WorldWideScience

Sample records for stable synaptotoxic protofibrils

  1. Amyloid oligomers and protofibrils, but not filaments, self-replicate from native lysozyme.

    Science.gov (United States)

    Mulaj, Mentor; Foley, Joseph; Muschol, Martin

    2014-06-25

    Self-assembly of amyloid fibrils is the molecular mechanism best known for its connection with debilitating human disorders such as Alzheimer's disease but is also associated with various functional cellular responses. There is increasing evidence that amyloid formation proceeds along two distinct assembly pathways involving either globular oligomers and protofibrils or rigid monomeric filaments. Oligomers, in particular, have been implicated as the dominant molecular species responsible for pathogenesis. Yet the molecular mechanisms regulating their self-assembly have remained elusive. Here we show that oligomers/protofibrils and monomeric filaments, formed along distinct assembly pathways, display critical differences in their ability to template amyloid growth at physiological vs denaturing temperatures. At physiological temperatures, amyloid filaments remained stable but could not seed growth of native monomers. In contrast, oligomers and protofibrils not only remained intact but were capable of self-replication using native monomers as the substrate. Kinetic data further suggested that this prion-like growth mode of oligomers/protofibrils involved two distinct activities operating orthogonal from each other: autocatalytic self-replication of oligomers from native monomers and nucleated polymerization of oligomers into protofibrils. The environmental changes to stability and templating competence of these different amyloid species in different environments are likely to be important for understanding the molecular mechanisms underlying both pathogenic and functional amyloid self-assembly.

  2. A Neuronal Culture System to Detect Prion Synaptotoxicity.

    Directory of Open Access Journals (Sweden)

    Cheng Fang

    2016-05-01

    Full Text Available Synaptic pathology is an early feature of prion as well as other neurodegenerative diseases. Although the self-templating process by which prions propagate is well established, the mechanisms by which prions cause synaptotoxicity are poorly understood, due largely to the absence of experimentally tractable cell culture models. Here, we report that exposure of cultured hippocampal neurons to PrPSc, the infectious isoform of the prion protein, results in rapid retraction of dendritic spines. This effect is entirely dependent on expression of the cellular prion protein, PrPC, by target neurons, and on the presence of a nine-amino acid, polybasic region at the N-terminus of the PrPC molecule. Both protease-resistant and protease-sensitive forms of PrPSc cause dendritic loss. This system provides new insights into the mechanisms responsible for prion neurotoxicity, and it provides a platform for characterizing different pathogenic forms of PrPSc and testing potential therapeutic agents.

  3. Amyloid-β(1–42) Protofibrils Formed in Modified Artificial Cerebrospinal Fluid Bind and Activate Microglia

    Science.gov (United States)

    Paranjape, Geeta S.; Terrill, Shana E.; Gouwens, Lisa K.; Ruck, Benjamin M.; Nichols, Michael R.

    2012-01-01

    Soluble aggregated forms of amyloid-β protein (Aβ) have garnered significant attention recently for their role in Alzheimer’s disease (AD). Protofibrils are a subset of these soluble species and are considered intermediates in the aggregation pathway to mature Aβ fibrils. Biological studies have demonstrated that protofibrils exhibit both toxic and inflammatory activities. It is important in these in vitro studies to prepare protofibrils using solution conditions that are appropriate for cellular studies as well as conducive to biophysical characterization of protofibrils. Here we describe the preparation and characterization of Aβ(1–42) protofibrils in modified artificial cerebrospinal fluid (aCSF) and demonstrate their prominent binding and activation of microglial cells. A simple phosphate/bicarbonate buffer system was prepared that maintained the ionic strength and cell compatibility of F-12 medium but did not contain numerous supplements that interfere with spectroscopic analyses of Aβ protofibrils. Reconstitution of Aβ(1–42) in aCSF and isolation with size exclusion chromatography (SEC) revealed curvilinear β-sheet protofibrils <100 nm in length and hydrodynamic radii of 21 nm. Protofibril concentration determination by BCA assay, which was not possible in F-12 medium, was more accurately measured in aCSF. Protofibrils formed and isolated in aCSF, but not monomers, markedly stimulated TNFα production in BV-2 and primary microglia and bound in significant amounts to microglial membranes. This report demonstrates the suitability of a modified aCSF system for preparing SEC-isolated Aβ(1–42) protofibrils and underscores the unique ability of protofibrils to functionally interact with microglia. PMID:23242692

  4. Considerably Unfolded Transthyretin Monomers Preceed and Exchange with Dynamically Structured Amyloid Protofibrils

    DEFF Research Database (Denmark)

    Groenning, Minna; Campos, Raul I; Hirschberg, Daniel

    2015-01-01

    describe an unexpectedly dynamic TTR protofibril structure which exchanges protomers with highly unfolded monomers in solution. The protofibrils only grow to an approximate final size of 2,900 kDa and a length of 70 nm and a comparative HXMS analysis of native and aggregated samples revealed a much higher...... average solvent exposure of TTR upon fibrillation. With SAXS, we reveal the continuous presence of a considerably unfolded TTR monomer throughout the fibrillation process, and show that a considerable fraction of the fibrillating protein remains in solution even at a late maturation state. Together......, these data reveal that the fibrillar state interchanges with the solution state. Accordingly, we suggest that TTR fibrillation proceeds via addition of considerably unfolded monomers, and the continuous presence of amyloidogenic structures near the protofibril surface offers a plausible explanation...

  5. The Off-rate of Monomers Dissociating from Amyloid-β Protofibrils*

    Science.gov (United States)

    Grüning, Clara S. R.; Klinker, Stefan; Wolff, Martin; Schneider, Mario; Toksöz, Küpra; Klein, Antonia N.; Nagel-Steger, Luitgard; Willbold, Dieter; Hoyer, Wolfgang

    2013-01-01

    The interconversion of monomers, oligomers, and amyloid fibrils of the amyloid-β peptide (Aβ) has been implicated in the pathogenesis of Alzheimer disease. The determination of the kinetics of the individual association and dissociation reactions is hampered by the fact that forward and reverse reactions to/from different aggregation states occur simultaneously. Here, we report the kinetics of dissociation of Aβ monomers from protofibrils, prefibrillar high molecular weight oligomers previously shown to possess pronounced neurotoxicity. An engineered binding protein sequestering specifically monomeric Aβ was employed to follow protofibril dissociation by tryptophan fluorescence, precluding confounding effects of reverse or competing reactions. Aβ protofibril dissociation into monomers follows exponential decay kinetics with a time constant of ∼2 h at 25 °C and an activation energy of 80 kJ/mol, values typical for high affinity biomolecular interactions. This study demonstrates the high kinetic stability of Aβ protofibrils toward dissociation into monomers and supports the delineation of the Aβ folding and assembly energy landscape. PMID:24247242

  6. Cationization increases brain distribution of an amyloid-beta protofibril selective F(ab')2 fragment

    OpenAIRE

    Syvänen, Stina; Edén, Desireé; Sehlin, Dag

    2017-01-01

    Antibodies and fragments thereof are, because of high selectivity for their targets, considered as potential therapeutics and biomarkers for several neurological disorders. However, due to their large molecular size, antibodies/fragments do not easily penetrate into the brain. The aim of the present study was to improve the brain distribution via adsorptive-mediated transcytosis of an amyloid-beta (A beta) protofibril selective F(ab')2 fragment (F(ab')2-h158). F(ab')2-h158 was cationized to d...

  7. Protofibrils, pores, fibrils, and neurodegeneration: separating the responsible protein aggregates from the innocent bystanders.

    Science.gov (United States)

    Caughey, Byron; Lansbury, Peter T

    2003-01-01

    Many neurodegenerative diseases, including Alzheimer's and Parkinson's and the transmissible spongiform encephalopathies (prion diseases), are characterized at autopsy by neuronal loss and protein aggregates that are typically fibrillar. A convergence of evidence strongly suggests that protein aggregation is neurotoxic and not a product of cell death. However, the identity of the neurotoxic aggregate and the mechanism by which it disables and eventually kills a neuron are unknown. Both biophysical studies aimed at elucidating the precise mechanism of in vitro aggregation and animal modeling studies support the emerging notion that an ordered prefibrillar oligomer, or protofibril, may be responsible for cell death and that the fibrillar form that is typically observed at autopsy may actually be neuroprotective. A subpopulation of protofibrils may function as pathogenic amyloid pores. An analogous mechanism may explain the neurotoxicity of the prion protein; recent data demonstrates that the disease-associated, infectious form of the prion protein differs from the neurotoxic species. This review focuses on recent experimental studies aimed at identification and characterization of the neurotoxic protein aggregates.

  8. Caffeine and an adenosine A(2A) receptor antagonist prevent memory impairment and synaptotoxicity in adult rats triggered by a convulsive episode in early life.

    Science.gov (United States)

    Cognato, Giana P; Agostinho, Paula M; Hockemeyer, Jörg; Müller, Christa E; Souza, Diogo O; Cunha, Rodrigo A

    2010-01-01

    Seizures early in life cause long-term behavioral modifications, namely long-term memory deficits in experimental animals. Since caffeine and adenosine A(2A) receptor (A(2A)R) antagonists prevent memory deficits in adult animals, we now investigated if they also prevented the long-term memory deficits caused by a convulsive period early in life. Administration of kainate (KA, 2 mg/kg) to 7-days-old (P7) rats caused a single period of self-extinguishable convulsions which lead to a poorer memory performance in the Y-maze only when rats were older than 90 days, without modification of locomotion or anxiety-like behavior in the elevated-plus maze. In accordance with the relationship between synaptotoxicity and memory dysfunction, the hippocampus of these adult rats treated with kainate at P7 displayed a lower density of synaptic proteins such as SNAP-25 and syntaxin (but not synaptophysin), as well as vesicular glutamate transporters type 1 (but not vesicular GABA transporters), with no changes in PSD-95, NMDA receptor subunits (NR1, NR2A, NR2B) or alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate receptor subunits (GluR1, GluR2) compared with controls. Caffeine (1 g/L) or the A(2A)R antagonist, KW6002 (3 mg/kg) applied in the drinking water from P21 onwards, prevented these memory deficits in P90 rats treated with KA at P7, as well as the accompanying synaptotoxicity. These results show that a single convulsive episode in early life causes a delayed memory deficit in adulthood accompanied by a glutamatergic synaptotoxicity that was prevented by caffeine or adenosine A(2A)R antagonists.

  9. Alzheimer's-associated Aβ oligomers show altered structure, immunoreactivity and synaptotoxicity with low doses of oleocanthal

    International Nuclear Information System (INIS)

    Pitt, Jason; Roth, William; Lacor, Pascale; Smith, Amos B.; Blankenship, Matthew; Velasco, Pauline; De Felice, Fernanda; Breslin, Paul; Klein, William L.

    2009-01-01

    It now appears likely that soluble oligomers of amyloid-β 1-42 peptide, rather than insoluble fibrils, act as the primary neurotoxin in Alzheimer's disease (AD). Consequently, compounds capable of altering the assembly state of these oligomers (referred to as ADDLs) may have potential for AD therapeutics. Phenolic compounds are of particular interest for their ability to disrupt Aβ oligomerization and reduce pathogenicity. This study has focused on oleocanthal (OC), a naturally-occurring phenolic compound found in extra-virgin olive oil. OC increased the immunoreactivity of soluble Aβ species, when assayed with both sequence- and conformation-specific Aβ antibodies, indicating changes in oligomer structure. Analysis of oligomers in the presence of OC showed an upward shift in MW and a ladder-like distribution of SDS-stable ADDL subspecies. In comparison with control ADDLs, oligomers formed in the presence of OC (Aβ-OC) showed equivalent colocalization at synapses but exhibited greater immunofluorescence as a result of increased antibody recognition. The enhanced signal at synapses was not due to increased synaptic binding, as direct detection of fluorescently-labeled ADDLs showed an overall reduction in ADDL signal in the presence of OC. Decreased binding to synapses was accompanied by significantly less synaptic deterioration assayed by drebrin loss. Additionally, treatment with OC improved antibody clearance of ADDLs. These results indicate oleocanthal is capable of altering the oligomerization state of ADDLs while protecting neurons from the synaptopathological effects of ADDLs and suggest OC as a lead compound for development in AD therapeutics.

  10. Perspectives on future Alzheimer therapies: amyloid-β protofibrils - a new target for immunotherapy with BAN2401 in Alzheimer's disease.

    Science.gov (United States)

    Lannfelt, Lars; Möller, Christer; Basun, Hans; Osswald, Gunilla; Sehlin, Dag; Satlin, Andrew; Logovinsky, Veronika; Gellerfors, Pär

    2014-01-01

    The symptomatic drugs currently on the market for Alzheimer's disease (AD) have no effect on disease progression, and this creates a large unmet medical need. The type of drug that has developed most rapidly in the last decade is immunotherapy: vaccines and, especially, passive vaccination with monoclonal antibodies. Antibodies are attractive drugs as they can be made highly specific for their target and often with few side effects. Data from recent clinical AD trials indicate that a treatment effect by immunotherapy is possible, providing hope for a new generation of drugs. The first anti-amyloid-beta (anti-Aβ) vaccine developed by Elan, AN1792, was halted in phase 2 because of aseptic meningoencephalitis. However, in a follow-up study, patients with antibody response to the vaccine demonstrated reduced cognitive decline, supporting the hypothesis that Aβ immunotherapy may have clinically relevant effects. Bapineuzumab (Elan/Pfizer Inc./Johnson & Johnson), a monoclonal antibody targeting fibrillar Aβ, was stopped because the desired clinical effect was not seen. Solanezumab (Eli Lilly and Company) was developed to target soluble, monomeric Aβ. In two phase 3 studies, Solanezumab did not meet primary endpoints. When data from the two studies were pooled, a positive pattern emerged, revealing a significant slowing of cognitive decline in the subgroup of mild AD. The Arctic mutation has been shown to specifically increase the formation of soluble Aβ protofibrils, an Aβ species shown to be toxic to neurons and likely to be present in all cases of AD. A monoclonal antibody, mAb158, was developed to target Aβ protofibrils with high selectivity. It has at least a 1,000-fold higher selectivity for protofibrils as compared with monomers of Aβ, thus targeting the toxic species of the peptide. A humanized version of mAb158, BAN2401, has now entered a clinical phase 2b trial in a collaboration between BioArctic Neuroscience and Eisai without the safety concerns seen

  11. Stable isotopes

    International Nuclear Information System (INIS)

    Evans, D.K.

    1986-01-01

    Seventy-five percent of the world's stable isotope supply comes from one producer, Oak Ridge Nuclear Laboratory (ORNL) in the US. Canadian concern is that foreign needs will be met only after domestic needs, thus creating a shortage of stable isotopes in Canada. This article describes the present situation in Canada (availability and cost) of stable isotopes, the isotope enrichment techniques, and related research programs at Chalk River Nuclear Laboratories (CRNL)

  12. Unpredictably Stable

    DEFF Research Database (Denmark)

    Failla, Virgilio; Melillo, Francesca; Reichstein, Toke

    2014-01-01

    Is entrepreneurship a more stable career choice for high employment turnover individuals? We find that a transition to entrepreneurship induces a shift towards stayer behavior and identify job matching, job satisfaction and lock-in effects as main drivers. These findings have major implications...

  13. Stable particles

    International Nuclear Information System (INIS)

    Samios, N.P.

    1993-01-01

    I have been asked to review the subject of stable particles, essentially the particles that eventually comprised the meson and baryon octets. with a few more additions -- with an emphasis on the contributions made by experiments utilizing the bubble chamber technique. In this activity, much work had been done by the photographic emulsion technique and cloud chambers-exposed to cosmic rays as well as accelerator based beams. In fact, many if not most of the stable particles were found by these latter two techniques, however, the forte of the bubble chamber (coupled with the newer and more powerful accelerators) was to verify, and reinforce with large statistics, the existence of these states, to find some of the more difficult ones, mainly neutrals and further to elucidate their properties, i.e., spin, parity, lifetimes, decay parameters, etc

  14. Stable isotopes

    International Nuclear Information System (INIS)

    Brazier, J.L.; Guinamant, J.L.

    1995-01-01

    According to the progress which has been realised in the technology of separating and measuring isotopes, the stable isotopes are used as preferable 'labelling elements' for big number of applications. The isotopic composition of natural products shows significant variations as a result of different reasons like the climate, the seasons, or their geographic origins. So, it was proved that the same product has a different isotopic composition of alimentary and agriculture products. It is also important in detecting the pharmacological and medical chemicals. This review article deals with the technology, like chromatography and spectrophotometry, adapted to this aim, and some important applications. 17 refs. 6 figs

  15. Stable Tetraquarks

    Energy Technology Data Exchange (ETDEWEB)

    Quigg, Chris [Fermilab

    2018-04-13

    For very heavy quarks, relations derived from heavy-quark symmetry imply novel narrow doubly heavy tetraquark states containing two heavy quarks and two light antiquarks. We predict that double-beauty states will be stable against strong decays, whereas the double-charm states and mixed beauty+charm states will dissociate into pairs of heavy-light mesons. Observing a new double-beauty state through its weak decays would establish the existence of tetraquarks and illuminate the role of heavy color-antitriplet diquarks as hadron constituents.

  16. Stable beams

    CERN Multimedia

    2015-01-01

    Stable beams: two simple words that carry so much meaning at CERN. When LHC page one switched from "squeeze" to "stable beams" at 10.40 a.m. on Wednesday, 3 June, it triggered scenes of jubilation in control rooms around the CERN sites, as the LHC experiments started to record physics data for the first time in 27 months. This is what CERN is here for, and it’s great to be back in business after such a long period of preparation for the next stage in the LHC adventure.   I’ve said it before, but I’ll say it again. This was a great achievement, and testimony to the hard and dedicated work of so many people in the global CERN community. I could start to list the teams that have contributed, but that would be a mistake. Instead, I’d simply like to say that an achievement as impressive as running the LHC – a machine of superlatives in every respect – takes the combined effort and enthusiasm of everyone ...

  17. Stable Isotope Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Tissue samples (skin, bone, blood, muscle) are analyzed for stable carbon, stable nitrogen, and stable sulfur analysis. Many samples are used in their entirety for...

  18. Stable convergence and stable limit theorems

    CERN Document Server

    Häusler, Erich

    2015-01-01

    The authors present a concise but complete exposition of the mathematical theory of stable convergence and give various applications in different areas of probability theory and mathematical statistics to illustrate the usefulness of this concept. Stable convergence holds in many limit theorems of probability theory and statistics – such as the classical central limit theorem – which are usually formulated in terms of convergence in distribution. Originated by Alfred Rényi, the notion of stable convergence is stronger than the classical weak convergence of probability measures. A variety of methods is described which can be used to establish this stronger stable convergence in many limit theorems which were originally formulated only in terms of weak convergence. Naturally, these stronger limit theorems have new and stronger consequences which should not be missed by neglecting the notion of stable convergence. The presentation will be accessible to researchers and advanced students at the master's level...

  19. stableGP

    Data.gov (United States)

    National Aeronautics and Space Administration — The code in the stableGP package implements Gaussian process calculations using efficient and numerically stable algorithms. Description of the algorithms is in the...

  20. Angina Pectoris (Stable Angina)

    Science.gov (United States)

    ... Peripheral Artery Disease Venous Thromboembolism Aortic Aneurysm More Angina Pectoris (Stable Angina) Updated:Aug 21,2017 You may have heard the term “angina pectoris” or “stable angina” in your doctor’s office, ...

  1. Stable Boundary Layer Issues

    OpenAIRE

    Steeneveld, G.J.

    2012-01-01

    Understanding and prediction of the stable atmospheric boundary layer is a challenging task. Many physical processes are relevant in the stable boundary layer, i.e. turbulence, radiation, land surface coupling, orographic turbulent and gravity wave drag, and land surface heterogeneity. The development of robust stable boundary layer parameterizations for use in NWP and climate models is hampered by the multiplicity of processes and their unknown interactions. As a result, these models suffer ...

  2. Stable isotopes labelled compounds

    International Nuclear Information System (INIS)

    1982-09-01

    The catalogue on stable isotopes labelled compounds offers deuterium, nitrogen-15, and multiply labelled compounds. It includes: (1) conditions of sale and delivery, (2) the application of stable isotopes, (3) technical information, (4) product specifications, and (5) the complete delivery programme

  3. Evolutionary Stable Strategy

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 21; Issue 9. Evolutionary Stable Strategy: Application of Nash Equilibrium in Biology. General Article Volume 21 Issue 9 September 2016 pp 803- ... Keywords. Evolutionary game theory, evolutionary stable state, conflict, cooperation, biological games.

  4. Stable Boundary Layer Issues

    NARCIS (Netherlands)

    Steeneveld, G.J.

    2012-01-01

    Understanding and prediction of the stable atmospheric boundary layer is a challenging task. Many physical processes are relevant in the stable boundary layer, i.e. turbulence, radiation, land surface coupling, orographic turbulent and gravity wave drag, and land surface heterogeneity. The

  5. Normal modified stable processes

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole Eiler; Shephard, N.

    2002-01-01

    Gaussian (NGIG) laws. The wider framework thus established provides, in particular, for added flexibility in the modelling of the dynamics of financial time series, of importance especially as regards OU based stochastic volatility models for equities. In the special case of the tempered stable OU process......This paper discusses two classes of distributions, and stochastic processes derived from them: modified stable (MS) laws and normal modified stable (NMS) laws. This extends corresponding results for the generalised inverse Gaussian (GIG) and generalised hyperbolic (GH) or normal generalised inverse...

  6. Applications of stable isotopes

    International Nuclear Information System (INIS)

    Letolle, R.; Mariotti, A.; Bariac, T.

    1991-06-01

    This report reviews the historical background and the properties of stable isotopes, the methods used for their measurement (mass spectrometry and others), the present technics for isotope enrichment and separation, and at last the various present and foreseeable application (in nuclear energy, physical and chemical research, materials industry and research; tracing in industrial, medical and agronomical tests; the use of natural isotope variations for environmental studies, agronomy, natural resources appraising: water, minerals, energy). Some new possibilities in the use of stable isotope are offered. A last chapter gives the present state and forecast development of stable isotope uses in France and Europe

  7. Analysing Stable Time Series

    National Research Council Canada - National Science Library

    Adler, Robert

    1997-01-01

    We describe how to take a stable, ARMA, time series through the various stages of model identification, parameter estimation, and diagnostic checking, and accompany the discussion with a goodly number...

  8. Uses of stable isotopes

    International Nuclear Information System (INIS)

    Axente, Damian

    1998-01-01

    The most important fields of stable isotope use with examples are presented. These are: 1. Isotope dilution analysis: trace analysis, measurements of volumes and masses; 2. Stable isotopes as tracers: transport phenomena, environmental studies, agricultural research, authentication of products and objects, archaeometry, studies of reaction mechanisms, structure and function determination of complex biological entities, studies of metabolism, breath test for diagnostic; 3. Isotope equilibrium effects: measurement of equilibrium effects, investigation of equilibrium conditions, mechanism of drug action, study of natural processes, water cycle, temperature measurements; 4. Stable isotope for advanced nuclear reactors: uranium nitride with 15 N as nuclear fuel, 157 Gd for reactor control. In spite of some difficulties of stable isotope use, particularly related to the analytical techniques, which are slow and expensive, the number of papers reporting on this subject is steadily growing as well as the number of scientific meetings organized by International Isotope Section and IAEA, Gordon Conferences, and regional meeting in Germany, France, etc. Stable isotope application development on large scale is determined by improving their production technologies as well as those of labeled compound and the analytical techniques. (author)

  9. Calcium stable isotope geochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Gausonne, Nikolaus [Muenster Univ. (Germany). Inst. fuer Mineralogie; Schmitt, Anne-Desiree [Strasbourg Univ. (France). LHyGeS/EOST; Heuser, Alexander [Bonn Univ. (Germany). Steinmann-Inst. fuer Geologie, Mineralogie und Palaeontologie; Wombacher, Frank [Koeln Univ. (Germany). Inst. fuer Geologie und Mineralogie; Dietzel, Martin [Technische Univ. Graz (Austria). Inst. fuer Angewandte Geowissenschaften; Tipper, Edward [Cambridge Univ. (United Kingdom). Dept. of Earth Sciences; Schiller, Martin [Copenhagen Univ. (Denmark). Natural History Museum of Denmark

    2016-08-01

    This book provides an overview of the fundamentals and reference values for Ca stable isotope research, as well as current analytical methodologies including detailed instructions for sample preparation and isotope analysis. As such, it introduces readers to the different fields of application, including low-temperature mineral precipitation and biomineralisation, Earth surface processes and global cycling, high-temperature processes and cosmochemistry, and lastly human studies and biomedical applications. The current state of the art in these major areas is discussed, and open questions and possible future directions are identified. In terms of its depth and coverage, the current work extends and complements the previous reviews of Ca stable isotope geochemistry, addressing the needs of graduate students and advanced researchers who want to familiarize themselves with Ca stable isotope research.

  10. Calcium stable isotope geochemistry

    International Nuclear Information System (INIS)

    Gausonne, Nikolaus; Schmitt, Anne-Desiree; Heuser, Alexander; Wombacher, Frank; Dietzel, Martin; Tipper, Edward; Schiller, Martin

    2016-01-01

    This book provides an overview of the fundamentals and reference values for Ca stable isotope research, as well as current analytical methodologies including detailed instructions for sample preparation and isotope analysis. As such, it introduces readers to the different fields of application, including low-temperature mineral precipitation and biomineralisation, Earth surface processes and global cycling, high-temperature processes and cosmochemistry, and lastly human studies and biomedical applications. The current state of the art in these major areas is discussed, and open questions and possible future directions are identified. In terms of its depth and coverage, the current work extends and complements the previous reviews of Ca stable isotope geochemistry, addressing the needs of graduate students and advanced researchers who want to familiarize themselves with Ca stable isotope research.

  11. Stable isotope studies

    International Nuclear Information System (INIS)

    Ishida, T.

    1992-01-01

    The research has been in four general areas: (1) correlation of isotope effects with molecular forces and molecular structures, (2) correlation of zero-point energy and its isotope effects with molecular structure and molecular forces, (3) vapor pressure isotope effects, and (4) fractionation of stable isotopes. 73 refs, 38 figs, 29 tabs

  12. Interactive Stable Ray Tracing

    DEFF Research Database (Denmark)

    Dal Corso, Alessandro; Salvi, Marco; Kolb, Craig

    2017-01-01

    Interactive ray tracing applications running on commodity hardware can suffer from objectionable temporal artifacts due to a low sample count. We introduce stable ray tracing, a technique that improves temporal stability without the over-blurring and ghosting artifacts typical of temporal post-pr...

  13. The Stable Concordance Genus

    OpenAIRE

    Kearney, M. Kate

    2013-01-01

    The concordance genus of a knot is the least genus of any knot in its concordance class. Although difficult to compute, it is a useful invariant that highlights the distinction between the three-genus and four-genus. In this paper we define and discuss the stable concordance genus of a knot, which describes the behavior of the concordance genus under connected sum.

  14. Stable radiographic scanning agents

    International Nuclear Information System (INIS)

    1976-01-01

    Stable compositions which are useful in the preparation of Technetium-99m-based scintigraphic agents are discussed. They are comprised of ascorbic acid or a pharmaceutically acceptable salt or ester thereof in combination with a pertechnetate reducing agent or dissolved in oxidized pertechnetate-99m (sup(99m)TcO 4 - ) solution

  15. Some stable hydromagnetic equilibria

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, J L; Oberman, C R; Kulsrud, R M; Frieman, E A [Project Matterhorn, Princeton University, Princeton, NJ (United States)

    1958-07-01

    We have been able to find and investigate the properties of equilibria which are hydromagnetically stable. These equilibria can be obtained, for example, by wrapping conductors helically around the stellarator tube. Systems with I = 3 or 4 are indicated to be optimum for stability purposes. In some cases an admixture of I = 2 fields can be advantageous for achieving equilibrium. (author)

  16. Stable isotope analysis

    International Nuclear Information System (INIS)

    Tibari, Elghali; Taous, Fouad; Marah, Hamid

    2014-01-01

    This report presents results related to stable isotopes analysis carried out at the CNESTEN DASTE in Rabat (Morocco), on behalf of Senegal. These analyzes cover 127 samples. These results demonstrate that Oxygen-18 and Deuterium in water analysis were performed by infrared Laser spectroscopy using a LGR / DLT-100 with Autosampler. Also, the results are expressed in δ values (‰) relative to V-SMOW to ± 0.3 ‰ for oxygen-18 and ± 1 ‰ for deuterium.

  17. Forensic Stable Isotope Biogeochemistry

    Science.gov (United States)

    Cerling, Thure E.; Barnette, Janet E.; Bowen, Gabriel J.; Chesson, Lesley A.; Ehleringer, James R.; Remien, Christopher H.; Shea, Patrick; Tipple, Brett J.; West, Jason B.

    2016-06-01

    Stable isotopes are being used for forensic science studies, with applications to both natural and manufactured products. In this review we discuss how scientific evidence can be used in the legal context and where the scientific progress of hypothesis revisions can be in tension with the legal expectations of widely used methods for measurements. Although this review is written in the context of US law, many of the considerations of scientific reproducibility and acceptance of relevant scientific data span other legal systems that might apply different legal principles and therefore reach different conclusions. Stable isotopes are used in legal situations for comparing samples for authenticity or evidentiary considerations, in understanding trade patterns of illegal materials, and in understanding the origins of unknown decedents. Isotope evidence is particularly useful when considered in the broad framework of physiochemical processes and in recognizing regional to global patterns found in many materials, including foods and food products, drugs, and humans. Stable isotopes considered in the larger spatial context add an important dimension to forensic science.

  18. Theory of stable allocations

    Directory of Open Access Journals (Sweden)

    Pantelić Svetlana

    2014-01-01

    Full Text Available The Swedish Royal Academy awarded the 2012 Nobel Prize in Economics to Lloyd Shapley and Alvin Roth, for the theory of stable allocations and the practice of market design. These two American researchers worked independently from each other, combining basic theory and empirical investigations. Through their experiments and practical design they generated a flourishing field of research and improved the performance of many markets. Born in 1923 in Cambridge, Massachusetts, Shapley defended his doctoral thesis at Princeton University in 1953. For many years he worked at RAND, and for more than thirty years he was a professor at UCLA University. He published numerous scientific papers, either by himself or in cooperation with other economists.

  19. Bi-stable optical actuator

    Science.gov (United States)

    Holdener, Fred R.; Boyd, Robert D.

    2000-01-01

    The present invention is a bi-stable optical actuator device that is depowered in both stable positions. A bearing is used to transfer motion and smoothly transition from one state to another. The optical actuator device may be maintained in a stable position either by gravity or a restraining device.

  20. One-dimensional stable distributions

    CERN Document Server

    Zolotarev, V M

    1986-01-01

    This is the first book specifically devoted to a systematic exposition of the essential facts known about the properties of stable distributions. In addition to its main focus on the analytic properties of stable laws, the book also includes examples of the occurrence of stable distributions in applied problems and a chapter on the problem of statistical estimation of the parameters determining stable laws. A valuable feature of the book is the author's use of several formally different ways of expressing characteristic functions corresponding to these laws.

  1. Stable isotope research pool inventory

    International Nuclear Information System (INIS)

    1980-12-01

    This report contains a listing of electromagnetically separated stable isotopes which are available for distribution within the United States for non-destructive research use from the Oak Ridge National Laboratory on a loan basis. This inventory includes all samples of stable isotopes in the Materials Research Collection and does not designate whether a sample is out on loan or in reprocessing

  2. Stable configurations in social networks

    Science.gov (United States)

    Bronski, Jared C.; DeVille, Lee; Ferguson, Timothy; Livesay, Michael

    2018-06-01

    We present and analyze a model of opinion formation on an arbitrary network whose dynamics comes from a global energy function. We study the global and local minimizers of this energy, which we call stable opinion configurations, and describe the global minimizers under certain assumptions on the friendship graph. We show a surprising result that the number of stable configurations is not necessarily monotone in the strength of connection in the social network, i.e. the model sometimes supports more stable configurations when the interpersonal connections are made stronger.

  3. Development of Stable Isotope Technology

    International Nuclear Information System (INIS)

    Jeong, Do Young; Kim, Cheol Jung; Han, Jae Min

    2009-03-01

    KAERI has obtained an advanced technology with singular originality for laser stable isotope separation. Objectives for this project are to get production technology of Tl-203 stable isotope used for medical application and are to establish the foundation of the pilot system, while we are taking aim at 'Laser Isotope Separation Technology to make resistance to the nuclear proliferation'. And we will contribute to ensuring a nuclear transparency in the world society by taking part in a practical group of NSG and being collaboration with various international groups related to stable isotope separation technology

  4. Stable isotope research pool inventory

    International Nuclear Information System (INIS)

    1984-03-01

    This report contains a listing of electromagnetically separated stable isotopes which are available at the Oak Ridge National Laboratory for distribution for nondestructive research use on a loan basis. This inventory includes all samples of stable isotopes in the Research Materials Collection and does not designate whether a sample is out on loan or is in reprocessing. For some of the high abundance naturally occurring isotopes, larger amounts can be made available; for example, Ca-40 and Fe-56

  5. French days on stable isotopes

    International Nuclear Information System (INIS)

    2000-01-01

    These first French days on stable isotopes took place in parallel with the 1. French days of environmental chemistry. Both conferences had common plenary sessions. The conference covers all aspects of the use of stable isotopes in the following domains: medicine, biology, environment, tracer techniques, agronomy, food industry, geology, petroleum geochemistry, cosmo-geochemistry, archaeology, bio-geochemistry, hydrology, climatology, nuclear and particle physics, astrophysics, isotope separations etc.. Abstracts available on CD-Rom only. (J.S.)

  6. Stable isotope research pool inventory

    International Nuclear Information System (INIS)

    1982-01-01

    This report contains a listing of electromagnetically separated stable isotopes which are available for distribution within the United States for nondestructive research use from the Oak Ridge National Laboratory on a loan basis. This inventory includes all samples of stable isotopes in the Material Research Collection and does not designate whether a sample is out on loan or in reprocessing. For some of the high abundance naturally occurring isotopes, larger amounts can be made available; for example, Ca-40 and Fe-56

  7. Pharmaceuticals labelled with stable isotopes

    International Nuclear Information System (INIS)

    Krumbiegel, P.

    1986-11-01

    The relatively new field of pharmaceuticals labelled with stable isotopes is reviewed. Scientific, juridical, and ethical questions are discussed concerning the application of these pharmaceuticals in human medicine. 13 C, 15 N, and 2 H are the stable isotopes mainly utilized in metabolic function tests. Methodical contributions are given to the application of 2 H, 13 C, and 15 N pharmaceuticals showing new aspects and different states of development in the field under discussion. (author)

  8. [Current Treatment of Stable Angina].

    Science.gov (United States)

    Toggweiler, Stefan; Jamshidi, Peiman; Cuculi, Florim

    2015-06-17

    Current therapy for stable angina includes surgical and percutaneous revascularization, which has been improved tremendously over the last decades. Smoking cessation and regular exercise are the cornerstone for prevention of further cerebrovascular events. Medical treatment includes treatment of cardiovascular risk factors and antithrombotic management, which can be a challenge in some patients. Owing to the fact the coronary revascularization is readily accessible these days in many industrialized countries, the importance of antianginal therapy has decreased over the past years. This article presents a contemporary overview of the management of patients with stable angina in the year 2015.

  9. Possibility of stable quark stars

    International Nuclear Information System (INIS)

    Bowers, R.L.; Gleeson, A.M.; Pedigo, R.D.

    1976-08-01

    A recent zero temperature equation of state which contains quark-partons separated from conventional baryons by a phase transition is used to investigate the stability of quark stars. The sensitivity to the input physics is also considered. The conclusions, which are found to be relatively model independent, indicate that a separately identifiable class of stable objects called quark stars does not exist

  10. Radiation-stable polyolefin compositions

    International Nuclear Information System (INIS)

    Rekers, J.W.

    1986-01-01

    This invention relates to compositions of olefinic polymers suitable for high energy radiation treatment. In particular, the invention relates to olefinic polymer compositions that are stable to sterilizing dosages of high energy radiation such as a gamma radiation. Stabilizers are described that include benzhydrol and benzhydrol derivatives; these stabilizers may be used alone or in combination with secondary antioxidants or synergists

  11. Toward Practical Secure Stable Matching

    Directory of Open Access Journals (Sweden)

    Riazi M. Sadegh

    2017-01-01

    Full Text Available The Stable Matching (SM algorithm has been deployed in many real-world scenarios including the National Residency Matching Program (NRMP and financial applications such as matching of suppliers and consumers in capital markets. Since these applications typically involve highly sensitive information such as the underlying preference lists, their current implementations rely on trusted third parties. This paper introduces the first provably secure and scalable implementation of SM based on Yao’s garbled circuit protocol and Oblivious RAM (ORAM. Our scheme can securely compute a stable match for 8k pairs four orders of magnitude faster than the previously best known method. We achieve this by introducing a compact and efficient sub-linear size circuit. We even further decrease the computation cost by three orders of magnitude by proposing a novel technique to avoid unnecessary iterations in the SM algorithm. We evaluate our implementation for several problem sizes and plan to publish it as open-source.

  12. Stable isotope research pool inventory

    International Nuclear Information System (INIS)

    1986-08-01

    This report contains a listing of electromagnetically separated stable isotopes which are available at the Oak Ridge National Laboratory for distribution for nondestructive research use on a loan basis. This inventory includes all samples of stable isotopes in the Research Materials Collection and does not designate whether a sample is out on loan or is in reprocessing. For some of the high-abundance, naturally occurring isotopes, larger amounts can be made available; for example, Ca-40 and Fe-56. All requests for the loan of samples should be submitted with a summary of the purpose of the loan to: Iotope Distribution Office, Oak Ridge National Laboratory, P.O. Box X, Oak Ridge, Tennessee 37831. Requests from non-DOE contractors and from foreign institutions require DOE approval

  13. Stable isotopes and the environment

    International Nuclear Information System (INIS)

    Krouse, H.R.

    1990-01-01

    Whereas traditionally, stable isotope research has been directed towards resource exploration and development, it is finding more frequent applications in helping to assess the impacts of resource utilization upon ecosystems. Among the many pursuits, two themes are evident: tracing the transport and conversions of pollutants in the environment and better understanding of the interplay among environmental receptors, e.g. food web studies. Stable isotope data are used primarily to identify the presence of pollutants in the environment and with a few exceptions, the consequence of their presence must be assessed by other techniques. Increasing attention has been given to the isotopic composition of humans with many potential applications in areas such as paleodiets, medicine, and criminology. In this brief overview examples are used from the Pacific Rim to illustrate the above concepts. 26 refs., 1 tab., 3 figs

  14. Towards stable acceleration in LINACS

    CERN Document Server

    Dubrovskiy, A D

    2014-01-01

    Ultra-stable and -reproducible high-energy particle beams with short bunches are needed in novel linear accelerators and, in particular, in the Compact Linear Collider CLIC. A passive beam phase stabilization system based on a bunch compression with a negative transfer matrix element R56 and acceleration at a positive off-crest phase is proposed. The motivation and expected advantages of the proposed scheme are outlined.

  15. Stable Structures for Distributed Applications

    OpenAIRE

    Eugen DUMITRASCU; Ion IVAN

    2008-01-01

    For distributed applications, we define the linear, tree and graph structure types with different variants and modalities to aggregate them. The distributed applications have assigned structures that through their characteristics influence the costs of stages for developing cycle and the costs for exploitation, transferred to each user. We also present the quality characteristics of a structure for a stable application, which is focused on stability characteristic. For that characteristic we ...

  16. Organic synthesis with stable isotopes

    International Nuclear Information System (INIS)

    Daub, G.H.; Kerr, V.N.; Williams, D.L.; Whaley, T.W.

    1978-01-01

    Some general considerations concerning organic synthesis with stable isotopes are presented. Illustrative examples are described and discussed. The examples include DL-2-amino-3-methyl- 13 C-butanoic-3,4- 13 C 2 acid (DL-valine- 13 C 3 ); methyl oleate-1- 13 C; thymine-2,6- 13 C 2 ; 2-aminoethanesulfonic- 13 C acid (taurine- 13 C); D-glucose-6- 13 C; DL-2-amino-3-methylpentanoic-3,4- 13 C 2 acid (DL-isoleucine- 13 C 2 ); benzidine- 15 N 2 ; and 4-ethylsulfonyl-1-naphthalene-sulfonamide- 15 N

  17. Stable isotopes - separation and application

    International Nuclear Information System (INIS)

    Lockhart, I.M.

    1980-01-01

    In this review, methods used for the separation of stable isotopes ( 12 C, 13 C, 14 N, 15 N, 16 O, 17 O, 18 O, 34 S) will be described. The synthesis of labelled compounds, techniques for detection and assay, and areas of application will also be discussed. Particular attention will be paid to the isotopes of carbon, nitrogen, and oxygen; to date, sulphur isotopes have only assumed a minor role. The field of deuterium chemistry is too extensive for adequate treatment; it will therefore be essentially excluded. (author)

  18. Stable agents for imaging investigations

    International Nuclear Information System (INIS)

    Tofe, A.J.

    1976-01-01

    This invention concerns highly stable compounds useful in preparing technetium 99m based scintiscanning exploration agents. The compounds of this invention include a pertechnetate reducing agent or a solution of oxidized pertechnetate and an efficient proportion, sufficient to stabilize the compounds in the presence of oxygen and of radiolysis products, of ascorbic acid or a pharmaceutically acceptable salt or ester of this acid. The invention also concerns a perfected process for preparing a technetium based exploration agent, consisting in codissolving the ascorbic acid or a pharmaceutically acceptable salt or ester of such an acid and a pertechnetate reducing agent in a solution of oxidized pertechnetate [fr

  19. Stable cosmology in chameleon bigravity

    Science.gov (United States)

    De Felice, Antonio; Mukohyama, Shinji; Oliosi, Michele; Watanabe, Yota

    2018-02-01

    The recently proposed chameleonic extension of bigravity theory, by including a scalar field dependence in the graviton potential, avoids several fine-tunings found to be necessary in usual massive bigravity. In particular it ensures that the Higuchi bound is satisfied at all scales, that no Vainshtein mechanism is needed to satisfy Solar System experiments, and that the strong coupling scale is always above the scale of cosmological interest all the way up to the early Universe. This paper extends the previous work by presenting a stable example of cosmology in the chameleon bigravity model. We find a set of initial conditions and parameters such that the derived stability conditions on general flat Friedmann background are satisfied at all times. The evolution goes through radiation-dominated, matter-dominated, and de Sitter eras. We argue that the parameter space allowing for such a stable evolution may be large enough to encompass an observationally viable evolution. We also argue that our model satisfies all known constraints due to gravitational wave observations so far and thus can be considered as a unique testing ground of gravitational wave phenomenologies in bimetric theories of gravity.

  20. Stable Heavy Hadrons in ATLAS

    CERN Document Server

    Mackeprang, Rasmus

    2007-01-01

    Several extensions to the SM feature heavy long-lived particles with masses of O(10^2-10^3 GeV) and mean lifetimes fulfilling $CT \\geq 10m$. Among such theories are supersymmetric scenarios as well as extra-dimensional models in which the heavy new particles are seen as Kaluza-Klein excitations of the well-known SM particles. Such particles will, from the point of view of a collider experiment be seen as stable. This thesis is concerned with the case where the exotic heavy particles emph{can} be considered stable while traversing the detector. Specifically the case is considered where the particles in question carry the charge of the strong nuclear force, commonly referred to as emph{colour charge}. A simulation kit has been developed using GEANT4. This framework is the current standard in experimental particle physics for the simulation of interactions of particles with matter, and it is used extensively for detector simulation. The simulation describes the interactions of these particles with matter which i...

  1. Stable isotope mass spectrometry in petroleum exploration

    International Nuclear Information System (INIS)

    Mathur, Manju

    1997-01-01

    The stable isotope mass spectrometry plays an important role to evaluate the stable isotopic composition of hydrocarbons. The isotopic ratios of certain elements in petroleum samples reflect certain characteristics which are useful for petroleum exploration

  2. Stable rotating dipole solitons in nonlocal media

    DEFF Research Database (Denmark)

    Lopez-Aguayo, Servando; Skupin, Stefan; Desyatnikov, Anton S.

    2006-01-01

    We present the first example of stable rotating two-soliton bound states in nonlinear optical media with nonlocal response. We show that, in contrast to media with local response, nonlocality opens possibilities to generate stable azimuthons.......We present the first example of stable rotating two-soliton bound states in nonlinear optical media with nonlocal response. We show that, in contrast to media with local response, nonlocality opens possibilities to generate stable azimuthons....

  3. Tempered stable laws as random walk limits

    OpenAIRE

    Chakrabarty, Arijit; Meerschaert, Mark M.

    2010-01-01

    Stable laws can be tempered by modifying the L\\'evy measure to cool the probability of large jumps. Tempered stable laws retain their signature power law behavior at infinity, and infinite divisibility. This paper develops random walk models that converge to a tempered stable law under a triangular array scheme. Since tempered stable laws and processes are useful in statistical physics, these random walk models can provide a basic physical model for the underlying physical phenomena.

  4. Stable States of Biological Organisms

    Science.gov (United States)

    Yukalov, V. I.; Sornette, D.; Yukalova, E. P.; Henry, J.-Y.; Cobb, J. P.

    2009-04-01

    A novel model of biological organisms is advanced, treating an organism as a self-consistent system subject to a pathogen flux. The principal novelty of the model is that it describes not some parts, but a biological organism as a whole. The organism is modeled by a five-dimensional dynamical system. The organism homeostasis is described by the evolution equations for five interacting components: healthy cells, ill cells, innate immune cells, specific immune cells, and pathogens. The stability analysis demonstrates that, in a wide domain of the parameter space, the system exhibits robust structural stability. There always exist four stable stationary solutions characterizing four qualitatively differing states of the organism: alive state, boundary state, critical state, and dead state.

  5. Super-stable Poissonian structures

    International Nuclear Information System (INIS)

    Eliazar, Iddo

    2012-01-01

    In this paper we characterize classes of Poisson processes whose statistical structures are super-stable. We consider a flow generated by a one-dimensional ordinary differential equation, and an ensemble of particles ‘surfing’ the flow. The particles start from random initial positions, and are propagated along the flow by stochastic ‘wave processes’ with general statistics and general cross correlations. Setting the initial positions to be Poisson processes, we characterize the classes of Poisson processes that render the particles’ positions—at all times, and invariantly with respect to the wave processes—statistically identical to their initial positions. These Poisson processes are termed ‘super-stable’ and facilitate the generalization of the notion of stationary distributions far beyond the realm of Markov dynamics. (paper)

  6. Super-stable Poissonian structures

    Science.gov (United States)

    Eliazar, Iddo

    2012-10-01

    In this paper we characterize classes of Poisson processes whose statistical structures are super-stable. We consider a flow generated by a one-dimensional ordinary differential equation, and an ensemble of particles ‘surfing’ the flow. The particles start from random initial positions, and are propagated along the flow by stochastic ‘wave processes’ with general statistics and general cross correlations. Setting the initial positions to be Poisson processes, we characterize the classes of Poisson processes that render the particles’ positions—at all times, and invariantly with respect to the wave processes—statistically identical to their initial positions. These Poisson processes are termed ‘super-stable’ and facilitate the generalization of the notion of stationary distributions far beyond the realm of Markov dynamics.

  7. Periodicity of the stable isotopes

    CERN Document Server

    Boeyens, J C A

    2003-01-01

    It is demonstrated that all stable (non-radioactive) isotopes are formally interrelated as the products of systematically adding alpha particles to four elementary units. The region of stability against radioactive decay is shown to obey a general trend based on number theory and contains the periodic law of the elements as a special case. This general law restricts the number of what may be considered as natural elements to 100 and is based on a proton:neutron ratio that matches the golden ratio, characteristic of biological and crystal growth structures. Different forms of the periodic table inferred at other proton:neutron ratios indicate that the electronic configuration of atoms is variable and may be a function of environmental pressure. Cosmic consequences of this postulate are examined. (author)

  8. Stable massive particles at colliders

    Energy Technology Data Exchange (ETDEWEB)

    Fairbairn, M.; /Stockholm U.; Kraan, A.C.; /Pennsylvania U.; Milstead, D.A.; /Stockholm U.; Sjostrand, T.; /Lund U.; Skands, P.; /Fermilab; Sloan, T.; /Lancaster U.

    2006-11-01

    We review the theoretical motivations and experimental status of searches for stable massive particles (SMPs) which could be sufficiently long-lived as to be directly detected at collider experiments. The discovery of such particles would address a number of important questions in modern physics including the origin and composition of dark matter in the universe and the unification of the fundamental forces. This review describes the techniques used in SMP-searches at collider experiments and the limits so far obtained on the production of SMPs which possess various colour, electric and magnetic charge quantum numbers. We also describe theoretical scenarios which predict SMPs, the phenomenology needed to model their production at colliders and interactions with matter. In addition, the interplay between collider searches and open questions in cosmology such as dark matter composition are addressed.

  9. The Myopic Stable Set for Social Environments

    NARCIS (Netherlands)

    Demuynck, Thomas; Herings, P. Jean-Jacques; Saulle, Riccardo; Seel, Christian

    2017-01-01

    We introduce a new solution concept for models of coalition formation, called the myopic stable set. The myopic stable set is defined for a very general class of social environments and allows for an infinite state space. We show that the myopic stable set exists and is non-empty. Under minor

  10. Effectiveness and risks of stable iodine prophylaxis

    International Nuclear Information System (INIS)

    Waight, P.J.

    1995-01-01

    The factors upon which the efficacy of stable iodine prophylaxis depends are reviewed, with particular reference to the dose of stable iodine, the timing of the dose, the influence of dietary iodine and the impact of the other prospective actions. The risks of stable iodine ingestion are estimated, and their application to the principle of Justification in outlined. (Author)

  11. Temperature and Humidity Control in Livestock Stables

    DEFF Research Database (Denmark)

    Hansen, Michael; Andersen, Palle; Nielsen, Kirsten M.

    2010-01-01

    The paper describes temperature and humidity control of a livestock stable. It is important to have a correct air flow pattern in the livestock stable in order to achieve proper temperature and humidity control as well as to avoid draught. In the investigated livestock stable the air flow...

  12. Moltex Energy's stable salt reactors

    International Nuclear Information System (INIS)

    O'Sullivan, R.; Laurie, J.

    2016-01-01

    A stable salt reactor is a molten salt reactor in which the molten fuel salt is contained in fuel rods. This concept was invented in 1951 and re-discovered and improved recently by Moltex Energy Company. The main advantage of using molten salt fuel is that the 2 problematic fission products cesium and iodine do not exist in gaseous form but rather in a form of a salt that present no danger in case of accident. Another advantage is the strongly negative temperature coefficient for reactivity which means the reactor self-regulates. The feasibility studies have been performed on a molten salt fuel composed of sodium chloride and plutonium/uranium/lanthanide/actinide trichloride. The coolant fluid is a mix of sodium and zirconium fluoride salts that will need low flow rates. The addition of 1 mol% of metal zirconium to the coolant fluid reduces the risk of corrosion with standard steels and the addition of 2% of hafnium reduces the neutron dose. The temperature of the coolant is expected to reach 650 Celsius degrees at the exit of the core. This reactor is designed to be modular and it will be able to burn actinides. (A.C.)

  13. Rare stable isotopes in meteorites

    International Nuclear Information System (INIS)

    Wilson, G.C.

    1981-01-01

    Secondary Ion Mass Spectrometry (SIMS) using accelerators has been applied with success to cosmic ray exposure ages and terrestrial residence times of meteorites by measuring cosmogenic nuclides of Be, Cl, and I. It is proposed to complement this work with experiments on rare stable isotopes, in the hope of setting constraints on the processes of solar nebula/meteoritic formation. The relevant species can be classified as: a) daughter products of extinct nuclides (halflife less than or equal to 2 x 10 8 y) -chronology of the early solar system; b) products of high temperature astrophysical processes - different components incorporated into the solar nebula; and c) products of relatively low temperature processes, stellar winds and cosmic ray reactions - early solar system radiation history. The use of micron-scale primary ion beams will allow detailed sampling of phases within meteorites. Strategies of charge-state selection, molecular disintegration and detection should bring a new set of targets within analytical range. The developing accelerator field is compared to existing (keV energy) ion microprobes

  14. Stable piecewise polynomial vector fields

    Directory of Open Access Journals (Sweden)

    Claudio Pessoa

    2012-09-01

    Full Text Available Let $N={y>0}$ and $S={y<0}$ be the semi-planes of $mathbb{R}^2$ having as common boundary the line $D={y=0}$. Let $X$ and $Y$ be polynomial vector fields defined in $N$ and $S$, respectively, leading to a discontinuous piecewise polynomial vector field $Z=(X,Y$. This work pursues the stability and the transition analysis of solutions of $Z$ between $N$ and $S$, started by Filippov (1988 and Kozlova (1984 and reformulated by Sotomayor-Teixeira (1995 in terms of the regularization method. This method consists in analyzing a one parameter family of continuous vector fields $Z_{epsilon}$, defined by averaging $X$ and $Y$. This family approaches $Z$ when the parameter goes to zero. The results of Sotomayor-Teixeira and Sotomayor-Machado (2002 providing conditions on $(X,Y$ for the regularized vector fields to be structurally stable on planar compact connected regions are extended to discontinuous piecewise polynomial vector fields on $mathbb{R}^2$. Pertinent genericity results for vector fields satisfying the above stability conditions are also extended to the present case. A procedure for the study of discontinuous piecewise vector fields at infinity through a compactification is proposed here.

  15. Stable Structures for Distributed Applications

    Directory of Open Access Journals (Sweden)

    Eugen DUMITRASCU

    2008-01-01

    Full Text Available For distributed applications, we define the linear, tree and graph structure types with different variants and modalities to aggregate them. The distributed applications have assigned structures that through their characteristics influence the costs of stages for developing cycle and the costs for exploitation, transferred to each user. We also present the quality characteristics of a structure for a stable application, which is focused on stability characteristic. For that characteristic we define the estimated measure indicators for a level. The influence of the factors of stability and the ways for increasing it are thus identified, and at the same time the costs of development stages, the costs of usage and the costs of maintenance to be keep on between limits that assure the global efficiency of application. It is presented the base aspects for distributed applications: definition, peculiarities and importance. The aspects for the development cycle of distributed application are detailed. In this article, we alongside give the mechanisms for building the defined structures and analyze the complexity of the defined structures for a distributed application of a virtual store.

  16. Advanced thermally stable jet fuels

    Energy Technology Data Exchange (ETDEWEB)

    Schobert, H.H.

    1999-01-31

    The Pennsylvania State University program in advanced thermally stable coal-based jet fuels has five broad objectives: (1) Development of mechanisms of degradation and solids formation; (2) Quantitative measurement of growth of sub-micrometer and micrometer-sized particles suspended in fuels during thermal stressing; (3) Characterization of carbonaceous deposits by various instrumental and microscopic methods; (4) Elucidation of the role of additives in retarding the formation of carbonaceous solids; (5) Assessment of the potential of production of high yields of cycloalkanes by direct liquefaction of coal. Future high-Mach aircraft will place severe thermal demands on jet fuels, requiring the development of novel, hybrid fuel mixtures capable of withstanding temperatures in the range of 400--500 C. In the new aircraft, jet fuel will serve as both an energy source and a heat sink for cooling the airframe, engine, and system components. The ultimate development of such advanced fuels requires a thorough understanding of the thermal decomposition behavior of jet fuels under supercritical conditions. Considering that jet fuels consist of hundreds of compounds, this task must begin with a study of the thermal degradation behavior of select model compounds under supercritical conditions. The research performed by The Pennsylvania State University was focused on five major tasks that reflect the objectives stated above: Task 1: Investigation of the Quantitative Degradation of Fuels; Task 2: Investigation of Incipient Deposition; Task 3: Characterization of Solid Gums, Sediments, and Carbonaceous Deposits; Task 4: Coal-Based Fuel Stabilization Studies; and Task 5: Exploratory Studies on the Direct Conversion of Coal to High Quality Jet Fuels. The major findings of each of these tasks are presented in this executive summary. A description of the sub-tasks performed under each of these tasks and the findings of those studies are provided in the remainder of this volume

  17. Synaptotoxicity of Alzheimer beta amyloid can be explained by its membrane perforating property.

    Directory of Open Access Journals (Sweden)

    Fernando J Sepulveda

    Full Text Available The mechanisms that induce Alzheimer's disease (AD are largely unknown thereby deterring the development of disease-modifying therapies. One working hypothesis of AD is that Abeta excess disrupts membranes causing pore formation leading to alterations in ionic homeostasis. However, it is largely unknown if this also occurs in native brain neuronal membranes. Here we show that similar to other pore forming toxins, Abeta induces perforation of neuronal membranes causing an increase in membrane conductance, intracellular calcium and ethidium bromide influx. These data reveal that the target of Abeta is not another membrane protein, but that Abeta itself is the cellular target thereby explaining the failure of current therapies to interfere with the course of AD. We propose that this novel effect of Abeta could be useful for the discovery of anti AD drugs capable of blocking these "Abeta perforates". In addition, we demonstrate that peptides that block Abeta neurotoxicity also slow or prevent the membrane-perforating action of Abeta.

  18. Population Games, Stable Games, and Passivity

    Directory of Open Access Journals (Sweden)

    Michael J. Fox

    2013-10-01

    Full Text Available The class of “stable games”, introduced by Hofbauer and Sandholm in 2009, has the attractive property of admitting global convergence to equilibria under many evolutionary dynamics. We show that stable games can be identified as a special case of the feedback-system-theoretic notion of a “passive” dynamical system. Motivated by this observation, we develop a notion of passivity for evolutionary dynamics that complements the definition of the class of stable games. Since interconnections of passive dynamical systems exhibit stable behavior, we can make conclusions about passive evolutionary dynamics coupled with stable games. We show how established evolutionary dynamics qualify as passive dynamical systems. Moreover, we exploit the flexibility of the definition of passive dynamical systems to analyze generalizations of stable games and evolutionary dynamics that include forecasting heuristics as well as certain games with memory.

  19. Applications of stable isotopes in clinical pharmacology

    NARCIS (Netherlands)

    Schellekens, Reinout C A; Stellaard, Frans; Woerdenbag, Herman J; Frijlink, Henderik W; Kosterink, Jos G W

    2011-01-01

    This review aims to present an overview of the application of stable isotope technology in clinical pharmacology. Three main categories of stable isotope technology can be distinguished in clinical pharmacology. Firstly, it is applied in the assessment of drug pharmacology to determine the

  20. Stable isotopes and biomarkers in microbial ecology

    NARCIS (Netherlands)

    Boschker, H.T.S.; Middelburg, J.J.

    2002-01-01

    The use of biomarkers in combination with stable isotope analysis is a new approach in microbial ecology and a number of papers on a variety of subjects have appeared. We will first discuss the techniques for analysing stable isotopes in biomarkers, primarily gas chromatography-combustion-isotope

  1. Modelling stable atmospheric boundary layers over snow

    NARCIS (Netherlands)

    Sterk, H.A.M.

    2015-01-01

    Thesis entitled:

    Modelling Stable Atmospheric Boundary Layers over Snow

    H.A.M. Sterk

    Wageningen, 29th of April, 2015

    Summary

    The emphasis of this thesis is on the understanding and forecasting of the Stable Boundary Layer (SBL) over snow-covered surfaces. SBLs

  2. Gas phase thermal diffusion of stable isotopes

    International Nuclear Information System (INIS)

    Eck, C.F.

    1979-01-01

    The separation of stable isotopes at Mound Facility is reviewed from a historical perspective. The historical development of thermal diffusion from a laboratory process to a separation facility that handles all the noble gases is described. In addition, elementary thermal diffusion theory and elementary cascade theory are presented along with a brief review of the uses of stable isotopes

  3. Structure of acid-stable carmine.

    Science.gov (United States)

    Sugimoto, Naoki; Kawasaki, Yoko; Sato, Kyoko; Aoki, Hiromitsu; Ichi, Takahito; Koda, Takatoshi; Yamazaki, Takeshi; Maitani, Tamio

    2002-02-01

    Acid-stable carmine has recently been distributed in the U.S. market because of its good acid stability, but it is not permitted in Japan. We analyzed and determined the structure of the major pigment in acid-stable carmine, in order to establish an analytical method for it. Carminic acid was transformed into a different type of pigment, named acid-stable carmine, through amination when heated in ammonia solution. The features of the structure were clarified using a model compound, purpurin, in which the orientation of hydroxyl groups on the A ring of the anthraquinone skeleton is the same as that of carminic acid. By spectroscopic means and the synthesis of acid-stable carmine and purpurin derivatives, the structure of the major pigment in acid-stable carmine was established as 4-aminocarminic acid, a novel compound.

  4. Ballooning stable high beta tokamak equilibria

    International Nuclear Information System (INIS)

    Tuda, Takashi; Azumi, Masafumi; Kurita, Gen-ichi; Takizuka, Tomonori; Takeda, Tatsuoki

    1981-04-01

    The second stable regime of ballooning modes is numerically studied by using the two-dimensional tokamak transport code with the ballooning stability code. Using the simple FCT heating scheme, we find that the plasma can locally enter this second stable regime. And we obtained equilibria with fairly high beta (β -- 23%) stable against ballooning modes in a whole plasma region, by taking into account of finite thermal diffusion due to unstable ballooning modes. These results show that a tokamak fusion reactor can operate in a high beta state, which is economically favourable. (author)

  5. Development of stable isotope manufacturing in Russia

    International Nuclear Information System (INIS)

    Pokidychev, A.; Pokidycheva, M.

    1999-01-01

    For the past 25 years, Russia has relied heavily on the electromagnetic separation process for the production of middle and heavy mass stable isotopes. The separation of most light isotopes had been centered in Georgia which, after the collapse of the USSR, left Russia without this capability. In the mid-1970s, development of centrifuge technology for the separation of stable isotopes was begun. Alternative techniques such as laser separation, physical-chemical methods, and ion cyclotron resonance have also been investigated. Economic considerations have played a major role in the development and current status of the stable isotope enrichment capabilities of Russia

  6. Stable Isotope Group 1982 progress report

    International Nuclear Information System (INIS)

    Stewart, M.K.

    1983-06-01

    The work of the Stable Isotope Group of the Institute of Nuclear Sciences during 1982, in the fields of isotope geology, isotope hydrology, geochronology, isotope biology and mass spectrometer instrumentation, is described

  7. Bartolome Island, Galapagos Stable Oxygen Calibration Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Galapagos Coral Stable Oxygen Calibration Data. Sites: Bartolome Island: 0 deg, 17'S, 90 deg 33' W. Champion Island: 1 deg, 15'S, 90 deg, 05' W. Urvina Bay (Isabela...

  8. Stable Isotope Group 1983 progress report

    International Nuclear Information System (INIS)

    Stewart, M.K.

    1984-06-01

    The work of the Stable Isotope Group of the Institute of Nuclear Sciences in the fields of isotope geology, isotope hydrology, geochronology, isotope biology and related fields, and mass spectrometer instrumentation, during 1983, is described

  9. Stable atomic hydrogen: Polarized atomic beam source

    International Nuclear Information System (INIS)

    Niinikoski, T.O.; Penttilae, S.; Rieubland, J.M.; Rijllart, A.

    1984-01-01

    We have carried out experiments with stable atomic hydrogen with a view to possible applications in polarized targets or polarized atomic beam sources. Recent results from the stabilization apparatus are described. The first stable atomic hydrogen beam source based on the microwave extraction method (which is being tested ) is presented. The effect of the stabilized hydrogen gas density on the properties of the source is discussed. (orig.)

  10. Local Search Approaches in Stable Matching Problems

    Directory of Open Access Journals (Sweden)

    Toby Walsh

    2013-10-01

    Full Text Available The stable marriage (SM problem has a wide variety of practical applications, ranging from matching resident doctors to hospitals, to matching students to schools or, more generally, to any two-sided market. In the classical formulation, n men and n women express their preferences (via a strict total order over the members of the other sex. Solving an SM problem means finding a stable marriage where stability is an envy-free notion: no man and woman who are not married to each other would both prefer each other to their partners or to being single. We consider both the classical stable marriage problem and one of its useful variations (denoted SMTI (Stable Marriage with Ties and Incomplete lists where the men and women express their preferences in the form of an incomplete preference list with ties over a subset of the members of the other sex. Matchings are permitted only with people who appear in these preference lists, and we try to find a stable matching that marries as many people as possible. Whilst the SM problem is polynomial to solve, the SMTI problem is NP-hard. We propose to tackle both problems via a local search approach, which exploits properties of the problems to reduce the size of the neighborhood and to make local moves efficiently. We empirically evaluate our algorithm for SM problems by measuring its runtime behavior and its ability to sample the lattice of all possible stable marriages. We evaluate our algorithm for SMTI problems in terms of both its runtime behavior and its ability to find a maximum cardinality stable marriage. Experimental results suggest that for SM problems, the number of steps of our algorithm grows only as O(n log(n, and that it samples very well the set of all stable marriages. It is thus a fair and efficient approach to generate stable marriages. Furthermore, our approach for SMTI problems is able to solve large problems, quickly returning stable matchings of large and often optimal size, despite the

  11. Metabolic studies in man using stable isotopes

    International Nuclear Information System (INIS)

    Faust, H.; Jung, K.; Krumbiegel, P.

    1993-01-01

    In this project, stable isotope compounds and stable isotope pharmaceuticals were used (with emphasis on the application of 15 N) to study several aspects of nitrogen metabolism in man. Of the many methods available, the 15 N stable isotope tracer technique holds a special position because the methodology for application and nitrogen isotope analysis is proven and reliable. Valid routine methods using 15 N analysis by emission spectrometry have been demonstrated. Several methods for the preparation of biological material were developed during our participation in the Coordinated Research Programme. In these studies, direct procedures (i.e. use of diluted urine as a samples without chemical preparation) or rapid isolation methods were favoured. Within the scope of the Analytical Quality Control Service (AQCS) enriched stable isotope reference materials for medical and biological studies were prepared and are now available through the International Atomic Energy Agency. The materials are of special importance as the increasing application of stable isotopes as tracers in medical, biological and agricultural studies has focused interest on reliable measurements of biological material of different origin. 24 refs

  12. Perspective: Highly stable vapor-deposited glasses

    Science.gov (United States)

    Ediger, M. D.

    2017-12-01

    This article describes recent progress in understanding highly stable glasses prepared by physical vapor deposition and provides perspective on further research directions for the field. For a given molecule, vapor-deposited glasses can have higher density and lower enthalpy than any glass that can be prepared by the more traditional route of cooling a liquid, and such glasses also exhibit greatly enhanced kinetic stability. Because vapor-deposited glasses can approach the bottom of the amorphous part of the potential energy landscape, they provide insights into the properties expected for the "ideal glass." Connections between vapor-deposited glasses, liquid-cooled glasses, and deeply supercooled liquids are explored. The generality of stable glass formation for organic molecules is discussed along with the prospects for stable glasses of other types of materials.

  13. Concentration of stable elements in food products

    International Nuclear Information System (INIS)

    Montford, M.A.; Shank, K.E.; Hendricks, C.; Oakes, T.W.

    1980-01-01

    Food samples were taken from commercial markets and analyzed for stable element content. The concentrations of most stable elements (Ag, Al, As, Au, Ba, Br, Ca, Ce, Cl, Co, Cr, Cs, Cu, Fe, Hf, I, K, La, Mg, Mn, Mo, Na, Rb, Sb, Sc, Se, Sr, Ta, Th, Ti, V, Zn, Zr) were determined using multiple-element neutron activation analysis, while the concentrations of other elements (Cd, Hg, Ni, Pb) were determined using atomic absorption. The relevance of the concentrations found are noted in relation to other literature values. An earlier study was extended to include the determination of the concentration of stable elements in home-grown products in the vicinity of the Oak Ridge National Laboratory. Comparisons between the commercial and local food-stuff values are discussed

  14. Stable Chimeras and Independently Synchronizable Clusters

    Science.gov (United States)

    Cho, Young Sul; Nishikawa, Takashi; Motter, Adilson E.

    2017-08-01

    Cluster synchronization is a phenomenon in which a network self-organizes into a pattern of synchronized sets. It has been shown that diverse patterns of stable cluster synchronization can be captured by symmetries of the network. Here, we establish a theoretical basis to divide an arbitrary pattern of symmetry clusters into independently synchronizable cluster sets, in which the synchronization stability of the individual clusters in each set is decoupled from that in all the other sets. Using this framework, we suggest a new approach to find permanently stable chimera states by capturing two or more symmetry clusters—at least one stable and one unstable—that compose the entire fully symmetric network.

  15. On some topological properties of stable measures

    DEFF Research Database (Denmark)

    Nielsen, Carsten Krabbe

    1996-01-01

    Summary The paper shows that the set of stable probability measures and the set of Rational Beliefs relative to a given stationary measure are closed in the strong topology, but not closed in the topology of weak convergence. However, subsets of the set of stable probability measures which...... are characterized by uniformity of convergence of the empirical distribution are closed in the topology of weak convergence. It is demonstrated that such subsets exist. In particular, there is an increasing sequence of sets of SIDS measures who's union is the set of all SIDS measures generated by a particular...... system and such that each subset consists of stable measures. The uniformity requirement has a natural interpretation in terms of plausibility of Rational Beliefs...

  16. Faster and Simpler Approximation of Stable Matchings

    Directory of Open Access Journals (Sweden)

    Katarzyna Paluch

    2014-04-01

    Full Text Available We give a 3 2 -approximation algorithm for finding stable matchings that runs in O(m time. The previous most well-known algorithm, by McDermid, has the same approximation ratio but runs in O(n3/2m time, where n denotes the number of people andm is the total length of the preference lists in a given instance. In addition, the algorithm and the analysis are much simpler. We also give the extension of the algorithm for computing stable many-to-many matchings.

  17. Moving stable solitons in Galileon theory

    International Nuclear Information System (INIS)

    Masoumi, Ali; Xiao Xiao

    2012-01-01

    Despite the no-go theorem Endlich et al. (2011) which rules out static stable solitons in Galileon theory, we propose a family of solitons that evade the theorem by traveling at the speed of light. These domain-wall-like solitons are stable under small fluctuations-analysis of perturbation shows neither ghost-like nor tachyon-like instabilities, and perturbative collision of these solitons suggests that they pass through each other asymptotically, which maybe an indication of the integrability of the theory itself.

  18. Bordism, stable homotopy and adams spectral sequences

    CERN Document Server

    Kochman, Stanley O

    1996-01-01

    This book is a compilation of lecture notes that were prepared for the graduate course "Adams Spectral Sequences and Stable Homotopy Theory" given at The Fields Institute during the fall of 1995. The aim of this volume is to prepare students with a knowledge of elementary algebraic topology to study recent developments in stable homotopy theory, such as the nilpotence and periodicity theorems. Suitable as a text for an intermediate course in algebraic topology, this book provides a direct exposition of the basic concepts of bordism, characteristic classes, Adams spectral sequences, Brown-Peter

  19. Stable isotopes in Lithuanian bioarcheological material

    Science.gov (United States)

    Skipityte, Raminta; Jankauskas, Rimantas; Remeikis, Vidmantas

    2015-04-01

    Investigation of bioarcheological material of ancient human populations allows us to understand the subsistence behavior associated with various adaptations to the environment. Feeding habits are essential to the survival and growth of ancient populations. Stable isotope analysis is accepted tool in paleodiet (Schutkowski et al, 1999) and paleoenvironmental (Zernitskaya et al, 2014) studies. However, stable isotopes can be useful not only in investigating human feeding habits but also in describing social and cultural structure of the past populations (Le Huray and Schutkowski, 2005). Only few stable isotope investigations have been performed before in Lithuanian region suggesting a quite uniform diet between males and females and protein intake from freshwater fish and animal protein. Previously, stable isotope analysis has only been used to study a Stone Age population however, more recently studies have been conducted on Iron Age and Late medieval samples (Jacobs et al, 2009). Anyway, there was a need for more precise examination. Stable isotope analysis were performed on human bone collagen and apatite samples in this study. Data represented various ages (from 5-7th cent. to 18th cent.). Stable carbon and nitrogen isotope analysis on medieval populations indicated that individuals in studied sites in Lithuania were almost exclusively consuming C3 plants, C3 fed terrestrial animals, and some freshwater resources. Current investigation demonstrated social differences between elites and country people and is promising in paleodietary and daily life reconstruction. Acknowledgement I thank prof. dr. G. Grupe, Director of the Anthropological and Palaeoanatomical State Collection in Munich for providing the opportunity to work in her laboratory. The part of this work was funded by DAAD. Antanaitis-Jacobs, Indre, et al. "Diet in early Lithuanian prehistory and the new stable isotope evidence." Archaeologia Baltica 12 (2009): 12-30. Le Huray, Jonathan D., and Holger

  20. Unconditionally stable microwave Si-IMPATT amplifiers

    International Nuclear Information System (INIS)

    Seddik, M.M.

    1986-07-01

    The purpose of this investigation has been the development of an improved understanding of the design and analysis of microwave reflection amplifiers employing the negative resistance property of the IMPATT devices. Unconditionally stable amplifier circuit using a Silicon IMPATT diode is designed. The problems associated with the design procedures and the stability criterion are discussed. A computer program is developed to perform the computations. The stable characteristics of a reflection-type Si-IMPATT amplifier, such as gain, frequency and bandwidth are examined. It was found that at large signal drive levels, 7 dB gain with bandwidth of 800 MHz at 22,5 mA was obtained. (author)

  1. petrography, compositional characteristics and stable isotope ...

    African Journals Online (AJOL)

    PROF EKWUEME

    Subsurface samples of the predominantly carbonate Ewekoro Formation, obtained from Ibese core hole within the Dahomey basin were used in this study. Investigations entail petrographic, elemental composition as well as stable isotopes (carbon and oxygen) geochemistry in order to deduce the different microfacies and ...

  2. Working conditions remain stable in the Netherlands

    NARCIS (Netherlands)

    Houtman, I.; Hooftman, W.

    2008-01-01

    Despite significant changes in the national questionnaires on work and health, the quality of work as well as health complaints in the Netherlands appear to be relatively stable. Pace of work seems to be on the increase again and more people are working in excess of their contractual hours.

  3. Thermally stable sintered porous metal articles

    International Nuclear Information System (INIS)

    Gombach, A.L.; Thellmann, E.L.

    1980-01-01

    A sintered porous metal article is provided which is essentially thermally stable at elevated temperatures. In addition, a method for producing such an article is also provided which method comprises preparing a blend of base metal particles and active dispersoid particles, forming the mixture into an article of the desired shape, and heating the so-formed article at sintering temperatures

  4. TOF for heavy stable particle identification

    International Nuclear Information System (INIS)

    Chang, C.Y.

    1983-01-01

    Searching for heavy stable particle production in a new energy region of hadron-hadron collisions is of fundamental theoretical interest. Observation of such particles produced in high energy collisions would indicate the existence of stable heavy leptons or any massive hadronic system carrying new quantum numbers. Experimentally, evidence of its production has not been found for PP collisions either at FNAL or at the CERN ISR for √S = 23 and 62 GeV respectively. However, many theories beyond the standard model do predict its existence on a mass scale ranging from 50 to a few hundred GeV. If so, it would make a high luminosity TeV collider an extremely ideal hunting ground for searching the production of such a speculated object. To measure the mass of a heavy stable charged particle, one usually uses its time of flight (TOF) and/or dE/dX information. For heavy neutral particle, one hopes it may decay at some later time after its production. Hence a pair of jets or a jet associated with a high P/sub t/ muon originated from some places other than the interacting point (IP) of the colliding beams may be a good signal. In this note, we examine the feasibility of TOF measurement on a heavy stable particle produced in PP collisions at √S = 1 TeV and a luminosity of 10 33 cm -2 sec -1 with a single arm spectrometer pointing to the IP

  5. Axisymmetric MHD stable sloshing ion distributions

    International Nuclear Information System (INIS)

    Berk, H.L.; Dominguez, N.; Roslyakov, G.V.

    1986-07-01

    The MHD stability of a sloshing ion distribution is investigated in a symmetric mirror cell. Fokker-Planck calculations show that stable configurations are possible for ion injection energies that are at least 150 times greater than the electron temperture. Special axial magnetic field profiles are suggested to optimize the favorable MHD properties

  6. Exact simulation of max-stable processes.

    Science.gov (United States)

    Dombry, Clément; Engelke, Sebastian; Oesting, Marco

    2016-06-01

    Max-stable processes play an important role as models for spatial extreme events. Their complex structure as the pointwise maximum over an infinite number of random functions makes their simulation difficult. Algorithms based on finite approximations are often inexact and computationally inefficient. We present a new algorithm for exact simulation of a max-stable process at a finite number of locations. It relies on the idea of simulating only the extremal functions, that is, those functions in the construction of a max-stable process that effectively contribute to the pointwise maximum. We further generalize the algorithm by Dieker & Mikosch (2015) for Brown-Resnick processes and use it for exact simulation via the spectral measure. We study the complexity of both algorithms, prove that our new approach via extremal functions is always more efficient, and provide closed-form expressions for their implementation that cover most popular models for max-stable processes and multivariate extreme value distributions. For simulation on dense grids, an adaptive design of the extremal function algorithm is proposed.

  7. Unconditionally stable integration of Maxwell's equations

    NARCIS (Netherlands)

    Verwer, J.G.; Bochev, Mikhail A.

    Numerical integration of Maxwell's equations is often based on explicit methods accepting a stability step size restriction. In literature evidence is given that there is also a need for unconditionally stable methods, as exemplified by the successful alternating direction implicit finite difference

  8. Unconditionally stable integration of Maxwell's equations

    NARCIS (Netherlands)

    J.G. Verwer (Jan); M.A. Botchev

    2008-01-01

    htmlabstractNumerical integration of Maxwell''s equations is often based on explicit methods accepting a stability step size restriction. In literature evidence is given that there is also a need for unconditionally stable methods, as exemplified by the successful alternating direction

  9. Unconditionally stable integration of Maxwell's equations

    NARCIS (Netherlands)

    J.G. Verwer (Jan); M.A. Botchev

    2009-01-01

    textabstractNumerical integration of Maxwell’s equations is often based on explicit methods accepting a stability step size restriction. In literature evidence is given that there is also a need for unconditionally stable methods, as exemplified by the successful alternating direction implicit –

  10. Method of producing thermally stable uranium carbonitrides

    International Nuclear Information System (INIS)

    Ugajin, M.; Takahashi, I.

    1975-01-01

    A thermally stable uranium carbonitride can be produced by adding tungsten and/or molybdenum in the amount of 0.2 wt percent or more, preferably 0.5 wt percent or more, to a pure uranium carbonitride. (U.S.)

  11. Champion Island, Galapagos Stable Oxygen Calibration Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Galapagos Coral Stable Oxygen Calibration Data. Sites: Bartolome Island: 0 deg, 17 min S, 90 deg 33 min W. Champion Island: 1 deg, 15 min S, 90 deg, 05 min W. Urvina...

  12. 26 S proteasomes function as stable entities

    DEFF Research Database (Denmark)

    Hendil, Klavs B; Hartmann-Petersen, Rasmus; Tanaka, Keiji

    2002-01-01

    , shuttles between a free state and the 26-S proteasome, bringing substrate to the complex. However, S5a was not found in the free state in HeLa cells. Besides, all subunits in PA700, including S5a, exchanged at similar low rates. It therefore seems that 26-S proteasomes function as stable entities during...

  13. Formal derivation of a stable marriage algorithm.

    NARCIS (Netherlands)

    Bijlsma, A.

    1991-01-01

    In this paper the well-known Stable Marriage Problem is considered once again. The name of this programming problem comes from the terms in which it was first described [2]: A certain community consists of n men and n women. Each person ranks those of the opposite sex in accordance with his or

  14. The Nature of Stable Insomnia Phenotypes

    Science.gov (United States)

    Pillai, Vivek; Roth, Thomas; Drake, Christopher L.

    2015-01-01

    Study Objectives: We examined the 1-y stability of four insomnia symptom profiles: sleep onset insomnia; sleep maintenance insomnia; combined onset and maintenance insomnia; and neither criterion (i.e., insomnia cases that do not meet quantitative thresholds for onset or maintenance problems). Insomnia cases that exhibited the same symptom profile over a 1-y period were considered to be phenotypes, and were compared in terms of clinical and demographic characteristics. Design: Longitudinal. Setting: Urban, community-based. Participants: Nine hundred fifty-four adults with Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition based current insomnia (46.6 ± 12.6 y; 69.4% female). Interventions: None. Measurements and results: At baseline, participants were divided into four symptom profile groups based on quantitative criteria. Follow-up assessment 1 y later revealed that approximately 60% of participants retained the same symptom profile, and were hence judged to be phenotypes. Stability varied significantly by phenotype, such that sleep onset insomnia (SOI) was the least stable (42%), whereas combined insomnia (CI) was the most stable (69%). Baseline symptom groups (cross-sectionally defined) differed significantly across various clinical indices, including daytime impairment, depression, and anxiety. Importantly, however, a comparison of stable phenotypes (longitudinally defined) did not reveal any differences in impairment or comorbid psychopathology. Another interesting finding was that whereas all other insomnia phenotypes showed evidence of an elevated wake drive both at night and during the day, the “neither criterion” phenotype did not; this latter phenotype exhibited significantly higher daytime sleepiness despite subthreshold onset and maintenance difficulties. Conclusions: By adopting a stringent, stability-based definition, this study offers timely and important data on the longitudinal trajectory of specific insomnia phenotypes. With

  15. Strontium stable isotope behaviour accompanying basalt weathering

    Science.gov (United States)

    Burton, K. W.; Parkinson, I. J.; Gíslason, S. G. R.

    2016-12-01

    The strontium (Sr) stable isotope composition of rivers is strongly controlled by the balance of carbonate to silicate weathering (Krabbenhöft et al. 2010; Pearce et al. 2015). However, rivers draining silicate catchments possess distinctly heavier Sr stable isotope values than their bedrock compositions, pointing to significant fractionation during weathering. Some have argued for preferential release of heavy Sr from primary phases during chemical weathering, others for the formation of secondary weathering minerals that incorporate light isotopes. This study presents high-precision double-spike Sr stable isotope data for soils, rivers, ground waters and estuarine waters from Iceland, reflecting both natural weathering and societal impacts on those environments. The bedrock in Iceland is dominantly basaltic, d88/86Sr ≈ +0.27, extending to lighter values for rhyolites. Geothermal waters range from basaltic Sr stable compositions to those akin to seawater. Soil pore waters reflect a balance of input from primary mineral weathering, precipitation and litter recycling and removal into secondary phases and vegetation. Rivers and ground waters possess a wide range of d88/86Sr compositions from +0.101 to +0.858. Elemental and isotope data indicate that this fractionation primarily results from the formation or dissolution of secondary zeolite (d88/86Sr ≈ +0.10), but also carbonate (d88/86Sr ≈ +0.22) and sometimes anhydrite (d88/86Sr ≈ -0.73), driving the residual waters to heavier or lighter values, respectively. Estuarine waters largely reflect mixing with seawater, but are also be affected by adsorption onto particulates, again driving water to heavy values. Overall, these data indicate that the stability and nature of secondary weathering phases, exerts a strong control on the Sr stable isotope composition of silicate rivers. [1] Krabbenhöft et al. (2010) Geochim. Cosmochim. Acta 74, 4097-4109. [2] Pearce et al. (2015) Geochim. Cosmochim. Acta 157, 125-146.

  16. Development of a Safety Management Web Tool for Horse Stables.

    Science.gov (United States)

    Leppälä, Jarkko; Kolstrup, Christina Lunner; Pinzke, Stefan; Rautiainen, Risto; Saastamoinen, Markku; Särkijärvi, Susanna

    2015-11-12

    Managing a horse stable involves risks, which can have serious consequences for the stable, employees, clients, visitors and horses. Existing industrial or farm production risk management tools are not directly applicable to horse stables and they need to be adapted for use by managers of different types of stables. As a part of the InnoEquine project, an innovative web tool, InnoHorse, was developed to support horse stable managers in business, safety, pasture and manure management. A literature review, empirical horse stable case studies, expert panel workshops and stakeholder interviews were carried out to support the design. The InnoHorse web tool includes a safety section containing a horse stable safety map, stable safety checklists, and examples of good practices in stable safety, horse handling and rescue planning. This new horse stable safety management tool can also help in organizing work processes in horse stables in general.

  17. Fundamentals of the LISA stable flight formation

    International Nuclear Information System (INIS)

    Dhurandhar, S V; Nayak, K Rajesh; Koshti, S; Vinet, J-Y

    2005-01-01

    The joint NASA-ESA mission, LISA, relies crucially on the stability of the three-spacecraft constellation. Each of the spacecraft is in heliocentric orbit forming a stable triangle. In this paper we explicitly show with the help of the Clohessy-Wiltshire equations that any configuration of spacecraft lying in the planes making angles of ±60 0 with the ecliptic and given suitable initial velocities within the plane, can be made stable in the sense that the inter-spacecraft distances remain constant to first order in the dimensions of the configuration compared with the distance to the Sun. Such analysis would be useful in order to carry out theoretical studies on the optical links, simulators, etc

  18. A model for a stable coronal loop

    International Nuclear Information System (INIS)

    Hoven, G.V.; Chiuderi, C.; Giachetti, R.

    1977-01-01

    We present here a new plasma-physics model of a stable active-region arch which corresponds to the structure observed in the EUV. Pressure gradients are seen, so that the equilibrium magnetic field must depart from the force-free form valid in the surrounding corona. We take advantage of the data and of the approximate cylindrical symmetry to develop a modified form of the commonly assumed sheared-spiral structure. The dynamic MHD behavior of this new pressure/field model is then evaluated by the Newcomb criterion, taken from controlled-fusion physics, and the results show short-wavelength stability in a specific parameter range. Thus we demonstrate the possibility, for pressure profiles with widths of the order of the magnetic-field scale, that such arches can persist for reasonable periods. Finally, the spatial proportions and magnetic fields of a characteristic stable coronal loop are described

  19. Utilization of stable isotopes in medicine

    International Nuclear Information System (INIS)

    1980-11-01

    The ten lectures given at this round table are presented together with a discussion. Five lectures, relating to studies in which deuterium oxide was employed as a tracer of body water, dealt with pulmonary water measurements in man and animals, the total water pool in adipose subjects, and liquid compartments in children undergoing hemodyalisis. The heavy water is analysed by infrared spectrometry and a new double spectrodoser is described. Two studies using 13 C as tracer, described the diagnosis of liver troubles and diabetes respectively. A general review of the perspectives of the application of stable isotopes in clinical medicine is followed by a comparison of the use of stable and radioactive isotopes in France [fr

  20. Stable isotope enrichment: Current and future potential

    International Nuclear Information System (INIS)

    Tracy, J.G.; Aaron, W.S.

    1992-01-01

    Oak Ridge National Laboratory (ORNL) operates the Isotope Enrichment Facility for the purpose of providing enriched stable isotopes, selected radioactive isotopes (including the actinides), and isotope-related materials and services for use in various research applications. ORNL is responsible for isotope enrichment and the distribution of approximately 225 nongaseous stable isotopes from 50 multi-isotopic elements. Many enriched isotope products are of prime importance in the fabrication of nuclear targets and the subsequent production of special radionuclides. State-of-the-art techniques to achieve special isotopic, chemical, and physical requirements are performed at ORNL This report describes the status and capabilities of the Isotope Enrichment Facility and the Isotope Research Materials Laboratory as well as emphasizing potential advancements in enrichment capabilities

  1. Stable plastid transformation in Scoparia dulcis L.

    Science.gov (United States)

    Muralikrishna, Narra; Srinivas, Kota; Kumar, Kalva Bharath; Sadanandam, Abbagani

    2016-10-01

    In the present investigation we report stable plastid transformation in Scoparia dulcis L., a versatile medicinal herb via particle gun method. The vector KNTc, harbouring aadA as a selectable marker and egfp as a reporter gene which were under the control of synthetic promoter pNG1014a, targets inverted repeats, trnR / t rnN of the plastid genome. By use of this heterologous vector, recovery of transplastomic lines with suitable selection protocol have been successfully established with overall efficiency of two transgenic lines for 25 bombarded leaf explants. PCR and Southern blot analysis demonstrated stable integration of foreign gene into the target sequences. The results represent a significant advancement of the plastid transformation technology in medicinal plants, which relevantly implements a change over in enhancing and regulating of certain metabolic pathways.

  2. On The Roman Domination Stable Graphs

    Directory of Open Access Journals (Sweden)

    Hajian Majid

    2017-11-01

    Full Text Available A Roman dominating function (or just RDF on a graph G = (V,E is a function f : V → {0, 1, 2} satisfying the condition that every vertex u for which f(u = 0 is adjacent to at least one vertex v for which f(v = 2. The weight of an RDF f is the value f(V (G = Pu2V (G f(u. The Roman domination number of a graph G, denoted by R(G, is the minimum weight of a Roman dominating function on G. A graph G is Roman domination stable if the Roman domination number of G remains unchanged under removal of any vertex. In this paper we present upper bounds for the Roman domination number in the class of Roman domination stable graphs, improving bounds posed in [V. Samodivkin, Roman domination in graphs: the class RUV R, Discrete Math. Algorithms Appl. 8 (2016 1650049].

  3. Design of optically stable image reflector system.

    Science.gov (United States)

    Tsai, Chung-Yu

    2013-08-01

    The design of a partially optically stable (POS) reflector system, in which the exit ray direction and image pose are unchanged as the reflector system rotates about a specific directional vector, was presented in an earlier study by the current group [Appl. Phys. B100, 883-890 (2010)]. The present study further proposes an optically stable image (OSI) reflector system, in which not only is the optical stability property of the POS system retained, but the image position and total ray path length are also fixed. An analytical method is proposed for the design of OSI reflector systems comprising multiple reflectors. The validity of the proposed approach is demonstrated by means of two illustrative examples.

  4. Formation of stable radicals during perfluoroalkane radiolysis

    International Nuclear Information System (INIS)

    Allayarov, S.R.; Demidov, S.V.; Kiryukhin, D.P.; Mikhajlov, A.I.; Barkalov, I.M.

    1984-01-01

    Accumulation and stabilization kinetics of perfluoroalkyls during α-radiolysis ( 60 Co) of perfluoralkanes (PFA) in a wide temperature range for different PFA fractions differing in the average molecular weight, is investigated. It is noted that low temperature (PFA) radiolysis (77 K) is of a linear nature of accumulation of stabilized radicals up to doses of approximately 700 KGy. In the case of PFA radiolysis at 300 K radiation yields of stable radicals are somewhat lower than at 47 K and at doses of 200-300 KGy, their accumulation ceases. It is shown that kinetics of formation and accumulation of stable radicals does not depend on molecular mass and PFA fraction viscosity. Perfluoroalkyl stability is explained by intra molecular conformation spheric insulation of the free valency. Perfluoroalkyl stability in different PFA fractions in a wide time range in different media is investigated

  5. Stable isotope enrichment - current and future potential

    International Nuclear Information System (INIS)

    Tracy, J.G.; Aaron, W.S.

    1993-01-01

    Oak Ridge National Laboratory (ORNL) operates the Isotope Enrichment Facility for the purpose of providing enriched stable isotopes, selected radioactive isotopes (including the actinides), and isotope-related materials and services for use in various research applications. ORNL is responsible for isotope enrichment and the distribution of approximately 225 nongaseous stable isotopes from 50 multi-isotopic elements. Many enriched isotope products are of prime importance in the fabrication of nuclear targets and the subsequent production of special radionuclides. State-of-the-art techniques to achieve special isotopic, chemical, and physical requirements are performed at ORNL. This report describes the status and capabilities of the Isotope Enrichment Facility and the Isotope Research Materials Laboratory as well as emphasizing potential advancements in enrichment capabilities. (orig.)

  6. Optimization of Parameters of Asymptotically Stable Systems

    Directory of Open Access Journals (Sweden)

    Anna Guerman

    2011-01-01

    Full Text Available This work deals with numerical methods of parameter optimization for asymptotically stable systems. We formulate a special mathematical programming problem that allows us to determine optimal parameters of a stabilizer. This problem involves solutions to a differential equation. We show how to chose the mesh in order to obtain discrete problem guaranteeing the necessary accuracy. The developed methodology is illustrated by an example concerning optimization of parameters for a satellite stabilization system.

  7. Multi-Stable Morphing Cellular Structures

    Science.gov (United States)

    2015-05-14

    stiffness on critical buckling load and arch stres - ses. It should be noted that although the arches in these studies snapped-through, they did not...switch roles in moving the VMT back from the second to the first stable equilibrium state. A prototype is designed and fabricated and the transition...pulling forward on the insert on the right blade and assisting its deployment. During this process the cable 3-4-1 goes slack and plays no role , but if

  8. The nature of stable insomnia phenotypes.

    Science.gov (United States)

    Pillai, Vivek; Roth, Thomas; Drake, Christopher L

    2015-01-01

    We examined the 1-y stability of four insomnia symptom profiles: sleep onset insomnia; sleep maintenance insomnia; combined onset and maintenance insomnia; and neither criterion (i.e., insomnia cases that do not meet quantitative thresholds for onset or maintenance problems). Insomnia cases that exhibited the same symptom profile over a 1-y period were considered to be phenotypes, and were compared in terms of clinical and demographic characteristics. Longitudinal. Urban, community-based. Nine hundred fifty-four adults with Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition based current insomnia (46.6 ± 12.6 y; 69.4% female). None. At baseline, participants were divided into four symptom profile groups based on quantitative criteria. Follow-up assessment 1 y later revealed that approximately 60% of participants retained the same symptom profile, and were hence judged to be phenotypes. Stability varied significantly by phenotype, such that sleep onset insomnia (SOI) was the least stable (42%), whereas combined insomnia (CI) was the most stable (69%). Baseline symptom groups (cross-sectionally defined) differed significantly across various clinical indices, including daytime impairment, depression, and anxiety. Importantly, however, a comparison of stable phenotypes (longitudinally defined) did not reveal any differences in impairment or comorbid psychopathology. Another interesting finding was that whereas all other insomnia phenotypes showed evidence of an elevated wake drive both at night and during the day, the 'neither criterion' phenotype did not; this latter phenotype exhibited significantly higher daytime sleepiness despite subthreshold onset and maintenance difficulties. By adopting a stringent, stability-based definition, this study offers timely and important data on the longitudinal trajectory of specific insomnia phenotypes. With the exception of daytime sleepiness, few clinical differences are apparent across stable phenotypes.

  9. Strongly stable real infinitesimally symplectic mappings

    NARCIS (Netherlands)

    Cushman, R.; Kelley, A.

    We prove that a mapA εsp(σ,R), the set of infinitesimally symplectic maps, is strongly stable if and only if its centralizerC(A) insp(σ,R) contains only semisimple elements. Using the theorem that everyB insp(σ,R) close toA is conjugate by a real symplectic map to an element ofC(A), we give a new

  10. A belief-based evolutionarily stable strategy

    OpenAIRE

    Deng, Xinyang; Wang, Zhen; Liu, Qi; Deng, Yong; Mahadevan, Sankaran

    2014-01-01

    As an equilibrium refinement of the Nash equilibrium, evolutionarily stable strategy (ESS) is a key concept in evolutionary game theory and has attracted growing interest. An ESS can be either a pure strategy or a mixed strategy. Even though the randomness is allowed in mixed strategy, the selection probability of pure strategy in a mixed strategy may fluctuate due to the impact of many factors. The fluctuation can lead to more uncertainty. In this paper, such uncertainty involved in mixed st...

  11. Mechanical Properties of Stable Glasses Using Nanoindentation

    Science.gov (United States)

    Wolf, Sarah; Liu, Tianyi; Jiang, Yijie; Ablajan, Keyume; Zhang, Yue; Walsh, Patrick; Turner, Kevin; Fakhraai, Zahra

    Glasses with enhanced stability over ordinary, liquid quenched glasses have been formed via the process of Physical Vapor Deposition (PVD) by using a sufficiently slow deposition rate and a substrate temperature slightly below the glass transition temperature. These stable glasses have been shown to exhibit higher density, lower enthalpy, and better kinetic stability over ordinary glass, and are typically optically birefringent, due to packing and orientational anisotropy. Given these exceptional properties, it is of interest to further investigate how the properties of stable glasses compare to those of ordinary glass. In particular, the mechanical properties of stable glasses remain relatively under-investigated. While the speed of sound and elastic moduli have been shown to increase with increased stability, little is known about their hardness and fracture toughness compared to ordinary glasses. In this study, glasses of 9-(3,5-di(naphthalen-1-yl)phenyl)anthracene were deposited at varying temperatures relative to their glass transition temperature, and their mechanical properties measured by nanoindentation. Hardness and elastic modulus of the glasses were compared across substrate temperatures. After indentation, the topography of these films were studied using Atomic Force Microscopy (AFM) in order to further compare the relationship between thermodynamic and kinetic stability and mechanical failure. Z.F. and P.W. acknowledge funding from NSF(DMREF-1628407).

  12. Detonation of Meta-stable Clusters

    Energy Technology Data Exchange (ETDEWEB)

    Kuhl, Allen; Kuhl, Allen L.; Fried, Laurence E.; Howard, W. Michael; Seizew, Michael R.; Bell, John B.; Beckner, Vincent; Grcar, Joseph F.

    2008-05-31

    We consider the energy accumulation in meta-stable clusters. This energy can be much larger than the typical chemical bond energy (~;;1 ev/atom). For example, polymeric nitrogen can accumulate 4 ev/atom in the N8 (fcc) structure, while helium can accumulate 9 ev/atom in the excited triplet state He2* . They release their energy by cluster fission: N8 -> 4N2 and He2* -> 2He. We study the locus of states in thermodynamic state space for the detonation of such meta-stable clusters. In particular, the equilibrium isentrope, starting at the Chapman-Jouguet state, and expanding down to 1 atmosphere was calculated with the Cheetah code. Large detonation pressures (3 and 16 Mbar), temperatures (12 and 34 kilo-K) and velocities (20 and 43 km/s) are a consequence of the large heats of detonation (6.6 and 50 kilo-cal/g) for nitrogen and helium clusters respectively. If such meta-stable clusters could be synthesized, they offer the potential for large increases in the energy density of materials.

  13. Clinically stable angina pectoris is not necessarily associated with histologically stable atherosclerotic plaques

    NARCIS (Netherlands)

    van der Wal, A. C.; Becker, A. E.; Koch, K. T.; Piek, J. J.; Teeling, P.; van der Loos, C. M.; David, G. K.

    1996-01-01

    OBJECTIVE: To investigate the extent of plaque inflammation in culprit lesions of patients with chronic stable angina. DESIGN: Retrospective study. SETTING: Amsterdam reference centre. SUBJECTS: 89 consecutive patients who underwent directional coronary atherectomy, 58 of whom met the following

  14. Stable isogeometric analysis of trimmed geometries

    Science.gov (United States)

    Marussig, Benjamin; Zechner, Jürgen; Beer, Gernot; Fries, Thomas-Peter

    2017-04-01

    We explore extended B-splines as a stable basis for isogeometric analysis with trimmed parameter spaces. The stabilization is accomplished by an appropriate substitution of B-splines that may lead to ill-conditioned system matrices. The construction for non-uniform knot vectors is presented. The properties of extended B-splines are examined in the context of interpolation, potential, and linear elasticity problems and excellent results are attained. The analysis is performed by an isogeometric boundary element formulation using collocation. It is argued that extended B-splines provide a flexible and simple stabilization scheme which ideally suits the isogeometric paradigm.

  15. The observation of a stable dibaryon

    International Nuclear Information System (INIS)

    Shakhbazyan, B.A.; Sashin, V.A.; Kecheryan, A.O.; Martynov, A.S.

    1989-01-01

    V 0 -particle which is unambiguously interpreted as a weak decay of the stable dibaryon value of cross section H→p+Σ - ,Σ→n+π - is observed. Its mass is M H =(2218+-12) MeV c 2 with a standard deviation S=12 MeV/c 2 and the error of the mean σ=2.8 MeV/c 2 . The investigation has been performed at the Laboratory of High energies, JINR. 10 refs.; 1 fig.; 3 tabs

  16. Protein labelling with stable isotopes: strategies

    International Nuclear Information System (INIS)

    Lirsac, P.N.; Gilles, N.; Jamin, N.; Toma, F.; Gabrielsen, O.; Boulain, J.C.; Menez, A.

    1994-01-01

    A protein labelling technique with stable isotopes has been developed at the CEA: a labelled complete medium has been developed, performing as well as the Luria medium, but differing from it because it contains not only free aminated acids and peptides, but also sugars (96% of D-glucopyrannose) and labelled nucleosides. These precursors are produced from a labelled photosynthetic micro-organisms biomass, obtained with micro-algae having incorporated carbon 13, nitrogen 15 and deuterium during their culture. Labelling costs are reduced. 1 fig., 1 tab., 3 refs

  17. Remarks on stable and quasi-stable k-strings at large N

    International Nuclear Information System (INIS)

    Armoni, A.; Shifman, M.

    2003-01-01

    We discuss k-strings in the large-N Yang-Mills theory and its supersymmetric extension. Whereas the tension of the bona fide (stable) QCD string is expected to depend only on the N-ality of the representation, tensions that depend on specific representation R are often reported in the lattice literature. In particular, adjoint strings are discussed and found in certain simulations. We clarify this issue by systematically exploiting the notion of the quasi-stable strings which becomes well-defined at large N. The quasi-stable strings with representation-dependent tensions decay, but the decay rate (per unit length per unit time) is suppressed as Λ 2 F(N) where F(N) falls off as a function of N. It can be determined on the case-by-case basis. The quasi-stable strings eventually decay into stable strings whose tension indeed depends only on the N-ality. We also briefly review large-N arguments showing why the Casimir formula for the string tension cannot be correct, and present additional arguments in favor of the sine formula. Finally, we comment on the relevance of our estimates to Euclidean lattice measurements

  18. Stable isotope measurements of atmospheric CO2

    International Nuclear Information System (INIS)

    White, J.W.C.; Ferretti, D.F.; Vaughn, B.H.; Francey, R.J.; Allison, C.E.

    2002-01-01

    The measurement of stable carbon isotope ratios of atmospheric carbon dioxide, δ 13 CO 2 are useful for partitioning surface-atmospheric fluxes into terrestrial and oceanic components. δC 18 OO also has potential for segregating photosynthetic and respiratory fluxes in terrestrial ecosystems. Here we describe in detail the techniques for making these measurements. The primary challenge for all of the techniques used to measure isotopes of atmospheric CO 2 is to achieve acceptable accuracy and precision and to maintain them over the decades needed to observe carbon cycle variability. The keys to success such an approach are diligent intercalibrations of laboratories from around the world, as well as the use of multiple techniques such as dual inlet and GC-IRMS and the intercomparison of such measurements. We focus here on two laboratories, the Stable Isotope Lab at the Institute for Arctic and Alpine Research (INSTAAR) at the University of Colorado is described and the Commonwealth Scientific and Industrial Research Organisation - Atmospheric Research (CSIRO). Different approaches exist at other laboratories (e.g. programs operated by Scripps Institution of Oceanography (SIO) and The Center for Atmospheric and Oceanic Studies, Toboku University (TU)) however these are not discussed here. Finally, we also discuss the recently developed Gas Chromatography - Isotope Ratio Mass Spectrometry (GC-IRMS) technique which holds significant promise for measuring ultra-small samples of gas with good precision. (author)

  19. Stable statistical representations facilitate visual search.

    Science.gov (United States)

    Corbett, Jennifer E; Melcher, David

    2014-10-01

    Observers represent the average properties of object ensembles even when they cannot identify individual elements. To investigate the functional role of ensemble statistics, we examined how modulating statistical stability affects visual search. We varied the mean and/or individual sizes of an array of Gabor patches while observers searched for a tilted target. In "stable" blocks, the mean and/or local sizes of the Gabors were constant over successive displays, whereas in "unstable" baseline blocks they changed from trial to trial. Although there was no relationship between the context and the spatial location of the target, observers found targets faster (as indexed by faster correct responses and fewer saccades) as the global mean size became stable over several displays. Building statistical stability also facilitated scanning the scene, as measured by larger saccadic amplitudes, faster saccadic reaction times, and shorter fixation durations. These findings suggest a central role for peripheral visual information, creating context to free resources for detailed processing of salient targets and maintaining the illusion of visual stability.

  20. Color stable manganese-doped phosphors

    Science.gov (United States)

    Lyons, Robert Joseph [Burnt Hills, NY; Setlur, Anant Achyut [Niskayuna, NY; Deshpande, Anirudha Rajendra [Twinsburg, OH; Grigorov, Ljudmil Slavchev [Sofia, BG

    2012-08-28

    A process for preparing color stable Mn.sup.+4 doped phosphors includes providing a phosphor of formula I; A.sub.x[MF.sub.y]:Mn.sup.+4 I and contacting the phosphor in particulate form with a saturated solution of a composition of formula II in aqueous hydrofluoric acid; A.sub.x[MF.sub.y]; II wherein A is Li, Na, K, Rb, Cs, NR.sub.4 or a combination thereof; M is Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Y, La, Nb, Ta, Bi, Gd, or a combination thereof; R is H, lower alkyl, or a combination thereof; x is the absolute value of the charge of the [MF.sub.y] ion; and y is 5, 6 or 7. In particular embodiments, M is Si, Ge, Sn, Ti, Zr, or a combination thereof. A lighting apparatus capable of emitting white light includes a semiconductor light source; and a phosphor composition radiationally coupled to the light source, and which includes a color stable Mn.sup.+4 doped phosphor.

  1. Protein-based stable isotope probing.

    Science.gov (United States)

    Jehmlich, Nico; Schmidt, Frank; Taubert, Martin; Seifert, Jana; Bastida, Felipe; von Bergen, Martin; Richnow, Hans-Hermann; Vogt, Carsten

    2010-12-01

    We describe a stable isotope probing (SIP) technique that was developed to link microbe-specific metabolic function to phylogenetic information. Carbon ((13)C)- or nitrogen ((15)N)-labeled substrates (typically with >98% heavy label) were used in cultivation experiments and the heavy isotope incorporation into proteins (protein-SIP) on growth was determined. The amount of incorporation provides a measure for assimilation of a substrate, and the sequence information from peptide analysis obtained by mass spectrometry delivers phylogenetic information about the microorganisms responsible for the metabolism of the particular substrate. In this article, we provide guidelines for incubating microbial cultures with labeled substrates and a protocol for protein-SIP. The protocol guides readers through the proteomics pipeline, including protein extraction, gel-free and gel-based protein separation, the subsequent mass spectrometric analysis of peptides and the calculation of the incorporation of stable isotopes into peptides. Extraction of proteins and the mass fingerprint measurements of unlabeled and labeled fractions can be performed in 2-3 d.

  2. Multivariate Max-Stable Spatial Processes

    KAUST Repository

    Genton, Marc G.

    2014-01-06

    Analysis of spatial extremes is currently based on univariate processes. Max-stable processes allow the spatial dependence of extremes to be modelled and explicitly quantified, they are therefore widely adopted in applications. For a better understanding of extreme events of real processes, such as environmental phenomena, it may be useful to study several spatial variables simultaneously. To this end, we extend some theoretical results and applications of max-stable processes to the multivariate setting to analyze extreme events of several variables observed across space. In particular, we study the maxima of independent replicates of multivariate processes, both in the Gaussian and Student-t cases. Then, we define a Poisson process construction in the multivariate setting and introduce multivariate versions of the Smith Gaussian extremevalue, the Schlather extremal-Gaussian and extremal-t, and the BrownResnick models. Inferential aspects of those models based on composite likelihoods are developed. We present results of various Monte Carlo simulations and of an application to a dataset of summer daily temperature maxima and minima in Oklahoma, U.S.A., highlighting the utility of working with multivariate models in contrast to the univariate case. Based on joint work with Simone Padoan and Huiyan Sang.

  3. Multivariate Max-Stable Spatial Processes

    KAUST Repository

    Genton, Marc G.

    2014-01-01

    Analysis of spatial extremes is currently based on univariate processes. Max-stable processes allow the spatial dependence of extremes to be modelled and explicitly quantified, they are therefore widely adopted in applications. For a better understanding of extreme events of real processes, such as environmental phenomena, it may be useful to study several spatial variables simultaneously. To this end, we extend some theoretical results and applications of max-stable processes to the multivariate setting to analyze extreme events of several variables observed across space. In particular, we study the maxima of independent replicates of multivariate processes, both in the Gaussian and Student-t cases. Then, we define a Poisson process construction in the multivariate setting and introduce multivariate versions of the Smith Gaussian extremevalue, the Schlather extremal-Gaussian and extremal-t, and the BrownResnick models. Inferential aspects of those models based on composite likelihoods are developed. We present results of various Monte Carlo simulations and of an application to a dataset of summer daily temperature maxima and minima in Oklahoma, U.S.A., highlighting the utility of working with multivariate models in contrast to the univariate case. Based on joint work with Simone Padoan and Huiyan Sang.

  4. Wall-crossing between stable and co-stable ADHM data

    Science.gov (United States)

    Ohkawa, Ryo

    2018-06-01

    We prove formula between Nekrasov partition functions defined from stable and co-stable ADHM data for the plane following method by Nakajima and Yoshioka (Kyoto J Math 51(2):263-335, 2011) based on the theory of wall-crossing formula developed by Mochizuki (Donaldson type invariants for algebraic surfaces: transition of moduli stacks, Lecture notes in mathematics, vol 1972, Springer, Berlin, 2009). This formula is similar to conjectures by Ito et al. [J High Energy Phys 2013(5):045, 2013, (4.1), (4.2)] for A1 singularity.

  5. Stable CSR in storage rings: A model

    International Nuclear Information System (INIS)

    Sannibale, Fernando; Byrd, John M.; Loftsdottir, Agusta; Venturini, Marco; Abo-Bakr, Michael; Feikes, Jorge; Holldack, Karsten; Kuske, Peter; Wustefeld, Godehart; Hubers, Heinz-Willerm; Warnock, Robert

    2005-01-01

    A comprehensive historical view of the work done on coherent synchrotron radiation (CSR) in storage rings is given in reference [1]. Here we want just to point out that even if the issue of CSR in storage rings was already discussed over 50 years ago, it is only recently that a considerable number of observations have been reported. In fact, intense bursts of coherent synchrotron radiation with a stochastic character were measured in the terahertz frequency range, at several synchrotron light source storage rings [2-8]. It has been shown [8-11], that this bursting emission of CSR is associated with a single bunch instability, usually referred as microbunching instability (MBI), driven by the fields of the synchrotron radiation emitted by the bunch itself. Of remarkably different characteristics was the CSR emission observed at BESSY II in Berlin, when the storage ring was tuned into a special low momentum compaction mode [12, 13]. In fact, the emitted radiation was not the quasi-random bursting observed in the other machines, but a powerful and stable flux of broadband CSR in the terahertz range. This was an important result, because it experimentally demonstrated the concrete possibility of constructing a stable broadband source with extremely high power in the terahertz region. Since the publication of the first successful experiment using the ring as a CSR source [14], BESSY II has regular scheduled user s shifts dedicated to CSR experiments. At the present time, several other laboratories are investigating the possibility of a CSR mode of operation [15-17] and a design for a new ring optimized for CSR is at an advanced stage [18]. In what follows, we describe a model that first accounts for the BESSY II observations and then indicates that the special case of BESSY II is actually quite general and typical when relativistic electron storage rings are tuned for short bunches. The model provides a scheme for predicting and optimizing the performance of ring

  6. Stable CSR in Storage Rings: A Model

    International Nuclear Information System (INIS)

    Sannibale, F.

    2005-01-01

    A comprehensive historical view of the work done on coherent synchrotron radiation (CSR) in storage rings is given in reference [1]. Here we want just to point out that even if the issue of CSR in storage rings was already discussed over 50 years ago, it is only recently that a considerable number of observations have been reported. In fact, intense bursts of coherent synchrotron radiation with a stochastic character were measured in the terahertz frequency range, at several synchrotron light source storage rings [2-8]. It has been shown [8-11], that this bursting emission of CSR is associated with a single bunch instability, usually referred as microbunching instability (MBI), driven by the fields of the synchrotron radiation emitted by the bunch itself. Of remarkably different characteristics was the CSR emission observed at BESSY II in Berlin, when the storage ring was tuned into a special low momentum compaction mode [12, 13]. In fact, the emitted radiation was not the quasi-random bursting observed in the other machines, but a powerful and stable flux of broadband CSR in the terahertz range. This was an important result, because it experimentally demonstrated the concrete possibility of constructing a stable broadband source with extremely high power in the terahertz region. Since the publication of the first successful experiment using the ring as a CSR source [14], BESSY II has regular scheduled user's shifts dedicated to CSR experiments. At the present time, several other laboratories are investigating the possibility of a CSR mode of operation [15-17] and a design for a new ring optimized for CSR is at an advanced stage [18]. In what follows, we describe a model that first accounts for the BESSY II observations and then indicates that the special case of BESSY II is actually quite general and typical when relativistic electron storage rings are tuned for short bunches. The model provides a scheme for predicting and optimizing the performance of ring

  7. Tukey max-stable processes for spatial extremes

    KAUST Repository

    Xu, Ganggang; Genton, Marc G.

    2016-01-01

    We propose a new type of max-stable process that we call the Tukey max-stable process for spatial extremes. It brings additional flexibility to modeling dependence structures among spatial extremes. The statistical properties of the Tukey max

  8. Chance and stability stable distributions and their applications

    CERN Document Server

    Uchaikin, Vladimir V

    1999-01-01

    An introduction to the theory of stable distributions and their applications. It contains a modern outlook on the mathematical aspects of the theory. The authors explain numerous peculiarities of stable distributions and describe the principle concept of probability theory and function analysis. A significant part of the book is devoted to applications of stable distributions. Another notable feature is the material on the interconnection of stable laws with fractals, chaos and anomalous transport processes.

  9. Stable orbits for lunar landing assistance

    Science.gov (United States)

    Condoleo, Ennio; Cinelli, Marco; Ortore, Emiliano; Circi, Christian

    2017-10-01

    To improve lunar landing performances in terms of mission costs, trajectory determination and visibility the use of a single probe located over an assistance orbit around the Moon has been taken into consideration. To this end, the properties of two quasi-circular orbits characterised by a stable behaviour of semi-major axis, eccentricity and inclination have been investigated. The analysis has demonstrated the possibility of using an assistance probe, located over one of these orbits, as a relay satellite between lander and Earth, even in the case of landings on the far side of the Moon. A comparison about the accuracy in retrieving the lander's state with respect to the use of a probe located in the Lagrangian point L2 of the Earth-Moon system has also been carried out.

  10. The Search for Stable, Massive, Elementary Particles

    International Nuclear Information System (INIS)

    Kim, Peter C.

    2001-01-01

    In this paper we review the experimental and observational searches for stable, massive, elementary particles other than the electron and proton. The particles may be neutral, may have unit charge or may have fractional charge. They may interact through the strong, electromagnetic, weak or gravitational forces or through some unknown force. The purpose of this review is to provide a guide for future searches--what is known, what is not known, and what appear to be the most fruitful areas for new searches. A variety of experimental and observational methods such as accelerator experiments, cosmic ray studies, searches for exotic particles in bulk matter and searches using astrophysical observations is included in this review

  11. The production of stable isotopes in Spain

    Energy Technology Data Exchange (ETDEWEB)

    Urgel, M; Iglesias, J; Casas, J; Saviron, J M; Quintanilla, M

    1965-07-01

    The activities developed in the field of the production of stable isotopes by means of ion-exchange chromatography and thermal diffusion techniques are reported. The first method was used to study the separation of the nitrogen and boron isotopes, whereby the separation factor was determined by the break through method. Values ranging from 1,028 to 1,022 were obtained for the separation factor of nitrogen by using ammonium hydroxide solutions while the corresponding values as obtained for boron amounted to 1,035-1,027 using boric acid solutions. Using ammonium chloride or acetate and sodium borate, respectively, resulted in the obtention of values for the separation factor approaching unity. The isotopic separation has been carried out according to the method of development by displacement. The separation of the isotopes of the noble gases, oxygen, nitrogen and carbon has been accomplished resorting to the method of thermal diffusion. (Author) 16 refs.

  12. Multivariate max-stable spatial processes

    KAUST Repository

    Genton, Marc G.; Padoan, S. A.; Sang, H.

    2015-01-01

    Max-stable processes allow the spatial dependence of extremes to be modelled and quantified, so they are widely adopted in applications. For a better understanding of extremes, it may be useful to study several variables simultaneously. To this end, we study the maxima of independent replicates of multivariate processes, both in the Gaussian and Student-t cases. We define a Poisson process construction and introduce multivariate versions of the Smith Gaussian extreme-value, the Schlather extremal-Gaussian and extremal-t, and the Brown–Resnick models. We develop inference for the models based on composite likelihoods. We present results of Monte Carlo simulations and an application to daily maximum wind speed and wind gust.

  13. Bounded excursion stable gravastars and black holes

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, P [Instituto de Fisica, Universidade Federal Fluminense, Avenida Litoranea, s/n, Boa Viagem 24210-340, Niteroi, RJ (Brazil); Miguelote, A Y; Chan, R [Coordenacao de Astronomia e Astrofisica, Observatorio Nacional, Rua General Jose Cristino, 77, Sao Cristovao 20921-400, Rio de Janeiro, RJ (Brazil); Da Silva, M F; Wang, Anzhong [Departamento de Fisica Teorica, Instituto de Fisica, Universidade do Estado do Rio de Janeiro, Rua Sao Francisco Xavier 524, Maracana 20550-900, Rio de Janeiro-RJ (Brazil); Santos, N O, E-mail: pedrosennarocha@gmail.com, E-mail: yasuda@on.br, E-mail: chan@on.br, E-mail: mfasnic@gmail.com, E-mail: N.O.Santos@qmul.ac.uk, E-mail: anzhong_wang@baylor.edu [LERMA/CNRS-FRE 2460, Universite Pierre et Marie Curie, ERGA, Boite 142, 4 Place Jussieu, 75005 Paris Cedex 05 (France)

    2008-06-15

    Dynamical models of prototype gravastars were constructed in order to study their stability. The models are the Visser-Wiltshire three-layer gravastars, in which an infinitely thin spherical shell of stiff fluid divides the whole spacetime into two regions, where the internal region is de Sitter, and the external one is Schwarzschild. It is found that in some cases the models represent the 'bounded excursion' stable gravastars, where the thin shell is oscillating between two finite radii, while in other cases they collapse until the formation of black holes occurs. In the phase space, the region for the 'bounded excursion' gravastars is very small in comparison to that of black holes, but not empty. Therefore, although the possibility of the existence of gravastars cannot be excluded from such dynamical models, our results indicate that, even if gravastars do indeed exist, that does not exclude the possibility of the existence of black holes.

  14. Use of stable isotopes in agriculture

    International Nuclear Information System (INIS)

    Ali, F. K.

    2011-01-01

    Scientific research is considered to be one of the most important steps to achieve sustainable agriculture development. This paper is focused on the role of stable isotopes and their applications in agriculture for plant and animal production, and to study the relationship between soil, plant, air, water, nutrients and agricultural pests. Symbiotic N 2 fixation and efficient use of chemical and organic N fertilizers using 15 N were reported. Factors affecting 13 C values and application of carbon isotope discrimination to physiological and eco-physiological studies and selection of genotypes with improved water-use efficiency and drought tolerance and the recent progress in this field are reviewed. Moreover, the use of carbon isotope compositions in monitoring environmental changes and its various applications in food technology, animal production and entomology are discussed. (author)

  15. Multivariate max-stable spatial processes

    KAUST Repository

    Genton, Marc G.

    2015-02-11

    Max-stable processes allow the spatial dependence of extremes to be modelled and quantified, so they are widely adopted in applications. For a better understanding of extremes, it may be useful to study several variables simultaneously. To this end, we study the maxima of independent replicates of multivariate processes, both in the Gaussian and Student-t cases. We define a Poisson process construction and introduce multivariate versions of the Smith Gaussian extreme-value, the Schlather extremal-Gaussian and extremal-t, and the Brown–Resnick models. We develop inference for the models based on composite likelihoods. We present results of Monte Carlo simulations and an application to daily maximum wind speed and wind gust.

  16. Perceptually stable regions for arbitrary polygons.

    Science.gov (United States)

    Rocha, J

    2003-01-01

    Zou and Yan have recently developed a skeletonization algorithm of digital shapes based on a regularity/singularity analysis; they use the polygon whose vertices are the boundary pixels of the image to compute a constrained Delaunay triangulation (CDT) in order to find local symmetries and stable regions. Their method has produced good results but it is slow since its complexity depends on the number of contour pixels. This paper presents an extension of their technique to handle arbitrary polygons, not only polygons of short edges. Consequently, not only can we achieve results as good as theirs for digital images, but we can also compute skeletons of polygons of any number of edges. Since we can handle polygonal approximations of figures, the skeletons are more resilient to noise and faster to process.

  17. Stable Oxygen-18 and Deuterium Isotopes

    DEFF Research Database (Denmark)

    Müller, Sascha

    The application of stable Oxygen-18 (18O) and Deuterium (2H) isotopes, as a tracer for fluxes between different compartments of the water cycle was subject of the present PhD-thesis. During a three year period, temporal data from a wide range of water cycle constituents was collected from...... the Skjern River catchment, Denmark. The presented applications focused on studying the isotopic 'input signal' to the hydrosphere in the form of precipitation, the isotopic 'output signal' with its related dynamic processes at a coastal saltwater-freshwater interface (groundwater isotopes) and the temporal...... development within a given lowland headwater catchment (stream water isotopes). Based on our investigations on the precipitation isotopic composition a local meteoric water line (LMWL) was constructed and expressed as: δ2H=7.4 δ18O + 5.36‰. Moreover, we showed that under maritime temperature climate influence...

  18. A belief-based evolutionarily stable strategy.

    Science.gov (United States)

    Deng, Xinyang; Wang, Zhen; Liu, Qi; Deng, Yong; Mahadevan, Sankaran

    2014-11-21

    As an equilibrium refinement of the Nash equilibrium, evolutionarily stable strategy (ESS) is a key concept in evolutionary game theory and has attracted growing interest. An ESS can be either a pure strategy or a mixed strategy. Even though the randomness is allowed in mixed strategy, the selection probability of pure strategy in a mixed strategy may fluctuate due to the impact of many factors. The fluctuation can lead to more uncertainty. In this paper, such uncertainty involved in mixed strategy has been further taken into consideration: a belief strategy is proposed in terms of Dempster-Shafer evidence theory. Furthermore, based on the proposed belief strategy, a belief-based ESS has been developed. The belief strategy and belief-based ESS can reduce to the mixed strategy and mixed ESS, which provide more realistic and powerful tools to describe interactions among agents. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Stable computation of generalized singular values

    Energy Technology Data Exchange (ETDEWEB)

    Drmac, Z.; Jessup, E.R. [Univ. of Colorado, Boulder, CO (United States)

    1996-12-31

    We study floating-point computation of the generalized singular value decomposition (GSVD) of a general matrix pair (A, B), where A and B are real matrices with the same numbers of columns. The GSVD is a powerful analytical and computational tool. For instance, the GSVD is an implicit way to solve the generalized symmetric eigenvalue problem Kx = {lambda}Mx, where K = A{sup {tau}}A and M = B{sup {tau}}B. Our goal is to develop stable numerical algorithms for the GSVD that are capable of computing the singular value approximations with the high relative accuracy that the perturbation theory says is possible. We assume that the singular values are well-determined by the data, i.e., that small relative perturbations {delta}A and {delta}B (pointwise rounding errors, for example) cause in each singular value {sigma} of (A, B) only a small relative perturbation {vert_bar}{delta}{sigma}{vert_bar}/{sigma}.

  20. Stable carbides in transition metal alloys

    International Nuclear Information System (INIS)

    Piotrkowski, R.

    1991-01-01

    In the present work different techniques were employed for the identification of stable carbides in two sets of transition metal alloys of wide technological application: a set of three high alloy M2 type steels in which W and/or Mo were total or partially replaced by Nb, and a Zr-2.5 Nb alloy. The M2 steel is a high speed steel worldwide used and the Zr-2.5 Nb alloy is the base material for the pressure tubes in the CANDU type nuclear reactors. The stability of carbide was studied in the frame of Goldschmidt's theory of interstitial alloys. The identification of stable carbides in steels was performed by determining their metallic composition with an energy analyzer attached to the scanning electron microscope (SEM). By these means typical carbides of the M2 steel, MC and M 6 C, were found. Moreover, the spatial and size distribution of carbide particles were determined after different heat treatments, and both microstructure and microhardness were correlated with the appearance of the secondary hardening phenomenon. In the Zr-Nb alloy a study of the α and β phases present after different heat treatments was performed with optical and SEM metallographic techniques, with the guide of Abriata and Bolcich phase diagram. The α-β interphase boundaries were characterized as short circuits for diffusion with radiotracer techniques and applying Fisher-Bondy-Martin model. The precipitation of carbides was promoted by heat treatments that produced first the C diffusion into the samples at high temperatures (β phase), and then the precipitation of carbide particles at lower temperature (α phase or (α+β)) two phase field. The precipitated carbides were identified as (Zr, Nb)C 1-x with SEM, electron microprobe and X-ray diffraction techniques. (Author) [es

  1. Stable isotopes as tracers for radionuclides

    International Nuclear Information System (INIS)

    Giussani, A.; Bartolo, D. de; Cantone, M.C.; Zilker, T.; Greim, H.; Roth, P.; Werner, E.

    2000-01-01

    The assessment of internal dose after incorporation of radionuclides requires as input data the knowledge of the uptake into the systemic circulation, the distribution and retention in selected organs, the excretion pathways. Realistic biokinetic models are needed for reliable estimates, correct interpretation of bioassay measurements, appropriate decision-making in radiological emergencies. For many radionuclides, however, the biokinetic models currently recommended are often generic, with very few specific parameters, due to the lack of experimental human data. The use of stable isotopes as tracers enables to determine important biokinetic parameters such as the fractional uptake, the clearance from the transfer compartment, the excretion patterns under experimentally controlled conditions. The subjects investigated are not exposed to any radiation risk, so this technique enables to obtain biokinetic information also for sensitive groups of the population, such as children or pregnant women, and to determine age- and gender-specific model parameters. Sophisticated analytical method, able to discriminate and quantitate different isotopes of the same element in complex matrices such as biological fluids, have to be purposely developed and optimized. Activation analysis and mass spectrometry are the most proper techniques of choice. Experiments were conducted with molybdenum, tellurium, ruthenium and zirconium. Activation analysis with protons, thermal ionization mass spectrometry and inductively coupled mass spectrometry were employed for the determination of stable isotopes of these elements in blood plasma and urine samples. Several deviations from the predictions of the ICRP models were observed. For example, modifications to the current model for molybdenum have been suggested on the basis of these results. The dose coefficients to the target regions calculated with this proposed model are even of one order of magnitude different than the ICRP estimates

  2. A Note on Interpolation of Stable Processes | Nassiuma | Journal of ...

    African Journals Online (AJOL)

    Interpolation procedures tailored for gaussian processes may not be applied to infinite variance stable processes. Alternative techniques suitable for a limited set of stable case with index α∈(1,2] were initially studied by Pourahmadi (1984) for harmonizable processes. This was later extended to the ARMA stable process ...

  3. Stable cycling in discrete-time genetic models.

    OpenAIRE

    Hastings, A

    1981-01-01

    Examples of stable cycling are discussed for two-locus, two-allele, deterministic, discrete-time models with constant fitnesses. The cases that cycle were found by using numerical techniques to search for stable Hopf bifurcations. One consequence of the results is that apparent cases of directional selection may be due to stable cycling.

  4. Stable cycling in discrete-time genetic models.

    Science.gov (United States)

    Hastings, A

    1981-11-01

    Examples of stable cycling are discussed for two-locus, two-allele, deterministic, discrete-time models with constant fitnesses. The cases that cycle were found by using numerical techniques to search for stable Hopf bifurcations. One consequence of the results is that apparent cases of directional selection may be due to stable cycling.

  5. Malaria infection during pregnancy in area of stable transmission ...

    African Journals Online (AJOL)

    Malaria infection during pregnancy in area of stable transmission. ... (LBW), a leading cause of neonatal death in areas of stable malaria transmission. ... areas of stable malaria transmission and the effective strategies for prevention and control. Keywords: malaria, pregnancy, semi-immune women, anaemia, low birthweight

  6. Influence of horse stable environment on human airways.

    Science.gov (United States)

    Elfman, Lena; Riihimäki, Miia; Pringle, John; Wålinder, Robert

    2009-05-25

    Many people spend considerable amount of time each day in equine stable environments either as employees in the care and training of horses or in leisure activity. However, there are few studies available on how the stable environment affects human airways. This study examined in one horse stable qualitative differences in indoor air during winter and late summer conditions and assessed whether air quality was associated with clinically detectable respiratory signs or alterations to selected biomarkers of inflammation and lung function in stable personnel. The horse stable environment and stable-workers (n = 13) in one stable were investigated three times; first in the winter, second in the interjacent late summer and the third time in the following winter stabling period. The stable measurements included levels of ammonia, hydrogen sulphide, total and respirable dust, airborne horse allergen, microorganisms, endotoxin and glucan. The stable-workers completed a questionnaire on respiratory symptoms, underwent nasal lavage with subsequent analysis of inflammation markers, and performed repeated measurements of pulmonary function. Measurements in the horse stable showed low organic dust levels and high horse allergen levels. Increased viable level of fungi in the air indicated a growing source in the stable. Air particle load as well as 1,3-beta-glucan was higher at the two winter time-points, whereas endotoxin levels were higher at the summer time-point. Two stable-workers showed signs of bronchial obstruction with increased PEF-variability, increased inflammation biomarkers relating to reported allergy, cold or smoking and reported partly work-related symptoms. Furthermore, two other stable-workers reported work-related airway symptoms, of which one had doctor's diagnosed asthma which was well treated. Biomarkers involved in the development of airway diseases have been studied in relation to environmental exposure levels in equine stables. Respirable dust and 1

  7. Stability properties of nonlinear dynamical systems and evolutionary stable states

    Energy Technology Data Exchange (ETDEWEB)

    Gleria, Iram, E-mail: iram@fis.ufal.br [Instituto de Física, Universidade Federal de Alagoas, 57072-970 Maceió-AL (Brazil); Brenig, Leon [Faculté des Sciences, Université Libre de Bruxelles, 1050 Brussels (Belgium); Rocha Filho, Tarcísio M.; Figueiredo, Annibal [Instituto de Física and International Center for Condensed Matter Physics, Universidade de Brasília, 70919-970 Brasília-DF (Brazil)

    2017-03-18

    Highlights: • We address the problem of equilibrium stability in a general class of non-linear systems. • We link Evolutionary Stable States (ESS) to stable fixed points of square quasi-polynomial (QP) systems. • We show that an interior ES point may be related to stable interior fixed points of QP systems. - Abstract: In this paper we address the problem of stability in a general class of non-linear systems. We establish a link between the concepts of asymptotic stable interior fixed points of square Quasi-Polynomial systems and evolutionary stable states, a property of some payoff matrices arising from evolutionary games.

  8. Influence of horse stable environment on human airways

    Directory of Open Access Journals (Sweden)

    Pringle John

    2009-05-01

    Full Text Available Abstract Background Many people spend considerable amount of time each day in equine stable environments either as employees in the care and training of horses or in leisure activity. However, there are few studies available on how the stable environment affects human airways. This study examined in one horse stable qualitative differences in indoor air during winter and late summer conditions and assessed whether air quality was associated with clinically detectable respiratory signs or alterations to selected biomarkers of inflammation and lung function in stable personnel. Methods The horse stable environment and stable-workers (n = 13 in one stable were investigated three times; first in the winter, second in the interjacent late summer and the third time in the following winter stabling period. The stable measurements included levels of ammonia, hydrogen sulphide, total and respirable dust, airborne horse allergen, microorganisms, endotoxin and glucan. The stable-workers completed a questionnaire on respiratory symptoms, underwent nasal lavage with subsequent analysis of inflammation markers, and performed repeated measurements of pulmonary function. Results Measurements in the horse stable showed low organic dust levels and high horse allergen levels. Increased viable level of fungi in the air indicated a growing source in the stable. Air particle load as well as 1,3-β-glucan was higher at the two winter time-points, whereas endotoxin levels were higher at the summer time-point. Two stable-workers showed signs of bronchial obstruction with increased PEF-variability, increased inflammation biomarkers relating to reported allergy, cold or smoking and reported partly work-related symptoms. Furthermore, two other stable-workers reported work-related airway symptoms, of which one had doctor's diagnosed asthma which was well treated. Conclusion Biomarkers involved in the development of airway diseases have been studied in relation to

  9. Stable isotope analysis in primatology: a critical review.

    Science.gov (United States)

    Sandberg, Paul A; Loudon, James E; Sponheimer, Matt

    2012-11-01

    Stable isotope analysis has become an important tool in ecology over the last 25 years. A wealth of ecological information is stored in animal tissues in the relative abundances of the stable isotopes of several elements, particularly carbon and nitrogen, because these isotopes navigate through ecological processes in predictable ways. Stable carbon and nitrogen isotopes have been measured in most primate taxonomic groups and have yielded information about dietary content, dietary variability, and habitat use. Stable isotopes have recently proven useful for addressing more fine-grained questions about niche dynamics and anthropogenic effects on feeding ecology. Here, we discuss stable carbon and nitrogen isotope systematics and critically review the published stable carbon and nitrogen isotope data for modern primates with a focus on the problems and prospects for future stable isotope applications in primatology. © 2012 Wiley Periodicals, Inc.

  10. Crystal engineering of stable temozolomide cocrystals.

    Science.gov (United States)

    Babu, N Jagadeesh; Sanphui, Palash; Nangia, Ashwini

    2012-10-01

    The antitumor prodrug temozolomide (TMZ) decomposes in aqueous medium of pH≥7 but is relatively stable under acidic conditions. Pure TMZ is obtained as a white powder but turns pink and then brown, which is indicative of chemical degradation. Pharmaceutical cocrystals of TMZ were engineered with safe coformers such as oxalic acid, succinic acid, salicylic acid, d,l-malic acid, and d,l-tartaric acid, to stabilize the drug as a cocrystal. All cocrystals were characterized by powder X-ray diffraction (PXRD), single crystal X-ray diffraction, and FT-IR as well as FT-Raman spectroscopy. Temozolomide cocrystals with organic acids (pK(a) 2-6) were found to be more stable than the reference drug under physiological conditions. The half-life (T(1/2)) of TMZ-oxalic and TMZ-salicylic acid measured by UV/Vis spectroscopy in pH 7 buffer is two times longer than that of TMZ (3.5 h and 3.6 h vs. 1.7 h); TMZ-succinic acid, TMZ-tartaric acid, and TMZ-malic acid also exhibited a longer half-life (2.3, 2.5, and 2.8 h, respectively). Stability studies at 40 °C and 75 % relative humidity (ICH conditions) showed that hydrolytic degradation of temozolomide in the solid state started after one week, as determined by PXRD, whereas its cocrystals with succinic acid and oxalic acid were intact at 28 weeks, thus confirming the greater stability of cocrystals compared to the reference drug. The intrinsic dissolution rate (IDR) profile of TMZ-oxalic acid and TMZ-succinic acid cocrystals in buffer of pH 7 is comparable to that of temozolomide. Among the temozolomide cocrystals examined, those with succinic acid and oxalic acid exhibited both an improved stability and a comparable dissolution rate to the reference drug. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Stable nuclear transformation of Eudorina elegans

    Directory of Open Access Journals (Sweden)

    Lerche Kai

    2013-02-01

    Full Text Available Abstract Background A fundamental step in evolution was the transition from unicellular to differentiated, multicellular organisms. Volvocine algae have been used for several decades as a model lineage to investigate the evolutionary aspects of multicellularity and cellular differentiation. There are two well-studied volvocine species, a unicellular alga (Chlamydomonas reinhardtii and a multicellular alga with differentiated cell types (Volvox carteri. Species with intermediate characteristics also exist, which blur the boundaries between unicellularity and differentiated multicellularity. These species include the globular alga Eudorina elegans, which is composed of 16–32 cells. However, detailed molecular analyses of E. elegans require genetic manipulation. Unfortunately, genetic engineering has not yet been established for Eudorina, and only limited DNA and/or protein sequence information is available. Results Here, we describe the stable nuclear transformation of E. elegans by particle bombardment using both a chimeric selectable marker and reporter genes from different heterologous sources. Transgenic algae resistant to paromomycin were achieved using the aminoglycoside 3′-phosphotransferase VIII (aphVIII gene of Streptomyces rimosus, an actinobacterium, under the control of an artificial promoter consisting of two V. carteri promoters in tandem. Transformants exhibited an increase in resistance to paromomycin by up to 333-fold. Co-transformation with non-selectable plasmids was achieved with a rate of 50 - 100%. The luciferase (gluc gene from the marine copepod Gaussia princeps, which previously was engineered to match the codon usage of C. reinhardtii, was used as a reporter gene. The expression of gluc was mediated by promoters from C. reinhardtii and V. carteri. Heterologous heat shock promoters induced an increase in luciferase activity (up to 600-fold at elevated temperatures. Long-term stability and both constitutive and

  12. Caffeine Consumption Prevents Diabetes-Induced Memory Impairment and Synaptotoxicity in the Hippocampus of NONcZNO10/LTJ Mice

    OpenAIRE

    Duarte, João M. N.; Agostinho, Paula M.; Carvalho, Rui A.; Cunha, Rodrigo A.

    2012-01-01

    Diabetic conditions are associated with modified brain function, namely with cognitive deficits, through largely undetermined processes. More than understanding the underlying mechanism, it is important to devise novel strategies to alleviate diabetes-induced cognitive deficits. Caffeine (a mixed antagonist of adenosine A(1) and A(2A) receptors) emerges as a promising candidate since caffeine consumption reduces the risk of diabetes and effectively prevents memory deficits caused by different...

  13. Caffeine consumption prevents diabetes-induced memory impairment and synaptotoxicity in the hippocampus of NONcZNO10/LTJ mice.

    Directory of Open Access Journals (Sweden)

    João M N Duarte

    Full Text Available Diabetic conditions are associated with modified brain function, namely with cognitive deficits, through largely undetermined processes. More than understanding the underlying mechanism, it is important to devise novel strategies to alleviate diabetes-induced cognitive deficits. Caffeine (a mixed antagonist of adenosine A(1 and A(2A receptors emerges as a promising candidate since caffeine consumption reduces the risk of diabetes and effectively prevents memory deficits caused by different noxious stimuli. Thus, we took advantage of a novel animal model of type 2 diabetes to investigate the behavioural, neurochemical and morphological modifications present in the hippocampus and tested if caffeine consumption might prevent these changes. We used a model closely mimicking the human type 2 diabetes condition, NONcNZO10/LtJ mice, which become diabetic at 7-11 months when kept under an 11% fat diet. Caffeine (1 g/l was applied in the drinking water from 7 months onwards. Diabetic mice displayed a decreased spontaneous alternation in the Y-maze accompanied by a decreased density of nerve terminal markers (synaptophysin, SNAP25, mainly glutamatergic (vesicular glutamate transporters, and increased astrogliosis (GFAP immunoreactivity compared to their wild type littermates kept under the same diet. Furthermore, diabetic mice displayed up-regulated A(2A receptors and down-regulated A(1 receptors in the hippocampus. Caffeine consumption restored memory performance and abrogated the diabetes-induced loss of nerve terminals and astrogliosis. These results provide the first evidence that type 2 diabetic mice display a loss of nerve terminal markers and astrogliosis, which is associated with memory impairment; furthermore, caffeine consumption prevents synaptic dysfunction and astrogliosis as well as memory impairment in type 2 diabetes.

  14. Caffeine consumption prevents diabetes-induced memory impairment and synaptotoxicity in the hippocampus of NONcZNO10/LTJ mice.

    Science.gov (United States)

    Duarte, João M N; Agostinho, Paula M; Carvalho, Rui A; Cunha, Rodrigo A

    2012-01-01

    Diabetic conditions are associated with modified brain function, namely with cognitive deficits, through largely undetermined processes. More than understanding the underlying mechanism, it is important to devise novel strategies to alleviate diabetes-induced cognitive deficits. Caffeine (a mixed antagonist of adenosine A(1) and A(2A) receptors) emerges as a promising candidate since caffeine consumption reduces the risk of diabetes and effectively prevents memory deficits caused by different noxious stimuli. Thus, we took advantage of a novel animal model of type 2 diabetes to investigate the behavioural, neurochemical and morphological modifications present in the hippocampus and tested if caffeine consumption might prevent these changes. We used a model closely mimicking the human type 2 diabetes condition, NONcNZO10/LtJ mice, which become diabetic at 7-11 months when kept under an 11% fat diet. Caffeine (1 g/l) was applied in the drinking water from 7 months onwards. Diabetic mice displayed a decreased spontaneous alternation in the Y-maze accompanied by a decreased density of nerve terminal markers (synaptophysin, SNAP25), mainly glutamatergic (vesicular glutamate transporters), and increased astrogliosis (GFAP immunoreactivity) compared to their wild type littermates kept under the same diet. Furthermore, diabetic mice displayed up-regulated A(2A) receptors and down-regulated A(1) receptors in the hippocampus. Caffeine consumption restored memory performance and abrogated the diabetes-induced loss of nerve terminals and astrogliosis. These results provide the first evidence that type 2 diabetic mice display a loss of nerve terminal markers and astrogliosis, which is associated with memory impairment; furthermore, caffeine consumption prevents synaptic dysfunction and astrogliosis as well as memory impairment in type 2 diabetes.

  15. Microsatellites grant more stable flanking genes

    Directory of Open Access Journals (Sweden)

    Joukhadar Reem

    2012-10-01

    Full Text Available Abstract Background Microsatellites, or simple sequence repeats (SSRs, are DNA sequences that include tandem copies of specific sequences no longer than six bases. SSRs are ubiquitous in all genomes and highly mutable. Presentation of the hypothesis Results from previous studies suggest that flanking regions of SSR are exhibit high stability in a wide range of organisms. We hypothesized that the SSRs ability to discard weak DNA polymerases could be responsible for this unusual stability. . When the weak polymerases are being decayed over SSRs, the flanking sequences would have higher opportunity to be replicated by more stable DNA polymerases. We present evidence of the molecular basis of our hypothesis. Testing the hypothesis The hypothesis could be tested by examining the activity of DNA polymerase during and after a number of PCRs. The PCR reactions should be run with the same SSR locus possessing differences in the SSR length. The hypothesis could also be tested by comparing the mutational rate of a transferred gene between two transformations. The first one has a naked T-DNA (transferred DNA, while the second one has the same T-DNA flanked with two SSRs. Implications of the hypothesis In any transformation experiment, flanking the T-DNA fragment with SSR sequences would result in more stably transferred genes. This process would decrease the unpredictable risks that may occur because of the mutational pressure on this foreign segment.

  16. LHC Report: Towards stable beams and collisions

    CERN Multimedia

    CERN Bulletin

    2011-01-01

    Over the past two weeks, the LHC re-commissioning with beam has continued at a brisk pace. The first collisions of 2011 were produced on 2 March, with stable beams and collisions for physics planned for the coming days. Low intensity beams with just a few bunches of particles were used to test the energy ramp to 3.5 TeV and the squeeze. The results were successful and, as a by-product, the first collisions of 2011 were recorded 2 March. One of the main activities carried out by the operation teams has been the careful set-up of the collimation system, and the injection and beam dump protection devices. The collimation system provides essential beam cleaning, preventing stray particles from impacting other elements of the machine, particularly the superconducting magnets. In addition to the collimation system, also the injection and beam dump protection devices perform a vital machine protection role, as they detect any beam that might be mis-directed during rare, but not totally unavoidable, hardware hiccups...

  17. Shelf-stable foods through irradiation processing

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-11-01

    This survey has been produced from a database on analytical reference materials of biological and environmental origin, which is maintained at the International Atomic Energy Agency. It is an updated version of earlier reports, the last published in 1990. The information presented refers mostly to reference materials for trace element constituents; however, information is also included on a number of other selected measurands of relevance to IAEA programmes, i.e. radionuclides, stable isotopes, anions, cations, organometallic compounds and organic contaminants. The database presently contains over 10,000 analyte values for 455 measurands in 650 reference materials produced by 30 different suppliers. Additional information on the cost of the materials, the unit size supplied, and recommended minimum weight of material for analysis is also provided, if this information is available to the authors. It is expected that this survey will help analysts to select reference materials for quality assurance purposes that match as closely as possible, with respect to matrix type and concentrations of the measurands of interest, their samples to be analyzed. 22 refs, 2 tabs.

  18. Organized polysaccharide fibers as stable drug carriers

    Science.gov (United States)

    Janaswamy, Srinivas; Gill, Kristin L.; Campanella, Osvaldo H.; Pinal, Rodolfo

    2013-01-01

    Many challenges arise during the development of new drug carrier systems, and paramount among them are safety, solubility and controlled release requirements. Although synthetic polymers are effective, the possibility of side effects imposes restrictions on their acceptable use and dose limits. Thus, a new drug carrier system that is safe to handle and free from side effects is very much in need and food grade polysaccharides stand tall as worthy alternatives. Herein, we demonstrate for the first time the feasibility of sodium iota-carrageenan fibers and their distinctive water pockets to embed and release a wide variety of drug molecules. Structural analysis has revealed the existence of crystalline network in the fibers even after encapsulating the drug molecules, and iota-carrageenan maintains its characteristic and reproducible double helical structure suggesting that the composites thus produced are reminiscent of cocrystals. The melting properties of iota-carrageenan:drug complexes are distinctly different from those of either drug or iota-carrageenan fiber. The encapsulated drugs are released in a sustained manner from the fiber matrix. Overall, our research provides an elegant opportunity for developing effective drug carriers with stable network toward enhancing and/or controlling bioavailability and extending shelf-life of drug molecules using GRAS excipients, food polysaccharides, that are inexpensive and non–toxic. PMID:23544530

  19. Shelf-stable foods through irradiation processing

    International Nuclear Information System (INIS)

    1995-11-01

    This survey has been produced from a database on analytical reference materials of biological and environmental origin, which is maintained at the International Atomic Energy Agency. It is an updated version of earlier reports, the last published in 1990. The information presented refers mostly to reference materials for trace element constituents; however, information is also included on a number of other selected measurands of relevance to IAEA programmes, i.e. radionuclides, stable isotopes, anions, cations, organometallic compounds and organic contaminants. The database presently contains over 10,000 analyte values for 455 measurands in 650 reference materials produced by 30 different suppliers. Additional information on the cost of the materials, the unit size supplied, and recommended minimum weight of material for analysis is also provided, if this information is available to the authors. It is expected that this survey will help analysts to select reference materials for quality assurance purposes that match as closely as possible, with respect to matrix type and concentrations of the measurands of interest, their samples to be analyzed. 22 refs, 2 tabs

  20. Geochemistry of the stable isotopes of silicon

    Energy Technology Data Exchange (ETDEWEB)

    Douthitt, C B [California Inst. of Tech., Pasadena (USA). Div. of Geological and Planetary Sciences

    1982-08-01

    One hundred thirty two new measurements of the relative abundances of the stable isotopes of silicon in terrestrial materials are presented. The total variation of delta/sup 30/Si found is 6.2 parts per thousand, centered on the mean of terrestrial mafic and ultramafic igneous rocks, delta/sup 30/Si = -0.4 parts per thousand. Igneous rocks show limited variation; coexisting minerals exhibit small, systematic silicon isotopic fractionations that are roughly 1/3 the magnitude of concomitant oxygen isotopic fractionations at 1150/sup 0/C. In both igneous minerals and rocks, delta/sup 30/Si shows a positive correlation with silicon content, as does delta/sup 18/O. Opal from both sponge spicules and sinters is light, with delta/sup 30/Si = -2.3 and -1.4 parts per thousand respectively. Large delta/sup 30/Si values of both positive and negative sign are reported for the first time from clay minerals, opaline phytoliths, and authigenic quartz. All highly fractionated samples were precipitated from solution at low temperatures; however, aqueous silicon is not measurably fractionated relative to quartz at equilibrium. A kinetic isotope fractionation of approximately 3.5 parts per thousand is postulated to occur during the low temperature precipitation of opal and, possibly, poorly ordered phyllosilicates, with the silicate phase being enriched in /sup 28/Si. This fractionation, coupled with a Rayleigh precipitation model, is capable of explaining most non-magmatic delta/sup 30/Si variations.

  1. Magneto-hydrodynamically stable axisymmetric mirrorsa)

    Science.gov (United States)

    Ryutov, D. D.; Berk, H. L.; Cohen, B. I.; Molvik, A. W.; Simonen, T. C.

    2011-09-01

    Making axisymmetric mirrors magnetohydrodynamically (MHD) stable opens up exciting opportunities for using mirror devices as neutron sources, fusion-fission hybrids, and pure-fusion reactors. This is also of interest from a general physics standpoint (as it seemingly contradicts well-established criteria of curvature-driven instabilities). The axial symmetry allows for much simpler and more reliable designs of mirror-based fusion facilities than the well-known quadrupole mirror configurations. In this tutorial, after a summary of classical results, several techniques for achieving MHD stabilization of the axisymmetric mirrors are considered, in particular: (1) employing the favorable field-line curvature in the end tanks; (2) using the line-tying effect; (3) controlling the radial potential distribution; (4) imposing a divertor configuration on the solenoidal magnetic field; and (5) affecting the plasma dynamics by the ponderomotive force. Some illuminative theoretical approaches for understanding axisymmetric mirror stability are described. The applicability of the various stabilization techniques to axisymmetric mirrors as neutron sources, hybrids, and pure-fusion reactors are discussed; and the constraints on the plasma parameters are formulated.

  2. Magneto-hydrodynamically stable axisymmetric mirrors

    Energy Technology Data Exchange (ETDEWEB)

    Ryutov, D. D.; Cohen, B. I.; Molvik, A. W. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Berk, H. L. [University of Texas, Austin, Texas 78712 (United States); Simonen, T. C. [University of California, Berkeley, California 94720 (United States)

    2011-09-15

    Making axisymmetric mirrors magnetohydrodynamically (MHD) stable opens up exciting opportunities for using mirror devices as neutron sources, fusion-fission hybrids, and pure-fusion reactors. This is also of interest from a general physics standpoint (as it seemingly contradicts well-established criteria of curvature-driven instabilities). The axial symmetry allows for much simpler and more reliable designs of mirror-based fusion facilities than the well-known quadrupole mirror configurations. In this tutorial, after a summary of classical results, several techniques for achieving MHD stabilization of the axisymmetric mirrors are considered, in particular: (1) employing the favorable field-line curvature in the end tanks; (2) using the line-tying effect; (3) controlling the radial potential distribution; (4) imposing a divertor configuration on the solenoidal magnetic field; and (5) affecting the plasma dynamics by the ponderomotive force. Some illuminative theoretical approaches for understanding axisymmetric mirror stability are described. The applicability of the various stabilization techniques to axisymmetric mirrors as neutron sources, hybrids, and pure-fusion reactors are discussed; and the constraints on the plasma parameters are formulated.

  3. Introducing Stable Radicals into Molecular Machines.

    Science.gov (United States)

    Wang, Yuping; Frasconi, Marco; Stoddart, J Fraser

    2017-09-27

    Ever since their discovery, stable organic radicals have received considerable attention from chemists because of their unique optical, electronic, and magnetic properties. Currently, one of the most appealing challenges for the chemical community is to develop sophisticated artificial molecular machines that can do work by consuming external energy, after the manner of motor proteins. In this context, radical-pairing interactions are important in addressing the challenge: they not only provide supramolecular assistance in the synthesis of molecular machines but also open the door to developing multifunctional systems relying on the various properties of the radical species. In this Outlook, by taking the radical cationic state of 1,1'-dialkyl-4,4'-bipyridinium (BIPY •+ ) as an example, we highlight our research on the art and science of introducing radical-pairing interactions into functional systems, from prototypical molecular switches to complex molecular machines, followed by a discussion of the (i) limitations of the current systems and (ii) future research directions for designing BIPY •+ -based molecular machines with useful functions.

  4. STABLE ISOTOPE GEOCHEMISTRY OF MASSIVE ICE

    Directory of Open Access Journals (Sweden)

    Yurij K. Vasil’chuk

    2016-01-01

    Full Text Available The paper summarises stable-isotope research on massive ice in the Russian and North American Arctic, and includes the latest understanding of massive-ice formation. A new classification of massive-ice complexes is proposed, encompassing the range and variabilityof massive ice. It distinguishes two new categories of massive-ice complexes: homogeneousmassive-ice complexes have a similar structure, properties and genesis throughout, whereasheterogeneous massive-ice complexes vary spatially (in their structure and properties andgenetically within a locality and consist of two or more homogeneous massive-ice bodies.Analysis of pollen and spores in massive ice from Subarctic regions and from ice and snow cover of Arctic ice caps assists with interpretation of the origin of massive ice. Radiocarbon ages of massive ice and host sediments are considered together with isotope values of heavy oxygen and deuterium from massive ice plotted at a uniform scale in order to assist interpretation and correlation of the ice.

  5. Stable Isotope Group 1984 progress report

    International Nuclear Information System (INIS)

    Lyon, G.L.

    1985-04-01

    The work of the group in 1984 is described and includes studies in isotope geology, isotope hydrology, geochronology, isotope biology and mass spectrometer instrumentation. Geothermal studies have decreased compared to other years, but major data summaries were made for Wairakei and Ngawha. The hydrology of Whakarewarewa and Rotorua is being elucidated using water isotopes. Models of the subsurface flows at Kawerau and Ngawha are being made to relate fluid to mineral isotope compositions. A study of the δ 13 C and δ 34 S compositions of New Zealand oils has been started. Groups of oils of related origin are being defined, and compositions will be compared with those of potential source rocks. A method was developed for isotope analysis of sulphur in rocks. The isotopic composition of water is being used to identify and characterise groundwater aquifers in the Wairarapa and at Poverty Bay. Stable carbon isotopes have been used to identify food sources for invertebrates, and to show biochemical pathways in lactation by cows. The geochronology group is involved in major studies in Antarctica, using U-Pb, Rb-Sr and K-Ar methods. Rocks from North Victoria Land, Marie Byrd Land and the USARP mountains are being compared with possible correlatives in New Zealand and Argentina. Strontium isotope data is being applied to the origin of magmas in several regions of New Zealand. The K-Ar data is being stored on computer files. Fission track measurements are being applied to unravel uplift histories in Westland and Taranaki

  6. ROBUST MPC FOR STABLE LINEAR SYSTEMS

    Directory of Open Access Journals (Sweden)

    M.A. Rodrigues

    2002-03-01

    Full Text Available In this paper, a new model predictive controller (MPC, which is robust for a class of model uncertainties, is developed. Systems with stable dynamics and time-invariant model uncertainty are treated. The development herein proposed is focused on real industrial systems where the controller is part of an on-line optimization scheme and works in the output-tracking mode. In addition, the system has a time-varying number of degrees of freedom since some of the manipulated inputs may become constrained. Moreover, the number of controlled outputs may also vary during system operation. Consequently, the actual system may show operating conditions with a number of controlled outputs larger than the number of available manipulated inputs. The proposed controller uses a state-space model, which is aimed at the representation of the output-predicted trajectory. Based on this model, a cost function is proposed whereby the output error is integrated along an infinite prediction horizon. It is considered the case of multiple operating points, where the controller stabilizes a set of models corresponding to different operating conditions for the system. It is shown that closed-loop stability is guaranteed by the feasibility of a linear matrix optimization problem.

  7. Canonical, stable, general mapping using context schemes.

    Science.gov (United States)

    Novak, Adam M; Rosen, Yohei; Haussler, David; Paten, Benedict

    2015-11-15

    Sequence mapping is the cornerstone of modern genomics. However, most existing sequence mapping algorithms are insufficiently general. We introduce context schemes: a method that allows the unambiguous recognition of a reference base in a query sequence by testing the query for substrings from an algorithmically defined set. Context schemes only map when there is a unique best mapping, and define this criterion uniformly for all reference bases. Mappings under context schemes can also be made stable, so that extension of the query string (e.g. by increasing read length) will not alter the mapping of previously mapped positions. Context schemes are general in several senses. They natively support the detection of arbitrary complex, novel rearrangements relative to the reference. They can scale over orders of magnitude in query sequence length. Finally, they are trivially extensible to more complex reference structures, such as graphs, that incorporate additional variation. We demonstrate empirically the existence of high-performance context schemes, and present efficient context scheme mapping algorithms. The software test framework created for this study is available from https://registry.hub.docker.com/u/adamnovak/sequence-graphs/. anovak@soe.ucsc.edu Supplementary data are available at Bioinformatics online. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  8. Minute synthesis of extremely stable gold nanoparticles.

    Science.gov (United States)

    Zhou, Min; Wang, Baoxiang; Rozynek, Zbigniew; Xie, Zhaohui; Fossum, Jon Otto; Yu, Xiaofeng; Raaen, Steinar

    2009-12-16

    We describe a rapid environmentally friendly wet-chemical approach to synthesize extremely stable non-toxic, biocompatible, water-soluble monodispersed gold nanoparticles (AuNPs) in one step at room temperature. The particles have been successfully achieved in just a few minutes by merely adding sodium hydroxide (NaOH) acting as an initiator for the reduction of HAuCl(4) in aqueous solution in the presence of polyvinylpyrrolidone (PVP) without the use of any reducing agent. It is also proved to be highly efficient for the preparation of AuNPs with controllable sizes. The AuNPs show remarkable stability in water media with high concentrations of salt, various buffer solutions and physiological conditions in biotechnology and biomedicine. Moreover, the AuNPs are also non-toxic at high concentration (100 microM). Therefore, it provides great opportunities to use these AuNPs for biotechnology and biomedicine. This new approach also involved several green chemistry concepts, such as the selection of environmentally benign reagents and solvents, without energy consumption, and less reaction time.

  9. Minute synthesis of extremely stable gold nanoparticles

    International Nuclear Information System (INIS)

    Zhou Min; Wang Baoxiang; Rozynek, Zbigniew; Xie Zhaohui; Fossum, Jon Otto; Yu Xiaofeng; Raaen, Steinar

    2009-01-01

    We describe a rapid environmentally friendly wet-chemical approach to synthesize extremely stable non-toxic, biocompatible, water-soluble monodispersed gold nanoparticles (AuNPs) in one step at room temperature. The particles have been successfully achieved in just a few minutes by merely adding sodium hydroxide (NaOH) acting as an initiator for the reduction of HAuCl 4 in aqueous solution in the presence of polyvinylpyrrolidone (PVP) without the use of any reducing agent. It is also proved to be highly efficient for the preparation of AuNPs with controllable sizes. The AuNPs show remarkable stability in water media with high concentrations of salt, various buffer solutions and physiological conditions in biotechnology and biomedicine. Moreover, the AuNPs are also non-toxic at high concentration (100 μM). Therefore, it provides great opportunities to use these AuNPs for biotechnology and biomedicine. This new approach also involved several green chemistry concepts, such as the selection of environmentally benign reagents and solvents, without energy consumption, and less reaction time.

  10. Stable boron nitride diamondoids as nanoscale materials

    International Nuclear Information System (INIS)

    Fyta, Maria

    2014-01-01

    We predict the stability of diamondoids made up of boron and nitrogen instead of carbon atoms. The results are based on quantum-mechanical calculations within density functional theory (DFT) and show some very distinct features compared to the regular carbon-based diamondoids. These features are evaluated with respect to the energetics and electronic properties of the boron nitride diamondoids as compared to the respective properties of the carbon-based diamondoids. We find that BN-diamondoids are overall more stable than their respective C-diamondoid counterparts. The electronic band-gaps (E g ) of the former are overall lower than those for the latter nanostructures but do not show a very distinct trend with their size. Contrary to the lower C-diamondoids, the BN-diamondoids are semiconducting and show a depletion of charge on the nitrogen site. Their differences in the distribution of the molecular orbitals, compared to their carbon-based counterparts, offer additional bonding and functionalization possibilities. These tiny BN-based nanostructures could potentially be used as nanobuilding blocks complementing or substituting the C-diamondoids, based on the desired properties. An experimental realization of boron nitride diamondoids remains to show their feasibility. (paper)

  11. Unit of stable isotopic N15 analysis

    International Nuclear Information System (INIS)

    Cabrera de Bisbal, Evelin; Paredes U, Maria

    1997-01-01

    The continuous and growing demand of crops and cattle for the domestic inhabitants, forces the search of technical solutions in agriculture. One of the solutions able to be covered in a near future it is the escalation of agricultural production in lands already being cultivated, either by means of an intensification of cultivation and / or increasing the unitary yields. In the intensive cropping systems, the crops extract substantial quantities of nutriments that is recovered by means of the application of fertilizers. Due to the lack of resources and to the increase of commercial inputs prices, it has been necessary to pay attention to the analysis and improvement of low inputs cropping systems and to the effective use of resources. Everything has made to establish a concept of plant nutrition focused system, which integrate the sources of nutriments for plants and the production factors of crops in a productive cropping system, to improve the fertility of soils, the agricultural productivity and profitability. This system includes the biggest efficiency of chemical fertilizers as the maximum profit of alternative sources of nutriments, such as organic fertilizers, citrate-phosphate rocks and biological nitrogen fixation. By means of field experiments under different environmental conditions (soils and climate) it can be determined the best combination of fertilizers practice (dose, placement, opportunity and source) for selected cropping systems. The experimentation with fertilizer, marked with stable and radioactive isotopes, provides a direct and express method to obtain conclusive answers to the questions: where, when and how should be applied. The fertilizers marked with N 1 5 have been used to understand the application of marked fertilizer to the cultivations, and the determination of the proportion of crops nutritious element derived from fertilizer. The isotopic techniques offer a fast and reliable mean to obtain information about the distribution of

  12. Stable gastric pentadecapeptide BPC 157 and bupivacaine.

    Science.gov (United States)

    Zivanovic-Posilovic, Gordana; Balenovic, Diana; Barisic, Ivan; Strinic, Dean; Stambolija, Vasilije; Udovicic, Mario; Uzun, Sandra; Drmic, Domagoj; Vlainic, Josipa; Bencic, Martina Lovric; Sindic, Aleksandra; Seiwerth, Sven; Sikiric, Predrag

    2016-12-15

    Bupivacaine toxicity following accidental overdose still lacks therapeutic solution. However, there are major arguments for testing BPC 157 against bupivacaine toxicity in vivo in rats, in particular, and then finally, in vitro. These are: the lack of any known BPC 157 toxicity, a lifesaving effect via the mitigation of arrhythmias in rats underwent hyperkalemia or digitalis toxicity, the elimination of hyperkalemia and arrhythmias in rats underwent succinylcholine toxicity and finally, the reduction of potassium-induced depolarization in vitro (in HEK293 cells) in severe hyperkalemia. Most importantly, BPC 157 successfully prevents and counteracts bupivacaine cardiotoxicity; BPC 157 is effective even against the worst outcomes such as a severely prolonged QRS complex. Here, rats injected with bupivacaine (100mg/kg IP) exhibited bradycardia, AV-block, ventricular ectopies, ventricular tachycardia, T-wave elevation and asystole. All of the fatalities had developed T-wave elevation, high-degree AV-block, respiratory arrest and asystole. These were largely counteracted by BPC 157 administration (50µg/kg, 10µg/kg, 10ng/kg, or 10pg/kg IP) given 30min before or 1min after the bupivacaine injection. When BPC 157 was given 6min after bupivacaine administration, and after the development of prolonged QRS intervals (20ms), the fatal outcome was markedly postponed. Additionally, the effect of bupivacaine on cell membrane depolarization was explored by measuring membrane voltages (Vm) in HEK293 cells. Bupivacaine (1mM) alone caused depolarization of the cells, while in combination with BPC 157 (1µm), the bupivacaine-induced depolarization was inhibited. Together, these findings suggest that the stable gastric pentadecapeptide BPC 157 should be a potential antidote for bupivacaine cardiotoxicity. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Stable isotope separation by thermal diffusion

    International Nuclear Information System (INIS)

    Vasaru, Gheorghe

    2001-01-01

    Thermal diffusion in both gaseous and liquid phase has been subject of extensive experimental and theoretical investigations, especially after the invention of K. Clusius and G. Dickel of the thermal diffusion column, sixty three years ago. This paper gives a brief overview of the most important research and developments performed during the time at the National Institute for Research and Development for Isotopic and Molecular Technology (ITIM) at Cluj - Napoca, Romania in the field of separation of stable isotopes by thermal diffusion. An retrospective analysis of the research and results concerning isotope separation by thermal diffusion entails the following conclusions: - thermal diffusion is an adequate method for hydrogen isotope separation (deuterium and tritium) and for noble gas isotope separation (He, Ne, Ar, Kr, Xe); - thermal diffusion is attractive also for 13 C enrichment using methane as raw material for separation, when annual yields of up to 100 g are envisaged; - lately, the thermal diffusion appears to be chosen as a final enrichment step for 17 O. An obvious advantage of this method is its non-specificity, i.e. the implied equipment can be utilized for isotope separation of other chemical elements too. Having in view the low investment costs for thermal diffusion cascades the method appears economically attractive for obtaining low-scale, laboratory isotope production. The paper has the following content: 1. The principle of method; 2. The method's application; 3. Research in the field of thermal diffusion at ITIM; 4. Thermal diffusion cascades for N, C, Ne, Ar and Kr isotope separation; 5. Conclusion

  14. Applications of stable isotopes in agriculture

    International Nuclear Information System (INIS)

    Koren'kov, D.A.; Faust, Kh.

    1977-01-01

    The stable isotope 15 N has become widely used in agricultural studies. With it one can determine the true uptake of fertilizer and soil nitrogen by different crops as a function of their particular biological characteristics. Under field conditions, the extent of fertilizer nitrogen uptake by plants does not as a rule exceed 50%, being less for winter cereals and significantly more for perennial grasses. Applied fertilizer nitrogen, by intensifying the mobilization processes, increases the mobility of soil nitrogen. As a result, the accessibility of soil nitrogen to plants increases, and there is a greater chance of its being lost through washing-out. A considerable fraction of fertilizer nitrogen (on average 20-30%) becomes fixed in the soil in compounds which are not easily hydrolized and hence not readily available to plants. Nitrogen fixed in fulvic acids and non-specific compounds is the most mobile and can be used by plants. Fertilizer nitrogen in the soil undergoes various changes, as a result of which some is lost in the form of gaseous compounds. A certain amount of fertilizer nitrogen may become lost through washing-out. On the basis of 15 N investigations, it is possible to find ways of increasing the effectiveness of nitrogenous fertilizers and reducing nitrogen losses - for example, fertilizer application closer to the beginning of the period of active utilization of nutrients by plants, selection of more efficient fertilizer forms and the use of nitrification inhibitors. The wider employment of 15 N in agricultural studies should become possible through the use of cheaper compounds depleted or slightly enriched in 15 N. (author)

  15. Stable configurations of graphene on silicon

    Energy Technology Data Exchange (ETDEWEB)

    Javvaji, Brahmanandam; Shenoy, Bhamy Maithry [Department of Aerospace Engineering, Indian Institute of Science, Bangalore 560012 (India); Mahapatra, D. Roy, E-mail: droymahapatra@aero.iisc.ernet.in [Department of Aerospace Engineering, Indian Institute of Science, Bangalore 560012 (India); Ravikumar, Abhilash [Department of Metallurgical and Materials Engineering, National Institute of Technology Karnataka, Surathkal 575025 (India); Hegde, G.M. [Center for Nano Science and Engineering, Indian Institute of Science, Bangalore 560012 (India); Rizwan, M.R. [Department of Metallurgical and Materials Engineering, National Institute of Technology Karnataka, Surathkal 575025 (India)

    2017-08-31

    Highlights: • Simulations of epitaxial growth process for silicon–graphene system is performed. • Identified the most favourable orientation of graphene sheet on silicon substrate. • Atomic local strain due to the silicon–carbon bond formation is analyzed. - Abstract: Integration of graphene on silicon-based nanostructures is crucial in advancing graphene based nanoelectronic device technologies. The present paper provides a new insight on the combined effect of graphene structure and silicon (001) substrate on their two-dimensional anisotropic interface. Molecular dynamics simulations involving the sub-nanoscale interface reveal a most favourable set of temperature independent orientations of the monolayer graphene sheet with an angle of ∽15° between its armchair direction and [010] axis of the silicon substrate. While computing the favorable stable orientations, both the translation and the rotational vibrations of graphene are included. The possible interactions between the graphene atoms and the silicon atoms are identified from their coordination. Graphene sheet shows maximum bonding density with bond length 0.195 nm and minimum bond energy when interfaced with silicon substrate at 15° orientation. Local deformation analysis reveals probability distribution with maximum strain levels of 0.134, 0.047 and 0.029 for 900 K, 300 K and 100 K, respectively in silicon surface for 15° oriented graphene whereas the maximum probable strain in graphene is about 0.041 irrespective of temperature. Silicon–silicon dimer formation is changed due to silicon–carbon bonding. These results may help further in band structure engineering of silicon–graphene lattice.

  16. Tempered stable distributions stochastic models for multiscale processes

    CERN Document Server

    Grabchak, Michael

    2015-01-01

    This brief is concerned with tempered stable distributions and their associated Levy processes. It is a good text for researchers interested in learning about tempered stable distributions.  A tempered stable distribution is one which takes a stable distribution and modifies its tails to make them lighter. The motivation for this class comes from the fact that infinite variance stable distributions appear to provide a good fit to data in a variety of situations, but the extremely heavy tails of these models are not realistic for most real world applications. The idea of using distributions that modify the tails of stable models to make them lighter seems to have originated in the influential paper of Mantegna and Stanley (1994). Since then, these distributions have been extended and generalized in a variety of ways. They have been applied to a wide variety of areas including mathematical finance, biostatistics,computer science, and physics.

  17. Applications of stable isotope analysis in mammalian ecology.

    Science.gov (United States)

    Walter, W David; Kurle, Carolyn M; Hopkins, John B

    2014-01-01

    In this editorial, we provide a brief introduction and summarize the 10 research articles included in this Special Issue on Applications of stable isotope analysis in mammalian ecology. The first three articles report correction and discrimination factors that can be used to more accurately estimate the diets of extinct and extant mammals using stable isotope analysis. The remaining seven applied research articles use stable isotope analysis to address a variety of wildlife conservation and management questions from the oceans to the mountains.

  18. Tukey max-stable processes for spatial extremes

    KAUST Repository

    Xu, Ganggang

    2016-09-21

    We propose a new type of max-stable process that we call the Tukey max-stable process for spatial extremes. It brings additional flexibility to modeling dependence structures among spatial extremes. The statistical properties of the Tukey max-stable process are demonstrated theoretically and numerically. Simulation studies and an application to Swiss rainfall data indicate the effectiveness of the proposed process. © 2016 Elsevier B.V.

  19. Stable SU(5) monopoles with higher magnetic charge

    International Nuclear Information System (INIS)

    Miyamoto, S.; Sato, H.; Tomohiro, S.

    1985-01-01

    Taking into account the electroweak breaking effects, some multiply charged monopoles were shown to be stable by Gardner and Harvey. We give the explicit Ansa$uml: tze for finite-energy, nonsingular solutions of these stable higher-strength monopoles with eg = 1,(3/2),3. We also give the general stability conditions and the detailed behavior of the interaction potentials between two monopoles which produce the stable higher-strength monopoles

  20. Sense of Humor, Stable Affect, and Psychological Well-Being

    Directory of Open Access Journals (Sweden)

    Arnie Cann

    2014-08-01

    Full Text Available A good sense of humor has been implicated as a quality that could contribute to psychological well-being. The mechanisms through which sense of humor might operate include helping to reappraise threats, serving as a character strength, or facilitating happiness. The current research attempts to integrate these possibilities by examining whether a good sense of humor might operate globally by helping to maintain a more stable positive affect. Stable positive affect has been shown to facilitate more effective problem solving and to build resilience. However, not all humor is adaptive humor, so we also examine the roles that different styles of humor use might play. Individual differences in humor styles were used to predict stable levels of affect. Then, in a longitudinal design, humor styles and stable affect were used to predict subsequent resilience and psychological health. The results indicated that stable affect was related to resilience and psychological well-being, and that a sense of humor that involves self-enhancing humor, humor based on maintaining a humorous perspective about one’s experiences, was positively related to stable positive affect, negatively related to stable negative affect, and was mediated through stable affect in influencing resilience, well-being and distress. Thus, while a good sense of humor can lead to greater resilience and better psychological health, the current results, focusing on stable affect, find only self-enhancing humor provides reliable benefits.

  1. Tellurium Stable Isotopes as a Paleoredox Proxy

    Science.gov (United States)

    Wasserman, N.; Johnson, T. M.

    2017-12-01

    Despite arguments for variably-oxygenated shallow waters and anoxic deep marine waters, which delayed animal development until the Neoproterozoic Oxidation Event, the magnitude of atmospheric oxygen during the Proterozoic is still uncertain [1]. The evidence for low pO2 (<0.1-1% PAL) is based on geochemical and isotopic proxies, which track the mobilization of Fe and Mn on the continents. For example, large chromium isotope shifts occur at the Neoproterozoic Oxidation Event due to the initiation of Cr redox cycling, but this proxy is insensitive to fluctuations in the lower-pO2 conditions at other times during the Proterozoic. Tellurium, a metalloid with a lower threshold to oxidation, may be sensitive to pO2 shifts in a lower range. In the reduced forms, Te(-II) and Te(0), the element is insoluble and immobile. However, in the more oxidized phases, Te(IV) and Te(VI), Te can form soluble oxyanions (though it tends to adsorb to Fe-oxyhydroxides and clays) [2]. Te stable isotopes have been shown to fractionate during abiotic or biologic reduction of Te(VI) or Te(IV) to elemental Te(0) [3, 4]. Utilizing hydride generation MC-ICP-MS, we are able to obtain high precision (2σ 0.04‰) measurements of δ128Te/125Te for natural samples containing < 10 ng of Te. A suite of Phanerozoic and Proterozoic ironstones show significant variation in δ128Te/125Te (<0.5‰), suggesting that the Te redox cycle was active during the Proterozoic. Future directions will include Te isotope measurements of Precambrian paleosols to determine natural isotope variation before the Great Oxidation Event and experiments to determine fractionation during adsorption to Fe-oxyhydroxides. [1] Planavsky et al. (2014) Science 346 (6209), pp. 635-638 [2] Qin et al. (2017) Environmental Science and Technology 51 (11), pp 6027-6035 [3] Baesman et al. (2007) Applied Environmental Microbiology 73 (7), pp 2135-2143 [4] Smithers and Krause (1968) Canadian Journal of Chemistry 46(4): pp 583-591

  2. Use of FISH-translocations analyses for retrospective biological dosimetry: How stable are stable chromosome aberrations?

    International Nuclear Information System (INIS)

    Darroudi, F.

    2000-01-01

    Chromosome aberrations, in particular dicentrics, in peripheral blood lymphocytes are used to estimate the absorbed dose immediately following a radiation accident. However, difficulties for dose estimation arise with old exposures, due to a decline of cells containing unstable dicentric aberrations. The fluorescence in situ hybridisation (FISH) technique employing chromosome specific DNA libraries to 'paint' individual human chromosomes has opened new perspectives for rapid and reliable detection of stable chromosome aberrations such as translocations. The inherent stability of translocations over cell generations has enabled them to be used as a biodosemeter. However, due to the limited life of circulating T-lymphocytes, a level of uncertainty exists on the long-term persistence of stable translocations. The objectives of the present work are to present the current state of knowledge on the stability of translocations detected by FISH. The following aspects have been considered; (1) experience so far of retrospective biological dosimetry in humans following accidental and occupational over-exposure, (2) animal studies using mice and monkeys, (3) the influence of subsequent cell divisions on the yield and persistence of translocations following in vitro irradiation of human lymphocytes, and (4) the needs for further work to standardise and validate the use of FISH as a biological dosemeter, and to investigate the influence of various parameters such as radiation quality, dose rate and the discrimination of sub-types of translocations on persistence. (author)

  3. Exploring Scintillometry in the Stable Atmospheric Surface Layer

    NARCIS (Netherlands)

    Hartogensis, O.K.

    2006-01-01

    The main objective of this thesis is to investigate observation methods of heat and momentum exchange and key variables that characterise turbulence in the atmospheric stable surface layer (SSL), a layer defined as the lower part of the stable boundary layer (SBL) where surface fluxes do not change

  4. Stable isotope methodology and its application to nutrition and gastroenterology

    International Nuclear Information System (INIS)

    Klein, P.D.; Hachey, D.L.; Wong, W.W.; Abrams, S.A.

    1993-01-01

    This report describes the activities of the Stable Isotope Laboratory in its function as a core resource facility for stable isotope applications in human nutrition research. Three aspects are covered: Training of visitors, assessment of new instrumentation, and development of new methodology. The research achievements of the laboratory are indicated in the publications that appeared during this period. (author). 23 refs

  5. Optimization for getting stable plasma initiation in JT-60

    International Nuclear Information System (INIS)

    Yoshino, Ryuji; Neyatani, Yuzuru; Abe, T.

    1988-06-01

    This paper analyses the plasma current build-up just after the breakdown, and investigates the method for obtaining more stable plasma initiation with reduced Volt-second consumption. Control of the amount of particles contained in the wall is necessary for getting the optimum plasma density just after the breakdown, and is essential for obtaining the stable current build-up. (author)

  6. Biomedical applications of mass spectrometry. Clinical uses of stable isotopes

    International Nuclear Information System (INIS)

    Krahmer, U.I.; McCloskey, J.A.

    1978-01-01

    The review covers typical or important examples of stable isotope usage in clinical fields during the period since the last triennial mass spectrometry conference in 1973. Items are included which involve uses of stable isotopes in human or clinically oriented studies, including measurements carried out on materials of human origin. 163 references. (U.K.)

  7. Solutions for the stable roommates problem with payments

    NARCIS (Netherlands)

    Biró, Péter; Bomhoff, M.J.; Golovach, Petr A.; Kern, Walter

    2014-01-01

    The stable roommates problem with payments has as input a graph G = (V , E ) with an edge weighting w : E → R≥0 and the problem is to find a stable solution. By pinpointing a relationship to the accessibility of the coalition structure core of matching games, we give a constructive proof for showing

  8. DFT computations of the lattice constant, stable atomic structure and ...

    African Journals Online (AJOL)

    This paper presents the most stable atomic structure and lattice constant of Fullerenes (C60). FHI-aims DFT code was used to predict the stable structure and the computational lattice constant of C60. These were compared with known experimental structures and lattice constants of C60. The results obtained showed that ...

  9. Formulation of stable protein powders by supercritical fluid drying

    NARCIS (Netherlands)

    Jovanović, N.

    2007-01-01

    Protein pharmaceuticals are potent drugs for the treatment of several chronic and life-threatening diseases. However, the complex and sensitive nature of protein molecules requires special attention in the development of stable dosage forms. Developing stable aqueous protein formulations is often a

  10. Method for recovering or recirculating stable nitroxide radicals

    NARCIS (Netherlands)

    Heeres, Andre; Van Doren, Hendrik Arend; Bleeker, Ido Pieter; Gotlieb, Kornelis Fester.

    1996-01-01

    The invention relates fo a method for recovering stable nitroxide radicals, wherein at least a part of a reaction mixt. consisting of a soln. or suspension, or a filtrate or supernatant of a suspension, in which stable nitroxide radicals are present in non-solid form, is subjected to an azeotropic

  11. Stability of Picard Bundle Over Moduli Space of Stable Vector ...

    Indian Academy of Sciences (India)

    Abstract. Answering a question of [BV] it is proved that the Picard bundle on the moduli space of stable vector bundles of rank two, on a Riemann surface of genus at least three, with fixed determinant of odd degree is stable.

  12. Stable isotope geochemistry. 3. rev. and enl. ed.

    International Nuclear Information System (INIS)

    Hoefs, J.

    1987-01-01

    Stable Isotope Geochemistry is an authoritative book comprising theoretical and experimental principles; surveying important fractionation mechanisms affecting the most important elements; discussing the natural variations of geologically important reservoirs. This updated 3rd edition, with a completely rewritten and extended main part, contains two new chapters on stable isotope composition of mantle material and on changes of the ocean during the geological past. (orig.)

  13. Trophic position of coexisting krill species: a stable isotope approach

    DEFF Research Database (Denmark)

    Agersted, Mette Dalgaard; Bode, Antonio; Nielsen, Torkel Gissel

    2014-01-01

    Four krill species with overlapping functional biology coexist in Greenland waters. Here, we used stable isotopes to investigate and discuss their trophic role and mode of coexistence. Bulk carbon (δ13C) and nitrogen (δ15N) stable isotope analyses of Thysanoessa longicaudata, T. inermis, T. raschii...

  14. Stable isotopes for improving human nutrition

    International Nuclear Information System (INIS)

    Uauy, Ricardo

    2001-01-01

    recent FAO review of nutrition programs in 19 Latin American countries found that over 20 percent of the population - approximately 83 million people out of an estimated 414 million in the study countries - receives some level of benefits in nutrition-related programs. The allocation of limited national and international assistance resources for these activities in the region is on the order of several billion dollars annually. Undoubtedly these programs are influencing child growth. Significant reductions in underweight and wasting have occurred; but stunting has been more resistant to change. In this setting providing food supplements may be beneficial for some while it may be detrimental for others. The definition of who should benefit from the programs and what is the right combination of nutrients/foods, education, and lifestyle interventions that is required to optimise nutrition and health at each stage of the life cycle is a truly complex problem. This demands the use of the best scientific tools to define who should benefit, what should done and measured as an outcome, how programs should be evaluated, when programs should be expanded, and when they should be stopped. Isotopic and nuclear techniques are tools, not solutions. This presentation will serve to demonstrate how isotopes can contribute to refining nutrition interventions and their impact on public health. Isotopic methods can shorten the time needed to evaluate impact, because they provide sensitive measurements of biological effects. They are faster than traditional methods such as anthropometry for detecting changes in growth and body composition. Micronutrient malnutrition, and especially the bioavailability of vitamins and minerals from traditional foods, are not well evaluated using routine biochemical methods. Radioisotopes have been used successfully in the past. But recent developments in stable isotope techniques offer unique advantages for the design and evaluation of programmes that address

  15. Stable glomerular filtration rate in normotensive IDDM patients with stable microalbuminuria. A 5-year prospective study

    DEFF Research Database (Denmark)

    Mathiesen, E R; Feldt-Rasmussen, B; Hommel, E

    1997-01-01

    patients with persistent microalbuminuria (mean urinary albumin excretion [UAE] 84 mg/24 h [range 30-300]) were followed prospectively for 5 years of clinical examinations that included the measurement of GFR (51Cr-labeled EDTA clearance) at least once a year. The mean GFR at baseline was 120 +/- 18 ml x....... Out of 40 patients, 14 progressed to diabetic nephropathy (UAE > 300 mg/24 h). These patients had a significant reduction in GFR (mean -2.2 +/- 3.8 ml x min-1 x year-1; P = 0.05), while GFR remained stable in the remaining 26 patients with nonprogressive microalbuminuria (change in GFR 0.5 +/- 2.1 ml...

  16. High-Order Entropy Stable Formulations for Computational Fluid Dynamics

    Science.gov (United States)

    Carpenter, Mark H.; Fisher, Travis C.

    2013-01-01

    A systematic approach is presented for developing entropy stable (SS) formulations of any order for the Navier-Stokes equations. These SS formulations discretely conserve mass, momentum, energy and satisfy a mathematical entropy inequality. They are valid for smooth as well as discontinuous flows provided sufficient dissipation is added at shocks and discontinuities. Entropy stable formulations exist for all diagonal norm, summation-by-parts (SBP) operators, including all centered finite-difference operators, Legendre collocation finite-element operators, and certain finite-volume operators. Examples are presented using various entropy stable formulations that demonstrate the current state-of-the-art of these schemes.

  17. Stable black phosphorus quantum dots for alkali PH sensor

    Science.gov (United States)

    Guo, Weilan; Song, Haizeng; Yan, Shancheng

    2018-01-01

    Black phosphorus, as a new two-dimensional material has been widely used in sensors, photovoltaic devices, etc. However, thin layered black phosphorus chemically degrades rapidly under ambient and aqueous conditions, which hinders the application of it in the chemical sensors. In this work, stable black phosphorus quantum dots (BPQDs) in solution are successfully synthesized by functionalization with 4-nitrobenzene-diazonium (4-NBD). The stable BPQDs are investigated by TEM, AFM, Raman, and UV-absorption. As a potential application, the stable BPQDs are used as sensors in alkali solution, which exhibit outstanding performance. Our work paves the way towards a new application with BPQDs in solution.

  18. Use of stable isotopes in human nutrition in Senegal

    International Nuclear Information System (INIS)

    2016-01-01

    In Senegal, the Laboratory of Nutrition of the Department of Animal Biology of the Faculty of Science and Technology of UCAD has been using stable isotopic techniques for nearly twenty years. Stable isotopes were applied to different target populations to measure milk production, exclusive breastfeeding, body composition, micronutrient bioavailability and total energy expenditure.The application of stable isotopic techniques in nutrition has contributed to advocacy for exclusive breastfeeding for up to 6 months in Senegal. It enabled government decision-makers to obtain essential information on the quality of foods needed for optimal effect during pregnancy and for infant growth and the results were reflected in the national policy on micronutrient supplementation.

  19. Stable monopole-antimonopole string background in SU(2) QCD

    International Nuclear Information System (INIS)

    Cho, Y.M.; Pak, D.G.

    2006-01-01

    Motivated by the instability of the Savvidy-Nielsen-Olesen (SNO) vacuum we make a systematic search for a stable magnetic background in pure SU(2) QCD. It is shown that a pair of axially symmetric monopole and antimonopole strings is stable, provided that the distance between the two strings is less than a critical value. The existence of a stable monopole-antimonopole string background strongly supports that a magnetic condensation of monopole-antimonopole pairs can generate a dynamical symmetry breaking, and thus the magnetic confinement of color in QCD

  20. Application of stable isotopes in ecological research : it's all elemental

    International Nuclear Information System (INIS)

    Rogers, K.M.

    2005-01-01

    Stable isotopes have been used traditionally in the physical sciences, primarily in geochemistry, sedimentology, and oceanography. Increasingly, however, stable isotopes are also being used in the biological sciences. Application of stable isotopes in ecological studies can provide new and innovative ways of examining a host of topics of fundamental importance to biologists. These topics include, among others, feeding ecology and food webs, nutrient flow and assimilation, habitat use, migration patterns, and distribution and discrimination of species subpopulations. Furthermore, ecological research with isotopes can be applied at many levels (i.e. tissue and organ, whole animal, population, community, and ecosystem). (author). 38 refs., 2 figs

  1. A Model Describing Stable Coherent Synchrotron Radiation in Storage Rings

    International Nuclear Information System (INIS)

    Sannibale, F.

    2004-01-01

    We present a model describing high power stable broadband coherent synchrotron radiation (CSR) in the terahertz frequency region in an electron storage ring. The model includes distortion of bunch shape from the synchrotron radiation (SR), which enhances higher frequency coherent emission, and limits to stable emission due to an instability excited by the SR wakefield. It gives a quantitative explanation of several features of the recent observations of CSR at the BESSY II storage ring. We also use this model to optimize the performance of a source for stable CSR emission

  2. A model describing stable coherent synchrotron radiation in storage rings

    International Nuclear Information System (INIS)

    Sannibale, F.; Byrd, J.M.; Loftsdottir, A.; Venturini, M.; Abo-Bakr, M.; Feikes, J.; Holldack, K.; Kuske, P.; Wuestefeld, G.; Huebers, H.-W.; Warnock, R.

    2004-01-01

    We present a model describing high power stable broadband coherent synchrotron radiation (CSR) in the terahertz frequency region in an electron storage ring. The model includes distortion of bunch shape from the synchrotron radiation (SR), which enhances higher frequency coherent emission, and limits to stable emission due to an instability excited by the SR wakefield. It gives a quantitative explanation of several features of the recent observations of CSR at the BESSY II storage ring. We also use this model to optimize the performance of a source for stable CSR emission

  3. Stable isotope labeling strategy based on coding theory

    Energy Technology Data Exchange (ETDEWEB)

    Kasai, Takuma; Koshiba, Seizo; Yokoyama, Jun; Kigawa, Takanori, E-mail: kigawa@riken.jp [RIKEN Quantitative Biology Center (QBiC), Laboratory for Biomolecular Structure and Dynamics (Japan)

    2015-10-15

    We describe a strategy for stable isotope-aided protein nuclear magnetic resonance (NMR) analysis, called stable isotope encoding. The basic idea of this strategy is that amino-acid selective labeling can be considered as “encoding and decoding” processes, in which the information of amino acid type is encoded by the stable isotope labeling ratio of the corresponding residue and it is decoded by analyzing NMR spectra. According to the idea, the strategy can diminish the required number of labelled samples by increasing information content per sample, enabling discrimination of 19 kinds of non-proline amino acids with only three labeled samples. The idea also enables this strategy to combine with information technologies, such as error detection by check digit, to improve the robustness of analyses with low quality data. Stable isotope encoding will facilitate NMR analyses of proteins under non-ideal conditions, such as those in large complex systems, with low-solubility, and in living cells.

  4. Stable isotope labeling strategy based on coding theory

    International Nuclear Information System (INIS)

    Kasai, Takuma; Koshiba, Seizo; Yokoyama, Jun; Kigawa, Takanori

    2015-01-01

    We describe a strategy for stable isotope-aided protein nuclear magnetic resonance (NMR) analysis, called stable isotope encoding. The basic idea of this strategy is that amino-acid selective labeling can be considered as “encoding and decoding” processes, in which the information of amino acid type is encoded by the stable isotope labeling ratio of the corresponding residue and it is decoded by analyzing NMR spectra. According to the idea, the strategy can diminish the required number of labelled samples by increasing information content per sample, enabling discrimination of 19 kinds of non-proline amino acids with only three labeled samples. The idea also enables this strategy to combine with information technologies, such as error detection by check digit, to improve the robustness of analyses with low quality data. Stable isotope encoding will facilitate NMR analyses of proteins under non-ideal conditions, such as those in large complex systems, with low-solubility, and in living cells

  5. A theory of stable-isotope dilution mass spectrometry

    International Nuclear Information System (INIS)

    Pickup, J.F.; McPherson, C.K.

    1977-01-01

    In order to perform quantitative analysis using stable isotope dilution with mass spectrometry, an equation is derived which describes the relationship between the relative proportions of natural and labelled material and measured isotope ratios

  6. On the classification of complex vector bundles of stable rank

    Indian Academy of Sciences (India)

    , the tuples of cohomology classes on a compact, complex manifold, corresponding to the Chern classes of a complex vector bundle of stable rank. This classification becomes more effective on generalized flag manifolds, where the Lie ...

  7. Stable isotope views on ecosystem function: challenging or challenged?

    Science.gov (United States)

    Resco, Víctor; Querejeta, José I; Ogle, Kiona; Voltas, Jordi; Sebastià, Maria-Teresa; Serrano-Ortiz, Penélope; Linares, Juan C; Moreno-Gutiérrez, Cristina; Herrero, Asier; Carreira, José A; Torres-Cañabate, Patricia; Valladares, Fernando

    2010-06-23

    Stable isotopes and their potential for detecting various and complex ecosystem processes are attracting an increasing number of scientists. Progress is challenging, particularly under global change scenarios, but some established views have been challenged. The IX meeting of the Spanish Association of Terrestrial Ecology (AAET, Ubeda, 18-22 October 2009) hosted a symposium on the ecology of stable isotopes where the linear mixing model approach of partitioning sinks and sources of carbon and water fluxes within an ecosystem was challenged, and new applications of stable isotopes for the study of plant interactions were evaluated. Discussion was also centred on the need for networks that monitor ecological processes using stable isotopes and key ideas for fostering future research with isotopes.

  8. A new intermediate for the production of flexible stable polymers

    Science.gov (United States)

    Webster, J. A.

    1973-01-01

    Method of incorporating ether linkages into perfluoroalkylene segment of a dianydride intermediate yields intermediate that may be used in synthesis of flexible, stable polyimides for use as high-temperature, solvent-resistant sealants.

  9. Stable Blind Deconvolution over the Reals from Additional Autocorrelations

    KAUST Repository

    Walk, Philipp; Hassibi, Babak

    2017-01-01

    that under a sufficient zero separation of the corresponding signal in the $z-$domain, a stable reconstruction against additive noise is possible. Moreover, the stability constant depends on the signal dimension and on the signals magnitude of the first

  10. Distribution of radiocesium and stable elements within a pine tree

    International Nuclear Information System (INIS)

    Yoshida, S.; Watanabe, M.; Suzuki, A.

    2011-01-01

    Distributions of 137 Cs and stable elements in different parts of a pine tree collected in Chernobyl-contaminated area in Belarus were determined. Samples include annual tree rings of wood, branches and needles with different ages. The concentrations of 137 Cs and stable Cs in annual tree rings were the highest in cambium and decreased sharply towards inside. The youngest needles and branches contained higher 137 Cs and stable Cs than older ones. The concentration of 137 Cs being highest in growing parts suggests the highest radiation dose to the radiation-sensitive parts of tree. Distribution patterns of stable elements in pine tree differ among the elements. Distributions similar to those of Cs were observed for K and Rb, suggesting that alkaline metals tend to be translocated to young growing parts of pine tree. A similar distribution was also observed for phosphorus. Distributions of alkaline earth metals and several heavy metals were different from those of alkaline metals. (authors)

  11. Development of stable marker-free nuclear transformation strategy ...

    African Journals Online (AJOL)

    Development of stable marker-free nuclear transformation strategy in the green microalga Chlorella vulgaris. ... into Chlorella by electroporation has very low stability and it is hard to screen the transformants without antibiotic marker genes.

  12. The use of stable isotopes in medicinal chemistry

    International Nuclear Information System (INIS)

    Halliday, D.; Thompson, G.N.

    1988-01-01

    Stable isotopes have been employed increasingly as tracers over the last decade both to provide the clinician with the opportunity to broaden, in a quantitative manner, discrete areas of diagnosis and research, and the clinical chemist with definitive methodology for specific analyte analysis. These non-radioactive 'heavy' isotopes contain one or more extra neutrons in the nucleus compared with their more abundant 'lighter' analogues. Impetus in the application of stable isotopes for in vivo studies has come from an increased awareness of the possible harmful effects in the use of radionuclides, and a realisation of several positive advantages conferred by the use of stable isotopes in their own right - certain elements of clinical importance (especially nitrogen) lack a useable radio-nuclide equivalent; use of a 'cocktail' of stable isotopes permits a range of studies to be performed in the same patient simultaneously and, within specific constraints, serial studies can be performed in the same patients. (author)

  13. (2+1)-dimensional stable spatial Raman solitons

    International Nuclear Information System (INIS)

    Shverdin, M.Y.; Yavuz, D.D.; Walker, D.R.

    2004-01-01

    We analyze the formation, propagation, and interaction of stable two-frequency (2+1)-dimensional solitons, formed in a Raman media driven near maximum molecular coherence. The propagating light is trapped in the two transverse dimensions

  14. Stable isotope views on ecosystem function: challenging or challenged?

    Science.gov (United States)

    Resco, Víctor; Querejeta, José I.; Ogle, Kiona; Voltas, Jordi; Sebastià, Maria-Teresa; Serrano-Ortiz, Penélope; Linares, Juan C.; Moreno-Gutiérrez, Cristina; Herrero, Asier; Carreira, José A.; Torres-Cañabate, Patricia; Valladares, Fernando

    2010-01-01

    Stable isotopes and their potential for detecting various and complex ecosystem processes are attracting an increasing number of scientists. Progress is challenging, particularly under global change scenarios, but some established views have been challenged. The IX meeting of the Spanish Association of Terrestrial Ecology (AAET, Úbeda, 18–22 October 2009) hosted a symposium on the ecology of stable isotopes where the linear mixing model approach of partitioning sinks and sources of carbon and water fluxes within an ecosystem was challenged, and new applications of stable isotopes for the study of plant interactions were evaluated. Discussion was also centred on the need for networks that monitor ecological processes using stable isotopes and key ideas for fostering future research with isotopes. PMID:20015858

  15. Stable isotopes: essential tools in biological and medical research

    Energy Technology Data Exchange (ETDEWEB)

    Klein, P. D.; Hachey, D. L.; Kreek, M. J.; Schoeller, D. A.

    1977-01-01

    Recent developments in the use of the stable isotopes, /sup 13/C, /sup 15/N, /sup 17/O, and /sup 18/O, as tracers in research studies in the fields of biology, medicine, pharmacology, and agriculture are briefly reviewed. (CH)

  16. The stable stiffness triangle - drained sand during deformation cycles

    DEFF Research Database (Denmark)

    Sabaliauskas, Tomas; Ibsen, Lars Bo

    2017-01-01

    Cyclic, drained sand stiffness was observed using the Danish triaxial appa- ratus. New, deformation dependant soil property (the stable stiffness triangle) was detected. Using the the stable stiffness triangle, secant stiffness of drained sand was plausible to predict (and control) even during ir...... findings can find application in off-shore, seismic and other engi- neering practice, or inspire new branches of research and modelling wherever dynamic, cyclic or transient loaded sand is encountered....

  17. A constrained variational calculation for beta-stable matter

    International Nuclear Information System (INIS)

    Howes, C.; Bishop, R.F.; Irvine, J.M

    1978-01-01

    A method of lowest-order constrained variation previously applied by the authors to asymmetric nuclear matter is extended to include electrons and muons making the nucleon fluid electrically neutral and stable against beta decay. The equilibrium composition of a nucleon fluid is calculated as a function of baryon number density and an equation of state for beta-stable matter is deduced for the Reid soft-core interaction. (author)

  18. [Fractionation of hydrogen stable isotopes in the human body].

    Science.gov (United States)

    Siniak, Iu E; Grigor'ev, A I; Skuratov, V M; Ivanova, S M; Pokrovskiĭ, B G

    2006-01-01

    Fractionation of hydrogen stable isotopes was studied in 9 human subjects in a chamber with normal air pressure imitating a space cabin. Mass-spectrometry of isotopes in blood, urine, saliva, and potable water evidenced increases in the contents of heavy H isotope (deuterium) in the body liquids as compared with water. These results support one of the theories according to which the human organism eliminates heavy stable isotopes of biogenous chemical elements.

  19. Jealousy Graphs: Structure and Complexity of Decentralized Stable Matching

    Science.gov (United States)

    2013-01-01

    REPORT Jealousy Graphs: Structure and Complexity of Decentralized Stable Matching 14. ABSTRACT 16. SECURITY CLASSIFICATION OF: The stable matching...Franceschetti 858-822-2284 3. DATES COVERED (From - To) Standard Form 298 (Rev 8/98) Prescribed by ANSI Std. Z39.18 - Jealousy Graphs: Structure and...market. Using this structure, we are able to provide a ner analysis of the complexity of a subclass of decentralized matching markets. Jealousy

  20. Selection of medical treatment in stable angina pectoris

    DEFF Research Database (Denmark)

    Ardissino, D; Savonitto, S; Egstrup, K

    1995-01-01

    pectoris. BACKGROUND: The characteristics of anginal symptoms and the results of exercise testing are considered of great importance for selecting medical treatment in patients with chronic stable angina pectoris. However, little information is available on how this first evaluation may be used to select....... CONCLUSIONS: The results of a baseline exercise test, but not the characteristics of anginal symptoms, may offer useful information for selecting medical treatment in stable angina pectoris....

  1. Refining a brief decision aid in stable CAD: cognitive interviews

    OpenAIRE

    Kelly-Blake, Karen; Clark, Stacie; Dontje, Katherine; Olomu, Adesuwa; Henry, Rebecca C; Rovner, David R; Rothert, Marilyn L; Holmes-Rovner, Margaret

    2014-01-01

    Background We describe the results of cognitive interviews to refine the “Making Choices©” Decision Aid (DA) for shared decision-making (SDM) about stress testing in patients with stable coronary artery disease (CAD). Methods We conducted a systematic development process to design a DA consistent with International Patient Decision Aid Standards (IPDAS) focused on Alpha testing criteria. Cognitive interviews were conducted with ten stable CAD patients using the “think aloud” interview techniq...

  2. Risk following hospitalization in stable chronic systolic heart failure

    DEFF Research Database (Denmark)

    Abrahamsson, Putte; Swedberg, Karl; Borer, Jeffrey S

    2013-01-01

    We explored the impact of being hospitalized due to worsening heart failure (WHF) or a myocardial infarction (MI) on subsequent mortality in a large contemporary data set of patients with stable chronic systolic heart failure (HF).......We explored the impact of being hospitalized due to worsening heart failure (WHF) or a myocardial infarction (MI) on subsequent mortality in a large contemporary data set of patients with stable chronic systolic heart failure (HF)....

  3. A parallel approach to the stable marriage problem

    DEFF Research Database (Denmark)

    Larsen, Jesper

    1997-01-01

    This paper describes two parallel algorithms for the stable marriage problem implemented on a MIMD parallel computer. The algorithms are tested against sequential algorithms on randomly generated and worst-case instances. The results clearly show that the combination fo a very simple problem...... and a commercial MIMD system results in parallel algorithms which are not competitive with sequential algorithms wrt. practical performance. 1 Introduction In 1962 the Stable Marriage Problem was....

  4. Equilibrium contact angle or the most-stable contact angle?

    Science.gov (United States)

    Montes Ruiz-Cabello, F J; Rodríguez-Valverde, M A; Cabrerizo-Vílchez, M A

    2014-04-01

    It is well-established that the equilibrium contact angle in a thermodynamic framework is an "unattainable" contact angle. Instead, the most-stable contact angle obtained from mechanical stimuli of the system is indeed experimentally accessible. Monitoring the susceptibility of a sessile drop to a mechanical stimulus enables to identify the most stable drop configuration within the practical range of contact angle hysteresis. Two different stimuli may be used with sessile drops: mechanical vibration and tilting. The most stable drop against vibration should reveal the changeless contact angle but against the gravity force, it should reveal the highest resistance to slide down. After the corresponding mechanical stimulus, once the excited drop configuration is examined, the focus will be on the contact angle of the initial drop configuration. This methodology needs to map significantly the static drop configurations with different stable contact angles. The most-stable contact angle, together with the advancing and receding contact angles, completes the description of physically realizable configurations of a solid-liquid system. Since the most-stable contact angle is energetically significant, it may be used in the Wenzel, Cassie or Cassie-Baxter equations accordingly or for the surface energy evaluation. © 2013 Elsevier B.V. All rights reserved.

  5. Medieval Horse Stable; The Results of Multi Proxy Interdisciplinary Research

    Science.gov (United States)

    Dejmal, Miroslav; Lisá, Lenka; Fišáková Nývltová, Miriam; Bajer, Aleš; Petr, Libor; Kočár, Petr; Kočárová, Romana; Nejman, Ladislav; Rybníček, Michal; Sůvová, Zdenka; Culp, Randy; Vavrčík, Hanuš

    2014-01-01

    A multi proxy approach was applied in the reconstruction of the architecture of Medieval horse stable architecture, the maintenance practices associated with that structure as well as horse alimentation at the beginning of 13th century in Central Europe. Finally, an interpretation of the local vegetation structure along Morava River, Czech Republic is presented. The investigated stable experienced two construction phases. The infill was well preserved and its composition reflects maintenance practices. The uppermost part of the infill was composed of fresh stabling, which accumulated within a few months at the end of summer. Horses from different backgrounds were kept in the stable and this is reflected in the results of isotope analyses. Horses were fed meadow grasses as well as woody vegetation, millet, oat, and less commonly hemp, wheat and rye. Three possible explanations of stable usage are suggested. The stable was probably used on a temporary basis for horses of workers employed at the castle, courier horses and horses used in battle. PMID:24670874

  6. Wideband quin-stable energy harvesting via combined nonlinearity

    Directory of Open Access Journals (Sweden)

    Chen Wang

    2017-04-01

    Full Text Available In this work, we propose a wideband quintuple-well potential piezoelectric-based vibration energy harvester using a combined nonlinearity: the magnetic nonlinearity induced by magnetic force and the piecewise-linearity produced by mechanical impact. With extra stable states compared to other multi-stable harvesters, the quin-stable harvester can distribute its potential energy more uniformly, which provides shallower potential wells and results in lower excitation threshold for interwell motion. The mathematical model of this quin-stable harvester is derived and its equivalent piecewise-nonlinear restoring force is measured in the experiment and identified as piecewise polynomials. Numerical simulations and experimental verifications are performed in different levels of sinusoid excitation ranging from 1 to 25 Hz. The results demonstrate that, with lower potential barriers compared with tri-stable counterpart, the quin-stable arrangement can escape potential wells more easily for doing high-energy interwell motion over a wider band of frequencies. Moreover, by utilizing the mechanical stoppers, this harvester can produce significant output voltage under small tip deflections, which results in a high power density and is especially suitable for a compact MEMS approach.

  7. Multi-stable perception balances stability and sensitivity

    Directory of Open Access Journals (Sweden)

    Alexander ePastukhov

    2013-03-01

    Full Text Available We report that multi-stable perception operates in a consistent, dynamical regime, balancing the conflicting goals of stability and sensitivity. When a multi-stable visual display is viewed continuously, its phenomenal appearance reverses spontaneously at irregular intervals. We characterized the perceptual dynamics of individual observers in terms of four statistical measures: the distribution of dominance times (mean and variance and the novel, subtle dependence on prior history (correlation and time-constant.The dynamics of multi-stable perception is known to reflect several stabilizing and destabilizing factors. Phenomenologically, its main aspects are captured by a simplistic computational model with competition, adaptation, and noise. We identified small parameter volumes (~3% of the possible volume in which the model reproduced both dominance distribution and history-dependence of each observer. For 21 of 24 data sets, the identified volumes clustered tightly (~15% of the possible volume, revealing a consistent `operating regime' of multi-stable perception. The `operating regime' turned out to be marginally stable or, equivalently, near the brink of an oscillatory instability. The chance probability of the observed clustering was <0.02.To understand the functional significance of this empirical `operating regime', we compared it to the theoretical `sweet spot' of the model. We computed this `sweet spot' as the intersection of the parameter volumes in which the model produced stable perceptual outcomes and in which it was sensitive to input modulations. Remarkably, the empirical `operating regime' proved to be largely coextensive with the theoretical `sweet spot'. This demonstrated that perceptual dynamics was not merely consistent but also functionally optimized (in that it balances stability with sensitivity. Our results imply that multi-stable perception is not a laboratory curiosity, but reflects a functional optimization of perceptual

  8. Dynamics and control of twisting bi-stable structures

    Science.gov (United States)

    Arrieta, Andres F.; van Gemmeren, Valentin; Anderson, Aaron J.; Weaver, Paul M.

    2018-02-01

    Compliance-based morphing structures have the potential to offer large shape adaptation, high stiffness and low weight, while reducing complexity, friction, and scalability problems of mechanism based systems. A promising class of structure that enables these characteristics are multi-stable structures given their ability to exhibit large deflections and rotations without the expensive need for continuous actuation, with the latter only required intermittently. Furthermore, multi-stable structures exhibit inherently fast response due to the snap-through instability governing changes between stable states, enabling rapid configuration switching between the discrete number of programmed shapes of the structure. In this paper, the design and utilisation of the inherent nonlinear dynamics of bi-stable twisting I-beam structures for actuation with low strain piezoelectric materials is presented. The I-beam structure consists of three compliant components assembled into a monolithic single element, free of moving parts, and showing large deflections between two stable states. Finite element analysis is utilised to uncover the distribution of strain across the width of the flange, guiding the choice of positioning for piezoelectric actuators. In addition, the actuation authority is maximised by calculating the generalised coupling coefficient for different positions of the piezoelectric actuators. The results obtained are employed to tailor and test I-beam designs exhibiting desired large deflection between stable states, while still enabling the activation of snap-through with the low strain piezoelectric actuators. To this end, the dynamic response of the I-beams to piezoelectric excitation is investigated, revealing that resonant excitations are insufficient to dynamically trigger snap-through. A novel bang-bang control strategy, which exploits the nonlinear dynamics of the structure successfully triggers both single and constant snap-through between the stable states

  9. Effectiveness of Ivabradine in Treating Stable Angina Pectoris.

    Science.gov (United States)

    Ye, Liwen; Ke, Dazhi; Chen, Qingwei; Li, Guiqiong; Deng, Wei; Wu, Zhiqin

    2016-04-01

    Many studies show that ivabradine is effective for stable angina.This meta-analysis was performed to determine the effect of treatment duration and control group type on ivabradine efficacy in stable angina pectoris.Relevant articles in the English language in the PUBMED and EMBASE databases and related websites were identified by using the search terms "ivabradine," "angina," "randomized controlled trials," and "Iva." The final search date was November 2, 2015.Articles were included if they were published randomized controlled trials that related to ivabradine treatment of stable angina pectoris.Patients with stable angina pectoris were included.The patients were classified according to treatment duration (Angina outcomes were heart rate at rest or peak, exercise duration, and time to angina onset.Seven articles were selected. There were 3747 patients: 2100 and 1647 were in the ivabradine and control groups, respectively. The ivabradine group had significantly longer exercise duration when they had been treated for at least 3 months, but not when treatment time was less than 3 months. Ivabradine significantly improved time to angina onset regardless of treatment duration. Control group type did not influence the effect of exercise duration (significant) or time to angina onset (significant).Compared with beta-blocker and placebo, ivabradine improved exercise duration and time to onset of angina in patients with stable angina. However, its ability to improve exercise duration only became significant after at least 3 months of treatment.

  10. Ranking stability and super-stable nodes in complex networks.

    Science.gov (United States)

    Ghoshal, Gourab; Barabási, Albert-László

    2011-07-19

    Pagerank, a network-based diffusion algorithm, has emerged as the leading method to rank web content, ecological species and even scientists. Despite its wide use, it remains unknown how the structure of the network on which it operates affects its performance. Here we show that for random networks the ranking provided by pagerank is sensitive to perturbations in the network topology, making it unreliable for incomplete or noisy systems. In contrast, in scale-free networks we predict analytically the emergence of super-stable nodes whose ranking is exceptionally stable to perturbations. We calculate the dependence of the number of super-stable nodes on network characteristics and demonstrate their presence in real networks, in agreement with the analytical predictions. These results not only deepen our understanding of the interplay between network topology and dynamical processes but also have implications in all areas where ranking has a role, from science to marketing.

  11. Development of redox stable, multifunctional substrates for anode supported SOFCS

    DEFF Research Database (Denmark)

    Sudireddy, Bhaskar Reddy; Foghmoes, Søren Preben Vagn; Ramos, Tania

    2017-01-01

    Redox stable solid oxide fuel cells are beneficial in many aspects such as tolerance against system failures e.g fuel cut off and emergency shut down, but also allow for higher fuel utilization, which increases efficiency. State-ofthe-art Ni-cermet based anodes suffer from microstructural changes...... with a multifunctional anode support, the development of a two layer fuel electrode based on a redox stable strontium titanate layer for the electrochemically active layer and a redox stable Ni-YSZ support was pursued. Half-cells with well adhearing strontium titante anode layers on stateof-the-art Ni-YSZ cermet...... supports have been achieved. Redox tolerance of the half-cell depends could be increased by optimizing the redox stability of the cermet support....

  12. Do planetary seasons play a role in attaining stable climates?

    Science.gov (United States)

    Olsen, Kasper Wibeck; Bohr, Jakob

    2018-05-01

    A simple phenomenological account for planetary climate instabilities is presented. The description is based on the standard model where the balance of incoming stellar radiation and outward thermal radiation is described by the effective planet temperature. Often, it is found to have three different points, or temperatures, where the influx of radiation is balanced with the out-flux, even with conserved boundary conditions. Two of these points are relatively long-term stable, namely the point corresponding to a cold climate and the point corresponding to a hot climate. In a classical sense these points are equilibrium balance points. The hypothesis promoted in this paper is the possibility that the intermediate third point can become long-term stable by being driven dynamically. The initially unstable point is made relatively stable over a long period by the presence of seasonal climate variations.

  13. Self-similar anomalous diffusion and Levy-stable laws

    International Nuclear Information System (INIS)

    Uchaikin, Vladimir V

    2003-01-01

    Stochastic principles for constructing the process of anomalous diffusion are considered, and corresponding models of random processes are reviewed. The self-similarity and the independent-increments principles are used to extend the notion of diffusion process to the class of Levy-stable processes. Replacing the independent-increments principle with the renewal principle allows us to take the next step in generalizing the notion of diffusion, which results in fractional-order partial space-time differential equations of diffusion. Fundamental solutions to these equations are represented in terms of stable laws, and their relationship to the fractality and memory of the medium is discussed. A new class of distributions, called fractional stable distributions, is introduced. (reviews of topical problems)

  14. Stable isotope customer list and summary of shipments:

    International Nuclear Information System (INIS)

    Tracy, J.G.

    1988-03-01

    This compilation is published as an aid to those concerned with the separation and sale of stable isotopes. The information is divided into four sections: alphabetical lists of domestic and foreign customers;alphabetical lists of isotopes and services;alphabetical lists of states and countries;tabulation of the shipments, quantities, and dollars for each isotope and dollars for services divided into domestic, foreign, and DOE project categories. During FY 1987 sales of stable isotope products and services were made to 272 differnt customers, of whom 159 were domestic and 113 were foreign, representing 18 different foreign countries. The total revenue was $3,785,609 of which 12.3% was from sales to DOE project customers, 60.4% was from sales to other domestic customers, and 27.3% was from sales to foreign customers. this represented sales of 189 different stable isotopes plus associated services and was a 16.5% increase over FY 1986

  15. Stable radio frequency dissemination by simple hybrid frequency modulation scheme.

    Science.gov (United States)

    Yu, Longqiang; Wang, Rong; Lu, Lin; Zhu, Yong; Wu, Chuanxin; Zhang, Baofu; Wang, Peizhang

    2014-09-15

    In this Letter, we propose a fiber-based stable radio frequency transfer system by a hybrid frequency modulation scheme. Creatively, two radio frequency signals are combined and simultaneously transferred by only one laser diode. One frequency component is used to detect the phase fluctuation, and the other one is the derivative compensated signal providing a stable frequency for the remote end. A proper ratio of the frequencies of the components is well maintained by parameter m to avoid interference between them. Experimentally, a stable 200 MHz signal is transferred over 100 km optical fiber with the help of a 1 GHz detecting signal, and fractional instability of 2×10(-17) at 10(5) s is achieved.

  16. High precision and stable structures for particle detectors

    CERN Document Server

    Da Mota Silva, S; Hauviller, Claude

    1999-01-01

    The central detectors used in High Energy Physics Experiments require the use of light and stable structures capable of supporting delicate and precise radiation detection elements. These structures need to be highly stable under environmental conditions where external vibrations, high radiation levels, temperature and humidity gradients should be taken into account. Their main design drivers are high dimension and dynamic stability, high stiffness to mass ratio and large radiation length. For most applications, these constraints lead us to choose Carbon Fiber Reinforced Plastics ( CFRP) as structural element. The construction of light and stable structures with CFRP for these applications can be achieved by careful design engineering and further confirmation at the prototyping phase. However, the experimental environment can influence their characteristics and behavior. In this case, theuse of adaptive structures could become a solution for this problem. We are studying structures in CFRP with bonded piezoel...

  17. Design of partially optically stable reflector systems and prisms

    Science.gov (United States)

    Tsai, Chuang-Yu

    2010-09-01

    The characteristics and design method of the total optically stable (TOS) reflector systems/prisms were introduced in an early paper (Tsai and Lin in Appl. Opt. 47:4158-4163, 2008), where only two types of TOS reflector system exist, namely preservation or retroreflection. In this paper, we introduce the partially optically stable (POS) reflector system, which is only optically stable about a specific directional vector; nevertheless, the exiting light ray is not restricted to preservation or retroreflection. The proposed paper also presents an analytic method for the design of POS reflector systems comprised of multiple reflectors. Furthermore, it is shown that a POS prism can be obtained by adding two refracting flat boundary surfaces with specific conditions at the entrance and exit positions of the light ray in an optical system with multiple reflectors.

  18. Dynamical SUSY breaking in meta-stable vacua

    International Nuclear Information System (INIS)

    Intriligator, Kenneth; Seiberg, Nathan; Shih, David

    2006-01-01

    Dynamical supersymmetry breaking in a long-lived meta-stable vacuum is a phenomenologically viable possibility. This relatively unexplored avenue leads to many new models of dynamical supersymmetry breaking. Here, we present a surprisingly simple class of models with meta-stable dynamical supersymmetry breaking: N = 1 supersymmetric QCD, with massive flavors. Though these theories are strongly coupled, we definitively demonstrate the existence of meta-stable vacua by using the free-magnetic dual. Model building challenges, such as large flavor symmetries and the absence of an R-symmetry, are easily accommodated in these theories. Their simplicity also suggests that broken supersymmetry is generic in supersymmetric field theory and in the landscape of string vacua

  19. Leaf water stable isotopes and water transport outside the xylem.

    Science.gov (United States)

    Barbour, M M; Farquhar, G D; Buckley, T N

    2017-06-01

    How water moves through leaves, and where the phase change from liquid to vapour occurs within leaves, remain largely mysterious. Some time ago, we suggested that the stable isotope composition of leaf water may contain information on transport pathways beyond the xylem, through differences in the development of gradients in enrichment within the various pathways. Subsequent testing of this suggestion provided ambiguous results and even questioned the existence of gradients in enrichment within the mesophyll. In this review, we bring together recent theoretical developments in understanding leaf water transport pathways and stable isotope theory to map a path for future work into understanding pathways of water transport and leaf water stable isotope composition. We emphasize the need for a spatially, anatomically and isotopically explicit model of leaf water transport. © 2016 John Wiley & Sons Ltd.

  20. Preparation of thermally stable nanocrystalline hydroxyapatite by hydrothermal method.

    Science.gov (United States)

    Prakash Parthiban, S; Elayaraja, K; Girija, E K; Yokogawa, Y; Kesavamoorthy, R; Palanichamy, M; Asokan, K; Narayana Kalkura, S

    2009-12-01

    Thermally stable hydroxyapatite (HAp) was synthesized by hydrothermal method in the presence of malic acid. X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FT-IR), Raman spectroscopy, scanning electron microscopy (SEM), differential thermal analysis (DTA), thermogravimetric analysis (TGA) was done on the synthesized powders. These analyses confirmed the sample to be free from impurities and other phases of calcium phosphates, and were of rhombus morphology along with nanosized particles. IR and Raman analyses indicated the adsorption of malic acid on HAp. Thermal stability of the synthesized HAp was confirmed by DTA and TGA. The synthesized powders were thermally stable upto 1,400 degrees C and showed no phase change. The proposed method might be useful for producing thermally stable HAp which is a necessity for high temperature coating applications.

  1. Application of enriched stable isotopes as tracers in biological systems

    DEFF Research Database (Denmark)

    Stürup, Stefan; Hansen, Helle Rüsz; Gammelgaard, Bente

    2008-01-01

    The application of enriched stable isotopes of minerals and trace elements as tracers in biological systems is a rapidly growing research field that benefits from the many new developments in inorganic mass spectrometric instrumentation, primarily within inductively coupled plasma mass spectrometry...... (ICP-MS) instrumentation, such as reaction/collision cell ICP-MS and multicollector ICP-MS with improved isotope ratio measurement and interference removal capabilities. Adaptation and refinement of radioisotope tracer experiment methodologies for enriched stable isotope experiments......, and the development of new methodologies coupled with more advanced compartmental and mathematical models for the distribution of elements in living organisms has enabled a broader use of enriched stable isotope experiments in the biological sciences. This review discusses the current and future uses of enriched...

  2. Stable isotope tracers and exercise physiology: past, present and future.

    Science.gov (United States)

    Wilkinson, Daniel J; Brook, Matthew S; Smith, Kenneth; Atherton, Philip J

    2017-05-01

    Stable isotope tracers have been invaluable assets in physiological research for over 80 years. The application of substrate-specific stable isotope tracers has permitted exquisite insight into amino acid, fatty-acid and carbohydrate metabolic regulation (i.e. incorporation, flux, and oxidation, in a tissue-specific and whole-body fashion) in health, disease and response to acute and chronic exercise. Yet, despite many breakthroughs, there are limitations to 'substrate-specific' stable isotope tracers, which limit physiological insight, e.g. the need for intravenous infusions and restriction to short-term studies (hours) in controlled laboratory settings. In recent years significant interest has developed in alternative stable isotope tracer techniques that overcome these limitations, in particular deuterium oxide (D 2 O or heavy water). The unique properties of this tracer mean that through oral administration, the turnover and flux through a number of different substrates (muscle proteins, lipids, glucose, DNA (satellite cells)) can be monitored simultaneously and flexibly (hours/weeks/months) without the need for restrictive experimental control. This makes it uniquely suited for the study of 'real world' human exercise physiology (amongst many other applications). Moreover, using D 2 O permits evaluation of turnover of plasma and muscle proteins (e.g. dynamic proteomics) in addition to metabolomics (e.g. fluxomics) to seek molecular underpinnings, e.g. of exercise adaptation. Here, we provide insight into the role of stable isotope tracers, from substrate-specific to novel D 2 O approaches, in facilitating our understanding of metabolism. Further novel potential applications of stable isotope tracers are also discussed in the context of integration with the snowballing field of 'omic' technologies. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

  3. Stable propagation of interacting crack systems and modeling of damage

    International Nuclear Information System (INIS)

    Bazant, Z.P.; Tabbara, M.R.

    1989-01-01

    This paper presents general thermodynamic criteria for the stable states and stable path of structures with an interacting system of cracks. In combination with numerical finite element results for various cracked structure geometries, these criteria indicate that the crack response path of structures may exhibit bifurcations, after which the symmetry of the crack system is broken and some cracks grow preferentially. The problem is of interest for the prediction of ultimate loads, ductility and energy absorption capability of nuclear concrete structures as well as structures made of composites and ceramics

  4. Remarks on search methods for stable, massive, elementary particles

    International Nuclear Information System (INIS)

    Perl, Martin L.

    2001-01-01

    This paper was presented at the 69th birthday celebration of Professor Eugene Commins, honoring his research achievements. These remarks are about the experimental techniques used in the search for new stable, massive particles, particles at least as massive as the electron. A variety of experimental methods such as accelerator experiments, cosmic ray studies, searches for halo particles in the galaxy and searches for exotic particles in bulk matter are described. A summary is presented of the measured limits on the existence of new stable, massive particle

  5. Coexistence of collapse and stable spatiotemporal solitons in multimode fibers

    Science.gov (United States)

    Shtyrina, Olga V.; Fedoruk, Mikhail P.; Kivshar, Yuri S.; Turitsyn, Sergei K.

    2018-01-01

    We analyze spatiotemporal solitons in multimode optical fibers and demonstrate the existence of stable solitons, in a sharp contrast to earlier predictions of collapse of multidimensional solitons in three-dimensional media. We discuss the coexistence of blow-up solutions and collapse stabilization by a low-dimensional external potential in graded-index media, and also predict the existence of stable higher-order nonlinear waves such as dipole-mode spatiotemporal solitons. To support the main conclusions of our numerical studies we employ a variational approach and derive analytically the stability criterion for input powers for the collapse stabilization.

  6. Enriching stable isotopes: Alternative use for Urenco technology

    International Nuclear Information System (INIS)

    Rakhorst, H.; de Jong, P.G.T.; Dawson, P.D.

    1996-01-01

    The International Urenco Group utilizes a technologically advanced centrifuge process to enrich uranium in the fissionable isotope 235 U. The group operates plants in the United Kingdom, the Netherlands, and Germany and currently holds a 10% share of the multibillion dollar world enrichment market. In the early 1990s, Urenco embarked on a strategy of building on the company's uniquely advanced centrifuge process and laser isotope separation (LIS) experience to enrich nonradioactive isotopes colloquially known as stable isotopes. This paper summarizes the present status of Urenco's stable isotopes business

  7. Stable isotope geochemistry : definitions, terminology, measurement and some applications

    International Nuclear Information System (INIS)

    Faure, K.

    2005-01-01

    In 1936, Alfred Nier produced the first precise measurement of isotope abundance ratios and his design still remains the basis of stable isotope mass spectrometry. With this gift from the physicists for routine measurement of isotope ratios, earth scientists began to explore the natural variations of isotopes. Thus began a new era in geoscience research with the hydrological cycle and marine palaeoclimatic research being the first topics to be investigated. Stable isotope measurements have been applied to many fundamental problems in geochemistry, petrology and paleoclimatology, as well as related fields in archaeology, anthropology, physical chemistry, biology and forensic sciences. (author). 52 refs., 11 figs., 2 tabs

  8. Stable isotope customer list and summary of shipments: FY 1975

    International Nuclear Information System (INIS)

    Davis, W.C.

    1975-10-01

    This compilation is published as an aid to those concerned with the separation and sale of stable isotopes. The information is divided into four sections: an alphabetical list of domestic and foreign customers, showing the stable isotopes purchased during the fiscal year; an alphabetical list of isotopes, cross-referenced to customer numbers and divided into domestic and foreign categories; an alphabetical list of states and countries, cross-referenced to customer numbers and indicating geographical concentrations of isotope users; and a tabulation of the shipments, quantities, and dollars for domestic, foreign, and project categories for each isotope, with the totals for loaned isotopes shown at the end of the table. (auth)

  9. Stable-carbon isotope variability in tree foliage and wood

    International Nuclear Information System (INIS)

    Leavitt, S.W.; Long, A.

    1986-01-01

    This study documents variation of stable-carbon isotope ratios ( 13 C/ 12 C) in trees of genera Juniperus and Pinus under field conditions. Results are from cellulose analysis on leaves, twigs, and wood from a number of localities in the southwestern US. Substantial variability, typically 1-3%, exists among leaves, within wood (radially, vertically, circumferentially), and between individuals at a site. These results may help guide sampling in tracer-type studies with stable-carbon isotope ratios and aid in the interpretation of isotopic results from such studies

  10. [Progress in stable isotope labeled quantitative proteomics methods].

    Science.gov (United States)

    Zhou, Yuan; Shan, Yichu; Zhang, Lihua; Zhang, Yukui

    2013-06-01

    Quantitative proteomics is an important research field in post-genomics era. There are two strategies for proteome quantification: label-free methods and stable isotope labeling methods which have become the most important strategy for quantitative proteomics at present. In the past few years, a number of quantitative methods have been developed, which support the fast development in biology research. In this work, we discuss the progress in the stable isotope labeling methods for quantitative proteomics including relative and absolute quantitative proteomics, and then give our opinions on the outlook of proteome quantification methods.

  11. Stable isotope dimethyl labelling for quantitative proteomics and beyond

    Science.gov (United States)

    Hsu, Jue-Liang; Chen, Shu-Hui

    2016-01-01

    Stable-isotope reductive dimethylation, a cost-effective, simple, robust, reliable and easy-to- multiplex labelling method, is widely applied to quantitative proteomics using liquid chromatography-mass spectrometry. This review focuses on biological applications of stable-isotope dimethyl labelling for a large-scale comparative analysis of protein expression and post-translational modifications based on its unique properties of the labelling chemistry. Some other applications of the labelling method for sample preparation and mass spectrometry-based protein identification and characterization are also summarized. This article is part of the themed issue ‘Quantitative mass spectrometry’. PMID:27644970

  12. Target-like pigmentation after minipunch grafting in stable vitiligo

    Directory of Open Access Journals (Sweden)

    Nelee Bisen

    2014-01-01

    Full Text Available Surgical treatment for vitiligo has been ever evolving. Each surgical modality has its own benefits and limitations. Miniature punch grafting is the most extensively performed surgery, which gives good results in stable vitiligo. Herein we report an unusual type of repigmentation observed after minipunch grafting in a patient of stable vitiligo, which resembled target-like lesions with a "perigraft halo" surrounding individual grafts. Such pigment spread occurred despite the use of 0.5 mm larger graft from the donor site.

  13. SIMPLE ESTIMATOR AND CONSISTENT STRONGLY OF STABLE DISTRIBUTIONS

    Directory of Open Access Journals (Sweden)

    Cira E. Guevara Otiniano

    2016-06-01

    Full Text Available Stable distributions are extensively used to analyze earnings of financial assets, such as exchange rates and stock prices assets. In this paper we propose a simple and strongly consistent estimator for the scale parameter of a symmetric stable L´evy distribution. The advantage of this estimator is that your computational time is minimum thus it can be used to initialize intensive computational procedure such as maximum likelihood. With random samples of sized n we tested the efficacy of these estimators by Monte Carlo method. We also included applications for three data sets.

  14. Stable isotope customer list and summary of shipments: FY 1984

    International Nuclear Information System (INIS)

    Tracy, J.G.

    1984-12-01

    This compilation is published as an aid to those concerned with the separation and sale of stable isotopes. The information is divided into four sections: (1) alphabetical list of domestic and foreign customers, showing the stable isotopes purchased during the fiscal year; (2) alphabetical list of isotopes, cross-referenced to customer numbers and divided into domestic and foreign categories; (3) alphabetical list of states and countries, cross-referenced to customer numbers and indicating geographical concentrations of isotope users; and (4) tabulation of the shipments, quantities, and dollars for domestic, foreign, and project categories for each isotope

  15. Stable isotope customer list and summary of shipments - FY 1983

    International Nuclear Information System (INIS)

    Davis, W.C.

    1983-12-01

    This compilation is published as an aid to those concerned with the separation and sale of stable isotopes. The information is divided into four sections: (1) alphabetical list of domestic and foreign customers, showing the stable isotopes purchased during the fiscal year; (2) alphabetical list of isotopes, cross-referenced to customer numbers and divided into domestic and foreign categories; (3) alphabetical list of states and countries, cross-referenced to customer numbers and indicating geographical concentrations of isotope users; and (4) tabulation of the shipments, quantities, and dollars for domestic, foreign, and project categories for each isotope

  16. Manipulation and gender neutrality in stable marriage procedures

    OpenAIRE

    Pini, Maria; Rossi, Francesca; Venable, Brent; Walsh, Toby

    2009-01-01

    The stable marriage problem is a well-known problem of matching men to women so that no man and woman who are not married to each other both prefer each other. Such a problem has a wide variety of practical applications ranging from matching resident doctors to hospitals to matching students to schools. A well-known algorithm to solve this problem is the Gale-Shapley algorithm, which runs in polynomial time. It has been proven that stable marriage procedures can always be manipulated. Whilst ...

  17. Myocardial perfusion SPECT in stable angina;Place de la scintigraphie myocardique dans l'angor stable

    Energy Technology Data Exchange (ETDEWEB)

    Jau, P.; Jacob, T. [HP Clairval, Service de medecine nucleaire, 13 - Marseille (France); Lecorff, G.; Bouvier, J.L.; Novella, P.; Bechet, V.; Pelet, V. [HP Clairval, Service de cardiologie, 13 - Marseille (France)

    2010-03-15

    We study the precise contribution of myocardial scintigraphy in the therapeutic management of stable coronary artery disease. Until recently, treatment was focused on revascularization, often by coronary angioplasty.Recent studies have challenged this practice by showing the absence of superiority of angioplasty compared to optimal medical therapy.The problem now is to define for each stable coronary artery disease, and individually, the best of both treatment options. In this spirit, the functional approach to coronary artery disease by myocardial perfusion scintigraphy is most interesting.The diagnostic performance, including sensitivity and negative predictive value, and the prognostic value of the technique are clearly established. Recent studies show that a therapeutic decision based on a functional approach to the patient is valid.We need to know this development in cardiology for best position in the multidisciplinary discussions, myocardial scintigraphy as a functional approach to stable coronary artery disease. (N.C.)

  18. Stable isotopes in plant nutrition, soil fertility and environmental studies

    International Nuclear Information System (INIS)

    1991-01-01

    The individual contributions in these proceedings are indexed separately. Main topics covered include the measurement of biological nitrogen fixation, studies of soil organic matter, investigations of nutrient uptake and use by plants, studies of plant metabolism and new methodologies in the analysis of stable isotopes. Refs, figs and tabs

  19. Bias-corrected estimation of stable tail dependence function

    DEFF Research Database (Denmark)

    Beirlant, Jan; Escobar-Bach, Mikael; Goegebeur, Yuri

    2016-01-01

    We consider the estimation of the stable tail dependence function. We propose a bias-corrected estimator and we establish its asymptotic behaviour under suitable assumptions. The finite sample performance of the proposed estimator is evaluated by means of an extensive simulation study where...

  20. Horseshoes in a Chaotic System with Only One Stable Equilibrium

    Science.gov (United States)

    Huan, Songmei; Li, Qingdu; Yang, Xiao-Song

    To confirm the numerically demonstrated chaotic behavior in a chaotic system with only one stable equilibrium reported by Wang and Chen, we resort to Poincaré map technique and present a rigorous computer-assisted verification of horseshoe chaos by virtue of topological horseshoes theory.

  1. Robust chaos synchronization using input-to-state stable control

    Indian Academy of Sciences (India)

    In this paper, we propose a new input-to-state stable (ISS) synchronization method for a general class of chaotic systems with disturbances. Based on Lyapunov theory and linear matrix inequality (LMI) approach, for the first time, the ISS synchronization controller is presented not only to guarantee the asymptotic ...

  2. Possible THz gain in superlattices at a stable operation point

    DEFF Research Database (Denmark)

    Wacker, Andreas; Allen, S. J.; Scott, J. S.

    1997-01-01

    We demonstrate that semiconductor superlattices may provide gain at THz frequencies at an operation point which is stable against fluctuations at lower frequency. While an explicit experimental demonstration for the sample considered could not be achieved, the underlying principle of quantum resp...... response is quite general and may prove successful for differently designed superlattices....

  3. Applications of DNA-Stable Isotope Probing in Bioremediation Studies

    Science.gov (United States)

    Chen, Yin; Vohra, Jyotsna; Murrell, J. Colin

    DNA-stable isotope probing, a method to identify active microorganisms without the prerequisite of cultivation, has been widely applied in the study of microorganisms involved in the degradation of environmental pollutants. Recent advances and technique considerations in applying DNA-SIP in bioremediation are highlighted. A detailed protocol of a DNA-SIP experiment is provided.

  4. Stable limits for sums of dependent infinite variance random variables

    DEFF Research Database (Denmark)

    Bartkiewicz, Katarzyna; Jakubowski, Adam; Mikosch, Thomas

    2011-01-01

    The aim of this paper is to provide conditions which ensure that the affinely transformed partial sums of a strictly stationary process converge in distribution to an infinite variance stable distribution. Conditions for this convergence to hold are known in the literature. However, most of these...

  5. Isolation and characterization of stable mutants of Streptomyces

    Indian Academy of Sciences (India)

    Daunorubicin and its derivative doxorubicin are antitumour anthracycline antibiotics produced by Streptomyces peucetius. In this study we report isolation of stable mutants of S. peucetius blocked in different steps of the daunorubicin biosynthesis pathway. Mutants were screened on the basis of colony colour since producer ...

  6. Broken Homes: Stable Risk, Changing Reasons, Changing Forms.

    Science.gov (United States)

    Sweetser, Dorrian Apple

    1985-01-01

    Cohort membership and two measures of social disadvantage were used as explanatory variables in analysis of the risk of growing up in a broken home and of the living arrangements of children with broken homes. The risk of a broken home by age 16 proved to be stable across cohorts and greater for those from disadvantaged homes. (Author/BL)

  7. Handelman's hierarchy for the maximum stable set problem

    NARCIS (Netherlands)

    Laurent, M.; Sun, Z.

    2014-01-01

    The maximum stable set problem is a well-known NP-hard problem in combinatorial optimization, which can be formulated as the maximization of a quadratic square-free polynomial over the (Boolean) hypercube. We investigate a hierarchy of linear programming relaxations for this problem, based on a

  8. Superradiantly stable non-extremal Reissner-Nordstroem black holes

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Jia-Hui [School of Physics and Telecommunication Engineering, South China Normal University, Laboratory of Quantum Engineering and Quantum Materials, Guangzhou (China); Mai, Zhan-Feng [Beijing Normal University, Department of Physics, Center for Advanced Quantum Studies, Beijing (China)

    2016-06-15

    The superradiant stability is investigated for non-extremal Reissner-Nordstroem black holes. We use an algebraic method to demonstrate that all non-extremal Reissner-Nordstroem black holes are superradiantly stable against a charged massive scalar perturbation. This improves the results obtained before for non-extremal Reissner-Nordstroem black holes. (orig.)

  9. New criteria on the existence of stable-limit cycles

    Energy Technology Data Exchange (ETDEWEB)

    Gonzales-Gascon, F [Instituto de Estructura de la Materia (GIFT) y Dep. de Fisica Teorica Universidad Complutense, Madrid (Espana); Kumpera, A [Universidade Estadual de Campinas (Brazil). Inst. de Matematica

    1978-06-10

    Negative criteria are given assuring the absence of stable limit cycles. These criteria are valid for vector fields over R/sup 3/ and R/sup 4/ and some of them can be applied to vector fields over Rsup(n).

  10. Stable polyfluorinated cycloalkenyl cations and their NMR spectra

    International Nuclear Information System (INIS)

    Snegirev, V.F.; Galakhov, M.V.; Makarov, K.N.; Bakhmutov, V.I.

    1986-01-01

    New stable 1-methoxyperfluoro-2-ethylcyclobutenyl, 1-methoxyperfluoro-2-methylcyclo-pentenyl, and 1-methoxyperfluoro-2-ethylcyclohexenyl cations were obtained by the action of antimony pentafluoride on the corresponding olefins. The distribution of the charges in the investigated polyfluorinated cycloalkenyl cations was investigated by 13 C NMR method

  11. Stable carbon isotope biogeochemistry of lakes along a trophic gradient

    NARCIS (Netherlands)

    de Kluijver, A.; Schoon, P.L.; Downing, J.A.; Schouten, S.; Middelburg, J.J.

    2014-01-01

    The stable carbon (C) isotope variability of dissolved inorganic and organic C (DIC and DOC), particulate organic carbon (POC), glucose and polar-lipid derived fatty acids (PLFAs) was studied in a survey of 22 North American oligotrophic to eutrophic lakes. The d13C of different PLFAs were used as

  12. Safety of nifedipine GITS in stable angina: The ACTION trial

    NARCIS (Netherlands)

    P. Poole-Wilson (Philip); B.A. Kirwan (Bridget Anne); Z. Vokó (Zoltán); S. de Brouwer (Sophie); F.J. van Dalen (Frederik); J. Lubsen (Jacob)

    2006-01-01

    textabstractAim: We describe the safety profile of nifedipine GITS as assessed from adverse events reported in the ACTION trial in which 7,665 patients with stable, symptomatic coronary artery disease were randomly assigned nifedipine GITS or placebo and followed for a mean of 4.9 years. Methods:

  13. Biosensors engineered from conditionally stable ligand-binding domains

    Science.gov (United States)

    Church, George M.; Feng, Justin; Mandell, Daniel J.; Baker, David; Fields, Stanley; Jester, Benjamin Ward; Tinberg, Christine Elaine

    2017-09-19

    Disclosed is a biosensor engineered to conditionally respond to the presence of specific small molecules, the biosensors including conditionally stable ligand-binding domains (LBDs) which respond to the presence of specific small molecules, wherein readout of binding is provided by reporter genes or transcription factors (TFs) fused to the LBDs.

  14. Stable isotope compositions of organic carbon and contents of ...

    African Journals Online (AJOL)

    The stable isotope compositions of organic carbon (OC), and contents of OC and nitrogen for four sediment cores recovered from lakes Makat (located in the Ngorongoro Crater), Ndutu and Masek (located in the Serengeti Plains) are used to document sources of organic matter (OM) and climatic changes in sub-arid ...

  15. Stable isotope geochemistry : definitions, terminology, measurement and some applications

    International Nuclear Information System (INIS)

    Faure, K.

    2009-01-01

    In 1936, Alfred Nier produced the first precise measurement of isotope abundance ratios and his design still remains the basis of stable isotope mass spectrometry. With this gift from the physicists for routine measurement of isotope ratios, earth scientists began to explore the natural variations of isotopes. Thus began a new era in geoscience research with the hydrological cycle and marine palaeolimatic research being the first topics to be investigated. Stable isotope measurements have been applied to many fundamental problems in geochemistry, petrology, and paleoclimatology, as well as related fields in archaeology, anthropology, physical chemistry, biology and forensic sciences. These applications can be broadly classified into four main types: 1. Thermometry: Formation temperatures of rock and mineral systems are determined on the basis of temperature-dependent fractionations of the isotopic ratios between two or more cogenetic phases. 2. Tracers: Reservoirs like the ocean, the mantle, meteroic waters and organic matter have distinct stable isotope signatures that can be used to trace the origin of rocks, fluids, contaminants etc. 3. Reaction mechanism: Distinctions can be made between diffusion and recrystallization, open and closed systems and bacterial and thermogenic processes. 4. Chemostratigraphy: Abrupt changes (excursions) in the stable isotope ratios of ocean sediments and certain terrestrial materials can be used as stratigraphic markers. (author). 56 refs., 11 figs., 2 tabs.

  16. Stable isotope geochemistry : definitions, terminology, measurement and some applications

    International Nuclear Information System (INIS)

    Faure, K.

    2004-01-01

    Stable isotope measurements have been applied to many fundamental problems in geochemistry, petrology, and paleoclimatology, as well as related fields in archaeology, anthropology, physical chemistry, biology and forensic sciences. These applications can be broadly classified into four main types: thermometry, tracers, reaction mechanisms and chemostratigraphy. 52 refs., 11 figs., 2 tabs

  17. Stable isotope geochemistry : definitions, terminology, measurement and some applications

    International Nuclear Information System (INIS)

    Faure, K.

    2014-01-01

    In 1936, Alfred Nier produced the first precise measurement of isotope abundance ratios and his design still remains the basis of stable isotope mass spectrometry. With this gift from the physicists for routine measurement of isotope ratios, earth scientists began to explore the natural variations of isotopes. Thus began a new era in geoscience research with the hydrological cycle and marine palaeoclimatic research being the first topics to be investigated. Stable isotope measurements have been applied to many fundamental problems in geochemistry, petrology, and paleoclimatology, as well as related fields in archaeology, anthropology, physical chemistry, biology and forensic sciences. These applications can be broadly classified into four main types: 1. Thermometry: Formation temperatures of rock and mineral systems are determined on the basis of temperature-dependent fractionations of the isotopic ratios between two or more cogenetic phases. 2. Tracers: Reservoirs like the ocean, the mantle, meteoric waters and organic matter have distinct stable isotope signatures that can be used to trace the origin of rocks, fluids, contaminants etc. 3. Reaction mechanism: Distinctions can be made between diffusion and recrystallization, open and closed systems and bacterial and thermogenic processes. 4. Chemostratigraphy: Abrupt changes (excursions) in the stable isotope ratios of ocean sediments and certain terrestrial materials can be used as stratigraphic markers. (author)

  18. Stable isotope geochemistry: definitions, terminology, measurement and some applications

    International Nuclear Information System (INIS)

    Faure, K.

    2015-01-01

    In 1936, Alfred Nier produced the first precise measurement of isotope abundance ratios and his design still remains the basis of stable isotope mass spectrometry. With this gift from the physicists for routine measurement of isotope ratios, earth scientists began to explore the natural variations of isotopes. Thus began a new era in geoscience research with the hydrological cycle and marine palaeoclimatic research being the first topics to be investigated. Stable isotope measurements have been applied to many fundamental problems in geochemistry, petrology, and paleoclimatology, as well as related fields in archaeology, anthropology, physical chemistry, biology and forensic sciences. These applications can be broadly classified into four main types: 1. Thermometry: Formation temperatures of rock and mineral systems are determined on the basis of temperature-dependent fractionations of the isotopic ratios between two or more cogenetic phases. 2. Tracers: Reservoirs like the ocean, the mantle, meteoric waters and organic matter have distinct stable isotope signatures that can be used to trace the origin of rocks, fluids, contaminants etc. 3. Reaction mechanism: Distinctions can be made between diffusion and recrystallization, open and closed systems and bacterial and thermogenic processes. 4. Chemostratigraphy: Abrupt changes (excursions) in the stable isotope ratios of ocean sediments and certain terrestrial materials can be used as stratigraphic markers. (author).

  19. Stable isotope geochemistry : definitions, terminology, measurement and some applications

    International Nuclear Information System (INIS)

    Faure, K.

    2012-01-01

    In 1936, Alfred Nier produced the first precise measurement of isotope abundance ratios and his design still remains the basis of stable isotope mass spectrometry. With this gift from the physicists for routine measurement of isotope ratios, earth scientists began to explore the natural variations of isotopes. Thus began a new era in geoscience research with the hydrological cycle and marine palaeoclimatic research being the first topics to be investigated. Stable isotope measurements have been applied to many fundamental problems in geochemistry, petrology, and paleoclimatology, as well as related fields in archaeology, anthropology, physical chemistry, biology and forensic sciences. These applications can be broadly classified into four main types: 1. Thermometry: Formation temperatures of rock and mineral systems are determined on the basis of temperature-dependent fractionations of the isotopic ratios between two or more cogenetic phases. 2. Tracers: Reservoirs like the ocean, the mantle, meteoric waters and organic matter have distinct stable isotope signatures that can be used to trace the origin of rocks, fluids, contaminants etc. 3. Reaction mechanism: Distinctions can be made between diffusion and recrystallization, open and closed systems and bacterial and thermogenic processes. 4. Chemostratigraphy: Abrupt changes (excursions) in the stable isotope ratios of ocean sediments and certain terrestrial materials can be used as stratigraphic markers. (author). 89 refs., 12 figs., 2 tabs.

  20. Stable isotope geochemistry : definitions, terminology, measurement and some applications

    International Nuclear Information System (INIS)

    Faure, K.

    2008-01-01

    In 1936, Alfred Nier produced the first precise measurement of isotope abundance ratios and his design still remains the basis of stable isotope mass spectrometry. With this gift from the physicists for routine measurement of isotope ratios, earth scientists began to explore the natural variations of isotopes. Thus began a new era in geoscience research with the hydrological cycle and marine palaeolimatic research being the first topics to be investigated. Stable isotope measurements have been applied to many fundamental problems in geochemistry, petrology, and paleoclimatology, as well as related fields in archaeology, anthropology, physical chemistry, biology and forensic sciences. These applications can be broadly classified into four main types: 1. Thermometry: Formation temperatures of rock and mineral systems are determined on the basis of temperature-dependent fractionations of the isotopic ratios between two or more cogenetic phases. 2. Tracers: Reservoirs like the ocean, the mantle, meteroic waters and organic matter have distinct stable isotope signatures that can be used to trace the origin of rocks, fluids, contaminants etc. 3. Reaction mechanism: Distinctions can be made between diffusion and recrystallization, open and closed systems and bacterial and thermogenic processes. 4. Chemostratigraphy: Abrupt changes (excursions) in the stable isotope ratios of ocean sediments and certain terrestrial materials can be used as stratigraphic markers. (author). 56 refs., 11 figs., 2 tabs

  1. Stable isotope geochemistry : definitions, terminology, measurement and some applications

    International Nuclear Information System (INIS)

    Faure, K.

    2009-01-01

    In 1936, Alfred Nier produced the first precise measurement of isotope abundance ratios and his design still remains the basis of stable isotope mass spectrometry. With this gift from the physicists for routine measurement of isotope ratios, earth scientists began to explore the natural variations of isotopes. Thus began a new era in geoscience research with the hydrological cycle and marine palaeolimatic research being the first topics to be investigated. Stable isotope measurements have been applied to many fundamental problems in geochemistry, petrology, and paleoclimatology, as well as related fields in archaeology, anthropology, physical chemistry, biology and forensic sciences. These applications can be broadly classified into four main types: 1. Thermometry: Formation temperatures of rock and mineral systems are determined on the basis of temperature-dependent fractionations of the isotopic ratios between two or more cogenetic phases. 2. Tracers: Reservoirs like the ocean, the mantle, meteroic waters and organic matter have distinct stable isotope signatures that can be used to trace the origin of rocks, fluids, contaminants etc. 3. Reaction mechanism: Distinctions can be made between diffusion and recrystallization, open and closed systems and bacterial and thermogenic processes. 4. Chemostratigraphy: Abrupt changes (excursions) in the stable isotope ratios of ocean sediments and certain terrestrial materials can be used as stratigraphic markers. (author). 56 refs., 11 figs., 2 tabs

  2. Stable isotope geochemistry : definitions, terminology, measurement and some applications

    International Nuclear Information System (INIS)

    Faure, K.

    2016-01-01

    In 1936, Alfred Nier produced the first precise measurement of isotope abundance ratios and his design still remains the basis of stable isotope mass spectrometry. With this gift from the physicists for routine measurement of isotope ratios, earth scientists began to explore the natural variations of isotopes. Thus began a new era in geoscience research with the hydrological cycle and marine palaeoclimatic research being the first topics to be investigated. Stable isotope measurements have been applied to many fundamental problems in geochemistry, petrology, and paleoclimatology, as well as related fields in archaeology, anthropology, physical chemistry, biology and forensic sciences. These applications can be broadly classified into four main types: 1. Thermometry: Formation temperatures of rock and mineral systems are determined on the basis of temperature-dependent fractionations of the isotopic ratios between two or more cogenetic phases. 2. Tracers: Reservoirs like the ocean, the mantle, meteoric waters and organic matter have distinct stable isotope signatures that can be used to trace the origin of rocks, fluids, contaminants etc. 3. Reaction mechanism: Distinctions can be made between diffusion and recrystallization, open and closed systems and bacterial and thermogenic processes. 4. Chemostratigraphy: Abrupt changes (excursions) in the stable isotope ratios of ocean sediments and certain terrestrial materials can be used as stratigraphic markers. (author).

  3. Stable isotope geochemistry : definitions, terminology, measurement and some applications

    International Nuclear Information System (INIS)

    Faure, K.

    2013-01-01

    In 1936, Alfred Nier produced the first precise measurement of isotope abundance ratios and his design still remains the basis of stable isotope mass spectrometry. With this gift from the physicists for routine measurement of isotope ratios, earth scientists began to explore the natural variations of isotopes. Thus began a new era in geoscience research with the hydrological cycle and marine palaeoclimatic research being the first topics to be investigated. Stable isotope measurements have been applied to many fundamental problems in geochemistry, petrology, and paleoclimatology, as well as related fields in archaeology, anthropology, physical chemistry, biology and forensic sciences. These applications can be broadly classified into four main types: 1. Thermometry: Formation temperatures of rock and mineral systems are determined on the basis of temperature-dependent fractionations of the isotopic ratios between two or more cogenetic phases. 2. Tracers: Reservoirs like the ocean, the mantle, meteoric waters and organic matter have distinct stable isotope signatures that can be used to trace the origin of rocks, fluids, contaminants etc. 3. Reaction mechanism: Distinctions can be made between diffusion and recrystallization, open and closed systems and bacterial and thermogenic processes. 4. Chemostratigraphy: Abrupt changes (excursions) in the stable isotope ratios of ocean sediments and certain terrestrial materials can be used as stratigraphic markers. (author). 91 refs., 12 figs., 2 tabs.

  4. Recent applications of stable isotopes in environmental medicine in germany

    International Nuclear Information System (INIS)

    Krumbiegel, P.; Herbarth, O.

    2000-01-01

    In the last few years, a new quality in the application of stable isotopes became manifest. It is the establishment of stable isotopes as a tool in medical routine diagnosis - a novel field of nuclear medicine - and in environmental-medical epidemiological surveys. Owing to missing suitable radioactive isotopes of the bio elements carbon and nitrogen and because of ethical problems in the human use of some radionuclides, the stable isotopes 13 C and 1% N play a key role in this new field. A review is given about four new stable isotope-aided methods for in vivo organ function test. Three of them were developed in Leipzig, germany, and one in houston/Texas. We have validated the tests and then introduced into medical and environmental routine diagnostic use: ( 15 N Methacetin and ( 13 C) methacetin liver function tests to characterize the detoxification capacity of the human liver; ( 15 N) Urea and ( 13 C) urea tests to detect the colonization of the human stomach by the bacterium helicobacter pylori. This bacterium is, as known, responsible for gastritis and ulcer of the gastrointestinal tract. The transmission ways of H. Pylori are under investigation world-wide

  5. A note on thick subcategories of stable derived categories

    OpenAIRE

    Krause, Henning; Stevenson, Greg

    2013-01-01

    For an exact category having enough projective objects, we establish a bijection between thick subcategories containing the projective objects and thick subcategories of the stable derived category. Using this bijection, we classify thick subcategories of finitely generated modules over strict local complete intersections and produce generators for the category of coherent sheaves on a separated Noetherian scheme with an ample family of line bundles.

  6. Unconditionally stable integration of Maxwell’s equations

    NARCIS (Netherlands)

    Verwer, J.G.; Botchev, M.A.

    2009-01-01

    Numerical integration of Maxwell’s equations is often based on explicit methods accepting a stability step size restriction. In literature evidence is given that there is also a need for unconditionally stable methods, as exemplified by the successful alternating direction implicit - finite

  7. Exact solutions, energy, and charge of stable Q-balls

    Energy Technology Data Exchange (ETDEWEB)

    Bazeia, D.; Marques, M.A. [Universidade Federal da Paraiba, Departamento de Fisica, Joao Pessoa, PB (Brazil); Menezes, R. [Universidade Federal da Paraiba, Departamento de Ciencias Exatas, Rio Tinto, PB (Brazil); Universidade Federal de Campina Grande, Departamento de Fisica, Campina Grande, PB (Brazil)

    2016-05-15

    In this work we deal with nontopological solutions of the Q-ball type in two spacetime dimensions. We study models of current interest, described by a Higgs-like and other, similar potentials which unveil the presence of exact solutions. We use the analytic results to investigate how to control the energy and charge to make the Q-balls stable. (orig.)

  8. Modified calcium oxide as stable solid base catalyst for Aldol

    Indian Academy of Sciences (India)

    A highly efficient and stable solid-base catalyst for Aldol condensation was prepared by modifying commercial CaO with benzyl bromide in a simple way. It was found that modified CaO can effectively catalyse the Aldol condensation of cyclohexanone and benzaldehyde, as well as various benzaldehydes, to produce ...

  9. Production of stable isotopes at Urenco. 10 years of progress

    International Nuclear Information System (INIS)

    Mol, C.A.; Rakhorst, H.

    2003-01-01

    In the last ten years, Urenco has built its spin-off activity of stable isotopes in a multi-million dollar business. It is a high quality, ISO certified, client oriented and profitable European business with further growth potential. (author)

  10. Synthesis and characterization of thermally stable oligomer-metal ...

    African Journals Online (AJOL)

    The thermal stabilities of the oligomer-metal complexes were compared by thermogravimetric (TG) and differential thermal (DTA) analyses. According to TG, oligomer-metal complexes were stable against to temperature and thermooxidative decomposition. The weight losses of oligomer-metal complexes were found to be 5 ...

  11. Linear operator inequalities for strongly stable weakly regular linear systems

    NARCIS (Netherlands)

    Curtain, RF

    2001-01-01

    We consider the question of the existence of solutions to certain linear operator inequalities (Lur'e equations) for strongly stable, weakly regular linear systems with generating operators A, B, C, 0. These operator inequalities are related to the spectral factorization of an associated Popov

  12. A comparison of stable platform and strapdown airborne gravity

    DEFF Research Database (Denmark)

    Glennie, C.L.; Schwarz, K.P.; Bruton, A.M.

    2000-01-01

    To date, operational airborne gravity results have been obtained using either a damped two-axis stable platform gravimeter system such as the LaCoste and Romberg (LCR) S-model marine gravimeter or a strapdown inertial navigation system (INS), showing comparable accuracies. In June 1998 three flight...

  13. On the solution of high order stable time integration methods

    Czech Academy of Sciences Publication Activity Database

    Axelsson, Owe; Blaheta, Radim; Sysala, Stanislav; Ahmad, B.

    2013-01-01

    Roč. 108, č. 1 (2013), s. 1-22 ISSN 1687-2770 Institutional support: RVO:68145535 Keywords : evolution equations * preconditioners for quadratic matrix polynomials * a stiffly stable time integration method Subject RIV: BA - General Mathematics Impact factor: 0.836, year: 2013 http://www.boundaryvalueproblems.com/content/2013/1/108

  14. Rivaroxaban with or without Aspirin in Stable Cardiovascular Disease

    NARCIS (Netherlands)

    Eikelboom, John W.; Connolly, Stuart J.; Bosch, Jackie; Dagenais, Gilles R.; Hart, Robert G.; Shestakovska, Olga; Diaz, Rafael; Alings, Marco; Lonn, Eva M.; Anand, Sonia S.; Widimsky, Petr; Hori, Masatsugu; Avezum, Alvaro; Piegas, Leopoldo S.; Branch, Kelley R. H.; Probstfield, Jeffrey; Bhatt, Deepak L.; Zhu, Jun; Liang, Yan; Maggioni, Aldo P.; Lopez-Jaramillo, Patricio; O'Donnell, Martin; Kakkar, Ajay K.; Fox, Keith A. A.; Parkhomenko, Alexander N.; Ertl, Georg; Störk, Stefan; Keltai, Matyas; Ryden, Lars; Pogosova, Nana; Dans, Antonio L.; Lanas, Fernando; Commerford, Patrick J.; Torp-Pedersen, Christian; Guzik, Tomek J.; Verhamme, Peter B.; Vinereanu, Dragos; Kim, Jae-Hyung; Tonkin, Andrew M.; Lewis, Basil S.; Felix, Camilo; Yusoff, Khalid; Steg, P. Gabriel; Metsarinne, Kaj P.; Cook Bruns, Nancy; Misselwitz, Frank; Chen, Edmond; Leong, Darryl; Hashimoto, S.; Maas, M.

    2017-01-01

    We evaluated whether rivaroxaban alone or in combination with aspirin would be more effective than aspirin alone for secondary cardiovascular prevention. In this double-blind trial, we randomly assigned 27,395 participants with stable atherosclerotic vascular disease to receive rivaroxaban (2.5 mg

  15. France's Administrative Tertiary: Stable Numbers for Occupations in Flux.

    Science.gov (United States)

    Liaroutzos, Olivier; Meriot, Sylvie-Anne

    1995-01-01

    During the past decade, the number of jobs in France's administrative service sector has remained stable. General administrative work has become more infrequent; however, the basic occupations of secretary and accountancy have been maintained. Although the number of typists has declined, the number of "secretarial" jobs has increased…

  16. Modified calcium oxide as stable solid base catalyst for Aldol ...

    Indian Academy of Sciences (India)

    A highly efficient and stable solid-base catalyst for Aldol condensation was ... was bonded on surface of CaO chemically and almost no Ca(OH)2 formed during the modification process. ... cation, corrosion and waste generation attract great.

  17. Oxidant and solvent stable alkaline protease from Aspergillus flavus ...

    African Journals Online (AJOL)

    The increase in agricultural practices has necessitated the judicious use of agricultural wastes into value added products. In this study, an extracellular, organic solvent and oxidant stable, serine protease was produced by Aspergillus flavus MTCC 9952 under solid state fermentation. Maximum protease yield was obtained ...

  18. Synthesis and Photophysical Characterizations of Thermal -Stable Naphthalene Benzimidazoles

    OpenAIRE

    Erten Ela, Şule; Özçelik, Serdar; Eren, Ersin

    2011-01-01

    Microwave-assisted synthesis, photophysical and electrochemical properties of thermal-stable naphthalene benzimidazoles and naphthalimides are studied in this paper. Microwave-assisted synthesis of naphthalene benzimidazoles provide higher yields than the conventional thermal synthesis. Comparative photophysical properties of naphthalene benzimidazoles and naphthalimides are revealed that conjugation of electron-donating group onto naphthalimide moiety increases fluorescence ...

  19. Exhaled nitric oxide in stable chronic obstructive pulmonary disease

    International Nuclear Information System (INIS)

    Beg Mohammed F S; Alzoghaibi, Mohammad A; Habib, Syed S; Abba, Abdullah A

    2009-01-01

    The objective of the study was to test the hypothesis that fraction of exhaled nitric oxide (FENO) is elevated in nonsmoking subjects with stable chronic obstructive pulmonary disease (COPD) and compare it with the results in patients with asthma and a control population. Pulmonology Clinic at a University Hospital. Twenty five control subjects, 25 steroid naive asthmatics and 14 COPD patients were studied. All the patients were nonsmokers and stable at the time of the study. All subjects completed a questionnaire and underwent spirometry. Exhaled nitric oxide was measured online by chemiluminescence, using single-breath technique. All the study subjects were males. Subjects with stable COPD had significantly higher values of FENO than controls (56.54+ - 28.01 vs 22.00 + -6.69; P =0.0001) but lower than the subjects with asthma (56.54+ - 28.01 vs 84.78+ - 39.32 P 0.0285). The FENO values in COPD subjects were inversely related to the FEV 1 /FVC ratio. There was a significant overlap between the FENO values in COPD and the control subjects. There is a significant elevation in FENO in patients with stable COPD, but the elevation is less than in asthmatic subjects. Its value in clinical practice may be limited by the significant overlap with control subjects. (author)

  20. COMBINING SOURCES IN STABLE ISOTOPE MIXING MODELS: ALTERNATIVE METHODS

    Science.gov (United States)

    Stable isotope mixing models are often used to quantify source contributions to a mixture. Examples include pollution source identification; trophic web studies; analysis of water sources for soils, plants, or water bodies; and many others. A common problem is having too many s...

  1. Which compactifications of D=11 supergravity are stable

    International Nuclear Information System (INIS)

    Page, D.N.; Pope, C.N.

    1984-01-01

    We complete the stability analysis of all known Freund-Rubin solutions of eleven-dimensional supergravity by determining the necessary and sufficient conditions for Qsup(pqr) spaces (U(1) bundles over S 2 xS 2 xS 2 ) to be stable. (orig.)

  2. Stable Kernel Representations as Nonlinear Left Coprime Factorizations

    NARCIS (Netherlands)

    Paice, A.D.B.; Schaft, A.J. van der

    1994-01-01

    A representation of nonlinear systems based on the idea of representing the input-output pairs of the system as elements of the kernel of a stable operator has been recently introduced. This has been denoted the kernel representation of the system. In this paper it is demonstrated that the kernel

  3. Stable Kernel Representations and the Youla Parameterization for Nonlinear Systems

    NARCIS (Netherlands)

    Paice, A.D.B.; Schaft, A.J. van der

    1994-01-01

    In this paper a general approach is taken to yield a characterization of the class of stable plant controller pairs, which is a generalization of the Youla parameterization for linear systems. This is based on the idea of representing the input-output pairs of the plant and controller as elements of

  4. Highly stable thin film transistors using multilayer channel structure

    KAUST Repository

    Nayak, Pradipta K.; Wang, Zhenwei; Anjum, Dalaver H.; Hedhili, Mohamed N.; Alshareef, Husam N.

    2015-01-01

    We report highly stable gate-bias stress performance of thin film transistors (TFTs) using zinc oxide (ZnO)/hafnium oxide (HfO2) multilayer structure as the channel layer. Positive and negative gate-bias stress stability of the TFTs was measured

  5. Modified yupingfeng formula for the treatment of stable chronic ...

    African Journals Online (AJOL)

    The following outcomes were evaluated: (1) lung function; (2) 6-minute walk distance (6MWD); (3) effective rate; (4) serum levels of IgA, IgG and IgE; and (5) adverse ... when combined with Western medications can provide more benefits for patients with stable COPD, without any serious adverse reactions being identified.

  6. Reactions of a stable dialkylsilylene and their mechanisms

    Indian Academy of Sciences (India)

    Stable silylene; mechanisms; photoreaction; addition; insertion; DFT. 1. ... Some of these reactions provide useful ... Although much attention has been ... sis, structure, and spectroscopic properties of 1 that .... Because silylenes are usually in the singlet ground state ..... selective 1,2-/1,4-addition reactions of dialkylsilylenes.

  7. Production and use of stable isotopes in France

    International Nuclear Information System (INIS)

    Roth, E.; Letolle, R.

    1991-01-01

    This paper can not cover the field of production and use of stable isotopes in France exhaustively within six pages. We have chosen to concentrate on highlights of the subject and on recent work, and to give references for further reading. 26 refs

  8. Stable classification of the energy-momentum tensor. Summary

    International Nuclear Information System (INIS)

    Guzman-Sanchez, A.R.; Przanowski, M.; Plevansky, J.

    1990-01-01

    Starting with the algebraic classification of the energy-momentum tensor given by Plebansky, it is established that this classification is unstable under versal deformations and a new (stable) classification is given. In order to keep the text to reasonable length, we just write the basic ideas and some results. (Author) (Author)

  9. Stable isotope composition of human fingernails from Slovakia

    International Nuclear Information System (INIS)

    Grolmusová, Zuzana; Rapčanová, Anna; Michalko, Juraj; Čech, Peter; Veis, Pavel

    2014-01-01

    Stable isotope composition of human fingernails has proven to be useful for documenting human dietary information and geographical patterns in archeological, forensic, anthropological and biological studies. Therefore, it is of interest to detect all factors influencing the stable isotopic composition in the certain regions in the world. Carbon and nitrogen isotope data of human fingernail keratin from 52 individuals from Slovakia were reported in this study. The online combustion and continuous flow isotope-ratio mass spectrometer Delta V Advantage was used for δ 13 C and δ 15 N analysis of fingernail keratin samples from 24 vegetarian and 28 omnivorous individuals. A group of people with frequent meat consumption showed enrichment in 13 C and 15 N isotopes in fingernails. A similar trend was observed with increasing seafood in an individual's diet. Moreover a significant difference was revealed between smokers and nonsmokers for both δ 13 C and δ 15 N values. These data were compared to previously published δ 13 C and δ 15 N fingernail values from across the globe. This study brings new information on the stable isotope signature of individuals from Slovakia and characterizes the Central European region for the first time. The stable isotope composition of fingernails is influenced by the frequency of meat and seafood consumption as well as smoking. - Highlights: • This study deals with stable isotope analyses of fingernails from Slovak volunteers. • δ 13 C and δ 15 N values of vegetarian and omnivore fingernails were compared. • Influence of sex, diet and smoking was studied

  10. Stable isotope composition of human fingernails from Slovakia

    Energy Technology Data Exchange (ETDEWEB)

    Grolmusová, Zuzana, E-mail: zuzana.grolmusova@geology.sk [Comenius University in Bratislava, Faculty of Mathematics, Physics and Informatics, Department of Experimental Physics, Mlynská dolina F2, 842 48 Bratislava (Slovakia); State Geological Institute of Dionýz Štúr, Laboratory of Isotope Geology, Mlynská dolina 1, 817 04 Bratislava (Slovakia); Rapčanová, Anna [Comenius University in Bratislava, Faculty of Mathematics, Physics and Informatics, Department of Experimental Physics, Mlynská dolina F2, 842 48 Bratislava (Slovakia); Michalko, Juraj; Čech, Peter [State Geological Institute of Dionýz Štúr, Laboratory of Isotope Geology, Mlynská dolina 1, 817 04 Bratislava (Slovakia); Veis, Pavel [Comenius University in Bratislava, Faculty of Mathematics, Physics and Informatics, Department of Experimental Physics, Mlynská dolina F2, 842 48 Bratislava (Slovakia); State Geological Institute of Dionýz Štúr, Laboratory of Isotope Geology, Mlynská dolina 1, 817 04 Bratislava (Slovakia)

    2014-10-15

    Stable isotope composition of human fingernails has proven to be useful for documenting human dietary information and geographical patterns in archeological, forensic, anthropological and biological studies. Therefore, it is of interest to detect all factors influencing the stable isotopic composition in the certain regions in the world. Carbon and nitrogen isotope data of human fingernail keratin from 52 individuals from Slovakia were reported in this study. The online combustion and continuous flow isotope-ratio mass spectrometer Delta V Advantage was used for δ{sup 13}C and δ{sup 15}N analysis of fingernail keratin samples from 24 vegetarian and 28 omnivorous individuals. A group of people with frequent meat consumption showed enrichment in {sup 13}C and {sup 15}N isotopes in fingernails. A similar trend was observed with increasing seafood in an individual's diet. Moreover a significant difference was revealed between smokers and nonsmokers for both δ{sup 13}C and δ{sup 15}N values. These data were compared to previously published δ{sup 13}C and δ{sup 15}N fingernail values from across the globe. This study brings new information on the stable isotope signature of individuals from Slovakia and characterizes the Central European region for the first time. The stable isotope composition of fingernails is influenced by the frequency of meat and seafood consumption as well as smoking. - Highlights: • This study deals with stable isotope analyses of fingernails from Slovak volunteers. • δ{sup 13}C and δ{sup 15}N values of vegetarian and omnivore fingernails were compared. • Influence of sex, diet and smoking was studied.

  11. Manual for the Use of Stable Isotopes in Entomology

    International Nuclear Information System (INIS)

    2009-06-01

    result of problem driven inquisitiveness and technological advances, and are framed by the social and political environment. Although the external environment may mould the technological path, a technology will only become obsolete if there are viable substitution products or methods. Stable isotope methods are a substitute for many radionuclide methods. The progress made in stable isotope science over the past twenty years is a direct result of the interplay of the above factors. Stable isotopes are omnipresent in the environment and pose no health or environmental risks. Advances in isotope ratio mass spectrometry in terms of detection, accuracy and automation have broadened experimental possibilities immensely over the past twenty years. It was recognised that there was significant potential for answering many of the entomologist?s biological and ecological questions using stable isotopes, an expertise the Soil Science Unit of the FAO/IAEA Agriculture and Biotechnology Laboratory in Seibersdorf had long fostered; therefore collaboration with the Entomology Unit at the same Laboratory was established. A number of collaborative experiments were carried and subsequently published. It was soon recognised that stable isotopes have tremendous potential in entomological research and although there were numerous studies using stable isotopes in ecology, their use in entomology per se was limited. Thus it was felt that a publication was required to make stable isotope techniques more widely known among entomologists. This manual will attempt to provide an introduction to the use of stable isotopes in entomological research. It will strive to communicate the basic principles and techniques of stable isotope science and provide a springboard for further interest and research in this area

  12. Testbed for High-Acuity Imaging and Stable Photometry

    Science.gov (United States)

    Gregory, James

    This proposal from MIT Lincoln Laboratory (LL) accompanies the NASA/APRA proposal enti-tled THAI-SPICE: Testbed for High-Acuity Imaging - Stable Photometry and Image-Motion Compensa-tion Experiment (submitted by Eliot Young, Southwest Research Institute). The goal of the THAI-SPICE project is to demonstrate three technologies that will help low-cost balloon-borne telescopes achieve diffraction-limited imaging: stable pointing, passive thermal stabilization and in-flight monitoring of the wave front error. This MIT LL proposal supplies a key element of the pointing stabilization component of THAI-SPICE: an electronic camera based on an orthogonaltransfer charge-coupled device (OTCCD). OTCCD cameras have been demonstrated with charge-transfer efficiencies >0.99999, noise of 90%. In addition to supplying a camera with an OTCCD detector, MIT LL will help with integration and testing of the OTCCD with the THAI-SPICE payload’s guide camera.

  13. England and Wales: Stable fertility and pronounced social status differences

    Directory of Open Access Journals (Sweden)

    Wendy Sigle-Rushton

    2008-07-01

    Full Text Available For nearly three decades, the total fertility rate in England and Wales has remained high relative to other European countries, and stable at about 1.7 births per woman. In this chapter, we examine trends in both period and cohort fertility throughout the twentieth century, and demonstrate some important differences across demographic and social groups in the timing and quantum of fertility. Breaking with a market-oriented and laissez-faire approach to work and family issues, the last 10 years have seen the introduction of new social and economic policies aimed at providing greater support to families with children. However, the effect of the changes is likely to be limited to families on the lower end of the income scale. Rather than facilitating work and parenthood, some policies create incentives for a traditional gendered division of labour. Fertility appears to have remained stable despite, rather than because of, government actions.

  14. Membrane-sculpting BAR domains generate stable lipid microdomains

    DEFF Research Database (Denmark)

    Zhao, Hongxia; Michelot, Alphée; Koskela, Essi V.

    2013-01-01

    Bin-Amphiphysin-Rvs (BAR) domain proteins are central regulators of many cellular processes involving membrane dynamics. BAR domains sculpt phosphoinositide-rich membranes to generate membrane protrusions or invaginations. Here, we report that, in addition to regulating membrane geometry, BAR...... domains can generate extremely stable lipid microdomains by "freezing" phosphoinositide dynamics. This is a general feature of BAR domains, because the yeast endocytic BAR and Fes/CIP4 homology BAR (F-BAR) domains, the inverse BAR domain of Pinkbar, and the eisosomal BAR protein Lsp1 induced...... phosphoinositide clustering and halted lipid diffusion, despite differences in mechanisms of membrane interactions. Lsp1 displays comparable low diffusion rates in vitro and in vivo, suggesting that BAR domain proteins also generate stable phosphoinositide microdomains in cells. These results uncover a conserved...

  15. High efficiency and stable white OLED using a single emitter

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jian [Arizona State Univ., Tempe, AZ (United States). School of Mechanical, Aerospace, Chemical and Materials Engineering

    2016-01-18

    The ultimate objective of this project was to demonstrate an efficient and stable white OLED using a single emitter on a planar glass substrate. The focus of the project is on the development of efficient and stable square planar phosphorescent emitters and evaluation of such class of materials in the device settings. Key challenges included improving the emission efficiency of molecular dopants and excimers, controlling emission color of emitters and their excimers, and improving optical and electrical stability of emissive dopants. At the end of this research program, the PI has made enough progress to demonstrate the potential of excimer-based white OLED as a cost-effective solution for WOLED panel in the solid state lighting applications.

  16. Antibiotic therapy for stable non-CF bronchiectasis in adults

    DEFF Research Database (Denmark)

    Fjaellegaard, Katrine; Sin, Melda Dönmez; Browatzki, Andrea

    2017-01-01

    To provide an update on efficacy and safety of antibiotic treatments for stable non-cystic fibrosis (CF) bronchiectasis (BE). Systematic review based on the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines was done. Twenty-six studies (1.898 patients) fulfilled......, exacerbations and QoL, whereas studies on aztreonam revealed no significant clinical improvements in the outcomes of interest, including exacerbation rate. Adverse events, including bronchospasm, have been reported in association with tobramycin and aztreonam. Several antibiotic treatment regimens have been...... shown to improve QoL and exacerbation rate, whereas findings regarding sputum production, lung function and admissions have been conflicting. Evidence-based treatment algorithms for antibiotic treatment of stable non-CF BE will have to await large-scale, long-term controlled studies....

  17. DNA stable-isotope probing (DNA-SIP).

    Science.gov (United States)

    Dunford, Eric A; Neufeld, Josh D

    2010-08-02

    DNA stable-isotope probing (DNA-SIP) is a powerful technique for identifying active microorganisms that assimilate particular carbon substrates and nutrients into cellular biomass. As such, this cultivation-independent technique has been an important methodology for assigning metabolic function to the diverse communities inhabiting a wide range of terrestrial and aquatic environments. Following the incubation of an environmental sample with stable-isotope labelled compounds, extracted nucleic acid is subjected to density gradient ultracentrifugation and subsequent gradient fractionation to separate nucleic acids of differing densities. Purification of DNA from cesium chloride retrieves labelled and unlabelled DNA for subsequent molecular characterization (e.g. fingerprinting, microarrays, clone libraries, metagenomics). This JoVE video protocol provides visual step-by-step explanations of the protocol for density gradient ultracentrifugation, gradient fractionation and recovery of labelled DNA. The protocol also includes sample SIP data and highlights important tips and cautions that must be considered to ensure a successful DNA-SIP analysis.

  18. PRIORITY DIRECTIONS OF PROVISION OF STABLE LAND USE

    Directory of Open Access Journals (Sweden)

    L. Hun’ko

    2016-10-01

    Full Text Available The conditions of stable land use are highlighted in this article. The question of the territory of agricultural enterprises is considered as well. The characteristic of the type of land use is given here. The recommendations are shown on the formation of ecologically safe types of land use. In the terms of new land relations is important to resolve the issue of land use regulation to with stand landscapes against adverse natural and anthropogenic influences. The main instrument of the state, which aims to provide an ecologically permissible and economically effective land use, land use is as an important component of land relations. Planning should include a system of legal, technical, economic and environmental activities that will ensure the preservation, restoration and rational use of land and other natural resources for the benefit of the whole society. Keywords: land use, land management, stable development, landscape, soil erosion, protection of land.

  19. MR imaging of stable posttraumatic spinal cord injury

    International Nuclear Information System (INIS)

    Braun, I.F.; Hoffman, J.C. Jr.; Murphy, C.; Davis, P.C.

    1986-01-01

    Posttraumatic spinal cord cysts have been thought to be infrequent sequelae of spinal trauma. To evaluate the incidence of spinal cord abnormalities in patients who have previously sustained cord trauma, the authors studied the incidence of these changes in clinically stable patients following injury. Twenty-five patients with a history of previous cord injury and stable neurologic status volunteered for MR imaging studies. Studies performed using a 0.5-T and 1.5-T unit revealed focal kinking of the cord at the trauma site as well as intramedullary hypointense areas on T1-weighted images in most volunteers. There was close clinical correlation between MR imaging findings and experimental pathologic data, which suggests that these lesions are much more prevalent than once thought

  20. Development of O-18 stable isotope separation technology using membrane

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Woo; Kim, Taek Soo; Choi, Hwa Rim; Park, Sung Hee; Lee, Ki Tae; Chang, Dae Shik

    2006-06-15

    The ultimate goal of this investigation is to develop the separation technology for O-18 oxygen stable isotope used in a cyclotron as a target for production of radioisotope F-18. F-18 is a base material for synthesis of [F-18]FDG radio-pharmaceutical, which is one of the most important tumor diagnostic agent used in PET (Positron Emission Tomography). More specifically, this investigation is focused on three categories as follow, 1) development of the membrane distillation isotope separation process to re-enrich O-18 stable isotope whose isotopic concentration is reduced after used in a cyclotron, 2) development of organic impurity purification technology to remove acetone, methanol, ethanol, and acetonitrile contained in a used cyclotron O-18 enriched target water, and 3) development of a laser absorption spectroscopic system for analyzing oxygen isotopic concentration in water.

  1. Chaotic and stable perturbed maps: 2-cycles and spatial models

    Science.gov (United States)

    Braverman, E.; Haroutunian, J.

    2010-06-01

    As the growth rate parameter increases in the Ricker, logistic and some other maps, the models exhibit an irreversible period doubling route to chaos. If a constant positive perturbation is introduced, then the Ricker model (but not the classical logistic map) experiences period doubling reversals; the break of chaos finally gives birth to a stable two-cycle. We outline the maps which demonstrate a similar behavior and also study relevant discrete spatial models where the value in each cell at the next step is defined only by the values at the cell and its nearest neighbors. The stable 2-cycle in a scalar map does not necessarily imply 2-cyclic-type behavior in each cell for the spatial generalization of the map.

  2. Unconditionally stable diffusion-acceleration of the transport equation

    International Nuclear Information System (INIS)

    Larson, E.W.

    1982-01-01

    The standard iterative procedure for solving fixed-source discrete-ordinates problems converges very slowly for problems in optically thick regions with scattering ratios c near unity. The diffusion-synthetic acceleration method has been proposed to make use of the fact that for this class of problems, the diffusion equation is often an accurate approximation to the transport equation. However, stability difficulties have historically hampered the implementation of this method for general transport differencing schemes. In this article we discuss a recently developed procedure for obtaining unconditionally stable diffusion-synthetic acceleration methods for various transport differencing schemes. We motivate the analysis by first discussing the exact transport equation; then we illustrate the procedure by deriving a new stable acceleration method for the linear discontinuous transport differencing scheme. We also provide some numerical results

  3. Unconditionally stable diffusion-acceleration of the transport equation

    International Nuclear Information System (INIS)

    Larsen, E.W.

    1982-01-01

    The standard iterative procedure for solving fixed-source discrete-ordinates problems converges very slowly for problems in optically large regions with scattering ratios c near unity. The diffusion-synthetic acceleration method has been proposed to make use of the fact that for this class of problems the diffusion equation is often an accurate approximation to the transport equation. However, stability difficulties have historically hampered the implementation of this method for general transport differencing schemes. In this article we discuss a recently developed procedure for obtaining unconditionally stable diffusion-synthetic acceleration methods for various transport differencing schemes. We motivate the analysis by first discussing the exact transport equation; then we illustrate the procedure by deriving a new stable acceleration method for the linear discontinuous transport differencing scheme. We also provide some numerical results

  4. A simple route to prepare stable hydroxyapatite nanoparticles suspension

    International Nuclear Information System (INIS)

    Han Yingchao; Wang Xinyu; Li Shipu

    2009-01-01

    A simple ultrasound assisted precipitation method with addition of glycosaminoglycans (GAGs) is proposed to prepare stable hydroxyapatite (HAP) nanoparticles suspension from the mixture of Ca(H 2 PO 4 ) 2 solution and Ca(OH) 2 solution. The product was characterized by XRD, FT-IR, TEM, HRTEM and particle size, and zeta potential analyzer. TEM observation shows that the suspension is composed of 10-20 nm x 20-50 nm short rod-like and 10-30 nm similar spherical HAP nanoparticles. The number-averaged particle size of stable suspension is about 30 nm between 11.6 and 110.5 nm and the zeta potential is -60.9 mV. The increase of stability of HAP nanoparticles suspension mainly depends on the electrostatic effect and steric effect of GAGs. The HAP nanoparticles can be easily transported into the cancer cells and exhibit good potential as gene or drug carrier system.

  5. Fractionation of Stable Isotopes in Atmospheric Aerosol Reactions

    DEFF Research Database (Denmark)

    Meusinger, Carl

    -independent) fractionation processes of stable isotopes of C, N, O and S in order to investigate three different systems related to aerosols: 1. Post-depositional processes of nitrate in snow that obscure nitrate ice core records 2. Formation and aging of secondary organic aerosol generated by ozonolysis of X...... reactions and undergo complex chemical and physical changes during their lifetimes. In order to assess processes that form and alter aerosols, information provided by stable isotopes can be used to help constrain estimates on the strength of aerosol sources and sinks. This thesis studies (mass...... as required. The kndings provide important results for the studies' respective felds, including a description of the isotopic fractionation and quantum yield of nitrate photolysis in snow, equilibrium fractionation in secondary organic aerosol and fractionation constants of different oxidation pathways of SO2....

  6. Relevant signs of stable and unstable thoracolumbar vertebral column trauma

    International Nuclear Information System (INIS)

    Gehweiler, J.A.; Daffner, R.H.; Osborne, R.L.

    1981-01-01

    One-hundred and seventeen patients with acute thoracolumbar vertebral column fracture or fracture-dislocations were analyzed and classified into stable (36%) and unstable (64%). Eight helpful roentgen signs were observed that may serve to direct attention to serious underlying, often occult, fractures and dislocations. The changes fall into four principal groups: abnormal soft tissues, abnormal vertebral alignment, abnormal joints, and widened vertebral canal. All stable and unstable lesions showed abnormal soft tissues, while 70% demonstrated kyphosis and/or scoliosis, and an abnormal adjacent intervertebral disk space. All unstable lesions showed one or more of the following signs: displaced vertebra, widened interspinous space, abnormal apophyseal joint(s), and widened vertebral canal. (orig.)

  7. Symmetric and Asymmetric Tendencies in Stable Complex Systems.

    Science.gov (United States)

    Tan, James P L

    2016-08-22

    A commonly used approach to study stability in a complex system is by analyzing the Jacobian matrix at an equilibrium point of a dynamical system. The equilibrium point is stable if all eigenvalues have negative real parts. Here, by obtaining eigenvalue bounds of the Jacobian, we show that stable complex systems will favor mutualistic and competitive relationships that are asymmetrical (non-reciprocative) and trophic relationships that are symmetrical (reciprocative). Additionally, we define a measure called the interdependence diversity that quantifies how distributed the dependencies are between the dynamical variables in the system. We find that increasing interdependence diversity has a destabilizing effect on the equilibrium point, and the effect is greater for trophic relationships than for mutualistic and competitive relationships. These predictions are consistent with empirical observations in ecology. More importantly, our findings suggest stabilization algorithms that can apply very generally to a variety of complex systems.

  8. Stable Higgs Bosons - new candidate for cold dark matter

    International Nuclear Information System (INIS)

    Hosotani, Yutaka

    2010-01-01

    The Higgs boson is in the backbone of the standard model of electroweak interactions. It must exist in some form for achieving unification of interactions. In the gauge-Higgs unification scenario the Higgs boson becomes a part of the extra-dimensional component of gauge fields. The Higgs boson becomes absolutely stable in a class of the gauge-Higgs unification models, serving as a promising candidate for cold dark matter in the universe. The observed relic abundance of cold dark matter is obtained with the Higgs mass around 70 GeV. The Higgs-nucleon scattering cross section is found to be close to the recent CDMS II XENON10 bounds in the direct detection of dark matter. In collider experiments stable Higgs bosons are produced in a pair, appearing as missing energies momenta so that the way of detecting Higgs bosons must be altered.

  9. What can Fe stable isotopes tell us about magmas?

    DEFF Research Database (Denmark)

    Stausberg, Niklas

    the differentiation of magmas from the perspective of Fe stable isotopes, integrated with petrology, by studying igneous rocks and their constituent phases (minerals and glasses) from the Bushveld Complex, South Africa, Thingmuli, Iceland, Pantelleria, Italy, and the Bishop Tuff, USA. The findings are interpreted......The majority of the Earth’s crust is formed by magmas, and understanding their production and differentiation is important to interpret the geologic rock record. A powerful tool to investigate magmatic processes is the distribution of the stable isotopes of the major redox-sensitive element...... in magmas, Fe. Fe isotope compositions of magmatic rocks exhibit systematic differences, where the heaviest compositions are found in rhyolites and granites. Understanding of these systematics is complicated by a lack of constraints on Fe isotope fractionation among minerals and liquids under magmatic...

  10. The tempered stable process with infinitely divisible inverse subordinators

    International Nuclear Information System (INIS)

    Wyłomańska, Agnieszka

    2013-01-01

    In the last decade processes driven by inverse subordinators have become extremely popular. They have been used in many different applications, especially for data with observable constant time periods. However, the classical model, i.e. the subordinated Brownian motion, can be inappropriate for the description of observed phenomena that exhibit behavior not adequate for Gaussian systems. Therefore, in this paper we extend the classical approach and replace the Brownian motion by the tempered stable process. Moreover, on the other hand, as an extension of the classical model, we analyze the general class of inverse subordinators. We examine the main properties of the tempered stable process driven by inverse subordinators from the infinitely divisible class of distributions. We show the fractional Fokker–Planck equation of the examined process and the asymptotic behavior of the mean square displacement for two cases of subordinators. Additionally, we examine how an external force can influence the examined characteristics. (paper)

  11. Stereoselective synthesis of stable-isotope-labeled amino acids

    Energy Technology Data Exchange (ETDEWEB)

    Unkefer, C.J.; Martinez, R.A.; Silks, L.A. III [Los Alamos National Laboratory, NM (United States); Lodwig, S.N. [Centralia College, WA (United States)

    1994-12-01

    For magnetic resonance and vibrational spectroscopies to reach their full potential, they must be used in combination with sophisticated site-specific stable isotope labeling of biological macromolecules. Labeled amino acids are required for the study of the structure and function of enzymes and proteins. Because there are 20 common amino acids, each with its own distinguishing chemistry, they remain a synthetic challenge. The Oppolzer chiral auxiliary provides a general tool with which to approach the synthesis of labeled amino acids. By using the Oppolzer auxiliary, amino acids can be constructed from several small molecules, which is ideal for stable isotope labeling. In addition to directing the stereochemistry at the {alpha}-carbon, the camphorsultam can be used for stereo-specific isotope labeling at prochiral centers in amino acids. By using the camphorsultam auxiliary we have the potential to synthesize virtually any isotopomer of all of the common amino acids.

  12. Application of Stable Isotope Signatures in Food Traceability

    International Nuclear Information System (INIS)

    Nazaratul Ashifa Abdullah Salim; Roslanzairi Mostapha; Zainon Othman; Nor Afiqah Harun; Mohd Suhaimi Hamzah; Shamsiah Abdul Rahman; Md Suhaimi Elias; Salmah Moosa

    2015-01-01

    Stable isotope analysis has widely been used to trace the origin of organic materials in various fields, such as geochemistry, biochemistry, archaeology and petroleum. In past a decade, it has also become an important tool for food traceability study. The globalization of food markets and the relative ease with which food commodities are transported through and between countries and continents, means that consumers are increasingly concerned about the origin of the foods they eat. The natural abundance isotope variation such as carbon, nitrogen, hydrogen and oxygen are use as geographic tracers or marker to determine the geographic origin of fruits, crop, vegetables and food products from animal. The isotopic compositions of plant materials reflect various factors such as isotopic compositions of source materials and their assimilation processes as well as growth environments. This paper will discuss on stable carbon and nitrogen isotopic compositions in rice, advantages, limitations and potential of other analysis applications that can be incorporated in food traceability system. (author)

  13. Stereoselective synthesis of stable-isotope-labeled amino acids

    International Nuclear Information System (INIS)

    Unkefer, C.J.; Martinez, R.A.; Silks, L.A. III; Lodwig, S.N.

    1994-01-01

    For magnetic resonance and vibrational spectroscopies to reach their full potential, they must be used in combination with sophisticated site-specific stable isotope labeling of biological macromolecules. Labeled amino acids are required for the study of the structure and function of enzymes and proteins. Because there are 20 common amino acids, each with its own distinguishing chemistry, they remain a synthetic challenge. The Oppolzer chiral auxiliary provides a general tool with which to approach the synthesis of labeled amino acids. By using the Oppolzer auxiliary, amino acids can be constructed from several small molecules, which is ideal for stable isotope labeling. In addition to directing the stereochemistry at the α-carbon, the camphorsultam can be used for stereo-specific isotope labeling at prochiral centers in amino acids. By using the camphorsultam auxiliary we have the potential to synthesize virtually any isotopomer of all of the common amino acids

  14. Recombinant protein production from stable mammalian cell lines and pools.

    Science.gov (United States)

    Hacker, David L; Balasubramanian, Sowmya

    2016-06-01

    We highlight recent developments for the production of recombinant proteins from suspension-adapted mammalian cell lines. We discuss the generation of stable cell lines using transposons and lentivirus vectors (non-targeted transgene integration) and site-specific recombinases (targeted transgene integration). Each of these methods results in the generation of cell lines with protein yields that are generally superior to those achievable through classical plasmid transfection that depends on the integration of the transfected DNA by non-homologous DNA end-joining. This is the main reason why these techniques can also be used for the generation of stable cell pools, heterogenous populations of recombinant cells generated by gene delivery and genetic selection without resorting to single cell cloning. This allows the time line from gene transfer to protein production to be reduced. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Closed-Cycle, Frequency-Stable CO2 Laser Technology

    Science.gov (United States)

    Batten, Carmen E. (Editor); Miller, Irvin M. (Editor); Wood, George M., Jr. (Editor); Willetts, David V. (Editor)

    1987-01-01

    These proceedings contain a collection of papers and comments presented at a workshop on technology associated with long-duration closed-cycle operation of frequency-stable, pulsed carbon dioxide lasers. This workshop was held at the NASA Langley Research Center June 10 to 12, 1986. The workshop, jointly sponsored by the National Aeronautics and Space Administration (NASA) and the Royal Signals and Radar Establishment (RSRE), was attended by 63 engineers and scientists from the United States and the United Kingdom. During the 2 1/2 days of the workshop, a number of issues relating to obtaining frequency-stable operation and to the catalytic control of laser gas chemistry were discussed, and specific recommendations concerning future activities were drafted.

  16. Stable aesthetic standards delusion: changing 'artistic quality' by elaboration.

    Science.gov (United States)

    Carbon, Claus-Christian; Hesslinger, Vera M

    2014-01-01

    The present study challenges the notion that judgments of artistic quality are based on stable aesthetic standards. We propose that such standards are a delusion and that judgments of artistic quality are the combined result of exposure, elaboration, and discourse. We ran two experiments using elaboration tasks based on the repeated evaluation technique in which different versions of the Mona Lisa had to be elaborated deeply. During the initial task either the version known from the Louvre or an alternative version owned by the Prado was elaborated; during the second task both versions were elaborated in a comparative fashion. After both tasks multiple blends of the two versions had to be evaluated concerning several aesthetic key variables. Judgments of artistic quality of the blends were significantly different depending on the initially elaborated version of the Mona Lisa, indicating experience-based aesthetic processing, which contradicts the notion of stable aesthetic standards.

  17. Stable platinum isotope measurements in presolar nanodiamonds by TEAMS

    Energy Technology Data Exchange (ETDEWEB)

    Wallner, A., E-mail: anton.wallner@univie.ac.at [University of Vienna, Faculty of Physics, VERA Laboratory, Waehringer Strasse 17, A-1090 Vienna (Austria); Department of Nuclear Physics, Research School of Physics and Engineering, Australian National University, Canberra (Australia); Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights (Australia); Melber, K. [University of Vienna, Faculty of Physics, VERA Laboratory, Waehringer Strasse 17, A-1090 Vienna (Austria); Merchel, S. [Helmholtz-Zentrum Dresden-Rossendorf (HZDR), D-01314 Dresden (Germany); Ott, U. [Max-Planck-Institut fuer Chemie, Joh.-J.-Becherweg 27, D-55128 Mainz (Germany); Forstner, O.; Golser, R.; Kutschera, W.; Priller, A.; Steier, P. [University of Vienna, Faculty of Physics, VERA Laboratory, Waehringer Strasse 17, A-1090 Vienna (Austria)

    2013-01-15

    Nanodiamonds are stardust grains commonly found in primitive meteorites. They survived the formation of the solar system and kept their own individuality. Measurements of trace-element isotopic signatures in these grains will help understanding heavy element nucleosynthesis in massive stars and dust formation from their ejecta. We have continued previous attempts to search for stable Pt isotope anomalies in nanodiamonds via trace element accelerator mass spectrometry (TEAMS). The installation of a new injector beam line at the VERA facility allowed studying low traces of stable elements in different materials. Moreover, recent experiments showed that VERA provides the required measurement precision together with a low Pt machine background. Here, we observed for the first time an indication for enhancements of {sup 198}Pt/{sup 195}Pt isotope ratios in two diamond residues prepared by different chemical separation techniques from the Allende meteorite. Variations in other isotopic ratios were within analytical uncertainty, and no anomaly was identified in a third diamond fraction.

  18. Stable platinum isotope measurements in presolar nanodiamonds by TEAMS

    International Nuclear Information System (INIS)

    Wallner, A.; Melber, K.; Merchel, S.; Ott, U.; Forstner, O.; Golser, R.; Kutschera, W.; Priller, A.; Steier, P.

    2013-01-01

    Nanodiamonds are stardust grains commonly found in primitive meteorites. They survived the formation of the solar system and kept their own individuality. Measurements of trace-element isotopic signatures in these grains will help understanding heavy element nucleosynthesis in massive stars and dust formation from their ejecta. We have continued previous attempts to search for stable Pt isotope anomalies in nanodiamonds via trace element accelerator mass spectrometry (TEAMS). The installation of a new injector beam line at the VERA facility allowed studying low traces of stable elements in different materials. Moreover, recent experiments showed that VERA provides the required measurement precision together with a low Pt machine background. Here, we observed for the first time an indication for enhancements of 198 Pt/ 195 Pt isotope ratios in two diamond residues prepared by different chemical separation techniques from the Allende meteorite. Variations in other isotopic ratios were within analytical uncertainty, and no anomaly was identified in a third diamond fraction.

  19. Tunable and stable in time ferroelectric imprint through polarization coupling

    NARCIS (Netherlands)

    Ghosh, Anirban; Koster, Gertjan; Rijnders, Augustinus J.H.M.

    2016-01-01

    Here we demonstrate a method to tune a ferroelectric imprint, which is stable in time, based on the coupling between the non-switchable polarization of ZnO and switchable polarization of PbZrxTi(1−x)O3. SrRuO3/PbZrxTi(1−x)O3/ZnO/SrRuO3 heterostructures were grown with different ZnO thicknesses. It

  20. Self-interacting dark matter with a stable vector mediator

    OpenAIRE

    Duerr, Michael; Schmidt-Hoberg, Kai; Wild, Sebastian

    2018-01-01

    Light vector mediators can naturally induce velocity-dependent dark matter self-interactions while at the same time allowing for the correct dark matter relic abundance via thermal freeze-out. If these mediators subsequently decay into Standard Model states such as electrons or photons however, this is robustly excluded by constraints from the Cosmic Microwave Background. We study to what extent this conclusion can be circumvented if the vector mediator is stable and hence contributes to the ...

  1. Stable isotope utilization for research on human nutrition

    International Nuclear Information System (INIS)

    Desjeux, J.F.

    1994-01-01

    In the framework of nutritional molecule metabolism research, this paper presents the various stable isotopes used as labels for biological molecules, the reasons for their application in human nutritional study (mainly because of their non toxicity) and the various analysis methods (isotope ratio mass spectrometry, coupled gaseous chromatography and mass spectrometry, nuclear magnetic resonance). Several application examples in nutrition research are then discussed: metabolic conversion measurement for a molecule into its different metabolites, energetic losses. 23 refs

  2. Soluble and stable zethrenebis(dicarboximide) and its quinone

    KAUST Repository

    Sun, Zhe

    2010-10-15

    Soluble and stable zethrenebis(dicarboximide) (1) was synthesized by an in situ Stille cross coupling/transannular cyclization reaction. 1 showed largely improved photostability and solubility compared with the very unstable zethrene and it also exhibited far-red absorption and emission with high photoluminescence quantum yield. Bromination of 1 with NBS/DMF gave its quinone form 2 via an unusual pathway. © 2010 American Chemical Society.

  3. Development of Laser Application Technology for Stable Isotope Production

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Do Young; Ko, Kwang Hoon; Kwon, Duck Hee [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)] (and others)

    2007-04-15

    Tl-203 is used as a source material to produce Tl-201 radioisotope which is produced in a cyclotron by irradiating the enriched Tl-203 target. Tl-201 is a radiopharmaceutical for SPECT (single photon emission computerized tomography) to diagnose heart diseases and tumors. This Project aim to develop laser application technology to product stable isotopes such as Tl-203, Yb-168, and Yb-176. For this, photoion extraction device, atomic beam generator, dye lasers, and high power IR lasers are developed.

  4. Parameter estimation of sub-Gaussian stable distributions

    Czech Academy of Sciences Publication Activity Database

    Omelchenko, Vadym

    2014-01-01

    Roč. 50, č. 6 (2014), s. 929-949 ISSN 0023-5954 R&D Projects: GA ČR GA13-14445S Institutional support: RVO:67985556 Keywords : stable distribution * sub-Gaussian distribution * maximum likelihood Subject RIV: AH - Economics Impact factor: 0.541, year: 2014 http://library.utia.cas.cz/separaty/2014/E/omelchenko-0439707.pdf

  5. Investigating the Relationship between Stable Personality Characteristics and Automatic Imitation

    OpenAIRE

    Butler, Emily E.; Ward, Robert; Ramsey, Richard

    2015-01-01

    Automatic imitation is a cornerstone of nonverbal communication that fosters rapport between interaction partners. Recent research has suggested that stable dimensions of personality are antecedents to automatic imitation, but the empirical evidence linking imitation with personality traits is restricted to a few studies with modest sample sizes. Additionally, atypical imitation has been documented in autism spectrum disorders and schizophrenia, but the mechanisms underpinning these behaviour...

  6. A stable wireless energy transmission system for gastrointestinal microsystems.

    Science.gov (United States)

    Xin, W H; Yan, G Z; Wang, W X

    2010-01-01

    A wireless energy transmission system using a Helmholtz primary coil outside and a 3-dimensional secondary coil inside the body is introduced. It is designed to transmit stable power to a gastrointestinal microsystem regardless of its position and orientation when working in the gastric tract. Up to 310 mW of usable DC power can be delivered under worst-case geometrical conditions. Measured data of the system performance are presented and evaluated.

  7. Stable isotope deltas: Tiny, yet robust signatures in nature

    Science.gov (United States)

    Brand, Willi A.; Coplen, Tyler B.

    2012-01-01

    Although most of them are relatively small, stable isotope deltas of naturally occurring substances are robust and enable workers in anthropology, atmospheric sciences, biology, chemistry, environmental sciences, food and drug authentication, forensic science, geochemistry, geology, oceanography, and paleoclimatology to study a variety of topics. Two fundamental processes explain the stable isotope deltas measured in most terrestrial systems: isotopic fractionation and isotope mixing. Isotopic fractionation is the result of equilibrium or kinetic physicochemical processes that fractionate isotopes because of small differences in physical or chemical properties of molecular species having different isotopes. It is shown that the mixing of radioactive and stable isotope end members can be modelled to provide information on many natural processes, including 14C abundances in the modern atmosphere and the stable hydrogen and oxygen isotopic compositions of the oceans during glacial and interglacial times. The calculation of mixing fractions using isotope balance equations with isotope deltas can be substantially in error when substances with high concentrations of heavy isotopes (e.g. 13C, 2H, and 18O ) are mixed. In such cases, calculations using mole fractions are preferred as they produce accurate mixing fractions. Isotope deltas are dimensionless quantities. In the International System of Units (SI), these quantities have the unit 1 and the usual list of prefixes is not applicable. To overcome traditional limitations with expressing orders of magnitude differences in isotope deltas, we propose the term urey (symbol Ur), after Harold C. Urey, for the unit 1. In such a manner, an isotope delta value expressed traditionally as−25 per mil can be written as−25 mUr (or−2.5 cUr or−0.25 dUr; the use of any SI prefix is possible). Likewise, very small isotopic differences often expressed in per meg ‘units’ are easily included (e.g. either+0.015 ‰ or+15 per meg

  8. Radionuclide bone image in growing and stable bone island

    International Nuclear Information System (INIS)

    Go, R.T.; El-Khoury, G.Y.; Iowa Univ., Iowa City; Wehbe, M.A.

    1980-01-01

    A normal radionuclide bone image can facilitate distinction between a bone island and significant pathologic processes, especially an osteoblastic metastasis. This distinction becomes more crucial when growth is detected in an isolated sclerotic bone lesion or if a relatively large sclerotic lesion is detected de novo in patients with a known neoplasm. This report presents three patients with isolated bone islands: two with interval growth, the other with a relatively large stable lesion; all showing a normal radionuclide bone image. (orig.) [de

  9. On the likelihood function of Gaussian max-stable processes

    KAUST Repository

    Genton, M. G.; Ma, Y.; Sang, H.

    2011-01-01

    We derive a closed form expression for the likelihood function of a Gaussian max-stable process indexed by ℝd at p≤d+1 sites, d≥1. We demonstrate the gain in efficiency in the maximum composite likelihood estimators of the covariance matrix from p=2 to p=3 sites in ℝ2 by means of a Monte Carlo simulation study. © 2011 Biometrika Trust.

  10. Stable propagation of an electron beam in gas

    International Nuclear Information System (INIS)

    Lee, E.P.; Chambers, F.W.; Lodestro, L.L.; Yu, S.S.

    1977-01-01

    Conditions for the stable propagation of a pinched electron beam in low pressure gas (p approximately 0.1 to 100 torr) are described. The observed window of good propagation around p approximately 2 torr air is interpreted as the quenching of the two-stream mode by sufficiently high plasma density and collision frequency, and the simultaneous suppression of the resistive hose mode by sufficiently rapid generation of electrical conductivity from breakdown ionization

  11. T-regulatory cells in chronic rejection versus stable grafts.

    Science.gov (United States)

    Al-Wedaie, Fatima; Farid, Eman; Tabbara, Khaled; El-Agroudy, Amgad E; Al-Ghareeb, Sumaya M

    2015-04-01

    Studying regulatory T cells in kidney allograft acceptance versus chronic rejection may help in the understanding of more mechanisms of immune tolerance and, in the future, may enable clinicians to induce immune tolerance and decrease the use of immunosuppressive drugs. The aim of the current study was to evaluate regulatory T cells in kidney transplant patients with stable graft versus transplant with biopsy-proven chronic rejection. The 3 groups that were studied included: kidney transplanted patients with no rejection episodes (n = 43); transplanted patients with biopsy-proven renal rejection (n = 27); and healthy age-matched nontransplanted individuals as controls (n = 42).The percentage of regulatory T cells (CD4+CD25+Foxp3+) in blood was determined by flow cytometry. The regulatory T cell percentage was significantly lower in chronic rejection patients than control or stable graft groups. No significant difference was observed in regulatory T cell percentage between the stable graft and control groups. In the stable graft group, patients on rapamycin had a significantly higher regulatory T cell percentage than patients on cyclosporine. No effect of donor type, infection, or duration after transplant was observed on regulatory T cell percentage. The results of the current study are consistent with previous studies addressing the function of regulatory T cells in inducing immunotolerance after kidney transplant. Considering the established role of regulatory T cells in graft maintenance and our observation of high regulatory T cell percentage in patients receiving rapamycin than cyclosporine, we recommend including rapamycin when possible in immunosuppressive protocols. The findings from the current study on the chronic rejection group support ongoing research of having treatment with regulatory T cells, which may constitute a novel, efficient antirejection therapy in the future.

  12. Stochastic systems driven by alpha-stable noises

    DEFF Research Database (Denmark)

    Ditlevsen, Ove Dalager; Ditlevsen, P.

    1998-01-01

    with observed data. In particular the tailsof the observed response distributions may even for linear systems be more fat than the tails obtained for Gaussianwhite noise input. Also the excitation may show jumps that cannot be modeled by Gaussian white noise. The paper supports the possibility of using...... the larger class of so-calledalpha-stable white noises to provide a better fit. A geophysical application concerning ice age climate variations is described....

  13. Highly Stable and Active Catalyst for Sabatier Reactions

    Science.gov (United States)

    Hu, Jianli; Brooks, Kriston P.

    2012-01-01

    Highly active Ru/TiO2 catalysts for Sabatier reaction have been developed. The catalysts have shown to be stable under repeated shutting down/startup conditions. When the Ru/TiO2 catalyst is coated on the engineered substrate Fe-CrAlY felt, activity enhancement is more than doubled when compared with an identically prepared engineered catalyst made from commercial Degussa catalyst. Also, bimetallic Ru-Rh/TiO2 catalysts show high activity at high throughput.

  14. On Nash-Equilibria of Approximation-Stable Games

    Science.gov (United States)

    Awasthi, Pranjal; Balcan, Maria-Florina; Blum, Avrim; Sheffet, Or; Vempala, Santosh

    One reason for wanting to compute an (approximate) Nash equilibrium of a game is to predict how players will play. However, if the game has multiple equilibria that are far apart, or ɛ-equilibria that are far in variation distance from the true Nash equilibrium strategies, then this prediction may not be possible even in principle. Motivated by this consideration, in this paper we define the notion of games that are approximation stable, meaning that all ɛ-approximate equilibria are contained inside a small ball of radius Δ around a true equilibrium, and investigate a number of their properties. Many natural small games such as matching pennies and rock-paper-scissors are indeed approximation stable. We show furthermore there exist 2-player n-by-n approximation-stable games in which the Nash equilibrium and all approximate equilibria have support Ω(log n). On the other hand, we show all (ɛ,Δ) approximation-stable games must have an ɛ-equilibrium of support O(Δ^{2-o(1)}/ɛ2{log n}), yielding an immediate n^{O(Δ^{2-o(1)}/ɛ^2log n)}-time algorithm, improving over the bound of [11] for games satisfying this condition. We in addition give a polynomial-time algorithm for the case that Δ and ɛ are sufficiently close together. We also consider an inverse property, namely that all non-approximate equilibria are far from some true equilibrium, and give an efficient algorithm for games satisfying that condition.

  15. Stable black strings in anti-de sitter space

    International Nuclear Information System (INIS)

    Hirayama, Takayuki

    2002-01-01

    In my talk I show a black string which is a foliation of anti-de Sitter (AdS) Schwarzschild black hole becomes classically stable if the size of black hole horizon is larger than the AdS radius even if the black string extends infinitely. I will also give a comment on the relation with the Gubser-Mitra conjecture. This talk is based on our paper (Phys. Rev. D64: 064010, 2001) which is a collaboration with Gungwon Kang

  16. Melting point of high-purity germanium stable isotopes

    Science.gov (United States)

    Gavva, V. A.; Bulanov, A. D.; Kut'in, A. M.; Plekhovich, A. D.; Churbanov, M. F.

    2018-05-01

    The melting point (Tm) of germanium stable isotopes 72Ge, 73Ge, 74Ge, 76Ge was determined by differential scanning calorimetry. With the increase in atomic mass of isotope the decrease in Tm is observed. The decrease was equal to 0.15 °C per the unit of atomic mass which qualitatively agrees with the value calculated by Lindemann formula accounting for the effect of "isotopic compression" of elementary cell.

  17. Development of Laser Application Technology for Stable Isotope Production

    International Nuclear Information System (INIS)

    Jeong, Do Young; Ko, Kwang Hoon; Kwon, Duck Hee

    2007-04-01

    Tl-203 is used as a source material to produce Tl-201 radioisotope which is produced in a cyclotron by irradiating the enriched Tl-203 target. Tl-201 is a radiopharmaceutical for SPECT (single photon emission computerized tomography) to diagnose heart diseases and tumors. This Project aim to develop laser application technology to product stable isotopes such as Tl-203, Yb-168, and Yb-176. For this, photoion extraction device, atomic beam generator, dye lasers, and high power IR lasers are developed

  18. Phosphorus K4 Crystal: A New Stable Allotrope

    OpenAIRE

    Jie Liu; Shunhong Zhang; Yaguang Guo; Qian Wang

    2016-01-01

    The intriguing properties of phosphorene motivate scientists to further explore the structures and properties of phosphorus materials. Here, we report a new allotrope named K 4 phosphorus composed of three-coordinated phosphorus atoms in non-layered structure which is not only dynamically and mechanically stable, but also possesses thermal stability comparable to that of the orthorhombic black phosphorus (A17). Due to its unique configuration, K 4 phosphorus exhibits exceptional properties: i...

  19. Net Stable Funding Ratio: Impact on Funding Value Adjustment

    OpenAIRE

    Siadat, Medya; Hammarlid, Ola

    2017-01-01

    In this paper we investigate the relationship between Funding Value Adjustment (FVA) and Net Stable Funding Ratio (NSFR). FVA is defined in a consistent way with NSFR such that the new framework of FVA monitors the costs due to keeping NSFR at an acceptable level, as well. In addition, the problem of choosing the optimal funding strategy is formulated as a shortest path problem where the proposed FVA framework is applied in the optimization process. The solution provides us with the optimal f...

  20. Searching for stable orbits in the HD 10180 planetary system

    Directory of Open Access Journals (Sweden)

    Laskar J.

    2011-02-01

    Full Text Available A planetary system with at least seven planets has been found around the star HD 10180. However, the traditional Keplerian and n-body fits to the data provide an orbital solution that becomes unstable very quickly, which may quest the reliability of the observations. Here we show that stable orbital configurations can be obtained if general relativity and long-term dissipation raised by tides on the innermost planet are taken into account.

  1. On the Hitting Probability of Max-Stable Processes

    OpenAIRE

    Hofmann, Martin

    2012-01-01

    The probability that a max-stable process {\\eta} in C[0, 1] with identical marginal distribution function F hits x \\in R with 0 < F (x) < 1 is the hitting probability of x. We show that the hitting probability is always positive, unless the components of {\\eta} are completely dependent. Moreover, we consider the event that the paths of standard MSP hit some x \\in R twice and we give a sufficient condition for a positive probability of this event.

  2. Long-term stable surface modification of DLC coatings

    Directory of Open Access Journals (Sweden)

    Gotzmann Gaby

    2017-09-01

    Full Text Available The use of coatings based on diamond like carbon (DLC for medical applications was established during the last years. Main advantages of these coatings are its high hardness, good wear and friction behavior and its biocompatibility. Using low-energy electron-beam treatment, we addressed the surface modification of DLC coatings. The aim was to generate new biofunctional surface characteristics that are long-term stable.

  3. Stable solutions of nonlocal electron heat transport equations

    International Nuclear Information System (INIS)

    Prasad, M.K.; Kershaw, D.S.

    1991-01-01

    Electron heat transport equations with a nonlocal heat flux are in general ill-posed and intrinsically unstable, as proved by the present authors [Phys. Fluids B 1, 2430 (1989)]. A straightforward numerical solution of these equations will therefore lead to absurd results. It is shown here that by imposing a minimal set of constraints on the problem it is possible to arrive at a globally stable, consistent, and energy conserving numerical solution

  4. Long-term Stable Conservative Multiscale Methods for Vortex Flows

    Science.gov (United States)

    2017-10-31

    Computing Department, Florida State (January 2016) - L. Rebholz, SIAM Southeast 2016, Special session on Recent advances in fluid flow and...Multiscale Methods for Vortex Flows (x) Material has been given an OPSEC review and it has been determined to be non sensitive and, except for...distribution is unlimited. UU UU UU UU 31-10-2017 1-Aug-2014 31-Jul-2017 Final Report: Long-term Stable Conservative Multiscale Methods for Vortex Flows

  5. Development of Stable Solidification Method for Insoluble Ferrocyanides-13170

    Energy Technology Data Exchange (ETDEWEB)

    Ikarashi, Yuki; Masud, Rana Syed; Mimura, Hitoshi [Dept. of Quantum Science and Energy Engineering, Graduate School of Engineering, Tohoku University, Aramaki-Aza-Aoba6-6-01-2, Sendai, 980-8579 (Japan); Ishizaki, Eiji; Matsukura, Minoru [UNION SHOWA K.K. 17-20, Mita 2-chome, Minato-ku, Tokyo 108-0073 (Japan)

    2013-07-01

    The development of stable solidification method of insoluble ferrocyanides sludge is an important subject for the safety decontamination in Fukushima NPP-1. By using the excellent immobilizing properties of zeolites such as gas trapping ability and self-sintering properties, the stable solidification of insoluble ferrocyanides was accomplished. The immobilization ratio of Cs for K{sub 2}[CoFe(CN){sub 6}].nH{sub 2}O saturated with Cs{sup +} ions (Cs{sub 2}[CoFe(CN){sub 6}].nH{sub 2}O) was estimated to be less than 0.1% above 1,000 deg. C; the adsorbed Cs{sup +} ions are completely volatilized. In contrast, the novel stable solid form was produced by the press-sintering of the mixture of Cs{sub 2}[CoFe(CN){sub 6}].nH{sub 2}O and zeolites at higher temperature of 1,000 deg. C and 1,100 deg. C; Cs volatilization and cyanide release were completely depressed. The immobilization ratio of Cs, under the mixing conditions of Cs{sub 2}[CoFe(CN){sub 6}].nH{sub 2}O:CP= 1:1 and calcining temperature: 1,000 deg. C, was estimated to be nearly 100%. As for the kinds of zeolites, natural mordenite (NM), clinoptilolite (CP) and Chabazite tended to have higher immobilization ratio compared to zeolite A. This may be due to the difference in the phase transformation between natural zeolites and synthetic zeolite A. In the case of the composites (K{sub 2-X}Ni{sub X/2}[NiFe(CN){sub 6}].nH{sub 2}O loaded natural mordenite), relatively high immobilization ratio of Cs was also obtained. This method using zeolite matrices can be applied to the stable solidification of the solid wastes of insoluble ferrocyanides sludge. (authors)

  6. The Fractional Poisson Process and the Inverse Stable Subordinator

    OpenAIRE

    Meerschaert, Mark; Nane, Erkan; Vellaisamy, P.

    2011-01-01

    The fractional Poisson process is a renewal process with Mittag-Leffler waiting times. Its distributions solve a time-fractional analogue of the Kolmogorov forward equation for a Poisson process. This paper shows that a traditional Poisson process, with the time variable replaced by an independent inverse stable subordinator, is also a fractional Poisson process. This result unifies the two main approaches in the stochastic theory of time-fractional diffusion equations. The equivalence extend...

  7. On the likelihood function of Gaussian max-stable processes

    KAUST Repository

    Genton, M. G.

    2011-05-24

    We derive a closed form expression for the likelihood function of a Gaussian max-stable process indexed by ℝd at p≤d+1 sites, d≥1. We demonstrate the gain in efficiency in the maximum composite likelihood estimators of the covariance matrix from p=2 to p=3 sites in ℝ2 by means of a Monte Carlo simulation study. © 2011 Biometrika Trust.

  8. Stable-label intravenous glucose tolerance test minimal model

    International Nuclear Information System (INIS)

    Avogaro, A.; Bristow, J.D.; Bier, D.M.; Cobelli, C.; Toffolo, G.

    1989-01-01

    The minimal model approach to estimating insulin sensitivity (Sl) and glucose effectiveness in promoting its own disposition at basal insulin (SG) is a powerful tool that has been underutilized given its potential applications. In part, this has been due to its inability to separate insulin and glucose effects on peripheral uptake from their effects on hepatic glucose inflow. Prior enhancements, with radiotracer labeling of the dosage, permit this separation but are unsuitable for use in pregnancy and childhood. In this study, we labeled the intravenous glucose tolerance test (IVGTT) dosage with [6,6- 2 H 2 ]glucose, [2- 2 H]glucose, or both stable isotopically labeled glucose tracers and modeled glucose kinetics in six postabsorptive, nonobese adults. As previously found with the radiotracer model, the tracer-estimated S*l derived from the stable-label IVGTT was greater than Sl in each case except one, and the tracer-estimated SG* was less than SG in each instance. More importantly, however, the stable-label IVGTT estimated each parameter with an average precision of +/- 5% (range 3-9%) compared to average precisions of +/- 74% (range 7-309%) for SG and +/- 22% (range 3-72%) for Sl. In addition, because of the different metabolic fates of the two deuterated tracers, there were minor differences in basal insulin-derived measures of glucose effectiveness, but these differences were negligible for parameters describing insulin-stimulated processes. In conclusion, the stable-label IVGTT is a simple, highly precise means of assessing insulin sensitivity and glucose effectiveness at basal insulin that can be used to measure these parameters in individuals of all ages, including children and pregnant women

  9. Stable Superstring Relics and Ultrahigh Energy Cosmic Rays

    CERN Document Server

    Coriano, Claudio; Plumacher, Michael; Coriano, Claudio; Faraggi, Alon E.; Plumacher, Michael

    2001-01-01

    One of the most intriguing experimental results of recent years is the observation of Ultrahigh Energy Cosmic Rays (UHECRs) above the GZK cutoff. Plausible candidates for the UHECR primaries are the decay products of a meta--stable matter state with mass of order O(10^{12-15 GeV}), which simultaneously is a good cold dark matter candidate. We study possible meta-stable matter states that arise from Wilson line breaking of GUT symmetries in semi-realistic heterotic string models. In the models that we study the exotic matter states can be classified according to patterns of SO(10) symmetry breaking. We show that cryptons, which are states that carry fractional electric charge $\\pm1/2$, and are confined by a hidden gauge group cannot produce viable dark matter. This is due to the fact that, in addition to the lightest neutral bound state, cryptons give rise to meta-stable charged bound states. However, these states may still account for the UHECR events. We argue that the uniton, which is an exotic Standard Mod...

  10. Membrane-Sculpting BAR Domains Generate Stable Lipid Microdomains

    Science.gov (United States)

    Zhao, Hongxia; Michelot, Alphée; Koskela, Essi V.; Tkach, Vadym; Stamou, Dimitrios; Drubin, David G.; Lappalainen, Pekka

    2014-01-01

    SUMMARY Bin-Amphiphysin-Rvs (BAR) domain proteins are central regulators of many cellular processes involving membrane dynamics. BAR domains sculpt phosphoinositide-rich membranes to generate membrane protrusions or invaginations. Here, we report that, in addition to regulating membrane geometry, BAR domains can generate extremely stable lipid microdomains by “freezing” phosphoinositide dynamics. This is a general feature of BAR domains, because the yeast endocytic BAR and Fes/CIP4 homology BAR (F-BAR) domains, the inverse BAR domain of Pinkbar, and the eisosomal BAR protein Lsp1 induced phosphoinositide clustering and halted lipid diffusion, despite differences in mechanisms of membrane interactions. Lsp1 displays comparable low diffusion rates in vitro and in vivo, suggesting that BAR domain proteins also generate stable phosphoinositide microdomains in cells. These results uncover a conserved role for BAR superfamily proteins in regulating lipid dynamics within membranes. Stable microdomains induced by BAR domain scaffolds and specific lipids can generate phase boundaries and diffusion barriers, which may have profound impacts on diverse cellular processes. PMID:24055060

  11. Active Fault Tolerant Control of Livestock Stable Ventilation System

    DEFF Research Database (Denmark)

    Gholami, Mehdi

    2011-01-01

    Modern stables and greenhouses are equipped with different components for providing a comfortable climate for animals and plant. A component malfunction may result in loss of production. Therefore, it is desirable to design a control system, which is stable, and is able to provide an acceptable d...... are not included, while due to the physical limitation, the input signal can not have any value. In continuing, a passive fault tolerant controller (PFTC) based on state feedback is proposed to track a reference signal while the control inputs are bounded....... of fault. Designing a fault tolerant control scheme for the climate control system. In the first step, a conceptual multi-zone model for climate control of a live-stock building is derived. The model is a nonlinear hybrid model. Hybrid systems contain both discrete and continuous components. The parameters...... affine (PWA) components such as dead-zones, saturation, etc or contain piecewise nonlinear models which is the case for the climate control systems of the stables. Fault tolerant controller (FTC) is based on a switching scheme between a set of predefined passive fault tolerant controller (PFTC...

  12. A highly stable microchannel heat sink for convective boiling

    International Nuclear Information System (INIS)

    Lu, Chun Ting; Pan Chin

    2009-01-01

    To develop a highly stable two-phase microchannel heat sink, we experimented with convective boiling in diverging, parallel microchannels with different distributions of laser-etched artificial nucleation sites. Each microchannel had a mean hydraulic diameter of 120 µm. The two-phase flow visualization and the magnitudes of pressure drop and inlet temperature oscillations under boiling conditions demonstrated clearly the merits of using artificial nucleation sites to further stabilize the flow boiling in diverging, parallel microchannels. The stability map showed the plane of subcooling number versus phase change number. It illustrated that diverging, parallel microchannels with artificial nucleation cavities have a much wider stable region than parallel microchannels with uniform cross-sections or diverging, parallel microchannels without artificial nucleation cavities. In addition, the results revealed that the design with cavities distributed uniformly along the downstream half of the channel presented the best stability performance among the three distributions of nucleation sites. This particular design can be regarded as a highly stable microchannel heat sink for convective boiling

  13. Discrimination of ginseng cultivation regions using light stable isotope analysis.

    Science.gov (United States)

    Kim, Kiwook; Song, Joo-Hyun; Heo, Sang-Cheol; Lee, Jin-Hee; Jung, In-Woo; Min, Ji-Sook

    2015-10-01

    Korean ginseng is considered to be a precious health food in Asia. Today, thieves frequently compromise ginseng farms by pervasive theft. Thus, studies regarding the characteristics of ginseng according to growth region are required in order to deter ginseng thieves and prevent theft. In this study, 6 regions were selected on the basis of Korea regional criteria (si, gun, gu), and two ginseng-farms were randomly selected from each of the 6 regions. Then 4-6 samples of ginseng were acquired from each ginseng farm. The stable isotopic compositions of H, O, C, and N of the collected ginseng samples were analyzed. As a result, differences in the hydrogen isotope ratios could be used to distinguish regional differences, and differences in the nitrogen isotope ratios yielded characteristic information regarding the farms from which the samples were obtained. Thus, stable isotope values could be used to differentiate samples according to regional differences. Therefore, stable isotope analysis serves as a powerful tool to discriminate the regional origin of Korean ginseng samples from across Korea. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  14. Factors controlling stable isotope composition of European precipitation

    International Nuclear Information System (INIS)

    Rozanski, K.; Sonntag, C.; Muennich, K.O.

    1982-01-01

    The seasonal and spatial variations of stable isotope ratios in present day European precipitation are simulated with a simple multibox model of the mean west-east horizontal transport of the atmospheric water vapour across the European continent. Isotope fractionation during the formation of precipitation leads to an increasing depletion of heavy isotopes in the residual air moisture as it moves towards the centre of the continent. This isotopic depletion is partly compensated, particularly in summer, by evapotranspiration, which is assumed to transfer soil water into the atmosphere without isotope fractionation. The model estimates are based on horizontal water vapour flux data, varying seasonally between 88 and 130 kg m -1 s -1 for the Atlantic coast region, and on the monthly precipitation, evapotranspiration and surface air temperature data available for various locations in Europe. Both continental and seasonal temperature effects observed in the stable isotope composition of European precipitation are fairly well reproduced by the model. The calculations show that the isotopic composition of local precipitation is primarily controlled by regional scale processes, i.e. by the water vapour transport patterns into the continent, and by the average precipitation-evapotranspiration history of the air masses precipitating at a given place. Local parameters such as the surface and/or cloud base temperature or the amount of precipitation modify the isotope ratios only slightly. Implications of the model predictions for the interpretation of stable isotope ratios in earlier periods as they are preserved in ice cores and in groundwater are also discussed. (Auth.)

  15. Meiotically stable natural epialleles of Sadhu, a novel Arabidopsis retroposon.

    Directory of Open Access Journals (Sweden)

    Sanjida H Rangwala

    2006-03-01

    Full Text Available Epigenetic variation is a potential source of genomic and phenotypic variation among different individuals in a population, and among different varieties within a species. We used a two-tiered approach to identify naturally occurring epigenetic alleles in the flowering plant Arabidopsis: a primary screen for transcript level polymorphisms among three strains (Col, Cvi, Ler, followed by a secondary screen for epigenetic alleles. Here, we describe the identification of stable, meiotically transmissible epigenetic alleles that correspond to one member of a previously uncharacterized non-LTR retroposon family, which we have designated Sadhu. The pericentromeric At2g10410 element is highly expressed in strain Col, but silenced in Ler and 18 other strains surveyed. Transcription of this locus is inversely correlated with cytosine methylation and both the expression and DNA methylation states map in a Mendelian manner to stable cis-acting variation. The silent Ler allele can be converted by the epigenetic modifier mutation ddm1 to a meiotically stable expressing allele with an identical primary nucleotide sequence, demonstrating that the variation responsible for transcript level polymorphism among Arabidopsis strains is epigenetic. We extended our characterization of the Sadhu family members and show that different elements are subject to both genetic and epigenetic variation in natural populations. These findings support the view that an important component of natural variation in retroelements is epigenetic.

  16. Adaptive Sniping for Volatile and Stable Continuous Double Auction Markets

    Science.gov (United States)

    Toft, I. E.; Bagnall, A. J.

    This paper introduces a new adaptive sniping agent for the Continuous Double Auction. We begin by analysing the performance of the well known Kaplan sniper in two extremes of market conditions. We generate volatile and stable market conditions using the well known Zero Intelligence-Constrained agent and a new zero-intelligence agent Small Increment (SI). ZI-C agents submit random but profitable bids/offers and cause high volatility in prices and individual trader performance. Our new zero-intelligence agent, SI, makes small random adjustments to the outstanding bid/offer and hence is more cautious than ZI-C. We present results for SI in self-play and then analyse Kaplan in volatile and stable markets. We demonstrate that the non-adaptive Kaplan sniper can be configured to suit either market conditions, but no single configuration is performs well across both market types. We believe that in a dynamic auction environment where current or future market conditions cannot be predicted a viable sniping strategy should adapt its behaviour to suit prevailing market conditions. To this end, we propose the Adaptive Sniper (AS) agent for the CDA. AS traders classify sniping opportunities using a statistical model of market activity and adjust their classification thresholds using a Widrow-Hoff adapted search. Our AS agent requires little configuration, and outperforms the original Kaplan sniper in volatile and stable markets, and in a mixed trader type scenario that includes adaptive strategies from the literature.

  17. An algebraic method for constructing stable and consistent autoregressive filters

    International Nuclear Information System (INIS)

    Harlim, John; Hong, Hoon; Robbins, Jacob L.

    2015-01-01

    In this paper, we introduce an algebraic method to construct stable and consistent univariate autoregressive (AR) models of low order for filtering and predicting nonlinear turbulent signals with memory depth. By stable, we refer to the classical stability condition for the AR model. By consistent, we refer to the classical consistency constraints of Adams–Bashforth methods of order-two. One attractive feature of this algebraic method is that the model parameters can be obtained without directly knowing any training data set as opposed to many standard, regression-based parameterization methods. It takes only long-time average statistics as inputs. The proposed method provides a discretization time step interval which guarantees the existence of stable and consistent AR model and simultaneously produces the parameters for the AR models. In our numerical examples with two chaotic time series with different characteristics of decaying time scales, we find that the proposed AR models produce significantly more accurate short-term predictive skill and comparable filtering skill relative to the linear regression-based AR models. These encouraging results are robust across wide ranges of discretization times, observation times, and observation noise variances. Finally, we also find that the proposed model produces an improved short-time prediction relative to the linear regression-based AR-models in forecasting a data set that characterizes the variability of the Madden–Julian Oscillation, a dominant tropical atmospheric wave pattern

  18. The stable nonequilibrium state of bicarbonate aqueous systems

    Science.gov (United States)

    Voeikov, V. L.; Vilenskaya, N. D.; Ha, Do Minh; Malyshenko, S. I.; Buravleva, E. V.; Yablonskaya, O. I.; Timofeev, K. N.

    2012-09-01

    Data obtained by electron paramagnetic resonance (EPR) and chemiluminescence analysis indicate that in aqueous solutions of bicarbonates, superoxide radical and other reactive oxygen species (ROS) are constantly produced. The stationary level of the superoxide radical is found to increase when a solution is illuminated. Reactions involving ROS are shown to be accompanied by the generation of electron excitation energy, keeping bicarbonate solutions in a stable nonequilibrium state. The system can emit part of this energy. Variations in emitting activity are found to correlate with variations in the cosmophysical factors. The emitting activity of solutions is found to vary in the presence of low and ultralow concentrations of hydrated fullerenes. It is noted that the phenomenon of spontaneous charge separation in aqueous systems (G. H. Pollack) could play a role in maintaining a stable nonequilibrium state in bicarbonate systems where the reactions with ROS participation are catalyzed by forms of carbonate. It is concluded that the abovementioned properties of bicarbonate aqueous systems most likely keep living matter whose structural basis is formed by these systems in a stable excited state, thereby making it highly sensitive to the action of external factors with low and ultralow intensities.

  19. Deposition of radionuclides and stable elements in Tokai-mura

    Energy Technology Data Exchange (ETDEWEB)

    Ueno, Takashi; Amano, Hikaru [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-03-01

    This report presents the data of deposition of radionuclides (Sep. 1993-March 2001) and stable elements (Sep. 1993-Oct. 1995) in Tokai-mura. To evaluate the migration of radionuclides and stable elements from the atmosphere to the ground surface, atmospheric deposition samples were collected from Sep. 1993 to March 2001 with three basins (distance to grand surface were 1.5 m, 4 m, 10 m) set up in the enclosure of JAERI in Tokai-mura, Ibaraki-ken, Japan. Monthly samples were evaporated to dryness to obtain residual samples and measured with a well type Ge detector for {sup 7}Be, {sup 40}K, {sup 137}Cs and {sup 210}Pb. According to the analysis of radioactivity, clear seasonal variations with spring peaks of deposition weight (dry) and deposition amounts of all objective radionuclides were found. Correlation analysis of deposition data also showed that these radionuclides can be divided into two groups. A part of dried sample was irradiated to reactor neutrons at JRR-4 for determination of stable element's deposition. (author)

  20. Studies of Stable Octupole Deformations in the Radium Region

    CERN Multimedia

    2002-01-01

    The purpose of the present project is to locate and identify states in the atomic nuclei possessing stable pearshaped octupole deformation. Such states, formally related to the structures known in molecular physics, manifest themselves as families of parity doublets in odd nuclei.\\\\ \\\\ The best possibilities for observing stable octupole deformations are offered in the Ra-region. Both theoretical calculations and experimental indications support such expectations. Such indications are the non-observation of two-phonon octupole vibrational states in the ISOLDE studies of the even-even radium nuclei, and the reversed sign of the decoupling factor of the ground state band in |2|2|5Ra observed in the single-neutron transfer reactions. In order to establish the predicted strong E1 and E3-transitions between the parity doublets in odd nuclei with stable octupole deformations it is proposed to study conversion electrons in odd-mass francium radium and radon isotopes following the @b-decay of francium and astatine. \\...

  1. Turbulence Spreading into Linearly Stable Zone and Transport Scaling

    International Nuclear Information System (INIS)

    Hahm, T.S.; Diamond, P.H.; Lin, Z.; Itoh, K.; Itoh, S.-I.

    2003-01-01

    We study the simplest problem of turbulence spreading corresponding to the spatio-temporal propagation of a patch of turbulence from a region where it is locally excited to a region of weaker excitation, or even local damping. A single model equation for the local turbulence intensity I(x, t) includes the effects of local linear growth and damping, spatially local nonlinear coupling to dissipation and spatial scattering of turbulence energy induced by nonlinear coupling. In the absence of dissipation, the front propagation into the linearly stable zone occurs with the property of rapid progression at small t, followed by slower subdiffusive progression at late times. The turbulence radial spreading into the linearly stable zone reduces the turbulent intensity in the linearly unstable zone, and introduces an additional dependence on the rho* is always equal to rho i/a to the turbulent intensity and the transport scaling. These are in broad, semi-quantitative agreements with a number of global gyrokinetic simulation results with zonal flows and without zonal flows. The front propagation stops when the radial flux of fluctuation energy from the linearly unstable region is balanced by local dissipation in the linearly stable region

  2. Search for stable stau production at the LHC

    International Nuclear Information System (INIS)

    Kaschube, Kolja

    2011-10-01

    In this thesis, a search for heavy stable charge particle production, in particular a quasistable supersymmetric tau lepton (''stau'') arising in gauge-mediated supersymmetry breaking (GMSB) models, is presented. This stable stau would cross detectors without decaying, resembling a muon, and produce signatures of high momentum or high ionization energy loss. The energy loss measurement represents a direct handle on the particle mass via the Bethe-Bloch formula. Proton-proton collisions at 7 TeV center-of-mass energy produced by the Large Hadron Collider and recorded by the CMS detector are investigated. Low-momentum collision data tracks are used to predict the background of highly ionizing tracks at high momenta. A high signal-to-background ratio is achieved by separating the search into channels with differing muon or stau multiplicities and by using the transverse momentum and energy loss measurement as the discriminating variables. Using 35.8 pb -1 of data recorded in the 2010 LHC run, no excess is observed with respect to the expected Standard Model background. As a result, upper limits on the mass of stable status are derived within the context of the investigated GMSB models. (orig.)

  3. On the joint statistics of stable random processes

    International Nuclear Information System (INIS)

    Hopcraft, K I; Jakeman, E

    2011-01-01

    A utilitarian continuous bi-variate random process whose first-order probability density function is a stable random variable is constructed. Results paralleling some of those familiar from the theory of Gaussian noise are derived. In addition to the joint-probability density for the process, these include fractional moments and structure functions. Although the correlation functions for stable processes other than Gaussian do not exist, we show that there is coherence between values adopted by the process at different times, which identifies a characteristic evolution with time. The distribution of the derivative of the process, and the joint-density function of the value of the process and its derivative measured at the same time are evaluated. These enable properties to be calculated analytically such as level crossing statistics and those related to the random telegraph wave. When the stable process is fractal, the proportion of time it spends at zero is finite and some properties of this quantity are evaluated, an optical interpretation for which is provided. (paper)

  4. Air-stable n-type colloidal quantum dot solids

    KAUST Repository

    Ning, Zhijun; Voznyy, Oleksandr; Pan, Jun; Hoogland, Sjoerd H.; Adinolfi, Valerio; Xu, Jixian; Li, Min; Kirmani, Ahmad R.; Sun, Jonpaul; Minor, James C.; Kemp, Kyle W.; Dong, Haopeng; Rollny, Lisa R.; Labelle, André J.; Carey, Graham H.; Sutherland, Brandon R.; Hill, Ian G.; Amassian, Aram; Liu, Huan; Tang, Jiang; Bakr, Osman; Sargent, E. H.

    2014-01-01

    Colloidal quantum dots (CQDs) offer promise in flexible electronics, light sensing and energy conversion. These applications rely on rectifying junctions that require the creation of high-quality CQD solids that are controllably n-type (electron-rich) or p-type (hole-rich). Unfortunately, n-type semiconductors made using soft matter are notoriously prone to oxidation within minutes of air exposure. Here we report high-performance, air-stable n-type CQD solids. Using density functional theory we identify inorganic passivants that bind strongly to the CQD surface and repel oxidative attack. A materials processing strategy that wards off strong protic attack by polar solvents enabled the synthesis of an air-stable n-type PbS CQD solid. This material was used to build an air-processed inverted quantum junction device, which shows the highest current density from any CQD solar cell and a solar power conversion efficiency as high as 8%. We also feature the n-type CQD solid in the rapid, sensitive, and specific detection of atmospheric NO2. This work paves the way for new families of electronic devices that leverage air-stable quantum-tuned materials. © 2014 Macmillan Publishers Limited. All rights reserved.

  5. From stable to unstable anomaly-induced inflation

    Science.gov (United States)

    Netto, Tibério de Paula; Pelinson, Ana M.; Shapiro, Ilya L.; Starobinsky, Alexei A.

    2016-10-01

    Quantum effects derived through conformal anomaly lead to an inflationary model that can be either stable or unstable. The unstable version requires a large dimensionless coefficient of about 5× {10}^8 in front of the {R}^2 term that results in the inflationary regime in the R+{R}^2 ("Starobinsky") model being a generic intermediate attractor. In this case the non-local terms in the effective action are practically irrelevant, and there is a `graceful exit' to a low curvature matter-like dominated stage driven by high-frequency oscillations of R - scalarons, which later decay to pairs of all particles and antiparticles, with the amount of primordial scalar (density) perturbations required by observations. The stable version is a genuine generic attractor, so there is no exit from it. We discuss a possible transition from stable to unstable phases of inflation. It is shown that this transition is automatic if the sharp cut-off approximation is assumed for quantum corrections in the period of transition. Furthermore, we describe two different quantum mechanisms that may provide a required large {R}^2-term in the transition period.

  6. Air-stable n-type colloidal quantum dot solids

    KAUST Repository

    Ning, Zhijun

    2014-06-08

    Colloidal quantum dots (CQDs) offer promise in flexible electronics, light sensing and energy conversion. These applications rely on rectifying junctions that require the creation of high-quality CQD solids that are controllably n-type (electron-rich) or p-type (hole-rich). Unfortunately, n-type semiconductors made using soft matter are notoriously prone to oxidation within minutes of air exposure. Here we report high-performance, air-stable n-type CQD solids. Using density functional theory we identify inorganic passivants that bind strongly to the CQD surface and repel oxidative attack. A materials processing strategy that wards off strong protic attack by polar solvents enabled the synthesis of an air-stable n-type PbS CQD solid. This material was used to build an air-processed inverted quantum junction device, which shows the highest current density from any CQD solar cell and a solar power conversion efficiency as high as 8%. We also feature the n-type CQD solid in the rapid, sensitive, and specific detection of atmospheric NO2. This work paves the way for new families of electronic devices that leverage air-stable quantum-tuned materials. © 2014 Macmillan Publishers Limited. All rights reserved.

  7. NEBIVOLOL IN TREATMENT OF STABLE EXERTIONAL ANGINA PECTORIS

    Directory of Open Access Journals (Sweden)

    Y. V. Gavrilov

    2015-12-01

    Full Text Available Aim. To evaluate antianginal and antiischemic efficiency of nebivolol in patients with stable angina pectoris.Material and methods. 100 patients with ischemic heart disease showing stable exertional angina pectoris and having no contraindications to beta-blockers were studied. After 5-7 days of control period 50 randomly selected patients began to take nebivolol in initial dose of 5mg once daily and 50 patients started to take metoprolol in initial dose of 50 mg twice daily. Duration of treatment was 8 weeks. Efficiency of treatment was assessed according to the results of control treadmill assessment and control daily ECG monitoring.Results. 56-day therapy with nebivolol at a dose of 7,5 mg per day results in increase in duration of treadmill test before angina or ST depression (p<0.05. Antianginal and antiischemic effect of nebivolol 7.5 mg once daily is rather similar with that of metoprolol in average daily dose of 175 mg. Nebivolol compared to metoprolol significantly (p<0.05 more effectively reduces the number of silent myocardial ischemia.Conclusion. Nebivolol is an efficient antianginal and antiischemic drug for patients with stable exertional angina pectoris.

  8. From stable to unstable anomaly-induced inflation

    Energy Technology Data Exchange (ETDEWEB)

    Paula Netto, Tiberio de [Universidade Federal de Juiz de Fora, Departamento de Fisica, ICE, Juiz de Fora, MG (Brazil); Pelinson, Ana M. [Universidade Federal de Santa Catarina, Departamento de Fisica, CFM, Bairro da Trindade, Florianopolis, SC (Brazil); Shapiro, Ilya L. [Universidade Federal de Juiz de Fora, Departamento de Fisica, ICE, Juiz de Fora, MG (Brazil); Tomsk State Pedagogical University and Tomsk State University, Tomsk (Russian Federation); Starobinsky, Alexei A. [L.D. Landau Institute for Theoretical Physics RAS, Moscow (Russian Federation); Utrecht University, Department of Physics and Astronomy, Institute for Theoretical Physics, Utrecht (Netherlands)

    2016-10-15

    Quantum effects derived through conformal anomaly lead to an inflationary model that can be either stable or unstable. The unstable version requires a large dimensionless coefficient of about 5 x 10{sup 8} in front of the R{sup 2} term that results in the inflationary regime in the R+R{sup 2} (''Starobinsky'') model being a generic intermediate attractor. In this case the non-local terms in the effective action are practically irrelevant, and there is a 'graceful exit' to a low curvature matter-like dominated stage driven by high-frequency oscillations of R - scalarons, which later decay to pairs of all particles and antiparticles, with the amount of primordial scalar (density) perturbations required by observations. The stable version is a genuine generic attractor, so there is no exit from it. We discuss a possible transition from stable to unstable phases of inflation. It is shown that this transition is automatic if the sharp cut-off approximation is assumed for quantum corrections in the period of transition. Furthermore, we describe two different quantum mechanisms that may provide a required large R{sup 2}-term in the transition period. (orig.)

  9. The separation of stable water-in-oil emulsions

    International Nuclear Information System (INIS)

    Velicogna, D.; Koundakjiian, A.; Beausejour, I.

    1993-01-01

    Stable oil-in-water emulsions are a major problem in the recovery of spilled oils. Such emulsions can contain as little as 10% oil and can have properties very different from the original oils, making their storage and disposal difficult. These problems have led to experiments testing the feasibility of a process for separating these stable emulsions into dischargeable water and reusable oil. The technique investigated involves use of a recyclable solvent to remove the oil and subsequent distillation and/or membrane treatment to recover the oil and recycle the solvent. Results of preliminary tests show that stable water-in-oil emulsions can be separated quite readily with a regenerated solvent system. The only products of these systems are oil, which can be sent to a refinery, and dischargeable water. The recycled solvent can be used many times without any significant decrease in separation efficiency. In order to enhance the throughput of the system, a solvent vapor stripping method was invented. This stripping method also improves the quality of the products and the recycled solvent. Membrane methods can be used as a post-treatment for the produced water in order to achieve more adequate compliance with discharge limits. 4 refs., 3 figs., 5 tabs

  10. Gauging the likelihood of stable cavitation from ultrasound contrast agents.

    Science.gov (United States)

    Bader, Kenneth B; Holland, Christy K

    2013-01-07

    The mechanical index (MI) was formulated to gauge the likelihood of adverse bioeffects from inertial cavitation. However, the MI formulation did not consider bubble activity from stable cavitation. This type of bubble activity can be readily nucleated from ultrasound contrast agents (UCAs) and has the potential to promote beneficial bioeffects. Here, the presence of stable cavitation is determined numerically by tracking the onset of subharmonic oscillations within a population of bubbles for frequencies up to 7 MHz and peak rarefactional pressures up to 3 MPa. In addition, the acoustic pressure rupture threshold of an UCA population was determined using the Marmottant model. The threshold for subharmonic emissions of optimally sized bubbles was found to be lower than the inertial cavitation threshold for all frequencies studied. The rupture thresholds of optimally sized UCAs were found to be lower than the threshold for subharmonic emissions for either single cycle or steady state acoustic excitations. Because the thresholds of both subharmonic emissions and UCA rupture are linearly dependent on frequency, an index of the form I(CAV) = P(r)/f (where P(r) is the peak rarefactional pressure in MPa and f is the frequency in MHz) was derived to gauge the likelihood of subharmonic emissions due to stable cavitation activity nucleated from UCAs.

  11. Application of Stable Isotope Signatures in Food Traceability

    International Nuclear Information System (INIS)

    Nazaratul Ashifa Abdullah Salim; Roslanzairi Mostapha; Zainon Othman

    2016-01-01

    Stable isotope analysis has widely been used to trace the origin of organic materials in various fields, such as geochemistry, biochemistry, archaeology and petroleum. In past a decade, it has also become an important tool for food traceability study. The globalisation of food markets and the relative ease which food commodities are transported through and between countries and continents means that consumers are increasingly concerned about the origin of the foods they eat. The natural abundance of stable isotope variation such as carbon, nitrogen, hydrogen and oxygen are used as geographic tracers or marker to determine the geographic origin of fruits, crop, vegetables and food products from animal. The isotopic compositions of plant materials reflect various factors such as isotopic compositions of source materials and their assimilation processes as well as growth environments. This paper will discuss on stable carbon and nitrogen isotopic compositions in rice that been determined by Isotope Ratio Mass Spectrometry, advantages, limitations and potential of other analysis applications that can be incorporated in food traceability system. (author)

  12. Search for stable stau production at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Kaschube, Kolja

    2011-10-15

    In this thesis, a search for heavy stable charge particle production, in particular a quasistable supersymmetric tau lepton (''stau'') arising in gauge-mediated supersymmetry breaking (GMSB) models, is presented. This stable stau would cross detectors without decaying, resembling a muon, and produce signatures of high momentum or high ionization energy loss. The energy loss measurement represents a direct handle on the particle mass via the Bethe-Bloch formula. Proton-proton collisions at 7 TeV center-of-mass energy produced by the Large Hadron Collider and recorded by the CMS detector are investigated. Low-momentum collision data tracks are used to predict the background of highly ionizing tracks at high momenta. A high signal-to-background ratio is achieved by separating the search into channels with differing muon or stau multiplicities and by using the transverse momentum and energy loss measurement as the discriminating variables. Using 35.8 pb{sup -1} of data recorded in the 2010 LHC run, no excess is observed with respect to the expected Standard Model background. As a result, upper limits on the mass of stable status are derived within the context of the investigated GMSB models. (orig.)

  13. Effects of euthanasia method on stable-carbon and stable-nitrogen isotope analysis for an ectothermic vertebrate.

    Science.gov (United States)

    Atwood, Meredith A

    2013-04-30

    Stable isotope analysis is a critical tool for understanding ecological food webs; however, results can be sensitive to sample preparation methods. To limit the possibility of sample contamination, freezing is commonly used to euthanize invertebrates and preserve non-lethal samples from vertebrates. For destructive sampling of vertebrates, more humane euthanasia methods are preferred to freezing and it is essential to evaluate how these euthanasia methods affect stable isotope results. Stable isotope ratios and elemental composition of carbon and nitrogen were used to evaluate whether the euthanasia method compromised the integrity of the sample for analysis. Specifically, the stable isotope and C:N ratios were compared for larval wood frogs (Rana sylvatica  =  Lithobates sylvaticus), an ectothermic vertebrate, that had been euthanized by freezing with four different humane euthanasia methods: CO2, benzocaine, MS-222 (tricaine methanesulfonate), and 70% ethanol. The euthanasia method was not related to the δ(13)C or δ(15)N values and the comparisons revealed no differences between freezing and any of the other treatments. However, there were slight (non-significant) differences in the isotope ratios of benzocaine and CO2 when each was compared with freezing. The elemental composition was altered by the euthanasia method employed. The percentage nitrogen was higher in CO2 treatments than in freezing, and similar (non-significant) trends were seen for ethanol treatments relative to freezing. The resulting C:N ratios were higher for benzocaine treatments than for both CO2 and ethanol. Similar (non-significant) trends suggested that the C:N ratios were also higher for animals euthanized by freezing than for both CO2 and ethanol euthanasia methods. The euthanasia method had a larger effect on elemental composition than stable isotope ratios. The percentage nitrogen and the subsequent C:N ratios were most affected by the CO2 and ethanol euthanasia methods, whereas

  14. Leg-adjustment strategies for stable running in three dimensions

    International Nuclear Information System (INIS)

    Peuker, Frank; Maufroy, Christophe; Seyfarth, André

    2012-01-01

    The dynamics of the center of mass (CoM) in the sagittal plane in humans and animals during running is well described by the spring-loaded inverted pendulum (SLIP). With appropriate parameters, SLIP running patterns are stable, and these models can recover from perturbations without the need for corrective strategies, such as the application of additional forces. Rather, it is sufficient to adjust the leg to a fixed angle relative to the ground. In this work, we consider the extension of the SLIP to three dimensions (3D SLIP) and investigate feed-forward strategies for leg adjustment during the flight phase. As in the SLIP model, the leg is placed at a fixed angle. We extend the scope of possible reference axes from only fixed horizontal and vertical axes to include the CoM velocity vector as a movement-related reference, resulting in six leg-adjustment strategies. Only leg-adjustment strategies that include the CoM velocity vector produced stable running and large parameter domains of stability. The ability of the model to recover from perturbations along the direction of motion (directional stability) depended on the strategy for lateral leg adjustment. Specifically, asymptotic and neutral directional stability was observed for strategies based on the global reference axis and the velocity vector, respectively. Additional features of velocity-based leg adjustment are running at arbitrary low speed (kinetic energy) and the emergence of large domains of stable 3D running that are smoothly transferred to 2D SLIP stability and even to 1D SLIP hopping. One of the additional leg-adjustment strategies represented a large convex region of parameters where stable and robust hopping and running patterns exist. Therefore, this strategy is a promising candidate for implementation into engineering applications, such as robots, for instance. In a preliminary comparison, the model predictions were in good agreement with the experimental data, suggesting that the 3D SLIP is an

  15. Structure of stable degeneration of K3 surfaces into pairs of rational elliptic surfaces

    OpenAIRE

    Kimura, Yusuke

    2018-01-01

    F-theory/heterotic duality is formulated in the stable degeneration limit of a K3 fibration on the F-theory side. In this note, we analyze the structure of the stable degeneration limit. We discuss whether stable degeneration exists for pairs of rational elliptic surfaces. We demonstrate that, when two rational elliptic surfaces have an identical complex structure, stable degeneration always exists. We provide an equation that systematically describes the stable degeneration of a K3 surface i...

  16. The status of applying stable isotope in the studies of environmental science

    International Nuclear Information System (INIS)

    Bai Zhipeng; Zhang Liwen; Zhu Tan; Feng Yinchang

    2007-01-01

    The stable isotope composition is characteristic in the pollution source, and it is relatively fixed in the process of transferring and reaction. At present the precise analysis result of stable isotope ratio can be obtained easily. So the stable isotopes can be applied to the pollution affair arbitration and source study. The concept and analytical method of stable isotopes are introduced. The research status of the stable isotopes in the field of environmental science and the isotope fractionation is reviewed. (authors)

  17. Study on stable fly eradication by sterile-male technique. Effects of X-ray irradiation on the stable fly

    Energy Technology Data Exchange (ETDEWEB)

    Chung, K H; Ryu, J; Kwon, S H [Korea Atomic Energy Research Inst., Seoul (Republic of Korea)

    1975-01-01

    This experiment was performed to investigate the X-ray sensitivities at the various stages of life cycle and to determine the sterillizing dose of stable fly, Stomoxys calcitrans(L). A dose of 300 rad caused about 50% mortality in 2-hour-old eggs as measured by egg hatch, and 100% mortality was obtained with a dose of 1 Krad. Sub-lethal dose (LDsub(50)) for the pupal age at irradiation. A significant reduction of egg hatch by 1.5% was observed when treated males with 3 Krad at pupal stage were mated to untreated virgin females. On the other hand, 100% sterility in females was resulted by Krad irradiation and oviposition was completely inhibited with 3 Krad. Thus, both sexes of stable fly could be sterilized with a dose of 4 Krad irradiated 50 3-5 days old pupae.

  18. Alzheimer’s disease Aβ assemblies mediating rapid disruption of synaptic plasticity and memory

    Directory of Open Access Journals (Sweden)

    Klyubin Igor

    2012-07-01

    Full Text Available Abstract Alzheimer’s disease (AD is characterized by episodic memory impairment that often precedes clinical diagnosis by many years. Probing the mechanisms of such impairment may provide much needed means of diagnosis and therapeutic intervention at an early, pre-dementia, stage. Prior to the onset of significant neurodegeneration, the structural and functional integrity of synapses in mnemonic circuitry is severely compromised in the presence of amyloidosis. This review examines recent evidence evaluating the role of amyloid-ß protein (Aβ in causing rapid disruption of synaptic plasticity and memory impairment. We evaluate the relative importance of different sizes and conformations of Aβ, including monomer, oligomer, protofibril and fibril. We pay particular attention to recent controversies over the relevance to the pathophysiology of AD of different water soluble Aβ aggregates and the importance of cellular prion protein in mediating their effects. Current data are consistent with the view that both low-n oligomers and larger soluble assemblies present in AD brain, some of them via a direct interaction with cellular prion protein, cause synaptic memory failure. At the two extremes of aggregation, monomers and fibrils appear to act in vivo both as sources and sinks of certain metastable conformations of soluble aggregates that powerfully disrupt synaptic plasticity. The same principle appears to apply to other synaptotoxic amyloidogenic proteins including tau, α-synuclein and prion protein.

  19. Patterns in Stable Isotope Values of Nitrogen and Carbon in ...

    Science.gov (United States)

    Stable isotope measurements of nitrogen and carbon (15N, 13ddC) are often used to characterize estuarine, nearshore, and open ocean ecosystems. Reliable information about the spatial distribution of base-level stable isotope values, often represented by primary producers, is critical to interpreting values in these ecosystems. While base-level isotope data are generally readily available for estuaries, nearshore coastal waters, and the open ocean, the continental shelf is less studied. To address this, and as a first step toward developing a surrogate for base-level isotopic signature in this region, we collected surface and deep water samples from the United States’ eastern continental shelf in the Western Atlantic Ocean, from the Gulf of Maine to Cape Hatteras, periodically between 2000 and 2013. During the study, particulate matter 15dN values ranged from 0.8 to 17.4‰, and 13dC values from −26.4 to −15.6‰over the region. We used spatial autocorrelation analysis and random forest modeling to examine the spatial trends and potential environmental drivers of the stable isotope values. We observed general trends toward lower values for both nitrogen and carbon isotopes at the seaward edge of the shelf. Conversely, higher 15dN and 13dC values were observed on the landward edge of the shelf, in particular in the southern portion of the sampling area. Across all sites, the magnitude of the difference between the 15dN of subsurface and surface particulate m

  20. Stable isotope-resolved metabolomics and applications for drug development

    Science.gov (United States)

    Fan, Teresa W-M.; Lorkiewicz, Pawel; Sellers, Katherine; Moseley, Hunter N.B.; Higashi, Richard M.; Lane, Andrew N.

    2012-01-01

    Advances in analytical methodologies, principally nuclear magnetic resonance spectroscopy (NMR) and mass spectrometry (MS), during the last decade have made large-scale analysis of the human metabolome a reality. This is leading to the reawakening of the importance of metabolism in human diseases, particularly cancer. The metabolome is the functional readout of the genome, functional genome, and proteome; it is also an integral partner in molecular regulations for homeostasis. The interrogation of the metabolome, or metabolomics, is now being applied to numerous diseases, largely by metabolite profiling for biomarker discovery, but also in pharmacology and therapeutics. Recent advances in stable isotope tracer-based metabolomic approaches enable unambiguous tracking of individual atoms through compartmentalized metabolic networks directly in human subjects, which promises to decipher the complexity of the human metabolome at an unprecedented pace. This knowledge will revolutionize our understanding of complex human diseases, clinical diagnostics, as well as individualized therapeutics and drug response. In this review, we focus on the use of stable isotope tracers with metabolomics technologies for understanding metabolic network dynamics in both model systems and in clinical applications. Atom-resolved isotope tracing via the two major analytical platforms, NMR and MS, has the power to determine novel metabolic reprogramming in diseases, discover new drug targets, and facilitates ADME studies. We also illustrate new metabolic tracer-based imaging technologies, which enable direct visualization of metabolic processes in vivo. We further outline current practices and future requirements for biochemoinformatics development, which is an integral part of translating stable isotope-resolved metabolomics into clinical reality. PMID:22212615

  1. A crawling robot driven by multi-stable origami

    Science.gov (United States)

    Pagano, Alexander; Yan, Tongxi; Chien, Brian; Wissa, A.; Tawfick, S.

    2017-09-01

    Using origami folding to construct and actuate mechanisms and machines offers attractive opportunities from small, scalable, and cheap robots to deployable adaptive structures. This paper presents the design of a bio-inspired origami crawling robot constructed by folding sheets of paper. The origami building block structure is based on the Kresling crease pattern (CP), a chiral tower with a polygonal base, which expands and contracts through coupled longitudinal and rotational motion similar to a screw. We design the origami to have multi-stable structural equilibria which can be tuned by changing the folding CP. Kinematic analysis of these structures based on rigid-plates and hinges at fold lines precludes the shape transformation associated with the bistability of the physical models. To capture the kinematics of the bi-stable origami, the panels’ deformation behavior is modeled utilizing principles of virtual folds. Virtual folds approximate material bending by hinged, rigid panels, which facilitates the development of a kinematic solution via rigid-plate rotation analysis. As such, the kinetics and stability of folded structures are investigated by assigning suitable torsional spring constants to the fold lines. The results presented demonstrate the effect of fold-pattern geometries on the snapping behavior of the bi-stable origami structure based on the Kresling pattern. The crawling robot is presented as a case study for the use of this origami structure to mimic crawling locomotion. The robot is comprised of two origami towers nested inside a paper bellow, and connected by 3D printed end plates. DC motors are used to actuate the expansion and contraction of the internal origami structures to achieve forward locomotion and steering. Beyond locomotion, this simple design can find applications in manipulators, booms, and active structures.

  2. Delay in the Diagnosis of Stable Slipped Capital Femoral Epiphysis.

    Science.gov (United States)

    Hosseinzadeh, Pooya; Iwinski, Henry J; Salava, Jonathon; Oeffinger, Donna

    2017-01-01

    Delays in the diagnosis of stable slipped capital femoral epiphysis (SCFE) is common due to the vague symptomatology and the lack of awareness of this entity by healthcare providers. Delays in the diagnosis of this condition can lead to poor outcomes for the patients. This study was designed to identify factors that contributed to delays in the diagnosis or the treatment of patients with SCFE seen at our institution. A retrospective chart review of patients with the diagnosis of a stable SCFE who had undergone screw stabilization between 1989 and 2010 at our hospital was performed. For each patient, demographic data, the date of initial onset of symptoms, the date of the first visit to the medical provider, the type of provider seen initially (orthopaedic surgeon or not), the date of diagnosis of SCFE, the type of physician who made the diagnosis (orthopaedic surgeon or not), and the date of surgery were recorded. For each patient, the presenting symptom was recorded as hip, thigh, or knee pain. The effect of demographic data, presenting symptoms, and the type of initial provider seen on the delay to diagnosis was studied using 2 Cox models. A total of 149 patients with 196 stable SCFE were included. The average time from the first physician visit to diagnosis was 94 days in the group seen by a nonorthopaedic provider compared with an average of 2.9 days in the group seen by an orthopaedist (Pprovider versus 97% in the group seen by orthopaedic surgeons. It took significantly longer to be diagnosed with SCFE in patients who presented with initial knee pain (P=0.0097) compared with those who presented with hip pain at the initial visit. This study shows a significant delay in the diagnosis of SCFE in the United States, particularly in patients seen by nonorthopaedic providers initially. Level III-prognostic.

  3. Biological factors of natural and artificial ecosystems stable (unstable) functioning

    Science.gov (United States)

    Pechurkin, Nikolai S.

    The problem of sustainable development of humanity on Earth and the problem of supporting human life in space have the same scientific and methodological bases. The key to solve both problems is a long term maintenance of balanced material cycle. As a whole, natural or artificial ecosystems are to be more closed than open, but their elements (links of systems) are to be substantially open in interactions with each other. Prolonged stable interactions of different links have to have unique joint results - closed material cycling or biotic turnover. It is necessary to include, at least, three types of main links into any system to support real material cycling: producers, consumers, reducers. Producer links are now under studies in many laboratories. It is evident that the higher productivity of link, the lower link stability. Especially, it concerns with parasite impact to plants. As usual, artificial ecosystems are more simple (incomplete) than natural ecosystems, sometimes, they have not enough links for prolonged stable functioning. For example, life support system for space flight can be incomplete in consumer link, having only some crew persons, instead of interacting populations of consumers. As for reducer link, it is necessary to "organize" a special coordinated work of microbial biocenoses to fulfill proper cycling. Possible evolution of links, their self development is a matter of special attention for the maintenance of prolonged stable functioning. It's the most danger for systems with populations of quickly reproducing, so-called, R - strategists, according to symbols of logistic equation. From another side, quick reproduction of R - strategists is able to increase artificial ecosystems and their links functioning. After some damages of system, R - strategist's link can be quickly "self repaired" up to level of normal functioning. Some experimental data of this kind and mathematical models are to be discussed in the paper. This work is supported by

  4. On the Fractional Poisson Process and the Discretized Stable Subordinator

    Directory of Open Access Journals (Sweden)

    Rudolf Gorenflo

    2015-08-01

    Full Text Available We consider the renewal counting number process N = N(t as a forward march over the non-negative integers with independent identically distributed waiting times. We embed the values of the counting numbers N in a “pseudo-spatial” non-negative half-line x ≥ 0 and observe that for physical time likewise we have t ≥ 0. Thus we apply the Laplace transform with respect to both variables x and t. Applying then a modification of the Montroll-Weiss-Cox formalism of continuous time random walk we obtain the essential characteristics of a renewal process in the transform domain and, if we are lucky, also in the physical domain. The process t = t(N of accumulation of waiting times is inverse to the counting number process, in honour of the Danish mathematician and telecommunication engineer A.K. Erlang we call it the Erlang process. It yields the probability of exactly n renewal events in the interval (0; t]. We apply our Laplace-Laplace formalism to the fractional Poisson process whose waiting times are of Mittag-Leffler type and to a renewal process whose waiting times are of Wright type. The process of Mittag-Leffler type includes as a limiting case the classical Poisson process, the process of Wright type represents the discretized stable subordinator and a re-scaled version of it was used in our method of parametric subordination of time-space fractional diffusion processes. Properly rescaling the counting number process N(t and the Erlang process t(N yields as diffusion limits the inverse stable and the stable subordinator, respectively.

  5. Preparation and characterization of stable aqueous higher-order fullerenes

    International Nuclear Information System (INIS)

    Aich, Nirupam; Flora, Joseph R V; Saleh, Navid B

    2012-01-01

    Stable aqueous suspensions of nC 60 and individual higher fullerenes, i.e. C 70 , C 76 and C 84 , are prepared by a calorimetric modification of a commonly used liquid–liquid extraction technique. The energy requirement for synthesis of higher fullerenes has been guided by molecular-scale interaction energy calculations. Solubilized fullerenes show crystalline behavior by exhibiting lattice fringes in high resolution transmission electron microscopy images. The fullerene colloidal suspensions thus prepared are stable with a narrow distribution of cluster radii (42.7 ± 0.8 nm, 46.0 ± 14.0 nm, 60 ± 3.2 nm and 56.3 ± 1.1 nm for nC 60 , nC 70 , nC 76 and nC 84 , respectively) as measured by time-resolved dynamic light scattering. The ζ-potential values for all fullerene samples showed negative surface potentials with similar magnitude ( − 38.6 ± 5.8 mV, − 39.1 ± 4.2 mV, − 38.9 ± 5.8 mV and − 41.7 ± 5.1 mV for nC 60 , nC 70 , nC 76 and nC 84 , respectively), which provide electrostatic stability to the colloidal clusters. This energy-based modified solubilization technique to produce stable aqueous fullerenes will likely aid in future studies focusing on better applicability, determination of colloidal properties, and understanding of environmental fate, transport and toxicity of higher-order fullerenes. (paper)

  6. Zinc absorption study using an enriched stable isotope (70Zn)

    International Nuclear Information System (INIS)

    Li Gongpan.

    1990-04-01

    A weaning food from fermented soybean was prepared for increasing the bioavailability of zinc. The zinc absorption was compared with that of a weaning food from non-fermented soybean and normal staple food. A stable isotope tracer technique ( 70 Zn) and neutron activation were used for determining the absorption of zinc. Nine children aged 7 to 18 months were tested. Zinc bioavailability of weaning food from fermented soybean is higher than that of normal weaning food. The weight increment and zinc nutrition of children having weaning food from fermented soybean are improved by this diet. 5 tabs

  7. Stable isotopes. Enriched wheat: a new chance for nutrition research

    International Nuclear Information System (INIS)

    Chagvardieff, P.

    1996-01-01

    The Department of Plant Eco-physiology (DEV) from the CEA/Life Sciences Department of Cadarache (France) has artificially produced two kg of carbon 13 labelled wheat for nutrition research. It is the first successful stable isotope labelling of complex nutriments with a 10% enrichment in carbon 13. This wheat has been used for the manufacturing of pastas to follow the assimilation of nutrients by the organism. This short paper gives some details about the experimental procedure of labelled wheat cultivation. (J.S.)

  8. Strategies for stable water splitting via protected photoelectrodes

    DEFF Research Database (Denmark)

    Bae, Dowon; Seger, Brian; Vesborg, Peter Christian Kjærgaard

    2017-01-01

    Photoelectrochemical (PEC) solar-fuel conversion is a promising approach to provide clean and storable fuel (e.g., hydrogen and methanol) directly from sunlight, water and CO2. However, major challenges still have to be overcome before commercialization can be achieved. One of the largest barriers...... photocathodes. In addition, we review protection layer approaches and their stabilities for a wide variety of experimental photoelectrodes for water reduction. Finally, we discuss key aspects which should be addressed in continued work on realizing stable and practical PEC solar water splitting systems....

  9. Innermost stable circular orbit of Kerr-MOG black hole

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyun-Chul; Han, Yong-Jin [Soonchunhyang University, Department of Physics, Asan (Korea, Republic of)

    2017-10-15

    We study the innermost stable circular orbit (ISCO) of the metric of the Kerr black hole in modified gravity (Kerr-MOG black hole), which is one of the exact solutions of the field equation of modified gravity in the strong gravity regime. The Kerr-MOG metric is constructed; it is the commonly known Kerr metric in Boyer-Lindquist coordinates by adding a repulsive term like the Yukawa force, which is explained in quantum gravity. In this paper, we numerically calculate the circular orbit of a photon and the ISCO of a test particle of Kerr-MOG black holes. (orig.)

  10. Is synaesthesia really stable – or does it gradually consolidate?

    DEFF Research Database (Denmark)

    Sørensen, Thomas Alrik

    Synaesthesia is a condition describing a perceptual variation where experience an additional concurrent following an inducer stimulus (Grossenbacher & Lovelace, 2001); some may experience that weekdays or letters have a specific colour, or that a number has a certain size or relate to a particular...... is that the associations are stable over time. However, here we present the case of AR, a colour-grapheme synaesthete who clearly demonstrate synaesthesia, but also a gradual consolidation over time (Sørensen, Nordfang, & Ásgeirsson, accepted). Also, AR does not demonstrate some of the typical modulations of attention...

  11. Nonlinear density waves in a marginally stable gravitating disk

    International Nuclear Information System (INIS)

    Korchagin, V.I.

    1986-01-01

    The evolution of short nonlinear density waves in a disk at the stability limit is studied for arbitrary values of the radial wave number k/sub r/. For waves with wave numbers that do not lie at the minimum of the dispersion curve, the behavior of the amplitude is described by a nonlinear parabolic equation; however, stationary soliton solutions cannot exist in such a system since there is no dispersion spreading of a packet. For wave numbers lying at the minimum of the dispersion curve, soliton structures with determined amplitude are possible. In stable gravitating disks and in a disk at the stability limit, two physically different types of soliton can exist

  12. Electropolishing of Stainless Steel Implants for Stable Functional Osteosynthesis

    Directory of Open Access Journals (Sweden)

    Omel’chuk, A.О.

    2016-01-01

    Full Text Available A new method for the electropolishing stainless steel for stable functional osteosynthesis has been developed. The polishing of implants was carried out in solutions, based on the ternary system H2SO4—H3PO4—H2O with stepwise decreasing the current density and increasing the orthophosphoric acid concentration. The optimal polishing conditions (current density, solution composition, temperature and duration have been determined. The developed method improves the quality and mechanical properties of the surface.

  13. Periodic orbits from Δ-modulation of stable linear systems

    OpenAIRE

    Xia, X.; Zinober, A.

    2004-01-01

    The �-modulated control of a single input, discrete time, linear stable system is investigated. The modulation direction is given by cTx where c �Rn/{0} is a given, otherwise arbitrary, vector. We obtain necessary and sufficient conditions for the existence of periodic points of a finite order. Some concrete results about the existence of a certain order of periodic points are also derived. We also study the relationship between certain polyhedra and the periodicity of the �-modulated orb...

  14. Shelf stable intermediate moisture fruit cubes using radiation technology

    International Nuclear Information System (INIS)

    Mishra, Bibhuti B.; Saxena, Sudhanshu; Gautam, Satyendra; Chander, Ramesh; Sharma, Arun

    2009-01-01

    A process has been developed to prepare shelf stable ready-to-eat (RTE) intermediate moisture pineapple slices and papaya cubes using radiation technology. The combination of hurdles including osmotic dehydration, blanching, infrared drying, and gamma radiation dose of 1 kGy successfully reduced the microbial load to below detectable limit. The shelf life of the intermediate moisture pineapple slices and papaya cubes was found to be 40 days at ambient temperature (28 ± 2 deg C). The control samples spoiled within 6 days. The RTE intermediate moisture fruit products were found to have good texture, colour and sensory acceptability during this 40 days storage. (author)

  15. Apparatus to detect stable fractional charges on matter

    International Nuclear Information System (INIS)

    Vanderspek, R.

    1980-04-01

    The construction of an apparatus designed to detect stable fractional charges on matter, if they exist, to the level of 10 -24 per nucleon is reported and discussed. The charges on a stream of highly consistent droplets produced by the apparatus are determined by accurate measurement of the deflection of the droplets in falling through a static electric field. Maintenance of certain parameters of operation calculated to limit the random effects of electrical and aerodynamical disturbances on the droplets indicate a precision in the measurement of the charge on a droplet of 0.02e can be attained. 7 figures

  16. Complex cobordism and stable homotopy groups of spheres

    CERN Document Server

    Ravenel, Douglas C

    2003-01-01

    Since the publication of its first edition, this book has served as one of the few available on the classical Adams spectral sequence, and is the best account on the Adams-Novikov spectral sequence. This new edition has been updated in many places, especially the final chapter, which has been completely rewritten with an eye toward future research in the field. It remains the definitive reference on the stable homotopy groups of spheres. The first three chapters introduce the homotopy groups of spheres and take the reader from the classical results in the field though the computational aspects

  17. Formation of stable products from cluster-cluster collisions

    International Nuclear Information System (INIS)

    Alamanova, Denitsa; Grigoryan, Valeri G; Springborg, Michael

    2007-01-01

    The formation of stable products from copper cluster-cluster collisions is investigated by using classical molecular-dynamics simulations in combination with an embedded-atom potential. The dependence of the product clusters on impact energy, relative orientation of the clusters, and size of the clusters is studied. The structures and total energies of the product clusters are analysed and compared with those of the colliding clusters before impact. These results, together with the internal temperature, are used in obtaining an increased understanding of cluster fusion processes

  18. Stable lead isotopes as a tracer in coastal waters

    International Nuclear Information System (INIS)

    Stukas, V.J.; Wong, C.S.

    1981-01-01

    The natural abundances of the stable isotopes of lead are used to identify natural and industrial sources of lead in the coastal waters of British Columbia, Canada. The 206 Pb/ 207 Pb ratios, used to characterize the lead source, had values of approx. 1.24 for coastal oceanic water, approx. 1.22 for fjord waters receiving lead from mine tailings, and approx. 1.163 for waters near urban centers. The lead concentration data are in agreement with presently accepted seawater values

  19. Stable solid state reference electrodes for high temperature water chemistry

    International Nuclear Information System (INIS)

    Jayaweera, P.; Millett, P.J.

    1995-01-01

    A solid state electrode capable of providing a stable reference potential under a wide range of temperatures and chemical conditions has been demonstrated. The electrode consists of a zirconia or yttria-stabilized zirconia tube packed with an inorganic polymer electrolyte and a silver/silver chloride sensing element. The sensing element is maintained near room temperature by a passive cooling heat sink. The electrode stability was demonstrated by testing it in high temperature (280 C) aqueous solutions over extended periods of time. This reference electrode is useful in many applications, particularly for monitoring the chemistry in nuclear and fossil power plants

  20. Tunable Stable Levitation Based on Casimir Interaction between Nanostructures

    Science.gov (United States)

    Liu, Xianglei; Zhang, Zhuomin M.

    2016-03-01

    Quantum levitation enabled by repulsive Casimir force has been desirable due to the potential exciting applications in passive-suspension devices and frictionless bearings. In this paper, dynamically tunable stable levitation is theoretically demonstrated based on the configuration of dissimilar gratings separated by an intervening fluid using exact scattering theory. The levitation position is insensitive to temperature variations and can be actively tuned by adjusting the lateral displacement between the two gratings. This work investigates the possibility of applying quantum Casimir interactions into macroscopic mechanical devices working in a noncontact and low-friction environment for controlling the position or transducing lateral movement into vertical displacement at the nanoscale.

  1. The stable model semantics under the any-world assumption

    OpenAIRE

    Straccia, Umberto; Loyer, Yann

    2004-01-01

    The stable model semantics has become a dominating approach to complete the knowledge provided by a logic program by means of the Closed World Assumption (CWA). The CWA asserts that any atom whose truth-value cannot be inferred from the facts and rules is supposed to be false. This assumption is orthogonal to the so-called the Open World Assumption (OWA), which asserts that every such atom's truth is supposed to be unknown. The topic of this paper is to be more fine-grained. Indeed, the objec...

  2. Quasi-stable injection channels in a wakefield accelerator

    CERN Document Server

    Wiltshire-Turkay, Mara; Pukhov, Alexander

    2016-01-01

    Particle-driven plasma-wakefield acceleration is a promising alternative to conventional electron acceleration techniques, potentially allowing electron acceleration to energies orders of magnitude higher than can currently be achieved. In this work we investigate the dependence of the energy gain on the position at which electrons are injected into the wake. Test particle simulations show previously unobserved complex structure in the parameter space, with quasi-stable injection channels forming for particles injected in narrow regions away from the centre of the wake. The result is relevant to the planning and tuning of experiments making use of external injection.

  3. Ferroelectric nanostructure having switchable multi-stable vortex states

    Science.gov (United States)

    Naumov, Ivan I [Fayetteville, AR; Bellaiche, Laurent M [Fayetteville, AR; Prosandeev, Sergey A [Fayetteville, AR; Ponomareva, Inna V [Fayetteville, AR; Kornev, Igor A [Fayetteville, AR

    2009-09-22

    A ferroelectric nanostructure formed as a low dimensional nano-scale ferroelectric material having at least one vortex ring of polarization generating an ordered toroid moment switchable between multi-stable states. A stress-free ferroelectric nanodot under open-circuit-like electrical boundary conditions maintains such a vortex structure for their local dipoles when subject to a transverse inhomogeneous static electric field controlling the direction of the macroscopic toroidal moment. Stress is also capable of controlling the vortex's chirality, because of the electromechanical coupling that exists in ferroelectric nanodots.

  4. Issues and opportunities in accelerator mass spectrometry for stable isotopes.

    Science.gov (United States)

    Matteson, Sam

    2008-01-01

    Accelerator mass spectrometry (AMS) has developed in the last 30 years many notable applications to the spectrometry of radioisotopes, particularly in radiocarbon dating. The instrumentation science of trace element AMS (TEAMS) that analyzes stable isotopes, also called Accelerator SIMS or MegaSIMS, while unique in many features, has also shared in many of these significant advances and has pushed TEAMS sensitivity to concentration levels surpassing many competing mass spectroscopic technologies. This review examines recent instrumentation developments, the capabilities of the new instrumentation and discernable trends for future development. Copyright 2008 Wiley Periodicals, Inc.

  5. Embedded Controller Design for Pig Stable Ventilation Systems

    DEFF Research Database (Denmark)

    Jessen, Jan Jacob

    This thesis focuses on zone based climate control in pig stables and how to implement climate controllers in a new range of products. The presented controllers are based on simple models of climate dynamics and simple models of actuators. The implementation uses graphical point and click features....... The thesis is a collection of eight papers. The first two papers deal with the mplementation of controllers and how to integrate the development of controllers into a complete framework that can provide different services e.g. remote monitoring. The same framework is also capable of automatically generating...

  6. Uncertainty principle and the stable interpretation of spectrometric experiment results

    International Nuclear Information System (INIS)

    Zhukovskij, E.L.

    1984-01-01

    Two stable forms for recording least-swuare method used for evaluation of parameters durmng automated processing and interpretation of various type spectra were derived on the basis of the Kramer-Rao inequality. Spectra described by linear equations are considered for which parameter evaluations are recorded in a final form. It is shown that the suggested form of the interpreting functional is maintained for the spectra of different nature (NMR-, IR-, UV-, RS- and mass-spectra), their parameters depending nonlinearly on the wave number

  7. Policy on stable iodine prophylaxis following nuclear reactor accidents (1989)

    International Nuclear Information System (INIS)

    1989-09-01

    This policy considers the alleviation of possible hazards that may arise from any radioiodines inhaled from a plume of fission products emanating from a nuclear reactor accident. Such a nuclear reactor may be land or ship-based. In any accident that releases radioiodines to the environment, one countermeasure that may need to be considered to reduce the effect of inhalation of radioiodines by persons downwind of the point of release is to provide those persons with tablets containing stable iodine. Both potassium iodide (KI) and potassium iodate (KIO 3 ) are recommended as effective prophylactics tablets for this purpose in Australia. Action levels, doses and contraindicatories are briefly outlined

  8. Approach to securing of stable nuclear fuel supplies

    International Nuclear Information System (INIS)

    Koike, Kunihisa; Imamura, Isao; Noda, Tetsuya

    2010-01-01

    With the dual objectives of not only ensuring stable electric power supplies but also preventing global warming, the construction of new nuclear power plants is being planned in many countries throughout the world. Toshiba and Westinghouse Electric Company (WEC), a member of the Toshiba Group, are capable of supplying both boiling water reactor (BWR) and pressurized water reactor (PWR) plants to satisfy a broad range of customer requirements. Furthermore, to meet the growing demand for the securing of nuclear fuel supplies, Toshiba and WEC have been promoting the strengthening and further expansion of supply chains in the fields of uranium production, uranium hexafluoride (UF 6 ) conversion, uranium enrichment, and fuel fabrication. (author)

  9. Metabolic Alkalosis in Adults with Stable Cystic Fibrosis

    OpenAIRE

    Al-Ghimlas, Fahad; Faughnan, Marie E; Tullis, Elizabeth

    2012-01-01

    Background: The frequency of metabolic alkalosis among adults with stable severe CF-lung disease is unknown. Methods: Retrospective chart review. Results: Fourteen CF and 6 COPD (controls) patients were included. FEV1 was similar between the two groups. PaO2 was significantly higher in the COPD (mean ± 2 SD is 72.0 ± 6.8 mmHg,) than in the CF group (56.1 ± 4.1 mmHg). The frequency of metabolic alkalosis in CF patients (12/14, 86%) was significantly greater (p=0.04) than in the COPD group (2/6...

  10. Stable nitrogen isotopes in coastal macroalgae: geographic and anthropogenic variability

    OpenAIRE

    González-Viana, I. (Inés); Bode, A. (Antonio)

    2013-01-01

    Proyectos ANILE (CTM2009-08396 and CTM2010-08804-E) del Plan Nacional de I+D+i y RADIALES del Instituto Español de Oceanografía (IEO). I.G.V. recibió un contrato FPI del Ministerio de Economía y Competividad Growing human population add to the natural nitrogen loads to coastal waters. As the excess nitrogen is readily incorporated in new biomass anthropogenic and natural nitrogen sources may be traced by the measurement of stable nitrogen isotopes (δ15N). In this study δ15N was dete...

  11. Stable Blind Deconvolution over the Reals from Additional Autocorrelations

    KAUST Repository

    Walk, Philipp

    2017-10-22

    Recently the one-dimensional time-discrete blind deconvolution problem was shown to be solvable uniquely, up to a global phase, by a semi-definite program for almost any signal, provided its autocorrelation is known. We will show in this work that under a sufficient zero separation of the corresponding signal in the $z-$domain, a stable reconstruction against additive noise is possible. Moreover, the stability constant depends on the signal dimension and on the signals magnitude of the first and last coefficients. We give an analytical expression for this constant by using spectral bounds of Vandermonde matrices.

  12. New stable phase in binary Fe-Nd

    International Nuclear Information System (INIS)

    Schneider, G.; Landgraf, F.J.G.; Villas-Boas, V.; Bezerra, G.H.; Missell, F.P.; Ray, A.E.

    1992-01-01

    An investigation of binary Fe-Nd alloys revealed the existence of an oxygen-free, stable Fe-rich phase A 2 , formed peritecticly in the range 750-800 deg C. EPMA shows this phase to contain 22.8 atomic percent Nd. This ferromagnetic phase has T c = 230 de C, but is magnetically soft. The X-ray diffraction pattern can be indexed using a hexagonal cell with a = 2.021 nm. and c = 1.235 nm. (author)

  13. Stable emergent Universe - a creation without Big-Bang

    Science.gov (United States)

    Guendelman, E.; Herrera, R.; Labrana, P.; Nissimov, E.; Pacheva, S.

    2015-11-01

    Based on an earlier introduced new class of generalized gravity-matter models defined in terms of two independent non-Riemannian volume forms (alternative generally covariant integration measure densities) on the space-time manifold, we derive an effective ``Einstein-frame'' theory featuring the following remarkable properties: (i) We obtain effective potential for the cosmological scalar field possessing two infinitely large flat regions which allows for a unified description of both early Universe inflation as well as of present dark energy epoch; (ii) for a specific parameter range the model possesses a non-singular stable ``emergent Universe'' solution which describes an initial phase of evolution that precedes the inflationary phase.

  14. Applications of stable isotope analysis to atmospheric trace gas budgets

    Directory of Open Access Journals (Sweden)

    Brenninkmeijer C. A.M.

    2009-02-01

    Full Text Available Stable isotope analysis has become established as a useful method for tracing the budgets of atmospheric trace gases and even atmospheric oxygen. Several new developments are briefly discussed in a systematic way to give a practical guide to the scope of recent work. Emphasis is on applications and not on instrumental developments. Processes and reactions are less considered than applications to resolve trace gas budgets. Several new developments are promising and applications hitherto not considered to be possible may allow new uses.

  15. Decreasing the stable trapping region during geomagnetic storm

    International Nuclear Information System (INIS)

    Mal'tsev, Yu.P.; Feshchenko, E.Yu.

    1998-01-01

    Within the frameworks of the magnetic field model, depending on the solar wind pressure, the B = B s (B s is the magnetic field in the undersolar point) contour behaviour in the equatorial plane is calculated. The boundary of stable trapping in the quiet time is at the distance of 10-11 R E by day and ∼ 7 R E by night. During strong storms this distance may be decreased up 4-5 R E . The calculation results coincide satisfactorily with satellite measurements

  16. Infrared Spectroscopy and Stable Isotope Geochemistry of Hydrous Silicate Glasses

    Energy Technology Data Exchange (ETDEWEB)

    Stolper, Edward

    2007-03-05

    The focus of this DOE-funded project has been the study of volatile components in magmas and the atmosphere. Over the twenty-one year period of this project, we have used experimental petrology and stable isotope geochemistry to study the behavior and properties of volatile components dissolved in silicate minerals and melts and glasses. More recently, we have also studied the concentration and isotopic composition of CO2 in the atmosphere, especially in relation to air quality issues in the Los Angeles basin.

  17. An Unconditionally Stable Method for Solving the Acoustic Wave Equation

    Directory of Open Access Journals (Sweden)

    Zhi-Kai Fu

    2015-01-01

    Full Text Available An unconditionally stable method for solving the time-domain acoustic wave equation using Associated Hermit orthogonal functions is proposed. The second-order time derivatives in acoustic wave equation are expanded by these orthogonal basis functions. By applying Galerkin temporal testing procedure, the time variable can be eliminated from the calculations. The restriction of Courant-Friedrichs-Levy (CFL condition in selecting time step for analyzing thin layer can be avoided. Numerical results show the accuracy and the efficiency of the proposed method.

  18. Hermitian-Einstein metrics on parabolic stable bundles

    International Nuclear Information System (INIS)

    Li Jiayu; Narasimhan, M.S.

    1995-12-01

    Let M-bar be a compact complex manifold of complex dimension two with a smooth Kaehler metric and D a smooth divisor on M-bar. If E is a rank 2 holomorphic vector bundle on M-bar with a stable parabolic structure along D, we prove the existence of a metric on E' = E module MbarD (compatible with the parabolic structure) which is Hermitian-Einstein with respect to the restriction of Kaehler metric of M-barD. A converse is also proved. (author). 24 refs

  19. Culture of microalgae Spirulina platensis with isotope stable Carbon-13

    International Nuclear Information System (INIS)

    Cronemberger, Luiz C.A.; Costa, Vladimir E.

    2017-01-01

    Gastric emptying time abnormalities cause complications that affect the quality of life in humans and scintigraphy is the gold standard for this diagnosis. However its application has restrictions due to the use of the radiopharmaceutical 99m Tc. An alternative to this method is the stable carbon isotope respiratory test. This is a non-radioactive, noninvasive technique with no contraindications. Its application varies according to the substrate used. For evaluation of gastric emptying time one of the substrates that can be used in the respiratory test is Spirulina platensis labeled at 97% carbon atoms with the stable isotope carbon-13 ( 13 C). In Brazil, there is no production of this substrate and its high cost (US$475.00/g, excluding import taxes) makes it difficult to apply the test. Thus, the objective of the work is to cultivate labeled S. platensis at 97% of 13 C for use in the respiratory test for gastric emptying and to establish optimization parameters for the best cost-benefit of this culture. In the cultivation process the microalgae will be kept in a closed sterilized glass volumetric flask, with deionized water and a pure 13 C source. The light (photoperiod 12h light / dark), pH (∼ 9.5) and temperature (30 deg C) will be controlled and after 35-40 days of growth, the cyanobacteria will be lyophilized and ground for the acquisition of a powder that will be analyzed by IRMS and compared to S. platensis, which will be our reference standard

  20. An L-stable method for solving stiff hydrodynamics

    Science.gov (United States)

    Li, Shengtai

    2017-07-01

    We develop a new method for simulating the coupled dynamics of gas and multi-species dust grains. The dust grains are treated as pressure-less fluids and their coupling with gas is through stiff drag terms. If an explicit method is used, the numerical time step is subject to the stopping time of the dust particles, which can become extremely small for small grains. The previous semi-implicit method [1] uses second-order trapezoidal rule (TR) on the stiff drag terms and it works only for moderately small size of the dust particles. This is because TR method is only A-stable not L-stable. In this work, we use TR-BDF2 method [2] for the stiff terms in the coupled hydrodynamic equations. The L-stability of TR-BDF2 proves essential in treating a number of dust species. The combination of TR-BDF2 method with the explicit discretization of other hydro terms can solve a wide variety of stiff hydrodynamics equations accurately and efficiently. We have implemented our method in our LA-COMPASS (Los Alamos Computational Astrophysics Suite) package. We have applied the code to simulate some dusty proto-planetary disks and obtained very good match with astronomical observations.

  1. Magnetohydrodynamically stable plasma with supercritical current density at the axis

    Energy Technology Data Exchange (ETDEWEB)

    Burdakov, A. V. [Budker Institute of Nuclear Physics, 11 Lavrentjev Avenue, 630090 Novosibirsk (Russian Federation); Novosibirsk State Technical University, 20 Karl Marks Avenue, 630092 Novosibirsk (Russian Federation); Postupaev, V. V., E-mail: V.V.Postupaev@inp.nsk.su; Sudnikov, A. V. [Budker Institute of Nuclear Physics, 11 Lavrentjev Avenue, 630090 Novosibirsk (Russian Federation); Novosibirsk State University, 2 Pirogova st., 630090 Novosibirsk (Russian Federation)

    2014-05-15

    In this work, an analysis of magnetic perturbations in the GOL-3 experiment is given. In GOL-3, plasma is collectively heated in a multiple-mirror trap by a high-power electron beam. During the beam injection, the beam-plasma interaction maintains a high-level microturbulence. This provides an unusual radial profile of the net current (that consists of the beam current, current of the preliminary discharge, and the return current). The plasma core carries supercritical current density with the safety factor well below unity, but as a whole, the plasma is stable with q(a) ≈ 4. The net plasma current is counter-directed to the beam current; helicities of the magnetic field in the core and at the edge are of different signs. This forms a system with a strong magnetic shear that stabilizes the plasma core in good confinement regimes. We have found that the most pronounced magnetic perturbation is the well-known n = 1, m = 1 mode for both stable and disruptive regimes.

  2. Application of Stable Isotope in Detection of Veterinary Drug Residues

    International Nuclear Information System (INIS)

    Wang Wei; Liu Zhanfeng; Du Xiaoning

    2010-01-01

    In recent years, there has happened a series of significant food safety events worldwide, which lower down consumers' confidence in food safety, and they are taking increasing care about the sources of their foods. The safety problem of animal-origin foods has become a global topic for discussion. Therefore, it is a pressing task to establish a precise, sensitive and reliable method for analyzing veterinary drug residue. An introduction of the present status regarding veterinary drug residue analysis was made in the paper, and it briefly summarized the limit of detection (LOD) and quantification (LOQ) which could be reached in veterinary drug residue analysis by isotopic internal standard method domestically and abroad. The paper also made a review of the progress in applied research of stable isotope labeled compound in veterinary drug residue analysis of, such as, antibiotic medicines, furans and sulfonamides. The paper elucidated the great importance of the application of stable isotopes in the sane development of China's food safety system. (authors)

  3. Tapered composite likelihood for spatial max-stable models

    KAUST Repository

    Sang, Huiyan

    2014-05-01

    Spatial extreme value analysis is useful to environmental studies, in which extreme value phenomena are of interest and meaningful spatial patterns can be discerned. Max-stable process models are able to describe such phenomena. This class of models is asymptotically justified to characterize the spatial dependence among extremes. However, likelihood inference is challenging for such models because their corresponding joint likelihood is unavailable and only bivariate or trivariate distributions are known. In this paper, we propose a tapered composite likelihood approach by utilizing lower dimensional marginal likelihoods for inference on parameters of various max-stable process models. We consider a weighting strategy based on a "taper range" to exclude distant pairs or triples. The "optimal taper range" is selected to maximize various measures of the Godambe information associated with the tapered composite likelihood function. This method substantially reduces the computational cost and improves the efficiency over equally weighted composite likelihood estimators. We illustrate its utility with simulation experiments and an analysis of rainfall data in Switzerland.

  4. Platinum stable isotopes in ferromanganese crust and nodules

    Science.gov (United States)

    Corcoran, Loretta; Seward, Terry; Handler, Monica R.

    2015-04-01

    Hydrogenetic ferromanganese (Fe-Mn) crust and nodules are slow-growing chemical sediments that form by direct precipitation from seawater, resulting in a record of changing seawater chemistry. These sediments are the primary sink for platinum in the modern oxic marine environment, hosting well-documented enrichments over other platinum-group elements (PGEs): the Pt anomaly [1]. Platinum is a non-bio-essential, highly siderophile, transition metal with six stable isotopes (190Pt, 192Pt, 194Pt, 195Pt, 196Pt, and 198Pt) with several oxidation states (Pt0, Pt2+ and Pt4+). Platinum is generally considered to exist in the hydrosphere as Pt2+ although its behaviour in the marine environment is poorly constrained, and Pt4+may also be present. Variations in ocean redox state, together with changes in source fluxes to the oceans, may therefore lead to small variations (Leaching experiments conducted on platinum rich terrestrial materials underwent platinum stable isotopic measurement as an analogue for the Pt isotopic fractionation associated with continental weathering. [1] Hodge, V.F. et al. (1985) Earth and Planetary Science Letters, 72, 158-162. [2] Creech, J. et al. (2013) Journal of Analytical Atomic Spectrometry, 28. 853-865.

  5. Shelf-stable food through high dose irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Placek, V. E-mail: pla@ujv.cz; Svobodova, V.; Bartonicek, B.; Rosmus, J.; Camra, M

    2004-10-01

    Irradiation of food with high doses (radappertization) is a way, how to prepare shelf-stable ready-to-eat food. The radappertization process requires that the food be heated at first to an internal temperature of at least 75 deg. C to inactivate autolytic enzyme, which could cause the spoilage during storage without refrigeration. In order to prevent radiation induced changes in sensory properties (off flavors, odors, undesirable color change, etc.) the food was vacuum packed and irradiated in frozen state at -30 deg. C or less to a minimum dose of 35 kGy. Such products have characteristics of fresh food prepared for eating even if they are stored for long time under tropical conditions. The wholesomeness (safety for consumption) has been confirmed during 40 years of testing. Within the NRI Rez 10 kinds of shelf-stable meat products have been prepared. The meat was cooked, vacuum packed in SiO{sub x}-containing pouch, freezed in liquid nitrogen and irradiated with electron beam accelerator. The microbial, chemical, and organoleptic properties have been tested.

  6. Advances in stable isotope assisted labeling strategies with information science.

    Science.gov (United States)

    Kigawa, Takanori

    2017-08-15

    Stable-isotope (SI) labeling of proteins is an essential technique to investigate their structures, interactions or dynamics by nuclear magnetic resonance (NMR) spectroscopy. The assignment of the main-chain signals, which is the fundamental first step in these analyses, is usually achieved by a sequential assignment method based on triple resonance experiments. Independently of the triple resonance experiment-based sequential assignment, amino acid-selective SI labeling is beneficial for discriminating the amino acid type of each signal; therefore, it is especially useful for the signal assignment of difficult targets. Various combinatorial selective labeling schemes have been developed as more sophisticated labeling strategies. In these strategies, amino acids are represented by combinations of SI labeled samples, rather than simply assigning one amino acid to one SI labeled sample as in the case of conventional amino acid-selective labeling. These strategies have proven to be useful for NMR analyses of difficult proteins, such as those in large complex systems, in living cells, attached or integrated into membranes, or with poor solubility. In this review, recent advances in stable isotope assisted labeling strategies will be discussed. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Metallization systems for stable ohmic contacts to GaAs

    International Nuclear Information System (INIS)

    Tandon, J.L.; Douglas, K.D.; Vendura, G.; Kolawa, E.; So, F.C.T.; Nicolet, M.A.

    1986-01-01

    A metallization scheme to form reproducible and stable ohmic contacts to GaAs is described. The approach is based on the configuration: GaAs/X/Y/Z; where X is a thin metal film (e.g. Pt, Ti, Pd, Ru), Y is an electrically conducting diffusion barrier layer (TiN, W or W/sub 0.7/N/sub 0.3/), and Z is a thick metal layer (e.g. Ag) typically required for bonding or soldering purposes. The value and reproducibility of the contact resistance in these metallization systems results from the uniform steady-state solid-phase reaction of the metal X with GaAs. The stability of the contacts is achieved by the diffusion barrier layer Y, which not only confines the reaction of X with GaAs, but also prevents the top metal layer Z from interfering with this reaction. Applications of such contacts in fabricating stable solar cells are also discussed

  8. Investigating the Relationship between Stable Personality Characteristics and Automatic Imitation.

    Directory of Open Access Journals (Sweden)

    Emily E Butler

    Full Text Available Automatic imitation is a cornerstone of nonverbal communication that fosters rapport between interaction partners. Recent research has suggested that stable dimensions of personality are antecedents to automatic imitation, but the empirical evidence linking imitation with personality traits is restricted to a few studies with modest sample sizes. Additionally, atypical imitation has been documented in autism spectrum disorders and schizophrenia, but the mechanisms underpinning these behavioural profiles remain unclear. Using a larger sample than prior studies (N=243, the current study tested whether performance on a computer-based automatic imitation task could be predicted by personality traits associated with social behaviour (extraversion and agreeableness and with disorders of social cognition (autistic-like and schizotypal traits. Further personality traits (narcissism and empathy were assessed in a subsample of participants (N=57. Multiple regression analyses showed that personality measures did not predict automatic imitation. In addition, using a similar analytical approach to prior studies, no differences in imitation performance emerged when only the highest and lowest 20 participants on each trait variable were compared. These data weaken support for the view that stable personality traits are antecedents to automatic imitation and that neural mechanisms thought to support automatic imitation, such as the mirror neuron system, are dysfunctional in autism spectrum disorders or schizophrenia. In sum, the impact that personality variables have on automatic imitation is less universal than initial reports suggest.

  9. Investigating the Relationship between Stable Personality Characteristics and Automatic Imitation.

    Science.gov (United States)

    Butler, Emily E; Ward, Robert; Ramsey, Richard

    2015-01-01

    Automatic imitation is a cornerstone of nonverbal communication that fosters rapport between interaction partners. Recent research has suggested that stable dimensions of personality are antecedents to automatic imitation, but the empirical evidence linking imitation with personality traits is restricted to a few studies with modest sample sizes. Additionally, atypical imitation has been documented in autism spectrum disorders and schizophrenia, but the mechanisms underpinning these behavioural profiles remain unclear. Using a larger sample than prior studies (N=243), the current study tested whether performance on a computer-based automatic imitation task could be predicted by personality traits associated with social behaviour (extraversion and agreeableness) and with disorders of social cognition (autistic-like and schizotypal traits). Further personality traits (narcissism and empathy) were assessed in a subsample of participants (N=57). Multiple regression analyses showed that personality measures did not predict automatic imitation. In addition, using a similar analytical approach to prior studies, no differences in imitation performance emerged when only the highest and lowest 20 participants on each trait variable were compared. These data weaken support for the view that stable personality traits are antecedents to automatic imitation and that neural mechanisms thought to support automatic imitation, such as the mirror neuron system, are dysfunctional in autism spectrum disorders or schizophrenia. In sum, the impact that personality variables have on automatic imitation is less universal than initial reports suggest.

  10. Heavy element stable isotope ratios. Analytical approaches and applications

    International Nuclear Information System (INIS)

    Tanimizu, Masaharu; Sohrin, Yoshiki; Hirata, Takafumi

    2013-01-01

    Continuous developments in inorganic mass spectrometry techniques, including a combination of an inductively coupled plasma ion source and a magnetic sector-based mass spectrometer equipped with a multiple-collector array, have revolutionized the precision of isotope ratio measurements, and applications of inorganic mass spectrometry for biochemistry, geochemistry, and marine chemistry are beginning to appear on the horizon. Series of pioneering studies have revealed that natural stable isotope fractionations of many elements heavier than S (e.g., Fe, Cu, Zn, Sr, Ce, Nd, Mo, Cd, W, Tl, and U) are common on Earth, and it had been widely recognized that most physicochemical reactions or biochemical processes induce mass-dependent isotope fractionation. The variations in isotope ratios of the heavy elements can provide new insights into past and present biochemical and geochemical processes. To achieve this, the analytical community is actively solving problems such as spectral interference, mass discrimination drift, chemical separation and purification, and reduction of the contamination of analytes. This article describes data calibration and standardization protocols to allow interlaboratory comparisons or to maintain traceability of data, and basic principles of isotope fractionation in nature, together with high-selectivity and high-yield chemical separation and purification techniques for stable isotope studies.

  11. Shelf-stable food through high dose irradiation

    International Nuclear Information System (INIS)

    Placek, V.; Svobodova, V.; Bartonicek, B.; Rosmus, J.; Camra, M.

    2004-01-01

    Irradiation of food with high doses (radappertization) is a way, how to prepare shelf-stable ready-to-eat food. The radappertization process requires that the food be heated at first to an internal temperature of at least 75 deg. C to inactivate autolytic enzyme, which could cause the spoilage during storage without refrigeration. In order to prevent radiation induced changes in sensory properties (off flavors, odors, undesirable color change, etc.) the food was vacuum packed and irradiated in frozen state at -30 deg. C or less to a minimum dose of 35 kGy. Such products have characteristics of fresh food prepared for eating even if they are stored for long time under tropical conditions. The wholesomeness (safety for consumption) has been confirmed during 40 years of testing. Within the NRI Rez 10 kinds of shelf-stable meat products have been prepared. The meat was cooked, vacuum packed in SiO x -containing pouch, freezed in liquid nitrogen and irradiated with electron beam accelerator. The microbial, chemical, and organoleptic properties have been tested

  12. Phase Stable RF-over-fiber Transmission using Heterodyne Interferometry

    International Nuclear Information System (INIS)

    Wilcox, R.; Byrd, J.M.; Doolittle, L.; Huang, G.; Staples, J.W.

    2010-01-01

    New scientific applications require phase-stabilized RF distribution to multiple remote locations. These include phased-array radio telescopes and short pulse free electron lasers. RF modulated onto a CW optical carrier and transmitted via fiber is capable of low noise, but commercially available systems aren't long term stable enough for these applications. Typical requirements are for less than 50fs long term temporal stability between receivers, which is 0.05 degrees at 3GHz. Good results have been demonstrated for RF distribution schemes based on transmission of short pulses, but these require specialized free-space optics and high stability mechanical infrastructure. We report a method which uses only standard telecom optical and RF components, and achieves less than 20fs RMS error over 300m of standard single-mode fiber. We demonstrate stable transmission of 3GHz over 300m of fiber with less than 0.017 degree (17fs) RMS phase error. An interferometer measures optical phase delay, providing information to a feed-forward correction of RF phase.

  13. Entropy of stable seasonal rainfall distribution in Kelantan

    Science.gov (United States)

    Azman, Muhammad Az-zuhri; Zakaria, Roslinazairimah; Satari, Siti Zanariah; Radi, Noor Fadhilah Ahmad

    2017-05-01

    Investigating the rainfall variability is vital for any planning and management in many fields related to water resources. Climate change can gives an impact of water availability and may aggravate water scarcity in the future. Two statistics measurements which have been used by many researchers to measure the rainfall variability are variance and coefficient of variation. However, these two measurements are insufficient since rainfall distribution in Malaysia especially in the East Coast of Peninsular Malaysia is not symmetric instead it is positively skewed. In this study, the entropy concept is used as a tool to measure the seasonal rainfall variability in Kelantan and ten rainfall stations were selected. In previous studies, entropy of stable rainfall (ESR) and apportionment entropy (AE) were used to describe the rainfall amount variability during years for Australian rainfall data. In this study, the entropy of stable seasonal rainfall (ESSR) is suggested to model rainfall amount variability during northeast monsoon (NEM) and southwest monsoon (SWM) seasons in Kelantan. The ESSR is defined to measure the long-term average seasonal rainfall amount variability within a given year (1960-2012). On the other hand, the AE measures the rainfall amounts variability across the months. The results of ESSR and AE values show that stations in east coastline are more variable as compared to other stations inland for Kelantan rainfall. The contour maps of ESSR for Kelantan rainfall stations are also presented.

  14. Application of stable isotopes to hydrogeology in coal mine

    International Nuclear Information System (INIS)

    Duan Qi; Duan Yucheng

    1988-01-01

    Stable isotopes including Oxygen-18 and Deuterium have been applied to investigation of hydrogeology in main coal mines. By determination of stable isotopic composition of hydrogen and oxygen together with water analysis, the following studies have been developed: Identification of the hydrogeochemical characteristics of the groundwater from varied aquifers; Analysis of the hydraulic relationship between varied aquifers; Interpretation of the probable recharge source of mine water. The research results mentioned above reveal that: 1. The groundwater from main aquifers at coal mines in north China is of meteoric origin, which is recharged from hilly area surrounding the coal mine. Its isotopic composition differs slightly from that of the local precipitation. 2. There is a mutual hydraulic relationship between the Ordovician and Quarternary aquifers, so the difference of isotopic composition is very small. 3. By way of the variation of isotopic composition of groundwater from coal-bearing strata, we can infer the hydraulic relationship extent between overlaid alluvial layer and underlaid Ordovician limestone. (author). 9 refs, 6 figs, 8 tabs

  15. Quantum dot-polymer conjugates for stable luminescent displays.

    Science.gov (United States)

    Ghimire, Sushant; Sivadas, Anjaly; Yuyama, Ken-Ichi; Takano, Yuta; Francis, Raju; Biju, Vasudevanpillai

    2018-05-23

    The broad absorption of light in the UV-Vis-NIR region and the size-based tunable photoluminescence color of semiconductor quantum dots make these tiny crystals one of the most attractive antennae in solar cells and phosphors in electrooptical devices. One of the primary requirements for such real-world applications of quantum dots is their stable and uniform distribution in optically transparent matrices. In this work, we prepare transparent thin films of polymer-quantum dot conjugates, where CdSe/ZnS quantum dots are uniformly distributed at high densities in a chitosan-polystyrene copolymer (CS-g-PS) matrix. Here, quantum dots in an aqueous solution are conjugated to the copolymer by a phase transfer reaction. With the stable conjugation of quantum dots to the copolymer, we prevent undesired phase separation between the two and aggregation of quantum dots. Furthermore, the conjugate allows us to prepare transparent thin films in which quantum dots are uniformly distributed at high densities. The CS-g-PS copolymer helps us in not only preserving the photoluminescence properties of quantum dots in the film but also rendering excellent photostability to quantum dots at the ensemble and single particle levels, making the conjugate a promising material for photoluminescence-based devices.

  16. Tracking ENSO with tropical trees: Progress in stable isotope dendroclimatology

    Science.gov (United States)

    Evans, M. N.; Poussart, P. F.; Saleska, S. R.; Schrag, D. P.

    2002-12-01

    The terrestrial tropics remain an important gap in the growing proxy network used to characterize past ENSO behavior. Here we describe a strategy for development of proxy estimates of paleo-ENSO, via proxy rainfall estimates derived from stable isotope (δ18O) measurements made on tropical trees. The approach applies a new model of oxygen isotopic composition of alpha-cellulose (Roden et al., 2000), a rapid method for cellulose extraction from raw wood (Brendel et al., 2000), and continuous flow isotope ratio mass spectrometry (Brand, 1996) to develop proxy chronological, rainfall and growth rate estimates from tropical trees, even those lacking annual rings. The promise and pitfalls of the approach are illustrated in pilot datasets from the US, Costa Rica, Brazil, and Peru, which show isotopic cycles of 4-6 per mil, and interannual anomalies of up to 8 per mil. Together with the mature ENSO proxies (corals, extratropical tree-rings, varved sediments, and ice cores), replicated and well-dated stable isotope chronologies from tropical trees may eventually improve our understanding of ENSO history over the past several hundred years.

  17. Diets of introduced predators using stable isotopes and stomach contents

    Science.gov (United States)

    Meckstroth, A.M.; Miles, A.K.; Chandra, S.

    2007-01-01

    In a study of predation on ground-nesting birds at South San Francisco Bay (South Bay), California, USA, we analyzed stomach contents and stable isotopes of carbon and nitrogen to identify commonly consumed prey. We obtained the stomach contents from 206 nonnative red foxes (Vulpes vulpes regalis) collected in the South Bay area and Monterey County during 1995-2001 and from 68 feral cats (Felis silvestris) from the South Bay area during 2001-2002. We determined prey identity, biomass, and frequency, described seasonal diet trends, and derived an Index of Relative Importance. Avian species were the most frequent prey we found in the stomachs of red foxes from South Bay (61%), whereas small rodents were most frequent for red foxes from Monterey County (62%). Small rodents were the most frequent prey we found in feral cats (63%). Carbon and nitrogen isotopic signatures for foxes supported stomach content findings. However, isotope results indicated that cats received a majority of their energy from a source other than rodents and outside the natural system, which differed from the stomach content analysis. We demonstrated the utility of both stable isotope and stomach content analyses to establish a more complete understanding of predators' diets. This information aids natural resource managers in planning and evaluating future predator-removal programs and increases our understanding of the impacts of nonnative foxes and cats on native species.

  18. Biomedical research applications of electromagnetically separated enriched stable isotopes

    International Nuclear Information System (INIS)

    Lambrecht, R.M.

    1982-01-01

    The current and projected annual requirements through 1985 for stable isotopes enriched by electromagnetic separation methods were reviewed for applications in various types of biomedical research: (1) medical radiosotope production, labeled compounds, and potential radiopharmaceuticals; (2) nutrition, food science, and pharmacology; (3) metallobiochemistry and environmental toxicology; (4) nuclear magnetic resonance, electron paramagnetic resonance, and Moessbauer spectroscopy in biochemical, biophysical, and biomedical research; and (5) miscellaneous advances in radioactive and non-radioactive tracer technology. Radioisotopes available from commercial sources or routinely used in clinical nuclear medicine were excluded. Priorities and summaries are based on statements in the references and from answers to a survey conducted in the fall of 1981. Current requirements for enriched stable isotopes in biomedical research are not being satisfied. Severe shortages exist for 26 Mg, 43 Ca, 70 Zn, 76 Se, 78 Se, 102 Pd, 111 Cd, 113 Cd, and 190 Os. Many interesting and potentially important investigations in biomedical research require small quantities of specific elements at high isotopic enrichments

  19. Stable Lévy motion with inverse Gaussian subordinator

    Science.gov (United States)

    Kumar, A.; Wyłomańska, A.; Gajda, J.

    2017-09-01

    In this paper we study the stable Lévy motion subordinated by the so-called inverse Gaussian process. This process extends the well known normal inverse Gaussian (NIG) process introduced by Barndorff-Nielsen, which arises by subordinating ordinary Brownian motion (with drift) with inverse Gaussian process. The NIG process found many interesting applications, especially in financial data description. We discuss here the main features of the introduced subordinated process, such as distributional properties, existence of fractional order moments and asymptotic tail behavior. We show the connection of the process with continuous time random walk. Further, the governing fractional partial differential equations for the probability density function is also obtained. Moreover, we discuss the asymptotic distribution of sample mean square displacement, the main tool in detection of anomalous diffusion phenomena (Metzler et al., 2014). In order to apply the stable Lévy motion time-changed by inverse Gaussian subordinator we propose a step-by-step procedure of parameters estimation. At the end, we show how the examined process can be useful to model financial time series.

  20. Stable isotopes and elasmobranchs: tissue types, methods, applications and assumptions.

    Science.gov (United States)

    Hussey, N E; MacNeil, M A; Olin, J A; McMeans, B C; Kinney, M J; Chapman, D D; Fisk, A T

    2012-04-01

    Stable-isotope analysis (SIA) can act as a powerful ecological tracer with which to examine diet, trophic position and movement, as well as more complex questions pertaining to community dynamics and feeding strategies or behaviour among aquatic organisms. With major advances in the understanding of the methodological approaches and assumptions of SIA through dedicated experimental work in the broader literature coupled with the inherent difficulty of studying typically large, highly mobile marine predators, SIA is increasingly being used to investigate the ecology of elasmobranchs (sharks, skates and rays). Here, the current state of SIA in elasmobranchs is reviewed, focusing on available tissues for analysis, methodological issues relating to the effects of lipid extraction and urea, the experimental dynamics of isotopic incorporation, diet-tissue discrimination factors, estimating trophic position, diet and mixing models and individual specialization and niche-width analyses. These areas are discussed in terms of assumptions made when applying SIA to the study of elasmobranch ecology and the requirement that investigators standardize analytical approaches. Recommendations are made for future SIA experimental work that would improve understanding of stable-isotope dynamics and advance their application in the study of sharks, skates and rays. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

  1. Topical tazarotene vs. coal tar in stable plaque psoriasis

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, U.; Kaur, I.; Dogra, S.; De, D.; Kumar, B. [Postgraduate Institute of Medical Education & Research, Chandigarh (India)

    2010-07-15

    The efficacy of topical tazarotene has not previously been compared with the conventional topical treatment of crude coal tar (CCT) in stable plaque psoriasis. In this nonblinded side-to-side comparison study, patients with chronic stable plaque psoriasis, who had bilaterally symmetrical plaques on the limbs, applied 0.1% tazarotene gel on the right side and 5% CCT ointment on the left side once daily for 12 weeks followed by an 8-week treatment-free follow up period. Severity of psoriatic lesions and response to treatment was evaluated by scoring erythema, scaling and induration (ESI). Of 30 patients recruited, 27 could be assessed. In the per-protocol analysis, the mean percentage reduction in ESI score at the end of the treatment period was 74.15% {+-} 9.43 and 77.37% {+-} 10.93 with tazarotene and CCT, respectively (P {gt} 0.05). A reduction in ESI score of {gt} 75% was seen in 11 (40.74%) and 16 (59.26%) patients with tazarotene and CCT, respectively, at the end of 12 weeks. Side-effects were seen in 48.14% of patients treated with tazarotene, but in no patient treated with CCT. Tazarotene 0.1% gel has comparable clinical efficacy to CCT 5% ointment. CCT ointment remains a cost-effective therapy for plaque psoriasis.

  2. Designing a stable feedback control system for blind image deconvolution.

    Science.gov (United States)

    Cheng, Shichao; Liu, Risheng; Fan, Xin; Luo, Zhongxuan

    2018-05-01

    Blind image deconvolution is one of the main low-level vision problems with wide applications. Many previous works manually design regularization to simultaneously estimate the latent sharp image and the blur kernel under maximum a posterior framework. However, it has been demonstrated that such joint estimation strategies may lead to the undesired trivial solution. In this paper, we present a novel perspective, using a stable feedback control system, to simulate the latent sharp image propagation. The controller of our system consists of regularization and guidance, which decide the sparsity and sharp features of latent image, respectively. Furthermore, the formational model of blind image is introduced into the feedback process to avoid the image restoration deviating from the stable point. The stability analysis of the system indicates the latent image propagation in blind deconvolution task can be efficiently estimated and controlled by cues and priors. Thus the kernel estimation used for image restoration becomes more precision. Experimental results show that our system is effective on image propagation, and can perform favorably against the state-of-the-art blind image deconvolution methods on different benchmark image sets and special blurred images. Copyright © 2018 Elsevier Ltd. All rights reserved.

  3. 5-Hydroxymethylcytosine is a predominantly stable DNA modification

    Science.gov (United States)

    Bachman, Martin; Uribe-Lewis, Santiago; Yang, Xiaoping; Williams, Michael; Murrell, Adele; Balasubramanian, Shankar

    2014-12-01

    5-Hydroxymethylcytosine (hmC) is an oxidation product of 5-methylcytosine which is present in the deoxyribonucleic acid (DNA) of most mammalian cells. Reduction of hmC levels in DNA is a hallmark of cancers. Elucidating the dynamics of this oxidation reaction and the lifetime of hmC in DNA is fundamental to understanding hmC function. Using stable isotope labelling of cytosine derivatives in the DNA of mammalian cells and ultrasensitive tandem liquid-chromatography mass spectrometry, we show that the majority of hmC is a stable modification, as opposed to a transient intermediate. In contrast with DNA methylation, which occurs immediately during replication, hmC forms slowly during the first 30 hours following DNA synthesis. Isotopic labelling of DNA in mouse tissues confirmed the stability of hmC in vivo and demonstrated a relationship between global levels of hmC and cell proliferation. These insights have important implications for understanding the states of chemically modified DNA bases in health and disease.

  4. Study Tranport Barrier Formation using Bi- Stable Sandpile Model

    International Nuclear Information System (INIS)

    Kitpitak, B.; Kanjanaput, W.; Poolyarat, N.; Picha, R; Onjun, T.

    2014-01-01

    The formation of plasma transport barrier in Tokamak is an important issue for achieving high energy confinement and sufficient fusion performance. The simulation using in this experiment simulates cycles of dropping grains in a sandpile with two stable and two unstable slope regimes which share the same characteristic as the formation of pedestal and there are several parameters used, including stable boundaries, grains in a toppling, relax process iterations per cycle, grains in a drop and number of drops per cycle. By using this simulation, the effects of the relaxation times and number of trooping grain (the number of collapsing grain in the relaxation process) can be investigated. It is found in the simulations that the pedestal region can be observed only when the number of deposited grain exceeds a critical value which is related to number of relaxation times and number of allowed trooping grain. In another words, the pedestal formation occurs when the particle deposition rate is higher than the average diffusion rate. In addition, altering amount of trooping grain can lead to remarkable effects on slope and height of the profiles. In order to achieve better energy confinement, further study of formation of plasma transport barrier is needed.

  5. Stable Nafion-functionalized graphene dispersions for transparent conducting films

    International Nuclear Information System (INIS)

    Liu Yangqiao; Gao Lian; Sun Jing; Wang Yan; Zhang Jing

    2009-01-01

    Nafion was used for the first time to aid in preparing stable graphene dispersions in mixed water/ethanol (1:1) solvents via the reduction of graphite oxide using hydrazine. The dispersion was characterized by ultraviolet-visible (UV-vis) spectra, transmission electron microscopy, zeta potential analysis, etc. It was found that for Nafion-to-graphene ratios higher than 5:1, graphene solutions with concentrations up to 1 mg ml -1 and stabilities of over three months were obtained. It was proposed that the Nafion adsorbed onto the graphene by the hydrophobic interaction of its fluoro-backbones with the graphene layer and imparted stability by an electrosteric mechanism. Furthermore, transparent and conductive films were prepared using these highly stable Nafion-stabilized graphene dispersions. The prepared Nafion-graphene films possess smooth and homogeneous surfaces and the sheet resistance was as low as 30 kΩ/sq for a transmittance of 80% at 550 nm, which was much lower than for other graphene films obtained by chemical reduction. X-ray photoelectron spectroscopy and Raman spectroscopy confirmed the p-doping of the graphene by Nafion. It was expected that this p-doping effect, as well as the high dispersing ability of Nafion for graphene and the connection of the sp 2 domains by residual Nafion combined to produce good properties of the Nafion-graphene films.

  6. Vegetation engineers marsh morphology through multiple competing stable states

    Science.gov (United States)

    Marani, Marco; Da Lio, Cristina; D’Alpaos, Andrea

    2013-01-01

    Marshes display impressive biogeomorphic features, such as zonation, a mosaic of extensive vegetation patches of rather uniform composition, exhibiting sharp transitions in the presence of extremely small topographic gradients. Although generally associated with the accretion processes necessary for marshes to keep up with relative sea level rise, competing environmental constraints, and ecologic controls, zonation is still poorly understood in terms of the underlying biogeomorphic mechanisms. Here we find, through observations and modeling interpretation, that zonation is the result of coupled geomorphological–biological dynamics and that it stems from the ability of vegetation to actively engineer the landscape by tuning soil elevation within preferential ranges of optimal adaptation. We find multiple peaks in the frequency distribution of observed topographic elevation and identify them as the signature of biologic controls on geomorphodynamics through competing stable states modulated by the interplay of inorganic and organic deposition. Interestingly, the stable biogeomorphic equilibria correspond to suboptimal rates of biomass production, a result coherent with recent observations. The emerging biogeomorphic structures may display varying degrees of robustness to changes in the rate of sea level rise and sediment availability, with implications for the overall resilience of marsh ecosystems to climatic changes. PMID:23401529

  7. Hydrothermally stable molecular separation membranes from organically linked silica

    Energy Technology Data Exchange (ETDEWEB)

    Castricum, H.L.; Sah, A; Blank, D.H.A.; Ten Elshof, J.E. [Inorganic Materials Science, MESA Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands); Kreiter, R.; Vente, J.F. [ECN Energy Efficiency in the Industry, Petten (Netherlands)

    2008-06-15

    A highly hydrothermally stable microporous network material has been developed that can be applied in energy-efficient molecular sieving. The material was synthesized by employing organically bridged monomers in acid-catalysed sol-gel hydrolysis and condensation, and is composed of covalently bonded organic and inorganic moieties. Due to its hybrid nature, it withstands higher temperatures than organic polymers and exhibits high solvolytical and acid stability. A thin film membrane that was prepared with the hybrid material was found to be stable in the dehydration of n-butanol at 150C for almost two years. This membrane is the first that combines a high resistance against water at elevated temperatures with a high separation factor and permeance. It therefore has high potential for energy-efficient molecular separation under industrial conditions, including the dehydration of organic solvents. The organically bridged monomers induce increased toughness in the thin film layer. This suppresses hydrolysis of Si-O-Si network bonds and results in a high resistance towards stress-induced cracking. The large non-hydrolysable units thus remain well incorporated in the surrounding matrix such that the material combines high (pore) structural and mechanical stability. The sol mean particle size was found to be a viable parameter to tune the thickness of the membrane layer and thus optimize the separation performance. We anticipate that other hybrid organosilicas can be made in a similar fashion, to yield a whole new class of materials with superior molecular sieving properties and high hydrothermal stability.

  8. Metabolic alkalosis in adults with stable cystic fibrosis.

    Science.gov (United States)

    Al-Ghimlas, Fahad; Faughnan, Marie E; Tullis, Elizabeth

    2012-01-01

    The frequency of metabolic alkalosis among adults with stable severe CF-lung disease is unknown. Retrospective chart review. Fourteen CF and 6 COPD (controls) patients were included. FEV1 was similar between the two groups. PaO2 was significantly higher in the COPD (mean ± 2 SD is 72.0 ± 6.8 mmHg,) than in the CF group (56.1 ± 4.1 mmHg). The frequency of metabolic alkalosis in CF patients (12/14, 86%) was significantly greater (p=0.04) than in the COPD group (2/6, 33%). Mixed respiratory acidosis and metabolic alkalosis was evident in 4 CF and 1 COPD patients. Primary metabolic alkalosis was observed in 8 CF and none of the COPD patients. One COPD patient had respiratory and metabolic alkalosis. Metabolic alkalosis is more frequent in stable patients with CF lung disease than in COPD patients. This might be due to defective CFTR function with abnormal electrolyte transport within the kidney and/ or gastrointestinal tract.

  9. Stable Isotope Identification of Nitrogen Sources for United ...

    Science.gov (United States)

    We used natural abundance stable isotope data to evaluate nitrogen sources to U.S. west coast estuaries. We collected δ15N of macroalgae data and supplemented this with available data from the literature for estuaries from Mexico to Alaska. Stable isotope ratios of green macroalgae were compared to δ15N of dissolved inorganic nitrogen of oceanic and watershed end members. There was a latitudinal gradient in δ15N of macroalgae with southern estuaries being 7 per mil heavier than northern estuaries. Gradients in isotope data were compared to nitrogen sources estimated by the USGS using the SPARROW model. In California estuaries, the elevation of isotope data appeared to be related to anthropogenic nitrogen sources. In Oregon systems, the nitrogen levels of streams flowing into the estuaries are related to forest cover, rather than to developed land classes. In addition, the δ15N of macroalgae suggested that the ocean and nitrogen-fixing trees in the watersheds were the dominant nitrogen sources. There was also a strong gradient in δ15N of macroalgae with heavier sites located near the estuary mouth. In some Oregon estuaries, there was an elevation an elevation of δ15N above marine end members in the vicinity of wastewater treatment facility discharge locations, suggesting isotopes may be useful for distinguishing inputs along an estuarine gradient. Nutrients are the leading cause of water quality impairments in the United States, and as a result too

  10. Tapered composite likelihood for spatial max-stable models

    KAUST Repository

    Sang, Huiyan; Genton, Marc G.

    2014-01-01

    Spatial extreme value analysis is useful to environmental studies, in which extreme value phenomena are of interest and meaningful spatial patterns can be discerned. Max-stable process models are able to describe such phenomena. This class of models is asymptotically justified to characterize the spatial dependence among extremes. However, likelihood inference is challenging for such models because their corresponding joint likelihood is unavailable and only bivariate or trivariate distributions are known. In this paper, we propose a tapered composite likelihood approach by utilizing lower dimensional marginal likelihoods for inference on parameters of various max-stable process models. We consider a weighting strategy based on a "taper range" to exclude distant pairs or triples. The "optimal taper range" is selected to maximize various measures of the Godambe information associated with the tapered composite likelihood function. This method substantially reduces the computational cost and improves the efficiency over equally weighted composite likelihood estimators. We illustrate its utility with simulation experiments and an analysis of rainfall data in Switzerland.

  11. Chemistry of Stable Carbenes and «Green» Technologies

    Directory of Open Access Journals (Sweden)

    Korotkikh, N.I.

    2015-11-01

    Full Text Available Brief analysis of fundamental research in the chemistry of stable carbenes and applications in the field of «green» chemistry on their basis carried out at the L.M. Litvinenko Institute of Physical Organic & Coal Chemistry of NAS of Ukraine over the last decade is given. Carbene versions of ester Claisen condensation to form zwitterionic compounds, the Leuckart-Wallach reaction with the autoreduction of carbenoid azolium salts, Hofmann cleavage of aminocarbene insertion products, an induced tandem autotransformation of 1,2,4-triazol-5-ylidenes into 5-amidino-1,2,4-triazoles were found. New carbene reactions of ad dition, deesterification, oxidation and complexation were revealed. Effective methods of obtaining stable carbenes and carbenoids were suggested. New types of carbenes, namely benzimidazolylidenes, superstable conjugated biscarbenes and new types of carbenoids were synthesized. The existence of hypernucleophilic carbenes was theoretically predicted and experimentally confirmed. The prospects of the use of carbenes and their derivatives, in particular, carbene complexes of transition metals in catalysis of organic reactions and the search of biologically active compounds were shown.

  12. Thermally Stable Gold Nanoparticles with a Crosslinked Diblock Copolymer Shell

    Science.gov (United States)

    Jang, Se Gyu; Khan, Anzar; Hawker, Craig J.; Kramer, Edward J.

    2010-03-01

    The use of polymer-coated Au nanoparticles prepared using oligomeric- or polymeric-ligands tethered by Au-S bonds for incorporation into block copolymer templates under thermal processing has been limited due to dissociation of the Au-S bond at T > 100^oC where compromises their colloidal stability. We report a simple route to prepare sub-5nm gold nanoparticles with a thermally stable polymeric shell. An end-functional thiol ligand consisting of poly(styrene-b-1,2&3,4-isoprene-SH) is synthesized by anionic polymerization. After a standard thiol ligand synthesis of Au nanoparticles, the inner PI block is cross-linked through reaction with 1,1,3,3-tetramethyldisiloxane. Gold nanoparticles with the cross-linked shell are stable in organic solvents at 160^oC as well as in block copolymer films of PS-b-P2VP annealed in vacuum at 170^oC for several days. These nanoparticles can be designed to strongly segregate to the PS-P2VP interface resulting in very large Au nanoparticle volume fractions φp without macrophase separation as well as transitions between lamellar and bicontinuous morphologies as φp increases.

  13. Mechanisms of stable lipid loss in a social insect

    Science.gov (United States)

    Ament, Seth A.; Chan, Queenie W.; Wheeler, Marsha M.; Nixon, Scott E.; Johnson, S. Peir; Rodriguez-Zas, Sandra L.; Foster, Leonard J.; Robinson, Gene E.

    2011-01-01

    SUMMARY Worker honey bees undergo a socially regulated, highly stable lipid loss as part of their behavioral maturation. We used large-scale transcriptomic and proteomic experiments, physiological experiments and RNA interference to explore the mechanistic basis for this lipid loss. Lipid loss was associated with thousands of gene expression changes in abdominal fat bodies. Many of these genes were also regulated in young bees by nutrition during an initial period of lipid gain. Surprisingly, in older bees, which is when maximum lipid loss occurs, diet played less of a role in regulating fat body gene expression for components of evolutionarily conserved nutrition-related endocrine systems involving insulin and juvenile hormone signaling. By contrast, fat body gene expression in older bees was regulated more strongly by evolutionarily novel regulatory factors, queen mandibular pheromone (a honey bee-specific social signal) and vitellogenin (a conserved yolk protein that has evolved novel, maturation-related functions in the bee), independent of nutrition. These results demonstrate that conserved molecular pathways can be manipulated to achieve stable lipid loss through evolutionarily novel regulatory processes. PMID:22031746

  14. Mechanisms of stable lipid loss in a social insect.

    Science.gov (United States)

    Ament, Seth A; Chan, Queenie W; Wheeler, Marsha M; Nixon, Scott E; Johnson, S Peir; Rodriguez-Zas, Sandra L; Foster, Leonard J; Robinson, Gene E

    2011-11-15

    Worker honey bees undergo a socially regulated, highly stable lipid loss as part of their behavioral maturation. We used large-scale transcriptomic and proteomic experiments, physiological experiments and RNA interference to explore the mechanistic basis for this lipid loss. Lipid loss was associated with thousands of gene expression changes in abdominal fat bodies. Many of these genes were also regulated in young bees by nutrition during an initial period of lipid gain. Surprisingly, in older bees, which is when maximum lipid loss occurs, diet played less of a role in regulating fat body gene expression for components of evolutionarily conserved nutrition-related endocrine systems involving insulin and juvenile hormone signaling. By contrast, fat body gene expression in older bees was regulated more strongly by evolutionarily novel regulatory factors, queen mandibular pheromone (a honey bee-specific social signal) and vitellogenin (a conserved yolk protein that has evolved novel, maturation-related functions in the bee), independent of nutrition. These results demonstrate that conserved molecular pathways can be manipulated to achieve stable lipid loss through evolutionarily novel regulatory processes.

  15. Recent developments in low cost stable structures for space

    International Nuclear Information System (INIS)

    Thompson, T.C.; Grastataro, C.; Smith, B.G.

    1994-01-01

    The Los Alamos National Laboratory (LANL) in partnership with Composite Optics Incorporated (COI) is advancing the development of low cost, lightweight, composite technology for use in spacecraft and stable structures. The use of advanced composites is well developed, but the application of an all-composite tracker structure has never been achieved. This paper investigates the application of composite technology to the design and fabrication of an all-composite spacecraft bus for small satellites, using technology directly applicable to central tracking in a high luminosity environment. The satellite program Fast On-Orbit Recording of Transient Events (FORTE) is the second in a series of satellites to be launched into orbit for the US Department of Energy (DOE). This paper will discuss recent developments in the area of low cost composites, used for either spacecraft or ultra stable applications in high energy physics (HEP) detectors. The use of advanced composites is a relatively new development in the area of HEP. The Superconducting Super Collider (SSC) spawned a new generation of Trackers which made extensive use of graphite fiber reinforced plastic (GFRP) composite systems. LANL has designed a structure employing new fabrication technology. This concept will lower the cost of composite structures to a point that they may now compete with conventional materials. This paper will discuss the design, analysis and proposed fabrication of a small satellite structure. Central tracking structures using advanced materials capable of operating in an adverse environment typical of that found in a high luminosity collider could use identical concepts

  16. Refining a brief decision aid in stable CAD: cognitive interviews.

    Science.gov (United States)

    Kelly-Blake, Karen; Clark, Stacie; Dontje, Katherine; Olomu, Adesuwa; Henry, Rebecca C; Rovner, David R; Rothert, Marilyn L; Holmes-Rovner, Margaret

    2014-02-13

    We describe the results of cognitive interviews to refine the "Making Choices©" Decision Aid (DA) for shared decision-making (SDM) about stress testing in patients with stable coronary artery disease (CAD). We conducted a systematic development process to design a DA consistent with International Patient Decision Aid Standards (IPDAS) focused on Alpha testing criteria. Cognitive interviews were conducted with ten stable CAD patients using the "think aloud" interview technique to assess the clarity, usefulness, and design of each page of the DA. Participants identified three main messages: 1) patients have multiple options based on stress tests and they should be discussed with a physician, 2) take care of yourself, 3) the stress test is the gold standard for determining the severity of your heart disease. Revisions corrected the inaccurate assumption of item number three. Cognitive interviews proved critical for engaging patients in the development process and highlighted the necessity of clear message development and use of design principles that make decision materials easy to read and easy to use. Cognitive interviews appear to contribute critical information from the patient perspective to the overall systematic development process for designing decision aids.

  17. Spatial-Frequency Azimuthally Stable Cartography of Biological Polycrystalline Networks

    Directory of Open Access Journals (Sweden)

    V. A. Ushenko

    2013-01-01

    Full Text Available A new azimuthally stable polarimetric technique processing microscopic images of optically anisotropic structures of biological tissues histological sections is proposed. It has been used as a generalized model of phase anisotropy definition of biological tissues by using superposition of Mueller matrices of linear birefringence and optical activity. The matrix element M44 has been chosen as the main information parameter, whose value is independent of the rotation angle of both sample and probing beam polarization plane. For the first time, the technique of concerted spatial-frequency filtration has been used in order to separate the manifestation of linear birefringence and optical activity. Thereupon, the method of azimuthally stable spatial-frequency cartography of biological tissues histological sections has been elaborated. As the analyzing tool, complex statistic, correlation, and fractal analysis of coordinate distributions of M44 element has been performed. The possibility of using the biopsy of the uterine wall tissue in order to differentiate benign (fibromyoma and malignant (adenocarcinoma conditions has been estimated.

  18. Stable lithium electrodeposition in liquid and nanoporous solid electrolytes

    KAUST Repository

    Lu, Yingying

    2014-08-10

    Rechargeable lithium, sodium and aluminium metal-based batteries are among the most versatile platforms for high-energy, cost-effective electrochemical energy storage. Non-uniform metal deposition and dendrite formation on the negative electrode during repeated cycles of charge and discharge are major hurdles to commercialization of energy-storage devices based on each of these chemistries. A long-held view is that unstable electrodeposition is a consequence of inherent characteristics of these metals and their inability to form uniform electrodeposits on surfaces with inevitable defects. We report on electrodeposition of lithium in simple liquid electrolytes and in nanoporous solids infused with liquid electrolytes. We find that simple liquid electrolytes reinforced with halogenated salt blends exhibit stable long-term cycling at room temperature, often with no signs of deposition instabilities over hundreds of cycles of charge and discharge and thousands of operating hours. We rationalize these observations with the help of surface energy data for the electrolyte/lithium interface and impedance analysis of the interface during different stages of cell operation. Our findings provide support for an important recent theoretical prediction that the surface mobility of lithium is significantly enhanced in the presence of lithium halide salts. Our results also show that a high electrolyte modulus is unnecessary for stable electrodeposition of lithium.

  19. Dark halos and elliptical galaxies as marginally stable dynamical systems

    Energy Technology Data Exchange (ETDEWEB)

    El Zant, A. A. [Centre for Theoretical Physics, Zewail City of Science and Technology, Sheikh Zayed, 12588 Giza (Egypt); The British University in Egypt, Sherouk City, Cairo 11837 (Egypt)

    2013-12-10

    The origin of equilibrium gravitational configurations is sought in terms of the stability of their trajectories, as described by the curvature of their Lagrangian configuration manifold of particle positions—a context in which subtle spurious effects originating from the singularity in the two-body potential become particularly clear. We focus on the case of spherical systems, which support only regular orbits in the collisionless limit, despite the persistence of local exponential instability of N-body trajectories in the anomalous case of discrete point particle representation even as N → ∞. When the singularity in the potential is removed, this apparent contradiction disappears. In the absence of fluctuations, equilibrium configurations generally correspond to positive scalar curvature and thus support stable trajectories. A null scalar curvature is associated with an effective, averaged equation of state describing dynamically relaxed equilibria with marginally stable trajectories. The associated configurations are quite similar to those of observed elliptical galaxies and simulated cosmological halos and are necessarily different from the systems dominated by isothermal cores, expected from entropy maximization in the context of the standard theory of violent relaxation. It is suggested that this is the case because a system starting far from equilibrium does not reach a 'most probable state' via violent relaxation, but that this process comes to an end as the system finds and (settles in) a configuration where it can most efficiently wash out perturbations. We explicitly test this interpretation by means of direct simulations.

  20. Low-cost electrodes for stable perovskite solar cells

    Science.gov (United States)

    Bastos, João P.; Manghooli, Sara; Jaysankar, Manoj; Tait, Jeffrey G.; Qiu, Weiming; Gehlhaar, Robert; De Volder, Michael; Uytterhoeven, Griet; Poortmans, Jef; Paetzold, Ulrich W.

    2017-06-01

    Cost-effective production of perovskite solar cells on an industrial scale requires the utilization of exclusively inexpensive materials. However, to date, highly efficient and stable perovskite solar cells rely on expensive gold electrodes since other metal electrodes are known to cause degradation of the devices. Finding a low-cost electrode that can replace gold and ensure both efficiency and long-term stability is essential for the success of the perovskite-based solar cell technology. In this work, we systematically compare three types of electrode materials: multi-walled carbon nanotubes (MWCNTs), alternative metals (silver, aluminum, and copper), and transparent oxides [indium tin oxide (ITO)] in terms of efficiency, stability, and cost. We show that multi-walled carbon nanotubes are the only electrode that is both more cost-effective and stable than gold. Devices with multi-walled carbon nanotube electrodes present remarkable shelf-life stability, with no decrease in the efficiency even after 180 h of storage in 77% relative humidity (RH). Furthermore, we demonstrate the potential of devices with multi-walled carbon nanotube electrodes to achieve high efficiencies. These developments are an important step forward to mass produce perovskite photovoltaics in a commercially viable way.