Aviation Turbine Fuels – 10 PPM (MIL-STD-3004, ATP 4-43...Unclassified • September 2012 – March 2015 • ASTM D5452 Laboratory filtration • IP 564 – Parker ACM20 (59 samples only) • IP 565/ASTM D7619 – Stanhope-Seta...0.415 mg/L • repeatability formula based on 5 liter sample • 36 samples may be lower than 1.0 mg/L based on repeatability calculations. • 14 samples have

  14. Will human populations be limited by food? (United States)

    Warren, S. G.


    Historical examples of demographic change, in China, Italy, Nigeria, Utah, the Philippines, and elsewhere, together with simple mathematics and biological principles, show that stabilizing world population before it is limited by food supply will be more difficult than is generally appreciated. United Nations population projections are based on a logical fallacy in that they assume, in spite of the absence of necessary negative feedbacks, that all nations will converge rapidly to replacement-level fertility and thereafter remain at that level. The benign projections that have resulted from this assumption may have hindered efforts to make availability of birth-control a priority in development-aid. Education of women and provision of contraceptives have caused dramatic reductions in fertility, but many groups, including some that are well-educated, maintain high fertility. Small groups with persistent high fertility can grow to supplant low-fertility groups, resulting in continued growth of the total population. The global average fertility rate could rise even if each country's fertility rate is falling. In some low-fertility European countries where deaths exceed births, the population continues to grow because of immigration. Producing more than two offspring is normal for all animal species with stable populations, because their populations are limited by resources or predation rather than birth control. It may therefore be appropriate to view the growth of human population as the result not of excess fertility but rather of excess food. Even if the fertility rate is maintained far in excess of 2, the population cannot grow if food is limiting. Without the agricultural advances of the 20thcentury, world population could not have grown as it did from 1.7 billion in 1900 to 6 billion in 2000. The food supply may be enhanced in the future by genetic engineering and other innovations, but it may be limited by water shortage, climate change, pollution, and energy

  15. Torque limited drive for manual valves (United States)

    Elliott, Philip G.; Underwood, Daniel E.


    The present invention is directed to a torque-limiting handwheel device for preventing manual valves from being damaged due to the application of excessive torque during the opening or closing operation of the valves. Torque can only be applied when ridges in the handwheel assembly engage in channels machined in the face of the baseplate. The amount of torque required for disengagement of the ridges from the channels is determined by the force exerted by various Bellville springs and the inclination of the side faces of the channels.

  16. The semiclassical limit of causal dynamical triangulations

    Energy Technology Data Exchange (ETDEWEB)

    Ambjorn, J., E-mail: ambjorn@nbi.d [Niels Bohr Institute, Copenhagen University, Blegdamsvej 17, DK-2100 Copenhagen O (Denmark); Institute for Theoretical Physics, Utrecht University, Leuvenlaan 4, NL-3584 CE Utrecht (Netherlands); Goerlich, A., E-mail: [Institute of Physics, Jagellonian University, Reymonta 4, PL 30-059 Krakow (Poland); Jurkiewicz, J., E-mail: [Institute of Physics, Jagellonian University, Reymonta 4, PL 30-059 Krakow (Poland); Loll, R., E-mail: r.loll@uu.n [Institute for Theoretical Physics, Utrecht University, Leuvenlaan 4, NL-3584 CE Utrecht (Netherlands); Perimeter Institute for Theoretical Physics, 31 Caroline St. N., Waterloo, Ontario, N2L 2Y5 (Canada); Gizbert-Studnicki, J., E-mail: [Institute of Physics, Jagellonian University, Reymonta 4, PL 30-059 Krakow (Poland); Trzesniewski, T., E-mail: [Institute of Physics, Jagellonian University, Reymonta 4, PL 30-059 Krakow (Poland)


    Previous work has shown that the macroscopic structure of the theory of quantum gravity defined by causal dynamical triangulations (CDT) is compatible with that of a de Sitter universe. After emphasizing the strictly nonperturbative nature of this semiclassical limit we present a detailed study of the three-volume data, which allows us to re-confirm the de Sitter structure, exhibit short-distance discretization effects, and make a first detailed investigation of the presence of higher-order curvature terms in the effective action for the scale factor. Technically, we make use of a novel way of fixing the total four-volume in the simulations.

  17. Ultraspinning limits and rotating hyperboloid membranes

    Energy Technology Data Exchange (ETDEWEB)

    Hennigar, Robie A., E-mail: [Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario, N2L 3G1 (Canada); Kubizňák, David, E-mail: [Perimeter Institute, 31 Caroline St. N., Waterloo, Ontario, N2L 2Y5 (Canada); Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario, N2L 3G1 (Canada); Mann, Robert B., E-mail: [Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario, N2L 3G1 (Canada); Musoke, Nathan, E-mail: [Perimeter Institute, 31 Caroline St. N., Waterloo, Ontario, N2L 2Y5 (Canada)


    We apply the hyperboloid membrane limit to the general Kerr-AdS metrics and their recently studied super-entropic cousins and obtain a new class of rotating black holes, for which the rotational parameters in multiple directions attain their maximal value—equal to the AdS radius. These new solutions have a potential application in the description of holographic fluids with vorticity. They also possess interesting thermodynamic properties: we show that—despite the absence of Misner strings—the Bekenstein–Hawking entropy/area law is still violated, raising a question about the origin of this violation.

  18. Central limit theorems under special relativity. (United States)

    McKeague, Ian W


    Several relativistic extensions of the Maxwell-Boltzmann distribution have been proposed, but they do not explain observed lognormal tail-behavior in the flux distribution of various astrophysical sources. Motivated by this question, extensions of classical central limit theorems are developed under the conditions of special relativity. The results are related to CLTs on locally compact Lie groups developed by Wehn, Stroock and Varadhan, but in this special case the asymptotic distribution has an explicit form that is readily seen to exhibit lognormal tail behavior.

  19. Dose. Detriment. Limit assessment; Dosis. Schadensmass. Grenzwertsetzung

    Energy Technology Data Exchange (ETDEWEB)

    Breckow, J. [Technische Hochschule Mittelhessen, Giessen (Germany). Inst. fuer Medizinische Physik und Strahlenschutz (IMPS)


    One goal of radiation protection is the limitation of stochastic effects due to radiation exposure. The probability of occurrence of a radiation induced stochastic effect, however, is only one of several other parameters which determine the radiation detriment. Though the ICRP-concept of detriment is a quantitative definition, the kind of detriment weighting includes somewhat subjective elements. In this sense, the detriment-concept of ICRP represents already at the stage of effective dose a kind of assessment. Thus, by comparing radiation protection standards and concepts interconvertible or with those of environment or occupational protection one should be aware of the possibly different principles of detriment assessment.

  20. Limitations to the capacity to love. (United States)

    Kernberg, Otto F


    This paper is a meditation on the potential and problems of establishing and maintaining loving and passionate relationships, drawn from a lifetime of struggling with these issues in the course of doing analysis. It describes interferences with the capacity for mature sexual love as reflecting various psychopathological conditions. These limitations include a variety of psychological restrictions determined most frequently by masochistic, narcissistic and paranoid personality features. Clinical case material illustrates both mature and disturbed capability for love relations. Copyright © 2011 Institute of Psychoanalysis.

  1. Indications and limits of the microabrasion technique. (United States)

    Benbachir, Nacer; Ardu, Stefano; Krejci, Ivo


    This clinical report illustrates with clinical cases the indications and limits of microabrasion in patients with discolored anterior teeth. The proposed techniques are based on the elimination of the dysplastic external enamel layer through microabrasion, completed by home bleaching and the use of modern adhesive restorative techniques, if necessary. In specific cases, the proposed technique may eliminate dysplastic enamel lesions without being invasive. The use of minimally invasive techniques based on microabrasion allows for treatment of slight enamel defects. In more severe cases, megabrasion combined with a minimally invasive adhesive resin composite restoration may present a valuable alternative to microabrasion.

  2. Limits of copyright in visual art


    Sýkora, Matěj


    Résumé: Limits of work of copyright in visual art This diploma thesis primarily deals with the concept of copyright work in the current Czech law and its relation towards works of contemporary visual art. The main aim of this thesis is to carry out a complex analysis of conceptual features of work of copyright under the Czech Copyright Act No. 121/2000 Coll. (including key and not always properly interpreted terms such as work of art, originality, or creativity) and then to apply these featur...

  3. Triangle anomaly in triple-Regge limits (United States)

    White, Alan R.


    Reggeized gluon interactions due to a single quark loop are studied in the full triple-Regge limit and in closely related helicity-flip helicity-pole limits. Triangle diagram Reggeon interactions are generated that include local axial-vector effective vertices. It is shown that the massless quark triangle anomaly is present as a chirality-violating infrared divergence in the interactions generated by maximally nonplanar Feynman diagrams. An asymptotic dispersion relation formalism is developed which provides a systematic counting of anomaly contributions. The asymptotic amplitude is written as a sum over dispersion integrals of triple discontinuities, one set of which is unphysical and can produce chirality transitions. The physical-region anomaly appears in the generalized real parts, determined by multi-Regge theory, of the unphysical discontinuities. The amplitudes satisfy a signature conservation rule that implies color parity is not conserved by vertices containing the anomaly. In the scattering of elementary quarks or gluons the signature and color parity of the exchanged Reggeon states are such that the anomaly cancels. At lowest order, it cancels in individual diagrams after the transverse momentum integrations are performed.

  4. Singular limits in thermodynamics of viscous fluids

    CERN Document Server

    Feireisl, Eduard


    This book is about singular limits of systems of partial differential equations governing the motion of thermally conducting compressible viscous fluids. "The main aim is to provide mathematically rigorous arguments how to get from the compressible Navier-Stokes-Fourier system several less complex systems of partial differential equations used e.g. in meteorology or astrophysics. However, the book contains also a detailed introduction to the modelling in mechanics and thermodynamics of fluids from the viewpoint of continuum physics. The book is very interesting and important. It can be recommended not only to specialists in the field, but it can also be used for doctoral students and young researches who want to start to work in the mathematical theory of compressible fluids and their asymptotic limits." Milan Pokorný (zbMATH) "This book is of the highest quality from every point of view. It presents, in a unified way, recent research material of fundament al importance. It is self-contained, thanks to Chapt...

  5. Fundamental limits of repeaterless quantum communications (United States)

    Pirandola, Stefano; Laurenza, Riccardo; Ottaviani, Carlo; Banchi, Leonardo


    Quantum communications promises reliable transmission of quantum information, efficient distribution of entanglement and generation of completely secure keys. For all these tasks, we need to determine the optimal point-to-point rates that are achievable by two remote parties at the ends of a quantum channel, without restrictions on their local operations and classical communication, which can be unlimited and two-way. These two-way assisted capacities represent the ultimate rates that are reachable without quantum repeaters. Here, by constructing an upper bound based on the relative entropy of entanglement and devising a dimension-independent technique dubbed ‘teleportation stretching', we establish these capacities for many fundamental channels, namely bosonic lossy channels, quantum-limited amplifiers, dephasing and erasure channels in arbitrary dimension. In particular, we exactly determine the fundamental rate-loss tradeoff affecting any protocol of quantum key distribution. Our findings set the limits of point-to-point quantum communications and provide precise and general benchmarks for quantum repeaters. PMID:28443624

  6. Quantum Speed Limits for Leakage and Decoherence. (United States)

    Marvian, Iman; Lidar, Daniel A


    We introduce state-independent, nonperturbative Hamiltonian quantum speed limits for population leakage and fidelity loss, for a gapped open system interacting with a reservoir. These results hold in the presence of initial correlations between the system and the reservoir, under the sole assumption that their interaction and its commutator with the reservoir Hamiltonian are norm bounded. The reservoir need not be thermal and can be time dependent. We study the significance of energy mismatch between the system and the local degrees of freedom of the reservoir that directly interact with the system. We demonstrate that, in general, by increasing the system gap we may reduce this energy mismatch, and, consequently, drive the system and the reservoir into resonance; this can accelerate fidelity loss, irrespective of the thermal properties or state of the reservoir. This implies that quantum error suppression strategies based on increasing the gap are not uniformly beneficial. Our speed limits also yield an elementary lower bound on the relaxation time of spin systems.

  7. Fundamental limits of repeaterless quantum communications. (United States)

    Pirandola, Stefano; Laurenza, Riccardo; Ottaviani, Carlo; Banchi, Leonardo


    Quantum communications promises reliable transmission of quantum information, efficient distribution of entanglement and generation of completely secure keys. For all these tasks, we need to determine the optimal point-to-point rates that are achievable by two remote parties at the ends of a quantum channel, without restrictions on their local operations and classical communication, which can be unlimited and two-way. These two-way assisted capacities represent the ultimate rates that are reachable without quantum repeaters. Here, by constructing an upper bound based on the relative entropy of entanglement and devising a dimension-independent technique dubbed 'teleportation stretching', we establish these capacities for many fundamental channels, namely bosonic lossy channels, quantum-limited amplifiers, dephasing and erasure channels in arbitrary dimension. In particular, we exactly determine the fundamental rate-loss tradeoff affecting any protocol of quantum key distribution. Our findings set the limits of point-to-point quantum communications and provide precise and general benchmarks for quantum repeaters.

  8. Spatial resolution limits of an optical profiler (United States)

    Creath, Katherine


    Interferometric optical profilers have a spatial resolution which is either limited by the detector array sample spacing and element size or by the optical resolution of the system. To test the working spatial resolution of an optical profiler a sinsusoidal grating with 300 lines/mm was measured using an optical profiler at lOx 2Ox 40x and 200x with detector arrays having element-to-element spacings of 6. 8 j. tm and 40 tm. The highest magnification gave the greatest and most accurate depth for the grating for all of the detectors. At 40x as long as there were more than about 8 sample points per cycle as there were with the two smaller detector spacings the grating depth can be measured quite accurately. With fewer points the peak-to-valley height measurement of the grating is too low even though the optical resolution of the system is sufficient enough to resolve the grating. The results of this work show that for accurate representation of surface heights containing high frequency structures oversampling is desirable. Summary The spatial resolution of an interferometric optical proffler depends upon both the optical resolution of the system and the characteristics of the detector array used to sample the image. The limiting resolution wifi be the larger of the optical and detector resolution. One means of defining optical resolution is the Sparrow criterion which states that the image of two points is just

  9. The thermodynamic limits of light concentrators

    Energy Technology Data Exchange (ETDEWEB)

    Smestad, G. (Hewlett Packard Co., San Jose, CA (United States)); Ries, H. (Paul Scherrer Inst., Wuerenlingen (Switzerland)); Winston, R. (Univ. of Chicago, IL (United States)); Yablonovitch, E. (Bell Communications Research, Red Bank, NJ (United States))


    Much work has been done over the past 10 years on the concentration of solar radiation using a variety of devices. To concentrate the light, photons from a larger area are collected and directed to a smaller areas. Some devices use geometrical optics, or a change in index of refraction to increase the illumination on a surface above the incident solar level. Other systems use a frequency or Stokes shift to increase the illumination of light at one photon energy at the expense of another. There is often confusion as to the concentration limit imposed by basic physical laws on these different types of systems. Presented is a unification of the ideas and principles developed for the various classifications of concentrators. Equations are developed that describe the limits of concentration in geometrical and fluorescent systems. Concentration is shown to be a function of the index of refraction, angular collection range, as well as the frequency shift. Applications of the ideas involve the understanding of diffuse radiation concentrators and the solar powered laser.


    Directory of Open Access Journals (Sweden)



    Full Text Available The studies assembled in Universitatis Sapientiae – Social Analysis, 4: (1–2/ 2014 comprise a multiplicity of themes and assorted research perspectives on the process commonly known as “Europeanization”. Despite their diversity, their analytical common denominator is that they highlight the conceptual and heuristic limits of the dominant convergence paradigm. Officially endorsed by EU institutions, this socialscientific paradigm focuses on overcoming differences in levels of regional development. It is also characterized by a uniform approach regarding disparities in development levels and towards the progress of convergence. More specifically, it focuses primarily on quantitative indicators. By contrast, this volume engages with a host of hitherto neglected issues such as the local differences and specificities that developed within the convergence process. These include, but are not limited to: the emergence of a distinct type of “post-peasant” society in the Romanian rural milieu, the practice of ethnography in the archives of the Romanian secret police, as well drug policy in Hungary from the 1970s through the 1990s. My objective here is to provide a critical précis and commentary to some of the studies collected in this volume

  11. Current limitations and recommendations to improve testing ... (United States)

    In this paper existing regulatory frameworks and test systems for assessing potential endocrine-active chemicals are described, and associated challenges discussed, along with proposed approaches to address these challenges. Regulatory frameworks vary somewhat across organizations, but all basically evaluate whether a chemical possesses endocrine activity and whether this activity can result in adverse outcomes either to humans or the environment. Current test systems include in silico, in vitro and in vivo techniques focused on detecting potential endocrine activity, and in vivo tests that collect apical data to detect possible adverse effects. These test systems are currently designed to robustly assess endocrine activity and/or adverse effects in the estrogen, androgen, and thyroid hormonal pathways; however, there are some limitations of current test systems for evaluating endocrine hazard and risk. These limitations include a lack of certainty regarding: 1)adequately sensitive species and life-stages, 2) mechanistic endpoints that are diagnostic for endocrine pathways of concern, and 3) the linkage between mechanistic responses and apical, adverse outcomes. Furthermore, some existing test methods are resource intensive in regard to time, cost, and use of animals. However, based on recent experiences, there are opportunities to improve approaches to, and guidance for existing test methods, and to reduce uncertainty. For example, in vitro high throughput

  12. Selected Parametric Effects on Materials Flammability Limits (United States)

    Hirsch, David B.; Juarez, Alfredo; Peyton, Gary J.; Harper, Susana A.; Olson, Sandra L.


    NASA-STD-(I)-6001B Test 1 is currently used to evaluate the flammability of materials intended for use in habitable environments of U.S. spacecraft. The method is a pass/fail upward flame propagation test conducted in the worst case configuration, which is defined as a combination of a material s thickness, test pressure, oxygen concentration, and temperature that make the material most flammable. Although simple parametric effects may be intuitive (such as increasing oxygen concentrations resulting in increased flammability), combinations of multi-parameter effects could be more complex. In addition, there are a variety of material configurations used in spacecraft. Such configurations could include, for example, exposed free edges where fire propagation may be different when compared to configurations commonly employed in standard testing. Studies involving combined oxygen concentration, pressure, and temperature on flammability limits have been conducted and are summarized in this paper. Additional effects on flammability limits of a material s thickness, mode of ignition, burn-length criteria, and exposed edges are presented. The information obtained will allow proper selection of ground flammability test conditions, support further studies comparing flammability in 1-g with microgravity and reduced gravity environments, and contribute to persuasive scientific cases for rigorous space system fire risk assessments.

  13. Photon Mass Limits from Fast Radio Bursts

    CERN Document Server

    Bonetti, Luca; Mavromatos, Nikolaos E.; Sakharov, Alexander S.; Sarkisyan-Grinbaum, Edward K.G.; Spallicci, Alessandro D.A.M.


    The frequency-dependent time delays in fast radio bursts (FRBs) can be used to constrain the photon mass, if the FRB redshifts are known, but the similarity between the frequency dependences of dispersion due to plasma effects and a photon mass complicates the derivation of a limit on $m_\\gamma$. The redshift of FRB 150418 has been measured to $\\sim 2$% and its dispersion measure (DM) is known to $\\sim 0.1$%, but the strength of the constraint on $m_\\gamma$ is limited by uncertainties in the modelling of the host galaxy and the Milky Way, as well as possible inhomogeneities in the intergalactic medium (IGM). Allowing for these uncertainties, the recent data on FRB 150418 indicate that $m_\\gamma \\lesssim 1.7 \\times 10^{-14}$ eV c$^{-2}$ ($4.6 \\times 10^{-50}$ kg). In the future, the different redshift dependences of the plasma and photon mass contributions to DM can be used to improve the sensitivity to $m_\\gamma$ if more FRB redshifts are measured. For a fixed fractional uncertainty in the extra-galactic cont...

  14. Pedestrian Flow in the Mean Field Limit

    KAUST Repository

    Haji Ali, Abdul Lateef


    We study the mean-field limit of a particle-based system modeling the behavior of many indistinguishable pedestrians as their number increases. The base model is a modified version of Helbing\\'s social force model. In the mean-field limit, the time-dependent density of two-dimensional pedestrians satisfies a four-dimensional integro-differential Fokker-Planck equation. To approximate the solution of the Fokker-Planck equation we use a time-splitting approach and solve the diffusion part using a Crank-Nicholson method. The advection part is solved using a Lax-Wendroff-Leveque method or an upwind Backward Euler method depending on the advection speed. Moreover, we use multilevel Monte Carlo to estimate observables from the particle-based system. We discuss these numerical methods, and present numerical results showing the convergence of observables that were calculated using the particle-based model as the number of pedestrians increases to those calculated using the probability density function satisfying the Fokker-Planck equation.

  15. Mass transport limitation in implantable defibrillator batteries (United States)

    Schmidt, C.; Tam, G.; Scott, E.; Norton, J.; Chen, K.

    Using cells with lithium reference electrodes, the power-limiting behavior in the lithium-SVO cell was shown to be due to a rapid voltage transition at the anode. A novel test cell was developed to explore the influence of current density, bulk LiAsF 6 concentration, separator type and separator proximity to the anode on the time to onset ( τ) of the anode polarization. The results were found to follow a relationship, iτ1/2∝ Cbulk, consistent with the Sand equation. This relationship also predicts that the critical concentration of LiAsF 6, at which onset of the anode polarization occurs, is near the solubility limit of LiAsF 6 in our system (around 3.5-4.0 M). This general phenomenon was found to be quantitatively similar for two dissimilar separator types, and the anode polarization could also be induced in the absence of separator at high concentration and current density. However, it appears that τ decreases with closer proximity of the separator to the anode surface (i.e. cell stack pressure), suggesting that the effect of separator is to inhibit convective transport to and from the Li surface.

  16. Quantum speed limits, coherence, and asymmetry (United States)

    Marvian, Iman; Spekkens, Robert W.; Zanardi, Paolo


    The resource theory of asymmetry is a framework for classifying and quantifying the symmetry-breaking properties of both states and operations relative to a given symmetry. In the special case where the symmetry is the set of translations generated by a fixed observable, asymmetry can be interpreted as coherence relative to the observable eigenbasis, and the resource theory of asymmetry provides a framework to study this notion of coherence. We here show that this notion of coherence naturally arises in the context of quantum speed limits. Indeed, the very concept of speed of evolution, i.e., the inverse of the minimum time it takes the system to evolve to another (partially) distinguishable state, is a measure of asymmetry relative to the time translations generated by the system Hamiltonian. Furthermore, the celebrated Mandelstam-Tamm and Margolus-Levitin speed limits can be interpreted as upper bounds on this measure of asymmetry by functions which are themselves measures of asymmetry in the special case of pure states. Using measures of asymmetry that are not restricted to pure states, such as the Wigner-Yanase skew information, we obtain extensions of the Mandelstam-Tamm bound which are significantly tighter in the case of mixed states. We also clarify some confusions in the literature about coherence and asymmetry, and show that measures of coherence are a proper subset of measures of asymmetry.

  17. Fastlim: a fast LHC limit calculator. (United States)

    Papucci, Michele; Sakurai, Kazuki; Weiler, Andreas; Zeune, Lisa

    Fastlim is a tool to calculate conservative limits on extensions of the Standard Model from direct LHC searches without performing any Monte Carlo event generation. The program reconstructs the visible cross sections (cross sections after event selection cuts) from pre-calculated efficiency tables and cross section tables for simplified event topologies. As a proof of concept of the approach, we have implemented searches relevant for supersymmetric models with R-parity conservation. Fastlim takes the spectrum and coupling information of a given model point and provides, for each signal region of the implemented analyses, the visible cross sections normalised to the corresponding upper limit, reported by the experiments, as well as the [Formula: see text] value. To demonstrate the utility of the program we study the sensitivity of the recent ATLAS missing energy searches to the parameter space of natural SUSY models. The program structure allows the straightforward inclusion of external efficiency tables and can be generalised to R-parity violating scenarios and non-SUSY models. This paper serves as a self-contained user guide and indicates the conventions and approximations used.

  18. Thermodynamical limits of diluted magnetic semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Buerger, Danilo; Seeger, Michael; Zhou, Shengqiang; Helm, Manfred; Schmidt, Heidemarie [Forschungszentrum Dresden-Rossendorf e.V., Bautzner Landstrasse 400, 01328 Dresden (Germany)


    The incorporation of transition metals dopants in semiconductors over their solubility limit is the main challenge for the fabrication of diluted ferromagnetic semiconductors. Dietl et al. calculated the Curie temperatures for various semiconductors doped with 5 at% Mn. A lot of experimental effort was focused on the fabrication of diluted magnetic semiconductors. Unfortunately, such metastable alloys try to reach their thermodynamical equilibrium by the diffusion of the incorporated dopants. The equilibrium state at room temperature for semiconductors with a low solubility of magnetic dopant atoms is characterized by unwanted secondary phases. We present the results from combined random walk simulations and heat-flow calculations and explain the successful fabrication of GaAs:Mn and the impossibility to produce diluted Si:Mn. The clustering process is simulated under the assumption that neighbouring magnetic atoms stick together. This is a general approach for the growth of clusters in supersaturated materials. With the knowledge of the diffusion coefficient our modelling can be used to predict the thermodynamical limit at room temperature and the producibility by pulsed laser annealing of diluted magnetic semiconductors.

  19. Resistive-Type Fault Current Limiter (United States)

    Martini, L.; Bocchi, M.; Angeli, G.

    Among the wide range of High-Temperature Superconducting (HTS) materials presently known Bismuth Strontium Calcium Copper Oxide (BSCCO) is a very suitable candidate for power applications either at low temperature (e.g. framework of a R&D national project, started focusing on a preliminary single-phase device, which was submitted to dielectric and short-circuit current testing. The first success paved the way for the finalization of the remaining two phases and the final result was a three-phase resistive-type 9 kV/3.4 MVA SFCL device, based on first generation (1G) BSCCO tapes that was installed in the S. Dionigi substation, belonging to the Italian utility A2A Reti Elettriche S.p.A. (A2A), in the Milan MV distribution grid. The in-field activity lasted for more than two years, demonstrating the SFCL capability to cope with the grid in every-day operating conditions. Moreover, at the end of the experimentation, the SFCL device was able to perform a true limitation during a three-phase fault, thereby becoming one of the first SFCL devices in the world (the first in Italy) installed in a real grid and to have limited a real short-circuit current.

  20. Os limites da crítica

    Directory of Open Access Journals (Sweden)

    Gerbase, Carlos


    Full Text Available A importância da crítica cinematográfica é indiscutível, assim como a necessidade de que o crítico tenha ampla liberdade para exercer seu ofício. Isso não quer dizer, contudo, que ele possa dizer qualquer coisa. Este ensaio parte do princípio de que há limites na interpretação de um filme. Partindo de textos de Umberto Eco e outros autores, que estudam o jogo interpretativo de textos literários, este ensaio pretende levar a discussão para o campo cinematográfico e estabelecer algumas destas fronteiras. The importance of the cinematographic criticism is undiscussable. It is also important that the critic could feel free to do his job. Nevertheless, he has no right to say anything he wants. This paper deals with the idea that there is some limits to interpretate a film and is based on Umberto Eco and others authors texts about the interpretative games in literature focusing the cinematographic field to established some frontiers.

  1. Global phylogeographic limits of Hawaii's avian malaria (United States)

    Beadell, J.S.; Ishtiaq, F.; Covas, R.; Melo, M.; Warren, B.H.; Atkinson, C.T.; Bensch, S.; Graves, G.R.; Jhala, Y.V.; Peirce, M.A.; Rahmani, A.R.; Fonseca, D.M.; Fleischer, R.C.


    The introduction of avian malaria (Plasmodium relictum) to Hawaii has provided a model system for studying the influence of exotic disease on naive host populations. Little is known, however, about the origin or the genetic variation of Hawaii's malaria and traditional classification methods have confounded attempts to place the parasite within a global ecological and evolutionary context. Using fragments of the parasite mitochondrial gene cytochrome b and the nuclear gene dihydrofolate reductase-thymidylate synthase obtained from a global survey of greater than 13 000 avian samples, we show that Hawaii's avian malaria, which can cause high mortality and is a major limiting factor for many species of native passerines, represents just one of the numerous lineages composing the morphological parasite species. The single parasite lineage detected in Hawaii exhibits a broad host distribution worldwide and is dominant on several other remote oceanic islands, including Bermuda and Moorea, French Polynesia. The rarity of this lineage in the continental New World and the restriction of closely related lineages to the Old World suggest limitations to the transmission of reproductively isolated parasite groups within the morphological species. ?? 2006 The Royal Society.

  2. Legal time limits vs. discretional limits of administrative judicial review in Albania

    Directory of Open Access Journals (Sweden)

    Gerti Shella


    Full Text Available Administrative courts in Albania were established in 2012, as a separate branch of the court system, following enactment of the Law No. 49/2012 “On the Organization and Functioning of the Administrative Courts and Adjudication of Administrative Disputes”. One of the main features of the administrative adjudication is the swiftness at which it should be carried out. The law provides carefully for many time limits and procedural deadlines, to achieve such intended effect. This article focuses specifically on the time limits of concluding (1 the judicial review in administrative courts and 2 on due delivery of the final decision in court secretariat. These two distinct procedural phases constitute 98% of the length of a court case in time terms. The main thesis of this paper is that time limits which are explicitly written and required by the law produce better results in terms of compliance of judges with law and higher efficiency compared to discretional time limits.

  3. The constitutional limits to the tributary planning Os limites constitucionais ao planejamento tributário

    Directory of Open Access Journals (Sweden)

    Marlene Kempfer Bassoli


    Full Text Available Tax planning is a self-organization’s right of tax payers, due to that, they can organize its activities in the limits of legality, in order to reduce, to postpone or even to prevent rate of tributes. However, this right to self-organization is not, and cannot be, absolute. It has to find its limits in the respect to constitutional principles like: the fact’s precision with the hypothesis of the law, and strict legality.O planejamento tributário é o direito de auto-organização do contribuinte, para que, agindo nos limites da licitude, possa planejar suas atividades, de forma a reduzir, retardar, ou mesmo evitar o pagamento de tributos. Todavia, este direito de auto-organizar-se não é, e nem pode ser absoluto, devendo encontrar os seus limites no respeito aos princípios da Tipicidade e da Estrita Legalidade.

  4. First Amendment Limits on Compulsory Speech. (United States)

    Barrella, Nigel

    Government-mandated labeling requirements have a long history, and are used extensively by FDA in regulating the industries under its jurisdiction. All such requirements can be characterized as a form of “compelled speech,” opening the door to First Amendment challenges. And some of these challenges, depending on the nature of the labeling requirement, have even been successful. Under Zauderer v. Office of Disciplinary Counsel of Supreme Court of Ohio, regulations that compel disclosure of information will, in many cases, merit only very limited First Amendment scrutiny—less, even, than most other regulations of commercial speech, which receive a type of “intermediate scrutiny.” The labeling requirement that can best avoid or overcome a First Amendment challenge, therefore, will follow the example of the regulation described in Zauderer. For example, Zauderer applied its lower scrutiny by noting that the compelled speech at issue was a disclosure of “purely factual and uncontroversial information.” Conversely, a successful First Amendment challenge to a labeling requirement will often involve an argument that the labeling requirement is outside the scope of what the Zauderer Court contemplated: so, for example, one may argue that a compelled disclosure is either “not factual” or else “controversial,” putting it beyond Zauderer’s reach. After briefly reviewing the major Supreme Court cases that establish the levels of scrutiny for commercial speech and compelled disclosures, the paper will discuss how the various elements of Zauderer have been analyzed by several lower courts, and how some courts have distinguished Zauderer in the context of labeling and other mandatory disclosure laws. In particular, the paper will focus on cases involving First Amendment challenges to food, tobacco, and drug labeling requirements—some successful, some not, and some ongoing—including cases challenging FDA, USDA, and state-level labeling requirements. The

  5. Limits on the photon mass; Limites sur la masse du photon

    Energy Technology Data Exchange (ETDEWEB)

    Vasseur, G.


    Is the photon mass strictly null as it is told in quantum electrodynamics. In fact, a coherent theory can be build with a massive photon. Experiences have been regularly led to try to make obvious an eventual non null photon mass. Superior limits more and more strict have been found. Here is given a general survey of the consequences of a non null photon mass, different methods to measure it and the achieved limits. (author). 30 refs., 1 fig.

  6. Quantity and quality limit detritivore growth: mechanisms revealed by ecological stoichiometry and co-limitation theory. (United States)

    Halvorson, Halvor M; Sperfeld, Erik; Evans-White, Michelle A


    Resource quantity and quality are fundamental bottom-up constraints on consumers. Best understood in autotroph-based systems, co-occurrence of these constraints may be common but remains poorly studied in detrital-based systems. Here, we used a laboratory growth experiment to test limitation of the detritivorous caddisfly larvae Pycnopsyche lepida across a concurrent gradient of oak litter quantity (food supply) and quality (phosphorus : carbon [P:C ratios]). Growth increased simultaneously with quantity and quality, indicating co-limitation across the resource gradients. We merged approaches of ecological stoichiometry and co-limitation theory, showing how co-limitation reflected shifts in C and P acquisition throughout homeostatic regulation. Increased growth was best explained by elevated consumption rates and improved P assimilation, which both increased with elevated quantity and quality. Notably, C assimilation efficiencies remained unchanged and achieved maximum 18% at low quantity despite pronounced C limitation. Detrital C recalcitrance and substantive post-assimilatory C losses probably set a minimum quantity threshold to achieve positive C balance. Above this threshold, greater quality enhanced larval growth probably by improving P assimilation toward P-intensive growth. We suggest this interplay of C and P acquisition contributes to detritivore co-limitation, highlighting quantity and quality as potential simultaneous bottom-up controls in detrital-based ecosystems, including under anthropogenic change like nutrient enrichment. © 2017 by the Ecological Society of America.

  7. Designs of LiMIT as a Limiter in the EAST Tokamak (United States)

    Szott, Matthew; Christenson, Michael; Kalathiparambil, Kishor; Ruzic, David


    Liquid metal plasma facing components (PFCs) provide a constantly refreshing, self-healing surface that can reduce erosion and thermal stress damage to prolong device lifetime, and additionally decrease edge recycling, reduce impurities, and enhance plasma performance. The Liquid Metal Infused Trench (LiMIT) system, developed at UIUC, has demonstrated thermoelectric magnetohydrodynamic (TEMHD) driven flow of liquid lithium through series of solid trenches. This TEMHD effect drives liquid lithium in fusion systems using the plasma heat flux and the toroidal magnetic field, and the surface tension of the liquid lithium maintains a fresh surface on top of the solid trenches. LiMIT has been successfully tested at UIUC as well as HT-7 and Magnum PSI at heat fluxes up to 3 MW/m2. The next step is demonstrating system viability in full-scale fusion-relevant conditions. In collaboration with a team in Hefei, design and testing has begun for a large scale LiMIT system that will act as a limiter in EAST. The designs improve upon previous versions of LiMIT tested at Illinois and incorporate lessons learned from earlier tests of liquid metal PFCs at EAST. Existing infrastructure is used to load and supply lithium to the system, and the LiMIT trenches will help maintain a smooth, fresh surface as well as aid in propelling the lithium out of direct plasma flux to improve heat transfer. Supported by DOE/ALPS DE-FG02-99ER54515.

  8. Liberty through limits: The bill of rights as limited government provisions

    Directory of Open Access Journals (Sweden)

    Patrick M. Garry


    Full Text Available Under the modern view, individual autonomy has become the primary if not exclusive focus of the Bill of Rights. But the Bill of Rights came about not because of a desire to preserve individual autonomy, nor to insulate the individual from the democratic community. The impetus for the Bill of Rights arose from the same set of concerns that motivated the original Constitution. These concerns involved creating the appropriate structures so as to keep the new central government in check. The Bill of Rights sought to further ensure that the federal government would have limited power and operate in a limited role. Not only does this limited government model coincide with the original intent underlying the Bill of Rights, but it also provides for a more objective and manageable application. Under an individual autonomy view of the Bill of Rights, courts must define the ingredients necessary for such autonomy. However, this endeavor is fraught with ambiguity, and courts must constantly pit the individual against democratic society. But under the limited government model, the judicial role is more objective. Instead of trying to define an ambiguous individual autonomy, courts simply need to focus on whether a particular right is needed so as to maintain limited government. In addition, the limited government model does not put the Bill of Rights in conflict with democratic society. Instead, it just uses the Bill of Rights to maintain a check on government, just as the original Constitution seeks to do.

  9. Detection limits with spectral differential imaging data (United States)

    Rameau, J.; Chauvin, G.; Lagrange, A.-M.; Maire, A.-L.; Boccaletti, A.; Bonnefoy, M.


    Context. Direct imaging of exoplanets is polluted by speckle noise that severely limits the achievable contrast. Angular and spectral differential imaging have been proposed to make use of the temporal and chromatic properties of the speckles. Both modes, associated with extreme adaptive-optics and coronagraphy, are at the core of the new generation of planet imagers SPHERE and GPI. Aims: We aim to illustrate and characterize the impact of the SDI and SDI+ADI (ASDI) data reduction on the detection of giant planets. We also propose an unbiased method to derive the detection limits from SDI/ASDI data. Methods: Observations of AB Dor B and β Pictoris made with VLT/NaCo were used to simulate and quantify the effects of SDI and ASDI. The novel method is compared to the traditional injection of artificial point sources. Results: The SDI reduction process creates a typical radial positive-negative pattern of any point-source. Its characteristics and its self-subtraction depend on the separation, but also on the spectral properties of the object. This work demonstrates that the self-subtraction cannot be reduced to a simple geometric effect. As a consequence, the detection performances of SDI observations cannot be expressed as a contrast in magnitude with the central star without the knowledge of the spectral properties of detectable companions. In addition, the residual noise cannot be converted into contrast and physical characteristics (mass, temperature) by standard calibration of flux losses. The proposed method takes the SDI bias into account to derive detection limits without the cost of massively injecting artificial sources into the data. Finally, the sensitivity of ASDI observations can be measured only with a control parameter on the algorithms that controls the minimum rotation that is necessary to build the reference image. Based on observations collected at the European Organization for Astronomical Research in the Southern Hemisphere, Chile, ESO : 60.A

  10. Theoretical and Practical Limits for Transparent Photovoltaics (United States)

    Lunt, Richard


    Transparent photovoltaics (TPVs) offer a new paradigm for solar energy harvesting, integration, and deployment. These devices have recently been shown to be enabled by exploiting the excitonic nature of molecular and organic semiconductors.[1] Here, we present the theoretical and practical efficiency limits of these novel electronic architectures as a function of bandgap, transparency and aesthetic quality for both single and multi-junction cells. For example, power-production from ultraviolet and near-infrared photons alone leads to a theoretical single-junction efficiency of 21% in completely transparent structures, compared to 33% for opaque-junctions. This approach for transparent photovoltaics will be contrasted with other semi-transparent approaches, where TPVs with selective absorption offer the highest possible potential for combined transparency and efficiency. The impact of transparent PVs will be discussed for a range of applications from electronic displays to window integration.

  11. Quantum cryptography approaching the classical limit. (United States)

    Weedbrook, Christian; Pirandola, Stefano; Lloyd, Seth; Ralph, Timothy C


    We consider the security of continuous-variable quantum cryptography as we approach the classical limit, i.e., when the unknown preparation noise at the sender's station becomes significantly noisy or thermal (even by as much as 10(4) times greater than the variance of the vacuum mode). We show that, provided the channel transmission losses do not exceed 50%, the security of quantum cryptography is not dependent on the channel transmission, and is therefore incredibly robust against significant amounts of excess preparation noise. We extend these results to consider for the first time quantum cryptography at wavelengths considerably longer than optical and find that regions of security still exist all the way down to the microwave.

  12. Advancing the Limits of Dual Fuel Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Koenigsson, Fredrik


    There is a growing interest in alternative transport fuels. There are two underlying reasons for this interest; the desire to decrease the environmental impact of transports and the need to compensate for the declining availability of petroleum. In the light of both these factors the Diesel Dual Fuel, DDF, engine is an attractive concept. The primary fuel of the DDF engine is methane, which can be derived both from renewables and from fossil sources. Methane from organic waste; commonly referred to as biomethane, can provide a reduction in greenhouse gases unmatched by any other fuel. The DDF engine is from a combustion point of view a hybrid between the diesel and the otto engine and it shares characteristics with both. This work identifies the main challenges of DDF operation and suggests methods to overcome them. Injector tip temperature and pre-ignitions have been found to limit performance in addition to the restrictions known from literature such as knock and emissions of NO{sub x} and HC. HC emissions are especially challenging at light load where throttling is required to promote flame propagation. For this reason it is desired to increase the lean limit in the light load range in order to reduce pumping losses and increase efficiency. It is shown that the best results in this area are achieved by using early diesel injection to achieve HCCI/RCCI combustion where combustion phasing is controlled by the ratio between diesel and methane. However, even without committing to HCCI/RCCI combustion and the difficult control issues associated with it, substantial gains are accomplished by splitting the diesel injection into two and allocating most of the diesel fuel to the early injection. HCCI/RCCI and PPCI combustion can be used with great effect to reduce the emissions of unburned hydrocarbons at light load. At high load, the challenges that need to be overcome are mostly related to heat. Injector tip temperatures need to be observed since the cooling effect of

  13. Immobilizing Biomolecules Near the Diffraction Limit

    DEFF Research Database (Denmark)

    Skovsen, Esben; Petersen, Maria Teresa Neves; Gennaro, Ane Kold Di


    Our group has previously shown that biomolecules containing disulfide bridges in close proximity to aromatic residues can be immobilized, through covalent bonds, onto thiol derivatized surfaces upon UV excitation of the aromatic residue(s). We have also previously shown that our new technology can...... be used to print arrays of biomolecules and to immobilize biomolecules according to any specific pattern on a planar substrates with micrometer scale resolution. In this paper we show that we can immobilize proteins according to diffraction patterns of UV light. We also show that the feature size...... of the immobilized patterns can be as small as the diffraction limit for the excitation light, and that the immobilized patterns correspond to the diffraction pattern used to generate it. The flexibility of this new technology will in principle make it possible to create any pattern of biomolecules onto a substrate...

  14. Nanoscale heat engine beyond the Carnot limit. (United States)

    Roßnagel, J; Abah, O; Schmidt-Kaler, F; Singer, K; Lutz, E


    We consider a quantum Otto cycle for a time-dependent harmonic oscillator coupled to a squeezed thermal reservoir. We show that the efficiency at maximum power increases with the degree of squeezing, surpassing the standard Carnot limit and approaching unity exponentially for large squeezing parameters. We further propose an experimental scheme to implement such a model system by using a single trapped ion in a linear Paul trap with special geometry. Our analytical investigations are supported by Monte Carlo simulations that demonstrate the feasibility of our proposal. For realistic trap parameters, an increase of the efficiency at maximum power of up to a factor of 4 is reached, largely exceeding the Carnot bound.

  15. A night without limits for science

    CERN Multimedia

    CERN Bulletin


    On 10 and 11 July some 400 scientists came down to Geneva's Perle du Lac park to meet the public for the Nuit de la Science.   One of the many attractions at the Nuit de la Science. The theme of this year's event, now in its eighth year, was "Extremes and Limits". Numerous attractions including stands, workshops, mini-conferences and plays were set up in the park, all with the aim of conveying their passion for research and thirst for knowledge to the visitors. Several CERN guides were on hand to tell the public about that machine of the extreme, the LHC. CERN was also represented on the stand of the Réseau romand science & cité. For more information, clic here.      

  16. Fundamental limitations in filtering and control

    CERN Document Server

    Seron, Maria M


    The issue of fundamental limitations in filtering and control lies at the very heart of any feedback system design, since it reveals what is and is not achievable on the basis of that system's structural and dynamic characteristics. Alongside new succinct treatments of Bode's original results from the 1940s, this book presents a comprehensive analysis of modern results, featuring contemporary developments in multivariable systems, sampled-data, periodic and nonlinear problems. The text gives particular prominence to sensitivity functions which measure the fundamental qualities of the system, including performance and robustness. With extensive appendices covering the necessary background on complex variable theory, this book is an ideal self-contained resource for researchers and practitioners in this field.

  17. The height limit of a siphon (United States)

    Boatwright, A.; Hughes, S.; Barry, J.


    The maximum height of a siphon is generally assumed to be dependent on barometric pressure—about 10 m at sea level. This limit arises because the pressure in a siphon above the upper reservoir level is below the ambient pressure, and when the height of a siphon approaches 10 m, the pressure at the crown of the siphon falls below the vapour pressure of water causing water to boil breaking the column. After breaking, the columns on either side are supported by differential pressure between ambient and the low-pressure region at the top of the siphon. Here we report an experiment of a siphon operating at sea level at a height of 15 m, well above 10 m. Prior degassing of the water prevented cavitation. This experiment provides conclusive evidence that siphons operate through gravity and molecular cohesion.

  18. Authorized limits for Fernald copper ingots

    Energy Technology Data Exchange (ETDEWEB)

    Frink, N.; Kamboj, S.; Hensley, J.; Chen, S. Y.


    This development document contains data and analysis to support the approval of authorized limits for the unrestricted release of 59 t of copper ingots containing residual radioactive material from the U.S. Department of Energy (DOE) Fernald Environmental Management Project (FEMP). The analysis presented in this document comply with the requirements of DOE Order 5400.5, {open_quotes}Radiation Protection of the Public and the Environment,{close_quotes} as well as the requirements of the proposed promulgation of this order as 10 CFR Part 834. The document was developed following the step-by-step process described in the Draft Handbook for Controlling Release for Reuse or Recycle Property Containing Residual Radioactive Material.

  19. Polybinary modulation for bandwidth limited optical links

    DEFF Research Database (Denmark)

    Vegas Olmos, Juan José; Jurado-Navas, Antonio


    Optical links using traditional modulation formats are reaching a plateau in terms of capacity, mainly due to bandwidth limitations in the devices employed at the transmitter and receivers. Advanced modulation formats, which boost the spectral efficiency, provide a smooth migration path towards...... effectively increase the available capacity. Advanced modulation formats however require digitalization of the signals and digital signal processing blocks to both generate and recover the data. There is therefore a trade-off in terms of efficiency gain vs. complexity. Poly binary modulation, a generalized...... form of partial response modulation, employs simple codification and filtering at the transmitter to drastically increase the spectral efficiency. At the receiver side, poly binary modulation requires low complexity direct detection and very little digital signal processing. This talk will review...

  20. Mass limit for the lightest neutralino (United States)

    Buskulic, D.; de Bonis, I.; Decamp, D.; Ghez, P.; Goy, C.; Lees, J.-P.; Lucotte, A.; Minard, M.-N.; Nief, J.-Y.; Odier, P.; Pietrzyk, B.; Casado, M. P.; Chmeissani, M.; Crespo, J. M.; Delfino, M.; Efthymiopoulos, I.; Fernandez, E.; Fernandez-Bosman, M.; Garrido, Ll.; Juste, A.; Martinez, M.; Orteu, S.; Padilla, C.; Park, I. C.; Pascual, A.; Perlas, J. A.; Riu, I.; Sanchez, F.; Teubert, F.; Colaleo, A.; Creanza, D.; de Palma, M.; Gelao, G.; Girone, M.; Iaselli, G.; Maggi, G.; Maggi, M.; Marinelli, N.; Nuzzo, S.; Ranieri, A.; Raso, G.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Zito, G.; Huang, X.; Lin, J.; Quyang, Q.; Wang, T.; Xie, Y.; Xu, R.; Xue, S.; Zhang, J.; Zhang, L.; Zhao, W.; Alemany, R.; Bazarko, A. O.; Bright-Thomas, P.; Cattaneo, M.; Comas, P.; Coyle, P.; Drevermann, H.; Forty, R. W.; Frank, M.; Hagelberg, R.; Harvey, J.; Janot, P.; Jost, B.; Kneringer, E.; Knobloch, J.; Lehraus, I.; Lutters, G.; Martin, E. B.; Mato, P.; Minten, A.; Miquel, R.; Mir, Ll. M.; Moneta, L.; Oest, T.; Pacheco, A.; Pusztaszeri, J.-F.; Ranjard, F.; Rensing, P.; Rolandi, L.; Schlatter, D.; Schmelling, M.; Schmitt, M.; Schneider, O.; Tejessy, W.; Tomalin, I. R.; Venturi, A.; Wachsmuth, H.; Wagner, A.; Ajaltouni, Z.; Barrès, A.; Boyer, C.; Falvard, A.; Gay, P.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Monteil, S.; Montret, J.-C.; Pallin, D.; Perret, P.; Podlyski, F.; Proriol, J.; Rosnet, P.; Rossignol, J.-M.; Fearnley, T.; Hansen, J. B.; Hansen, J. D.; Hansen, J. R.; Hansen, P. H.; Nilsson, B. S.; Wäänänen, A.; Kyriakis, A.; Markou, C.; Simopoulou, E.; Siotis, I.; Vayaki, A.; Zachariadou, K.; Blondel, A.; Brient, J. C.; Rougé, A.; Rumpf, M.; Valassi, A.; Videau, H.; Focardi, E.; Parrini, G.; Corden, M.; Georgiopoulos, C.; Jaffe, D. E.; Antonelli, A.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Casper, D.; Chiarella, V.; Felici, G.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G. P.; Passalacqua, L.; Pepe-Altarelli, M.; Curtis, L.; Dorris, S. J.; Halley, A. W.; Knowles, I. G.; Lynch, J. G.; O'Shea, V.; Raine, C.; Reeves, P.; Scarr, J. M.; Smith, K.; Teixeira-Dias, P.; Thompson, A. S.; Thomson, F.; Thorn, S.; Turnbull, R. M.; Becker, U.; Geweniger, C.; Graefe, G.; Hanke, P.; Hansper, G.; Hepp, V.; Kluge, E. E.; Putzer, A.; Schmidt, M.; Sommer, J.; Stenzel, H.; Tittel, K.; Werner, S.; Wunsch, M.; Abbaneo, D.; Beuselinck, R.; Binnie, D. M.; Cameron, W.; Dornan, P. J.; Morawitz, P.; Moutoussi, A.; Nash, J.; Sedgbeer, J. K.; Stacey, A. M.; Williams, M. D.; Dissertori, G.; Girtler, P.; Kuhn, D.; Rudolph, G.; Betteridge, A. P.; Bowdery, C. K.; Colrain, P.; Crawford, G.; Finch, A. J.; Foster, F.; Hughes, G.; Sloan, T.; Whelan, E. P.; Williams, M. I.; Galla, A.; Greene, A. M.; Hoffmann, C.; Jacobs, K.; Kleinknecht, K.; Quast, G.; Renk, B.; Rohne, E.; Sander, H.-G.; van Gemmeren, P.; Zeitnitz, C.; Aubert, J. J.; Bencheikh, A. M.; Benchouk, C.; Bonissent, A.; Bujosa, G.; Calvet, D.; Carr, J.; Diaconu, C.; Konstantinidis, N.; Payre, P.; Rousseau, D.; Talby, M.; Sadouki, A.; Thulasidas, M.; Tilquin, A.; Trabelsi, K.; Aleppo, M.; Ragusa, F.; Bauer, C.; Berlich, R.; Blum, W.; Büscher, V.; Dietl, H.; Dydak, F.; Ganis, G.; Gotzhein, C.; Kroha, H.; Lütjens, G.; Lutz, G.; Männer, W.; Moser, H.-G.; Richter, R.; Rosado-Schlosser, A.; Schael, S.; Settles, R.; Seywerd, H.; Denis, R. St.; Stenzel, H.; Wiedenmann, W.; Wolf, G.; Boucrot, J.; Callot, O.; Cordier, A.; Davier, M.; Duflot, L.; Grivaz, J.-F.; Heusse, Ph.; Höcker, A.; Jacholkowska, A.; Jacquet, M.; Kim, D. W.; Le Diberder, F.; Lefrançois, J.; Lutz, A.-M.; Nikolic, I.; Park, H. J.; Schune, M.-H.; Simion, S.; Veillet, J.-J.; Videau, I.; Zerwas, D.; Azzurri, P.; Bagliesi, G.; Batignain, G.; Bettarini, S.; Bozzi, C.; Calderini, G.; Carpinelli, M.; Ciocci, M. A.; Ciulli, V.; Dell'Orso, R.; Fantechi, R.; Ferrante, I.; Giassi, A.; Gregorio, A.; Ligabue, F.; Lusiani, A.; Marrocchesi, P. S.; Messineo, A.; Palla, F.; Rizzo, G.; Sanguinetti, G.; Sciabà, A.; Spagnolo, P.; Steinberger, J.; Tenchini, R.; Tonelli, G.; Vannini, C.; Verdini, P. G.; Walsh, J.; Blair, G. A.; Bryant, L. M.; Cerutti, F.; Chambers, J. T.; Gao, Y.; Green, M. G.; Medcalf, T.; Perrodo, P.; Strong, J. A.; von Wimmersperg-Toeller, J. H.; Botterill, D. R.; Clifft, R. W.; Edgecock, T. R.; Haywood, S.; Maley, P.; Norton, P. R.; Thompson, J. C.; Wright, A. E.; Bloch-Devaux, B.; Colas, P.; Emerya, S.; Kozanecki, W.; Lançon, E.; Lemaire, M. C.; Locci, E.; Marx, B.; Perez, P.; Rander, J.; Renardy, J.-F.; Roussarie, A.; Schuller, J.-P.; Schwindling, J.; Trabelsi, A.; Vallage, B.; Black, S. N.; Dann, J. H.; Johnson, R. P.; Kim, H. Y.; Litke, A. M.; McNeil, M. A.; Taylor, G.; Booth, C. N.; Boswell, R.; Brew, C. A. J.; Cartwright, S.; Combley, F.; Koksal, A.; Letho, M.; Newton, W. M.; Reeve, J.; Thompson, L. F.; Böhrer, A.; Brandt, S.; Cowan, G.; Grupen, C.; Saraiva, P.; Smolik, L.; Stephan, F.; Apollonio, M.; Bosisio, L.; Della Marina, R.; Giannini, G.; Gobbo, B.; Musolino, G.; Putz, J.; Rothberg, J.; Wasserbaech, S.; Williams, R. W.; Armstrong, S. R.; Elmer, P.; Feng, Z.; Ferguson, D. P. S.; Gao, Y. S.; González, S.; Grahl, J.; Greening, T. C.; Hayes, O. J.; Hu, H.; McNamara, P. A.; Nachtman, J. M.; Orejudos, W.; Pan, Y. B.; Saadi, Y.; Scott, I. J.; Walsh, A. M.; Wu, Sau Lan; Wu, X.; Yamartino, J. M.; Zheng, M.; Zobernig, G.


    Indirect limits on the mass of the lightest neutralino are derived from the results of searches for charginos, neutralinos, and sleptons performed with data taken by the ALEPH Collaboration at centre-of-mass energies near the Z peak and at 130 and 136 GeV. Within the context of the Minimal Supersymmetric Standard Model and whenM_{tilde ν } ≥slant 200 GeV/c^2 , the bound M x > 12.8 GeV/ c 2 at the 95% confidence level applies for any tan β. The impact of lighter sneutrinos is presented in the framework of SUSY grand unified theories; a massless neutralino is allowed only for a narrow range of tan β, μ, and the scalar mass parameter m 0. Finally, by including Higgs mass constraints and requiring that radiative electroweak symmetry breaking occur, more stringent bounds on M x as a function of tan β are derived.

  1. Current-limited electron beam injection (United States)

    Stenzel, R. L.


    The injection of an electron beam into a weakly collisional, magnetized background plasma was investigated experimentally. The injected beam was energetic and cold, the background plasma was initially isothermal. Beam and plasma dimensions were so large that the system was considered unbounded. The temporal and spatial evolution of the beam-plasma system was dominated by collective effects. High-frequency electrostatic instabilities rapidly thermalized the beam and heated the background electrons. The injected beam current was balanced by a return current consisting of background electrons drifting toward the beam source. The drift between electrons and ions gave rise to an ion acoustic instability which developed into strong three-dimensional turbulence. It was shown that the injected beam current was limited by the return current which is approximately given by the electron saturation current. Non-Maxwellian electron distribution functions were observed.

  2. Limitations of Animal Models of Parkinson's Disease

    Directory of Open Access Journals (Sweden)

    J. A. Potashkin


    Full Text Available Most cases of Parkinson's disease (PD are sporadic. When choosing an animal model for idiopathic PD, one must consider the extent of similarity or divergence between the physiology, anatomy, behavior, and regulation of gene expression between humans and the animal. Rodents and nonhuman primates are used most frequently in PD research because when a Parkinsonian state is induced, they mimic many aspects of idiopathic PD. These models have been useful in our understanding of the etiology of the disease and provide a means for testing new treatments. However, the current animal models often fall short in replicating the true pathophysiology occurring in idiopathic PD, and thus results from animal models often do not translate to the clinic. In this paper we will explain the limitations of animal models of PD and why their use is inappropriate for the study of some aspects of PD.

  3. Novel 3-Phase Inductive Fault Current Limiter (United States)

    Kosa, Janos

    The paper describes the inductive three-phase fault current limiter. In this work I examine the novel arrangements of the perfect closed superconducting loop made of HTS wire. I applied one iron core with 3 limbs and special loops for uniform temperature of the superconducting wire. In this work I present the results of my experiments with this device. I present the static and dynamic measured results of this solution. It has got several advantages e. g. fast switching and less fault power for high-power electric machines. The advantage of the equipment is that in the case of single-phase short circuit the current will decrease in all the three phases. This can be an appropriate solution for high power machines. For example, in the case of high-power electric motor if there is a single-phase breaking or a single phase short circuit, we can decrease the current in the three phases.

  4. Planetary Overload, Limits to Growth and Health. (United States)

    Butler, Colin D


    Since the use of atomic weapons in 1945 visionaries have warned that without major changes the survival of global civilization is in question. These concerns deepened in following decades, during the Cold War, with The Limits to Growth, the best-selling environmental book of the 1970s. Yet, since then, most concern has faded, fuelled by technological developments and a shift in dominant global ideology. Public health, with a few exceptions (one of which is the book Planetary Overload), has been slow to recognize this debate, even as evidence emerges that civilization may indeed be at risk, driven by an increasingly ominous complex of events. This article outlines the key relevant literature and concepts, attempting to bring emerging and future health consequences to the attention of health workers, including the idea of a "social vaccine," conveying sufficient anxiety to provoke action for environmental protection, but insufficient to induce paralysis.

  5. A Passive Optical Location with Limited Range

    Directory of Open Access Journals (Sweden)

    Pavel Fiala


    Full Text Available We know active and passive methods of a location. This article deals only with a passive location of dynamic targets. The passive optics location is suitable just for tracking of targets with mean velocity which is limited by the hardware basis. The aim of this work is to recognize plasma, particles etc. It is possible to propose such kind of evaluation methods which improve the capture probability markedly. Suggested method is dealing with the short-distance evaluation of targets. We suppose the application of three independent principles how to recognize an object in a scanned picture. These principles use similar stochastic functions in order to evaluate an object location by means of simple mathematical operations. Methods are based on direct evaluation of picture sequence by the help of the histogram and frequency spectrum. We find out the probability of unidentified moving object in pictures. If the probability reaches a setting value we will get a signal.


    Directory of Open Access Journals (Sweden)

    Adrian Liviu IVAN


    Full Text Available An important part of the reform of the intelligence community is felt in the opening linked with the widening spectrum of methods and spaces which can be used to collect and analyse dates and information. One of these methods that produce large mutations in the system is connected to the world of social media which proves to be a huge source of information. Social Media Intelligence (SOCMINT, the newest member of the family INT's, is undoubtedly a separate domain, a practice rooted in the work of the intelligence community. This paper proposes a general characterization of the most important aspects of Social Media Intelligence, a brand new way for the intelligence community to collect and analyse information for national security purposes (but not only in the context of the current global challenges. Moreover, the work is focused in identifying the further limitations and opportunities of this practice in the upcoming decade.

  7. Pain, madness and the limits of medicine

    Directory of Open Access Journals (Sweden)

    Sean Baumann


    Full Text Available The problem of pain poses questions pertaining to some of the assumptions that underpin modern medicine, including the conceptualisation and treatment of psychiatric disorders. Problematic issues, such as subjectivity and meaning, seem particularly critical in the domains of pain and madness, but have relevance in the broader ranges of medicine. Of central concern is the relation such issues bear to notions of scientific practice. The subjective experience of illness and the meanings attached to it need to be accounted for, and cannot be considered to lie beyond the scope of scientific thinking, as not being measurable or objectively verifiable: yet attempts to incorporate these intrinsic dimensions remain elusive, and shape some of the shifting limitations of the various definitions of what might be considered to be a scientific perspective.

  8. Informed consent and the limits of confidentiality. (United States)

    Haggerty, L A; Hawkins, J


    Investigators encounter many legal and ethical issues when they conduct research on partner abuse. Balancing abused women's rights to privacy with legally mandated reporting requirements involves considerable thought and planning. Failure to protect participants may result in escalation of abuse as well as loss of children to protective services. Various perspectives on maintaining participant privacy while conforming to legal mandates to report child abuse, homicidality, and suicidality are discussed. The role of confidentiality certificates in providing legal immunity for researchers and the method of obtaining the certificates are presented. In addition, the authors describe the strategies for participant protection that are implemented in a federally funded study of abuse, women's self-care, and pregnancy outcomes. The decision to clearly and specifically inform abused women of the limits of confidentiality allows participants to make informed decisions about disclosures, but may result in diminished recruitment.

  9. Thermodynamic stability limits of simple monoatomic materials. (United States)

    Gallington, Leighanne C; Bongiorno, Angelo


    This computational study addresses the thermodynamical stability of superheated crystals. Molecular dynamics simulations are employed to derive the caloric curves of the solid and liquid phases of a material. Caloric curves are used to derive thermodynamic state functions, the parameters of the equilibrium melting phase transition, and the regions of thermodynamical stability of the liquid and solid phases. Molecular dynamics trajectories are also analyzed to gain insight on the mechanisms leading to the instability of the homogeneous superheated solid phase. This study shows that in simple and homogeneous solids the configurational entropy is not zero and that its excitations can occur without disrupting the crystallinity of the lattice. The superheating and supercooling limits of the solid and liquid phases are found to correspond to states of equal entropy and enthalpy.

  10. The Urbana MST radar, capabilities and limitations (United States)

    Royrvik, O.; Goss, L. D.


    The 41-MHz coherent-scatter radar located northeast of the University of Illinois at Urbana is being used for studies of the troposphere, stratosphere and mesosphere regions. The antenna consists of 1008 halfwave dipoles with a physical aperture of 11000 sq m. Transmitted peak power is about 750 kW. Clear-air returns may be received from 6 km to 90 km altitude. Autocorrelation functions of the scattered signal are calculated on-line. From the autocorrelation functions the scattered power, line-of-sight velocity and signal correlation time are calculated. Some aspects of the troposphere/stratosphere and the mesosphere observations are discussed. Capabilities and limitations of the Urbana MST radar are pointed out, and recent and planned improvements to the radar are described.

  11. Regulatory environment and claims - limits and opportunities. (United States)

    Martin, Ambroise


    During the past decade, the use of claims became more and more important in many countries in relation to the increased awareness of consumer about the link between foods and health, offering to industry a valuable opportunity to differentiate and valorize their products and to promote innovation. However, more and more stringent regulations are developed, all based on the general principles adopted by the Codex Alimentarius Commission. In addition to the different regulatory processes and administrative requirements according to the country, the high level (and cost) of scientific substantiation of claims, the constraints introduced by nutrient profiles and the poor knowledge of the impact on consumer depending on the cultural contexts may limit these opportunities or, at least complicate their use. All these issues are briefly analyzed, highlighting some striking convergences and differences between countries. Copyright © 2010 S. Karger AG, Basel.

  12. Fundamental limits of positron emission mammography

    Energy Technology Data Exchange (ETDEWEB)

    Moses, William W.; Qi, Jinyi


    We explore the causes of performance limitation in positron emission mammography cameras. We compare two basic camera geometries containing the same volume of 511 keV photon detectors, one with a parallel plane geometry and another with a rectangular geometry. We find that both geometries have similar performance for the phantom imaged (in Monte Carlo simulation), even though the solid angle coverage of the rectangular camera is about 50 percent higher than the parallel plane camera. The reconstruction algorithm used significantly affects the resulting image; iterative methods significantly outperform the commonly used focal plane tomography. Finally, the characteristics of the tumor itself, specifically the absolute amount of radiotracer taken up by the tumor, will significantly affect the imaging performance.

  13. Quantum limits on postselected, probabilistic quantum metrology (United States)

    Combes, Joshua; Ferrie, Christopher; Jiang, Zhang; Caves, Carlton M.


    Probabilistic metrology attempts to improve parameter estimation by occasionally reporting an excellent estimate and the rest of the time either guessing or doing nothing at all. Here we show that probabilistic metrology can never improve quantum limits on estimation of a single parameter, both on average and asymptotically in number of trials, if performance is judged relative to mean-square estimation error. We extend the result by showing that for a finite number of trials, the probability of obtaining better estimates using probabilistic metrology, as measured by mean-square error, decreases exponentially with the number of trials. To be tight, the performance bounds we derive require that likelihood functions be approximately normal, which in turn depends on how rapidly specific distributions converge to a normal distribution with number of trials.

  14. The motivation and limits of compassion

    Directory of Open Access Journals (Sweden)

    Elma Cornelius


    Full Text Available What motivates people to serve others? Why do we help those in need, the poor, the sick, the lonely, orphans and widows? Is compassion for humans a natural instinct or is it a learnt response? In the biblical tradition, it is a clear imperative to show one’s faith in God in one’s behaviour by reaching out to others. Luke 10:25−37 seems to be a key passage in the Bible that teaches and exhorts Christians to be compassionate. Psychology teaches us that compassion is a natural instinct in humans although choice is involved too, and it turns out that religion plays a role in reinforcing compassion. This article is an attempt to understand the motivation and limits of compassion as reinforced by the Christian religion by (1 interpreting Luke 10:25−37 in the New Testament and by (2 using modern psychological insights. It often happens that people reach out to others for self-interested reasons, as serving others psychologically gives them a sense of meaning and fulfilment as well as a positive public image. Compassion, however, is also motivated by a love for God and a love and concern for people in general. As caring for others also affects one emotionally and might cause burnout, it is important to set some limits and boundaries on compassion. As God’s love for us leads us to reach out to others, we need to be sure about how and when we should fulfil people’s needs, help them to cope with their own needs, help them to understand the reason for their needs, guide them to fulfilling their own needs or help them to find a place where help is available.

  15. Axion mass limits from pulsar x rays

    Energy Technology Data Exchange (ETDEWEB)

    Morris, D.E.


    Axions thermally emitted by a neutron star would be converted into x rays in the strong magnetic field surrounding the star. An improvement in the observational upper limit of pulsed x rays from the Vela pulsar (PSR 0833-45) by a factor of 12 would constrain the axion mass M/sub a/ < 2 x 10/sup -3/eV if the core is non-superfluid and at temperature T/sub c/ greater than or equal to 2 x 10/sup 8/K. If the core is superfluid throughout, an improvement factor of 240 would be needed to provide the same constraint on the axion mass, while in the absence of superfluidity, an improvement factor of 200 could constrain M/sub a/ < 6 x 10/sup -4/eV. A search for modulated hard x rays from PSR 1509-58 or other young pulsars at presently attainable sensitivities may enable the setting of an upper limit for the axion mass. Observation of hard x rays from a very young hot pulsar with T/sub c/ greater than or equal to 7 x 10/sup 8/K could set a firm bound on the axion mass, since neutron superfluidity is not expected above this temperature. The remaining axion mass range 6 x 10/sup -4/eV > M/sub a/ > 10/sup -5/eV (the cosmological lower bound) can be covered by an improved Sikivie type laboratory cavity detector for relic axions constituting the galactic halo. 48 refs.

  16. Establishing Medical Schools in Limited Resource Settings. (United States)

    Tsinuel, Girma; Tsedeke, Asaminew; Matthias, Siebeck; Fischer, Martin R; Jacobs, Fabian; Sebsibe, Desalegn; Yoseph, Mamo; Abraham, Haileamlak


    One urgent goal of countries in sub-Saharan Africa is to dynamically scale up the education and work force of medical doctors in the training institutions and health facilities, respectively. These countries face challenges related to the rapid scale up which is mostly done without proper strategic planning, without the basic elements of infrastructure development, educational as well as academic and administrative human resources. Medical education done in the context of limited resources is thus compromising the quality of graduates. In the future, a collaborative and need-based approach involving major stakeholders such as medical educators concerned, ministries, planners and policy makers is needed. This article identifies the challenges of establishing medical schools and sustaining the quality of education through rapid scale-up in Sub-Saharan Africa in the settings of limited resources. It also outlines the minimum requirements for establishing medical schools. A consensus building workshop was conducted in Bishoftu, Ethiopia, from Nov 8-12, 2013. Participants were professionals from 13 Ethiopian medical schools, and representatives of medical schools from South Sudan, Somaliland, Somalia, and Mozambique. Participants are listed in Appendix 1. The governments and stakeholders should jointly develop strategic plans and a roadmaps for opening or expanding medical schools to scale up educational resources. It is advisable that medical schools have autonomy regarding the number of student-intake, student selection, curriculum ownership, resource allocation including for infrastructure and staff development. Health science and medical curricula should be integrated within and harmonized nationally. An educational evaluation framework needs to be embedded in the curricula, and all medical schools should have Health Science Education Development Centers.

  17. Scaling of Metabolic Scaling within Physical Limits

    Directory of Open Access Journals (Sweden)

    Douglas S. Glazier


    Full Text Available Both the slope and elevation of scaling relationships between log metabolic rate and log body size vary taxonomically and in relation to physiological or developmental state, ecological lifestyle and environmental conditions. Here I discuss how the recently proposed metabolic-level boundaries hypothesis (MLBH provides a useful conceptual framework for explaining and predicting much, but not all of this variation. This hypothesis is based on three major assumptions: (1 various processes related to body volume and surface area exert state-dependent effects on the scaling slope for metabolic rate in relation to body mass; (2 the elevation and slope of metabolic scaling relationships are linked; and (3 both intrinsic (anatomical, biochemical and physiological and extrinsic (ecological factors can affect metabolic scaling. According to the MLBH, the diversity of metabolic scaling relationships occurs within physical boundary limits related to body volume and surface area. Within these limits, specific metabolic scaling slopes can be predicted from the metabolic level (or scaling elevation of a species or group of species. In essence, metabolic scaling itself scales with metabolic level, which is in turn contingent on various intrinsic and extrinsic conditions operating in physiological or evolutionary time. The MLBH represents a “meta-mechanism” or collection of multiple, specific mechanisms that have contingent, state-dependent effects. As such, the MLBH is Darwinian in approach (the theory of natural selection is also meta-mechanistic, in contrast to currently influential metabolic scaling theory that is Newtonian in approach (i.e., based on unitary deterministic laws. Furthermore, the MLBH can be viewed as part of a more general theory that includes other mechanisms that may also affect metabolic scaling.

  18. 47 CFR 15.109 - Radiated emission limits. (United States)


    ... ultrasonic devices not covered under part 18 of this chapter, shall comply with the radiated emission limits... conducted limits shown in § 15.107(e). (h) Radar detectors shall comply with the emission limits in...

  19. Pharmaceuticals as Groundwater Tracers - Applications and Limitations (United States)

    Scheytt, T. J.; Mersmann, P.; Heberer, T.


    Pharmaceutically active substances and metabolites are found at concentrations up to the microgram/L-level in groundwater samples from the Berlin (Germany) area and from several other places world wide. Among the compounds detected in groundwater are clofibric acid, propyphenazone, diclofenac, ibuprofen, and carbamazepine. Clofibric acid, the active metabolite of clofibrate and etofibrate (blood lipid regulators) is detected in groundwater at maximum concentrations of 7300 ng/L. Among the most important input paths of drugs are excretion and disposal into the sewage system. Groundwater contamination is likely to be due to leaky sewage systems, influent streams, bank filtration, and irrigation with effluent water from sewage treatment plants. There are no known natural sources of the above mentioned pharmaceuticals. The use of pharmaceuticals as tracers may include: (a) Quantification of infiltration from underground septic tanks (b) Detection of leaky sewage systems / leaky sewage pipes (c) Estimation of the effectiveness of sewage treatment plants (d) Identification of transport pathways of other organic compounds (e) Quantification of surface water / groundwater interaction (f) Characterization of the biodegradation potential. The use of pharmaceuticals as tracers is limited by variations in input. These variations depend on the amount of drugs prescribed and used in the study area, the social structure of the community, the amount of hospital discharge, and temporal concentration variations. Furthermore, the analysis of trace amounts of pharmaceuticals is sophisticated and expensive and may therefore limit the applicability of pharmaceuticals as tracers. Finally, the transport and degradation behavior of pharmaceuticals is not fully understood. Preliminary experiments in the laboratory were conducted using sediment material and groundwater from the Berlin area to evaluate the transport and sorption behavior of selected drugs. Results of the column experiments

  20. Hydraulic Limits on Maximum Plant Transpiration (United States)

    Manzoni, S.; Vico, G.; Katul, G. G.; Palmroth, S.; Jackson, R. B.; Porporato, A. M.


    Photosynthesis occurs at the expense of water losses through transpiration. As a consequence of this basic carbon-water interaction at the leaf level, plant growth and ecosystem carbon exchanges are tightly coupled to transpiration. In this contribution, the hydraulic constraints that limit transpiration rates under well-watered conditions are examined across plant functional types and climates. The potential water flow through plants is proportional to both xylem hydraulic conductivity (which depends on plant carbon economy) and the difference in water potential between the soil and the atmosphere (the driving force that pulls water from the soil). Differently from previous works, we study how this potential flux changes with the amplitude of the driving force (i.e., we focus on xylem properties and not on stomatal regulation). Xylem hydraulic conductivity decreases as the driving force increases due to cavitation of the tissues. As a result of this negative feedback, more negative leaf (and xylem) water potentials would provide a stronger driving force for water transport, while at the same time limiting xylem hydraulic conductivity due to cavitation. Here, the leaf water potential value that allows an optimum balance between driving force and xylem conductivity is quantified, thus defining the maximum transpiration rate that can be sustained by the soil-to-leaf hydraulic system. To apply the proposed framework at the global scale, a novel database of xylem conductivity and cavitation vulnerability across plant types and biomes is developed. Conductivity and water potential at 50% cavitation are shown to be complementary (in particular between angiosperms and conifers), suggesting a tradeoff between transport efficiency and hydraulic safety. Plants from warmer and drier biomes tend to achieve larger maximum transpiration than plants growing in environments with lower atmospheric water demand. The predicted maximum transpiration and the corresponding leaf water

  1. Compliance of feed limits, does not mean compliance of food limits

    Directory of Open Access Journals (Sweden)

    van Raamsdonk LWD.


    Full Text Available The carry-over of contaminants from feed to animal food products is an important aspect of the animal production chain. For a proper containment, limits for feed as well food products are fixed for a series of chemicals, e.g. dioxins and dioxin-like PCBs, lead, cadmium, some chlorinated pesticides, and aflatoxin B1 (and its metabolite M1 in milk. The relationship between feed and food limits is an important issue. An ideal goal is to assure that compliance to a feed limits automatically results in compliance to food limits. In order to collect information about this relationship, several simulation models and a large database on transfer factors have been developed. An optimal choice between either a model or an application of data from the Transfer Database is based on both the knowledge level, and on the circumstances of the specific situation. To reach and validate such an optimal choice an Expert System Carry-Over is currently in development, containing four different modules: 1 the different calculation models and the Transfer Database, 2 a decision tree for choosing the optimal strategy, 3 data tables indicating knowledge levels of compound/animal/product parameters, and 4 supporting databases containing information on consumption and composition of daily diets, animal parameters, and amounts of (daily production. Calculations indicate that for dioxins compliance to feed levels does not necessarily mean that food limits are complied as well. Besides an estimation of the compliance to limits, the expert system is a tool for feed related risk assessments, and for planning of future research.

  2. Performance limits on three-dimensional particle localization in photon-limited microscopy. (United States)

    Grover, Ginni; Pavani, Sri Rama Prasanna; Piestun, Rafael


    We present the performance limits on three-dimensional (3D) localization accuracy of currently used methods of wide-field superlocalization microscopy. The three methods investigated are double-helix microscopy, astigmatic imaging, and biplane detection. In the shot-noise limit, Cramer-Rao lower bound calculations show that, among these techniques, the double-helix microscope exhibits the best axial and 3D localization accuracy over short as well as long depth-of-field systems. The fundamental advantage of engineered point-spread function systems, like the double-helix, stems from the additional degrees of freedom available to control diffraction in three dimensions over variable regions of interest.

  3. Prochlorococcus: Advantages and Limits of Minimalism (United States)

    Partensky, Frédéric; Garczarek, Laurence


    Prochlorococcus is the key phytoplanktonic organism of tropical gyres, large ocean regions that are depleted of the essential macronutrients needed for photosynthesis and cell growth. This cyanobacterium has adapted itself to oligotrophy by minimizing the resources necessary for life through a drastic reduction of cell and genome sizes. This rarely observed strategy in free-living organisms has conferred on Prochlorococcus a considerable advantage over other phototrophs, including its closest relative Synechococcus, for life in this vast yet little variable ecosystem. However, this strategy seems to reach its limits in the upper layer of the S Pacific gyre, the most oligotrophic region of the world ocean. By losing some important genes and/or functions during evolution, Prochlorococcus has seemingly become dependent on co-occurring microorganisms. In this review, we present some of the recent advances in the ecology, biology, and evolution of Prochlorococcus, which because of its ecological importance and tiny genome is rapidly imposing itself as a model organism in environmental microbiology.

  4. Cosmetic lengthening: what are the limits? (United States)

    Guerreschi, F; Tsibidakis, H


    In the last decades, limb lengthening has not been limited to the treatment of patients with dwarfism and deformities resulting from congenital anomalies, trauma, tumor and infections, but, has also been used for aesthetic reasons. Cosmetic lengthening by the Ilizarov method with circular external fixation has been applied to individuals with constitutional short stature who wish to be taller. From January 1985 to December 2010, the medical records of 63 patients with constitutional short stature (36 M, 27F; 126 legs) who underwent cosmetic bilateral leg lengthening using a hybrid advanced fixator according to the Ilizarov method, were reviewed, retrospectively. The mean age was 24.8 years, while the mean preoperative height was 152.6 cm. Paley's criteria were used to evaluate problems, obstacles, and complications from the time of surgery until 1 year after frame's removal. The mean lengthening achieved in all patients was 7.2 cm (range: 5-11 cm), with a mean duration of treatment of 9 months and 15 days (range: 7-18 months). The mean follow-up time was 6.14 years (range 1-10). The cosmetic leg lengthening was helpful to all patients, improving their social capabilities and self-confidence. All patients considered their stature as normal and they reported satisfaction and gratification with important changes in their professional and personal life. Cosmetic leg lengthening may raise some ethical objections and for that reason patients should be well informed about all the risks and complications related to this type of surgery.

  5. Limitations of modeling snow in ski resorts (United States)

    Steiger, Robert; Abegg, Bruno


    The body of literature on snow modeling in a ski area operations context has been growing over the last decades in an accelerating speed. The majority of snow model applications for ski areas can be found in the climate change impacts literature. These studies differ in many aspects: the type of model used; the meteorological variables used in the models; the spatial and temporal resolution of the meteorological variables; the method how the climate change signal is derived and applied in the model concept; the number of climate models and emission scenarios used and consequently the handling of uncertainties; the indicators used to interpret the impacts for the skiing tourism industry; the incorporation of adaptation measures (e.g. snowmaking); and the geographical scale of analysis. In this contribution we will present a review of approaches used for modeling snow conditions in a ski area context. The major limitations both from a scientific as well as from a users' perspective will be discussed and solutions for shortcomings of existing approaches will be presented.

  6. Electrokinetic trapping at the one nanometer limit (United States)

    Fields, Alexander P.; Cohen, Adam E.


    Anti-Brownian electrokinetic traps have been used to trap and study the free-solution dynamics of large protein complexes and long chains of DNA. Small molecules in solution have thus far proved too mobile to trap by any means. Here we explore the ultimate limits on trapping single molecules. We developed a feedback-based anti-Brownian electrokinetic trap in which classical thermal noise is compensated to the maximal extent allowed by quantum measurement noise. We trapped single fluorophores with a molecular weight of < 1 kDa and a hydrodynamic radius of 6.7 Å for longer than one second, in aqueous buffer at room temperature. This achievement represents an 800-fold decrease in the mass of objects trapped in solution, and opens the possibility to trap and manipulate any soluble molecule that can be fluorescently labeled. To illustrate the use of this trap, we studied the binding of unlabeled RecA to fluorescently labeled single-stranded DNA. Binding of RecA induced changes in the DNA diffusion coefficient, electrophoretic mobility, and brightness, all of which were measured simultaneously and on a molecule-by-molecule basis. This device greatly extends the size range of molecules that can be studied by room temperature feedback trapping, and opens the door to further studies of the binding of unmodified proteins to DNA in free solution. PMID:21562206

  7. Operating limitations due to low gas temperature

    Energy Technology Data Exchange (ETDEWEB)

    Bruschi, R.; Ghiselli, W.; Spinazze, M.


    A number of projects concerning continental links for the transport of treated natural gas over long distance, both on and offshore, have been implemented during the last few years or are currently being implemented. The long trunklines in North America and subsea trunklines planned or already in operation in the North Sea, are outstanding examples of such long distance transmission of gas in large diameter pipelines operated at high pressure. The development of such network has paid special attention to the effects that low temperature resulting from the transportation process may imply in terms of pipe structural integrity and environmental impact. Scope of this paper is to discuss operating limitations due to low gas temperature. New project scenarios are presented in a brief introduction. The fluido-thermo-dynamic background for the development of low temperatures are outlined. Finally some topics relevant to structural integrity are discussed in particular such as the pipe steel behaviour at low temperature, the prediction techniques of the ice bulb growth around the pipe, the interactions of the cold line with the soil and the consequences due to the differential compliancy of the pipeline towards points of fixity (in-line valves/tees or fixed plants). 30 refs., 22 figs., 1 tab.

  8. Observational research--opportunities and limitations. (United States)

    Boyko, Edward J


    Medical research continues to progress in its ability to identify treatments and characteristics associated with benefits and adverse outcomes. The principal engine for the evaluation of treatment efficacy is the randomized controlled trial (RCT). Due to the cost and other considerations, RCTs cannot address all clinically important decisions. Observational research often is used to address issues not addressed or not addressable by RCTs. This article provides an overview of the benefits and limitations of observational research to serve as a guide to the interpretation of this category of research designs in diabetes investigations. The potential for bias is higher in observational research but there are design and analysis features that can address these concerns although not completely eliminate them. Pharmacoepidemiologic research may provide important information regarding relative safety and effectiveness of diabetes pharmaceuticals. Such research must effectively address the important issue of confounding by indication in order to produce clinically meaningful results. Other methods such as instrumental variable analysis are being employed to enable stronger causal inference but these methods also require fulfillment of several key assumptions that may or may not be realistic. Nearly all clinical decisions involve probabilistic reasoning and confronting uncertainly, so a realistic goal for observational research may not be the high standard set by RCTs but instead the level of certainty needed to influence a diagnostic or treatment decision. © 2013.

  9. Seizure Freedom After Limited Hippocampal Radiofrequency Thermocoagulation. (United States)

    Li, Han-Tao; Lee, Ching-Yi; Lim, Siew-Na; Chang, Chun-Wei; Lee, Shih-Tseng; Wu, Tony


    Surgical interventions are often used for freedom from seizure in patients with drug-resistant mesial temporal lobe epilepsy. A patient with seizure foci in the left mesiotemporal region underwent limited-size stereotactic radiofrequency thermocoagulation (RF-TC) over the left hippocampus. A 37-year-old woman with febrile convulsion in her childhood was admitted to our neurologic department with complex partial seizure with secondary generalization. Electroencephalography showed epileptogenic focus mainly from the left mesiotemporal region, and magnetic resonance imaging confirmed a left hippocampal atrophy. Because of failure to control seizure after use of several antiepileptic drugs, drug-resistant mesial temporal lobe epilepsy was diagnosed. RF-TC was done in the left hippocampus. Unique features of our technique include intraoperative electroencephalography recordings directly from electrodes on the left hippocampus, an aura sensation provoked during the low-temperature test thermocoagulation, and therapeutic thermocoagulation performed via a Radionics radiofrequency lead. In the 16-week period following the surgery, the patient experienced no seizure attacks and no significant postoperative adverse effects or memory impairments. Compared with other reports using RF-TC, our case demonstrates a 1-step minimally invasive surgery that reduces hippocampal volume loss, shortens the length of hospital stay, decreases the occurrence of postoperative infection, and achieves good outcomes for epilepsy control. Favorable seizure control was achieved with minimally invasive RF-TC. Further use of this technique is warranted in cases of drug-resistant mesial temporal lobe epilepsy. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Resolution limits for wave equation imaging

    KAUST Repository

    Huang, Yunsong


    Formulas are derived for the resolution limits of migration-data kernels associated with diving waves, primary reflections, diffractions, and multiple reflections. They are applicable to images formed by reverse time migration (RTM), least squares migration (LSM), and full waveform inversion (FWI), and suggest a multiscale approach to iterative FWI based on multiscale physics. That is, at the early stages of the inversion, events that only generate low-wavenumber resolution should be emphasized relative to the high-wavenumber resolution events. As the iterations proceed, the higher-resolution events should be emphasized. The formulas also suggest that inverting multiples can provide some low- and intermediate-wavenumber components of the velocity model not available in the primaries. Finally, diffractions can provide twice or better the resolution than specular reflections for comparable depths of the reflector and diffractor. The width of the diffraction-transmission wavepath is approximately λ at the diffractor location for the diffraction-transmission wavepath. © 2014 Elsevier B.V.

  11. Cambodia passes new limits on abortion. (United States)


    According to international news sources, Cambodia's parliament approved a law limiting the circumstances under which abortions can be performed on October 6 [1997]. Members of parliament say the new law, the first ever passed regulating abortion in Cambodia, is intended to reduce maternal morality rates from abortions performed by unlicensed health practitioners under unsanitary conditions. Local news outlets report that the Cambodian Health Ministry estimates the maternal mortality at 4.7 deaths per 1000 live births. The rate in the US is 0.12 deaths per 1000 live births. The law requires that abortions be performed by licensed health professionals in hospitals and certified clinics within the first trimester of pregnancy, and that women under the age of 18 must obtain parental consent. The new law also sets harsh penalties for those who harm women during illegal procedures--up to 5 years in prison if a woman is injured and up to 10 years if she dies. Opponents of the law say they fear that the new restrictions will push abortion even further underground, as the hospital system cannot handle the current demand for abortion. full text

  12. The ultimate downscaling limit of FETs.

    Energy Technology Data Exchange (ETDEWEB)

    Mamaluy, Denis; Gao, Xujiao; Tierney, Brian David


    We created a highly efficient, universal 3D quant um transport simulator. We demonstrated that the simulator scales linearly - both with the problem size (N) and number of CPUs, which presents an important break-through in the field of computational nanoelectronics. It allowed us, for the first time, to accurately simulate and optim ize a large number of realistic nanodevices in a much shorter time, when compared to other methods/codes such as RGF[%7EN 2.333 ]/KNIT, KWANT, and QTBM[%7EN 3 ]/NEMO5. In order to determine the best-in-class for different beyond-CMOS paradigms, we performed rigorous device optimization for high-performance logic devices at 6-, 5- and 4-nm gate lengths. We have discovered that there exists a fundamental down-scaling limit for CMOS technology and other Field-Effect Transistors (FETs). We have found that, at room temperatures, all FETs, irre spective of their channel material, will start experiencing unacceptable level of thermally induced errors around 5-nm gate lengths.

  13. Fluidized bed combustion: mixing and pollutant limitation

    Energy Technology Data Exchange (ETDEWEB)

    Leckner, B. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Energy Conversion


    Fluidized bed combustion (FBC) has been applied commercially during a few decades, and sufficient knowledge is gained to design boilers with sizes of up to several hundreds of megawatt thermal power (MW{sub th}). The knowledge of what goes on inside a large combustion chamber is still limited, however, and this impedes further optimization and efficient solution of problems that might occur. Despite this lack of knowledge the present survey deals with combustion chamber processes and discusses mixing and distribution of fuel and air in the combustion chamber and its importance for sulphur capture and reduction of emissions of nitrogen oxides. It is desirable to present the material in a general way and to cover the entire field of FBC. However, the scarce openly published information deals mostly with coal combustion in atmospheric circulating fluidized bed (CFB) combustors, and therefore this application will receive most attention, but reference is also made to pressurized combustion and to other fuels than coal. In this context the important work made in the LIEKKI project on the analysis of different fuels and on the influence of pressure should be especially pointed out. (orig.)

  14. Lyman Limit Absorbers in GALEX Spectra (United States)

    Williger, Gerard M.; Haberzettl, Lutz G.; Ribaudo, Joseph; Kuchner, Marc J.; Burchett, Joseph; Clowes, Roger G.; Lauroesch, James T.; Mills, Brianna; Borden, Jeremy


    We describe the method and early results for crowdsourcing a search for low-redshift partial and complete Lyman Limit Systems (pLLSs and LLSs) in the GALEX spectral archive. LLSs have been found in large numbers at z>3 and traced to lower redshift through a relatively small number of QSO spectra from spaced-based telescopes. From a sample of 44 pLLSs and 11 LLSs at 0.1 = -0.32 +/- 0.07 and the low-metallicity portion centered at = -1.87 +/- 0.11.The GALEX spectral archive offers a vast dataset potentially containing hundreds of LLSs, which may be leveraged to search for such a bimodality and track its evolution within the unconstrained near-UV gap at 1search. We have therefore begun crowdsourcing a subset of the GALEX archive for LLSs and pLLSs via a Zooniverse project. Initially, undergraduate physics majors are performing a pilot project before releasing to citizen scientists in the public at large. We will then vet candidate systems and estimate column densities in a follow-up analysis. Upon assessing the accuracy of the physics majors’ identifications, the results will be used to devise a larger program with the help of the general public. The resulting data set would then provide the best available link between the HST-selected far-UV and ground-based pLLS+LLS samples and provide an ideal sample for consequent metallicity determinations.

  15. Limits of Nb3Sn Accelerator Magnets

    CERN Document Server

    Caspi, Shlomo


    Pushing accelerator magnets beyond 10T holds a promise of future upgrades to machines like the Tevatron at FermiLab and the LHC at CERN. Exhausting the current density limits of NbTi, superconductor, Nb3Sn is at the present time the only practical superconductor capable of generating fields beyond 10T. Several Nb3Sn pilot magnets, with fields as high as 16T, have been built and tested, paving the way for future attempts at fields approaching 20T. The combination of high current density and the required high magnetic fields has resulted in reduced conductor volume and significantly increased the accumulated Lorentz forces. Future coil and structure designs will be required to deal with stresses of several 100’s of MPa and forces of 10’s of MN/m. The combined engineering requirements on size and cost of accelerator magnets will require a magnet technology that diverges from the one currently used with NbTi conductor. How far can the engineering of high field magnets be pushed, what are the i...

  16. Astronomy and the limits of vision (United States)

    Schaefer, Bradley E.


    Celestial visibility is the study of the limits of observability of objects in the sky, with application to deducing the truth about historical events or to the derivation of astronomical information of modern utility. This study is based on what is seen by ordinary humans, either in their everyday lives or at times of historical events. The results of such studies have more relevance to non-scientists than does any other area of astronomy. Celestial visibility is a young discipline in the sense that the number of interesting applications with simple solutions outnumber the solved problems; it is a broad interdisciplinary field that involves work with astronomy, meteorology, optics, physics, physiology, history, and archeology. Each of these disciplines contribute specialized mathematical formulations which quantify the many processes that affect light as it leaves a source, traverses the atmosphere, and is detected by the human eye. These formulas can then be combined as appropriate to create mathematical models for the visibility of the source under the conditions of interest. These model results can then be applied a wide variety of problems arising in history, astronomy, archeology, meteorological optics, and archeoastronomy. This review also presents a dozen suggestions for observing projects, many of which can be directly taken for individual study, for classroom projects, or for professional research.

  17. Resolution limits in imaging ladar systems (United States)

    Khoury, Jed; Woods, Charles L.; Lorenzo, Joseph; Kierstead, John; Pyburn, Dana; Sengupta, Sandip K.


    We introduce a new design concept of laser radar systems that combines both phase comparison and time-of-flight methods. We show from signal-to-noise ratio considerations that there is a fundamental limit to the overall resolution in three-dimensional imaging range laser radar (ladar). We introduce a new metric, volume of resolution, and we show from quantum noise considerations that there is a maximum resolution volume that can be achieved for a given set of system parameters. Consequently, there is a direct trade-off between range resolution and spatial resolution. Thus, in a ladar system, range resolution may be maximized at the expense of spatial image resolution and vice versa. We introduce resolution efficiency etar as a new figure of merit for ladar that describes system resolution under the constraints of a specific design, compared with its optimal resolution performance derived from quantum noise considerations. We analyze how the resolution efficiency could be utilized to improve the resolution performance of a ladar system. Our analysis could be extended to all ladars, regardless of whether they are imaging or scanning laser systems.

  18. Limited restaurant service over the Easter weekend

    CERN Multimedia


    As Friday, 25 March and Monday, 28 March 2005 are CERN holidays, restaurants No. 1 (Bldg. 501- Meyrin) and No. 3 (Bldg. 866 - Prévessin) will be closed and will remain closed on Saturday, 26 March and Sunday, 27 March. They will re-open on Tuesday, 29 March at 7.00 a.m. During these four days, a limited service will be provided by restaurant No. 2 (Bldg. 504 - Meyrin): on Friday and Monday from 8 a.m. to 8.30 p.m. and on Saturday and Sunday from 9 a.m. to 8.00 p.m. Hot meals will be served from 12.00 p.m. to 2 p.m. and from 6 p.m. to 7.30 p.m. They will be served at the self-service restaurant on the first floor on Friday and at the cafeteria on the ground floor on Saturday, Sunday and Monday. On Thursday, March 24, all three restaurants will operate according to their usual opening times except for restaurant No. 1, which will close at 9 p.m. instead of 1 a.m.

  19. Limited restaurant service over the Easter weekend

    CERN Multimedia


    As Friday, 25 March and Monday, 28 March 2005 are CERN holidays, restaurants no. 1 (Bldg. 501- Meyrin) and no. 3 (Bldg. 866 - Prévessin) will be closed and will remain closed on Saturday, 26 March and Sunday, 27 March. They will re-open on Tuesday, 29 March. During these four days, a limited service will be provided by restaurant no. 2 (Bldg. 504 - Meyrin): on Friday and Monday from 8 a.m. to 8.30 p.m. and on Saturday and Sunday from 9 a.m. to 8.00 p.m. Hot meals will be served from 12.00 p.m. to 2 p.m. and from 6 p.m. to 7.30 p.m. They will be served at the self-service restaurant on the first floor on Friday and at the cafeteria on the ground floor on Saturday, Sunday and Monday. On Thursday, March 24, all three restaurants will operate according to their usual opening times except for restaurant no. 1 which will close at 9 p.m. instead of 1 a.m.

  20. Direct limits on the oscillation frequency. (United States)

    Abazov, V M; Abbott, B; Abolins, M; Acharya, B S; Adams, M; Adams, T; Agelou, M; Agram, J-L; Ahn, S H; Ahsan, M; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Anastasoaie, M; Andeen, T; Anderson, S; Andrieu, B; Anzelc, M S; Arnoud, Y; Arov, M; Askew, A; Asman, B; Assis Jesus, A C S; Atramentov, O; Autermann, C; Avila, C; Ay, C; Badaud, F; Baden, A; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, P; Banerjee, S; Barberis, E; Bargassa, P; Baringer, P; Barnes, C; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Bean, A; Begalli, M; Begel, M; Belanger-Champagne, C; Bellavance, A; Benitez, J A; Beri, S B; Bernardi, G; Bernhard, R; Berntzon, L; Bertram, I; Besançon, M; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Binder, M; Biscarat, C; Black, K M; Blackler, I; Blazey, G; Blekman, F; Blessing, S; Bloch, D; Bloom, K; Blumenschein, U; Boehnlein, A; Boeriu, O; Bolton, T A; Borcherding, F; Borissov, G; Bos, K; Bose, T; Brandt, A; Brock, R; Brooijmans, G; Bross, A; Brown, D; Buchanan, N J; Buchholz, D; Buehler, M; Buescher, V; Burdin, S; Burke, S; Burnett, T H; Busato, E; Buszello, C P; Butler, J M; Calvet, S; Cammin, J; Caron, S; Carvalho, W; Casey, B C K; Cason, N M; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K M; Chandra, A; Chapin, D; Charles, F; Cheu, E; Chevallier, F; Cho, D K; Choi, S; Choudhary, B; Christofek, L; Claes, D; Clément, B; Clément, C; Coadou, Y; Cooke, M; Cooper, W E; Coppage, D; Corcoran, M; Cousinou, M-C; Cox, B; Crépé-Renaudin, S; Cutts, D; Cwiok, M; da Motta, H; Das, A; Das, M; Davies, B; Davies, G; Davis, G A; De, K; de Jong, P; de Jong, S J; De La Cruz-Burelo, E; De Oliveira Martins, C; Degenhardt, J D; Déliot, F; Demarteau, M; Demina, R; Demine, P; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Doidge, M; Dominguez, A; Dong, H; Dudko, L V; Duflot, L; Dugad, S R; Duperrin, A; Dyer, J; Dyshkant, A; Eads, M; Edmunds, D; Edwards, T; Ellison, J; Elmsheuser, J; Elvira, V D; Eno, S; Ermolov, P; Estrada, J; Evans, H; Evdokimov, A; Evdokimov, V N; Fatakia, S N; Feligioni, L; Ferapontov, A V; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Fleck, I; Ford, M; Fortner, M; Fox, H; Fu, S; Fuess, S; Gadfort, T; Galea, C F; Gallas, E; Galyaev, E; Garcia, C; Garcia-Bellido, A; Gardner, J; Gavrilov, V; Gay, A; Gay, P; Gelé, D; Gelhaus, R; Gerber, C E; Gershtein, Y; Gillberg, D; Ginther, G; Gollub, N; Gómez, B; Gounder, K; Goussiou, A; Grannis, P D; Greenlee, H; Greenwood, Z D; Gregores, E M; Grenier, G; Gris, Ph; Grivaz, J-F; Grünendahl, S; Grünewald, M W; Guo, F; Guo, J; Gutierrez, G; Gutierrez, P; Haas, A; Hadley, N J; Haefner, P; Hagopian, S; Haley, J; Hall, I; Hall, R E; Han, L; Hanagaki, K; Harder, K; Harel, A; Harrington, R; Hauptman, J M; Hauser, R; Hays, J; Hebbeker, T; Hedin, D; Hegeman, J G; Heinmiller, J M; Heinson, A P; Heintz, U; Hensel, C; Hesketh, G; Hildreth, M D; Hirosky, R; Hobbs, J D; Hoeneisen, B; Hohlfeld, M; Hong, S J; Hooper, R; Houben, P; Hu, Y; Hynek, V; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jain, S; Jain, V; Jakobs, K; Jarvis, C; Jenkins, A; Jesik, R; Johns, K; Johnson, C; Johnson, M; Jonckheere, A; Jonsson, P; Juste, A; Käfer, D; Kahn, S; Kajfasz, E; Kalinin, A M; Kalk, J M; Kalk, J R; Kappler, S; Karmanov, D; Kasper, J; Katsanos, I; Kau, D; Kaur, R; Kehoe, R; Kermiche, S; Kesisoglou, S; Khanov, A; Kharchilava, A; Kharzheev, Y M; Khatidze, D; Kim, H; Kim, T J; Kirby, M H; Klima, B; Kohli, J M; Konrath, J-P; Kopal, M; Korablev, V M; Kotcher, J; Kothari, B; Koubarovsky, A; Kozelov, A V; Kozminski, J; Kryemadhi, A; Krzywdzinski, S; Kuhl, T; Kumar, A; Kunori, S; Kupco, A; Kurca, T; Kvita, J; Lager, S; Lammers, S; Landsberg, G; Lazoflores, J; Le Bihan, A-C; Lebrun, P; Lee, W M; Leflat, A; Lehner, F; Leonidopoulos, C; Lesne, V; Leveque, J; Lewis, P; Li, J; Li, Q Z; Lima, J G R; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, Z; Lobo, L; Lobodenko, A; Lokajicek, M; Lounis, A; Love, P; Lubatti, H J; Lynker, M; Lyon, A L; Maciel, A K A; Madaras, R J; Mättig, P; Magass, C; Magerkurth, A; Magnan, A-M; Makovec, N; Mal, P K; Malbouisson, H B; Malik, S; Malyshev, V L; Mao, H S; Maravin, Y; Martens, M; Mattingly, S E K; McCarthy, R; McCroskey, R; Meder, D; Melnitchouk, A; Mendes, A; Mendoza, L; Merkin, M; Merritt, K W; Meyer, A; Meyer, J; Michaut, M; Miettinen, H; Millet, T; Mitrevski, J; Molina, J; Mondal, N K; Monk, J; Moore, R W; Moulik, T; Muanza, G S; Mulders, M; Mulhearn, M; Mundim, L; Mutaf, Y D; Nagy, E; Naimuddin, M; Narain, M; Naumann, N A; Neal, H A; Negret, J P; Nelson, S; Neustroev, P; Noeding, C; Nomerotski, A; Novaes, S F; Nunnemann, T; O'Dell, V; O'Neil, D C; Obrant, G; Oguri, V; Oliveira, N; Oshima, N; Otec, R; Otero y Garzón, G J; Owen, M; Padley, P; Parashar, N; Park, S-J; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Pawloski, G; Perea, P M; Perez, E; Peters, K; Pétroff, P; Petteni, M; Piegaia, R; Pleier, M-A; Podesta-Lerma, P L M; Podstavkov, V M; Pogorelov, Y; Pol, M-E; Pompos, A; Pope, B G; Popov, A V; Prado da Silva, W L; Prosper, H B; Protopopescu, S; Qian, J; Quadt, A; Quinn, B; Rani, K J; Ranjan, K; Rapidis, P A; Ratoff, P N; Renkel, P; Reucroft, S; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F; Robinson, S; Rodrigues, R F; Royon, C; Rubinov, P; Ruchti, R; Rud, V I; Sajot, G; Sánchez-Hernández, A; Sanders, M P; Santoro, A; Savage, G; Sawyer, L; Scanlon, T; Schaile, D; Schamberger, R D; Scheglov, Y; Schellman, H; Schieferdecker, P; Schmitt, C; Schwanenberger, C; Schwartzman, A; Schwienhorst, R; Sengupta, S; Severini, H; Shabalina, E; Shamim, M; Shary, V; Shchukin, A A; Shephard, W D; Shivpuri, R K; Shpakov, D; Siccardi, V; Sidwell, R A; Simak, V; Sirotenko, V; Skubic, P; Slattery, P; Smith, R P; Snow, G R; Snow, J; Snyder, S; Söldner-Rembold, S; Song, X; Sonnenschein, L; Sopczak, A; Sosebee, M; Soustruznik, K; Souza, M; Spurlock, B; Stark, J; Steele, J; Stevenson, K; Stolin, V; Stone, A; Stoyanova, D A; Strandberg, J; Strang, M A; Strauss, M; Ströhmer, R; Strom, D; Strovink, M; Stutte, L; Sumowidagdo, S; Sznajder, A; Talby, M; Tamburello, P; Taylor, W; Telford, P; Temple, J; Tiller, B; Titov, M; Tokmenin, V V; Tomoto, M; Toole, T; Torchiani, I; Towers, S; Trefzger, T; Trincaz-Duvoid, S; Tsybychev, D; Tuchming, B; Tully, C; Turcot, A S; Tuts, P M; Unalan, R; Uvarov, L; Uvarov, S; Uzunyan, S; Vachon, B; van den Berg, P J; Van Kooten, R; van Leeuwen, W M; Varelas, N; Varnes, E W; Vartapetian, A; Vasilyev, I A; Vaupel, M; Verdier, P; Vertogradov, L S; Verzocchi, M; Villeneuve-Seguier, F; Vint, P; Vlimant, J-R; Von Toerne, E; Voutilainen, M; Vreeswijk, M; Wahl, H D; Wang, L; Warchol, J; Watts, G; Wayne, M; Weber, M; Weerts, H; Wermes, N; Wetstein, M; White, A; Wicke, D; Wilson, G W; Wimpenny, S J; Wobisch, M; Womersley, J; Wood, D R; Wyatt, T R; Xie, Y; Xuan, N; Yacoob, S; Yamada, R; Yan, M; Yasuda, T; Yatsunenko, Y A; Yip, K; Yoo, H D; Youn, S W; Yu, C; Yu, J; Yurkewicz, A; Zatserklyaniy, A; Zeitnitz, C; Zhang, D; Zhao, T; Zhao, Z; Zhou, B; Zhu, J; Zielinski, M; Zieminska, D; Zieminski, A; Zutshi, V; Zverev, E G


    We report results of a study of the B(s)(0) oscillation frequency using a large sample of B(s)(0) semileptonic decays corresponding to approximately 1 fb(-1) of integrated luminosity collected by the D0 experiment at the Fermilab Tevatron Collider in 2002-2006. The amplitude method gives a lower limit on the B(s)(0) oscillation frequency at 14.8 ps(-1) at the 95% C.L. At delta m(s) = 19 ps(-1), the amplitude deviates from the hypothesis A= 0(1) by 2.5 (1.6) standard deviations, corresponding to a two-sided C.L. of 1% (10%). A likelihood scan over the oscillation frequency, delta m(s), gives a most probable value of 19 ps(-1) and a range of 17 < delta m(s) < 21 ps(-1)at the 90% C.L., assuming Gaussian uncertainties. This is the first direct two-sided bound measured by a single experiment. If delta m(s) lies above 22 ps(-1), then the probability that it would produce a likelihood minimum similar to the one observed in the interval 16-22 ps(-1) is (5.0 +/- 0.3)%.

  1. Astronomy and the limits of vision (United States)

    Schaefer, Bradley E.

    Celestial visibility is the study of the limits of observability of objects in the sky, with application to deducing the truth about historical events or to the derivation of astronomical information of modern utility. This study is based on what is seen by ordinary humans, either in their everyday lives or at times of historical events. The results of such studies have more relevance to non-scientists than does any other area of astronomy. Celestial visibility is a young discipline in the sense that the number of interesting applications with simple solutions outnumber the solved problems; it is a broad interdisciplinary field that involves work with astronomy, meteorology, optics, physics, physiology, history, and archeology. Each of these disciplines contribute specialized mathematical formulations which quantify the many processes that affect light as it leaves a source, traverses the atmosphere, and is detected by the human eye. These formulas can then be combined as appropriate to create mathematical models for the visibility of the source under the conditions of interest. These model results can then be applied a wide variety of problems arising in history, astronomy, archeology, meteorological optics, and archeoastronomy. This review also presents a dozen suggestions for observing projects, many of which can be directly taken for individual study, for classroom projects, or for professional research.

  2. Ultrasonic recording system without intrinsic limits. (United States)

    Andreassen, Tórur; Surlykke, Annemarie; Hallam, John; Brandt, David


    Today state-of-the-art bioacoustic research requires high-sample-rate, multi-channel, and often long-term recording systems. Commercial systems are very costly. This paper proposes and demonstrates an ultrasonic recording system design that is arbitrarily scalable. The system is modular and based on retail components and open source software/hardware. Each module has four microphones and modules can be combined to extend the coverage area, obtain higher spatial recording resolution, and/or add recording redundancy. The system is designed to have no inherent scalability limits. The system has been deployed in four different test settings. The first setup tests the system's ability to make medium-term recordings (1 to 2 min) with many microphones. The second setup tests the robustness of the system, being deployed throughout the Danish winter with only minor issues. The third setup integrates the system in a mobile robot as an echolocating guidance system, while the fourth setup demonstrates full-spectrum transducer calibration. In most respects this system's hardware specification surpasses all competitors on the market at a quarter of the price. Tests demonstrate that large deployments are feasible and accurate ultrasonic measurements can be obtained.

  3. Localization beyond the diffraction limit (Conference Presentation) (United States)

    Petrov, Petar N.; Shechtman, Yoav; Moerner, William E.


    Point spread function (PSF) engineering has extended far-field localization microscopy into three dimensions by encoding the axial position of each emitter into the shape of its image on the detector. By fitting the observed PSF to a model function, one can extract position information with sub-diffraction precision. However, in practice this procedure is often complicated by optical aberrations present in the imaging system, which distort the shape of the observed PSF relative to the model function. The mismatch between the model and observed PSFs can limit the accuracy and precision achieved by the localization procedure. Here, we present a simple method to experimentally improve the model PSF by phase retrieval of the pupil function of the imaging system using a set of images of an isolated emitter at different displacements from the focal plane. The pupil function is estimated by adding a phase term consisting of a combination of Zernike modes to the theoretical electric field at the back focal plane of the microscope. The amplitudes of the Zernike modes are determined by maximizing the likelihood function over all pixels in the experimental data set. Importantly, since all data is taken with the phase mask in place, we account for any aberrations it introduces. Using the resulting pupil function, we generate a model PSF which is significantly improved over the theoretical model in both the accuracy and precision of experimental emitter localizations. We also provide a MATLAB package which performs the entire fitting procedure, from phase retrieval to single-emitter localization.

  4. Attenuation limits in longitudinal phononic crystals (United States)

    Luschi, L.; Iannaccone, G.; Pieri, F.


    The acoustic attenuation inside the bandgaps is, together with the bandgap width, a fundamental design parameter for phononic-crystal-based systems. We discuss approximate expressions for the maximum attenuation inside the bandgaps of one-dimensional longitudinal phononic crystals and its dependence on the acoustic contrast and the fractional bandwidth. We provide different approximations at small and large fractional bandwidths, computed from the trace of the transmission matrix of the crystal elementary cell. We show that, for relatively small gaps, the attenuation is roughly proportional to the fractional bandwidth, in analogy with the flexural case. For larger gaps, a large attenuation can be obtained only for high (and possibly impractical) acoustic contrasts. Approximate expressions are validated through comparison with FEM results. We also derive asymptotic upper limits for the bandgap borders and show that high contrasts do not necessarily lead to wide bandgaps, a fact connected to geometrical phase inversion for the acoustic wave in the crystal. We finally compare the attenuation of flexural and longitudinal waves at a fixed fractional bandwidth and derive regions of optimum attenuation for the two propagation modes.

  5. Limiting our impact on the environment

    CERN Multimedia


    CERN’s fourth safety objective for 2012 concerns the reduction of the environmental impact of noise and energy consumption associated with CERN's activities.   In order to continue to reduce the impact of noise on our neighbours, the HSE Unit is coordinating measures to reduce noise in the environment at all the LHC and SPS points, and on the Meyrin and Prévessin sites. If you are aware of a high-intensity noise that could disturb those living and working close to our sites, you can contact the HSE Unit. And most important of all, please take this potential nuisance into account when you're planning new projects. The HSE Unit is there to help you. The other aspect of our environmental target for the year is to optimise CERN's energy consumption. We can achieve this by limiting the energy consumption of facilities right from the design stage - from small components to large installations - and by using renewable energies even on a sma...

  6. Os limites do desenvolvimento e do turismo

    Directory of Open Access Journals (Sweden)

    Menezes Teixeira Coriolano, Luzia Neide


    Full Text Available This paper is a historical analysis of the background and evolution of the concept of development and the limits to development, supported by links with economic science, thus pervading all social sciences. The assumptions of developmentalist theories, the so-called modernization theories, are shown and identified as traditional, conservative and consensual, thus differing from critical theories which adopt the assumptions of historical materialism. The paper examines those aspects of globalization which pertain to new approaches to development, whereby tourism becomes a link between the local and the global. The study explains how and why development is an unequal and joint process. Underdevelopment is a result of the structural adjustments which determine concentration of wealth and income, generating poverty as the ultimate expression of social inequality. It is shown that development only takes place when people benefit, when a human scale is reached, that tourism can both connect with concentrated economic growth and promote social development, otherwise known as local development

  7. Limitations of Commercializing Fuel Cell Technologies (United States)

    Nordin, Normayati


    Fuel cell is the technology that, nowadays, is deemed having a great potential to be used in supplying energy. Basically, fuel cells can be categorized particularly by the kind of employed electrolyte. Several fuel cells types which are currently identified having huge potential to be utilized, namely, Solid Oxide Fuel Cells (SOFC), Molten Carbonate Fuel Cells (MCFC), Alkaline Fuel Cells (AFC), Phosphoric Acid Fuel Cells (PAFC), Polymer Electron Membrane Fuel Cell (PEMFC), Direct Methanol Fuel Cells (DMFC) and Regenerative Fuel Cells (RFC). In general, each of these fuel cells types has their own characteristics and specifications which assign the capability and suitability of them to be utilized for any particular applications. Stationary power generations and transport applications are the two most significant applications currently aimed for the fuel cell market. It is generally accepted that there are lots of advantages if fuel cells can be excessively commercialized primarily in context of environmental concerns and energy security. Nevertheless, this is a demanding task to be accomplished, as there is some gap in fuel cells technology itself which needs a major enhancement. It can be concluded, from the previous study, cost, durability and performance are identified as the main limitations to be firstly overcome in enabling fuel cells technology become viable for the market.

  8. Ultimate Precision Limits for Noisy Frequency Estimation. (United States)

    Smirne, Andrea; Kołodyński, Jan; Huelga, Susana F; Demkowicz-Dobrzański, Rafał


    Quantum metrology protocols allow us to surpass precision limits typical to classical statistics. However, in recent years, no-go theorems have been formulated, which state that typical forms of uncorrelated noise can constrain the quantum enhancement to a constant factor and, thus, bound the error to the standard asymptotic scaling. In particular, that is the case of time-homogeneous (Lindbladian) dephasing and, more generally, all semigroup dynamics that include phase covariant terms, which commute with the system Hamiltonian. We show that the standard scaling can be surpassed when the dynamics is no longer ruled by a semigroup and becomes time inhomogeneous. In this case, the ultimate precision is determined by the system short-time behavior, which when exhibiting the natural Zeno regime leads to a nonstandard asymptotic resolution. In particular, we demonstrate that the relevant noise feature dictating the precision is the violation of the semigroup property at short time scales, while non-Markovianity does not play any specific role.

  9. Remanufacturing in automotive industry: Challenges and limitations

    Directory of Open Access Journals (Sweden)

    Paulina Golinska


    Full Text Available Purpose: The aim of this paper is to provide the framework for management of reverse flow of materials in automotive industry. The emphasis is placed on the remanufacturing activities. Materials management in such conditions is a real challenge. The cause for this is parallel use of raw materials and reused materials. Such hybrid flows of materials are characterized by increased level of uncertainty connected with amount, quality and timing. Design/methodology/approach: This paper presents a comprehensive review of remanufacturing and traditional manufacturing. The stabilization of reverse flows is crucial for continuity of remanufacturing operations. The simulation model and results are discussed regarding stabilization of the reverse flows. Findings: Authors identify main problems that appear in the area of combining at the production system forward and reverse flows of materials. The agent-based technology is applied for configuration and stabilization of reverse network. Research limitations/implications: Paper is case – oriented. Practical implications: Both logistician and IT researchers might benefit from authors approach. Originality/value: Authors provide an interdisciplinary approach combining operations management, logistics and information technology.

  10. Transnasal endoscopy: Technical considerations, advantages and limitations (United States)

    Atar, Mustafa; Kadayifci, Abdurrahman


    Transnasal endoscopy (TNE) is an upper endoscopy method which is performed by the nasal route using a thin endoscope less than 6 mm in diameter. The primary goal of this method is to improve patient tolerance and convenience of the procedure. TNE can be performed without sedation and thus eliminates the risks associated with general anesthesia. In this way, TNE decreases the cost and total duration of endoscopic procedures, while maintaining the image quality of standard caliber endoscopes, providing good results for diagnostic purposes. However, the small working channel of the ultra-thin endoscope used for TNE makes it difficult to use for therapeutic procedures except in certain conditions which require a thinner endoscope. Biopsy is possible with special forceps less than 2 mm in diameter. Recently, TNE has been used for screening endoscopy in Far East Asia, including Japan. In most controlled studies, TNE was found to have better patient tolerance when compared to unsedated endoscopy. Nasal pain is the most significant symptom associated with endoscopic procedures but can be reduced with nasal pretreatment. Despite the potential advantage of TNE, it is not common in Western countries, usually due to a lack of training in the technique and a lack of awareness of its potential advantages. This paper briefly reviews the technical considerations as well as the potential advantages and limitations of TNE with ultra-thin scopes. PMID:24567791

  11. Potentials and limits of physiotherapy in osteoarthritis. (United States)

    Richter, Katrin; Müller-Ladner, Ulf; Dischereit, Gabnel; Lange, Uwe


    In view of the already existing and the expected growing costs due to the pathological osteoarthritic joint alterations and the related consequences, preventive and conservative strategies which can avoid or delay osteoarthritic joint alterations are welcomed from a socio-economical perspective. Here, it should be mentioned that corresponding primary prevention measures should take place early by already educating children about a healthy diet and motivating them to regular physical exercise. In overt or symptomatic osteoarthritis a good joint function and reduction of disease-related pain as well as a delay in the progression of osteoarthritis should be the primary goals of non-surgical therapeutic approaches. The current body of studies is already able to prove the effectiveness of differential indicative physiotherapeutic and physical measures and should be further developed in the future. Nevertheless, the implementation of the available knowledge from the studies under evidence-based medicine criteria proves difficult during the daily routine in clinics. On one hand, an assessment of the effectiveness of physical therapy within the framework of a multimodal treatment approach (e.g., thermotherapy in combination with manual therapy) is difficult to define. On the other hand, an objective assessment of treatment success, owing to the heterogeneity among the patients (above all varied disease activity, functional limitations, accompanying diseases and therapy) will also remain complicated. Copyright© Bentham Science Publishers; For any queries, please email at

  12. Environmental implications of carbon limits on market ... (United States)

    Combined heat and power (CHP) is promoted as an economical, energy-efficient option for combating climate change. To fully examine the viability of CHP as a clean-technology solution, its market potential and impacts need to be analyzed as part of scenarios of the future energy system, particularly those with policies limiting greenhouse gas (GHG) emissions. This paper develops and analyzes scenarios using a bottom-up, technology rich optimization model of the U.S. energy system. Two distinct carbon reduction goals were set up for analysis. In Target 1, carbon emission reduction goals were only included for the electric sector. In Target 2, carbon emission reduction goals were set across the entire energy system with the target patterned after the U.S.’s commitment to reducing GHG emissions as part of the Paris Agreement reached at the COP21 summit. From a system-wide carbon reduction standpoint, Target 2 is significantly more stringent. In addition, these scenarios examine the implications of various CHP capacity expansion and contraction assumptions and energy prices. The largest CHP capacity expansion are observed in scenarios that included Target 1, but investments were scaled back in scenarios that incorporated Target 2. The latter scenario spurred rapid development of zero-emissions technologies within the electric sector, and purchased electricity increased dramatically in many end-use sectors. The results suggest that CHP may play a role in a carbon-c

  13. Biological Nitrogen Fixation: Perspective and Limitation

    Directory of Open Access Journals (Sweden)

    N D Purwantari


    Full Text Available The demand of chemical fertilizer, N in particular will be increasing until 2020. In Indonesia, the demand of fertilizer from 1999 – 2002 increased 37.5 and 12.4% for urea and ammonium sulphate, respectively. At the same time, the price of this fertilizer is also increasing and it can not be afforded by the farmer. Other problem in using chemical fertilizer is damaging to the soil and environment. One of the problem solvings for this condition is to maximize biological nitrogen fixation (BNF. BNF is the fixation of N atmosphere by association between soil bacteria rhizobia and leguminous plant. BNF is sustainable and environmentally friendly in providing nitrogen fertilizer. Therefore, it would reduce the requirement of chemical nitrogen fertilizer for the plant. Gliricidia sepium fixes 170 kg N/ha/12 months, equivalent with 377 kg urea, Sesbania sesban 179 kg N/ha/10 months, equivalent 397 kg with urea, soybean 26 – 57 kg/2 months equivalent with 57 – 126 kg urea. The amount of N2- fixed varies, affected by species, environmental and biological factors. There are some limitations in applying this technology. The effect of N contribution is very slow at the beginning but in the long term, it would be beneficial for plant production and at the same time, maintain condition of physical and chemical of soil, soil microbes and therefore soil fertility.

  14. Evolutionary psychology. Controversies, questions, prospects, and limitations. (United States)

    Confer, Jaime C; Easton, Judith A; Fleischman, Diana S; Goetz, Cari D; Lewis, David M G; Perilloux, Carin; Buss, David M


    Evolutionary psychology has emerged over the past 15 years as a major theoretical perspective, generating an increasing volume of empirical studies and assuming a larger presence within psychological science. At the same time, it has generated critiques and remains controversial among some psychologists. Some of the controversy stems from hypotheses that go against traditional psychological theories; some from empirical findings that may have disturbing implications; some from misunderstandings about the logic of evolutionary psychology; and some from reasonable scientific concerns about its underlying framework. This article identifies some of the most common concerns and attempts to elucidate evolutionary psychology's stance pertaining to them. These include issues of testability and falsifiability; the domain specificity versus domain generality of psychological mechanisms; the role of novel environments as they interact with evolved psychological circuits; the role of genes in the conceptual structure of evolutionary psychology; the roles of learning, socialization, and culture in evolutionary psychology; and the practical value of applied evolutionary psychology. The article concludes with a discussion of the limitations of current evolutionary psychology. 2009 APA, all rights reserved.

  15. Conceptualizing the Limiting Issues Inhibiting Sustainability Embeddedness

    Directory of Open Access Journals (Sweden)

    Catherine le Roux


    Full Text Available There can be little doubt that sustainability has become one of the most important issues in business in recent years. In spite of sustainability’s importance, there is agreement amongst leaders and practitioners that sustainability is not as embedded as desired. This study reports a framework on inhibitors that limit sustainability embeddedness in organizations. The framework can assist management to address the non-achievement antecedents of embeddedness specifically and holistically. This study obtained empirical data from employees on all management levels in a stock exchange-listed company. Through in-depth analysis in a case organization, valuable insights about embeddedness were inductively identified, interpreted and presented using descriptive labels, namely: “Professing What Is Right”; “Green Distraction”; the belief of “Not My Job”; “Firefighter”; the “Past Performance Anchor”; “Strategy Discourse” and “Harmony”—a mediator to sustainability embeddedness. All these were also found to be altered by the transformation of culture and the communication of the strategy message by sustainable leadership—the moderator. The findings were also corroborated by related and supporting literature as part of our contribution and pursuit for better understanding of this phenomenon.

  16. Suspended sediments limit coral sperm availability (United States)

    Ricardo, Gerard F.; Jones, Ross J.; Clode, Peta L.; Humanes, Adriana; Negri, Andrew P.


    Suspended sediment from dredging activities and natural resuspension events represent a risk to the reproductive processes of coral, and therefore the ongoing maintenance of reefal populations. To investigate the underlying mechanisms that could reduce the fertilisation success in turbid water, we conducted several experiments exposing gametes of the corals Acropora tenuis and A. millepora to two sediment types. Sperm limitation was identified in the presence of siliciclastic sediment (230 and ~700 mg L−1), with 2–37 fold more sperm required to achieve maximum fertilisation rates, when compared with sediment-free treatments. This effect was more pronounced at sub-optimum sperm concentrations. Considerable (>45%) decreases in sperm concentration at the water’s surface was recorded in the presence of siliciclastic sediment and a >20% decrease for carbonate sediment. Electron microscopy then confirmed sediment entangled sperm and we propose entrapment and sinking is the primary mechanism reducing sperm available to the egg. Longer exposure to suspended sediments and gamete aging further decreased fertilisation success when compared with a shorter exposure. Collectively, these findings demonstrate that high concentrations of suspended sediments effectively remove sperm from the water’s surface during coral spawning events, reducing the window for fertilisation with potential subsequent flow-on effects for recruitment. PMID:26659008

  17. Uplink SDMA with Limited Feedback: Throughput Scaling

    Directory of Open Access Journals (Sweden)

    Jeffrey G. Andrews


    Full Text Available Combined space division multiple access (SDMA and scheduling exploit both spatial multiplexing and multiuser diversity, increasing throughput significantly. Both SDMA and scheduling require feedback of multiuser channel sate information (CSI. This paper focuses on uplink SDMA with limited feedback, which refers to efficient techniques for CSI quantization and feedback. To quantify the throughput of uplink SDMA and derive design guidelines, the throughput scaling with system parameters is analyzed. The specific parameters considered include the numbers of users, antennas, and feedback bits. Furthermore, different SNR regimes and beamforming methods are considered. The derived throughput scaling laws are observed to change for different SNR regimes. For instance, the throughput scales logarithmically with the number of users in the high SNR regime but double logarithmically in the low SNR regime. The analysis of throughput scaling suggests guidelines for scheduling in uplink SDMA. For example, to maximize throughput scaling, scheduling should use the criterion of minimum quantization errors for the high SNR regime and maximum channel power for the low SNR regime.

  18. Advantages and limitations of peer assessment

    Directory of Open Access Journals (Sweden)

    Karmen Goršak, Karmen Pižorn


    Full Text Available This article examines current theoretical work and research findings regarding the effectiveness of peer assessment. The main purpose of the article is to define peer asses sment and its subcategory peer feedback and to present the advantages and limitations of peer assessment derived from different research findings. In addition, conditions and strategies to successfully guarantee the benefits of peer assessment are presented. The main research studies, mentioned in this article, have been carried out in different disciplines in higher education programmes and their findings reveal positive students’ and teachers’ attitude to peer assessment as well as high correlation between peers’ and te achers’ grades. The main results of the studies show a positive effect of peer assessment on student’s active role in the process of learning and assessment, the development of social and professional skills, student’s autonomy, critical thinking, peer and selfassessment skills. Recommendations for implementing peer assessment within foreign language tea ching, as well as implications for future research work are provided.

  19. Collapsing Dimensions, Physical Limitation, and Other Student Metaphors for Limit Concepts (United States)

    Oehrtman, Michael


    This study investigated introductory calculus students' spontaneous reasoning about limit concepts guided by an interactionist theory of metaphorical reasoning developed by Max Black. In this perspective, strong metaphors are ontologically creative by virtue of their emphasis (commitment by the producer) and resonance (support for high degrees of…

  20. Correlation of Normal Gravity Mixed Convection Blowoff Limits with Microgravity Forced Flow Blowoff Limits (United States)

    Marcum, Jeremy W.; Olson, Sandra L.; Ferkul, Paul V.


    The axisymmetric rod geometry in upward axial stagnation flow provides a simple way to measure normal gravity blowoff limits to compare with microgravity Burning and Suppression of Solids - II (BASS-II) results recently obtained aboard the International Space Station. This testing utilized the same BASS-II concurrent rod geometry, but with the addition of normal gravity buoyant flow. Cast polymethylmethacrylate (PMMA) rods of diameters ranging from 0.635 cm to 3.81 cm were burned at oxygen concentrations ranging from 14 to 18% by volume. The forced flow velocity where blowoff occurred was determined for each rod size and oxygen concentration. These blowoff limits compare favorably with the BASS-II results when the buoyant stretch is included and the flow is corrected by considering the blockage factor of the fuel. From these results, the normal gravity blowoff boundary for this axisymmetric rod geometry is determined to be linear, with oxygen concentration directly proportional to flow speed. We describe a new normal gravity 'upward flame spread test' method which extrapolates the linear blowoff boundary to the zero stretch limit in order to resolve microgravity flammability limits-something current methods cannot do. This new test method can improve spacecraft fire safety for future exploration missions by providing a tractable way to obtain good estimates of material flammability in low gravity.